Proliferation and differentiation of intestinal stem cell(ISC)to replace damaged gut mucosal epithelial cells in inflammatory states is a critical step in ameliorating gut inflammation.However,when this disordered pro...Proliferation and differentiation of intestinal stem cell(ISC)to replace damaged gut mucosal epithelial cells in inflammatory states is a critical step in ameliorating gut inflammation.However,when this disordered proliferation continues,it induces the ISC to enter a cancerous state.The gut microbiota on the free surface of the gut mucosal barrier is able to interact with ISC on a sustained basis.Micro-biota metabolites are able to regulate the proliferation of gut stem and progenitor cells through transcription factors,while in steady state,differentiated colono-cytes are able to break down such metabolites,thereby protecting stem cells at the gut crypt.In the future,the gut flora and its metabolites mediating the regulation of ISC differentiation will be a potential treatment for enteropathies.展开更多
Interactions between diet and the intestinal microbiome play an important role in human health and disease development.It is well known that such interactions,whether direct or indirect,trigger a series of metabolic r...Interactions between diet and the intestinal microbiome play an important role in human health and disease development.It is well known that such interactions,whether direct or indirect,trigger a series of metabolic reactions in the body.Evidence suggests that intestinal stem cells(ISCs),which are phenotypic precursors of various intestinal epithelial cells,play a significant role in the regulation of intestinal barrier function and homeostasis.The advent and evolution of intestinal organoid culture techniques have presented a key opportunity to study the association between the intestinal microenvironment and ISCs.As a result,the effects exerted by dietary factors,intestinal microbiomes,and their metabolites on the metabolic regulation of ISCs and the potential mechanisms underlying such effects are being gradually revealed.This review summarises the effects of different dietary patterns on the behaviour and functioning of ISCs and focuses on the crosstalk between intestinal microbiota,related metabolites,and ISCs,with the aim of fully understanding the relationship between these three factors and providing further insights into the complex mechanisms associated with ISCs in the human body.Gaining an understanding of these mechanisms may lead to the development of novel dietary interventions or drugs conducive to intestinal health.展开更多
The mammalian intestinal epithelium constitutes the largest barrier against the external environment and makes flexible responses to various types of stimuli.Epithelial cells are fast-renewed to counteract constant da...The mammalian intestinal epithelium constitutes the largest barrier against the external environment and makes flexible responses to various types of stimuli.Epithelial cells are fast-renewed to counteract constant damage and disrupted barrier function to maintain their integrity.The homeostatic repair and regeneration of the intestinal epithelium are governed by the Lgr5+intestinal stem cells(ISCs)located at the base of crypts,which fuel rapid renewal and give rise to the different epithelial cell types.Protracted biological and physicochemical stress may challenge epithelial integrity and the function of ISCs.The field of ISCs is thus of interest for complete mucosal healing,given its relevance to diseases of intestinal injury and inflammation such as inflammatory bowel diseases.Here,we review the current understanding of the signals and mechanisms that control homeostasis and regeneration of the intestinal epithelium.We focus on recent insights into the intrinsic and extrinsic elements involved in the process of intestinal homeostasis,injury,and repair,which fine-tune the balance between self-renewal and cell fate specification in ISCs.Deciphering the regulatory machinery that modulates stem cell fate would aid in the development of novel therapeutics that facilitate mucosal healing and restore epithelial barrier function.展开更多
Qiurong Li1,Qiang Zhang1,Chenyang Wang1,Shaojun Jiang2,Ning Li1,Jieshou Li1 Intestinal stem cells may have important roles in the maintenance of epithelial integrity during tissue repair.Alemtuzumab is a humanized ant...Qiurong Li1,Qiang Zhang1,Chenyang Wang1,Shaojun Jiang2,Ning Li1,Jieshou Li1 Intestinal stem cells may have important roles in the maintenance of epithelial integrity during tissue repair.Alemtuzumab is a humanized anti-CD52 lymphocytic antibody that is increasingly being used to induce immunosuppression;intestinal barrier function is impaired during treatment with alemtuzumab.We investigated the response of intestinal stem cells to epithelial damage resulting from alemtuzumab treatment.Intestinal epithelial cell loss and abnormal Paneth cell morphology were found following a single dose of alemtuzumab.The animals receiving alemtuzumab exhibited increased apoptosis in the villi 3 days after alemtuzumab treatment and in the crypt on day 9,but apoptosis was scarce on day 35.We assessed expression of Musashi-1-and Lgr5-positive stem cells following alemtuzumab treatment.Increased numbers of cells staining positive for both Musashi-1 and Lgr5 were found in the stem cell zone after alemtuzumab treatment for 3 and 9 days.These data indicated that the epithelial cells were injured following alemtuzumab treatment,with the associated expansion of intestinal stem cells.After alemtuzumab treatment for 35 days,the numbers of intestinal epithelial cells and intestinal stem cells returned to normal.This study suggests that alemtuzumab treatment induced the increase in stem cells,resulting in the availability of more enterocytes for repair.展开更多
The remarkable ability of rapid self-renewal makes the intestinal epithelium an ideal model for the study of adult stem cells. The intestinal epithelium is organized into villus and crypt, and a group of intestinal st...The remarkable ability of rapid self-renewal makes the intestinal epithelium an ideal model for the study of adult stem cells. The intestinal epithelium is organized into villus and crypt, and a group of intestinal stem cells located at the base of crypt are responsible for this constant self-renewal throughout the life. Identification of the intestinal stem cell marker Lgr5, isolation and in vitro culture of Lgr5+ intestinal stem cells and the use of transgenic mouse models have significantly facilitated the studies of intestinal stem cell homeostasis and differentiation, therefore greatly expanding our knowledge of the regulatory mechanisms underlying the intestinal stem cell fate determination. In this review, we summarize the current understanding of how signals of Wnt, BMP, Notch and EGF in the stem cell niche modulate the intestinal stem cell fate.展开更多
The rapidly self-renewing epithelium in the mammalian intestine is maintained by multipotent intestinal stem cells(ISCs) located at the bottom of the intestinal crypt that are interspersed with Paneth cells in the sma...The rapidly self-renewing epithelium in the mammalian intestine is maintained by multipotent intestinal stem cells(ISCs) located at the bottom of the intestinal crypt that are interspersed with Paneth cells in the small intestine andPaneth-like cells in the colon. The ISC compartment is also closely associated with a sub-epithelial compartmentthat contains multiple types of mesenchymal stromal cells. With the advances in single cell and gene editingtechnologies, rapid progress has been made for the identification and characterization of the cellular componentsof the niche microenvironment that is essential for self-renewal and differentiation of ISCs. It has becomeincreasingly clear that a heterogeneous population of mesenchymal cells as well as the Paneth cells collectivelyprovide multiple secreted niche signals to promote ISC self-renewal. Here we review and summarize recentadvances in the regulation of ISCs with a main focus on the definition of niche cells that sustain ISCs.展开更多
