Digestive Diseases and Sciences

, Volume 51, Issue 5, pp 834–843 | Cite as

Protein Kinase C Involvement in Deoxycholate-Induced Apoptosis in Human Gastric Cells

  • Maria J. Redlak
  • Jacinda J. Power
  • Thomas A. Miller


Bile acids, such as deoxycholic acid (DC), are known to mediate some of their actions by differentially activating various protein kinase C (PKC) isoforms. This study confirms that DC induces apoptosis in gastric epithelial cells through PARP and caspase cascade activation, and examined the role of PKC in DC-induced apoptosis. We found increased activation of PKC in membrane fractions in response to DC that was concentration and time related. The PKC (βI) isoform expression increased with translocation into the cell membrane fraction after DC (300 μ M) stimulation. In contrast, PKCε expression markedly decreased in response to DC treatment in a time- and concentration-dependent manner. In addition, this process was regulated by caspases, since the pan-caspase inhibitor z-VAD-fmk and caspase-3-, -6-, and -9–specific inhibitors prevented PKC (βI) and (ε ɛ processing induced by DC. Treatment with the caspase-8–specific inhibitor, however, did not affect expression of either PKC isoform. No significant differences in the apoptotic response were observed when PKC (ɛ) overexpressed cells were exposed to DC in the presence of calcium-dependent conventional PKC inhibitors (Gö 6850 or Gö 6976). Our findings demonstrate that PKC is activated in gastric epithelial cells treated with DC with the PKC (βI) and PKC (ɛ) isoforms being particularly involved in this process. The processing of PKC (βI and ε) was shown to be closely regulated by caspases; however, modulations in PKC isoform concentrations by themselves have no effect on the apoptotic death of gastric mucosal cells induced by DC.

