[Mechanisms of oxidative stress in myocardial ischemia-reperfusion injury and protective effects of traditional Chinese medicines].

Myocardial ischemia is a disease characterized by high morbidity and mortality rates, restoring blood supply to the ischemic area through reperfusion is an effective intervention method. However, numerous studies have shown that reperfusion may cause severe myocardial damage, resulting in myocardial systolic and diastolic dysfunction and seriously affecting myocardial function. This phenomenon is called myocardial ischemia reperfusion injury(MIRI). The physiological and pathological mechanisms of MIRI include oxidative stress, calcium overload, autophagy, pyrolysis, endoplasmic reticulum stress, apoptosis, etc. Oxidative stress plays an important role in MIRI-related cell death and is considered to be the main mechanism of MIRI. The occurrence of oxidative stress is mainly due to the excessive production of reactive oxygen species(ROS), which disrupts the balance of the redox system of the body or tissue. A large number of highly reactive ROS exceed the antioxidant defense capacity of cardiomyocytes, causing modifications in biological macromolecules such as DNA and proteins and resulting in severe reactions like DNA damage, protein dysfunction, cell damage or death, and local inflammation. Oxidative stress mediates apoptosis, autophagy, and inflammatory injury through various pathways, resulting in irreversible cardiomyocyte injury and myocardial dysfunction, which brings significant challenges for clinical treatment and prognosis. In recent years, remarkable progress has been made in understanding oxidative stress in ischemia reperfusion(I/R) injury of different organs and tissue. However, the injury mechanism caused by oxidative stress in restoring blood supply to the ischemic area and the protective effect of TCM remain largely unexplored. This article reviewed the role of oxidative stress in MIRI, the main production pathways of ROS, and the protective effects of TCM on oxidative stress injury during ischemic myocardial reperfusion, so as to provide a reference for future research and clinical treatment in this field.

Hydroxysafflor Yellow A Inhibits Pyroptosis and Protecting HUVECs from OGD/R via NLRP3/Caspase-1/GSDMD Pathway.

OBJECTIVE: To observe the protective effect and mechanism of hydroxyl safflower yellow A (HSYA) from myocardial ischemia-reperfusion injury on human umbilical vein endothelial cells (HUVECs). METHODS: HUVECs were treated with oxygen-glucose deprivation reperfusion (OGD/R) to simulate the ischemia reperfusion model, and cell counting kit-8 was used to detect the protective effect of different concentrations (1.25-160 µ mol/L) of HSYA on HUVECs after OGD/R. HSYA 80 µ mol/L was used for follow-up experiments. The contents of inflammatory cytokines interleukin (IL)-18, IL-1 ß, monocyte chemotactic protein 1 (MCP-1), tumor necrosis factor α (TNF-α) and IL-6 before and after administration were measured by enzyme-linked immunosorbent assay. The protein expressions of toll-like receptor, NOD-like receptor containing pyrin domain 3 (NLRP3), gasdermin D (GSDMD) and GSDMD-N-terminal domain (GSDMD-N) before and after administration were detected by Western blot. NLRP3 inflammasome inhibitor cytokine release inhibitory drug 3 sodium salt (CRID3 sodium salt, also known as MCC950) and agonist were added, and the changes of NLRP3, cysteine-aspartic acid protease 1 (Caspase-1), GSDMD and GSDMD-N protein expressions were detected by Western blot. RESULTS: HSYA inhibited OGD/R-induced inflammation and significantly decreased the contents of inflammatory cytokines IL-18, IL-1 ß, MCP-1, TNF-α and IL-6 (P<0.01 or P<0.05). At the same time, by inhibiting NLRP3/Caspase-1/GSDMD pathway, HSYA can reduce the occurrence of pyroptosis after OGD/R and reduce the expression of NLRP3, Caspase-1, GSDMD and GSDMD-N proteins (P<0.01). CONCLUSIONS: The protective effect of HSYA on HUVECs after OGD/R is related to down-regulating the expression of NLRP3 inflammasome and inhibiting pyroptosis.

Shuangshen ningxin formula attenuates cardiac microvascular ischemia/reperfusion injury through improving mitochondrial function.

