ABSTRACT
Apoptosis is a cardinal feature of liver injury. Death receptors are major mediators of the apoptotic pathway in the liver and have been implicated in the pathogenesis of diverse human diseases. More importantly, several studies have demonstrated a link between apoptosis and hepatic fibrosis; the latter is the most ominous consequence of chronic liver injury. In this article, we focus on the four death receptors: Fas, tumor necrosis factor receptor 1, tumor necrosis factor-related apoptosis-inducing ligand receptor 1, and tumor necrosis factor-related apoptosis-inducing ligand receptor 2. Although the death receptors have similar structures, they also possess distinct characteristics in their signaling pathways. Fas is abundantly expressed by all cells in the liver and plays a central role in variety of liver diseases. Tumor necrosis factor receptor 1 can induce both proapoptotic and prosurvival pathways. Tumor necrosis factor-related apoptosis-inducing ligand receptors likely trigger selective cell death in malignant and viral infected cells. Understanding the mechanism of liver injury caused by death receptors will enable therapeutic strategies to ameliorate human liver diseases.
KEYWORDS
Caspase inhibition - fibrosis - lipoapotosis
REFERENCES
1
Yoon J H, Gores G J.
Death receptor-mediated apoptosis and the liver.
J Hepatol.
2002;
37
400-410
2
Ockner R K.
Apoptosis and liver diseases: recent concepts of mechanism and significance.
J Gastroenterol Hepatol.
2001;
16
248-260
3
Nagata S.
Apoptosis by death factor.
Cell.
1997;
88
355-365
4
Canbay A, Friedman S, Gores G J.
Apoptosis: the nexus of liver injury and fibrosis.
Hepatology.
2004;
39
273-278
5
Tanaka M, Suda T, Yatomi T et al..
Lethal effect of recombinant human Fas ligand in mice pretreated with Propionibacterium acnes.
J Immunol.
1997;
158
2303-2309
6
Bajt M L, Lawson J A, Vonderfecht S L et al..
Protection against Fas receptor-mediated apoptosis in hepatocytes and nonparenchymal cells by a caspase-8 inhibitor in vivo: evidence for a postmitochondrial processing of caspase-8.
Toxicol Sci.
2000;
58
109-117
7
Holler N, Zaru R, Micheau O et al..
Fas triggers an alternative, caspase-8-independent cell death pathway using the kinase RIP as effector molecule.
Nat Immunol.
2000;
1
489-495
8
Zender L, Hutker S, Liedtke C et al..
Caspase 8 small interfering RNA prevents acute liver failure in mice.
Proc Natl Acad Sci USA.
2003;
100
7797-7802
9
Chen J, Nagayama T, Jin K et al..
Induction of caspase-3-like protease may mediate delayed neuronal death in the hippocampus after transient cerebral ischemia.
J Neurosci.
1998;
18
4914-4928
10
Strobel T, Swanson L, Korsmeyer S et al..
BAX enhances paclitaxel-induced apoptosis through a p53-independent pathway.
Proc Natl Acad Sci USA.
1996;
93
14094-14099
11
Ekert P G, Read S H, Silke J et al..
Apaf-1 and caspase-9 accelerate apoptosis, but do not determine whether factor-deprived or drug-treated cells die.
J Cell Biol.
2004;
165
835-842
12
Adachi M, Suematsu S, Kondo T et al..
Targeted mutation in the Fas gene causes hyperplasia in peripheral lymphoid organs and liver.
Nat Genet.
1995;
11
294-300
13
Pfeffer K, Matsuyama T, Kundig T M et al..
Mice deficient for the 55 kd tumor necrosis factor receptor are resistant to endotoxic shock, yet succumb to L. monocytogenes infection.
Cell.
1993;
73
457-467
14
Yue H H, Diehl G E, Winoto A.
Loss of TRAIL-R does not affect thymic or intestinal tumor development in p53 and adenomatous polyposis coli mutant mice.
Cell Death Differ.
2005;
12
94-97
15
Wang Y, Cui F, Lv Y et al..
HBsAg and HBx knocked into the p21 locus causes hepatocellular carcinoma in mice.
