Fibroblast

Original Editor - Lucinda hampton

Top Contributors - Lucinda hampton, Vidya Acharya and Kim Jackson  

Introduction

Fibroblast synthesis the ECM fibres

Fibroblasts are the most common cell in connective tissue and connective tissues permanent residents. They secrete the fibers (notably collagen and elastin) and ground substance of the extracellular matrix.

Fibroblasts are often spindle-shaped with an elongated nucleus. When active fibroblasts are easily recognized by their abundant rough endoplasmic reticulum and prominent Golgi apparatus.

Obtained from a person through a simple skin biopsy, fibroblasts can be grown in the laboratory for use in genetic and other scientific studies of that individual. In recent years, studies on reprogramming human fibroblasts into neurons or heart cells have emerged.

Fibroblasts are cells are diverse, participating in tissue homeostasis and disease by producing the complex extracellular matrix and creating signaling niches through biophysical and biochemical cues. These properties, when activated aberrantly, drive fibrotic disorders in humans.

Adaptability

Fibroblasts are known for their ability to change function. Adipocytes, pericytes, endothelial and epithelial cells can de-differentiate into fibroblasts. Stimulation of fibroblasts further increases vulnerability to epigenetic modifications. The ability of fibroblasts to transform is partly due to the variety of cell-surface adhesion receptors that facilitate the communication of fibroblasts with their surroundings. An example is the fibroblast transformation into the myofibroblast, essential in wound healing.

Connective Tissue Repair

File:4-STAGES-OF-WOUND-HEALING.png

Connective tissue repair is carried out by new fibroblasts which are derived from cells called pericytes. Pericytes are embedded in the basement membrane of blood capillaries These new fibroblasts then migrate into wounds, following injury, and helping repair the damage. Contractile fibroblasts, called myofibroblasts are also often generated, and these help to contract wounds.

Terminology and More

• Fibroblast: Synthetically active state
• Fybrocyte: Synthetically inactive state
• Tenoblast: specialised fibroblast
• Osteoblast: specialised fibroblast
• Myofibroblasts: contractile fibroblasts, having contractile properties, play a critical part in wound healing.
• Cardiac fibroblast: a cell that produces connective tissue (in contrast to the connective tissue of bone and tendon, which is organized into regular patterns of collagen, heart ECM is dense, irregular, and composed of collagens, proteoglycans, and glycoproteins)
• Reticular cell: type of fibroblast that synthesizes collagen alpha-1(III) and uses it to produce reticular fibers. Eg Reticular cells provide structural support, producing and maintaining the thin networks of fibres, that are a framework for most lymphoid organs.
• Bone marrow fibroblasts regulate hematopoiesis by interacting directly (cell-to-cell contact) with hematopoietic cells and by secreting regulatory molecules that have a positive or negative effect.