You searched for: Proteins and Peptides

Supplier: STEMCELL Technologies

Butyrophilin 1A1 (BTN1A1) is a glycoprotein belonging to the butyrophilin (BTN) family which collectively modulates immune responses, through excitatory and inhibitory signals targeting immune cells. Butyrophilins are composed of two extracellular immunoglobulin domains and a transmembrane region, with a conserved B30.2 domain (PRYSPRY) that is present in most members (Malinowska et al.). BTN1A1, along with BTN2A2, has been shown to inhibit the proliferation of CD4+ and CD8+ T cells, modify T cell metabolism, and affect the expression of IL-2 and IFN-γ (Smith et al.). Due to these modulatory effects on T cells, BTN1A1 may have a role in inhibiting the development of autoimmune diseases (Stefferl et al.). BTN1A1 is also expressed in mammary glands and is required for the secretion of milk lipids during lactation (Ogg et al.). This protein contains a His-residue tag at the carboxyl end of the polypeptide chain. For consistency and reproducibility across your applications, Serpin A12 from STEMCELL comes lyophilized with ≥92% purity, and is verified by LAL analysis to ensure endotoxin levels are ≤1.0 EU/μg protein.

Supplier: Anaspec Inc

Pituitary adenylate cyclase-activating polypeptide (PACAP), a member of the vasoactive intestinal peptide/secretin/glucagon family, has an amino acid sequence identity of 68% with vasoactive intestinal polypeptide (VIP). PACAP38, derived from a 176-amino acid precursor (preproPACAP), is a 38-amino acid peptide discovered as an ovine hypothalamic neuropeptide. The amino acid sequence of PACAP is identical in all mammals, and in species such as chicken, frog, salmon, only 1–3 amino acids are different. It is abundant in both the central and peripheral nervous systems and exerts a variety of effects. PACAP in pancreatic islets may play a parasympathetic and sensory neurotransmitter role. PACAP stimulates insulin secretion from islets in a glucose-dependent manner at femtomolar concentrations, acting as an insulinotropic factor. PACAP and VIP are two multifunctional neuropeptides modulating innate and adaptive immunity. VIP/PACAP protect T cells from activation-induced cell death through down-regulation of Fas ligand. PACAP immunoreactivity has been shown in nerve fibers innervating the intrapancreatic ganglia as well as the islets of Langerhans in pancreas. PACAP (1-38) is more active than VIP in stimulating adenylate cyclase EC50=7 nM.
Sequence: HSDGIFTDSYSRYRKQMAVKKYLAAVLGKRYKQRVKNK-NH2
MW: 4534.3 Da
% Peak area by HPLC: 95
Storage condition: -20° C

Supplier: Anaspec Inc

Matrix Metalloproteinases (MMPs) are a large family of endopeptidases. Collectively, MMPs can degrade all kinds of extracellular matrix proteins, and can also process a number of bioactive molecules. They are known to be involved in the cleavage of cell surface receptors, the release of apoptotic ligands, and chemokine/cytokine inactivation. MMPs are also thought to play a major role in cell behaviors such as cell proliferation, migration (adhesion/dispersion), differentiation, angiogenesis, apoptosis, and host defense.
This substrate is hydrolyzed rapidly by MMP-13, but slowly by MMP-1, 2, 3, 8, 9 and 12, Abs/Em = 494/521 nm.
Sequence:QXL™ 520-PLGLWArK(5-FAM)-NH2
MW:1789.9 Da
% peak area by HPLC:95
Storage condition:-20° C

Supplier: STEMCELL Technologies

Oncostatin M (OSM) is a member of interleukin 6 (IL-6) family of cytokines and bears close resemblance to leukemia inhibitory factor (LIF) and granulocyte colony-stimulating factor (G-CSF) in amino acid sequence and its modulation of differentiation in a variety of cell types (Rose and Bruce). OSM signals through type I receptor (consisting of gp130 and LIF receptor [LIFR]) and type II receptor (consisting of gp130 and OSM receptor [OSMR]), which eventually activate the JAK/STAT pathway (Auguste et al.; Gómez-Lechón). OSM is primarily produced by activated T cells and monocytes, and also by activated macrophages, neutrophils, mast cells, and dendritic cells. OSM is also produced within the bone microenvironment by cells of both hematopoietic and mesenchymal origin, including osteocytes and osteoblasts. OSM is involved in differentiation, cell proliferation, hematopoiesis, and inflammation, and also has been shown to have implications in liver development and bone formation and resorption (Sims and Quinn; Tanaka and Miyajima). This product is animal component-free.

