Ischemic preconditioning-induced protective effect for promoting angiogenesis in renal ischemia-reperfusion injury by regulating miR-376c-3p/HIF-1α/VEGF axis in male rats

XBP1 Modulates the Aging Cardiorenal System by Regulating Oxidative Stress

X-box binding protein 1 (XBP1) is a unique basic-region leucine zipper (bZIP) transcription factor. Over recent years, the powerful biological functions of XBP1 in oxidative stress have been gradually revealed. When the redox balance remains undisturbed, oxidative stress plays a role in physiological adaptations and signal transduction. However, during the aging process, increased cellular senescence and reduced levels of endogenous antioxidants cause an oxidative imbalance in the cardiorenal system. Recent studies from our laboratory and others have indicated that these age-related cardiorenal diseases caused by oxidative stress are guided and controlled by a versatile network composed of diversified XBP1 pathways. In this review, we describe the mechanisms that link XBP1 and oxidative stress in a range of cardiorenal disorders, including mitochondrial instability, inflammation, and alterations in neurohumoral drive. Furthermore, we propose that differing degrees of XBP1 activation may cause beneficial or harmful effects in the cardiorenal system. Gaining a comprehensive understanding of how XBP1 exerts influence on the aging cardiorenal system by regulating oxidative stress will enhance our ability to provide new directions and strategies for cardiovascular and renal safety outcomes.

Emodin prevents renal ischemia-reperfusion injury via suppression of p53-mediated cell apoptosis based on network pharmacology

Background

Previous evidence indicated that emodin has significant advantages for preventing acute kidney injury (AKI). However, the mechanisms responsible for these effects of emodin have yet to be elucidated.

Methods

We first used network pharmacology and molecular docking to identify the core targets of emodin for AKI and performed a range of experiments to validate this result. Pretreatment with emodin for 7 days, the rats were treated with bilateral renal artery clipping for 45 min to identify the prevention effect. Hypoxia/reoxygenation (H/R), and vancomycin - induced renal tubular epithelial cells (HK-2 cells) were treated with emodin to explore the related molecular mechanism.

Results

Network pharmacology and molecular docking showed that anti-apoptosis might be the core mechanism responsible for the action of emodin on AKI; this anti-apoptotic effect appears to because by regulation p53-related signaling pathway. Our data showed that pretreatment with emodin significantly improved renal function and renal tubular injury in renal I/R model rats (P < 0.05. The prevention effect of emodin was proved to be related to anti - apoptosis of HK-2 cells, possibly by downregulating the levels of p53, cleaved-caspase-3, pro-caspase-9, and upregulated the levels of Bcl-2. The efficacy and mechanism of emodin on anti - apoptosis was also confirmed in vancomycin - induced HK-2 cells. Meanwhile, the data also showed that emodin promoted angiogenesis in I/R damaged kidneys and H/R-induced HK-2 cells, which was associated with decreasing HIF-1α levels and increasing VEGF levels.

Conclusions

Our findings indicated that the preventive effect of emodin on AKI is probably attributable to anti-apoptosis response and promoting angiogenesis effect.

Current Status of Experimental Animal Skin Flap Models: Ischemic Preconditioning and Molecular Factors

Skin flaps are necessary in plastic and reconstructive surgery for the removal of skin cancer, wounds, and ulcers. A skin flap is a portion of skin with its own blood supply that is partially separated from its original position and moved from one place to another. The use of skin flaps is often accompanied by cell necrosis or apoptosis due to ischemia-reperfusion (I/R) injury. Proinflammatory cytokines, such as nuclear factor kappa B (NF-κB), inhibitor of kappa B (IκB), interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), and oxygen free radicals are known causative agents of cell necrosis and apoptosis. To prevent I/R injury, many investigators have suggested the inhibition of proinflammatory cytokines, stem-cell therapies, and drug-based therapies. Ischemic preconditioning (IPC) is a strategy used to prevent I/R injury. IPC is an experimental technique that uses short-term repetition of occlusion and reperfusion to adapt the area to the loss of blood supply. IPC can prevent I/R injury by inhibiting proinflammatory cytokine activity. Various stem cell applications have been studied to facilitate flap survival and promote angiogenesis and vascularization in animal models. The possibility of constructing tissue engineered flaps has also been investigated. Although numerous animal studies have been published, clinical data with regard to IPC in flap reconstruction have never been reported. In this study, we present various experimental skin flap methods, IPC methods, and methods utilizing molecular factors associated with IPC.