Can Bone-Specific Alkaline Phosphatase be a Marker of Vascular Calcification in Type 2 Diabetes Mellitus?

Background and Aims: Alkaline phosphatase (ALP) enzyme has been linked to vascular calcification. Unexplained elevations in serum ALP levels have been reported in patients with type 2 diabetes mellitus (T2DM). We assessed bone-specific alkaline phosphatase (BAP) levels in patients with T2DM who had unexplained ALP elevations and studied the association between BAP and other markers of vascular calcification. Methods: Patients with T2DM who had high serum ALP in the absence of known causes of ALP elevation were studied. The control group was T2DM patients with normal ALP. We measured the serum levels of BAP along with the leptin, fetuin-A, and vitamin K2 levels. Ankle-brachial index (ABI) was also measured in both groups. Results: Serum BAP levels were significantly higher in the group with high ALP when compared with the normal ALP group. A significant positive correlation was present between BAP and serum fetuin-A as well as between BAP and Vit K2 levels. There was no correlation between BAP and serum leptin. ABI was comparable between the two groups. Conclusions: Patients with T2DM may have unexplained elevation in ALP due to an increase in BAP. Elevation in BAP may be associated with other markers of vascular calcification suggesting an increased risk of vascular calcification.

Role of Survivin and p53 Expression in Response of Primary Culture of Ovarian Cancer Cells to Treatment With Chemotherapeutic Agents.

BACKGROUND: Ovarian cancer is associated with a high relapse rate and is the fifth leading cause of cancer deaths in women. The genetic profile of a tumor is responsible for deciding response to chemotherapeutic agents. In this study, we investigate the relation between survivin and p53 expression and response to chemotherapeutic agents of primary cultures of ovarian cancer cells established from ascitic fluid. MATERIALS AND METHOD: Ascitic fluid and Dulbecco's modified Eagle medium was mixed in equal proportion in culture flasks and incubated to establish primary culture. The cells were treated with different combinations of carboplatin and paclitaxel with and without survivin small interfering RNA transfection. Cell survival was estimated by MTT assay. Survivin and p53 expression was quantified by real-time polymerase chain reaction. RESULTS: Out of 19 ascitic fluid samples, 13 primary cultures of ovarian cancer cells were established. The half maximal inhibitory concentration doses of carboplatin (≥70 µg/mL) and paclitaxel (≥18 µg/mL) were high for 10/13 and 5/13 patients, respectively. Survivin messenger RNA expression was significantly downregulated on treatment with carboplatin (100 µg/mL), paclitaxel (12.5 µg/mL), and a combination of carboplatin (50 µg/mL) and paclitaxel (6.25 µg/mL). Only paclitaxel-treated ovarian cancer cells showed decrease in expression of p53. Survivin small interfering RNA increased sensitivity of the primary cultures to chemotherapeutic agents. CONCLUSIONS: The present study highlights the fact that establishing primary cultures from ascitic fluid may help to develop personalized treatment regime for individual patients based on their molecular profile. Our study also shows that supplementing taxols drugs with survivin inhibitors may prove to be beneficial in the treatment of ovarian cancer patients.

Lead-induced DNA damage and cell apoptosis in human renal proximal tubular epithelial cell: Attenuation via N-acetyl cysteine and tannic acid.

This study investigates the exposure of lead-induced reactive oxygen species (ROS) generation, DNA damage, and apoptosis and also evaluates the therapeutic intervention using antioxidants in human renal proximal tubular cells (HK-2 cells). Following treatment of HK-2 cells with an increasing concentration of lead nitrate (0-50 µM) for 24 h, the intracellular ROS level increased whereas the GSH level decreased significantly in a dose-dependent manner. Comet assay results revealed that lead nitrate showed the ability to increase the levels of DNA strand breaks in HK-2 cells. Lead exposure also induced apoptosis through caspase-3 activation at 30 µg/mL. Pretreatment with N-acetylcysteine (NAC) and tannic acid showed a significant ameliorating effect on lead-induced ROS, DNA damage, and apoptosis. In conclusion, lead induces ROS, which may exacerbate the DNA damage and apoptosis via caspase-3 activation. Additionally, supplementation of antioxidants such as NAC and tannic acid may be used as salvage therapy for lead-induced DNA damage and apoptosis in an exposed person.

Association of polymorphic variants in IL1B gene with secretion of IL-1ß protein and inflammatory markers in north Indian rheumatoid arthritis patients.

