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Hou Y, Wang Z, Liu P, Wei X, Zhang Z, Fan S, Zhang L, Han F, Song Y, Chu L, Zhang C. SMPDL3A is a cGAMP-degrading enzyme induced by LXR-mediated lipid metabolism to restrict cGAS-STING DNA sensing. Immunity 2023; 56:2492-2507.e10. [PMID: 37890481 DOI: 10.1016/j.immuni.2023.10.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2023] [Revised: 07/19/2023] [Accepted: 10/03/2023] [Indexed: 10/29/2023]
Abstract
Lipid metabolism has been associated with the cyclic guanosine monophosphate (GMP)-AMP synthase (cGAS) stimulator of interferon genes (STING) DNA-sensing pathway, but our understanding of how these signals are integrated into a cohesive immunometabolic program is lacking. Here, we have identified liver X receptor (LXR) agonists as potent inhibitors of STING signaling. We show that stimulation of lipid metabolism by LXR agonists specifically suppressed cyclic GMP-AMP (cGAMP)-STING signaling. Moreover, we developed cyclic dinucleotide-conjugated beads to biochemically isolate host effectors for cGAMP inhibition, and we found that LXR ligands stimulated the expression of sphingomyelin phosphodiesterase acid-like 3A (SMPDL3A), which is a 2'3'-cGAMP-degrading enzyme. Results of crystal structures suggest that cGAMP analog induces dimerization of SMPDL3A, and the dimerization is critical for cGAMP degradation. Additionally, we have provided evidence that SMPDL3A cleaves cGAMP to restrict STING signaling in cell culture and mouse models. Our results reveal SMPDL3A as a cGAMP-specific nuclease and demonstrate a mechanism for how LXR-associated lipid metabolism modulates STING-mediated innate immunity.
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Affiliation(s)
- Yanfei Hou
- State Key Laboratory of Membrane Biology, School of Pharmaceutical Sciences, Tsinghua University, Beijing 100084, China
| | - Zhimeng Wang
- State Key Laboratory of Membrane Biology, School of Pharmaceutical Sciences, Tsinghua University, Beijing 100084, China; Tsinghua-Peking Center for Life Sciences, Beijing 100084, China
| | - Peiyuan Liu
- School of Life Sciences, Tianjin University, Tianjin 300072, China
| | - Xubiao Wei
- State Key Laboratory of Membrane Biology, School of Pharmaceutical Sciences, Tsinghua University, Beijing 100084, China; Tsinghua-Peking Center for Life Sciences, Beijing 100084, China; State Key Laboratory of Animal Nutrition, College of Animal Science and Technology, China Agricultural University, Beijing 100193, China
| | - Zhengyin Zhang
- State Key Laboratory of Membrane Biology, School of Pharmaceutical Sciences, Tsinghua University, Beijing 100084, China
| | - Shilong Fan
- Center for Structural Biology, Tsinghua University, Beijing 100084, China
| | - Lulu Zhang
- State Key Laboratory of Membrane Biology, School of Pharmaceutical Sciences, Tsinghua University, Beijing 100084, China; Tsinghua-Peking Center for Life Sciences, Beijing 100084, China
| | - Fangping Han
- State Key Laboratory of Membrane Biology, School of Pharmaceutical Sciences, Tsinghua University, Beijing 100084, China
| | - Yikang Song
- State Key Laboratory of Membrane Biology, School of Pharmaceutical Sciences, Tsinghua University, Beijing 100084, China
| | - Ling Chu
- State Key Laboratory of Membrane Biology, School of Pharmaceutical Sciences, Tsinghua University, Beijing 100084, China
| | - Conggang Zhang
- State Key Laboratory of Membrane Biology, School of Pharmaceutical Sciences, Tsinghua University, Beijing 100084, China; Tsinghua-Peking Center for Life Sciences, Beijing 100084, China.
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Zhang Y, Chen W, Cheng X, Wang F, Gao C, Song F, Song F, Liang X, Fang W, Chen Z. Sphingomyelin Phodiesterase Acid-Like 3A Promotes Hepatocellular Carcinoma Growth Through the Enhancer of Rudimentary Homolog. Front Oncol 2022; 12:852765. [PMID: 35686107 PMCID: PMC9171240 DOI: 10.3389/fonc.2022.852765] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2022] [Accepted: 04/25/2022] [Indexed: 12/24/2022] Open
Abstract
Background Hepatocellular carcinoma (HCC) is one of the most common malignant tumors worldwide, with unclear pathogenesis. Sphingomyelin phodiesterase acid-like 3A (SMPDL3A) affects cell differentiation and participates in immune regulation. However, its molecular biological function in HCC has not yet been elucidated. Methods Data from 180 HCC patients were analyzed the relationship between the expression of SMPDL3A in liver cancer tissues and the prognosis of liver cancer patients. Crispr-Cas9 dual vector lentivirus was used to knock out SMPDL3A in HCC cell lines. The effects of SMPDL3A on cell viability were determined by CCK8 assay, clone formation experiment, cell cycle assay, cell scratch, TUNEL experiment and flow cytometry. Xenograft tumor assays in BALB/c nude mice confirmed that SMPDL3A promoted tumor growth and in vivo. Preliminary exploration of SMPDL3A interacting protein by mass spectrometry analysis and co-immunoprecipitation. Results This study showed that the expression of SMPDL3A in HCC tissue differed from that in tumor-adjacent tissues. Moreover, the overall survival rate and tumor-free survival rate of patients with high-SMPDL3A expression were significantly lower than those with low-SMPDL3A expression. SMPDL3A expression was closely related to the level of protein induced by PIVKA-II, liver cirrhosis, tumor diameter, microvascular invasion, and Barcelona clinic liver cancer staging. Thus, SMPDL3A is an independent risk factor that affects the tumor-free survival rate and overall survival rate of HCC patients. In vitro study using Crispr-Cas9 genome editing technology revealed the knockout effect of SMPDL3A on cell proliferation, apoptosis, and migration. Cell counting kit-8 assay and clone formation experiment showed that sgSMPDL3A inhibited tumor cell proliferation and migration. Flow cytometry and TUNEL assay showed that sgSMPDL3A promoted apoptosis in tumors. Moreover, sgSMPDL3A inhibited tumor growth during subcutaneous tumor formation in nude mice. Immunohistochemistry of Ki67 and PNCA also indicated that sgSMPDL3A inhibited subcutaneous tumor proliferation in tumor-bearing nude mice. Further experiments showed that SMPDL3A interacts with the enhancer of rudimentary homolog (ERH). Conclusions High-SMPDL3A expression was related to poor prognosis of patients with HCC. Knockout of SMPDL3A inhibited the proliferation and migration and accelerated the migration of HCC cells. SMPDL3A interacted with ERH to affect the tumorigenesis and progression of HCC.