Early weaning in piglets can cause a series of negative effects.This causes serious losses to the livestock industry.N-Acetyl-D-glucosamine(D-GlcNAc)plays an important role in regulating the homeostasis of the intesti...Early weaning in piglets can cause a series of negative effects.This causes serious losses to the livestock industry.N-Acetyl-D-glucosamine(D-GlcNAc)plays an important role in regulating the homeostasis of the intestine.This study aimed to investigate the effects of D-GlcNAc on the growth performance and intestinal function of weaned piglets.Twenty-four weaned piglets([Yorkshire×Landrace]Duroc,6.58±0.15 kg,n=8)at 21 d old were fed 3 diets supplemented with 0(control),1 and 3 g/kg D-GlcNAc.The intestinal organoid model was used to verify the regulatory mechanism of D-GlcNAc on intestinal epithelial cells.On the whole,supplementation of D-GlcNAc in the piglet diet has no significant effect on the growth performance and diarrhoea of weaned piglets(P>0.05).The apparent digestibility of nutrients and mRNA abundance of nutrient transporters in the 1 g/kg D-GlcNAc group were increased significantly(P<0.05).D-GlcNAc did not affect villus height(VH)and crypt depth(CD)but resulted in a numerically shorter VH and shallower CD,which lead to an increase in ileal VH:CD ratio(P<0.05).Cell shedding rates in the ileum villi increased(P<0.05).The relative length and weight of the small intestine of weaned piglets increased(P<0.05).In vitro studies found that the budding rates of organoids treated with 0.1 mmol/L D-GlcNAc increased on the d 3 and 5(P<0.05).The average budding numbers per budding organoid treated with 0.1 and 10 mmol/L D-GlcNAc increased on d 3(P<0.05).D-GlcNAc upregulated leucine rich repeat containing G protein-coupled receptor 5(Lgr5^(+))and Chromogranin A mRNA abundance in organoids(P<0.05).Mucin 2(Muc2)expression increased when treated with 1 and 10 mmol/L D-GlcNAc(P<0.05).In conclusion,dietary D-GlcNAc cannot improve the growth performance of weaned piglets.However,it can promote the growth and development of the intestinal tract and improve the digestion and absorption capacity of the intestine,which is achieved by affecting the activity of intestinal stem cells.展开更多
The intestinal epithelium is one of the most rapidly renewing tissues,which is fueled by stem cells at the base of the crypts.Strategies of genetic lineage tracing and organoids,which capture major features of origina...The intestinal epithelium is one of the most rapidly renewing tissues,which is fueled by stem cells at the base of the crypts.Strategies of genetic lineage tracing and organoids,which capture major features of original tissues,are powerful avenues for exploring the biology of intestinal stem cells in vivo and in vitro,respectively.The combination of intestinal organoideculturing system and genetic modification approaches provides an attractive platform to uncover the mechanism of colorectal cancer and genetic disorders in the human minigut.Here,we will provide a comprehensive overview of studies on intestinal epithelium and intestinal stem cells.We will also review the applications of organoids and genetic markers in intestinal research studies.Furthermore,we will discuss the advantages and drawbacks of organoids as disease models compared with mice models and cell lines.展开更多
Adult stem cells or progenitors are essential for maintaining the normal structure and function of adult tissues (i.e., ho- meostasis). One of the best examples is the adult intestinal epithelium which is constantly...Adult stem cells or progenitors are essential for maintaining the normal structure and function of adult tissues (i.e., ho- meostasis). One of the best examples is the adult intestinal epithelium which is constantly renewed by the progeny of intestinal stem cells (ISCs). The proliferation and differentiation of adult stem cells must be tightly controlled in order to maintain resident tissue homeostasis. Mis-regulation of stem cell proliferation and differentiation leads to depletion or excessive proliferation of stem cells, eventually resulting in severe diseases such as cancer (Radtke and Clevers, 2005; Morrison and Spradling, 2008). Understanding the detailed regulatory mechanisms of stem cell proliferation and differ- entiation will shed insights into the causes of related human diseases.展开更多
BACKGROUND Colon cancer cell lines are widely used for research and for the screening of drugs that specifically target the stem cell compartment of colon cancers.It was reported that colon cancer carcinoma specimens ...BACKGROUND Colon cancer cell lines are widely used for research and for the screening of drugs that specifically target the stem cell compartment of colon cancers.It was reported that colon cancer carcinoma specimens contain a subset of leucine-rich repeatcontaining G protein-coupled receptor 5(LGR5)-expressing stem cells,these socalled“tumour-initiating”cells,reminiscent in their properties of the normal intestinal stem cells(ISCs),may explain the apparent heterogeneity of colon cancer cell lines.Also,colon cancer is initiated by aberrant Wnt signaling in ISCs known to express high levels of LGR5.Furthermore,in vivo reports demonstrate the clonal expansion of intestinal adenomas from a single LGR5-expressing cell.AIM To investigate whether colon cancer cell lines contain cancer stem cells and to characterize these putative cancer stem cells.METHODS A portable fluorescent reporter construct based on a conserved fragment of the LGR5 promoter was used to isolate the cell compartments expressing different levels of LGR5 in two widely used colon cancer cell lines(Caco-2 and LoVo).These cells were then characterized according to their proliferation capacity,gene expression signatures of ISC markers,and their tumorigenic properties in vivo and in vitro.RESULTS The data revealed that the LGR5 reporter can be used to identify and isolate a classical intestinal crypt stem cell-like population from the Caco-2,but not from the LoVo,cell lines,in which the cancer stem cell population is more akin to B lymphoma Moloney murine leukemia virus insertion region 1 homolog(+4 crypt)stem cells.This sub-population within Caco-2 cells exhibits an intestinal cancer stem cell gene expression signature and can both self-renew and generate differentiated LGR5 negative progeny.Our data also show that cells expressing high levels of LGR5/enhanced yellow fluorescent protein(EYFP)from this cell line exhibit tumorigenic-like properties in vivo and in vitro.In contrast,cell compartments of LoVo that are expressing high levels of LGR5/EYFP did not show these stem cell-like properties.Thus,cells that exhibit high levels of LGR5/EYFP expression represent the cancer stem cell compartment of Caco-2 colon cancer cells,but not LoVo cells.CONCLUSION Our findings highlight the presence of a spectrum of different ISC-like compartments in different colon cancer cell lines.Their existence is an important consideration for their screening applications and should be taken into account when interpreting drug screening data.We have generated a portable LGR5-reporter that serves as a valuable tool for the identification and isolation of different colon cancer stem cell populations in colon cancer lines.展开更多
