Cerebral organoids exhibit mature neurons and astrocytes and recapitulate electrophysiological activity of the human brain

Multiple protocols have been devised to generate cerebral organoids that recapitulate features of the developing human brain, including the presence of a large, multi-layered, cortical-like neuronal zone. However, the central question is whether these organoids truly present mature, functional neurons and astrocytes, which may qualify the system for in-depth molecular neuroscience studies focused at neuronal and synaptic functions. Here, we demonstrate that cerebral organoids derived under optimal differentiation conditions exhibit mature, fully functional neurons and astrocytes, as validated by immunohistological, gene expression, and electrophysiological, analyses. Neurons in cerebral organoids showed gene expression profiles and electrophysiological properties similar to those reported for fetal human brain. These important findings indicate that cerebral organoids recapitulate the developing human brain and may enhance use of cerebral organoids in modeling human brain development or investigating neural deficits that underlie neurodevelopmental and neuropsychiatric conditions, such as autism or intellectual disorders.

Pregnancy and inflammatory bowel diseases: Current perspectives, risks and patient management

Inflammatory bowel diseases(IBD) are chronic idiopathic inflammatory conditions characterized by relapsing and remitting episodes of inflammation which can affect several different regions of the gastrointestinal tract, but also shows extra-intestinal manifestations. IBD is most frequently diagnosed during peak female reproductive years, with 25% of women with IBD conceiving after their diagnosis. While IBD therapy has improved dramatically with enhanced surveillance and more abundant and powerful treatment options, IBD disease can have important effects on pregnancy and presents several challenges for maintaining optimal outcomes for mothers with IBD and the developing fetus/neonate. Women with IBD, the medical team treating them(both gastroenterologists and obstetricians/gynecologists) must often make highly complicated choices regarding conception, pregnancy, and post-natal care(particularly breastfeeding) related to their choice of treatment options at different phases of pregnancy as well as post-partum. This current review discusses current concerns and recommendations for pregnancy duringIBD and is intended for gastroenterologists, general practitioners and IBD patients intending to become,(or already) pregnant, and their families. We have addressed patterns of IBD inheritance, effects of IBD on fertility and conception(in both men and women), the effects of IBD disease activity on maintenance of pregnancy and outcomes, risks of diagnostic procedures during pregnancy and potential risks and complications associated with different classes of IBD therapeutics. We also have evaluated the clinical experience using "top-down" care with biologics, which is currently the standard care at our institution. Post-partum care and breastfeeding recommendations are also addressed.

GENERATION OF TRANSGENIC MICE FOR IN VIVO DETECTION OF INSULIN-CONTAINING GRANULE EXOCYTOSIS AND QUANTIFICATION OF INSULIN SECRETION

Insulin secretion is a complex and highly regulated process.Although much progress has been made in understanding the cellular mechanisms of insulin secretion and regulation,it remains unclear how conclusions from these studies apply to living animals.That few studies have been done to address these issues is largely due to the lack of suitable tools in detecting secretory events at high spatial and temporal resolution in vivo.When combined with genetically encoded biosensor,optical imaging is a powerful tool for visualization of molecular events in vivo.In this study,we generated a DNA construct encoding a secretory granule resident protein that is linked with two spectrally separate fluorescent proteins,a highly pH-sensitive green pHluorin on the intra-granular side and a red mCherry in the cytosol.Upon exocytosis of secretory granules,the dim pHluorin inside the acidic secretory granules became highly fluorescent outside the cells at neutral pH,while mCherry fluorescence remained constant in the process,thus allowing ratiometric quantification of insulin secretory events.Furthermore,mCherry fluorescence enabled tracking the movement of secretory granules in living cells.We validated this approach in insulin-secreting cells,and generated a transgenic mouse line expressing the optical sensor specifically in pancreaticβ-cells.The transgenic mice will be a useful tool for future investigations of molecular mechanism of insulin secretion in vitro and in vivo.

