Role of transforming growth factor-βin peripheral nerve regeneration

Injuries caused by trauma and neurodegenerative diseases can damage the peripheral nervous system and cause functional deficits.Unlike in the central nervous system,damaged axons in peripheral nerves can be induced to regenerate in response to intrinsic cues after reprogramming or in a growth-promoting microenvironment created by Schwann cells.However,axon regeneration and repair do not automatically result in the restoration of function,which is the ultimate therapeutic goal but also a major clinical challenge.Transforming growth factor(TGF)is a multifunctional cytokine that regulates various biological processes including tissue repair,embryo development,and cell growth and differentiation.There is accumulating evidence that TGF-βfamily proteins participate in peripheral nerve repair through various factors and signaling pathways by regulating the growth and transformation of Schwann cells;recruiting specific immune cells;controlling the permeability of the blood-nerve barrier,thereby stimulating axon growth;and inhibiting remyelination of regenerated axons.TGF-βhas been applied to the treatment of peripheral nerve injury in animal models.In this context,we review the functions of TGF-βin peripheral nerve regeneration and potential clinical applications.

Exosome-transported IncRNA H19 regulates insulin-like growth factor-1 via the H19/let-7a/insulin-like growth factor-1 receptor axis in ischemic stroke

LncRNA(long non-coding RNA) H19 is a transcript of the H19 gene that is expressed during embryogenesis.We previously discove red a role for circular lncRNA H19 in the onset and prognosis of cerebral ischemic stroke.In this study,we used serum from patients with ischemic stroke,and mouse and cell culture models to elucidate the roles of plasma and neuronal exosomes in the regulatory effect of lncRNA H19 on insulin-like growth factor-1 and its mechanism in ischemic stroke,using western blotting,quantitative real-time polymerase chain reaction,and enzyme-linked immunosorbent assays.Plasma exosomal IncRNA H19 was negatively associated with blood levels of insulin-like growth factor-1 in samples from patients with cerebral ischemic stroke.In a mouse model,levels of exosomal IncRNA H19 were positively correlated with plasma and cerebral lncRNA H19.In a cell co-culture model,we confirmed that IncRNA H19 was transported from neuro ns to astrocytes by exosomes to induce downregulation of insulin-like growth factor-1 through the H19/let-7 a/insulin-like growth factor-1 receptor axis.This study provides the first evidence for the transpo rtation of IncRNA H19 by exosomes and the relationship between IncRNA H19 and insulinlike growth factor-1.

Low-temperature 3D-printed collagen/chitosan scaffolds loaded with exosomes derived from neural stem cells pretreated with insulin growth factor-1 enhance neural regeneration after traumatic brain injury

There are various clinical treatments for traumatic brain injury,including surgery,drug therapy,and rehabilitation therapy;howeve r,the therapeutic effects are limited.Scaffolds combined with exosomes represent a promising but challenging method for improving the repair of traumatic brain injury.In this study,we determined the ability of a novel 3D-printed collagen/chitosan scaffold loaded with exosomes derived from neural stem cells pretreated with insulin-like growth factor-1(3D-CC-INEXOS) to improve traumatic brain injury repair and functional recove ry after traumatic brain injury in rats.Composite scaffolds comprising collagen,chitosan,and exosomes derived from neural stem cells pretreated with insulin-like growth fa ctor-1(INEXOS) continuously released exosomes for 2weeks.Transplantation of 3D-CC-INExos scaffolds significantly improved motor and cognitive functions in a rat traumatic brain injury model,as assessed by the Morris water maze test and modified neurological seve rity scores.In addition,immunofluorescence staining and transmission electron microscopy showed that3D-CC-INExos implantation significantly improved the recove ry of damaged nerve tissue in the injured area.In conclusion,this study suggests that transplanted3D-CC-INExos scaffolds might provide a potential strategy for the treatment of traumatic brain injury and lay a solid foundation for clinical translation.

