1
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Lebeau PF, Wassef H, Byun JH, Platko K, Ason B, Jackson S, Dobroff J, Shetterly S, Richards WG, Al-Hashimi AA, Won KD, Mbikay M, Prat A, Tang A, Paré G, Pasqualini R, Seidah NG, Arap W, Chrétien M, Austin RC. The loss-of-function PCSK9Q152H variant increases ER chaperones GRP78 and GRP94 and protects against liver injury. J Clin Invest 2021; 131:128650. [PMID: 33211673 DOI: 10.1172/jci128650] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2019] [Accepted: 11/03/2020] [Indexed: 12/11/2022] Open
Abstract
Individuals harboring the loss-of-function (LOF) proprotein convertase subtilisin/kexin type 9 Gln152His variation (PCSK9Q152H) have low circulating low-density lipoprotein cholesterol levels and are therefore protected against cardiovascular disease (CVD). This uncleavable form of proPCSK9, however, is retained in the endoplasmic reticulum (ER) of liver hepatocytes, where it would be expected to contribute to ER storage disease (ERSD), a heritable condition known to cause systemic ER stress and liver injury. Here, we examined liver function in members of several French-Canadian families known to carry the PCSK9Q152H variation. We report that PCSK9Q152H carriers exhibited marked hypocholesterolemia and normal liver function despite their lifelong state of ER PCSK9 retention. Mechanistically, hepatic overexpression of PCSK9Q152H using adeno-associated viruses in male mice greatly increased the stability of key ER stress-response chaperones in liver hepatocytes and unexpectedly protected against ER stress and liver injury rather than inducing them. Our findings show that ER retention of PCSK9 not only reduced CVD risk in patients but may also protect against ERSD and other ER stress-driven conditions of the liver. In summary, we have uncovered a cochaperone function for PCSK9Q152H that explains its hepatoprotective effects and generated a translational mouse model for further mechanistic insights into this clinically relevant LOF PCSK9 variant.
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Affiliation(s)
- Paul F Lebeau
- Department of Medicine, McMaster University, The Research Institute of St. Joe's Hamilton and Hamilton Centre for Kidney Research, Hamilton, Ontario, Canada
| | - Hanny Wassef
- Laboratory of Functional Endoproteolysis, Clinical Research Institute of Montreal, affiliated with the University of Montreal, Montreal, Quebec, Canada
| | - Jae Hyun Byun
- Department of Medicine, McMaster University, The Research Institute of St. Joe's Hamilton and Hamilton Centre for Kidney Research, Hamilton, Ontario, Canada
| | - Khrystyna Platko
- Department of Medicine, McMaster University, The Research Institute of St. Joe's Hamilton and Hamilton Centre for Kidney Research, Hamilton, Ontario, Canada
| | - Brandon Ason
- Cardiometabolic Disorders, Amgen Research Inc., South San Francisco, California, USA
| | - Simon Jackson
- Cardiometabolic Disorders, Amgen Research Inc., South San Francisco, California, USA
| | | | - Susan Shetterly
- Cardiometabolic Disorders, Amgen Research Inc., South San Francisco, California, USA
| | | | - Ali A Al-Hashimi
- Department of Medicine, McMaster University, The Research Institute of St. Joe's Hamilton and Hamilton Centre for Kidney Research, Hamilton, Ontario, Canada
| | - Kevin Doyoon Won
- Department of Medicine, McMaster University, The Research Institute of St. Joe's Hamilton and Hamilton Centre for Kidney Research, Hamilton, Ontario, Canada
| | - Majambu Mbikay
- Laboratory of Functional Endoproteolysis, Clinical Research Institute of Montreal, affiliated with the University of Montreal, Montreal, Quebec, Canada
| | - Annik Prat
- Laboratory of Biochemical Neuroendocrinology, Clinical Research Institute of Montreal, affiliated with the University of Montreal, Montreal, Quebec, Canada
| | - An Tang
- Department of Radiology at the Centre Hospitalier Universitaire de Montréal, University of Montreal, Montreal, Quebec, Canada
| | - Guillaume Paré
- Population Health Research Institute and Departments of Medicine, Epidemiology, and Pathology, McMaster University, Hamilton, Ontario, Canada
| | | | - Nabil G Seidah
- Laboratory of Biochemical Neuroendocrinology, Clinical Research Institute of Montreal, affiliated with the University of Montreal, Montreal, Quebec, Canada
| | - Wadih Arap
- Division of Hematology/Oncology, Department of Medicine, Rutgers New Jersey Medical School and Rutgers Cancer Institute of New Jersey, Newark, New Jersey, USA