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Affiliation(s)
- Yu Zhang
- Department of Hepatobiliary Surgery, Affiliated Hospital of Nantong University, Nantong, China.,School of Medicine, Nantong University, Nantong, China
| | - Weipeng Chen
- School of Medicine, Nantong University, Nantong, China.,Department of General Surgery, Binhai County People's Hospital, Yancheng, China
| | - Xin Cheng
- School of Medicine, Nantong University, Nantong, China.,Department of General Surgery, Jingjiang People's Hospital, Taizhou, China
| | - Feiran Wang
- Department of Hepatobiliary Surgery, Affiliated Hospital of Nantong University, Nantong, China.,School of Medicine, Nantong University, Nantong, China
| | - Cheng Gao
- Department of Hepatobiliary Surgery, Affiliated Hospital of Nantong University, Nantong, China.,School of Medicine, Nantong University, Nantong, China
| | - Fei Song
- Department of Hepatobiliary Surgery, Affiliated Hospital of Nantong University, Nantong, China
| | - Fengliang Song
- Department of Hepatobiliary Surgery, Affiliated Hospital of Nantong University, Nantong, China
| | - Xiaoliang Liang
- Department of Hepatobiliary Surgery, Affiliated Hospital of Nantong University, Nantong, China
| | - Wanzhi Fang
- Department of Hepatobiliary Surgery, Affiliated Hospital of Nantong University, Nantong, China
| | - Zhong Chen
- Department of Hepatobiliary Surgery, Affiliated Hospital of Nantong University, Nantong, China
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Zhang P, Li Q, Wu Y, Zhang Y, Zhang B, Zhang H. Identification of candidate genes that specifically regulate subcutaneous and intramuscular fat deposition using transcriptomic and proteomic profiles in Dingyuan pigs. Sci Rep 2022; 12:2844. [PMID: 35181733 PMCID: PMC8857214 DOI: 10.1038/s41598-022-06868-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2021] [Accepted: 02/08/2022] [Indexed: 12/13/2022] Open
Abstract
Subcutaneous fat and intramuscular fat (IMF) deposition are closely related to meat production and pork quality. Dingyuan pig, as a native pig breed in China, low selection leads to obvious genetic and phenotypic differences in the population. Individuals with extreme fat content in the population are ideal models for studying the mechanism of fat deposition. In this study, we used RNA-Seq and tandem mass tags-based (TMT) proteomics to analyze the key pathways and genes that specifically regulate subcutaneous fat and IMF deposition in Dingyuan pigs. We identified 191 differentially expressed genes (DEGs) and 61 differentially abundant proteins (DAPs) in the high and low back fat thickness (HBF, LBF) groups, 85 DEGs and 12 DAPs were obtained in the high and low intramuscular fat (HIMF, LIMF) groups. The functional analysis showed that the DEGs and DAPs in the backfat groups were mainly involved in carbohydrates, amino acids, and fatty acids metabolism, whereas the IMF groups were involved in the insulin pathway, longevity, and some disease-related pathways. We found 40 candidate genes that might tissue-specifically lipids deposition for subcutaneous and intramuscular fat. Our research provides theoretical reference materials for the improvement of fat deposition traits of local pig breeds in my country.
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Affiliation(s)
- Pan Zhang
- National Engineering Laboratory for Animal Breeding, China Agricultural University, Beijing, 100193, China
| | - Qinggang Li
- Institute of Animal Sciences and Veterinary Medicine, Anhui Academy of Agricultural Sciences, Hefei, 230031, Anhui, China
| | - Yijing Wu
- Institute of Animal Sciences and Veterinary Medicine, Anhui Academy of Agricultural Sciences, Hefei, 230031, Anhui, China
| | - Yawen Zhang
- National Engineering Laboratory for Animal Breeding, China Agricultural University, Beijing, 100193, China
| | - Bo Zhang
- National Engineering Laboratory for Animal Breeding, China Agricultural University, Beijing, 100193, China.
| | - Hao Zhang
- National Engineering Laboratory for Animal Breeding, China Agricultural University, Beijing, 100193, China
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LXR directly regulates glycosphingolipid synthesis and affects human CD4+ T cell function. Proc Natl Acad Sci U S A 2021; 118:2017394118. [PMID: 34006637 DOI: 10.1073/pnas.2017394118] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The liver X receptor (LXR) is a key transcriptional regulator of cholesterol, fatty acid, and phospholipid metabolism. Dynamic remodeling of immunometabolic pathways, including lipid metabolism, is a crucial step in T cell activation. Here, we explored the role of LXR-regulated metabolic processes in primary human CD4+ T cells and their role in controlling plasma membrane lipids (glycosphingolipids and cholesterol), which strongly influence T cell immune signaling and function. Crucially, we identified the glycosphingolipid biosynthesis enzyme glucosylceramide synthase as a direct transcriptional LXR target. LXR activation by agonist GW3965 or endogenous oxysterol ligands significantly altered the glycosphingolipid:cholesterol balance in the plasma membrane by increasing glycosphingolipid levels and reducing cholesterol. Consequently, LXR activation lowered plasma membrane lipid order (stability), and an LXR antagonist could block this effect. LXR stimulation also reduced lipid order at the immune synapse and accelerated activation of proximal T cell signaling molecules. Ultimately, LXR activation dampened proinflammatory T cell function. Finally, compared with responder T cells, regulatory T cells had a distinct pattern of LXR target gene expression corresponding to reduced lipid order. This suggests LXR-driven lipid metabolism could contribute to functional specialization of these T cell subsets. Overall, we report a mode of action for LXR in T cells involving the regulation of glycosphingolipid and cholesterol metabolism and demonstrate its relevance in modulating T cell function.
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Tsui PF, Chern CY, Lien CF, Lin FY, Tsai CS, Tsai MC, Lin CS. An octimibate derivative, Oxa17, enhances cholesterol efflux and exerts anti-inflammatory and atheroprotective effects in experimental atherosclerosis. Biochem Pharmacol 2021; 188:114581. [PMID: 33895158 DOI: 10.1016/j.bcp.2021.114581] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2021] [Revised: 04/19/2021] [Accepted: 04/21/2021] [Indexed: 12/22/2022]
Abstract
Atherosclerotic cardiovascular diseases (ASCVDs), associated with vascular inflammation and lipid dysregulation, are responsible for high morbidity and mortality rates globally. For ASCVD treatment, cholesterol efflux plays an atheroprotective role in ameliorating inflammation and lipid dysregulation. To develop a multidisciplinary agent for promoting cholesterol efflux, octimibate derivatives were screened and investigated for the expression of ATP-binding cassette transporter A1 (ABCA1). Western blotting and qPCR analysis were conducted to determine the molecular mechanism associated with ABCA1 expression in THP-1 macrophages; results revealed that Oxa17, an octimibate derivative, enhanced ABCA1 expression through liver X receptors alpha (LXRα) activation but not through the microRNA pathway. We also investigated the role of Oxa17 in high-fat diet (HFD)-fed mice used as an in vivo atherosclerosis-prone model. In ldlr-/- mice, Oxa17 increased plasma high-density lipoprotein (HDL) and reduced plaque formation in the aorta. Plaque stability improved via reduction of macrophage accumulation and via narrowing of the necrotic core size under Oxa17 treatment. Our study demonstrates that Oxa17 is a novel and potential agent for ASCVD treatment with atheroprotective and anti-inflammatory properties.
