残留リポプロテイン誘発の滑らかな筋肉細胞の増殖には,表皮成長因子受容体のトランザクティベーションが含まれます
Akio Kawakami1, Akira Tanaka, Tsuyoshi Chiba
1Department of Medical Biochemistry, Graduate School of Medicine, Tokyo Medical and Dental University, 1-5-45, Yushima, Building D-256, Bunkyo-ku, Tokyo 113-8519, Japan.
Circulation
|November 19, 2003
まとめ
残留リポタンパク質 (RLP) は,表皮成長因子 (EGF) 受容体経路を活性化することによって,滑らかな筋肉細胞 (SMC) の増殖を促進します. このメカニズムには,タンパク質キナーゼC (PKC) とヘパリン結合型EGFのような成長因子 (HB-EGF) の流出が関与し,動脈硬化症の発症に寄与する.
科学分野:
- 心血管生物学 心血管生物学
- セルラー・シグナリング
- 動脈硬化症の研究 動脈硬化症の研究
背景:
- 残留リポタンパク質 (RLP) は,動脈硬化に関与しています.
- 血管の滑らかな筋肉細胞 (SMC) の増殖は,動脈硬化症とレステノシスの鍵です.
- RLPが中小企業に与える直接的な影響については,さらなる解明が必要である.
研究 の 目的:
- SMCの増殖に対するRLPの直接的な影響を調査する.
- RLP媒介のSMC応答に関与する信号伝達経路を探求する.
主な方法:
- ネズミの大動脈SMCは,RLPでインキュベートされました.
- 細胞増殖を測定した.
- タンパク質のリン酸化 (EGF受容体,MAPK) と流出 (HB-EGF) を評価した.
- PKCの阻害剤,メタロプロテアゼ,HB-EGFを中和する抗体を使用した.
- アポリポプロテインEノックアウトとC57BL6マウスで実験を行った.
主要な成果:
- RLPsは,SMCの拡散を (2.3倍) 大幅に増加させた.
- RLPsはEGF受容体のリン酸化を誘発し,その後のMAPK活性化,PKC活性化を引き起こした.
- RLP治療は,PKCおよびメタロプロテアゼ阻害剤によって抑制されたHB-EGFの流出につながりました.
- EGF受容体のトランザクティベーションとHB-EGFの流出は,抗HB-EGF抗体によって阻害されました.
- これらの分子現象は,動脈硬化症のマウスモデルで in vivo で観察されました.
結論:
- RLPは,EGF受容体のトランザクティベーションを通じて,SMCの増殖を刺激する.
- このトランザクティベーションは,PKCの活性化とHB-EGFの脱落によって媒介されます.
- これらの発見は,RLPを動脈性滑らかな筋肉細胞の増殖と動脈硬化で結びつける新しいメカニズムを強調しています.
さらに関連する動画
関連する概念動画
Insulin Secretory Vesicles
Insulin secretory vesicles release insulin to stimulate blood glucose uptake and regulate carbohydrate metabolism. When the blood glucose levels increase, glucose enters the pancreatic β-islet cells through glucose transporters. Once inside, glucose is metabolized through glycolysis, the citric acid cycle, and the electron transport chain, producing ATP. This increase in ATP concentration closes ATP-sensitive potassium channels, leading to depolarization of the membrane and the opening of...
TGF - β Signaling Pathway
The TGF-β signaling pathway regulates cell growth, differentiation, adhesion, motility, and development. TGF-β ligands that induce TGF-β signaling are synthesized in their latent form. Several proteases or cell surface receptors such as integrins act upon the latent form, releasing the active ligand. There are three types of mammalian TGF-βs: (TGF-β1, TGF-β2, and TGF-β3) that bind as homodimers or heterodimers to TGF-β receptors. The TGF-β receptors are of three kinds RI, RII, and RIII. The RI...
Renewal of Skin Epidermal Stem Cells
The skin is divided into epidermis, dermis, and hypodermis, the skin's outermost, middle, and inner layers. The human epidermal layer regularly undergoes renewal, where old, dead cells are replaced by new cells. Epidermal stem cells or EpiSCs divide and differentiate to restore the lost cells. For the renewal process, some EpiSCs continuously self-renew. In contrast, few others differentiate into transit-amplifying cells, which later form prickle or spinous cells, followed by granular cells,...
Somatic to iPS Cell Reprogramming
Reprogramming alters the gene expression in somatic cells, transforming them into induced pluripotent stem (iPS) cells over several generations. Scientists can reprogram cells by introducing genes for four transcription factors—Oct4, Sox2, Klf4, and c-Myc (OSKM) by viral or non-viral methods. These factors are also known as Yamanaka factors after Shinya Yamanaka, who first generated iPS cells using mouse skin cells. Yamanaka was awarded the Nobel Prize in Physiology or Medicine in 2012 for this...
Pigmentation
The color of the skin is influenced by a number of pigments, including melanin, carotene, and hemoglobin. Recall that melanin is produced by cells called melanocytes, which are found scattered throughout the stratum basale of the epidermis. The melanin is transferred to the keratinocytes via melanosomes.
Melanin occurs in two primary forms: eumelanin that provides black and brown pigment and pheomelanin that provides red color. Dark-skinned individuals produce more melanin than those with pale...
Melanin occurs in two primary forms: eumelanin that provides black and brown pigment and pheomelanin that provides red color. Dark-skinned individuals produce more melanin than those with pale...
Cellular Adaptation III: Hyperplasia
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...