Gut sterilization in experimental colitis leukocyte mediated colon injury, and effects on angiogenesis/lymphangiogenesis

Inappropriate responses to normal commensal bacteria trigger immune activation in both inflammatory bowel disease and experimental colitis. How gut flora contribute to the pathogenesis of inflammatory bowel disease is unclear, but may involve entrapment of leukocytes and remodeling of the vascular system. Here we evaluated how the progression and tissue remodeling in experimental colitis differ in a germ- free model of mouse colitis. Four treatment groups were used: control, antibiotic-treated (ABX), dextran sulfate colitis (DSS) and DSS pre- and co-treated with antibiotics (DSS + ABX). In days 0 - 3 of the study, germ-free mice received antibiotics (vancomycin, neomycin, and metronidazole). During the next 11 days, antibiotics were continued and DSS (3%) added to “colitis” groups. Disease activity, weight, stool form and blood were monitored daily. Mice were sacrificed and tissue samples harvested. Histopathological scores in controls (0.00) and in ABX (1.0+/–0.81) were significantly (p –0). Extents of injury, inflammation and crypt damage were all improved in DSS + ABX. The Disease Activity Index score (day 11) was significantly worse in the DSS group compared to the DSS + ABX group. Stool blood and form scores were also significantly improved among these groups. Importantly, myeloper- oxidase was significantly reduced in DSS + ABX, indicating that neutrophil infiltration was blocked. Colitis was associated with an increase in blood and lymphatic vessels;both of these events were also significantly reduced by gut sterilization. Our experiment shows that clinical and histopathological severity of colitis was significantly worse in the DSS colitis group compared to the DSS + ABX group, supporting the hypothesis that development of IBD is likely to be less severe with appropriate antibiotic treatment. In particular, gut sterilization effectively reduces leuko- cyte-dependent (PMN) injury to improve outcomes and may be an important target for therapy.

Role of Sonic Hedgehog signaling during progression from inflammation to cancer in the stomach

Despite advances in treatment and the declining incidence,gastric cancer remains the second leading cause of cancer-related deaths in the world.Understanding the progression from inflammation to cancer in the stomach is crucial in the development of novel therapies and strategies for treating this disease.Chronic inflammation of the stomach is typically caused by Helicobacter pylori(H.pylori)and resulting lesions may lead to gastric cancer.During the progression from inflammation to cancer,the stomach epithelium changes with evidence of the disruption of normal epithelial cell differentiation and infiltrating inflammatory cells.Coincident with the development of atrophic gastritis and metaplasia,is the loss of the gastric morphogen Sonic Hedgehog(Shh).Given its critical role as a regulator of gastric tissue homeostasis,the disruption of Shh expression during inflammation correlates with the loss of normal epithelial cell differentiation,but this has only recently been rigorously tested in vivo using a unique mouse model of targeted gastric Shh deletion.While pre-neoplastic lesions such as atrophic gastritis and in-testinal metaplasia are associated with the loss of Shh within the acid-secreting glands of the stomach,there is a clear link between elevated Shh and signaling to gastric cancers.The current review focuses on the effects of aberrant Shh expression and its role in the development of gastric cancer,specifically in response to H.pylori infection.

Ischemic post-conditioning to counteract intestinal ischemia/reperfusion injury

Intestinal ischemia is a severe disorder with a variety of causes.Reperfusion is a common occurrence during treatment of acute intestinal ischemia but the injury resulting from ischemia/reperfusion(IR)may lead toeven more serious complications from intestinal atrophy to multiple organ failure and death.The susceptibility of the intestine to IR-induced injury(IRI)appears from various experimental studies and clinical settings such as cardiac and major vascular surgery and organ transplantation.Where as oxygen free radicals,activation of leukocytes,failure of microvascular perfusion,cellular acidosis and disturbance of intracellular homeo-stasis have been implicated as important factors inthe pathogenesis of intestinal IRI,the mechanisms underlying this disorder are not well known.To date,increasing attention is being paid in animal studies to potential pre-and post-ischemia treatments that protect against intestinal IRI such as drug interference with IR-induced apoptosis and inflammation processes and ischemic pre-conditioning.However,better insight is needed into the molecular and cellular events associated with reperfusion-induced damage to develop effective clinical protection protocols to combat this disorder.In this respect,the use of ischemic post-conditioning in combination with experimentally prolonged acidosis blocking deleterious reperfusion actions may turn out to have particular clinical relevance.

