Modulation of muscarinic receptors by anisodine hydrobromide in cerebral ischemia.

Ischemic cerebrovascular diseases pose significant challenges due to their high mortality, disability rates, and recurrence risk, imposing substantial societal and healthcare burdens. Current treatment modalities, including medication and surgical interventions, have limitations. This study explores the therapeutic potential of anisodine hydrobromide, a neuroprotective compound, with a focus on its interaction with muscarinic receptors (M1-M5) in cerebral ischemic diseases, employing a middle cerebral artery occlusion (MCAO) rat model, and microglial HM cells and astrocytes SVG12 as models. Immunohistochemistry comprehensively assessed M1-M5 receptor expression in cerebral arteries, hippocampus, and parenchymal tissues in MCAO rats before and after anisodine hydrobromide administration. Additionally, a hypoxia/reoxygenation (H/R) model validated our findings using SVG12 and HM cells. M receptor mechanisms under hypoxia, including calcium ion influx, reactive oxygen species (ROS) levels, and aspartate expression were explored. Anisodine hydrobromide effectively reduced exacerbated M1, M2, M4, and M5 receptor expression in hypoxia/reoxygenation (H/R)-treated brain tissues and M2 receptors in H/R-treated cells. Concentration-dependent inhibition of calcium ion influx and ROS levels was observed, elucidating its neuroprotective mechanisms. Under H/R conditions, HM cells exhibited decreased aspartate levels by anisodine hydrobromide, Atropine, and M2 inhibitor treatments. These findings shed light on the modulation of muscarinic receptors, particularly the M2 subtype, by anisodine hydrobromide in cerebral ischemia. The neuroprotective effects observed in this study highlight the promising clinical prospects of anisodine hydrobromide as a potential therapeutic agent for ischemic brain diseases, warranting further investigation into its mechanisms of action.

Indirubin-3-Oxime Prevents H2O2-Induced Neuronal Apoptosis via Concurrently Inhibiting GSK3ß and the ERK Pathway.

Oxidative stress-induced neuronal apoptosis plays an important role in many neurodegenerative disorders. In this study, we have shown that indirubin-3-oxime, a derivative of indirubin originally designed for leukemia therapy, could prevent hydrogen peroxide (H2O2)-induced apoptosis in both SH-SY5Y cells and primary cerebellar granule neurons. H2O2 exposure led to the increased activities of glycogen synthase kinase 3ß (GSK3ß) and extracellular signal-regulated kinase (ERK) in SH-SY5Y cells. Indirubin-3-oxime treatment significantly reversed the altered activity of both the PI3-K/Akt/GSK3ß cascade and the ERK pathway induced by H2O2. In addition, both GSK3ß and mitogen-activated protein kinase inhibitors significantly prevented H2O2-induced neuronal apoptosis. Moreover, specific inhibitors of the phosphoinositide 3-kinase (PI3-K) abolished the neuroprotective effects of indirubin-3-oxime against H2O2-induced neuronal apoptosis. These results strongly suggest that indirubin-3-oxime prevents H2O2-induced apoptosis via concurrent inhibiting GSK3ß and the ERK pathway in SH-SY5Y cells, providing support for the use of indirubin-3-oxime to treat neurodegenerative disorders caused or exacerbated by oxidative stress.

Harnessing Mitochondrial Stress for Health and Disease: Opportunities and Challenges.

Mitochondria, essential organelles orchestrating cellular metabolism, have emerged as central players in various disease pathologies. Recent research has shed light on mitohormesis, a concept proposing an adaptive response of mitochondria to minor disturbances in homeostasis, offering novel therapeutic avenues for mitochondria-related diseases. This comprehensive review explores the concept of mitohormesis, elucidating its induction mechanisms and occurrence. Intracellular molecules like reactive oxygen species (ROS), calcium, mitochondrial unfolded proteins (UPRmt), and integrated stress response (ISR), along with external factors such as hydrogen sulfide (H2S), physical stimuli, and exercise, play pivotal roles in regulating mitohormesis. Based on the available evidence, we elucidate how mitohormesis maintains mitochondrial homeostasis through mechanisms like mitochondrial quality control and mitophagy. Furthermore, the regulatory role of mitohormesis in mitochondria-related diseases is discussed. By envisioning future applications, this review underscores the significance of mitohormesis as a potential therapeutic target, paving the way for innovative interventions in disease management.

Osteogenic differentiation of bone mesenchymal stem cells on linearly aligned triangular micropatterns.

Mesenchymal stem cells (MSCs) hold promise for regenerative medicine, particularly for bone tissue engineering. However, directing MSC differentiation towards specific lineages, such as osteogenic, while minimizing undesired phenotypes remains a challenge. Here, we investigate the influence of micropatterns on the behavior and lineage commitment of rat bone marrow-derived MSCs (rBMSCs), focusing on osteogenic differentiation. Linearly aligned triangular micropatterns (TPs) and circular micropatterns (CPs) coated with fibronectin were fabricated to study their effects on rBMSC morphology and differentiation and the underlying mechanobiological mechanisms. TPs, especially TP15 (15 µm), induced the cell elongation and thinning, while CPs also promoted the cell stretching, as evidenced by the decreased circularity and increased aspect ratio. TP15 significantly promoted osteogenic differentiation, with increased expression of osteogenic genes (Runx2, Spp1, Alpl, Bglap, Col1a1) and decreased expression of adipogenic genes (Pparg, Cebpa, Fabp4). Conversely, CPs inhibited both osteogenic and adipogenic differentiation. Mechanistically, TP15 increased Piezo1 activity, cytoskeletal remodeling including the aggregates of F-actin and myosin filaments at the cell periphery, YAP1 nuclear translocation, and integrin upregulation. Piezo1 inhibition suppressed the osteogenic genes expression, myosin remodeling, and YAP1 nuclear translocation, indicating Piezo1-mediated the mechanotransduction in rBMSCs on TPs. TP15 also induced osteogenic differentiation of BMSCs from aging rats, with upregulated Piezo1 and nuclear translocation of YAP1. Therefore, triangular micropatterns, particularly TP15, promote osteogenesis and inhibit adipogenesis of rBMSCs through Piezo1-mediated myosin and YAP1 pathways. Our study provides novel insights into the mechanobiological mechanisms governing MSC behaviors on micropatterns, offering new strategies for tissue engineering and regenerative medicine.