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Yin H, Liu W, Ji X, Yan G, Zeng X, Zhao W, Wang Y. Study on the mechanism of Wumei San in treating piglet diarrhea using network pharmacology and molecular docking. Front Vet Sci 2023; 10:1138684. [PMID: 36925608 PMCID: PMC10011153 DOI: 10.3389/fvets.2023.1138684] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2023] [Accepted: 02/13/2023] [Indexed: 03/08/2023] Open
Abstract
Wumei San (WMS) is a traditional Chinese medicine that has been widely applied in the treatment of piglet diarrhea (PD). However, the mechanism of WMS in PD has not been investigated. In this study, the main active compounds of WMS and the target proteins were obtained from the Traditional Chinese Medicine Systematic Pharmacology, PubChem, and SwissTargetPrediction databases. The molecular targets of PD were identified using GeneCards, OMIM, and NCBI databases. The common targets of WMS and PD were screened out and converted into UniProt gene symbols. PD-related target genes were constructed into a protein-protein interaction network, which was further analyzed by the STRING online database. Gene Ontology and the Kyoto Encyclopedia of Genes and Genomes enrichment analyses were performed to construct the component-target gene-disease network. Molecular docking was then used to examine the relationship between the core compounds and proteins. As a result, a total of 32 active compounds and 638 target genes of WMS were identified, and a WMS-compound-target network was successfully constructed. Through network pharmacology analysis, 14 core compounds in WMS that showed an effect on PD were identified. The targets revealed by GO and KEGG enrichment analysis were associated with the AGE-RAGE signaling pathway, PI3K-Akt signaling pathway, TNF signaling pathway, NOD-like receptor signaling pathway, IL-17 signaling pathway, and other pathways and physiological processes. Molecular docking analysis revealed that the active compounds in WMS spontaneously bind to their targets. The results indicated that WMS may regulate the local immune response and inflammatory factors mainly through the TNF signaling pathway, IL-17 signaling pathway, and other pathways. WMS is a promising treatment strategy for PD. This study provides new insights into the potential mechanism of WMS in PD.
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Affiliation(s)
- Huihui Yin
- Guangxi Key Laboratory of Veterinary Biotechnology, Key Laboratory of China (Guangxi)-ASEAN Cross-Border Animal Disease Prevention and Control, Ministry of Agriculture and Rural Affairs of China, Guangxi Veterinary Research Institute, Nanning, China
| | - Wei Liu
- Guangxi Key Laboratory of Veterinary Biotechnology, Key Laboratory of China (Guangxi)-ASEAN Cross-Border Animal Disease Prevention and Control, Ministry of Agriculture and Rural Affairs of China, Guangxi Veterinary Research Institute, Nanning, China
- *Correspondence: Wei Liu ✉
| | - Xiaoyu Ji
- Brain Function and Disease Laboratory, Shantou University Medical College, Shantou, Guangdong, China
| | - Guoqing Yan
- Guangxi Key Laboratory of Veterinary Biotechnology, Key Laboratory of China (Guangxi)-ASEAN Cross-Border Animal Disease Prevention and Control, Ministry of Agriculture and Rural Affairs of China, Guangxi Veterinary Research Institute, Nanning, China
| | - Xueyan Zeng
- Guangxi Key Laboratory of Veterinary Biotechnology, Key Laboratory of China (Guangxi)-ASEAN Cross-Border Animal Disease Prevention and Control, Ministry of Agriculture and Rural Affairs of China, Guangxi Veterinary Research Institute, Nanning, China
| | - Wu Zhao
- Guangxi Key Laboratory of Veterinary Biotechnology, Key Laboratory of China (Guangxi)-ASEAN Cross-Border Animal Disease Prevention and Control, Ministry of Agriculture and Rural Affairs of China, Guangxi Veterinary Research Institute, Nanning, China
| | - Yanhua Wang
- Guangxi Mountain Comprehensive Technology Development Center, Nanning, China
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Abdalkareem Jasim S, Jade Catalan Opulencia M, Alexis Ramírez-Coronel A, Kamal Abdelbasset W, Hasan Abed M, Markov A, Raheem Lateef Al-Awsi G, Azamatovich Shamsiev J, Thaeer Hammid A, Nader Shalaby M, Karampoor S, Mirzaei R. The emerging role of microbiota-derived short-chain fatty acids in immunometabolism. Int Immunopharmacol 2022; 110:108983. [PMID: 35750016 DOI: 10.1016/j.intimp.2022.108983] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2022] [Revised: 06/16/2022] [Accepted: 06/16/2022] [Indexed: 02/07/2023]
Abstract
The accumulating evidence revealed that microbiota plays a significant function in training, function, and the induction of host immunity. Once this interaction (immune system-microbiota) works correctly, it enables the production of protective responses against pathogens and keeps the regulatory pathways essential for maintaining tolerance to innocent antigens. This concept of immunity and metabolic activity redefines the realm of immunometabolism, paving the way for innovative therapeutic interventions to modulate immune cells through immune metabolic alterations. A body of evidence suggests that microbiota-derived metabolites, including short-chain fatty acids (SCFAs) such as butyrate, acetate, and propionate, play a key role in immune balance. SCFAs act on many cell types to regulate various vital biological processes, including host metabolism, intestinal function, and the immune system. Such SCFAs generated by gut bacteria also impact immunity, cellular function, and immune cell fate. This is a new concept of immune metabolism, and better knowledge about how lifestyle affects intestinal immunometabolism is crucial for preventing and treating disease. In this review article, we explicitly focus on the function of SCFAs in the metabolism of immune cells, especially macrophages, neutrophils, dendritic cells (DCs), B cells, T (Th) helper cells, and cytotoxic T cells (CTLs).
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Affiliation(s)
- Saade Abdalkareem Jasim
- Medical Laboratory Techniques Department, Al-maarif University College, Al-anbar-Ramadi, Iraq.
| | | | - Andrés Alexis Ramírez-Coronel
- Laboratory of Psychometrics, Comparative Psychology and Ethology (LABPPCE), Universidad Católica de Cuenca, Ecuador and Universidad CES, Medellín, Colombia, Cuenca, Ecuador.
| | - Walid Kamal Abdelbasset
- Department of Health and Rehabilitation Sciences, College of Applied Medical Sciences, Prince Sattam bin Abdulaziz University, Al Kharj, Saudi Arabia; Department of Physical Therapy, Kasr Al-Aini Hospital, Cairo University, Giza, Egypt.
| | - Murtadha Hasan Abed
- Department of Medical Laboratory, College of Health and Medical Technology, Al-Ayen University, Thi-Qar, Iraq.
| | - Alexander Markov
- Tyumen State Medical University, Tyumen, Russian Federation; Tyumen Industrial University, Tyumen, Russian Federation.
| | | | - Jamshid Azamatovich Shamsiev
- Department of Pediatric Surgery, Anesthesiology and Intensive Care, Samarkand State Medical Institute, Samarkand, Uzbekistan; Research scholar, Department of Scientific Affairs, Tashkent State Dental Institute, Makhtumkuli Street 103, Tashkent, 100047, Uzbekistan.
| | - Ali Thaeer Hammid
- Computer Engineering Techniques Department, Faculty of Information Technology, Imam Ja'afar Al-Sadiq University, Baghdad, Iraq.
| | - Mohammed Nader Shalaby
- Biological Sciences and Sports Health Department, Faculty of Physical Education, Suez Canal University, Egypt.
| | - Sajad Karampoor
- Gastrointestinal and Liver Diseases Research Center, Iran University of Medical Sciences, Tehran, Iran.
| | - Rasoul Mirzaei
- Venom and Biotherapeutics Molecules Lab, Medical Biotechnology Department, Biotechnology Research Center, Pasteur Institute of Iran, Tehran, Iran.
