Inactivated pseudomonas aeruginosa protects against myocardial ischemia reperfusion injury via Nrf2 and HO-1

Heat-Killed Lacticaseibacillus paracasei Ameliorated UVB-Induced Oxidative Damage and Photoaging and Its Underlying Mechanisms

Ultraviolet B (UVB) radiation is a major environmental causative factor of skin oxidative damage and photoaging. Lacticaseibacillus paracasei is a well-known probiotic strain that can regulate skin health. The present study investigated the effects of heat-killed Lacticaseibacillus paracasei (PL) on UVB linked oxidative damage and photoaging in skin cells (Normal human dermal fibroblast (NHDF) cells and B16F10 murine melanoma cells). Results demonstrated that: (1) PL prevented UVB-induced cytotoxicity relating to decreased DNA damage in NHDF and B16F10 cells; (2) PL alleviated UVB-induced oxidative damage through increasing GSH content, as well as antioxidant enzyme activities and mRNA levels (except MnSOD activity and mRNA levels as well as CAT mRNA level) relating to the activation of Sirt1/PGC-1α/Nrf2 signaling in NHDF cells; (3) PL attenuated UVB-induced photoaging was noticed with a decrease in the percentage of SA-β-gal positive cells in NHDF cells model. Moreover, PL attenuated UVB-induced photoaging through exerting an anti-wrinkling effect by enhancing the type I collagen level relating to the inhibition (JNK, p38)/(c-Fos, c-Jun) of signaling in NHDF cells, and exerting an anti-melanogenic effect by suppressing tyrosinase and TYRP-1 activity and/or expressions relating to the inhibition of PKA/CREB/MITF signaling in B16F10 cells. In conclusion, PL could ameliorate UVB-induced oxidative damage and photoaging. Therefore, PL may be a potential antioxidant and anti-photoaging active ingredient for the cosmetic industry.

APPL1 ameliorates myocardial ischemia‑reperfusion injury by regulating the AMPK signaling pathway

Myocardial ischemia-reperfusion injury results in elevated reactive oxygen species (ROS) production and causes oxidative stress damage. Therefore, the current study aimed to investigate whether adaptor protein phosphotyrosine interacting with PH domain and leucine zipper 1 (APPL1) could induce the expression of antioxidant enzymes through AMP-activated protein kinase (AMPK) signaling in order to alleviate the injury caused by ischemia/hypoxia-reperfusion. Following induction of hypoxia-reoxygenation (H/R) injury in H9c2 cells, the liver kinase B1 (LKB1)/AMPK/acetyl-CoA carboxylase α (ACC) signaling pathway was investigated using western blot analysis, along with the detection of superoxide dismutase (SOD)2 and SOD3 expression. Additionally, cell viability was detected using a Cell Counting Kit-8 assay and ROS production was analyzed using ROS staining, whereas the expression levels of inflammatory mediators (TNF-α, monocyte chemoattractant protein 1 and IL-1β), apoptosis mediators [cleaved caspase-3, cleaved poly (ADP-ribose) polymerase and Bcl-2] and nuclear factor erythroid 2-related factor 2 signaling pathway-related proteins were detected via western blot analysis following overexpression of APPL1 alone or in combination with compound C treatment (an AMPK inhibitor). The results indicated that H/R induction upregulated the phosphorylation levels of LKB1, AMPK and ACC, and decreased the expression levels of APPL1 and SOD enzyme activities. APPL1 overexpression increased the phosphorylation levels of LKB1, AMPK and ACC, SOD enzyme activity and cell viability whereas the expression levels of proinflammatory mediators and proapoptotic mediators, and the levels of ROS production were markedly decreased when compared with H/R group with empty plasmid transfection. APPL overexpression-mediated effects were significantly abrogated by compound C. Taken together, the data indicated that APPL1 inhibited ROS production and H/R-induced myocardial injury via the AMPK signaling pathway. Therefore, APPL1 may serve as a potential therapeutic target for myocardial H/R injury.

