OBJECTIVES: Hyperhomocysteinaemia (Hcy) is an independent risk factor for cardiovascular and cerebrovascular diseases. MicroRNA (miR)-18a-5p is closely related to cardiovascular diseases. This study aims to investigate the effects of miR-18a-5p on homocysteine (Hcy)-induced myocardial cells injury. METHODS: H9c2 cells were transfected with miR-18a-5p mimic/miR-18a-5p mimic negative control (NC) or combined with Hcy for intervention, and untreated cells were set as a control group. The transfection efficiency was verified by real-time RT-PCR, and cell counting kit-8 (CCK-8) assay was used to determine cell viability. Flow cytometry was used to detect apoptosis and reactive oxygen species (ROS) levels. Western blotting was performed to measure the protein levels of microtubule-associated protein 1 light chain 3 (LC3)-I, LC3-II, Beclin1, p62, Bax, Bcl-2, and Notch2. Dual luciferase reporter assay was used to detect the interaction of miR-18a-5p with Notch2. RESULTS: Compared with the control, treatment with Hcy or transfection with miR-18a-5p mimic alone, or combined treatment with Hcy and miR-18a-5p mimic/miR-18a-5p mimic NC significantly reduced the H9c2 cell viability, promoted apoptosis and ROS production, up-regulated the expressions of Bax and Beclin, down-regulated the expressions of Bcl-2, p62, and Notch2, and increased the ratio of LC3-II/LC3-I (all P<0.05). Compared with the combined intervention of miR-18a-5p mimic NC and Hcy group, the above indexes were more significantly changed in the combined intervention of miR-18a-5p mimic and Hcy group, and the difference between the 2 groups was statistically significant (all P<0.05). There is a targeted binding between Notch2 and miR-18a-5p. CONCLUSIONS MiR-18a-5p could induce autophagy and apoptosis via increasing ROS production in cardiomyocytes, and aggravate Hcy-induced myocardial injury. Notch2 is a target of miR-18a-5p.
Apoptosis/genetics* ; Autophagy/genetics* ; bcl-2-Associated X Protein ; MicroRNAs/metabolism* ; Proto-Oncogene Proteins c-bcl-2/genetics* ; Reactive Oxygen Species ; Rats ; Animals ; Myocytes, Cardiac/drug effects* ; Homocysteine/adverse effects* ; Hyperhomocysteinemia

Hyperhomocysteinemia (HHcy) is considered to be an independent risk factor for cardiovascular diseases, but the molecular mechanisms underlying its pathogenesis are not fully understood. Endothelial dysfunction is a key initiating factor in the pathogenesis of atherosclerosis, which is commonly observed in almost all HHcy-induced vascular diseases. HHcy promotes oxidative stress, inhibits nitric oxide production, suppresses hydrogen sulfide signaling pathway, promotes endothelial mesenchymal transition, activates coagulation pathways, and promotes protein N-homocysteination and cellular hypomethylation, all of which can cause endothelial dysfunction. This article reviews the specific links between HHcy and endothelial dysfunction, and highlights recent evidence that endothelial mesenchymal transition contributes to HHcy-induced vascular damage, with a hope to provide new ideas for the clinical treatment of HHcy-related vascular diseases.
Humans ; Atherosclerosis ; Cardiovascular Diseases ; Endothelium, Vascular ; Homocysteine/metabolism* ; Hyperhomocysteinemia/complications* ; Oxidative Stress ; Risk Factors