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Nikolovska K, Seidler UE, Stock C. The Role of Plasma Membrane Sodium/Hydrogen Exchangers in Gastrointestinal Functions: Proliferation and Differentiation, Fluid/Electrolyte Transport and Barrier Integrity. Front Physiol 2022; 13:899286. [PMID: 35665228 PMCID: PMC9159811 DOI: 10.3389/fphys.2022.899286] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2022] [Accepted: 04/19/2022] [Indexed: 12/11/2022] Open
Abstract
The five plasma membrane Na+/H+ exchanger (NHE) isoforms in the gastrointestinal tract are characterized by distinct cellular localization, tissue distribution, inhibitor sensitivities, and physiological regulation. NHE1 (Slc9a1) is ubiquitously expressed along the gastrointestinal tract in the basolateral membrane of enterocytes, but so far, an exclusive role for NHE1 in enterocyte physiology has remained elusive. NHE2 (Slc9a2) and NHE8 (Slc9a8) are apically expressed isoforms with ubiquitous distribution along the colonic crypt axis. They are involved in pHi regulation of intestinal epithelial cells. Combined use of a knockout mouse model, intestinal organoid technology, and specific inhibitors revealed previously unrecognized actions of NHE2 and NHE8 in enterocyte proliferation and differentiation. NHE3 (Slc9a3), expressed in the apical membrane of differentiated intestinal epithelial cells, functions as the predominant nutrient-independent Na+ absorptive mechanism in the gut. The new selective NHE3 inhibitor (Tenapanor) allowed discovery of novel pathophysiological and drug-targetable NHE3 functions in cystic-fibrosis associated intestinal obstructions. NHE4, expressed in the basolateral membrane of parietal cells, is essential for parietal cell integrity and acid secretory function, through its role in cell volume regulation. This review focuses on the expression, regulation and activity of the five plasma membrane Na+/H+ exchangers in the gastrointestinal tract, emphasizing their role in maintaining intestinal homeostasis, or their impact on disease pathogenesis. We point to major open questions in identifying NHE interacting partners in central cellular pathways and processes and the necessity of determining their physiological role in a system where their endogenous expression/activity is maintained, such as organoids derived from different parts of the gastrointestinal tract.
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Mirzaei R, Dehkhodaie E, Bouzari B, Rahimi M, Gholestani A, Hosseini-Fard SR, Keyvani H, Teimoori A, Karampoor S. Dual role of microbiota-derived short-chain fatty acids on host and pathogen. Biomed Pharmacother 2021; 145:112352. [PMID: 34840032 DOI: 10.1016/j.biopha.2021.112352] [Citation(s) in RCA: 63] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2021] [Revised: 10/15/2021] [Accepted: 10/19/2021] [Indexed: 12/12/2022] Open
Abstract
A growing body of documents shows microbiota produce metabolites such as short-chain fatty acids (SCFAs) as crucial executors of diet-based microbial influence the host and bacterial pathogens. The production of SCFAs depends on the metabolic activity of intestinal microflora and is also affected by dietary changes. SCFAs play important roles in maintaining colonic health as an energy source, as a regulator of gene expression and cell differentiation, and as an anti-inflammatory agent. Additionally, the regulated expression of virulence genes is critical for successful infection by an intestinal pathogen. Bacteria rely on sensing environmental signals to find preferable niches and reach the infectious state. This review will present data supporting the diverse functional roles of microbiota-derived butyrate, propionate, and acetate on host cellular activities such as immune modulation, energy metabolism, nervous system, inflammation, cellular differentiation, and anti-tumor effects, among others. On the other hand, we will discuss and summarize data about the role of these SCFAs on the virulence factor of bacterial pathogens. In this regard, receptors and signaling routes for SCFAs metabolites in host and pathogens will be introduced.
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Affiliation(s)
- Rasoul Mirzaei
- Department of Microbiology, School of Medicine, Hamadan University of Medical Sciences, Hamadan, Iran; Venom and Biotherapeutics Molecules Lab, Medical Biotechnology Department, Biotechnology Research Center, Pasteur Institute of Iran, Tehran, Iran.
| | - Elahe Dehkhodaie
- Department of Biology, Science and Research Branch, Islamic Azad University Tehran, Iran
| | - Behnaz Bouzari
- Department of Pathology, Firouzgar Hospital, Iran University of Medical Sciences, Tehran, Iran
| | - Mandana Rahimi
- Department of Pathology, School of Medicine, Hasheminejad Kidney Center, Iran University of Medical Sciences, Tehran, Iran
| | - Abolfazl Gholestani
- Department of Biochemistry, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran
| | - Seyed Reza Hosseini-Fard
- Department of Biochemistry, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran
| | - Hossein Keyvani
- Gastrointestinal and Liver Diseases Research Center, Iran University of Medical Sciences, Tehran, Iran; Department of Virology, School of Medicine, Iran University of Medical Sciences, Tehran, Iran.
| | - Ali Teimoori
- Department of Virology, School of Medicine, Hamadan University of Medical Sciences, Hamadan, Iran.
| | - Sajad Karampoor
- Gastrointestinal and Liver Diseases Research Center, Iran University of Medical Sciences, Tehran, Iran; Department of Virology, School of Medicine, Iran University of Medical Sciences, Tehran, Iran.
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Koltai T. Targeting the pH Paradigm at the Bedside: A Practical Approach. Int J Mol Sci 2020; 21:E9221. [PMID: 33287221 PMCID: PMC7730959 DOI: 10.3390/ijms21239221] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2020] [Revised: 11/27/2020] [Accepted: 11/28/2020] [Indexed: 02/07/2023] Open
Abstract
The inversion of the pH gradient in malignant tumors, known as the pH paradigm, is increasingly becoming accepted by the scientific community as a hallmark of cancer. Accumulated evidence shows that this is not simply a metabolic consequence of a dysregulated behavior, but rather an essential process in the physiopathology of accelerated proliferation and invasion. From the over-simplification of increased lactate production as the cause of the paradigm, as initially proposed, basic science researchers have arrived at highly complex and far-reaching knowledge, that substantially modified that initial belief. These new developments show that the paradigm entails a different regulation of membrane transporters, electrolyte exchangers, cellular and membrane enzymes, water trafficking, specialized membrane structures, transcription factors, and metabolic changes that go far beyond fermentative glycolysis. This complex world of dysregulations is still shuttered behind the walls of experimental laboratories and has not yet reached bedside medicine. However, there are many known pharmaceuticals and nutraceuticals that are capable of targeting the pH paradigm. Most of these products are well known, have low toxicity, and are also inexpensive. They need to be repurposed, and this would entail shorter clinical studies and enormous cost savings if we compare them with the time and expense required for the development of a new molecule. Will targeting the pH paradigm solve the "cancer problem"? Absolutely not. However, reversing the pH inversion would strongly enhance standard treatments, rendering them more efficient, and in some cases permitting lower doses of toxic drugs. This article's goal is to describe how to reverse the pH gradient inversion with existing drugs and nutraceuticals that can easily be used in bedside medicine, without adding toxicity to established treatments. It also aims at increasing awareness among practicing physicians that targeting the pH paradigm would be able to improve the results of standard therapies. Some clinical cases will be presented as well, showing how the pH gradient inversion can be treated at the bedside in a simple manner with repurposed drugs.
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Affiliation(s)
- Tomas Koltai
- Centro de Diagnostico y Tratamiento de la Obra Social del Personal de la Alimentacion, Talar de Pacheco, Buenos Aires 1617, Argentina
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Pedersen SF, Counillon L. The SLC9A-C Mammalian Na +/H + Exchanger Family: Molecules, Mechanisms, and Physiology. Physiol Rev 2019; 99:2015-2113. [PMID: 31507243 DOI: 10.1152/physrev.00028.2018] [Citation(s) in RCA: 103] [Impact Index Per Article: 20.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Na+/H+ exchangers play pivotal roles in the control of cell and tissue pH by mediating the electroneutral exchange of Na+ and H+ across cellular membranes. They belong to an ancient family of highly evolutionarily conserved proteins, and they play essential physiological roles in all phyla. In this review, we focus on the mammalian Na+/H+ exchangers (NHEs), the solute carrier (SLC) 9 family. This family of electroneutral transporters constitutes three branches: SLC9A, -B, and -C. Within these, each isoform exhibits distinct tissue expression profiles, regulation, and physiological roles. Some of these transporters are highly studied, with hundreds of original articles, and some are still only rudimentarily understood. In this review, we present and discuss the pioneering original work as well as the current state-of-the-art research on mammalian NHEs. We aim to provide the reader with a comprehensive view of core knowledge and recent insights into each family member, from gene organization over protein structure and regulation to physiological and pathophysiological roles. Particular attention is given to the integrated physiology of NHEs in the main organ systems. We provide several novel analyses and useful overviews, and we pinpoint main remaining enigmas, which we hope will inspire novel research on these highly versatile proteins.