Background:The rapid turnover of the intestinal epithelium is driven by the proliferation and differentiation of intestinal stem cells(ISCs).The dynamics of the F-actin cytoskeleton are critical for maintaining interc...Background:The rapid turnover of the intestinal epithelium is driven by the proliferation and differentiation of intestinal stem cells(ISCs).The dynamics of the F-actin cytoskeleton are critical for maintaining intercellular force and the signal transduction network.However,it remains unclear how direct interference with actin polymerization impacts ISC homeostasis.This study aims to reveal the regulatory effects of the F-actin cytoskeleton on the homeostasis of intestinal epithelium,as well as the potential risks of benproperine(BPP)as an anti-tumor drug.Methods:Phalloidin fluorescence staining was utilized to test F-actin polymerization.Flow cytom-etry and IHC staining were employed to discriminate different types of intestinal epithelial cells.Cell proliferation was assessed through bromo-deoxyuridine(BrdU)and 5-ethynyl-2-deoxyuridine(EdU)incorporation assays.The proliferation and differentiation of intestinal stem cells were replicated in vitro through organoid culture.Epithelial migrationwas evaluated through BrdU pulse labeling and chasing in mice.Results:The F-actin content was observed to significantly increase as crypt cells migrated into the villus region.Additionally,actin polymerization in secretory cells,especially in Paneth cells(PCs),was much higher than that in neighboring ISCs.Treatment with the newly identified actin-related protein 2/3 complex subunit 2(ARPC2)inhibitor BPP led to a dose-dependent increase or inhibition of intestinal organoid growth in vitro and crypt cell proliferation in vivo.Compared with the vehicle group,BPP treatment decreased the expression of Lgr5 ISC feature genes in vivo and in organoid culture.Meanwhile,PC differentiation derived from ISCs and progenitors was decreased by inhibition of F-actin polymerization.Mechanistically,BPP-induced actin polymerization inhibition may activate the Yes1-associated transcriptional regulator pathway,which affects ISC proliferation and differentiation.Accordingly,BPP treatment affected intestinal epithelial cell migration in a dose-dependent manner.Conclusion:Our findings indicate that the regulation of cytoskeleton reorganization can affect ISC homeostasis.In addition,inhibiting ARPC2 with the Food and Drug Administration-approved drug BPP represents a novel approach to influencing the turnover of intestinal epithelial cells.展开更多
AIM:To investigate the role and potential mechanisms of bone marrow mesenchymal stem cells(MSCs) in severe acute peritonitis(SAP).METHODS:Pancreatic acinar cells from Sprague Dawley rats were randomly divided into thr...AIM:To investigate the role and potential mechanisms of bone marrow mesenchymal stem cells(MSCs) in severe acute peritonitis(SAP).METHODS:Pancreatic acinar cells from Sprague Dawley rats were randomly divided into three groups:nonsodium deoxycholate(SDOC) group(non-SODC group),SDOC group,and a MSCs intervention group(i.e.,a co-culture system of MSCs and pancreatic acinar cells + SDOC).The cell survival rate,the concentration of malonaldehyde(MDA),the density of superoxide dismutase(SOD),serum amylase(AMS) secretion rate and lactate dehydrogenase(LDH) leakage rate were detected at various time points.In a separate study,Sprague Dawley rats were randomly divided into either an SAP group or an SAP + MSCs group.Serum AMS,MDA and SOD,interleukin(IL)-6,IL-10,and tumor necrosis factor(TNF)-α levels,intestinal mucosa injury scores and proliferating cells of small intestinal mucosa were measured at various time points after injecting either MSCs or saline into rats.In both studies,the protective effect of MSCs was evaluated.RESULTS:In vitro,The cell survival rate of pancreatic acinar cells and the density of SOD were significantly reduced,and the concentration of MDA,AMS secretion rate and LDH leakage rate were significantly increased in the SDOC group compared with the MSCs intervention group and the Non-SDOC group at each time point.In vivo,Serum AMS,IL-6,TNF-α and MAD level in the SAP + MSCs group were lower than the SAP group;however serum IL-10 level was higher than the SAP group.Serum SOD level was higher than the SAP group at each time point,whereas a significant betweengroup difference in SOD level was only noted after 24 h.Intestinal mucosa injury scores was significantly reduced and the proliferating cells of small intestinal mucosa became obvious after injecting MSCs.CONCLUSION:MSCs can effectively relieve injury to pancreatic acinar cells and small intestinal epithelium,promote the proliferation of enteric epithelium and repair of the mucosa,attenuate systemic inflammation in rats with SAP.展开更多
Adult stem cells are necessary for self-renewal tissues and regeneration after damage.Especially in the intestine,which self-renews every few days,they play a key role in tissue homeostasis.Therefore,complex regulator...Adult stem cells are necessary for self-renewal tissues and regeneration after damage.Especially in the intestine,which self-renews every few days,they play a key role in tissue homeostasis.Therefore,complex regulatory mechanisms are needed to prevent hyperproliferation,which can lead in the worst case to carcinogenesis or under-activation of stem cells,which can result in dysfunctional epithelial.One main regulatory signaling pathway is the Wnt/β-catenin signaling pathway.It is a highly conserved pathway,withβ-catenin,a transcription factor,as target protein.Translocation ofβ-catenin from cytoplasm to nucleus activates the transcription of numerous genes involved in regulating stem cell pluripotency,proliferation,cell differentiation and regulation of cell death.This review presents a brief overview of the Wnt/β-catenin signaling pathway,the regulatory mechanism of this pathway and its role in intestinal homeostasis.Additionally,this review highlights the molecular mechanisms and the histomorphological features of Wnt hyperactivation.Furthermore,the central role of the Wnt signaling pathway in intestinal carcinogenesis as well as its clinical relevance in colorectal carcinoma are discussed.展开更多
Leucine-rich repeat containing G protein-coupled receptor 5(Lgr5), a marker of intestinal stem cells(ISCs), is considered to play key roles in tissue homoeostasis and regeneration after acute radiation injury. However...Leucine-rich repeat containing G protein-coupled receptor 5(Lgr5), a marker of intestinal stem cells(ISCs), is considered to play key roles in tissue homoeostasis and regeneration after acute radiation injury. However, the activation of Lgr5 by integrated signaling pathways upon radiation remains poorly understood. Here, we show that irradiation of mice with whole-body depletion or conditional ablation of REGγ in Lgr5^(+) stem cell impairs proliferation of intestinal crypts, delaying regeneration of intestine epithelial cells. Mechanistically, REGγ enhances transcriptional activation of Lgr5 via the potentiation of both Wnt and Hippo signal pathways. TEAD4 alone or cooperates with TCF4, a transcription factor mediating Wnt signaling, to enhance the expression of Lgr5. Silencing TEAD4 drastically attenuated β-catenin/TCF4 dependent expression of Lgr5. Together, our study reveals how REGγ controls Lgr5 expression and expansion of Lgr5+stem cells in the regeneration of intestinal epithelial cells.Thus, REGγ proteasome appears to be a potential therapeutic target for radiation-induced gastrointestinal disorders.展开更多
CDC42 controls intestinal epithelial(IEC)stem cell(IESC)division.How aberrant CDC42 initiates intestinal inflammation or neoplasia is unclear.We utilized models of inflam-matory bowel diseases(IBD),colorectal cancer,a...CDC42 controls intestinal epithelial(IEC)stem cell(IESC)division.How aberrant CDC42 initiates intestinal inflammation or neoplasia is unclear.We utilized models of inflam-matory bowel diseases(IBD),colorectal cancer,aging,and IESC injury to determine the loss of intestinal Cdc42 upon inflammation and neoplasia.Intestinal specimens were collected to determine the levels of CDC42 in IBD or colorectal cancer.Cdc42 floxed mice were crossed with Villin-Cre,Villin-CreERT2 and/or Lgr5-eGFP-IRES-CreERT2,or Bmi1-CreERT2 mice to generate Cdc42 deficient mice.Irradiation,colitis,aging,and intestinal organoid were used to evaluate CDC42 upon mucosal inflammation,IESC/progenitor regenerative capacity,and IEC repair.Our studies revealed that increased CDC42 in colorectal cancer correlated with lower survival;in contrast,lower levels of CDC42 were found in the inflamed IBD colon.Colonic Cdc42 depletion significantly reduced Lgr5+IEsCs,increased progenitors'hyperplasia,and induced mucosal inflammation,which led to crypt dysplasia.Colonic Cdc42 depletion markedly enhanced irra-diation-or chemical-induced colitis.Depletion or inhibition of Cdc42 reduced colonic Lgr5+IESC regeneration.In conclusion,depletion of Cdc42 reduces the IESC regeneration and IEC repair,leading to prolonged mucosal inflammation.Constitutive monogenic loss of Cdc42 in-duces mucosal inflammation,which could result in intestinal neoplasia in the context of aging.展开更多