| | - Michel Chrétien
- Laboratory of Functional Endoproteolysis, Clinical Research Institute of Montreal, affiliated with the University of Montreal, Montreal, Quebec, Canada
| | - Richard C Austin
- Department of Medicine, McMaster University, The Research Institute of St. Joe's Hamilton and Hamilton Centre for Kidney Research, Hamilton, Ontario, Canada
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2
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Zhang G, Wang X, Bi X, Li C, Deng Y, Al-Hashimi AA, Luo X, Gillette TG, Austin RC, Wang Y, Wang ZV. GRP78 (Glucose-Regulated Protein of 78 kDa) Promotes Cardiomyocyte Growth Through Activation of GATA4 (GATA-Binding Protein 4). Hypertension 2019; 73:390-398. [PMID: 30580686 DOI: 10.1161/hypertensionaha.118.12084] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The heart manifests hypertrophic growth in response to elevation of afterload pressure. Cardiac myocyte growth involves new protein synthesis and membrane expansion, of which a number of cellular quality control machineries are stimulated to maintain function and homeostasis. The unfolded protein response is potently induced during cardiac hypertrophy to enhance protein-folding capacity and eliminate terminally misfolded proteins. However, whether the unfolded protein response directly regulates cardiac myocyte growth remains to be fully determined. Here, we show that GRP78 (glucose-regulated protein of 78 kDa)-an endoplasmic reticulum-resident chaperone and a critical unfolded protein response regulator-is induced by cardiac hypertrophy. Importantly, overexpression of GRP78 in cardiomyocytes is sufficient to potentiate hypertrophic stimulus-triggered growth. At the in vivo level, TG (transgenic) hearts overexpressing GRP78 mount elevated hypertrophic growth in response to pressure overload. We went further to show that GRP78 increases GATA4 (GATA-binding protein 4) level, which may stimulate Anf (atrial natriuretic factor) expression and promote cardiac hypertrophic growth. Silencing of GATA4 in cultured neonatal rat ventricular myocytes significantly diminishes GRP78-mediated growth response. Our results, therefore, reveal that protein-folding chaperone GRP78 may directly enhance cardiomyocyte growth by stimulating cardiac-specific transcriptional factor GATA4.
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Affiliation(s)
- Guangyu Zhang
- From the Department of Cardiology, Zhongnan Hospital of Wuhan University, Hubei, China (G.Z., Y.W.).,Division of Cardiology, Department of Internal Medicine (G.Z., X.W., X.B., C.L., X.L., T.G.G., Z.V.W.), University of Texas Southwestern Medical Center, Dallas
| | - Xiaoding Wang
- Division of Cardiology, Department of Internal Medicine (G.Z., X.W., X.B., C.L., X.L., T.G.G., Z.V.W.), University of Texas Southwestern Medical Center, Dallas
| | - Xukun Bi
- Division of Cardiology, Department of Internal Medicine (G.Z., X.W., X.B., C.L., X.L., T.G.G., Z.V.W.), University of Texas Southwestern Medical Center, Dallas.,Department of Cardiology, Biomedical Research (Therapy) Center, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University, Hangzhou, China (X.B.)
| | - Chao Li
- Division of Cardiology, Department of Internal Medicine (G.Z., X.W., X.B., C.L., X.L., T.G.G., Z.V.W.), University of Texas Southwestern Medical Center, Dallas
| | - Yingfeng Deng
- Department of Internal Medicine, Touchstone Diabetes Center (Y.D.), University of Texas Southwestern Medical Center, Dallas
| | - Ali A Al-Hashimi
- Division of Nephrology, Department of Medicine, McMaster University, The Research Institute of St. Joe's Hamilton and Hamilton Center for Kidney Research, ON, Canada (A.A.A.-H., R.C.A.)
| | - Xiang Luo
- Division of Cardiology, Department of Internal Medicine (G.Z., X.W., X.B., C.L., X.L., T.G.G., Z.V.W.), University of Texas Southwestern Medical Center, Dallas
| | - Thomas G Gillette
- Division of Cardiology, Department of Internal Medicine (G.Z., X.W., X.B., C.L., X.L., T.G.G., Z.V.W.), University of Texas Southwestern Medical Center, Dallas
| | - Richard C Austin
- Division of Nephrology, Department of Medicine, McMaster University, The Research Institute of St. Joe's Hamilton and Hamilton Center for Kidney Research, ON, Canada (A.A.A.-H., R.C.A.)
| | - Yanggan Wang
- From the Department of Cardiology, Zhongnan Hospital of Wuhan University, Hubei, China (G.Z., Y.W.).,Medical Research Institute of Wuhan University, Wuhan University, Hubei, China (Y.W.)