ETHNOPHARMACOLOGICAL RELEVANCE: Shuangshen Ningxin Formula (SSNX) is a traditional Chinese medicine formula used to treat myocardial ischemia-reperfusion injury (MIRI). A randomized controlled trial previously showed that SSNX reduced cardiovascular events, and experiments have also verified that SSNX attenuated ischemia-reperfusion (I/R) injury. However, the mechanism of SSNX in the treatment of microvascular I/R injury is still unclear. AIM OF THE STUDY: To determine whether SSNX protects the microvasculature by regulating I/R induction in rats and whether this effect depends on the regulation of NR4A1/Mff/Drp1 pathway. METHODS: The anterior descending coronary artery was ligated to establish a rat MIRI model with 45 min of ischemia and 24 h of reperfusion. The rats were subjected to a 7-day pretreatment with SSNX and nicorandil, after which their cardiac function and microvascular functional morphology were evaluated through diverse methods, including hematoxylin and eosin (HE) staining, wheat germ agglutinin (WGA) staining, and transmission electron microscopy. Cell apoptosis was assessed using terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining. Additionally, serum levels of ET-1 and eNOS were determined through an enzyme-linked immunosorbent assay (ELISA). The expression levels of NR4A1, Mff, and proteins related to mitochondrial fission were examined by Western blot (WB). Cardiac microcirculation endothelial cells (CMECs) were cultured and the oxygen-glucose deprivation/reoxygenation (OGD/R) model was duplicated. Following treatment with SSNX and DIM-C-pPhOH, an NR4A1 inhibitor, cell viability was assessed. Fluorescence was used to evaluate mitochondrial membrane potential (MMP) and mitochondrial permeability transition pore (MPTP) opening. Moreover, vascular endothelial function was evaluated through transendothelial electrical resistance (TEER), Transwell assays and tube formation assays. RESULTS: The results showed that SSNX reduced the infarction area and no-flow area, improved cardiac function, mitigated pathological alterations, increased endothelial nitric oxide synthase expression, protected endothelial function, and attenuated microvascular damage after I/R injury. I/R triggered mitochondrial fission and apoptotic signaling in CMECs, while SSNX restored mitochondrial fission to normal levels and inhibited mitochondrial apoptosis. A study using CMECs revealed that SSNX protected endothelial function after OGD/R, attenuating the increase in NR4A1/Mff/Drp1 protein and inactivating VDAC1, HK2, cytochrome c (cyt-c) and caspase-9. Research also shows that SSNX can affect CMEC cell migration and angiogenesis, reduce mitochondrial membrane potential damage, and inhibit membrane opening. Moreover, DIM-C-pPhOH, an NR4A1 inhibitor, partially imitated the effect of SSNX. CONCLUSION: SSNX has a protective effect on the cardiac microvasculature by inhibiting the NR4A1/Mff/Drp1 pathway both in vivo and in vitro.

Electroactive properties of EABs in response to long-term exposure to polystyrene microplastics/nanoplastics and the underlying adaptive mechanisms.

Given widespread presence of polystyrene (PS) microplastics/nanoplastics (MPs/NPs), the electroactive responses and adaptation mechanisms of electroactive biofilms (EABs) exposed long-term to PS-containing aquatic environments remain unclear. Therefore, this study investigated the impacts of PS MPs/NPs on electroactivity of EABs. Results found that EABs exhibited delayed formation upon initially exposure but displayed an increased maximum current density (Imax) after subsequent exposure for up to 55 days. Notably, EABs exposure to NH2PS NPs (EAB-NH2PSNPs) demonstrated a 50% higher Imax than the control, along with a 17.84% increase in viability and a 58.10% increase in biomass. The cytochrome c (c-Cyts) content in EAB-NH2PSNPs rose by 178.35%, benefiting the extracellular electron transfer (EET) of EABs. Moreover, bacterial community assembly indicated the relative abundance of electroactive bacteria increased to 87.56% in EAB-NH2PSNPs. The adaptability mechanisms of EABs under prolonged exposure to PS MPs/NPs predominantly operate by adjusting viability, EET, and bacterial community assembly, which were further confirmed a positive correlation with Imax through structural equation model. These findings provide deeper insights into long-term effects and mechanisms of MPs/NPs on the electroactive properties of EABs and even functional microorganisms in aquatic ecosystems.

