Uncoupling protein 2 prevents ischaemia reperfusion injury through the regulation ROS/NF-κB signalling in mice

Phosphocreatine ameliorates hepatocellular apoptosis mediated by protecting mitochondrial damage in liver ischemia/reperfusion injury through inhibiting TLR4 and Agonizing Akt Pathway

Hepatic ischemia/reperfusion (HI/R) presents significant challenges in surgical liver transplantation and hepatic ischemic shock, with few effective clinical preventive measures available. This study explores the potential protective effects and underlying mechanisms of phosphocreatine (PCr) in the context of HI/R. We established an in vitro ischemia/reperfusion model using hepatocellular carcinoma HepG2 cells and normal liver L02 cells. For in vivo assessments, C57BL/6 mice were subjected to the HI/R model to evaluate the impact of PCr on liver protection. PCr pretreatment significantly improved liver cell survival rates, maintained mitochondrial membrane potential (MMP), reduced apoptosis, and alleviated oxidative damage and inflammatory responses. Importantly, PCr exerted its protective effects by downregulating TLR4 and activating the Akt signaling pathway, which suppressed inflammation, mitigated oxidative stress, inhibited apoptosis, and modulated key biomarkers, including ALT, AST, IL-6, IL-1β, TNF-α, SOD, MDA, and reactive oxygen species (ROS). Western blot analyses demonstrated PCr's anti-inflammatory effects through the regulation of UCP2, Cyp-D, Cyt-C, and PGC-1α, thereby preserving mitochondrial structure and function, maintaining MMP, and regulating membrane pores. Transmission electron microscopy further highlighted PCr's role in sustaining mitochondrial integrity. In conclusion, our findings suggest that PCr helps maintain mitochondrial homeostasis by intervening in the TLR4 inflammatory pathway and activating the Akt signaling pathway, ultimately reducing liver injury. This study offers new insights and potential treatment strategies for HI/R, providing valuable guidance for future clinical applications.

C23 ameliorates carbon tetrachloride-induced liver fibrosis in mice

BACKGROUND

C23, an oligo-peptide derived from cold-inducible RNA-binding protein (CIRP), has been reported to inhibit tissue inflammation, apoptosis and fibrosis by binding to the CIRP receptor; however, there are few reports on its role in liver fibrosis and the underlying mechanism is unknown.

AIM

To explore whether C23 plays a significant role in carbon tetrachloride (CCl4)-induced liver fibrosis.

METHODS

CCl4 was injected for 6 weeks to induce liver fibrosis and C23 was used beginning in the second week. Masson and Sirius red staining were used to examine changes in fiber levels. Inflammatory factors in the liver were detected and changes in α-smooth muscle actin (α-SMA) and collagen I expression were detected via immunohistochemical staining to evaluate the activation of hematopoietic stellate cells (HSCs). Western blotting was used to detect the activation status of the transforming growth factor-beta (TGF-β)/Smad3 axis after C23 treatment.

RESULTS

CCl4 successfully induced liver fibrosis in mice, while tumor necrosis factor-alpha (TNF-α), IL (interleukin)-1β, and IL-6 levels increased significantly and the IL-10 level decreased significantly. Interestingly, C23 inhibited this process. On the other hand, C23 significantly inhibited the activation of HSCs induced by CCl4, which inhibited the expression of α-SMA and the synthesis of collagen I. In terms of mechanism, C23 can block Smad3 phosphorylation significantly and inhibits TGF-β/Smad3 pathway activation, thereby improving liver injury caused by CCl4.

CONCLUSION

C23 may block TGF-β/Smad3 axis activation, inhibit the expression of inflammatory factors, and inhibit the activation of HSCs induced by CCl4, alleviating liver fibrosis.

