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Perrino BA, Malogan J, Cobine CA, Sasse KC. Mfge8 is expressed by pericytes in gastric antrum submucosa from patients with obesity. Am J Physiol Cell Physiol 2023; 324:C992-C1006. [PMID: 36939201 PMCID: PMC10110711 DOI: 10.1152/ajpcell.00043.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2023] [Revised: 03/07/2023] [Accepted: 03/08/2023] [Indexed: 03/21/2023]
Abstract
The main function of the stomach is to digest ingested food. Gastric antrum muscular contractions mix ingested food with digestive enzymes and stomach acid and propel the chyme through the pyloric sphincter at a rate in which the small intestine can process the chyme for optimal nutrient absorption. Mfge8 binding to α8β1 integrins helps regulate gastric emptying by reducing the force of antral smooth muscle contractions. The source of Mfge8 within gastric muscles is unclear. Since Mfge8 is a secreted protein, Mfge8 could be delivered via the circulation, or be locally secreted by cells within the muscle layers. In this study, we identify a source of Mfge8 within human gastric antrum muscles using spatial transcriptomic analysis. We show that Mfge8 is expressed in subpopulations of Mef2c+ perivascular cells within the submucosa layer of the gastric antrum. Mef2c is expressed in subpopulations of NG2+ and PDGFRB+ pericytes. Mfge8 is expressed in NG2+/Mef2c+ pericytes, but not in NG2+/Mef2c-, PDGFRB+/Mef2c-, or PDGFRB+/Mef2c+ pericytes. Mfge8 is absent from CD34+ endothelial cells but is expressed in a small population of perivascular ACTA2+ cells. We also show that α8 integrin is not expressed by interstitial cells of Cajal (ICC), supporting the findings that Mfge8 attenuates gastric antrum smooth muscle contractions by binding to α8β1 integrins on enteric smooth muscle cells. These findings suggest a novel, supplementary mechanism of regulation of gastric antrum motility by cellular regulators of capillary blood flow, in addition to the regulation of gastric antrum motility by the enteric nervous system and the SMC, ICC, and PDGFRα+ cell (SIP) syncytium.
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Affiliation(s)
- Brian A Perrino
- Department of Physiology and Cell Biology, University of Nevada, Reno School of Medicine, Reno, Nevada, United States
| | - Justin Malogan
- Department of Physiology and Cell Biology, University of Nevada, Reno School of Medicine, Reno, Nevada, United States
| | - Caroline A Cobine
- Department of Physiology and Cell Biology, University of Nevada, Reno School of Medicine, Reno, Nevada, United States
| | - Kent C Sasse
- Nevada Surgical Associates, Reno, Nevada, United States
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Cui R, Shao M, Bi H. Phosphorylated Protein Levels in Animal-Sourced Food Muscles Based on Fe 3+ and UV/Vis Spectrometry. ACS OMEGA 2022; 7:6560-6567. [PMID: 35252652 PMCID: PMC8892633 DOI: 10.1021/acsomega.1c05641] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/09/2021] [Accepted: 02/03/2022] [Indexed: 06/14/2023]
Abstract
Protein phosphorylation, a post-translational modification of proteins, is important in biological regulation. The quantity of phosphorylated proteins is a key requirement for the quality change of animal muscle foods. In the present study, a new approach to quantify phosphorylated proteins and/or peptides was developed based on ferric ions (Fe3+) and UV/vis spectrometry. This method is proved to be ultra-effective in discriminating phosphopeptides and non-phosphopeptides with the assistance of Fe3+. The protocol of extracting proteins with 0.1% trifluoroacetic acid (TFA) solution from animal muscle samples coupled with Fe3+ was verified by using an artificial mixture of peptides with different phosphorylation sites and was successfully used to characterize the phosphorylation quantity in the samples via UV/vis spectrometry. A peptide with one phosphorylated site was taken as a reference standard and successfully utilized for the absolute quantification of phosphorylated proteins in caprine muscles during frozen storage and in fish muscle food samples. This present study paves a new way for the evaluation of phosphorylated protein quantitative levels in bio-samples.
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Affiliation(s)
| | | | - Hongyan Bi
- . Phone: +86-21-61900364. Fax: +86-21-61900365
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Suraritdechachai S, Lakkanasirorat B, Uttamapinant C. Molecular probes for cellular imaging of post-translational proteoforms. RSC Chem Biol 2022; 3:201-219. [PMID: 35360891 PMCID: PMC8826509 DOI: 10.1039/d1cb00190f] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2021] [Accepted: 01/04/2022] [Indexed: 12/29/2022] Open
Abstract
Specific post-translational modification (PTM) states of a protein affect its property and function; understanding their dynamics in cells would provide deep insight into diverse signaling pathways and biological processes. However, it is not trivial to visualize post-translational modifications in a protein- and site-specific manner, especially in a living-cell context. Herein, we review recent advances in the development of molecular imaging tools to detect diverse classes of post-translational proteoforms in individual cells, and their applications in studying precise roles of PTMs in regulating the function of cellular proteins.
