ABSTRACT
Insulin secretion is regulated by ATP-sensitive potassium channels (KATP). The potassium inwardly-rectifying channel, subfamily J, member 11 (KCNJ11) gene, located on chromosome 11p15.1, encodes the subunit Kir6.2 that forms the pore region of KATP channels in pancreatic ß-cells. Among the single nucleotide polymorphisms (SNPs) associated with KCNJ11, the E23K polymorphism (rs5219) promotes a substitution (G > A) of a glutamic acid residue for lysine at position 23. The E23K SNP has been associated with diabetes in several populations, although with controversial results. The aim of this study was to evaluate the association of the E23K SNP with type 1 and 2 diabetes in a case-control study approved by the Ethics Committee. We genotyped 458 Euro-Brazilian individuals, classified as healthy (control group, CTRL, N = 217), patients with type 1 diabetes mellitus (T1D, N = 102), and patients with type 2 diabetes mellitus (T2D, N = 139). Genotyping was performed by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) using BanII restriction digestion. The restriction fragments were separated by polyacrylamide gel electrophoresis and visualized by ethidium bromide staining. The genotype (EE/EK/KK) frequencies (%) for the CTRL group (38.2/50.2/11.6), T1D (34.3/52.0/13.7), and T2D (38.2/48.9/12.9) were in Hardy-Weinberg equilibrium and there were no significant differences (CRTL vs T1D, P = 0.771; CRTL vs T2D, P = 0.937; T1D vs T2D, P = 0.831). The minor allele frequencies (MAF; K) for CTRL (37.0%), T1D (39.7%), and T2D (37.4%) were not different among the groups (P > 0.05). The MAF value for healthy subjects was similar to other Caucasian populations (34.5-37.5%). In summary, the E23K polymorphism (rs5219) was not associated with type 1 or 2 diabetes mellitus in the studied population.
Subject(s)
Diabetes Mellitus, Type 1/genetics , Diabetes Mellitus, Type 2/genetics , Potassium Channels, Inwardly Rectifying/genetics , Adult , Aged , Brazil , Case-Control Studies , Diabetes Mellitus, Type 1/metabolism , Diabetes Mellitus, Type 2/metabolism , Female , Gene Frequency , Genetic Association Studies , Genetic Predisposition to Disease , Humans , Insulin-Secreting Cells/metabolism , KATP Channels/genetics , KATP Channels/metabolism , Male , Middle Aged , Polymorphism, Single Nucleotide , Potassium Channels, Inwardly Rectifying/metabolism , White People/geneticsABSTRACT
Matrix metalloproteinases (MMPs) are a family of zinc (Zn)-dependent endopeptidases that are collectively capable of cleaving virtually all extracellular matrix (ECM) substrates and play an important role in diverse physiological and pathological processes. The activity of MMPs is regulated at multiple levels. The transcriptional regulation of MMP appears to represent the key step in MMP regulation. There are diverse types of MMPs that differ structural and functionally. MMP-1 is the most ubiquitously expressed interstitial collagenase and has a prominent role in initial cleavage of the ECM. The level of MMP-1 expression can be influenced by different single-nucleotide polymorphisms (SNPs) in the promoter region. A functional polymorphism at position -1607 has been shown to alter the transcriptional activity of MMP-1 and was associated with diverse pathological processes. The aim of our review was to discuss some topics related to MMP in physiological and pathological processes, with a focus on MMP-1 polymorphism.