Supplier: STEMCELL Technologies

Ciliary neurotrophic factor (CNTF) is a neurotrophic factor that belongs to the four-helix bundle cytokine family and is structurally related to interleukin 6 (IL-6), interleukin 11 (IL-11), leukemia inhibitory factor (LIF), and oncostatin M (OSM). CNTF binds to its receptor CNFTRα and induces formation of a heterodimer of the signal-transducing IL-6 receptor gp130 and LIF receptor (LIFR)-β, which triggers JAK/STAT, ERK, and the PI3K signaling cascades (Schuster et al.). CNTF plays an important role in neurogenesis and the differentiation of neural stem cells and has been suggested to possess a therapeutic role in treating neurological disorders (Ding et al.; Oppenheim et al.). CNTF has also been shown to protect rod photoreceptors from light-induced damage and to have therapeutic effects on retinal degenerative diseases caused by genetic defect or damage induced by toxins, autoantibodies, or strong light (Pernet et al.; Rhee et al.). Another therapeutic role of CNTF has been reported in protecting oligodendrocytes from death induced by apoptosis (Louis et al.). Additionally, CNTF is commonly used to differentiate human pluripotent stem cell (hPSC)-derived neural progenitor cells into astrocytes (Krencik and Zhang).

Supplier: STEMCELL Technologies

Interleukin 31 (IL-31), a four-helix bundle inflammatory cytokine, belongs to the IL-6 cytokine family which includes IL-6 (MSPP-78050), oncostatin M (MSPP-78094), leukemia inhibitory factor (LIF; MSPP-78055), and cardiotrophin-1 (Dillon et al.). IL-31 signals through a heterodimer composed of IL-31RA (also known as gp130-like receptor or GPL) and the oncostatin-M receptor (OSMR), both of which are expressed on monocytes (Diveu et al.; Ghilardi et al.), epithelial cells (Ip et al.), and keratinocytes (Kato et al.). Signaling through the GPL/OSMR complex activates the JAK/STAT, RAS/ERK, and PI3K/AKT signaling pathways, resulting in the downstream activation of STAT1, STAT3, and STAT5 transcription factors (Cornelissen et al.; Dambacher et al.; Dillon et al.; Ip et al.). IL-31 responses have been associated with allergic responses and inflammatory skin diseases including atopic dermatitis (Cornelissen et al.; Gangemi et al.).

Supplier: STEMCELL Technologies

Betacellulin is a member of the epidermal growth factor (EGF) family, and signals through EGF receptor and ERBB4. It activates ERK and AKT pathways, which induces neural stem cell proliferation and prevents spontaneous differentiation in culture. Betacellulin stimulates the expansion of neural stem cells, transit-amplifying cells, and neuroblasts derived from subventricular zone and dentate gyrus (Gómez-Gaviro et al.). It is a potent mitogen for retinal pigment epithelial cells and vascular smooth muscle cells. Betacellulin down-regulates E-cadherin expression in ovarian cancer cell lines via MEK/ERK1/2 and PI3K/AKT signaling pathways, thus increasing cell migration (Zhao et al.). It is a modulator of interferon (IFN) response and enhances anti-viral effects of IFN (Al-Yahya et al.). Betacellulin is expressed in pancreatic α cells, β cells, and duct cells. It induces the proliferation of pancreatic cancer cell lines, inhibits apoptosis, promotes the neogenesis of β cells, and converts non-β cells into insulin-producing cells (Kawaguchi et al.; Miyagawa al.; Saito et al.).

