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Ma JX, Chen T, Xue H, Zhang M, Li ZY, Li X, Wang YT, Kang N, Wang FY, Tang XD. Jian-Pi-Yin decoction attenuates lactose-induced chronic diarrhea in rats by regulating GLP-1 and reducing NHE3 ubiquitination and phosphorylation. Heliyon 2023; 9:e17444. [PMID: 37539150 PMCID: PMC10395042 DOI: 10.1016/j.heliyon.2023.e17444] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2023] [Revised: 06/13/2023] [Accepted: 06/16/2023] [Indexed: 08/05/2023] Open
Abstract
Objectives Jian-Pi-Yin decoction (JPY), a prescription derived from the traditional Chinese medicine Shen-Ling-Bai-Zhu-San, has shown good clinical efficacy in the treatment of diarrhea caused by lactose intolerance. However, the mechanism of action of JPY in the treatment of diarrhea is not fully understood. Design In this study, a rat diarrhea model was induced by high lactose feeding combined with standing on a small platform to investigate the ameliorating effect of JPY on hyper lactose-induced diarrhea in rats and its possible mechanism. Methods The rat model of hyper lactose diarrhea was given high, medium, and low doses of JPY and the positive control drug Smida by gavage for 1 week. At the same time, NA+-H+ exchanger 3 (NHE3) inhibitor Tenapanor was administered orally for 3 weeks. Body weight, food intake, water intake, grip strength, and severity of diarrhea symptoms were measured in rats throughout the study. The serum, colon, and jejunum tissues of the model and drug-treated rats were collected for histopathological examination and analysis of relevant indicators. Results JPY significantly alleviated the symptoms of fatigue, diet reduction and diarrhea in the model group. Glucagon-like peptide-1 (GLP-1) and cyclic adenosine monophosphate (cAMP) expression were also down-regulated after JPY treatment. JPY can significantly promote NHE3 in intestinal tissues of rats with diarrhea, and the mechanism is related to the decrease of GLP-1, inhibition of cAMP/PKA pathway activation, an increase of ubiquitin-specific protease 7 (USP7) and USP10 expression, and decrease of NHE3 ubiquitination and phosphorylation. Conclusion JPY can reduce the expression of GLP-1, reduce the ubiquitination and phosphorylation of NHE3, regulate the expression of NHE3, at least partly improve ion transport in the intestinal epithelium, and improve the imbalance of electrolyte absorption, thus significantly reducing the diarrhea symptoms of rats with high lactose combined with small platform standing. Innovation In this study, we explored the mechanism of intestinal GLP-1 activation of cAMP/PKA signaling pathway from multiple dimensions, and increased its expression by reducing phosphorylation and ubiquitination of NHE3, thereby treating chronic diarrhea associated with lactose intolerance.
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Affiliation(s)
- Jin-xin Ma
- Department of Gastroenterology, Peking University Traditional Chinese Medicine Clinical Medical School (Xiyuan), Zhongzhi Dong Lu, Haidian District, Beijing, 100091, China
- Academy of Integration of Chinese and Western Medicine, Peking University Health Science Center, 38 Xueyuan Road, Haidian District, Beijing, 100191, China
| | - Ting Chen
- Institute of Digestive Diseases, Xiyuan Hospital of China Academy of Chinese Medical Sciences, Zhongzhi Dong Lu, Haidian District, Beijing, 100091, China
| | - Hong Xue
- Institute of Digestive Diseases, Xiyuan Hospital of China Academy of Chinese Medical Sciences, Zhongzhi Dong Lu, Haidian District, Beijing, 100091, China
| | - Min Zhang
- Institute of Digestive Diseases, Xiyuan Hospital of China Academy of Chinese Medical Sciences, Zhongzhi Dong Lu, Haidian District, Beijing, 100091, China
| | - Zhong-yu Li
- Institute of Digestive Diseases, Xiyuan Hospital of China Academy of Chinese Medical Sciences, Zhongzhi Dong Lu, Haidian District, Beijing, 100091, China
| | - Xuan Li
- Department of Traditional Chinese Medicine, Beijing University of Chinese Medicine, 11 North Third Ring East Road, Beijing, 100029, China
| | - Yi-tian Wang
- Institute of Digestive Diseases, Xiyuan Hospital of China Academy of Chinese Medical Sciences, Zhongzhi Dong Lu, Haidian District, Beijing, 100091, China
| | - Nan Kang
- Affiliated Hospital of Jining Medical University, Jining, Shandong, China
| | - Feng-yun Wang
- Institute of Digestive Diseases, Xiyuan Hospital of China Academy of Chinese Medical Sciences, Zhongzhi Dong Lu, Haidian District, Beijing, 100091, China
| | - Xu-dong Tang
- Department of Gastroenterology, Peking University Traditional Chinese Medicine Clinical Medical School (Xiyuan), Zhongzhi Dong Lu, Haidian District, Beijing, 100091, China
- Academy of Integration of Chinese and Western Medicine, Peking University Health Science Center, 38 Xueyuan Road, Haidian District, Beijing, 100191, China
- China Academy of Chinese Medical Sciences, 16 Nanxiao Street, Dongzhimen Nei, Beijing, 100700, China
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Durairajan SSK, Singh AK, Saravanan UB, Namachivayam M, Radhakrishnan M, Huang JD, Dhodapkar R, Zhang H. Gastrointestinal Manifestations of SARS-CoV-2: Transmission, Pathogenesis, Immunomodulation, Microflora Dysbiosis, and Clinical Implications. Viruses 2023; 15:1231. [PMID: 37376531 DOI: 10.3390/v15061231] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2023] [Revised: 05/12/2023] [Accepted: 05/15/2023] [Indexed: 06/29/2023] Open
Abstract
The clinical manifestation of COVID-19, caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), in the respiratory system of humans is widely recognized. There is increasing evidence suggesting that SARS-CoV-2 possesses the capability to invade the gastrointestinal (GI) system, leading to the manifestation of symptoms such as vomiting, diarrhea, abdominal pain, and GI lesions. These symptoms subsequently contribute to the development of gastroenteritis and inflammatory bowel disease (IBD). Nevertheless, the pathophysiological mechanisms linking these GI symptoms to SARS-CoV-2 infection remain unelucidated. During infection, SARS-CoV-2 binds to angiotensin-converting enzyme 2 and other host proteases in the GI tract during the infection, possibly causing GI symptoms by damaging the intestinal barrier and stimulating inflammatory factor production, respectively. The symptoms of COVID-19-induced GI infection and IBD include intestinal inflammation, mucosal hyperpermeability, bacterial overgrowth, dysbiosis, and changes in blood and fecal metabolomics. Deciphering the pathogenesis of COVID-19 and understanding its exacerbation may provide insights into disease prognosis and pave the way for the discovery of potential novel targets for disease prevention or treatment. Besides the usual transmission routes, SARS-CoV-2 can also be transmitted via the feces of an infected person. Hence, it is crucial to implement preventive and control measures in order to mitigate the fecal-to-oral transmission of SARS-CoV-2. Within this context, the identification and diagnosis of GI tract symptoms during these infections assume significance as they facilitate early detection of the disease and the development of targeted therapeutics. The present review discusses the receptors, pathogenesis, and transmission of SARS-CoV-2, with a particular focus on the induction of gut immune responses, the influence of gut microbes, and potential therapeutic targets against COVID-19-induced GI infection and IBD.