The proinflammatory cytokine interleukin-1beta (IL-1ß) is a key mediator of inflammation which affects cell proliferation and differentiation. IL-1ß is considered to contribute to the pathophysiology of rheumatoid arthritis (RA). Polymorphisms in cytokine genes are highly influenced by ethnicity. Hence, in this study polymorphism of the IL1B-511(C/T) within promoter region was analyzed by using polymerase chain reaction-restriction fragment length Polymorphism (PCR-RFLP) in 187 RA patients and 214 controls. The prevalence of different genotypes and allelic frequency distribution was compared in RA patients and controls. Levels of inflammatory markers and serum levels of IL-1ß were estimated by ELISA The serum inflammatory markers levels were significantly higher in RA patients as compared to controls (RF=127.3±21.3U/mL, Anti-CCP=17.8±8.3U/mL, CRP=17.86±7.1mg/L and IL-1ß=21.25±4.19pg/mL in RA patients p<0.01). The frequency of heterozygous mutant (C/T) and homozygous mutant (T/T) variants were significantly higher in RA patients as compared to controls and the odds ratios by logistic regression were (OR=2.2, p<0.001) and (OR=3.21, p<0.01) respectively. The association persisted on combining the heterozygous mutant and homozygous mutant (CT+TT) together as compared to controls (OR=2.39; p<0.001). Positive and significant (p<0.05) correlation of circulating IL-1ß levels with RF (r=0.232), anti-CCP (r=0.207) and CRP (r=0.166) among RA patients were found. The levels of anti-CCP were significantly higher in homozygous mutant variants (TT) as well as the heterozygous mutant variants (C/T) in comparison to the wild variants (CC) (p<0.01). The results of this study reveal that mutant allele (T) of IL1B-511 promoter SNP tends to be associated with elevated anti-CCP and IL-1ß levels as observed in RA patients and hence disease susceptibility.

Establishment of Primary Cell Culture From Ascitic Fluid and Solid Tumor Obtained From Epithelial Ovarian Carcinoma Patients.

OBJECTIVE: Ovarian cancer is the seventh leading cause of cancer death worldwide. This is mainly due to late diagnosis and high rate of relapse and resistance following chemotherapy. In the present study, we describe simple and cost-effective method to establish primary culture from ascitic fluid and solid tumor obtained from epithelial ovarian carcinoma patient, which may provide a better tool for in vitro testing of drug sensitivity and designing individualized treatment protocol. METHODS: Complete Dulbecco modified Eagle medium (DMEM) was prepared by supplementing DMEM with 10% fetal bovine serum and antibiotics (ciprofloxacin and amphotericin B). Establishment of primary culture of ovarian cancer cells from ascites fluid and solid tumor was done by using complete DMEM media. RESULTS: Primary cultures of ovarian cancer cells were established from ascitic fluid and solid tumor tissue. Of the 7 ascitic fluid samples, we were able to establish 5 primary cultures of ovarian cancer cells. All the 7 samples were diagnosed as serous papillary adenocarcinoma. Some fibroblasts were also attached to culture flask on day 4; they were removed by exposing them to trypsin for a brief period. On day 7, grape-like clusters were visualized under inverted microscope. The cells became confluent on the 10th and 11th day and showed cobblestone appearance, which is a hallmark of ovarian cancer cells. Senescent irregularly shaped cells that have ceased dividing were seen after 8 to 10 passages. CONCLUSION: This study highlights the fact that establishing primary cultures from ascitic fluid or solid tumor tissue may help us to understand the molecular profile of the cancer cells, which allow us to select the best chemotherapeutic agent for ovarian cancer patients and thus take a step toward patient-tailored therapy so that patients are not exposed to drugs to which they are not likely to respond.

Tumor necrosis factor-α -308 polymorphism in North Indian rheumatoid arthritis patients and association with mRNA and serum TNF-α.

