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Duraisamy K, Kumar M, Nawabjan A, Lo EKK, Hui Lin M, Lefranc B, Bonnafé E, Treilhou M, El-Nezami H, Leprince J, Chow BKC. MRGPRB2/X2 and the analogous effects of its agonist and antagonist in DSS-induced colitis in mice. Biomed Pharmacother 2024; 174:116471. [PMID: 38547764 DOI: 10.1016/j.biopha.2024.116471] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2023] [Revised: 03/08/2024] [Accepted: 03/18/2024] [Indexed: 05/01/2024] Open
Abstract
The mast cell receptor Mrgprb2, a mouse orthologue of human Mrgprx2, is known as an inflammatory receptor and its elevated expression is associated with various diseases such as ulcerative colitis. We aimed to elucidate the role of Mrgprb2/x2 and the effect of its ligands on a chemically induced murine colitis model. We showed that in Mrgprb2-/- mice, there is a differential regulation of cytokine releases in the blood plasma and severe colonic damages after DSS treatment. Unexpectedly, we demonstrated that known Mrgprb2/x2 agonists (peptide P17, P17 analogues and CST-14) and antagonist (GE1111) similarly increased the survival rate of WT mice subjected to 4% DSS-induced colitis, ameliorated the colonic damages of 2.5% DSS-induced colitis, restored major protein mRNA expression involved in colon integrity, reduced CD68+ and F4/80+ immune cell infiltration and restored cytokine levels. Collectively, our findings highlight the eminent role of Mrpgrb2/x2 in conferring a beneficial effect in the colitis model, and this significance is demonstrated by the heightened severity of colitis with altered cytokine releases and inflammatory immune cell infiltration observed in the Mrgprb2 knockout mice. Elevated expression of Mrgprb2 in WT colitis murine models may represent the organism's adaptive protective mechanism since Mrgprb2 knockout results in severe colitis. On the other hand, both agonist and antagonist of Mrgprb2 analogously mitigated the severity of colitis in DSS-induced colitis model by altering Mrgprb2 expression, immune cell infiltration and inflammatory cytokine releases.
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Affiliation(s)
- Karthi Duraisamy
- School of Biological Sciences, The University of Hong Kong, Hong Kong, China; INSERM U1239 NorDiC, PRIMACEN, Université Rouen Normandie, Rouen, France
| | - Mukesh Kumar
- School of Biological Sciences, The University of Hong Kong, Hong Kong, China
| | - Abdullah Nawabjan
- School of Biological Sciences, The University of Hong Kong, Hong Kong, China
| | - Emily Kwun Kwan Lo
- School of Biological Sciences, The University of Hong Kong, Hong Kong, China
| | - Ming Hui Lin
- School of Biological Sciences, The University of Hong Kong, Hong Kong, China
| | - Benjamin Lefranc
- INSERM U1239 NorDiC, PRIMACEN, Université Rouen Normandie, Rouen, France
| | - Elsa Bonnafé
- EA7417 BTSB, Université Fédérale Toulouse Midi-Pyrénées, INU Champollion, Albi, France
| | - Michel Treilhou
- EA7417 BTSB, Université Fédérale Toulouse Midi-Pyrénées, INU Champollion, Albi, France
| | - Hani El-Nezami
- School of Biological Sciences, The University of Hong Kong, Hong Kong, China; Institute of Public Health and Clinical Nutrition, University of Eastern Finland, Kuopio, Finland
| | - Jérôme Leprince
- INSERM U1239 NorDiC, PRIMACEN, Université Rouen Normandie, Rouen, France.
| | - Billy K C Chow
- School of Biological Sciences, The University of Hong Kong, Hong Kong, China.
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Berg P, Jensen T, Andersen JF, Svendsen SL, Modvig IM, Wang T, Frische S, Chow BKC, Malte H, Holst JJ, Sørensen MV, Leipziger J. Loss of the Secretin Receptor Impairs Renal Bicarbonate Excretion and Aggravates Metabolic Alkalosis in Mice during Acute Base-Loading. J Am Soc Nephrol 2023; 34:1329-1342. [PMID: 37344929 PMCID: PMC10400107 DOI: 10.1681/asn.0000000000000173] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2023] [Accepted: 05/12/2023] [Indexed: 06/23/2023] Open
Abstract
SIGNIFICANCE STATEMENT During acute base excess, the renal collecting duct β -intercalated cells ( β -ICs) become activated to increase urine base excretion. This process is dependent on pendrin and cystic fibrosis transmembrane regulator (CFTR) expressed in the apical membrane of β -ICs. The signal that leads to activation of this process was unknown. Plasma secretin levels increase during acute alkalosis, and the secretin receptor (SCTR) is functionally expressed in β -ICs. We find that mice with global knockout for the SCTR lose their ability to acutely increase renal base excretion. This forces the mice to lower their ventilation to cope with this challenge. Our findings suggest that secretin is a systemic bicarbonate-regulating hormone, likely being released from the small intestine during alkalosis. BACKGROUND The secretin receptor (SCTR) is functionally expressed in the basolateral membrane of the β -intercalated cells of the kidney cortical collecting duct and stimulates urine alkalization by activating the β -intercalated cells. Interestingly, the plasma secretin level increases during acute metabolic alkalosis, but its role in systemic acid-base homeostasis was unclear. We hypothesized that the SCTR system is essential for renal base excretion during acute metabolic alkalosis. METHODS We conducted bladder catheterization experiments, metabolic cage studies, blood gas analysis, barometric respirometry, perfusion of isolated cortical collecting ducts, immunoblotting, and immunohistochemistry in SCTR wild-type and knockout (KO) mice. We also perfused isolated rat small intestines to study secretin release. RESULTS In wild-type mice, secretin acutely increased urine pH and pendrin function in isolated perfused cortical collecting ducts. These effects were absent in KO mice, which also did not sufficiently increase renal base excretion during acute base loading. In line with these findings, KO mice developed prolonged metabolic alkalosis when exposed to acute oral or intraperitoneal base loading. Furthermore, KO mice exhibited transient but marked hypoventilation after acute base loading. In rats, increased blood alkalinity of the perfused upper small intestine increased venous secretin release. CONCLUSIONS Our results suggest that loss of SCTR impairs the appropriate increase of renal base excretion during acute base loading and that SCTR is necessary for acute correction of metabolic alkalosis. In addition, our findings suggest that blood alkalinity increases secretin release from the small intestine and that secretin action is critical for bicarbonate homeostasis.
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Affiliation(s)
- Peder Berg
- Department of Biomedicine, Aarhus University, Aarhus, Denmark
| | - Tobias Jensen
- Department of Biomedicine, Aarhus University, Aarhus, Denmark
| | | | | | - Ida Maria Modvig
- Department of Biomedical Sciences, Copenhagen University, Copenhagen, Denmark
| | - Tobias Wang
- Department of Biology, Zoophysiology, Aarhus University, Aarhus, Denmark
| | | | - Billy K. C. Chow
- School of Biological Sciences, The University of Hong Kong, Hong Kong
| | - Hans Malte
- Department of Biology, Zoophysiology, Aarhus University, Aarhus, Denmark
| | - Jens Juul Holst
- Department of Biomedical Sciences, Copenhagen University, Copenhagen, Denmark
- Novo Nordisk Foundation Center for Basic Metabolic Research, Copenhagen University, Copenhagen, Denmark
| | | | - Jens Leipziger
- Department of Biomedicine, Aarhus University, Aarhus, Denmark
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Kumar M, Duraisamy K, Annapureddy RR, Chan CB, Chow BKC. Novel small molecule MRGPRX2 antagonists inhibit a murine model of allergic reaction. J Allergy Clin Immunol 2022; 151:1110-1122. [PMID: 36581009 DOI: 10.1016/j.jaci.2022.12.805] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [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: 06/07/2022] [Revised: 11/15/2022] [Accepted: 12/06/2022] [Indexed: 12/27/2022]
Abstract
BACKGROUND Activation of Mas-related G protein-coupled receptor X2 (MRGPRX2) is a crucial non-IgE pathway for mast cell activation associated with allergic reactions and inflammation. Only a few peptides and small compounds targeting MRGPRX2 have been reported, with limited information on their pharmacologic activity. OBJECTIVE We sought to develop novel small molecule MRGPRX2 antagonists to treat MRGPRX2-mediated allergies and inflammation. METHODS A computational approach was used to design novel small molecules as MRGPRX2 antagonists. The short-listed molecules were synthesized and characterized by liquid chromatography and mass spectrometry as well as nuclear magnetic resonance. Inhibitory activity on MRGPRX2 signaling was assessed in vitro by using functional bioassays (β-hexosaminidase, calcium flux, and chemokine synthesis) and receptor activation assays (β-arrestin recruitment and Western blot analysis) in human LAD-2 mast cells and HTLA cells. In vivo effects of the novel MRGPRX2 antagonists were assessed using a mouse model of acute allergy and systemic anaphylaxis. RESULTS The novel small molecules demonstrated higher binding affinity with MRGPRX2 in the docking study. The half-maximal inhibitory concentration is in the low micromolar range (5-21 μM). The small molecules inhibited not only the early phase of mast cell activation but also the late phase, associated with chemokine and prostaglandin release. Further, Western blot analysis revealed inhibition of downstream phospholipase C-γ, extracellular signal-regulated protein kinase 1/2, and Akt signaling pathway. Moreover, in the mouse models of allergies, small molecule administration effectively blocks acute, systemic allergic reactions and inflammation and prevents systemic anaphylaxis. CONCLUSION The small molecules might hold a significant therapeutic promise to treat MRGPRX2-mediated allergies and inflammation.
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Affiliation(s)
- Mukesh Kumar
- School of Biological Sciences, University of Hong Kong, Hong Kong SAR
| | - Karthi Duraisamy
- School of Biological Sciences, University of Hong Kong, Hong Kong SAR
| | | | - Chi Bun Chan
- School of Biological Sciences, University of Hong Kong, Hong Kong SAR
| | - Billy K C Chow
- School of Biological Sciences, University of Hong Kong, Hong Kong SAR.
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Wei JA, Han Q, Luo Z, Liu L, Cui J, Tan J, Chow BKC, So KF, Zhang L. Amygdala neural ensemble mediates mouse social investigation behaviors. Natl Sci Rev 2022; 10:nwac179. [PMID: 36845323 PMCID: PMC9952061 DOI: 10.1093/nsr/nwac179] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2021] [Revised: 05/22/2022] [Accepted: 08/15/2022] [Indexed: 11/15/2022] Open
Abstract
Innate social investigation behaviors are critical for animal survival and are regulated by both neural circuits and neuroendocrine factors. Our understanding of how neuropeptides regulate social interest, however, is incomplete at the current stage. In this study, we identified the expression of secretin (SCT) in a subpopulation of excitatory neurons in the basolateral amygdala. With distinct molecular and physiological features, BLASCT+ cells projected to the medial prefrontal cortex and were necessary and sufficient for promoting social investigation behaviors, whilst other basolateral amygdala neurons were anxiogenic and antagonized social behaviors. Moreover, the exogenous application of secretin effectively promoted social interest in both healthy and autism spectrum disorder model mice. These results collectively demonstrate a previously unrecognized group of amygdala neurons for mediating social behaviors and suggest promising strategies for social deficits.
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Affiliation(s)
| | | | | | - Linglin Liu
- Key Laboratory of CNS Regeneration (Ministry of Education), Guangdong-Hong Kong-Macau Institute of CNS Regeneration, Jinan University, Guangzhou 510632, China
| | - Jing Cui
- Key Laboratory of CNS Regeneration (Ministry of Education), Guangdong-Hong Kong-Macau Institute of CNS Regeneration, Jinan University, Guangzhou 510632, China
| | - Jiahui Tan
- Key Laboratory of CNS Regeneration (Ministry of Education), Guangdong-Hong Kong-Macau Institute of CNS Regeneration, Jinan University, Guangzhou 510632, China
| | - Billy K C Chow
- School of Biological Sciences, The University of Hong Kong, Hong Kong, China
| | - Kwok-Fai So
- Key Laboratory of CNS Regeneration (Ministry of Education), Guangdong-Hong Kong-Macau Institute of CNS Regeneration, Jinan University, Guangzhou 510632, China,State Key Laboratory of Brain and Cognitive Science, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, China,Center for Brain Science and Brain-Inspired Intelligence, Guangdong-Hong Kong-Macao Greater Bay Area, Guangzhou 510030, China,BiolandLaboratory (Guangzhou Regenerative Medicine and Health Guangdong Laboratory), Guangzhou 510006, China,Co-Innovation Center of Neuroregeneration, Nantong University, Nantong 220619, China,Neuroscience and Neurorehabilitation Institute, University of Health and Rehabilitation Sciences, Qingdao 266113, China,Institute of Clinical Research for Mental Health, Jinan University, Guangzhou 510632, China
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Sun Y, Wang Z, Nie C, Xue L, Wang Y, Liu J, Fan M, Zhang D, He R, Zhang X, Qian H, Chow BKC, Li Y, Wang L. Hydroxysafflor yellow A triggered a fast-to-slow muscle fiber-type conversion via regulating FoxO1 in myocytes. Food Funct 2022; 13:6317-6328. [PMID: 35611953 DOI: 10.1039/d1fo03612b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Hydroxysafflor yellow A (HSYA) is the main bioactive component of safflower and has been reported to have significant health-promoting abilities. However, the regulation of HSYA on different types of skeletal myofibers is largely unknown. Here, in vitro experiments found that the water extract of safflower could significantly increase MyHC I, MB and Tnni1 mRNA expression while downregulating MyHC IIb mRNA expression. Furthermore, HSYA triggered fast-to-slow fiber-type switching and increased gene expression related to mitochondrial biosynthesis both in vitro and in vivo. Autodock analyses proved that FoxO1 is a potential target of HSYA, and qRT-PCR and western blotting further showed that HSYA significantly promoted the activation of the FoxO1 signaling pathway. Additionally, the levels of PGC1α, downstream of FoxO1, also significantly increased after HSYA treatment. Together, our findings suggested that HSYA triggered a fast-to-slow myofiber-type shift through the FoxO1 signaling pathway.
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Affiliation(s)
- Yujie Sun
- State Key Laboratory of Food Science and Technology, School of Food Science and Technology, Jiangnan University, Wuxi 214122, China.
| | - Zhijun Wang
- COFCO Aerocean Oils & Grain Industrial Co. Ltd, Shawan, No. 1 West Park Road, West Urumqi Road, Shawan County, Tacheng District, Xinjiang Province 832100, China
| | - Chenzhipeng Nie
- State Key Laboratory of Food Science and Technology, School of Food Science and Technology, Jiangnan University, Wuxi 214122, China.
| | - Lamei Xue
- State Key Laboratory of Food Science and Technology, School of Food Science and Technology, Jiangnan University, Wuxi 214122, China.
| | - Yu Wang
- State Key Laboratory of Food Science and Technology, School of Food Science and Technology, Jiangnan University, Wuxi 214122, China.
| | - Jinxin Liu
- State Key Laboratory of Food Science and Technology, School of Food Science and Technology, Jiangnan University, Wuxi 214122, China.
| | - Mingcong Fan
- State Key Laboratory of Food Science and Technology, School of Food Science and Technology, Jiangnan University, Wuxi 214122, China.
| | - Duo Zhang
- Clinical and Experimental Therapeutics, College of Pharmacy, University of Georgia and Charlie Norwood VA Medical Center, Augusta, Georgia, USA
| | - Ruikun He
- BYHEALTH Institute of Nutrition & Health, No. 3 Kehui 3rd Street, No. 99 Kexue Avenue Central, Huangpu District, Guangzhou 510663, China
| | - Xuguang Zhang
- BYHEALTH Institute of Nutrition & Health, No. 3 Kehui 3rd Street, No. 99 Kexue Avenue Central, Huangpu District, Guangzhou 510663, China
| | - Haifeng Qian
- State Key Laboratory of Food Science and Technology, School of Food Science and Technology, Jiangnan University, Wuxi 214122, China.
| | - Billy K C Chow
- School of Biological Sciences, University of Hong Kong, Hong Kong, China
| | - Yan Li
- State Key Laboratory of Food Science and Technology, School of Food Science and Technology, Jiangnan University, Wuxi 214122, China.
| | - Li Wang
- State Key Laboratory of Food Science and Technology, School of Food Science and Technology, Jiangnan University, Wuxi 214122, China.