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Affiliation(s)
| | - Abhay Kumar Singh
- Department of Microbiology, School of Life Sciences, Central University of Tamil Nadu, Tiruvarur 610005, India
| | - Udhaya Bharathy Saravanan
- Department of Microbiology, School of Life Sciences, Central University of Tamil Nadu, Tiruvarur 610005, India
| | - Mayurikaa Namachivayam
- Department of Microbiology, School of Life Sciences, Central University of Tamil Nadu, Tiruvarur 610005, India
| | - Moorthi Radhakrishnan
- Department of Microbiology, School of Life Sciences, Central University of Tamil Nadu, Tiruvarur 610005, India
| | - Jian-Dong Huang
- Department of Biochemistry, School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, 21 Sassoon Road, Pokfulam, Hong Kong 999077, China
- CAS Key Laboratory of Quantitative Engineering Biology, Shenzhen Institute of Synthetic Biology, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, China
| | - Rahul Dhodapkar
- Department of Microbiology, Jawaharlal Institute of Postgraduate Medical Education & Research (JIPMER), Government of India, Puducherry 605006, India
| | - Hongjie Zhang
- School of Chinese Medicine, Hong Kong Baptist University, Kowloon Tong, Hong Kong 999077, China
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Khreefa Z, Barbier MT, Koksal AR, Love G, Del Valle L. Pathogenesis and Mechanisms of SARS-CoV-2 Infection in the Intestine, Liver, and Pancreas. Cells 2023; 12:cells12020262. [PMID: 36672197 PMCID: PMC9856332 DOI: 10.3390/cells12020262] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2022] [Revised: 12/30/2022] [Accepted: 01/05/2023] [Indexed: 01/11/2023] Open
Abstract
The novel coronavirus, SARS-CoV-2, rapidly spread worldwide, causing an ongoing global pandemic. While the respiratory system is the most common site of infection, a significant number of reported cases indicate gastrointestinal (GI) involvement. GI symptoms include anorexia, abdominal pain, nausea, vomiting, and diarrhea. Although the mechanisms of GI pathogenesis are still being examined, viral components isolated from stool samples of infected patients suggest a potential fecal-oral transmission route. In addition, viral RNA has been detected in blood samples of infected patients, making hematologic dissemination of the virus a proposed route for GI involvement. Angiotensin-converting enzyme 2 (ACE2) receptors serve as the cellular entry mechanism for the virus, and these receptors are particularly abundant throughout the GI tract, making the intestine, liver, and pancreas potential extrapulmonary sites for infection and reservoirs sites for developing mutations and new variants that contribute to the uncontrolled spread of the disease and resistance to treatments. This transmission mechanism and the dysregulation of the immune system play a significant role in the profound inflammatory and coagulative cascades that contribute to the increased severity and risk of death in several COVID-19 patients. This article reviews various potential mechanisms of gastrointestinal, liver, and pancreatic injury.
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Affiliation(s)
- Zaid Khreefa
- Department of Pathology, School of Medicine, Louisiana State University Health School of Medicine, New Orleans, LA 70112, USA
| | - Mallory T. Barbier
- Louisiana Cancer Research Center, Louisiana State University Health Sciences Center, New Orleans, LA 70112, USA
| | - Ali Riza Koksal
- Department of Pathology and Laboratory Medicine, Tulane University School of Medicine, New Orleans, LA 70112, USA
| | - Gordon Love
- Department of Pathology, School of Medicine, Louisiana State University Health School of Medicine, New Orleans, LA 70112, USA
| | - Luis Del Valle
- Department of Pathology, School of Medicine, Louisiana State University Health School of Medicine, New Orleans, LA 70112, USA
- Louisiana Cancer Research Center, Louisiana State University Health Sciences Center, New Orleans, LA 70112, USA
- Correspondence:
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Armando I, Cuevas S, Fan C, Kumar M, Izzi Z, Jose PA, Konkalmatt PR. G Protein-Coupled Receptor 37L1 Modulates Epigenetic Changes in Human Renal Proximal Tubule Cells. Int J Mol Sci 2022; 23:ijms232214456. [PMID: 36430934 PMCID: PMC9698582 DOI: 10.3390/ijms232214456] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2022] [Revised: 10/19/2022] [Accepted: 10/31/2022] [Indexed: 11/23/2022] Open
Abstract
Renal luminal sodium transport is essential for physiological blood pressure control, and abnormalities in this process are strongly implicated in the pathogenesis of essential hypertension. Renal G protein-coupled receptors (GPCRs) are critical for the regulation of the reabsorption of essential nutrients, ions, and water from the glomerular filtrate. Recently, we showed that GPCR 37L1 (GPR37L1) is expressed on the apical membrane of renal proximal tubules (RPT) and regulates luminal sodium transport and blood pressure by modulating the function of the sodium proton exchanger 3 (NHE3). However, little is known about GPR37L1 intracellular signaling. Here, we show that GPR37L1 is localized to the nuclear membrane, in addition to the plasma membrane in human RPT cells. Furthermore, GPR37L1 signals via the PI3K/AKT/mTOR pathway to decrease the expression of DNA (cytosine-5)-methyltransferase 1 (DNMT1) and enhance NHE3 transcription. Overall, we demonstrate the direct role of a nuclear membrane GPCR in the regulation of renal sodium through epigenetic gene regulation.
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Steenwinkel TE, Hamre KK, Werner T. The use of non-model Drosophila species to study natural variation in TOR pathway signaling. PLoS One 2022; 17:e0270436. [PMID: 36137094 PMCID: PMC9499319 DOI: 10.1371/journal.pone.0270436] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2022] [Accepted: 09/06/2022] [Indexed: 11/25/2022] Open
Abstract
Nutrition and growth are strongly linked, but not much is known about how nutrition leads to growth. To understand the connection between nutrition through the diet, growth, and proliferation, we need to study the phenotypes resulting from the activation and inhibition of central metabolic pathways. One of the most highly conserved metabolic pathways across eukaryotes is the Target of Rapamycin (TOR) pathway, whose primary role is to detect the availability of nutrients and to either induce or halt cellular growth. Here we used the model organism Drosophila melanogaster (D. mel.) and three non-model Drosophila species with different dietary needs, Drosophila guttifera (D. gut.), Drosophila deflecta (D. def.), and Drosophila tripunctata (D. tri.), to study the effects of dietary amino acid availability on fecundity and longevity. In addition, we inhibited the Target of Rapamycin (TOR) pathway, using rapamycin, to test how the inhibition interplays with the nutritional stimuli in these four fruit fly species. We hypothesized that the inhibition of the TOR pathway would reverse the phenotypes observed under conditions of overfeeding. Our results show that female fecundity increased with higher yeast availability in all four species but decreased in response to TOR inhibition. The longevity data were more varied: most species experienced an increase in median lifespan in both genders with an increase in yeast availability, while the lifespan of D. mel. females decreased. When exposed to the TOR inhibitor rapamycin, the life spans of most species decreased, except for D. tri, while we observed a major reduction in fecundity across all species. The obtained data can benefit future studies on the evolution of metabolism by showing the potential of using non-model species to track changes in metabolism. Particularly, our data show the possibility to use relatively closely related Drosophila species to gain insight on the evolution of TOR signaling.
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Affiliation(s)
- Tessa E. Steenwinkel
- Department of Biological Sciences, Michigan Technological University, Houghton, Michigan, United States of America
| | - Kailee K. Hamre
- Department of Biological Sciences, Michigan Technological University, Houghton, Michigan, United States of America
| | - Thomas Werner
- Department of Biological Sciences, Michigan Technological University, Houghton, Michigan, United States of America
- * E-mail:
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Awadalla A, Hussein AM, El-Far YM, El-Senduny FF, Barakat N, Hamam ET, Abdeen HM, El-Sherbiny M, Serria MS, Sarhan AA, Sena AM, Shokeir AA. Rapamycin Improves Adipose-Derived Mesenchymal Stem Cells (ADMSCs) Renoprotective Effect against Cisplatin-Induced Acute Nephrotoxicity in Rats by Inhibiting the mTOR/AKT Signaling Pathway. Biomedicines 2022; 10:biomedicines10061295. [PMID: 35740317 PMCID: PMC9220220 DOI: 10.3390/biomedicines10061295] [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: 05/08/2022] [Revised: 05/20/2022] [Accepted: 05/27/2022] [Indexed: 12/17/2022] Open
Abstract
Objective: Because the poor survival of transplanted cells in a hostile microenvironment limits stem cell therapy, in the current study, we investigated the effect of rapamycin (Rapa)-preactivated autophagy on the survival and homing of transplanted adipose mesenchymal stem cells (ADMSCs) in a rat model of cisplatin (Cis)-induced nephrotoxicity, as well as the possible role of the mTOR/AKT signaling pathway. Materials and methods: In vitro, ADMSCs isolated from rats were treated with 50 nmol/L rapamycin for 2 h, after which the cytoprotective and autophagy-inducing effects of Rapa were investigated. The cis-induced acute nephrotoxicity rat model was constructed in vivo. ADMSCs and Rapa-ADMSCs were administered into the tail vein before Cis therapy. At 3, 7, and 10 days after Cis injection, all animals were euthanized. The renal functions and morphology as well as autophagy response were assessed. Results: The pretreatment of cultured ADMSCs with Rapa caused a significant increase in autophagic activities and lysosome production of the cells, with a significant increase in the secretion of SDF-1, IL-10 and autophagy promoter LC3 and Beclin from these cells, while mTOR/AKT pathways were inhibited. In addition, the transplantation of Rapa-pretreated ADMSCs restored the kidney functions and morphology dramatically. Renal expression of SDF-1 and HIF1 was upregulated, while expression of IL-6, NF-kB and TGF-β1 was downregulated. Conclusions: We concluded that the preactivation of autophagy with Rapa improves the survival and differentiation of the transplanted ADMSCs by inhibiting the mTOR/AKT signaling pathway, which in turn could significantly attenuate the Cis-induced acute renal injury.
