Ligustrazine prevents coronary microcirculation dysfunction in rats via suppression of miR-34a-5p and promotion of Sirt1

Platelet-derived exosomes regulate endothelial cell inflammation and M1 macrophage polarization in coronary artery thrombosis via modulating miR-34a-5p expression

As the important factors in coronary artery thrombosis, endothelial injury and M1 macrophage polarization are closely related to the expression of miR-34a-5p. Exosomes in plasma are mainly derived from platelets and play an important role in thrombosis. Based on these facts, this study was conducted to investigate the acting mechanism of platelet-derived exosomes (PLT-exo) in the effects of endothelial injury and M1 macrophage polarization on coronary artery thrombosis. Firstly, rats were divided into the sham-operated group and the coronary microembolization (CME) group, and their plasma-derived exosomes were extracted to detect the expression of miR-34a-5p. Next, the PLT-exo were extracted from healthy volunteers and then co-cultured with ox-LDL-induced endothelial cells and LPS-induced macrophages, respectively. Subsequently, the expression of IL-1β, IL-6, TNF-α, and ICAM-1 in endothelial cells was measured, and the level of markers related to M1 macrophage polarization and Sirt1/NF-κB pathway was detected. Finally, the above indicators were examined again after PLT-exo combined with miR-34a-5p mimic were co-cultured with endothelial cells and macrophages, respectively. The results demonstrated that the expression of miR-34a-5p in the CME group was up-regulated compared with the sham-operated group. In cell experiments, PLT-exo modulated the Sirt1/NF-κB pathway by inhibiting the expression of intracellular miR-34a-5p and down-regulated the expression of IL-1β, IL-6, TNF-α, and ICAM-1 in endothelial cells and M1 macrophage polarization. After the transfection with miR-34a-5p mimic, endothelial cell inflammatory injury and M1 macrophage polarization increased to varying degrees. In conclusion, PLT-exo can alleviate coronary artery thrombosis by reducing endothelial cell inflammation and M1 macrophage polarization via inhibiting miR-34a-5p expression. In contrast, miR-34a-5p overexpression in PLT-exo may exacerbate these pathological injuries in coronary artery thrombosis.

Pinocembrin's protective effect against acute pancreatitis in a rat model: The correlation between TLR4/NF-κB/NLRP3 and miR-34a-5p/SIRT1/Nrf2/HO-1 pathways

BACKGROUND

Acute pancreatitis (APS) is a prevalent acute pancreatic inflammation, where oxidative stress, inflammatory signaling pathways, and apoptosis activation contribute to pancreatic injury.

METHODS

Pinocembrin, the predominant flavonoid in propolis, was explored for its likely shielding effect against APS provoked by two intraperitoneal doses of L-arginine (250 mg / 100 g) in a rat model.

RESULTS

Pinocembrin ameliorated the histological and immunohistochemical changes in pancreatic tissues and lowered the activities of pancreatic amylase and lipase that were markedly elevated with L-arginine administration. Moreover, pinocembrin reinstated the oxidant/antioxidant equilibrium, which was perturbed by L-arginine, and boosted the pancreatic levels of nuclear factor erythroid 2-related factor 2 (Nrf2) and heme oxygenase-1 (HO-1). Pinocembrin markedly reduced the elevation in serum C-reactive protein (CRP) level induced by L-arginine. Additionally, it decreased the expression of high motility group box protein 1 (HMGB1), toll-like receptor 4 (TLR4), nuclear factor kappa B (NF-κB), tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), and NOD-like receptor (NLR) Family Pyrin Domain Containing 3 (NLRP3) inflammasome in the pancreas. Furthermore, it also reduced myeloperoxidase (MPO) activity. Pinocembrin markedly downregulated miR-34a-5p expression and upregulated the protein levels of peroxisome proliferator-activated receptor alpha (PPAR-α) and Sirtuin 1 (SIRT1) and the gene expression level of the inhibitor protein of NF-κB (IκB-α), along with normalizing the Bax/Bcl-2 ratio.

CONCLUSIONS

Pinocembrin notably improved L-arginine-induced APS by its antioxidant, anti-inflammatory, and anti-apoptotic activities. Pinocembrin exhibited a protective role in APS by suppressing inflammatory signaling via the TLR4/NF-κB/NLRP3 pathway and enhancing cytoprotective signaling via the miR-34a-5p/SIRT1/Nrf2/HO-1 pathway.

