Effect of Annona muricata Leaf Extract Towards the Sertoli Cells on Alloxan-Induced Mice.

<b>Background and Objective:</b> Prolonged and uncontrolled hyperglycemia in diabetes mellitus can increase the production of reactive oxygen and enhance the risk of male infertility by reducing the number of Sertoli cells. This study aimed to investigate the potential effect of Ethanol Extract of <i>Annona muricata </i>leaf (EEAL) on the amount of Sertoli cells in alloxan-induced mice antioxidant to prevent reducing the number of Sertoli cells. <b>Materials and Methods:</b> The samples used for this study are 30 alloxan-induced Swiss Webster mice divided into a negative control group, a positive control group (glibenclamide 0.65 mg kg¹) and three plant extract groups (EEAL 150, 300 and 600 mg kg¹). Every solution was given every day for 14 days. Histological examination using HE-stained preparations was performed on 40x magnification to evaluate many Sertoli cells counted using Image J software. <b>Results:</b> three EEAL groups of 150, 300 and 600 mg kg¹ have significant effects (p<0.05) to increase the amounts of Sertoli cells compared to a negative control group. In contrast, it does not significantly affect the amounts of Sertoli cells than the positive control group. <b>Conclusion:</b> The administration of <i>A. muricata</i> leaf extract during 14 days significantly reduced the number of Sertoli cells on alloxan-induced mice.

Estimated glomerular filtration rate and its association with the retinol-binding protein 4 (RBP4) locus on human chromosome 10q23.

BACKGROUND: We tested for associations between estimated glomerular filtration rate (eGFR) and retinol-binding protein 4 (RBP4) haplotypes found on human chromosome 10q23. This locus had been linked to eGFR in a previous linkage scan in patients with Type 2 diabetes mellitus. METHODS: We analysed 469 patients with Type 2 diabetes and 174 normoalbuminuric controls for associations between RBP4 haplotypes and eGFR. For comparison with controls, 295 cases with proteinuria/end-stage renal disease were tested for associations with advanced diabetic nephropathy. Genotyping was performed using high-resolution DNA melting assays. Data analysis was performed using the haplo.stats package. RESULTS: Genetic variations in RBP4 were not associated with advanced diabetic nephropathy. Compared with the common A/G/G/C haplotype, C/A/A/C carriers among the normoalbuminuric controls had higher eGFR values among younger patients but lower eGFRs among the older patients (effect size=2.2, P=3.3×10(-7)). Furthermore, while eGFR values were fairly consistent over the range of systolic blood pressure (SBP) values for the common haplotype, eGFR in C/A/A/C carriers increased with SBP (effect size=3.6, P=1.5×10(-2)). There was a significant interaction between the C/A/A/C haplotype and HbA1c as they affect eGFR compared to the common haplotype (effect size=2.1, P=2.1×10(-3)). Power calculations demonstrated that our study had >90% power to detect the observed interactions even while performing multiple hypotheses testing. The interaction between SBP and the C/A/A/C haplotype remained significant (P=2.8×10(-2)) even when these three haplotype-environment interactions were simultaneously estimated. CONCLUSION: RBP4 haplotypes may be important in genetically modulating renal function in response to environmental challenges among patients with Type 2 diabetes.

Nephrinuria associates with multiple renal traits in type 2 diabetes.

BACKGROUND: The involvement of nephrin in controlling renal function is unclear with the literature only emphasizing its role in albuminuria. We therefore investigated the potential association between nephrinuria as evidenced by the appearance of urinary immunopositive nephrin fragments, with multiple renal traits. METHODS: Western blot analysis of the urine samples from a cross-sectional study of 381 Chinese type 2 diabetic patients revealed four distinct protein fragments, indicative of nephrinuria. Albuminuria was measured in random spot urine samples using the albumin/creatinine ratio (ACR), while estimated glomerular filtration rate (eGFR) was calculated using the creatinine-based Modification of Diet in Renal Disease formula. RESULTS: Each nephrin fragment was associated with a decline in eGFR (smallest P = 0.001). Even with the inclusion of logarithmic form of ACR (ln ACR) in the multivariate model, nephrinuria still remained significantly associated with lower eGFR (smallest P < 0.05). Nephrinuria was also strongly associated with lnACR and this finding was independent of eGFR (smallest P < 0.001). Thus, nephrinuria was independently associated with both renal traits in the form of lnACR and eGFR. Furthermore, nephrinuria was significantly associated with lower eGFR even among normoalbuminuric patients (ACR ≤ 30 mg/g) (smallest P = 0.002), potentially implicating nephrinuria in the development of normoalbuminuric renal insufficiency. Apart from the renal traits under investigation, the presence of nephrinuria did not associate with other patient clinical characteristics. CONCLUSIONS: Nephrinuria was associated with multiple renal traits in type 2 diabetes even in normoalbuminuric patients who are traditionally perceived as having a low risk of chronic kidney disease.