Investigation of the active ingredients of Shuangshen Ningxin Fomula and the mechanism underlying their protective effects against myocardial ischemia-reperfusion injury by mass spectrometric imaging.

BACKGROUND: Traditional Chinese medicine, particularly Shuangshen Ningxin Capsule (SSNX), has been studied intensely. SSNX includes total ginseng saponins (from Panax ginseng Meyer), total phenolic acids from Salvia miltiorrhiza Bunge, and total alkaloids from Corydalis yanhusuo W. T. Wang. It has been suggested to protect against myocardial ischemia by a mechanism that has not been fully elucidated. METHODS: The composition and content of SSNX were determined by UHPLC-Q-TOFQ-TOF / MS. Then, a rat model of myocardial ischemia-reperfusion injury was established, and the protective effect of SSNX was measured. The protective mechanism was investigated using spatial metabolomics. RESULTS: We found that SSNX significantly improved left ventricular function and ameliorated pathological damages in rats with myocardial ischemia-reperfusion injury. Using matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS), the protective mechanism of SSNX was examined by comparing the monomer components of drugs targeted in myocardial tissue with the distribution of myocardial energy metabolism-related molecules and phospholipids. Interestingly, some lipids display inconsistent content distribution in the myocardial ischemia risk and non-risk zones. These discrepancies reflect the degree of myocardial injury in different regions. CONCLUSION: These findings suggest that SSNX protects against myocardial ischemia-reperfusion injury by correcting abnormal myocardial energy metabolism, changing the levels and distribution patterns of phospholipids, and stabilizing the structure of the myocardial cell membrane. MALDI-TOF MS can detect the spatial distribution of small molecule metabolites in the myocardium and can be used in pharmacological research.

Nkx2.5: a crucial regulator of cardiac development, regeneration and diseases.

Cardiomyocytes fail to regenerate after birth and respond to mitotic signals through cellular hypertrophy rather than cellular proliferation. Necrotic cardiomyocytes in the infarcted ventricular tissue are eventually replaced by fibroblasts, generating scar tissue. Cardiomyocyte loss causes localized systolic dysfunction. Therefore, achieving the regeneration of cardiomyocytes is of great significance for cardiac function and development. Heart development is a complex biological process. An integral cardiac developmental network plays a decisive role in the regeneration of cardiomyocytes. During this process, genetic epigenetic factors, transcription factors, signaling pathways and small RNAs are involved in regulating the developmental process of the heart. Cardiomyocyte-specific genes largely promote myocardial regeneration, among which the Nkx2.5 transcription factor is one of the earliest markers of cardiac progenitor cells, and the loss or overexpression of Nkx2.5 affects cardiac development and is a promising candidate factor. Nkx2.5 affects the development and function of the heart through its multiple functional domains. However, until now, the specific mechanism of Nkx2.5 in cardiac development and regeneration is not been fully understood. Therefore, this article will review the molecular structure, function and interaction regulation of Nkx2.5 to provide a new direction for cardiac development and the treatment of heart regeneration.

Huoxin Pill Reduces Myocardial Ischemia Reperfusion Injury in Rats via TLR4/NFκB/NLRP3 Signaling Pathway.