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Affiliation(s)
- Pi-Fen Tsui
- Graduate Institute of Life Sciences, National Defense Medical Center, Taipei 11490, Taiwan; Division of Cardiology, Department of Medicine, Tri-Service General Hospital, National Defense Medical Center, Taipei 11490, Taiwan
| | - Ching-Yuh Chern
- Department of Applied Chemistry, National Chiayi University, Chiayi City 60004, Taiwan
| | - Chih-Feng Lien
- Division of Cardiology, Department of Medicine, Tri-Service General Hospital, National Defense Medical Center, Taipei 11490, Taiwan
| | - Feng-Yen Lin
- Taipei Heart Research Institute and Departments of Internal Medicine, Taipei Medical University, Taipei 11031, Taiwan; Division of Cardiology and Cardiovascular Research Center, Department of Internal Medicine, Taipei Medical University Hospital, Taipei 11031, Taiwan
| | - Chien-Sung Tsai
- Division of Cardiovascular Surgery, Tri-Service General Hospital, National Defense Medical Center, Taipei 11490, Taiwan; Department and Graduate Institute of Pharmacology, National Defense Medical Center, Taipei 11490, Taiwan; Institute of Pharmacy, I.M. Sechenov First Moscow State Medical University, Moscow 119991, Russia
| | - Min-Chien Tsai
- Department of Physiology and Biophysics, Graduate Institute of Physiology, National Defense Medical Center, Taipei 11490, Taiwan
| | - Chin-Sheng Lin
- Graduate Institute of Life Sciences, National Defense Medical Center, Taipei 11490, Taiwan; Division of Cardiology, Department of Medicine, Tri-Service General Hospital, National Defense Medical Center, Taipei 11490, Taiwan.
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Bryja A, Latosiński G, Jankowski M, Angelova Volponi A, Mozdziak P, Shibli JA, Bryl R, Spaczyńska J, Piotrowska-Kempisty H, Krawiec K, Kempisty B, Dyszkiewicz-Konwińska M. Transcriptomic and Morphological Analysis of Cells Derived from Porcine Buccal Mucosa-Studies on an In Vitro Model. Animals (Basel) 2020; 11:ani11010015. [PMID: 33374146 PMCID: PMC7824432 DOI: 10.3390/ani11010015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2020] [Revised: 12/16/2020] [Accepted: 12/18/2020] [Indexed: 11/16/2022] Open
Abstract
Simple Summary Domestic pigs express high phylogenetic similarity to humans and are often used as a compatible model in biomedical research. Porcine tissues are used as an accessible biomaterial in human skin transplants and tissue architecture reconstruction. We used transcriptional analysis to investigate the dynamics of complex biological system of the mucosa. Additionally, we performed computer analysis of microscopic images of cultured cells in vitro. Computer analysis of images identified epithelial cells and connective tissue cells in in vitro culture. Abstract Transcriptional analysis and live-cell imaging are a powerful tool to investigate the dynamics of complex biological systems. In vitro expanded porcine oral mucosal cells, consisting of populations of epithelial and connective lineages, are interesting and complex systems for study via microarray transcriptomic assays to analyze gene expression profile. The transcriptomic analysis included 56 ontological groups with particular focus on 7 gene ontology groups that are related to the processes of differentiation and development. Most analyzed genes were upregulated after 7 days and downregulated after 15 and 30 days of in vitro culture. The performed transcriptomic analysis was then extended to include automated analysis of differential interference contrast microscopy (DIC) images obtained during in vitro culture. The analysis of DIC imaging allowed to identify the different populations of keratinocytes and fibroblasts during seven days of in vitro culture, and it was possible to evaluate the proportion of these two populations of cells. Porcine mucosa may be a suitable model for reference research on human tissues. In addition, it can provide a reference point for research on the use of cells, scaffolds, or tissues derived from transgenic animals for applications in human tissues reconstruction.
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Affiliation(s)
- Artur Bryja
- Department of Anatomy, Poznan University of Medical Sciences, 60-781 Poznań, Poland; (A.B.); (M.J.); (R.B.); (M.D.-K.)
| | - Grzegorz Latosiński
- Institute of Computing Science, Poznan University of Technology, 60-965 Poznań, Poland; (G.L.); (K.K.)
| | - Maurycy Jankowski
- Department of Anatomy, Poznan University of Medical Sciences, 60-781 Poznań, Poland; (A.B.); (M.J.); (R.B.); (M.D.-K.)
| | - Ana Angelova Volponi
- Department of Craniofacial Development and Stem Cell Biology, King’s College University of London, London WC2R 2LS, UK;
| | - Paul Mozdziak
- Graduate Physiology Program, North Carolina State University, Raleigh, NC 27695, USA;
| | - Jamil A. Shibli
- Department of Periodontology and Oral Implantology, Dental Research Division, University of Guarulhos, Guarulhos 07030-010, SP, Brazil;
| | - Rut Bryl
- Department of Anatomy, Poznan University of Medical Sciences, 60-781 Poznań, Poland; (A.B.); (M.J.); (R.B.); (M.D.-K.)
| | - Julia Spaczyńska
- Department of Toxicology, Poznan University of Medical Sciences, 61-631 Poznań, Poland; (J.S.); (H.P.-K.)
| | - Hanna Piotrowska-Kempisty
- Department of Toxicology, Poznan University of Medical Sciences, 61-631 Poznań, Poland; (J.S.); (H.P.-K.)
| | - Krzysztof Krawiec
- Institute of Computing Science, Poznan University of Technology, 60-965 Poznań, Poland; (G.L.); (K.K.)
| | - Bartosz Kempisty
- Department of Anatomy, Poznan University of Medical Sciences, 60-781 Poznań, Poland; (A.B.); (M.J.); (R.B.); (M.D.-K.)
- Department of Histology and Embryology, Poznan University of Medical Sciences, 60-781 Poznań, Poland
- Department of Veterinary Surgery, Nicolaus Copernicus University in Torun, 87-100 Toruń, Poland
- Correspondence: ; Tel.: +48-61-8546418
| | - Marta Dyszkiewicz-Konwińska
- Department of Anatomy, Poznan University of Medical Sciences, 60-781 Poznań, Poland; (A.B.); (M.J.); (R.B.); (M.D.-K.)