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Duraisamy K, Singh K, Kumar M, Lefranc B, Bonnafé E, Treilhou M, Leprince J, Chow BKC. P17 induces chemotaxis and differentiation of monocytes via MRGPRX2-mediated mast cell-line activation. J Allergy Clin Immunol 2022; 149:275-291. [PMID: 34111449 DOI: 10.1016/j.jaci.2021.04.040] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2020] [Revised: 03/29/2021] [Accepted: 04/23/2021] [Indexed: 12/14/2022]
Abstract
BACKGROUND P17, a peptide isolated from Tetramorium bicarinatum ant venom, is known to induce an alternative phenotype of human monocyte-derived macrophages via activation of an unknown G protein-coupled receptor (GPCR). OBJECTIVE We sought to investigate the mechanism of action and the immunomodulatory effects of P17 mediated through MRGPRX2 (Mas-related G protein-coupled receptor X2). METHODS To identify the GPCR for P17, we screened 314 GPCRs. Upon identification of MRGPRX2, a battery of in silico, in vitro, ex vivo, and in vivo assays along with the receptor mutation studies were performed. In particular, to investigate the immunomodulatory actions, we used β-hexosaminidase release assay, cytokine releases, quantification of mRNA expression, cell migration and differentiation assays, immunohistochemical labeling, hematoxylin and eosin, and immunofluorescence staining. RESULTS P17 activated MRGPRX2 in a dose-dependent manner in β-arrestin recruitment assay. In LAD2 cells, P17 induced calcium and β-hexosaminidase release. Quercetin- and short hairpin RNA-mediated knockdown of MRGPRX2 reduced P17-evoked β-hexosaminidase release. In silico and in vitro mutagenesis studies showed that residue Lys8 of P17 formed a cation-π interaction with the Phe172 of MRGPRX2 and [Ala8]P17 lost its activity partially. P17 activated LAD2 cells to recruit THP-1 and human monocytes in Transwell migration assay, whereas MRGPRX2-impaired LAD2 cells cannot. In addition, P17-treated LAD2 cells stimulated differentiation of THP-1 and human monocytes, as indicated by the enhanced expression of macrophage markers cluster of differentiation 11b and TNF-α by quantitative RT-PCR. Immunohistochemical and immunofluorescent staining suggested monocyte recruitment in mice ears injected with P17. CONCLUSIONS Our data provide novel structural information regarding the interaction of P17 with MRGPRX2 and intracellular pathways for its immunomodulatory action.
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Affiliation(s)
- Karthi Duraisamy
- School of Biological Sciences, The University of Hong Kong, Hong Kong, China
| | - Kailash Singh
- School of Biological Sciences, The University of Hong Kong, Hong Kong, China
| | - Mukesh Kumar
- School of Biological Sciences, The University of Hong Kong, Hong Kong, China
| | - Benjamin Lefranc
- INSERM U1239, PRIMACEN, IRIB, Normandy University, Rouen, France
| | - Elsa Bonnafé
- EA7417 BTSB, Université Fédérale Toulouse Midi-Pyrénées, INU Champollion, Albi, France
| | - Michel Treilhou
- EA7417 BTSB, Université Fédérale Toulouse Midi-Pyrénées, INU Champollion, Albi, France
| | - Jérôme Leprince
- INSERM U1239, PRIMACEN, IRIB, Normandy University, Rouen, France.
| | - Billy K C Chow
- School of Biological Sciences, The University of Hong Kong, Hong Kong, China.
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On JSW, Su L, Shen H, Arokiaraj AWR, Cardoso JCR, Li G, Chow BKC. PACAP/GCGa Is an Important Modulator of the Amphioxus CNS-Hatschek's Pit Axis, the Homolog of the Vertebrate Hypothalamic-Pituitary Axis in the Basal Chordates. Front Endocrinol (Lausanne) 2022; 13:850040. [PMID: 35498398 PMCID: PMC9049855 DOI: 10.3389/fendo.2022.850040] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/07/2022] [Accepted: 03/01/2022] [Indexed: 11/13/2022] Open
Abstract
The Hatschek's pit in the cephalochordate amphioxus, an invertebrate deuterostome basal to chordates is suggested to be the functional homolog structure of the vertebrate adenohypophysis based on anatomy and expression of homologous neuroendocrine genes. However, the endocrine potential of the cephalochordate Hatschek's pit remains to be demonstrated as well as the physiological actions of the secreted neuropeptides. In this study, we have explored the distribution and characterize the potential function of the amphioxus PACAP/GCG precursor, which is the ortholog of the hypothalamic PACAP neuropeptide in vertebrates. In amphioxi, two PACAP/GCG transcripts PACAP/GCGa and PACAP/GCGbc that are alternative isoforms of a single gene with different peptide coding potentials were isolated. Immunofluorescence staining detected their expression around the nucleus of Rohde, supporting that this structure may be homologous of the neurosecretory cells of the vertebrate hypothalamus where abundant PACAP is found. PACAP/GCGa was also detected in the infundibulum-like downgrowth approaching the Hatschek's pit, indicating diffusion of PACAP/GCGa from the CNS to the pit via the infundibulum-like downgrowth. Under a high salinity challenge, PACAP/GCGa was upregulated in amphioxi head and PACAP/GCGa treatment increased expression of GHl in Hatschek's pit in a dose-dependent manner, suggesting that PACAP/GCGa may be involved in the regulation of GHl via hypothalamic-pituitary (HP)-like axis similar as in the vertebrates. Our results support that the amphioxus Hatschek's pit is likely to be the functional homolog of pituitary gland in vertebrates.
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Affiliation(s)
- Jason S. W. On
- School of Biological Sciences, The University of Hong Kong, Hong Kong SAR, China
| | - Liuru Su
- School of Biological Sciences, The University of Hong Kong, Hong Kong SAR, China
- State Key Laboratory of Cellular Stress Biology, School of Life Sciences, Xiamen University, Xiamen, China
| | - Hong Shen
- School of Biological Sciences, The University of Hong Kong, Hong Kong SAR, China
| | | | - João C. R. Cardoso
- Comparative Endocrinology and Integrative Biology, Centre of Marine Sciences, Universidade do Algarve, Faro, Portugal
| | - Guang Li
- State Key Laboratory of Cellular Stress Biology, School of Life Sciences, Xiamen University, Xiamen, China
- *Correspondence: Billy K. C. Chow, ; Guang Li,
| | - Billy K. C. Chow
- School of Biological Sciences, The University of Hong Kong, Hong Kong SAR, China
- *Correspondence: Billy K. C. Chow, ; Guang Li,
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Ke R, Lok SIS, Singh K, Chow BKC, Lee LTO. GIP receptor suppresses PAC1receptor-mediated neuronal differentiation via formation of a receptor heterocomplex. J Neurochem 2020; 157:1850-1860. [PMID: 33078390 DOI: 10.1111/jnc.15220] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2020] [Revised: 10/07/2020] [Accepted: 10/13/2020] [Indexed: 01/22/2023]
Abstract
Pituitary adenylate cyclase-activating peptide (PACAP) receptor (PAC1R) is a class B Gprotein-coupled receptor (GPCR) that is widely expressed in the human body and is involved in neuronal differentiation. As class B GPCRs are known to form heterocomplexes with family members, we hypothesized that PAC1R mediates neuronal differentiation through interaction with a class B GPCR. We used the BRET assay to identify potential interactions between PAC1R and 11 class B GPCRs. Gastric inhibitory polypeptide receptor (GIPR) and secretin receptor were identified as putative binding partners of PAC1R. The effect of heterocomplex formation by PAC1R on receptor activation was evaluated with the cyclic (c)AMP, luciferase reporter, and calcium signaling assays; and the effects on receptor internalization and subcellular localization were examined by confocal microscopy. The results suggested he PAC1R/GIPR heterocomplex suppressed signaling events downstream of PAC1R, including cAMP production, serum response element and calcium signaling, and β-arrestin recruitment. Protein-protein interaction was analyzed in silico, and induction of neuronal differentiation by the PAC1R heterocomplex was assessed in SH-SY5Y neuronal cells by measure the morphological changes and marker genes expression by real-time quantitative PCR and western blot. Over-expression of GIPR suppressed PACAP/PAC1R-mediated neuronal differentiation and the differentiation markers expression in SH-SY5Y cells. GIPR regulates neuronal differentiation through heterocomplex formation with PAC1R.
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Affiliation(s)
- Ran Ke
- Centre of Reproduction, Development and Aging, Faculty of Health Sciences, University of Macau, Taipa, Macau, China
| | - Samson I S Lok
- Centre of Reproduction, Development and Aging, Faculty of Health Sciences, University of Macau, Taipa, Macau, China
| | - Kailash Singh
- School of Biological Sciences, The University of Hong Kong, Hong Kong SAR, China
| | - Billy K C Chow
- School of Biological Sciences, The University of Hong Kong, Hong Kong SAR, China
| | - Leo T O Lee
- Centre of Reproduction, Development and Aging, Faculty of Health Sciences, University of Macau, Taipa, Macau, China.,Cancer Centre, Faculty of Health Sciences, University of Macau, Taipa, Macau, China
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Heshiki Y, Vazquez-Uribe R, Li J, Ni Y, Quainoo S, Imamovic L, Li J, Sørensen M, Chow BKC, Weiss GJ, Xu A, Sommer MOA, Panagiotou G. Predictable modulation of cancer treatment outcomes by the gut microbiota. Microbiome 2020; 8:28. [PMID: 32138779 PMCID: PMC7059390 DOI: 10.1186/s40168-020-00811-2] [Citation(s) in RCA: 81] [Impact Index Per Article: 20.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/30/2019] [Accepted: 02/21/2020] [Indexed: 05/18/2023]
Abstract
The gut microbiota has the potential to influence the efficacy of cancer therapy. Here, we investigated the contribution of the intestinal microbiome on treatment outcomes in a heterogeneous cohort that included multiple cancer types to identify microbes with a global impact on immune response. Human gut metagenomic analysis revealed that responder patients had significantly higher microbial diversity and different microbiota compositions compared to non-responders. A machine-learning model was developed and validated in an independent cohort to predict treatment outcomes based on gut microbiota composition and functional repertoires of responders and non-responders. Specific species, Bacteroides ovatus and Bacteroides xylanisolvens, were positively correlated with treatment outcomes. Oral gavage of these responder bacteria significantly increased the efficacy of erlotinib and induced the expression of CXCL9 and IFN-γ in a murine lung cancer model. These data suggest a predictable impact of specific constituents of the microbiota on tumor growth and cancer treatment outcomes with implications for both prognosis and therapy.
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Affiliation(s)
- Yoshitaro Heshiki
- Systems Biology & Bioinformatics Unit, Leibniz Institute for Natural Product Research and Infection Biology, Hans Knöll Institute, Jena, Germany
- Systems Biology and Bioinformatics Group, School of Biological Sciences, Faculty of Sciences, The University of Hong Kong, Hong Kong, China
| | - Ruben Vazquez-Uribe
- Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, 2800 Kgs., Lyngby, Denmark
| | - Jin Li
- State Key Laboratory of Pharmaceutical Biotechnology, University of Hong Kong, Hong Kong, China
- Department of Medicine, Li Ka Shing Faculty of Medicine, University of Hong Kong, Hong Kong, China
| | - Yueqiong Ni
- Systems Biology and Bioinformatics Group, School of Biological Sciences, Faculty of Sciences, The University of Hong Kong, Hong Kong, China
| | - Scott Quainoo
- Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, 2800 Kgs., Lyngby, Denmark
| | - Lejla Imamovic
- Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, 2800 Kgs., Lyngby, Denmark
| | - Jun Li
- Department of Infectious Diseases and Public Health, The Jockey Club College of Veterinary Medicine and Life Sciences, City University of Hong Kong, Hong Kong, China
- School of Data Science, City University of Hong Kong, Hong Kong, China
| | - Maria Sørensen
- Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, 2800 Kgs., Lyngby, Denmark
| | - Billy K C Chow
- School of Biological Sciences, Faculty of Sciences, The University of Hong Kong, Hong Kong, China
| | - Glen J Weiss
- University of Arizona College of Medicine-Phoenix, Phoenix, AZ, USA.
| | - Aimin Xu
- State Key Laboratory of Pharmaceutical Biotechnology, University of Hong Kong, Hong Kong, China.
- Department of Medicine, Li Ka Shing Faculty of Medicine, University of Hong Kong, Hong Kong, China.
| | - Morten O A Sommer
- Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, 2800 Kgs., Lyngby, Denmark.
| | - Gianni Panagiotou
- Systems Biology & Bioinformatics Unit, Leibniz Institute for Natural Product Research and Infection Biology, Hans Knöll Institute, Jena, Germany.
- Systems Biology and Bioinformatics Group, School of Biological Sciences, Faculty of Sciences, The University of Hong Kong, Hong Kong, China.
- Department of Microbiology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, China.
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10
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Nong W, Chai ZYH, Jiang X, Qin J, Ma KY, Chan KM, Chan TF, Chow BKC, Kwan HS, Wong CKC, Qiu JW, Hui JHL, Chu KH. A crustacean annotated transcriptome (CAT) database. BMC Genomics 2020; 21:32. [PMID: 31918660 PMCID: PMC6953184 DOI: 10.1186/s12864-019-6433-3] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2019] [Accepted: 12/26/2019] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Decapods are an order of crustaceans which includes shrimps, crabs, lobsters and crayfish. They occur worldwide and are of great scientific interest as well as being of ecological and economic importance in fisheries and aquaculture. However, our knowledge of their biology mainly comes from the group which is most closely related to crustaceans - insects. Here we produce a de novo transcriptome database, crustacean annotated transcriptome (CAT) database, spanning multiple tissues and the life stages of seven crustaceans. DESCRIPTION A total of 71 transcriptome assemblies from six decapod species and a stomatopod species, including the coral shrimp Stenopus hispidus, the cherry shrimp Neocaridina davidi, the redclaw crayfish Cherax quadricarinatus, the spiny lobster Panulirus ornatus, the red king crab Paralithodes camtschaticus, the coconut crab Birgus latro, and the zebra mantis shrimp Lysiosquillina maculata, were generated. Differential gene expression analyses within species were generated as a reference and included in a graphical user interface database at http://cat.sls.cuhk.edu.hk/. Users can carry out gene name searches and also access gene sequences based on a sequence query using the BLAST search function. CONCLUSIONS The data generated and deposited in this database offers a valuable resource for the further study of these crustaceans, as well as being of use in aquaculture development.
