TY - JOUR
T1 - Substance P promotes expansion of human mesenteric preadipocytes through proliferative and antiapoptotic pathways
AU - Gross, Kara
AU - Karagiannides, Iordanes
AU - Thomou, Thomas
AU - Hon, Wai Koon
AU - Bowe, Collin
AU - Kim, Ho
AU - Giorgadze, Nino
AU - Tchkonia, Tamara
AU - Pirtskhalava, Tamara
AU - Kirkland, James L.
AU - Pothoulakis, Charalabos
PY - 2009/5
Y1 - 2009/5
N2 - White adipose tissue is intimately involved in the regulation of immunity and inflammation. We reported that human mesenteric preadipocytes express the substance P (SP)-mediated neurokinin-1 receptor (NK-1R), which signals proinflammatory responses. Here we tested the hypothesis that SP promotes proliferation and survival of human mesenteric preadipocytes and investigated responsible mechanism(s). Preadipocytes were isolated from mesenteric fat biopsies during gastric bypass surgery. Proliferative and antiapoptotic responses were delineated in 3-(4,5-dimethylthiazol-2-yl)-5-(3- carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium (MTS), bromodeoxyuridine (BrdU), caspase-3, and TUNEL assays, as well as Western immunoanalysis. SP (10-7 M) increased MTS and proliferation (BrdU) and time dependently (15-30 min) induced Akt, EGF receptor, IGF receptor, integrin αVβ3, phosphatidylinositol 3-kinase, and PKC-θ phosphorylation. Furthermore, pharmacological antagonism of Akt and PKC-θ activation significantly attenuated SP-induced preadipocyte proliferation. Exposure of preadipocytes to the proapoptotic Fas ligand (FasL, 100 μM) resulted in nuclear DNA fragmentation (TUNEL assay), as well as increased cleaved poly (ADP-ribose) polymerase, cleaved caspase-7, and caspase-3 expression. Cotreatment with SP almost completely abolished these responses in a NK-1R-dependent fashion. SP (10-7 M) also time dependently stimulated expression 4E binding protein 1 and phosphorylation of p70 S6 kinase, which increased protein translation efficiency. SP increases preadipocyte viability, reduces apoptosis, and stimulates proliferation, possibly via cell cycle upregulation and increased protein translation efficiency. SP-induced proliferative and antiapoptotic pathways in fat depots may contribute to development of the creeping fat and inflammation characteristic of Crohn's disease.
AB - White adipose tissue is intimately involved in the regulation of immunity and inflammation. We reported that human mesenteric preadipocytes express the substance P (SP)-mediated neurokinin-1 receptor (NK-1R), which signals proinflammatory responses. Here we tested the hypothesis that SP promotes proliferation and survival of human mesenteric preadipocytes and investigated responsible mechanism(s). Preadipocytes were isolated from mesenteric fat biopsies during gastric bypass surgery. Proliferative and antiapoptotic responses were delineated in 3-(4,5-dimethylthiazol-2-yl)-5-(3- carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium (MTS), bromodeoxyuridine (BrdU), caspase-3, and TUNEL assays, as well as Western immunoanalysis. SP (10-7 M) increased MTS and proliferation (BrdU) and time dependently (15-30 min) induced Akt, EGF receptor, IGF receptor, integrin αVβ3, phosphatidylinositol 3-kinase, and PKC-θ phosphorylation. Furthermore, pharmacological antagonism of Akt and PKC-θ activation significantly attenuated SP-induced preadipocyte proliferation. Exposure of preadipocytes to the proapoptotic Fas ligand (FasL, 100 μM) resulted in nuclear DNA fragmentation (TUNEL assay), as well as increased cleaved poly (ADP-ribose) polymerase, cleaved caspase-7, and caspase-3 expression. Cotreatment with SP almost completely abolished these responses in a NK-1R-dependent fashion. SP (10-7 M) also time dependently stimulated expression 4E binding protein 1 and phosphorylation of p70 S6 kinase, which increased protein translation efficiency. SP increases preadipocyte viability, reduces apoptosis, and stimulates proliferation, possibly via cell cycle upregulation and increased protein translation efficiency. SP-induced proliferative and antiapoptotic pathways in fat depots may contribute to development of the creeping fat and inflammation characteristic of Crohn's disease.
KW - Adipocyte
KW - Akt
KW - Creeping fat
KW - Crohn's disease
KW - Neuropeptide
KW - Proliferation
KW - Protein kinase C-θ
UR - http://www.scopus.com/inward/record.url?scp=66149105495&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=66149105495&partnerID=8YFLogxK
U2 - 10.1152/ajpgi.90351.2008
DO - 10.1152/ajpgi.90351.2008
M3 - Article
C2 - 19282377
AN - SCOPUS:66149105495
SN - 0193-1857
VL - 296
SP - G1012-G1019
JO - American Journal of Physiology - Gastrointestinal and Liver Physiology
JF - American Journal of Physiology - Gastrointestinal and Liver Physiology
IS - 5
ER -