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Affiliation(s)
- S F Pedersen
- Section for Cell Biology and Physiology, Department of Biology, University of Copenhagen, Copenhagen, Denmark; and Université Côte d'Azur, CNRS, Laboratoire de Physiomédecine Moléculaire, LP2M, France, and Laboratories of Excellence Ion Channel Science and Therapeutics, Nice, France
| | - L Counillon
- Section for Cell Biology and Physiology, Department of Biology, University of Copenhagen, Copenhagen, Denmark; and Université Côte d'Azur, CNRS, Laboratoire de Physiomédecine Moléculaire, LP2M, France, and Laboratories of Excellence Ion Channel Science and Therapeutics, Nice, France
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Palaniappan B, Arthur S, Sundaram VL, Butts M, Sundaram S, Mani K, Singh S, Nepal N, Sundaram U. Inhibition of intestinal villus cell Na/K-ATPase mediates altered glucose and NaCl absorption in obesity-associated diabetes and hypertension. FASEB J 2019; 33:9323-9333. [PMID: 31107610 PMCID: PMC6662973 DOI: 10.1096/fj.201802673r] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2018] [Accepted: 04/23/2019] [Indexed: 01/07/2023]
Abstract
During obesity, diabetes and hypertension inevitably coexist and cause innumerable health disparities. In the obesity, diabetes, and hypertension triad (ODHT), deregulation of glucose and NaCl homeostasis, respectively, causes diabetes and hypertension. In the mammalian intestine, glucose is primarily absorbed by Na-glucose cotransport 1 (SGLT1) and coupled NaCl by the dual operation of Na-H exchange 3 (NHE3) and Cl-HCO3 [down-regulated in adenoma (DRA) or putative anion transporter 1 (PAT1)] exchange in the brush border membrane (BBM) of villus cells. The basolateral membrane (BLM) Na/K-ATPase provides the favorable transcellular Na gradient for BBM SGLT1 and NHE3. How these multiple, distinct transport processes may be affected in ODHT is unclear. Here, we show the novel and broad regulation by Na/K-ATPase of glucose and NaCl absorption in ODHT in multiple species (mice, rats, and humans). In vivo, during obesity inhibition of villus-cell BLM, Na/K-ATPase led to compensatory stimulation of BBM SGLT1 and DRA or PAT1, whereas NHE3 was unaffected. Supporting this new cellular adaptive mechanism, direct silencing of BLM Na/K-ATPase in intestinal epithelial cells resulted in selective stimulation of BBM SGLT1 and DRA or PAT1 but not NHE3. These changes will lead to an increase in glucose absorption, maintenance of traditional coupled NaCl absorption, and a de novo increase in NaCl absorption from the novel coupling of stimulated SGLT1 with DRA or PAT1. Thus, these novel observations provide the pathophysiologic basis for the deregulation of glucose and NaCl homeostasis of diabetes and hypertension, respectively, during obesity. These observations may lead to more efficacious treatment for obesity-associated diabetes and hypertension.-Palaniappan, B., Arthur, S., Sundaram, V. L., Butts, M., Sundaram, S., Mani, K., Singh, S., Nepal, N., Sundaram, U. Inhibition of intestinal villus cell Na/K-ATPase mediates altered glucose and NaCl absorption in obesity-associated diabetes and hypertension.
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Affiliation(s)
- Balasubramanian Palaniappan
- Department of Clinical and Translational Sciences, Joan C. Edwards School of Medicine, Marshall University, Huntington, West Virginia, USA
| | - Subha Arthur
- Department of Clinical and Translational Sciences, Joan C. Edwards School of Medicine, Marshall University, Huntington, West Virginia, USA
| | - Vijaya Lakshmi Sundaram
- Department of Clinical and Translational Sciences, Joan C. Edwards School of Medicine, Marshall University, Huntington, West Virginia, USA
| | - Molly Butts
- Department of Clinical and Translational Sciences, Joan C. Edwards School of Medicine, Marshall University, Huntington, West Virginia, USA
| | - Shanmuga Sundaram
- Department of Clinical and Translational Sciences, Joan C. Edwards School of Medicine, Marshall University, Huntington, West Virginia, USA
| | - Kathiresh Mani
- Department of Clinical and Translational Sciences, Joan C. Edwards School of Medicine, Marshall University, Huntington, West Virginia, USA
| | - Soudamani Singh
- Department of Clinical and Translational Sciences, Joan C. Edwards School of Medicine, Marshall University, Huntington, West Virginia, USA
| | - Niraj Nepal
- Department of Clinical and Translational Sciences, Joan C. Edwards School of Medicine, Marshall University, Huntington, West Virginia, USA
| | - Uma Sundaram
- Department of Clinical and Translational Sciences, Joan C. Edwards School of Medicine, Marshall University, Huntington, West Virginia, USA
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Amelioration of Lipopolysaccharide-Induced Acute Lung Injury in Rats by Na-H Exchanger-1 Inhibitor Amiloride Is Associated with Reversal of ERK Mitogen-Activated Protein Kinase. BIOMED RESEARCH INTERNATIONAL 2018; 2018:3560234. [PMID: 30627552 PMCID: PMC6304609 DOI: 10.1155/2018/3560234] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/04/2018] [Accepted: 11/27/2018] [Indexed: 12/15/2022]
Abstract
Background Na-H exchanger-1 (NHE-1) is expressed in the lung of rats. Accumulating evidence shows that Na-H exchangers are involved in inflammation. Amiloride, an inhibitor of NHE-1, inhibits the activation of macrophages and endothelial cells and reduces their production of cytokines. Since these processes have been implicated in acute lung injury (ALI) induced by lipopolysaccharide (LPS), we examined the protective effect of amiloride on ALI induced by LPS in rats. Material and Methods ALI in specific pathogen-free male Sprague-Dawley rats was induced by an intravenous injection of 6 mg/kg LPS. Amiloride pretreated rats received an intravenous injection of 10 mg/kg amiloride 30 min before the administration of LPS. Controls received normal saline in a similar manner. All animals were sacrificed 6 h after LPS or normal saline administration. The degree of ALI was assessed by wet-to-dry weight ratio (W/D) and lung histological examination. Neutrophilic infiltration was determined by myeloperoxidase (MPO) activity in lung tissue. Concentrations of total protein (TP), tumor necrosis factor-alpha (TNF-α), and macrophage inflammatory protein-2 (MIP-2) in bronchoalveolar lavage fluid (BALF) were also measured. Expression of NHE-1 and mitogen-activated protein kinase (MAPK) p38, p-p38, ERK, and p-ERK was evaluated by western blot analysis. Results Pretreatment with amiloride significantly reduced the increase in W/D, ALI score, lung tissue MPO activity, concentrations of TP, TNF-α, and MIP-2 in BALF, resulting in attenuation of ALI induced by LPS. Meanwhile, levels of NHE-1 and p-ERK proteins were reversed, whereas that of p-p38 was not. Conclusions These findings suggest that NHE-1 inhibitor amiloride could attenuate ALI induced by LPS in rats. This effect is mediated through reversal of ERK.
