L-Cystathionine Protects against Homocysteine-Induced Mitochondria-Dependent Apoptosis of Vascular Endothelial Cells

Apoptotic mechanism of development inhibition in zebrafish induced by esketamine

Esketamine, a widely used intravenous general anesthetic, is also employed for obstetric and pediatric anesthesia, and depression treatment. However, concerns regarding esketamine abuse have emerged. Moreover, the potential in vivo toxicity of esketamine on growth and development remains unclear. To address these concerns, we investigated the effects of esketamine exposure on developmental parameters, cell apoptosis, and gene expression in zebrafish. Esketamine exposure concentration-dependently decreased the heart rate and body length of zebrafish embryos/larvae while increasing the hatching rate and spontaneous movement frequency. Developmental retardation of zebrafish larvae, including shallow pigmentation, small eyes, and delayed yolk sac absorption, was also observed following esketamine treatment. Esketamine exposure altered the expression of apoptosis-related genes in zebrafish heads, primarily downregulating bax, caspase9, caspase3, caspase6, and caspase7. Intriguingly, BTSA1, a Bax agonist, reversed the anti-apoptotic and decelerated body growth effects of esketamine in zebrafish. Collectively, our findings suggest that esketamine may hinder embryonic development by inhibiting embryonic apoptosis via the Bax/Caspase9/Caspase3 pathway. To the best of our knowledge, this is the first study to report the lethal toxicity of esketamine in zebrafish. We have elucidated the developmental toxic effects of esketamine on zebrafish larvae and its potential apoptotic mechanisms. Further studies are warranted to evaluate the safety of esketamine in animals and humans.

Surgical outcomes following encephaloduroarteriosynangiosis in moyamoya disease associated with hyperhomocysteinemia

INTRODUCTION

This study investigated the effect of indirect revascularization surgery in adult patients with moyamoya disease (MMD) complicated with hyperhomocysteinemia (HHcy), and the effect of HHcy on the progression of adult MMD.

METHODS

A retrospective case-control study was conducted in patients with MMD, with or without HHcy (n = 123). Postoperative collateral angiogenesis was evaluated using the Matsushima grading system and disease progression using the Suzuki staging system. Cerebral blood flow was evaluated before and after surgery using dynamic susceptibility contrast magnetic resonance imaging (DSC-MRI) and neurological function prognosis using the improved Rankin score (mRS). Univariate and multivariate logistic regression analyses were performed to determine risk factors for the clinical outcomes.

RESULTS

There was no significant difference in the Suzuki stage composition ratios between the HHcy group and the non-HHcy group before and after surgery. Non-HHcy patients were more likely to grow new collateral circulating vessels after encephaloduroarteriosynangiosis (EDAS). Moreover, postoperative DSC-MRI indicated that the time to peak significantly improved.

CONCLUSIONS

HHcy level may be a specific predictor of adverse clinical outcomes after EDAS in patients with MMD and a risk factor for poor collateral circulation and poor prognosis. Patients with MMD complicated with HHcy need to strictly control homocysteine levels before EDAS surgery.