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Affiliation(s)
- Amira Awadalla
- Center of Excellence for Genome and Cancer Research, Urology and Nephrology Center, Mansoura University, Mansoura 35516, Egypt; (A.A.); (N.B.); (E.T.H.); (A.A.S.); (A.M.S.); (A.A.S.)
| | - Abdelaziz M. Hussein
- Medical Physiology Department, Faculty of Medicine, Mansoura University, Mansoura 35516, Egypt
- Correspondence: ; Tel.: +20-100-2421-140; Fax: +20-502-263-717
| | - Yousra M. El-Far
- Department of Biochemistry, Faculty of Pharmacy, Mansoura University, Mansoura 35516, Egypt;
| | - Fardous F. El-Senduny
- Biochemistry Division, Chemistry Department, Faculty of Sciences, Mansoura University, Mansoura 35516, Egypt;
| | - Nashwa Barakat
- Center of Excellence for Genome and Cancer Research, Urology and Nephrology Center, Mansoura University, Mansoura 35516, Egypt; (A.A.); (N.B.); (E.T.H.); (A.A.S.); (A.M.S.); (A.A.S.)
| | - Eman T. Hamam
- Center of Excellence for Genome and Cancer Research, Urology and Nephrology Center, Mansoura University, Mansoura 35516, Egypt; (A.A.); (N.B.); (E.T.H.); (A.A.S.); (A.M.S.); (A.A.S.)
| | - Hanaa M. Abdeen
- Medical Biochemistry and Molecular Biology Department, Faculty of Medicine, Mansoura University, Mansoura 35516, Egypt; (H.M.A.); (M.S.S.)
| | - Mohamed El-Sherbiny
- Department of Basic Medical Sciences, College of Medicine, AlMaarefa University, Riyadh 13713, Saudi Arabia;
- Department of Anatomy, Faculty of Medicine, Mansoura University, Mansoura 35516, Egypt
| | - Mohamed S. Serria
- Medical Biochemistry and Molecular Biology Department, Faculty of Medicine, Mansoura University, Mansoura 35516, Egypt; (H.M.A.); (M.S.S.)
| | - Amira A. Sarhan
- Center of Excellence for Genome and Cancer Research, Urology and Nephrology Center, Mansoura University, Mansoura 35516, Egypt; (A.A.); (N.B.); (E.T.H.); (A.A.S.); (A.M.S.); (A.A.S.)
| | - Asmaa M. Sena
- Center of Excellence for Genome and Cancer Research, Urology and Nephrology Center, Mansoura University, Mansoura 35516, Egypt; (A.A.); (N.B.); (E.T.H.); (A.A.S.); (A.M.S.); (A.A.S.)
| | - Ahmed A. Shokeir
- Center of Excellence for Genome and Cancer Research, Urology and Nephrology Center, Mansoura University, Mansoura 35516, Egypt; (A.A.); (N.B.); (E.T.H.); (A.A.S.); (A.M.S.); (A.A.S.)
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Ono Y, Matsuzawa K, Ikenouchi J. mTORC2 suppresses cell death induced by hypo-osmotic stress by promoting sphingomyelin transport. J Cell Biol 2022; 221:213090. [PMID: 35319770 PMCID: PMC8952684 DOI: 10.1083/jcb.202106160] [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: 06/25/2021] [Revised: 12/28/2021] [Accepted: 01/24/2022] [Indexed: 11/22/2022] Open
Abstract
Epithelial cells are constantly exposed to osmotic stress. The influx of water molecules into the cell in a hypo-osmotic environment increases plasma membrane tension as it rapidly expands. Therefore, the plasma membrane must be supplied with membrane lipids since expansion beyond its elastic limit will cause the cell to rupture. However, the molecular mechanism to maintain a constant plasma membrane tension is not known. In this study, we found that the apical membrane selectively expands when epithelial cells are exposed to hypo-osmotic stress. This requires the activation of mTORC2, which enhances the transport of secretory vesicles containing sphingomyelin, the major lipid of the apical membrane. We further show that the mTORC2–Rab35 axis plays an essential role in the defense against hypotonic stress by promoting the degradation of the actin cortex through the up-regulation of PI(4,5)P2 metabolism, which facilitates the apical tethering of sphingomyelin-loaded vesicles to relieve plasma membrane tension.
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Affiliation(s)
- Yumiko Ono
- Department of Biology, Faculty of Sciences, Kyushu University, Nishi-ku, Fukuoka, Japan
| | - Kenji Matsuzawa
- Department of Biology, Faculty of Sciences, Kyushu University, Nishi-ku, Fukuoka, Japan
| | - Junichi Ikenouchi
- Department of Biology, Faculty of Sciences, Kyushu University, Nishi-ku, Fukuoka, Japan
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Du HY, Wang R, Li JL, Luo H, Xie XY, Yan R, Jian YL, Cai JY. Ligustrazine protects against chronic hypertensive glaucoma in rats by inhibiting autophagy via the PI3K-Akt/mTOR pathway. Mol Vis 2021; 27:725-733. [PMID: 35035207 PMCID: PMC8711580] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2021] [Accepted: 12/10/2021] [Indexed: 10/25/2022] Open
Abstract
PURPOSE Glaucoma is a leading cause of global irreversible blindness, and characterized by the progressive loss of retinal ganglion cells (RGCs). Ligustrazine (TMP) is a natural product that has shown beneficial effects on various diseases. This study aimed to determine whether ligustrazine produces a therapeutic effect on glaucoma and to investigate its underlying mechanisms. METHODS A rat chronic hypertensive glaucoma model was induced by episcleral vein cauterization (EVC). Adult Sprague-Dawley (SD) rats were intraperitoneally administered TMP at a dose of 80 mg/kg once a day, from two days before EVC to one month after EVC. To elucidate the role of the mammalian target of rapamycin (mTOR) and phosphoinositide 3-kinase (PI3K), TMP-treated experimental rats were co-treated with the mTOR inhibitor rapamycin (5 mg/kg) or the PI3K inhibitor Ly294002 (10 mg/kg). The intraocular pressure (IOP) of the experimental and control rats was measured every six days. Retinal cells were examined by hematoxylin-eosin and terminal deoxynucleotidyltransferase-mediated biotinylated UTP nick end labeling (TUNEL) staining, as well as transmission electron microscopy. Immunohistochemistry and western blot analysis were performed to measure proteins involved in apoptosis and autophagy. RESULTS Ligustrazine protected retinal cells from death in experimental glaucoma rats, which was not due to the lowering of IOP, but could be attributable to direct suppression of retinal cell apoptosis. In glaucoma rats, autophagy was markedly activated in retina cells, as evidenced by increased numbers of autophagosomes and the expression of autophagy-related proteins (ATG5 and LC3-II/I). Notably, such alterations in glaucoma rats were almost completely reversed by ligustrazine. The suppressive effects of ligustrazine on apoptosis and autophagy of retina cells were markedly attenuated by the mTOR inhibitor rapamycin or the PI3K inhibitor Ly294002. Additionally, ligustrazine significantly increased the protein levels of phosphorylated PI3K (p-PI3K), protein kinase B (p-Akt), and mTOR (p-mTOR) in glaucoma rats, whereas such increases were attenuated by rapamycin or Ly294002. CONCLUSIONS These results demonstrate that ligustrazine is protective in experimental glaucoma by inhibiting autophagy via the activation of the PI3K-Akt/mTOR pathway, providing compelling evidence that ligustrazine is potentially therapeutic for patients with glaucoma.