| | - Zhao V Wang
- Division of Cardiology, Department of Internal Medicine (G.Z., X.W., X.B., C.L., X.L., T.G.G., Z.V.W.), University of Texas Southwestern Medical Center, Dallas
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3
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Lebeau PF, Byun JH, Platko K, Al-Hashimi AA, Lhoták Š, MacDonald ME, Mejia-Benitez A, Prat A, Igdoura SA, Trigatti B, Maclean KN, Seidah NG, Austin RC. Pcsk9 knockout exacerbates diet-induced non-alcoholic steatohepatitis, fibrosis and liver injury in mice. JHEP Rep 2019; 1:418-429. [PMID: 32039393 PMCID: PMC7005770 DOI: 10.1016/j.jhepr.2019.10.009] [Citation(s) in RCA: 48] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/13/2019] [Revised: 10/16/2019] [Accepted: 10/24/2019] [Indexed: 12/15/2022] Open
Abstract
The fatty acid translocase, also known as CD36, is a well-established scavenger receptor for fatty acid (FA) uptake and is abundantly expressed in many metabolically active tissues. In the liver, CD36 is known to contribute to the progression of non-alcoholic fatty liver disease and to the more severe non-alcoholic steatohepatitis, by promoting triglyceride accumulation and subsequent lipid-induced endoplasmic reticulum (ER) stress. Given the recent discovery that the hepatocyte-secreted proprotein convertase subtilisin/kexin type 9 (PCSK9) blocks CD36 expression, we sought to investigate the role of PCSK9 in liver fat accumulation and injury in response to saturated FAs and in a mouse model of diet-induced hepatic steatosis. Methods In this study, we investigated the role of PCSK9 on the uptake and accumulation of FAs, as well as FA-induced toxicity, in a variety of cultured hepatocytes. Diet-induced hepatic steatosis and liver injury were also assessed in Pcsk9-/- mice. Results Our results indicate that PCSK9 deficiency in cultured hepatocytes increased the uptake and accumulation of saturated and unsaturated FAs. In the presence of saturated FAs, PCSK9 also protected cultured hepatocytes from ER stress and cytotoxicity. In line with these findings, a metabolic challenge using a high-fat diet caused severe hepatic steatosis, ER stress inflammation and fibrosis in the livers of Pcsk9-/- mice compared to controls. Given that inhibition of CD36 ablated the observed accumulation of lipid in vitro and in vivo, our findings also highlight CD36 as a strong contributor to steatosis and liver injury in the context of PCSK9 deficiency. Conclusions Collectively, our findings demonstrate that PCSK9 regulates hepatic triglyceride content in a manner dependent on CD36. In the presence of excess dietary fats, PCSK9 can also protect against hepatic steatosis and liver injury. Lay summary The proprotein convertase subtilisin/kexin type 9 (PCSK9) is a circulating protein known to reduce the abundance of receptors on the surface of liver cells charged with the task of lipid uptake from the circulation. Although PCSK9 deficiency is known to cause lipid accumulation in mice and in cultured cells, the toxicological implications of this observation have not yet been reported. In this study, we demonstrate that PCSK9 can protect against cytotoxicity in cultured liver cells treated with a saturated fatty acid and we also show that Pcsk9 knockout mice develop increased liver injury in response to a high-fat diet. PCSK9 reduces the expression of hepatic CD36 in mice. CD36 is a known driver of liver steatosis and injury. PCSK9 protects from palmitate-induced ER stress and ROS in cultured hepatocytes. High-fat diet causes severe hepatic steatosis, ER stress, inflammation and insulin resistance in Pcsk9-/- mice. PCSK9 expression protects mice from diet-induced liver injury.
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Affiliation(s)
- Paul F. Lebeau
- Department of Medicine, Division of Nephrology, McMaster University, St. Joseph’s Healthcare Hamilton, Ontario L8N 4A6, Canada
| | - Jae Hyun Byun
- Department of Medicine, Division of Nephrology, McMaster University, St. Joseph’s Healthcare Hamilton, Ontario L8N 4A6, Canada
| | - Khrystyna Platko
- Department of Medicine, Division of Nephrology, McMaster University, St. Joseph’s Healthcare Hamilton, Ontario L8N 4A6, Canada
| | - Ali A. Al-Hashimi
- Department of Medicine, Division of Nephrology, McMaster University, St. Joseph’s Healthcare Hamilton, Ontario L8N 4A6, Canada
| | - Šárka Lhoták
- Department of Medicine, Division of Nephrology, McMaster University, St. Joseph’s Healthcare Hamilton, Ontario L8N 4A6, Canada
| | - Melissa E. MacDonald
- Department of Medicine, Division of Nephrology, McMaster University, St. Joseph’s Healthcare Hamilton, Ontario L8N 4A6, Canada
| | - Aurora Mejia-Benitez
- Department of Medicine, Division of Nephrology, McMaster University, St. Joseph’s Healthcare Hamilton, Ontario L8N 4A6, Canada
| | - Annik Prat
- Laboratory of Biochemical Neuroendocrinology, Clinical Research Institute of Montreal, affiliated to the University of Montreal, Montreal, Quebec H2W 1R7, Canada
| | - Suleiman A. Igdoura
- Department of Biology and Pathology, McMaster University, Hamilton, Ontario, L8S 4K1, Canada
| | - Bernardo Trigatti
- Thrombosis and Atherosclerosis Research Institute (TaARI), Hamilton Health Sciences and McMaster University, Hamilton, Ontario L8L 2X2, Canada
- Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, Ontario L8S 4L8, Canada
| | - Kenneth N. Maclean
- the Department of Pediatrics, University of Colorado School of Medicine, Aurora, Colorado, USA, 80045
| | - Nabil G. Seidah
- Laboratory of Biochemical Neuroendocrinology, Clinical Research Institute of Montreal, affiliated to the University of Montreal, Montreal, Quebec H2W 1R7, Canada
| | - Richard C. Austin
- Department of Medicine, Division of Nephrology, McMaster University, St. Joseph’s Healthcare Hamilton, Ontario L8N 4A6, Canada
- Corresponding author. Address: Dr. Richard C. Austin, 50 Charlton Ave East, Room T-3313, Hamilton, Ontario, L8N 4A6. Tel.: 905-522-1155 x35175; Fax: 905-540-6589.
