The generation and properties of human cortical organoids as a disease model for malformations of cortical development.

As three-dimensional "organ-like" aggregates, human cortical organoids have emerged as powerful models for studying human brain evolution and brain disorders with unique advantages of human-specificity, fidelity and manipulation. Human cortical organoids derived from human pluripotent stem cells can elaborately replicate many of the key properties of human cortical development at the molecular, cellular, structural, and functional levels, including the anatomy, functional neural network, and interaction among different brain regions, thus facilitating the discovery of brain development and evolution. In addition to studying the neuro-electrophysiological features of brain cortex development, human cortical organoids have been widely used to mimic the pathophysiological features of cortical-related disease, especially in mimicking malformations of cortical development, thus revealing pathological mechanism and identifying effective drugs. In this review, we provide an overview of the generation of human cortical organoids and the properties of recapitulated cortical development and further outline their applications in modeling malformations of cortical development including pathological phenotype, underlying mechanisms and rescue strategies.

Humanized cerebral organoids-based ischemic stroke model for discovering of potential anti-stroke agents.

Establishing a stoke experimental model, which is better in line with the physiology and function of human brain, is the bottleneck for the development of effective anti-stroke drugs. A three-dimensional cerebral organoids (COs) from human pluripotent stem cells can mimic cell composition, cortical structure, brain neural connectivity and epigenetic genomics of in-vivo human brain, which provides a promising application in establishing humanized ischemic stroke model. COs have been used for modeling low oxygen condition-induced hypoxic injury, but there is no report on the changes of COs in response to in vitro oxygen-glucose deprivation (OGD)-induced damage of ischemic stroke as well as its application in testing anti-stroke drugs. In this study we compared the cell composition of COs at different culture time and explored the cell types, cell ratios and volume size of COs at 85 days (85 d-CO). The 85 d-CO with diameter more than 2 mm was chosen for establishing humanized ischemic stroke model of OGD. By determining the time-injury relationship of the model, we observed aggravated ischemic injury of COs with OGD exposure time, obtaining first-hand evidence for the damage degree of COs under different OGD condition. The sensitivity of the model to ischemic injury and related treatment was validated by the proven pan-Caspase inhibitor Z-VAD-FMK (20 µM) and Bcl-2 inhibitor navitoclax (0.5 µM). Neuroprotective agents edaravone, butylphthalide, P7C3-A20 and ZL006 (10 µM for each) exerted similar beneficial effects in this model. Taken together, this study establishes a humanized ischemic stroke model based on COs, and provides evidence as a new research platform for anti-stroke drug development.

Trichomonas vaginalis infection impairs anion secretion in vaginal epithelium.

Trichomonas vaginalis is a common protozoan parasite, which causes trichomoniasis associated with severe adverse reproductive outcomes. However, the underlying pathogenesis has not been fully understood. As the first line of defense against invading pathogens, the vaginal epithelial cells are highly responsive to environmental stimuli and contribute to the formation of the optimal luminal fluid microenvironment. The cystic fibrosis transmembrane conductance regulator (CFTR), an anion channel widely distributed at the apical membrane of epithelial cells, plays a crucial role in mediating the secretion of Cl- and HCO3-. In this study, we investigated the effect of T. vaginalis on vaginal epithelial ion transport elicited by prostaglandin E2 (PGE2), a major prostaglandin in the semen. Luminal administration of PGE2 triggered a remarkable and sustained increase of short-circuit current (ISC) in rat vaginal epithelium, which was mainly due to Cl- and HCO3- secretion mediated by the cAMP-activated CFTR. However, T. vaginalis infection significantly abrogated the ISC response evoked by PGE2, indicating impaired transepithelial anion transport via CFTR. Using a primary cell culture system of rat vaginal epithelium and a human vaginal epithelial cell line, we demonstrated that the expression of CFTR was significantly down-regulated after T. vaginalis infection. In addition, defective Cl- transport function of CFTR was observed in T. vaginalis-infected cells by measuring intracellular Cl- signals. Conclusively, T. vaginalis restrained exogenous PGE2-induced anion secretion through down-regulation of CFTR in vaginal epithelium. These results provide novel insights into the intervention of reproductive complications associated with T. vaginalis infection such as infertility and disequilibrium in vaginal fluid microenvironment.

Liquid Crystals in Curved Confined Geometries: Microfluidics Bring New Capabilities for Photonic Applications and Beyond.

The quest for interesting properties and phenomena in liquid crystals toward their employment in nondisplay application is an intense and vibrant endeavor. Remarkable progress has recently been achieved with regard to liquid crystals in curved confined geometries, typically represented as enclosed spherical geometries and cylindrical geometries with an infinitely extended axial-symmetrical space. Liquid-crystal emulsion droplets and fibers are intriguing examples from these fields and have attracted considerable attention. It is especially noteworthy that the rapid development of microfluidics brings about new capabilities to generate complex soft microstructures composed of both thermotropic and lyotropic liquid crystals. This review attempts to outline the recent developments related to the liquid crystals in curved confined geometries by focusing on microfluidics-mediated approaches. We highlight a wealth of novel photonic applications and beyond and also offer perspectives on the challenges, opportunities, and new directions for future development in this emerging research area.

Combined use of Y-tube conduits with human umbilical cord stem cells for repairing nerve bifurcation defects.

Given the anatomic complexity at the bifurcation point of a nerve trunk, enforced suturing between stumps can lead to misdirection of nerve axons, thereby resulting in adverse consequences. We assumed that Y-tube conduits injected with human umbilical cord stem cells could be an effective method to solve such problems, but studies focused on the best type of Y-tube conduit remain controversial. Therefore, the present study evaluated the applicability and efficacy of various types of Y-tube conduits containing human umbilical cord stem cells for treating rat femoral nerve defects on their bifurcation points. At 12 weeks after the bridging surgery that included treatment with different types of Y-tube conduits, there were no differences in quadriceps femoris muscle weight or femoral nerve ultrastructure. However, the Y-tube conduit group with longer branches and a short trunk resulted in a better outcome according to retrograde labeling and electrophysiological analysis. It can be concluded from the study that repairing a mixed nerve defect at its bifurcation point with Y-tube conduits, in particular those with long branches and a short trunk, is effective and results in good outcomes.

[Effect of wortmannin on endothelial cell proliferation and migration induced by high glucose Müller cell conditioned medium].

OBJECTIVE: To investigate the effect of wortmannin on endothelial cells proliferation and migration induced by high glucose Müller cell conditioned medium (HGMCM). METHODS: Immunofluorescence, flow cytometry and Boyden chamber migration models were used to analyze the effect of wortmannin on endothelial cells. RESULTS: 50 nmol/L wortmannin could significantly inhibit the proliferation and migration of endothelial cells induced by HGMCM. The percentage of endothelial cells in S phase was obviously decreased [from (37.82 +/- 0.57)% to (21.91 +/- 0.23)%, P < 0.01], while there was an increase in the percentage of cells in G(0)/G(1) phase [from (54.57 +/- 1.19)% to (65.59 +/- 0.41)%, < 0.01] and G(2)/M phase (< 0.05). CONCLUSION: Wortmannin can inhibit proliferation and migration of endothelial cells induced by HGMCM, suggesting that wortmannin carries an anti-angiogenetic ability in diseased retina.