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PDGF-BB is a member of the platelet-derived growth factor family. The four members of this family are mitogenic factors for cells of mesenchymal origin and are characterized by a motif of eight cysteines. This gene product can exist either as a homodimer (PDGF-BB) or as a heterodimer with the platelet-derived growth factor alpha polypeptide (PDGF-AB), where the dimers are connected by disulfide bonds. Mutations in this gene are associated with meningioma. Reciprocal translocations between chromosomes 22 and 7, at sites where this gene and that for COL1A1 are located, are associated with a particular type of skin tumor called dermatofibrosarcoma protuberans resulting from unregulated expression of growth factor. Two splice variants have been identified for this gene.

Chemokine (C-X-C motif) ligand (CXCL7) is a small cytokine belonging to the CXC chemokine family. It is a protein that is released in large amounts from platelets following their activation. It stimulates various processes including mitogenesis, synthesis of extracellular matrix, glucose metabolism and synthesis of plasminogen activator.

NANOG is a multidomain homeobox transcription factor which functions to maintain the undifferentiated state of pluripotent stem cells. NANOG expression counteracts the differentiation-promoting signals induced by the extrinsic factors LIF, Stat3 and BMP. Once NANOG expression is downregulated, cell differentiation can proceed. Proteins which regulate NANOG expression include transcription factors Oct4, SOX2, FoxD3, and Tcf3 and tumor suppressor p53.

HMGB1 is an abundant chromatin-binding protein found in eukaryotic cell nucleus and acts in the assembly of nucleoprotein complexes. Inside the cell, HMGB1 binds to DNA and is involved in transcriptional regulation. Outside the cell, HMGB1 acts as a cytokine with activities that resemble those of tumor necrosis factor (TNF). HMGB1 is elevated significantly in chronic kidney disease patients and correlates with glomerular filtration rate as well as with markers of inflammation and malnutrition. HMGB1 is involved in Gram-negative sepsis by catalyzing movement of LPS monomers from LPS aggregates to CD14 to initiate a TLR4-mediated proinflammatory response. HMGB1 plays an important role in the relationship between necrosis and malignancy in glioma tumours. HMG1 protein is induced by Mycobacterium bovis BCG. Overexpression of HMGB1 is common in gastrointestinal stromal tumors and is related to the KIT mutation. HMG1 induces growth inhibition and apoptosis in macrophages through RAGE intracellular signaling pathway. The increase of extracellular HMGB1 observed in salivary glands of Sjogren's syndrome patients indicates that HMGB-1 is involved in the inflammatory process of the disease. HMGB-1 together with estrogen increase cell cycle progression in tumor cell lines.

Mimitin (NDUFAF2) is a member of the complex I NDUFA12 subunit family.NADH dehydrogenase is an enzyme located in the inner mitochondrial membrane, which catalyzes the transfer of electrons from NADH to coenzyme Q (CoQ). NDUFAF2 is the "entry enzyme" of oxidative phosphorylation in the mitochondria. Mimitin protein functions as a molecular chaperone for mitochondrial complex I assembly.

Endothelial cells express three different vascular endothelial growth factor (VEGF) receptors, belonging to the family of receptor tyrosine kinases (RTKs). They are named VEGFR-1 (Flt-1), VEGFR-2 (KDR/Flk-1), VEGFR-3 (Flt-4). Their expression is almost exclusively restricted to endothelial cells, but VEGFR-1 can also be found on monocytes, dendritic cells and on trophoblast cells. The flt-1 gene was first described in 1990. The receptor contains seven immunoglobulin-like extracellular domains, a single transmembrane region and an intracellular splited tyrosine kinase domain. Compared to VEGFR-2 the Flt-1 receptor has a higher affinity for VEGF but a weaker signaling activity. VEGFR-1 thus leads not to proliferation of endothelial cells, but mediates signals for differentiation. Interestingly a naturally occuring soluble variant of VEGFR-1 (sVEGFR-1) was found in HUVE supernatants in 1996, which is generated by alternative splicing of the flt-1 mRNA. The biological functions of sVEGFR-1 still are not clear, but it seems to be an endogenous regulator of angiogenesis, binding VEGF with the same affinity as the full-length receptor.