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4
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Crane ED, Al-Hashimi AA, Chen J, Lynn EG, Won KD, Lhoták Š, Naeim M, Platko K, Lebeau P, Byun JH, Shayegan B, Krepinsky JC, Rayner KJ, Marchiò S, Pasqualini R, Arap W, Austin RC. Anti-GRP78 autoantibodies induce endothelial cell activation and accelerate the development of atherosclerotic lesions. JCI Insight 2018; 3:99363. [PMID: 30568038 DOI: 10.1172/jci.insight.99363] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2017] [Accepted: 11/09/2018] [Indexed: 12/31/2022] Open
Abstract
The 78-kDa glucose-regulated protein (GRP78) is an ER molecular chaperone that aids in protein folding and secretion. However, pathological conditions that cause ER stress can promote the relocalization of GRP78 to the cell surface (csGRP78), where it acts as a signaling receptor to promote cancer progression. csGRP78 also possesses antigenic properties, leading to the production of anti-GRP78 autoantibodies, which contribute to tumor growth. In contrast, the presence and role of anti-GRP78 autoantibodies in atherosclerosis is unknown. Here, we show that atherosclerotic-prone ApoE-/- mice develop circulating anti-GRP78 autoantibodies that bind to csGRP78 on lesion-resident endothelial cells. Moreover, GRP78-immunized ApoE-/- mice exhibit a marked increase in circulating anti-GRP78 autoantibody titers that correlated with accelerated lesion growth. Mechanistically, engagement of anti-GRP78 autoantibodies with csGRP78 on human endothelial cells activated NF-κB, thereby inducing the expression of ICAM-1 and VCAM-1, a process blocked by NF-κB inhibitors. Disrupting the autoantibody/csGRP78 complex with enoxaparin, a low-molecular-weight heparin, reduced the expression of adhesion molecules and attenuated lesion growth. In conclusion, anti-GRP78 autoantibodies play a crucial role in atherosclerosis development, and disruption of the interaction between anti-GRP78 autoantibodies and csGRP78 represents a therapeutic strategy.
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Affiliation(s)
| | - Ali A Al-Hashimi
- Department of Medicine, Division of Nephrology, and.,Division of Urology, Department of Surgery, McMaster University and The Research Institute of St. Joe's Hamilton, Hamilton, Ontario, Canada
| | - Jack Chen
- Department of Medicine, Division of Nephrology, and
| | | | | | - Šárka Lhoták
- Department of Medicine, Division of Nephrology, and
| | - Magda Naeim
- Department of Medicine, Division of Nephrology, and
| | | | - Paul Lebeau
- Department of Medicine, Division of Nephrology, and
| | | | - Bobby Shayegan
- Division of Urology, Department of Surgery, McMaster University and The Research Institute of St. Joe's Hamilton, Hamilton, Ontario, Canada
| | | | - Katey J Rayner
- Department of Biochemistry, Microbiology, and Immunology, Faculty of Medicine, University of Ottawa and University of Ottawa Heart Institute, Ottawa, Ontario, Canada
| | - Serena Marchiò
- Department of Oncology, University of Turin, Candiolo, Italy.,Candiolo Cancer Institute - Fondazione del Piemonte per l'Oncologia, Istituto di Ricerca e Cura a Carattere Scientifico, Candiolo, Italy
| | - Renata Pasqualini
- Rutgers Cancer Institute of New Jersey, Newark, New Jersey, USA.,Division of Cancer Biology, Department of Radiation Oncology, and
| | - Wadih Arap
- Rutgers Cancer Institute of New Jersey, Newark, New Jersey, USA.,Division of Hematology/Oncology, Department of Medicine, Rutgers New Jersey Medical School, Newark, New Jersey, USA
| | - Richard C Austin
- Department of Biochemistry and Biomedical Sciences.,Department of Medicine, Division of Nephrology, and
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5
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Bi X, Zhang G, Wang X, Nguyen C, May HI, Li X, Al-Hashimi AA, Austin RC, Gillette TG, Fu G, Wang ZV, Hill JA. Endoplasmic Reticulum Chaperone GRP78 Protects Heart From Ischemia/Reperfusion Injury Through Akt Activation. Circ Res 2018; 122:1545-1554. [PMID: 29669712 DOI: 10.1161/circresaha.117.312641] [Citation(s) in RCA: 104] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/29/2017] [Revised: 03/30/2018] [Accepted: 04/17/2018] [Indexed: 12/14/2022]
Abstract
RATIONALE Restoration of coronary artery blood flow is the most effective means of ameliorating myocardial damage triggered by ischemic heart disease. However, coronary reperfusion elicits an increment of additional injury to the myocardium. Accumulating evidence indicates that the unfolded protein response (UPR) in cardiomyocytes is activated by ischemia/reperfusion (I/R) injury. Xbp1s (spliced X-box binding protein 1), the most highly conserved branch of the unfolded protein response, is protective in response to cardiac I/R injury. GRP78 (78 kDa glucose-regulated protein), a master regulator of the UPR and an Xbp1s target, is upregulated after I/R. However, its role in the protective response of Xbp1s during I/R remains largely undefined. OBJECTIVE To elucidate the role of GRP78 in the cardiomyocyte response to I/R using both in vitro and in vivo approaches. METHODS AND RESULTS Simulated I/R injury to cultured neonatal rat ventricular myocytes induced apoptotic cell death and strong activation of the UPR and GRP78. Overexpression of GRP78 in neonatal rat ventricular myocytes significantly protected myocytes from I/R-induced cell death. Furthermore, cardiomyocyte-specific overexpression of GRP78 ameliorated I/R damage to the heart in vivo. Exploration of underlying mechanisms revealed that GRP78 mitigates cellular damage by suppressing the accumulation of reactive oxygen species. We go on to show that the GRP78-mediated cytoprotective response involves plasma membrane translocation of GRP78 and interaction with PI3 kinase, culminating in stimulation of Akt. This response is required as inhibition of the Akt pathway significantly blunted the antioxidant activity and cardioprotective effects of GRP78. CONCLUSIONS I/R induction of GRP78 in cardiomyocytes stimulates Akt signaling and protects against oxidative stress, which together protect cells from I/R damage.