Hepatology.
2004;
39
318-324
16
Nakamoto Y, Kaneko S, Fan H et al..
Prevention of hepatocellular carcinoma development associated with chronic hepatitis by anti-fas ligand antibody therapy.
J Exp Med.
2002;
196
1105-1111
17
Hoffmann A, Xia Y, Verma I M.
Inflammatory tales of liver cancer.
Cancer Cell.
2007;
11
99-101
18 Guicciardi M E, Gores G J. The Fas/FasL signaling pathway . In: Dufour J-F, Clavien P-A Signaling Pathways in Liver Diseases. Berlin, Heidelberg; Springer-Verlag 2005: 129-138
19
Peter M E, Krammer P H.
The CD95(APO-1/Fas) Dros Inf ServC and beyond.
Cell Death Differ.
2003;
10
26-35
20
Kischkel F C, Hellbardt S, Behrmann I et al..
Cytotoxicity-dependent APO-1 (Fas/CD95)-associated proteins form a death-inducing signaling complex (Dros Inf ServC) with the receptor.
EMBO J.
1995;
14
5579-5588
21
Chinnaiyan A M, Tepper C G, Seldin M F et al..
FADD/MORT1 is a common mediator of CD95 (Fas/APO-1) and tumor necrosis factor receptor-induced apoptosis.
J Biol Chem.
1996;
271
4961-4965
22
Scaffidi C, Fulda S, Srinivasan A et al..
Two CD95 (APO-1/Fas) signaling pathways.
EMBO J.
1998;
17
1675-1687
23
Baskin-Bey E S, Gores G J.
Death by association: BH3 domain-only proteins and liver injury.
Am J Physiol Gastrointest Liver Physiol.
2005;
289
G987-G990
24
Wei M C, Zong W X, Cheng E H et al..
Proapoptotic BAX and BAK: a requisite gateway to mitochondrial dysfunction and death.
Science.
2001;
292
727-730
25
Willis S N, Adams J M.
Life in the balance: how BH3-only proteins induce apoptosis.
Curr Opin Cell Biol.
2005;
17
617-625
26
Kurosawa H, Que F G, Roberts L R et al..
Hepatocytes in the bile duct-ligated rat express Bcl-2.
Am J Physiol.
1997;
272(6 Pt 1)
G1587-G1593
27
Tzung S P, Fausto N, Hockenbery D M.
Expression of Bcl-2 family during liver regeneration and identification of Bcl-x as a delayed early response gene.
Am J Pathol.
1997;
150
1985-1995
28
Li H, Zhu H, Xu C J et al..
Cleavage of BID by caspase 8 mediates the mitochondrial damage in the Fas pathway of apoptosis.
Cell.
1998;
94
491-501
29
Li S, Zhao Y, He X et al..
Relief of extrinsic pathway inhibition by the Bid-dependent mitochondrial release of Smac in Fas-mediated hepatocyte apoptosis.
J Biol Chem.
2002;
277
26912-26920
30
Wiley S R, Schooley K, Smolak P J et al..
Identification and characterization of a new member of the TNF family that induces apoptosis.
Immunity.
1995;
3
673-682
31
MacFarlane M.
TRAIL-induced signalling and apoptosis.
Toxicol Lett.
2003;
139
89-97
32
Kimberley F C, Screaton G R.
Following a TRAIL: update on a ligand and its five receptors.
Cell Res.
2004;
14
359-372
33
Wu G S, Burns T F, Zhan Y et al..
Molecular cloning and functional analysis of the mouse homologue of the KILLER/DR5 tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) death receptor.
Cancer Res.
1999;
59
2770-2775
34
Thon L, Mathieu S, Kabelitz D et al..
The murine TRAIL receptor signals caspase-independent cell death through ceramide.
Exp Cell Res.
2006;
312
3808-3821
35
van der Sloot A M, Tur V, Szegezdi E et al..
Designed tumor necrosis factor-related apoptosis-inducing ligand variants initiating apoptosis exclusively via the DR5 receptor.
Proc Natl Acad Sci USA.
2006;
103
8634-8639
36
Ashkenazi A, Pai R C, Fong S et al..