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Affiliation(s)
- Surased Suraritdechachai
- School of Biomolecular Science and Engineering, Vidyasirimedhi Institute of Science and Technology (VISTEC) Rayong Thailand
| | - Benya Lakkanasirorat
- School of Biomolecular Science and Engineering, Vidyasirimedhi Institute of Science and Technology (VISTEC) Rayong Thailand
| | - Chayasith Uttamapinant
- School of Biomolecular Science and Engineering, Vidyasirimedhi Institute of Science and Technology (VISTEC) Rayong Thailand
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Mfge8 attenuates human gastric antrum smooth muscle contractions. J Muscle Res Cell Motil 2021; 42:219-231. [PMID: 34085177 PMCID: PMC8332633 DOI: 10.1007/s10974-021-09604-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2021] [Accepted: 05/21/2021] [Indexed: 12/02/2022]
Abstract
Coordinated gastric smooth muscle contraction is critical for proper digestion and is adversely affected by a number of gastric motility disorders. In this study we report that the secreted protein Mfge8 (milk fat globule-EGF factor 8) inhibits the contractile responses of human gastric antrum muscles to cholinergic stimuli by reducing the inhibitory phosphorylation of the MYPT1 (myosin phosphatase-targeting subunit (1) subunit of MLCP (myosin light chain phosphatase), resulting in reduced LC20 (smooth muscle myosin regulatory light chain (2) phosphorylation. Mfge8 reduced the agonist-induced increase in the F-actin/G-actin ratios of β-actin and γ-actin1. We show that endogenous Mfge8 is bound to its receptor, α8β1 integrin, in human gastric antrum muscles, suggesting that human gastric antrum muscle mechanical responses are regulated by Mfge8. The regulation of gastric antrum smooth muscles by Mfge8 and α8 integrin functions as a brake on gastric antrum mechanical activities. Further studies of the role of Mfge8 and α8 integrin in regulating gastric antrum function will likely reveal additional novel aspects of gastric smooth muscle motility mechanisms.
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Perrino BA, Xie Y, Alexandru C. Analyzing the Integrin Adhesome by In Situ Proximity Ligation Assay. Methods Mol Biol 2021; 2217:71-81. [PMID: 33215378 DOI: 10.1007/978-1-0716-0962-0_7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
The in situ proximity ligation assay (PLA) is capable of detecting single protein events such as protein protein-interactions and posttranslational modifications (e.g., protein phosphorylation) in tissue and cell samples prepared for analysis by immunofluorescent or immunohistochemical microscopy. The targets are detected using two primary antibodies which must be from different host species. A pair of secondary antibodies (PLA probes) conjugated to complementary oligonucleotides is applied to the sample, and a signal is generated only when the two PLA probes are in close proximity by their binding to the two primary antibodies that have bound to their targets in close proximity. The signal from each pair of PLA probes is visualized as an individual fluorescent spot. These PLA signals can be quantified (counted) using image analysis software (ImageJ), and also assigned to a specific subcellular location based on microscopy image overlays. In principle, in situ PLA offers a relatively simple and sensitive technique to analyze interactions among any proteins for which suitable antibodies are available. Integrin-mediated focal adhesions (FAs) are large multiprotein complexes consisting of more than 150 proteins, also known as the integrin adhesome, which link the extracellular matrix (ECM) to the actin cytoskeleton and regulate the functioning of mechanosignaling pathways. The in situ PLA approach is well suited for examining the spatiotemporal aspects of protein posttranslational modifications and protein interactions occurring in dynamic multiprotein complexes such as integrin mediated focal adhesions.
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Affiliation(s)
- Brian A Perrino
- Department of Physiology and Cell Biology, University of Nevada, Reno School of Medicine, Reno, NV, USA.
