Investigation of ACE, ACE2 and AGTR1 genes for association with nephropathy in Type 1 diabetes mellitus

The genetic side of diabetic kidney disease: a review

BACKGROUND

Diabetic kidney disease (DKD) is one of the most common complications of diabetes, with approximately 30-40% of patients with type 1 diabetes mellitus and 20% of patients with type 2 diabetes mellitus eventually developing DKD. If DKD is not controlled in the early clinical stage and proteinuria develops, the disease will progress to end-stage renal disease. The pathogenesis of DKD remains largely unknown and is multifactorial, likely due to interactions between genetic and environmental factors. Familial clustering also supports a critical role of hereditary factors in DKD. The development of gene detection technology has promoted the exploration of DKD susceptibility genes in different cohorts of patients with diabetes. Identifying susceptibility genes can provide insights into the pathogenesis of DKD, as well as a basis for its clinical diagnosis and therapy.

RESULTS

Numerous candidate gene loci have been found to be associated with DKD, many of which play critical regulatory roles in the pathogenesis of this disease, including genes involved in glycol-metabolism, lipid metabolism, the renin-angiotensin-aldosterone system, inflammation and oxidative stress. In this review, we summarize the functions of several susceptibility genes involved in the development of DKD.

CONCLUSION

Based on our findings, we recommend that studying susceptibility gene polymorphisms can lead to a better understanding of the pathogenesis of DKD and could help prevent this disease or improve its outcomes.

Investigation of angiotensin-1 converting enzyme 2 gene (G8790A) polymorphism in patients of type 2 diabetes mellitus with diabetic nephropathy in Pakistani population

Background

Type 2 diabetes mellitus is a multifactorial disease that escalates the risk of other associated complications such as diabetic neuropathy, retinopathy, and nephropathy. Diabetic nephropathy is a microvascular condition that leads to end-stage renal disease (ESRD). There are several genes involved in disease development and it is a challenging task to investigate all of these. Nonetheless, identifying individual gene roles can assist in evaluating the combinatorial effects with other genes. Angiotensin-1 converting enzyme 2 (ACE2), is the key regulator of blood pressure in the Renin-Angiotensin-Aldosterone System that hydrolyzes angiotensin II (vasoconstrictor) into angiotensin 1–7 (vasodilator). The association of different variants of the ACE2 with the risk of type 2 diabetes mellitus has been determined in various populations with susceptibility to other complications. This study was aimed to investigate the association of Angiotensin-1 converting enzyme 2 polymorphism, G8790A, with the increased risk of type 2 diabetes mellitus (T2DM) development with the complication of diabetic nephropathy (DN) in the Pakistani population.

Methods

In this case-control study, a total of 100 healthy controls and 100 patients of type 2 diabetes mellitus aged > 40 years, having disease duration ≥ 10 years were compared. The G8790A polymorphism in ACE2 was analyzed by allele-specific polymerase chain reaction (AS-PCR). The urinary albumin excretion (UAE), urinary creatinine, and albumin to creatinine ratios (ACR) were determined to assess renal function status. Pearson bivariate correlation coefficients were calculated to investigate the relationship among all the parameters. Crude and adjusted odds ratios were found to determine any risk association between ACE2 G8790A polymorphisms and disease development. The p-values < 0.05 were considered significant.

Results

A homogeneity was obtained regarding the distribution of data by sex, BMI, diastolic blood pressure, pulse rate and urinary creatinine levels between case and control groups. The ACR showed a significant correlation with UAE (r = 0.524, p = 0.001), urinary creatinine (r = -0.375, p = 0.001) and random blood sugar levels (r = 0.323, p = 0.005) with the complication of diabetic nephropathy in T2DM patient. Females with the AA genotype had a 10-fold increased risk for the development of type 2 Diabetes (OR = 9.5 [95% CI = 2.00–21.63] p<0.002). Males having A allele showed a significant association for susceptibility of type 2 Diabetes (OR = 3.807 [95% CI = 1.657–8.747] p<0.002). However, none of the genotypes or alleles revealed an association for diabetic nephropathy in male and female patients. Urinary ACR was also found to be positively correlated with UAE (r = 0.642 p = 0.001 & 0.524, p = 0.001) and random blood sugar levels (r = 0.302, p = 0.002 & r = 0.323, p = 0.005) in T2DM and T2DM+DN groups, respectively.