Safety and antitumor activity of recombinant soluble Apo2 ligand.
J Clin Invest.
1999;
104
155-162
37
Walczak H, Miller R E, Ariail K et al..
Tumoricidal activity of tumor necrosis factor-related apoptosis-inducing ligand in vivo.
Nat Med.
1999;
5
157-163
38
Sadarangani A, Kato S, Espinoza N et al..
TRAIL mediates apoptosis in cancerous but not normal primary cultured cells of the human reproductive tract.
Apoptosis.
2007;
12
73-85
39
Yagita H, Takeda K, Hayakawa Y et al..
TRAIL and its receptors as targets for cancer therapy.
Cancer Sci.
2004;
95
777-783
40
Janssen H L, Higuchi H, Abdulkarim A et al..
Hepatitis B virus enhances tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) cytotoxicity by increasing TRAIL-R1/death receptor 4 expression.
J Hepatol.
2003;
39
414-420
41
Higuchi H, Bronk S F, Takikawa Y et al..
The bile acid glycochenodeoxycholate induces trail-receptor 2/DR5 expression and apoptosis.
J Biol Chem.
2001;
276
38610-38618
42
Wajant H, Pfizenmaier K, Scheurich P.
Tumor necrosis factor signaling.
Cell Death Differ.
2003;
10
45-65
43
Ding W X, Yin X M.
Dissection of the multiple mechanisms of TNF-alpha-induced apoptosis in liver injury.
J Cell Mol Med.
2004;
8
445-454
44
Schwabe R F, Brenner D A.
Mechanisms of liver injury. I. TNF-alpha-induced liver injury: role of IKK, JNK, and ROS pathways.
Am J Physiol Gastrointest Liver Physiol.
2006;
290
G583-G589
45
Micheau O, Tschopp J.
Induction of TNF receptor I-mediated apoptosis via two sequential signaling complexes.
Cell.
2003;
114
181-190
46
Wullaert A, Heyninck K, Beyaert R.
Mechanisms of crosstalk between TNF-induced NF-kappaB and JNK activation in hepatocytes.
Biochem Pharmacol.
2006;
72
1090-1101
47
Chen X, Ding W X, Ni H M et al..
Bid-independent mitochondrial activation in tumor necrosis factor alpha-induced apoptosis and liver injury.
Mol Cell Biol.
2007;
27
541-553
48
Kamata H, Honda S, Maeda S et al..
Reactive oxygen species promote TNFalpha-induced death and sustained JNK activation by inhibiting MAP kinase phosphatases.
Cell.
2005;
120
649-661
49
Guicciardi M E, Deussing J, Miyoshi H et al..
Cathepsin B contributes to TNF-alpha-mediated hepatocyte apoptosis by promoting mitochondrial release of cytochrome c.
J Clin Invest.
2000;
106
1127-1137
50
Werneburg N, Guicciardi M E, Yin X M et al..
TNF-alpha-mediated lysosomal permeabilization is FAN and caspase 8/Bid dependent.
Am J Physiol Gastrointest Liver Physiol.
2004;
287
G436-G443
51
Werneburg N W, Guicciardi M E, Bronk S F et al..
Tumor necrosis factor-alpha-associated lysosomal permeabilization is cathepsin B dependent.
Am J Physiol Gastrointest Liver Physiol.
2002;
283
G947-G956
52
Guicciardi M E, Leist M, Gores G J.
Lysosomes in cell death.
Oncogene.
2004;
23
2881-2890
53
Guicciardi M E, Bronk S F, Werneburg N W et al..
Bid is upstream of lysosome-mediated caspase 2 activation in tumor necrosis factor alpha-induced hepatocyte apoptosis.
Gastroenterology.
2005;
129
269-284
54
Baskin-Bey E S, Canbay A, Bronk S F et al..
Cathepsin B inactivation attenuates hepatocyte apoptosis and liver damage in steatotic livers after cold ischemia-warm reperfusion injury.
Am J Physiol Gastrointest Liver Physiol.
2005;
288
G396-G402
55
Canbay A, Feldstein A E, Higuchi H et al..
