Vialinin A alleviates oxidative stress and neuronal injuries after ischaemic stroke by accelerating Keap1 degradation through inhibiting USP4-mediated deubiquitination.

BACKGROUND: Oxidative stress is known as a hallmark of cerebral ischaemia‒reperfusion injury and it exacerbates the pathologic progression of ischaemic brain damage. Vialinin A, derived from a Chinese edible mushroom, possesses multiple pharmacological activities in cancer, Kawasaki disease, asthma and pathological scarring. Notably, vialinin A is an inhibitor of ubiquitin-specific peptidase 4 (USP4) that shows anti-inflammatory and antioxidative properties. However, the precise effect of vialinin A in ischaemic stroke, as well as its underlying mechanisms, remains largely unexplored. PURPOSE: The present research focuses on the impacts of vialinin A on oxidative stress and explores the underlying mechanisms involved while also examining its potentiality as a therapeutic candidate for ischaemic stroke. METHODS: Mouse ischaemic stroke was conducted by MCAO surgery. Vialinin A was administered via lateral ventricular injection at a dose of 2 mg/kg after reperfusion. Subsequent experiments were meticulously conducted at the appropriate time points. Stroke outcomes were evaluated by TTC staining, neurological score, Nissl staining and behavioural analysis. Co-IP assays were operated to examine the protein-protein interactions. Immunoblot analysis, qRT-PCR, and luciferase reporter assays were conducted to further investigate its underlying mechanisms. RESULTS: In this study, we initially showed that administration of vialinin A alleviated cerebral ischaemia‒reperfusion injury-induced neurological deficits and neuronal apoptosis. Furthermore, vialinin A, which is an antioxidant, reduced oxidative stress injury, promoted the activation of the Keap1-Nrf2-ARE signaling pathway and increased the protein degradation of Keap1. The substantial neuroprotective effects of vialinin A against ischaemic stroke were compromised by the overexpression of USP4. Mechanistically, vialinin A inhibited the deubiquitinating enzymatic activity of USP4, leading to enhanced ubiquitination of Keap1 and subsequently promoting its degradation. This cascade caused the activation of Nrf2-dependent antioxidant response, culminating in a reduction of neuronal apoptosis and the amelioration of neurological dysfunction following ischaemic stroke. CONCLUSIONS: This study demonstrates that inhibition of USP4 to activate Keap1-Nrf2-ARE signaling pathway may represent a mechanism by which vialinin A conferred protection against cerebral ischaemia‒reperfusion injury and sheds light on its promising prospects as a therapeutic intervention for ischaemic stroke.

Sodium butyrate activates HMGCS2 to promote ketone body production through SIRT5-mediated desuccinylation.

Ketone bodies have beneficial metabolic activities, and the induction of plasma ketone bodies is a health promotion strategy. Dietary supplementation of sodium butyrate (SB) is an effective approach in the induction of plasma ketone bodies. However, the cellular and molecular mechanisms are unknown. In this study, SB was found to enhance the catalytic activity of 3-hydroxy-3-methylglutaryl-CoA synthase 2 (HMGCS2), a rate-limiting enzyme in ketogenesis, to promote ketone body production in hepatocytes. SB administrated by gavage or intraperitoneal injection significantly induced blood ß-hydroxybutyrate (BHB) in mice. BHB production was induced in the primary hepatocytes by SB. Protein succinylation was altered by SB in the liver tissues with down-regulation in 58 proteins and up-regulation in 26 proteins in the proteomics analysis. However, the alteration was mostly observed in mitochondrial proteins with 41% down- and 65% up-regulation, respectively. Succinylation status of HMGCS2 protein was altered by a reduction at two sites (K221 and K358) without a change in the protein level. The SB effect was significantly reduced by a SIRT5 inhibitor and in Sirt5-KO mice. The data suggests that SB activated HMGCS2 through SIRT5-mediated desuccinylation for ketone body production by the liver. The effect was not associated with an elevation in NAD+/NADH ratio according to our metabolomics analysis. The data provide a novel molecular mechanism for SB activity in the induction of ketone body production.

Mechanism of Astragali Radix for the treatment of osteoarthritis: A study based on network pharmacology and molecular docking.

Osteoarthritis (OA) is a degenerative joint disease caused by many factors. Astragali Radix (Huangqi), a traditional Chinese medicine (TCM), is widely used to treat OA. Although it can inhibit the progression of OA, its pharmacological mechanism is unclear. In this study, we used a network pharmacological approach to determine the mechanism by which Huangqi inhibits the progression of OA. We obtained the active ingredients of Huangqi from the Traditional Chinese Systems Pharmacology database and identified potential targets of these ingredients. Next, we identified the OA-related targets by using the GeneCards and Online Mendelian Inheritance in Man databases. Then, a protein-protein interaction (PPI) network was established based on the overlapping genes between the Huangqi targets and the OA targets, and the interactions were analyzed. Subsequently, the Metascape database was used to perform the Gene Ontology biological functions and Kyoto Encyclopedia of Genes and Genomes pathways enrichment analysis. Furthermore, selected active ingredients and corresponding targets were investigated through molecular docking. In total, 20 active ingredients and 206 related targets were identified. The results of Gene Ontology enrichment analysis showed that the intersection targets were mainly involved in immune inflammation, proliferation, and apoptosis. The Kyoto Encyclopedia of Genes and Genomes pathway analysis revealed that Huangqi might exert antiosteoarthritis effect mainly through the PI3K-Akt signaling pathway, apoptosis, the mitogen-activated protein kinases signaling pathway, and the p53 signaling pathway. Moreover, the molecular docking results indicated that quercetin and kaempferol exhibited the good binding capacity to transcription factor JUN, tumor necrosis factor, and protein kinase B. In summary, we investigated the therapeutic effects of Huangqi from a systemic perspective. These key targets and pathways provide promising directions for future studies to reveal the exact regulating mechanism of Huangqi against OA.

The Effects of Long-Term Tai-Chi Practice on Blood Pressure Under Normal Conditions.

BACKGROUND: Tai-Chi is a popular form of mind-body activity that is suitable for people of all ages. Accumulating evidence have shown that Tai-Chi can help ameliorate cardiovascular diseases. However, the benefits of long-term practice of Tai-Chi on blood pressure control remains unclear. A total of 898 villagers of Chenjiagou were enrolled in this study based on certain inclusion and exclusion criteria. METHODS: All basic information and clinical data were collected by physicians. The effects of Tai-Chi on the systolic blood pressure (SBP), diastolic blood pressure (DBP) and mental status of participants were analyzed. The average practice time of Tai-Chi in the Tai-Chi group was 28.53 years (median 29 years, range 2-69 years). RESULTS: The results showed that SBP and DBP were significantly lower in the Tai-Chi group, compared with the control group and the stop group. Meanwhile, the long-term practice of Tai-Chi significantly improved the body mass index (BMI) (P=0.021). Stepwise regression results demonstrated that Tai-Chi practice, age and BMI could significantly affect blood pressure, with adjusted R2 of 0.218 and 0.159 for SBP and DBP, respectively. In addition, Tai-chi is associated with a lower rate of hypertension after age 40. However, compared with the control group, participants who practiced Tai-Chi for a short time, then stopped, showed no significant improvement in the above-mentioned measurements. CONCLUSIONS: The long-term practice of Tai-Chi was associated with better blood pressure, at least partly through the improvement of BMI and mental state. However, the short-term practice of Tai-Chi may not provide significant benefits on blood pressure in the long term.