Myofibroblast

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Myofibroblasts are a cell type that was first detected in granulation tissue using an electron microscope in 1971 . They also occur as pericytes in the capillary walls, in the cortical stroma of the ovary and in the tunica albuginea of the testicle . They represent an intermediate form between smooth muscle cells and fibroblasts and contain contractile actin and myosin filaments as well as a high endogenous production of collagen . Myofibroblasts have the ability to contract; in contrast to smooth muscle cells, they are not surrounded by a basal lamina .

Myofibroblasts have elongated cell bodies and numerous cytoplasmic processes that sometimes give the cells a star-shaped appearance. They are in contact with neighboring cells via adherence connections and gap junctions . The intracellular microfilaments are aligned parallel to the longitudinal axis of the cell and show densification zones (dense bodies). They are connected to the abundant extracellular matrix via cell-stroma contact points . A transmembrane complex (fibronexus) creates a continuity between intracellular microfilaments and extracellular fibronectin fibers. The nucleus of the myofibroblasts shows deep indentations.

During wound healing, myofibroblasts usually arise from fibroblasts that have been stimulated to divide by activated macrophages . These resulting myofibroblasts migrate with the macrophages into the wound area. The production of collagen restores the integrity of the tissues and leads to scarring . Reduced activation of myofibroblast leads to insufficient wound healing. The prolonged action of too many myofibroblasts, on the other hand, leads to pronounced scar constrictions and fibrosis and can thus impair organ function.

Web links

Commons : Myofibroblast  - collection of images, videos and audio files

Individual evidence

  1. ↑ a b Boris Hinz et al .: Myofibroblast . In: Stacey E. Mills (Ed.): Histology for Pathologists . 4th edition. Lippincott Williams & Wilkins, 2012, ISBN 978-1-4511-7780-0 .
  2. ↑ Wolfgang Kühnel: Pocket Atlas of Histology . 13th edition. Georg Thieme, Stuttgart 2014, ISBN 978-3-13-151533-9 , pp. 400 .
  3. ↑ Wolfgang Kühnel: Pocket Atlas of Histology . 13th edition. Georg Thieme, Stuttgart 2014, ISBN 978-3-13-151533-9 , pp. 382 .
  4. ^ Henrik Holtmann: Last Minute Histology . Elsevier, Urban & Fischer, 2012, ISBN 978-3-437-43015-2 , pp. 11 .
  5. ↑ Michael H. Ross, Wojciech Pawlina: Histology . Lippincott Williams & Wilkins, 2006, ISBN 978-0-7817-6790-3 , pp. 166 .
  6. ^ B. Hinz: The role of myofibroblasts in wound healing. In: Current research in translational medicine. Volume 64, number 4, 2016 Oct - Dec, pp. 171-177, doi : 10.1016 / j.retram.2016.09.003 , PMID 27939455 (review).