Crohn’s disease may prinicipally involve the whole gastrointestinal tract. Most commonly, the inflammation occurs in the small intestine and/or in the colon with stable disease location over the years. The pathogenes...Crohn’s disease may prinicipally involve the whole gastrointestinal tract. Most commonly, the inflammation occurs in the small intestine and/or in the colon with stable disease location over the years. The pathogenesis of both disease phenotypes is complex, the likely primary defect lies in the innate rather than adaptive immunity, particularly in the chemical antimicrobial barrier of the mucosa. Crohn’s ileitis is associated with a reduced expression of the Wnt signalling pathway transcription factor T-cell factor 4 (TCF4), which is regulating Paneth cell differentiation. As a result, the alpha-defensins and principal Paneth cell products HD5 and HD6 are deficiently expressed in ileal disease, independent of current inflammation. In contrast, Crohn’s colitis is typically associated with an impaired induction of the beta-defensins HBD2 and HBD3 caused by fewer gene copy numbers in the gene locus of the beta-defensins on chromosome 8. This ileal and colonic defect in innate defence mediated by a deficiency of the protective alpha- and beta- defensins may enable the luminal microbes to invade the mucosa and trigger the inflammation. A better understanding of the exact molecular mechanisms behind ileal and colonic Crohn’s disease may give rise to new therapeutic strategies based on a stimulation of the protective innate immune system.展开更多
Stem cells are undifferentiated cells capable of self-renewal and differentiation,giving rise to specialized functional cells.Stem cells are of pivotal importance for organ and tissue development,homeostasis,and injur...Stem cells are undifferentiated cells capable of self-renewal and differentiation,giving rise to specialized functional cells.Stem cells are of pivotal importance for organ and tissue development,homeostasis,and injury and disease repair.Tissue-specific stem cells are a rare population residing in specific tissues and present powerful potential for regeneration when required.They are usually named based on the resident tissue,such as hematopoietic stem cells and germline stem cells.This review discusses the recent advances in stem cells of various tissues,including neural stem cells,muscle stem cells,liver progenitors,pancreatic islet stem/progenitor cells,intestinal stem cells,and prostate stem cells,and the future perspectives for tissue stem cell research.展开更多
The Hippo pathway plays a crucial role in controlling organ size by inhibiting cell proliferation and promoting cell death.Recent findings implicate that this pathway is involved in the process of intestinal regenerat...The Hippo pathway plays a crucial role in controlling organ size by inhibiting cell proliferation and promoting cell death.Recent findings implicate that this pathway is involved in the process of intestinal regeneration and tumorigenesis.Here we summarize current studies for the function of the Hippo signaling pathway in intestinal homeostasis,regeneration and tumorigenesis,and the crosstalk between the Hippo signaling pathway and other major signaling pathways,i.e.Wnt,Notch and Jak/Stat signaling pathways in intestinal compartment.展开更多
This study aimed to assess the changes of small intestinal morphology,progenitors,differentiated epithelial cells,and potential mechanisms in neonatal piglets.Hematoxylin and eosin staining of samples from 36 piglets ...This study aimed to assess the changes of small intestinal morphology,progenitors,differentiated epithelial cells,and potential mechanisms in neonatal piglets.Hematoxylin and eosin staining of samples from 36 piglets suggested that dramatic changes were observed in the jejunum crypts depth and crypt fission index of neonatal piglets(P<0.001).The number of intestinal stem cells(ISC)tended to increase(P<0.10),and a decreased number of enteroendocrine cells appeared in the jejunal crypt on d 7(P<0.05).Furthermore,the mRNA expression of jejunal chromogranin A(ChgA)was down-regulated in d 7 piglets(P<0.05).There was an up-regulation of the adult ISC marker gene of SPARC related modular calcium binding 2(Smoc2),and Wnt/b-catenin target genes on d 7(P<0.05).These results were further verified in vitro enteroid culture experiments.A mass of hollow spheroids was cultured from the fetal intestine of 0-d-old piglets(P<0.001),whereas substantial organoids with budding and branching structures were cultured from the intestine of 7-d-old piglets(P<0.001).The difference was reflected by the organoid budding efficiency,crypt domains per organoid,and the surface area of the organoid.Furthermore,spheroids on d 0 had more Ki67-positive cells and enteroendocrine cells(P<0.05)and showed a decreasing trend in the ISC and goblet cells(P<0.10).Moreover,the mRNA expression of spheroids differed markedly from that of organoids,with low expression of intestinal differentiation gene(Lysozyme;P<0.05),epithelial-specific markers(Villin,E-cadherin;P<0.05),and adult ISC markers(leucine-rich repeat-containing G protein-coupled receptor 5[Lgr5],Smoc2;P<0.001),and upregulation of fetal marker(connexin 43[Cnx43];P<0.05).The mRNA expression of relevant genes was up-regulated,and involved in Wnt/b-catenin,epidermal growth factor(EGF),Notch,and bone morphogenetic protein(BMP)signaling on d 7 organoids(P<0.05).Spheroids displayed low differentiated phenotype and high proliferation,while organoids exhibited strong differentiation potential.These results indicated that the conversion from the fetal progenitors(spheroids)to adult ISC(normal organoids)might largely be responsible for the fast development of intestinal epithelial cells in neonatal piglets.展开更多
The in vitro organoid model is a major technological breakthrough that has been established as an important tool in many basic biological and clinical applications.This near-physiological 3D culture system accurately ...The in vitro organoid model is a major technological breakthrough that has been established as an important tool in many basic biological and clinical applications.This near-physiological 3D culture system accurately models various biological processes,including tissue renewal,stem cell/niche functions and tissue responses to drugs,mutations or damage.Organoids have the potential value of being an accurate model for disease predictions or drug screening applications and to identify the ideal treatment for that patient.Carcinogenesis can be modeled by mutating specific cancer genes in wild-type organoids;and patient-derived organoids provide an important resource in the development of personalized cancer treatment.Organoids from cancer patients could be used to identify the ideal treatment for a specific patient by growing matched healthy and diseased organoids from human cancer patients which additionally enables clinical screens for drug combinations.Organoids could also provide autologous cells ordin the futuredtissue for transplantation.In this review,we discuss the current advances,challenges and potential applications of this technique in gastrointestinal neoplasms.展开更多
基金Supported by Scientific Research Fund Project of Education Department of Yunnan Province,No.2023J0346the Kunming Health Commission Kunming Health Science and Technology Personnel Training Project,No.2021-SW-75the Medical and Health Science and Technology Project of Kunming Health Committee,No.2022-03-09-008.
文摘Proliferation and differentiation of intestinal stem cell(ISC)to replace damaged gut mucosal epithelial cells in inflammatory states is a critical step in ameliorating gut inflammation.However,when this disordered proliferation continues,it induces the ISC to enter a cancerous state.The gut microbiota on the free surface of the gut mucosal barrier is able to interact with ISC on a sustained basis.Micro-biota metabolites are able to regulate the proliferation of gut stem and progenitor cells through transcription factors,while in steady state,differentiated colono-cytes are able to break down such metabolites,thereby protecting stem cells at the gut crypt.In the future,the gut flora and its metabolites mediating the regulation of ISC differentiation will be a potential treatment for enteropathies.