Kupffer cell engulfment of apoptotic bodies stimulates death ligand and cytokine expression.
Hepatology.
2003;
38
1188-1198
56
Reuben A.
Alcohol and the liver.
Curr Opin Gastroenterol.
2006;
22
263-271
57
Kawahara H, Matsuda Y, Takase S.
Is apoptosis involved in alcoholic hepatitis?.
Alcohol Alcohol Suppl.
1994;
29
113-118
58
Natori S, Rust C, Stadheim L M et al..
Hepatocyte apoptosis is a pathologic feature of human alcoholic hepatitis.
J Hepatol.
2001;
34
248-253
59
Ribeiro P S, Cortez-Pinto H, Sola S et al..
Hepatocyte apoptosis, expression of death receptors, and activation of NF-kappaB in the liver of nonalcoholic and alcoholic steatohepatitis patients.
Am J Gastroenterol.
2004;
99
1708-1717
60
Zhou Z, Sun X, Kang Y J.
Ethanol-induced apoptosis in mouse liver: Fas- and cytochrome c-mediated caspase-3 activation pathway.
Am J Pathol.
2001;
159
329-338
61
Deaciuc I V, Fortunato F, D'Souza N B et al..
Modulation of caspase-3 activity and Fas ligand mRNA expression in rat liver cells in vivo by alcohol and lipopolysaccharide.
Alcohol Clin Exp Res.
1999;
23
349-356
62
Minana J B, Gomez-Cambronero L, Lloret A et al..
Mitochondrial oxidative stress and CD95 ligand: a dual mechanism for hepatocyte apoptosis in chronic alcoholism.
Hepatology.
2002;
35
1205-1214
63
Ramalho R M, Cortez-Pinto H, Castro R E et al..
Apoptosis and Bcl-2 expression in the livers of patients with steatohepatitis.
Eur J Gastroenterol Hepatol.
2006;
18
21-29
64
Bird G L, Sheron N, Goka A K et al..
Increased plasma tumor necrosis factor in severe alcoholic hepatitis.
Ann Intern Med.
1990;
112
917-920
65
Yin M, Wheeler M D, Kono H et al..
Essential role of tumor necrosis factor alpha in alcohol-induced liver injury in mice.
Gastroenterology.
1999;
117
942-952
66
Iimuro Y, Gallucci R M, Luster M I et al..
Antibodies to tumor necrosis factor alfa attenuate hepatic necrosis and inflammation caused by chronic exposure to ethanol in the rat.
Hepatology.
1997;
26
1530-1537
67
Spahr L, Rubbia-Brandt L, Frossard J L et al..
Combination of steroids with infliximab or placebo in severe alcoholic hepatitis: a randomized controlled pilot study.
J Hepatol.
2002;
37
448-455
68
Cortez-Pinto H, de Moura M C, Day C P.
Non-alcoholic steatohepatitis: from cell biology to clinical practice.
J Hepatol.
2006;
44
197-208
69
Day C P, James O F.
Steatohepatitis: a tale of two “hits”?.
Gastroenterology.
1998;
114
842-845
70
Wieckowska A, Zein N N, Yerian L M et al..
In vivo assessment of liver cell apoptosis as a novel biomarker of disease severity in nonalcoholic fatty liver disease.
Hepatology.
2006;
44
27-33
71
Nehra V, Angulo P, Buchman A L et al..
Nutritional and metabolic considerations in the etiology of nonalcoholic steatohepatitis.
Dig Dis Sci.
2001;
46
2347-2352
72
Malhi H, Bronk S F, Werneburg N W et al..
Free fatty acids induce JNK-dependent hepatocyte lipoapoptosis.
J Biol Chem.
2006;
281
12093-12101
73
Feldstein A E, Canbay A, Angulo P et al..
Hepatocyte apoptosis and fas expression are prominent features of human nonalcoholic steatohepatitis.
Gastroenterology.
2003;
125
437-443
74
Robertson G, Leclercq I, Farrell G C.
Nonalcoholic steatosis and steatohepatitis. II. Cytochrome P-450 enzymes and oxidative stress.
Am J Physiol Gastrointest Liver Physiol.