China stroke surveillance report 2021

Since 2015, stroke has become the leading cause of death and disability in China, posing a significant threat to the health of its citizens as a major chronic non-communicable disease. According to the China Stroke High-risk Population Screening and Intervention Program, an estimated 17.8 million [95% confidence interval (CI) 17.6-18.0 million] adults in China had experienced a stroke in 2020, with 3.4 million (95% CI 3.3-3.5 million) experiencing their first-ever stroke and another 2.3 million (95% CI 2.2-2.4 million) dying as a result. Additionally, approximately 12.5% (95% CI 12.4-12.5%) of stroke survivors were left disabled, as defined by a modified Rankin Scale score greater than 1, equating to 2.2 million (95% CI 2.1-2.2 million) stroke-related disabilities in 2020. As the population ages and the prevalence of risk factors like diabetes, hypertension, and hyperlipidemia continues to rise and remains poorly controlled, the burden of stroke in China is also increasing. A large national epidemiological survey initiated by the China Hypertension League in 2017 showed that the prevalence of hypertension was 24.7%; the awareness, treatment, and control rates in hypertensive patients were: 60.1%, 42.5%, and 25.4%, respectively. A nationally representative sample of the Chinese mainland population showed that the weighted prevalence of total diabetes diagnosed by the American Diabetes Association criteria was 12.8%, suggesting there are 120 million adults with diabetes in China, and the awareness, treatment, and control rates in diabetic patients were: 43.3%, 49.0%, and 49.4%, respectively. The "Sixth National Health Service Statistical Survey Report in 2018" showed that the proportion of the obese population in China was 37.4%, an increase of 7.2 points from 2013. Data from 1599 hospitals in the Hospital Quality Monitoring System and Bigdata Observatory Platform for Stroke of China (BOSC) showed that a total of 3,418,432 stroke cases [mean age ± standard error (SE) was (65.700 ± 0.006) years, and 59.1% were male] were admitted during 2020. Of those, over 80% (81.9%) were ischemic stroke (IS), 14.9% were intracerebral hemorrhage (ICH) strokes, and 3.1% were subarachnoid hemorrhage (SAH) strokes. The mean ± SE of hospitalization expenditures was Chinese Yuan (CNY) (16,975.6 ± 16.3), ranging from (13,310.1 ± 12.8) in IS to (81,369.8 ± 260.7) in SAH, and out-of-pocket expenses were (5788.9 ± 8.6), ranging from (4449.0 ± 6.6) in IS to (30,778.2 ± 156.8) in SAH. It was estimated that the medical cost of hospitalization for stroke in 2020 was CNY 58.0 billion, of which the patient pays approximately CNY 19.8 billion. In-hospital death/discharge against medical advice rate was 9.2% (95% CI 9.2-9.2%), ranging from 6.4% (95% CI 6.4-6.5%) for IS to 21.8% for ICH (95% CI 21.8-21.9%). From 2019 to 2020, the information about 188,648 patients with acute IS receiving intravenous thrombolytic therapy (IVT), 49,845 patients receiving mechanical thrombectomy (MT), and 14,087 patients receiving bridging (IVT + MT) were collected through BOSC. The incidence of intracranial hemorrhage during treatment was 3.2% (95% CI 3.2-3.3%), 7.7% (95% CI 7.5-8.0%), and 12.9% (95% CI 12.3-13.4%), respectively. And in-hospital death/discharge against medical advice rate was 8.9% (95% CI 8.8-9.0%), 16.5% (95% CI 16.2-16.9%), and 16.8% (95% CI 16.2-17.4%), respectively. A prospective nationwide hospital-based study was conducted at 231 stroke base hospitals (Level III) from 31 provinces in China through BOSC from January 2019 to December 2020 and 136,282 stroke patients were included and finished 12-month follow-up. Of those, over 86.9% were IS, 10.8% were ICH strokes, and 2.3% were SAH strokes. The disability rate [% (95% CI)] in survivors of stroke at 3-month and 12-month was 14.8% (95% CI 14.6-15.0%) and 14.0% (95% CI 13.8-14.2%), respectively. The mortality rate [% (95% CI)] of stroke at 3-month and 12-month was 4.2% (95% CI 4.1-4.3%) and 8.5% (95% CI 8.4-8.6%), respectively. The recurrence rate [% (95% CI)] of stroke at 3-month and 12-month was 3.6% (95% CI 3.5-3.7%) and 5.6% (95% CI 5.4-5.7%), respectively. The Healthy China 2030 Stroke Action Plan was launched as part of this review, and the above data provide valuable guidelines for future stroke prevention and treatment efforts in China.

