Protein kinase C/ζ (PRKCZ) Gene is associated with type 2 diabetes in Han population of North China and analysis of its haplotypes

Genetic polymorphism in untranslated regions of PRKCZ influences mRNA structure, stability and binding sites

BACKGROUND

Variations in untranslated regions (UTR) alter regulatory pathways impacting phenotype, disease onset, and course of disease. Protein kinase C Zeta (PRKCZ), a serine-threonine kinase, is implicated in cardiovascular, neurological and oncological disorders. Due to limited research on PRKCZ, this study aimed to investigate the impact of UTR genetic variants' on binding sites for transcription factors and miRNA. RNA secondary structure, eQTLs, and variation tolerance analysis were also part of the study.

METHODS

The data related to PRKCZ gene variants was downloaded from the Ensembl genome browser, COSMIC and gnomAD. The RegulomeDB database was used to assess the functional impact of 5' UTR and 3'UTR variants. The analysis of the transcription binding sites (TFBS) was done through the Alibaba tool, and the Kyoto Encyclopaedia of Genes and Genomes (KEGG) was employed to identify pathways associated with PRKCZ. To predict the effect of variants on microRNA binding sites, PolymiRTS was utilized for 3' UTR variants, and the SNPinfo tool was used for 5' UTR variants.

RESULTS

The results obtained indicated that a total of 24 variants present in the 3' UTR and 25 variants present in the 5' UTR were most detrimental. TFBS analysis revealed that 5' UTR variants added YY1, repressor, and Oct1, whereas 3' UTR variants added AP-2alpha, AhR, Da, GR, and USF binding sites. The study predicted TFs that influenced PRKCZ expression. RNA secondary structure analysis showed that eight 5' UTR and six 3' UTR altered the RNA structure by either removal or addition of the stem-loop. The microRNA binding site analysis highlighted that seven 3' UTR and one 5' UTR variant altered the conserved site and also created new binding sites. eQTLs analysis showed that one variant was associated with PRKCZ expression in the lung and thyroid. The variation tolerance analysis revealed that PRKCZ was an intolerant gene.

CONCLUSION

This study laid the groundwork for future studies aimed at targeting PRKCZ as a therapeutic target.

The role of DNA methylation in the pathogenesis of type 2 diabetes mellitus

Diabetes mellitus (DM) is a chronic condition characterised by β cell dysfunction and persistent hyperglycaemia. The disorder can be due to the absence of adequate pancreatic insulin production or a weak cellular response to insulin signalling. Among the three types of DM, namely, type 1 DM (T1DM), type 2 DM (T2DM), and gestational DM (GDM); T2DM accounts for almost 90% of diabetes cases worldwide.

Epigenetic traits are stably heritable phenotypes that result from certain changes that affect gene function without altering the gene sequence. While epigenetic traits are considered reversible modifications, they can be inherited mitotically and meiotically. In addition, epigenetic traits can randomly arise in response to environmental factors or certain genetic mutations or lesions, such as those affecting the enzymes that catalyse the epigenetic modification. In this review, we focus on the role of DNA methylation, a type of epigenetic modification, in the pathogenesis of T2DM.

PKCζ Is Essential for Pancreatic β-Cell Replication During Insulin Resistance by Regulating mTOR and Cyclin-D2

Adaptive β-cell replication occurs in response to increased metabolic demand during insulin resistance. The intracellular mediators of this compensatory response are poorly defined and their identification could provide significant targets for β-cell regeneration therapies. Here we show that glucose and insulin in vitro and insulin resistance in vivo activate protein kinase C ζ (PKCζ) in pancreatic islets and β-cells. PKCζ is required for glucose- and glucokinase activator-induced proliferation of rodent and human β-cells in vitro. Furthermore, either kinase-dead PKCζ expression (KD-PKCζ) or disruption of PKCζ in mouse β-cells blocks compensatory β-cell replication when acute hyperglycemia/hyperinsulinemia is induced. Importantly, KD-PKCζ inhibits insulin resistance-mediated mammalian target of rapamycin (mTOR) activation and cyclin-D2 upregulation independent of Akt activation. In summary, PKCζ activation is key for early compensatory β-cell replication in insulin resistance by regulating the downstream signals mTOR and cyclin-D2. This suggests that alterations in PKCζ expression or activity might contribute to inadequate β-cell mass expansion and β-cell failure leading to type 2 diabetes.