Ethnicity, gender, genotype, and anger as related to nocturnal dipping.

Bishop, Pek, and Ngau (2005) found a significant interaction in Singapore between anger and nocturnal dipping among Indians but not Chinese and Malays. The current study examines the role of 5-HTTLPR genotype in this relationship. Two hundred thirty-one undergraduates participated in up to 4 days of 24-h ambulatory monitoring, completed the State-Trait Anger Expression Inventory, and provided blood samples for genotyping of 5-HTTLPR. Results indicated individuals with two copies of the short allele (SS) showed reduced dipping when they were high in Outward Anger (OA) but increased dipping when they were low in OA. Further, for Indian men only, dipping was reduced for individuals having the SS genotype when they were low on Anger In and increased when they were high on Anger In. These data provide further evidence for the role of 5-HTTLPR in cardiovascular risk as well as ethnic differences in the 5-HTTLPR-phenotype relationship. They also provide further evidence for 5-HTTLPR as a "plasticity gene."

Polymorphisms identified through genome-wide association studies and their associations with type 2 diabetes in Chinese, Malays, and Asian-Indians in Singapore.

CONTEXT: Novel type 2 diabetes mellitus (T2DM) susceptibility loci, identified through genome-wide association studies (GWAS), have been replicated in many European and Japanese populations. However, the association in other East Asian populations is less well characterized. OBJECTIVE: To examine the effects of SNPs in CDKAL1, CDKN2A/B, IGF2BP2, HHEX, SLC30A8, PKN2, LOC387761, and KCNQ1 on risk of T2DM in Chinese, Malays, and Asian-Indians in Singapore. DESIGN: We genotyped these candidate single-nucleotide polymorphisms (SNPs) in subjects from three major ethnic groups in Asia, namely, the Chinese (2196 controls and 1541 cases), Malays (2257 controls and 1076 cases), and Asian-Indians (364 controls and 246 cases). We also performed a metaanalysis of our results with published studies in East Asians. RESULTS: In Chinese, SNPs in CDKAL1 [odds ratio (OR) = 1.19; P = 2 x 10(-4)], HHEX (OR = 1.15; P = 0.013), and KCNQ1 (OR = 1.21; P = 3 x 10(-4)) were significantly associated with T2DM. Among Malays, SNPs in CDKN2A/B (OR = 1.22; P = 3.7 x 10(-4)), HHEX (OR = 1.12; P = 0.044), SLC30A8 (OR = 1.12; P = 0.037), and KCNQ1 (OR = 1.19-1.25; P = 0.003-2.5 x 10(-4)) showed significant association with T2DM. The combined analysis of the three ethnic groups revealed significant associations between SNPs in CDKAL1 (OR = 1.13; P = 3 x 10(-4)), CDKN2A/B (OR = 1.16; P = 9 x 10(-5)), HHEX (OR = 1.14; P = 6 x 10(-4)), and KCNQ1 (OR = 1.16-1.20; P = 3 x 10(-4) to 3 x 10(-6)) with T2DM. SLC30A8 (OR = 1.06; P = 0.039) showed association only after adjustment for gender and body mass index. Metaanalysis with data from other East Asian populations showed similar effect sizes to those observed in populations of European ancestry. CONCLUSIONS: SNPs at T2DM susceptibility loci identified through GWAS in populations of European ancestry show similar effects in Asian populations. Failure to detect these effects across different populations may be due to issues of power owing to limited sample size, lower minor allele frequency, or differences in genetic effect sizes.

Genetic variation in KCNQ1 associates with fasting glucose and beta-cell function: a study of 3,734 subjects comprising three ethnicities living in Singapore.

OBJECTIVE: The potassium voltage-gated channel, KQT-like subfamily, member 1 (KCNQ1) has been found through a genome-wide association study to be a strong candidate for conferring susceptibility to type 2 diabetes in East Asian and European populations. Our objective was to describe the association between polymorphisms at the KCNQ1 locus with insulin resistance, beta-cell function, and other type 2 diabetes-related traits in a sample of Chinese, Malays, and Asian Indians living in Singapore. RESEARCH DESIGN AND METHODS: We examined the associations between four previously reported KCNQ1 single-nucleotide polymorphisms (SNPs) with type 2 diabetes-related traits in 3,734 participants from the population-based 1998 Singapore National Health Survey cohort (2,520 Chinese, 693 Malay, and 521 Asian Indians). Insulin resistance was calculated from fasting insulin and glucose using the homeostasis model assessment method, whereas pancreatic beta-cell function was assessed using the corrected insulin response at 120 min (CIR(120)). RESULTS: SNPs rs2237897, rs2237892, and rs2283228 were significantly associated with type 2 diabetes (odds ratio [OR] 1.48, P = 3 x 10(-4); OR 1.38, P = 0.002; OR 1.31, P = 0.012, respectively). Within the Chinese population, the risk alleles for rs2237897, rs2237892, and rs2283228 were significantly associated with higher fasting glucose levels (P = 0.014, 0.011, and 0.034, respectively) and reduced CIR(120)(P = 0.007, 0.013, and 0.014, respectively). A similar trend was observed among the Malay and Asian Indian minority groups, although this did not reach statistical significance because of limited sample sizes. CONCLUSIONS: The increased risk for type 2 diabetes associated with KCNQ1 is likely to be caused by a reduction in insulin secretion. Further studies will be useful to replicate these findings and to fully delineate the role of KCNQ1 and its related pathways in disease pathogenesis.

