Sirtuin 1 rs1467568 and rs7895833 in South African Indians with early-onset coronary artery disease

Genetic variants in DBC1, SIRT1, UCP2 and ADRB2 as potential biomarkers for severe obesity and metabolic complications

Introduction

Obesity is a multifactorial disease associated with the development of many comorbidities. This disease is associated with several metabolic alterations; however, it has been shown that some individuals with obesity do not exhibit metabolic syndrome. Adipose tissue neutralizes the detrimental effects of circulating fatty acids, ectopic deposition, and inflammation, among others, through its esterification into neutral lipids that are stored in the adipocyte. However, when the adipocyte is overloaded, i.e., its expansion capacity is exceeded, this protection is lost, resulting in fatty acid toxicity with ectopic fat accumulation in peripheral tissues and inflammation. In this line, this study aimed to investigate whether polymorphisms in genes that control adipose tissue fat storage capacity are potential biomarkers for severe obesity susceptibility and also metabolic complications.

Methods

This study enrolled 305 individuals with severe obesity (cases, BMI≥35 kg/m2) and 196 individuals with normal weight (controls, 18.5≤BMI≤24.9 kg/m2). Demographic, anthropometric, biochemical, and blood pressure variables were collected from the participants. Plasma levels of leptin, resistin, MCP1, and PAI1 were measured by Bio-Plex 200 Multiplexing Analyzer System. Genomic DNA was extracted and variants in DBC1 (rs17060940), SIRT1 (rs7895833 and rs1467568), UCP2 (rs660339), PPARG (rs1801282) and ADRB2 (rs1042713 and rs1042714) genes were genotyped by PCR allelic discrimination using TaqMan® assays.

Results

Our findings indicated that SIRT1 rs7895833 polymorphism was a risk factor for severe obesity development in the overdominant model. SIRT1 rs1467568 and UCP2 rs660339 were associated with anthropometric traits. SIRT1 rs1467568 G allele was related to lower medians of body adipose index and hip circumference, while the UCP2 rs660339 AA genotype was associate with increased body mass index. Additionally, DBC1 rs17060940 influenced glycated hemoglobin. Regarding metabolic alterations, 27% of individuals with obesity presented balanced metabolic status in our cohort. Furthermore, SIRT1 rs1467568 AG genotype increased 2.5 times the risk of developing metabolic alterations. No statistically significant results were observed with Peroxisome Proliferator-Activated Receptor Gama and ADRB2 polymorphisms.

Discussion/Conclusion

This study revealed that SIRT1 rs7895833 and rs1467568 are potential biomarkers for severe obesity susceptibility and the development of unbalanced metabolic status in obesity, respectively. UCP2 rs660339 and DBC1 rs17060940 also showed a significant role in obesity related-traits.

Exploring the moderating effects of SIRT1 and gene polymorphisms rs7895833 on the relationship between hemoglobin levels and physical frailty in elderly adults with comorbid chronic diseases: A moderated mediation analysis

Background

Relationship age, hemoglobin, and physical frailty have all been investigated in older people with more than one chronic disease. There has been little analysis of the relationship between hemoglobin, age, physical frailty, plasma levels of Sirtuin1 (SIRT1), and the gene polymorphism (SNP) rs7895833 A>G. The goal of this study was to find out how SIRT1 level, SNP rs7895833, hemoglobin, age, and physical frailty (frail score) are related in older Indonesian adults with comorbid chronic diseases.

Methods

This was an observational study. Demographic and clinical data were retrieved from the electronic health records of Universitas Sumatera Utara Hospital, Medan, Indonesia. Physical frailty, SIRT1 level, and SNP rs7895833 were measured using an appropriate and valid method. Purposive sampling was used to determine the eligibility of 132 elderly adults from November 2022 to February 2023.

Results

The indirect effect of hemoglobin on the frail score (FS) through age was negative and significant, according to a conditional mediation analysis (β=-0.0731; p=0.023). Meanwhile, the direct effect of hemoglobin on the FS was negative and not significant (β=0.1632; p=0.052). According to the conditional moderated mediation analysis, the size of the direct effect of age on FS was increased by genotype AG-GG and SIRT1 level (β low=0.2647; p=0.002, β middle=0.2956; p<0.001, and β high=0.319; p<0.001). The size of the conditional indirect effect of Hemoglobin on FS through age was negative and significantly increased by SNP genotype AG-GG and SIRT1 level (β low=-0.0647; p=0.032, β middle=-0.0723; p=0.024, and β high=-0.078; p=0.02).