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Histone deacetylase inhibitors induce the expression of tumor suppressor genes Per1 and Per2 in human gastric cancer cells. Oncol Lett 2018; 16:1981-1990. [PMID: 30008892 DOI: 10.3892/ol.2018.8851] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2017] [Accepted: 04/16/2018] [Indexed: 12/22/2022] Open
Abstract
Period circadian regulator (Per)1 and Per2 genes are involved in the molecular mechanism of the circadian clock, and exhibit tumor suppressor properties. Several studies have reported a decreased expression of Per1, Per2 and Per3 genes in different types of cancer and cancer cell lines. Promoter methylation downregulates Per1, Per2 or Per3 expression in myeloid leukemia, breast, lung, and other cancer cells; whereas histone deacetylase inhibitors (HDACi) upregulate Per1 or Per3 expression in certain cancer cell lines. However, the transcriptional regulation of Per1 and Per2 in cancer cells by chromatin modifications is not fully understood. The present study aimed to determine whether HDACi regulate Per1 and Per2 expression in gastric cancer cell lines, and to investigate changes in chromatin modifications in response to HDACi. Treatment of KATO III and NCI-N87 human gastric cancer cells with sodium butyrate (NaB) or Trichostatin A (TSA) induced Per1 and Per2 mRNA expression in a dose-dependent manner. Chromatin immunoprecipitaion assays revealed that NaB and TSA decreased lysine 9 trimethylation on histone H3 (H3K9me3) at the Per1 promoter. TSA, but not NaB increased H3K9 acetylation at the Per2 promoter. It was also observed that binding of Sp1 and Sp3 to the Per1 promoter decreased following NaB treatment, whereas Sp1 binding increased at the Per2 promoter of NaB- and TSA-treated cells. In addition, Per1 promoter is not methylated in KATO III cells, while Per2 promoter was methylated, although NaB, TSA, and 5-Azacytidine do not change the methylated CpGs analyzed. In conclusion, HDACi induce Per1 and Per2 expression, in part, through mechanisms involving chromatin remodeling at the proximal promoter of these genes; however, other indirect mechanisms triggered by these HDACi cannot be ruled out. These findings reveal a previously unappreciated regulatory pathway between silencing of Per1 gene by H3K9me3 and upregulation of Per2 by HDACi in cancer cells.
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Xu H, Ghishan FK, Kiela PR. SLC9 Gene Family: Function, Expression, and Regulation. Compr Physiol 2018; 8:555-583. [PMID: 29687889 DOI: 10.1002/cphy.c170027] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
The Slc9 family of Na+ /H+ exchangers (NHEs) plays a critical role in electroneutral exchange of Na+ and H+ in the mammalian intestine as well as other absorptive and secretory epithelia of digestive organs. These transport proteins contribute to the transepithelial Na+ and water absorption, intracellular pH and cellular volume regulation as well as the electrolyte, acid-base, and fluid volume homeostasis at the systemic level. They also influence the function of other membrane transport mechanisms, affect cellular proliferation and apoptosis as well as cell migration, adherence to the extracellular matrix, and tissue repair. Additionally, they modulate the extracellular milieu to facilitate other nutrient absorption and to regulate the intestinal microbial microenvironment. Na+ /H+ exchange is inhibited in selected gastrointestinal diseases, either by intrinsic factors (e.g., bile acids, inflammatory mediators) or infectious agents and associated bacterial toxins. Disrupted NHE activity may contribute not only to local and systemic electrolyte imbalance but also to the disease severity via multiple mechanisms. In this review, we describe the cation proton antiporter superfamily of Na+ /H+ exchangers with a particular emphasis on the eight SLC9A isoforms found in the digestive tract, followed by a more integrative description in their roles in each of the digestive organs. We discuss regulatory mechanisms that determine the function of Na+ /H+ exchangers as pertinent to the digestive tract, their regulation in pathological states of the digestive organs, and reciprocally, the contribution of dysregulated Na+ /H+ exchange to the disease pathogenesis and progression. © 2018 American Physiological Society. Compr Physiol 8:555-583, 2018.
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Affiliation(s)
- Hua Xu
- Department of Pediatrics, Steele Children's Research Center, University of Arizona, Tucson, Arizona, USA
| | - Fayez K Ghishan
- Department of Pediatrics, Steele Children's Research Center, University of Arizona, Tucson, Arizona, USA
| | - Pawel R Kiela
- Department of Pediatrics, Steele Children's Research Center, University of Arizona, Tucson, Arizona, USA.,Department of Immunobiology, University of Arizona, Tucson, Arizona, USA
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Guanylate Cyclase C Activation Shapes the Intestinal Microbiota in Patients with Familial Diarrhea and Increased Susceptibility for Crohn's Disease. Inflamm Bowel Dis 2017; 23:1752-1761. [PMID: 28902124 DOI: 10.1097/mib.0000000000001264] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
BACKGROUND With 25% prevalence of Crohn's disease, Familial GUCY2C diarrhea syndrome (FGDS) is a monogenic disorder potentially suited to study initiating factors in inflammatory bowel disease (IBD). We aimed to characterize the impact of an activating GUCY2C mutation on the gut microbiota in patients with FGDS controlling for Crohn's disease status and to determine whether changes share features with those observed in unrelated patients with IBD. METHODS Bacterial DNA from fecal samples collected from patients with FGDS (N = 20), healthy relatives (N = 11), unrelated healthy individuals (N = 263), and IBD controls (N = 46) was subjected to sequencing of the V3-V4 region of the 16S rRNA gene to determine gut microbiota composition. Food frequency questionnaires were obtained from patients with FGDS and their relatives. RESULTS Compared with healthy controls, FGDS displayed prominent changes in many microbial lineages including increase in Enterobacteriaceae, loss of Bifidobacterium and Faecalibacterium prausnitzii but an unchanged intraindividual (alpha) diversity. The depletion of F. prausnitzii is in line with what is typically observed in Crohn's disease. There was no significant difference in the dietary profile between the patients and related controls. The gut microbiota in related and unrelated healthy controls was also similar, suggesting that diet and familial factors do not explain the gut microbiota alterations in FGDS. CONCLUSIONS The findings support that the activating mutation in GUCY2C creates an intestinal environment with a major influence on the microbiota, which could contribute to the increased susceptibility to IBD in patients with FGDS.
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Nistala R, Savin V. Diabetes, hypertension, and chronic kidney disease progression: role of DPP4. Am J Physiol Renal Physiol 2017; 312:F661-F670. [PMID: 28122713 DOI: 10.1152/ajprenal.00316.2016] [Citation(s) in RCA: 61] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2016] [Revised: 01/18/2017] [Accepted: 01/20/2017] [Indexed: 12/11/2022] Open
Abstract
The protein dipeptidyl peptidase 4 (DPP4) is a target in diabetes management and reduction of associated cardiovascular risk. Inhibition of the enzymatic function and genetic deletion of DPP4 is associated with tremendous benefits to the heart, vasculature, adipose tissue, and the kidney in rodent models of obesity, diabetes and hypertension, and associated complications. The recently concluded, "Saxagliptin Assessment of Vascular Outcomes Recorded in Patients with Diabetes Mellitus-Thrombolysis in Myocardial Infarction 53" trial revealed a reduction in proteinuria in chronic kidney disease patients (stages 1-3). These results have spurred immense interest in the nonenzymatic and enzymatic role of DPP4 in the kidney. DPP4 is expressed predominantly in the glomeruli and S1-S3 segments of the nephron and to a lesser extent in other segments. DPP4 is known to facilitate absorption of cleaved dipeptides and regulate the function of the sodium/hydrogen exchanger-3 in the proximal tubules. DPP4, also known as CD26, has an important role in costimulation of lymphocytes via caveolin-1 on antigen-presenting cells in peripheral blood. Herein, we present our perspectives for the ongoing interest in the role of DPP4 in the kidney.