Neuroprotective effects of insulin-like growth factor-2 in 6-hydroxydopamine-induced cellular and mouse models of Parkinson’s disease

Skin-derived precursor Schwann cells have been reported to play a protective role in the central nervous system. The neuroprotective effects of skin-derived precursor Schwann cells may be attributable to the release of growth factors that nourish host cells. In this study, we first established a cellular model of Parkinson’s disease using 6-hydroxydopamine. When SH-SY5 Y cells were pretreated with conditioned medium from skin-derived precursor Schwann cells, their activity was greatly increased. The addition of insulin-like growth factor-2 neutralizing antibody markedly attenuated the neuroprotective effects of skin-derived precursor Schwann cells. We also found that insulin-like growth factor-2 levels in the peripheral blood were greatly increased in patients with Parkinson’s disease and in a mouse model of Parkinson’s disease. Next, we pretreated cell models of Parkinson’s disease with insulin-like growth factor-2 and administered insulin-like growth factor-2 intranasally to a mouse model of Parkinson’s disease induced by 6-hydroxydopamine and found that the level of tyrosine hydroxylase, a marker of dopamine neurons, was markedly restored, α-synuclein aggregation decreased, and insulin-like growth factor-2 receptor downregulation was alleviated. Finally, in vitro experiments showed that insulin-like growth factor-2 activated the phosphatidylinositol 3 kinase(PI3 K)/AKT pathway. These findings suggest that the neuroprotective effects of skin-derived precursor Schwann cells on the central nervous system were achieved through insulinlike growth factor-2, and that insulin-like growth factor-2 may play a neuroprotective role through the insulin-like growth factor-2 receptor/PI3 K/AKT pathway. Therefore, insulin-like growth factor-2 may be an useful target for Parkinson’s disease treatment.

Insulin-like growth factor-1 induces lymphangiogenesis and facilitates lymphatic metastasis in colorectal cancer

AIM:To investigate the expression of insulin-like growth factor-1(IGF-1)/insulin-like growth factor-1 receptor(IGF-1R)in colorectal cancer(CRC)tissues and to analyze their correlation with lymphangiogenesis and lymphatic metastasis.METHODS:Immunohistochemistry was used to evaluate IGF-1 and IGF-1R expression and lymphatic vessel density(LVD)in 40 CRC specimens.The correlation between IGF-1/IGF-1R and LVD was investigated.Effects of IGF-1 on migration and invasion of CRC cells were examined using transwell chamber assays.A LoVo cell xenograft model was established to further detect the role of IGF-1 in CRC lymphangiogenesis in vivo. RESULTS:Elevated IGF-1 and IGF-1R expression in CRC tissues was correlated with lymph node metastasis(r=0.715 and 0.569,respectively,P<0.05)and tumor TNM stage(r=0.731 and 0.609,P<0.05).A higher LVD was also found in CRC tissues and was correlated with lymphatic metastasis(r=0.405,P<0.05).A positive correlation was found between LVD and IGF-1R expression(r=0.437,P<0.05).Transwell assays revealed that IGF-1 increased the migration and invasion of CRC cells.In vivo mouse studies showed that IGF-1 also increased LVD in LoVo cell xenografts.CONCLUSION:IGF-1/IGF-1R signaling induces tumorassociated lymphangiogenesis and contributes to lymphatic metastasis of CRC.

Abnormal expression of insulin-like growth factor-Ⅱ and its dynamic quantitative analysis at different stages of hepatocellular carcinoma development

BACKGROUND:Hepatocellular carcinoma(HCC)is characterized by multiple causes,clear multiple stages and a multifocal process of tumor progression related intimately to the overexpression of many cellular factors. The aim of this study was to investigate the dynamic expression of insulin-like growth factor-Ⅱ(IGF-Ⅱ) and its abnormal alteration in the early stages of HCC development. METHODS:Hepatoma models were induced by 2-fluorenylacetamide(2-FAA)in male Sprague-Dawley rats.Morphological changes of rat livers were assessed by pathological examination(HE staining).The levels of IGF-Ⅱexpression in the livers and sera of rats were quantitatively detected by an enzyme-linked immunosorbent assay(ELISA).Simultaneously,the expression and cellular distribution of liver IGF-Ⅱwere analyzed by immunohistochemistry. RESULTS:Histological examination confirmed that rat hepatocytes showed changes from granule-like degeneration to atypical hyperplasia to HCC,and progressively increasing hepatic IGF-Ⅱlevels during HCC development.The levels of hepatic or serum IGF- Ⅱin HCC tissues and sera were significantly higher than those in normals and rats with degeneration.The immunohistochemical evidence indicated the positiveexpression and hepatocyte distribution of IGF-Ⅱin rat hepatoma.A positive relationship of IGF-Ⅱlevels was found between liver tissues and sera of experimental rats (P【0.01). CONCLUSION:Hepatic IGF-Ⅱmay participate in hepatocyte cancer development and detection of IGF-Ⅱ expression during HCC development could be a useful molecular marker for its early diagnosis.

