Dendrobine regulates STAT3 to attenuate mitochondrial dysfunction and senescence in vascular endothelial cells triggered by oxidized low-density lipoprotein.

Our previous studies have highlighted the potential therapeutic efficacy of dendrobine, an alkaloid, in atherosclerosis (AS), nevertheless, the underlying mechanism remains unclear. This study employs a combination of network pharmacology and in vitro experiments to explore the regulatory pathways involved. Through network pharmacology, the biological function for intersection targets between dendrobine and AS were identified. Molecular docking was conducted to investigate the interaction between the dominant target and dendrobine. Human umbilical vein endothelial cells (HUVECs) were treated with oxidized low-density lipoprotein (ox-LDL) to mimic AS, and the effects of dendrobine on cell viability, lipid deposition, mitochondrial function, and cellular senescence were evaluated. Subsequently, cells were treated with the mitophagy inhibitor Mdivi-1 and the STAT3 agonist colivelin to assess the role of mitophagy and STAT3 signaling in dendrobine regulation. Intersection targets were associated with biological processes, including reactive oxygen species production. Dendrobine attenuated the effects of ox-LDL treatment on HUVECs, mitigating changes in cell activity, lipid deposition, mitochondrial function, and cellular senescence. Both Mdivi-1 and colivelin treatments resulted in decreased cell viability and increased cellular senescence, with colivelin suppressing mitophagy. Cotreatment with Mdivi-1 and colivelin further aggravated cellular senescence and inhibited FoxO signaling. Together, this study indicated that dendrobine regulated the STAT3/FoxO signaling pathway, alleviating mitochondrial dysfunction and cellular senescence. This study contributes valuable insights to the potential clinical application of dendrobine.

Coptisine prevents angiotensin II­induced endothelial cell injury and senescence via the lncRNA SNHG12/miR­603/NAMPT pathway.

Atherosclerosis (AS) is a major health problem and targeting the associated molecular pathways is critical for developing therapies. The present study investigated the effect of coptisine on human umbilical vein endothelial cells (HUVECs) in response to angiotensin II (Ang II) induction by focusing on cellular senescence, apoptosis and inflammation. HUVECs were treated with different Ang II concentrations and long non-coding RNA small nucleolar RNA host gene 12 (SNHG12), microRNA (miRNA/miR)-603 and nicotinamide phosphoribosyltransferase (NAMPT) expressions were assessed. Cell viability, nicotinamide adenine dinucleotide (NAD+) levels, senescence, apoptosis and inflammation were assessed. The interactions among SNHG12, miR-603 and NAMPT were investigated using dual-luciferase reporter gene assays and RNA pull-down experiments. Coptisine treatment increased SNHG12 expression and attenuated Ang II-induced adverse effects in HUVECs. SNHG12 silencing abrogated coptisine's protective effects, indicating that SNHG12 is a key mediator. SNHG12 targets miR-603, which then directly targets NAMPT, an age-related gene involved in NAD(+) regulation. Coptisine modulated the SNHG12/miR-603/NAMPT pathway and miR-603 inhibition enhanced the protective effects of coptisine. NAMPT overexpression reversed the negative effects of miR-603 and enhanced the protective effect of the miR-603 inhibitor. Finally, the protective mechanism of coptisine is linked to the regulation of NAD(+), sirtuin 3 (SIRT3) and p53. Coptisine treatment counteracted the AngII-induced increase in SIRT3 and p53 protein levels, whereas the miR-603 inhibitor potentiated the effect of coptisine. SNHG12 knockdown partially abolished these effects, which were reversed by NAMPT overexpression. In conclusion, the present study revealed a novel protective mechanism involving the SNHG12/miR-603/NAMPT pathway in HUVECs exposed to Ang II, highlighting the potential therapeutic application of coptisine in treating atherosclerosis. These results suggested that coptisine exerts its protective effects by modulating the SNHG12/miR-603/NAMPT axis, which ultimately affects the regulation of NAD(+), SIRT3 and p53. Future studies should explore the potential of the SNHG12/miR-603/NAMPT pathway as a target for developing novel AS therapies.

Association of lactate detection with in-hospital mortality in critically ill patients with acute myocardial infarction: a retrospective cohort study.