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Affiliation(s)
- Ravi Nistala
- Division of Nephrology and Hypertension, Department of Medicine, University of Missouri-Columbia School of Medicine, Columbia, Missouri; and
| | - Virginia Savin
- Department of Nephrology, Kansas City Veterans Affairs Medical Center, Kansas City, Missouri
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Abstract
Several members of the SLC9A family of Na+/H+ exchangers are expressed in the gut, with varying expression patterns and cellular localization. Not only do they participate in the regulation of basic epithelial cell functions, including control of transepithelial Na+ absorption, intracellular pH (pH i ), cell volume, and nutrient absorption, but also in cellular proliferation, migration, and apoptosis. Additionally, they modulate the extracellular milieu in order to facilitate other nutrient absorption and to regulate the intestinal microbial microenvironment. Na+/H+ exchangers are frequent targets of inhibition in gastrointestinal pathologies, either by intrinsic factors (e.g. bile acids, inflammatory mediators) or infectious agents and associated microbial toxins. Based on emerging evidence, disruption of NHE activity via impaired expression or function of respective isoforms may contribute not only to local and systemic electrolyte imbalance, but also to the disease severity via multiple mechanisms. Here, we review the current state of knowledge about the roles Na+/H+ exchangers play in the pathogenesis of disorders of diverse origin and affecting a range of GI tissues.
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Affiliation(s)
- Michael A. Gurney
- Department of Pediatrics, Steele Children’s Research Center, University of Arizona, Tucson, Arizona
| | - Daniel Laubitz
- Department of Pediatrics, Steele Children’s Research Center, University of Arizona, Tucson, Arizona
| | - Fayez K. Ghishan
- Department of Pediatrics, Steele Children’s Research Center, University of Arizona, Tucson, Arizona
| | - Pawel R. Kiela
- Department of Pediatrics, Steele Children’s Research Center, University of Arizona, Tucson, Arizona,Department of Immunobiology, University of Arizona, Tucson, Arizona,Correspondence Address correspondence to: Pawel R. Kiela, DVM, PhD, Department of Pediatrics, University of Arizona, 1501 North Campbell Avenue, Tucson, Arizona 85724. fax: (520) 626-4141.Department of Pediatrics, University of Arizona1501 North Campbell AvenueTucsonArizona 85724
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14
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Thakur BK, Dasgupta N, Ta A, Das S. Physiological TLR5 expression in the intestine is regulated by differential DNA binding of Sp1/Sp3 through simultaneous Sp1 dephosphorylation and Sp3 phosphorylation by two different PKC isoforms. Nucleic Acids Res 2016; 44:5658-72. [PMID: 27060138 PMCID: PMC4937308 DOI: 10.1093/nar/gkw189] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2015] [Accepted: 03/10/2016] [Indexed: 12/24/2022] Open
Abstract
Toll-like receptor 5 (TLR5) expression in the intestinal epithelial cells (IECs) is critical to maintain health, as underscored by multiple intestinal and extra-intestinal diseases in mice genetically engineered for IEC-specific TLR5 knockout. A gradient of expression exists in the colonic epithelial cells from the cecum to the distal colon. Intriguingly, an identical gradient for the dietary metabolite, butyrate also exists in the luminal contents. However, both being critical for intestinal homeostasis and immune response, no studies examined the role of butyrate in the regulation of TLR5 expression. We showed that butyrate transcriptionally upregulates TLR5 in the IECs and augments flagellin-induced immune responses. Both basal and butyrate-induced transcription is regulated by differential binding of Sp-family transcription factors to the GC-box sequences over the TLR5 promoter. Butyrate activates two different protein kinase C isoforms to dephosphorylate/acetylate Sp1 by serine/threonine phosphatases and phosphorylate Sp3 by ERK-MAPK, respectively. This resulted in Sp1 displacement from the promoter and binding of Sp3 to it, leading to p300 recruitment and histone acetylation, activating transcription. This is the first study addressing the mechanisms of physiological TLR5 expression in the intestine. Additionally, a novel insight is gained into Sp1/Sp3-mediated gene regulation that may apply to other genes.
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Affiliation(s)
- Bhupesh Kumar Thakur
- Division of Clinical Medicine, National Institute of Cholera and Enteric Diseases, P-33, CIT Road, Scheme XM, Beliaghata, Kolkata 700010, India
| | - Nirmalya Dasgupta
- Division of Clinical Medicine, National Institute of Cholera and Enteric Diseases, P-33, CIT Road, Scheme XM, Beliaghata, Kolkata 700010, India
| | - Atri Ta
- Division of Clinical Medicine, National Institute of Cholera and Enteric Diseases, P-33, CIT Road, Scheme XM, Beliaghata, Kolkata 700010, India
| | - Santasabuj Das
- Division of Clinical Medicine, National Institute of Cholera and Enteric Diseases, P-33, CIT Road, Scheme XM, Beliaghata, Kolkata 700010, India
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15
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Kuan CS, See Too WC, Few LL. Sp1 and Sp3 Are the Transcription Activators of Human ek1 Promoter in TSA-Treated Human Colon Carcinoma Cells. PLoS One 2016; 11:e0147886. [PMID: 26807725 PMCID: PMC4725723 DOI: 10.1371/journal.pone.0147886] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2015] [Accepted: 01/08/2016] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Ethanolamine kinase (EK) catalyzes the phosphorylation of ethanolamine, the first step in the CDP-ethanolamine pathway for the biosynthesis of phosphatidylethanolamine (PE). Human EK exists as EK1, EK2α and EK2β isoforms, encoded by two separate genes, named ek1 and ek2. EK activity is stimulated by carcinogens and oncogenes, suggesting the involvement of EK in carcinogenesis. Currently, little is known about EK transcriptional regulation by endogenous or exogenous signals, and the ek gene promoter has never been studied. METHODOLOGY/PRINCIPAL FINDINGS In this report, we mapped the important regulatory regions in the human ek1 promoter. 5' deletion analysis and site-directed mutagenesis identified a Sp site at position (-40/-31) that was essential for the basal transcription of this gene. Treatment of HCT116 cells with trichostatin A (TSA), a histone deacetylase inhibitor, significantly upregulated the ek1 promoter activity through the Sp(-40/-31) site and increased the endogenous expression of ek1. Chromatin immunoprecipitation assay revealed that TSA increased the binding of Sp1, Sp3 and RNA polymerase II to the ek1 promoter in HCT116 cells. The effect of TSA on ek1 promoter activity was cell-line specific as TSA treatment did not affect ek1 promoter activity in HepG2 cells. CONCLUSION/SIGNIFICANCE In conclusion, we showed that Sp1 and Sp3 are not only essential for the basal transcription of the ek1 gene, their accessibility to the target site on the ek1 promoter is regulated by histone protein modification in a cell line dependent manner.
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Affiliation(s)
- Chee Sian Kuan
- School of Health Sciences, Health Campus, Universiti Sains Malaysia, 16150 Kubang Kerian, Kelantan, Malaysia
| | - Wei Cun See Too
- School of Health Sciences, Health Campus, Universiti Sains Malaysia, 16150 Kubang Kerian, Kelantan, Malaysia
| | - Ling Ling Few
- School of Health Sciences, Health Campus, Universiti Sains Malaysia, 16150 Kubang Kerian, Kelantan, Malaysia
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16
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Chueh AC, Tse JWT, Tögel L, Mariadason JM. Mechanisms of Histone Deacetylase Inhibitor-Regulated Gene Expression in Cancer Cells. Antioxid Redox Signal 2015; 23:66-84. [PMID: 24512308 PMCID: PMC4492771 DOI: 10.1089/ars.2014.5863] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
SIGNIFICANCE Class I and II histone deacetylase inhibitors (HDACis) are approved for the treatment of cutaneous T-cell lymphoma and are undergoing clinical trials as single agents, and in combination, for other hematological and solid tumors. Understanding their mechanisms of action is essential for their more effective clinical use, and broadening their clinical potential. RECENT ADVANCES HDACi induce extensive transcriptional changes in tumor cells by activating and repressing similar numbers of genes. These transcriptional changes mediate, at least in part, HDACi-mediated growth inhibition, apoptosis, and differentiation. Here, we highlight two fundamental mechanisms by which HDACi regulate gene expression—histone and transcription factor acetylation. We also review the transcriptional responses invoked by HDACi, and compare these effects within and across tumor types. CRITICAL ISSUES The mechanistic basis for how HDACi activate, and in particular repress gene expression, is not well understood. In addition, whether subsets of genes are reproducibly regulated by these agents both within and across tumor types has not been systematically addressed. A detailed understanding of the transcriptional changes elicited by HDACi in various tumor types, and the mechanistic basis for these effects, may provide insights into the specificity of these drugs for transformed cells and specific tumor types. FUTURE DIRECTIONS Understanding the mechanisms by which HDACi regulate gene expression and an appreciation of their transcriptional targets could facilitate the ongoing clinical development of these emerging therapeutics. In particular, this knowledge could inform the design of rational drug combinations involving HDACi, and facilitate the identification of mechanism-based biomarkers of response.