OBJECTIVE: To explore the protective effect of Huoxin Pill (HXP) on acute myocardial ischemia-reperfusion (MIRI) injury in rats. METHODS: Seventy-five adult SD rats were divided into the sham-operated group, model group, positive drug group (diltiazem hydrochloride, DH), high dose group (24 mg/kg, HXP-H) and low dose group (12 mg/kg, HXP-L) of Huoxin Pill (n=15 for every group) according to the complete randomization method. After 1 week of intragastric administration, the left anterior descending coronary artery of the rat's heart was ligated for 45 min and reperfused for 3 h. Serum was separated and the levels of creatine kinase (CK), creatine kinase isoenzyme (CK-MB) and lactate dehydrogenase (LDH), superoxide dismutase (SOD), and malondialdehyde (MDA), hypersensitive C-reactive protein (hs-CRP) and interleukin-1ß (IL-1ß) were measured. Myocardial ischemia rate, myocardial infarction rate and myocardial no-reflow rate were determined by staining with Evans blue and 2,3,5-triphenyltetrazolium chloride (TTC). Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform (TCMSP) and Bioinformatics Analysis Tool for Molecular mechANism of Traditional Chinese Medicine (BATMAN) databases were used to screen for possible active compounds of HXP and their potential therapeutic targets; the results of anti-inflammatory genes associated with MIRI were obtained from GeneCards, Drugbank, Online Mendelian Inheritance in Man (OMIM), and Therapeutic Target Datebase (TTD) databases was performed; Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment were used to analyze the intersected targets; molecular docking was performed using AutoDock Tools. Western blot was used to detect the protein expression of Toll-like receptor 4 (TLR4)/nuclear factor kappa-B (NFκB)/NOD-like receptor protein 3 (NLRP3). RESULTS: Compared with the model group, all doses of HXP significantly reduced the levels of LDH, CK and CK-MB (P<0.05, P<0.01); HXP significantly increased serum activity of SOD (P<0.05, P<0.01); all doses of HXP significantly reduced the levels of hs-CRP and IL-1ß (P<0.05, P<0.01) and the myocardial infarction rate and myocardial no-reflow rate (P<0.01). GO enrichment analysis mainly involved positive regulation of gene expression, extracellular space and identical protein binding, KEGG pathway enrichment mainly involved PI3K-Akt signaling pathway and lipid and atherosclerosis. Molecular docking results showed that kaempferol and luteolin had a better affinity with TLR4, NFκB and NLRP3 molecules. The protein expressions of TLR4, NFκB and NLRP3 were reduced in the HXP group (P<0.01). CONCLUSIONS: HXP has a significant protective effect on myocardial ischemia-reperfusion injury in rats, and its effect may be related to the inhibition of redox response and reduction of the inflammatory response by inhibiting the TLR4NFκB/NLRP3 signaling pathway.

Mechanistic insights into the response of electroactive biofilms to Cd2+ shock: bacterial viability and electron transfer behavior at the cellular and community levels.

Electroactive biofilms (EABs) play a crucial role in environmental bioremediation due to their excellent extracellular electron transfer (EET) capabilities. However, Cd2+ can have toxic effects on the electrochemical performance of EABs, and the comprehensive inhibition mechanism of EABs in response to Cd2+ shock remains elusive. This study indicated that Cd2+ shock significantly reduced biomass and increased oxidative stress in EABs at the cellular level. The bacterial viability of EABs in phase III under 0.5 mM Cd2+ shock (EABCd2+-III0.5) decreased by 16.31% compared to EABCK-III. Moreover, intracellular NADH, c-Cyts, and the abundance of electroactive species were essential indicators to evaluate EET behavior of EABs. In EABCd2+-III0.5, these indicators decreased by 26.32%, 33.40%, and 20.65%, respectively. Structural equation modeling analysis established quantitative correlations between core components and electrochemical activity at cellular and community levels. The correlation analysis revealed that the growth and electron transfer functions of EABs were predictive indicators for their electrochemical performance, with standardized path coefficients of 0.407 and 0.358, respectively. These findings enhance our understanding of EABs' response to Cd2+ shock and provide insights for improving their performance in heavy metal wastewater.

Robot Motor Skill Transfer With Alternate Learning in Two Spaces.

Recent research achievements in learning from demonstration (LfD) illustrate that the reinforcement learning is effective for the robots to improve their movement skills. The current challenge mainly remains in how to generate new robot motions automatically to perform new tasks, which have a similar preassigned performance indicator but are different from the demonstration tasks. To deal with the abovementioned issue, this article proposes a framework to represent the policy and conduct imitation learning and optimization for robot intelligent trajectory planning, based on the improved locally weighted regression (iLWR) and policy improvement with path integral by dual perturbation (PI2-DP). Besides, the reward-guided weight searching and basis function's adaptive evolving are performed alternately in two spaces, i.e., the basis function space and the weight space, to deal with the abovementioned problem. The alternate learning process constructs a sequence of two-tuples that join the demonstration task and new one together for motor skill transfer, so that the robot gradually acquires motor skill, from the task similar to demonstration to dissimilar tasks with different performance metrics. Classical via-points trajectory planning experiments are performed with the SCARA manipulator, a 10-degree of freedom (DOF) planar, and the UR robot. These results show that the proposed method is not only feasible but also effective.