Supplier: Anaspec Inc

This peptide is PACAP (1-38) with a Biotin label on its N-terminus. Pituitary adenylate cyclase-activating polypeptide (PACAP), a member of the vasoactive intestinal peptide/secretin/glucagon family, has an amino acid sequence identity of 68% with vasoactive intestinal polypeptide (VIP). PACAP38, derived from a 176-amino acid precursor (preproPACAP), is a 38-amino acid peptide discovered as an ovine hypothalamic neuropeptide. The amino acid sequence of PACAP is identical in all mammals, and in species such as chicken, frog, salmon, only 1–3 amino acids are different. It is abundant in both the central and peripheral nervous systems and exerts a variety of effects. PACAP in pancreatic islets may play a parasympathetic and sensory neurotransmitter role. PACAP stimulates insulin secretion from islets in a glucose-dependent manner at femtomolar concentrations, acting as an insulinotropic factor. PACAP and VIP are two multifunctional neuropeptides modulating innate and adaptive immunity. VIP/PACAP protect T cells from activation-induced cell death through down-regulation of Fas ligand. PACAP immunoreactivity has been shown in nerve fibers innervating the intrapancreatic ganglia as well as the islets of Langerhans in pancreas. PACAP (1-38) is more active than VIP in stimulating adenylate cyclase EC50=7 nM.
Sequence: HSDGIFTDSYSRYRKQMAVKKYLAAVLGKRYKQRVKNKK(Biotin)-NH2
MW: 4888.8 Da
% Peak area by HPLC: 95
Storage condition: -20° C

Supplier: STEMCELL Technologies

Interleukin 21 (IL-21) is a pleiotropic cytokine that is composed of four α-helical bundles and primarily produced by natural killer T (NKT) cells, T follicular helper (Tfh) cells, and Th17 cells (Spolski and Leonard 2008). IL-21 signals via receptor heterodimerization of IL-21 receptor and IL-2 receptor subunit gamma (IL-2RG or CD132), both of which have a common gamma-chain subunit and activate the JAK/STAT, MAPK, and PI3K pathways (Parrish-Novak et al.; Ozaki et al. 2000; Spolski and Leonard 2014). IL-21 has been shown to have a critical role in regulating immunoglobulin production and differentiation of the pro-inflammatory Th17 population of cells (Ozaki et al. 2002; Nurieva et al.). Additionally, IL-21 specifically sustains CD8+ T cell effector activity and provides a mechanism of CD4+ T cell help during chronic viral infection (Elsaesser et al.). IL-21 signaling was also found critical for the development of type 1 diabetes in non-obese diabetic (NOD) mice (Sutherland et al.) and control of T cell autoimmunity by regulatory B cells (Yoshizaki et al.).

Supplier: STEMCELL Technologies

Leukemia inhibitory factor (LIF) is an interleukin 6 class cytokine that regulates a broad variety of developmental functions. After LIF binds to LIF receptor (LIFR), LIFR associates with gp130 and activates JAK/STAT and MAPK signaling (Auernhammer and Melmed; Suman et al.). LIFR activation of STAT3 is essential for maintaining the mouse embryonic stem cell phenotype (Niwa et al.). Produced by the endometrium, LIF plays an important autocrine and paracrine role in implantation by regulating proliferation, invasion, and differentiation of trophoblasts following blastocyst attachment (Auernhammer and Melmed; Suman et al.). Human LIF can be used for the maintenance of mouse embryonic stem cells, however mouse LIF cannot bind to the human receptor, thus rendering mouse LIF inactive (Dahéron et al.). LIF is produced by CD4+ and activated regulatory T cells, and promotes Foxp3 expression, while repressing Th17 lineage-specific genes (Metcalfe). LIF is also secreted by mesenchymal stromal cells, where it supports hematopoiesis and immune modulation (Nasef et al.).

Supplier: STEMCELL Technologies

Use resistin to modulate various cellular responses, such as promoting neutrophil extracellular trap (NET) formation (Jiang et al.) and regulating anti-inflammatory signaling pathways through toll-like receptor 4 (TLR4) (Jang et al., 2017). A member of the resistin-like molecule (RELM) family, resistin is produced by adipocytes in mice, and has been implicated in insulin resistance, reducing glucose tolerance, and insulin sensitivity in vivo (Li et al.). In humans, resistin is expressed predominantly in leukocytes, modulating inflammation in numerous diseases (Jamaluddin et al.; Jang et al., 2015; Mantula et al.). Studies also show that resistin facilitates vascular endothelial growth factor (VEGF)-A-dependent angiogenesis in human chondrosarcoma cells, highlighting it as a promising target for chondrosarcoma angiogenesis (Chen et al.). For consistency and reproducibility across your applications, resistin from STEMCELL comes lyophilized with ≥ 95% purity, and endotoxin levels are verified to be ≤1.0 EU/μg protein.

