Inosine attenuates post-stroke neuroinflammation by modulating inflammasome mediated microglial activation and polarization

To date, various agents and molecules have been developed to treat post-stroke neuroinflammation; however, none of them are clinically successful. Post-stroke neuroinflammation is primarily attributed to microglial polarization as the generation of inflammasome complexes shifts microglia to their M1 phenotype and regulate the downstream cascade. Inosine, an adenosine derivative reported to maintain cellular energy homeostasis in stressed condition. Although, the exact mechanism is still unexplored, various studies have reported that it can stimulate axonal sprouting in different neurodegenerative diseases. Hence, our present study aims to decipher the molecular mechanism of inosine mediated neuroprotection by modulating inflammasome signaling towards altered microglial polarization in ischemic stroke. Inosine was administered intraperitoneally to male Sprague Dawley rats at 1 h post ischemic stroke and were further evaluated for neurodeficit score, motor coordination and long-term neuroprotection. Brains were harvested for infarct size estimation, biochemical assays and molecular studies. Inosine administration at 1 h post ischemic stroke decreased infarct size, neurodeficit score, and improved motor co-ordination. Normalization of biochemical parameters were achieved in the treatment groups. Microglial polarization towards its anti-inflammatory phenotype and modulation of inflammation were evident by relevant gene and protein expression studies. The outcome provides preliminary evidence of inosine mediated alleviation of post-stroke neuroinflammation via modulation of microglial polarization towards its anti-inflammatory form through regulating the inflammasome activation.

Modulation of Sel1L can alleviate altered ER homeostasis towards white matter damage in CKD-stroke complex

Stroke is one of the major causes of mortality and long-term disability worldwide. Chronic-kidney-disease (CKD) is a condition where patients have shown increased vulnerability to stroke with poor functional and cognitive outcomes. Impaired cerebral autoregulation in CKD patients may impose a high risk of stroke. To date, the mechanism of worsened stroke outcomes in CKD patients are limitedly understood. Alterations of endoplasmic-reticulum (ER) homoeostasis via modification of Sel1L-Hrd1 complex is one of the many cellular events that gets triggered following both CKD and stroke leading to accumulation of misfolded proteins, culminating in ER-stress. Therefore, the present study aims to explore the involvement of Sel1L mediated altered ER functions towards worsening of stroke outcome in CKD and further its crucial role towards white matter damage. CKD-stroke complex was induced in male Sprague-Dawley rats followed by middle-cerebral-artery occlusion. At 24 h and 7th day of reperfusion, animals were subjected to behavioral analysis followed by euthanasia, brain harvest and molecular studies. CKD-Stroke-complex animals showed aggravated neurofunctional and cognitive impairment which were further normalized by treatment of an ER-stress inhibitor. This indicates exacerbated stroke outcome in CKD-stroke-complex may be mediated by imbalanced ER-homeostasis due to decreased Sel1L expression leading to enhanced cellular death and neurodegeneration.