MicroRNA-24 protects against myocardial ischemia-reperfusion injury via the NF-κB/TNF-α pathway

Acute myocardial infarction (AMI) is a form of cardiomyopathy in which a blocked coronary artery leads to an irreversible loss of cardiomyocytes due to inadequate blood and oxygen supply to the distal myocardium tissues, eventually leading to heart failure. Recently, studies have revealed that microRNA (miRNA/miR)-24 has diagnostic value in the pathogenesis of AMI by affecting multiple cell processes such as cell proliferation, differentiation and apoptosis. However, the specific mechanism of miR-24 in ischemia-reperfusion injury (IRI) after AMI remains to be fully elucidated. The present study aimed to investigate the effects and mechanisms of miR-24 in IRI. In vitro, the current study detected cellular apoptosis and apoptotic-related protein expression levels in the cardiomyocyte H9C2 cell line (negative control group, model group and miRNA group) via flow cytometry and western blot analysis. In the in vivo study, rats were randomly divided into sham, model and miRNA groups. The infarct area was observed using nitro blue tetrazolium staining, pathological changes of the myocardium were detected via hematoxylin and eosin staining and TUNEL staining was used to detect cardiomyocyte apoptosis. The expression levels of related proteins were evaluated via immunohistochemistry and western blot analysis. The in vitro and in vivo results demonstrated that miR-24 significantly inhibited cardiomyocyte apoptosis compared with the model group. Concurrently, the expression levels of proteins associated with the NF-κB/TNF-α pathway (NF-κB, caspase-3, Bax, Bcl-2, TNF-α, vascular cell adhesion molecule 1, intercellular adhesion molecule 1 and monocyte chemoattractant protein-1) in the miRNA group were significantly different from the model group (P<0.001). Compared with the model group, miR-24 significantly improved pathological damage and infarct size of rat myocardium. Overall, the present results suggested that miR-24 improves myocardial injury in rats by inhibiting the NF-κB/TNF-α pathway.

Protective Effect of Blood Cora Polysaccharides on H9c2 Rat Heart Cells Injury Induced by Oxidative Stress by Activating Nrf2/HO-1 Signal Pathway

The protective effect of blood cora polysaccharides (BCP) on H9c2 rat heart cells under oxidative stress was explored with the use of a H9c2 cell oxidative stress model. The ability of BCP to scavenge 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), 1,1-diphenyl-2-picrylhydrazyl (DPPH), and hydroxyl radicals and its reducing power were measured in vitro, indicating a more powerful antioxidant effect of BCP compared to a similar concentration of vitamin C. The cellular metabolic activity was tested through the MTT [3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide] assay. Additionally, the relevant oxidation indicator level within the cell supernatant and cells was tested with reagent kits, and mRNA and protein expression levels in the cells were tested through quantitative polymerase chain reaction (qPCR) and western blot. The chemical composition of BCP was determined through high performance liquid chromatography (HPLC). The results show that compared with the normal group, the model group's cell survival rate (28.75 ± 2.56%) decreased, lactate dehydrogenase (LDH) leakage and the malondialdehyde (MDA) content increased, and superoxide dismutase (SOD), catalase (CAT), and glutathione (GSH) levels decreased. The results of qPCR and western blot show that compared with the normal group, the model group's Bcl-2 associated X protein (Bax), caspase-3, nuclear factor erythroid-2 related factor 2 (Nrf2), heme oxygenase-1 (HO-1) expression, NAD(P)H:quinoneoxidoreductase 1 (NQO1), and cytochrome c (Cyt C) decreased, and B-cell lymphoma-2 (Bcl-2) expression was increased, with significant statistical differences. Compared with the model group, the cell survival rate for each BCP-treated group increased, the LDH leakage decreased, the SOD, CAT, and GSH levels in the cells increased, the MDA content decreased, the Bax, caspase-3, Nrf2, HO-1, NQO1, and Cyt C expression was weakened, and the Bcl-2 expression was strengthened. BCP inhibited the reduction of mitochondrial membrane potential caused by H2O2 treatment. According to the component analysis, BCP mainly consist of mannitol, ribose, glucosum anhydricum, galactose, and xylose. It was observed that the Nrf2/HO-1 signaling pathway can be activated, regulated, and controlled by functional BCP to protect H9c2 cells injured by oxidative stress.