Conclusions

Higher plasma levels of SIRT1 and the SNP genotype AG-GG may both contribute to physical frailty in the elderly population. Hemoglobin levels in the blood fall with age, which can negatively impact older persons who already have chronic diseases. However, the interactions between these factors are intricate, requiring more study to completely understand the processes underlying development.

Analysis of SIRT1 genetic variants in young Mexican individuals: relationships with overweight and obesity

The high prevalence of obesity in Mexico starting from the early stages of life is concerning and represents a major public health problem. Genetic association studies have reported that single nucleotide variants (SNVs) in SIRT1, an NAD+-dependent deacetylase that plays an important role in the regulation of metabolic cellular functions, are associated with multiple metabolic disorders and the risk of obesity. In the present study, we analyzed the effect that the SNVs rs1467568 and rs7895833 of the SIRT1 gene may have on cardiometabolic risk factors in a young adult population from Mexico. A cross-sectional study was carried out with young adults between the ages of 18 and 25 who had a body mass index (BMI) greater than 18.5 kg/m2. This study included 1122 young adults who were classified into the normal weight (n = 731), overweight group (n = 277), and obesity group (n = 114) according to BMI of whom 405 and 404 volunteers were genotyped for rs1467568 and rs7895833 respectively using TaqMan probes through allelic discrimination assays. We found that the male sex carrying the G allele of rs7895833 had slightly lower BMI levels (p = 0.009). Furthermore, subjects carrying rs1467568 (G allele) showed a 34% lower probability of presenting with hyperbetalipoproteinemia where female carrying rs1467568 had lower levels of total cholesterol (p = 0.030), triglycerides (p = 0.026) and LDL cholesterol (p = 0.013). In conclusion, these findings suggest that the presence of both SNVs could have a non-risk effect against dyslipidemia in the Mexican population.

A Potential Role for Sirtuin-1 in Alzheimer's Disease: Reviewing the Biological and Environmental Evidence

Sirtuin-1 (Sirt1), encoded by the SIRT1 gene, is a conserved Nicotinamide adenine dinucleotide (NAD+) dependent deacetylase enzyme, considered as the master regulator of metabolism in humans. Sirt1 contributes to a wide range of biological pathways via several mechanisms influenced by lifestyle, such as diet and exercise. The importance of a healthy lifestyle is of relevance to highly prevalent modern chronic diseases, such as Alzheimer's disease (AD). There is growing evidence at multiple levels for a role of Sirt1/SIRT1 in AD pathological mechanisms. As such, this review will explore the relevance of Sirt1 to AD pathological mechanisms, by describing the involvement of Sirt1/SIRT1 in the development of AD pathological hallmarks, through its impact on the metabolism of amyloid-β and degradation of phosphorylated tau. We then explore the involvement of Sirt1/SIRT1 across different AD-relevant biological processes, including cholesterol metabolism, inflammation, circadian rhythm, and gut microbiome, before discussing the interplay between Sirt1 and AD-related lifestyle factors, such as diet, physical activity, and smoking, as well as depression, a common comorbidity. Genome-wide association studies have explored potential associations between SIRT1 and AD, as well as AD risk factors and co-morbidities. We summarize this evidence at the genetic level to highlight links between SIRT1 and AD, particularly associations with AD-related risk factors, such as heart disease. Finally, we review the current literature of potential interactions between SIRT1 genetic variants and lifestyle factors and how this evidence supports the need for further research to determine the relevance of these interactions with respect to AD and dementia.

Association of Sirtuin Gene Polymorphisms with Susceptibility to Coronary Artery Disease in a North Chinese Population

Aims

Coronary artery disease (CAD) represents the leading cause of death worldwide. Accumulating evidence also suggests that sirtuins (SIRTS) have been associated with CAD. The present study was aimed at investigating the association between 12 gene polymorphisms for SIRTs and the development of CAD in a Chinese population.

Materials and Methods

12 SNPs (rs12778366 (T > C), rs3758391 (T > C), rs3740051 (A > G), rs4746720 (C > T), rs7895833 (G > A), rs932658 (A > C) for SIRT1, rs2015 (G > T) for SIRT2, rs28365927 (G > A), rs11246020 (C > T) for SIRT3, rs350844 (G > A), rs350846 (G > C), and rs107251 (C > T) for SIRT6) were selected and assessed in a cohort of 509 CAD patients and 552 matched healthy controls for this study. Genomic DNA from whole blood was extracted, and the SNPs were assessed using MassARRAY method.