Improvement in erectile dysfunction after insulin-like growth factor-1 gene therapy in diabetic rats

Aim： To determine whether adenoviral gene transfer of insulin like growth factor-1 （IGF-1） to the penis of streptozotocin （STZ）-induced diabetic rats could improve erectile capacity. Methods： The STZ diabetic rats were transfected with AdCMV-βgal or AdCMV-IGF-1. These rats underwent cavernous nerve stimulation to assess erectile function and their responses were compared with those of age-matched control rats 1 to 2 days after transfection. In control and transfected STZ diabetic rats, IGF-1 expression were examined by reverse transcription polymerase chain reaction （RT-PCR）, Western blot and histology. The penis β-galactosidase activity and localization of the STZ diabetic rats were also determined. Results： One to two days after transfection, the β-galactosidase was found in the smooth muscle cells of the diabetic rat penis transfected with AdCMV-βgal. One to 2 days after administration of AdCMV- IGF-1, the cavernosal pressure, as determined by the ratio of maximal intracavernous pressure-to-mean arterial pressure （ICP/MAP） and total intracavernous pressure （ICP）, was increased in response to cavernous nerve stimulation. Transgene expression was confirmed by RT-PCR, Western blot and histology. Conclusion： Gene transfer of IGF-1 significantly increased erectile function in the STZ diabetic rats. These results suggest that in vivo gene transfer of IGF- 1 might be a new therapeutic intervention for the treatment of erectile dysfunction （ED） in the STZ diabetic rats.

Overexpression of insulin-like growth factor-Ⅰ receptor as a pertinent biomarker for hepatocytes malignant transformation

AIM:To investigate the dynamic features of insulinlike growth factor-Ⅰreceptor(IGF-ⅠR)expression in rat hepatocarcinogenesis,and the relationship between IGF-ⅠR and hepatocytes malignant transformation at mRNA or protein level.METHODS:Hepatoma models were made by inducing with 2-fluorenylacetamide(2-FAA)on male SpragueDawley rats.Morphological changes of hepatocytes were observed by pathological Hematoxylin and eosin staining,the dynamic expressions of liver and serum IGF-ⅠR were quantitatively analyzed by an enzymelinked immunosorbent assay.The distribution of hepatic IGF-ⅠR was located by immunohistochemistry.The fragments of IGF-ⅠR gene were amplified by reverse transcription-polymerase chain reaction,and confirmed by sequencing.RESULTS:Rat hepatocytes after induced by 2-FAA were changed dynamically from granule-like degeneration,precancerous to hepatoma formation with the progressing increasing of hepatic mRNA or IGF-ⅠR expression.The incidences of liver IGF-ⅠR,IGF-ⅠR mRNA,specific IGF-ⅠR concentration(ng/mg wet liver),and serum IGF-ⅠR level(ng/mL)were 0.0%,0.0%,0.63±0.17,and 1.33±0.47 in the control;50.0%,61.1%,0.65±0.2,and 1.51±0.46 in the degeneration;88.9%,100%,0.66±0.14,and 1.92±0.29 in the precancerosis;and 100%,100%,0.96±0.09,and2.43±0.57 in the cancerous group,respectively.IGF-ⅠR expression in the cancerous group was significantly higher(P<0.01)than that in any of other groups at mRNA or protein level.The closely positive IGF-ⅠR relationship was found between livers and sera(r=0.91,t=14.222,P<0.01),respectively.CONCLUSION:IGF-ⅠR expression may participate in rat hepatocarcinogenesis and its abnormality should be an early marker for hepatocytes malignant transformation.