Cholestatic liver diseases:An era of emerging therapies

Recently the field of cholestasis has expanded enormously reflecting an improved understanding of the molecular mechanisms underlying bile secretion and its perturbation in chronic cholestatic disease. Novel anti-cholestatic therapeutic options have been developed for patients not favorably responding to ursodeoxycholic acid (UDCA), the current standard treatment for cholestatic liver disease. Important novel treatment targets now also include nuclear receptors involved in bile acid (BA) homoeostasis like farnesoid X receptor and G proteincoupled receptors e.g., the G-protein-coupled BA receptor “transmembrane G coupled receptor 5”. Fibroblast growth factor-19 and enterohepatic BA transporters also deserve attention as additional drug targets as does the potential treatment agent norUDCA. In this review, we discuss recent and future promising therapeutic agents and their potential molecular mechanisms in cholestatic liver disorders.

小胶质细胞可能通过选择性吞噬丘脑底核谷氨酸能突触来代偿多巴胺能神经元丢失造成的帕金森模型鼠的功能缺失

当帕金森患者出现临床症状时,其黑质致密部的绝大部分多巴胺神经元已发生退行性改变。这提示可能存在某些代偿机制,延缓了临床症状的出现。本研究制作6-羟多巴胺诱导的偏侧帕金森大鼠模型,观察位于黑质下网状部和苍白球的激活的小胶质细胞在代偿机制中的作用。研究发现,在偏侧帕金森大鼠中,黑质下网状部聚集的激活的小胶质细胞远多于苍白球中。激活的小胶质细胞胞体增大并表达吞噬物标志物CD68和NG2蛋白多糖。激活的小胶质细胞聚集在黑质下网状部的特定部位,该部位的突触蛋白I和突触后密集蛋白95的表达降低。活化的小胶质细胞吞噬突触前、后膜上的各种蛋白,包括NMDA受体。将红色荧光标记物Di I作为顺行示踪剂注入丘脑底核,可见黑质下网状部和苍白球内的细胞吞噬了Di I。在谷氨酸刺激下,原代培养的小胶质细胞吞噬活动增强,编码吞噬相关因子的m RNA转录水平也增加。人工合成的糖皮质激素地塞米松可以减弱这种改变。给PD大鼠皮下注射地塞米松,可以抑制黑质下网状部小胶质细胞的活化,运动功能障碍进一步加重,谷氨酸能突触转录m RNA增加,GABA能突触转录m RNA水平未增加。这些发现提示,当谷氨酸能神经元活动增强时,黑质下网状部和苍白球的小胶质细胞活化,选择性吞噬丘脑底核的谷氨酸能突触。因此,在基底核区可能存在一个负反馈环路,间接地代偿了由于多巴胺能神经元丢失而导致的功能障碍。小胶质细胞在这个负反馈环路中扮演了重要的角色。

A remembrance of Professor TP FENG

It is both an honor and pleasure to be given this opportunity to remember Professor TP FENG and his many contributions.He made many important scientific discoveries,labored mightily to establish firmly Physiology and Neuroscience in China,and was a major force in setting a high standard for scientific inquiry.It is safe to say that the past and future of Neuroscience in China would be very different had Professor FENG not provided leadership,by dint of organization,persuasion and strong personal example.

Histamine 3 receptor activation mediates inhibition of acid secretion during Helicobacter-induced gastritis