Supplier: STEMCELL Technologies

Granulocyte-macrophage colony-stimulating factor (GM-CSF) promotes the proliferation and differentiation of hematopoietic progenitor cells and the generation of neutrophils, eosinophils, and macrophages. In synergy with other cytokines such as stem cell factor, IL-3, erythropoietin, and thrombopoietin, it also stimulates erythroid and megakaryocyte progenitor cells (Barreda et al.). GM-CSF is produced by multiple cell types, including stromal cells, Paneth cells, macrophages, dendritic cells (DCs), endothelial cells, smooth muscle cells, fibroblasts, chondrocytes, and Th1 and Th17 T cells (Francisco-Cruz et al.). The receptor for GM-CSF (GM-CSFR) is composed of two subunits: the cytokine-specific α subunit (GMRα; CD116) and the common subunit βc (CD131) shared with IL-3 and IL-5 receptors (Broughton et al.). GM-CSFR is expressed on hematopoietic cells, including progenitor cells and immune cells, as well as non-hematopoietic cells. Recombinant human GM-CSF (rhGM-CSF) promotes the production of myeloid cells of the granulocytic (neutrophils, eosinophils, and basophils) and monocytic lineages in vivo. It has been tested for mobilization of hematopoietic progenitor cells and used to treat chemotherapy-induced neutropenia in patients. GM-CSF is able to stimulate the development of DCs that ingest, process, and present antigens to the immune system (Francisco-Cruz et al.).

Supplier: STEMCELL Technologies

Interleukin 3 (IL-3) is a species-specific pleiotropic cytokine that promotes the survival and proliferation of pluripotent hematopoietic stem cells and lineage-committed progenitor cells and their differentiation into mature cells of most lineages, including basophils, neutrophils, eosinophils, macrophages, dendritic cells, erythrocytes, and megakaryocytes (Yang et al.; Dorssers et al.; Broughton et al.). IL-3 is produced by activated T cells and has a physiological role in inflammation and allergies by promoting the secretion of inflammatory mediators such as histamine, IL-4, and IL-6 by basophils and eosinophils (Broughton et al.). The IL-3 receptor consists of a unique alpha subunit (CD123) and a beta common subunit (βc or CD131) that is shared with the receptors for IL-5 and GM-CSF, and is the principal signal transduction subunit for these cytokines. IL-3 binding to the heterodimeric receptor activates JAK/STAT, MAPK, and PI3K signaling pathways (Woodcock et al.).

Supplier: STEMCELL Technologies

Interferon-gamma (IFN-γ), also known as type II interferon, is produced by T and NK cells, and in smaller amounts by dendritic cells and macrophages. IFN-γ is controlled by cytokines such as IL-12 and IL-18 secreted in response to infection (Schroder et al.). IFN-γ binds to a receptor complex and initiates signal transduction via the JAK/STAT pathway; this culminates in the transcription and activation of many genes that control a diverse array of immunological functions (de Weerd and Nguyen; Krause et al.). IFN-γ stimulates the antimicrobial and anti-tumor activity of macrophages, NK cells, and neutrophils (Billiau and Matthys) by promoting the activation of microbial effector functions such as production of reactive oxygen species, NO intermediates, and complement (Schroder et al.). IFN-γ enhances MHC class I and II expression in dendritic cells and mononuclear phagocytes, as well as the production of IL-12 by dendritic cells. In B cells, IFN-γ stimulates survival and growth in both mouse and human cells, and redirects B cells from proliferation towards differentiation. IFN-γ favors the development of Th1 vs Th2 cells and stimulates monocyte differentiation and function (Schroder et al.). This product is animal component-free.

Supplier: STEMCELL Technologies

Interleukin 13 (IL-13) is a type I cytokine, and signals through type I cytokine receptors to activate JAK/STAT and IRS-1/IRS-2 pathways. IL-13 is produced by T cells and innate lymphoid cells (Pulendran and Artis) and it inhibits production of pro-inflammatory cytokines, prostaglandins, and reactive oxygen and nitrogen species by monocytes and macrophages (Hershey). Unlike human B cells, IL-13 has no effect on mouse B cell development and function. IL-13 promotes eosinophil survival, activation, and recruitment, and also activates mast cells (Hershey). IL-13 regulates gastrointestinal parasite expulsion, airway hyperresponsiveness, allergic inflammation, tissue eosinophilia, goblet cell hyperplasia, intracellular parasitism, tissue remodeling, tumor cell growth, and fibrosis. IL-13 induces hypercontractility of smooth muscles by directly acting on the muscle cells as well as the enteric nerves (Wynn).

