1 / 12

Growth factors

Growth factors. Polypeptides in nature Work through cell surface receptors Endocrine, paracrine or autocrine actions Stimulation of cell proliferation (alone or in combination with other growth factors). IGF-I. ↑ GH, ↑ IGF-I or Somatomedin “C”

shensley
Download Presentation

Growth factors

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Growth factors • Polypeptides in nature • Work through cell surface receptors • Endocrine, paracrine or autocrine actions • Stimulation of cell proliferation (alone or in combination with other growth factors)

  2. IGF-I • ↑ GH, ↑ IGF-I or Somatomedin “C” • Plays role in cell cycle control, ↑cell growth (growth of bone and cartilage), and  apoptosis • Shares common properties with the insulin receptor and binds with lower affinity to the insulin receptor •  GH,  IGF-I • Acromegaly, ↑ IGF-I levels

  3. IGF-I binding proteins • IGF-I Circulates in plasma with a large (MW 150,000) carrier proteins (at least six binding proteins have been isolated) • Very long plasma half life of IGF-I due to the binding proteins • Facilitators or inhibitors of IGF-I actions

  4. IGF-II • Involved in regulation of fetal growth • Receptor is quite different from the insulin and IGF-I receptor • Receptor is single polypeptide (identical to mannose-6-phosphate receptor) without any intrinsic phospho kinase activity

  5. Epidermal growth factor (EGF): • The epidermal growth factor (EGF) family of polypeptides are regulators for tissue • development, proliferation, differentiation, survival (inhibitor of apoptosis) and repair of various cells. • EGF = urogastrone, a potent inhibitor of gastric acid secretion isolated from human urine.

  6. Platelet - derived growth factor (PDGF): • Purified from platelet; present in serum (after clotting and platelet lysis) but not plasma. • Multifaceted inflammatory mediator secreted by fibroblasts, smooth muscle cells, • macrophages and endothelial cells.

  7. Fibroblast growth factor (FGF): • Major biological role: stimulation of angiogenesis (capillary proliferation).

  8. NGF (Nerve growth factor) • Purified from mouse salivary glands and snake venom • Promote growth, differentiation and survival of neurons

  9. Erythropoietin • Regulates red blood cell proliferation • Made in kidney

  10. Lymphocytes growth factors • Interleukins, thymosin • Activate lymphocytes proliferation and maturation • Important role in regulating immune response and inflammation

  11. Growth factors and neoplasia • Normal Growth: Growth Stimulatory Factors = Growth Inhibitoy Factors • Development of Cancers by↑ in Growth Stimulatory Factors or  in Growth Inhibitory Factors

  12. Transforming Growth Factors • TGF-α – Similar in structure to EGF and stimulates cell growth • TGF-β – Inhibits cell division

More Related