1
|
Marsch P, Rajagopal N, Nangia S. Biophysics of claudin proteins in tight junction architecture: Three decades of progress. Biophys J 2024:S0006-3495(24)00393-X. [PMID: 38859584 DOI: 10.1016/j.bpj.2024.06.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2024] [Revised: 05/19/2024] [Accepted: 06/07/2024] [Indexed: 06/12/2024] Open
Abstract
Tight junctions are cell-cell adhesion complexes that act as gatekeepers of the paracellular space. Formed by several transmembrane proteins, the claudin family performs the primary gate-keeping function. The claudin proteins form charge and size-selective diffusion barriers to maintain homeostasis across endothelial and epithelial tissue. Of the 27 known claudins in mammals, some are known to seal the paracellular space, while others provide selective permeability. The differences in permeability arise due to the varying expression levels of claudins in each tissue. The tight junctions are observed as strands in freeze-fracture electron monographs; however, at the molecular level, tight junction strands form when multiple claudin proteins assemble laterally (cis assembly) within a cell and head-on (trans assembly) with claudins of the adjacent cell in a zipper-like architecture, closing the gap between the neighboring cells. The disruption of tight junctions caused by changing claudin expression levels or mutations can lead to diseases. Therefore, knowledge of the molecular architecture of the tight junctions and how that is tied to tissue-specific function is critical for fighting diseases. Here, we review the current understanding of the tight junctions accrued over the last three decades from experimental and computational biophysics perspectives.
Collapse
Affiliation(s)
- Patrick Marsch
- Department of Biomedical and Chemical Engineering, Syracuse University, Syracuse, New York
| | - Nandhini Rajagopal
- Department of Biomedical and Chemical Engineering, Syracuse University, Syracuse, New York
| | - Shikha Nangia
- Department of Biomedical and Chemical Engineering, Syracuse University, Syracuse, New York.
| |
Collapse
|
2
|
Hashimoto Y, Greene C, Munnich A, Campbell M. The CLDN5 gene at the blood-brain barrier in health and disease. Fluids Barriers CNS 2023; 20:22. [PMID: 36978081 PMCID: PMC10044825 DOI: 10.1186/s12987-023-00424-5] [Citation(s) in RCA: 12] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2023] [Accepted: 03/14/2023] [Indexed: 03/30/2023] Open
Abstract
The CLDN5 gene encodes claudin-5 (CLDN-5) that is expressed in endothelial cells and forms tight junctions which limit the passive diffusions of ions and solutes. The blood-brain barrier (BBB), composed of brain microvascular endothelial cells and associated pericytes and end-feet of astrocytes, is a physical and biological barrier to maintain the brain microenvironment. The expression of CLDN-5 is tightly regulated in the BBB by other junctional proteins in endothelial cells and by supports from pericytes and astrocytes. The most recent literature clearly shows a compromised BBB with a decline in CLDN-5 expression increasing the risks of developing neuropsychiatric disorders, epilepsy, brain calcification and dementia. The purpose of this review is to summarize the known diseases associated with CLDN-5 expression and function. In the first part of this review, we highlight the recent understanding of how other junctional proteins as well as pericytes and astrocytes maintain CLDN-5 expression in brain endothelial cells. We detail some drugs that can enhance these supports and are being developed or currently in use to treat diseases associated with CLDN-5 decline. We then summarise mutagenesis-based studies which have facilitated a better understanding of the physiological role of the CLDN-5 protein at the BBB and have demonstrated the functional consequences of a recently identified pathogenic CLDN-5 missense mutation from patients with alternating hemiplegia of childhood. This mutation is the first gain-of-function mutation identified in the CLDN gene family with all others representing loss-of-function mutations resulting in mis-localization of CLDN protein and/or attenuated barrier function. Finally, we summarize recent reports about the dosage-dependent effect of CLDN-5 expression on the development of neurological diseases in mice and discuss what cellular supports for CLDN-5 regulation are compromised in the BBB in human diseases.
Collapse
Affiliation(s)
- Yosuke Hashimoto
- Trinity College Dublin, Smurfit Institute of Genetics, Dublin, D02 VF25, Ireland.
| | - Chris Greene
- Trinity College Dublin, Smurfit Institute of Genetics, Dublin, D02 VF25, Ireland
| | - Arnold Munnich
- Institut Imagine, INSERM UMR1163, Université Paris Cité, Paris, F-75015, France
- Departments of Pediatric Neurology and Medical Genetics, Hospital Necker Enfants Malades, Université Paris Cité, Paris, F-75015, France
| | - Matthew Campbell
- Trinity College Dublin, Smurfit Institute of Genetics, Dublin, D02 VF25, Ireland.