- Department of Biomaterials and Experimental Dentistry, Poznan University of Medical Sciences, 61-701 Poznań, Poland
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Yao X, Tan J, Lim KJ, Koh J, Ooi WF, Li Z, Huang D, Xing M, Chan YS, Qu JZ, Tay ST, Wijaya G, Lam YN, Hong JH, Lee-Lim AP, Guan P, Ng MSW, He CZ, Lin JS, Nandi T, Qamra A, Xu C, Myint SS, Davies JOJ, Goh JY, Loh G, Tan BC, Rozen SG, Yu Q, Tan IBH, Cheng CWS, Li S, Chang KTE, Tan PH, Silver DL, Lezhava A, Steger G, Hughes JR, Teh BT, Tan P. VHL Deficiency Drives Enhancer Activation of Oncogenes in Clear Cell Renal Cell Carcinoma. Cancer Discov 2017; 7:1284-1305. [DOI: 10.1158/2159-8290.cd-17-0375] [Citation(s) in RCA: 83] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2017] [Revised: 07/19/2017] [Accepted: 08/25/2017] [Indexed: 11/16/2022]
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8
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Ligand-dependent and -independent regulation of human hepatic sphingomyelin phosphodiesterase acid-like 3A expression by pregnane X receptor and crosstalk with liver X receptor. Biochem Pharmacol 2017; 136:122-135. [DOI: 10.1016/j.bcp.2017.04.013] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2017] [Accepted: 04/12/2017] [Indexed: 11/18/2022]
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N-glycosylation of human sphingomyelin phosphodiesterase acid-like 3A (SMPDL3A) is essential for stability, secretion and activity. Biochem J 2017; 474:1071-1092. [PMID: 28104755 DOI: 10.1042/bcj20160735] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2016] [Revised: 01/14/2017] [Accepted: 01/18/2017] [Indexed: 11/17/2022]
Abstract
Sphingomyelin phosphodiesterase acid-like 3A (SMPDL3A) is a recently identified phosphodiesterase, which is a secreted N-linked glycoprotein. SMPDL3A is highly homologous to acid sphingomyelinase (aSMase), but unlike aSMase cannot cleave sphingomyelin. Rather, SMPDL3A hydrolyzes nucleotide tri- and diphosphates and their derivatives. While recent structural studies have shed light on these unexpected substrate preferences, many other aspects of SMPDL3A biology, which may give insight into its function in vivo, remain obscure. Here, we investigate the roles of N-glycosylation in the expression, secretion and activity of human SMPDL3A, using inhibitors of N-glycosylation and site-directed mutagenesis, with either THP-1 macrophages or CHO cells expressing human SMPDL3A. Tunicamycin (TM) treatment resulted in expression of non-glycosylated SMPDL3A that was not secreted, and was largely degraded by the proteasome. Proteasomal inhibition restored levels of SMPDL3A in TM-treated cells, although this non-glycosylated protein lacked phosphodiesterase activity. Enzymatic deglycosylation of purified recombinant SMPDL3A also resulted in significant loss of phosphodiesterase activity. Site-directed mutagenesis of individual N-glycosylation sites in SMPDL3A identified glycosylation of Asn69 and Asn222 as affecting maturation of its N-glycans and secretion. Glycosylation of Asn356 in SMPDL3A, an N-linked site conserved throughout the aSMase-like family, was critical for protection against proteasomal degradation and preservation of enzymatic activity. We provide the first experimental evidence for a predicted 22 residue N-terminal signal peptide in SMPDL3A, which is essential for facilitating glycosylation and is removed from the mature protein secreted from CHO cells. In conclusion, site-specific N-glycosylation is essential for the intracellular stability, secretion and activity of human SMPDL3A.
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Nelson JK, Koenis DS, Scheij S, Cook ECL, Moeton M, Santos A, Lobaccaro JMA, Baron S, Zelcer N. EEPD1 Is a Novel LXR Target Gene in Macrophages Which Regulates ABCA1 Abundance and Cholesterol Efflux. Arterioscler Thromb Vasc Biol 2017; 37:423-432. [PMID: 28082258 PMCID: PMC5321112 DOI: 10.1161/atvbaha.116.308434] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2016] [Accepted: 01/02/2017] [Indexed: 11/16/2022]
Abstract
Supplemental Digital Content is available in the text. Objective— The sterol-responsive nuclear receptors, liver X receptors α (LXRα, NR1H3) and β (LXRβ, NR1H2), are key determinants of cellular cholesterol homeostasis. LXRs are activated under conditions of high cellular sterol load and induce expression of the cholesterol efflux transporters ABCA1 and ABCG1 to promote efflux of excess cellular cholesterol. However, the full set of genes that contribute to LXR-stimulated cholesterol efflux is unknown, and their identification is the objective of this study. Approach and Results— We systematically compared the global transcriptional response of macrophages to distinct classes of LXR ligands. This allowed us to identify both common and ligand-specific transcriptional responses in macrophages. Among these, we identified endonuclease–exonuclease–phosphatase family domain containing 1 (EEPD1/KIAA1706) as a direct transcriptional target of LXRs in human and murine macrophages. EEPD1 specifically localizes to the plasma membrane owing to the presence of a myristoylation site in its N terminus. Accordingly, the first 10 amino acids of EEPD1 are sufficient to confer plasma membrane localization in the context of a chimeric protein with GFP. Functionally, we report that silencing expression of EEPD1 blunts maximal LXR-stimulated Apo AI-dependent efflux and demonstrate that this is the result of reduced abundance of ABCA1 protein in human and murine macrophages. Conclusions— In this study, we identify EEPD1 as a novel LXR-regulated gene in macrophages and propose that it promotes cellular cholesterol efflux by controlling cellular levels and activity of ABCA1.
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Affiliation(s)
- Jessica Kristine Nelson
- From the Department of Medical Biochemistry, Academic Medical Center, University of Amsterdam, The Netherlands (J.K.N., D.S.K., S.S., E.C.L.C., M.M., A.S., N.Z.); and Université Clermont Auvergne, CNRS, Inserm, GReD, Clermont-Ferrand, France (J.-M.A.L., S.B.)
| | - Duco Steven Koenis
- From the Department of Medical Biochemistry, Academic Medical Center, University of Amsterdam, The Netherlands (J.K.N., D.S.K., S.S., E.C.L.C., M.M., A.S., N.Z.); and Université Clermont Auvergne, CNRS, Inserm, GReD, Clermont-Ferrand, France (J.-M.A.L., S.B.)
| | - Saskia Scheij
- From the Department of Medical Biochemistry, Academic Medical Center, University of Amsterdam, The Netherlands (J.K.N., D.S.K., S.S., E.C.L.C., M.M., A.S., N.Z.); and Université Clermont Auvergne, CNRS, Inserm, GReD, Clermont-Ferrand, France (J.-M.A.L., S.B.)
| | - Emma Clare Laura Cook
- From the Department of Medical Biochemistry, Academic Medical Center, University of Amsterdam, The Netherlands (J.K.N., D.S.K., S.S., E.C.L.C., M.M., A.S., N.Z.); and Université Clermont Auvergne, CNRS, Inserm, GReD, Clermont-Ferrand, France (J.-M.A.L., S.B.)
