Fuchs Endothelial Corneal Dystrophy (FECD) is a corneal endothelial disease that causes microenvironment alterations and endothelial cell loss, which leads to vision impairment. It has a high global prevalence, especially in elderly populations. FECD is also one of the leading indications of corneal transplantation globally. Currently, there is no clearly defined canonical pathway for this disease, and it has been proposed that the combinatorial effects of genetic mutations and exogenous factors cause FECD. Clinical studies and observations have provided valuable knowledge and understanding of FECD, while preclinical studies are essential for gaining insights into disease progression and mechanisms for the development and testing of regenerative medicine therapies. In this review, we first introduce the proposed genetic and molecular pathologies of FECD. Notably, we discuss the impact of abnormal extracellular matrix deposition (guttata), endothelial-to-mesenchymal transition, cell senescence, and oxidative stress on the pathology and etiology of FECD. We review and summarize the in vitro cell models, ex vivo tissues, and in vivo animal models used to study FECD. The benefits and challenges of each model are also discussed.

Cell cultures of dispersed cells within hydrogels depict the interaction of the cell–extracellular matrix (ECM) in 3D, while the coculture of different cells within spheroids combines both the effects of cell–cell and cell–ECM interactions. In this study, the cell co-spheroids of human bone mesenchymal stem cells/human umbilical vein endothelial cells (HBMSC/HUVECs) are prepared with the assistance of a nanopattern, named colloidal self-assembled patterns (cSAPs), which is superior to low-adhesion surfaces. A phenol-modified gelatin/hyaluronan (Gel-Ph/HA-Ph) hydrogel is used to encapsulate the multicellular spheroids and the constructs are photo-crosslinked using blue light. The results show that Gel-Ph/HA-Ph hydrogels with a 5%-to-0.3% ratio have the best properties. Cells in HBMSC/HUVEC co-spheroids are more favorable for osteogenic differentiation (Runx2, ALP, Col1a1 and OPN) and vascular network formation (CD31+ cells) compared to HBMSC spheroids. In a subcutaneous nude mouse model, the HBMSC/HUVEC co-spheroids showed better performance than HBMSC spheroids in angiogenesis and the development of blood vessels. Overall, this study paves a new way for using nanopatterns, cell coculturing and hydrogel technology for the generation and application of multicellular spheroids.

Background: Previous studies have reported the presence of interferon‐responsive microglia in the brain after central nervous system injury. However, their roles and the underlying mechanisms in neurological function recovery remain poorly understood. Methods: Adult male mice were subjected to 90‐minute transient middle cerebral artery occlusion, and brain tissues were analyzed using single‐cell RNA sequencing (scRNA‐seq) at 14 days after stroke. Immunostaining, quantitative real‐time polymerase chain reaction and ELISA were conducted to validate the presence of interferon‐γ–responsive microglia in stroke mice brains. Extracellular vesicles (EVs) were isolated from interferon‐γ–treated BV2 microglia via ultracentrifugation. Interferon‐γ EVs were then used to treat neural stem cells (NSCs) in vitro or administered intravenously to mice every other day, starting at 7 days after transient middle cerebral artery occlusion. Neurobehavioral tests, cresyl violet staining, Golgi staining, and immunostaining were performed to evaluate NSC differentiation, neurogenesis, and neurobehavioral recovery. Micro RNA (miR) sequencing and bioinformatic analysis were conducted to explore targeted genes and signaling pathways underlying interferon‐γ EV‐mediated inhibition of neurogenesis. Results: Single‐cell RNA sequencing, immunostaining, quantitative real‐time polymerase chain reaction, and ELISA showed the presence of interferon‐γ–responsive microglia in stroke mice brains. Interferon‐γ EVs were internalized by NSCs, leading to reduced NSC survival and neuronal differentiation. Administration of interferon‐γ EVs increased brain atrophy volume, inhibited neurobehavioral recovery and neurogenesis in mice after stroke. miRNA array revealed 12 upregulated microRNAs, and treatment with miR‐199a‐5p mimic inhibited the survival and neuronal differentiation of NSCs, and knockdown of miR‐199a‐5p in interferon‐γ EVs increased neurogenesis in stroke mice. miRNA database analysis and luciferase reporter assay identified SIRT1 as a downstream target gene of miR‐199a‐5p. Treatment with SIRT1 agonist promoted the survival and neuronal differentiation of NSCs, confirming that interferon‐γ EVs inhibited neurogenesis via miR‐199a‐5p/ SIRT1 . Conclusions: Our study demonstrated that interferon‐γ EVs inhibited the survival and neuronal differentiation of NSCs, exacerbating brain injury via the miR‐199a‐5p/ SIRT1 axis after ischemic stroke, providing a novel target for treating ischemic stroke.