OBJECTIVES: To assess the associations of lactate level or lactate clearance at different time points with in-hospital mortality in critically ill patients with acute myocardial infarction (AMI). DESIGN: A cohort study. SETTING: The Medical Information Mart for Intensive Care III database. PARTICIPANT: 490 AMI patients. INTERVENTION: None. PRIMARY AND SECONDARY OUTCOME MEASURES: In-hospital mortality of patients. RESULTS: In total, 120 (24.49%) patients died at the end of follow-up. After adjusting for confounders, increased risk of in-hospital mortality in patients with AMI was observed in those with high lactate level (24 hours) (HR=1.156, 95%CI: 1.002 to 1.333). Increased lactate clearance (24 hours) was correlated with a decreased risk of in-hospital mortality in patients with AMI (HR=0.995, 95% CI: 0.994 to 0.997). The area under the curves (AUCs) of lactate level (24 hours) and lactate clearance (24 hours) were 0.689 (95% CI: 0.655 to 0.723) and 0.672 (95% CI: 0.637 to 0.706), respectively. The AUC of lactate level (24 hours) and lactate clearance (24 hours) was higher than lactate level (baseline). CONCLUSIONS: Increased lactate level (24 hours) was associated with an elevated risk of in-hospital mortality in patients with AMI and increased lactate clearance (24 hours) was correlated with a decreased risk of in-hospital mortality in patients with AMI despite the age and genders.

Dendrobine modulates autophagy to alleviate ox-LDL-induced oxidative stress and senescence in HUVECs.

Dendrobine has potential advantages in suppressing atherosclerosis (AS). FK506-binding protein 1A (FKBP1A) is implicated in the regulation of autophagy, inflammation, and apoptosis. To reveal the mechanism by which dendrobine inhibits AS by modulating autophagy, oxidative stress, apoptosis, and senescence. An in vitro AS cell model was induced by culturing human umbilical vein endothelial cells (HUVECs) with oxidized low-density lipoprotein (ox-LDL). The cells were treated with dendrobine alone or in combination with short hairpin RNA (shRNA) targeting FKBP1A or together with 3-methyladenine (3MA), an autophagy inhibitor. Inflammatory cytokines levels tumor necrosis factor-α, interleukin-6 (IL-6), and IL-1ß were analyzed and oxidative stress levels were detected by the analysis of reactive oxygen species, malondialdehyde, and superoxide dismutase levels, followed by the analysis of apoptosis levels through terminal deoxynucleotidyl transferase dUTP nick end labeling staining. Cell senescence was evaluated by senescence-associated ß-galactosidase and light chain 3 (LC3) levels were detected by immunofluorescence (IF) staining. The targeting relationship of dendrobine and FKBP1A was predicted by SwissTarget, PyMol, Autodock, and Open Babel software. Dendrobine reduced the levels of proinflammation factors, oxidative stress levels, apoptosis levels, and senescence phenotype in ox-LDL-induced HUVECs. Besides, cell viability has an opposite change. Furthermore, there was an increase in LC3 IF tensity, and LC3-II/I and Beclin1 expressions, and a decrease in p62 expression. However, these effects of dendrobine could be markedly destroyed by shRNA silencing FKBP1A and 3MA. Dendrobine can suppress inflammatory responses, oxidative stress, apoptosis, and senescence via FKBP1A-involved autophagy ox-LDL-treated HUVECs.

Endothelial progenitor cells-derived exosomes transfer microRNA-30e-5p to regulate Erastin-induced ferroptosis in human umbilical vein endothelial cells via the specificity protein 1/adenosine monophosphate-activated protein kinase axis.

Ferroptosis is a kind of cell death triggered by intracellular phospholipid peroxidation. Human umbilical vein blood endothelial progenitor cells-Exosomes (EPCs-Exos) affect ferroptosis. This study sought to explore the mechanism of EPCs-Exos in human umbilical vein endothelial cell (HUVEC) ferroptosis. EPCs-Exos were isolated and identified. HUVECs were treated with Erastin at IC50 concentration. Ferroptosis-related indexes and iron ion content were detected using kits. HUVEC migration and angiogenesis before/after ferroptosis inhibitor treatment were observed by cell scratch and angiogenesis assays. After Erastin induction, HUVECs were transfected with miR-30e-5p mimic, or treated with EPCs-Exos and EPCs-Exos transfected with miR-30e-5p inhibitor. miR-30e-5p expression was detected by RT-qPCR. The binding relationship between miR-30e-5p and specificity protein 1 (SP1) was verified by dual-luciferase assay. SP1 expression was detected by Western blot. HUVECs treated with Erastin and EPCs-Exos were transfected with pcDNA3.1-SP1. Protein levels of adenosine monophosphate-activated protein kinase (AMPK) and p-AMPK were detected by Western blot. EPCs-Exos inhibited Erastin-induced HUVEC ferroptosis and endothelial injury. Erastin inhibited miR-30e-5p and EPCs-Exo treatment recovered miR-30e-5p expression. miR-30e-5p was encapsulated in EPCs-Exos. After inhibiting miR-30e-5p in EPCs, the inhibitory effect of EPCs-Exos on HUVEC ferroptosis was attenuated. miR-30e-5p targeted SP1. Overexpression of SP1 partially reversed the effect of EPCs-Exos on improving HUVEC ferroptosis and increasing phosphorylation levels of AMPK. Collectively, EPCs-Exos inhibited Erastin-induced HUVEC ferroptosis by upregulating miR-30e-5p, inhibiting SP1, and activating the AMPK pathway.