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Affiliation(s)
- Anderly C Chueh
- Ludwig Institute for Cancer Research , Olivia Newton John Cancer and Wellness Centre, Austin Health, Melbourne, Australia
| | - Janson W T Tse
- Ludwig Institute for Cancer Research , Olivia Newton John Cancer and Wellness Centre, Austin Health, Melbourne, Australia
| | - Lars Tögel
- Ludwig Institute for Cancer Research , Olivia Newton John Cancer and Wellness Centre, Austin Health, Melbourne, Australia
| | - John M Mariadason
- Ludwig Institute for Cancer Research , Olivia Newton John Cancer and Wellness Centre, Austin Health, Melbourne, Australia
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17
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Abstract
Tightly coupled exchange of Na(+) for H(+) occurs across the surface membrane of virtually all living cells. For years, the underlying molecular entity was unknown and the full physiological significance of the exchange process was not appreciated, but much knowledge has been gained in the last two decades. We now realize that, unlike most of the other transporters that specialize in supporting one specific function, Na(+)/H(+) exchangers (NHE) participate in a remarkable assortment of physiological processes, ranging from pH homeostasis and epithelial salt transport, to systemic and cellular volume regulation. In parallel, we have learned a great deal about the biochemistry and molecular biology of Na(+)/H(+) exchange. Indeed, it has now become apparent that exchange is mediated not by one, but by a diverse family of related yet distinct carriers (antiporters) sometimes present in different cell types and located in various intracellular compartments. Each one of these has unique structural features that dictate its functional role and mode of regulation. The biological relevance of Na(+)/H(+) exchange is emphasized by its evolutionary conservation; analogous exchangers are present from bacteria to man. Because of its wide distribution and versatile function, Na(+)/H(+) exchange has attracted an enormous amount of interest and therefore generated a vast literature. The vastness and complexity of the field has been compounded by the multiplicity of NHE isoforms. For reasons of space and in the spirit of this series, this overview is restricted to the family of mammalian NHEs.
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Affiliation(s)
- John Orlowski
- Department of Physiology, McGill University, Montreal, Canada
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18
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Singh V, Raheja G, Borthakur A, Kumar A, Gill RK, Alakkam A, Malakooti J, Dudeja PK. Lactobacillus acidophilus upregulates intestinal NHE3 expression and function. Am J Physiol Gastrointest Liver Physiol 2012; 303:G1393-401. [PMID: 23086913 PMCID: PMC3532544 DOI: 10.1152/ajpgi.00345.2012] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
A major mechanism of electroneutral NaCl absorption in the human ileum and colon involves coupling of Na(+)/H(+) and Cl(-)/HCO(3)(-) exchangers. Disturbances in these mechanisms have been implicated in diarrheal conditions. Probiotics such as Lactobacillus have been indicated to be beneficial in the management of gastrointestinal disorders, including diarrhea. However, the molecular mechanisms underlying antidiarrheal effects of probiotics have not been fully understood. We have previously demonstrated Lactobacillus acidophilus (LA) to stimulate Cl(-)/HCO3- exchange activity via an increase in the surface levels and expression of the Cl(-)/HCO3- exchanger DRA in vitro and in vivo. However, the effects of LA on NHE3, the Na(+)/H(+) exchanger involved in the coupled electroneutral NaCl absorption, are not known. Current studies were, therefore, undertaken to investigate the effects of LA on the function and expression of NHE3 and to determine the mechanisms involved. Treatment of Caco2 cells with LA or its conditioned culture supernatant (CS) for 8-24 h resulted in a significant increase in Na(+)/H(+) exchange activity, mRNA, and protein levels of NHE3. LA-CS upregulation of NHE3 function and expression was also observed in SK-CO15 cells, a human colonic adenocarcinoma cell line. Additionally, LA treatment increased NHE3 promoter activity, suggesting involvement of transcriptional mechanisms. In vivo, mice gavaged with live LA showed significant increase in NHE3 mRNA and protein expression in the ileum and colonic regions. In conclusion, LA-induced increase in NHE3 expression may contribute to the upregulation of intestinal electrolyte absorption and might underlie the potential antidiarrheal effects of probiotics.
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Affiliation(s)
- Varsha Singh
- Section of Digestive Diseases and Nutrition, Department of Medicine, University of Illinois at Chicago and Jesse Brown VA Medical Center, Chicago, Illinois
| | - Geetu Raheja
- Section of Digestive Diseases and Nutrition, Department of Medicine, University of Illinois at Chicago and Jesse Brown VA Medical Center, Chicago, Illinois
| | - Alip Borthakur
- Section of Digestive Diseases and Nutrition, Department of Medicine, University of Illinois at Chicago and Jesse Brown VA Medical Center, Chicago, Illinois
| | - Anoop Kumar
- Section of Digestive Diseases and Nutrition, Department of Medicine, University of Illinois at Chicago and Jesse Brown VA Medical Center, Chicago, Illinois
| | - Ravinder K. Gill
- Section of Digestive Diseases and Nutrition, Department of Medicine, University of Illinois at Chicago and Jesse Brown VA Medical Center, Chicago, Illinois
| | - Anas Alakkam
- Section of Digestive Diseases and Nutrition, Department of Medicine, University of Illinois at Chicago and Jesse Brown VA Medical Center, Chicago, Illinois
| | - Jaleh Malakooti
- Section of Digestive Diseases and Nutrition, Department of Medicine, University of Illinois at Chicago and Jesse Brown VA Medical Center, Chicago, Illinois
| | - Pradeep K. Dudeja
- Section of Digestive Diseases and Nutrition, Department of Medicine, University of Illinois at Chicago and Jesse Brown VA Medical Center, Chicago, Illinois
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19
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Abstract
The epithelial apical membrane Na+/H+ exchangers [NHE (sodium hydrogen exchanger)2 and NHE3] and Cl-/HCO3- exchangers [DRA (down-regulated in adenoma) and PAT-1 (putative anion transporter 1)] are key luminal membrane transporters involved in electroneutral NaCl absorption in the mammalian intestine. During the last decade, there has been a surge of studies focusing on the short-term regulation of these electrolyte transporters, particularly for NHE3 regulation. However, the long-term regulation of the electrolyte transporters, involving transcriptional mechanisms and transcription factors that govern their basal regulation or dysregulation in diseased states, has only now started to unfold with the cloning and characterization of their gene promoters. The present review provides a detailed analysis of the core promoters of NHE2, NHE3, DRA and PAT-1 and outlines the transcription factors involved in their basal regulation as well as in response to both physiological (butyrate, protein kinases and probiotics) and pathophysiological (cytokines and high levels of serotonin) stimuli. The information available on the transcriptional regulation of the recently identified NHE8 isoform is also highlighted. Therefore the present review bridges a gap in our knowledge of the transcriptional mechanisms underlying the alterations in the gene expression of intestinal epithelial luminal membrane Na+ and Cl- transporters involved in electroneutral NaCl absorption. An understanding of the mechanisms of the modulation of gene expression of these transporters is important for a better assessment of the pathophysiology of diarrhoea associated with inflammatory and infectious diseases and may aid in designing better management protocols.
