Extracellular vesicle‐mediated crosstalk between NPCE cells and TM cells result in modulation of Wnt signalling pathway and ECM remodelling

Primary open‐angle glaucoma is a leading cause of irreversible blindness, often associated with increased intraocular pressure. Extracellular vesicles (EVs) carry a specific composition of proteins, lipids and nucleotides have been considered as essential mediators of cell‐cell communication. Their potential impact for crosstalk between tissues responsible for aqueous humour production and out‐flow is largely unknown. The study objective was to investigate the effects of EVs derived from non‐pigmented ciliary epithelium (NPCE) primary cells on the expression of Wnt proteins in a human primary trabecular meshwork (TM) cells and define the mechanism underlying exosome‐mediated regulation that signalling pathway. Consistent with the results in TM cell line, EVs released by both primary NPCE cells and NPCE cell line showed diminished pGSK3β phosphorylation and decreased cytosolic levels of β‐catenin in primary TM cells. At the molecular level, we showed that NPCE exosome treatment downregulated the expression of positive GSKβ regulator‐AKT protein but increased the levels of GSKβ negative regulator‐PP2A protein in TM cells. NPCE exosome protein analysis revealed 584 miRNAs and 182 proteins involved in the regulation of TM cellular processes, including WNT/β‐catenin signalling pathway, cell adhesion and extracellular matrix deposition. We found that negative modulator of Wnt signalling miR‐29b was abundant in NPCE exosomal samples and treatment of TM cells with NPCE EVs significantly decreased COL3A1 expression. Suggesting that miR‐29b can be responsible for decreased levels of WNT/β‐catenin pathway. Overall, this study highlights a potential role of EVs derived from NPCE cells in modulating ECM proteins and TM canonical Wnt signalling.     

Regulation of Gdnf expression by retinoic acid in Sertoli cells

Glial cell line‐derived neurotrophic factor (GDNF) and retinoic acid (RA) are two molecules crucial for the regulation of the spermatogonial compartment of the testis. During the cycle of the seminiferous epithelium, their relative concentration oscillates with lower GDNF levels in stages where RA levels are high. It has been recently shown that RA negatively regulates Gdnf expression but the mechanisms behind are so far unknown. Here, we show that RA directly downregulates Gdnf mRNA levels in primary murine Sertoli cells through binding of RARα to a novel DR5‐RARE on Gdnf promoter. Pharmacological inhibition and chromatin immunoprecipitation–quantitative polymerase chain reaction analysis suggested that the underlying mechanism involved histone deacetylase activity and epigenetic repression of Gdnf promoter upon RA treatment.     

丁酸调控幼龄反刍动物瘤胃上皮发育研究进展

瘤胃是反刍动物营养物质消化吸收和代谢的重要器官,其发育状态直接影响反刍动物生产性能和健康。初生犊牛和羔羊,瘤胃功能尚未发育完全,不能够充分消化和吸收固体饲料。因此,在幼龄时期,通过营养调控手段促进反刍动物的瘤胃发育对维持动物健康及提高生产性能具有重要意义。丁酸是瘤胃微生物降解植物性饲料的主要产物,也是瘤胃上皮及宿主的重要能量来源。丁酸调控幼龄反刍动物瘤胃上皮发育是一个历久弥新的话题。主要介绍了幼龄反刍动物瘤胃上皮形态及功能的发育以及丁酸调控幼龄反刍动物瘤胃上皮发育的研究进展。     

Transient rho-associated coiled-coil containing kinase (ROCK) inhibition on human retinal pigment epithelium results in persistent Rho/ROCK downregulation

Retinal pigment epithelium (RPE) cells is the outermost layer of the retina and RPE dysfunction is a key factor in the disease pathogenesis of age-related macular degeneration (AMD). Transplantation therapy using induced pluripotent stem cell (iPSC)-derived RPEs has recently received much attention as a treatment for AMD. Preserving these cells under the best possible conditions is important, and preservation methods using Y-27632 have been reported. Rho-associated coiled-coil containing kinase (ROCK) inhibitors are known to inhibit cell death, emerging as important drug candidates for stem cell differentiation and regenerative medicine. However, it has recently been shown that ROCK inhibitors may have a vasodilatory effect on human retinal arterioles, a side effect that should ideally be avoided in RPE transplantation. Although ROCK inhibitors hold great potential, optimizing efficacy while minimizing adverse reactions is critical for translation into a clinical treatment. We examined the effect of transient exposure of RPE cells to ROCK inhibitor Y-27632 to determine whether the extracellular presence of the drug is necessary for ongoing Rho/ROCK downregulation. Human RPE cells were subcultured as a suspension for 4 h in drug-free medium following exposure to Y-27632 for 2 h. A Y-27632 concentration of >10 μM improved cell survival beyond 4 h and cell proliferation in recovery culture medium. ROCK2 expression levels were specifically downregulated by Y-27632 in the Rho/ROCK signaling pathway. In conclusion, we demonstrated that the effect of Y-27632 is not dependent on its extracellular availability and can last beyond the 2 h of exposure. The lasting Rho/ROCK signaling pathway downregulation by Y-27632 suggests that RPE cell transplantation with ROCK inhibitor-free media is possible, which can minimize side effects to host tissue and have wider implications for transplantation methods requiring ROCK inhibition.     

