The cell body of fibroblast is spindle or irregular triangle, with oval nucleus in the center and cytoplasmic processes, which are radial when growing.In addition to true fibroblasts, all tissues originating from mesoderm mesenchyme, such as myocardium, smooth muscleOsteoblastVascular endothelium often presents this type of state.In addition, any cell in culture whose morphology is similar to that of fibroblasts can be called fibroblasts.in vitro cultureOfFibroblastMost of them are fusiform, polygonal and flat star, and their morphology can be changed according to the functional changes of cells and the physical properties of their attachment.Electron microscopeThere are abundant rough endoplasmic reticulum, free ribosomes and developedGolgi complex。In mature or quiescent fibroblasts, the cell body becomes small, long spindle shaped, rough endoplasmic reticulum and Golgi complex are underdeveloped.It has strong ability of division and proliferation, strong adaptability, and is the easiest to cultivateAnimal cellOne of the types.
Chinese name
Fibroblast
Foreign name
Fibroblast
Form
Shuttle or irregular triangle
Classification
Fibroblasts and Fibroblasts
Features
Ability to divide and multiply, strong adaptability, easy to cultivate
Fibroblasts areLoose connective tissueThe main cell component of the cell is spindle shaped or flat star shaped, with protrusions.According to different functional activities, cells are divided into fibroblasts and fibroblasts.
Fibroblasts are cells with vigorous functional activities. The cells and nuclei are large, with clear outlines, large and obvious nucleoli, and the cytoplasm is weakly basophilic, with obviousprotein synthesisAnd secretory activity;Fibroblasts in mature or static state are called fibroblasts because their cell bodies become small and long spindle shaped, rough endoplasmic reticulum and Golgi complex are underdeveloped.Fibroblasts are not active in functional activities, the cell outline is not obvious, the nucleus is small and deeply stained, the nucleolus is not obvious, and the cytoplasm is few.Under the stimulation of trauma and other factors, some fibroblasts can be transformed into immature fibroblasts again, and their functional activities can also be recovered, participating in the repair of tissue damage.[1]
Fibroblasts participate in the formation of collagen fibers
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Fibroblasts ingest the required amino acids, such as proline and lysine, synthesize pre alpha polypeptide chains on the ribosomes of rough endoplasmic reticulum, and deliver the polypeptide chains toGolgi complexAfter the formation of procollagen molecules.Precollagen molecules are carried from secretory vesicles tocell surfaceAnd then released out of the cell through exocytosis.Under the catalysis of procollagen peptidase, the tail segment of each procollagen polypeptide chain is removed to become procollagen molecules.Many tropocollagen molecules are arranged in parallel rows and combined into a periodic cross striatedCollagen fibril。It is formed by the combination of collagen fibrilsCollagen fiber。
Fibroblasts and connective tissue
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Fibroblasts are the most common cells in connective tissueMesenchymal cells(mesenchymal cell).In the connective tissue, fibroblasts also exist in the form of their mature state - fibroblasts, and they can transform each other under certain conditions.The number of fibroblasts in different types of connective tissue is different.Generally, the number of fibroblasts in loose connective tissue is less than that in dense connective tissue of the same volume, soIsolation cultureFibroblasts are mostly taken from dense connective tissue such as dermis.[2]
Fibroblasts and protein secretion and synthesis
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Fibroblasts have various shapes, such as spindle, polygonal and flat star. Their shapes can also be changed according to the functional changes of cells and the physical properties of their attachment.Fibroblasts have large cell bodies, weakly basophilic cytoplasm, large oval nuclei, loose chromatin and light staining, and obvious nucleoli.Under electron microscope, abundant rough endoplasmic reticulum, free ribosomes and developed Golgi complex can be seen in its cytoplasm, indicating that it has the function of synthesizing and secreting proteins.
The role of fibroblasts in wound repair
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The expression of fibroblasts in general wound repair All kinds of trauma will cause varying degrees of cell degeneration, necrosis and tissue defect, and tissue repair must be carried out through cell proliferation and the formation of intercellular matrix.In this repair process, fibroblasts play a very important role.Take the wound healing process as an example. Fibroblasts proliferate massively through mitosis, and synthesize and secrete a large number of collagen fibers and matrix components from 4-5 days or 6 days. Together with new capillaries, they form granulation tissue to fill the wound tissue defectsEpidermal cellCreate conditions for coverage.In wound healing, fibroblasts mainly come from local fibroblasts and undifferentiated mesenchymal cells in dermal papillary layer, as well as fibroblasts and pericytes around blood vessels.Visceral injuryThe fibroblasts involved in the repair process mostly come from the stroma and capsule, as well as the connective tissue under the mucosa or serosa.Some people think that a large number of fibroblasts gathered at the wound site during the wound healing process, on the one hand, are derived from the fibroblast through division and proliferation, on the other hand, they are more evolved or migrated to the wound site from adjacent mesenchymal cells, fibroblasts and pericapillary cells.In the later stage of wound repair, fibroblasts participate in the tissue remodeling after repair by secreting collagenase.Under some pathological conditions, granulation tissue or proliferative tissue mass with fibroblasts as the main cell component can also calcified in non bone tissue, causing ectopic ossification.However, the cells involved in heterotopic ossification and its mechanism are not very clear. Undifferentiated mesenchymal cells, fibroblasts, endothelial cells and pericapillary cells can be classified as inducibleBone progenitor cellIt is possible that all of the cells may participate in this process.[3]