TSNAX is a member of translin family. TSNAX particularly interacts with translin, a DNA-binding protein that binds consensus sequences at breakpoint junctions of chromosomal translocations. TSNAX works in combination with TSN as an endonuclease involves in the activation of the RNA-induced silencing complex (RISC). TSNAX has bipartite nuclear targeting sequences that afford nuclear transport for translin, which lacks any nuclear targeting motifs.

Platelet-activating factor acetylhydrolase 2 cytoplasmic (PAFAH2) has a marked selectivity for phospholipids with short acyl chains at the sn-2 position. PAFAH2 may share a mutual physiologic function with the plasma-type enzyme.

Translin is a DNA and RNA binding protein that identifies specifically preserved target sequences at the breakpoint junction of chromosomal translocations. TSN forms a ring-shaped configuration, that is in charge of DNA binding, and in addition has a leucine zipper motif, which is believed to assist TSN to form dimers. TSN exports specific mRNAs out of the nucleus, reinforced by its localization in both the nuclei and cytoplasm of neurons, and regulates their translation.

Excess adiposity is the most important risk in the development of insulin resistance and type 2 diabetes mellitus (T2DM). Adipose tissue produces several proteins (adipocytokines) such as leptin, adiponectin, resistin, tumor necrosis factor-?, and IL-6, that modulate insulin sensitivity and appear to play an important role in the pathogenesis of insulin resistance, diabetes, dyslipidemia, inflammation, and atherosclerosis. However, the mechanisms by which fat tissue induces insulin resistance and the role of adipocytokines in the pathogenesis of T2DM have not been well established. Visfatin, also known as pre-B cell colony-enhancing factor (PBEF), is a cytokine that is highly expressed in visceral fat and was originally isolated as a secreted factor that synergizes with IL-7 and stem cell factors to promote the growth of B cell precursors. Visfatin homologs have been identified in carp, invertebrate mollusks, and bacteria, as well as in vertebrates, including humans and the mouse. It has been postulated to play a role in innate immunity.
Visfatin exerts insulin-mimetic effects that are dose-dependent and quantitatively similar to those of insulin in stimulating muscle and adipocyte glucose transport, and in inhibiting hepatocyte glucose production. Intravenous injection of recombinant visfatin in mice decreased plasma glucose in a dose-dependent fashion. In keeping with its insulin-mimetic effects, visfatin was as effective as insulin in reducing hyperglycemia in insulin-deficient diabetic mice. Visfatin was also found to be bound to and activate insulin receptor, causing receptor phosphorylation and the activation of downstream signaling molecules. However, visfatin and insulin did not compete for binding to the insulin receptor, indicating that the two proteins were recognized by different regions of the receptor. Thus, visfatin might play a role in glucose homeostasis and dysregulation in biosynthesis or signal transduction, and might contribute to the pathogenesis of diabetes.

GCSF is a cytokine that controls the production, differentiation, and function of granulocytes. The active protein is found extracellularly. Three transcript variants encoding three different isoforms have been found for this gene.
Granulocyte/macrophage colony-stimulating factors are cytokines that act in hematopoiesis by controlling the production, differentiation, and function of 2 related white cell populations of the blood, the granulocytes and the monocytes-macrophages. This csf induces granulocytes.

Complement factor H (CFH) is an important regulatory component of the alternative pathway of complement. CFH is prevents complement activation on host cells and tissues, mainly the kidney. CFH controls the formation and decay of the alternative pathway C3/C5 convertase and acts as a cofactor for factor I which proteolytically inactivates C3b when C3b is bound to factor H. The N-terminal 5 domains of CFH bind to C3b and inhibit binding of factor B thus reducing the formation of C3/C5 convertase. CFH also binds to preformed C3/C5 convertases and causes quick release of the catalytic subunit Bb. These activities are necessary for controlling the spontaneous activation of the alternative pathway amplification process in plasma. In addition, CFH controls the formation and decay of these enzymes when C3b is attached to the surface of particles.

Non-homologous end-joining factor 1 (NHEJ1) is a member of the XLF family. NHEJ1 is a DNA repair factor vital for the nonhomologous end-joining pathway, which preferentially mediates repair of double-stranded breaks. NHEJ1 gene mutations cause different kinds of severe combined immunodeficiency disorders. NHEJ1 was initially detected as the protein mutated in five patients with growth retardation, microcephaly, and immunodeficiency. In addition, patients with NHEJ1 mutations have immunodeficiency caused by a defect in V(D)J recombination, which employs NHEJ to promote immune system diversity.