Supplier: STEMCELL Technologies

Fibroblast growth factor 16 (FGF-16) is a heparin-binding member of the FGF family. FGFs possess broad mitogenic and cell survival activities and are expressed during embryonic development. FGFs act primarily on cells of mesodermal and neuroectodermal origin to regulate diverse physiological functions including angiogenesis, cell growth, pattern formation, embryonic development, metabolic regulation, cell migration, and tissue repair (Goldfarb; Green et al.). in vitro, FGF-16 has been shown to promote the proliferation of brown adipocytes and in rat embryos it is predominantly expressed in these cells. FGF-16 has also been shown to play a critical role in embryonic heart development and is thought to play a cardioprotective role after birth (Hotta et al.; Lu et al.; Wang et al.).

Supplier: STEMCELL Technologies

Tumor necrosis factor-α (TNF-α) is a pro-inflammatory cytokine that activates NF-kB, MAPK, and PI3K/AKT pathways. Activated T cells and macrophages are the primary producers of TNF-α in response to inflammation and infectious conditions. Many other cell types have been shown to produce TNF-α, among them B cells, NK cells, mast cells, neutrophils, dendritic cells, microglia, endothelial cells, smooth muscle cells, cardiomyocytes, and fibroblasts. TNF-α has cytotoxic effects on cancer cells in vitro by stimulating anti-tumor immuno- suppressive responses. TNF-α stimulates expression of E- and P-selectins, thus facilitating adhesion of neutrophils, monocytes, and memory T cells to activated platelets and endothelial cells (Zelová and Hosek). Other effects of TNF-α include vasodilatation and edema formation. This product is animal component-free.

Supplier: STEMCELL Technologies

Use angiopoietin-like protein 2 (ANGPTL2) to regulate tissue remodeling through integrin α5β signaling and activation of p38 mitogen-activated protein kinases (MAPK) (Odagiri et al.; Tabata et al.). Highly expressed in the heart, small intestine, and stomach, ANGPTL2 is a glycosylated secretory protein that contains a coiled domain and a fibrinogen-like domain (Kim et al.). Studies have shown that the coiled-coil domain of ANGPTL2 functions as a growth factor, enhancing the survival of hematopoietic stem cells (HSCs) ex vivo (Broxmeyer et al.). ANGPTL2 is also known to play a role in obesity and metabolic diseases, promoting local inflammation in adipose tissue and systemic insulin resistance in mice models (Tabata et al.). By activating an inflammatory cascade in endothelial cells and increasing macrophage infiltration, ANGPTL2 accelerates vascular inflammation which may lead to endothelial dysfunction and atherosclerosis progression (Horio et al.). This protein product contains a His-residue tag at the amino end of the polypeptide chain. For consistency and reproducibility across your applications, sclerostin from STEMCELL comes lyophilized with ≥92% purity, and endotoxin levels are verified to be ≤1.0 EU/μg protein.

Supplier: STEMCELL Technologies

Interleukin 13 (IL-13) is a cytokine important in type 2 immune responses and is expressed by T helper type 2 (Th2) cells and group 2 innate lymphoid cells (ILC2s) (Pulendran and Artis). IL-13 binds a receptor composed of IL-4Ra and IL-13Ra1 or IL-13Ra2 (Wynn 2003). IL-13 receptor is expressed on B cells and promotes B cell proliferation, induces class switching to IgG4 and IgE, and functions in the recruitment and activation of IgE-producing B cells (Hershey). The receptor is also expressed on basophils, eosinophils, mast cells, endothelial cells, fibroblasts, monocytes, macrophages, respiratory epithelial cells, and smooth muscle cells (Hershey). Signaling through the IL-13 receptor activates the JAK/STAT and IRS-1/IRS-2 pathways. in vivo, IL-13 has a role in resistance to extracellular helminth parasites by regulating gastrointestinal parasite expulsion, as well as in airway hyperresponsiveness, allergic inflammation, tissue remodeling, tumor cell growth, and fibrosis (Wynn 2015). Secreted IL-13 is a protein consisting of 112 amino acids with a molecular mass of 10 kDa (Hershey). Human IL-13 is not species-specific but has greater activity on human cells compared to mouse cells (Hershey).