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Reduced activity of intestinal surface Na +/H + exchanger NHE3 is a key factor for induction of diarrhea after PEDV infection in neonatal piglets. Virology 2021; 563:64-73. [PMID: 34464882 DOI: 10.1016/j.virol.2021.08.011] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2020] [Revised: 07/26/2021] [Accepted: 08/19/2021] [Indexed: 11/20/2022]
Abstract
Porcine epidemic diarrhea virus (PEDV; family Coronaviridae, genus Alphacoronavirus) causes acute diarrhea and vomiting, dehydration, and high mortality in neonatal piglets. Despite extensive research focusing on the pathogenesis of PEDV infection, the molecular pathogenesis of PEDV-induced diarrhea in piglets remains unclear. Na+/H+ exchanger 3 (NHE3), the main exchanger of electroneutral sodium in intestinal epithelial cells, is closely associated with the occurrence of diarrhea. To date, there is no study on whether diarrhea caused by PEDV infection is related to the activity of NHE3. In the present study, it was found that the expression level of cell membrane protein NHE3 significantly decreased after PEDV infection, whereas the total level of protein expression was not significantly changed. The Na+/H+ transport rate and the mRNA abundance of NHE3 decreased; the NHE3 activity decreased gradually with increasing infection time. In vivo, after PEDV infection of newborn piglets, rupture of intestinal villi and interstitial degeneration of intestinal epithelial cells in different intestinal segments were observed by hematoxylin-eosin staining. Immunohistochemical and immunofluorescence methods were used to observe the decreased expression of NHE3 protein on the membrane of intestinal epithelial cells in the jejunum and ileum. Taken together, these data indicate that PEDV infection reduces NHE3 activity in intestinal epithelial cells, hindering Na+ transport and thus causing diarrhea.
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Fritsch SD, Weichhart T. Metabolic and immunologic control of intestinal cell function by mTOR. Int Immunol 2020; 32:455-465. [PMID: 32140726 DOI: 10.1093/intimm/dxaa015] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2020] [Accepted: 02/28/2020] [Indexed: 02/06/2023] Open
Abstract
The intestinal epithelium is one of the most quickly dividing tissues in our body, combining the absorptive advantages of a single layer with the protection of a constantly renewing barrier. It is continuously exposed to nutrients and commensal bacteria as well as microbial and host-derived metabolites, but also to hazards such as pathogenic bacteria and toxins. These environmental cues are sensed by the mucosa and a vast repertory of immune cells, especially macrophages. A disruption of intestinal homeostasis in terms of barrier interruption can lead to inflammatory bowel diseases and colorectal cancer, and macrophages have an important role in restoring epithelial function following injury. The mammalian/mechanistic target of rapamycin (mTOR) signalling pathway senses environmental cues and integrates metabolic responses. It has emerged as an important regulator of intestinal functions in homeostasis and disease. In this review, we are going to discuss intestinal mTOR signalling and metabolic regulation in different intestinal cell populations with a special focus on immune cells and their actions on intestinal function.
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Affiliation(s)
- Stephanie D Fritsch
- Center of Pathobiochemistry and Genetics, Institute of Medical Genetics, Medical University of Vienna, Währinger Straße, Vienna, Austria
| | - Thomas Weichhart
- Center of Pathobiochemistry and Genetics, Institute of Medical Genetics, Medical University of Vienna, Währinger Straße, Vienna, Austria
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11
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Premises among SARS-CoV-2, dysbiosis and diarrhea: Walking through the ACE2/mTOR/autophagy route. Med Hypotheses 2020; 144:110243. [PMID: 33254549 PMCID: PMC7467124 DOI: 10.1016/j.mehy.2020.110243] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2020] [Revised: 07/30/2020] [Accepted: 08/30/2020] [Indexed: 12/22/2022]
Abstract
Recently, a new coronavirus (SARS-CoV-2) was discovered in China. Due to its high level of contagion, it has already reached most countries, quickly becoming a pandemic. Although the most common symptoms are related to breathing problems, SARS-CoV-2 infections also affect the gastrointestinal tract culminating in inflammation and diarrhea. However, the mechanisms related to these enteric manifestations are still not well understood. Evidence shows that the SARS-CoV-2 binds to the angiotensin-converting enzyme receptor 2 (ACE2) in host cells as a viral invasion mechanism and can infect the lungs and the gut. Other viruses have already been linked to intestinal symptoms through binding to ACE2. In turn, this medical hypothesis article conjectures that the ACE2 downregulation caused by the SARS-CoV-2 internalization could lead to decreased activation of the mechanistic target of mTOR with increased autophagy and lead to intestinal dysbiosis, resulting in diarrhea. Besides that, dysbiosis can directly affect the respiratory system through the lungs. Although there are clues to other viruses that modulate the ACE2/gut/lungs axis, including the participation of autophagy and dysbiosis in the development of gastrointestinal symptoms, there is still no evidence of the ACE2/mTOR/autophagy pathway in SARS-CoV-2 infections. Thus, we propose that the new coronavirus causes a change in the intestinal microbiota, which culminates in a diarrheal process through the ACE2/mTOR/autophagy pathway into enterocytes. Our assumption is supported by premises that unregulated intestinal microbiota increases the susceptibility to other diseases and extra-intestinal manifestations, which can even cause remote damage in lungs. These putative connections lead us to suggest and encourage future studies aiming at assessing the aforementioned hypothesis and regulating dysbiosis caused by SARS-CoV-2 infection, in order to confirm the decrease in lung injuries and the improvement in the prognosis of the disease.
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12
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Packer M. Critical examination of mechanisms underlying the reduction in heart failure events with SGLT2 inhibitors: identification of a molecular link between their actions to stimulate erythrocytosis and to alleviate cellular stress. Cardiovasc Res 2020; 117:74-84. [PMID: 32243505 DOI: 10.1093/cvr/cvaa064] [Citation(s) in RCA: 45] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/23/2019] [Revised: 02/10/2020] [Accepted: 03/30/2020] [Indexed: 12/13/2022] Open
Abstract
Sodium-glucose co-transporter 2 (SGLT2) inhibitors reduce the risk of serious heart failure events, even though SGLT2 is not expressed in the myocardium. This cardioprotective benefit is not related to an effect of these drugs to lower blood glucose, promote ketone body utilization or enhance natriuresis, but it is linked statistically with their action to increase haematocrit. SGLT2 inhibitors increase both erythropoietin and erythropoiesis, but the increase in red blood cell mass does not directly prevent heart failure events. Instead, erythrocytosis is a biomarker of a state of hypoxia mimicry, which is induced by SGLT2 inhibitors in manner akin to cobalt chloride. The primary mediators of the cellular response to states of energy depletion are sirtuin-1 and hypoxia-inducible factors (HIF-1α/HIF-2α). These master regulators promote the cellular adaptation to states of nutrient and oxygen deprivation, promoting mitochondrial capacity and minimizing the generation of oxidative stress. Activation of sirtuin-1 and HIF-1α/HIF-2α also stimulates autophagy, a lysosome-mediated degradative pathway that maintains cellular homoeostasis by removing dangerous constituents (particularly unhealthy mitochondria and peroxisomes), which are a major source of oxidative stress and cardiomyocyte dysfunction and demise. SGLT2 inhibitors can activate SIRT-1 and stimulate autophagy in the heart, and thereby, favourably influence the course of cardiomyopathy. Therefore, the linkage between erythrocytosis and the reduction in heart failure events with SGLT2 inhibitors may be related to a shared underlying molecular mechanism that is triggered by the action of these drugs to induce a perceived state of oxygen and nutrient deprivation.