Stem‐cell‐based therapies for retinal degenerative diseases: Current challenges in the establishment of new treatment strategies

Various advances have been made in the treatment of retinal diseases, including new treatment strategies and innovations in surgical devices. However, the treatment of degenerative retinal diseases, such as retinitis pigmentosa (RP) and age‐related macular degeneration (AMD), continues to pose a significant challenge. In this review, we focus on the use of embryonic stem cells (ESCs) and induced pluripotent stem cells (iPSCs) to treat retinal diseases by harnessing the ability of stem cells to differentiate into different body tissues. The retina is a tissue specialized for light sensing, and its degradation leads to vision loss. As part of the central nervous system, the retina has very low regenerative capability, and therefore, treatment options are limited once it degenerates. Nevertheless, innovations in methods to induce the generation of retinal cells and tissues from ESCs/iPSCs enable the development of novel approaches for these irreversible diseases. Here we review some historical background and current clinical trials involving the use of stem‐cell‐derived retinal pigment epithelial cells for AMD treatment and stem cell‐derived retinal cells/tissues for RP therapy. Finally, we discuss our future vision of regenerative treatment for retinal diseases with a partial focus on our studies and introduce other interesting approaches for restoring vision.     

尿液诊断膀胱癌的研究进展

摘要：膀胱癌是临床常见的发生在泌尿系统的恶性肿瘤,该病的发病率呈现逐年升高的趋势,其复发率也相对较高。早期诊断和定期随访是保证膀胱癌患者长期生存的关键。对于膀胱癌的诊断以及患者的随访通常凭借膀胱镜检查或尿脱落细胞学的测定。然而,前者的检查费用较为昂贵,且属于有创诊断;后者则具有检查敏感性相对较低的特点,还存在较大程度受病理科诊断医生主观因素影响的局限,目前还没有尿液生物标志物可以替代传统的诊断方法。膀胱肿瘤具有广泛的异质性,不同的疾病表型具有不同的分子差异。因此,引入尿液生物标志物来诊断疾病,评估疾病的侵袭性、进展的风险、复发的可能性和预后具有重要的临床价值。本文总结了目前尿液所含生物标志物诊断膀胱癌的研究现状,并对此领域的主要研究进展进行综述。     

Mesenchymal stem cell‐conditioned medium attenuates the retinal pathology in amyloid‐β‐induced rat model of Alzheimer's disease: Underlying mechanisms

Amyloid‐beta (Aβ) oligomer is known to contribute to the pathophysiology of age‐related macular degeneration. Herein, we aimed to elucidate the in vivo and in vitro effects of Aβ_1‐42 application on retinal morphology in rats. Our in vivo studies revealed that intracerebroventricular administration of Aβ_1‐42 oligomer caused dysmorphological changes in both retinal ganglion cells and retinal pigment epithelium. In addition, in vitro studies revealed that ARPE‐19 cells following Aβ_1‐42 oligomer application had decreased viability along with apoptosis and decreased expression of the tight junction proteins, increased expression of both phosphor‐AKT and phosphor‐GSK3β and decreased expression of both SIRT1 and β‐catenin. Application of conditioned medium (CM) obtained from mesenchymal stem cells (MSC) protected against Aβ_1‐42 oligomer‐induced retinal pathology in both rats and ARPE‐19 cells. In order to explore the potential role of peptides secreted from the MSCs, we applied mass spectrometry to compare the peptidomics profiles of the MSC‐CM. Gene ontology enrichment analysis and String analysis were performed to explore the differentially expressed peptides by predicting the functions of their precursor proteins. Bioinformatics analysis showed that 3‐8 out of 155–163 proteins in the MSC‐CM maybe associated with SIRT1/pAKT/pGSK3β/β‐catenin, tight junction proteins, and apoptosis pathway. In particular, the secretomes information on the MSC‐CM may be helpful for the prevention and treatment of retinal pathology in age‐related macular degeneration.