LuQi Formula Regulates NLRP3 Inflammasome to Relieve Myocardial-Infarction-Induced Cardiac Remodeling in Mice

Effects of NLRP3 Inflammasome Mediated Pyroptosis on Cardiovascular Diseases and Intervention Mechanism of Chinese Medicine

Activation of the NOD-like receptor protein 3 (NLRP3) inflammasome signaling pathway is an important mechanism underlying myocardial pyroptosis and plays an important role in inflammatory damage to myocardial tissue in patients with cardiovascular diseases (CVDs), such as diabetic cardiomyopathy, ischemia/reperfusion injury, myocardial infarction, heart failure and hypertension. Noncoding RNAs (ncRNAs) are important regulatory factors. Many Chinese medicine (CM) compounds, including their effective components, can regulate pyroptosis and exert myocardium-protecting effects. The mechanisms underlying this protection include inhibition of inflammasome protein expression, Toll-like receptor 4-NF-κB signal pathway activation, oxidative stress, endoplasmic reticulum stress (ERS), and mixed lineage kinase 3 expression and the regulation of silent information regulator 1. The NLRP3 protein is an important regulatory target for CVD prevention and treatment with CM. Exploring the effects of the interventions mediated by CM and the related mechanisms provides new ideas and perspectives for CVD prevention and treatment.

Hypoxia-Induced Myocardial Hypertrophy Companies with Apoptosis Enhancement and p38-MAPK Pathway Activation

Li, Xiaoxu, Zhijun Pu, Gang Xu, Yidong Yang, Yu Cui, Xiaoying Zhou, Chenyuan Wang, Zhifeng Zhong, Simin Zhou, Jun Yin, Fabo Shan, Chengzhong Yang, Li Jiao, Dewei Chen, and Jian Huang. Hypoxia-induced myocardial hypertrophy companies with apoptosis enhancement and p38-MAPK pathway activation. High Alt Med Biol. 00:00-00, 2024. Background: Right ventricular function and remodeling are closely associated with symptom severity and patient survival in hypoxic pulmonary hypertension. However, the detailed molecular mechanisms underlying hypoxia-induced myocardial hypertrophy remain unclear. Methods: In Sprague-Dawley rats, hemodynamics were assessed under both normoxia and hypobaric hypoxia at intervals of 7 (H7), 14 (H14), and 28 (H28) days. Morphological changes in myocardial tissue were examined using hematoxylin and eosin (HE) staining, while myocardial hypertrophy was evaluated with wheat germ agglutinin (WGA) staining. Apoptosis was determined through TUNEL assays. To further understand the mechanism of myocardial hypertrophy, RNA sequencing was conducted, with findings validated via Western blot analysis. Results: The study demonstrated increased hypoxic pulmonary hypertension and improved right ventricular diastolic and systolic function in the rat models. Significant elevations in pulmonary arterial systolic pressure (PASP), mean pulmonary arterial pressure (mPAP), right ventricular mean pressure (RVMP), and the absolute value of +dp/dtmax were observed in the H14 and H28 groups compared with controls. In addition, right ventricular systolic pressure (RVSP), -dp/dtmax, and the mean dp/dt during isovolumetric relaxation period were notably higher in the H28 group. Heart rate increased in the H14 group, whereas the time constant of right ventricular isovolumic relaxation (tau) was reduced in both H14 and H28 groups. Both the right heart hypertrophy index and the heart weight/body weight ratio (HW/BW) were elevated in the H14 and H28 groups. Myocardial cell cross-sectional area also increased, as shown by HE and WGA staining. Western blot results revealed upregulated HIF-1α levels and enhanced HIF-2α expression in the H7 group. In addition, phosphorylation of p38 and c-fos was augmented in the H28 group. The H28 group showed elevated levels of Cytochrome C (Cyto C), whereas the H14 and H28 groups exhibited increased levels of Cleaved Caspase-3 and the Bax/Bcl-2 ratio. TUNEL analysis revealed a rise in apoptosis with the extension of hypoxia duration in the right ventricle. Conclusions: The study established a link between apoptosis and p38-MAPK pathway activation in hypoxia-induced myocardial hypertrophy, suggesting their significant roles in this pathological process.