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Affiliation(s)
- Xukun Bi
- From the Department of Cardiology, Biomedical Research (Therapy) Center, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University, Hangzhou, China (X.B., X.L., G.F.).,Division of Cardiology, Department of Internal Medicine (X.B., G.Z., X.W., C.N., H.I.M., T.G.G., Z.V.W., J.A.H.)
| | - Guangyu Zhang
- Division of Cardiology, Department of Internal Medicine (X.B., G.Z., X.W., C.N., H.I.M., T.G.G., Z.V.W., J.A.H.).,University of Texas Southwestern Medical Center, Dallas; Department of Cardiology, Zhongnan Hospital of Wuhan University, Hubei, China (G.Z.)
| | - Xiaoding Wang
- Division of Cardiology, Department of Internal Medicine (X.B., G.Z., X.W., C.N., H.I.M., T.G.G., Z.V.W., J.A.H.).,Department of Cardiology, Renmin Hospital of Wuhan University, Hubei, China (X.W.)
| | - Chau Nguyen
- Division of Cardiology, Department of Internal Medicine (X.B., G.Z., X.W., C.N., H.I.M., T.G.G., Z.V.W., J.A.H.)
| | - Herman I May
- Division of Cardiology, Department of Internal Medicine (X.B., G.Z., X.W., C.N., H.I.M., T.G.G., Z.V.W., J.A.H.)
| | - Xiaoting Li
- From the Department of Cardiology, Biomedical Research (Therapy) Center, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University, Hangzhou, China (X.B., X.L., G.F.)
| | - Ali A Al-Hashimi
- Department of Medicine, Hamilton Center for Kidney Research, McMaster University and the Research Institute of St. Joseph's Healthcare Hamilton, ON, Canada (A.A.A.-H., R.C.A.)
| | - Richard C Austin
- Department of Medicine, Hamilton Center for Kidney Research, McMaster University and the Research Institute of St. Joseph's Healthcare Hamilton, ON, Canada (A.A.A.-H., R.C.A.)
| | - Thomas G Gillette
- Division of Cardiology, Department of Internal Medicine (X.B., G.Z., X.W., C.N., H.I.M., T.G.G., Z.V.W., J.A.H.)
| | - Guosheng Fu
- From the Department of Cardiology, Biomedical Research (Therapy) Center, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University, Hangzhou, China (X.B., X.L., G.F.)
| | - Zhao V Wang
- Division of Cardiology, Department of Internal Medicine (X.B., G.Z., X.W., C.N., H.I.M., T.G.G., Z.V.W., J.A.H.)
| | - Joseph A Hill
- Division of Cardiology, Department of Internal Medicine (X.B., G.Z., X.W., C.N., H.I.M., T.G.G., Z.V.W., J.A.H.).,Department of Molecular Biology (J.A.H.)
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6
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Lebeau P, Platko K, Al-Hashimi AA, Byun JH, Lhoták Š, Holzapfel N, Gyulay G, Igdoura SA, Cool DR, Trigatti B, Seidah NG, Austin RC. Loss-of-function PCSK9 mutants evade the unfolded protein response sensor GRP78 and fail to induce endoplasmic reticulum stress when retained. J Biol Chem 2018; 293:7329-7343. [PMID: 29593095 DOI: 10.1074/jbc.ra117.001049] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2017] [Revised: 03/15/2018] [Indexed: 01/07/2023] Open
Abstract
The proprotein convertase subtilisin/kexin type-9 (PCSK9) plays a central role in cardiovascular disease (CVD) by degrading hepatic low-density lipoprotein receptor (LDLR). As such, loss-of-function (LOF) PCSK9 variants that fail to exit the endoplasmic reticulum (ER) increase hepatic LDLR levels and lower the risk of developing CVD. The retention of misfolded protein in the ER can cause ER stress and activate the unfolded protein response (UPR). In this study, we investigated whether a variety of LOF PCSK9 variants that are retained in the ER can cause ER stress and hepatic cytotoxicity. Although overexpression of these PCSK9 variants caused an accumulation in the ER of hepatocytes, UPR activation or apoptosis was not observed. Furthermore, ER retention of endogenous PCSK9 via splice switching also failed to induce the UPR. Consistent with these in vitro studies, overexpression of PCSK9 in the livers of mice had no impact on UPR activation. To elucidate the cellular mechanism to explain these surprising findings, we observed that the 94-kDa glucose-regulated protein (GRP94) sequesters PCSK9 away from the 78-kDa glucose-regulated protein (GRP78), the major activator of the UPR. As a result, GRP94 knockdown increased the stability of GRP78-PCSK9 complex and resulted in UPR activation following overexpression of ER-retained PCSK9 variants relative to WT secreted controls. Given that overexpression of these LOF PCSK9 variants does not cause UPR activation under normal homeostatic conditions, therapeutic strategies aimed at blocking the autocatalytic cleavage of PCSK9 in the ER represent a viable strategy for reducing circulating PCSK9.