Organ fibrosis inhibited by blocking transforming growth factor-β signaling via peroxisome proliferator-activated receptor γ agonists

BACKGROUND:Organ fibrosis has been viewed as one of the major medical problems, which can lead to progressive dysfunction of the liver, lung, kidney, skin, heart, and eventually death of patients. Fibrosis is initiated by a variety of pathological, physiological, biochemical, and physical factors. Regardless of their different etiologies, they all share a common pathogenetic process: excessive activation of the key profibrotic cytokine, transforming growth factor-β (TGF-β). Peroxisome proliferator-activated receptor γ (PPARγ), a ligand-activated transcription factor of the nuclear receptor superfamily, has received particular attention in recent years, because the activation of PPARγ by both natural and synthetic agonists could effectively inhibit TGF-β-induced profibrotic effects in many organs. DATA SOURCES: The English-language medical databases, PubMed, Elsevier and SpringerLink were searched for articles on PPARγ, TGF-β, and fibrosis, and related topics. RESULTS: TGF-β is recognized as a key profibrotic cytokine. Excessive activation of TGF-β increases synthesis of extracellular matrix proteins and decreases their degradation, associated with a gradual destruction of normal tissue architecture and function, whereas PPARγ agonists inhibit TGF-β signal transduction and are effective antifibrogenic agents in many organs including the liver, lung, kidney, skin and heart. CONCLUSIONS: The main antifibrotic activity of PPARγ agonists is to suppress the TGF-β signaling pathway by so-called PPARγ-dependent effect. In addition, PPARγ agonists, especially 15d-PGJ2, also exert potentially antifibrotic activity independent of PPARγ activation. TGF-β1/Smads signaling not only plays many essential roles in multiple developmental processes, butalso forms cross-talk networks with other signal pathways, and their inhibition by PPARγ agonists certainly affects the cytokine networks and causes non-suspected side-effects. Anti-TGF-β therapies with PPARγ agonists may have to be carefully tailored to be tissue-and target gene-specific to minimize side-effects, indicating a great challenge to the medical research at present.

Vascular endothelial growth factor A, secreted in response to transforming growth factor-β1 under hypoxic conditions, induces autocrine effects on migration of prostate cancer cells

Hypoxia and transforming growth factor-β1 （TGF-β1） increase vascular endothelial growth factor A （VEGFA） expression in a number of malignancies. This effect of hypoxia and TGF-β1 might be responsible for tumor progression and metastasis of advanced prostate cancer. In the present study, TGF-β1 was shown to induce VEGFA165 secretion from both normal cell lines （HPV7 and RWPE1） and prostate cancer cell lines （DU 145 and PC3）. Conversely, hypoxia-stimulated VEGFA165 secretion was observed only in prostate cancer cell lines. Hypoxia induced TGF-β1 expression in PC3 prostate cancer cells, and the TGF-β1 type I receptor （ALK5） kinase inhibitor partially blocked hypoxia-mediated VEGFA16s secretion. This effect of hypoxia provides a novel mechanism to increase VEGFA expression in prostate cancer cells. Although autocrine signaling of VEGFA has been implicated in prostate cancer progression and metastasis, the associated mechanism is poorly characterized. VEGFA activity is mediated via VEGF receptor （VEGFR） 1 （Fit-l） and 2 （FIk-I/KDR）. Whereas VEGFR-1 mRNA was detected in normal prostate epithelial cells, VEGFR-2 mRNA and VEGFR protein were expressed only in PC3 cells. VEGFA165 treatment induced phosphorylation of extracellular signal-regulated kinase 1/2 （ERKI/2） in PC3 cells but not in HPV7 cells, suggesting that the autocrine function of VEGFA may be uniquely associated with prostate cancer. Activation of VEGFR-2 by VEGFA165 was shown to enhance migration of PC3 cells. A similar effect was also observed with endogenous VEGFA induced by TGF-β1 and hypoxia. These findings illustrate that an autocrine loop of VEGFA via VEGFR-2 is critical for the tumorigenic effects of TGF-β1 and hypoxia on metastatic prostate cancers.

