Clinically significant findings of high-risk mutations in human SLC29A4 gene associated with diabetes mellitus type 2 in Pakistani population.

This study conducted an in-depth analysis combining computational and experimental verifications of the deleterious missense mutations associated with the SLC29A4 protein. The functional annotation of the non-synonymous single nucleotide polymorphism (nsSNPs), followed by structure-function analysis, revealed 13 single nucleotide polymorphisms (SNP) as the most damaging. Among these, six mutants P429T/S, L144S, M108V, N86H, and V79E, were predicted as structurally and functionally damaging by protein stability analysis. Also, these variants are located at evolutionary conserved regions, either buried, contributing to the structural damage, or exposed, causing functional changes in the protein. These mutants were further taken for molecular docking studies. When verified via experimental analysis, the SNPs M108V (rs149798710), N86H (rs151039853), and V79E (rs17854505) showed an association with type 2 diabetes mellitus (T2DM). Minor allele frequency for rs149798710 (A > G) was 0.23 in controls, 0.29 in metformin responders, 0.37 in metformin non-responder, for rs151039853 (A > C) was 0.21 in controls, 0.28 in metformin responders, 0.36 in metformin non-responder and for rs17854505 (T > A) was 0.20 in controls, 0.25 in metformin responders, 0.37 in metformin non-responder. Hence, this study concludes that SLC29A4 M108V (rs149798710), N86H (rs151039853), and V79E (rs17854505) polymorphisms were associated with the increased risk of T2DM as well as with the increased risk towards the failure of metformin therapeutic response in T2DM patients of Pakistan. Communicated by Ramaswamy H. Sarma.

Effects of SLC22A2 (rs201919874) and SLC47A2 (rs138244461) genetic variants on Metformin Pharmacokinetics in Pakistani T2DM patients.

OBJECTIVE: To determine the frequencies of single nucleotide polymorphisms rs201919874 and rs138244461 in genes SLC22A2 and SLC47A2 respectively in Pakistani diabetes patients in order to characterise the genetic variants and determine their association with the pharmacokinetics of metformin. METHODS: The case-control study was conducted at the International Islamic University, Islamabad, Pakistan, from June 2016 to June 2017, and comprised genotypes of diabetic cases and matching controls which were determined following allele-specific polymerase chain reaction. Cases were further divided into Group A and Group B. The former consisted of diabetics who were on monotherapy of metformin, while the latter consisted of diabetics treated with a combination of metformin and sulfonylureas. In-silico analysis was performed to verify the effect of single nucleotide polymorphisms rs201919874 and rs138244461 on the structure of genes. Association was statistically determined using SPSS 18. RESULTS: Of the 1200 subjects, 800(66.6%) were cases and 400(33.3%) were controls. Among the cases, 400(50%) each were in Group A and Group B. Significant difference was observed in the distribution of rs201919874 between Group A and controls (p<0.05) and between Group B and controls (p<0.05) for heterozygous genotypic frequency and for allelic frequency. Conversely, statistically significant difference was observed in rs138244461 (p<0.05) for all genotypic and allelic frequencies. Genotypes were significantly associated with glycated haemoglobin, random and fasting glucose levels in Group A compared to Group B (p<0.05). In-silico analysis showed that both single nucleotide polymorphisms were expected to create significantly damaging structural changes in domains and helix (p<0.05 each). CONCLUSIONS: Both exonic single nucleotide polymorphisms were found to be associated with the pharmacokinetics of metformin.

Evaluation of the rs3088442 G>A SLC22A3 Gene Polymorphism and the Role of microRNA 147 in Groups of Adult Pakistani Populations With Type 2 Diabetes in Response to Metformin.

OBJECTIVES: Type 2 diabetes is a complex genetic disorder, and a large number of genetic polymorphisms may be involved in its pathogenesis. Pharmacologically, type 2 diabetes can be treated with 9 different approved classes of drugs, but metformin is suggested as the first line of therapy, followed by sulfonylureas. METHODS: This was a case-control study consisting of 300 metformin responders and 300 metformin nonresponders in patients with type 2 diabetes and 300 healthy Pakistani subjects. Genotyping of the SLC22A3 G>A polymorphism was performed by allele-specific polymerase chain reaction (PCR) for microRNA 147 expression; real-time polymerase chain reaction was used, and expressional analysis of SLC22A3 was done by semiquantitative polymerase chain reaction. RESULTS: GA and AA genotypes were highly significantly associated with the drug treatments when compared with controls. A statistically significant difference was observed in the distribution of the SLC22A3 A allele between healthy subjects and patients with type 2 diabetes. When odds ratios were adjusted for glycated hemoglobin levels and postprandial and fasting blood glucose levels, our findings showed that the overexpression of allele A of the rs3088442 G>A variant may act as a protective allele and is associated with the clinical response to metformin. microRNA 147 expression was found to be increased in patients who were metformin responders compared with the nonresponder group and controls. mRNA expression of SLC22A3 was significantly reduced in patients taking metformin as compared to other groups. CONCLUSIONS: These results suggested that the SLC22A3 rs3088442 at position 2282 A allele may confer metformin clinical responses in patients with type 2 diabetes in the Pakistani population. Overexpression of microRNA 147 is associated with a downward expression of the SLC22A3 gene in patients who have type 2 diabetes.

Anti-citrullinated protein antibodies: role in pathogenesis of RA and potential as a diagnostic tool.

Rheumatoid arthritis is an autoimmune disorder which involves inflammation of the synovial tissue, leading to synovial proliferation, bone erosion and ultimately joint disability. It is a complex disorder, and the proper etiology is still unknown. Both environmental and genetic factors are responsible for the development of rheumatoid arthritis. Clinically, the disease is generally diagnosed by the presence of auto-antibodies like rheumatoid factor. But these are not specifically associated with rheumatoid arthritis. These are also present in patients with other autoimmune disorders and also in healthy persons. Citrullinated epitopes are shown to be more specific for rheumatoid arthritis. Citrullination normally occurs in cells undergoing apoptosis, and hence, citrullinated proteins are cleared from body and not encountered by immune system. However, in rheumatoid arthritis patients, these are not cleared. Anti-citrullinated protein antibodies are detectable in patients at risk of rheumatoid arthritis long before the onset of the disease. The concentration of which normally increases as the disease progress. Hence, these are important for diagnosis of rheumatoid arthritis. This review is focused on the importance of anti-citrullinated protein antibodies in disease pathogenesis and its importance in the diagnosis of rheumatoid arthritis.