Rheumatoid arthritis (RA) is a severely disabling chronic autoimmune disorder that leads to progressive inflammation of the joints and surrounding tissues. TNF-α, a potent proinflammatory cytokine, plays a pivotal role in the pathogenesis of RA. The endogenous formation of TNF-α may be influenced by TNF-α promoter polymorphisms. Hence, the present study was designed to explore any possible association between genetic polymorphism of TNF-α -308 G/A, messenger RNA (mRNA) expression, serum levels of TNF-α, and inflammatory markers in North Indian RA patients. A total of 214 controls and 187 RA patients were recruited according to the revised American College of Rheumatology 2010 criteria. TNF-α -308 G/A genetic polymorphism within promoter region was analyzed by using PCR-RFLP. Levels of inflammatory markers and serum TNF-α were estimated by ELISA. The mRNA expression of TNF-α gene was measured by quantitative real-time PCR. Higher levels of autoantibodies (RF and anti-CCP) were present in RA patients as compared to controls. We found a positive and significant correlation of circulating TNF-α levels with RF (r = 0.18), anti-CCP (r = 0.16), and mRNA expression of TNF-α gene (r = 0.57) in RA patients. The mRNA expression levels of TNF-α was 4.5-fold higher in patients with RA as compared to controls. The heterozygous mutant variants (G/A) and homozygous mutant variants (A/A) were found to be significantly associated with RA as compared to control (OR = 1.52 and 3.02, respectively). Our observations illustrated a significant association of allele -308 A TNF-α with progression of RA. Significant and positive correlation of TNF-α levels with mRNA expression and inflammatory marker levels suggests that serum TNF-α may be a susceptibility marker for RA.

Role of advanced glycation end product (AGE)-induced receptor (RAGE) expression in diabetic vascular complications.

AIMS: Vascular complications are the major causes of morbidity and mortality in diabetic subjects. Interaction of advanced glycation end products (AGEs) with their receptor (RAGE) induces signal transduction that culminates in vascular complications. Therefore, in the present study we investigated the dependence of RAGE expression on circulating AGEs and evaluated the outcome of AGE-RAGE interaction by the oxidative stress and nature of vascular complications in type 2 diabetes mellitus (T2DM) patients. METHODS: RAGE expression was determined by quantitative real-time PCR and western blotting, serum AGEs were estimated by ELISA and spectrofluorometry and oxidative stress markers namely protein carbonyl (PCO), advanced oxidation protein products (AOPP) and lipid peroxidation (MDA) were assayed spectrophotometerically in 75 T2DM patients (DM without vascular complication n=25; DM with microvascular complications n=25; DM with macrovascular complications n=25) and 25 healthy controls. RESULTS: Serum AGE level was significantly higher in diabetic patients having vascular complications as compared to T2DM without complications (p<0.01). RAGE m-RNA expression level in PBMCs assayed by quantitative real time PCR was four times higher in diabetic subjects without vascular complications while DM patients having microvascular and macrovascular complications showed 12 fold and 8 fold higher RAGE m-RNA expression respectively compared to healthy controls. Circulating AGE level showed significant positive correlation with RAGE m-RNA expression and oxidative stress markers. CONCLUSION: AGE-mediated exacerbation of RAGE expression may contribute to oxidative stress generation that plays a key role in pathogenesis of vascular complications in diabetes.

Association of RAGE gene polymorphism with vascular complications in Indian type 2 diabetes mellitus patients.

AIMS: The study was designed to evaluate the association of -374T/A and -429T/C polymorphism in the promoter region and Gly82Ser polymorphism in exon 3 region of RAGE gene with diabetic vascular complications in Indian population. METHODS: We screened 603 subjects which includes 176 healthy controls, 140 type 2 diabetes mellitus (T2DM) subjects without any vascular complications (DM), 152 T2DM subjects with microvascular complications (DM-micro) and 135 T2DM subjects with macrovascular complications (DM-macro) for -374T/A, -429T/C and Gly82Ser polymorphisms of RAGE gene. DNA isolated from the enrolled subjects were genotyped by PCR-RFLP. Logistic regression analysis was used to evaluate the association of single nucleotide polymorphisms (SNPs). RESULTS: The -429 T/C and Gly82Ser RAGE polymorphisms were found to be significantly associated with the development of macrovascular and microvascular complications, respectively, in T2DM subjects while -374A allele showed reduced risk towards the development of macrovascular complications. Further, -429T/C, -374T/A and Gly82Ser haplotype analysis revealed association of CTG haplotype with development of macrovascular complications while haplotype TAG was observed to be significantly protective towards development of macrovascular complications in T2DM subjects (OR=0.617, p=0.0202). CONCLUSIONS: Our data indicates significant association of RAGE SNPs and haplotypes with vascular complications in North Indian T2DM subjects.

