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MECHANISMS OF CHIEF CELL DEDIFFERENTIATION

主要细胞去分化的机制

基本信息

批准号：
10439356
负责人：
Jason C Mills
金额：
$ 44.28万
依托单位：
BAYLOR COLLEGE OF MEDICINE
依托单位国家：
美国
项目类别：
财政年份：
2021
资助国家：
美国
起止时间：
2021-09-01 至 2024-08-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10439356
关键词：
3-Dimensional Address Apoptosis Applications Grants Architecture Automobile Driving Autophagocytosis Award Back Bacteria Binding Cell Cycle Cell Cycle Stage Cell Differentiation process Cells Cellular Stress Cellular Structures Cessation of life ChIP-seq Chief Cell Chronic Chronic Disease Clustered Regularly Interspaced Short Palindromic Repeats Complex Data Development Disease Disease model Dysplasia Electron Microscopy Enzymes Epitopes Event Future Gene Expression Genes Genetic Genetic Transcription Goals Helicobacter pylori Human Hyperactivity Infection Inflammation Initiator tRNA Injury Knockout Mice Knowledge Lesion Malignant Neoplasms Messenger RNA Metaplasia Mitosis Modeling Molecular Mus Mutagenesis Natural regeneration Organ Output Pathway interactions Patients Pharmacology Phenotype Phosphoric Monoester Hydrolases Phosphorylation Phosphotransferases Physiological Process Proteins Repression Research Resistance Ribosomes Risk Role S Phase Sampling Scaffolding Protein Secretory Vesicles Stomach Stress Techniques Testing Tissue Microarray Tissues Translating Translations activating transcription factor 3 adult stem cell biological adaptation to stress cancer risk cell dedifferentiation chronic infection disease phenotype experimental study gastric organoids gastric tumorigenesis genetic manipulation human disease human tissue in vivo malignant stomach neoplasm mouse model new therapeutic target overexpression paligenosis polyposis progenitor programs protein complex recruit repaired response scaffold spasmolytic polypeptide tissue regeneration transcription factor transcriptome sequencing translation factor tumorigenesis

项目摘要

PROJECT SUMMARY We study how injury and inflammation induce mature cells like the digestive-enzyme-secreting zymogenic chief cell (ZC) to disassemble their complex cell architecture and re-enter the cell cycle. We previously showed that ZCs become proliferative via a sequence of molecular-cellular events conserved across many tissues and species in scenarios where mature cells are recruited back into the cell cycle in response to tissue damage. Thus, cells have an evolutionarily conserved program for this reprogramming, as they do for death (apoptosis) and division (mitosis). We call this program paligenosis and showed that mature cells: first degrade/recycle their differentiated cell components (Stage 1), then induce expression of progenitor-like genes (eg. Sox9 = Stage 2), and finally re-enter the cell cycle (Stage 3). Paligenotic ZCs convert to cells that can be seen histopathologically as the type of metaplasia that occurs in stomach during long-term infection with the bacterium Helicobacter pylori: pseudopyloric or Spasmolytic Polypeptide Expressing Metaplasia (SPEM). Metaplasia can either resolve as tissue is repaired or become chronic and increase risk for progression to dysplasia and cancer. We have shown that paligenosis is governed by dynamic changes in mTORC1, the cellular translation control protein complex. mTORC1 is elevated at baseline in ZCs to drive translation of digestive enzymes, it shuts off at Stage 1, and reactivates at Stage 3. Without mTORC1, paligenosis stops at Stage 2 with cells looking metaplastic, but unable to enter S-phase. Here, we explore the mechanisms that induce and promote paligenosis. We show preliminary data implicating the Integrated Stress Response (ISR) pathway as a central paligenosis hub with a particular role for the transcription factor Atf3, which is associated with the ISR, and another gene which we hypothesize is a target of ATF3: Ifrd1, a multifunctional scaffolding protein. We hypothesize that the stress of large-scale tissue damage and/or inflammation triggers ISR hyperactivity, which leads to greatly increased ATF3 and IFRD1, to help push cells back into the cell cycle. In the absence of Atf3 or Ifrd1, we show paligenosis is defective. Our Specific Aims will be: 1) to confirm and further characterize at which stages ISR is active and confirm and characterize the role for ATF3 using, in part Atf3−/− mice; 2) to identify additional genes involved in the ISR and paligenosis by confirming the role of IFRD1 with Ifrd1−/− mice, probe relative contributions of ATF3 and IFRD1 by characterizing double knockout mice, and finally to perform ChIP- and RNA- Seq during paligenosis ±ATF3; 3) to test known ATF3 and ISR genes and new targets developed in Aim 2 in a pipeline of more physiological disease models (eg chronic infection of mice with H pylori), human translational samples (Tissue Microarray and additional human samples of metaplasia and cancer with nearly a 1000 patients), and in a mouse model of tumorigenesis ±ATF3. Together, the experiments may help us understand fundamental mechanisms cells use in regeneration and tumorigenesis that apply not just to the stomach but potentially other organs as well.

项目总结