Inflammation and coronary microvascular disease: relationship, mechanism and treatment

Coronary microvascular disease (CMVD) is common in patients with cardiovascular risk factors and is linked to an elevated risk of adverse cardiovascular events. Although modern medicine has made significant strides in researching CMVD, we still lack a comprehensive understanding of its pathophysiological mechanisms due to its complex and somewhat cryptic etiology. This greatly impedes the clinical diagnosis and treatment of CMVD. The primary pathological mechanisms of CMVD are structural abnormalities and/or dysfunction of coronary microvascular endothelial cells. The development of CMVD may also involve a variety of inflammatory factors through the endothelial cell injury pathway. This paper first reviews the correlation between the inflammatory response and CMVD, then summarizes the possible mechanisms of inflammatory response in CMVD, and finally categorizes the drugs used to treat CMVD based on their effect on the inflammatory response. We hope that this paper draws attention to CMVD and provides novel ideas for potential therapeutic strategies based on the inflammatory response.

Therapeutic effects and molecular mechanisms of natural products in thrombosis

Thrombotic disorders, such as myocardial infarction and stroke, are the leading cause of death in the global population and have become a health problem worldwide. Drug therapy is one of the main antithrombotic strategies, but antithrombotic drugs are not completely safe, especially the risk of bleeding at therapeutic doses. Recently, natural products have received widespread interest due to their significant efficacy and high safety, and an increasing number of studies have demonstrated their antithrombotic activity. In this review, articles from databases, such as Web of Science, PubMed, and China National Knowledge Infrastructure, were filtered and the relevant information was extracted according to predefined criteria. As a result, more than 100 natural products with significant antithrombotic activity were identified, including flavonoids, phenylpropanoids, quinones, terpenoids, steroids, and alkaloids. These compounds exert antithrombotic effects by inhibiting platelet activation, suppressing the coagulation cascade, and promoting fibrinolysis. In addition, several natural products also inhibit thrombosis by regulating miRNA expression, anti-inflammatory, and other pathways. This review systematically summarizes the natural products with antithrombotic activity, including their therapeutic effects, mechanisms, and clinical applications, aiming to provide a reference for the development of new antithrombotic drugs.

Inhibiting mir-34a-5p regulates doxorubicin-induced autophagy disorder and alleviates myocardial pyroptosis by targeting Sirt3-AMPK pathway

Doxorubicin (DOX) is a commonly used chemotherapy drug widely applied in various cancers such as breast cancer, leukemia, and sarcomas. However, its usage is limited by cardiotoxicity. Additionally, the cardiac toxicity of DOX accumulates with dose and duration, making it imperative to identify therapeutic targets for DOX-induced cardiomyopathy (DIC). It has been reported that miRNAs are involved in the progression of DIC. Mir-34a-5p has been identified as an early diagnostic marker for DIC. While studies have shown the involvement of mir-34a-5p in DIC apoptosis, it has not been validated in animal models, nor has the potential improvement of DIC by inhibiting mir-34a-5p been confirmed. Autophagy and pyroptosis are key factors in the development of DIC and can serve as therapeutic targets for its treatment. In this study, we found that mir-34a-5p was upregulated in the heart after DOX treatment and that the inhibition of mir-34-5p reduced autophagy and pyroptosis in DIC. We also found that the inhibition of mir-34a-5p inhibited pyroptosis by regulating autophagy and reducing mitochondrial reactive oxygen species. Moreover, we identified Sirtuin3 (Sirt3) as a target gene of mir-34a-5p using a double-luciferase reporter assay. overexpression Sirt3 reduced pyroptosis by alleviating autophagy. Our research findings suggest that inhibiting mir-34a-5p has a beneficial role in alleviating autophagy and pyroptosis in DIC. This provides therapeutic prospects for treating DIC.