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Affiliation(s)
- Wenyan Nong
- School of Life Sciences, Simon F.S. Li Marine Science Laboratory, State Key Laboratory of Agrobiotechnology, The Chinese University of Hong Kong, Hong Kong, China
| | - Zacary Y H Chai
- School of Life Sciences, Simon F.S. Li Marine Science Laboratory, The Chinese University of Hong Kong, Hong Kong, China
| | - Xiaosen Jiang
- School of Future Technology, University of Chinese Academy of Sciences, Hong Kong, China
| | - Jing Qin
- School of Pharmaceutical Sciences (Shenzhen), Sun Yat-sen University, Shenzhen, China
| | - Ka Yan Ma
- School of Life Sciences, Simon F.S. Li Marine Science Laboratory, The Chinese University of Hong Kong, Hong Kong, China
| | - King Ming Chan
- School of Life Sciences, The Chinese University of Hong Kong, Hong Kong, China
| | - Ting Fung Chan
- School of Life Sciences, State Key Laboratory of Agrobiotechnology, The Chinese University of Hong Kong, Hong Kong, China
| | - Billy K C Chow
- School of Biological Sciences, The University of Hong Kong, Hong Kong, China
| | - Hoi Shan Kwan
- School of Life Sciences, The Chinese University of Hong Kong, Hong Kong, China
| | - Chris K C Wong
- Department of Biology, Hong Kong Baptist University, Hong Kong, China
| | - Jian-Wen Qiu
- Department of Biology, Hong Kong Baptist University, Hong Kong, China
| | - Jerome H L Hui
- School of Life Sciences, Simon F.S. Li Marine Science Laboratory, State Key Laboratory of Agrobiotechnology, The Chinese University of Hong Kong, Hong Kong, China.
| | - Ka Hou Chu
- School of Life Sciences, Simon F.S. Li Marine Science Laboratory, The Chinese University of Hong Kong, Hong Kong, China
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11
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Bai J, Duraisamy K, Mak SOK, Allam A, Ajarem J, Li Z, Chow BKC. Role of SCTR/AT1aR heteromer in mediating ANGII-induced aldosterone secretion. PLoS One 2019; 14:e0222005. [PMID: 31479491 PMCID: PMC6719825 DOI: 10.1371/journal.pone.0222005] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2019] [Accepted: 08/20/2019] [Indexed: 12/26/2022] Open
Abstract
The involvement of secretin (SCT) and its receptor (SCTR) in angiotensin II (ANGII)-mediated osmoregulation by forming SCTR/ angiotensin II type 1 receptor (AT1R) heteromer is well established. In this study, we demonstrated that SCTR/AT1R complex can mediate ANGII-induced aldosterone secretion/release through potentiating calcium mobilization. Through IHC and cAMP studies, we showed the presence of functional SCTR and AT1R in the primary zona glomerulosa (ZG) cells of C57BL/6N (C57), and functional AT1R and non-functional SCTR in SCTR knockout (SCTR-/-) mice. Calcium mobilization studies revealed the important role of SCTR on ANGII-mediated calcium mobilization in adrenal gland. The fluo4-AM loaded primary adrenal ZG cells from the C57 mice displayed a dose-dependent increase in intracellular calcium influx ([Ca2+]i) when exposed to ANGII but not from the SCTR-/- ZG cells. Synthetic SCTR transmembrane (TM) peptides STM-II/-IV were able to alter [Ca2+]i in C57 mice, but not the mice with mutated STM-II/-IV (STM-IIm/IVm) peptides. Through enzyme immunoassay (EIA), we measured the aldosterone release from primary ZG cells of both C57 and SCTR-/- mice by exposing them to ANGII (10nM). SCTR-/- ZG cells showed impaired ANGII-induced aldosterone secretion compared to the C57 mice. TM peptide, STM-II hindered the aldosterone secretion in ZG cells of C57 mice. These findings support the involvement of SCTR/AT1R heterodimer complex in aldosterone secretion/release through [Ca2+]i.
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MESH Headings
- Aldosterone/metabolism
- Angiotensin II/metabolism
- Animals
- Calcium Signaling
- Male
- Mice
- Mice, Inbred C57BL
- Mice, Knockout
- Mutation
- Osmoregulation/genetics
- Osmoregulation/physiology
- Peptide Fragments/chemistry
- Peptide Fragments/genetics
- Peptide Fragments/metabolism
- Protein Structure, Quaternary
- Receptor, Angiotensin, Type 1/chemistry
- Receptor, Angiotensin, Type 1/metabolism
- Receptors, G-Protein-Coupled/chemistry
- Receptors, G-Protein-Coupled/deficiency
- Receptors, G-Protein-Coupled/metabolism
- Receptors, Gastrointestinal Hormone/chemistry
- Receptors, Gastrointestinal Hormone/deficiency
- Receptors, Gastrointestinal Hormone/metabolism
- Zona Glomerulosa/cytology
- Zona Glomerulosa/metabolism
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Affiliation(s)
- Juan Bai
- School of Biological Sciences, University of Hong Kong, Hong Kong, China
| | - Karthi Duraisamy
- School of Biological Sciences, University of Hong Kong, Hong Kong, China
| | - Sarah O. K. Mak
- School of Biological Sciences, University of Hong Kong, Hong Kong, China
| | - Ahmed Allam
- Department of Zoology, College of Science, King Saud University, Riyadh, KSA
- Department of Zoology, Faculty of Science, Beni-Suef University, Beni-Suef, Egypt
| | - Jamaan Ajarem
- Department of Zoology, College of Science, King Saud University, Riyadh, KSA
| | - Zhang Li
- GHM Institute of CNS Regeneration, Jinan University, Guangzhou, China
| | - Billy K. C. Chow
- School of Biological Sciences, University of Hong Kong, Hong Kong, China
- * E-mail:
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12
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Yang X, Brobst D, Chan WS, Tse MCL, Herlea-Pana O, Ahuja P, Bi X, Zaw AM, Kwong ZSW, Jia WH, Zhang ZG, Zhang N, Chow SKH, Cheung WH, Louie JCY, Griffin TM, Nong W, Hui JHL, Du GH, Noh HL, Saengnipanthkul S, Chow BKC, Kim JK, Lee CW, Chan CB. Muscle-generated BDNF is a sexually dimorphic myokine that controls metabolic flexibility. Sci Signal 2019; 12:12/594/eaau1468. [PMID: 31409756 DOI: 10.1126/scisignal.aau1468] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The ability of skeletal muscle to switch between lipid and glucose oxidation for ATP production during metabolic stress is pivotal for maintaining systemic energy homeostasis, and dysregulation of this metabolic flexibility is a dominant cause of several metabolic disorders. However, the molecular mechanism that governs fuel selection in muscle is not well understood. Here, we report that brain-derived neurotrophic factor (BDNF) is a fasting-induced myokine that controls metabolic reprograming through the AMPK/CREB/PGC-1α pathway in female mice. Female mice with a muscle-specific deficiency in BDNF (MBKO mice) were unable to switch the predominant fuel source from carbohydrates to fatty acids during fasting, which reduced ATP production in muscle. Fasting-induced muscle atrophy was also compromised in female MBKO mice, likely a result of autophagy inhibition. These mutant mice displayed myofiber necrosis, weaker muscle strength, reduced locomotion, and muscle-specific insulin resistance. Together, our results show that muscle-derived BDNF facilitates metabolic adaption during nutrient scarcity in a gender-specific manner and that insufficient BDNF production in skeletal muscle promotes the development of metabolic myopathies and insulin resistance.
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Affiliation(s)
- Xiuying Yang
- Department of Physiology, University of Oklahoma Health Sciences Center, 940 Stanton L. Young Blvd., BMSB 634, Oklahoma City, OK 73104, USA.,State Key Laboratory of Bioactive Substance and Function of Natural Medicines and Beijing Key Laboratory of Drug Target and Screening Research, Institute of Materia Medica of Peking Union Medical College, Beijing 100050, China
| | - Daniel Brobst
- Department of Physiology, University of Oklahoma Health Sciences Center, 940 Stanton L. Young Blvd., BMSB 634, Oklahoma City, OK 73104, USA
| | - Wing Suen Chan
- School of Biological Sciences, The University of Hong Kong, 6N01 Kadoorie Biological Sciences Building, Pokfulam Road, Hong Kong
| | - Margaret Chui Ling Tse
- School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong
| | - Oana Herlea-Pana
- Department of Physiology, University of Oklahoma Health Sciences Center, 940 Stanton L. Young Blvd., BMSB 634, Oklahoma City, OK 73104, USA
| | - Palak Ahuja
- School of Biological Sciences, The University of Hong Kong, 6N01 Kadoorie Biological Sciences Building, Pokfulam Road, Hong Kong
| | - Xinyi Bi
- School of Biological Sciences, The University of Hong Kong, 6N01 Kadoorie Biological Sciences Building, Pokfulam Road, Hong Kong
| | - Aung Moe Zaw
- School of Biological Sciences, The University of Hong Kong, 6N01 Kadoorie Biological Sciences Building, Pokfulam Road, Hong Kong.,Department of Chemical Engineering, University of Waterloo, ON N2L 3G1, Canada
| | - Zara Sau Wa Kwong
- School of Biological Sciences, The University of Hong Kong, 6N01 Kadoorie Biological Sciences Building, Pokfulam Road, Hong Kong
| | - Wei-Hua Jia
- State Key Laboratory of Bioactive Substance and Function of Natural Medicines and Beijing Key Laboratory of Drug Target and Screening Research, Institute of Materia Medica of Peking Union Medical College, Beijing 100050, China
| | - Zhong-Gou Zhang
- Department of Colorectal Cancer Oncological Surgery, Large-Scale Data Analysis Center of Cancer Precision Medicine, Cancer Hospital of Chinese Medical University, Liaoning Provincial Cancer Institute and Hospital, Shenyang 110042, China
| | - Ning Zhang
- Department of Orthopaedics and Traumatology, The Chinese University of Hong Kong, 5/F Lui Che Woo Clinical Sciences Building, Prince of Wales Hospital, Shatin, Hong Kong
| | - Simon Kwoon Ho Chow
- Department of Orthopaedics and Traumatology, The Chinese University of Hong Kong, 5/F Lui Che Woo Clinical Sciences Building, Prince of Wales Hospital, Shatin, Hong Kong
| | - Wing Hoi Cheung
- Department of Orthopaedics and Traumatology, The Chinese University of Hong Kong, 5/F Lui Che Woo Clinical Sciences Building, Prince of Wales Hospital, Shatin, Hong Kong
| | - Jimmy Chun Yu Louie
- School of Biological Sciences, The University of Hong Kong, 6N01 Kadoorie Biological Sciences Building, Pokfulam Road, Hong Kong
| | - Timothy M Griffin
- Department of Physiology, University of Oklahoma Health Sciences Center, 940 Stanton L. Young Blvd., BMSB 634, Oklahoma City, OK 73104, USA.,Aging and Metabolism Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK 73104, USA.,Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA
| | - Wenyan Nong
- School of Life Sciences, Chinese University of Hong Kong, Shatin, Hong Kong
| | - Jerome Ho Lam Hui
- School of Life Sciences, Chinese University of Hong Kong, Shatin, Hong Kong
| | - Guan-Hua Du
- State Key Laboratory of Bioactive Substance and Function of Natural Medicines and Beijing Key Laboratory of Drug Target and Screening Research, Institute of Materia Medica of Peking Union Medical College, Beijing 100050, China
| | - Hye Lim Noh
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, MA 01605, USA
| | - Suchaorn Saengnipanthkul
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, MA 01605, USA
| | - Billy K C Chow
- School of Biological Sciences, The University of Hong Kong, 6N01 Kadoorie Biological Sciences Building, Pokfulam Road, Hong Kong
| | - Jason K Kim
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, MA 01605, USA
| | - Chi Wai Lee
- School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong.
| | - Chi Bun Chan
- School of Biological Sciences, The University of Hong Kong, 6N01 Kadoorie Biological Sciences Building, Pokfulam Road, Hong Kong. .,State Key Laboratory of Pharmaceutical Biotechnology, University of Hong Kong, Hong Kong
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13
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Zheng T, Li J, Ni Y, Kang K, Misiakou MA, Imamovic L, Chow BKC, Rode AA, Bytzer P, Sommer M, Panagiotou G. Mining, analyzing, and integrating viral signals from metagenomic data. Microbiome 2019; 7:42. [PMID: 30890181 PMCID: PMC6425642 DOI: 10.1186/s40168-019-0657-y] [Citation(s) in RCA: 44] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/04/2018] [Accepted: 03/07/2019] [Indexed: 05/06/2023]
Abstract
BACKGROUND Viruses are important components of microbial communities modulating community structure and function; however, only a couple of tools are currently available for phage identification and analysis from metagenomic sequencing data. Here we employed the random forest algorithm to develop VirMiner, a web-based phage contig prediction tool especially sensitive for high-abundances phage contigs, trained and validated by paired metagenomic and phagenomic sequencing data from the human gut flora. RESULTS VirMiner achieved 41.06% ± 17.51% sensitivity and 81.91% ± 4.04% specificity in the prediction of phage contigs. In particular, for the high-abundance phage contigs, VirMiner outperformed other tools (VirFinder and VirSorter) with much higher sensitivity (65.23% ± 16.94%) than VirFinder (34.63% ± 17.96%) and VirSorter (18.75% ± 15.23%) at almost the same specificity. Moreover, VirMiner provides the most comprehensive phage analysis pipeline which is comprised of metagenomic raw reads processing, functional annotation, phage contig identification, and phage-host relationship prediction (CRISPR-spacer recognition) and supports two-group comparison when the input (metagenomic sequence data) includes different conditions (e.g., case and control). Application of VirMiner to an independent cohort of human gut metagenomes obtained from individuals treated with antibiotics revealed that 122 KEGG orthology and 118 Pfam groups had significantly differential abundance in the pre-treatment samples compared to samples at the end of antibiotic administration, including clustered regularly interspaced short palindromic repeats (CRISPR), multidrug resistance, and protein transport. The VirMiner webserver is available at http://sbb.hku.hk/VirMiner/ . CONCLUSIONS We developed a comprehensive tool for phage prediction and analysis for metagenomic samples. Compared to VirSorter and VirFinder-the most widely used tools-VirMiner is able to capture more high-abundance phage contigs which could play key roles in infecting bacteria and modulating microbial community dynamics. TRIAL REGISTRATION The European Union Clinical Trials Register, EudraCT Number: 2013-003378-28 . Registered on 9 April 2014.