Mechanism of homocysteine-mediated endothelial injury and its consequences for atherosclerosis

Homocysteine (Hcy) is an intermediate amino acid formed during the conversion from methionine to cysteine. When the fasting plasma Hcy level is higher than 15 μmol/L, it is considered as hyperhomocysteinemia (HHcy). The vascular endothelium is an important barrier to vascular homeostasis, and its impairment is the initiation of atherosclerosis (AS). HHcy is an important risk factor for AS, which can promote the development of AS and the occurrence of cardiovascular events, and Hcy damage to the endothelium is considered to play a very important role. However, the mechanism by which Hcy damages the endothelium is still not fully understood. This review summarizes the mechanism of Hcy-induced endothelial injury and the treatment methods to alleviate the Hcy induced endothelial dysfunction, in order to provide new thoughts for the diagnosis and treatment of Hcy-induced endothelial injury and subsequent AS-related diseases.

Natural Astaxanthin Improves Testosterone Synthesis and Sperm Mitochondrial Function in Aging Roosters

Spermatogenesis, sperm motility, and apoptosis are dependent on the regulation of glandular hormones and mitochondria. Natural astaxanthin (ASTA) has antioxidant, anti-inflammatory, and anti-apoptotic properties. The present study evaluates the effects of ASTA on testosterone synthesis and mitochondrial function in aging roosters. Jinghong No. 1 layer breeder roosters (n = 96, 53-week old) were fed a corn−soybean meal basal diet containing 0, 25, 50, or 100 mg/kg ASTA for 6 weeks. The levels of plasma reproductive hormones and the mRNA and protein levels of molecules related to testosterone synthesis were significantly improved (p < 0.05) in the testes of the ASTA group roosters. In addition, antioxidant activities and free radical scavenging abilities in roosters of the ASTA groups were higher than those of the control group (p < 0.05). Mitochondrial electron transport chain complexes activities and mitochondrial membrane potential in sperm increased linearly with dietary ASTA supplementation (p < 0.05). The levels of reactive oxygen species and apoptosis factors decreased in roosters of the ASTA groups (p < 0.05). Collectively, these results suggest that dietary ASTA may improve testosterone levels and reduce sperm apoptosis, which may be related to the upregulation of the testosterone synthesis pathway and the enhancement of mitochondrial function in aging roosters.

Hyperhomocysteinemia Is a Predictor for Poor Postoperative Angiogenesis in Adult Patients With Moyamoya Disease

Background and Purposes

The risk factors of poor postoperative angiogenesis in moyamoya disease (MMD) patients remain unknown. We aimed to investigate the association between hyperhomocysteinemia (HHcy) and postoperative angiogenesis of adult patients with MMD.

Methods

A total of 138 adult patients with MMD were prospectively recruited from July 1 to December 31, 2019. After excluding 10 patients accepting conservative therapy and 77 individuals without postoperative digital subtraction angiography (DSA), all 51 MMD patients were enrolled, and 28 patients received bilateral operations separately. Patients were grouped according to postoperative angiogenesis and HHcy presentation, respectively. Clinical data and laboratory examinations were compared. Potential risk factors were evaluated by univariate and multivariate logistic regression analysis. Nomogram was further performed. The biological functions of homocysteine (Hcy) were explored in vitro.

Results

Comparing to the normal, patients with poor postoperative angiogenesis were higher in serum Hcy (p = 0.004), HHcy ratio (p = 0.011), creatinine (Cr) (p < 0.001), uric acid (UA) (p = 0.036), Triglyceride (p = 0.001), high-density lipoprotein cholesterol (HDL-C) (p = 0.001), low-density lipoprotein cholesterol (LDL-C) (p = 0.009), ApoA (p = 0.022), apolipoprotein B (ApoB) (p = 0.013). Furthermore, HHcy was more common in men (p = 0.003) than women. Logistic analysis results showed that Hcy (OR = 0.817, 95% CI = 0.707–0.944, p = 0.006) was an independent risk factor. HHcy and Cr were significantly associated with poor postoperative angiogenesis in MMD patients. Further, Hcy could inhibit the proliferation, migration, and tube formation of human brain microvascular endothelial cells (HBMECs), which can be reversed by vascular endothelial growth factor (VEGF).