| | - Yeming Xie
- Department of Physiology and Cell Biology, University of Nevada, Reno School of Medicine, Reno, NV, USA
| | - Cristina Alexandru
- Department of Physiology and Cell Biology, University of Nevada, Reno School of Medicine, Reno, NV, USA
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Liu Y, Xiao J, Zhang B, Shelite TR, Su Z, Chang Q, Judy B, Li X, Drelich A, Bei J, Zhou Y, Zheng J, Jin Y, Rossi SL, Tang SJ, Wakamiya M, Saito T, Ksiazek T, Kaphalia B, Gong B. Increased talin-vinculin spatial proximities in livers in response to spotted fever group rickettsial and Ebola virus infections. J Transl Med 2020; 100:1030-1041. [PMID: 32238906 PMCID: PMC7111589 DOI: 10.1038/s41374-020-0420-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2019] [Revised: 03/12/2020] [Accepted: 03/12/2020] [Indexed: 12/17/2022] Open
Abstract
Talin and vinculin, both actin-cytoskeleton-related proteins, have been documented to participate in establishing bacterial infections, respectively, as the adapter protein to mediate cytoskeleton-driven dynamics of the plasma membrane. However, little is known regarding the potential role of the talin-vinculin complex during spotted fever group rickettsial and Ebola virus infections, two dreadful infectious diseases in humans. Many functional properties of proteins are determined by their participation in protein-protein complexes, in a temporal and/or spatial manner. To resolve the limitation of application in using mouse primary antibodies on archival, multiple formalin-fixed mouse tissue samples, which were collected from experiments requiring high biocontainment, we developed a practical strategic proximity ligation assay (PLA) capable of employing one primary antibody raised in mouse to probe talin-vinculin spatial proximal complex in mouse tissue. We observed an increase of talin-vinculin spatial proximities in the livers of spotted fever Rickettsia australis or Ebola virus-infected mice when compared with mock mice. Furthermore, using EPAC1-knockout mice, we found that deletion of EPAC1 could suppress the formation of spatial proximal complex of talin-vinculin in rickettsial infections. In addition, we observed increased colocalization between spatial proximity of talin-vinculin and filamentous actin-specific phalloidin staining in single survival mouse from an ordinarily lethal dose of rickettsial or Ebola virus infection. These findings may help to delineate a fresh insight into the mechanisms underlying liver specific pathogenesis during infection with spotted fever rickettsia or Ebola virus in the mouse model.
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Affiliation(s)
- Yakun Liu
- 0000 0001 1547 9964grid.176731.5Department of Pathology, University of Texas Medical Branch, Galveston, TX 77555 USA
| | - Jie Xiao
- 0000 0001 1547 9964grid.176731.5Department of Pathology, University of Texas Medical Branch, Galveston, TX 77555 USA
| | - Ben Zhang
- 0000 0001 1547 9964grid.176731.5Department of Pathology, University of Texas Medical Branch, Galveston, TX 77555 USA
| | - Thomas R. Shelite
- 0000 0001 1547 9964grid.176731.5Department of Internal Medicine, Infectious Diseases, University of Texas Medical Branch, Galveston, TX 77555 USA
| | - Zhengchen Su
- 0000 0001 1547 9964grid.176731.5Department of Pathology, University of Texas Medical Branch, Galveston, TX 77555 USA
| | - Qing Chang
- 0000 0001 1547 9964grid.176731.5Department of Pathology, University of Texas Medical Branch, Galveston, TX 77555 USA
| | - Barbara Judy
- 0000 0001 1547 9964grid.176731.5Department of Pathology, University of Texas Medical Branch, Galveston, TX 77555 USA
| | - Xiang Li
- 0000 0001 1547 9964grid.176731.5Department of Pathology, University of Texas Medical Branch, Galveston, TX 77555 USA
| | - Aleksandra Drelich
- 0000 0001 1547 9964grid.176731.5Department of Pathology, University of Texas Medical Branch, Galveston, TX 77555 USA
| | - Jiani Bei
- 0000 0001 1547 9964grid.176731.5Department of Pathology, University of Texas Medical Branch, Galveston, TX 77555 USA ,0000 0004 0532 1428grid.265231.1Present Address: Life Science Department, Tunghai University, Taichung City, Taiwan
| | - Yixuan Zhou
- 0000 0001 1547 9964grid.176731.5Department of Pathology, University of Texas Medical Branch, Galveston, TX 77555 USA ,0000 0004 0369 1599grid.411525.6Present Address: Department of Cardiovascular Surgery, Changhai Hospital, Shanghai, China
| | - Junying Zheng
- 0000 0001 1547 9964grid.176731.5Department of Neuroscience and Cell Biology, University of Texas Medical Branch, Galveston, TX 77555 USA
| | - Yang Jin
- 0000 0004 1936 7558grid.189504.1Division of Pulmonary and Critical Care Medicine, Department of Medicine, Boston University Medical Campus, Boston, MA USA
| | - Shannan L. Rossi
- 0000 0001 1547 9964grid.176731.5Department of Pathology, University of Texas Medical Branch, Galveston, TX 77555 USA
| | - Shao-Jun Tang
- 0000 0001 1547 9964grid.176731.5Department of Neuroscience and Cell Biology, University of Texas Medical Branch, Galveston, TX 77555 USA
| | - Maki Wakamiya
- 0000 0001 1547 9964grid.176731.5Department of Neurology, University of Texas Medical Branch, Galveston, TX 77555 USA
| | - Tais Saito
- 0000 0001 1547 9964grid.176731.5Department of Pathology, University of Texas Medical Branch, Galveston, TX 77555 USA
| | - Thomas Ksiazek
- 0000 0001 1547 9964grid.176731.5Department of Pathology, University of Texas Medical Branch, Galveston, TX 77555 USA
| | - Bhupendra Kaphalia
- 0000 0001 1547 9964grid.176731.5Department of Pathology, University of Texas Medical Branch, Galveston, TX 77555 USA
| | - Bin Gong
- Department of Pathology, University of Texas Medical Branch, Galveston, TX, 77555, USA.
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