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Affiliation(s)
- Tingting Zheng
- Systems Biology & Bioinformatics Group, School of Biological Sciences, Faculty of Sciences, The University of Hong Kong, Hong Kong, Hong Kong, Special Administrative Region of China
| | - Jun Li
- Department of Infectious Diseases and Public Health, The Jockey Club College of Veterinary Medicine and Life Sciences, City University of Hong Kong, Hong Kong, Hong Kong, Special Administrative Region of China
- School of Data Science, City University of Hong Kong, Hong Kong, Hong Kong, Special Administrative Region of China
| | - Yueqiong Ni
- Department of Systems Biology and Bioinformatics, Leibniz Institute for Natural Product Research and Infection Biology, Hans Knöll Institute (HKI), Beutenbergstraße 11a, 07745 Jena, Germany
| | - Kang Kang
- Department of Systems Biology and Bioinformatics, Leibniz Institute for Natural Product Research and Infection Biology, Hans Knöll Institute (HKI), Beutenbergstraße 11a, 07745 Jena, Germany
| | - Maria-Anna Misiakou
- Bacterial Synthetic Biology Section, Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, Kemitorvet, 2800 Kongens Lyngby, Denmark
| | - Lejla Imamovic
- Bacterial Synthetic Biology Section, Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, Kemitorvet, 2800 Kongens Lyngby, Denmark
| | - Billy K. C. Chow
- School of Biological Sciences, Faculty of Science, The University of Hong Kong, Hong Kong, Hong Kong, Special Administrative Region of China
| | - Anne A. Rode
- Department of Medicine, Zealand University Hospital, Køge, Denmark
- Department of Clinical Medicine, University of Copenhagen, Copenhagen, Denmark
| | - Peter Bytzer
- Department of Medicine, Zealand University Hospital, Køge, Denmark
- Department of Clinical Medicine, University of Copenhagen, Copenhagen, Denmark
| | - Morten Sommer
- Bacterial Synthetic Biology Section, Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, Kemitorvet, 2800 Kongens Lyngby, Denmark
| | - Gianni Panagiotou
- Systems Biology & Bioinformatics Group, School of Biological Sciences, Faculty of Sciences, The University of Hong Kong, Hong Kong, Hong Kong, Special Administrative Region of China
- Department of Systems Biology and Bioinformatics, Leibniz Institute for Natural Product Research and Infection Biology, Hans Knöll Institute (HKI), Beutenbergstraße 11a, 07745 Jena, Germany
- Department of Microbiology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, Hong Kong, Special Administrative Region of China
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14
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Wang L, Zhang L, Chow BKC. Secretin Prevents Apoptosis in the Developing Cerebellum Through Bcl-2 and Bcl-xL. J Mol Neurosci 2019; 68:494-503. [PMID: 30874970 DOI: 10.1007/s12031-019-01287-y] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [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: 01/07/2019] [Accepted: 02/28/2019] [Indexed: 01/30/2023]
Abstract
Secretin (SCT) is involved in a variety of physiological processes and has been implicated in preventing apoptosis during brain development. However, little is known about the molecular mechanism underlying its neuroprotective effects. The B cell lymphoma 2 (Bcl-2) family proteins, such as Bcl-2 and Bcl-xL, determine the commitment of neurons to apoptosis. In SCT knockout mice, we found reduced transcript levels of anti-apoptotic genes Bcl-2 and Bcl-xL, but not of pro-apoptotic gene Bax, in the developing cerebellum. SCT treatment on ex vivo cultured cerebellar slices triggered a time-dependent increase of Bcl-2 and Bcl-xL expression. This SCT-induced transcriptional regulation of Bcl-2 and Bcl-xL was dependent on the cyclic AMP (cAMP) response element-binding protein (CREB), which is a key survival factor at the convergence of multiple signaling cascades. We further demonstrated that activation of CREB by SCT was mediated by cAMP/protein kinase A (PKA) and mitogen-activated protein kinase (MAPK)/extracellular signal-regulated kinase 1/2 (ERK1/2) cascades. These findings, collectively, provide an uncharacterized signaling cascade for SCT-mediated neuronal survival, in which SCT promotes the key anti-apoptotic elements Bcl-2 and Bcl-xL in the intrinsic death pathway through PKA- and ERK-regulated CREB phosphorylation.
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Affiliation(s)
- Lei Wang
- School of Life Sciences, Guangzhou University, Guangzhou, China
| | - Li Zhang
- GHM Institute for CNS Regeneration, Jinan University, Guangzhou, China.
| | - Billy K C Chow
- School of Biological Sciences, The University of Hong Kong, Hong Kong, SAR, Hong Kong.
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15
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Mak SOK, Zhang L, Chow BKC. In vivo
actions of SCTR/AT1aR heteromer in controlling Vp expression and release
via
cFos/cAMP/CREB pathway in magnocellular neurons of PVN. FASEB J 2019; 33:5389-5398. [DOI: 10.1096/fj.201801732rr] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Affiliation(s)
- Sarah O. K. Mak
- School of Biological SciencesThe University of Hong Kong Hong Kong China
| | - Li Zhang
- Guangdong‐Hong Kong‐Macau (GHM) Institute of Central Nervous System (CNS) RegenerationJinan University Guangzhou China
| | - Billy K. C. Chow
- School of Biological SciencesThe University of Hong Kong Hong Kong China
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16
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Wood J, Tse MCL, Yang X, Brobst D, Liu Z, Pang BPS, Chan WS, Zaw AM, Chow BKC, Ye K, Lee CW, Chan CB. BDNF mimetic alleviates body weight gain in obese mice by enhancing mitochondrial biogenesis in skeletal muscle. Metabolism 2018; 87:113-122. [PMID: 29935237 DOI: 10.1016/j.metabol.2018.06.007] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/29/2018] [Revised: 05/14/2018] [Accepted: 06/17/2018] [Indexed: 12/25/2022]
Abstract
BACKGROUND 7,8-Dihydroxyflavone (7,8-DHF) is a small molecular weight compound that mimics the functions of brain-derived neurotrophic factor (BDNF). The current study aims to elucidate the molecular mechanism of 7,8-DHF-induced body weight regulation. METHODS Obese female C57/BL6 (20-week-old) mice that have been fed with high-fat diet for 13 weeks were treated with 7,8-DHF for 9 weeks. Various biochemical and molecular analyses were performed to examine the signal transduction pathway, metabolite content, and mitochondrial mass in the animals. Moreover, systemic energy metabolism and insulin sensitivity were determined by indirect calorimetry and insulin/glucose-tolerance tests. We have also determined the metabolic actions of 7,8-DHF on cultured myotubes. RESULTS 7,8-DHF treatment increased cellular respiration by promoting mitochondrial biogenesis in cultured skeletal muscle cells. In diet-induced obese mice, subsequent 7,8-DHF consumption triggered the AMPK/CREB/PGC-1α pathways to increase the muscular mitochondrial content. Systemic energy metabolism was thus elevated, which reduced the body weight gain in obese animals. Consequently, hyperlipidemia, hyperglycemia hyperinsulinemia, and ectopic lipid accumulation in skeletal muscle and liver of the obese animals were alleviated after 7,8-DHF treatment. Moreover, insulin sensitivity of the obese muscle was improved after 7,8-DHF consumption. CONCLUSION 7,8-DHF treatment increases muscular mitochondrial respiration and systemic energy expenditure, which alleviates the body weight gain and partially reverse the metabolic abnormalities induced by obesity.
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Affiliation(s)
- John Wood
- Department of Physiology, the University of Oklahoma Health Sciences Center, Oklahoma City, USA
| | - Margaret Chui Ling Tse
- School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, China
| | - Xiuying Yang
- State Key Laboratory of Bioactive Substance and Function of Natural Medicines, Beijing Key Laboratory of Drug Target and Screening Research, Institute of Materia Medica of Peking Union Medical College, Beijing, China
| | - Daniel Brobst
- Department of Physiology, the University of Oklahoma Health Sciences Center, Oklahoma City, USA
| | - Zhixue Liu
- Department of Physiology, the University of Oklahoma Health Sciences Center, Oklahoma City, USA
| | - Brian Pak Shing Pang
- School of Biological Sciences, the University of Hong Kong, Hong Kong, SAR, China
| | - Wing Suen Chan
- School of Biological Sciences, the University of Hong Kong, Hong Kong, SAR, China
| | - Aung Moe Zaw
- School of Biological Sciences, the University of Hong Kong, Hong Kong, SAR, China
| | - Billy K C Chow
- School of Biological Sciences, the University of Hong Kong, Hong Kong, SAR, China
| | - Keqiang Ye
- Department of Pathology, Emory University School of Medicine, Atlanta, USA
| | - Chi Wai Lee
- School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, China
| | - Chi Bun Chan
- School of Biological Sciences, the University of Hong Kong, Hong Kong, SAR, China; State Key Laboratory of Pharmaceutical Biotechnology, The University of Hong Kong, Hong Kong, SAR, China.
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17
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Wang R, Chow BKC, Zhang L. Distribution and Functional Implication of Secretin in Multiple Brain Regions. J Mol Neurosci 2018; 68:485-493. [PMID: 29882022 DOI: 10.1007/s12031-018-1089-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [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: 03/31/2018] [Accepted: 05/11/2018] [Indexed: 12/15/2022]
Abstract
Secretin is a polypeptide hormone initially identified for its gastrointestinal functions. However, emerging evidences show wide distribution of secretin and secretin receptor across various brain regions from cerebral cortex, hippocampus, hypothalamus to cerebellum. In this mini review, we will firstly describe the region-specific expression pattern of secretin and secretin receptor in the brain, followed by a summary of central physiological and neurological functions mediated by secretin. Using genetic manipulation and pharmaceutical approaches, one can elucidate the role of secretin in mediating various neurological functions from simple behaviors, such as water and food intake, to more complex functions including emotion, motor, and learning or memory. At last, current weakness and future perspectives of secretin in the central nervous system will be discussed, aiming to provide the potency of using secretin or its analog for treating various neurological disorders.
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Affiliation(s)
- Ruanna Wang
- Joint International Research Laboratory of CNS Regeneration, GHM Institute of CNS Regeneration, Jinan University, Guangzhou, China
| | - Billy K C Chow
- School of Biological Sciences, University of Hong Kong, Hong Kong SAR, China.
| | - Li Zhang
- Joint International Research Laboratory of CNS Regeneration, GHM Institute of CNS Regeneration, Jinan University, Guangzhou, China.
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18
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Wang L, Zhang L, Chow BKC. Secretin Modulates the Postnatal Development of Mouse Cerebellar Cortex Via PKA- and ERK-dependent Pathways. Front Cell Neurosci 2017; 11:382. [PMID: 29249942 PMCID: PMC5714926 DOI: 10.3389/fncel.2017.00382] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2017] [Accepted: 11/17/2017] [Indexed: 12/14/2022] Open
Abstract
Postnatal development of the cerebellum is critical for its intact function such as motor coordination and has been implicated in the pathogenesis of psychiatric disorders. We previously reported that deprivation of secretin (SCT) from cerebellar Purkinje neurons impaired motor coordination and motor learning function, while leaving the potential role of SCT in cerebellar development to be determined. SCT and its receptor (SCTR) were constitutively expressed in the postnatal cerebellum in a temporal and cell-specific manner. Using a SCT knockout mouse model, we provided direct evidence showing altered developmental patterns of Purkinje cells (PCs) and granular cells (GCs). SCT deprivation reduced the PC density, impaired the PC dendritic formation, induced accelerated GC migration and potentiated cerebellar apoptosis. Furthermore, our results indicated the involvement of protein kinase A (PKA) and extracellular signal regulated kinase (ERK) signaling pathways in SCT-mediated protective effects against neuronal apoptosis. Results of this study illustrated a novel function of SCT in the postnatal development of cerebellum, emphasizing the necessary role of SCT in cerebellar-related functions.
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Affiliation(s)
- Lei Wang
- School of Biological Sciences, University of Hong Kong, Pokfulam, Hong Kong
| | - Li Zhang
- GHM Institute of CNS Regeneration, Jinan University, Guangzhou, China
| | - Billy K. C. Chow
- School of Biological Sciences, University of Hong Kong, Pokfulam, Hong Kong
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19
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Zheng T, Ni Y, Li J, Chow BKC, Panagiotou G. Designing Dietary Recommendations Using System Level Interactomics Analysis and Network-Based Inference. Front Physiol 2017; 8:753. [PMID: 29033850 PMCID: PMC5625024 DOI: 10.3389/fphys.2017.00753] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2017] [Accepted: 09/19/2017] [Indexed: 12/14/2022] Open
Abstract
Background: A range of computational methods that rely on the analysis of genome-wide expression datasets have been developed and successfully used for drug repositioning. The success of these methods is based on the hypothesis that introducing a factor (in this case, a drug molecule) that could reverse the disease gene expression signature will lead to a therapeutic effect. However, it has also been shown that globally reversing the disease expression signature is not a prerequisite for drug activity. On the other hand, the basic idea of significant anti-correlation in expression profiles could have great value for establishing diet-disease associations and could provide new insights into the role of dietary interventions in disease. Methods: We performed an integrated analysis of publicly available gene expression profiles for foods, diseases and drugs, by calculating pairwise similarity scores for diet and disease gene expression signatures and characterizing their topological features in protein-protein interaction networks. Results: We identified 485 diet-disease pairs where diet could positively influence disease development and 472 pairs where specific diets should be avoided in a disease state. Multiple evidence suggests that orange, whey and coconut fat could be beneficial for psoriasis, lung adenocarcinoma and macular degeneration, respectively. On the other hand, fructose-rich diet should be restricted in patients with chronic intermittent hypoxia and ovarian cancer. Since humans normally do not consume foods in isolation, we also applied different algorithms to predict synergism; as a result, 58 food pairs were predicted. Interestingly, the diets identified as anti-correlated with diseases showed a topological proximity to the disease proteins similar to that of the corresponding drugs. Conclusions: In conclusion, we provide a computational framework for establishing diet-disease associations and additional information on the role of diet in disease development. Due to the complexity of analyzing the food composition and eating patterns of individuals our in silico analysis, using large-scale gene expression datasets and network-based topological features, may serve as a proof-of-concept in nutritional systems biology for identifying diet-disease relationships and subsequently designing dietary recommendations.
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Affiliation(s)
- Tingting Zheng
- Systems Biology and Bioinformatics Group, Faculty of Sciences, School of Biological Sciences, The University of HongKong, Hong Kong, Hong Kong
| | - Yueqiong Ni
- Systems Biology and Bioinformatics Group, Faculty of Sciences, School of Biological Sciences, The University of HongKong, Hong Kong, Hong Kong
| | - Jun Li
- Systems Biology and Bioinformatics Group, Faculty of Sciences, School of Biological Sciences, The University of HongKong, Hong Kong, Hong Kong
| | - Billy K C Chow
- Faculty of Science, School of Biological Sciences, The University of Hong Kong, Hong Kong, Hong Kong
| | - Gianni Panagiotou
- Systems Biology and Bioinformatics Group, Faculty of Sciences, School of Biological Sciences, The University of HongKong, Hong Kong, Hong Kong.,Department of Systems Biology and Bioinformatics, Leibniz Institute for Natural Product Research and Infection Biology, Hans Knöll Institute, Jena, Germany
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20
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Tse MCL, Herlea-Pana O, Brobst D, Yang X, Wood J, Hu X, Liu Z, Lee CW, Zaw AM, Chow BKC, Ye K, Chan CB. Tumor Necrosis Factor-α Promotes Phosphoinositide 3-Kinase Enhancer A and AMP-Activated Protein Kinase Interaction to Suppress Lipid Oxidation in Skeletal Muscle. Diabetes 2017; 66:1858-1870. [PMID: 28404596 PMCID: PMC5482076 DOI: 10.2337/db16-0270] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/26/2016] [Accepted: 03/29/2017] [Indexed: 12/12/2022]
Abstract
Tumor necrosis factor-α (TNF-α) is an inflammatory cytokine that plays a central role in obesity-induced insulin resistance. It also controls cellular lipid metabolism, but the underlining mechanism is poorly understood. We report in this study that phosphoinositide 3-kinase enhancer A (PIKE-A) is a novel effector of TNF-α to facilitate its metabolic modulation in the skeletal muscle. Depletion of PIKE-A in C2C12 myotubes diminished the inhibitory activities of TNF-α on mitochondrial respiration and lipid oxidation, whereas PIKE-A overexpression exacerbated these cellular responses. We also found that TNF-α promoted the interaction between PIKE-A and AMP-activated protein kinase (AMPK) to suppress its kinase activity in vitro and in vivo. As a result, animals with PIKE ablation in the skeletal muscle per se display an upregulation of AMPK phosphorylation and a higher preference to use lipid as the energy production substrate under high-fat diet feeding, which mitigates the development of diet-induced hyperlipidemia, ectopic lipid accumulation, and muscle insulin resistance. Hence, our data reveal PIKE-A as a new signaling factor that is important for TNF-α-initiated metabolic changes in skeletal muscle.
