Cytokines & Chemokines

Fibroblast Growth Factor 8a (FGF-8a) is a cytokine belonging to the heparin-binding FGF family, which has at least 23 members. FGF-8 has 8 different isoforms, named FGF-8a through FGF-8h. Different FGF-8 isoforms have different affinities to the receptors, and thus participate in different signaling cascade pathways. FGF-8 has very widespread expression during embryonic development, and is an organizer and inducer for gastrulation, somitogenesis, morphogenesis, and limb induction. However, FGF-8 is also a potential oncogene: in normal adult cells, FGF-8 has very low expression, but FGF-8 is highly expressed in cancer cells of breast, prostate, and ovarian tumors. FGF-8 promotes tumor angiogenesis by increasing neovascularization, and induces osteoblastic differentiation.

Fibroblast Growth Factor 8a (FGF-8a) is a cytokine belonging to the heparin-binding FGF family, which has at least 23 members. FGF-8 has 8 different isoforms, named FGF-8a through FGF-8h. Different FGF-8 isoforms have different affinities to the receptors, and thus participate in different signaling cascade pathways. FGF-8 has very widespread expression during embryonic development, and is an organizer and inducer for gastrulation, somitogenesis, morphogenesis, and limb induction. However, FGF-8 is also a potential oncogene: in normal adult cells, FGF-8 has very low expression, but FGF-8 is highly expressed in cancer cells of breast, prostate, and ovarian tumors. FGF-8 promotes tumor angiogenesis by increasing neovascularization, and induces osteoblastic differentiation.

Keratinocyte Growth Factor (KGF) is a highly specific epithelial mitogen produced by fibroblasts and mesenchymal stem cells. KGF belongs to the heparin binding Fibroblast Growth Factor (FGF) family, and is known as FGF-7. However, in contrast to the FGF-1, which binds to all known FGF receptors with high affinity, KGF only binds to a splice variant of an FGF receptor, FGFR2-IIIb. FGFR2-IIIb is produced by most of the epithelial cells, indicating that KGF plays roles as a paracrine mediator. KGF induces the differen-tiation and proliferation of various epithelial cells, including keratinocytes in the epidermis, hair follicles and sebaceous glands, and is responsible for the wound repairs of various tissues, including lung, bladder, and kidney.

Keratinocyte Growth Factor (KGF) is a highly specific epithelial mitogen produced by fibroblasts and mesenchymal stem cells. KGF belongs to the heparin binding Fibroblast Growth Factor (FGF) family, and is known as FGF-7. However, in contrast to the FGF-1, which binds to all known FGF receptors with high affinity, KGF only binds to a splice variant of an FGF receptor, FGFR2-IIIb. FGFR2-IIIb is produced by most of the epithelial cells, indicating that KGF plays roles as a paracrine mediator. KGF induces the differen-tiation and proliferation of various epithelial cells, including keratinocytes in the epidermis, hair follicles and sebaceous glands, and is responsible for the wound repairs of various tissues, including lung, bladder, and kidney.

Thrombopoietin (TPO), also known as C-mpl ligand, MGDF and Thpo, is a glycoprotein hormone belonging to the EPO/TPO family. It is expressed mainly in the liver, kidney and skeletal muscle. TPO binds and signals through MLP/C_MPL receptor. It stimulates the proliferation and maturation of megakaryocytes from their committed progenitor cells, and it regulates the production and circulation of platelets. TPO has also been reported to promote the apoptosis of hypoxia-sensitized neurons and to inhibit neuronal differentiation.

Thrombopoietin (TPO), also known as C-mpl ligand, MGDF and Thpo, is a glycoprotein hormone belonging to the EPO/TPO family. It is expressed mainly in the liver, kidney and skeletal muscle. TPO binds and signals through MLP/C_MPL receptor. It stimulates the proliferation and maturation of megakaryocytes from their committed progenitor cells, and it regulates the production and circulation of platelets. TPO has also been reported to promote the apoptosis of hypoxia-sensitized neurons and to inhibit neuronal differentiation.

Thrombopoietin (TPO), also known as C-mpl ligand, MGDF and Thpo, is a glycoprotein hormone belonging to the EPO/TPO family. It is expressed mainly in the liver, kidney and skeletal muscle. TPO binds and signals through MLP/C_MPL receptor. It stimulates the proliferation and maturation of megakaryocytes from their committed progenitor cells, and it regulates the production and circulation of platelets. TPO has also been reported to promote the apoptosis of hypoxia-sensitized neurons and to inhibit neuronal differentiation.

Insulin-like growth factor-binding protein 4 (IGF-BP-4), also known as IBP-4, is a secreted glycoprotein belonging to the IGFBP family. IGF-BP-4 is produced by osteoblasts, epidermis, ovarian follicles and other tissues. It binds both insulin-like growth factor (IGF) I and II, and it circulates in the plasma in both glycosylated and non-glycosylated forms. IGF-BP-4 prolongs the half-life of the IGFs and has been shown to inhibit or stimulate the growth-promoting effects of the IGFs. Pregnancy Associated Plasma Protein A (PAPP-A) proteolytically cleaves IGF-BP-4 and reduces its affinity to bind IGFs, and thus serves as an important regulator of IGF-BP-4 function.

Insulin-like growth factor-binding protein 4 (IGF-BP-4), also known as IBP-4, is a secreted glycoprotein belonging to the IGFBP family. IGF-BP-4 is produced by osteoblasts, epidermis, ovarian follicles and other tissues. It binds both insulin-like growth factor (IGF) I and II, and it circulates in the plasma in both glycosylated and non-glycosylated forms. IGF-BP-4 prolongs the half-life of the IGFs and has been shown to inhibit or stimulate the growth-promoting effects of the IGFs. Pregnancy Associated Plasma Protein A (PAPP-A) proteolytically cleaves IGF-BP-4 and reduces its affinity to bind IGFs, and thus serves as an important regulator of IGF-BP-4 function.