Dexmedetomidine Alleviates Hypoxic-Ischemic Brain Damage in Neonatal Rats Through Reducing MicroRNA-134-5p-Mediated NLRX1 Downregulation

Long Non-coding RNA MIR22HG Alleviates Ischemic Acute Kidney Injury by Targeting the miR-134-5p/NFAT5 axis

Acute kidney injury (AKI), often triggered by ischemia-reperfusion (I/R) injury, is a critical condition characterized by rapid loss of renal function, leading to high morbidity and mortality. Despite extensive research, therapeutic options for ischemic AKI remain limited, and understanding the molecular mechanisms involved is crucial for developing targeted therapies. Long non-coding RNAs (lncRNAs) have emerged as pivotal regulators of gene expression and cellular processes in various diseases, including cancer and renal injury. This study investigates the role of the lncRNA MIR22HG in mitigating renal injury during ischemic AKI. Using in vivo and in vitro models of I/R-induced AKI in mice and hypoxia/reoxygenation (H/R)-treated renal cells, we demonstrated that MIR22HG expression is significantly downregulated in ischemic AKI conditions. Functional assays showed that overexpression of MIR22HG in these models led to reduced renal cell apoptosis, inflammation, and improved renal function. Mechanistically, MIR22HG exerted its protective effects by negatively regulating miR-134-5p, which in turn alleviated renal injury by upregulating NFAT5, a transcription factor known to mitigate cellular stress. Furthermore, dual-luciferase and RNA pull-down assays confirmed direct interactions between MIR22HG and miR-134-5p, as well as miR-134-5p and NFAT5. Additionally, loss-and-gain-of-function assays demonstrated that overexpression of MIR22HG led to the upregulation of NFAT5, which mitigated renal apoptosis, and inflammation and improved renal function. Collectively, the results of our study highlight the therapeutic potential of targeting the MIR22HG/miR-134-5p/NFAT5 axis in the treatment of ischemic AKI, providing new insights into the molecular regulation of renal cell survival and repair during injury.

NOD-like receptor X1 promotes autophagy and inactivates NLR family pyrin domain containing 3 inflammasome signaling by binding autophagy-related gene 5 to alleviate cerebral ischemia/reperfusion-induced neuronal injury

Ischemic strokes pose serious risks to human health. We aimed to elucidate the function of NOD-like receptor X1 (NLRX1) in a rat middle cerebral artery occlusion (MCAO)-induced cerebral ischemia/reperfusion injury (CIRI) model and in an oxygen-glucose deprivation/reperfusion (OGD/R)-treated human microglial cell line (HMC3) model. Following NLRX1 upregulation, infarct volumes were measured with 2,3,5-triphenyltetrazolium chloride staining and pathological examination was conducted with hematoxylin-eosin staining. Results suggested that levels of NLRX1 were decreased in brain tissue of MCAO rats and in OGD/R-stimulated HMC3 cells. NOD-like receptor X1 overexpression mitigated the neuronal damage, reduced tumor necrosis factor-α and interleukin-6 expression, alleviated microglial activation, and induced autophagy in vivo and in vitro. Additionally, a coimmunoprecipitation assay indicated that NLRX1 bound to autophagy-related gene 5 (ATG5) to elevate ATG5 expression in HMC3 cells. Further, the elevated NLR family pyrin domain containing 3 (NLRP3), apoptosis-associated speck-like protein containing a CARD, and cleaved caspase 1 expression in MCAO rats and HMC3 cells with OGD/R induction was reduced after NLRX1 upregulation. Importantly, ATG5 depletion abrogated the effects of NLRX1 elevation on NLRP3 inflammasome signaling. These results indicate that NLRX1 promotes autophagy and inactivates NLRP3 inflammasome signaling by binding ATG5 in experimental cerebral ischemia. These data may help the development of novel therapeutic strategies for ischemic stroke.

Dexmedetomidine Regulates the miR-146a-5p/NF-κB Axis to Alleviate Electroconvulsive Therapy-Induced Cognitive Impairments

Electroconvulsive therapy (ECT) is a nonpharmacological treatment for depressive episodes and other psychiatric disorders. It is used to control the condition by causing a transient loss of consciousness through electrical stimulation. Dexmedetomidine (DEX) is a novel and highly selective adrenergic agonist with sedative, sympathetic nerve activity inhibiting and stress-responsive effects. This study focused on the effect of DEX on cerebral protection after ECT treatment. 68 depression patients were enrolled and divided into control group and DEX group. The occurrence of delirium after ECT treatment in depression cases was recorded. In vivo, we constructed chronic mild and unpredictable stress (CUMS) rats to mimic depression model. Meanwhile, ECT treatment and DEX injection were administrated in CUMS rats. Learning and memory in rats were measured by Morris water maze test, open field test (OFT), and forced swimming test (FST). Finally, the expression of miR-146a-5p and NF-κB was determined by RT-qPCR and western blot assay. The incidence of delirium after ECT treatment was prominently reduced in DEX group in relation to control group. In vivo, DEX injection had no effect on ECT treatment efficacy against depression conditions. After ECT treatment, the cognitive impairment was ameliorated in CUMS rats accomplished with decreased miR-146a-5p and increased NF-κB level. Finally, compared with ECT treatment, DEX injection could protect against depression-like behaviors by increasing miR-146a-5p level and inactivated NF-κB pathway. Overall, ECT-induced cognitive impairment in depression rats could be ameliorated by DEX injection via miR-146a-5p/NF-κB axis.