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Affiliation(s)
- Milton Packer
- Baylor Heart and Vascular Institute, Baylor University Medical Center, 621 N. Hall Street, Dallas, TX 75226, USA.,Imperial College, London, UK
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13
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Rao MC. Physiology of Electrolyte Transport in the Gut: Implications for Disease. Compr Physiol 2019; 9:947-1023. [PMID: 31187895 DOI: 10.1002/cphy.c180011] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
We now have an increased understanding of the genetics, cell biology, and physiology of electrolyte transport processes in the mammalian intestine, due to the availability of sophisticated methodologies ranging from genome wide association studies to CRISPR-CAS technology, stem cell-derived organoids, 3D microscopy, electron cryomicroscopy, single cell RNA sequencing, transgenic methodologies, and tools to manipulate cellular processes at a molecular level. This knowledge has simultaneously underscored the complexity of biological systems and the interdependence of multiple regulatory systems. In addition to the plethora of mammalian neurohumoral factors and their cross talk, advances in pyrosequencing and metagenomic analyses have highlighted the relevance of the microbiome to intestinal regulation. This article provides an overview of our current understanding of electrolyte transport processes in the small and large intestine, their regulation in health and how dysregulation at multiple levels can result in disease. Intestinal electrolyte transport is a balance of ion secretory and ion absorptive processes, all exquisitely dependent on the basolateral Na+ /K+ ATPase; when this balance goes awry, it can result in diarrhea or in constipation. The key transporters involved in secretion are the apical membrane Cl- channels and the basolateral Na+ -K+ -2Cl- cotransporter, NKCC1 and K+ channels. Absorption chiefly involves apical membrane Na+ /H+ exchangers and Cl- /HCO3 - exchangers in the small intestine and proximal colon and Na+ channels in the distal colon. Key examples of our current understanding of infectious, inflammatory, and genetic diarrheal diseases and of constipation are provided. © 2019 American Physiological Society. Compr Physiol 9:947-1023, 2019.
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Affiliation(s)
- Mrinalini C Rao
- Department of Physiology and Biophysics, University of Illinois at Chicago, Chicago, Illinois, USA
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14
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Mathur R, Alam MM, Zhao XF, Liao Y, Shen J, Morgan S, Huang T, Lee H, Lee E, Huang Y, Zhu X. Induction of autophagy in Cx3cr1 + mononuclear cells limits IL-23/IL-22 axis-mediated intestinal fibrosis. Mucosal Immunol 2019; 12:612-623. [PMID: 30765845 PMCID: PMC6927046 DOI: 10.1038/s41385-019-0146-4] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2018] [Revised: 01/21/2019] [Accepted: 01/27/2019] [Indexed: 02/04/2023]
Abstract
Intestinal fibrosis is an excessive proliferation of myofibroblasts and deposition of collagen, a condition frequently seen in Crohn's disease (CD). The mechanism underlying myofibroblast hyper-proliferation in CD needs to be better understood. In this report, we found that mTOR inhibitor rapamycin or mTOR deletion in CX3Cr1+ mononuclear phagocytes inhibits expression of interleukin (IL)-23, accompanied by reduced intestinal production of IL-22 and ameliorated fibrosis in the TNBS-induced fibrosis mouse model. This inhibition of IL-23 expression is associated with elevated autophagy activity. Ablating the autophagy gene Atg7 increases the expression of IL-23, leading to increased expression of IL-22 and increased fibrosis. Both induction of IL-22 and intestinal fibrosis occurred in RAG-/- mice and depletion of innate lymphoid cells (ILCs) attenuates the fibrotic reaction, suggesting that the pro-fibrotic process is independent of T and B cells. Moreover, IL-22 facilitates the transformation of fibroblasts into myofibroblasts. Finally, the fibrotic reaction was attenuated upon neutralization of either IL-23 or IL-22. Altogether, this study elucidated a signaling cascade underlying intestinal fibrosis in which altered mTOR/autophagy in CX3Cr1+ mononuclear phagocytes up-regulates the IL-23/IL-22 axis, leading to an excessive fibrotic response. Thus, our findings suggest that this cascade could be a therapeutic target for alleviation of CD fibrosis.
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Affiliation(s)
- Ramkumar Mathur
- Department of Molecular and Cellular Physiology, Albany Medical College, Albany, NY, 12208, USA.
- The IBD Center, Division of Gastroenterology, Department of Medicine, Albany Medical College, Albany, NY, 12208, USA.
| | - Mahabub Maraj Alam
- Department of Neuroscience and Experimental Therapeutics, Albany Medical College, Albany, NY, 12208, USA
| | - Xiao-Feng Zhao
- Department of Neuroscience and Experimental Therapeutics, Albany Medical College, Albany, NY, 12208, USA
| | - Yuan Liao
- Department of Molecular and Cellular Physiology, Albany Medical College, Albany, NY, 12208, USA
| | - Jeffrey Shen
- Department of Molecular and Cellular Physiology, Albany Medical College, Albany, NY, 12208, USA
| | - Shannon Morgan
- Department of Neuroscience and Experimental Therapeutics, Albany Medical College, Albany, NY, 12208, USA
| | - Tingting Huang
- Department of Neuroscience and Experimental Therapeutics, Albany Medical College, Albany, NY, 12208, USA
| | - HwaJeong Lee
- Department of Pathology, Albany Medical College, Albany, NY, 12208, USA
| | - Edward Lee
- Department of Surgery, Albany Medical College, Albany, NY, 12208, USA
| | - Yunfei Huang
- Department of Neuroscience and Experimental Therapeutics, Albany Medical College, Albany, NY, 12208, USA
| | - Xinjun Zhu
- Department of Molecular and Cellular Physiology, Albany Medical College, Albany, NY, 12208, USA.
- The IBD Center, Division of Gastroenterology, Department of Medicine, Albany Medical College, Albany, NY, 12208, USA.
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15
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Immunosuppressive drugs and the gastrointestinal tract in renal transplant patients. Transplant Rev (Orlando) 2018; 33:55-63. [PMID: 30473173 DOI: 10.1016/j.trre.2018.11.001] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2018] [Revised: 11/07/2018] [Accepted: 11/10/2018] [Indexed: 12/26/2022]
Abstract
Gastrointestinal (GI) discomfort is common after renal transplantation and can be caused by the use of various immunosuppressive drugs. GI symptoms affect the quality of life, lead to an impaired graft survival and an increased mortality. Moreover, diseases and disturbances of the GI tract also affect the pharmacokinetics of immunosuppressive drugs. This review addresses the interaction between immunosuppressive agents and GI disorders. The GI tract is involved in the metabolism of several immunosuppressive drugs. Calcineurin inhibitors, mTor inhibitors, and corticosteroids are subjected to metabolism by the intestinal cytochrome P450 (CYP3A) and by the drug efflux pump ABCB1. Mycophenolate is partly metabolized in the stomach and intestine and undergoes enterohepatic recirculation. Gastrointestinal disturbances can lead to a modified exposure to immunosuppressive drugs. In the first and second part of this review, we focus on the role of the GI tract in the pharmacokinetics of the immunosuppressive drugs and how to adjust immunosuppressive therapy in patients with vomiting, need for tube feeding, delayed gastric emptying, intestinal resection, and diarrhea. In the third part, we review the GI adverse effects of the various immunosuppressive drugs, with special attention for diarrhea and dyspepsia. Finally, we discuss the effects of drugs used for relief of GI complaints on the exposure to immunosuppressive agents.
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16
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Yang Z, Ran L, Yuan P, Yang Y, Wang K, Xie L, Huang S, Liu J, Song Z. EGFR as a Negative Regulatory Protein Adjusts the Activity and Mobility of NHE3 in the Cell Membrane of IPEC-J2 Cells With TGEV Infection. Front Microbiol 2018; 9:2734. [PMID: 30483239 PMCID: PMC6243134 DOI: 10.3389/fmicb.2018.02734] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2018] [Accepted: 10/25/2018] [Indexed: 11/13/2022] Open
Abstract
Transmissible gastroenteritis (TGE) has caused devastating economic losses to the swine industry worldwide, despite extensive research focusing on the pathogenesis of virus infection. The molecular pathogenic mechanism of TGEV-induced diarrhea in piglets is unknown. Intestinal diarrhea is closely related to the function of the Na+/H+ exchanger protein NHE3 in the brush border membrane of small intestine epithelial cells. The epidermal growth factor receptor (EGFR) may act to regulate NHE3 expression. In addition, EGFR may promote viral invasion of host cells. The present study aimed to determine whether NHE3 activity is regulated by altering EGFR expression to affect Na+ absorption in TGEV-infected intestinal epithelial cells. Porcine intestinal epithelial cells were used as models for TGEV infection. The results showed that Na+ absorption and NHE3 expression levels decreased in TGEV-infected cells. Proliferation of TGEV within IPEC-J2 cells could be inhibited by treatment with the EGFR inhibitor AG1478 and knockdown; resulting in recovery of Na+ absorption in TGEV infected cells and increasing the activity and expression of NHE3. Moreover, we demonstrated that NHE3 activity was regulated through the EGFR/ERK pathway. Importantly, NHE3 mobility on the plasma membrane of TGEV infected cells was significantly weaker than that in normal cells, and EGFR inhibition and knockdown recovered this mobility. Our research indicated that NHE3 activity was negatively regulated by EGFR in TGEV-infected intestinal epithelial cells.