Effect of Preoperative Nutritional Risk Screening on Postoperative Recovery in Patients with Laparoscopic-Assisted Radical Resection for Colorectal Cancer.

RESULTS: There were statistically significant differences in BMI, albumin, total cholesterol, and lymphocyte count between patients from the two groups (all P < 0.05). There was no difference in the incidence rate of postoperative complications between the two groups, but there was a statistically significant difference in the total number of complications (P < 0.05). There were no significant differences between the two groups regarding abdominal drainage volume, exhaust (flatus) time, hospitalization cost, morbidity, or 60 d readmission rate (all P > 0.05). However, patients with nutritional risk had higher postoperative blood transfusion volumes, albumin infusions, weight difference before and after surgery, and postoperative hospital stays than the nonnutritional risk group (all P < 0.05). Smoking, diabetes, and preoperative nutritional risk were the risk factors by the univariate and multivariate logistic regression analyses. CONCLUSIONS: The postoperative complication rate was increased, and the short-term efficacy was decreased in the preoperative nutritional risk group compared with those without nutritional risk.

Leaf nitrogen assimilation and partitioning differ among subtropical forest plants in response to canopy addition of nitrogen treatments.

Global increases in nitrogen deposition may alter forest structure and function by interfering with plant nitrogen metabolism (e.g., assimilation and partitioning) and subsequent carbon assimilation, but it is unclear how these responses to nitrogen deposition differ among species. In this study, we conducted a 2-year experiment to investigate the effects of canopy addition of nitrogen (CAN) on leaf nitrogen assimilation and partitioning in three subtropical forest plants (Castanea henryi, Ardisia quinquegona, and Blastus cochinchinensis). We hypothesized that responses of leaf nitrogen assimilation and partitioning to CAN differ among subtropical forest plants. CAN increased leaf nitrate reductase (NR) activity, and leaf nitrogen and chlorophyll contents but reduced leaf maximum photosynthetic rate (Amax), photosynthetic nitrogen use efficiency (PNUE), ribulose-1,5-bisphosphate carboxylase (Rubisco) activity, and metabolic protein content of an overstory tree species C. henryi. In an understory tree A. quinquegona, CAN increased NR activity and glutamine synthetase activity and therefore increased metabolic protein synthesis (e.g., Rubisco) in leaves. In the shrub B. cochinchinensis, CAN increased Amax, PNUE, Rubisco content, metabolic protein content, and Rubisco activity in leaves. Leaf nitrogen assimilation and partitioning results indicated that A. quinquegona and B. cochinchinensis may better acclimate to CAN than C. henryi and that the acclimation mechanism differs among the species. Results from this study suggest that long-term elevated atmospheric nitrogen deposition has contributed to the ongoing transformation of subtropical forests into communities dominated by small trees and shrubs.

Pollutant-induced cell death and reactive oxygen species accumulation in the aerial roots of Chinese banyan (Ficus microcarpa).

Industrial pollutants induce the production of toxic reactive oxygen species (ROS) such as O2.-, H2O2, and ·OH in plants, but they have not been well quantified or localized in tissues and cells. This study evaluated the pollutant- (HSO3-, NH4NO3, Al3+, Zn2+, and Fe2+) induced toxic effects of ROS on the aerial roots of Chinese banyan (Ficus microcarpa). Root cell viability was greatly reduced by treatment with 20 mM NaHSO3, 20 mM NH4NO3, 0.2 mM AlCl3, 0.2 mM ZnSO4, or 0.2 mM FeSO4. Biochemical assay and histochemical localization showed that O2.- accumulated in roots in response to pollutants, except that the staining of O2.- under NaHSO3 treatment was not detective. Cytochemical localization further indicated that the generated O2.- was present mainly in the root cortex, and pith cells, especially in NH4NO3- and FeSO4-treated roots. The pollutants also caused greatly accumulated H2O2 and ·OH in aerial roots, which finally resulted in lipid peroxidation as indicated by increased malondialdehyde contents. We conclude that the F. microcarpa aerial roots are sensitive to pollutant-induced ROS and that the histochemical localization of O2.- via nitrotetrazolium blue chloride staining is not effective for detecting the effects of HSO3- treatment because of the treatment's bleaching effect.