Results

TT genotype for rs3758391 and GG genotype for rs7895833 of SIRT1 were at higher risk of CAD, whereas the CC genotype for rs4746720 of SIRT1 was associated with a significantly decreased risk of CAD. The A allele of the rs28365927 of SIRT3 showed a significant decreased risk association with CAD patient group (P = 0.014). Significant difference in genotypes rs350844 (G > A) (P = 0.004), rs350846 (G > C) (P = 0.002), and rs107251 (C > T) (P ≤ 0.01) for SIRT6 was also found between the CAD patients and the healthy controls. Haplotype CTA significantly increased the risk of CAD (P = 0.000118, OR = 1.497, 95%CI = 1.218–1.840), while haplotype GCG significantly decreases the risk of CAD (P = 0.000414, OR = 1.131, 95%CI = 0.791–1.619).

Conclusions

The SNP rs28365927 in the SIRT3 gene and SNP rs350844, rs350846, and rs107251 in the SIRT6 gene present significant associations with CAD in a north Chinese population. Haplotype CTA and GCG generated by rs350846/rs107251/rs350844 in the SIRT6 might also increase and decrease the risk of CAD, respectively.

Gene polymorphisms of SIRT1 in patients with rheumatoid arthritis

AIM

Previous studies have shown that silent information regulator 1 (SIRT1) expression is elevated in rheumatoid arthritis (RA) patients. However, whether gene polymorphisms in SIRT1 gene associated with RA in a Chinese Han population remains to be discussed.

METHOD

In this case-control study, 529 RA patients and 700 healthy controls were selected, and association of 11 SIRT1 gene polymorphisms (rs12415800, rs3740051, rs932658, rs3740053, rs7895833, rs10509291, rs33957861, rs7069102, rs2273773, rs3818292, rs1467568) with RA susceptibility was evaluated.

RESULTS

Frequency of GA+GG genotype of rs3740051 in RA patients was significantly lower than that in healthy controls (P = .037). Frequencies of GC and GC+GG genotypes of rs7069102 were significantly lower than those in healthy controls (P = .036, P = .047). Frequencies of GA and GA+GG genotypes of rs1467568 were lower in RA patients as compared to those in healthy controls (P = .011, P = .013). For rs2273773, RA patients who carried the T allele had higher number of tender joints than patients who carried the C allele (P = .033). Other polymorphisms did not associate with RA risk.

CONCLUSION

The findings suggest that rs3740051, rs7069102 and rs1467568 variants in SIRT1 gene are related to RA susceptibility in a Chinese Han population.

Sirtuin1 in vascular endothelial function, an overview

Sirtuin1 is a nutrient-sensitive class III histone deacetylase which is a well-known regulator of organismal lifespan. It has been extensively studied for its role in metabolic regulation as well. Along with its involvement in ageing and metabolism, Sirtuin1 directly deacetylates many critical proteins controlling cardiovascular pathophysiology. Studies using conditional expression and deletion of Sirtuin1 have revealed that it functions in a highly tissue/organ-specific manner. In the vasculature, Sirtuin1 controls endothelial homoeostasis by governing the expression of inflammatory mediators, oxidants and essential transcription factors. Adding to this complexity, Sirtuin1 expression and/or function is also governed by some of these target proteins. Therefore, the importance of better understanding the organ and tissue specificity of Sirtuin1 is highly desirable. Considering the huge volume of research done in this field, this review focuses on Sirtuin1 targets regulating vascular endothelial function. Here, we summarize the discovery of Sirtuin1 as a transcription controller and the further identification of direct target proteins involved in the vascular physiology. Overall, this review presents a holistic picture of the complex cross-talk involved in the molecular regulation of vascular physiology by Sirtuin1.

