In addition, catestatins induced the production of cytokines and chemokines, and catestatin-mediated mast cell activation was regulated by G-proteins, phospholipase C (PLC), and the mitogen-activated protein kinase extracellular signal-regulated kinase

(MAPK ERK). We also found that human mast cells express the α7 subunit of the nAChR; however, this receptor is not likely to function in catestatin-caused mast cell activation. Our finding that the skin-derived AMP catestatin activates various functions of human mast cells suggests that this peptide may have an immunomodulatory role, and supports the hypothesis click here of a link between the neuroendocrine and cutaneous immune systems. Human wild-type catestatin (SSMKLSFRARAYGFRGPGPQL), catestatin natural variants Gly364Ser

(SSMKLSFRARAYSFRGPGPQL), Pro370Leu (SSMKLSFRARAYGFRGPGLQL), and Arg374Gln (SSMKLSFRARAYGFRGPGPQLRQGWRPSSREDSLEAGLPLQVRGYPEE), and a scrambled form of catestatin sCst (MKLSSSFRAYARGFRGPGPQL) were synthesized using a solid-phase method on a peptide synthesizer (model PSSM-8; Shimadzu, Kyoto, Japan) by fluoroenylmethoxycarbonyl (Fmoc) chemistry, and their molecular masses were confirmed using a mass spectrometer (model TSQ 700; Thermo Quest Finnigan, Manchester, UK). Compound 48/80 was purchased from Sigma-Aldrich (St Louis, MO). Enzyme immunoassay (EIA) kits for LTC4, PGD2 and PGE2 were purchased from Cayman Chemical Company (Ann Arbor, MI), and cytokine and chemokine ELISA kits were obtained from R&D Systems (Minneapolis, Natural Product Library MN). Rabbit polyclonal antibodies against phosphorylated p38, ERK and jun N-terminal kinase (JNK), in addition to unphosphorylated p38, ERK and

JNK, were from Cell Signaling Technology (Beverly, MA). The G-protein inhibitor pertussis toxin, ERK inhibitor U0126, JNK inhibitor II SP600125, PLC inhibitor U-73122, and PLC inhibitor inactive control U-73343 were obtained from Calbiochem (La Jolla, CA). The nAChR primers used were from Invitrogen (Camarillo, CA), and small interfering RNA (siRNA) targeting the α7 nAChR and control siRNA were purchased from Applied Biosystems (Branchburg, NJ). The LAD2 cell line isolated Idelalisib datasheet from the bone marrow of a patient with mast cell leukaemia was a kind gift from Dr Arnold Kirshenbaum (National Institutes of Health, National Institute of Allergy and Infectious Diseases, Bethesda, MD).19 These cells were grown in Stem Pro-34 medium containing nutrient supplements (Invitrogen), supplemented with 2 mm l-glutamine (Invitrogen), 100 IU/ml penicillin and 100 μg/ml streptomycin (Meiji Seika, Tokyo, Japan), and 100 ng/ml human stem cell factor (SCF) (Wako, Osaka, Japan). Cell culture medium was hemi-depleted every week with fresh medium. Human peripheral blood-derived cultured mast cells were obtained using previously described methods with some modifications.