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Affiliation(s)
- Zhou Yang
- Department of Veterinary Medicine, Southwest University, Chongqing, China
| | - Ling Ran
- Department of Veterinary Medicine, Southwest University, Chongqing, China
| | - Peng Yuan
- Department of Veterinary Medicine, Southwest University, Chongqing, China
| | - Yang Yang
- Department of Veterinary Medicine, Southwest University, Chongqing, China
| | - Kai Wang
- Department of Veterinary Medicine, Southwest University, Chongqing, China
| | - Luyi Xie
- Department of Veterinary Medicine, Southwest University, Chongqing, China
| | - Shilei Huang
- Department of Veterinary Medicine, Southwest University, Chongqing, China
| | - Jia Liu
- Department of Veterinary Medicine, Southwest University, Chongqing, China
| | - Zhenhui Song
- Department of Veterinary Medicine, Southwest University, Chongqing, China
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17
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Regnase-1 controls colon epithelial regeneration via regulation of mTOR and purine metabolism. Proc Natl Acad Sci U S A 2018; 115:11036-11041. [PMID: 30297433 PMCID: PMC6205455 DOI: 10.1073/pnas.1809575115] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Idiopathic inflammatory bowel disease (IBD) is associated with the gut microbiota and immune system of the host; however, the precise pathogenesis of IBD is poorly defined. We show that specific deletion of the endoribonuclease Regnase-1 in intestinal epithelial cells relieves the symptoms of experimental colitis during acute inflammation. Regnase-1 deficiency potentiates mTOR signaling and purine metabolism in the colon epithelium. These data provide insight into the role of epithelial Regnase-1 in IBD. Damage to intestinal epithelial cell (IEC) layers during intestinal inflammation is associated with inflammatory bowel disease. Here we show that the endoribonuclease Regnase-1 controls colon epithelial regeneration by regulating protein kinase mTOR (the mechanistic target of rapamycin kinase) and purine metabolism. During dextran sulfate sodium-induced intestinal epithelial injury and acute colitis, Regnase-1∆IEC mice, which lack Regnase-1 specifically in the intestinal epithelium, were resistant to body weight loss, maintained an intact intestinal barrier, and showed increased cell proliferation and decreased epithelial apoptosis. Chronic colitis and tumor progression were also attenuated in Regnase-1∆IEC mice. Regnase-1 predominantly regulates mTORC1 signaling. Metabolic analysis revealed that Regnase-1 participates in purine metabolism and energy metabolism during inflammation. Furthermore, increased expression of ectonucleotidases contributed to the resolution of acute inflammation in Regnase-1∆IEC mice. These findings provide evidence that Regnase-1 deficiency has beneficial effects on the prevention and/or blocking of intestinal inflammatory disorders.
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18
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Xu R, Lin J, Zhao GQ, Li C, Che CY, Xu Q, Liu M. Production of interleukin-1β related to mammalian target of rapamycin/Toll-like receptor 4 signaling pathway during Aspergillus fumigatus infection of the mouse cornea. Int J Ophthalmol 2018; 11:712-718. [PMID: 29862167 DOI: 10.18240/ijo.2018.05.02] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2017] [Accepted: 03/19/2018] [Indexed: 12/15/2022] Open
Abstract
AIM To elucidate the effect of rapamycin on regulating the production of interleukin (IL)-1β in Aspergillus fumigatus (A. fumigatus)-induced keratitis and to verify whether the expression of IL-1β in A. fumigatus keratitis is associated with the mammalian target of rapamycin (mTOR)/Toll-like receptor 4 (TLR4) signaling pathway. METHODS Fungal keratitis mouse models of susceptible C57BL/6 mice were established using A. fumigatus. The mice were subsequently treated with rapamycin. The protein levels of p-mTOR, TLR4, and IL-1β in normal and infected corneal tissue were measured by Western blot. The TLR4 and IL-1β mRNA levels were determined by real-time polymerase chain reaction (PCR). RESULTS In C57BL/6 mice, rapamycin treatment decreased the clinical scores and production of the pro-inflammatory cytokine, IL-1β. The expression of TLR4, stimulated by A. fumigatus, was reduced as well when the mTOR signaling pathway was suppressed by rapamycin. CONCLUSION Rapamycin is beneficial for the outcome of fungal keratitis and has an inhibitory effect expression of the inflammatory cytokine IL-1β. The inhibitory effect on IL-1β expression can be associated with the mTOR/TLR4 signaling pathway in A. fumigatus infection in mice.
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Affiliation(s)
- Rui Xu
- Department of Ophthalmology, the Affiliated Hospital of Qingdao University, Qingdao 266003, Shandong Province, China
| | - Jing Lin
- Department of Ophthalmology, the Affiliated Hospital of Qingdao University, Qingdao 266003, Shandong Province, China
| | - Gui-Qiu Zhao
- Department of Ophthalmology, the Affiliated Hospital of Qingdao University, Qingdao 266003, Shandong Province, China
| | - Cui Li
- Department of Ophthalmology, the Affiliated Hospital of Qingdao University, Qingdao 266003, Shandong Province, China
| | - Cheng-Ye Che
- Department of Ophthalmology, the Affiliated Hospital of Qingdao University, Qingdao 266003, Shandong Province, China
| | - Qiang Xu
- Department of Ophthalmology, the Affiliated Hospital of Qingdao University, Qingdao 266003, Shandong Province, China
| | - Min Liu
- Department of Ophthalmology, the Affiliated Hospital of Qingdao University, Qingdao 266003, Shandong Province, China
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19
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mTORC1 Inactivation Promotes Colitis-Induced Colorectal Cancer but Protects from APC Loss-Dependent Tumorigenesis. Cell Metab 2018; 27:118-135.e8. [PMID: 29275959 DOI: 10.1016/j.cmet.2017.11.006] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/07/2017] [Revised: 08/21/2017] [Accepted: 11/15/2017] [Indexed: 01/17/2023]
Abstract
Dietary habits that can induce inflammatory bowel disease (IBD) are major colorectal cancer (CRC) risk factors, but mechanisms linking nutrients, IBD, and CRC are unknown. Using human data and mouse models, we show that mTORC1 inactivation-induced chromosomal instability impairs intestinal crypt proliferation and regeneration, CDK4/6 dependently. This triggers interleukin (IL)-6-associated reparative inflammation, inducing crypt hyper-proliferation, wound healing, and CRC. Blocking IL-6 signaling or reactivating mTORC1 reduces inflammation-induced CRC, so mTORC1 activation suppresses tumorigenesis in IBD. Conversely, mTORC1 inactivation is beneficial in APC loss-dependent CRC. Thus, IL-6 blockers or protein-rich-diet-linked mTORC1 activation may prevent IBD-associated CRC. However, abolishing mTORC1 can mitigate CRC in predisposed patients with APC mutations. Our work reveals mTORC1 oncogenic and tumor-suppressive roles in intestinal epithelium and avenues to optimized and personalized therapeutic regimens for CRC.