LuQi Formula relieves ventricular remodeling through improvement of HIF-1α-mediated intestinal barrier integrity

BACKGROUND

Ventricular remodeling is the adaptive process in which the heart undergoes changes due to stress, leading to heart failure (HF). The progressive decline in cardiac function is considered to contribute to intestinal barrier impairment. LuQi Formula (LQF) is a traditional Chinese medicine preparation widely used in the treatment of ventricular remodeling and HF. However, the role of LQF in the impairment of intestinal barrier function induced by ventricular remodeling remains unclear.

MATERIALS AND METHODS

Ventricular remodeling was induced in rats by permanently ligating the left anterior descending branch coronary artery, and cardiac function indexes were assessed using echocardiography. Heart and colon tissue morphology were observed by hematoxylin-eosin, Masson's trichrome and Alcian Blue Periodic acid Schiff staining. Myocardial cell apoptosis was detected using TUNEL and immunohistochemistry. Circulatory levels of brain natriuretic peptide (BNP), intestinal permeability markers endotoxin, D-lactate and zonulin, as well as inflammatory cytokines tumor necrosis factor alpha and interleukin-1 beta were measured by Enzyme-linked immunosorbent assay. Expression levels of tight junction (TJ) proteins and hypoxia-inducible factor-1 alpha (HIF-1α) in colon tissue were detected by immunofluorescence, immunohistochemistry and western blotting. Cardiac function indexes and intestinal permeability markers of patients with HF were analyzed before and after 2-4 months of LQF treatment.

RESULTS

LQF protected cardiac function and alleviated myocardial fibrosis and apoptosis in rats with ventricular remodeling. LQF protected the intestinal barrier integrity in ventricular remodeling rats, including maintaining colonic tissue morphology, preserving the number of goblet cells and normal expression of TJ proteins. Furthermore, LQF upregulated the expression of HIF-1α protein in colon tissue. Intervention with a HIF-1α inhibitor weakened the protective effect of LQF on intestinal barrier integrity. Moreover, a reduction of HIF-1α aggravated ventricular remodeling, which could be alleviated by LQF. Correspondingly, the circulating levels of intestinal permeability markers and BNP in HF patients were significantly decreased, and cardiac function markedly improved following LQF treatment.

CONCLUSIONS

We demonstrated that LQF effectively protected cardiac function by preserving intestinal barrier integrity caused by ventricular remodeling, at least partially through upregulating HIF-1α expression.

NLRP3 Inflammasome May Be a Biomarker for Risk Stratification in Patients with Acute Coronary Syndrome

Purpose

Acute coronary syndrome (ACS) has a high incidence and mortality rate worldwide, which has a considerable negative impact on the global economy. This study aimed to identify a group of ACS patients at a high risk of recurrent adverse cardiac events using the plasma NLRP3 inflammasome.

Patients and methods

ACS patients admitted to Liaocheng People's Hospital between June 2021 and March 2022 were enrolled in this study. Patients were divided into low (levels < 3.84 ng/mL) and high (levels ≥ 3.84 ng/mL) groups based on the median NLRP3 inflammasome levels. The patients were divided into three groups according to the Thrombolysis in Myocardial Infarction Risk Score for Secondary Prevention (TRS-2P): low (scores ≤ 2 points), intermediate (scores = 3 points), and high (score ≥ 4 points) risk. We investigated the relationship between NLRP3 inflammasome and laboratory indicators. Additionally, we examined whether the NLRP3 inflammasome was an independent predictor of high TRS-2P and explored the applicability of the plasma NLRP3 inflammasome for predicting high TRS-2P.

Results

Logistic regression analysis revealed that NLRP3 inflammasome was an independent predictor of high TRS-2P (odds ratio [OR]:2.013; 95% confidence interval [CI]: 1.174-3.452). The area under the receiver operating characteristic curve value of the NLRP3 inflammasome was 0.674 (95% CI: 0.611-0.737; P < 0.001).