Osteopontin is a glycoprotein that was first identified in osteoblasts and is involved in bone remodeling, immune functions in fibroblasts, macrophages, and lymphocytes during inflammation and wound healing. SPP1 binds tightly to hydroxyapatite. SPP1 forms an integral part of the mineralized matrix. SPP1 is vital to cell-matrix interaction. Secreted Phosphoprotein-1 protects against cardiac ischemia-reperfusion injury via late preconditioning. Expression of both Ostepontin and CD44 in hepatocellular carcinoma is linked with advanced tumor stage and contributes to prognosis information. SPP1 is the most over-expressed gene in intrahepatic cholangiocarcinoma. Secreted Phosphoprotein-1 overexpression is related with interstitial lung diseases.

A 16-kDa peptide hormone secreted from white adipocytes and implicated in the regulation of food intake and energy balance. Leptin provides the key afferent signal from fat cells in the feedback system that controls body fat stores.

BDNF promotes the survival of neuronal populations that are all located either in the central nervous system or directly connected to it. Major regulator of synaptic transmission and plasticity at adult synapses in many regions of the cns. the versatility of bdnf is emphasized by its contribution to a range of adaptive neuronal responses including long-term potentiation (ltp), long-term depression (ltd), certain forms of short-term synaptic plasticity, as well as homeostatic regulation of intrinsic neuronal excitability.

PDGF-AA, PDGF-BB and PDGF-AB, are potent mitogens for a variety of cell types including smooth muscle cells, connective tissue cells, bone and cartilage cells, and some blood cells. The PDGF is stored in platelet alpha-granules and released upon platelet activation. The PDGF is involved in a number of biological processes, including hyperplasia, chemotaxis, embryonic neuron development, and respiratory tubule epithelial cell development. Two distinct signaling receptors used by PDGF
have been identified and named PDGFR-alpha and PDGFR-beta. PDGFR-alpha is high-affinity receptor for each of the three PDGF forms. On the other hand, PDGFR-beta interacts with only PDGF-BB and PDGF-AB.

The FGFs are a family of more than 20 small (~17–26 kDa) secreted peptides. The initial characterization of these proteins focused on their ability to stimulate fibroblast proliferation. This mitogenic activity was mediated through FGF receptors (FGFRs) 1, 2, or 3. A fourth closely related tyrosine kinase receptor (FGFR4) was able to bind the FGFs but did not lead to a mitogenic response.
FGFs modulate cellular activity via at least 5 distinct subfamilies of high-affinity FGF receptors (FGFRs): FGFR-1, -2, -3, and -4, all with intrinsic tyrosine kinase activity and, except for FGFR-4, multiple splice isoforms, and FGFR-5, which lacks an intracellular kinase domain. There is growing evidence that FGFRs can be important for regulation of glucose and lipid homeostasis. The overexpression of a dominant negative form of FGFR-1 in cells leads to diabetes in mice, which thus implies that proper FGF signaling is required for normal ? cell function and glycemia maintenance. FGFR-2 appears to be a key molecule during pancreatic development. Moreover, FGFR-4 has been implicated in cholesterol metabolism and bile acid synthesis.
FGF-19, has been shown to cause resistance to diet-induced obesity and desensitization and to improve glucose, and lipid profiles in diabetic rodents. Since these effects, at least in part, are mediated through the observed changes in metabolic rates, FGF-19 can be considered as a regulator of energy expenditure.
FGF-21 is preferentially expressed in liver, but an exact knowledge of FGF-21 bioactivity and its mode of action have been lacking to date. FGF-21 is a potent activator of glucose uptake on adipocytes, protects animals from diet-induced obesity when overexpressed in transgenic mice, and lowers blood glucose and triglyceride levels when therapeutically administered to diabetic rodents.