Chronic stress is generally accepted as the main risk factor in the development of cognitive decline; however, the underlying mechanisms remain unclear. Previous data have demonstrated that the levels of homocysteine (Hcy) are significantly elevated in the plasma of stressed animals, which suggests that Hcy is associated with stress and cognitive decline. To test this hypothesis, we analyzed the cognitive function, plasma concentrations of Hcy, and brain-derived neurotropic factor (BDNF) levels in rats undergoing chronic unpredicted mild stress (CUMS). The results showed that decreased cognitive behavioral performance and decreased BDNF transcription and protein expression were correlated with hyperhomocysteinemia (HHcy) levels in stressed rats. Diet-induced HHcy mimicked the cognitive decline and BDNF downregulation in the same manner as CUMS, while Hcy reduction (by means of vitamin B complex supplements) alleviated the cognitive deficits and BDNF reduction in CUMS rats. Furthermore, we also found that both stress and HHcy disturbed the DNA methylation process in the brain and induced DNA hypermethylation in the BDNF promoter. In contrast, control of Hcy blocked BDNF promoter methylation and upregulated BDNF levels in the brain. These results imply the possibility of a causal role of Hcy in stress-induced cognitive decline. We also used ten-eleven translocation (TET1), an enzyme that induces DNA demethylation, to verify the involvement of Hcy and DNA methylation in the regulation of BDNF expression and the development of stress-related cognitive decline. The data showed that TET1-expressing viral injection into the hippocampus inhibited BDNF promoter methylation and significantly mitigated the cognitive decline in HHcy rats. Taken together, novel evidence from the present study suggests that Hcy is likely involved in chronic stress-induced BDNF reduction and related cognitive deficits. In addition, the negative side-effects of HHcy may be associated with Hcy-induced DNA hypermethylation in the BDNF promoter. The results also suggest the possibility of Hcy as a target for therapy and the potential value of vitamin B intake in preventing stress-induced cognitive decline.
Animals ; Brain-Derived Neurotrophic Factor/metabolism* ; Cognitive Dysfunction/complications* ; DNA Methylation ; Homocysteine/metabolism* ; Hyperhomocysteinemia/metabolism* ; Rats ; Stress, Psychological/physiopathology*

Hyperhomocysteinemia (Hhcy) is an independent risk factor for Alzheimer's disease (AD). Visual dysfunction is commonly found and is positively correlated with the severity of cognitive defects in AD patients. Our previous study demonstrated that Hhcy induces memory deficits with AD-like tau and amyloid-β (Aβ) pathologies in the hippocampus, and supplementation with folate and vitamin B12 (FB) prevents the Hhcy-induced AD-like pathologies in the hippocampus. Here, we investigated whether Hhcy also induces AD-like pathologies in the retina and the effects of FB. An Hhcy rat model was produced by vena caudalis injection of homocysteine for 14 days, and the effects of FB were assessed by simultaneous supplementation with FB in drinking water. We found that Hhcy induced vessel damage with Aβ and tau pathologies in the retina, while simultaneous supplementation with FB remarkably attenuated the Hhcy-induced tau hyperphosphorylation at multiple AD-related sites and Aβ accumulation in the retina. The mechanisms involved downregulation of amyloid precursor protein (APP), presenilin-1, beta-site APP-cleaving enzyme 1, and protein phosphatase-2A. Our data suggest that the retina may serve as a window for evaluating the effects of FB on hyperhomocysteinemia-induced Alzheimer-like pathologies.
Alzheimer Disease ; etiology ; metabolism ; pathology ; therapy ; Amyloid beta-Peptides ; metabolism ; Animals ; Dietary Supplements ; Disease Models, Animal ; Folic Acid ; therapeutic use ; Homocysteine ; Hyperhomocysteinemia ; complications ; metabolism ; pathology ; therapy ; Male ; Rats, Sprague-Dawley ; Retina ; metabolism ; pathology ; Retinal Vessels ; metabolism ; pathology ; Vitamin B 12 ; therapeutic use ; tau Proteins ; metabolism

Adult ; Amino Acid Metabolism, Inborn Errors ; blood ; diagnosis ; Bipolar Disorder ; blood ; diagnosis ; Gas Chromatography-Mass Spectrometry ; Humans ; Hyperhomocysteinemia ; blood ; diagnosis ; Male ; Tandem Mass Spectrometry ; Vitamin B 12 ; blood