基金supported by the National Natural Science Foundation of China(81973837)Scientific and technological innovation project of China Academy of Chinese Medical Sciences(CI2021A016)National Key projects for international cooperation on science,technology and innovation(2021YFE0201100).
文摘Interactions between diet and the intestinal microbiome play an important role in human health and disease development.It is well known that such interactions,whether direct or indirect,trigger a series of metabolic reactions in the body.Evidence suggests that intestinal stem cells(ISCs),which are phenotypic precursors of various intestinal epithelial cells,play a significant role in the regulation of intestinal barrier function and homeostasis.The advent and evolution of intestinal organoid culture techniques have presented a key opportunity to study the association between the intestinal microenvironment and ISCs.As a result,the effects exerted by dietary factors,intestinal microbiomes,and their metabolites on the metabolic regulation of ISCs and the potential mechanisms underlying such effects are being gradually revealed.This review summarises the effects of different dietary patterns on the behaviour and functioning of ISCs and focuses on the crosstalk between intestinal microbiota,related metabolites,and ISCs,with the aim of fully understanding the relationship between these three factors and providing further insights into the complex mechanisms associated with ISCs in the human body.Gaining an understanding of these mechanisms may lead to the development of novel dietary interventions or drugs conducive to intestinal health.
基金Supported by the National Natural Science Foundation of China,No.82202766the Natural Science Foundation of Hubei Province of China,No.2022CFB686+1 种基金the Science Foundation of Union Hospital,No.2021xhyn102the Scientific Research Training Program for Young Talents in Union Hospital,Tongji Medical College,Huazhong University of Science and Technology,China。
文摘The mammalian intestinal epithelium constitutes the largest barrier against the external environment and makes flexible responses to various types of stimuli.Epithelial cells are fast-renewed to counteract constant damage and disrupted barrier function to maintain their integrity.The homeostatic repair and regeneration of the intestinal epithelium are governed by the Lgr5+intestinal stem cells(ISCs)located at the base of crypts,which fuel rapid renewal and give rise to the different epithelial cell types.Protracted biological and physicochemical stress may challenge epithelial integrity and the function of ISCs.The field of ISCs is thus of interest for complete mucosal healing,given its relevance to diseases of intestinal injury and inflammation such as inflammatory bowel diseases.Here,we review the current understanding of the signals and mechanisms that control homeostasis and regeneration of the intestinal epithelium.We focus on recent insights into the intrinsic and extrinsic elements involved in the process of intestinal homeostasis,injury,and repair,which fine-tune the balance between self-renewal and cell fate specification in ISCs.Deciphering the regulatory machinery that modulates stem cell fate would aid in the development of novel therapeutics that facilitate mucosal healing and restore epithelial barrier function.
基金the National Basic Research Program(973 Program)in China(nos.2009CB522405 and 2007CB513005)the Key Project of National Natural Science Foundation in China(30830098)+3 种基金the National Natural Science Foundation in China(81070375)the Scientific Research Fund in Jiangsu Province(BK2009317)the National Key Project of Scientific and Technical Supporting Programs Funded by the Ministry of Science and Technology of China(2008BAI60B06)the Military Scientific Research Fund(0603AM117).
文摘Qiurong Li1,Qiang Zhang1,Chenyang Wang1,Shaojun Jiang2,Ning Li1,Jieshou Li1 Intestinal stem cells may have important roles in the maintenance of epithelial integrity during tissue repair.Alemtuzumab is a humanized anti-CD52 lymphocytic antibody that is increasingly being used to induce immunosuppression;intestinal barrier function is impaired during treatment with alemtuzumab.We investigated the response of intestinal stem cells to epithelial damage resulting from alemtuzumab treatment.Intestinal epithelial cell loss and abnormal Paneth cell morphology were found following a single dose of alemtuzumab.The animals receiving alemtuzumab exhibited increased apoptosis in the villi 3 days after alemtuzumab treatment and in the crypt on day 9,but apoptosis was scarce on day 35.We assessed expression of Musashi-1-and Lgr5-positive stem cells following alemtuzumab treatment.Increased numbers of cells staining positive for both Musashi-1 and Lgr5 were found in the stem cell zone after alemtuzumab treatment for 3 and 9 days.These data indicated that the epithelial cells were injured following alemtuzumab treatment,with the associated expansion of intestinal stem cells.After alemtuzumab treatment for 35 days,the numbers of intestinal epithelial cells and intestinal stem cells returned to normal.This study suggests that alemtuzumab treatment induced the increase in stem cells,resulting in the availability of more enterocytes for repair.
基金supported by the National Natural Science Foundation of China(31330049,31221064)National Basic Research Program of China(2011CB943803,2011CBA01104,2010CB833706)to Chen Ye-Guang
文摘The remarkable ability of rapid self-renewal makes the intestinal epithelium an ideal model for the study of adult stem cells. The intestinal epithelium is organized into villus and crypt, and a group of intestinal stem cells located at the base of crypt are responsible for this constant self-renewal throughout the life. Identification of the intestinal stem cell marker Lgr5, isolation and in vitro culture of Lgr5+ intestinal stem cells and the use of transgenic mouse models have significantly facilitated the studies of intestinal stem cell homeostasis and differentiation, therefore greatly expanding our knowledge of the regulatory mechanisms underlying the intestinal stem cell fate determination. In this review, we summarize the current understanding of how signals of Wnt, BMP, Notch and EGF in the stem cell niche modulate the intestinal stem cell fate.
基金The research in the Xi’s lab is in part supported by the National Key Research and Development Program of China(2017YFA0103602)GZ is supported by grants from National Natural Science Foundation for Young Scientists of China(31801229)+1 种基金China Postdoctoral Science Foundation(2017 M610779)Beijing Postdoctoral Research Foundation(2016-ZZ-110).
文摘The rapidly self-renewing epithelium in the mammalian intestine is maintained by multipotent intestinal stem cells(ISCs) located at the bottom of the intestinal crypt that are interspersed with Paneth cells in the small intestine andPaneth-like cells in the colon. The ISC compartment is also closely associated with a sub-epithelial compartmentthat contains multiple types of mesenchymal stromal cells. With the advances in single cell and gene editingtechnologies, rapid progress has been made for the identification and characterization of the cellular componentsof the niche microenvironment that is essential for self-renewal and differentiation of ISCs. It has becomeincreasingly clear that a heterogeneous population of mesenchymal cells as well as the Paneth cells collectivelyprovide multiple secreted niche signals to promote ISC self-renewal. Here we review and summarize recentadvances in the regulation of ISCs with a main focus on the definition of niche cells that sustain ISCs.
基金This work was supported by Hunan Province Key Field R&D Program(2019NK2193)Key Programs of Frontier Scientific Research of the Chinese Academy of Sciences(QYZDY-SSWSMC008)+1 种基金Natural Science Foundation of Hunan Province(2017JJ1020)Young Elite Scientists Sponsorship Program by CAST(YESS20160086).