Key Words

caspases cell signaling gastric epithelial injury 


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  1. 1.
    DuPlessis DJ: Pathogenesis of gastric ulceration. Lancet 1:974–978, 1965CrossRefPubMedGoogle Scholar
  2. 2.
    Ritchie WP: Alkaline reflux gastritis. Ann Surg 203:537–544, 1986PubMedGoogle Scholar
  3. 3.
    Miller TA, Victor BE: Gastritis and gastric ulcer. In Surgical Treatment of Digestive Disease, 2nd ed. Moody FG, Carey LC, Jones RS, Kelly JA, Nahrwold DL, Skinner DB (eds). Chicago, Year Book Medical, 1989, pp. 174–196Google Scholar
  4. 4.
    Kokoska ER, Smith GS,Wolff AB, Deshpande Y, Rieckenberg CL, Banan A, Miller TA: Role of calcium in adaptive cytoprotection and cell injury induced by deoxycholate in human gastric cells. Am J Physiol 275:G322–G330, 1998Google Scholar
  5. 5.
    Kokoska ER, Smith GS, Rieckenberg CL, Deshpande Y, Banan A, Miller TA: Adaptive cytoprotection against deoxycholate-induced injury in human gastric cells in vitro. Dig Dis Sci 4:806–815, 1998CrossRefGoogle Scholar
  6. 6.
    Redlak MJ, Dennis MS, Miller TA: Apoptosis is a major mechanism of deoxycholate-induced gastric mucosal cell death. Am J Physiol Gastrointest Liver Physiol 285:G870–G879, 2003PubMedGoogle Scholar
  7. 7.
    Deacon EM, Pongracz J, Griffiths G, Lord JM: Isoenzymes of protein kinase C: differential involvement in apoptosis and pathogenesis. J Clin Pathol 50:124–131, 1997CrossRefGoogle Scholar
  8. 8.
    Looby E, Long A, Kelleher D, Volkov Y: Bile acid deoxycholate induces differential subcellular localization of the PKC isoenzymes β1, ε and δ in colonic epithelial cells in a sodium butyrate insensitive manner. Int J Cancer 114:887–895, 2005PubMedCrossRefGoogle Scholar
  9. 9.
    Pongracz J, Clark P, Neoptolemos JP, Lord JM: Expression of protein kinase C isoenzymes in colorectal cancer tissue and their differential activation by different bile acids. Int J Cancer 61:35–39, 1995PubMedGoogle Scholar
  10. 10.
    Jones BA, Rao YP, Stravitz RT, Gores GJ: Bile salt-induced apoptosis of hepatocytes involves activation of protein kinase C. Am J Physiol Gastrointest Liver Physiol 5:G1109–G1115, 1997Google Scholar
  11. 11.
    Facchinetti A, Tessarollo L, Mazzocchi M, Kingston R, Collavo D, Biasi G: An improved method for the detection of DNA fragmentation. J Immunol Meth 136:151–156, 1991CrossRefGoogle Scholar
  12. 12.
    Tseng CP, Verma AK: Functional expression and characterization of the mouse epitope tag-protein kinase C isoforms, alpha, beta I, beta II, gamma, delta and epsilon. Gene 169:287–288, 1996PubMedCrossRefGoogle Scholar
  13. 13.
    Bradford MM: A rapid and sensitive method for the quantitation of microgram quantities of protein utilizing the principle of protein-dye binding. Anal Biochem 72:248–254, 1976PubMedCrossRefGoogle Scholar
  14. 14.
    Newton AC: Protein kinase C: structure, function, and regulation. J Biol Chem 48:28495–28498, 1995Google Scholar
  15. 15.
    Darbon JM, Issandou M, Delassus F, Bayard F: Phorbol esters induce both intracellular translocation and down-regulation of protein kinase C in MCF-7 cells. Biochem Biophys Res Commun 137:1159–1166, 1986PubMedCrossRefGoogle Scholar
  16. 16.
    Mochly-Rosen D, Henrich CJ, Cheever L, Khaner H, Simpson PC: A protein kinase C isozyme is translocated to cytoskeletal elements on activation. Cell Regul 1:693–706, 1990PubMedGoogle Scholar
  17. 17.
    Domellof L, Reddy BS, Weisburger JH: Microflora and deconjugation of bile salts in alkaline reflux after partial gastrectomy. Am J Surg 140:291–295, 1980PubMedCrossRefGoogle Scholar
  18. 18.
    18. Zhu GH, Wong BC, Slosberg ED, Jiang SH, Kung HF, Soh JW, Weinstein IB: Over-expression of protein kinase C-β1 isoenzyme suppresses indomethacin-induced apoptosis in gastric epithelial cells. Gastroenterology 118:507–514, 2000Google Scholar
  19. 19.
    Jiang XH, Lam SK, Lin MCM, Eggo MC, Ching CK, Yuen ST, Lai KC, Soh JW, Weinstein IB, Lam SK et al.: Novel target for induction of apoptosis by cyclo-oxygenase-2 inhibitor SC-236 through a protein kinase C-β1-dependent pathway. Oncogene 21:6113–6122, 2002PubMedCrossRefGoogle Scholar
  20. 20.
    Akita Y: Protein kinase C-ε (PKC-ε): its unique structure and function. J Biochem 132:847–852, 2002PubMedGoogle Scholar
  21. 21.
    Prekeris R, Hernandez RM, Mayhew MW, White MK, Terrian DM: Molecular analysis of the interactions between protein kinase C-ε and filamentous actin. J Biol Chem 41:26790–26798, 1998CrossRefGoogle Scholar

Copyright information

© Springer Science + Business Media, Inc. 2006

Authors and Affiliations

  • Maria J. Redlak
    • 1
  • Jacinda J. Power
    • 1
  • Thomas A. Miller
    • 1
    • 2
  1. 1.Department of SurgeryMedical College of Virginia Campus of Virginia Commonwealth UniversityRichmondUSA
  2. 2.Department of SurgeryMedical College of Virginia Campus of Virginia Commonwealth UniversityRichmondUSA

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