2001;
281
G1135-G1139
75
Feldstein A E, Werneburg N W, Canbay A et al..
Free fatty acids promote hepatic lipotoxicity by stimulating TNF-alpha expression via a lysosomal pathway.
Hepatology.
2004;
40
185-194
76
Li Z, Yang S, Lin H et al..
Probiotics and antibodies to TNF inhibit inflammatory activity and improve nonalcoholic fatty liver disease.
Hepatology.
2003;
37
343-350
77
Kountouras J, Zavos C, Chatzopoulos D.
Apoptosis in hepatitis C.
J Viral Hepat.
2003;
10
335-342
78
Gonzalez-Amaro R, Garcia-Monzon C, Garcia-Buey L et al..
Induction of tumor necrosis factor alpha production by human hepatocytes in chronic viral hepatitis.
J Exp Med.
1994;
179
841-848
79
Liu Y G, Liu S X, Liang X H et al..
Blockade of TRAIL pathway ameliorates HBV-induced hepatocyte apoptosis in an acute hepatitis model.
Biochem Biophys Res Commun.
2007;
352
329-334
80
Chisari F V.
Hepatitis B virus transgenic mice: models of viral immunobiology and pathogenesis.
Curr Top Microbiol Immunol.
1996;
206
149-173
81
Lee J Y, Chae D W, Kim S M et al..
Expression of FasL and perforin/granzyme B mRNA in chronic hepatitis B virus infection.
J Viral Hepat.
2004;
11
130-135
82
Mochizuki K, Hayashi N, Hiramatsu N et al..
Fas antigen expression in liver tissues of patients with chronic hepatitis B.
J Hepatol.
1996;
24
1-7
83
Song le H, Binh V Q, Duy D N et al..
Variations in the serum concentrations of soluble Fas and soluble Fas ligand in Vietnamese patients infected with hepatitis B virus.
J Med Virol.
2004;
73
244-249
84
Fang J W, Shen W W, Meager A et al..
Activation of the tumor necrosis factor-alpha system in the liver in chronic hepatitis B virus infection.
Am J Gastroenterol.
1996;
91
748-753
85
Marinos G, Naoumov N V, Rossol S et al..
Tumor necrosis factor receptors in patients with chronic hepatitis B virus infection.
Gastroenterology.
1995;
108
1453-1463
86
Su F, Schneider R J.
Hepatitis B virus HBx protein sensitizes cells to apoptotic killing by tumor necrosis factor alpha.
Proc Natl Acad Sci USA.
1997;
94
8744-8749
87
Mundt B, Kuhnel F, Zender L et al..
Involvement of TRAIL and its receptors in viral hepatitis.
FASEB J.
2003;
17
94-96
88
Sato K, Hida S, Takayanagi H et al..
Antiviral response by natural killer cells through TRAIL gene induction by IFN-alpha/beta.
Eur J Immunol.
2001;
31
3138-3146
89
Takeda K, Hayakawa Y, Smyth M J et al..
Involvement of tumor necrosis factor-related apoptosis-inducing ligand in surveillance of tumor metastasis by liver natural killer cells.
Nat Med.
2001;
7
94-100
90
Han L H, Sun W S, Ma C H et al..
Detection of soluble TRAIL in HBV infected patients and its clinical implications.
World J Gastroenterol.
2002;
8
1077-1080
91
Liang X, Liu Y, Zhang Q et al..
Hepatitis B virus sensitizes hepatocytes to TRAIL-induced apoptosis through Bax.
J Immunol.
2007;
178
503-510
92
Alter M J.
Epidemiology of hepatitis C.
Hepatology.
1997;
26(3 suppl 1)
62S-65S
93
Bantel H, Schulze-Osthoff K.
Apoptosis in hepatitis C virus infection.
Cell Death Differ.
2003;
10(suppl 1)
S48-S58
94
Hiramatsu N, Hayashi N, Katayama K et al..
Immunohistochemical detection of Fas antigen in liver tissue of patients with chronic hepatitis C.
Hepatology.
1994;
19
1354-1359
95
Bantel H, Lugering A, Heidemann J et al..