| | - Martina Moeton
- From the Department of Medical Biochemistry, Academic Medical Center, University of Amsterdam, The Netherlands (J.K.N., D.S.K., S.S., E.C.L.C., M.M., A.S., N.Z.); and Université Clermont Auvergne, CNRS, Inserm, GReD, Clermont-Ferrand, France (J.-M.A.L., S.B.)
| | - Ana Santos
- From the Department of Medical Biochemistry, Academic Medical Center, University of Amsterdam, The Netherlands (J.K.N., D.S.K., S.S., E.C.L.C., M.M., A.S., N.Z.); and Université Clermont Auvergne, CNRS, Inserm, GReD, Clermont-Ferrand, France (J.-M.A.L., S.B.)
| | - Jean-Marc Adolphe Lobaccaro
- From the Department of Medical Biochemistry, Academic Medical Center, University of Amsterdam, The Netherlands (J.K.N., D.S.K., S.S., E.C.L.C., M.M., A.S., N.Z.); and Université Clermont Auvergne, CNRS, Inserm, GReD, Clermont-Ferrand, France (J.-M.A.L., S.B.)
| | - Silvere Baron
- From the Department of Medical Biochemistry, Academic Medical Center, University of Amsterdam, The Netherlands (J.K.N., D.S.K., S.S., E.C.L.C., M.M., A.S., N.Z.); and Université Clermont Auvergne, CNRS, Inserm, GReD, Clermont-Ferrand, France (J.-M.A.L., S.B.)
| | - Noam Zelcer
- From the Department of Medical Biochemistry, Academic Medical Center, University of Amsterdam, The Netherlands (J.K.N., D.S.K., S.S., E.C.L.C., M.M., A.S., N.Z.); and Université Clermont Auvergne, CNRS, Inserm, GReD, Clermont-Ferrand, France (J.-M.A.L., S.B.).
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Gorelik A, Heinz LX, Illes K, Superti-Furga G, Nagar B. Crystal Structure of the Acid Sphingomyelinase-like Phosphodiesterase SMPDL3B Provides Insights into Determinants of Substrate Specificity. J Biol Chem 2016; 291:24054-24064. [PMID: 27687724 DOI: 10.1074/jbc.m116.755801] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2016] [Revised: 09/18/2016] [Indexed: 01/24/2023] Open
Abstract
The enzyme acid sphingomyelinase-like phosphodiesterase 3B (SMPDL3B) was shown to act as a negative regulator of innate immune signaling, affecting cellular lipid composition and membrane fluidity. Furthermore, several reports identified this enzyme as an off target of the therapeutic antibody rituximab, with implications in kidney disorders. However, structural information for this protein is lacking. Here we present the high resolution crystal structure of murine SMPDL3B, which reveals a substrate binding site strikingly different from its paralogs. The active site is located in a narrow boot-shaped cavity. We identify a unique loop near the active site that appears to impose size constraints on incoming substrates. A structure in complex with phosphocholine indicates that the protein recognizes this head group via an aromatic box, a typical choline-binding motif. Although a potential substrate for SMPDL3B is sphingomyelin, we identify other possible substrates such as CDP-choline, ATP, and ADP. Functional experiments employing structure-guided mutagenesis in macrophages highlight amino acid residues potentially involved in recognition of endogenous substrates. Our study is an important step toward elucidating the specific function of this poorly characterized enzyme.
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Affiliation(s)
- Alexei Gorelik
- From the Department of Biochemistry and Groupe de Recherche Axé sur la Structure des Protéines, McGill University, Montreal, Quebec H3G 0B1, Canada
| | - Leonhard X Heinz
- the CeMM Research Center for Molecular Medicine, Austrian Academy of Sciences, 1090 Vienna, Austria, and
| | - Katalin Illes
- From the Department of Biochemistry and Groupe de Recherche Axé sur la Structure des Protéines, McGill University, Montreal, Quebec H3G 0B1, Canada
| | - Giulio Superti-Furga
- the CeMM Research Center for Molecular Medicine, Austrian Academy of Sciences, 1090 Vienna, Austria, and.,the Center for Physiology and Pharmacology, Medical University of Vienna, 1090 Vienna, Austria
| | - Bhushan Nagar
- From the Department of Biochemistry and Groupe de Recherche Axé sur la Structure des Protéines, McGill University, Montreal, Quebec H3G 0B1, Canada,
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12
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Lim SM, Yeung K, Trésaugues L, Ling TH, Nordlund P. The structure and catalytic mechanism of human sphingomyelin phosphodiesterase like 3a--an acid sphingomyelinase homologue with a novel nucleotide hydrolase activity. FEBS J 2016; 283:1107-23. [PMID: 26783088 DOI: 10.1111/febs.13655] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2015] [Revised: 12/29/2015] [Accepted: 01/12/2016] [Indexed: 10/22/2022]
Abstract
UNLABELLED Human sphingomyelinase phosphodiesterase like 3a (SMPDL3a) is a secreted enzyme that shares a conserved catalytic domain with human acid sphingomyelinase (aSMase), the enzyme carrying mutations causative of Niemann-Pick disease. We have solved the structure of SMPDL3a revealing a calcineurin-like fold. A dimetal site, glycosylation pattern and a disulfide bond network are likely to be conserved also in human aSMase. We show that the binuclear site of SMPDL3a is occupied by two Zn(2+) ions and that excess Zn(2+) leads to inhibition of enzyme activity through binding to additional sites. As an extension of recent biochemical work we uncovered that SMPDL3a catalyses the hydrolysis of several modified nucleotides that include cytidine 5'-diphosphocholine, cytidine diphosphate ethanolamine and ADP-ribose, but not the aSMase substrate, sphingomyelin. We subsequently determined the structure of SMPDL3a in complex with the product 5'-cytidine monophosphate (CMP), a structure that is consistent with several distinct coordination modes of the substrate/product in the active site during the reaction cycle. Based on the structure of CMP complexes, we propose a phosphoryl transfer mechanism for SMPDL3a. Finally, a homology model of human aSMase was constructed to allow for the mapping of selected Niemann-Pick disease mutations on a three-dimensional framework to guide further characterization of their effects on aSMase function. DATABASE Structural data are available in the PDB database under the accession numbers 5EBB and 5EBE.