Conclusion

The HHcy was significantly correlated with poor postoperative angiogenesis in adult patients with MMD. Hcy significantly inhibits HBMECs proliferation, migration, and tube formation. Furthermore, VEGF could reverse the inhibition effect induced by Hcy. Lowering the level of Hcy may be beneficial for postoperative MMD patients. Focusing on the pathophysiology and mechanism of HHcy might help to guide postoperative clinical management.

Endogenous Hydrogen Sulfide Persulfidates Caspase-3 at Cysteine 163 to Inhibit Doxorubicin-Induced Cardiomyocyte Apoptosis

Doxorubicin (DOX) is an efficient antitumor anthracycline drug, but its cardiotoxicity adversely affects the prognosis of the patients. In this study, we explored whether endogenous gasotransmitter hydrogen sulfide (H₂S) could protect against DOX-induced cardiomyocyte apoptosis and its mechanisms. The results indicated that DOX significantly downregulated endogenous H₂S production and endogenous synthetase cystathionine γ-lyase (CSE) expression and obviously stimulated the apoptosis in H9C2 cells. The supplement of H₂S donor sodium hydrosulfide (NaHS) or overexpression of CSE inhibited DOX-induced H9C2 cell apoptosis. DOX enhanced the activities of caspase family members in cardiomyocytes, while NaHS attenuated DOX-enhanced caspase-3, caspase-2, and caspase-9 activities by 223.1%, 73.94%, and 52.29%, respectively. Therefore, taking caspase-3 as a main target, we demonstrated that NaHS or CSE overexpression alleviated the cleavage of caspase-3, suppressed caspase-3 activity, and inhibited the cleavage of poly ADP-ribose polymerase (PARP). Mechanistically, we found that H₂S persulfidated caspase-3 in H9C2 cells and human recombinant caspase-3 protein, while the thiol-reducing agent dithiothreitol (DTT) abolished H₂S-induced persulfidation of caspase-3 and thereby prevented the antiapoptotic effect of H₂S on caspase-3 in H9C2 cells. The mutation of caspase-3 C148S and C170S failed to block caspase-3 persulfidation by H₂S in H9C2 cells. However, caspase-3 C163S mutation successfully abolished the effect of H₂S on caspase-3 persulfidation and the corresponding protection of H9C2 cells. Collectively, these findings indicate that endogenous H₂S persulfidates caspase-3 at cysteine 163, inhibiting its activity and cardiomyocyte apoptosis. Sufficient endogenous H₂S might be necessary for the protection against myocardial cell apoptosis induced by DOX. The results of the study might open new avenues with respect to the therapy of DOX-stimulated cardiomyopathy.

Cell surface nucleolin is a novel ADAMTS5 receptor mediating endothelial cell apoptosis

A Disintegrin and Metalloproteinase with ThromboSpondin motif (ADAMTS) 5 functions as an anti-angiogenic and anti-cancer protein independent of its metalloproteinase activity. Both full-length ADAMTS5 and TS5-p45, the autocatalytically cleaved C-terminal 45 kDa truncate of ADAMTS5, inhibits angiogenesis, and induces endothelial cell (EC) apoptosis. However, how ADAMTS5 triggers EC apoptosis remains unclear. This work shows that caspase-8 (Cas-8) and caspase-9 (Cas-9) are involved in TS5-p45-induced EC apoptosis. We identify cell surface nucleolin (NCL) as a novel high-affinity receptor for TS5-p45 in ECs, mediating TS5-p45's cell surface binding and pro-apoptotic function. We show that the central RNA-binding domain (RBD) of NCL is essential and sufficient for its binding to TS5-p45. Upon interacting with EC surface NCL, TS5-p45 is internalized through clathrin- and caveolin-dependent endocytosis and trafficked to the nucleus via late endosomes (LEs). We demonstrate that the nuclear trafficking of TS5-p45 is important for its pro-apoptotic activity as disruption of LE membrane integrity with an endosomolytic peptide suppressed both nuclear trafficking and pro-apoptotic activity of TS5-p45. Through cell surface biotinylation, we revealed that cell surface NCL shuttles extracellular TS5-p45 to the nucleus to mediate apoptosis. Furthermore, blocking the importin α1/ß1 receptor hindered the nuclear trafficking of TS5-p45, suggesting the involvement of the nuclear importing machinery for this nuclear translocation. RNA-seq identified many apoptosis-related genes that are differentially expressed at least two-fold in TS5-p45-treated ECs, with 10 of them qRT-PCR-validated and at least 5 of these genes potentially contributing to TS5-p45-NCL-induced apoptosis. Altogether, our work identifies NCL as a novel cell surface receptor for ADAMTS5 and demonstrates the critical role of NCL-mediated internalization and nuclear trafficking for ADAMTS5-induced EC apoptosis. These findings reveal novel mechanistic insights of the secreted metalloproteinase ADAMTS5 in angiogenesis inhibition.