Resveratrol Ameliorates Aortic Calcification in Ovariectomized Rats via SIRT1 Signaling

Postmenopausal women are at an increased risk of vascular calcification which is defined as the pathological deposition of minerals in the vasculature, and is strongly linked with increased cardiovascular disease risk. Since estrogen-replacement therapy is associated with increased cancer risk, there is a strong need for safer therapeutic approaches. In this study we aimed to investigate the protective and therapeutic effects of the phytoestrogen resveratrol against vascular calcification in ovariectomized rats, a preclinical model of postmenopause. Furthermore, we aimed to compare the effects of resveratrol to those of estrogen and to explore the mechanisms underpinning those effects. Treatment with resveratrol or estrogen ameliorated aortic calcification in ovariectomized rats, as shown by reduced calcium deposition in the arterial wall. Mechanistically, the effects of resveratrol and estrogen were mediated via the activation of SIRT1 signaling. SIRT1 protein expression was downregulated in the aortas of ovariectomized rats, and upregulated in rats treated with resveratrol or estrogen. Moreover, resveratrol and estrogen reduced the levels of the osteogenic markers: runt-related transcription factor 2 (RUNX2), osteocalcin and alkaline phosphatase (ALP) which have been shown to play a role during vascular calcification. Additionally, the senescence markers (p53, p16 and p21) which were also reported to play a role in the pathogenesis of vascular calcification, were reduced upon treatment with resveratrol and estrogen. In conclusion, the phytoestrogen resveratrol may be a safer alternative to estrogen, as a therapeutic approach against the progression of vascular calcification during postmenopause.

SIRT1 gene polymorphisms are associated with nondiabetic type 1 cardiorenal syndrome

Type 1 cardiorenal syndrome (CRS1) is characterized by acute cardiac disease (e.g., acute heart failure [AHF]), leading to acute kidney injury. Sirtuin 1 (SIRT1), an NAD⁺ -dependent deacylase, has been found to be associated with CRS1. To confirm whether a correlation exists between SIRT1 variants and the risk of CRS1, the association between the prevalence of CRS1 and single-nucleotide polymorphisms (SNPs) within the SIRT1 gene was investigated in AHF patients. A total of 316 Chinese AHF participants (158 patients with CRS1 and 158 age- and sex-matched controls) were recruited for the present observational study to investigate the association between nine common SIRT1 SNPs (i.e., rs7895833 G > A, rs10509291 T > A, rs3740051 A > G, rs932658 A > C, rs33957861 C > T, rs7069102 C > G, rs2273773 T > C, rs3818292 A > G, and rs1467568 A > G) and the susceptibility to CRS1. Significant differences in genotype distribution between the control and CRS1 groups were found for rs7895833 and rs1467568. After applying a Bonferroni adjustment, the A allele of rs7895833 was still found to be protective (p = 0.001; odds ratio [OR] = 0.77) against CRS1 in this study population. The AA genotype of rs7895833 and the GA genotype of rs1467568 were associated with a significantly reduced risk of CRS1 (OR = 0.23 and 0.49, respectively). rs7895833 and rs1467568 were further analyzed as a haplotype, and the GA haplotype (rs7895833-rs1467568) exhibited a significant association with CRS1 (p = 0.008), while the AA haplotype showed a significant protective effect (p = 0.022). Our study showed that SIRT1 rs7895833 and rs1467568 polymorphisms had a significant effect on the risk of developing CRS1 in a population in China.

SIRT1 Gene Polymorphisms Are Associated with Urinary Bladder Cancer in an Iranian Population

BACKGROUND

The present study was undertaken to evaluate the possible association between silent information regulator of transcription 1 gene (SIRT 1) polymorphisms and risk of urinary bladder cancer (UBC) in an Iranian population.

METHODS

The SIRT1 polymorphisms rs3758391 T/C and rs369274325 G/A were evaluated in 120 Iranian bladder cancer patients and 118 healthy individuals as the control group. The SIRT1 rs369274325 G/A and rs3758391 T/C polymorphisms were genotyped using tetra-primer ARMS PCR and PCR-RFLP methods, respectively.

RESULTS

The SIRT1 rs3758391 TT genotype occurred significantly more frequently in the UBC patients than in the controls (13.3 vs. 1.7%) in both the additive and recessive models due to a significant difference in either of additive (TT vs. CC; OR= 9.529, P = 0.003) or recessive models (TT vs. CC + CT genotype; OR= 8.923, P = 0.002). Also, for rs369274325, the AG genotype was found in a significantly greater percentage of UBC patients than in controls (75.8 vs. 43.2%, respectively, P < 0.0001.

CONCLUSION

Our preliminary study suggests that SIRT1 rs3758391 T/C and rs369274325 G/A polymorphisms may confer an increased risk of bladder cancer in our patients.