AIM:To test the hypothesis that histamine 3 receptor (H3R)activation during Helicobacter infection inhibits gastric acid secretion in vivo and in vitro.METHODS:Helicobacter felis(H.felis)infected and uninfected C57Bl/6 mice were infused with either PBS or the H3 receptor antagonist thioperamide(THIO)for 12 wk.After treatment,mice were analyzed for morphological changes and gastric acid content.Total RNA was prepared from the stomachs of each group and analyzed for changes in somatostatin and gastrin mRNA abundance by real time-polymerase chain reaction(RTPCR).Location of H3 receptors in the stomach was analyzed by co-localization using antibodies specific for the H3 receptor and parietal cell marker H + ,K + -ATPase βsubunit. RESULTS:Inflammation and parietal cell atrophy was observed after 12 wk of H.felis infection.Interestingly, treatment with the H3R antagonist thioperamide(THIO) prior to and during infection prevented H.felis-induced inflammation and atrophy.Compared to the uninfected controls,infected mice also had significantly decreased gastric acid.After eradication of H.felis with THIO treatment,gastric acidity was restored.Compared to the control mice,somatostatin mRNA abundance was decreased while gastrin gene expression was elevated during infection.Despite elevated gastric acid levels, after eradication of H.felis with THIO,somatostatin mRNA was elevated whereas gastrin mRNA was suppressed.Immunofluorescence revealed the presence of H3 receptors on the parietal cells,somatostatin-secreting D-cells as well as the inflammatory cells. CONCLUSION:This study shows that during H.felis infection,gastric acidity is suppressed as a consequence of an inhibitory effect on the parietal cell by H3R activation.The stimulation of gastric mucosal H3Rs increases gastrin expression and release by inhibiting release of somatostatin.

<i>Helicobacter</i>infection decreases basal colon inflammation, but increases disease activity in experimental IBD

Background: Helicobacter species are best known for their roles in the pathology of gastritis;however, several Helicobacter species also colonize the intestine, and less is known about effects of Helicobacter on the development of intestinal inflammation. To evaluate contributions of Helicobacter in inflammatory bowel disease, we investigated whether and how pre-existing intestinal colonization would affect disease severity and biomarkers of inflammation in experimental IBD. Materials and Methods: Mice were infected with H. muridarum 2 weeks prior to induction of colitis mediated by 3% dextran sulfate (DSS). Disease activity index, stool blood and consistency, colon length, myeloperoxidase, histopathology, blood and lymphatic vessels, and numbers of dilated mucosal crypts were measured in control, DSS-only, H. muridarum-infected, and H. muridarum-infected + DSS mice. Results: Prior to DSS challenge, H. muridarum-infected mice showed little distal gut injury by several indices of colon inflammation with decreased blood vessel density in the submucosa, and lower lymphatic density in the mucosa and submucosa. However, after DSS colitis, H. muridarum-infected mice exhibited significantly greater disease. Weight change, stool bleeding, diarrhea, and angiogenesis were all increased in H. muridarum-infected mice in DSS colitis compared to DSS controls. Conclusions: Our data show that Helicobacter colonization of the intestine, unlike that of the stomach, lowers basal gut inflammatory scores, but increases disease activity and inflammation in an acute colitis model. Intestinal Helicobacter infection may therefore represent a significant sub-clinical factor which predisposes the gut to inflammatory injury.

Non-celiac gluten sensitivity: All wheat attack is not celiac

Currently,1% of the United States population holds a diagnosis for celiac disease(CD),however,a more recently recognized and possibly related condition,"non-celiac gluten sensitivity"(NCGS)has been suggested to affect up to 6%of the United States public.While reliable clinical tests for CD exist,diagnosing individuals affected by NCGS is still complicated by the lack of reliable biomarkers and reliance upon a broad set of intestinal and extra intestinal symptoms possibly provoked by gluten.NCGS has been proposed to exhibit an innate immune response activated by gluten and several other wheat proteins.At present,an enormous food industry has developed to supply gluten-free products(GFP)with GFP sales in 2014 approaching$1 billion,with estimations projecting sales to reach$2 billion in the year 2020.The enormous demand for GFP also reflects a popular misconception among consumers that gluten avoidance is part of a healthy lifestyle choice.Features of NCGS and other gluten related disorders(e.g.,irritable bowel syndrome)call for a review of current distinctive diagnostic criteria that distinguish each,and identification of biomarkers selective or specific for NCGS.The aim of this paper is to review our current understanding of NCGS,highlighting the remaining challenges and questions which may improve its diagnosis and treatment.