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Affiliation(s)
- Paul Lebeau
- Department of Medicine, Division of Nephrology, McMaster University, St. Joseph's Healthcare Hamilton and Hamilton Center for Kidney Research, Hamilton, Ontario L8N 4A6, Canada
| | - Khrystyna Platko
- Department of Medicine, Division of Nephrology, McMaster University, St. Joseph's Healthcare Hamilton and Hamilton Center for Kidney Research, Hamilton, Ontario L8N 4A6, Canada
| | - Ali A Al-Hashimi
- Department of Medicine, Division of Nephrology, McMaster University, St. Joseph's Healthcare Hamilton and Hamilton Center for Kidney Research, Hamilton, Ontario L8N 4A6, Canada
| | - Jae Hyun Byun
- Department of Medicine, Division of Nephrology, McMaster University, St. Joseph's Healthcare Hamilton and Hamilton Center for Kidney Research, Hamilton, Ontario L8N 4A6, Canada
| | - Šárka Lhoták
- Department of Medicine, Division of Nephrology, McMaster University, St. Joseph's Healthcare Hamilton and Hamilton Center for Kidney Research, Hamilton, Ontario L8N 4A6, Canada
| | - Nicholas Holzapfel
- Department of Medicine, Division of Nephrology, McMaster University, St. Joseph's Healthcare Hamilton and Hamilton Center for Kidney Research, Hamilton, Ontario L8N 4A6, Canada
| | - Gabriel Gyulay
- Department of Medicine, Division of Nephrology, McMaster University, St. Joseph's Healthcare Hamilton and Hamilton Center for Kidney Research, Hamilton, Ontario L8N 4A6, Canada
| | - Suleiman A Igdoura
- Departments of Biology and Pathology, McMaster University, Hamilton, Ontario L8S 4K1, Canada
| | - David R Cool
- Department of Pharmacology and Toxicology, Boonshoft School of Medicine, Wright State University, Dayton, Ohio, 45435-0001
| | - Bernardo Trigatti
- Thrombosis and Atherosclerosis Research Institute (TaARI), Hamilton Health Sciences and McMaster University, Hamilton, Ontario L8L 2X2, Canada; Departments of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, Ontario L8S 4L8, Canada
| | - Nabil G Seidah
- Laboratory of Biochemical Neuroendocrinology, Clinical Research Institute of Montreal, University of Montreal, Montreal, Quebec H2W 1R7, Canada
| | - Richard C Austin
- Department of Medicine, Division of Nephrology, McMaster University, St. Joseph's Healthcare Hamilton and Hamilton Center for Kidney Research, Hamilton, Ontario L8N 4A6, Canada; Thrombosis and Atherosclerosis Research Institute (TaARI), Hamilton Health Sciences and McMaster University, Hamilton, Ontario L8L 2X2, Canada.
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7
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Al-Hashimi AA, Lebeau P, Majeed F, Polena E, Lhotak Š, Collins CAF, Pinthus JH, Gonzalez-Gronow M, Hoogenes J, Pizzo SV, Crowther M, Kapoor A, Rak J, Gyulay G, D'Angelo S, Marchiò S, Pasqualini R, Arap W, Shayegan B, Austin RC. Autoantibodies against the cell surface-associated chaperone GRP78 stimulate tumor growth via tissue factor. J Biol Chem 2017; 292:21180-21192. [PMID: 29066620 PMCID: PMC5743090 DOI: 10.1074/jbc.m117.799908] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2017] [Revised: 09/05/2017] [Indexed: 12/24/2022] Open
Abstract
Tumor cells display on their surface several molecular chaperones that normally reside in the endoplasmic reticulum. Because this display is unique to cancer cells, these chaperones are attractive targets for drug development. Previous epitope-mapping of autoantibodies (AutoAbs) from prostate cancer patients identified the 78-kDa glucose-regulated protein (GRP78) as one such target. Although we previously showed that anti-GRP78 AutoAbs increase tissue factor (TF) procoagulant activity on the surface of tumor cells, the direct effect of TF activation on tumor growth was not examined. In this study, we explore the interplay between the AutoAbs against cell surface-associated GRP78, TF expression/activity, and prostate cancer progression. First, we show that tumor GRP78 expression correlates with disease stage and that anti-GRP78 AutoAb levels parallel prostate-specific antigen concentrations in patient-derived serum samples. Second, we demonstrate that these anti-GRP78 AutoAbs target cell-surface GRP78, activating the unfolded protein response and inducing tumor cell proliferation through a TF-dependent mechanism, a specific effect reversed by neutralization or immunodepletion of the AutoAb pool. Finally, these AutoAbs enhance tumor growth in mice bearing human prostate cancer xenografts, and heparin derivatives specifically abrogate this effect by blocking AutoAb binding to cell-surface GRP78 and decreasing TF expression/activity. Together, these results establish a molecular mechanism in which AutoAbs against cell-surface GRP78 drive TF-mediated tumor progression in an experimental model of prostate cancer. Heparin derivatives counteract this mechanism and, as such, represent potentially appealing compounds to be evaluated in well-designed translational clinical trials.
