Project description:Through m6A mRNA-profiling, we aim to characterize the m6A mRNA changes in pancreatic islets between Wtapflox/flox and Wtap-βKO mice.
Project description:N(6)-methyladenosine (m6A) plays an important role in the tumorigenesis and progression of cancers. However, the clinical significance of m6A and their regulatory mechanisms in nasopharyngeal carcinogenesis (NPC) remain largely unknown. In this study, we used the microarray analysis to study WTAP-mediated m6A modification profiles in human nasopharyngeal carcinoma cell line, HONE-1, by comparing 3 pairs of samples with or without WTAP knockdown.
Project description:WTAP is an essential component of the RNA N-6-methyladenosine (m6A) modification complexes that guides METLL3-METLL14 heteroduplexes to target RNAs in the nucleus of mammalian cells. Through mining the genotype-tissue expression (GTEx) datasets, we initially found that TTC22 expression was highly correlated with WTAP and FTO in many normal human tissues. Our experimental results indicate that TTC22 could directly capture RNA binding protein RPL4, induce the binding between RPL4 and WTAP mRNA in the cytoplasm, which increased the m6A level, induced alterative splicing, enhanced the stability and translation efficiency of WTAP mRNA, and consequently upregulated the level of total m6A RNA. These results indicate that WTAP mRNA is a m6A target and there is a positive feedback loop between total m6A and WTAP expression. YTHDF1 was found to be an essential m6A WTAP mRNA binding protein. Downregulation of RPL4, WTAP, or YTHDF1 expression could reverse TTC22-enhanced total m6A RNA level. m6A-specific antibody immunoprecipitated RNA-sequencing (meRIP-seq) demonstrated that TTC22 caused dramatic expression changes of genes related to metabolic pathways, ribosome biogenesis, and RNA spliceosome. Furthermore, we also found that TTC22 upregulated the expression of epithelial-mesenchymal transition (EMT)-related gene SNAI1 via m6A, and promoted metastasis of colon cancer in vitro and in mice. In conclusion, our study illustrates that WTAP mRNA is a m6A target using YTHDF1 as the binding protein. TTC22 could upregulate the levels of WTAP expression and total m6A RNA through the PRL4 binding. The m6A-mediated upregulation of SNAI1 expression may contribute to TTC22-enhanced colon cancer metastasis.
Project description:The fundamental of regeneration process of invertebrates involves the renewal, differentiation and reprogramming of stem cell in an orchestrated manner. It has been known that N6-methyladenosine (m6A) regulates stem cell renewal and differentiation. It is still unclear if m6A is crucial for the regeneration at whole-organism level. Here, we demonstrate that wtap knockdown mediated m6A depletion impairs planarian regeneration upon amputation. The cell cycle related genes displayed decreased m6A while increased expression levels in response to wtap knockdown. The m6A depletion induced phenotypes can be rescued by double-knocking down these genes together with wtap, suggesting that m6A-mediated cell cycle controls planarian regeneration. Further analysis combining the single-cell sequencing unveils a unique neuronal progenitor-like cell type, named NCC and characterized by specific expression of grn, which is indispensable for neuroregeneration. Overall, our study uncovered an essential role of wtap-mediated m6A modification in regulating stem cell population dynamics and homeostasis in terms of general-body regeneration.
Project description:The fundamental of regeneration process of invertebrates involves the renewal, differentiation and reprogramming of stem cell in an orchestrated manner. It has been known that N6-methyladenosine (m6A) regulates stem cell renewal and differentiation. It is still unclear if m6A is crucial for the regeneration at whole-organism level. Here, we demonstrate that wtap knockdown mediated m6A depletion impairs planarian regeneration upon amputation. The cell cycle related genes displayed decreased m6A while increased expression levels in response to wtap knockdown. The m6A depletion induced phenotypes can be rescued by double-knocking down these genes together with wtap, suggesting that m6A-mediated cell cycle controls planarian regeneration. Further analysis combining the single-cell sequencing unveils a unique neuronal progenitor-like cell type, named NCC and characterized by specific expression of grn, which is indispensable for neuroregeneration. Overall, our study uncovered an essential role of wtap-mediated m6A modification in regulating stem cell population dynamics and homeostasis in terms of general-body regeneration.
Project description:Regeneration is the regrowth of damaged tissues or organs, a vital mechanism in response to damages from primitive organisms to higher mammals. Planarian possesses active whole-body regenerative capability owning to its vast reservoir of adult stem cells, neoblasts, providing an ideal model to delineate the underlying mechanisms for regeneration. RNA N6-methyladenosine (m6A) modification participates in many biological processes, including stem cell self-renewal and differentiation, in particular the regeneration of hematopoietic stem cells and axons. However, how m6A controls regeneration at the whole-organism level remains largely unknown. Here, we demonstrate that the depletion of m6A methyltransferase regulatory subunit wtap abolishes planarian regeneration, potentially through regulating genes related to cell-cell communication and cell cycle. Single-cell RNA-seq (scRNA-seq) analysis unveils that the wtap knockdown induces a unique type of neural progenitor-like cells (NP-like cells), characterized by specific expression of the cell-cell communication ligand grn. Intriguingly, the depletion of m6A-modified transcripts grn/cdk9 (or cdk7) axis rescues the defective regeneration of planarian caused by wtap knockdown. Overall, our study reveals an indispensable role of m6A modification in regulating whole-organism regeneration.
Project description:Recent advances in pancreatic differentiation from human pluripotent stem cells (hPSCs) hold great potentials for disease modeling and regenerative medicine, and more precise control over the dynamic differentiation process is critical. N6-methyladenosine (m6A) is the most prevalent internal messenger RNA (mRNA) modification, while the roles of m6A mark in pancreatic differentiation and development remain elusive. In addition, ALKBH5 is a major mRNA m6A demethylase and its role in pancreatic differentiation has not been reported. Here, we firstly studied mRNA m6A dynamics during pancreatic differentiation from hPSCs. Next, using the CRISPR-based genome editing tool, we generated ALKBH5 knockout hPSC lines and found that ALKBH5 plays important roles in pancreatic specification. After that, we conducted a series of functional and mechanistic studies, and demonstrated that ALKBH5 modulated many important genes involved in pancreatic differentiation. Collectively, our findings identified ALKBH5 as an essential regulator of human pancreatic differentiation and highlighted that m6A modification presents a new layer of regulation at epitranscriptome levels during cell-fate specification.
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.