Conclusion

The study finding indicated that female AG/AA genotype and male A genotype of G8790A polymorphism in the ACE2 gene were associated with type 2 diabetes mellitus as a genetic risk factor but are not associated with diabetic nephropathy in the Pakistani population.

The underlying mechanisms for severe COVID-19 progression in people with diabetes mellitus: a critical review

Diabetes mellitus (DM) has a high incidence of comorbidities among patients with severe coronavirus disease 2019 (COVID-19). The elevated prevalence of DM in the world population makes it a significant risk factor because diabetic individuals appear to be prone to clinical complications and have increased mortality rates. Here, we review the possible underlying mechanisms involved in DM that led to worse outcomes in COVID-19. The impacts of hyperglycemia side effects, secondary comorbidities, weakened innate and adaptive immunity, chronic inflammation, and poor nutritional status, commonly present in DM, are discussed. The role of the SARS-CoV-2 receptor and its polymorphic variations on higher binding affinity to facilitate viral uptake in people with DM were also considered. Clinical differences between individuals with type 1 DM and type 2 DM affected by COVID-19 and the potential diabetogenic effect of SARS-CoV-2 infection were addressed.

Association between AGTR1 A1166C polymorphism and the susceptibility to diabetic nephropathy: Evidence from a meta-analysis

BACKGROUND

Diabetic nephropathy (DN) is a common complication in patients with diabetic mellitus (DM). Growing evidences have demonstrated that the polymorphisms of angiotensin II receptor type 1 (AGTR1) showed significant association with DN onset, but no consensus has been achieved yet. Therefore, we performed this meta-analysis to combine the findings of previous researches for a more comprehensive conclusion.

METHODS

Eligible publications were identified through electronic databases. The intensity of the correlation between AGTR1 A1166C polymorphism and DN susceptibility was evaluated through calculating pooled odds ratios (ORs) with their 95% confidence intervals (95% CIs). Heterogeneity among included studies was examined with Q test. When P-value less than .05, significant heterogeneity presented, random-effects model was used to calculate the pooled ORs, otherwise, the fixed-effects model was used. Stratification analyses were also performed based on ethnicity and the type of DM.

RESULTS

Seventeen eligible articles were finally included in the present meta-analysis. The analysis results showed that AGTR1 A1166C polymorphism was significantly related to increased risk of DN under CC versus AA (OR = 1.723, 95% CI = 1.123-2.644), CC + AC versus AA (OR = 1.179, 95% CI = 1.004-1.383), CC versus AA + AC (OR = 1.662, 95% CI = 1.112-2.486), and C versus A (OR = 1.208, 95% CI = 1.044-1.397) genetic models. Additionally, a similar result was also found in Asian and T2DM (type 2 diabetic mellitus) groups after subgroup analyses of ethnicity and DM type.

CONCLUSION

AGTR1 A1166C polymorphism may increase the susceptibility to DN, especially in Asians and T2DM population.

ACE2 polymorphisms associated with cardiovascular risk in Uygurs with type 2 diabetes mellitus

Background

Type 2 diabetes mellitus (T2D), rapidly increasing to epidemic proportions, globally escalates cardiovascular disease risk. Although intensive interventions and comprehensive management of environmental risks factors for T2D are associated with reduced cardiovascular disease, such approaches are limited for individuals with high genetic T2D risk. In this study we investigated possible associations of ACE2 polymorphisms and cardiovascular risks in Uygur patients with T2D.

Methods

275 Uygur T2D patients and 272 non-diabetic Uygur individuals were enrolled as study participants. 14 ACE2 polymorphisms were genotyped by Matrix-assisted laser desorption ionization time-of-flight mass spectrometry.