Conclusion

NLRP3 inflammasome levels are an independent predictive factor for high TRS-2P levels, which indicates that the NLRP3 inflammasome may help predict the prognosis of ACS patients.

Pyroptosis is a drug target for prevention of adverse cardiac remodeling: The crosstalk between pyroptosis, apoptosis, and autophagy

Acute myocardial infarction (AMI) is one of the main reasons of cardiovascular disease-related death. The introduction of percutaneous coronary intervention to clinical practice dramatically decreased the mortality rate in AMI. Adverse cardiac remodeling is a serious problem in cardiology. An increase in the effectiveness of AMI treatment and prevention of adverse cardiac remodeling is difficult to achieve without understanding the mechanisms of reperfusion cardiac injury and cardiac remodeling. Inhibition of pyroptosis prevents the development of postinfarction and pressure overload-induced cardiac remodeling, and mitigates cardiomyopathy induced by diabetes and metabolic syndrome. Therefore, it is reasonable to hypothesize that the pyroptosis inhibitors may find a role in clinical practice for treatment of AMI and prevention of cardiac remodeling, diabetes and metabolic syndrome-triggered cardiomyopathy. It was demonstrated that pyroptosis interacts closely with apoptosis and autophagy. Pyroptosis could be inhibited by nucleotide-binding oligomerization domain-like receptor with a pyrin domain 3 inhibitors, caspase-1 inhibitors, microRNA, angiotensin-converting enzyme inhibitors, angiotensin Ⅱ receptor blockers, and traditional Chinese herbal medicines.

Serum Pharmacochemistry and Pharmacokinetics of Major Components after Oral Administration Luhong Recipe in Rats by Ultra Performance Liquid Chromatography-Tandem Mass Spectrometry

Luhong recipe (LHR) is an empirical prescription for the treatment of chronic heart failure for a long time, with safety, reliability and significant efficacy. However, its pharmacokinetics have not been studied. This study was to establish a UHPLC-MS/MS method for the simultaneous analysis of epimedin A, epimedin B, epimedin C, icariin, psoralen, isopsoralen in rat plasma, and apply it to the pharmacokinetic study of LHR after oral administration. These six analytes were ionized by electrospray positive ionization (ESI⁺ ). The MS/MS transitions used for monitoring is successively converted to m/z 839.3→369.1, m/z 809.2→369.1, m/z 823.3→369.1, m/z 677.2→205.2, m/z 187.1→115.2 and m/z 230→120.9. The linearity, precision, accuracy, stability, matrix effect and recovery of the established method were within the acceptable range. It was suitable for the determination of six analytes after oral administration LHR. The pharmacokinetic results showed the time to reach the peak concentration (T_max ) was 0.17-13.5h, the peak concentration (C_max ) was 109.23-980 ng/mL, the area under the concentration time curve (AUC_(0-t) ) was 65.48-8846.08 ng·h/mL, and the apparent distribution volume (Vd) was 24772-896132 mL/kg. These results provided a meaningful basis for formulating the clinical dose regimen of LHR.

LuQi Formula Ameliorates Myocardial Fibrosis by Suppressing TLR4/MyD88/NF-κB Pathway and NLRP3 Inflammasome Activation in Mice with Myocardial Infarction

Background

Myocardial fibrosis caused by myocardial infarction (MI) is the key factor leading to cardiac remodeling; nod-like receptor family pyrin domain-containing 3 (NLRP3) plays an important role in regulation of myocardial injury; however, its relationship with TLR4/MyD88/NF-κB signaling pathway is largely unreported. In recent years, traditional Chinese medicine (TCM) prevention and treatment of cardiovascular diseases has shown its unique advantages and broad application prospects. LuQi Formula (LQF) has been used for more than 20 years in Shuguang Hospital (Shanghai, China), and it was confirmed that it can improve the clinical symptoms of patients after MI. Here, we investigated the mechanism of LQF by suppressing NLRP3 inflammasome activation and TLR4/MyD88/NF-κB pathway in mice with MI.