Association of RAGE gene polymorphism with circulating AGEs level and paraoxonase activity in relation to macro-vascular complications in Indian type 2 diabetes mellitus patients.

BACKGROUND AND AIMS: Sustained interaction of advanced glycation end products (AGEs) with their receptor RAGE and subsequent signaling plays an important role in the development of diabetic complications. Genetic variation of RAGE gene may be associated with the development of vascular complications in type 2 diabetes mellitus (T2DM). OBJECTIVES: The present study aimed to explore the possible association of RAGE gene polymorphisms namely -374T/A, -429T/C and G82S with serum level of AGEs, paraoxonase (PON1) activity and macro-vascular complications (MVC) in Indian type 2 diabetes mellitus patients (T2DM). METHODS: A total of 265 diabetic patients, including DM without any complications (n=135), DM-MVC (n=130) and 171 healthy individuals were enrolled. Genotyping of RAGE variants were assessed by polymerase chain reaction-restriction fragment length polymorphism. Serum AGEs were estimated by ELISA and fluorometrically. and PON1 activity was assessed spectrophotometrically. RESULTS: Of the three examined SNPs, association of -429T/C polymorphism with MVC in T2DM was observed (OR=3.001, p=0.001) in the dominant model. Allele 'A' of -374T/A polymorphism seems to confer better cardiac outcome in T2DM. Patients carrying C allele (-429T/C) and S allele (G82S) had significantly higher AGEs levels. -429T/C polymorphism was also found to be associated with low PON1 activity. Interaction analysis revealed that the risk of development of MVC was higher in T2DM patients carrying both a CC genotype of -429T/C polymorphism and a higher level of AGEs (OR=1.343, p=0.040). CONCLUSION: RAGE gene polymorphism has a significant effect on AGEs level and PON1 activity in diabetic subjects compared to healthy individuals. Diabetic patients with a CC genotype of -429T/C are prone to develop MVC, more so if AGEs levels are high and PON1 activity is low.

A study on serum advanced glycation end products and its association with oxidative stress and paraoxonase activity in type 2 diabetic patients with vascular complications.

OBJECTIVES: Enhanced formation of advanced glycation end products (AGEs) formed secondary to hyperglycemic conditions has been linked to diabetes mellitus (DM) associated complications. We investigated the clinical relevance of estimating AGEs and their relationship with oxidative stress (OS) and paraoxonase (PON1) activity in type 2 DM (T2DM) in relation to development of vascular complications. DESIGN AND METHODS: Serum AGEs along with PON1 activity, protein carbonyl (PCO), advanced oxidation protein products (AOPP), lipid peroxidation (MDA), and total thiol (T-SH) were determined in 157 T2DM patients (DM without complications n=57, DM micro-vascular complications n=53, DM macro-vascular complications n=47) and 40 healthy controls. RESULTS: Serum AGE level increased significantly in various study groups in following manner: healthy control

Advanced glycation end products enhance reactive oxygen and nitrogen species generation in neutrophils in vitro.

Increased oxidative stress (OS) in diabetes mellitus is one of the major factors leading to diabetic pathology. However, the mediators and mechanism that provoke OS in diabetes is not fully understood, and it is possible that accumulation of advanced glycation end products (AGEs) formed secondary to hyperglycemic conditions may incite circulating polymorphonuclear neutrophils (PMN) to generate reactive oxygen species (ROS). In this report, we aim to investigate the effect of AGE on reactive oxygen and nitrogen species generation and subsequent OS in PMN. AGE-HSA exert dose- and time-dependent enhancement of ROS and reactive nitrogen intermediates (RNI) generation by PMN. Increased ROS and RNI generation were found to be mediated through the upregulation of NADPH oxidase and inducible nitric oxide synthase (iNOS), respectively, as evident from the fact that AGE-treated neutrophils failed to generate ROS and RNI in presence of diphenyleneiodonium, a flavoprotein inhibitor for both enzymes. Further increased generation of ROS and RNI ceased when the cells were incubated with anti-RAGE antibody suggesting the involvement of AGE-RAGE interaction. Also increased malondialdehyde (MDA) and protein carbonyl formation in AGE-exposed PMN suggest induction of OS by AGE. This study provides evidence that AGEs may play a key role in the induction of oxidative stress through the augmentation of PMN-mediated ROS and RNI generation and this may be in part responsible for development of AGE-induced diabetic pathology.