Sulphenylation of CypD at Cysteine 104: A Novel Mechanism by Which SO2 Inhibits Cardiomyocyte Apoptosis

Objectives: The study was designed to explore the role of endogenous gaseous signaling molecule sulfur dioxide (SO2) in the control of cardiomyocyte apoptosis and its molecular mechanisms.

Methods: Neonatal mouse cardiac myocytes (NMCMs) and H9c2 cells were used in the cell experiments. The endogenous SO2 pathway including SO2 level and the expression of SO2-generating enzyme aspartate aminotransferase 1/2 (AAT1/2) were detected in NMCMs. The apoptosis of cardiomyocytes was examined by a TUNEL assay. The cleavage and the activity of apoptotic proteins caspase9 and caspase3 were measured. The content of ATP, the opening of mitochondrial permeability transition pore (mPTP), and the cytochrome c (cytc) leakage were detected by immunofluorescence. The sulphenylation of cyclophilin-D (CypD) was detected by biotin switch analysis. The four CypD mutant plasmids in which cysteine sites were mutated to serine were constructed to identify the SO2-affected site in vitro.

Results: ISO down-regulated the endogenous SO2/AAT pathway of cardiomyocytes in association with a significant increase in cardiomyocyte apoptosis, demonstrated by the increases in apoptosis, cleaved-caspase3/caspase3 ratio, and caspase3 activity. Furthermore, ISO significantly reduced ATP production in H9c2 cells, but the supplement of SO2 significantly restored the content of ATP. ISO stimulated mPTP opening, resulting in an increase in the release of cytc, which further increased the ratio of cleaved caspase9/caspase9 and enhanced the protein activity of caspase9. While, the supplementation of SO2 reversed the above effects. Mechanistically, SO2 did not affect CypD protein expression, but sulphenylated CypD and inhibited mPTP opening, resulting in an inhibition of cardiomyocyte apoptosis. The C104S mutation in CypD abolished SO2-induced sulphenylation of CypD, and thereby blocked the inhibitory effect of SO2 on the mPTP opening and cardiomyocyte apoptosis.

Conclusion: Endogenous SO2 sulphenylated CypD at Cys104 to inhibit mPTP opening, and thus protected against cardiomyocyte apoptosis.

Mitochondrial Dynamics: Pathogenesis and Therapeutic Targets of Vascular Diseases

Vascular diseases, particularly atherosclerosis, are associated with high morbidity and mortality. Endothelial cell (EC) or vascular smooth muscle cell (VSMC) dysfunction leads to blood vessel abnormalities, which cause a series of vascular diseases. The mitochondria are the core sites of cell energy metabolism and function in blood vessel development and vascular disease pathogenesis. Mitochondrial dynamics, including fusion and fission, affect a variety of physiological or pathological processes. Multiple studies have confirmed the influence of mitochondrial dynamics on vascular diseases. This review discusses the regulatory mechanisms of mitochondrial dynamics, the key proteins that mediate mitochondrial fusion and fission, and their potential effects on ECs and VSMCs. We demonstrated the possibility of mitochondrial dynamics as a potential target for the treatment of vascular diseases.