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Affiliation(s)
- Sing Mei Lim
- Division of Biomedical Structural Biology, School of Biological Sciences, Nanyang Technological University, Singapore.,Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden
| | - Kit Yeung
- Division of Biomedical Structural Biology, School of Biological Sciences, Nanyang Technological University, Singapore
| | - Lionel Trésaugues
- Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden
| | - Teo Hsiang Ling
- Division of Biomedical Structural Biology, School of Biological Sciences, Nanyang Technological University, Singapore
| | - Pär Nordlund
- Division of Biomedical Structural Biology, School of Biological Sciences, Nanyang Technological University, Singapore.,Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden.,Institute of Molecular and Cell Biology, A*STAR, Singapore city, Singapore
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13
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Gorelik A, Illes K, Superti-Furga G, Nagar B. Structural Basis for Nucleotide Hydrolysis by the Acid Sphingomyelinase-like Phosphodiesterase SMPDL3A. J Biol Chem 2016; 291:6376-85. [PMID: 26792860 DOI: 10.1074/jbc.m115.711085] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2015] [Indexed: 11/06/2022] Open
Abstract
Sphingomyelin phosphodiesterase, acid-like 3A (SMPDL3A) is a member of a small family of proteins founded by the well characterized lysosomal enzyme, acid sphingomyelinase (ASMase). ASMase converts sphingomyelin into the signaling lipid, ceramide. It was recently discovered that, in contrast to ASMase, SMPDL3A is inactive against sphingomyelin and, surprisingly, can instead hydrolyze nucleoside diphosphates and triphosphates, which may play a role in purinergic signaling. As none of the ASMase-like proteins has been structurally characterized to date, the molecular basis for their substrate preferences is unknown. Here we report crystal structures of murine SMPDL3A, which represent the first structures of an ASMase-like protein. The catalytic domain consists of a central mixed β-sandwich surrounded by α-helices. Additionally, SMPDL3A possesses a unique C-terminal domain formed from a cluster of four α-helices that appears to distinguish this protein family from other phosphoesterases. We show that SMDPL3A is a di-zinc-dependent enzyme with an active site configuration that suggests a mechanism of phosphodiester hydrolysis by a metal-activated water molecule and protonation of the leaving group by a histidine residue. Co-crystal structures of SMPDL3A with AMP and α,β-methylene ADP (AMPCP) reveal that the substrate binding site accommodates nucleotides by establishing interactions with their base, sugar, and phosphate moieties, with the latter the major contributor to binding affinity. Our study provides the structural basis for SMPDL3A substrate specificity and sheds new light on the function of ASMase-like proteins.
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Affiliation(s)
- Alexei Gorelik
- From the Department of Biochemistry and Groupe de Recherche Axe sur la Structure des Proteines, Faculty of Medicine, McGill University, Montreal, Quebec H3G 0B1, Canada and
| | - Katalin Illes
- From the Department of Biochemistry and Groupe de Recherche Axe sur la Structure des Proteines, Faculty of Medicine, McGill University, Montreal, Quebec H3G 0B1, Canada and
| | - Giulio Superti-Furga
- CeMM Research Center for Molecular Medicine of the Austrian Academy of Sciences, A-1090 Vienna, Austria
| | - Bhushan Nagar
- From the Department of Biochemistry and Groupe de Recherche Axe sur la Structure des Proteines, Faculty of Medicine, McGill University, Montreal, Quebec H3G 0B1, Canada and
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14
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RNAi in murine hepatocytes: the agony of choice--a study of the influence of lipid-based transfection reagents on hepatocyte metabolism. Arch Toxicol 2015; 89:1579-88. [PMID: 26233687 DOI: 10.1007/s00204-015-1571-0] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2015] [Accepted: 07/15/2015] [Indexed: 10/23/2022]
Abstract
Primary hepatocyte cell cultures are widely used for studying hepatic diseases with alterations in hepatic glucose and lipid metabolism, such as diabetes and non-alcoholic fatty liver disease. Therefore, small interfering RNAs (siRNAs) provide a potent and specific tool to elucidate the signaling pathways and gene functions involved in these pathologies. Although RNA interference (RNAi) in vitro is frequently used in these investigations, the metabolic alterations elucidated by different siRNA delivery strategies have hardly been investigated in transfected hepatocytes. To elucidate the influence of the most commonly used lipid-based transfection reagents on cultured primary hepatocytes, we studied the cytotoxic effects and transfection efficiencies of INTERFERin(®), Lipofectamine(®)RNAiMAX, and HiPerFect(®). All of these transfection agents displayed low cytotoxicity (5.6-9.0 ± 1.3-3.4%), normal cell viability, and high transfection efficiency (fold change 0.08-0.13 ± 0.03-0.05), and they also favored the satisfactory down-regulation of target gene expression. However, when effects on the metabolome and lipidome were studied, considerable differences were observed among the transfection reagents. Cellular triacylglycerides levels were either up- or down-regulated [maximum fold change: INTERFERin(®) (48 h) 2.55 ± 0.34, HiPerFect(®) (24 h) 0.79 ± 0.08, Lipofectamine(®)RNAiMAX (48 h) 1.48 ± 0.21], and mRNA levels of genes associated with lipid metabolism were differentially affected. Likewise, metabolic functions such as amino acid utilization from were perturbed (alanine, arginine, glycine, ornithine, and pyruvate). In conclusion, these findings demonstrate that the choice of non-viral siRNA delivery agent is critical in hepatocytes. This should be remembered, especially if RNA silencing is used for studying hepatic lipid homeostasis and its regulation.