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20
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Neri EA, Bezerra CNA, Rebouças NA. Essential regulatory elements for NHE3 gene transcription in renal proximal tubule cells. Braz J Med Biol Res 2011; 44:514-23. [PMID: 21537610 DOI: 10.1590/s0100-879x2011007500054] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2010] [Accepted: 04/11/2011] [Indexed: 11/21/2022] Open
Abstract
The objectives of the present study were to identify the cis-elements of the promoter absolutely required for the efficient rat NHE3 gene transcription and to locate positive and negative regulatory elements in the 5'-flanking sequence (5'FS), which might modulate the gene expression in proximal tubules, and to compare this result to those reported for intestinal cell lines. We analyzed the promoter activity of different 5'FS segments of the rat NHE3 gene, in the OKP renal proximal tubule cell line by measuring the activity of the reporter gene luciferase. Because the segment spanning the first 157 bp of 5'FS was the most active it was studied in more detail by sequential deletions, point mutations, and gel shift assays. The essential elements for gene transcription are in the region -85 to -33, where we can identify consensual binding sites for Sp1 and EGR-1, which are relevant to NHE3 gene basal transcription. Although a low level of transcription is still possible when the first 25 bp of the 5'FS are used as promoter, efficient transcription only occurs with 44 bp of 5'FS. There are negative regulatory elements in the segments spanning -1196 to -889 and -467 to -152, and positive enhancers between -889 and -479 bp of 5'FS. Transcription factors in the OKP cell nuclear extract efficiently bound to DNA elements of rat NHE3 promoter as demonstrated by gel shift assays, suggesting a high level of similarity between transcription factors of both species, including Sp1 and EGR-1.
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Affiliation(s)
- E A Neri
- Departamento de Fisiologia e Biofísica, Instituto de Ciências Biomédicas, Universidade de São Paulo, São Paulo, SP, Brazil
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21
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Horita S, Seki G, Yamada H, Suzuki M, Koike K, Fujita T. Insulin resistance, obesity, hypertension, and renal sodium transport. Int J Hypertens 2011; 2011:391762. [PMID: 21629870 PMCID: PMC3095959 DOI: 10.4061/2011/391762] [Citation(s) in RCA: 66] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2011] [Accepted: 02/16/2011] [Indexed: 12/12/2022] Open
Abstract
Sodium transport through various nephron segments is quite important in regulating sodium reabsorption and blood pressure. Among several regulators of this process, insulin acts on almost all the nephron segments and is a strong enhancer of sodium reabsorption. Sodium-proton exchanger type 3 (NHE3) is a main regulator of sodium reabsorption in the luminal side of proximal tubule. In the basolateral side of the proximal tubule, sodium-bicarbonate cotransporter (NBCe1) mediates sodium and bicarbonate exit from tubular cells. In the distal nephron and the connecting tubule, epithelial sodium channel (ENaC) is of great importance to sodium reabsorption. NHE3, NBCe1, and ENaC are all regulated by insulin. Recently with-no-lysine (WNK) kinases, responsible for familial hypertension, stimulating sodium reabsorption in the distal nephron, have been found to be also regulated by insulin. We will discuss the regulation of renal sodium transport by insulin and its roles in the pathogenesis of hypertension in insulin resistance.
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Affiliation(s)
- Shoko Horita
- Department of Internal Medicine, Faculty of Medicine, The University of Tokyo 7-3-1 Hongo, Bunkyo, Tokyo 113-8655, Japan
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22
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Yeruva S, Farkas K, Hubricht J, Rode K, Riederer B, Bachmann O, Cinar A, Rakonczay Z, Molnár T, Nagy F, Wedemeyer J, Manns M, Raddatz D, Musch MW, Chang EB, Hegyi P, Seidler U. Preserved Na(+)/H(+) exchanger isoform 3 expression and localization, but decreased NHE3 function indicate regulatory sodium transport defect in ulcerative colitis. Inflamm Bowel Dis 2010; 16:1149-61. [PMID: 20027604 DOI: 10.1002/ibd.21183] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
BACKGROUND A major causative factor of diarrhea in ulcerative colitis (UC) patients is the loss of Na(+) absorptive capacity of the inflamed colonic mucosa. Potential contributing mechanisms include reduced driving force for active transport, and impaired expression, mislocalization, or defective transport function of Na(+) absorptive proteins. We therefore studied the expression, brush border membrane (BBM) localization, and transport capacity of the major intestinal Na(+) absorptive protein, the Na(+)/H(+) exchanger isoform 3 (NHE3) in biopsies from UC patients. METHODS In UC and control biopsies, inflammation was graded histologically, NHE3, tumor necrosis factor alpha (TNF-alpha), villin, as well as other housekeeping genes were analyzed by quantitative real-time polymerase chain reaction (PCR), BBM localization of NHE3 determined by immunohistochemistry, and confocal microscopy. Na(+) absorptive capacity was assessed by (22)Na(+) isotope fluxes and NHE3 transport activity measured microfluorometrically in BCECF-loaded surface colonocytes within isolated crypts. RESULTS In mildly, moderately, and severely inflamed sigmoid colon of UC patients, neither NHE3 mRNA expression nor the abundance of NHE3 in the BBM was significantly altered compared to other structural components of the BBM. However, Na(+) absorption was strongly reduced by approximately 80% and acid-activated NHE3 transport activity was significantly decreased in the surface cells of sigmoid colonic crypts even in moderately inflamed mucosa. CONCLUSIONS In the colonic mucosa of patients with active UC, NHE3 transport capacity was found significantly decreased despite correct NHE3 location and abundance in the brush border, independent of current treatment. These findings suggest functional NHE3 transport as a novel factor for inflammatory diarrhea in UC patients.
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Affiliation(s)
- Sunil Yeruva
- Department of Gastroenterology, Hannover Medical School, Hannover, Germany
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23
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Nunes MJ, Milagre I, Schnekenburger M, Gama MJ, Diederich M, Rodrigues E. Sp proteins play a critical role in histone deacetylase inhibitor-mediated derepression of CYP46A1 gene transcription. J Neurochem 2010; 113:418-31. [PMID: 20096088 DOI: 10.1111/j.1471-4159.2010.06612.x] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
We investigated whether the CYP46A1 gene, a neuronal-specific cytochrome P450, responsible for the majority of brain cholesterol turnover, is subject to transcriptional modulation through modifications in histone acetylation. We demonstrated that inhibition of histone deacetylase activity by trichostatin A (TSA), valproic acid and sodium butyrate caused a potent induction of both CYP46A1 promoter activity and endogenous expression. Silencing of Sp transcription factors through specific small interfering RNAs, or impairing Sp binding to the proximal promoter, by site-directed mutagenesis, led to a significant decrease in TSA-mediated induction of CYP46A1 expression/promoter activity. Electrophoretic mobility shift assay, DNA affinity precipitation assays and chromatin immunoprecipitation assays were used to determine the multiprotein complex recruited to the CYP46A1 promoter, upon TSA treatment. Our data showed that a decrease in Sp3 binding at particular responsive elements, can shift the Sp1/Sp3/Sp4 ratio, and favor the detachment of histone deacetylase (HDAC) 1 and HDAC2 and the recruitment of p300/CBP. Moreover, we observed a dynamic change in the chromatin structure upon TSA treatment, characterized by an increase in the local recruitment of euchromatic markers and RNA polymerase II. Our results show the critical participation of an epigenetic program in the control of CYP46A1 gene transcription, and suggest that brain cholesterol catabolism may be affected upon treatment with HDAC inhibitors.