SNPs in KCNQ1 are associated with susceptibility to type 2 diabetes in East Asian and European populations.

We conducted a genome-wide association study using 207,097 SNP markers in Japanese individuals with type 2 diabetes and unrelated controls, and identified KCNQ1 (potassium voltage-gated channel, KQT-like subfamily, member 1) to be a strong candidate for conferring susceptibility to type 2 diabetes. We detected consistent association of a SNP in KCNQ1 (rs2283228) with the disease in several independent case-control studies (additive model P = 3.1 x 10(-12); OR = 1.26, 95% CI = 1.18-1.34). Several other SNPs in the same linkage disequilibrium (LD) block were strongly associated with type 2 diabetes (additive model: rs2237895, P = 7.3 x 10(-9); OR = 1.32, 95% CI = 1.20-1.45, rs2237897, P = 6.8 x 10(-13); OR = 1.41, 95% CI = 1.29-1.55). The association of these SNPs with type 2 diabetes was replicated in samples from Singaporean (additive model: rs2237895, P = 8.5 x 10(-3); OR = 1.14, rs2237897, P = 2.4 x 10(-4); OR = 1.22) and Danish populations (additive model: rs2237895, P = 3.7 x 10(-11); OR = 1.24, rs2237897, P = 1.2 x 10(-4); OR = 1.36).

An IL-6 haplotype on human chromosome 7p21 confers risk for impaired renal function in type 2 diabetic patients.

The human chromosome 7p21 locus harbors a major gene that influences variation of glomerular filtration rate and development of end-stage renal disease. The pro-inflammatory IL-6 cytokine is a candidate gene since chronic inflammation has been implicated in diabetic nephropathy and this gene is located under the peak of linkage. To test this, single nucleotide polymorphism (SNP) and haplotype analyses were performed using a case-control study of 295 patients consisting of 138 with proteinuria, 157 with chronic renal failure and these were compared to 174 control patients with normal albumin excretion. Five tagging SNPs were selected for analysis based on linkage disequilibrium patterns and proximity to the functionally important -634G>C SNP in the IL-6 promoter. Initial analysis suggested that a -174G>C polymorphism may be associated with risk of chronic renal failure but this was not significant after Bonferroni correction. While haplotype analyses showed no association with proteinuria; a significant association with chronic renal failure was found. There was significantly more of the GGGAGC haplotype among patients with chronic renal failure compared to controls and this association remained significant even after correction for multiple testing. Our study has found a specific IL-6 haplotype conferring risk for impaired renal function in patients with type 2 diabetes.

Genetic variation at the SLC12A3 locus is unlikely to explain risk for advanced diabetic nephropathy in Caucasians with type 2 diabetes.

BACKGROUND: Large-scale genotyping efforts performed on Japanese subjects with type 2 diabetes have implicated polymorphisms in solute carrier family 12 (sodium/chloride transporters) member 3 (SLC12A3) as being associated with advanced diabetic nephropathy. However, it is not known whether these polymorphisms confer a risk for this complication in type 2 diabetic Caucasians. METHODS: A case-control study was conducted that consisted of 295 cases with advanced diabetic nephropathy and 174 controls who have remained normoalbuminuric despite >or=7 years of diabetes. A total of 11 single nucleotide polymorphisms (SNPs) spanning the SLC12A3 locus was analysed including +34372G>A (Arg913Gln) that was the marker previously showing the strongest evidence for disease association in type 2 diabetic Japanese. Power calculations indicated that with an alpha of 0.05, our study has >90% power to detect disease associations of the magnitude previously reported for +34372G>A (Arg913Gln). RESULTS: Allele and genotype distributions for all 11 SNPs were found to be comparable between cases and controls, consistent with the absence of disease association. This negative result was reiterated in subgroup analysis after taking into account potentially important covariates including gender, diabetes duration, blood pressure and glycaemic control. No significant disease associations were likewise found for SLC12A3 haplotypes. Allele, genotype and haplotype distributions were similar in cases regardless of whether they were proteinuric or had developed chronic renal failure/end-stage renal disease. CONCLUSIONS: Genetic variation at the SLC12A3 locus is unlikely to explain the risk for advanced diabetic nephropathy among type 2 diabetic Caucasians.