Importance of Mitochondria in Cardiac Pathologies: Focus on Uncoupling Proteins and Monoamine Oxidases

On the one hand, reactive oxygen species (ROS) are involved in the onset and progression of a wide array of diseases. On the other hand, these are a part of signaling pathways related to cell metabolism, growth and survival. While ROS are produced at various cellular sites, in cardiomyocytes the largest amount of ROS is generated by mitochondria. Apart from the electron transport chain and various other proteins, uncoupling protein (UCP) and monoamine oxidases (MAO) have been proposed to modify mitochondrial ROS formation. Here, we review the recent information on UCP and MAO in cardiac injuries induced by ischemia-reperfusion (I/R) as well as protection from I/R and heart failure secondary to I/R injury or pressure overload. The current data in the literature suggest that I/R will preferentially upregulate UCP2 in cardiac tissue but not UCP3. Studies addressing the consequences of such induction are currently inconclusive because the precise function of UCP2 in cardiac tissue is not well understood, and tissue- and species-specific aspects complicate the situation. In general, UCP2 may reduce oxidative stress by mild uncoupling and both UCP2 and UCP3 affect substrate utilization in cardiac tissue, thereby modifying post-ischemic remodeling. MAOs are important for the physiological regulation of substrate concentrations. Upon increased expression and or activity of MAOs, however, the increased production of ROS and reactive aldehydes contribute to cardiac alterations such as hypertrophy, inflammation, irreversible cardiomyocyte injury, and failure.

The cardioprotective actions of statins in targeting mitochondrial dysfunction associated with myocardial ischaemia-reperfusion injury

During cardiac reperfusion after myocardial infarction, the heart is subjected to cascading cycles of ischaemia reperfusion injury (IRI). Patients presenting with this injury succumb to myocardial dysfunction resulting in myocardial cell death, which contributes to morbidity and mortality. New targeted therapies are required if the myocardium is to be protected from this injury and improve patient outcomes. Extensive research into the role of mitochondria during ischaemia and reperfusion has unveiled one of the most important sites contributing towards this injury; specifically, the opening of the mitochondrial permeability transition pore. The opening of this pore occurs during reperfusion and results in mitochondria swelling and dysfunction, promoting apoptotic cell death. Activation of mitochondrial ATP-sensitive potassium channels (mitoK_ATP) channels, uncoupling proteins, and inhibition of glycogen synthase kinase-3β (GSK3β) phosphorylation have been identified to delay mitochondrial permeability transition pore opening and reduce reactive oxygen species formation, thereby decreasing infarct size. Statins have recently been identified to provide a direct cardioprotective effect on these specific mitochondrial components, all of which reduce the severity of myocardial IRI, promoting the ability of statins to be a considerate preconditioning agent. This review will outline what has currently been shown in regard to statins cardioprotective effects on mitochondria during myocardial IRI.

The Carotenoid Compound of Saffron Crocetin Alleviates Effects of Ischemia Reperfusion Injury via a Mechanism Possibly Involving MiR-127

Renal impairment is associated with high mortality rates in severely ill patients. The need to prevent and treat renal damage underlines the importance of understanding the pathophysiological mechanisms that characterize it. This could also enable early diagnosis and the design of alternative therapeutic approaches. The aim of this study is to investigate the effect of crocetin, a known antioxidant, on the prevention of renal damage due to ischemia-reperfusion injury and the investigation of the mechanisms involved. The present study was performed on C57BL/6 mice aged 10-12 weeks. The animals had access to water and food ad libitum. The experiment, as described in materials and methods, was completed at 24 h, in which case the kidneys were removed for further study, both at tissue morphology (with immunohistochemistry) and changes in the level of miRs’ expression by qRT-PCR. Accordingly, using the automatic precision analyzer, the serum levels of the basic parameters currently used clinically for the monitoring of renal function were determined. The administration of crocetin, despite the short presence of the substance in the body, affects all the biochemical parameters analyzed (urea, creatinine, uric acid, and ions of Na, K, Cl, P, Mg and Ca), ​​causing significant decrease of their measured values. Crocetin also resulted in a significant limitation of the inflammation elements and the degree of epithelial damage. Furthermore, the administration of crocetin appears to restore levels of expression of miR21, miR127 and miR132.