The OVERALL OBJECTIVE of this proposal is to define the cellular mechanisms culminating in lethal injury of cholangiocytes and hepatocytes in models relevant to human cholestatic liver diseases (e.g., primary sclerosing cholangitis). Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) contributes to both cholangiocyte and hepatocyte injury in models relevant to these liver diseases. Thus, our long term objectives are to understand the cellular and subcellular mechanisms causing cholangiocyte and hepatocyte injury by this death ligand. Our distinctive preliminary data implicate phosphofurin acidic cluster sorting-2 (PACS-2) protein as a critical regulator of TRAIL-induced cytotoxicity by a lysosomal cell death pathway. Cellular inhibitor of apoptosis-1 (cIAP-1) regulates the lysosomal cell death pathway by controlling PACS-2 protein levels. Cholangiocytes appear to be intrinsically sensitive to TRAIL killing via this pathway in vivo, whereas hepatocytes in vivo only become sensitive to TRAIL toxicity during cholestasis. Based upon this preliminary data, we propose the novel CENTRAL HYPOTHESIS that TRAIL induces liver cell death by a lysosomal pathway dependent upon PACS-2, and cholangiocytes, which express less cIAP-1 than hepatocytes, are preferentially sensitive to this pathway in vivo. We will now employ current and complementary molecular, biochemical and cell biological approaches to ascertain how TRAIL triggers this organelle-based pathway of apoptosis. Our proposal has three SPECIFIC AIMS. FIRST, we will directly test the hypothesis that PACS-2 mediates lysosomal membrane permeabilization during TRAIL cytotoxicity by: a) binding Bim, a BH3-only protein, which recruits and activates Bax, a potent proapoptotic protein of the Bcl-2 family;and b) facilitating Bax oligomerization within lysosomal membranes which causes lysosomal disruption. SECOND, we will directly test the hypothesis that cIAP-1, an E3 ligase, modulates TRAIL cytotoxicity by: a) regulating PACS- 2 protein levels via an ubiquitination-dependent mechanism resulting in its proteasomal degradation;and b) by regulating the lysosomal cell death pathway through control of PACS-2 protein levels. FINALLY, we will directly test the hypothesis that: PACS-2 deletion is salutary in models relevant to cholestatic liver injury by: a) reducing TRAIL-mediated cholangiocyte injury in vivo in a model reminiscent of primary sclerosing cholangitis;and b) by reducing hepatocyte injury in vivo during obstructive cholestasis in the bile duct ligated mouse. The proposal is innovative as it tests new concepts for TRAIL cytotoxicity using sophisticated technologies. The information generated will provide a framework for the development of novel therapeutic strategies effective for attenuating TRAIL-mediated human liver injury during cholestasis.

Public Health Relevance

The application examines the cellular mechanisms by which TRAIL, a natural protein, causes cell death. We propose that TRAIL induces cell death by disrupting a key cellular organelle referred to as the lysosome. Lysosome disruption results in the release of toxic compounds into the cell culminating in cellular demise. The results of these studies are germane to mechanisms of liver injury in a variety of human diseases.

National Institute of Health (NIH)
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
Research Project (R01)
Project #
Application #
Study Section
Hepatobiliary Pathophysiology Study Section (HBPP)
Program Officer
Doo, Edward
Project Start
Project End
Budget Start
Budget End
Support Year
Fiscal Year
Total Cost
Indirect Cost
Mayo Clinic, Rochester
United States
Zip Code
Guicciardi, Maria Eugenia; Trussoni, Christy E; Krishnan, Anuradha et al. (2018) Macrophages contribute to the pathogenesis of sclerosing cholangitis in mice. J Hepatol 69:676-686
Moncsek, Anja; Al-Suraih, Mohammed S; Trussoni, Christy E et al. (2018) Targeting senescent cholangiocytes and activated fibroblasts with B-cell lymphoma-extra large inhibitors ameliorates fibrosis in multidrug resistance 2 gene knockout (Mdr2-/- ) mice. Hepatology 67:247-259
Cheung, Angela C; LaRusso, Nicholas F; Gores, Gregory J et al. (2017) Epigenetics in the Primary Biliary Cholangitis and Primary Sclerosing Cholangitis. Semin Liver Dis 37:159-174
Cheung, Angela C; Lazaridis, Konstantinos N; LaRusso, Nicholas F et al. (2017) Emerging pharmacologic therapies for primary sclerosing cholangitis. Curr Opin Gastroenterol 33:149-157
Guicciardi, Maria Eugenia; Krishnan, Anuradha; Bronk, Steven F et al. (2017) Biliary tract instillation of a SMAC mimetic induces TRAIL-dependent acute sclerosing cholangitis-like injury in mice. Cell Death Dis 8:e2535
Hirsova, Petra; Guicciardi, Maria Eugenia; Gores, Gregory J (2017) Proapoptotic signaling induced by deletion of receptor-interacting kinase 1 and TNF receptor-associated factor 2 results in liver carcinogenesis. Hepatology 66:983-985
Bergquist, John R; Ivanics, Tommy; Storlie, Curtis B et al. (2016) Implications of CA19-9 elevation for survival, staging, and treatment sequencing in intrahepatic cholangiocarcinoma: A national cohort analysis. J Surg Oncol 114:475-82
Guicciardi, Maria Eugenia; Gores, Gregory J (2016) Paving the TRAIL to anti-fibrotic therapy. Hepatology 64:29-31
Guicciardi, Maria Eugenia; Gores, Gregory J; Jaeschke, Hartmut (2015) Acetaminophen knocks on death's door and receptor interacting protein 1 kinase answers. Hepatology 62:1664-6
Guicciardi, Maria Eugenia; Werneburg, Nathan W; Bronk, Steven F et al. (2014) Cellular inhibitor of apoptosis (cIAP)-mediated ubiquitination of phosphofurin acidic cluster sorting protein 2 (PACS-2) negatively regulates tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) cytotoxicity. PLoS One 9:e92124

Showing the most recent 10 out of 31 publications