Detoxification, Hydrogen Sulphide Metabolism and Wound Healing Are the Main Functions That Differentiate Caecum Protein Expression from Ileum of Week-Old Chicken

Simple Summary

Although the ileum and caecum represent adjacent parts of the gastrointestinal tract, both compartments differ by function as well as inner environment parameters such as oxygen availability or density of colonising microbiota. As the function of a particular tissue is generally reflected by protein expression, mass spectrometry proteomics was used to characterise expressed proteins of both segments of the gastrointestinal tract. Differentially expressed proteins were identified and grouped according to biological processes specific to both gut compartments.

Abstract

Sections of chicken gut differ in many aspects, e.g., the passage of digesta (continuous vs. discontinuous), the concentration of oxygen, and the density of colonising microbiota. Using an unbiased LC-MS/MS protocol, we compared protein expression in 18 ileal and 57 caecal tissue samples that originated from 7-day old ISA brown chickens. We found that proteins specific to the ileum were either structural (e.g., 3 actin isoforms, villin, or myosin 1A), or those required for nutrient digestion (e.g., sucrose isomaltase, maltase–glucoamylase, peptidase D) and absorption (e.g., fatty acid-binding protein 2 and 6 or bile acid–CoA:amino acid N-acyltransferase). On the other hand, proteins characteristic of the caecum were involved in sensing and limiting the consequences of oxidative stress (e.g., thioredoxin, peroxiredoxin 6), cell adhesion, and motility associated with wound healing (e.g., fibronectin 1, desmoyokin). These mechanisms are coupled with the activation of mechanisms suppressing the inflammatory response (galectin 1). Rather prominent were also expressions of proteins linked to hydrogen sulphide metabolism in caecum represented by cystathionin beta synthase, selenium-binding protein 1, mercaptopyruvate sulphurtransferase, and thiosulphate sulphurtransferase. Higher mRNA expression of nuclear factor, erythroid 2-like 2, the main oxidative stress transcriptional factor in caecum, further supported our observations.

DNAJA1 Dysregulates Metabolism Promoting an Antiapoptotic Phenotype in Pancreatic Ductal Adenocarcinoma

The cochaperone protein DNAJA1 (HSP40) is downregulated four-fold in pancreatic cancer cells. The impact of DNAJA1 expression on pancreatic ductal adenocarcinoma (PDAC) progression remains unclear. The metabolic impacts of increased DNAJA1 expression were evaluated using a combination of untargeted metabolomics, stable isotope-resolved metabolomics (SIRM), confocal microscopy, flow cytometry, and cell-based assays. Differential Warburg glycolysis, an increase in redox currency, and alterations in amino acid levels were observed in both overexpression cell lines. DNAJA1 overexpression also led to mitochondrial fusion, an increase in the expression of Bcl-2, a modest protection from redox-induced cell death, a loss of structural integrity due to the loss of actin fibers, and an increase in cell invasiveness in BxPC-3. These differences were more pronounced in BxPC-3, which contains a loss-of-function mutation in the tumor-suppressing gene SMAD4. These findings suggest a proto-oncogenic role of DNAJA1 in PDAC progression and suggest DNAJA1 may function synergistically with other proteins with altered activities in pancreatic cancer cell lines.

The Efficacy of Pilates on Urinary Incontinence in Korean Women: A Metabolomics Approach