Genes, Genetics, and Environment in Type 2 Diabetes: Implication in Personalized Medicine

Type 2 diabetes (T2D) is a multifactorial anomaly involving 57 genes located on 16 different chromosomes and 136 single nucleotide polymorphisms (SNPs). Ten genes are located on chromosome 1, followed by seven genes on chromosome 11 and six genes on chromosomes 3. Remaining chromosomes harbor two to five genes. Significantly, chromosomes 13, 14, 16, 18, 21, 22, X, and Y do not have any associated diabetogenic gene. Genetic components have their own pathways encompassing insulin secretion, resistance, signaling, and β-cell dysfunction. Environmental factors include epigenetic changes, nutrition, intrauterine surroundings, and obesity. In addition, ethnicity plays a role in conferring susceptibility to T2D. This scenario poses a challenge toward the development of biomarker for quick disease diagnosis or for generating a consensus to delineate different categories of T2D patients. We believe, before prescribing a generic drug, detailed genotypic information with the background of ethnicity and environmental factors may be taken into consideration. This nonconventional approach is envisaged to be more robust in the context of personalized medicine and perhaps would cause lot less burden on the patient ensuring better management of T2D.

Hypermethylation of the PRKCZ Gene in Type 2 Diabetes Mellitus

Objectives. To study the correlation between the methylation of protein kinase C epsilon zeta (PRKCZ) gene promoters and type 2 diabetes mellitus (T2DM). Methods. The case-control method was implemented in 272 unrelated to one another cases in Shiyan People's Hospital. Of those, 152 were diagnosed as T2DM cases, and the other 120 cases were healthy individuals visiting the hospital for a physical examination. The subjects were first divided into two groups: the T2DM group and the normal control (NC) group. Next, methylated DNA immunoprecipitation chip (MeDIP-chip) was used for detection. Bisulfite sequencing PCR (BSP) and gene sequencing were then performed to detect and analyze the correlation between PRKCZ gene promoter methylation and T2DM. Finally, Western blotting was applied to determine the serum level of PRKCZ. The data were then analyzed with the statistics analyzing software SPSS 17.0. Results. In contrast with cases in NC, T2DM patients showed a high level of methylation, with 7 of 9 CpG sites were shown to be methylated, whereas, in the control group, only one CpG site was found to be methylated. The methylated CpG sites for the two groups showed marked differences (P < 0.01). Additionally, the level of PRKCZ was decreased in T2DM subjects, and the difference between the two groups was statistically significant (P < 0.05). Discussion. This study suggests that the PRKCZ gene is the hypermethylated gene of T2DM and the hypermethylation PRKCZ gene may be involved in the pathogenesis of T2DM.

Genome-wide oligonucleotide microarray analysis of gene-expression profiles of Taiwanese patients with anaplastic astrocytoma and glioblastoma multiforme

This study investigated the relationship between gene expression and disease based on the expression profiles of tissue-specific genes, with the aim of discovering the candidate genes associated with disease risk as diagnostic markers. The gene-expression profiles of approximately 20,000 genes from 4 anaplastic astrocytomas (AAs), 7 glioblastoma multiformes (GBMs), and 1 nontumor brain (NB) were analyzed by in situ-synthesized 60-mer oligonucleotide microarray. The signal intensity of each feature was measured by laser scanner, and gene expression was quantified as the tumor/NB intensity ratio. Gene expression was defined as having increased or decreased when the ratio was >or=1.5 or <or= 0.67, respectively. In comparison with NB, 20 genes showed increased expression, and 32 showed decreased expression in AA, while 20 genes showed increased expression, and 164 showed decreased expression in GBM. This research indicates that changes in expression levels of 4 genes in AA and 6 genes in GBM may be useful diagnostic markers. Quantitative reverse transcription-polymerase chain reaction also supported the microarray results for the 6 selected genes. In conclusion, microarray images of excellent quality are of high data reproducibility using entirely standard procedures, and these genes may be associated with the molecular events leading to AA or GBM.

Epidemiology of childhood type 2 diabetes in the developing world

Type 2 diabetes in the young is an increasing problem with potentially serious outcomes. Our understanding of the worldwide burden of this condition is incomplete, with many studies adopting different methodologies to assess the condition and reporting on specific communities or ethnic groups. Most of the data come from developed nations, with few studies from developing nations. The purpose of this review is to bring together the available data on type 2 diabetes in the young from the developing world, in order to highlight deficiencies in the knowledge of the condition and also to promote strategies to deal with it. Noted also are some of the factors associated with the condition, such as family history, genetic influences, intrauterine environment as well as the importance of birth weight, insulin resistance, obesity, and development of complications. These are of relevance in both developed and developing nations.