Neurotensin stimulates IL-8 expression in human colonic epithelial cells through Rho GTPase-mediated NF-κB pathways

Abstract

Neurotensin (NT), a neuropeptide highly expressed in the gastrointestinal tract, participates in the pathophysiology of intestinal inflammation. We recently showed that NT stimulates interleukin-8 (IL-8) expression in NCM460 nontransformed human colonic epithelial cells via both mitogen-activating protein kinase (MAPK)- and NF-kappaB-dependent pathways. However, the molecular mechanism by which NT induces expression of proinflammatory cytokines such as IL-8 has not been investigated. In this study we show that inhibition of endogenous Rho family proteins (RhoA, Rac1, and Cdc42) by their respective dominant negative mutants inhibits NT-induced IL-8 protein production and promoter activity. Western blot experiments demonstrated that NT strongly activated RhoA, Rac1, and Cdc42. Overexpression of the dominant negative mutants of RhoA, Rac1, and Cdc42 significantly inhibited NT-induced NF-kappaB-dependent reporter gene expression and NF-kappaB DNA binding activity. NT also stimulated p38 MAPK phosphorylation, and overexpression of dominant negative mutants of RhoA, Rac1, and Cdc42 did not significantly alter p38 and ERK1/2 phosphorylation in response to NT. Together, our findings indicate that NT-stimulated IL-8 expression is mediated via a Rho-dependent NF-kappaB-mediated pathway.

Neurotensin induces IL-6 secretion in mouse preadipocytes and adipose tissues during 2,4,6,-trinitrobenzensulphonic acid-induced colitis

“…Full-length mouse NTR1 was cloned and ligated into the retroviral vector pCMBP (34). Retroviruses were prepared using a previously described procedure (35). Infected 3T3-L1 preadipocytes were used for NT (Calbiochem) or 0.1% trifluoroacetic acid (TFA, vehicle control) treatment.…”

The potential of neurotensin secreted from neuroendocrine tumor cells to promote gelsolin-mediated invasiveness of prostate adenocarcinoma cells

“…[40][41][42] These signaling factors are correlated with cell and tissue growth, apoptosis, and progression. In prostate cancer, the treatment of PC3 cells with neurotensin has been shown to induce cellular proliferation.…”

Prostate Cancer Cell Growth: Stimulatory Role of Neurotensin and Mechanism of Inhibition by Flavonoids as Related to Protein Kinase C

“…During C. deficile toxin-induced inflammation of the colon, NTS1 is dramatically upregulated and administration of SR48692 inhibits aspects of the inflammatory response [16]. NT also stimulates non-transformed human colonic epithelial NCM460 cells to release the inflammatory cytokine IL-8 by a NF-kB-dependent mechanism [88]. Since IL-8 is chemotactic for inflammatory cells and NFkB regulates the expression of many genes involved in inflammation, this suggests that upregulation of the NT system could lead to a cycle of inflammation and ultimately to cancer.…”

“…Metabolic inhibitors 83 and other conditions that deplete cellular ATP and elevate AMP 84 levels can initiate the activation of AMPK, which has an ability to 85 modulate ATP-consuming and ATP-generating pathways to 86 maintain cellular homeostasis [33][34][35]. The activation of 87 AMPK that occurs in response to metabolic stress has been 88 shown to protect cells from the ensuing apoptosis [36,37]. On the 89 other hand, treatment of cells with the AMPK activator AICAR 90 under non-stressful conditions was found to induce apoptosis in 91 human prostate cancer cells [4,38].…”