Alprostadil Injection Attenuates Coronary Microembolization-Induced Myocardial Injury Through GSK-3β/Nrf2/HO-1 Signaling-Mediated Apoptosis Inhibition

The role of serine/threonine protein kinases in cardiovascular disease and potential therapeutic methods

Protein phosphorylation is an important link in a variety of signaling pathways, and most of the important life processes in cells involve protein phosphorylation. Based on the amino acid residues of phosphorylated proteins, protein kinases can be categorized into the following families: serine/threonine protein kinases, tyrosine-specific protein kinases, histidine-specific protein kinases, tryptophan kinases, and aspartate/glutamyl protein kinases. Of all the protein kinases, most are serine/threonine kinases, where serine/threonine protein kinases are protein kinases that catalyze the phosphorylation of serine or threonine residues on target proteins using ATP as a phosphate donor. The current socially accepted classification of serine/threonine kinases is to divide them into seven major groups: protein kinase A, G, C (AGC), CMGC, Calmodulin-dependent protein kinase (CAMK), Casein kinase (CK1), STE, Tyrosine kinase (TKL) and others. After decades of research, a preliminary understanding of the specific classification and respective functions of serine/threonine kinases has entered a new period of exploration. In this paper, we review the literature of the previous years and introduce the specific signaling pathways and related therapeutic modalities played by each of the small protein kinases in the serine/threonine protein kinase family, respectively, in some common cardiovascular system diseases such as heart failure, myocardial infarction, ischemia-reperfusion injury, and diabetic cardiomyopathy. To a certain extent, the current research results, including molecular mechanisms and therapeutic methods, are fully summarized and a systematic report is made for the prevention and treatment of cardiovascular diseases in the future.

The Effect and Mechanism of Oleanolic Acid in the Treatment of Metabolic Syndrome and Related Cardiovascular Diseases

Metabolic syndromes (MetS) and related cardiovascular diseases (CVDs) pose a serious threat to human health. MetS are metabolic disorders characterized by obesity, dyslipidemia, and hypertension, which increase the risk of CVDs' initiation and development. Although there are many availabile drugs for treating MetS and related CVDs, some side effects also occur. Considering the low-level side effects, many natural products have been tried to treat MetS and CVDs. A five-cyclic triterpenoid natural product, oleanolic acid (OA), has been reported to have many pharmacologic actions such as anti-hypertension, anti-hyperlipidemia, and liver protection. OA has specific advantages in the treatment of MetS and CVDs. OA achieves therapeutic effects through a variety of pathways, attracting great interest and playing a vital role in the treatment of MetS and CVDs. Consequently, in this article, we aim to review the pharmacological actions and potential mechanisms of OA in treating MetS and related CVDs.

Protective Effect of Berberine on Acute Gastric Ulcer by Promotion of Tricarboxylic Acid Cycle-Mediated Arachidonic Acid Metabolism

Background and Objective

Peptic ulcer is a high incidence gastrointestinal disease in China. Berberine (BBR) is a natural product isolated from the Chinese herb Coptis chinensis Franch that has protective effects in digestive diseases. We aimed to evaluate the ability of BBR to attenuate acute gastric ulcer induced by one-time administration of ethanol in the rat.

Methods

Tissue pathological morphology, macroscopic score, ulcer healing rate, and serum levels of the inflammatory cytokines nitric oxide (NO), interleukin-6 (IL-6), and prostaglandin E2 (PGE2), and anti-inflammatory interleukin-10 (IL-10) were used to determine the efficacy of BBR and evaluated to identify the optimal dosage. Subsequently, transcriptome and metabolome sequencing were conducted in Control, Model, and optimal dosage groups to explore the pathogenesis of the disease and the mechanism of action of the drug. The levels of malondialdehyde (MDA), myeloperoxidase (MPO), as well as those of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) were determined by enzyme-linked immunosorbent assay to verify the results of transcriptomics and metabolomics analyses.

Results

BBR significantly improved the pathological morphology of gastric ulcers, increased the macroscopic score and healing rate, decreased serum levels of NO, IL-6, and PGE2, and increased serum levels of IL-10, thus effectively alleviating gastric ulcer severity. Transcriptome results showed that the therapeutic effect of BBR was mainly mediated by the arachidonic acid metabolism pathway at the gene level, which is closely associated with inflammation and increased levels of reactive oxygen species (ROS). The differentially accumulated metabolite prostaglandin E1, which is a negative regulator of ROS, was significantly up-regulated after BBR administration. The validation results indicated that BBR pretreatment increased SOD and GSH-Px enzyme activities, while reducing levels of the oxidative products MDA and MPO.

Conclusion

This study demonstrated that BBR exerts a protective effect on acute gastric ulcer by promoting tricarboxylic acid cycle-mediated arachidonic acid metabolism.

Upregulation of miR-29b-3p alleviates coronary microembolization-induced myocardial injury via regulating BMF and GSK-3β

Coronary microembolization (CME) is an intractable complication results from acute coronary syndrome. CME-induced myocardial apoptosis was associated with progressive cardiac contractile dysfunction. miR-29b-3p has been reported implicated in variety cardiovascular diseases, but its function in CME-induced myocardial injury is yet unknown. Herein, a rat model of CME was established by injecting microspheres into the left ventricle and found that the expression level of miR-29b-3p was markedly decreased in the CME rat heart tissues. By using echocardiography, CD31 immunohistochemistry staining, hematoxylin basic fuchsin picric acid (HBFP) staining, TUNEL staining, and western blotting analysis after CME, it was found that upregulating miR-29b-3p improved cardiac dysfunction, promoted angiogenesis, decreased myocardial microinfarct area, and inhibited myocardial apoptosis. Additionally, miR-29b-3p inhibition can reverse the protective benefits of miR-29b-3p overexpression. Mechanistically, the target genes of miR-29b-3p were identified as glycogen synthase kinase 3 (GSK-3β) and Bcl-2 modifying factor (BMF) by bioinformatics analysis and luciferase reporter experiment. Overall, our findings imply that induction of miR-29b-3p, which negatively regulates GSK-3β and BMF expression, attenuates CME-induced myocardial injury, suggesting a novel potential therapeutic target for cardioprotective after CME.

