ATP-binding cassette sub-family a member1 gene mutation improves lipid metabolic abnormalities in diabetes mellitus. Lipids Health Dis. 2019;18:103. [PMID: 31010439 PMCID: PMC6477720 DOI: 10.1186/s12944-019-0998-3]

Maternal high-calorie diet feeding programs hepatic cholesterol metabolism and Abca1 promoter methylation in the early life of offspring

Maternal high-calorie diet feeding can dramatically increase the susceptibility of metabolic diseases in offspring. However, whether maternal high-calorie diet feeding can program hepatic cholesterol metabolism in the early life of offspring is less understood, and the epigenetic mechanisms underlying this intergenerational effect, especially during the early life of offspring, are unknown. Female C57BL/6J mice were randomly assigned to a high-calorie diet or control diet before and during gestation, and lactation. Lipid metabolism was evaluated in male offspring at weaning. Gene expressions and quantitative methylation levels of key genes associated with hepatic cholesterol metabolism were further evaluated in offspring at weaning age. We found that maternal high-calorie diet feeding resulted in higher body weight, hypercholesterolemia, elevated total cholesterol in liver homogenates, and fat deposits in the liver in offspring at weaning. For key genes that regulate cholesterol metabolism in liver, we showed lower Hmgcr and Ldlr, and higher Abca1 mRNA and protein expressions in offspring from dams fed with high-calorie diet at weaning age. We further found that maternal high-calorie diet feeding significantly decreased Abca1 methylation level in offspring, with lower methylation levels of both CpG 11 and CpG 22 sites. Interestingly, we found that Abca1 methylation level was negatively associated with hepatic Abca1 mRNA expression in offspring from dams fed with high-calorie diet and controls. However, the expressions of key genes associated with hepatic cholesterol metabolism were not significant between fetuses of dams fed with high-calorie diet and control diet. In conclusion, our results indicate that maternal high-calorie diet feeding results in aberrant lipid metabolism, including hypercholesterolemia and fat deposits in the liver of offspring as early as weaning age. Furthermore, maternal high-calorie feeding can program hepatic cholesterol metabolism and Abca1 methylation in the early life of offspring.

ABCA1 C69T Gene Polymorphism Association with Dysglycemia in Saudi Prediabetic Adults

Studies suggest that ATP-binding cassette transporter A1 (ABCA1 C69T) polymorphism is associated with a decreased incidence of type 2 diabetes mellitus (T2DM) and that there is an association between ABCA1 C69T polymorphism and the risk of dyslipidemia in diabetic individuals. However, other studies contradict these suggestions. Therefore, we aimed to investigate the prevalence of ABCA1 C69T (rs1800977) gene polymorphism in a representative sample of the Saudi population not previously diagnosed with diabetes and its possible association with dyslipidemia and dysglycemia. A cross-sectional design was used to recruit nondiabetic adults of both genders from the Saudi population in Jeddah by employing a stratified, two-stage cluster sampling method. A total of 650 people (337 men and 313 women) were recruited. Demographic, dietary, and lifestyle variables, as well as medical history and family history of chronic diseases, were collected using a predesigned questionnaire. Fasting blood samples were taken for the determination of fasting plasma glucose (FPG), glycated hemoglobin (HbA1c), and lipids profile, which were followed by a 1-h oral glucose tolerance test (OGTT). Real-time PCR technology was used to determine the ABCA1 C69T gene SNP (rs1800977). The T allele of ABCA1 C69T (rs1800977) was very frequent (TT in 44.9% and CT in 43.7%). There was a trend toward significance for a higher dysglycemia percentage in people with CT and TT genotypes (25.7%, and 23.3%, respectively) compared with CC genotypes (16.2%). In addition, FPG and 1-h plasma glucose were significantly higher in people with both TT and CT genotypes compared to CC genotypes. However, T allele was not associated with any dysregulation of lipid parameters.

Genetic Determinants of Cardiovascular Disease: The Endothelial Nitric Oxide Synthase 3 (eNOS3), Krüppel-Like Factor-14 (KLF-14), Methylenetetrahydrofolate Reductase (MTHFR), MiRNAs27a and Their Association with the Predisposition and Susceptibility to Coronary Artery Disease