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20
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Vogel GF, van Rijn JM, Krainer IM, Janecke AR, Posovszky C, Cohen M, Searle C, Jantchou P, Escher JC, Patey N, Cutz E, Müller T, Middendorp S, Hess MW, Huber LA. Disrupted apical exocytosis of cargo vesicles causes enteropathy in FHL5 patients with Munc18-2 mutations. JCI Insight 2017; 2:94564. [PMID: 28724787 DOI: 10.1172/jci.insight.94564] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2017] [Accepted: 06/06/2017] [Indexed: 01/07/2023] Open
Abstract
Familial hemophagocytic lymphohistiocytosis 5 (FHL5) is an autosomal recessive disease caused by mutations in STXBP2, coding for Munc18-2, which is required for SNARE-mediated membrane fusion. FHL5 causes hematologic and gastrointestinal symptoms characterized by chronic enteropathy that is reminiscent of microvillus inclusion disease (MVID). However, the molecular pathophysiology of FHL5-associated diarrhea is poorly understood. Five FHL5 patients, including four previously unreported patients, were studied. Morphology of duodenal sections was analyzed by electron and fluorescence microscopy. Small intestinal enterocytes and organoid-derived monolayers displayed the subcellular characteristics of MVID. For the analyses of Munc18-2-dependent SNARE-protein interactions, a Munc18-2 CaCo2-KO model cell line was generated by applying CRISPR/Cas9 technology. Munc18-2 is required for Slp4a/Stx3 interaction in fusion of cargo vesicles with the apical plasma membrane. Cargo trafficking was investigated in patient biopsies, patient-derived organoids, and the genome-edited model cell line. Loss of Munc18-2 selectively disrupts trafficking of certain apical brush-border proteins (NHE3 and GLUT5), while transport of DPPIV remained unaffected. Here, we describe the molecular mechanism how the loss of function of Munc18-2 leads to cargo-selective mislocalization of brush-border components and a subapical accumulation of cargo vesicles, as it is known from the loss of polarity phenotype in MVID.
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Affiliation(s)
- Georg F Vogel
- Department of Paediatrics I and.,Division of Cell Biology, Medical University of Innsbruck, Innsbruck, Austria
| | - Jorik M van Rijn
- Division of Paediatrics, Department of Paediatric Gastroenterology and Regenerative Medicine Center Utrecht, Wilhelmina Children's Hospital, University Medical Centre (UMC) Utrecht, Utrecht, The Netherlands
| | - Iris M Krainer
- Department of Paediatrics I and.,Division of Cell Biology, Medical University of Innsbruck, Innsbruck, Austria
| | | | - Carsten Posovszky
- Department of Pediatrics and Adolescent Medicine, University Medical Center Ulm, Ulm, Germany
| | - Marta Cohen
- Sheffield Children's Hospital NHS Trust, Western Bank, Sheffield, United Kingdom
| | - Claire Searle
- Clinical Genetics, Nottingham University Hospitals NHS Trust, Nottingham, United Kingdom
| | - Prevost Jantchou
- Gastroentérologie Hépatologie et Nutrition Pédiatrique Hôpital Sainte-Justine, Université de Montréal, Montréal, Quebec, Canada
| | - Johanna C Escher
- Department of Pediatric Gastroenterology, Sophia Children's Hospital, Erasmus MC, Rotterdam, The Netherlands
| | - Natalie Patey
- Clinical Genetics, Nottingham University Hospitals NHS Trust, Nottingham, United Kingdom
| | - Ernest Cutz
- The Hospital for Sick Children, Toronto, Canada
| | | | - Sabine Middendorp
- Division of Paediatrics, Department of Paediatric Gastroenterology and Regenerative Medicine Center Utrecht, Wilhelmina Children's Hospital, University Medical Centre (UMC) Utrecht, Utrecht, The Netherlands
| | - Michael W Hess
- Division of Histology and Embryology, Medical University of Innsbruck, Innsbruck, Austria
| | - Lukas A Huber
- Division of Cell Biology, Medical University of Innsbruck, Innsbruck, Austria
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21
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Wang B, Jia H, Zhang B, Wang J, Ji C, Zhu X, Yan Y, Yin L, Yu J, Qian H, Xu W. Pre-incubation with hucMSC-exosomes prevents cisplatin-induced nephrotoxicity by activating autophagy. Stem Cell Res Ther 2017; 8:75. [PMID: 28388958 PMCID: PMC5385032 DOI: 10.1186/s13287-016-0463-4] [Citation(s) in RCA: 109] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2016] [Revised: 12/05/2016] [Accepted: 12/20/2016] [Indexed: 12/20/2022] Open
Abstract
Background The administration of cisplatin is limited due to its nephrotoxic side effects, and prevention of this nephrotoxicity of cisplatin is difficult. Mesenchymal stem cell (MSC)-derived exosomes have been implicated as a novel therapeutic approach for tissue injury. In this study, we demonstrated that the pretreatment of human umbilical cord MSC-derived exosomes (hucMSC-Ex) can prevent the development of cisplatin-induced renal toxicity by activation of autophagy in vitro and in vivo. Methods In vitro, rat renal tubular epithelial (NRK-52E) cells were pre-incubated with exosomes from hucMSC or HFL1 (human lung fibroblast cells; as control) for 30 min, and 3-methyladenine (an autophagic inhibitor) and rapamycin (an autophagic inducer) for 1 h before cisplatin treatment for 8 h, respectively. Cells were harvested for apoptosis assay, enzyme-linked immunosorbent assay (ELISA), Western blot, and quantitative real-time polymerase chain reaction (qRT-PCR). In vivo, we constructed cisplatin-induced acute kidney injury rat models. Prior to treatment with cisplatin for 0.5 h, hucMSC-Ex or HFL1-Ex were injected into the kidneys via the renal capsule. 3-methyladenine and rapamycin were injected under the kidney capsule before hucMSC-Ex. All animals were sacrificed at 3 days after cisplatin injection. Renal function, Luminex assay, tubular apoptosis and proliferation, and autophagy response were evaluated. Results hucMSC-Ex inhibited cisplatin-induced mitochondrial apoptosis and secretion of inflammatory cytokines in renal tubular epithelial cells in vitro. hucMSC-Ex increased the expression of the autophagic marker protein LC3B and the autophagy-related genes ATG5 and ATG7 in NRK-52E cells. Rapamycin mimicked the effects of hucMSC-Ex in protecting against cisplatin-induced renal injury, while the effects were abrogated by the autophagy inhibitor 3-methyladenine in the animals. Conclusions Our findings indicate that the activation of autophagy induced by hucMSC-Ex can effectively relieve the nephrotoxicity of cisplatin. Therefore, pre-treatment of hucMSC-Ex may be a new method to improve the therapeutic effect of cisplatin. Electronic supplementary material The online version of this article (doi:10.1186/s13287-016-0463-4) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Bingying Wang
- Key Laboratory of Laboratory Medicine of Jiangsu Province, School of Medicine, Jiangsu University, 301 Xuefu Road, Zhenjiang, Jiangsu, 212013, People's Republic of China.,The Second Affiliated Hospital of Soochow University, Suzhou, Jiangsu, People's Republic of China
| | - Haoyuan Jia
- Key Laboratory of Laboratory Medicine of Jiangsu Province, School of Medicine, Jiangsu University, 301 Xuefu Road, Zhenjiang, Jiangsu, 212013, People's Republic of China
| | - Bin Zhang
- Key Laboratory of Laboratory Medicine of Jiangsu Province, School of Medicine, Jiangsu University, 301 Xuefu Road, Zhenjiang, Jiangsu, 212013, People's Republic of China
| | - Juanjuan Wang
- Key Laboratory of Laboratory Medicine of Jiangsu Province, School of Medicine, Jiangsu University, 301 Xuefu Road, Zhenjiang, Jiangsu, 212013, People's Republic of China
| | - Cheng Ji
- Key Laboratory of Laboratory Medicine of Jiangsu Province, School of Medicine, Jiangsu University, 301 Xuefu Road, Zhenjiang, Jiangsu, 212013, People's Republic of China
| | - Xueming Zhu
- The Second Affiliated Hospital of Soochow University, Suzhou, Jiangsu, People's Republic of China
| | - Yongmin Yan
- Key Laboratory of Laboratory Medicine of Jiangsu Province, School of Medicine, Jiangsu University, 301 Xuefu Road, Zhenjiang, Jiangsu, 212013, People's Republic of China
| | - Lei Yin
- Key Laboratory of Laboratory Medicine of Jiangsu Province, School of Medicine, Jiangsu University, 301 Xuefu Road, Zhenjiang, Jiangsu, 212013, People's Republic of China
| | - Jing Yu
- Key Laboratory of Laboratory Medicine of Jiangsu Province, School of Medicine, Jiangsu University, 301 Xuefu Road, Zhenjiang, Jiangsu, 212013, People's Republic of China
| | - Hui Qian
- Key Laboratory of Laboratory Medicine of Jiangsu Province, School of Medicine, Jiangsu University, 301 Xuefu Road, Zhenjiang, Jiangsu, 212013, People's Republic of China.
| | - Wenrong Xu
- Key Laboratory of Laboratory Medicine of Jiangsu Province, School of Medicine, Jiangsu University, 301 Xuefu Road, Zhenjiang, Jiangsu, 212013, People's Republic of China.