Supplier: STEMCELL Technologies

Use hepassocin to bind to lymphocyte-activation gene 3 (LAG-3) in an MHC class II independent manner, and inhibit antigen-specific T-cell activation (Wang et al.). Hepassocin is known to play a restorative role in the liver, reducing apoptosis and accelerating hepatocyte proliferation in vivo (Li et al.). In addition to these hepatoprotective effects, studies have shown that hepassocin expression is upregulated in gastric cancer tissues (Zhang et al.) and in breast cancer cells (Du et al.), suggesting it has potential to predict cancer disease progression. Hepassocin is a member of the fibrinogen superfamily, whose members share a fibrinogen domain at their C-terminus. It is predominantly expressed in the liver, and weakly in the pancreas (Hara et al.), and is secreted as a homodimer that consists of 312 amino acids. Hepassocin is an acute-phase reactant whose expression in HepG2 cells has been shown to be regulated by IL-6 (Liu and Ukomadu). This protein product contains a His-residue tag at the carboxyl end of the polypeptide chain. For consistency and reproducibility across your applications, hepassocin from STEMCELL comes lyophilized with ≥ 87% purity, and endotoxin levels are verified to be ≤1.0 EU/μg protein.

Supplier: Anaspec Inc

NS3 protease of hepatitis C virus (HCV), located on the N-terminal domain of HCV NS3, is responsible for the cleavage at the NS3/NS4A, NS4A/NS4B, NS4B/NS5A, and NS5A/NS5B sites of the nonstructural protein. The HCV NS3 is a chymotrypsin-like serine protease. It requires a cofactor, a 54 amino acid NS4 protein, to reach its optimal activity. The X-ray crystal structure studies show that NS3 forms a tight non-covalent complex with NS4. The NS3/4A protease is essential for viral replication and the formation of infectious viral particles, and thus has been considered as one of the most attractive targets for anti-HCV therapy.

The recombinant HCV NS3/4A protease (genotype 1b, strain: HC-J4; NCBI Accession: AF054247) was expressed in E. Coli. HCV NS3/4A protease is a 217 amino acid fusion protein (22.7 kDa) with NS4A co-factor fused to the N-terminus of NS3 protease domain. Therefore, HCV NS3/4A protease is in active form and the pre-activation by pep4A or pep4AK is not necessary. 5-20 ng of HCV NS3/4A protease is sufficient for FRET-based activity assays (SensoLyte® HCV protease assay).

Supplier: STEMCELL Technologies

RANTES (regulated upon activation, normal T cell expressed and secreted), also known as CCL5, is a member of the CC family of chemokines and is able to recruit leukocytes to sites of inflammation (Schall et al.). RANTES is secreted by T lymphocytes, macrophages, platelets, synovial fibroblasts, tubular epithelium, and certain types of tumor cells (Aldinucci and Colombatti; Soria and Ben-Baruch). This chemokine exerts its effect by interacting with the chemokine receptors CCR1, CCR3, CCR4, and CCR5. RANTES plays an active role in recruiting a variety of leukocytes into inflammatory sites, including T cells, macrophages, eosinophils, and basophils. In collaboration with certain cytokines that are released by T cells such as IL-2 and IFN-γ, RANTES also induces the activation and proliferation of NK cells to generate CC chemokine-activated killer cells, which are highly cytolytic (Lv et al.; Maghazachi et al.). It has been shown that RANTES produced by CD8+ T cells inhibits HIV infection of primary human peripheral blood mononuclear cells (Appay and Rowland-Jones; Cocchi et al.).

Supplier: STEMCELL Technologies

Platelet-derived growth factor (PDGF) is a dimeric glycoprotein consisting of two disulfide bridge-stabilized polypeptide chains, A and B, which are assembled as heterodimers (PDGF-AB) or homodimers (PDGF-AA and PDGF-BB) (Fretto et al.; Westermark and Heldin). PDGF signals through the receptor tyrosine kinases PDGFRalpha and PDGFRbeta. PDGF-induced migration has been shown to involve MEK/ERK, EGFR, Src, and PI3K/Akt signaling pathways (Kim et al.). PDGF is a potent mitogen for cells of mesenchymal origin- like fibroblasts, glial cells, and vascular smooth muscle cells. PDGF has been implicated in pathogenesis of atherosclerosis, glomerulonephritis, cancer, and in the contraction of vascular smooth muscle cells of rat aortic tissues (Fretto et al.; Sachinidis et al.). PDGF-BB is secreted by osteoblasts to induce mesenchymal stem cell migration and angiogenesis. It has also been shown that PDGF-BB is secreted by preosteoclasts during bone modeling and remodeling to induce angiogenesis and thus proper osteogenesis (Xie et al.). This product is animal component-free.