文摘Early weaning in piglets can cause a series of negative effects.This causes serious losses to the livestock industry.N-Acetyl-D-glucosamine(D-GlcNAc)plays an important role in regulating the homeostasis of the intestine.This study aimed to investigate the effects of D-GlcNAc on the growth performance and intestinal function of weaned piglets.Twenty-four weaned piglets([Yorkshire×Landrace]Duroc,6.58±0.15 kg,n=8)at 21 d old were fed 3 diets supplemented with 0(control),1 and 3 g/kg D-GlcNAc.The intestinal organoid model was used to verify the regulatory mechanism of D-GlcNAc on intestinal epithelial cells.On the whole,supplementation of D-GlcNAc in the piglet diet has no significant effect on the growth performance and diarrhoea of weaned piglets(P>0.05).The apparent digestibility of nutrients and mRNA abundance of nutrient transporters in the 1 g/kg D-GlcNAc group were increased significantly(P<0.05).D-GlcNAc did not affect villus height(VH)and crypt depth(CD)but resulted in a numerically shorter VH and shallower CD,which lead to an increase in ileal VH:CD ratio(P<0.05).Cell shedding rates in the ileum villi increased(P<0.05).The relative length and weight of the small intestine of weaned piglets increased(P<0.05).In vitro studies found that the budding rates of organoids treated with 0.1 mmol/L D-GlcNAc increased on the d 3 and 5(P<0.05).The average budding numbers per budding organoid treated with 0.1 and 10 mmol/L D-GlcNAc increased on d 3(P<0.05).D-GlcNAc upregulated leucine rich repeat containing G protein-coupled receptor 5(Lgr5^(+))and Chromogranin A mRNA abundance in organoids(P<0.05).Mucin 2(Muc2)expression increased when treated with 1 and 10 mmol/L D-GlcNAc(P<0.05).In conclusion,dietary D-GlcNAc cannot improve the growth performance of weaned piglets.However,it can promote the growth and development of the intestinal tract and improve the digestion and absorption capacity of the intestine,which is achieved by affecting the activity of intestinal stem cells.
基金supported by the National Key Research and Development Program of China(2017YFA0103603 to X.W.)supported by Beijing Natural Science Foundation(Z190016 to X.W.)。
文摘The intestinal epithelium is one of the most rapidly renewing tissues,which is fueled by stem cells at the base of the crypts.Strategies of genetic lineage tracing and organoids,which capture major features of original tissues,are powerful avenues for exploring the biology of intestinal stem cells in vivo and in vitro,respectively.The combination of intestinal organoideculturing system and genetic modification approaches provides an attractive platform to uncover the mechanism of colorectal cancer and genetic disorders in the human minigut.Here,we will provide a comprehensive overview of studies on intestinal epithelium and intestinal stem cells.We will also review the applications of organoids and genetic markers in intestinal research studies.Furthermore,we will discuss the advantages and drawbacks of organoids as disease models compared with mice models and cell lines.
基金supported by the grants from the National Natural Science Foundation of China (Nos.31271582 and 31200213)China Postdoctoral Science Foundation (No.2012M510410)Beijing Scientific Research Foundation for Scholars Returned from Overseas,and Beijing Municipal Commission of Education (No.010135336400)
文摘Adult stem cells or progenitors are essential for maintaining the normal structure and function of adult tissues (i.e., ho- meostasis). One of the best examples is the adult intestinal epithelium which is constantly renewed by the progeny of intestinal stem cells (ISCs). The proliferation and differentiation of adult stem cells must be tightly controlled in order to maintain resident tissue homeostasis. Mis-regulation of stem cell proliferation and differentiation leads to depletion or excessive proliferation of stem cells, eventually resulting in severe diseases such as cancer (Radtke and Clevers, 2005; Morrison and Spradling, 2008). Understanding the detailed regulatory mechanisms of stem cell proliferation and differ- entiation will shed insights into the causes of related human diseases.
基金We thank Professor McGuckin M(MMRI,Brisbane)for providing human colon cancer cell lines(Caco-2,LoVo,and SW480)Dr.Rolfe B(AIBN,Brisbane)for providing mouse NSC-34 cells.
文摘BACKGROUND Colon cancer cell lines are widely used for research and for the screening of drugs that specifically target the stem cell compartment of colon cancers.It was reported that colon cancer carcinoma specimens contain a subset of leucine-rich repeatcontaining G protein-coupled receptor 5(LGR5)-expressing stem cells,these socalled“tumour-initiating”cells,reminiscent in their properties of the normal intestinal stem cells(ISCs),may explain the apparent heterogeneity of colon cancer cell lines.Also,colon cancer is initiated by aberrant Wnt signaling in ISCs known to express high levels of LGR5.Furthermore,in vivo reports demonstrate the clonal expansion of intestinal adenomas from a single LGR5-expressing cell.AIM To investigate whether colon cancer cell lines contain cancer stem cells and to characterize these putative cancer stem cells.METHODS A portable fluorescent reporter construct based on a conserved fragment of the LGR5 promoter was used to isolate the cell compartments expressing different levels of LGR5 in two widely used colon cancer cell lines(Caco-2 and LoVo).These cells were then characterized according to their proliferation capacity,gene expression signatures of ISC markers,and their tumorigenic properties in vivo and in vitro.RESULTS The data revealed that the LGR5 reporter can be used to identify and isolate a classical intestinal crypt stem cell-like population from the Caco-2,but not from the LoVo,cell lines,in which the cancer stem cell population is more akin to B lymphoma Moloney murine leukemia virus insertion region 1 homolog(+4 crypt)stem cells.This sub-population within Caco-2 cells exhibits an intestinal cancer stem cell gene expression signature and can both self-renew and generate differentiated LGR5 negative progeny.Our data also show that cells expressing high levels of LGR5/enhanced yellow fluorescent protein(EYFP)from this cell line exhibit tumorigenic-like properties in vivo and in vitro.In contrast,cell compartments of LoVo that are expressing high levels of LGR5/EYFP did not show these stem cell-like properties.Thus,cells that exhibit high levels of LGR5/EYFP expression represent the cancer stem cell compartment of Caco-2 colon cancer cells,but not LoVo cells.CONCLUSION Our findings highlight the presence of a spectrum of different ISC-like compartments in different colon cancer cell lines.Their existence is an important consideration for their screening applications and should be taken into account when interpreting drug screening data.We have generated a portable LGR5-reporter that serves as a valuable tool for the identification and isolation of different colon cancer stem cell populations in colon cancer lines.
基金supported by the National Natural Science Foundation of China(81872556)Chongqing Academician Program(Basic Research and Frontier Exploration)cstc2018jcyj-yszxX0004.
文摘Background:The rapid turnover of the intestinal epithelium is driven by the proliferation and differentiation of intestinal stem cells(ISCs).The dynamics of the F-actin cytoskeleton are critical for maintaining intercellular force and the signal transduction network.However,it remains unclear how direct interference with actin polymerization impacts ISC homeostasis.This study aims to reveal the regulatory effects of the F-actin cytoskeleton on the homeostasis of intestinal epithelium,as well as the potential risks of benproperine(BPP)as an anti-tumor drug.Methods:Phalloidin fluorescence staining was utilized to test F-actin polymerization.Flow cytom-etry and IHC staining were employed to discriminate different types of intestinal epithelial cells.Cell proliferation was assessed through bromo-deoxyuridine(BrdU)and 5-ethynyl-2-deoxyuridine(EdU)incorporation assays.The proliferation and differentiation of intestinal stem cells were replicated in vitro through organoid culture.Epithelial migrationwas evaluated through BrdU pulse labeling and chasing in mice.Results:The F-actin content was observed to significantly increase as crypt cells migrated into the villus region.Additionally,actin polymerization in secretory cells,especially in Paneth cells(PCs),was much higher than that in neighboring ISCs.Treatment with the newly identified actin-related protein 2/3 complex subunit 2(ARPC2)inhibitor BPP led to a dose-dependent increase or inhibition of intestinal organoid growth in vitro and crypt cell proliferation in vivo.Compared with the vehicle group,BPP treatment decreased the expression of Lgr5 ISC feature genes in vivo and in organoid culture.Meanwhile,PC differentiation derived from ISCs and progenitors was decreased by inhibition of F-actin polymerization.Mechanistically,BPP-induced actin polymerization inhibition may activate the Yes1-associated transcriptional regulator pathway,which affects ISC proliferation and differentiation.Accordingly,BPP treatment affected intestinal epithelial cell migration in a dose-dependent manner.Conclusion:Our findings indicate that the regulation of cytoskeleton reorganization can affect ISC homeostasis.In addition,inhibiting ARPC2 with the Food and Drug Administration-approved drug BPP represents a novel approach to influencing the turnover of intestinal epithelial cells.