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Affiliation(s)
- Ali A Al-Hashimi
- From the Department of Medicine, McMaster University and St. Joseph's Healthcare Hamilton, Hamilton, Ontario L8N 4A6, Canada
- the Department of Surgery, McMaster University and St. Joseph's Healthcare Hamilton, Hamilton, Ontario L8N 4A6, Canada
| | - Paul Lebeau
- From the Department of Medicine, McMaster University and St. Joseph's Healthcare Hamilton, Hamilton, Ontario L8N 4A6, Canada
| | - Fadwa Majeed
- From the Department of Medicine, McMaster University and St. Joseph's Healthcare Hamilton, Hamilton, Ontario L8N 4A6, Canada
| | - Enio Polena
- From the Department of Medicine, McMaster University and St. Joseph's Healthcare Hamilton, Hamilton, Ontario L8N 4A6, Canada
| | - Šárka Lhotak
- From the Department of Medicine, McMaster University and St. Joseph's Healthcare Hamilton, Hamilton, Ontario L8N 4A6, Canada
| | - Celeste A F Collins
- From the Department of Medicine, McMaster University and St. Joseph's Healthcare Hamilton, Hamilton, Ontario L8N 4A6, Canada
| | - Jehonathan H Pinthus
- From the Department of Medicine, McMaster University and St. Joseph's Healthcare Hamilton, Hamilton, Ontario L8N 4A6, Canada
- the Department of Surgery, McMaster University and St. Joseph's Healthcare Hamilton, Hamilton, Ontario L8N 4A6, Canada
| | - Mario Gonzalez-Gronow
- the Department of Pathology, Duke University Medical Center, Durham, North Carolina 27710
| | - Jen Hoogenes
- From the Department of Medicine, McMaster University and St. Joseph's Healthcare Hamilton, Hamilton, Ontario L8N 4A6, Canada
- the Department of Surgery, McMaster University and St. Joseph's Healthcare Hamilton, Hamilton, Ontario L8N 4A6, Canada
| | - Salvatore V Pizzo
- the Department of Pathology, Duke University Medical Center, Durham, North Carolina 27710
| | - Mark Crowther
- From the Department of Medicine, McMaster University and St. Joseph's Healthcare Hamilton, Hamilton, Ontario L8N 4A6, Canada
| | - Anil Kapoor
- From the Department of Medicine, McMaster University and St. Joseph's Healthcare Hamilton, Hamilton, Ontario L8N 4A6, Canada
- the Department of Surgery, McMaster University and St. Joseph's Healthcare Hamilton, Hamilton, Ontario L8N 4A6, Canada
| | - Janusz Rak
- the Department of Pediatrics, Division of Experimental Medicine, Faculty of Medicine, McGill University, Montreal, Quebec H3A 0G4, Canada
| | - Gabriel Gyulay
- From the Department of Medicine, McMaster University and St. Joseph's Healthcare Hamilton, Hamilton, Ontario L8N 4A6, Canada
| | - Sara D'Angelo
- the University of New Mexico Comprehensive Cancer Center, Albuquerque, New Mexico 87106
- the Divisions of Molecular Medicine and
| | - Serena Marchiò
- the University of New Mexico Comprehensive Cancer Center, Albuquerque, New Mexico 87106
- the Divisions of Molecular Medicine and
- the Department of Oncology, University of Turin, 10124 Turin, Italy, and
- the Candiolo Cancer Institute-Fondazione del Piemonte per l'Oncologia (FPO)-Istituto di Ricerca e Cura a Carattere Scientifico (IRCCS), 10060 Candiolo, Italy
| | - Renata Pasqualini
- the University of New Mexico Comprehensive Cancer Center, Albuquerque, New Mexico 87106
- the Divisions of Molecular Medicine and
| | - Wadih Arap
- the University of New Mexico Comprehensive Cancer Center, Albuquerque, New Mexico 87106
- Hematology/Oncology, Department of Internal Medicine, University of New Mexico School of Medicine, Albuquerque, New Mexico 87131
| | - Bobby Shayegan
- From the Department of Medicine, McMaster University and St. Joseph's Healthcare Hamilton, Hamilton, Ontario L8N 4A6, Canada
- the Department of Surgery, McMaster University and St. Joseph's Healthcare Hamilton, Hamilton, Ontario L8N 4A6, Canada
| | - Richard C Austin
- From the Department of Medicine, McMaster University and St. Joseph's Healthcare Hamilton, Hamilton, Ontario L8N 4A6, Canada,
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Al-Hashimi AA, Caldwell J, Gonzalez-Gronow M, Pizzo SV, Aboumrad D, Pozza L, Al-Bayati H, Weitz JI, Stafford A, Chan H, Kapoor A, Jacobsen DW, Dickhout JG, Austin RC. Binding of anti-GRP78 autoantibodies to cell surface GRP78 increases tissue factor procoagulant activity via the release of calcium from endoplasmic reticulum stores. J Biol Chem 2016; 290:28725. [PMID: 26614782 DOI: 10.1074/jbc.a110.119107] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
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9