Results

ACE2 SNP rs1978124, rs2048683, rs2074192, rs233575, rs4240157, rs4646156, rs4646188 and rs879922 were associated with T2D (all P < 0.05). The 8 diabetic risk related ACE2 SNPs were further associated with diabetic related cardiovascular complications or events but exhibited heterogeneity as fellows: firstly, almost all diabetic risk related ACE2 SNPs (all P < 0.05) were associated with increased SBP except rs1978124 and rs2074192, while rs2074192, rs4646188 and rs879922 were associated elevated DBP (all P < 0.05). Secondly, SNP rs4646188 was not correlated with any type of dyslipidemia (TRIG, HDL-C, LDL-C or CHOL), and the other 7 diabetic risk related loci were at least correlated with one type of dyslipidemia (all P < 0.05). In particular, rs879922 were simultaneously correlated with four type of dyslipidemia (all P < 0.05). Thirdly, ACE2 SNP rs2074192 and rs879922 were associated with carotid arteriosclerosis stenosis (CAS) ≥ 50% (both P < 0.05). Fourthly, ACE2 SNP rs2074192, rs4240157, rs4646188 and 879922 were associated with increased MAU (all P < 0.05). In addition, ACE2 SNP rs2048683, rs4240157, rs4646156, rs4646188 and rs879922 were linked to heavier LVMI (all P < 0.05), but only rs4240157, rs4646156 and rs4646188 were associated with lower LVEF (all P < 0.05).

Conclusion

ACE2 SNP rs879922 may be a common genetic loci and optimal genetic susceptibility marker for T2D and T2D related cardiovascular risks in Uygurs.

Electronic supplementary material

The online version of this article (10.1186/s12933-018-0771-3) contains supplementary material, which is available to authorized users.

The Susceptibility Genes in Diabetic Nephropathy

Background

Diabetes mellitus (DM) poses a severe threat to global public health. Diabetic nephropathy (DN) is one of the most common complications of diabetes and the leading cause of end-stage renal disease (ESRD). Approximately 30-40% of DM patients in the world progress to ESRD, which emphasizes the effect of genetic factors on DN. Family clustering also supports the important role of hereditary factors in DN and ESRD. Therefore, a large number of genetic studies have been carried out to identify susceptibility genes in different diabetic cohorts. Extensive susceptibility genes of DN and ESRD have not been identified until recently.

Summary and Key Messages

Some of these associated genes function as pivotal regulators in the pathogenesis of DN, such as those related to glycometabolism and lipid metabolism. However, the functions of most of these genes remain unclear. In this article, we review several susceptibility genes according to their genetic functions to make it easier to determine their exact effect on DN and to provide a better understanding of the advancements from genetic studies. However, several challenges associated with investigating the genetic factors of DN still exist. For instance, it is difficult to determine whether these variants affect the expression of the protein they encode or other cytokines. More efforts should be made to determine how these genes influence the progression of DN. In addition, many results could not be replicated among races, suggesting that the association between genetic polymorphisms and DN is race-specific. Therefore, large, well-designed studies involving more relevant variables and ethnic groups and more relevant functional studies are urgently needed. These studies may be beneficial and retard the progression of DN by early intervention, especially for patients who carry certain risk alleles or genotypes.

Integrated Bioinformatics Analysis of Potential Biomarkers for Prostate Cancer

The aim was to expound the pathogenesis of prostate cancer and to identify the potentially biomarkers for prostate cancer (PC). DNA methylation microarray data GSE38240 containing 8 prostate cancer metastases and 4 normal prostate samples as well as gene expression profile data GSE26910 containing 6 prostate primary tumors and 6 normal samples were used. Differentially expressed genes (DEGs) and differently methylated sites of PC were screened and the regulatory network was constructed with DEGs-related transcription factors (TFs). The obtained hub genes were subjected to protein-protein interaction network analysis. Enrichment analysis of down-regulated DEGs were performed. Total 351 DEGs including 190 down-regulated and 161 up-regulated genes and 3234 differently methylated sites were identified. In total 69 DEGs-related TFs were found. Regulatory network contained 1301 nodes and 2527 connection pairs and that FOXA1 (forkhead box A1), BZRAP1-AS1 (benzodiazapine receptor associated protein 1 antisense RNA 1) and KRT8 (keratin 8) were the top three nodes of it. The enriched GO terms were mainly biological activity of the blood and cells-related. Total 29 DEGs (such as AGTR1, angiotensin II receptor, type 1) and 57 none-DEGs involved in the PPI network. Biological functions in blood circulation and the involved AGTR1 may play important roles in PC by gene-methylation. Besides, BZRAP1-AS1 may be novel biomarker related with PC.

Association of polymorphisms of angiotensin I converting enzyme 2 with retinopathy in type 2 diabetes mellitus among Chinese individuals

AIMS

To examine the association of Angiotensin I converting enzyme 2 (ACE2) gene polymorphisms and retinopathy in a Chinese type 2 diabetes mellitus (T2DM) cohort.