C677T mutation in the gene encoding 5,10-methylenetetrahydrofolate reductase (MTHFR) predisposes to hyperhomocysteinemia in vivo and is known to be one of the causes of perinatal ischemic stroke. As MTHFR plays a role in the metabolism of homocysteine, C677T mutation may account for reduced enzymatic activity resulting in hyperhomocysteinemia. This may be prevented by introducing activity-enhancing coenzymes such as folic acid, vitamin B6, and B12. Though C677T mutation is known as a significant risk factor for cerebral infarction, reported cases of cerebral infarction among affected neonates are scarce. This report describes a case of a neonate homozygous for C677T mutation who had a perinatal ischemic stroke, born in a mother whose folic acid and nutritional consumption had been reduced during pregnancy.
Cerebral Infarction* ; Coenzymes ; Folic Acid ; Homocysteine ; Humans ; Hyperhomocysteinemia ; Infant, Newborn ; Metabolism ; Mothers ; Oxidoreductases ; Pregnancy ; Risk Factors ; Stroke ; Vitamin B 6

The aim of the present study is to explore the role of miR-124 and its promoter region DNA methylation in homocysteine (Hcy)-induced atherosclerosis. ApoE(-/-) mice were fed with hypermethionine diet for 16 weeks to duplicate hyperhomocysteinemia model. Meanwhile, a normal control group (C57BL/6J mice fed with normal diet, N-control) and a model control group (ApoE(-/-) mice fed with normal diet, A-control) were set. The degree of atherosclerosis was observed by HE and oil red O staining. Automatic biochemical analyzer was used to detect the serum levels of Hcy. Foam cell model was duplicated and oil red O staining was used to confirm whether the model was successfully established. And foam cells were stimulated with 0, 50, 100, 200, 500 μmol/L Hcy and 50 μmol/L Hcy + 10 μmol/L AZC respectively. Real-time quantitative PCR (RT-qPCR) was used to detect the expressions of miR-124 in mice aorta and foam cells; Nested landing methylation specific PCR (nMS-PCR) was used to detect the levels of miR-124 promoter DNA methylation in mice aorta and foam cells. Meanwhile, the effects of DNA methylation inhibitor AZC on miR-124 expression were observed at the cellular level. The effect of miR-124 promoter DNA methylation status on lipid accumulation in foam cells was observed by oil red O staining. The results showed that compared with model control group, the serum levels of Hcy in high methionine group were significantly increased (P < 0.01) and developed aortic atherosclerotic plaque, the expression of miR-124 was markedly decreased (P < 0.01), while the levels of miR-124 promoter DNA methylation were significantly increased (P < 0.01). Given different levels of Hcy, the expression of miR-124 in foam cells was decreased, while the levels of miR-124 promoter DNA methylation were increased in a dose-dependent manner (P < 0.05, P < 0.01). AZC reversed the results of mentioned indices as above markedly (P < 0.05). Downregulation of miR-124 may play a role in Hcy-induced atherosclerosis and its promoter DNA methylation status may be an important mechanism in this process.
Animals ; Aorta ; metabolism ; Apolipoproteins E ; Atherosclerosis ; chemically induced ; genetics ; DNA Methylation ; Diet ; Foam Cells ; metabolism ; Homocysteine ; adverse effects ; Hyperhomocysteinemia ; Mice ; Mice, Inbred C57BL ; Mice, Knockout ; MicroRNAs ; genetics ; Promoter Regions, Genetic

OBJECTIVETo study the clinical features and treatment outcomes of cardiovascular system involvement in children with methylmalonic aciduria combined with hyperhomocysteinemia (MMACHC).

METHODSThe clinical data of 10 children with methylmalonic aciduria combined with hyperhomocysteinemia and who had cardiovascular system involvement were retrospectively analyzed and the treatment outcomes were followed up.

RESULTSIn the 10 patients, there were 4 cases with initial presentations of cardiovascular system symptoms such as shortness of breath and dyspnea, 3 cases with urinary tract symptoms such as edema, hematuria and proteinuria, and 3 cases with nervous system symptoms such as developmental retardation and convulsions. The 10 patients had different types and severity of cardiovascular injuries. After 3 months to 8 years of follow-up, the congenital heart defects resolved naturally in 2 cases, and the patient with arrhythmia had no obvious changes. In 5 cases of hypertension, blood pressures recovered to normal in 3 cases, and 1 case was lost to follow-up. In 5 patients with pulmonary hypertension, 2 died, 2 recovered, and 1 case had mildly elevated pulmonary artery pressure. Seven patients underwent MMACHC gene testing, and 5 showed c.80A>G mutations.