Troxerutin regulates HIF-1α by activating JAK2/STAT3 signaling to inhibit oxidative stress, inflammation, and apoptosis of cardiomyocytes induced by H2 O2.

Heart failure (HF) is greatly threatening human health and affecting morbidity and mortality worldwide. Troxerutin can alleviate myocardial injury induced by ischemia and hypoxia. The present study aimed to investigate the protective effect of troxerutin on H2 O2 -induced cardiomyocytes and the underlying molecular mechanism. Primary mouse cardiomyocytes morphology induced by H2 O2 in a different duration time was observed by a microscope. After indicated treatment, the viability and apoptosis of cardiomyocytes were detected by CCK-8 assay and flow cytometry analysis. The expression of inflammatory factors and oxidative stress biomarkers was detected by Reverse transcription-quantitative polymerase chain reaction (RT-qPCR) and assay kits. Hypoxia inducible factor-1a (HIF-1α) expression was determined by western blot analysis, RT-qPCR analysis and immunofluorescence staining. The apoptosis-related protein expression and the phosphorylation level of janus-activated kinase 2 (JAK2)/signal transducer and activator of transcription 3 (STAT3) were detected by the western blot analysis. As a result, after the H2 O2 treatment in a different duration time, the primary mouse cardiomyocytes gradually stopped beating and the morphology of cardiomyocytes treated with H2 O2 was changed significantly from fusiform shape to round shape. The viability of cardiomyocytes was decreased after H2 O2 induction. The HIF-1α expression was increased after the H2 O2 treatment within 30 min while decreased over 30 min. In addition, troxerutin improved viability and suppressed apoptosis, inflammation and oxidative stress of H2 O2 -induced cardiomyocytes, which was reversed by KC7F2 (a HIF-1α inhibitor) or CHZ868 (a JAK inhibitor). To sum up, troxerutin could regulate HIF-1α by activating JAK2/STAT3 signaling to inhibit oxidative stress, inflammation, and apoptosis of cardiomyocytes induced by H2 O2 .

Melatonin Alleviates Age-Associated Endothelial Injury of Atherosclerosis via Regulating Telomere Function.

BACKGROUND: Atherosclerosis is an aging-related disease, partly attributed to telomerase dysfunction. This study aims to investigate whether telomere dysfunction-related vascular aging is involved in the protection mechanism of melatonin (MLT) in atherosclerosis. METHODS: Young and aged ApoE-/- mice were used to establish atherosclerotic mice model. H&E staining and immunofluorescence assay were performed to detect endothelial cell injury and apoptosis. Inflammatory cytokines and oxidative stress-related factors were determined using corresponding commercial assay kits. Telomerase activity was detected by TRAP assay, and SA-ß-gal staining was conducted to evaluate cellular senescence. HUVECs were treated with H2O2 for 1 h to induce senescence. Western blot was performed to measure protein expression. RESULTS: An obvious vascular endothelial injury, reflected by excessive production of inflammatory cytokines, elevated ROS, MDA and SOD levels, and more apoptotic endothelial cells, was found in atherosclerotic mice, especially in aged mice, which were then greatly suppressed by MLT. In addition, telomere dysfunction and senescence occurred in atherosclerosis, especially in aged mice, while MLT significantly alleviated the conditions. CYP1A1, one of the targeted genes of MLT, was verified to be upregulated in atherosclerotic mice but downregulated by MLT. Furthermore, H2O2 induced a senescence model in HUVECs, which was accompanied with a remarkably increased cell viability loss and apoptosis rate, and a downregulated telomerase activity of HUVECs, and this phenomenon was strengthened by RHPS4, an inhibitor of telomerase activity. However, MLT could partly abolish these changes in H2O2- and RHPS4-treated HUVECs, demonstrating that MLT alleviated vascular endothelial injury by regulating senescence and telomerase activity. CONCLUSIONS: Collectively, this study provided evidence for the protective role of MLT in atherosclerosis through regulating telomere dysfunction-related vascular aging.

