Elevated homocysteine is negatively correlated with plasma cystathionine β‐synthase activity in givosiran‐treated patients
Ontology highlight
ABSTRACT:
SUBMITTER: Keibler M
PROVIDER: S-EPMC11224493 | biostudies-literature | 2024 Apr
REPOSITORIES: biostudies-literature
Similar Datasets
Project description:Homocysteine (Hcy), a cardiovascular and neurovascular disease risk factor, is converted to hydrogen sulfide (H(2)S) through the transsulfuration pathway. H(2)S has attracted considerable attention in recent years for many positive effects on vascular health and homeostasis. Cystathionine β-synthase (CBS) is the first, and rate-limiting, enzyme in the transsulfuration pathway. Mutations in the CBS gene decrease enzymatic activity, which increases the plasma Hcy concentration, a condition called hyperhomocysteinemia (HHcy). Animal models of CBS deficiency have provided invaluable insights into the pathological effects of transsulfuration impairment and of both mild and severe HHcy. However, studies have also highlighted the complexity of HHcy and the need to explore the specific details of Hcy metabolism in addition to Hcy levels per se. There has been a relative paucity of work addressing the dysfunctional H(2)S production in CBS deficiency that may contribute to, or even create, HHcy-associated pathologies. Experiments using CBS knockout mice, both homozygous (-/-) and heterozygous (+/-), have provided 15 years of new knowledge and are the focus of this review. These murine models present the opportunity to study a specific mechanism for HHcy that matches one of the etiologies in many human patients. Therefore, the goal of this review was to integrate and highlight the critical information gained thus far from models of CBS deficiency and draw attention to critical gaps in knowledge, with particular emphasis on the modulation of H(2)S metabolism. We include findings from human and animal studies to identify important opportunities for future investigation that should be aimed at generating new basic and clinical understanding of the role of CBS and transsulfuration in cardiovascular and neurovascular disease.
| S-EPMC3023265 | biostudies-literature
Project description:To determine the effects of endogenous elevation of homocysteine on the retina using the cystathionine beta-synthase (cbs) mutant mouse.Retinal homocysteine in cbs mutant mice was measured by high-performance liquid chromatography (HPLC). Retinal cryosections from cbs(-/-) mice and cbs(+/-) mice were examined for histologic changes by light and electron microscopy. Morphometric analysis was performed on retinas of cbs(+/-) mice maintained on a high-methionine diet (cbs(+/-) HM). Changes in retinal gene expression were screened by microarray.HPLC analysis revealed an approximate twofold elevation in retinal homocysteine in cbs(+/-) mice and an approximate sevenfold elevation in cbs(-/-) mice. Distinct alterations in the ganglion, inner plexiform, inner nuclear, and epithelial layers were observed in retinas of cbs(-/-) and 1-year-old cbs(+/-) mice. Retinas of cbs(+/-) HM mice demonstrated an approximate 20% decrease in cells of the ganglion cell layer (GCL), which occurred as early as 5-weeks after onset of the HM diet. Microarray analysis revealed alterations in expression of several genes, including increased expression of Aven, Egr1, and Bat3 in retinas of cbs(+/-) HM mice.This study provides the first analysis of morphologic and molecular effects of endogenous elevations of retinal homocysteine in an in vivo model. Increased retinal homocysteine alters inner and outer retinal layers in cbs homozygous mice and older cbs heterozygous mice, and it primarily affects the cells of the GCL in younger heterozygous mice. Elevated retinal homocysteine alters expression of genes involved in endoplasmic reticular stress, N-methyl-d-aspartate (NMDA) receptor activation, cell cycle, and apoptosis.
| S-EPMC2756015 | biostudies-literature
Project description:Purpose: The goal of this study is to investigate the role of CBS enzyme in colorectal carcinogenesis Methods: RNA-Seq transcriptome analysis of CBS-overexpression in NCM356 cels compared to control vector cells
2017-12-07 | GSE91000 | GEO
Project description: Not available
| S-EPMC8370099 | biostudies-literature
Project description:Hydrogen sulfide (H2S), a cardioprotective gas, is endogenously produced from homocysteine by cystathionine beta synthase (CBS) and cystathionine gamma lyase (CSE) enzymes. However, effect of H2S or homocysteine on CBS and CSE expression, and cross-talk between CBS and CSE are unclear. We hypothesize that homocysteine and H2S regulate CBS and CSE expressions in a dose dependent manner in cardiomyocytes, and CBS deficiency induces cardiac CSE expression. To test the hypothesis, we treated murine atrial HL1 cardiomyocytes with increasing doses of homocysteine or Na2S/GYY4137, a H2S donor, and measured the levels of CBS and CSE. We found that homocysteine upregulates CSE but downregulates CBS whereas Na2S/GYY4137 downregulates CSE but upregulates CBS in a dose-dependent manner. Moreover, the Na2S-treatment downregulates specificity protein-1 (SP1), an inducer for CSE, and upregulates miR-133a that targets SP1 and inhibits cardiomyocytes hypertrophy. Conversely, in the homocysteine-treated cardiomyocytes, CBS and miR-133a were downregulated and hypertrophy was induced. In vivo studies using CBS+/-, a model for hyperhomocysteinemia, and sibling CBS+/+ control mice revealed that deficiency of CBS upregulates cardiac CSE, plausibly by inducing SP1. In conclusion, we revealed a novel mechanism for H2S-mediated regulation of homocysteine metabolism in cardiomyocytes, and a negative feedback regulation between CBS and CSE in the heart.