Purpose

The purpose of this study was to verify the positive effects of the LQF in ameliorating myocardial fibrosis and inflammasome infiltration in the MI mice in vivo.

Methods

Forty mice were randomized into four groups: the sham group, the MI group, the LQF group, and the perindopril group (n = 10 per group). Left anterior descending (LAD) coronary artery ligation was performed in all groups except the sham group. The mice were treated with LQF after MI. After 4 weeks, LDH, cTnI, IL-1β, and IL-18 were measured by enzyme-linked immunosorbent assay (ELISA) kit, and cardiac function was evaluated by echocardiography. Hematoxylin and eosin (H&E) and Masson staining were used to evaluate the myocardial injury and fibrosis. Western blot was used to evaluate the expression of collagen I, α-SMA, NLRP3 inflammasome, and TLR4/MyD88/NF-κB signaling pathway. Immunohistochemical analysis was used to further detect the expression of Fibronectin, α-SMA, collagen I, collagen III, NLRP3, and NF-κB in myocardial tissue.

Results

Compared with the MI group, the ejection fraction (EF) and fractional shortening (FS) in the LQF group were significantly improved, while the left ventricular end diastolic diameter (LVEDd) and left ventricular internal dimension systole (LVIDs) were significantly decreased. The representative staining of H&E and Masson showed that treatment with LQF could effectively reduce myocardial injury and fibrosis. ELISA results showed that serum LDH, cTnI, TNF-α, IL-18, and IL-1β in LQF group were significantly lower than those in MI group. The western blot results showed that the expressions of collagen I and α-SMA were decreased significantly in the LQF group. Moreover, the expressions of NLRP3 inflammasome and TLR4/MyD88/NF-κB signaling pathway were downregulated in the LQF treatment group.

Conclusion

Our results suggested that LQF could significantly improve cardiac function and ameliorate myocardial fibrosis. In addition, we found that LQF could downregulate the TLR4/MyD88/NF-κB signaling pathway and then inhibit the activation of NLRP3 inflammasome, suggesting that LQF alleviated cardiac fibrosis by decreasing the TLR4/MyD88/NF-κB signaling pathway and then inhibited NLRP3 inflammasome activation in MI mice, which indicates potential therapeutic effect of LQF on patients with MI.

Network pharmacology for systematic understanding of Schisandrin B reduces the epithelial cells injury of colitis through regulating pyroptosis by AMPK/Nrf2/NLRP3 inflammasome

Ulcerative colitis (UC) is a chronic inflammatory disease with increasing incidence and prevalence in many countries. The purpose of this study is to explore the function of Schisandrin B and its underlying molecular mechanisms in colitis.

In this study, mice with colitis were induced by giving 2.0% dextran sulfate sodium (DSS, MP) in the drinking water for seven days. Furthermore, TCMSP server and GEO DataSets were used to analyze the mechanism of Schisandrin B in colitis.

It was found that Schisandrin B presented colitis in mice model. At the same time, Schisandrin B not only reduced inflammation in vivo and vitro model of colitis, but also suppressed the nucleotide-binding oligomerization domain, leucine-rich repeat and pyrin domain-containing 3 (NLRP3) inflammasome in vivo and vitro model of colitis. In addition, Schisandrin B induced AMP-activated protein kinase (AMPK) / Nuclear factor erythroid 2-related factor 2 (Nrf2) signaling pathway in model of colitis, and regulated AMPK protein at 316 sites. The inhibition of AMPK reduced the anti-inflammation effects of Schisandrin B on NLRP3 inflammasome. Apart from that, Schisandrin B decreased reactive oxygen species (ROS)-induced mitochondrial damage and reduced epithelial cells damage of colitis through regulating pyroptosis.

Collectively, our novel findings for first time showed that, Schisandrin B suppressed NLRP3 inflammasome activation-mediated interleukin-1beta (IL-1β) level and pyroptosis in intestinal epithelial cells of colitis model through the activation of AMPK/Nrf2 dependent signaling-ROS-induced mitochondrial damage, which may be a significant therapeutic approach in the treatment of acute colitis.