Gastric cancer in women: A regional health-center seven year retrospective study

AIM: To investigate whether regional geography influences ethnic and gender trends for the development of gastric cancer(GC).METHODS: This retrospective analysis of the INVISION patient database at Louisiana State University Health Sciences Center-Shreveport(LSUHSC-S), a southern United States regional hospital, was performed from 2005-2011. Using the international statistical classification of diseases 9(ICD-9), inpatient, day surgery outpatient, and emergency outpatient diagnosis codes entered into medical records were used to identify GC patients. For each study year, the patients were evaluated for age, ethnicity, and gender, and each patient was counted only once throughout the study. Subsequent patient encounters were counted as visits and separated by inpatient and clinic visits. Complex or severe disease may require more frequent and intensive clinical management; therefore, we evaluated annual clinic visits as "surrogate markers" of disease severity. Finally, we studied the primary diagnosis for Helicobacter pylori(H. pylori) infection(ICD-9 code 41.86) as an additional factor that might increase the risk of GC.RESULTS: A total of 285 patients were diagnosed with GC at LSUHSC-S between 2005 and 2011. African Americans(181 patients, 89 males and 92 females, 63.5% of total patients) had significantly higher frequencies of GC diagnosis compared with non-Hispanic whites(104 patients, 54 males and 50 females, 36.5% of total patients), at a ratio of 1.74(P = 0.002). Within each ethnic group, men and women were diagnosed at approximately equal annual rates. Our findings differed significantly from United States national trends, which found that African American females and white females had lower risks for GC than their corresponding male counterparts. The United States national trend between 2005 and 2011 showed that African Americans males had a higher incidence of GC, with an annual mean(per 100000) of 16.31 ± 0.76 compared with white males(9 ± 0.1, P < 0.001), African American females(8.7 ± 0.34, P < 0.001) and white females(4.05 ± 0.07, P < 0.001). Among the GC patients, the number of clinic visits was highest among African American males(195.1 ± 28.1), who had significantly more clinic visits than African Americans females(123 ± 13.02, P < 0.05), white males(41.57 ± 4.74, P < 0.001) and white females(35 ± 8.9, P < 0.001). Similar trends were found for inpatient visits, with an annual mean of 11.43 ± 1.5 forAfrican American males, followed by African American females(7.29 ± 1.36), white males(2.57 ± 0.69) and white females(1.57 ± 0.612). African American males had significantly more inpatient visits than white males(P < 0.001), and African American females had more inpatient visits than white females(P < 0.01). African American patients showed the highest frequency of H. pylori positive status, with approximately 72% vs 28% for the white patients. CONCLUSION: Increase in GC diagnoses among women at LSUHSC-S is significantly higher than United States national averages, suggesting local geographic and socioeconomic influences may alter GC disease course.

Climate change and innovative paths to a more sustainable future

The challenges posed by climate change and greenhouse gas net-zero transition are discussed.Several key technology areas which require innovation are briefly reviewed in this article,including renewables,energy storage,distributed energy resources,CO2 utilization,agriculture,and the synergy between Al and energy transition.The shift in mindset from“re-cycling”to“re-using”and a redefinition of“wealth”for a more sustainable future are also proposed.

A novel long non-coding RNA Myolinc regulates myogenesis through TDP-43 and Filip1

Myogenesis is a complex process required for skeletal muscle formation during embryonic development and for regeneration and growth of myofibers in adults. Accumulating evidence suggests that long non-coding RNAs （IncRNAs） play key roles in regulating cell fate decision and function in various tissues. However, the role of IncRNAs in the regulation of myogenesis remains poorly understood. In this study, we identifed a novel muscle-enriched IncRNA called ＇Myolinc （AK142388）＇, which we functionally characterized in the C2C12 myoblast cell line. Myolinc is predominately localized in the nucleus, and its levels increase upon induction of the differ-entiation. Knockdown of Myolinc impairs the expression of myogenic regulatory factors and formation of multi-nucleated myotubes in cultured myoblasts. Myolinc also regulates the expression of Filipl in a cis-manner. Similar to MyoUnc, knockdown of FiUpl inhi-bits myogenic differentiation. Furthermore, Myolinc binds to TAR DNA-binding protein 43 （TDP-43）, a DNA/RNA-binding protein that regulates the expression of muscle genes （e.g. Actal and MyoD）. Knockdown of TDP-43 inhibits myogenic differentiation. We also show that Myolinc-TDP-43 interaction is essential for the binding of TDP-43 to the promoter regions of muscle marker genes. Finally, we show that silencing of Myolinc inhibits skeletal muscle regeneration in adult mice. Altogether, our study identifies a novel IncRNA that controls key regulatory networks of myogenesis.