METHODS

A total of 743 T2DM participants were involved in this study including 408 female and 335 male cases. Female cases were divided into two groups: diabetes without retinopathy (DNR group, n=171) and with retinopathy (DR group, n=237), the latter was further subclassified into nonproliferative DR (NPDR group, n=121) and proliferative DR (PDR group, n=116). Male cases were assigned to DNR group (n=153) and DR group (n=182) which was further grouped into NPDR group (n=86) and PDR group (n=96). Two single nucleotide polymorphisms (SNPs; rs2074192 and rs714205) in ACE2 gene were genotyped.

RESULTS

In female cases, the frequency of genotypes TT in rs2074192 and CC in rs714205 were higher in DR and PDR group than in DNR group (P<0.05). The frequency of alleles T in SNP rs2074192 and C in SNP rs714205 was higher in DR group (P<0.05) and PDR group (P<0.05) than in DNR group. The frequency of allele T in SNP rs2074192 was higher in PDR group (P=0.04) than in NPDR group. The frequency of haplotype TC and CG was higher in DR and PDR groups, respectively (P<0.05). No positive results were found in male cases.

CONCLUSIONS

Our results revealed that SNPs rs2074192 and rs714205 in ACE2 gene were associated with the susceptibility of DR and PDR.

Association between genetic polymorphisms of ACE & eNOS and diabetic nephropathy

Diabetic nephropathy (DN) is the leading cause of end-stage renal disease, with multiple genetic and environmental factors involving in its etiology. ACE and eNOS gene were considered to have important roles in the development and progression of DN. In this study, a case-control study was carried out to investigate the effects of 7 SNPs in ACE gene and 2 SNPs in eNOS gene in the development of DN in Northern China.7 SNPs including A240T, A2350G, A5466C, A2215G, T3892C, C1237T and C3409T of ACE gene and 2 SNPs (G894T and T786C) of eNOS gene were genotyped by polymerase chain reaction restriction fragment length polymorphism method. 431 type 2 diabetic patients with nephropathy (cases) were compared to 420 type 2 diabetic patients without nephropathy (controls) in the study. Data were analyzed by SPSS 17.0 and HaploView software. The frequency distribution of A2350G, 4 haplotyps in ACE gene and G894T in eNOS gene were demonstrated to be different between case and control groups significantly. Whereas other SNPs and haplotypes had no differences in two cohorts. The results revealed that variations of ACE and eNOS gene had association with DN, which indicated ACE and eNOS gene may play an important role in pathogenesis of DN in Northern Chinese Han population.

Non-dipping and arterial hypertension depend on clinical factors rather than on genetic variability of ACE and RGS2 genes in patients with type 1 diabetes

The aim of our study was to characterize the association of clinical and genetic risk factors such as: ACE genotype (rs17997552, rs1800764, rs4459609) and RGS2 (rs2746071) with the development of hypertension (HT) and non-dipping phenomenon in patients with type 1 diabetes mellitus (T1DM). A total of 238 adolescents and young adults with T1DM-103 females and 135 males, aged 8-30 years (mean 17.35 ± 5.2) with diabetes duration 1-26 years (mean 7.72 ± 6.2), with mean HbA1c (IFCC) 58 ± 15 mmol/mmol-were subjected to 24-h ambulatory blood pressure measurements (ABPM). The results of the ABPM were analyzed in association with the polymorphisms of ACE and RGS2 genes and clinical data of patients. HT was recognized in 65 (27 %) and non-dipping in 111 (46.63 %) patients. In the multivariate analysis of factors predisposing to HT, the variables that remained significant were the following: male sex (OR 1.62; 95 % CI 1.171-2.250), non-dipping (OR 1.40; 95 % CI 1.03-1.90) and total cholesterol level (OR 1.01; 95 % CI 1.005-1.021). The only factor influencing non-dipping was the duration of diabetes-OR 1.09 (95 % CI 1.04-1.14). The patients displaying non-dipping have a twice increased risk of development of HT (OR 2.17; 95 % CI 1.21-3.89). There was no association between disturbances of blood pressure (BP) and genotypes of ACE: rs17997552, rs1800764, rs4459609 and RGS2: rs2746071. Clinical rather than genetic risk factors seem to be connected with BP disturbances in young patients with T1DM. Although we have identified representative groups of HT versus non-HT and dipping versus non-dipping subjects, the effect of genetic predisposition to the development of higher BP is too weak to be statistically significant.