Pilates has been known as exercise intervention that improves the function of pelvic floor muscle (PFM) associated with impacting urinary incontinence (UI). This study investigated the effect of Pilates on UI in Korean women by determining the change in functional movement of PFM (FMP) and metabolic profiles. UI group with Pilates (UIP, n = 13) participated in 8-weeks Oov Pilates program, and 8 subjects were assigned to Control and UI group with no Pilates (UINP), respectively. Before and after 8 weeks, plasma samples were collected from all participants, and ultrasonography was used to measure the functional change of PFM for calculating FMP ratio. Plasma samples were analyzed by mass spectrometry to identify the change of metabolic features. After 8-weeks intervention, FMP ratio was remarkably decreased in UIP (48.1% ↓, p < 0.001), but not in Control and UINP (p > 0.05). In metabolic features, L-Glutamine (m/z: 147.07 [M + H]⁺), L-Cystathionine (m/z: 240.09 [M + NH₄]⁺), L-Arginine (m/z: 197.1 [M + Na]⁺), and L-1-Pyrroline-3-hydroxy-5-carboxylate (m/z: 147.07 [M + NH₄]⁺) were significantly elevated solely in UIP (p < 0.001). Our study elucidated that Pilates can ameliorate the FMP and enhance the specific metabolic characteristics, which was potentially associated with invigorated PFM contractility to effectively control the bladder base and continence.

Exposure to mono (2-ethylhexyl) phthalate facilitates apoptosis and pyroptosis of human endometrial microvascular endothelial cells through NLRP3 inflammasome

Mono (2-ethylhexyl) phthalate (MEHP) is a major metabolite of di (2-ethylhexyl) phthalate (DEHP). This study aimed to observe the toxic effect of MEHP on human endometrial microvascular endothelial cells (HEMECs) and its potential molecular mechanism. HEMECs were exposed to different concentrations of MEHP (0, 50, 100, and 200 nM). Cell viability and apoptosis were assessed by cell counting kit-8 (CCK-8) and flow cytometry assays. Western blot was performed to examine the expression of apoptosis-related proteins (Bcl-2, Bax, and Caspase-3). Moreover, the expression of pyroptosis-related Caspase-1 was detected by western blot and immunofluorescence assays. Lactate dehydrogenase (LDH) release levels were evaluated in HEMECs treated with MEHP and/or Caspase-1 inhibitor Ac-YVAD-CHO. After exposure to MEHP, NLRP3 expression was examined by reverse transcription quantitative polymerase chain reaction (RT-qPCR) and western blot. LDH release and apoptosis levels were tested in HEMECs induced by MEHP and/or siNLRP3. MEHP significantly induced cell viability and inhibited apoptosis for HEMECs, with a concentration-dependent manner. Furthermore, Bcl-2/Bax ratio was distinctly reduced and Caspase-3 expression was increased in HEMECs after exposure to MEHP. Western blot and immunofluorescence results confirmed that MEHP markedly augmented Caspase-1 expression in HEMECs. Furthermore, LDH release levels were fortified in HEMECs treated with MEHP, which were improved following cotreatment with Ac-YVAD-CHO. At the mRNA and protein levels, NLRP3 expression was prominently increased in HEMECs exposed to MEHP. NLRP3 knockdown markedly ameliorated the increase in LDH release and apoptosis induced by MEHP exposure in HEMECs. Our findings suggested that exposure to MEHP facilitates apoptosis and pyroptosis of HEMECs through NLRP3 inflammasome.

Homocysteine and Mitochondria in Cardiovascular and Cerebrovascular Systems

Elevated concentration of homocysteine (Hcy) in the blood plasma, hyperhomocysteinemia (HHcy), has been implicated in various disorders, including cardiovascular and neurodegenerative diseases. Accumulating evidence indicates that pathophysiology of these diseases is linked with mitochondrial dysfunction. In this review, we discuss the current knowledge concerning the effects of HHcy on mitochondrial homeostasis, including energy metabolism, mitochondrial apoptotic pathway, and mitochondrial dynamics. The recent studies suggest that the interaction between Hcy and mitochondria is complex, and reactive oxygen species (ROS) are possible mediators of Hcy effects. We focus on mechanisms contributing to HHcy-associated oxidative stress, such as sources of ROS generation and alterations in antioxidant defense resulting from altered gene expression and post-translational modifications of proteins. Moreover, we discuss some recent findings suggesting that HHcy may have beneficial effects on mitochondrial ROS homeostasis and antioxidant defense. A better understanding of complex mechanisms through which Hcy affects mitochondrial functions could contribute to the development of more specific therapeutic strategies targeted at HHcy-associated disorders.