| S-EPMC5473925 | biostudies-literature
Project description:A high homocysteine, low folate phenotype is a feature of many diseases. The effect of the cystathionine beta-synthase (CBS) 844ins68 polymorphism on homocysteine and folate concentrations was examined alone and in the context of the 5,10-methylenetetrahydrofolate reductase (MTHFR) 677C>T polymorphism in a Northwestern European male population. The MTHFR 677TT genotype is known to be associated with increased homocysteine and decreased folate relative to CT heterozygotes and CC homozygotes in this and other populations. MTHFR 677TT homozygotes who were also CBS 844ins68 carriers had homocysteine and folate concentrations similar to those of individuals with the MTHFR 677CT and CC genotypes. Homocysteine levels in MTHFR 677TT subjects carrying the CBS 844ins68 allele were 24.1% lower than in non-carriers (6.66 vs 8.77 micromol/l, P=0.045), and serum folate levels were 27.7% higher (11.16 vs 8.74 nmol/l, P=0.034). These findings suggest that the CBS 844ins68 allele 'normalizes' homocysteine and folate levels in MTHFR 677TT individuals.
| S-EPMC4051220 | biostudies-literature
Project description:The effects of endogenous elevation of homocysteine on retinal gene expression were screened by microarray analysis, which was performed in triplicate (i.e., three different paired RNA samples) with RNA isolated from neural retinas of cbs+/- HM at 5-weeks after a methionine diet and age-matched wildtype mice. The microarray chips used in this study permitted the screening of 36,212 genes. Of particular interest were those genes in cbs+/- HM mice whose expression levels changed by at least a factor of 2 (increased or decreased expression) compared with the wild-type in each of the replicate experiments. Using these selection criteria, we identified 1219 genes. They were categorized into six functional groups: (1) proapoptosis, (2) antiapoptosis, (3) cell cycle, (4) antioxidant, (5) calcium signaling, and (6) axon growth/guidance, with the remaining genes with marked changes in expression placed in a miscellaneous group. After categorization, relevant genes were further narrowed by SAM analysis; q < 0.06 was considered significant. Microarrays were performed in triplicate as biological repeats and reverse fluoro (i.e., three different paired RNA samples) with RNA isolated from neural retinas of cbs+/- HM at 5-weeks after a methionine diet and age-matched wildtype mice after a methionine diet.
2014-04-04 | E-GEOD-56458 | biostudies-arrayexpress
Project description:The catalytic potential for H(2)S biogenesis and homocysteine clearance converge at the active site of cystathionine β-synthase (CBS), a pyridoxal phosphate-dependent enzyme. CBS catalyzes β-replacement reactions of either serine or cysteine by homocysteine to give cystathionine and water or H(2)S, respectively. In this study, high-resolution structures of the full-length enzyme from Drosophila in which a carbanion (1.70 Å) and an aminoacrylate intermediate (1.55 Å) have been captured are reported. Electrostatic stabilization of the zwitterionic carbanion intermediate is afforded by the close positioning of an active site lysine residue that is initially used for Schiff base formation in the internal aldimine and later as a general base. Additional stabilizing interactions between active site residues and the catalytic intermediates are observed. Furthermore, the structure of the regulatory "energy-sensing" CBS domains, named after this protein, suggests a mechanism for allosteric activation by S-adenosylmethionine.
| S-EPMC3000283 | biostudies-literature
Project description:The effects of endogenous elevation of homocysteine on retinal gene expression were screened by microarray analysis, which was performed in triplicate (i.e., three different paired RNA samples) with RNA isolated from neural retinas of cbs+/- HM at 5-weeks after a methionine diet and age-matched wildtype mice. The microarray chips used in this study permitted the screening of 36,212 genes. Of particular interest were those genes in cbs+/- HM mice whose expression levels changed by at least a factor of 2 (increased or decreased expression) compared with the wild-type in each of the replicate experiments. Using these selection criteria, we identified 1219 genes. They were categorized into six functional groups: (1) proapoptosis, (2) antiapoptosis, (3) cell cycle, (4) antioxidant, (5) calcium signaling, and (6) axon growth/guidance, with the remaining genes with marked changes in expression placed in a miscellaneous group. After categorization, relevant genes were further narrowed by SAM analysis; q < 0.06 was considered significant.
2014-04-04 | GSE56458 | GEO
Project description:Cystathionine beta synthase (CBS) catalyzes the first step of the transsulfuration pathway from homocysteine to cystathionine, and its deficiency leads to hyperhomocysteinemia (HHcy) in humans and rodents. To date, scarce information is available about the HHcy effect on insulin secretion, and the link between CBS activity and the setting of type 2 diabetes is still unknown. We aimed to decipher the consequences of an inborn defect in CBS on glucose homeostasis in mice. We used a mouse model heterozygous for CBS (CBS+/-) that presented a mild HHcy. Other groups were supplemented with methionine in drinking water to increase the mild to intermediate HHcy, and were submitted to a high-fat diet (HFD). We measured the food intake, body weight gain, body composition, glucose homeostasis, plasma homocysteine level, and CBS activity. We evidenced a defect in the stimulated insulin secretion in CBS+/- mice with mild and intermediate HHcy, while mice with intermediate HHcy under HFD presented an improvement in insulin sensitivity that compensated for the decreased insulin secretion and permitted them to maintain a glucose tolerance similar to the CBS+/+ mice. Islets isolated from CBS+/- mice maintained their ability to respond to the elevated glucose levels, and we showed that a lower parasympathetic tone could, at least in part, be responsible for the insulin secretion defect. Our results emphasize the important role of Hcy metabolic enzymes in insulin secretion and overall glucose homeostasis.
| S-EPMC9179272 | biostudies-literature