Growth factor-and cytokine-driven pathways governing liver stemness and differentiation

Liver is unique in its capacity to regenerate in response to injury or tissue loss. Hepatocytes and other liver cells are able to proliferate and repopulate the liver. However, when this response is impaired, the contribution of hepatic progenitors becomes very relevant. Here, we present an update of recent studies on growth factors and cytokine-driven intracellular pathways that govern liver stem/pro-genitor cell expansion and differentiation, and the rel-evance of these signals in liver development, regeneration and carcinogenesis. Tyrosine kinase receptor signaling, in particular, c-Met, epidermal growth factor receptors or fibroblast growth factor receptors, contribute to prolifera-tion, survival and differentiation of liver stem/progenitor cells. Different evidence suggests a dual role for the trans-forming growth factor (TGF)-β signaling pathway in liver stemness and differentiation. On the one hand, TGF-βmediates progression of differentiation from a progenitor stage, but on the other hand, it contributes to the expan-sion of liver stem cells. Hedgehog family ligands are nec-essary to promote hepatoblast proliferation but need to be shut off to permit subsequent hepatoblast differentiation. In the same line, the Wnt family and β-catenin/T-cell fac-tor pathway is clearly involved in the maintenance of liver stemness phenotype, and its repression is necessary for liver differentiation during development. Collectively, data indicate that liver stem/progenitor cells follow their own rules and regulations. The same signals that are essential for their activation, expansion and differentiation are good candidates to contribute, under adequate conditions, to the paradigm of transformation from a pro-regenerative to a pro-tumorigenic role. From a clinical perspective, this is a fundamental issue for liver stem/progenitor cell-based therapies.

Effects of Bifidobacterium infantis on cytokine-induced neutrophil chemoattractant and insulin-like growth factor-1 in the ileum of rats with endotoxin injury

BACKGROUND The digestive tract is the maximal immunizing tissue in the body, and mucosal integrity and functional status of the gut is very important to maintain a healthy organism. Severe infection is one of the most common causes of gastrointestinal dysfunction, and the pathogenesis is closely related to endotoxemia and intestinal barrier injury. Bifidobacterium is one of the main probiotics in the human body that is involved in digestion, absorption, metabolism, nutrition, and immunity.Bifidobacterium plays an important role in maintaining the intestinal mucosal barrier integrity. This study investigated the protective mechanism of Bifidobacterium during ileal injury in rats.AIM To investigate the effects of Bifidobacterium on cytokine-induced neutrophil chemoattractant(CINC) and insulin-like growth factor 1(IGF-1) in the ileum of rats with endotoxin injury.METHODS Preweaning rats were randomly divided into three groups: Control(group C),model(group E) and treatment(group T). Group E was intraperitoneally injected with lipopolysaccharide(LPS) to create an animal model of intestinal injury.Group T was intragastrically administered Bifidobacterium suspension 7 d before LPS. Group C was intraperitoneally injected with normal saline. The rats were killed at 2, 6 or 12 h after LPS or physiological saline injection to collect ilealtissue samples. The expression of ileal CINC mRNA was evaluated by reverse transcription-polymerase chain reaction(RT-PCR), and expression of ileal IGF-1 protein and mRNA was detected by immunohistochemistry and RT-PCR,respectively.RESULTS The ileum of rats in Group C did not express CINC mRNA, ileums from Group E expressed high levels, which was then significantly decreased in Group T(F =23.947, P < 0.05). There was no significant difference in CINC mRNA expression at different times(F = 0.665, P > 0.05). There was a high level of IGF-1 brown granules in ileal crypts and epithelial cells in Group C, sparse staining in Group E, and dark, dense brown staining in Group T. There was a significant difference between Groups C and E and Groups E and T(P < 0.05). There was no significant difference in IGF-1 protein expression at different times(F = 1.269, P > 0.05). IGF-1 mRNA expression was significantly different among the three groups(P < 0.05),though not at different times(F = 0.086, P > 0.05).CONCLUSION Expression of CINC mRNA increased in the ileum of preweaning rats with endotoxin injury, and exogenous administration of Bifidobacterium reduced CINC m RNA expression. IGF-1 protein and mRNA expression decreased in the ileum of preweaning rats with endotoxin injury, and exogenous administration of Bifidobacterium prevented the decrease in IGF-1 expression. Bifidobacterium may increase IGF-1 expression and enhance intestinal immune barrier function in rats with endotoxin injury.