Mn-SOD alleviates methotrexate-related hepatocellular injury via GSK-3β affecting anti-oxidative stress of HO-1 and Drp1

OBJECTIVES

Methotrexate (MTX) is the most common therapeutic agent that may have the risk of drug-induced liver injury. Its pathogenic mechanism is related to oxidative stress caused by mitochondrial dysfunction. Superoxide dismutase (SOD), including manganese-containing SOD (Mn-SOD), can exert its effect of anti-oxidative stress by scavenging superoxide free radicals. Accordingly, this study is performed to explore the underlying molecular mechanism via observing whether Mn-SOD could affect the damage of MTX to hepatocytes.

METHODS

Human hepatocyte cell line L-02 was cultured in vitro and divided into 4 groups, including a blank group with the addition of the same volume of serum-free medium, a MTX group (40 μg/well MTX drug-treatment), a MTX+NC group (40 μg/well MTX drug-treatment+blank plasmid), and a MTX+SOD group (40 μg/well MTX drug-treatment+Mn-SOD plasmid). The levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), and microRNA-122 (miR-122) in the supernatant of cell culture were respectively detected by automatic biochemical analytical instrument and real-time RT-PCR to evaluate the degree of hepatocyte damage in each group. MitoSOX fluorescent probe was used to label intracellular superoxide in each group, and cell apoptosis was detected by flow cytometry. Meanwhile, the contents of glycogen synthase kinase-3 beta (GSK-3β), hemeoxygenase-1 (HO-1), mitochondrial fission-mediated protein of dynamin-related protein 1 (Drp1), and Mn-SOD were detected by Western blotting.

RESULTS

Compared with the blank group, the levels of ALT, AST, and miR-122 in the supernatant of hepatocyte culture of the MTX group and MTX+NC group were significantly elevated (all P <0.05), and that in the MTX+SOD group were significantly decreased ( P <0.05) and equivalent to that in the blank group. MitoSOX staining revealed that the MTX group and MTX+NC had the most abundant superoxide; and the amount was significantly reduced in the MTX+SOD group, without a significant difference when compared with the blank group. Furthermore, the results of flow cytometry indicated that compared with the blank group, the MTX group and MTX+NC group showed significantly increased cell apoptosis ( P <0.05); while there was obviously reduced cell apoptosis in the MTX+SOD group than that in the MTX group and MTX+NC group ( P <0.05). According to the results of Western blotting, the blank group and MTX+SOD group had higher expressions of Mn-SOD, p-GSK-3β, and HO-1; while the MTX group and MTX+NC group exhibited remarkably lower levels of Mn-SOD, p-GSK-3β, and HO-1 than those in the blank group ( P <0.05). Besides, a completely opposite trend was found in the expression of Drp1, which was highly expressed in the MTX group and MTX+NC group, but lowly expressed in the blank group and the MTX+SOD group.

CONCLUSIONS

MTX may induce hepatocyte damage, and one of the mechanisms may be due to the decrease of intracellular Mn-SOD level, which can cause the accumulation of superoxide, affect the levels of HO-1 and Drp1 through GSK-3β leading to mitochondrial damage and cell apoptosis. High expression of Mn-SOD intracellularly through exogenous introduction can scavenge drug-produced superoxide, affect HO-1 and Drp1 levels through GSK-3β, activate mitochondria, protect cells against damage from oxidative stress, and inhibit hepatocyte apoptosis eventually. So exogenous introduction of SOD may be a potential therapeutic approach to block or reverse MTX-related hepatocyte injury.

Oleanolic Acid Alleviates Cerebral Ischemia/Reperfusion Injury via Regulation of the GSK-3β/HO-1 Signaling Pathway

Oleanolic acid (OA), a bioactive ingredient of Panax ginseng, exhibits neuroprotective pharmacological effects. However, the protective role of OA in cerebral ischemia and involved mechanisms remain unclear. This study attempted to explore the therapeutic effects of OA both in vitro and in vivo. OA attenuated cytotoxicity and overproduction of intracellular reactive oxygen species (ROS) by regulation of glycogen synthase kinase-3β (GSK-3β)/heme oxygenase-1 (HO-1) signal in oxygen-glucose deprivation/reoxygenation (OGD/R)-exposed SH-SY5Y cells. Additionally, OA administration significantly reduced the area of cerebral infarction and the neurological scores in the rat models of cerebral ischemia with middle cerebral artery occlusion (MCAO). The OA administration group showed a higher percentage of Nissl⁺ and NeuN⁺ cells, along with lower TUNEL⁺ ratios in the infarct area of MCAO rats. Moreover, OA administration reduced ROS production while it suppressed the GSK-3β activation and upregulated the HO-1 expression in infarcted tissue. Our results illustrated that OA significantly counteracted cerebral ischemia-mediated injury through antioxidant effects induced by the regulation of the GSK-3β/HO-1 signaling pathway, implicating OA as a promising neuroprotective drug for the therapy of ischemic stroke.