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15
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Heinz LX, Baumann CL, Köberlin MS, Snijder B, Gawish R, Shui G, Sharif O, Aspalter IM, Müller AC, Kandasamy RK, Breitwieser FP, Pichlmair A, Bruckner M, Rebsamen M, Blüml S, Karonitsch T, Fauster A, Colinge J, Bennett KL, Knapp S, Wenk MR, Superti-Furga G. The Lipid-Modifying Enzyme SMPDL3B Negatively Regulates Innate Immunity. Cell Rep 2015; 11:1919-28. [PMID: 26095358 PMCID: PMC4508342 DOI: 10.1016/j.celrep.2015.05.006] [Citation(s) in RCA: 67] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2014] [Revised: 03/23/2015] [Accepted: 05/01/2015] [Indexed: 12/26/2022] Open
Abstract
Lipid metabolism and receptor-mediated signaling are highly intertwined processes that cooperate to fulfill cellular functions and safeguard cellular homeostasis. Activation of Toll-like receptors (TLRs) leads to a complex cellular response, orchestrating a diverse range of inflammatory events that need to be tightly controlled. Here, we identified the GPI-anchored Sphingomyelin Phosphodiesterase, Acid-Like 3B (SMPDL3B) in a mass spectrometry screening campaign for membrane proteins co-purifying with TLRs. Deficiency of Smpdl3b in macrophages enhanced responsiveness to TLR stimulation and profoundly changed the cellular lipid composition and membrane fluidity. Increased cellular responses could be reverted by re-introducing affected ceramides, functionally linking membrane lipid composition and innate immune signaling. Finally, Smpdl3b-deficient mice displayed an intensified inflammatory response in TLR-dependent peritonitis models, establishing its negative regulatory role in vivo. Taken together, our results identify the membrane-modulating enzyme SMPDL3B as a negative regulator of TLR signaling that functions at the interface of membrane biology and innate immunity. Identification of SMPDL3B as lipid-modulating phosphodiesterase on macrophages Negative regulatory role for SMPDL3B in Toll-like receptor function Strong influence of SMPDL3B on membrane lipid composition and fluidity Smpdl3b-deficient mice show enhanced responsiveness in TLR-dependent peritonitis
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Affiliation(s)
- Leonhard X Heinz
- CeMM Research Center for Molecular Medicine of the Austrian Academy of Sciences, 1090 Vienna, Austria
| | - Christoph L Baumann
- CeMM Research Center for Molecular Medicine of the Austrian Academy of Sciences, 1090 Vienna, Austria
| | - Marielle S Köberlin
- CeMM Research Center for Molecular Medicine of the Austrian Academy of Sciences, 1090 Vienna, Austria
| | - Berend Snijder
- CeMM Research Center for Molecular Medicine of the Austrian Academy of Sciences, 1090 Vienna, Austria
| | - Riem Gawish
- CeMM Research Center for Molecular Medicine of the Austrian Academy of Sciences, 1090 Vienna, Austria; Department of Medicine I, Laboratory of Infection Biology, Medical University of Vienna, 1090 Vienna, Austria
| | - Guanghou Shui
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China
| | - Omar Sharif
- CeMM Research Center for Molecular Medicine of the Austrian Academy of Sciences, 1090 Vienna, Austria; Department of Medicine I, Laboratory of Infection Biology, Medical University of Vienna, 1090 Vienna, Austria
| | - Irene M Aspalter
- CeMM Research Center for Molecular Medicine of the Austrian Academy of Sciences, 1090 Vienna, Austria
| | - André C Müller
- CeMM Research Center for Molecular Medicine of the Austrian Academy of Sciences, 1090 Vienna, Austria
| | - Richard K Kandasamy
- CeMM Research Center for Molecular Medicine of the Austrian Academy of Sciences, 1090 Vienna, Austria
| | - Florian P Breitwieser
- CeMM Research Center for Molecular Medicine of the Austrian Academy of Sciences, 1090 Vienna, Austria
| | - Andreas Pichlmair
- CeMM Research Center for Molecular Medicine of the Austrian Academy of Sciences, 1090 Vienna, Austria
| | - Manuela Bruckner
- CeMM Research Center for Molecular Medicine of the Austrian Academy of Sciences, 1090 Vienna, Austria
| | - Manuele Rebsamen
- CeMM Research Center for Molecular Medicine of the Austrian Academy of Sciences, 1090 Vienna, Austria
| | - Stephan Blüml
- CeMM Research Center for Molecular Medicine of the Austrian Academy of Sciences, 1090 Vienna, Austria; Division of Rheumatology, Department of Medicine III, Medical University of Vienna, 1090 Vienna, Austria
| | - Thomas Karonitsch
- CeMM Research Center for Molecular Medicine of the Austrian Academy of Sciences, 1090 Vienna, Austria
| | - Astrid Fauster
- CeMM Research Center for Molecular Medicine of the Austrian Academy of Sciences, 1090 Vienna, Austria
| | - Jacques Colinge
- CeMM Research Center for Molecular Medicine of the Austrian Academy of Sciences, 1090 Vienna, Austria
| | - Keiryn L Bennett
- CeMM Research Center for Molecular Medicine of the Austrian Academy of Sciences, 1090 Vienna, Austria
| | - Sylvia Knapp
- CeMM Research Center for Molecular Medicine of the Austrian Academy of Sciences, 1090 Vienna, Austria; Department of Medicine I, Laboratory of Infection Biology, Medical University of Vienna, 1090 Vienna, Austria
| | - Markus R Wenk
- Department of Biochemistry and Department of Biological Sciences, National University of Singapore, Singapore 117456, Singapore; Swiss Tropical and Public Health Institute, University of Basel, 4003 Basel, Switzerland
| | - Giulio Superti-Furga
- CeMM Research Center for Molecular Medicine of the Austrian Academy of Sciences, 1090 Vienna, Austria; Center for Physiology and Pharmacology, Medical University of Vienna, 1090 Vienna, Austria.
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16
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Kubota K, Inaba SI, Nakano R, Watanabe M, Sakurai H, Fukushima Y, Ichikawa K, Takahashi T, Izumi T, Shinagawa A. Identification of activating enzymes of a novel FBPase inhibitor prodrug, CS-917. Pharmacol Res Perspect 2015; 3:e00138. [PMID: 26171222 PMCID: PMC4492754 DOI: 10.1002/prp2.138] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2015] [Revised: 02/19/2015] [Accepted: 02/23/2015] [Indexed: 11/30/2022] Open
Abstract
CS-917 (MB06322) is a selective small compound inhibitor of fructose 1,6-bisphosphatase (FBPase), which is expected to be a novel drug for the treatment of type 2 diabetes by inhibiting gluconeogenesis. CS-917 is a bisamidate prodrug and activation of CS-917 requires a two-step enzyme catalyzed reaction. The first-step enzyme, esterase, catalyzes the conversion of CS-917 into the intermediate form (R-134450) and the second-step enzyme, phosphoramidase, catalyzes the conversion of R-134450 into the active form (R-125338). In this study, we biochemically purified the CS-917 esterase activity in monkey small intestine and liver. We identified cathepsin A (CTSA) and elastase 3B (ELA3B) as CS-917 esterases in the small intestine by mass spectrometry, whereas we found CTSA and carboxylesterase 1 (CES1) in monkey liver. We also purified R-134450 phosphoramidase activity in monkey liver and identified sphingomyelin phosphodiesterase, acid-like 3A (SMPADL3A), as an R-134450 phosphoramidase, which has not been reported to have any enzyme activity. Recombinant human CTSA, ELA3B, and CES1 showed CS-917 esterase activity and recombinant human SMPDL3A showed R-134450 phosphoramidase activity, which confirmed the identification of those enzymes. Identification of metabolic enzymes responsible for the activation process is the requisite first step to understanding the activation process, pharmacodynamics and pharmacokinetics of CS-917 at the molecular level. This is the first identification of a phosphoramidase other than histidine triad nucleotide-binding protein (HINT) family enzymes and SMPDL3A might generally contribute to activation of the other bisamidate prodrugs.