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22
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Barron L, Sun RC, Aladegbami B, Erwin CR, Warner BW, Guo J. Intestinal Epithelial-Specific mTORC1 Activation Enhances Intestinal Adaptation After Small Bowel Resection. Cell Mol Gastroenterol Hepatol 2016; 3:231-244. [PMID: 28275690 PMCID: PMC5331783 DOI: 10.1016/j.jcmgh.2016.10.006] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/12/2016] [Accepted: 10/18/2016] [Indexed: 01/21/2023]
Abstract
BACKGROUND & AIMS Intestinal adaptation is a compensatory response to the massive loss of small intestine after surgical resection. We investigated the role of intestinal epithelial cell-specific mammalian target of rapamycin complex 1 (i-mTORC1) in intestinal adaptation after massive small bowel resection (SBR). METHODS We performed 50% proximal SBR on mice to study adaptation. To manipulate i-mTORC1 activity, Villin-CreER transgenic mice were crossed with tuberous sclerosis complex (TSC)1flox/flox or Raptorflox/flox mice to inducibly activate or inactivate i-mTORC1 activity with tamoxifen. Western blot was used to confirm the activity of mTORC1. Crypt depth and villus height were measured to score adaptation. Immunohistochemistry was used to investigate differentiation and rates of crypt proliferation. RESULTS After SBR, mice treated with systemic rapamycin showed diminished structural adaptation, blunted crypt cell proliferation, and significant body weight loss. Activating i-mTORC1 via TSC1 deletion induced larger hyperproliferative crypts and disorganized Paneth cells without a significant change in villus height. After SBR, ablating TSC1 in intestinal epithelium induced a robust villus growth with much stronger crypt cell proliferation, but similar body weight recovery. Acute inactivation of i-mTORC1 through deletion of Raptor did not change crypt cell proliferation or mucosa structure, but significantly reduced lysozyme/matrix metalloproteinase-7-positive Paneth cell and goblet cell numbers, with increased enteroendocrine cells. Surprisingly, ablation of intestinal epithelial cell-specific Raptor after SBR did not affect adaptation or crypt proliferation, but dramatically reduced body weight recovery after surgery. CONCLUSIONS Systemic, but not intestinal-specific, mTORC1 is important for normal adaptation responses to SBR. Although not required, forced enterocyte mTORC1 signaling after resection causes an enhanced adaptive response.
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Key Words
- Differentiation
- EGF, epidermal growth factor
- IHC, immunohistochemistry
- MMP, matrix metalloproteinase
- PCR, polymerase chain reaction
- Raptor
- S6K, S6 kinase
- SBR, small bowel resection
- TAM, tamoxifen
- TSC, tuberous sclerosis complex
- TSC1
- WT, wild type
- i-TSC-/-, intestinal epithelial cell–specific tuberous sclerosis complex 1 null mice
- mTOR, mammalian target of rapamycin
- mTORC, mammalian target of rapamycin complex
- p-HH3, phosphorylated histone H3
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Affiliation(s)
| | | | | | | | | | - Jun Guo
- Correspondence Address correspondence to: Jun Guo, PhD, BJC Institute of Health Room 7118, 425 South Euclid Avenue, St. Louis, Missouri 63110. fax: (314) 747–0610.BJC Institute of Health Room 7118425 South Euclid AvenueSt. LouisMissouri 63110
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23
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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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24
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Fernandes-Silva G, Ivani de Paula M, Rangel ÉB. mTOR inhibitors in pancreas transplant: adverse effects and drug-drug interactions. Expert Opin Drug Metab Toxicol 2016; 13:367-385. [DOI: 10.1080/17425255.2017.1239708] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Affiliation(s)
- Gabriel Fernandes-Silva
- Universidade Federal de São Paulo/Hospital do Rim e Hipertensão, Nephrology Department, São Paulo, SP, Brazil
| | - Mayara Ivani de Paula
- Universidade Federal de São Paulo/Hospital do Rim e Hipertensão, Nephrology Department, São Paulo, SP, Brazil
| | - Érika B. Rangel
- Universidade Federal de São Paulo/Hospital do Rim e Hipertensão, Nephrology Department, São Paulo, SP, Brazil
- Hospital Israelita Albert Einstein, Instituto Israelita de Ensino e Pesquisa, São Paulo, SP, Brazil
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25
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Reiner J, Hsieh CJ, Straarup C, Bodammer P, Schäffler H, Graepler F, Stüker D, Kratt T, Linnebacher M, Nadalin S, Witte M, Königsrainer A, Lamprecht G. After Intestinal Transplantation Kidney Function Is Impaired by Downregulation of Epithelial Ion Transporters in the Ileum. Transplant Proc 2016; 48:499-506. [DOI: 10.1016/j.transproceed.2015.12.068] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2015] [Accepted: 12/29/2015] [Indexed: 12/18/2022]
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26
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Vogel GF, Klee KMC, Janecke AR, Müller T, Hess MW, Huber LA. Cargo-selective apical exocytosis in epithelial cells is conducted by Myo5B, Slp4a, Vamp7, and Syntaxin 3. J Cell Biol 2016; 211:587-604. [PMID: 26553929 PMCID: PMC4639860 DOI: 10.1083/jcb.201506112] [Citation(s) in RCA: 77] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The motor protein Myo5B and t-SNARE Stx3 drive cargo-selective apical exocytosis in polarized epithelial cells in a pathway dependent on v-SNARE–like Slp4a, v-SNARE Vamp7, Sec1/Munc18-like protein Munc18-2, and the Rab11/8 cascade. Mutations in the motor protein Myosin Vb (Myo5B) or the soluble NSF attachment protein receptor Syntaxin 3 (Stx3) disturb epithelial polarity and cause microvillus inclusion disease (MVID), a lethal hereditary enteropathy affecting neonates. To understand the molecular mechanism of Myo5B and Stx3 interplay, we used genome editing to introduce a defined Myo5B patient mutation in a human epithelial cell line. Our results demonstrate a selective role of Myo5B and Stx3 for apical cargo exocytosis in polarized epithelial cells. Apical exocytosis of NHE3, CFTR (cystic fibrosis transmembrane conductance regulator), and GLUT5 required an interaction cascade of Rab11, Myo5B, Slp4a, Munc18-2, and Vamp7 with Stx3, which cooperate in the final steps of this selective apical traffic pathway. The brush border enzymes DPPIV and sucrase-isomaltase still correctly localize at the apical plasma membrane independent of this pathway. Hence, our work demonstrates how Myo5B, Stx3, Slp4a, Vamp7, Munc18-2, and Rab8/11 cooperate during selective apical cargo trafficking and exocytosis in epithelial cells and thereby provides further insight into MVID pathophysiology.
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Affiliation(s)
- Georg F Vogel
- Division of Cell Biology, Biocenter, Medical University of Innsbruck, 6020 Innsbruck, Austria Division of Histology and Embryology, Medical University of Innsbruck, 6020 Innsbruck, Austria
| | - Katharina M C Klee
- Division of Cell Biology, Biocenter, Medical University of Innsbruck, 6020 Innsbruck, Austria Institute of Molecular Biology, University of Innsbruck, 6020 Innsbruck, Austria Center for Molecular Biosciences Innsbruck, University of Innsbruck, 6020 Innsbruck, Austria
| | - Andreas R Janecke
- Department of Paediatrics I, Medical University of Innsbruck, 6020 Innsbruck, Austria
| | - Thomas Müller
- Department of Paediatrics I, Medical University of Innsbruck, 6020 Innsbruck, Austria
| | - Michael W Hess
- Division of Histology and Embryology, Medical University of Innsbruck, 6020 Innsbruck, Austria
| | - Lukas A Huber
- Division of Cell Biology, Biocenter, Medical University of Innsbruck, 6020 Innsbruck, Austria
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