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Affiliation(s)
- Margaret Chui Ling Tse
- School of Biomedical Sciences, The University of Hong Kong, Hong Kong SAR, People's Republic of China
| | - Oana Herlea-Pana
- Department of Physiology, University of Oklahoma Health Sciences Center, Oklahoma City, OK
| | - Daniel Brobst
- Department of Physiology, University of Oklahoma Health Sciences Center, Oklahoma City, OK
| | - Xiuying Yang
- Department of Physiology, University of Oklahoma Health Sciences Center, Oklahoma City, OK
- Drug Screening Center, Institute of Materia Medica, Beijing, People's Republic of China
| | - John Wood
- Department of Physiology, University of Oklahoma Health Sciences Center, Oklahoma City, OK
| | - Xiang Hu
- Department of Physiology, University of Oklahoma Health Sciences Center, Oklahoma City, OK
| | - Zhixue Liu
- Department of Physiology, University of Oklahoma Health Sciences Center, Oklahoma City, OK
| | - Chi Wai Lee
- School of Biomedical Sciences, The University of Hong Kong, Hong Kong SAR, People's Republic of China
| | - Aung Moe Zaw
- School of Biological Sciences, The University of Hong Kong, Hong Kong SAR, People's Republic of China
| | - Billy K C Chow
- School of Biological Sciences, The University of Hong Kong, Hong Kong SAR, People's Republic of China
| | - Keqiang Ye
- Department of Pathology and Laboratory Medicine, Emory University School of Medicine, Atlanta, GA
| | - Chi Bun Chan
- School of Biological Sciences, The University of Hong Kong, Hong Kong SAR, People's Republic of China
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21
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Heshiki Y, Dissanayake T, Zheng T, Kang K, Yueqiong N, Xu Z, Sarkar C, Woo PCY, Chow BKC, Baker D, Yan A, Webster CJ, Panagiotou G, Li J. Toward a Metagenomic Understanding on the Bacterial Composition and Resistome in Hong Kong Banknotes. Front Microbiol 2017; 8:632. [PMID: 28450856 PMCID: PMC5389987 DOI: 10.3389/fmicb.2017.00632] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2017] [Accepted: 03/28/2017] [Indexed: 11/23/2022] Open
Abstract
Currency is possibly one of the main media transmitting pathogens and drug resistance due to its wide circulation in daily life. In this study, we made a comprehensive characterization of the bacterial community present on banknotes collected from different geographical regions of Hong Kong (HK) by performing in vitro characterization of the bacterial presence and resistome profile, as well as metagenomic analysis including microbial diversity, the prevalence of potential pathogens, the dissemination potential of antibiotic-resistance genes (ARGs), among others. When comparing the bacterial community of HK banknotes with other HK environmental samples, including water and marine sediment, we revealed that HK banknotes cover nearly 50% of total genera found in all the environmental samples, implying that banknotes harbor diverse bacteria originated from a variety of environments. Furthermore, the banknotes have higher abundance of potential pathogenic species (~5 times more) and ARGs (~5 times more) with higher dissemination potential (~48 times more) compared with other environmental samples. These findings unveiled the capabilities of this common medium of exchange to accommodate various bacteria, and transmit pathogens and antibiotic resistance. Furthermore, the observed independence of microbiome profile from the city's topological indices led us to formulate a hypothesis that due to their high circulation banknotes may harbor a homogenized microbiome.
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Affiliation(s)
- Yoshitaro Heshiki
- Systems Biology and Bioinformatics Group, School of Biological Sciences, Faculty of Sciences, University of Hong KongHong Kong, China
| | - Thrimendra Dissanayake
- Systems Biology and Bioinformatics Group, School of Biological Sciences, Faculty of Sciences, University of Hong KongHong Kong, China
| | - Tingting Zheng
- Systems Biology and Bioinformatics Group, School of Biological Sciences, Faculty of Sciences, University of Hong KongHong Kong, China
| | - Kang Kang
- Systems Biology and Bioinformatics Group, School of Biological Sciences, Faculty of Sciences, University of Hong KongHong Kong, China
| | - Ni Yueqiong
- Systems Biology and Bioinformatics Group, School of Biological Sciences, Faculty of Sciences, University of Hong KongHong Kong, China
| | - Zeling Xu
- School of Biological Sciences, Faculty of Science, University of Hong KongHong Kong, China
| | - Chinmoy Sarkar
- Healthy High Density Cities Lab, HKUrbanLab, University of Hong KongHong Kong, China
| | - Patrick C Y Woo
- Department of Microbiology, University of Hong KongHong Kong, Hong Kong.,State Key Laboratory of Emerging Infectious Diseases, University of Hong KongHong Kong, Hong Kong.,Research Centre of Infection and Immunology, University of Hong KongHong Kong, Hong Kong.,The Carol Yu Centre for Infection, University of Hong KongHong Kong.,Guangzhou Center for Disease Control and PreventionGuangzhou, China
| | - Billy K C Chow
- School of Biological Sciences, Faculty of Science, University of Hong KongHong Kong, China
| | - David Baker
- School of Biological Sciences, Faculty of Science, University of Hong KongHong Kong, China
| | - Aixin Yan
- School of Biological Sciences, Faculty of Science, University of Hong KongHong Kong, China
| | - Christopher J Webster
- Healthy High Density Cities Lab, HKUrbanLab, University of Hong KongHong Kong, China
| | - Gianni Panagiotou
- Systems Biology and Bioinformatics Group, School of Biological Sciences, Faculty of Sciences, University of Hong KongHong Kong, China.,Department of Systems Biology and Bioinformatics, Leibniz Institute for Natural Product Research and Infection Biology, Hans Knöll InstituteJena, Germany
| | - Jun Li
- Systems Biology and Bioinformatics Group, School of Biological Sciences, Faculty of Sciences, University of Hong KongHong Kong, China
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22
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Hu M, Yuan S, Ye ZW, Singh K, Li C, Shuai H, Fai N, Chow BKC, Chu H, Zheng BJ. PAN substitutions A37S, A37S/I61T and A37S/V63I attenuate the replication of H7N7 influenza A virus by impairing the polymerase and endonuclease activities. J Gen Virol 2017; 98:364-373. [PMID: 28113045 DOI: 10.1099/jgv.0.000717] [Citation(s) in RCA: 4] [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: 12/20/2022] Open
Abstract
Substitutions in the PA N-terminus (PAN) of influenza A viruses are associated with viral pathogenicity. During our previous study, which identified PAN-V63I and -A37S/I61T/V63I/V100A substitutions as virulence determinants, we observed a severe decrease in virus growth and transcription/replication capacity posed by PAN-A37S/V100A substitution. To further delineate the significance of substitutions at these positions, we generated mutant H7N7 viruses bearing the substitutions PAN-A37S, -A37S/I61T, -A37S/V63I, -V100A, -I61T/V100A and -V63I/V100A by reverse genetics. Our results showed that all mutant viruses except PAN-V100A showed a significantly reduced growth capability in infected cells. At the same time, the PAN-A37S, -A37S/I61T and -A37S/V63I mutant viruses displayed decreased viral transcription and replication by diminishing virus RNA synthesis activity. Biochemical assays indicated that the substitutions PAN-A37S, -A37S/I61T and -A37S/V63I suppressed the polymerase and endonuclease activities when compared with those of the wild-type. Together, our results demonstrated that the PAN-A37S, -A37S/I61T and -A37S/V63I substitutions contributed to a decreased pathogenicity of avian H7N7 influenza A virus.
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Affiliation(s)
- Meng Hu
- Department of Microbiology, The University of Hong Kong, Hong Kong SAR, PR China
| | - Shuofeng Yuan
- Department of Microbiology, The University of Hong Kong, Hong Kong SAR, PR China
| | - Zi-Wei Ye
- Department of Microbiology, The University of Hong Kong, Hong Kong SAR, PR China
| | - Kailash Singh
- School of Biological Sciences, The University of Hong Kong, Hong Kong SAR, PR China
| | - Cun Li
- Department of Microbiology, The University of Hong Kong, Hong Kong SAR, PR China
| | - Huiping Shuai
- Department of Microbiology, The University of Hong Kong, Hong Kong SAR, PR China
| | - Ng Fai
- Department of Microbiology, The University of Hong Kong, Hong Kong SAR, PR China
| | - Billy K C Chow
- School of Biological Sciences, The University of Hong Kong, Hong Kong SAR, PR China
| | - Hin Chu
- Department of Microbiology, The University of Hong Kong, Hong Kong SAR, PR China.,State Key Laboratory of Emerging Infectious Diseases, The University of Hong Kong, Hong Kong SAR, PR China
| | - Bo-Jian Zheng
- Carol Yu Centre for Infection, The University of Hong Kong, Hong Kong SAR, PR China.,Research Centre of Infection and Immunology, The University of Hong Kong, Hong Kong SAR, PR China.,Department of Microbiology, The University of Hong Kong, Hong Kong SAR, PR China.,State Key Laboratory of Emerging Infectious Diseases, The University of Hong Kong, Hong Kong SAR, PR China
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23
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Bai J, Chow BKC. Secretin is involved in sodium conservation through the renin-angiotensin-aldosterone system. FASEB J 2017; 31:1689-1697. [PMID: 28082350 DOI: 10.1096/fj.201600911r] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [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: 08/11/2016] [Accepted: 01/03/2017] [Indexed: 01/22/2023]
Abstract
Secretin (SCT) and its receptor (SCTR) are important in fluid regulation at multiple levels via the modulation of expression and translocation of renal aquaporin 2 and functions of central angiotensin II (ANGII). The functional interaction of SCT with peripheral ANGII, however, remains unknown. As the ANGII-aldosterone axis dominates the regulation of renal epithelial sodium channel (ENaC) function, we therefore tested whether SCT/SCTR can regulate sodium homeostasis via the renin-angiotensin-aldosterone system. SCTR-knockout (SCTR-/-) mice showed impaired aldosterone synthase (CYP11B2) expression and, consequently, aldosterone release upon intraperitoneal injection of ANGII. Endogenous ANGII production induced by dietary sodium restriction was higher in SCTR-/- than in C57BL/6N [wild-type (WT)] mice, but CYP11B2 and aldosterone synthesis were not elevated. Reduced accumulation of cholesteryl ester-the precursor of aldosterone-was observed in adrenal glands of SCTR-/- mice that were fed a low-sodium diet. Absence of SCTR resulted in elevated basal transcript levels of adrenal CYP11B2 and renal ENaCs. Although transcript and protein levels of ENaCs were similar in WT and SCTR-/- mice under sodium restriction, ENaCs in SCTR-/- mice were less sensitive to amiloride hydrochloride. In summary, the SCT/SCTR axis is involved in aldosterone precursor uptake, and the knockout of SCTR results in defective aldosterone biosynthesis/release and altered sensitivity of ENaCs to amiloride.-Bai, J., Chow, B. K. C. Secretin is involved in sodium conservation through the renin-angiotensin-aldosterone system.
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Affiliation(s)
- Juan Bai
- School of Biological Sciences, University of Hong Kong, Hong Kong, China
| | - Billy K C Chow
- School of Biological Sciences, University of Hong Kong, Hong Kong, China
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24
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Oren DA, Wei Y, Skrabanek L, Chow BKC, Mommsen T, Mojsov S. Structural Mapping and Functional Characterization of Zebrafish Class B G-Protein Coupled Receptor (GPCR) with Dual Ligand Selectivity towards GLP-1 and Glucagon. PLoS One 2016; 11:e0167718. [PMID: 27930690 PMCID: PMC5145181 DOI: 10.1371/journal.pone.0167718] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2016] [Accepted: 11/19/2016] [Indexed: 12/31/2022] Open
Abstract
GLP-1 and glucagon regulate glucose metabolism through a network of metabolic pathways initiated upon binding to their specific receptors that belong to class B G-protein coupled receptors (GPCRs). The therapeutic potential of glucagon is currently being evaluated, while GLP-1 is already used in the treatment of type 2 diabetes and obesity. Development of a second generation of GLP-1 based therapeutics depends on a molecular and structural understanding of the interactions between the GLP-1 receptor (GLP-1R) and its ligand GLP-1. There is considerable sequence conservation between GLP-1 and glucagon and between the hGLP-1R and human glucagon receptor (hGCGR), yet each receptor recognizes only its own specific ligand. Glucagon receptors in fish and frogs also exhibit ligand selectivity only towards glucagon and not GLP-1. Based on competitive binding experiments and assays of increase in intracellular cAMP, we demonstrate here that a GPCR in zebrafish (Danio rerio) exhibits dual ligand selectivity towards GLP-1 and glucagon, a characteristic not found in mammals. Further, many structural features found in hGLP-1R and hGCGR are also found in this zebrafish GPCR (zfGPCR). We show this by mapping of its sequence and structural features onto the hGLP-1R and hGCGR based on their partial and complementary crystal structures. Thus, we propose that zfGPCR represents a dual GLP-1R/GCGR. The main differences between the three receptors are in their stalk regions that connect their N-terminal extracellular domains (NECDs) with their transmembrane domains and the absence of loop 3 in the NECD in zfGLP-1R/GCGR. These observations suggest that the interactions between GLP-1 and glucagon with loop 3 and the stalk regions may induce different conformational changes in hGLP-1R and hGCGR upon ligand binding and activation that lead to selective recognition of their native ligands.
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Affiliation(s)
- Deena A. Oren
- The Rockefeller University, New York, New York, United States of America
| | - Yang Wei
- The Rockefeller University, New York, New York, United States of America
| | - Luce Skrabanek
- Applied Bioinformatics Core, Weill Cornell Medical College, New York, New York, United States of America
| | - Billy K. C. Chow
- School of Biological Sciences, The University of Hong Kong, Hong Kong SAR, China
| | - Thomas Mommsen
- Department of Biochemistry, University of Victoria, Victoria, British Columbia, Canada
| | - Svetlana Mojsov
- The Rockefeller University, New York, New York, United States of America
- * E-mail:
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25
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Yuan S, Chu H, Ye J, Singh K, Ye Z, Zhao H, Kao RYT, Chow BKC, Zhou J, Zheng BJ. Identification of a novel small-molecule compound targeting the influenza A virus polymerase PB1-PB2 interface. Antiviral Res 2016; 137:58-66. [PMID: 27840201 PMCID: PMC7113721 DOI: 10.1016/j.antiviral.2016.11.005] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2016] [Revised: 11/02/2016] [Accepted: 11/07/2016] [Indexed: 01/06/2023]
Abstract
The PB1 C-terminal domain and PB2 N-terminal domain interaction of the influenza A polymerase, which modulates the assembly of PB1 and PB2 subunits, may serve as a valuable target for the development of novel anti-influenza therapeutics. In this study, we performed a systematic screening of a chemical library, followed by the antiviral evaluation of primary hits and their analogues. Eventually, a novel small-molecule compound PP7 that abrogated the PB1-PB2 association and impaired viral polymerase activity was identified. PP7 exhibited antiviral activities against influenza virus subtypes A (H1N1)pdm09, A(H7N9) and A(H9N2) in cell cultures and partially protected mice against lethal challenge of mouse-adapted influenza A (H1N1)pdm09 virus. Surprisingly, a panel of other subtypes of influenza virus, including A(H5N1) and A(H7N7), showed various degrees of resistance to the compound. Biochemical studies revealed a similar pattern of resistance on the impairment of polymerase activity. Molecular docking analyses suggested a PP7-binding site that appeared to be completely conserved among the subtypes of the virus mentioned above. Thus, we propose that alternative/additional binding site (s) may exist for the regulation of PB1-PB2 subunits assembly of influenza A virus. A novel small-molecule compound was identified to provide anti-influenza effect in vitro and in vivo. An RT-qPCR based assay was modified to evaluate the polymerase activity of various subtypes of influenza viruses. The PB1-PB2 assembly strategies of the trimeric polymerase complex might be stain/subtype specific.
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Affiliation(s)
- Shuofeng Yuan
- Department of Microbiology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, China
| | - Hin Chu
- Department of Microbiology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, China
| | - Jiahui Ye
- Department of Microbiology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, China
| | - Kailash Singh
- School of Biological Sciences, Faculty of Science, The University of Hong Kong, Hong Kong, China
| | - Ziwei Ye
- Department of Microbiology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, China
| | - Hanjun Zhao
- Department of Microbiology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, China
| | - Richard Y T Kao
- Department of Microbiology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, China
| | - Billy K C Chow
- School of Biological Sciences, Faculty of Science, The University of Hong Kong, Hong Kong, China
| | - Jie Zhou
- Department of Microbiology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, China.
| | - Bo-Jian Zheng
- Department of Microbiology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, China.
