A proteomic study on gastric impairment in rats caused by microcystin-LR

Microcystins (MCs) are the most common cyanobacterial toxins. Epidemiological investigation showed that exposure to MCs can cause gastro-intestinal symptoms, gastroenteritis and gastric cancer. MCs can also accumulate in and cause histopathological damage to stomach. However, the exact mechanisms by which MCs cause gastric injury were unclear. In this study, Wistar rats were administrated 50, 75 or 100 μg microcystin-LR (MC-LR)/kg, body mass (bm) via tail vein, and histopathology, response of anti-oxidant system and the proteome of gastric tissues at 24 h after exposure were studied. Bleeding of fore-stomach and gastric corpus, inflammation and necrosis in gastric corpus and exfoliation of mucosal epithelial cells in gastric antrum were observed following acute MC-LR exposure. Compared with controls, activities of superoxide dismutase (SOD) were significantly greater in gastric tissues of exposed rats, while activities of catalase (CAT) were less in rats administrated 50 μg MC-LR/kg, bm, and concentrations of glutathione (GSH) and malondialdehyde (MDA) were greater in rats administrated 75 or 100 μg MC-LR/kg, bm. These results indicated that MC-LR could disrupt the anti-oxidant system and cause oxidative stress. The proteomic results revealed that MC-LR could affect expressions of proteins related to cytoskeleton, immune system, gastric functions, and some signaling pathways, including platelet activation, complement and coagulation cascades, and ferroptosis. Quantitative real-time PCR (qRT-PCR) analysis showed that transcriptions of genes for ferroptosis and gastric function were altered, which confirmed results of proteomics. Overall, this study illustrated that MC-LR could induce gastric dysfunction, and ferroptosis might be involved in MC-LR-induced gastric injury. This study provided novel insights into mechanisms of digestive diseases induced by MCs.

[Research progress in optogenetic therapy for retinitis pigmentosa]

Retinitis pigmentosa (RP) is a group of inherited retinal diseases characterized by progressive loss of photoreceptor cells and retinal pigment epithelium function. Its treatment has long been a focus and challenge in ophthalmic research. Despite advances in therapies such as stem cell transplantation, gene therapy, and retinal prosthetic implants, many difficulties remain. Optogenetic technology, an emerging biological technique combining optics and genetics, holds promise for treating RP by inducing the expression of light-sensitive proteins in degenerated retinal cells, thereby partially restoring patients' vision and light sensitivity. However, limitations such as difficulties in selecting target cells, potential risks of viral transfection, and uncertainties in visual restoration still exist. With the continuous improvement of light sensitivity of optogenetic proteins and the development of viral vectors with higher transfection efficiency, it is believed that optogenetic therapy will help more patients regain vision.