CONCLUSIONSMetabolic disease should be taken into account for the children with unexplained pulmonary hypertension and hypertension with the onset of the shortness of breath and dyspnea. The severity of cardiovascular system involvement might be one of the most important factors affecting the prognosis of children with MMACHC. Cardiavascular system involvement of the patients may be related to MMACHC c.80A>G mutations.

Amino Acid Metabolism, Inborn Errors ; complications ; genetics ; Cardiovascular Diseases ; etiology ; Child ; Child, Preschool ; Female ; Follow-Up Studies ; Humans ; Hyperhomocysteinemia ; complications ; genetics ; Infant ; Infant, Newborn ; Male ; Retrospective Studies

PURPOSE: Hyperhomocysteinemia has been identified as an independent risk factor in arterial and venous thrombosis. Mutations in genes encoding methylenetetrahydrofolate reductase (MTHFR), involved in the metabolism of homocysteine, may account for reduced enzyme activity and elevated plasma homocysteine levels. In this study, we investigated the interrelation of MTHFR C677T genotype and level of homocysteine in patients with arterial and venous thrombosis. MATERIALS AND METHODS: We retrospectively reviewed the medical records of 146 patients who were diagnosed as having arterial and venous thrombosis. We excluded patients diagnosed with atrial fibrillation. We examined routinely the plasma concentration of total homocysteine level and MTHFR C677T polymorphism for evaluation of thrombotic tendency in all patients. Screening processes of MTHFR C677T polymorphism were performed by real-time polymerase chain reaction. RESULTS: Investigated groups consisted of thrombotic arterial occlusion in 48 patients and venous occlusion in 63 patients. The distribution of the three genotypes was as follows: homozygous normal (CC) genotype in 29 (26.1%), heterozygous (CT) genotype in 57 (51.4%), and homozygous mutant (TT) genotype in 25 (22.5%) patients. There were no significant differences among individuals between each genotype group for baseline characteristics. Plasma concentration of homocysteine in patients with the TT genotype was significantly increased compared to the CC genotype (P<0.05). CONCLUSION: We observed a significant interaction between TT genotypes and homocysteine levels in our results. The results might reflect the complex interaction between candidate genes and external factors responsible for thrombosis.
Atrial Fibrillation ; Genotype ; Homocysteine* ; Humans ; Hyperhomocysteinemia ; Mass Screening ; Medical Records ; Metabolism ; Methylenetetrahydrofolate Reductase (NADPH2)* ; Plasma* ; Real-Time Polymerase Chain Reaction ; Retrospective Studies ; Risk Factors ; Thrombosis ; Venous Thrombosis

Acute mesenteric venous thrombosis (MVT) is an uncommon form of intestinal ischemia with high mortality and usually occurs in the setting of preexisting comorbidities including thrombophilia and abdominal inflammatory conditions. Hyperhomocysteinemia has been known to be a risk factor for thromboembolism, often located on an unusual site. Considering that homocysteine metabolism is determined genetically to a high degree, a mutant of methylenetetrahydrofolate reductase (MTHFR) C677T causes hyperhomocysteinemia, leading to thrombophilia. Until now, there have been few reports of MVT associated with MTHFR gene mutation. We, herein, report a case of small bowel infarction associated with MVT by MTHFR gene mutation in an adult without any other risk factors of thrombophilia.
Adult ; Comorbidity ; Homocysteine ; Humans ; Hyperhomocysteinemia ; Infarction* ; Ischemia ; Mesenteric Veins ; Metabolism ; Methylenetetrahydrofolate Reductase (NADPH2)* ; Mortality ; Risk Factors ; Thromboembolism ; Thrombophilia ; Thrombosis ; Venous Thrombosis*