Total flavone of Abelmoschus manihot suppresses epithelial-mesenchymal transition via interfering transforming growth factor-β1 signaling in Crohn's disease intestinal fibrosis

AIM To explore the role and mechanism of total flavone of Abelmoschus manihot(TFA) on epithelial-mesenchymal transition(EMT) progress of Crohn's disease(CD) intestinal fibrosis.METHODS First,CCK-8 assay was performed to assess TFA on the viability of intestinal epithelial(IEC-6) cells and select the optimal concentrations of TFA for our further studies.Then cell morphology,wound healing and transwell assays were performed to examine the effect of TFA on morphology,migration and invasion of IEC-6 cells treated with TGF-β1.In addition,immunofluorescence,real-time PCR analysis(q RT-PCR) and western blotting assays were carried out to detect the impact of TFA on EMT progress.Moreover,western blotting assay was performed to evaluate the function of TFA on the Smad and MAPK signaling pathways.Further,the role of co-treatment of TFA and si-Smad or MAPK inhibitors has been examined by q RTPCR,western blotting,morphology,wound healing andtranswell assays.RESULTS In this study,TFA promoted transforming growth factor-β1(TGF-β1)-induced(IEC-6) morphological change,migration and invasion,and increased the expression of epithelial markers and reduced the levels of mesenchymal markers,along with the inactivation of Smad and MAPK signaling pathways.Moreover,we revealed that si-Smad and MAPK inhibitors effectively attenuated TGF-β1-induced EMT in IEC-6 cells.Importantly,co-treatment of TFA and si-Smad or MAPK inhibitors had better inhibitory effects on TGF-β1-induced EMT in IEC-6 cells than either one of them.CONCLUSION These findings could provide new insight into the molecular mechanisms of TFA on TGF-β1-induced EMT in IEC-6 cells and TFA is expected to advance as a new therapy to treat CD intestinal fibrosis.

Progress of Targeting Transforming Growth Factor-β1 Small Interfering RNA in Liver Fibrosis

Liver fibrosis is a common pathological consequence of a variety of chronic stimuli, including viral, autoimmune, drug-induced, cholestatic and metabolic diseases. Fibrosis is driven by a dynamic process involving increased synthesis of matrix components and a failure of physiological mechanisms of matrix turnover. Activation of hepatic stellate cells(HSCs) remains a central event in fibrosis. HSCs are the main source of extracellular matrix(ECM). Transforming growth factor-beta(TGF-β), which is the fibrogenic master cytokine, can induce the activation of HSCs to produce a large amount of ECM, and is capable of inducing apoptosis of liver cells. RNA interference(RNAi) is a novel gene disruption technology. Studies have shown that small interfering RNA(si RNA) targeting TGF-β1 may inhibit the activation and proliferation of HSCs, suppress ECM synthesis and block liver fibrosis. TGF-β1 si RNA-mediated gene silencing therapy provides a new avenue for liver fibrosis. This review summarizes recent progresses in research on HSCs, TGF-β1 and TGF-β1 si RNA in liver fibrosis.

Expression of Nerve Growth Factor and Hypoxia Inducible Factor-1α and Its Correlation with Angiogenesis in Non-Small Cell Lung Cancer