Supplier: STEMCELL Technologies

Stromal cell-derived factor 1 alpha (SDF-1α) is a member of the CXC group of chemokines that binds to the G-protein coupled receptor, CXCR4, to regulate migration, proliferation, differentiation, and survival of many cell types including hematopoietic stem cells, B cells, and T cells. It is produced by bone marrow stromal cells, osteoblasts, endothelial cells, and neuronal cells. SDF-1α was first identified as the pre-B-cell growth-stimulating factor (PBSF) in the mouse bone marrow-derived stromal cell line, PA6, in the growth of B cell precursors (Hayashi et al.). SDF-1α primarily regulates cell motility during development and adulthood, including the homing of hematopoietic stem cells and neutrophils to fetal bone marrow during ontogeny (Ara et al. 2003a) and the recruitment of endothelial progenitor cells from bone marrow during angiogenesis in adulthood (Zheng et al.). In addition to its role in hematopoiesis, the SDF-1α/CXCR4 signaling pathway is also essential for the homing of primordial germ cells to gonads (Ara et al. 2003b), the migration of granule cells in the cerebellum during neurogenesis (Zou et al.), and the migration of breast cancer cells to sites of metastasis (Muller et al.).

Supplier: STEMCELL Technologies

The platelet-derived growth factor (PDGF) family has five heparin-binding members that assemble into four homodimers (PDGF-AA, PDGF-BB, PDGF-CC, and PDGF-DD) and one heterodimer (PDGF-AB; Fretto et al.; Li and Eriksson). PDGF signals through the receptor tyrosine kinases PDGFRα and PDGFRβ. It has been shown that PDGF-induced migration involves signaling pathways involving MEK/ERK, EGFR, Src, and PI3K/AKT (Kim et al.). PDGF is a potent mitogen for cells of mesenchymal origin, such as fibroblasts, glial cells, and vascular smooth muscle cells. PDGF has been implicated in pathogenesis of atherosclerosis, glomerulonephritis, cancer, and in the contraction of vascular smooth muscle cells of rat aortic tissues (Fretto et al.; Sachinidis et al.). PDGF-DD promotes growth and survival of renal artery smooth muscle cells and lens epithelial cells, and can act as a macrophage chemoattractant (Changsirikulchai et al.; Lokker et al.; Ray et al.; Uutela et al.).

Supplier: STEMCELL Technologies

Leukemia inhibitory factor (LIF) is an interleukin 6 class cytokine that regulates a broad variety of developmental functions. After LIF binds to LIF receptor (LIFR), LIFR associates with gp130 and activates JAK/STAT and MAPK signaling (Auernhammer and Melmed; Suman et al.). LIFR activation of STAT3 is essential for maintaining the mouse embryonic stem cell phenotype (Niwa et al.). Produced by the endometrium, LIF plays an important autocrine and paracrine role in implantation by regulating proliferation, invasion, and differentiation of trophoblasts following blastocyst attachment (Auernhammer and Melmed; Suman et al.). Human LIF can be used for the maintenance of mouse embryonic stem cells, however mouse LIF cannot bind to the human receptor, thus rendering mouse LIF inactive (Dahéron et al.). LIF is produced by CD4+ and activated regulatory T cells, and promotes Foxp3 expression, while repressing Th17 lineage-specific genes (Metcalfe). LIF is also secreted by mesenchymal stromal cells, where it supports hematopoiesis and immune modulation (Nasef et al.). This product is animal component-free.