基金Supported by Health and Medicine Scientific Research Foundation of Nanjing Military Area Command,No.08Z029
文摘AIM:To investigate the role and potential mechanisms of bone marrow mesenchymal stem cells(MSCs) in severe acute peritonitis(SAP).METHODS:Pancreatic acinar cells from Sprague Dawley rats were randomly divided into three groups:nonsodium deoxycholate(SDOC) group(non-SODC group),SDOC group,and a MSCs intervention group(i.e.,a co-culture system of MSCs and pancreatic acinar cells + SDOC).The cell survival rate,the concentration of malonaldehyde(MDA),the density of superoxide dismutase(SOD),serum amylase(AMS) secretion rate and lactate dehydrogenase(LDH) leakage rate were detected at various time points.In a separate study,Sprague Dawley rats were randomly divided into either an SAP group or an SAP + MSCs group.Serum AMS,MDA and SOD,interleukin(IL)-6,IL-10,and tumor necrosis factor(TNF)-α levels,intestinal mucosa injury scores and proliferating cells of small intestinal mucosa were measured at various time points after injecting either MSCs or saline into rats.In both studies,the protective effect of MSCs was evaluated.RESULTS:In vitro,The cell survival rate of pancreatic acinar cells and the density of SOD were significantly reduced,and the concentration of MDA,AMS secretion rate and LDH leakage rate were significantly increased in the SDOC group compared with the MSCs intervention group and the Non-SDOC group at each time point.In vivo,Serum AMS,IL-6,TNF-α and MAD level in the SAP + MSCs group were lower than the SAP group;however serum IL-10 level was higher than the SAP group.Serum SOD level was higher than the SAP group at each time point,whereas a significant betweengroup difference in SOD level was only noted after 24 h.Intestinal mucosa injury scores was significantly reduced and the proliferating cells of small intestinal mucosa became obvious after injecting MSCs.CONCLUSION:MSCs can effectively relieve injury to pancreatic acinar cells and small intestinal epithelium,promote the proliferation of enteric epithelium and repair of the mucosa,attenuate systemic inflammation in rats with SAP.
文摘Adult stem cells are necessary for self-renewal tissues and regeneration after damage.Especially in the intestine,which self-renews every few days,they play a key role in tissue homeostasis.Therefore,complex regulatory mechanisms are needed to prevent hyperproliferation,which can lead in the worst case to carcinogenesis or under-activation of stem cells,which can result in dysfunctional epithelial.One main regulatory signaling pathway is the Wnt/β-catenin signaling pathway.It is a highly conserved pathway,withβ-catenin,a transcription factor,as target protein.Translocation ofβ-catenin from cytoplasm to nucleus activates the transcription of numerous genes involved in regulating stem cell pluripotency,proliferation,cell differentiation and regulation of cell death.This review presents a brief overview of the Wnt/β-catenin signaling pathway,the regulatory mechanism of this pathway and its role in intestinal homeostasis.Additionally,this review highlights the molecular mechanisms and the histomorphological features of Wnt hyperactivation.Furthermore,the central role of the Wnt signaling pathway in intestinal carcinogenesis as well as its clinical relevance in colorectal carcinoma are discussed.
基金supported by the National Natural Science Foundation of China (82073483, 31730017, 82022051)the Science and Technology Commission of Shanghai Municipality (19JC1411900, 20s11901500)Changning Maternity and Infant Health Hospital PI team building project (311-20031)。
文摘Leucine-rich repeat containing G protein-coupled receptor 5(Lgr5), a marker of intestinal stem cells(ISCs), is considered to play key roles in tissue homoeostasis and regeneration after acute radiation injury. However, the activation of Lgr5 by integrated signaling pathways upon radiation remains poorly understood. Here, we show that irradiation of mice with whole-body depletion or conditional ablation of REGγ in Lgr5^(+) stem cell impairs proliferation of intestinal crypts, delaying regeneration of intestine epithelial cells. Mechanistically, REGγ enhances transcriptional activation of Lgr5 via the potentiation of both Wnt and Hippo signal pathways. TEAD4 alone or cooperates with TCF4, a transcription factor mediating Wnt signaling, to enhance the expression of Lgr5. Silencing TEAD4 drastically attenuated β-catenin/TCF4 dependent expression of Lgr5. Together, our study reveals how REGγ controls Lgr5 expression and expansion of Lgr5+stem cells in the regeneration of intestinal epithelial cells.Thus, REGγ proteasome appears to be a potential therapeutic target for radiation-induced gastrointestinal disorders.
基金supported by NIDDK RO1,USA(No.R01DK123299)(X.H.)MHMC/CWRU start-up(X.H.).R.M.was supported by a private cancer metabolism grant donation from Liechtenstein and the Austrian Science Fund(FWF)(No.SFB F4707 and SFB-F06105).
文摘CDC42 controls intestinal epithelial(IEC)stem cell(IESC)division.How aberrant CDC42 initiates intestinal inflammation or neoplasia is unclear.We utilized models of inflam-matory bowel diseases(IBD),colorectal cancer,aging,and IESC injury to determine the loss of intestinal Cdc42 upon inflammation and neoplasia.Intestinal specimens were collected to determine the levels of CDC42 in IBD or colorectal cancer.Cdc42 floxed mice were crossed with Villin-Cre,Villin-CreERT2 and/or Lgr5-eGFP-IRES-CreERT2,or Bmi1-CreERT2 mice to generate Cdc42 deficient mice.Irradiation,colitis,aging,and intestinal organoid were used to evaluate CDC42 upon mucosal inflammation,IESC/progenitor regenerative capacity,and IEC repair.Our studies revealed that increased CDC42 in colorectal cancer correlated with lower survival;in contrast,lower levels of CDC42 were found in the inflamed IBD colon.Colonic Cdc42 depletion significantly reduced Lgr5+IEsCs,increased progenitors'hyperplasia,and induced mucosal inflammation,which led to crypt dysplasia.Colonic Cdc42 depletion markedly enhanced irra-diation-or chemical-induced colitis.Depletion or inhibition of Cdc42 reduced colonic Lgr5+IESC regeneration.In conclusion,depletion of Cdc42 reduces the IESC regeneration and IEC repair,leading to prolonged mucosal inflammation.Constitutive monogenic loss of Cdc42 in-duces mucosal inflammation,which could result in intestinal neoplasia in the context of aging.
