幹細胞分裂の変異モードは,適応性腸の成長を促します
Lucy Erin O'Brien1, Sarah S Soliman, Xinghua Li
1Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720, USA.
Cell
|November 1, 2011
まとめ
成人の臓器の適応には,栄養素に対する幹細胞の反応があり,成長のためのホメオスタシスを破ります. この適応性のある組織再構築は逆行可能であり,幹細胞が生理学的トリガーに基づいて臓器を再構築することを実証しています.
科学分野:
- 発達生物学 発達生物学とは
- 幹細胞生物学 幹細胞生物学
- 生理学 生理学とは
背景:
- 成人の臓器は環境の変化に適応しますが,適応メカニズムはホメオスタシスとは異なります.
- 生理学的要因が組織の再編成を誘発するプロセスは,十分に理解されていません.
- ホメオスタシスを超えた臓器適応における幹細胞の役割については,さらなる調査が必要である.
研究 の 目的:
- 適応性臓器サイズ変更における専門的な幹細胞応答の役割を調査する.
- 栄養素の利用可能性のような生理学的ヒントが,組織再構築にどのように影響するかを理解する.
- 幹細胞がホメオスタティック維持から脱却するメカニズムを解明する.
主な方法:
- 大人のドロソフィラ・メラノガスターの中腸をモデルシステムとして利用した.
- 栄養素の誘導に反応する腸の幹細胞の行動を研究した.
- 異なる栄養条件下での幹細胞分裂率と命運決定を分析した.
主要な成果:
- 腸の幹細胞が臓器の成長を開始するために栄養素の可用性を解釈することを実証しました.
- 幹細胞成長プログラムの活性化における重要な要因としてインスリンシグナル伝達を特定した.
- 栄養素の豊富さ中の幹細胞における加速された分裂率と対称的分裂運命の優位性が観察され,細胞数が増加しました.
結論:
- 幹細胞の反応は,成熟した臓器の適応的なサイズ変更に不可欠です.
- 組織再生プログラムは,細胞の均衡を維持することにのみコミットしているわけではありません.
- 幹細胞は,栄養素の利用可能性などの生理学的トリガーに反応して,動的に臓器を再構成することができます.
関連する概念動画
Adult Stem Cells
27.8K
Stem cells are undifferentiated cells that divide and produce more stem cells or progenitor cells that differentiate into mature, specialized cell types. All the cells in the body are generated from stem cells in the early embryo, but small populations of stem cells are also present in many adult tissues including the bone marrow, brain, skin, and gut. These adult stem cells typically produce the various cell types found in that tissue—to replace cells that are damaged or to continuously...
27.8K
Stem Cell Niche
5.0K
The stem cell niche is the dynamic microenvironment where stem cells reside. Inside these niches, the cells may remain undifferentiated, undergo high self-renewal, or become lineage-specific progenitors. Stem cells coexist with other niche cells, such as stromal cells. They also interact closely with the ECM. Cell-cell and cell-matrix communication occur via adhesion molecules or soluble factors that signal the stem cells and determine their fate. Stromal cells also provide survival signals to...
5.0K
Renewal of Intestinal Stem Cells
2.7K
The intestinal epithelial lining rapidly renews every 4 to 5 days. The renewal is facilitated by intestinal stem cells (ISCs) located at the base of the crypt– a gland located at the bottom of each villus. ISCs divide asymmetrically to form new stem cells and progenitor daughter cells. The daughter cells are called transit-amplifying (TA) cells which move upwards along the crypt and either differentiate into absorptive cells– the enterocytes or secretory cells– including the...
2.7K
Role of Ephrin-Eph Signalling in Intestinal Stem Cell Renewal
1.8K
Erythropoietin-producing hepatocellular carcinoma receptor (Eph) and its ligand, Eph receptor-interacting protein (Ephrin) were first discovered in the human carcinoma cell line, hence the name. Ephrin-Eph interaction guides cells to reach their appropriate location in adult tissues. They also play an essential role in the immune system by helping in immune cell migration, adhesion, and activation. Based on their structure and function, Eph is divided into two classes — EphA and EphB.
1.8K
Role Of Notch Signalling In Intestinal Stem Cell Renewal
1.8K
Notch signaling was first discovered in Drosophila melanogaster, where it is involved in cell lineage differentiation. Notch signaling regulates the maintenance and differentiation of intestinal stem cells or ISCs by controlling the expression of atonal homolog 1 or Atoh1. Atoh1 directs cells to differentiate into secretory cells.
Direct cell-to-cell contact is needed for the activation of Notch signaling. The signal is initiated when a notch ligand binds to a receptor on an adjacent cell, also...
Direct cell-to-cell contact is needed for the activation of Notch signaling. The signal is initiated when a notch ligand binds to a receptor on an adjacent cell, also...
1.8K
Cellular Adaptation III: Hyperplasia
55
Hyperplasia is an increase in the number of cells in a tissue or organ due to enhanced cell division. It is an adaptive, controlled response to stimuli such as injury, hormones, or stress, involving mitosis to produce genetically identical cells and support tissue repair and regeneration.Tissue CapacityCertain tissues, including the epidermis, intestinal epithelium, bone marrow, and fibroblasts, have a high potential for hyperplasia. Others, such as bone, cartilage, and smooth muscle, show...
55