Detection of apoptotic caspase activation in sera from patients with chronic HCV infection is associated with fibrotic liver injury.
Hepatology.
2004;
40
1078-1087
96
Zhu N, Khoshnan A, Schneider R et al..
Hepatitis C virus core protein binds to the cytoplasmic domain of tumor necrosis factor (TNF) receptor 1 and enhances TNF-induced apoptosis.
J Virol.
1998;
72
3691-3697
97
Tokushige K, Yamaguchi N, Ikeda I et al..
Significance of soluble TNF receptor-I in acute-type fulminant hepatitis.
Am J Gastroenterol.
2000;
95
2040-2046
98
Chou A H, Tsai H F, Wu Y Y et al..
Hepatitis C virus core protein modulates TRAIL-mediated apoptosis by enhancing Bid cleavage and activation of mitochondria apoptosis signaling pathway.
J Immunol.
2005;
174
2160-2166
99
Machida K, Tsukiyama-Kohara K, Seike E et al..
Inhibition of cytochrome c release in Fas-mediated signaling pathway in transgenic mice induced to express hepatitis C viral proteins.
J Biol Chem.
2001;
276
12140-12146
100
Saito K, Meyer K, Warner R et al..
Hepatitis C virus core protein inhibits tumor necrosis factor alpha-mediated apoptosis by a protective effect involving cellular FLICE inhibitory protein.
J Virol.
2006;
80
4372-4379
101
Hsu E C, Hsi B, Hirota-Tsuchihara M et al..
Modified apoptotic molecule (BID) reduces hepatitis C virus infection in mice with chimeric human livers.
Nat Biotechnol.
2003;
21
519-525
102
Schiff E R, Pockros P, Schiffman M L et al..
Oral IDN-6556, an anti-apoptotic caspase inhibitor, lowers aminotransferases in HCV patients.
J Hepatol.
2004;
40(suppl 1)
24
103
Canbay A, Feldstein A, Baskin-Bey E et al..
The caspase inhibitor IDN-6556 attenuates hepatic injury and fibrosis in the bile duct ligated mouse.
J Pharmacol Exp Ther.
2004;
308
1191-1196
104
Canbay A, Taimr P, Torok N et al..
Apoptotic body engulfment by a human stellate cell line is profibrogenic.
Lab Invest.
2003;
83
655-663
105
Canbay A, Guicciardi M E, Higuchi H et al..
Cathepsin B inactivation attenuates hepatic injury and fibrosis during cholestasis.
J Clin Invest.
2003;
112
152-159
106
Anan A, Baskin-Bey E S, Bronk S F et al..
Proteasome inhibition induces hepatic stellate cell apoptosis.
Hepatology.
2006;
43
335-344
107
Wright M C, Issa R, Smart D E et al..
Gliotoxin stimulates the apoptosis of human and rat hepatic stellate cells and enhances the resolution of liver fibrosis in rats.
Gastroenterology.
2001;
121
685-698
108
Elsharkawy A M, Wright M C, Hay R T et al..
Persistent activation of nuclear factor-kappaB in cultured rat hepatic stellate cells involves the induction of potentially novel Rel-like factors and prolonged changes in the expression of IkappaB family proteins.
Hepatology.
1999;
30
761-769
109
Taimr P, Higuchi H, Kocova E et al..
Activated stellate cells express the TRAIL receptor-2/death receptor-5 and undergo TRAIL-mediated apoptosis.
Hepatology.
2003;
37
87-95
110
Fischer R, Cariers A, Reinehr R et al..
Caspase 9-dependent killing of hepatic stellate cells by activated Kupffer cells.
Gastroenterology.
2002;
123
845-861
111
Jeong W I, Park O, Radaeva S et al..
STAT1 inhibits liver fibrosis in mice by inhibiting stellate cell proliferation and stimulating NK cell cytotoxicity.
Hepatology.
2006;
44
1441-1451
Gregory J GoresM.D. F.A.C.P.
Division of Gastroenterology and Hepatology, Miles and Shirley Fiterman Center for Digestive Diseases, Mayo Clinic College of Medicine
200 First Street SW, Rochester, MN 55905
Email: gores.gregory@mayo.edu