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Al-Hashimi AA, Caldwell J, Gonzalez-Gronow M, Pizzo SV, Aboumrad D, Pozza L, Al-Bayati H, Weitz JI, Stafford A, Chan H, Kapoor A, Jacobsen DW, Dickhout JG, Austin RC. Binding of anti-GRP78 autoantibodies to cell surface GRP78 increases tissue factor procoagulant activity via the release of calcium from endoplasmic reticulum stores. J Biol Chem 2010; 285:28912-23. [PMID: 20605795 DOI: 10.1074/jbc.m110.119107] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The increased risk of venous thromboembolism in cancer patients has been attributed to enhanced tissue factor (TF) procoagulant activity (PCA) on the surface of cancer cells. Recent studies have shown that TF PCA can be modulated by GRP78, an endoplasmic reticulum (ER)-resident molecular chaperone. In this study, we investigated the role of cell surface GRP78 in modulating TF PCA in several human cancer cell lines. Although both GRP78 and TF are present on the cell surface of cancer cells, there was no evidence of a stable interaction between recombinant human GRP78 and TF, nor was there any effect of exogenously added recombinant GRP78 on cell surface TF PCA. Treatment of cells with the ER stress-inducing agent thapsigargin, an inhibitor of the sarco(endo)plasmic reticulum Ca(2+) pump that causes Ca(2+) efflux from ER stores, increased cytosolic [Ca(2+)] and induced TF PCA. Consistent with these findings, anti-GRP78 autoantibodies that were isolated from the serum of patients with prostate cancer and bind to a specific N-terminal epitope (Leu(98)-Leu(115)) on cell surface GRP78, caused a dose-dependent increase in cytosolic [Ca(2+)] and enhanced TF PCA. The ability to interfere with cell surface GRP78 binding, block phospholipase C activity, sequester ER Ca(2+), or prevent plasma membrane phosphatidylserine exposure resulted in a significant decrease in the TF PCA induced by anti-GRP78 autoantibodies. Taken together, these findings provide evidence that engagement of the anti-GRP78 autoantibodies with cell surface GRP78 increases TF PCA through a mechanism that involves the release of Ca(2+) from ER stores. Furthermore, blocking GRP78 signaling on the surface of cancer cells attenuates TF PCA and has the potential to reduce the risk of cancer-related venous thromboembolism.
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Affiliation(s)
- Ali A Al-Hashimi
- Department of Medicine and Division of Nephrology, St Joseph's Hospital and McMaster University, Hamilton, Ontario L8N 4A6, Canada
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Caldwell JA, Dickhout JG, Al-Hashimi AA, Austin RC. Development of a continuous assay for the measurement of tissue factor procoagulant activity on intact cells. J Transl Med 2010; 90:953-62. [PMID: 20212456 DOI: 10.1038/labinvest.2010.59] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
Tissue factor (TF) is the major physiological initiator of the coagulation cascade and has an important function in the morbidity and mortality associated with many disease states, including cancer-associated thrombosis and atherosclerosis. TF normally exists in a partially encrypted state and its de-encryption on circulating monocytes, platelets or endothelial cells by inflammatory mediators can lead to thrombosis. Furthermore, many cancer cells express large amounts of TF and these cells communicate readily with the circulation through the fenestrated tumor endothelium. To assess agents or conditions that modulate the encryption state of TF, we developed a continuous assay for the determination of TF procoagulant activity (PCA) in a cell-based system. We have shown the use of this assay at detecting agents that de-encrypt TF thereby leading to an increase in TF PCA in three cancer cell lines, namely, T24/83 bladder carcinoma cells and PC-3 and DU145 prostate cancer cells. Further, through use of this assay, we have shown that the endoplasmic reticulum calcium pump inhibitor, thapsigargin, stimulates the de-encryption of TF. The continuous assay for the determination of TF PCA proved to have inherently less intra- and inter-assay variability than the widely used discontinuous assay and is considerably less labor intensive. Further, the continuous assay produced progress curves that were compatible with curve fitting to allow for the determination of the nature of reaction as well as rate constants for the underlying enzymes, TF/FVIIa and FXa. The continuous assay for the assessment of TF PCA on intact cells is applicable for high-throughput screening to allow for the determination of compounds that modulate TF PCA.
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Affiliation(s)
- Jennifer A Caldwell
- Division of Nephrology, Department of Medicine, St Joseph's Healthcare Hamilton and Hamilton Centre for Kidney Research, McMaster University, Hamilton, ON, Canada
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