Coronary artery disease (CAD) is an important cause of death worldwide. CAD is caused by genetic and other factors including hypertension, hyperlipidemia, obesity, stress, unhealthy diet, physical inactively, smoking and Type 2 diabetes (T2D). The genome wide association studies (GWASs) have revealed the association of many loci with risk to diseases such as cancers, T2D and CAD. Nitric oxide (NO) is a potent vasodilator and is required for normal vascular health. It is produced in the endothelial cells in a reaction catalyzed by the endothelial NO synthase (eNOS). Methylenetetrahydrofolate reductase (MTHFR) is a very important enzyme involved in metabolism of folate and homocysteine, and its reduced function leads to cardiovascular disease. The Krüppel-like factor-14 (KLF-14) is an important transcriptional regulator that has been implicated in metabolic syndrome. MicroRNA (MiRNAs) are short non-coding RNAs that regulate the gene expression of proteins involved in important physiological processes including cell cycle and metabolism. In the present study, we have investigated the potential impact of germline pathogenic variants of endothelial eNOS, KLF-14, MTHFR, MiRNA-27a and their association with risk to CAD in the Saudi population. Methods: Amplification Refractory Mutation System (ARMS) PCR was used to detect MTHFR, KLF-14, miRNA-27a and eNOS3 genotyping in CAD patients and healthy controls. About 125 CAD cases and 125 controls were enrolled in this study and statistical associations were calculated including p-value, risk ratio (RR), and odds ratio (OD). Results: There were statistically significant differences (p < 0.05) in genotype distributions of MTHFR 677 C>T, KLF-14 rs972283 G>A, miRNAs27a rs895819 A>G and eNOS3 rs1799983 G>T between CAD patients and controls. In addition, our results indicated that the MTHFR-TT genotype was associated with increased CAD susceptibility with an OR 2.75 (95%) and p < 0.049, and the KLF14-AA genotype was also associated with increased CAD susceptibility with an OR of 2.24 (95%) and p < 0.024. Moreover, the miRNAs27a-GG genotype protects from CAD risk with an OR = 0.31 (0.016), p = 0.016. Our results also indicated that eNOS3 -GT genotype is associated with CAD susceptibility with an OR = 2.65, and p < 0.0003. Conclusion: The MTHFR 677C>T, KLF14 rs972283 G>A, miRNAs27a A>G, and eNOS3 rs1799983 G>T genotypes were associated with CAD susceptibility (p < 0.05). These findings require verification in future large-scale population based studies before these loci are used for the prediction and identification of individuals at risk to CAD. Weight control, physical activity, and smoking cessation are very influential recommendations given by clinicians to the at risk individuals to reduce or delay the development of CAD.

ABC transporters in breast cancer: their roles in multidrug resistance and beyond

ATP-binding cassette (ABC) transporters are membrane-spanning proteins involved in cholesterol homeostasis, transport of various molecules in and out of cells and organelles, oxidative stress, immune recognition, and drug efflux. They are long implicated in the development of multidrug resistance in cancer chemotherapy. Existing clinical and molecular evidence has also linked ABC transporters with cancer pathogenesis, prognostics, and therapy. In this review, we aim to provide a comprehensive update on all ABC transporters and their roles in drug resistance in breast cancer (BC). For solid tumours such as BC, various ABC transporters are highly expressed in less differentiated subtypes and metastases. ABCA1, ABCB1 and ABCG2 are key players in BC chemoresistance. Restraining these transporters has evolved as a possible mechanism to reverse this phenomenon. Further, ABCB1 and ABCC1 are important in BC prognosis. Newer therapeutic approaches have been developed to target all these molecules to dysregulate their effect, reduce cell viability, induce apoptosis, and increase drug sensitivity. In the future, targeted therapy for specific genetic variations and upstream or downstream molecules can help improve patient prognosis.

New insights into renal lipid dysmetabolism in diabetic kidney disease

Lipid dysmetabolism is one of the main features of diabetes mellitus and manifests by dyslipidemia as well as the ectopic accumulation of lipids in various tissues and organs, including the kidney. Research suggests that impaired cholesterol metabolism, increased lipid uptake or synthesis, increased fatty acid oxidation, lipid droplet accumulation and an imbalance in biologically active sphingolipids (such as ceramide, ceramide-1-phosphate and sphingosine-1-phosphate) contribute to the development of diabetic kidney disease (DKD). Currently, the literature suggests that both quality and quantity of lipids are associated with DKD and contribute to increased reactive oxygen species production, oxidative stress, inflammation, or cell death. Therefore, control of renal lipid dysmetabolism is a very important therapeutic goal, which needs to be archived. This article will review some of the recent advances leading to a better understanding of the mechanisms of dyslipidemia and the role of particular lipids and sphingolipids in DKD.

Association between ABC family variants rs1800977, rs4149313, and rs1128503 and susceptibility to type 2 diabetes in a Chinese Han population

OBJECTIVE

To investigate the association between three single nucleotide polymorphisms (SNPs) of the ATP-binding cassette (ABC) gene family and susceptibility to type 2 diabetes mellitus in a Chinese Han population.

METHODS

A total of 1086 type 2 diabetes patients and 1122 healthy controls were included in this retrospective study. Three genetic variants, rs1800977 and rs4149313 in ABCA1, and rs1128503 in ABCB1 were included in the study. Susceptibility to type 2 diabetes was evaluated under three genetic models.

RESULTS

A significant association between rs1800977 and type 2 diabetes was identified in three different genetic models (TT vs CC, odds ratio [OR] = 0.611 [95% confidence interval (CI), 0.469-0.798]; T vs C, OR = 0.841 [95% CI, 0.745-0.950]; and the recessive model, OR = 0.606 [95% CI, 0.474-0.774]). Additionally, a significant association between rs4149313 and type 2 diabetes was identified in three different genetic models (AA vs GG, OR = 0.467 [95% CI, 0.326-0.670]; A vs G, OR = 0.819 [95% CI, 0.717-0.935]; and the recessive model, OR = 0.478 [95% CI, 0.336-0.680]).

