Global Gene Expression Profiling in Omental Adipose Tissue of Morbidly Obese Diabetic African Americans
JOURNAL OF ENDOCRINOLOGY AND METABOLISM
Authors: Doumatey, Ayo P.; Xu, Huichun; Huang, Hanxia; Trivedi, Niraj S.; Lei, Lin; Elkahloun, Abdel; Adeyemo, Adebowale; Rotimi, Charles N.
Abstract
Background: Adipose tissues play an important role in the pathophysiology of obesity-related diseases including type 2 diabetes (T2D). To describe gene expression patterns and functional pathways in obesity-related T2D, we performed global transcript profiling of omental adipose tissue (OAT) in morbidly obese individuals with or without T2D. Methods: Twenty morbidly obese (mean BMI: about 54 kg/m(2)) subjects were studied, including 14 morbidly obese individuals with T2D (cases) and six morbidly obese individuals without T2D (reference group). Gene expression profiling was performed using the Affy-metrix U133 Plus 2.0 human genome expression array. Analysis of covariance was performed to identify differentially expressed genes (DEGs). Bioinformatics tools including PANTHER and Ingenuity Pathway Analysis (IPA) were applied to the DEGs to determine biological functions, networks and canonical pathways that were over-represented in these individuals. Results: At an absolute fold change threshold of 2 and false discovery rate (FDR) of < 0.05, 68 DEGs were identified in cases compared to the reference group. Myosin X (MYO10) and transforming growth factor beta regulator 1 (TBRG1) were upregulated. MYO10 encodes for an actin-based motor protein that has been associated with T2D. Telomere extension by telomerase (HNRNPA1, TNKS2), D-myo-inositol (1,4,5)-trisphosphate biosynthesis (PIP5K1A, PIP4K2A), and regulation of actin-based motility by Rho (ARPC3) were the most significant canonical pathways and overlay with T2D signaling path-way. Upstream regulator analysis predicted five miRNAs (miR-320b, miR-381-3p, miR-3679-3p, miR-494-3p, and miR-141-3p), as regulators of the expression changes identified. Conclusion: This study identified a number of transcripts and miRNAs in OAT as candidate novel players in the pathophysiology of T2D in African Americans.
Novel candidate genes and variants underlying autosomal recessive neurodevelopmental disorders with intellectual disability
HUMAN GENETICS
Authors: Santos-Cortez, Regie Lyn P.; Khan, Valeed; Khan, Falak Sher; Mughal, Zaib-un-Nisa; Chakchouk, Imen; Lee, Kwanghyuk; Rasheed, Memoona; Hamza, Rifat; Acharya, Anushree; Ullah, Ehsan; Saqib, Muhammad Arif Nadeem; Abbe, Izoduwa; Ali, Ghazanfar; Hassan, Muhammad Jawad; Khan, Saadullah; Azeem, Zahid; Ullah, Irfan; Bamshad, Michael J.; Nickerson, Deborah A.; Schrauwen, Isabelle; Ahmad, Wasim; Ansar, Muhammad; Leal, Suzanne M.
Abstract
Identification of Mendelian genes for neurodevelopmental disorders using exome sequencing to study autosomal recessive (AR) consanguineous pedigrees has been highly successful. To identify causal variants for syndromic and non-syndromic intellectual disability (ID), exome sequencing was performed using DNA samples from 22 consanguineous Pakistani families with ARID, of which 21 have additional phenotypes including microcephaly. To aid in variant identification, homozygosity mapping and linkage analysis were performed. DNA samples from affected family member(s) from every pedigree underwent exome sequencing. Identified rare damaging exome variants were tested for co-segregation with ID using Sanger sequencing. For seven ARID families, variants were identified in genes not previously associated with ID, including: EI24, FXR1 and TET3 for which knockout mouse models have brain defects; and CACNG7 and TRAPPC10 where cell studies suggest roles in important neural pathways. For two families, the novel ARID genes CARNMT1 and GARNL3 lie within previously reported ID microdeletion regions. We also observed homozygous variants in two ID candidate genes, GRAMD1B and TBRG1, for which each has been previously reported in a single family. An additional 14 families have homozygous variants in established ID genes, of which 11 variants are novel. All ARID genes have increased expression in specific structures of the developing and adult human brain and 91% of the genes are differentially expressed in utero or during early childhood. The identification of novel ARID candidate genes and variants adds to the knowledge base that is required to further understand human brain function and development.