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26
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Singh K, Senthil V, Arokiaraj AWR, Leprince J, Lefranc B, Vaudry D, Allam AA, Ajarem J, Chow BKC. Correction: Structure-Activity Relationship Studies of N- and C-Terminally Modified Secretin Analogs for the Human Secretin Receptor. PLoS One 2016; 11:e0165770. [PMID: 27783654 PMCID: PMC5081163 DOI: 10.1371/journal.pone.0165770] [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] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/04/2022] Open
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27
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Singh K, Zaw AM, Sekar R, Palak A, Allam AA, Ajarem J, Chow BKC. Glycyrrhizic Acid Reduces Heart Rate and Blood Pressure by a Dual Mechanism. Molecules 2016; 21:molecules21101291. [PMID: 27689971 PMCID: PMC6274536 DOI: 10.3390/molecules21101291] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2016] [Revised: 09/14/2016] [Accepted: 09/22/2016] [Indexed: 01/07/2023] Open
Abstract
Beta adrenergic receptors are crucial for their role in rhythmic contraction of heart along with their role in the pathological conditions such as tachycardia and high risk of heart failure. Studies report that the levels of beta-1 adrenergic receptor tend to decrease by 50%, whereas, the levels of beta-2 adrenergic receptor remains constant during the risk of heart failure. Beta blockers—the antagonistic molecules for beta-adrenergic receptors, function by slowing the heart rate, which thereby allows the left ventricle to fill completely during tachycardia incidents and hence helps in blood pumping capacity of heart and reducing the risk of heart failure. In the present study, we investigate the potential of glycyrrhizic acid (GA) as a possible principal drug molecule for cardiac arrhythmias owing to its ability to induce reduction in the heart rate and blood pressure. We use in vitro and in silico approach to study GA′s effect on beta adrenergic receptor along with an in vivo study to examine its effect on heart rate and blood pressure. Additionally, we explore GA′s proficiency in eliciting an increase in the plasma levels of vasoactive intestinal peptide, which by dilating the blood vessel consequently, can be a crucial aid during the occurrence of a potential heart attack. Therefore, we propose GA as a potential principal drug molecule via its potential in modulating heart rate and blood pressure.
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Affiliation(s)
- Kailash Singh
- School of Biological Sciences, The University of Hong Kong, Pokfulam Road, Hong Kong SAR, China.
| | - Aung Moe Zaw
- School of Biological Sciences, The University of Hong Kong, Pokfulam Road, Hong Kong SAR, China.
| | - Revathi Sekar
- School of Biological Sciences, The University of Hong Kong, Pokfulam Road, Hong Kong SAR, China.
| | - Ahuja Palak
- School of Biological Sciences, The University of Hong Kong, Pokfulam Road, Hong Kong SAR, China.
| | - Ahmed A Allam
- Department of Zoology, College of Science, King Saud University, Riyadh 11451, Saudi Arabia.
- Department of Zoology, Faculty of Science, Beni-Suef University, Beni-Suef 62511, Egypt.
| | - Jamaan Ajarem
- Department of Zoology, College of Science, King Saud University, Riyadh 11451, Saudi Arabia.
| | - Billy K C Chow
- School of Biological Sciences, The University of Hong Kong, Pokfulam Road, Hong Kong SAR, China.
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28
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Ng HKH, Harikumar KG, Miller LJ, Chow BKC. Signaling Modification by GPCR Heteromer and Its Implication on X-Linked Nephrogenic Diabetes Insipidus. PLoS One 2016; 11:e0163086. [PMID: 27649563 PMCID: PMC5029868 DOI: 10.1371/journal.pone.0163086] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2016] [Accepted: 09/04/2016] [Indexed: 11/18/2022] Open
Abstract
The involvement of secretin (SCT) and secretin receptor (SCTR) in regulating body water homeostasis is well established. Identified as one of the vasopressin (Vp)-independent mechanisms in fluid balance, SCT regulates aquaporin 2 (AQP2) in the kidney distal collecting duct cells through activating intracellular cAMP production. This ability to bypass Vp-mediated water reabsorption in kidney implicates SCT’s potential to treat nephrogenic diabetes insipidus (NDI). Research on NDI in the past has largely been focused on the searching for mutations in vasopressin receptor 2 (AVPR2), while the functional relationship between SCTR, AVPR2 and NDI remains unclear. Here, we demonstrate the interaction between SCTR and AVPR2 to modulate cellular signaling in vitro. Interestingly, we show in this report that upon heteromer formation with SCTR, R137H, a NDI-causing AVPR2 mutant that is defective in trafficking to cell surface, can functionally be rescued. Our data may provide an explanation for this clinically mild case of NDI, and insights into the pathological development of NDI in the future.
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MESH Headings
- Animals
- CHO Cells
- Cricetinae
- Cricetulus
- Diabetes Insipidus, Nephrogenic/genetics
- Diabetes Insipidus, Nephrogenic/metabolism
- Gene Expression
- Genetic Diseases, X-Linked/genetics
- Genetic Diseases, X-Linked/metabolism
- Humans
- Mice
- Microscopy, Confocal
- Mutation
- Protein Binding
- Protein Multimerization
- Receptors, G-Protein-Coupled/chemistry
- Receptors, G-Protein-Coupled/genetics
- Receptors, G-Protein-Coupled/metabolism
- Receptors, Gastrointestinal Hormone/chemistry
- Receptors, Gastrointestinal Hormone/genetics
- Receptors, Gastrointestinal Hormone/metabolism
- Receptors, Vasopressin/chemistry
- Receptors, Vasopressin/genetics
- Receptors, Vasopressin/metabolism
- Reverse Transcriptase Polymerase Chain Reaction
- Signal Transduction/genetics
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Affiliation(s)
- Hans K. H. Ng
- School of Biological Sciences, The University of Hong Kong, Hong Kong, China
| | - Kaleeckal G. Harikumar
- Department of Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic, Scottsdale, Arizona, 85259, United States of America
| | - Laurence J. Miller
- Department of Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic, Scottsdale, Arizona, 85259, United States of America
| | - Billy K. C. Chow
- School of Biological Sciences, The University of Hong Kong, Hong Kong, China
- * E-mail:
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Yuan S, Chu H, Ye J, Hu M, Singh K, Chow BKC, Zhou J, Zheng BJ. Peptide-Mediated Interference of PB2-eIF4G1 Interaction Inhibits Influenza A Viruses' Replication in Vitro and in Vivo. ACS Infect Dis 2016; 2:471-7. [PMID: 27626099 DOI: 10.1021/acsinfecdis.6b00064] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [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: 12/25/2022]
Abstract
Influenza viruses are obligate parasites that hijack the host cellular system. Previous results have shown that the influenza virus PB2 subunit confers a dependence of host eukaryotic translation initiation factor 4-γ 1 (eIF4G1) for viral mRNA translation. Here, we demonstrated that peptide-mediated interference of the PB2-eIF4G1 interaction inhibited virus replication in vitro and in vivo. Remarkably, intranasal administration of the peptide provided 100% protection against lethal challenges of influenza A viruses in BALB/c mice, including H1N1, H5N1, and H7N9 influenza virus subtypes. Mapping of the PB2 protein indicated that the eIF4G1 binding sites resided within the PB2 cap-binding domain. Virtual docking analysis suggested that the inhibitory peptide associated with the conserved amino acid residues that were essential to PB2 cap-binding activity. Overall, our results identified the PB2-eIF4G1 interactive site as a druggable target for influenza therapeutics.
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Affiliation(s)
- Shuofeng Yuan
- Department of Microbiology,
Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China
| | - Hin Chu
- Department of Microbiology,
Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China
| | - Jiahui Ye
- Department of Microbiology,
Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China
| | - Meng Hu
- Department of Microbiology,
Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China
| | - Kailash Singh
- School of Biological Sciences, Faculty of Science, The University of Hong Kong, Hong Kong SAR, China
| | - Billy K. C. Chow
- School of Biological Sciences, Faculty of Science, The University of Hong Kong, Hong Kong SAR, China
| | - Jie Zhou
- Department of Microbiology,
Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China
| | - Bo-Jian Zheng
- Department of Microbiology,
Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China
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Sekar R, Singh K, Arokiaraj AWR, Chow BKC. Pharmacological Actions of Glucagon-Like Peptide-1, Gastric Inhibitory Polypeptide, and Glucagon. Int Rev Cell Mol Biol 2016; 326:279-341. [PMID: 27572131 DOI: 10.1016/bs.ircmb.2016.05.002] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Glucagon family of peptide hormones is a group of structurally related brain-gut peptides that exert their pleiotropic actions through interactions with unique members of class B1 G protein-coupled receptors (GPCRs). They are key regulators of hormonal homeostasis and are important drug targets for metabolic disorders such as type-2 diabetes mellitus (T2DM), obesity, and dysregulations of the nervous systems such as migraine, anxiety, depression, neurodegeneration, psychiatric disorders, and cardiovascular diseases. The current review aims to provide a detailed overview of the current understanding of the pharmacological actions and therapeutic advances of three members within this family including glucagon-like peptide-1 (GLP-1), gastric inhibitory polypeptide (GIP), and glucagon.
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Affiliation(s)
- R Sekar
- School of Biological Sciences, University of Hong Kong, Hong Kong, China
| | - K Singh
- School of Biological Sciences, University of Hong Kong, Hong Kong, China
| | - A W R Arokiaraj
- School of Biological Sciences, University of Hong Kong, Hong Kong, China
| | - B K C Chow
- School of Biological Sciences, University of Hong Kong, Hong Kong, China.
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31
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Harikumar KG, Augustine ML, Lee LTO, Chow BKC, Miller LJ. Structure and Function of Cross-class Complexes of G Protein-coupled Secretin and Angiotensin 1a Receptors. J Biol Chem 2016; 291:17332-44. [PMID: 27330080 DOI: 10.1074/jbc.m116.730754] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [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: 04/02/2016] [Indexed: 01/14/2023] Open
Abstract
Complexes of secretin (SecR) and angiotensin 1a (Atr1a) receptors have been proposed to be functionally important in osmoregulation, providing an explanation for overlapping and interdependent functions of hormones that bind and activate different classes of GPCRs. However, the nature of these cross-class complexes has not been well characterized and their signaling properties have not been systematically explored. We now use competitive inhibition of receptor bioluminescence resonance energy transfer and bimolecular fluorescence complementation to establish the dominant functionally important state as a symmetrical homodimeric form of SecR decorated by monomeric Atr1a, interacting through lipid-exposed faces of Atr1a TM1 and TM4. Conditions increasing prevalence of this complex exhibited negative allosteric modulatory impact on secretin-stimulated cAMP responses at SecR. In contrast, activating Atr1a with full agonist in such a complex exhibited a positive allosteric modulatory impact on the same signaling event. This modulation was functionally biased, with secretin-stimulated calcium responses unaffected, whereas angiotensin-stimulated calcium responses through the complex were reduced or absent. Further supporting this interpretation, Atr1a with mutations of lipid-exposed faces of TM1 and TM4 that did not affect its ability to bind or signal, could be expressed in the same cell as SecR, yet not exhibit either the negative or positive allosteric impact on cAMP observed with the inactive or activated states of wild type Atr1a on function, and not interfere with angiotensin-stimulated calcium responses like complexes with Atr1a. This may provide a more selective means of exploring the physiologic functional impact of this cross-class receptor complex without interfering with the function of either component receptor.
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Affiliation(s)
- Kaleeckal G Harikumar
- From the Department of Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic, Scottsdale, Arizona 85259
| | - Mary Lou Augustine
- From the Department of Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic, Scottsdale, Arizona 85259
| | - Leo T O Lee
- the Centre of Reproduction, Development and Aging, University of Macau, Taipa, Macau, and
| | - Billy K C Chow
- the School of Biological Sciences, The University of Hong Kong, Pokfulam Road, Hong Kong
| | - Laurence J Miller
- From the Department of Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic, Scottsdale, Arizona 85259,
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Abstract
Water and salt metabolism are tightly regulated processes. Maintaining this milieu intérieur within narrow limits is critical for normal physiological processes to take place. Disturbances to this balance can result in disease and even death. Some of the better-characterized regulators of water and salt homeostasis include angiotensin II, aldosterone, arginine vasopressin, and oxytocin. Although secretin (SCT) was first described >100 years ago, little is known about the role of this classic gastrointestinal hormone in the maintenance of water-salt homeostasis. In recent years, increasing body of evidence suggested that SCT and its receptor play important roles in the central nervous system and kidney to ensure that the mammalian extracellular fluid osmolarity is kept within a healthy range. In this review, we focus on recent advances in our understanding of the molecular, cellular, and network mechanisms by which SCT and its receptor mediate the control of osmotic homeostasis. Implications of hormonal cross talk and receptor-receptor interaction are highlighted.
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Affiliation(s)
- Jenny Juan Bai
- School of Biological Sciences, University of Hong Kong, Hong Kong, China
| | - Chong Da Tan
- School of Biological Sciences, University of Hong Kong, Hong Kong, China
| | - Billy K C Chow
- School of Biological Sciences, University of Hong Kong, Hong Kong, China
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Yuan S, Chu H, Zhang K, Ye J, Singh K, Kao RYT, Chow BKC, Zhou J, Zheng BJ. A novel small-molecule compound disrupts influenza A virus PB2 cap-binding and inhibits viral replication. J Antimicrob Chemother 2016; 71:2489-97. [PMID: 27272726 DOI: 10.1093/jac/dkw194] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2016] [Accepted: 04/22/2016] [Indexed: 12/18/2022] Open
Abstract
OBJECTIVES The conserved residues 318-483 in the PB2 subunit of influenza A polymerase is an independently folded cap-binding domain (PB2cap) that exhibits a distinct binding mode from other host cap-binding proteins, which suggests that PB2cap might be an ideal drug target. This study aimed to identify a new class of anti-influenza inhibitors that specifically disrupts the interaction between PB2cap and host cap structures. METHODS An innovative fluorescence polarization assay was established for primary screening, followed by cap-binding inhibitory activity, antiviral efficacy and cytotoxicity evaluations of the selected compounds. The best compound was characterized by multi-cycle virus growth assay, cross-protection test, synergism evaluation, mini-replicon assay, binding affinity analysis, docking simulation and mouse study. RESULTS Several PB2 cap-binding inhibitors were discovered. The compound 7-(4-hydroxy-2-oxo-2H-chromen-3-yl)-6H,7H,8H-chromeno[3',4':5,6]pyrano[3,2-c]chromene-6,8-dione, designated PB2-39, was identified as a potent inhibitor of replication of multiple subtypes of influenza A virus, including H1N1, H3N2, H5N1, H7N7, H7N9 and H9N2 in vitro and H1N1, H5N1 and H7N9 in vivo. Combinational treatment with the influenza virus release inhibitor zanamivir and PB2-39 exerted a synergistic anti-influenza effect. Mechanistic experiments supported that PB2-39 suppressed viral polymerase activity. Docking and binding affinity analyses demonstrated that PB2-39 interacted with the PB2 cap-binding pocket, suggesting its role as a cap-binding competitor. CONCLUSIONS Our study provides new insights for the strategic development of novel cap-binding inhibitors of influenza A viruses.