Polymorphism rs7895833 in the SIRT1 gene and its association with dyslipidaemia in the elderly

OBJECTIVES

Sirtuin 1 is a human protein involved in gene silencing and in inducing the deacetylation of proteins involved in the metabolic and adaptive response mechanisms. Polymorphisms in the SIRT1 gene have been studied with respect to aging. This study aims to determine the allelic and genotypic frequencies of the rs7895833 A/G polymorphism in the SIRT1 gene, and to identify the association between this polymorphism and the co-morbidities prevalent in the elderly population.

MATERIAL AND METHODS

A total of 216 patients were evaluated in an outpatient clinic in Central Brazil. The individuals underwent validated tests for cognitive impairment and falls risk, serum biochemistry analysis, as well as polymer chain reaction (PCR) with confronting two-pair primers for polymorphism genotyping.

RESULTS

rs7895833 polymorphism in SIRT1 gene was observed in these patients as follows: AA (56/216), AG (138/216), and GG (22/216). The frequency of allele A was 0.58, and that of allele G was 0.42. In the multivariate analysis of the exploratory variables, glucose, high density lipoprotein (HDL) cholesterol, systemic arterial hypertension, dyslipidaemia, and depression, which were associated in the univariate analysis with the polymorphism rs7895833, only dyslipidaemia showed a statistically significant difference in a greater number of individuals with this polymorphism.

CONCLUSION

The variant allele G of the SIRT1 gene polymorphism was found in 42% of these Brazilian geriatric patients, and was associated with dyslipidaemia. Further studies should be performed to confirm this result and to elucidate the role of SIRT1 in lipid metabolism.

SIRT1 gene polymorphisms associated with decreased risk of atherosclerotic coronary artery disease

Coronary artery disease (CAD) exhibits the rules of the multifactorial hereditary. Notwithstanding, the role of genetic factors in the prevalence of CAD is estimated very high. SIRT1 plays an athero-protective role and alterations in its expression have some important consequence in the metabolism, cholesterol, and fat deposition. The aim of our study was to investigate the association between rs4746720, rs12413112, and rs1467568 polymorphisms in the SIRT1 gene and CAD in the high-risk cases. In the present retrospective case-control study, 150 healthy individuals and 150 cases diagnosed with atherosclerotic lesions were investigated. ARMS PCR was used to determine the genotypes of rs4746720 polymorphism, while tetra primer-ARMS PCR was used for genotyping of rs12413112 and rs1467568 polymorphisms. Considering rs12413112 polymorphism, the frequency of the AG heterozygote genotype was significantly lower in cases than controls (P < 0.001). Furthermore, the frequency of the A-positive (AA+AG vs. GG) genotype was significantly different between groups (P < 0.001). The frequency of the variant A allele was 0.36% in cases and 0.46% in controls (P = 0.01). Except for a borderline protective effect in the present of rs1467568AG genotype, the allele and genotype distributions of both rs1467568 and rs4746720 polymorphisms did not differ between two groups. The haplotype constructed from rs1467568A, rs12413112A, and rs4746720T alleles showed a significant protective effect on the risk of CAD (OR: 0.53; 95%CI: 0.35-0.78; P = 0.001). In conclusion, the SIRT1 gene may contribute to the pathogenesis of CAD, while further investigations were suggested to confirm our results.

Diabetic macroangiopathy: Pathogenetic insights and novel therapeutic approaches with focus on high glucose-mediated vascular damage

Diabetic macroangiopathy - a specific form of accelerated atherosclerosis - is characterized by intra-plaque new vessel formation due to excessive/abnormal neovasculogenesis and angiogenesis, increased vascular permeability of the capillary vessels, and tissue edema, resulting in frequent atherosclerotic plaque hemorrhage and plaque rupture. Mechanisms that may explain the premature and rapidly progressive nature of atherosclerosis in diabetes are multiple, and to a large extent still unclear. However, mechanisms related to hyperglycemia certainly play an important role. These include a dysregulated vascular regeneration. In addition, oxidative and hyperosmolar stresses, as well as the activation of inflammatory pathways triggered by a dysregulated activation of membrane channel proteins aquaporins, have been recognized as key events. Here, we review recent knowledge of cellular and molecular pathways of macrovascular disease related to hyperglycemia in diabetes. We also here highlight how new insights into pathogenic mechanisms of vascular damage in diabetes may indicate new targets for prevention and treatment.