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Affiliation(s)
- Maria João Nunes
- Faculty of Pharmacy, iMed.UL - Research Institute for Medicines and Pharmaceutical Sciences, University of Lisbon, 1649-003 Lisbon, Portugal
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24
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Bailón E, Cueto-Sola M, Utrilla P, Rodríguez-Cabezas ME, Garrido-Mesa N, Zarzuelo A, Xaus J, Gálvez J, Comalada M. Butyrate in vitro immune-modulatory effects might be mediated through a proliferation-related induction of apoptosis. Immunobiology 2010; 215:863-73. [PMID: 20149475 DOI: 10.1016/j.imbio.2010.01.001] [Citation(s) in RCA: 73] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2009] [Revised: 01/02/2010] [Accepted: 01/05/2010] [Indexed: 12/12/2022]
Abstract
Survival and proliferation signals are two processes closely interrelated and finely controlled in most cell types, whose deregulation may lead to carcinogenesis. In the last decade, different studies have suggested that both cellular functions are also intimately associated with other cellular activities such as differentiation and cellular activation, especially in immune cells. The aim of this study was to evaluate the effects of the short-chain fatty acid (SCFA) butyrate on the proliferation and activation state of different cell types involved in inflammatory bowel disease. We focused on intestinal epithelial cells, macrophages and T-lymphocytes, using both primary non-transformed cultures and established cell lines. The results showed that low concentrations of butyrate inhibited the proliferation of all the immune cell types tested in this work, whereas it only induced apoptosis in activated T-lymphocytes, non-differentiated epithelial cells and macrophage cell lines, but not in differentiated epithelial cells or primary macrophages. Butyrate apoptosis induction was mediated by caspase-3/7 activation. This SCFA was only able to modify cell activation, measured as expression of inflammatory cytokines, in those cell types in which apoptosis was induced. In conclusion, our results suggest a cell type-specificity of the immune-modulatory effects of butyrate based on the proliferation/activation characteristic physiology of these processes in different cells types.
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Affiliation(s)
- Elvira Bailón
- Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBEREHD), Department of Pharmacology, Center for Biomedical Research, University of Granada, Granada, Spain
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25
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Amin MR, Ghannad L, Othman A, Gill RK, Dudeja PK, Ramaswamy K, Malakooti J. Transcriptional regulation of the human Na+/H+ exchanger NHE3 by serotonin in intestinal epithelial cells. Biochem Biophys Res Commun 2009; 382:620-5. [PMID: 19303862 DOI: 10.1016/j.bbrc.2009.03.087] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2009] [Accepted: 03/14/2009] [Indexed: 11/15/2022]
Abstract
Serotonin (5-HT) decreases NHE2 and NHE3 activities under acute conditions in human intestinal epithelial cells. Here, we have investigated the effects of 5-HT on expression of the human NHE3 gene and the mechanisms underlying its transcriptional regulation in differentiated C2BBe1 cells. Treatment of the human intestinal epithelial cell line, C2BBe1, with 5-HT (20 microM) resulted in a significant decrease in NHE3 mRNA and protein expression. In transient transfection studies, 5-HT repressed the NHE3 promoter activity by approximately 55%. The repression of the NHE3 promoter activity in response to 5-HT was accompanied by reduced DNA-binding activity of transcription factors Sp1 and Sp3 to the NHE3 promoter without alteration in their nuclear levels. Pharmacological inhibitors of protein kinase C reversed the inhibitory effect of 5-HT on the promoter activity. Our data indicate that 5-HT suppresses the transcriptional activity of the NHE3 promoter and this effect may be mediated by PKCalpha and modulation of DNA-binding affinities of Sp1 and Sp3.
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Affiliation(s)
- Md Ruhul Amin
- Section of Digestive Diseases and Nutrition, Department of Medicine, University of Illinois at Chicago, 840 S. Wood Street, Chicago, IL 60612, USA
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26
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Su HW, Wang SW, Ghishan FK, Kiela PR, Tang MJ. Cell confluency-induced Stat3 activation regulates NHE3 expression by recruiting Sp1 and Sp3 to the proximal NHE3 promoter region during epithelial dome formation. Am J Physiol Cell Physiol 2008; 296:C13-24. [PMID: 19064501 DOI: 10.1152/ajpcell.00263.2008] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Activation of signal transducer and activator of transcription-3 (Stat3) during cell confluency is related to its regulatory roles in cell growth arrest- or survival-related physiological or developmental processes. We previously demonstrated that this signaling event triggers epithelial dome formation by transcriptional augmentation of sodium hydrogen exchanger-3 (NHE3) expression. However, the detailed molecular mechanism remained unclear. By using serial deletions, site-directed mutagenesis, and EMSA analysis, we now demonstrate Stat3 binding to an atypical Stat3-response element in the rat proximal NHE3 promoter, located adjacent to a cluster of Sp cis-elements (SpA/B/C), within -77/-36 nt of the gene. SpB (-58/-55 nt) site was more effective than SpA (-72/-69 nt) site for cooperative binding of Sp1/Sp3. Increasing cell density had no effect on Sp1/Sp3 expression but resulted in their increased binding to the SpA/B/C probe along with Stat3 and concurrently with enhanced nuclear pTyr705-Stat3 level. Immunoprecipitation performed with the nuclear extracts demonstrated physical interaction of Stat3 and Sp1/Sp3 triggered by cell confluency. Stat3 inhibition by overexpression of dominant-negative Stat3-D mutant in MDCK cells or by small interfering RNA-mediated knockdown in Caco-2 cells resulted in inhibition of the cell density-induced NHE3 expression, Sp1/Sp3 binding, and NHE3 promoter activity and in decreased dome formation. Thus, during confluency, ligand-independent Stat3 activation leads to its interaction with Sp1/Sp3, their recruitment to the SpA/B/C cluster in a Stat3 DNA-binding domain-dependent fashion, increased transcription, and expression of NHE3, to coordinate cell density-mediated epithelial dome formation.
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Affiliation(s)
- Hsiao-Wen Su
- Institute of Basic Medical Sciences, College of Medicine, National Cheng Kung University, 1 Univ. Road, Tainan 70101, Taiwan
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Laubitz D, Larmonier CB, Bai A, Midura-Kiela MT, Lipko MA, Thurston RD, Kiela PR, Ghishan FK. Colonic gene expression profile in NHE3-deficient mice: evidence for spontaneous distal colitis. Am J Physiol Gastrointest Liver Physiol 2008; 295:G63-G77. [PMID: 18467500 PMCID: PMC2494721 DOI: 10.1152/ajpgi.90207.2008] [Citation(s) in RCA: 71] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Na+/H+ exchanger 3 (NHE3) provides a major route for intestinal Na+ absorption. NHE3 has been considered a target of proinflammatory cytokines and enteropathogenic bacteria, and impaired NHE3 expression and/or activity may be responsible for inflammation-associated diarrhea. However, the possibility of loss of NHE3 function reciprocally affecting gut immune homeostasis has not been investigated. In this report, we describe that NHE3-deficient mice spontaneously develop colitis restricted to distal colonic mucosa. NHE3(-/-) mice housed in a conventional facility exhibited phenotypic features such as mild diarrhea, occasional rectal prolapse, and reduced body weight. Genomewide microarray analysis identified not only a large group of transport genes that potentially represent an adaptive response, but also a considerable number of genes consistent with an inflammatory response. Histological examination demonstrated changes in the distal colon consistent with active inflammation, including crypt hyperplasia with an increased number of 5-bromo-2'-deoxyuridine-positive cells, diffuse neutrophilic infiltrate with concomitant 15-fold increase in matrix metalloproteinase 8 expression, an increased number of pSer276-RelA-positive cells, and a significant decrease in periodic acid-Schiff-positive goblet cells. Real-time PCR demonstrated elevated expression of inducible nitric oxide synthase (38-fold), TNF-alpha (6-fold), macrophage inflammatory protein-2 (48-fold), and IL-18 (3-fold) in the distal colon of NHE3(-/-) mice. NHE3(-/-) mice showed enhanced bacterial adhesion and translocation in the distal colon. Colitis was ameliorated by oral administration of broad-spectrum antibiotics. In conclusion, NHE3 deficiency leads to an exacerbated innate immune response, an observation suggesting a potentially novel role of NHE3 as a modifier gene, which when downregulated during infectious or chronic colitis may modulate the extent and severity of colonic inflammation.
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Affiliation(s)
- Daniel Laubitz
- Department of Pediatrics, Steele Children's Research Center, University of Arizona Health Sciences Center, Tucson, AZ 85724, USA
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