Toll-like receptor signaling in hematopoietic homeostasis and the pathogenesis of hematologic diseases

Toll-like receptors （TLRs）, which are found in innate immune cells, are essential mediators of rapid inflammatory responses and appropriate T-cell activation in response to infection and tissue damage. Accumulating evidence suggests that TLR signaling is involved in normal hematopoiesis and specific hematologic pathologies. Particular TLRs and their downstream signaling mediators are expressed not only in terminally differentiated innate immune cells but also in early hematopoietic progenitors. Sterile activation of TLR signaling is required to generate early embryonic hematopoietic progenitor cells. In adult animals, TLR signaling directly or indirectly promotes differentiation of myeloid cells at the expense of that of lymphoid cells and the self renewal of hematopoietic stem cells during infection and tissue damage. Activating mutations of the MyD88 gene, which codes for a key adaptor involved in TLR signaling, are commonly detected in B-cell lymphomas and other B-cell hematopathologies. Dysregulated TLR signaling contributes to the pathogenesis of many hematopoietic disorders, including bone marrow failure, myelodysplastic syndrome, and acute myeloid leukemia. Complete elucidation of the molecular mechanisms by which TLR signaling mediates the regulation of both normal and pathogenic hematopoiesis will prove valuable to the development of targeted therapies and strategies for improved treatment of hematopoietic disorders.

Favorable and unfavorable roles of microglia and macrophages in the pathologic central nervous system

Resident microglia in the central nervous system (CNS) are activated rapidly in response to even minor pathologic changes in the CNS, releasing various cytokines, growth factors, reactive oxygen species and other bioactive substances, in addition to eliminating synapses and degenerating cells through phagocytosis. Monocytes in circulation invade the inflamed brain tissues and develop into macrophages that also produce several bioactive substances and engage in phagocytosis. This article introduces methods for distinguishing microglia and macrophages. The pathophysiological roles of resident microglia and macrophages are discussed in animal models with neuroinflammation in the brain either with or without disruption of the blood-brain barrier. Both cell types have ameliorating and aggravating effects on the pathologic CNS, and their different roles are addressed in this article. Furthermore, this article compares the effects of some pharmacological interventions to induce phenotypic cellular changes for improved outcomes of the pathologic CNS.

Gut microbiota and microbiota-derived metabolites in cardiovascular diseases

Cardiovascular diseases,including heart failure,coronary artery disease,atherosclerosis,aneurysm,thrombosis,and hypertension,are a great economic burden and threat to human health and are the major cause of death worldwide.Recently,researchers have begun to appreciate the role of microbial ecosystems within the human body in contributing to metabolic and cardiovascular disorders.Accumulating evidence has demonstrated that the gut microbiota is closely associated with the occurrence and development of cardiovascular diseases.The gut microbiota functions as an endocrine organ that secretes bioactive metabolites that participate in the maintenance of cardiovascular homeostasis,and their dysfunction can directly influence the progression of cardiovascular disease.This review summarizes the current literature demonstrating the role of the gut microbiota in the development of cardiovascular diseases.We also highlight the mechanism by which well-documented gut microbiota-derived metabolites,especially trimethylamine N-oxide,short-chain fatty acids,and phenylacetylglutamine,promote or inhibit the pathogenesis of cardiovascular diseases.We also discuss the therapeutic potential of altering the gut microbiota and microbiota-derived metabolites to improve or prevent cardiovascular diseases.

Eliminate mitochondrial diseases by gene editing in germ-line cells and embryos

Nuclease-based gene editing technologies have opened up opportunities for correcting human genetic diseases. For the first time, scientists achieved targeted gene editing of mitochondrial DNA in mouse oocytes fused with patient cells. This fascinating progression may encourage the development of novel therapy for human maternally inherent mitochondrial diseases.