N6-methyladenosine (m6A) profiling of EndoC-bH1 cell line and RNA seq of Mettl14 knockout mice beta cell
Ontology highlight
ABSTRACT: In type 2 diabetes, pancreatic beta-cells fail to compensate for the presence of insulin resistance in target tissues and represent a central player in the disease development. Identifying and studying innovative molecular mechanisms that lead to beta-cell failure in diabetes represent an interesting line of research and are necessary. N6-Methyladenosine (m6A) is the most abundant modification in mRNA and is found virtually in all mammals. Through m6A-profiling of m6A methyltransferase depleted animal model and human beta cell model, we aim to characterize the pathways affected by m6A methylation in the beta cells.
Project description:In type 2 diabetes, pancreatic beta-cells fail to compensate for the presence of insulin resistance in target tissues and represent a central player in the disease development. Identifying and studying innovative molecular mechanisms that lead to beta-cell failure in diabetes represent an interesting line of research and are necessary. N6-Methyladenosine (m6A) is the most abundant modification in mRNA and is found virtually in all mammals. Through m6A-profiling, we aim to characterize the dynamic RNA methylation changes in islets obtained from patients with type 2 diabetes.
Project description:β-cell specific Mettl14 knock-out mice display reduced N6-methyladenosine (m6A) levels and recapitulate human Type II diabetes (T2D) islet phenotype with early diabetes onset and mortality secondary to decreased β-cell proliferation and insulin degranulation. To gain insights into the role of m6A in regulating the IGF1/insulin -> AKT - > PDX1 pathway and to dissect the signaling networks modulating AKT phosphorylation, we subjected freshly isolated islets from control and Mettl14 knock-out mice to phospho-antibody microarrays.
Project description:The aim of the study was to characterize the role of PCSK9 in human beta cells. We performed siRNA-mediated knockdown of PCSK9 in human beta cell line EndoC-bH1 and compared the expression profiles against control siRNA-treated cells.
Project description:Obesity is associated with impaired β-adrenergic receptor (Adrb1-3) signaling and lipolysis, leading to aberrant white adipose tissue (WAT) growth. WAT research has been centered on transcriptional and posttranslational regulations, but posttranscriptional regulation and mRNA modifications are poorly understood. Here, we unveil a METTL14/N6-methyladenosine (m6A) paradigm guiding β-adrenergic signaling and lipolysis. METTL14 complex installs m6A on RNA, regulating mRNA fate and translation. We found that feeding and insulin increased adipose Mettl14 and m6A levels. Adipose Mettl14 and m6A were upregulated in high fat diet (HFD)-induced obesity. Ablation of adipose Mettl14 decreased Adrb2, Adrb3, Atgl (encoding lipase), and Cig-58 (Atgl activator) transcript m6A contents while increasing their translation and protein levels, thereby enhancing adipose β-adrenergic signaling and lipolysis. Consequently, adipocyte-specific Mettl14 knockout mice were resistant to HFD-induced obesity, insulin resistance, glucose intolerance, and NAFLD. These results unravel a METTL14/m6A-based epitranscriptomic mechanism governing β-adrenergic signaling, lipolysis, and adipose growth in health and disease.
Project description:Spermatogenesis is precisely controlled at the transcriptional, posttranscriptional, and translational levels. Here we report that N6-methyladenosine (m6A), an epitranscriptomic mark regulating gene expression, plays essential roles during spermatogenesis. We present comprehensive m6A mRNA methylomes of mouse spermatogenic cells from five developmental stages: undifferentiated spermatogonia, type A1 spermatogonia, preleptotene spermatocytes, pachytene/diplotene spermatocytes, and round spermatids. Germ cell-specific inactiva- tion of the m6A RNA methyltransferase Mettl3 or Mettl14 with Vasa-Cre causes loss of m6A and depletion of SSCs. m6A depletion dysregulates translation of transcripts that are required for SSC proliferation/differentiation. Com- bined deletion of Mettl3 and Mettl14 in advanced germ cells with Stra8-GFPCre disrupts spermiogenesis, whereas mice with single deletion of either Mettl3 or Mettl14 in advanced germ cells show normal spermatogenesis. The sper- matids from double-mutant mice exhibit impaired translation of haploid-specific genes that are essential for spermio- genesis. This study highlights crucial roles of mRNA m6A modification in germline development, potentially ensuring coordinated translation at different stages of spermatogenesis.
Project description:Both mRNA and proteins can be modified through addition of methyl groups. For example, addition of N6-methyladenosine (m6A) to mRNAs is critical for human development and health. Post-translational methylation of proteins can impact the dynamic regulation of enzymatic activity. Here we sought to explore the nexus of transcriptional and post-translational methylation by studying the role of methylation of the core methyltransferase METTL3/METTL14 in m6A regulation. We found by mass spectrometry that METTL14 arginine 255 (R255) is methylated (R255me). Global mRNA m6A levels were greatly decreased in METTL14 R255K mutant mouse embryonic stem cells (mESCs). We further found that R255me greatly enhances the interaction of METTL3/METTL14 with WTAP and promotes the binding of the complex to substrate RNA.
Project description:Spermatogenesis is a differentiation process during which diploid spermatogonial stem cells (SSCs) produce haploid spermatozoa. This highly specialized process is precisely controlled at the transcriptional, posttranscriptional, and translational levels. Here we report that N6-methyladenosine (m6A), an epitranscriptomic mark regulating gene expression, plays essential roles during spermatogenesis. We present comprehensive m6A mRNA methylomes of mouse spermatogenic cells from five developmental stages: undifferentiated spermatogonia, type A1 spermatogonia, preleptotene spermatocytes, pachytene/diplotene spermatocytes, and round spermatids. Germ cell-specific inactivation of the m6A RNA methyltransferase Mettl3 or Mettl14 with Vasa-Cre causes loss of m6A and depletion of SSCs. m6A depletion dysregulates translation of transcripts that are required for SSC proliferation/differentiation. Combined deletion of Mettl3 and Mettl14 in advanced germ cells with Stra8-GFPCre disrupts spermiogenesis, whereas mice with single deletion of either Mettl3 or Mettl14 in advanced germ cells show normal spermatogenesis. The spermatids from double-mutant mice exhibit impaired translation of haploid-specific genes that are essential for spermiogenesis. This study highlights crucial roles of mRNA m6A modification in germline development, potentially ensuring coordinated translation at different stages of spermatogenesis.