Elevated ACE Levels Indicate Diabetic Nephropathy Progression or Companied Retina Impaired

Gene Expression Analysis in T2DM and Its Associated Microvascular Diabetic Complications: Focus on Risk Factor and RAAS Pathway

Prolonged hyperglycemic conditions in type 2 diabetes mellitus (T2DM) cause pathological and functional damage to many organs and tissues, including the kidneys, retina, skin, and neuronal tissues, resulting in the development of microvascular diabetic complications. The altered renin angiotensin aldosterone system (RAAS) pathway has been reported to play an important role in the development of insulin resistance in T2DM and associated complications. The current study was carried out to evaluate the association of risk factors and altered expression of RAAS genes in T2DM patients without complications and T2DM patients with complications (retinopathy, nephropathy, and neuropathy). Four hundred and twenty subjects including 140 healthy controls, 140 T2DM patients with diabetic complications, and 140 T2DM patients without diabetic complications were included in the study. Risk factors associated with the development of T2DM and diabetic complications were evaluated. Further, expression analysis of RAAS genes (AGT, ACE, ACE2, and AGT1R) was carried out using qRTPCR in healthy controls, T2DM patients with complications, and T2DM patients without complications. Various risk factors like urban background, higher BMI, alcoholism, smoking, and family history of diabetes among others were found to be associated with the development of T2DM as well as diabetic complications. The expression level of AGT, ACE, and AGT1R was found to be upregulated whereas ACE2 was found to be downregulated in T2DM patients with complications and T2DM patients without complications as compared to controls. Altered expression of the studied genes of RAAS pathway is associated with the development of microvascular diabetic complications.

Association of angiotensin converting enzyme gene insertion/deletion polymorphism with diabetic retinopathy in middle-aged Indians with type 2 diabetes mellitus

OBJECTIVES

There are conflicting reports regarding the association of angiotensin 1 converting enzyme (ACE) gene polymorphism with diabetic retinopathy (DR). We compared ACE gene insertion/deletion (I/D) polymorphism between patients with and without DR in a middle-aged Indian population. The secondary outcome measure was the comparison of ACE gene I/D polymorphism in different grades of DR severity.

METHODS

Institutional cross-sectional case-control study with middle-aged (45-64 years) type 2 diabetes patients from Eastern India with DR (DR group) and without DR (NODR group). Polymerase chain reaction (PCR) was used to determine the ACE gene I/D polymorphism through primers flanking the polymorphic region of 287 bp Alu repeat sequence in intron 16.

RESULTS

Genotyping for the ACE gene I/D polymorphisms were done for 107 patients in each group. The presence of DR had no significant association with the prevalence of ACE I/D genotype compared to those without DR either in the recessive model (p=0.588) or in the dominant model (p=0.891). The allele contrast was also similar between DR and NODR (p=0.837) groups. The severity of retinopathy was associated with the ACE I/D genotype in the recessive model (p=0.043) but not in the dominant model (p=0.136). However, the severity of retinopathy was associated with allele contrast (p=0.016).

CONCLUSIONS

The ACE gene polymorphism was not associated with diabetic retinopathy in middle-aged Indian patients with type 2 diabetes in our study. However, the severity of DR was associated with the ACE gene polymorphism in these patients.

Metabolic effects of vasopressin in pathophysiology of diabetic kidney disease

The diabetic kidney disease (DKD) is the major cause of the chronic kidney disease (CKD). Enhanced plasma vasopressin (VP) levels have been associated with the pathophysiology of DKD and CKD. Stimulation of VP release in DKD is caused by glucose-dependent reset of the osmostat leading to secondary pathophysiologic effects mediated by distinct VP receptor types. VP is a stress hormone exhibiting the antidiuretic action in the kidney along with broad adaptive effects in other organs. Excessive activation of the vasopressin type 2 (V2) receptor in the kidney leads to glomerular hyperfiltration and nephron loss, whereas stimulation of vasopressin V1a or V1b receptors in the liver, pancreas, and adrenal glands promotes catabolic metabolism for energy mobilization, enhancing glucose production and aggravating DKD. Increasing availability of selective VP receptor antagonists opens new therapeutic windows separating the renal and extra-renal VP effects for the concrete applications. Improved understanding of these paradigms is mandatory for further drug design and translational implementation. The present concise review focuses on metabolic effects of VP affecting DKD pathophysiology.

Role of Cigarette Smoking on Serum Angiotensin-Converting Enzyme and Its Association With Inflammation and Lipid Peroxidation

Introduction Cigarette smoking promotes angiotensin-converting enzyme (ACE) production and causes a substantial change in inflammation and oxidative stress, resulting in an increase in antioxidant activity and lipid peroxidation. Objective The study's goal is to determine the role of cigarette smoking on serum ACE and its relation with inflammatory markers and lipid peroxidation. Methods The cross-sectional study consists of three groups. The study participants are all men between the age group of 20 to 55 years. Group 1 includes 120 healthy controls as nonsmokers, Group 2 consists of 120 active smokers with coronary heart disease (CHD) and Group 3 includes 120 active smokers with diabetic CHD patients attending the SRM Medical College Hospital in Tamil Nadu for cardiology and medical Outpatient. Measurements of serum ACE, oxidized low-density lipoprotein (oxLDL), high-sensitivity C-reactive protein (hsCRP), and matrix metalloprotease-9 (MMP-9) were performed using the ELISA method (enzyme-linked immunosorbent assay). Using a spectrophotometric approach, the total antioxidant capacity and lipid peroxidation, particularly Malondialdehyde (MDA), were assessed. Results The mean serum ACE (92.35±10.28), oxLDL (48.59±8.56), hs-CRP (5.87±1.62), MMP-9 (89.20±30.19), and MDA (1.146±0.198) levels were significantly (p-value <0.0001) higher in smokers with CHD and diabetes (group 3) when compared to group 1 and group 2. On the other hand, the total antioxidant capacity (0.413±0.097) of smokers of group 3 was found to be (p<0.0001) significantly lower than those of group 1 and group 2. The study also demonstrated a significant correlation between ACE with MDA, ox-LDL, total antioxidant capacity, hs-CRP, MMP-9, smoking load, and smoking intensity in smokers. Conclusion The study concludes a substantial correlation exists in smokers owing to ACE modification, which results in inflammation and lipid peroxidation activation. This is strongly associated with an increased risk of major cardiovascular events.