基金The Robert Bosch Foundation, Stuttgart, Germany the Emmy Noether program (J.W.) of the Deutsche Forschungsgemeinschaft (DFG)
文摘Crohn’s disease may prinicipally involve the whole gastrointestinal tract. Most commonly, the inflammation occurs in the small intestine and/or in the colon with stable disease location over the years. The pathogenesis of both disease phenotypes is complex, the likely primary defect lies in the innate rather than adaptive immunity, particularly in the chemical antimicrobial barrier of the mucosa. Crohn’s ileitis is associated with a reduced expression of the Wnt signalling pathway transcription factor T-cell factor 4 (TCF4), which is regulating Paneth cell differentiation. As a result, the alpha-defensins and principal Paneth cell products HD5 and HD6 are deficiently expressed in ileal disease, independent of current inflammation. In contrast, Crohn’s colitis is typically associated with an impaired induction of the beta-defensins HBD2 and HBD3 caused by fewer gene copy numbers in the gene locus of the beta-defensins on chromosome 8. This ileal and colonic defect in innate defence mediated by a deficiency of the protective alpha- and beta- defensins may enable the luminal microbes to invade the mucosa and trigger the inflammation. A better understanding of the exact molecular mechanisms behind ileal and colonic Crohn’s disease may give rise to new therapeutic strategies based on a stimulation of the protective innate immune system.
基金supported by grants from the National Natural Science Foundation of China(31988101 and 31730056 to YGC32125013 and 81772723 to DG+15 种基金32170804 to PH31930030 to LH91732301,31671072,31771140,81891001,91432111,81527901,31400977,31625013 to XW31625020,31830056,31861163006 to YAZ)the Ministry of Science and Technology of China(2017YFA0103601 to YGC2020YFA0509000,2017YFA0505500 to DG2017YFA0102700 to PH2019YFA0802001,2019YFA0801503 to LH2017YFA0102601,2019YFA0110100 to XW2020YFA0509002,2019YFA0802002 to YAZ)the Strategic Priority Research Program of the Chinese Academy of Science(XDA16020400 to PHXDA16020200 to YAZ)the Shanghai Science and Technology Commission(21XD1424200,21ZR1470100 to DG)the Basic Frontier Science Research Program of Chinese Academy of Sciences(ZDBS-LY-SM015 to DG)Space Medical Experiment Project of China Manned Space Program(HYZHXM01017 to PH)the Grants of Beijing Brain Initiative of Beijing Municipal Science&Technology Commission(Z181100001518004 to XW)。
文摘Stem cells are undifferentiated cells capable of self-renewal and differentiation,giving rise to specialized functional cells.Stem cells are of pivotal importance for organ and tissue development,homeostasis,and injury and disease repair.Tissue-specific stem cells are a rare population residing in specific tissues and present powerful potential for regeneration when required.They are usually named based on the resident tissue,such as hematopoietic stem cells and germline stem cells.This review discusses the recent advances in stem cells of various tissues,including neural stem cells,muscle stem cells,liver progenitors,pancreatic islet stem/progenitor cells,intestinal stem cells,and prostate stem cells,and the future perspectives for tissue stem cell research.
基金supported by grants from the China’s 1000 Young Talents Program,the 111 Project of The Ministration of Education of China(No.B06016)the Fundamental Research Funds for the Central Universities of China(No.2010111079)+1 种基金National Natural Science Foundation of China(Grant No.81101503)and Natural Science Foundation of Fujian(No.2011J05096)supported by the RO1 awards CA136567(JA),DK17776(JA)and institutional funds.The authors have no financial conflicts to disclose.
文摘The Hippo pathway plays a crucial role in controlling organ size by inhibiting cell proliferation and promoting cell death.Recent findings implicate that this pathway is involved in the process of intestinal regeneration and tumorigenesis.Here we summarize current studies for the function of the Hippo signaling pathway in intestinal homeostasis,regeneration and tumorigenesis,and the crosstalk between the Hippo signaling pathway and other major signaling pathways,i.e.Wnt,Notch and Jak/Stat signaling pathways in intestinal compartment.
文摘This study aimed to assess the changes of small intestinal morphology,progenitors,differentiated epithelial cells,and potential mechanisms in neonatal piglets.Hematoxylin and eosin staining of samples from 36 piglets suggested that dramatic changes were observed in the jejunum crypts depth and crypt fission index of neonatal piglets(P<0.001).The number of intestinal stem cells(ISC)tended to increase(P<0.10),and a decreased number of enteroendocrine cells appeared in the jejunal crypt on d 7(P<0.05).Furthermore,the mRNA expression of jejunal chromogranin A(ChgA)was down-regulated in d 7 piglets(P<0.05).There was an up-regulation of the adult ISC marker gene of SPARC related modular calcium binding 2(Smoc2),and Wnt/b-catenin target genes on d 7(P<0.05).These results were further verified in vitro enteroid culture experiments.A mass of hollow spheroids was cultured from the fetal intestine of 0-d-old piglets(P<0.001),whereas substantial organoids with budding and branching structures were cultured from the intestine of 7-d-old piglets(P<0.001).The difference was reflected by the organoid budding efficiency,crypt domains per organoid,and the surface area of the organoid.Furthermore,spheroids on d 0 had more Ki67-positive cells and enteroendocrine cells(P<0.05)and showed a decreasing trend in the ISC and goblet cells(P<0.10).Moreover,the mRNA expression of spheroids differed markedly from that of organoids,with low expression of intestinal differentiation gene(Lysozyme;P<0.05),epithelial-specific markers(Villin,E-cadherin;P<0.05),and adult ISC markers(leucine-rich repeat-containing G protein-coupled receptor 5[Lgr5],Smoc2;P<0.001),and upregulation of fetal marker(connexin 43[Cnx43];P<0.05).The mRNA expression of relevant genes was up-regulated,and involved in Wnt/b-catenin,epidermal growth factor(EGF),Notch,and bone morphogenetic protein(BMP)signaling on d 7 organoids(P<0.05).Spheroids displayed low differentiated phenotype and high proliferation,while organoids exhibited strong differentiation potential.These results indicated that the conversion from the fetal progenitors(spheroids)to adult ISC(normal organoids)might largely be responsible for the fast development of intestinal epithelial cells in neonatal piglets.
基金This project was supported by grants from the Shanghai Pujiang Program(16PJ1405700)The Program for Young Eastern Scholar at Shanghai Institutions of Higher Learning(QD2016004)Shanghai Science and Technology Commission Research Project(14441903103).
文摘The in vitro organoid model is a major technological breakthrough that has been established as an important tool in many basic biological and clinical applications.This near-physiological 3D culture system accurately models various biological processes,including tissue renewal,stem cell/niche functions and tissue responses to drugs,mutations or damage.Organoids have the potential value of being an accurate model for disease predictions or drug screening applications and to identify the ideal treatment for that patient.Carcinogenesis can be modeled by mutating specific cancer genes in wild-type organoids;and patient-derived organoids provide an important resource in the development of personalized cancer treatment.Organoids from cancer patients could be used to identify the ideal treatment for a specific patient by growing matched healthy and diseased organoids from human cancer patients which additionally enables clinical screens for drug combinations.Organoids could also provide autologous cells ordin the futuredtissue for transplantation.In this review,we discuss the current advances,challenges and potential applications of this technique in gastrointestinal neoplasms.