ACE2: angiotensin II/angiotensin-(1-7) balance in cardiac and renal injury

Our current recognition of the renin-angiotensin system is more convoluted than originally thought due to the discovery of multiple novel enzymes, peptides, and receptors inherent in this interactive biochemical cascade. Over the last decade, angiotensin-converting enzyme 2 (ACE2) has emerged as a key player in the pathophysiology of hypertension and cardiovascular and renal disease due to its pivotal role in metabolizing vasoconstrictive/hypertrophic/proliferative angiotensin II into favorable angiotensin-(1-7). This review addresses the considerable advancement in research on the role of tissue ACE2 in the development and progression of hypertension and cardiac and renal injury. We summarize the results from recent clinical and experimental studies suggesting that serum or urine soluble ACE2 may serve as a novel biomarker or independent risk factor relevant for diagnosis and prognosis of cardiorenal disease. We also review recent proceedings on novel therapeutic approaches to enhance ACE2/angiotensin-(1-7) axis.

Diabetic nephropathy: diagnosis and treatment

Nephropathy remains a major cause of morbidity and a key determinant of mortality in patients with type 1 or type 2 diabetes mellitus. Research is ongoing to identify biomarkers that in addition to albuminuria and glomerular filtration rate assist in the prediction and monitoring of renal disease in diabetes mellitus. Current strategies to treat this condition focus on intensification of glycaemic control and excellent control of blood pressure using regimens based on blockade of the renin-angiotensin system. Other approaches to control blood pressure and afford renoprotection are under active clinical investigation, including renal denervation and endothelin receptor antagonism. With increasing understanding of the underlying pathophysiological processes implicated in diabetic nephropathy, new specific renoprotective treatment strategies are anticipated to become available over the next few years.

Association of ACE2 genetic variants with blood pressure, left ventricular mass, and cardiac function in Caucasians with type 2 diabetes

BACKGROUND

Cardiovascular disease is common in diabetes, and is associated with activation of the renin-angiotensin system (RAS). Angiotensin-converting enzyme (ACE)2 is a recently described member of the RAS, and this study investigated whether ACE2 polymorphisms are associated with hypertension, left ventricular (LV) mass, and cardiac function in type 2 diabetes.

METHODS

Variants in ACE2 (rs1978124, rs2074192, rs4240157, rs4646156, rs4646188) were examined in 503 Caucasian subjects with type 2 diabetes. As ACE2 is located on the X chromosome, analyses were performed separately for men and women. Hypertension was defined by a history of hypertension, and/or antihypertensive medications or blood pressure (BP) >130/80 mm Hg. LV mass and systolic function (ejection fraction) were assessed by transthoracic echocardiography.

RESULTS

In men, hypertension was more prevalent with the ACE2 rs2074192 C allele (P = 0.023), rs4240157 G allele (P = 0.016) and rs4646188 T allele (P = 0.006). In men, the rs1978124 A allele was associated with a significantly lower ejection fraction compared to the G allele (62.3 ± 13.3 vs. 67.2 ± 10.9%, P = 0.002). This association remained significant after covariate adjustment for age, body mass index, hypertension, antihypertensive treatment, and BP. In women, the prevalence of hypertension was higher (P = 0.009) with the rs4240157 G allele, and the rs1978124 A allele was associated with significantly higher LV mass (P = 0.008).

CONCLUSIONS

In Caucasians with type 2 diabetes, genetic variation in ACE2 is associated with hypertension and reduced systolic function in men, and hypertension and increased LV mass in women.

Angiotensin-converting enzyme 2: enhancing the degradation of angiotensin II as a potential therapy for diabetic nephropathy

Angiotensin-converting enzyme 2 (ACE2) is a monocarboxypeptidase that degrades angiotensin II with high efficiency leading to the formation of angiotensin-(1-7). ACE2 within the kidneys is largely localized in tubular epithelial cells and in glomerular epithelial cells. Decreased glomerular expression of this enzyme coupled with increased expression of ACE has been described in diabetic kidney disease, both in mice and humans with type 2 diabetes. Moreover, both ACE2 genetic ablation and pharmacological ACE2 inhibition have been shown to increase albuminuria and promote glomerular injury. Studies using recombinant ACE2 have shown the ability of ACE2 to rapidly metabolize Ang II in vivo and form the basis for future studies to examine the potential of ACE2 amplification in the therapy of diabetic kidney disease and cardiovascular disease.