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Affiliation(s)
- Shuofeng Yuan
- Department of Microbiology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China
| | - Hin Chu
- Department of Microbiology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China
| | - Ke Zhang
- Department of Microbiology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China
| | - Jiahui Ye
- Department of Microbiology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China
| | - Kailash Singh
- School of Biological Sciences, Faculty of Science, The University of Hong Kong, Hong Kong SAR, China
| | - Richard Y T Kao
- Department of Microbiology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China
| | - Billy K C Chow
- School of Biological Sciences, Faculty of Science, The University of Hong Kong, Hong Kong SAR, China
| | - Jie Zhou
- Department of Microbiology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China
| | - Bo-Jian Zheng
- Department of Microbiology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China
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Chua OWH, Wong KKL, Ko BC, Chung SK, Chow BKC, Lee LTO. Role of nuclear factor of activated T-cells 5 in regulating hypertonic-mediated secretin receptor expression in kidney collecting duct cells. Biochim Biophys Acta 2016; 1859:922-32. [PMID: 27080132 DOI: 10.1016/j.bbagrm.2015.12.009] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/15/2015] [Revised: 11/27/2015] [Accepted: 12/21/2015] [Indexed: 11/18/2022]
Abstract
A growing body of evidence suggests that secretin (SCT) is an important element in the osmoregulatory pathway. It is interesting to note that both SCT and its receptor (SCTR) gene are activated upon hyperosmolality in the kidney. However, the precise molecular mechanisms underlying the induction of the SCTR gene expression in response to changes in osmolality have yet to be clarified. Detailed DNA sequence analysis of the promoter regions of the SCTR gene reveals the presence of multiple osmotic response elements (ORE). The ORE is the binding site of a key osmosensitive transactivator, namely, the nuclear factor of activated T-cells 5 (NFAT5). SCTR and NFAT5 are co-expressed in the kidney cortex and medulla collecting duct cells. We therefore hypothesize that NFAT5 is responsible for modulating SCTR expression in hypertonic environments. In this study, we found hypertonicity stimulates the promoter activities and endogenous gene expression of SCTR in mouse kidney cortex collecting duct cells (M1) and inner medulla collecting duct cells (mIMCD3). The overexpression and silencing of NFAT5 further confirmed it to be responsible for the up-regulation of the SCTR gene under hypertonic conditions. A significant increase in the interaction between NFAT5 and the SCTR promoter was also observed following chromatin immunoprecipitation assay. In vivo, osmotic stress up-regulates the SCTR gene in the kidney cortex and medulla of wild-type mice, but does not do so in NFAT5(+/-) animals. Hence, this study provides comprehensive information on how NFAT5 regulates SCTR expression in different osmotic environments.
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Affiliation(s)
- Oscar W H Chua
- School of Biological Sciences, The University of Hong Kong, Hong Kong, China
| | - Kenneth K L Wong
- School of Biological Sciences, The University of Hong Kong, Hong Kong, China
| | - Ben C Ko
- Department of Applied Biology and Chemical Technology, The Hong Kong Polytechnic University, Hong Kong, China
| | - Sookja K Chung
- Department of Anatomy and the State Key Laboratory of Pharmaceutical Biotechnology, The University of Hong Kong, Hong Kong, China; HBHA Research Center, Faculty of Medicine, The University of Hong Kong, China
| | - Billy K C Chow
- School of Biological Sciences, The University of Hong Kong, Hong Kong, China
| | - Leo T O Lee
- Faculty of Health Sciences, University of Macau, Taipa, Macau, China.
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Yuan S, Chu H, Singh K, Zhao H, Zhang K, Kao RYT, Chow BKC, Zhou J, Zheng BJ. A novel small-molecule inhibitor of influenza A virus acts by suppressing PA endonuclease activity of the viral polymerase. Sci Rep 2016; 6:22880. [PMID: 26956222 PMCID: PMC4783701 DOI: 10.1038/srep22880] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2015] [Accepted: 02/23/2016] [Indexed: 12/17/2022] Open
Abstract
The RNA-dependent RNA polymerase of influenza A virus comprises conserved and independently-folded subdomains with defined functionalities. The N-terminal domain of the PA subunit (PAN) harbors the endonuclease function so that it can serve as a desired target for drug discovery. To identify a class of anti-influenza inhibitors that impedes PAN endonuclease activity, a screening approach that integrated the fluorescence resonance energy transfer based endonuclease inhibitory assay with the DNA gel-based endonuclease inhibitory assay was conducted, followed by the evaluation of antiviral efficacies and potential cytotoxicity of the primary hits in vitro and in vivo. A small-molecule compound ANA-0 was identified as a potent inhibitor against the replication of multiple subtypes of influenza A virus, including H1N1, H3N2, H5N1, H7N7, H7N9 and H9N2, in cell cultures. Combinational treatment of zanamivir and ANA-0 exerted synergistic anti-influenza effect in vitro. Intranasal administration of ANA-0 protected mice from lethal challenge and reduced lung viral loads in H1N1 virus infected BALB/c mice. In summary, ANA-0 shows potential to be developed to novel anti-influenza agents.
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Affiliation(s)
- Shuofeng Yuan
- Department of Microbiology, The University of Hong Kong, Hong Kong SAR, China
| | - Hin Chu
- Department of Microbiology, The University of Hong Kong, Hong Kong SAR, China
| | - Kailash Singh
- School of Biological Sciences, The University of Hong Kong, Hong Kong SAR, China
| | - Hanjun Zhao
- Department of Microbiology, The University of Hong Kong, Hong Kong SAR, China
| | - Ke Zhang
- Department of Microbiology, The University of Hong Kong, Hong Kong SAR, China
| | - Richard Y T Kao
- Department of Microbiology, The University of Hong Kong, Hong Kong SAR, China
| | - Billy K C Chow
- School of Biological Sciences, The University of Hong Kong, Hong Kong SAR, China
| | - Jie Zhou
- Department of Microbiology, The University of Hong Kong, Hong Kong SAR, China
| | - Bo-Jian Zheng
- Department of Microbiology, The University of Hong Kong, Hong Kong SAR, China
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36
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Singh K, Senthil V, Arokiaraj AWR, Leprince J, Lefranc B, Vaudry D, Allam AA, Ajarem J, Chow BKC. Structure-Activity Relationship Studies of N- and C-Terminally Modified Secretin Analogs for the Human Secretin Receptor. PLoS One 2016; 11:e0149359. [PMID: 26930505 PMCID: PMC4773067 DOI: 10.1371/journal.pone.0149359] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2014] [Accepted: 01/03/2016] [Indexed: 11/18/2022] Open
Abstract
The pleiotropic role of human secretin (hSCT) validates its potential use as a therapeutic agent. Nevertheless, the structure of secretin in complex with its receptor is necessary to develop a suitable therapeutic agent. Therefore, in an effort to design a three-dimensional virtual homology model and identify a peptide agonist and/or antagonist for the human secretin receptor (hSR), the significance of the primary sequence of secretin peptides in allosteric binding and activation was elucidated using virtual docking, FRET competitive binding and assessment of the cAMP response. Secretin analogs containing various N- or C-terminal modifications were prepared based on previous findings of the role of these domains in receptor binding and activation. These analogs exhibited very low or no binding affinity in a virtual model, and were found to neither exhibit in vitro binding nor agonistic or antagonistic properties. A parallel analysis of the analogs in the virtual model and in vitro studies revealed instability of these peptide analogs to bind and activate the receptor.
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Affiliation(s)
- Kailash Singh
- School of Biological Sciences, The University of Hong Kong, Pokfulam Road, Hong Kong SAR, China
| | - Vijayalakshmi Senthil
- School of Biological Sciences, The University of Hong Kong, Pokfulam Road, Hong Kong SAR, China
| | | | - Jérôme Leprince
- Laboratory of Neuronal and Neuroendocrine Differentiation and Communication, Neurotrophic Factors and Neuronal Differentiation Team, Inserm U982, Associated International Laboratory Samuel de Champlain, Regional Platform for Cell Imaging of Haute-Normandie (PRIMACEN), University of Rouen, Mont-Saint-Aignan, France
| | - Benjamin Lefranc
- Laboratory of Neuronal and Neuroendocrine Differentiation and Communication, Neurotrophic Factors and Neuronal Differentiation Team, Inserm U982, Associated International Laboratory Samuel de Champlain, Regional Platform for Cell Imaging of Haute-Normandie (PRIMACEN), University of Rouen, Mont-Saint-Aignan, France
| | - David Vaudry
- Laboratory of Neuronal and Neuroendocrine Differentiation and Communication, Neurotrophic Factors and Neuronal Differentiation Team, Inserm U982, Associated International Laboratory Samuel de Champlain, Regional Platform for Cell Imaging of Haute-Normandie (PRIMACEN), University of Rouen, Mont-Saint-Aignan, France
| | - Ahmed A. Allam
- Department of Zoology, College of Science, King Saud University, Riyadh 11451, Saudi Arabia
- Department of Zoology, Faculty of Science, Beni-Suef University, Beni-Suef, Egypt
| | - Jamaan Ajarem
- Department of Zoology, College of Science, King Saud University, Riyadh 11451, Saudi Arabia
| | - Billy K. C. Chow
- School of Biological Sciences, The University of Hong Kong, Pokfulam Road, Hong Kong SAR, China
- * E-mail:
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37
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On JSW, Duan C, Chow BKC, Lee LTO. Functional Pairing of Class B1 Ligand-GPCR in Cephalochordate Provides Evidence of the Origin of PTH and PACAP/Glucagon Receptor Family. Mol Biol Evol 2015; 32:2048-59. [PMID: 25841489 DOI: 10.1093/molbev/msv087] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [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: 12/20/2022] Open
Abstract
Several hypotheses have been proposed regarding the origin and evolution of the secretin family of peptides and receptors. However, identification of homologous ligand-receptor pairs in invertebrates and vertebrates is difficult because of the low levels of sequence identity between orthologs of distant species. In this study, five receptors structurally related to the vertebrate class B1 G protein-coupled receptor (GPCR) family were characterized from amphioxus (Branchiostoma floridae). Phylogenetic analysis showed that they clustered with vertebrate parathyroid hormone receptors (PTHR) and pituitary adenylate cyclase-activating polypeptide (PACAP)/glucagon receptors. These PTHR-like receptors shared synteny with several PTH and PACAP/glucagon receptors identified in spotted gar, Xenopus, and human, indicating that amphioxus preserves the ancestral chordate genomic organization of these receptor subfamilies. According to recent data by Mirabeau and Joly, amphioxus also expresses putative peptide ligands including homologs of PTH (bfPTH1 and 2) and PACAP/GLUC-like peptides (bfPACAP/GLUCs) that may interact with these receptors. Functional analyses showed that bfPTH1 and bfPTH2 activated one of the amphioxus receptors (bf98C) whereas bfPACAP/GLUCs strongly interacted with bf95. In summary, our data confirm the presence of PTH and PACAP/GLUC ligand-receptor pairs in amphioxus, demonstrating that functional homologs of vertebrate PTH and PACAP/glucagon GPCR subfamilies arose before the cephalochordate divergence from the ancestor of tunicates and vertebrates.
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Affiliation(s)
- Jason S W On
- School of Biological Sciences, The University of Hong Kong, Hong Kong, China
| | - Cumming Duan
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor
| | - Billy K C Chow
- School of Biological Sciences, The University of Hong Kong, Hong Kong, China
| | - Leo T O Lee
- School of Biological Sciences, The University of Hong Kong, Hong Kong, China
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38
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Abstract
G-protein-coupled receptors (GPCRs) are classified into A to F subfamilies in which only families A, B, and C are present in mammals. Some of these GPCRs were found to form higher ordered structures such as oligomers with the discovery of interacting receptors in the form of homomers or heteromers. The importance of these oligomers on regulating receptor functions has recently been an intense research focus. It has been proposed that receptor oligomer formation has impact on its physiological importance on receptor trafficking, signaling, ligand-related regulation, and also is related to certain diseases. The present body of knowledge, however, comprises mainly intra-family oligomers formation and their consequences. Inter-family oligomers are recognized but there is limited information. This article aims to provide a current view regarding inter-family GPCR oligomerization in the subfamilies A, B, and C found in mammals.
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Affiliation(s)
- Hans K. H. Ng
- Department of Endocrinology, School of Biological Sciences, The University of Hong Kong, Hong Kong, China
| | - Billy K. C. Chow
- Department of Endocrinology, School of Biological Sciences, The University of Hong Kong, Hong Kong, China
- *Correspondence: Billy K. C. Chow, Endocrinology, School of Biological Sciences, The University of Hong Kong, Pokfulam Road, Hong Kong, China e-mail:
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39
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Abstract
The presence of the parathyroid hormones in vertebrates, including PTH, PTH-related peptide (PTHrP), and tuberoinfundibular peptide of 39 residues (TIP39), has been proposed to be the result of two rounds of whole genome duplication in the beginning of vertebrate diversification. Bioinformatics analyses, in particular chromosomal synteny study and the characterization of the PTH ligands and their receptors from various vertebrate species, provide evidence that strongly supports this hypothesis. In this mini-review, we summarize recent advances in studies regarding the molecular evolution and physiology of the PTH ligands and their receptors, with particular focus on non-mammalian vertebrates. In summary, the PTH family of peptides probably predates early vertebrate evolution, indicating a more ancient existence as well as a function of these peptides in invertebrates.
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Affiliation(s)
- Jason S. W. On
- School of Biological Sciences, The University of Hong Kong, Hong Kong, China
| | - Billy K. C. Chow
- School of Biological Sciences, The University of Hong Kong, Hong Kong, China
| | - Leo T. O. Lee
- School of Biological Sciences, The University of Hong Kong, Hong Kong, China
- *Correspondence: Leo T. O. Lee, School of Biological Sciences, The University of Hong Kong, Pokfulam Road, Hong Kong, China e-mail:
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40
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Abstract
In mammals, secretin is a 27-amino acid peptide that was first studied in 1902 by Bayliss and Starling from the extracts of the jejunal mucosa for its ability to stimulate pancreatic secretion. To date, secretin has only been identified in tetrapods, with the earliest diverged secretin found in frogs. Despite being the first hormone discovered, secretin's evolutionary origin remains enigmatic, it shows moderate sequence identity in nonmammalian tetrapods but is highly conserved in mammals. Current hypotheses suggest that although secretin has already emerged before the divergence of osteichthyans, it was lost in fish and retained only in land vertebrates. Nevertheless, the cognate receptor of secretin has been identified in both actinopterygian fish (zebrafish) and sarcopterygian fish (lungfish). However, the zebrafish secretin receptor was shown to be nonbioactive. Based on the present information that the earliest diverged bioactive secretin receptor was found in lungfish, and its ability to interact with both vasoactive intestinal peptide and pituitary adenylate cyclase-activating polypeptide potently suggested that secretin receptor was descended from a VPAC-like receptor gene before the Actinopterygii-Sarcopterygii split in the vertebrate lineage. Hence, secretin and secretin receptor have gone through independent evolutionary trajectories despite their concurrent emergence post-2R. A functional secretin-secretin receptor axis has probably emerged in the amphibians. Although the pleiotropic actions of secretin are well documented in the literature, only limited information of its physiological functions in nonmammalian tetrapods have been reported. To decipher the structural and functional divergence of secretin and secretin receptor, functional characterization of the ligand-receptor pair in nonmammals would be the next perspective for investigation.