Development of novel celastrol-ligustrazine hybrids as potent peroxiredoxin 1 inhibitors against lung cancer

The disruption of oxidation-reduction equilibrium through inhibiting reactive oxygen species (ROS) clearance or enhancing ROS production has emerged as a novel and promising strategy for cancer therapy. Herein, a series of celastrol-ligustrazine hybrids were designed and synthesized as effective ROS promoters, and their biological activities were further evaluated. Among them, compound 7e stood out as the most potent peroxiredoxin 1 (PRDX1) inhibitor (IC50 = 0.164 μM), which was significant super to the recognized PRDX1 inhibitor Conoidin A (IC50 = 14.80 μM) and the control compound celastrol (IC50 = 1.622 μM). Furthermore, 7e dramatically promoted intracellular ROS accumulation, and inhibited the proliferation, invasion and migration of cancer cells besides inducing apoptosis in vitro. Additionally, 7e suppressed the key signaling pathways (AKT and ERK) and promoted the expression of apoptosis-related proteins (cleaved caspase-3/8 and cleaved PARP) in A549 cells, which resulted in the prevention of tumor progression. Most importantly, compound 7e (TGI = 77.47%) showed more considerable in vivo antitumor efficacy and less toxicity than celastrol (TGI = 71.00%). Overall, this work indicates 7e as the most potential PRDX1 inhibitor and may be a promising candidate for the therapy of lung cancer.

Improving Chuanxiong Rhizoma quality standards using an effect-constituent index based bioassay

Chuanxiong Rhizoma is a traditional Chinese medicine (TCM) that is used to promote blood circulation. We set out to improve Chuanxiong Rhizoma quality standards using a bioassay-based Effect-constituent Index (ECI). We performed high performance liquid chromatography (HPLC) analysis to determine the chemical constituents of 10 Chuanxiong Rhizoma samples from different locations. We then constructed a direct bioassay method to investigate each sample's antiplatelet aggregation effects. To screen for active ingredients that promote antiplatelet aggregation, we carried out Pearson correlation analyses between biopotency and compounds identified in the HPLC data. We developed an ECI of platelet aggregation inhibition using a multi-indicator synthetic evaluation method based on the integration of biopotency and active constituents. To further assess the biopotency-based Chuanxiong Rhizoma quality evaluation result accuracy, we compared the ECI with the chemical indicator' method. Eight common chemical fingerprints peaks indicated notable content variation among samples. Biological evaluation showed that all 10 samples could inhibit platelet aggregation, although they had significantly different biological potencies. Using spectrum-effect relationships, we determined that Ligustilide was the significant active constituent responsible for antiplatelet aggregation. Using correlation analysis, we found that ECI correlated with the Chuanxiong Rhizoma extract's platelet aggregation inhibitory effect. Additionally, ECI proved to be a good indicator of Chuanxiong Rhizoma quality, whereas chemical indicators failed to distinguish and predict the biopotency-based quality grade. This work indicates that ECI is a useful tool for associating sample quality with chemical markers linked to TCM clinical effects. ECI also provides a paradigm for improving the quality control of other TCMs that invigorate blood circulation.

Melatonin ameliorates arsenic-induced cardiotoxicity through the regulation of the Sirt1/Nrf2 pathway in rats

Chronic arsenic (As) exposure, mainly as a result of drinking contaminated water, is associated with cardiovascular diseases. Mitochondrial dysfunction, oxidative stress, inflammation, apoptosis, and autophagy have been suggested as the molecular etiology of As cardiotoxicity. Melatonin (Mel) is a powerful antioxidant. Mel improves diabetic cardiomyopathy, cardiac remodeling, and heart failure. Following pre-treatment with Mel (10, 20, or 30 mg/kg/day i.p.), rats were orally gavaged with As (15 mg/kg/day) for 28 days. Electrocardiographic findings showed that Mel decreased the As-mediated QT interval prolongation. The effects of As on cardiac levels of glutathione (GSH) and malondialdehyde (MDA) were reversed by Mel pretreatment. Mel also modulated the Sirt1 and Nrf2 expressions promoted by As. Mel down-regulated autophagy markers such as Beclin-1 expression and the LC3-II/I ratio. Moreover, the cardiac expression of cleaved-caspase-3 and Bax/Bcl-2 ratio was decreased by Mel pretreatment. Reduced expression of miR-34a and miR-144 by As were reversed by Mel. The histopathological changes of cardiac injury associated with As exposure was moderated by Mel. Mel may improve As-induced cardiac dysfunction through anti-oxidative, anti-apoptotic, and anti-autophagic mechanisms.