Semaphorin 7A knockdown improves injury and prevents endothelial-to-mesenchymal transition in ox-LDL-induced HUVECs by regulating ß1 integrin expression.

Atherosclerosis is the most common cause of cardiovascular disease and is accompanied by high mortality rates and a poor prognosis. Semaphorin 7A (Sema7A) and its receptor ß1 integrin have been reported to participate in the development of atherosclerosis. However, the role of Sema7A and ß1 integrin in endothelial cell injury and endothelial-to-mesenchymal transition (EMT) in atherosclerosis remains undetermined, to the best of our knowledge. The mRNA and protein expression levels of Sema7A and ß1 integrin in HUVECs were analyzed using reverse transcription-quantitative PCR (RT-qPCR) and western blot analyses, respectively. HUVECs were induced with 50 µg/ml oxidized low-density lipoprotein (ox-LDL) to establish an atherosclerosis cell model. Cell viability was measured using Cell Counting Kit-8 assay and the production of IL-1ß, IL-6 and C-C motif chemokine ligand 2 was determined using ELISA. The expression levels of cell adhesion factors, intracellular adhesion molecule-1 and vascular cell adhesion molecule-1 were analyzed using RT-qPCR and western blot analyses. Cell apoptosis was detected using flow cytometry and western blotting. The levels of EMT-related markers were evaluated using RT-qPCR, western blotting and immunofluorescence staining. The results of the present study revealed that the expression levels of Sema7A and ß1 integrin were significantly upregulated in ox-LDL-treated HUVECs. Treatment with ox-LDL significantly decreased cell viability, and increased the levels of inflammatory and adhesion factors, the cell apoptotic rate and the expression levels of EMT-related proteins. Knockdown of Sema7A reversed the ox-LDL-induced inflammatory responses and EMT, while the overexpression of ß1 integrin reversed the Sema7A-mediated inhibitory effects on ox-LDL-treated HUVECs. In conclusion, the findings of the present study indicated that Sema7A and ß1 integrin may play significant roles in atherosclerosis by mediating endothelial cell injury and EMT progression.

Adiponectin inhibits D­gal­induced cardiomyocyte senescence via AdipoR1/APPL1.

The aim of the present study was to examine whether adiponectin could inhibit cardiomyocyte senescence induced by D­galactose (D­gal), and whether it functioned via the adiponectin receptor 1 (AdipoR1)/adaptor protein phosphotyrosine interacting with PH domain and leucine zipper 1 (APPL1) signaling pathway. For this purpose, the expression levels of adiponectin, AdipoR1 and APPL1 in mouse plasma and myocardial tissues were detected via reverse transcription­quantitative PCR (RT­qPCR) and western blotting. An adiponectin­overexpression plasmid was transfected into D­gal­treated H9c2 cells prior to the detection of AdipoR1 and APPL1 expression by RT­qPCR. Senescence­associated ß­galactose staining was then performed to observe cellular senescence following the transfection of small interfering RNAs (si) targeting AdipoR1 and APPL1 into D­gal­treated H9c2 cells overexpressing adiponectin. Commercial kits were used to detect reactive oxygen species (ROS) production and malondialdehyde (MDA) content in the different groups. The expression levels of heme oxygenase (HO)­1 and high mobility group box 1 (HMGB1) were examined by western blot analysis. The results revealed that the expression levels of adiponectin, AdipoR1 and APPL1 were downregulated in aged mouse plasma, myocardial tissues and D­gal­treated cardiomyocytes. It was also observed that AdipoR1 and APPL1 expression levels were significantly upregulated following the overexpression of adiponectin into D­gal­treated cardiomyocytes. Moreover, adiponectin overexpression reduced cellular senescence induced by D­gal and the expression of p16 and p21; these effects were reversed following transfection with si­AdipoR1 and si­APPL1. Adiponectin also downregulated the levels of ROS and MDA in D­gal­treated H9c2 cells via AdipoR1/APPL1. Additionally, the release of HO­11/HMGB1 was affected by adiponectin via AdipoR1/APPL1, and adiponectin/AdipoR1/APPL1 suppressed ROS production via HO­1/HMGB1. On the whole, the present study demonstrated that adiponectin played an inhibitory role in cardiomyocyte senescence via the AdioR1/APPL1 signaling pathway and inhibited the levels of oxidative stress in senescent cardiomyocytes via the HO­1/HMGB1 signaling pathway.