Summary： In order to investigate the expression of nerve growth factor （NGF） and hypoxia inducible factor-1α （HIF-1α） and its correlation with angiogenesis in non-small cell lung cancer （NSCLC）, paraffin-embedded tissue blocks from 20 patients with NSCLC were examined. Twenty corresponding para-cancerous lung tissue specimens were obtained to serve as a control. The expression of NGF, HIF-1α, and vascular endothelial growth factor （VEGF） in the NSCLC tissues was detected by using immunohistochemistry. The microvascular density （MVD） was determined by CD31 staining. The resuits showed that the expression levels ofNGF, HIF-1α and VEGF in the NSCLC tissues were remarkably higher than those in the para-cancerous lung tissues （P〈0.05）. There was significant difference in the MVD between the NSCLC tissues （9.19±1.43） and para-cancerous lung tissues （2.23±1.19） （P〈0.05）. There were positive correlations between NGF and VEGF, between HIF-1α and VEGF, and between NGF and HIF-1α in NSCLC tissues, with the spearman correlation coefficient being 0.588, 0.519 and 0.588, respectively. In NSCLC tissues, the MVD had a positive correlation with the three factors （P〈0.05）. Theses results suggest that NGF and HIF-1α are synergically involved in the angiogenesis of NSCLC.

Celastrol inhibits migration, proliferation and transforming growth factor-β2-induced epithelial-mesenchymal transition in lens epithelial cells

AIM: To investigate the mechanism of celastrol in inhibiting lens epithelial cells(LECs) fibrosis, which is the pathological basis of cataract.METHODS: Human LEC line SRA01/04 was treated with celastrol and transforming growth factor-β2(TGF-β2). Wound-healing assay, proliferation assay, flow cytometry, real-time polymerase chain reaction(PCR), Western blot and immunocytochemical staining were used to detect the pathological changes of celastrol on LECs. Then, we cultured Sprague-Dawley rat lens in medium as a semi-in vivo model to find the function of celastrol further.RESULTS: We found that celastrol inhibited the migration of LECs, as well as proliferation(P<0.05). In addition, it induced the G2/M phase arrest by cell cyclerelated proteins(P<0.01). Moreover, celastrol inhibited epithelial-mesenchymal transition(EMT) by the blockade of TGF-β/Smad and Jagged/Notch signaling pathways.CONCLUSION: Our study demonstrates that celastrol could inhibit TGF-β2-induced lens fibrosis and raises the possibility that celastrol could be a potential novel drug in prevention and treatment of fibrotic cataract.

Pirfenidone suppresses the abnormal activation of human Müller cells after platelet-derived growth factor-BB stimulation

AIM: To determine the effect of pirfenidone on the activated human Müller cells by platelet-derived growth factor-BB(PDGF-BB). METHODS: The primary human Müller cells were separated from retinal tissues and established the pathogenic model by stimulated with PDGF-BB. The Müller cells behaviour of normal group and the model group was measured by MTT assay, Trypan blue assay, cell migration assay, and collagen contraction assay. The expression of transforming growth factor(TGF)-β1,-β2, and pigment epithelium-derived factor(PEDF) was estimated with realtime polymerase chain reaction(PCR), Western blot and immunofluorescence analyses. RESULTS: A pathogenic/proliferative model of Müller cells was established by stimulating normal cultured Müller cells with 10 ng/mL PDGF-BB for 48 h. After treated with 0.2 and 0.3 mg/mL pirfenidone, the proliferation, migration and collagen contraction was statistically significantly depressed in the model group compared with the normal groups. The expression levels of TGF-β1 and TGF-β2 were significantly down-regulated, while the PEDF expression was significantly up-regulated after treated with 0.2 and 0.3 mg/mL pirfenidone in the model group. CONCLUSION: Pirfenidone effectively suppress the proliferation, migration and collagen contraction of the human Müller cells stimulated with PDGF-BB through down-regulation of TGF-β1/TGF-β2 and up-regulation of PEDF.

Transforming growth factor-β and peripheral regulatory cells are negatively correlated with the overall survival of hepatocellular carcinoma