Fibroblast Growth Factors (FGFs) comprise a family of at least eighteen structurally realted proteins that are involved in a multitude of physiological and pathological cellular processes, including cell growth, differentation, angiogenesis, wound healing and tumorgenesis. The biological activities of the FGFs are mediated by a family if type I transmembrane tyrosine kinases which undergo dimerization and autophosphorylation after ligand binding. Four distinct genes encoding closely related FGF receptors, FGFR-1to -4 are known. Multiple forms of FGFR-1 to -3 are generated by alternative splicing of the mRNAs. A frequent splicing event involving FGFR-1 and -2 results in receptors containing all three Ig domains, referred to as the alpha isoform, or only IgII and IgIII, referred to as the ? isoform. Only the alpha isoform has been identified for FGFR-3 and FGFR-4. Additional splicing events for FGFR-1 to -3, involving the C-terminal half of the IgIII domain encoded by two mutually exclusive alternative exons, generate FGF receptors with alternative IgIII domains (IIIb and IIIc). A IIIa isoform which is a secreted FGF binding protein containing only the N-terminal half of the IgIII domain plus some intron sequences has also been reported for FGFR-1. Mutations in FGFR-1 to -3 have been found in patients with birth defects involving craniosynostosis.

RARRES2 is a secreted chemotactic protein that initiates chemotaxis through the ChemR23 G protein-coupled seven-transmembrane domain ligand. RARRES2 is upregulated by the synthetic retinoid tazarotene and found in a vast variety of tissues. RARRES2 acts as an adipokine, and is truncated on both termini from the proprotein. RARRES2 is structurally related to the cathelicidin precursors, cystatin C and kininogens. RARRES2 promotes calcium mobilization and chemotaxis of immature dendritic cells and macrophages. RARRES2 is secreted as a precursor of little biological activity, which requires proteolytic cleavage of its COOH-terminal domain to be exchangeed into a potent and highly specific agonist of ChemR23. RARRES2 signals via its receptor, ChemR23 (CMKLR1), as a positive regulator of adipocyte differentiation and metabolic function. The Chemerin receptor acts as a coreceptor for SIV and some primary HIV-1 strains. The Chemerin receptor has another ligand, called tazarotene-induced gene.

Endothelial cells express three different vascular endothelial growth factor (VEGF) receptors, belonging to the family of receptor tyrosine kinases (RTKs). They are named VEGFR-1 (Flt-1), VEGFR-2 (KDR/Flk-1), VEGFR-3 (Flt-4). Their expression is almost exclusively restricted to endothelial cells, but VEGFR-1 can also be found on monocytes, dendritic cells and on trophoblast cells. The flt-1 gene was first described in 1990. The receptor contains seven immunoglobulin-like extracellular domains, a single transmembrane region and an intracellular splited tyrosine kinase domain. Compared to VEGFR-2 the Flt-1 receptor has a higher affinity for VEGF but a weaker signaling activity. VEGFR-1 thus leads not to proliferation of endothelial cells, but mediates signals for differentiation. Interestingly a naturally occuring soluble variant of VEGFR-1 (sVEGFR-1) was found in HUVE supernatants in 1996, which is generated by alternative splicing of the flt-1 mRNA. The biological functions of sVEGFR-1 still are not clear, but it seems to be an endogenous regulator of angiogenesis, binding VEGF with the same affinity as the full-length receptor.

SDF-1 (stromal cell-derived factor-1) is small cytokine belonging to the chemokine family that is officially designated Chemokine (C-X-C motif) ligand 12 (CXCL12). It is produced in two forms, SDF-1?/CXCL12a and SDF-1?/CXCL12b, by alternate splicing of the same gene. Chemokines are characterized by the presence of four conserved cysteines, which form two disulfide bonds. The CXCL12 proteins belong to the group of CXC chemokines, whose initial pair of cysteines are separated by one intervening amino acid. CXCL12 is strongly chemotactic for lymphocytes and has been implicated as an important cell co-ordinator during development. During embryogenesis it directs the migration of hematopoietic cells from foetal liver to bone marrow. Mice which were knocked-out for CXCL12 gene were lethal before the birth or within just 1 hour of life. As another role, CXCL12a alters also the electrophysiology of neurons. CXCL12 was shown to be expressend in many tissues in mice (including brain, thymus, heart, lung, liver, kidney, spleen and bone marrow).
The receptor for this chemokine is CXCR4, which was previously called fusin. This CXCL12-CXCR4 interaction used to be considered exclusive (unlike for other chemokines and their receptors), but recently it was suggested that CXCL12 is also bound by CXCR7 receptor.
The gene for CXCL12 is located on human chromosome 10. In human and mouse both CXCL12 and CXCR4 show high identity of sequence: 99% and 90%, respectively.