Dendrobine suppresses endoplasmic reticulum stress-induced apoptosis through upregulating microRNA miR-381-3p to decrease caspase-4.

Dendrobine has been reported to reduce blood lipid levels and apoptosis. The present study was designed to observe the effect of dendrobine in a model of ERS using vascular endothelial cells and to reveal the biological mechanisms and pathways responsible for the therapeutic effects of dendrobine on AS. Human umbilical vein endothelial cells (HUVECs) were pre-treated with various concentrations of dendrobine, followed by treatment with tunicamycin (TM) for the establishment of the cell models of ERS. The proliferation and apoptosis of HUVECs were detected by bromodeoxyuridine staining and flow cytometry, respectively. The target binding association was verified through dual luciferase reporter assay. It was found that TM treatment resulted in a low expression of miR-381-3p. Dendrobine treatment not only promoted the proliferation, but also inhibited the apoptosis of HUVECs induced by TM. The reduced expression of 78-kDa glucose-regulated protein, inositol-requiring enzyme 1, caspase-4, C/EBP homologous protein and caspase-3 was also observed following treatment with dendrobine. Dendrobine reduced the apoptosis of endothelial cells in the model of ERS by increasing miR-381-3p expression, and partially restored the cell proliferation level. This effect was significantly reduced after the expression of miR-381-3p was blocked. On the whole, the present study demonstrated that dendrobine upregulated miR-381-3p expression to inhibit apoptosis induced by ERS in HUVECs and this process was found to be mediated by caspase-4. The findings of the present study may provide new insight into the causes of endothelial cell apoptosis during AS and reveal the potent therapeutic effects of dendrobine in AS.

Cyclic nucleotide phosphodiesterase 1C contributes to abdominal aortic aneurysm.

Abdominal aortic aneurysm (AAA) is characterized by aorta dilation due to wall degeneration, which mostly occurs in elderly males. Vascular aging is implicated in degenerative vascular pathologies, including AAA. Cyclic nucleotide phosphodiesterases, by hydrolyzing cyclic nucleotides, play critical roles in regulating vascular structure remodeling and function. Cyclic nucleotide phosphodiesterase 1C (PDE1C) expression is induced in dedifferentiated and aging vascular smooth muscle cells (SMCs), while little is known about the role of PDE1C in aneurysm. We observed that PDE1C was not expressed in normal aorta but highly induced in SMC-like cells in human and murine AAA. In mouse AAA models induced by Angiotensin II or periaortic elastase, PDE1C deficiency significantly decreased AAA incidence, aortic dilation, and elastin degradation, which supported a causative role of PDE1C in AAA development in vivo. Pharmacological inhibition of PDE1C also significantly suppressed preestablished AAA. We showed that PDE1C depletion antagonized SMC senescence in vitro and/or in vivo, as assessed by multiple senescence biomarkers, including senescence-associated ß-galactosidase activity, γ-H2AX foci number, and p21 protein level. Interestingly, the role of PDE1C in SMC senescence in vitro and in vivo was dependent on Sirtuin 1 (SIRT1). Mechanistic studies further showed that cAMP derived from PDE1C inhibition stimulated SIRT1 activation, likely through a direct interaction between cAMP and SIRT1, which leads to subsequent up-regulation of SIRT1 expression. Our findings provide evidence that PDE1C elevation links SMC senescence to AAA development in both experimental animal models and human AAA, suggesting therapeutical significance of PDE1C as a potential target against aortic aneurysms.

Septin 4 activates PPARγ/LXRα signaling by upregulating ABCA1 and ABCG1 expression to inhibit the formation of THP-1 macrophage-derived foam cells.