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Affiliation(s)
- Janice K V Tam
- School of Biological SciencesThe University of Hong Kong, Pokfulam Road, Hong Kong, Hong Kong
| | - Leo T O Lee
- School of Biological SciencesThe University of Hong Kong, Pokfulam Road, Hong Kong, Hong Kong
| | - Jun Jin
- School of Biological SciencesThe University of Hong Kong, Pokfulam Road, Hong Kong, Hong Kong
| | - Billy K C Chow
- School of Biological SciencesThe University of Hong Kong, Pokfulam Road, Hong Kong, Hong Kong
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41
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Sekar R, Chow BKC. Secretin receptor‐knockout mice are resistant to high‐fat diet‐induced obesity and exhibit impaired intestinal lipid absorption. FASEB J 2014; 28:3494-505. [DOI: 10.1096/fj.13-247536] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Revathi Sekar
- School of Biological Sciences, The University of Hong KongHong KongChina
| | - Billy K. C. Chow
- School of Biological Sciences, The University of Hong KongHong KongChina
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42
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Lee LTO, Ng SYL, Chu JYS, Sekar R, Harikumar KG, Miller LJ, Chow BKC. Transmembrane peptides as unique tools to demonstrate the in vivo action of a cross-class GPCR heterocomplex. FASEB J 2014; 28:2632-44. [PMID: 24599969 DOI: 10.1096/fj.13-246868] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Angiotensin (ANGII) and secretin (SCT) share overlapping, interdependent osmoregulatory functions in brain, where SCT peptide/receptor function is required for ANGII action, yet the molecular basis is unknown. Since receptors for these peptides (AT1aR, SCTR) are coexpressed in osmoregulatory centers, a possible mechanism is formation of a cross-class receptor heterocomplex. Here, we demonstrate such a complex and its functional importance to modulate signaling. Association of AT1aR with SCTR reduced ability of SCT to stimulate cyclic adenosine monophosphate (cAMP), with signaling augmented in presence of ANGII or constitutively active AT1aR. Several transmembrane (TM) peptides of these receptors were able to affect their conformation within complexes, reducing receptor BRET signals. AT1aR TM1 affected only formation and activity of the heterocomplex, without effect on homomers of either receptor, and reduced SCT-stimulated cAMP responses in cells expressing both receptors. This peptide was active in vivo by injection into mouse lateral ventricle, thereby suppressing water-drinking behavior after hyperosmotic shock, similar to SCTR knockouts. This supports the interpretation that active conformation of AT1aR is a key modulator of cAMP responses induced by SCT stimulation of SCTR. The SCTR/AT1aR complex is physiologically important, providing differential signaling to SCT in settings of hyperosmolality or food intake, modulated by differences in levels of ANGII.
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Affiliation(s)
- Leo T O Lee
- School of Biological Sciences, University of Hong Kong, Hong Kong, China; and
| | - Stephanie Y L Ng
- School of Biological Sciences, University of Hong Kong, Hong Kong, China; and
| | - Jessica Y S Chu
- School of Biological Sciences, University of Hong Kong, Hong Kong, China; and
| | - Revathi Sekar
- School of Biological Sciences, University of Hong Kong, Hong Kong, China; and
| | - Kaleeckal G Harikumar
- Department of Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic, Scottsdale, Arizona, USA
| | - Laurence J Miller
- Department of Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic, Scottsdale, Arizona, USA
| | - Billy K C Chow
- School of Biological Sciences, University of Hong Kong, Hong Kong, China; and
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Abstract
Secretin (SCT) was firstly discovered as a gut peptide hormone in stimulating pancreatic secretion, while its novel neuropeptide role has drawn substantial research interests in recent years. SCT and its receptor (SCTR) are widely expressed in different brain regions, where they exert multiple cellular functions including neurotransmission, gene expression regulation, neurogenesis, and neural protection. As all these neural functions ultimately can affect behaviors, it is hypothesized that SCT controls multiple behavioral paradigms. Current findings support this hypothesis as SCT-SCTR axis participates in modulating social interaction, spatial learning, water and food intake, motor coordination, and motor learning behaviors. This mini-review focuses on various aspects of SCT and SCTR in hippocampus, hypothalamus, and cerebellum including distribution profiles, cellular functions, and behavioral phenotypes to elucidate the link between cellular mechanisms and behavioral control.
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Affiliation(s)
- Li Zhang
- School of Biological Sciences, University of Hong Kong, Hong Kong, China
| | - Billy K. C. Chow
- School of Biological Sciences, University of Hong Kong, Hong Kong, China
- *Correspondence: Billy K. C. Chow, School of Biological Sciences, University of Hong Kong, Kardoorie Biological Science Building, Pokfulam Road 4N-12, Sai Ying Pun, Hong Kong, China e-mail:
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44
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Abstract
Secretin family of peptide hormones is a group of structurally related brain-gut peptides that exert their functions via interactions with the class B1 G protein-coupled receptors (GPCRs). Recent researches of these peptides and receptors in metabolism have been an area of intense focus for the development of promising drug targets as therapeutic potentials for metabolic disorders. The fact that agonists of GLP-1, a member in the family, have already started being used as therapeutics clearly indicates the importance and relevance of further research on the clinical applications of these peptides. This review aims to provide an overview of the current understanding regarding the importance of this family of peptides as well as their receptors in metabolism with special focus on their actions in the hypothalamus.
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Affiliation(s)
- R Sekar
- School of Biological Sciences; The University of Hong Kong, Pokfulam, Hong Kong
| | - B K C Chow
- School of Biological Sciences; The University of Hong Kong, Pokfulam, Hong Kong
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45
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Abstract
Secretin (Sct), a classical gut hormone, is now known to play pleiotropic functions in the body including osmoregulation, digestion, and feeding control. As Sct has long been implicated to regulate metabolism, in this report, we have investigated a potential lipolytic action of Sct. In our preliminary studies, both Sct levels in circulation and Sct receptor (SctR) transcripts in adipose tissue were upregulated during fasting, suggesting a potential physiological relevance of Sct in regulating lipolysis. Using SctR knockout and Sct knockout mice as controls, we show that Sct is able to stimulate lipolysis in vitro in isolated adipocytes dose- and time-dependently, as well as acute lipolysis in vivo. H-89, a protein kinase A (PKA) inhibitor, was found to attenuate lipolytic effects of 1 μM Sct in vitro, while a significant increase in PKA activity upon Sct injection was observed in the adipose tissue in vivo. Sct was also found to stimulate phosphorylation at 660ser of hormone sensitive lipase (HSL) and to bring about the translocation of HSL from cytosol to the lipid droplet. In summary, our data demonstrate for the first time the in vivo and in vitro lipolytic effects of Sct, and that this function is mediated by PKA and HSL.
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Affiliation(s)
- Revathi Sekar
- School of Biological Sciences, University of Hong Kong, Pokfulam, Hong Kong
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46
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Abstract
Secretin (SCT) is a classical peptide hormone that is synthesized and released from the gastrointestinal tract after a meal. We have previously shown that it acts both as a central and peripheral anorectic peptide, and that its central effect is mediated via melanocortin system. As peripheral satiety signals from the gastrointestinal tract can be sent to the brain via the vagal afferent or by crossing the blood-brain barrier (BBB), we therefore sought to investigate the pathway by which peripheral SCT reduces appetite in this study. It is found that bilateral subdiaphragmatic vagotomy and treatment of capsaicin, an excitotoxin for primary afferent neurons, could both block the anorectic effect of peripherally injected SCT. These treatments are found to be capable of blunting i.p. SCT-induced Fos activation in pro-opiomelanocortin (POMC) neurons within the hypothalamic Arcuate Nucleus (Arc). Moreover, we have also found that bilateral midbrain transaction could block feeding reduction by peripheral SCT. Taken together, we conclude that the satiety signals of peripheral SCT released from the gastrointestinal tract are sent via the vagus nerves to the brainstem and subsequently Arc, where it controls central expression of other regulatory peptides to regulate food intake.
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Affiliation(s)
- Jessica Y. S. Chu
- School of Biological Sciences, The University of Hong Kong, Pokfulam, Hong Kong SAR, China
| | - Carrie Y. Y. Cheng
- School of Biological Sciences, The University of Hong Kong, Pokfulam, Hong Kong SAR, China
| | - Revathi Sekar
- School of Biological Sciences, The University of Hong Kong, Pokfulam, Hong Kong SAR, China
| | - Billy K. C. Chow
- School of Biological Sciences, The University of Hong Kong, Pokfulam, Hong Kong SAR, China
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47
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Abstract
Secretin (Sct), traditionally a gastrointestinal hormone backed by a century long research, is now beginning to be recognized also as a neuroactive peptide. Substantiation by recent evidence on the functional role of Sct in various regions of the brain, especially on its potential neurosecretion from the posterior pituitary, has revealed Sct's physiological actions in regulating water homeostasis. Recent advances in understanding the functional roles of central and peripheral Sct has been made possible by the development of Sct and Sct receptor (SctR) knockout animal models which have led to novel approaches in research on the physiology of this brain-gut peptide. While research on the role of Sct in appetite regulation and fatty acid metabolism has been initiated recently, its role in glucose homeostasis is unclear. This review focuses mainly on the metabolic role of Sct by discussing data from the last century and recent discoveries, with emphasis on the need for revisiting and elucidating the role of Sct in metabolism and energy homeostasis.
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Affiliation(s)
- Revathi Sekar
- School of Biological Sciences, The University of Hong Kong, Pokfulam Road, Hong Kong
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48
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Ng SYL, Chow BKC, Kasamatsu J, Kasahara M, Lee LTO. Agnathan VIP, PACAP and their receptors: ancestral origins of today's highly diversified forms. PLoS One 2012; 7:e44691. [PMID: 22957100 PMCID: PMC3434177 DOI: 10.1371/journal.pone.0044691] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2012] [Accepted: 08/06/2012] [Indexed: 01/04/2023] Open
Abstract
VIP and PACAP are pleiotropic peptides belonging to the secretin superfamily of brain-gut peptides and interact specifically with three receptors (VPAC1, PAC1 and VPAC2) from the class II B G protein-coupled receptor family. There is immense interest regarding their molecular evolution which is often described closely alongside gene and/or genome duplications. Despite the wide array of information available in various vertebrates and one invertebrate the tunicate, their evolutionary origins remain unresolved. Through searches of genome databases and molecular cloning techniques, the first lamprey VIP/PACAP ligands and VPAC receptors are identified from the Japanese lamprey. In addition, two VPAC receptors (VPACa/b) are identified from inshore hagfish and ligands predicted for sea lamprey. Phylogenetic analyses group these molecules into their respective PHI/VIP, PRP/PACAP and VPAC receptor families and show they resemble ancestral forms. Japanese lamprey VIP/PACAP peptides synthesized were tested with the hagfish VPAC receptors. hfVPACa transduces signal via both adenylyl cylase and phospholipase C pathways, whilst hfVPACb was only able to transduce through the calcium pathway. In contrast to the widespread distribution of VIP/PACAP ligands and receptors in many species, the agnathan PACAP and VPAC receptors were found almost exclusively in the brain. In situ hybridisation further showed their abundance throughout the brain. The range of VIP/PACAP ligands and receptors found are highly useful, providing a glimpse into the evolutionary events both at the structural and functional levels. Though representative of ancestral forms, the VIP/PACAP ligands in particular have retained high sequence conservation indicating the importance of their functions even early in vertebrate evolution. During these nascent stages, only two VPAC receptors are likely responsible for eliciting functions before evolving later into specific subtypes post-Agnatha. We also propose VIP and PACAP's first functions to predominate in the brain, evolving alongside the central nervous system, subsequently establishing peripheral functions.
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Affiliation(s)
- Stephanie Y. L. Ng
- School of Biological Sciences, The University of Hong Kong, Hong Kong, Special Administrative Region, China
| | - Billy K. C. Chow
- School of Biological Sciences, The University of Hong Kong, Hong Kong, Special Administrative Region, China
| | - Jun Kasamatsu
- Department of Pathology, Graduate School of Medicine, Hokkaido University, Kita-ku, Japan
| | - Masanori Kasahara
- Department of Pathology, Graduate School of Medicine, Hokkaido University, Kita-ku, Japan
| | - Leo T. O. Lee
- School of Biological Sciences, The University of Hong Kong, Hong Kong, Special Administrative Region, China
- * E-mail:
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49
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Wang X, Ye H, Ward CJ, Chu JYS, Masyuk TV, Larusso NF, Harris PC, Chow BKC, Torres VE. Insignificant effect of secretin in rodent models of polycystic kidney and liver disease. Am J Physiol Renal Physiol 2012; 303:F1089-98. [PMID: 22811488 DOI: 10.1152/ajprenal.00242.2012] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Polycystic kidney (PKD) and liver (PLD) diseases cause significant morbidity and mortality. A large body of evidence indicates that cyclic AMP plays an important role in their pathogenesis. Clinical trials of drugs that reduce cyclic AMP levels in target tissues are now in progress. Secretin may contribute to adenylyl cyclase-dependent urinary concentration and is a major agonist of adenylyl cyclase in cholangiocytes. To investigate the role of secretin in PKD and PLD, we have studied the expression of secretin and the secretin receptor in rodent models orthologous to autosomal recessive (PCK rat) and dominant (Pkd2(-/WS25) mouse) PKD; the effects of exogenous secretin administration to PCK rats, PCK rats lacking circulating vasopressin (PCK(di/di)), and Pkd2(-/WS25) mice; and the impact of a nonfunctional secretin receptor on disease development in Pkd2(-/WS25):SCTR(-/-) double mutants. Renal and hepatic secretin and secretin receptor mRNA and plasma secretin were increased in both models, and secretin receptor protein was increased in the kidneys and liver of Pkd2(-/WS25) mice. However, exogenous secretin administered subcutaneously via osmotic pumps had minimal or negligible effects and the absence of a functional secretin receptor had no influence on the severity of PKD or PLD. Therefore, it is unlikely that by itself secretin plays a significant role in the pathogenesis of PKD and/or PLD.
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Affiliation(s)
- Xiaofang Wang
- Mayo Clinic, 200 First St SW, Rochester, MN 55905, USA
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50
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Lee VHY, Lam IPY, Choi HS, Chow BKC, Lee LTO. The estrogen-related receptor alpha upregulates secretin expressions in response to hypertonicity and angiotensin II stimulation. PLoS One 2012; 7:e39913. [PMID: 22761926 PMCID: PMC3382582 DOI: 10.1371/journal.pone.0039913] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2011] [Accepted: 06/03/2012] [Indexed: 01/17/2023] Open
Abstract
Osmoregulation via maintenance of water and salt homeostasis is a vital process. In the brain, a functional secretin (SCT) and secretin receptor (SCTR) axis has recently been shown to mediate central actions of angiotensin II (ANGII), including initiation of water intake and stimulation of vasopressin (VP) expression and release. In this report, we provide evidence that estrogen-related receptor α (ERRα, NR3B1), a transcription factor mainly involved in metabolism, acts as an upstream activator of the SCT gene. In vitro studies using mouse hypothalamic cell line N-42 show that ERRα upregulates SCT promoter and gene expression. More importantly, knockdown of endogenous ERRα abolishes SCT promoter activation in response to hypertonic and ANGII stimulations. In mouse brain, ERRα coexpresses with SCT in various osmoregulatory brain regions, including the lamina terminalis and the paraventricular nucleus of the hypothalamus, and its expression is induced by hyperosmotic and ANGII treatments. Based on our data, we propose that both the upregulation of ERRα and/or the increased binding of ERRα to the mouse SCT promoter are two possible mechanisms for the elevated SCT expression upon hyperosmolality and central ANGII stimulation.
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Affiliation(s)
- Vien H. Y. Lee
- School of Biological Sciences, The University of Hong Kong, Pokfulam, Hong Kong SAR, China
| | - Ian P. Y. Lam
- School of Biological Sciences, The University of Hong Kong, Pokfulam, Hong Kong SAR, China
| | - Hueng-Sik Choi
- Hormone Research Center, School of Biological Sciences and Technology, Chonnam National University, Gwangju, Republic of Korea
| | - Billy K. C. Chow
- School of Biological Sciences, The University of Hong Kong, Pokfulam, Hong Kong SAR, China
| | - Leo T. O. Lee
- School of Biological Sciences, The University of Hong Kong, Pokfulam, Hong Kong SAR, China
- * E-mail:
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