Supplier: STEMCELL Technologies

Stem cell factor (SCF) is an early-acting cytokine that plays a pivotal role in the regulation of embryonic and adult hematopoiesis. SCF promotes cell survival, proliferation, differentiation, adhesion, and functional activation of cells at multiple levels of the hematopoietic hierarchy. Together with other cytokines such as thrombopoietin and Flt3/Flk-2 Ligand, SCF is commonly used to promote expansion of primitive hematopoietic stem cells and multi-potent progenitor cells in culture (Martin et al.; Kent et al.). In synergy with various growth factors, including IL-2, IL-3, IL-6, IL-7, G-CSF, and erythropoietin, SCF increases proliferation and differentiation of myeloid and erythroid progenitor cells and a subset of lymphoid progenitor cells (Broudy). SCF is also a primary growth and activation factor for mast cells and eosinophils. SCF exists in two biologically active splice forms: a soluble and a transmembrane isoform. Upon binding to its receptor (c-Kit tyrosine kinase receptor; CD117), it activates PI3K, JAK/STAT, and MAPK pathways. SCF and signaling from c-Kit have also been reported to play an important role in pigmentation, fertility, vasculogenesis, motility of the gut via c-Kit positive interstitial cells of Cajal, and in the migration of neuronal stem and progenitor cells to sites of injury in the brain. This product is animal component-free.

Supplier: STEMCELL Technologies

Interleukin 21 (IL-21) is a pleiotropic cytokine that is composed of four α-helical bundles and primarily produced by natural killer T (NKT) cells, T follicular helper (Tfh) cells, and Th17 cells (Spolski and Leonard 2008). IL-21 signals via heterodimers of the IL-21 receptor (IL-21R) and the IL2RG encoded common cytokine receptor γ-chain (Parrish-Novak et al.; Ozaki K et al. 2000), and utilizes the JAK/STAT, MAPK, and PI3K pathways (Spolski and Leonard 2014). IL-21 has been shown to have a critical role in regulating immunoglobulin production and differentiation of the pro-inflammatory Th17 population of cells (Ozaki et al. 2002; Nurieva et al.). Additionally, IL-21 specifically sustains CD8+ T cell effector activity and provides a mechanism of CD4+ T cell help during chronic viral infection (Elsaesser et al.). IL-21 signaling was also found critical for the development of type 1 diabetes in NOD mice (Sutherland et al.) and control of T cell autoimmunity by regulatory B cells (Yoshizaki et al.).

Supplier: STEMCELL Technologies

Interleukin 2 (IL-2) is a monomeric cytokine that was originally identified as a T cell growth factor (Gaffen and Liu). It binds to heterotrimeric receptors consisting of CD25, CD122, and CD132. Upon binding, it activates JAK3-, STAT5-, and AKT-dependent signaling pathways, which results in cellular proliferation and survival (Ma et al.). The majority of IL-2 is secreted by activated CD4+ and CD8+ T cells, although B cells and dendritic cells were found to produce IL-2 in small amounts. IL-2 downregulates immune responses to prevent autoimmunity during thymic development, influences the development of CD4+CD25+ regulatory T cells, and affects development of follicular helper T cells. IL-2 also controls inflammation by inhibiting Th17 differentiation (Banchereau et al.). High IL-2 levels in serum are associated with progression of scleroderma, rheumatoid arthritis, and gastric and non-small cell lung cancer, though no known disease can be directly attributed to the lack or excess of IL-2 (Gaffen and Liu).

Supplier: Peprotech

DKK-1 is a member of the DKK protein family which also includes DKK-2, DKK-3 and DKK-4. DKK-1 was originally identified as a Xenopus head-forming molecule that behaves as an antagonist for Wnt signaling. Subsequent studies have shown that DKK-1 and DKK-4 play important regulatory roles in the Wnt/beta-catenin signaling pathway by forming inhibitory complexes with LDL receptor-related proteins 5 and 6 (LRP5 and LRP6), which are essential components of the Wnt/beta-catenin signaling system. LPR5 and LPR6 are single-pass transmembrane proteins that appear to act as co-receptors for Wnt ligands involved in the Wnt/beta-catenin signaling cascade. It has been suggested that by inhibiting Wnt/beta-catenin signaling, which is essential for posterior patterning in vertebrates, DKK-1 permits anterior development. This notion is supported by the finding that mice deficient of DKK-1 expression lack head formation and die during embryogenesis. Mature human DKK-1 expressed in HEK293 cells is a 35-40 kDa glycoprotein containing 235 amino acid residues. The calculated molecular weight of Recombinant Human DKK-1 expressed in HEK293 cells is 25.8 kDa.