Septin 4 is a member of a family of GTP-binding proteins that has been previously reported regulate cytoskeletal organization. In addition, it has been suggested to serve a role in atherosclerosis. Therefore, the present study aimed to investigate the effects of Septin 4 on foam cell formation. THP-1 cells were first exposed to phorbol-12-myristate-13-acetate for differentiation into macrophages before being transformed into foam cells by treatment with oxidized low-density lipoprotein (ox-LDL). Septin 4 expression was then knocked down or overexpressed in THP-1 cells using transfection, whilst peroxisome proliferator activated receptor γ (PPARγ) was also inhibited using its selective antagonist (T0070907) in the presence of Septin 4 overexpression. Oil red staining was used to detect lipid uptake, and total cholesterol (TC), free cholesterol (FC) and ATP binding cassette subfamily A/G member 1 (ABCA1/G1) protein expression were also measured. The results demonstrated that upon ox-LDL stimulation, macrophages that were derived from THP-1 cells transformed into foam cells, where Septin 4 was highly expressed in ox-LDL-induced foam cells. Septin 4 knockdown promoted TC and FC levels, but reduced ABCA1/G1 protein expression. The protein expression levels of PPARγ and liver X receptor α (LXRα) were also decreased after Septin 4 knockdown. However, Septin 4 overexpression resulted in the opposite results being observed. Additionally, blocking PPARγ activity using its inhibitor T0070907 or knocking down LXRα expression using short hairpin RNA reversed the effects of Septin 4 overexpression on foam cell formation and cholesterol handling. In conclusion, Septin 4 may serve an important role in preventing foam cell formation by activating PPARγ/LXRα signaling and subsequently enhancing ABCA1/G1 expression.

Endogenous sex hormone levels and coronary heart disease risk in postmenopausal women: A meta-analysis of prospective studies.

Background Low testosterone levels have been associated with coronary heart disease (CHD) morbidity and mortality in men, but the influence of hormones in postmenopausal women is unclear. This meta-analysis aimed to examine whether there is an association between endogenous sex hormones and CHD risk in postmenopausal women. Methods A systematic search of the PubMed and EMBASE databases from 1966 to 30 November 2016 was performed for prospective studies that reported an association between endogenous sex hormones and CHD in postmenopausal women. Summary relative risks (RRs) and 95% confidence intervals (CIs) were combined by using a random-effects model. Results A total of 13 publications (12 studies, including six prospective cohort and six nested case-control studies) were included. The summary RRs for CHD were 1.01 (95% CI 0.77-1.31) comparing the highest versus lowest tertile of total testosterone, with evidence of high heterogeneity ( I2 = 80.7%). In subgroup and meta-regression analyses, none of the variables were identified as contributing to significant heterogeneity. Based on a comparison of the highest versus lowest tertile models, the summary RRs (95% CIs) for CHD were 0.88 (0.63-1.23, I2 = 48.7%) for free testosterone, 1.16 (0.82-1.63, I2 = 47.8%) for estradiol, 0.98 (0.90-1.07, I2 = 3.2%) for sex hormone-binding globulin and 1.19 (0.89-1.58, I2 = 0) for dehydroepiandrosterone. Conclusion There is limited evidence to suggest that endogenous levels of sex hormones are not significantly associated with CHD risk in postmenopausal women.

Soy Consumption with Risk of Coronary Heart Disease and Stroke: A Meta-Analysis of Observational Studies.

BACKGROUND: The association of soy product consumption with the relative risk of cardiovascular disease remains controversial. This meta-analysis aimed at investigating whether an association exists between soy consumption and the risk of stroke and coronary heart disease (CHD) in observational studies. METHODS: A systematic search of the PubMed and EMBASE databases was performed for case-control and cohort studies that assessed soy consumption and the risk of stroke and CHD. Summary relative risks (SRRs) and 95% CIs were combined by using a random-effects model. RESULTS: Of a total of 1,266 abstracts, 5 prospective cohort and 6 case-control studies met our inclusion criteria, and comprised 4,954 stroke and 7,616 CHD events. Based on the high vs. low analyses, combining cohort studies showed no association between soy intake and risk of stroke (SRR 0.92; 95% CI 0.70-1.10; Pheterogeneity = 0.236; I2 = 29.4%) or CHD (SRR 0.97; 95% CI 0.74-1.27; Pheterogeneity = 0.020; I2 = 62.7%), although a significantly inverse association between soy intake and the risk of stroke (SRR 0.54; 95% CI 0.34-0.87; Pheterogeneity = 0.001; I2 = 79.3%) and CHD (SRR 0.66; 95% CI 0.56-0.77; Pheterogeneity = 0.421; I2 = 0) was observed in case-control studies. No association between soy isoflavone intake and the risk of stroke and CHD was identified. CONCLUSION: There was limited evidence to indicate that soy consumption was inversely associated with the risk of stroke and CHD, although further studies, with prospective designs that use validated questionnaires and control for important confounders, are warranted.