AIM To understand the cellular and molecular changes inperipheral blood that can lead to the development of hepatocellular carcinoma(HCC) and provide new methods for its diagnosis and treatment.METHODS Peripheral blood mononuclear cells were isolated from the peripheral blood of HCC patients and normal controls and then analyzed by flow cytometry. The percentage of transforming growth factor-β(TGF-β)+ regulatory cells(Tregs) in the peripheral blood was measured, and the expression of TGF-β was also determined. Then, the relationship between the changes and the 5-year survival of patients was analyzed. In addition, recombinant human TGF-β(rh TGF-β) and recombinant human interleukin-6 were added to stimulate the cultured cells, and their effects on HCC were evaluated.RESULTS The expression of TGF-β and the percentage of TGF-β+ Tregs in the peripheral blood of HCC patients increased significantly compared with normal controls. Compared with the low TGF-β expression group, the high TGF-β expression group had a significantly lower 5-year survival rate, and the same result was found in the two TGF-β+ Treg groups, suggesting that TGF-β and TGF-β+ Tregs were negatively correlated with the overall survival of the patients. In addition, rh TGF-β promoted the growth of tumor cells and induced high expression levels of IL-6, which further promoted tumor proliferation.CONCLUSION The results showed that TGF-β may promote tumor growth and proliferation by inducing the production of IL-6, and TGF-β and TGF-β+ Tregs may serve as new markers for predicting a poor prognosis in HCC.

Chondrogenesis of periodontal ligament stem cells by transforming growth factor-β3 and bone morphogenetic protein-6 in a normal healthy impacted third molar

The periodontal ligament-derived mesenchymal stem cell is regarded as a source of adult stem cells due to its multipotency.However, the proof of chondrogenic potential of the cells is scarce.Therefore,we investigated the chondrogenic differentiation capacity of periodontal ligament derived mesenchymal stem cells induced by transforming growth factor(TGF)-p3 and bone morphogenetic protein(BMP)-6.After isolation of periodontal ligament stem cells(PDLSCs) from human periodontal ligament,the cells were cultured in Dulbecco’s modified Eagle’s medium(DMEM) with 20%fetal bovine serum(FBS).A mechanical force initiated chondrogenic differentiation of the cells.For chondrogenic differentiation,10μg·LTGF-β3 or 100μg·LBMP-6 and the combination treating group for synergistic effect of the growth factors.We analyzed the PDLSCs by fluorescence-activated cell sorting and chondrogenesis were evaluated by glycosaminoglycans assay,histology,immunohistochemistry and genetic analysis.PDLSCs showed mesenchymal stem cell properties proved by FACS analysis.Glycosaminoglycans contents were increased 217%by TGF-β3 and 220%by BMP-6. The synergetic effect of TGF-β3 and BMP-6 were shown up to 281%compared to control.The combination treatment increased Sox9, aggrecan and collagen II expression compared with not only controls,but also TGF-P3 or BMP-6 single treatment dramatically.The histological analysis also indicated the chondrogenic differentiation of PDLSCs in our conditions.The results of the present study demonstrate the potential of the dental stem cell as a valuable cell source for chondrogenesis,which may be applicable for regeneration of cartilage and bone fracture in the field of cell therapy.

Insulin like growth factor-1 increases fatty liver preservation in IGL-1 solution

AIM: To investigate the benefits of insulin like growth factor-1 (IGF-1) supplementation to serum-free institut georges lopez-1 (IGL-1) solution to protect fatty liver against cold ischemia reperfusion injury. METHODS: Steatotic livers were preserved for 24 h in IGL-1  solution supplemented with or without IGF-1 and then perfused "ex vivo " for 2 h at 37℃. We examined the effects of IGF-1 on hepatic damage and function (transaminases, percentage of sulfobromophthalein clearance in bile and vascular resistance). We also studied other factors associated with the poor tolerance of fatty livers to cold ischemia reperfusion injury such as mitochondrial damage, oxidative stress, nitric oxide, tumor necrosis factor-α (TNF-α) and mitogen-activated protein kinases.RESULTS: Steatotic livers preserved in IGL-1 solutionsupplemented with IGF-1 showed lower transaminase levels, increased bile clearance and a reduction in vascular resistance when compared to those preserved in IGL-1solution alone. These benefits are mediated by activation of AKT and constitutive endothelial nitric oxide synthase (eNOS), as well as the inhibition of inflammatory cytokines such as TNF-α. Mitochondrial damage and oxidative stress were also prevented.CONCLUSION: IGL-1  enrichment with IGF-1 increasedfatty liver graft preservation through AKT and eNOS activation, and prevented TNF-α release during normothermic reperfusion.