CONCLUSION

We found that SNPs rs1800977 and rs4149313 in ABCA1 are significantly associated with susceptibility to type 2 diabetes in a Chinese population, although this should be confirmed in a larger study.

Lipid efflux mechanisms, relation to disease and potential therapeutic aspects

Lipids are hydrophobic and amphiphilic molecules involved in diverse functions such as membrane structure, energy metabolism, immunity, and signaling. However, altered intra-cellular lipid levels or composition can lead to metabolic and inflammatory dysfunction, as well as lipotoxicity. Thus, intra-cellular lipid homeostasis is tightly regulated by multiple mechanisms. Since most peripheral cells do not catabolize cholesterol, efflux (extra-cellular transport) of cholesterol is vital for lipid homeostasis. Defective efflux contributes to atherosclerotic plaque development, impaired β-cell insulin secretion, and neuropathology. Of these, defective lipid efflux in macrophages in the arterial walls leading to foam cell and atherosclerotic plaque formation has been the most well studied, likely because a leading global cause of death is cardiovascular disease. Circulating high density lipoprotein particles play critical roles as acceptors of effluxed cellular lipids, suggesting their importance in disease etiology. We review here mechanisms and pathways that modulate lipid efflux, the role of lipid efflux in disease etiology, and therapeutic options aimed at modulating this critical process.

Association of rs2230806 in ABCA1 with coronary artery disease: An updated meta-analysis based on 43 research studies

BACKGROUND

As a key gene in the reverse transport pathway of cholesterol, ABCA1 (ATP-binding cassette transporter A1) plays an important role in the pathogenesis of coronary artery disease (CAD). In the ABCA1, rs2230806 is the most widely studied polymorphism and its role has been controversial.

METHODS

We performed an updated meta-analysis by searching online electronic databases using the PubMed, Web of Science, Embase, Cochrane Library, EMBASE, Google Scholar, China National Knowledge Infrastructure, and Wan Fang databases before June 28, 2019. STATA12.0 software was used to perform a series of analyses on the data, including genetic effect model, heterogeneity, sensitivity, and publication bias analysis.

RESULTS

Based on our inclusion and exclusion criteria, finally 43 articles including a total of 34,348 subjects (14,085 CAD cases and 20,263 healthy controls) were investigated. Results showed that carrying the K allele in rs223086 in the overall population significantly reduced the risk of CAD (OR = 0.745, 95% CI = 0.687-0.809, P < .001). After the ethnicity stratification analysis, the above phenomenon was found to be significant in Asian populations (OR = 0.686, 95% CI = 0.633-0.744, P < .001), marginally significant in Caucasians (OR = 0.887, 95% CI = 0.786-1.001, P = .051), and not significant in other populations (OR = 0.851, 95% CI = 0.558-1.297, P = .452). Further stratified according to the sample size in the Asian and Caucasian populations, in the Asian the K allele is more protective in small samples than large samples; however, in the Caucasian small samples carrying the K allele play a protective role while large samples are negative. In addition, according to the source of the control population and the geographical location in China, the results showed that rs2230806 was significantly associated with CAD in any group. Five genetic models (allelic, recessive, dominant, homozygote, and heterozygote) were analyzed in the above analysis.

CONCLUSION

The K allele of rs2230806 was significantly associated with decreased risk of CAD, especially in Asian populations and small sample Caucasians.

The ABC subfamily A transporters: Multifaceted players with incipient potentialities in cancer

Overexpression of ATP-binding cassette (ABC) transporters is a cause of drug resistance in a plethora of tumors. More recent evidence indicates additional contribution of these transporters to other processes, such as tumor cell dissemination and metastasis, thereby extending their possible roles in tumor progression. While the role of some ABC transporters, such as ABCB1, ABCC1 and ABCG2, in multidrug resistance is well documented, the mechanisms by which ABC transporters affect the proliferation, differentiation, migration and invasion of cancer cells are still poorly defined and are frequently controversial. This review, summarizes recent advances that highlight the role of subfamily A members in cancer. Emerging evidence highlights the potential value of ABCA members as biomarkers of risk and response in different tumors, but information is disperse and very little is known about their possible mechanisms of action. The only clear evidence is that ABCA members are involved in lipid metabolism and homeostasis. In particular, the relationship between ABCA1 and cholesterol is becoming evident in different fields of biology, including cancer. In parallel, emerging findings indicate that cholesterol, the main component of cell membranes, can influence many physiological and pathological processes, including cell migration, cancer progression and metastasis. This review aims to link the dispersed knowledge regarding the relationship of ABCA members with lipid metabolism and cancer in an effort to stimulate and guide readers to areas that the writers consider to have significant impact and relevant potentialities.