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Affiliation(s)
- Kazuishi Kubota
- Discovery Science and Technology Department, Daiichi Sankyo RD Novare Co., Ltd. Tokyo, Japan
| | - Shin-Ichi Inaba
- Drug Metabolism & Pharmacokinetics Research Laboratories, Daiichi Sankyo Co., Ltd. Tokyo, Japan
| | - Rika Nakano
- Discovery Science and Technology Department, Daiichi Sankyo RD Novare Co., Ltd. Tokyo, Japan
| | - Mihoko Watanabe
- Discovery Science and Technology Department, Daiichi Sankyo RD Novare Co., Ltd. Tokyo, Japan
| | - Hidetaka Sakurai
- Discovery Science and Technology Department, Daiichi Sankyo RD Novare Co., Ltd. Tokyo, Japan
| | - Yumiko Fukushima
- Discovery Science and Technology Department, Daiichi Sankyo RD Novare Co., Ltd. Tokyo, Japan
| | - Kimihisa Ichikawa
- Biologics Technology Research Laboratories, Daiichi Sankyo Co., Ltd. Tokyo, Japan
| | - Tohru Takahashi
- New Modality Research Laboratories, Daiichi Sankyo Co., Ltd. Tokyo, Japan
| | - Takashi Izumi
- Drug Metabolism & Pharmacokinetics Research Laboratories, Daiichi Sankyo Co., Ltd. Tokyo, Japan
| | - Akira Shinagawa
- Discovery Science and Technology Department, Daiichi Sankyo RD Novare Co., Ltd. Tokyo, Japan
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17
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Traini M, Quinn CM, Sandoval C, Johansson E, Schroder K, Kockx M, Meikle PJ, Jessup W, Kritharides L. Sphingomyelin phosphodiesterase acid-like 3A (SMPDL3A) is a novel nucleotide phosphodiesterase regulated by cholesterol in human macrophages. J Biol Chem 2014; 289:32895-913. [PMID: 25288789 DOI: 10.1074/jbc.m114.612341] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Cholesterol-loaded foam cell macrophages are prominent in atherosclerotic lesions and play complex roles in both inflammatory signaling and lipid metabolism, which are underpinned by large scale reprogramming of gene expression. We performed a microarray study of primary human macrophages that showed that transcription of the sphingomyelin phosphodiesterase acid-like 3A (SMPDL3A) gene is up-regulated after cholesterol loading. SMPDL3A protein expression in and secretion from primary macrophages are stimulated by cholesterol loading, liver X receptor ligands, and cyclic AMP, and N-glycosylated SMPDL3A protein is detectable in circulating blood. We demonstrate for the first time that SMPDL3A is a functional phosphodiesterase with an acidic pH optimum. We provide evidence that SMPDL3A is not an acid sphingomyelinase but unexpectedly is active against nucleotide diphosphate and triphosphate substrates at acidic and neutral pH. SMPDL3A is a major source of nucleotide phosphodiesterase activity secreted by liver X receptor-stimulated human macrophages. Extracellular nucleotides such as ATP may activate pro-inflammatory responses in immune cells. Increased expression and secretion of SMPDL3A by cholesterol-loaded macrophage foam cells in lesions may decrease local concentrations of pro-inflammatory nucleotides and potentially represent a novel anti-inflammatory axis linking lipid metabolism with purinergic signaling in atherosclerosis.
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Affiliation(s)
- Mathew Traini
- From the Atherosclerosis Laboratory, ANZAC Research Institute, University of Sydney, Sydney, New South Wales 2139,
| | - Carmel M Quinn
- the Centre for Vascular Research, University of New South Wales, Sydney, New South Wales 2052
| | - Cecilia Sandoval
- the Centre for Vascular Research, University of New South Wales, Sydney, New South Wales 2052
| | - Erik Johansson
- From the Atherosclerosis Laboratory, ANZAC Research Institute, University of Sydney, Sydney, New South Wales 2139
| | - Kate Schroder
- the Institute for Molecular Bioscience, University of Queensland, Queensland 4072
| | - Maaike Kockx
- From the Atherosclerosis Laboratory, ANZAC Research Institute, University of Sydney, Sydney, New South Wales 2139
| | - Peter J Meikle
- the Baker IDI Heart and Diabetes Institute, Melbourne, Victoria 3004, and
| | - Wendy Jessup
- From the Atherosclerosis Laboratory, ANZAC Research Institute, University of Sydney, Sydney, New South Wales 2139
| | - Leonard Kritharides
- From the Atherosclerosis Laboratory, ANZAC Research Institute, University of Sydney, Sydney, New South Wales 2139, the Department of Cardiology, Concord Repatriation General Hospital, Concord, New South Wales 2139, Australia
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18
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Airola MV, Tumolo JM, Snider J, Hannun YA. Identification and biochemical characterization of an acid sphingomyelinase-like protein from the bacterial plant pathogen Ralstonia solanacearum that hydrolyzes ATP to AMP but not sphingomyelin to ceramide. PLoS One 2014; 9:e105830. [PMID: 25144372 PMCID: PMC4140839 DOI: 10.1371/journal.pone.0105830] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2014] [Accepted: 07/25/2014] [Indexed: 11/18/2022] Open
Abstract
Acid sphingomyelinase (aSMase) is a human enzyme that catalyzes the hydrolysis of sphingomyelin to generate the bioactive lipid ceramide and phosphocholine. ASMase deficiency is the underlying cause of the genetic diseases Niemann-Pick Type A and B and has been implicated in the onset and progression of a number of other human diseases including cancer, depression, liver, and cardiovascular disease. ASMase is the founding member of the aSMase protein superfamily, which is a subset of the metallophosphatase (MPP) superfamily. To date, MPPs that share sequence homology with aSMase, termed aSMase-like proteins, have been annotated and presumed to function as aSMases. However, none of these aSMase-like proteins have been biochemically characterized to verify this. Here we identify RsASML, previously annotated as RSp1609: acid sphingomyelinase-like phosphodiesterase, as the first bacterial aSMase-like protein from the deadly plant pathogen Ralstonia solanacearum based on sequence homology with the catalytic and C-terminal domains of human aSMase. A biochemical characterization of RsASML does not support a role in sphingomyelin hydrolysis but rather finds RsASML capable of acting as an ATP diphosphohydrolase, catalyzing the hydrolysis of ATP and ADP to AMP. In addition, RsASML displays a neutral, not acidic, pH optimum and prefers Ni2+ or Mn2+, not Zn2+, for catalysis. This alters the expectation that all aSMase-like proteins function as acid SMases and expands the substrate possibilities of this protein superfamily to include nucleotides. Overall, we conclude that sequence homology with human aSMase is not sufficient to predict substrate specificity, pH optimum for catalysis, or metal dependence. This may have implications to the biochemically uncharacterized human aSMase paralogs, aSMase-like 3a (aSML3a) and aSML3b, which have been implicated in cancer and kidney disease, respectively, and assumed to function as aSMases.
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Affiliation(s)
- Michael V. Airola
- Department of Medicine and the Stony Brook University Cancer Center, Stony Brook University, Stony Brook, New York, United States of America
| | - Jessica M. Tumolo
- Department of Biochemistry and Molecular Biology, Medical University of South Carolina, Charleston, South Carolina, United States of America
| | - Justin Snider
- Department of Medicine and the Stony Brook University Cancer Center, Stony Brook University, Stony Brook, New York, United States of America
| | - Yusuf A. Hannun
- Department of Medicine and the Stony Brook University Cancer Center, Stony Brook University, Stony Brook, New York, United States of America
- * E-mail:
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