| |
Collapse
|
3
|
Houillier P, Lievre L, Hureaux M, Prot-Bertoye C. Mechanisms of paracellular transport of magnesium in intestinal and renal epithelia. Ann N Y Acad Sci 2023; 1521:14-31. [PMID: 36622354 DOI: 10.1111/nyas.14953] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Magnesium is the fourth most abundant cation in the body. It plays a critical role in many biological processes, including the process of energy release. Paracellular transport of magnesium is mandatory for magnesium homeostasis. In addition to intestinal absorption that occurs in part across the paracellular pathway, magnesium is reabsorbed by the kidney tubule. The bulk of magnesium is reabsorbed through the paracellular pathway in the proximal tubule and the thick ascending limb of the loop of Henle. The finding that rare genetic diseases due to pathogenic variants in genes encoding specific claudins (CLDNs), proteins located at the tight junction that determine the selectivity and the permeability of the paracellular pathway, led to an awareness of their importance in magnesium homeostasis. Familial hypomagnesemia with hypercalciuria and nephrocalcinosis is caused by a loss of function of CLDN16 or CLDN19. Pathogenic CLDN10 variants cause HELIX syndrome, which is associated with a severe renal loss of sodium chloride and hypermagnesemia. The present review summarizes the current knowledge of the mechanisms and factors involved in paracellular magnesium permeability. The review also highlights some of the unresolved questions that need to be addressed.
Collapse
Affiliation(s)
- Pascal Houillier
- Centre de Recherche des Cordeliers, INSERM, Sorbonne Université, Université Paris Cité, Paris, France
- CNRS ERL 8228 - Laboratoire de Physiologie Rénale et Tubulopathies, Paris, France
- Assistance Publique-Hôpitaux de Paris, Hôpital Européen Georges Pompidou, Service de Physiologie, Paris, France
- Centre de Référence des Maladies Rénales Héréditaires de l'Enfant et de l'Adulte (MARHEA), Paris, France
- Centre de Référence des Maladies Rares du Calcium et du Phosphate, Paris, France
| | - Loïc Lievre
- Centre de Recherche des Cordeliers, INSERM, Sorbonne Université, Université Paris Cité, Paris, France
- CNRS ERL 8228 - Laboratoire de Physiologie Rénale et Tubulopathies, Paris, France
| | - Marguerite Hureaux
- Centre de Référence des Maladies Rénales Héréditaires de l'Enfant et de l'Adulte (MARHEA), Paris, France
- Assistance Publique-Hôpitaux de Paris, Hôpital Européen Georges Pompidou, Service de Génétique, Paris, France
- Paris Centre de Recherche Cardio-vasculaire, INSERM, Université Paris Cité, Paris, France
| | - Caroline Prot-Bertoye
- Centre de Recherche des Cordeliers, INSERM, Sorbonne Université, Université Paris Cité, Paris, France
- CNRS ERL 8228 - Laboratoire de Physiologie Rénale et Tubulopathies, Paris, France
- Assistance Publique-Hôpitaux de Paris, Hôpital Européen Georges Pompidou, Service de Physiologie, Paris, France
- Centre de Référence des Maladies Rénales Héréditaires de l'Enfant et de l'Adulte (MARHEA), Paris, France
- Centre de Référence des Maladies Rares du Calcium et du Phosphate, Paris, France
| |
Collapse
|
4
|
Hashimoto Y, Poirier K, Boddaert N, Hubert L, Aubart M, Kaminska A, Alison M, Desguerre I, Munnich A, Campbell M. Recurrent de novo mutations in CLDN5 induce an anion-selective blood-brain barrier and alternating hemiplegia. Brain 2022; 145:3374-3382. [PMID: 35714222 PMCID: PMC9586545 DOI: 10.1093/brain/awac215] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2022] [Revised: 05/19/2022] [Accepted: 05/26/2022] [Indexed: 11/16/2022] Open
Abstract
Claudin-5 is the most enriched tight junction protein at the blood–brain barrier. Perturbations in its levels of expression have been observed across numerous neurological and neuropsychiatric conditions; however, pathogenic variants in the coding sequence of the gene have never been reported previously. Here, we report the identification of a novel de novo mutation (c.178G>A) in the CLDN5 gene in two unrelated cases of alternating hemiplegia with microcephaly. This mutation (G60R) lies within the first extracellular loop of claudin-5 and based on protein modelling and sequence alignment, we predicted it would modify claudin-5 to become an anion-selective junctional component as opposed to a purely barrier-forming protein. Generation of stably transfected cell lines expressing wild-type or G60R claudin-5 showed that the tight junctions could still form in the presence of the G60R mutation but that the barrier against small molecules was clearly attenuated and displayed higher Cl− ion permeability and lower Na+ permeability. While this study strongly suggests that CLDN5 associated alternating hemiplegia is a channelopathy, it is also the first study to identify the conversion of the blood–brain barrier to an anion-selective channel mediated by a dominant acting variant in CLDN5.
Collapse
Affiliation(s)
- Yosuke Hashimoto
- Smurfit Institute of Genetics, Trinity College Dublin, Dublin 2, Ireland
| | - Karine Poirier
- INSERM UMR1163, Institut Imagine, Université Paris Cité, F-75015, Paris France
| | - Nathalie Boddaert
- Department of pediatric radiology, Hospital Necker Enfants Malades, France
| | - Laurence Hubert
- INSERM UMR1163, Institut Imagine, Université Paris Cité, F-75015, Paris France
| | - Melodie Aubart
- Departments of pediatric neurology and medical genetics, Hospital Necker-Enfants Malades, Université Paris Cité, F-75015, Paris France
| | - Anna Kaminska
- Departments of pediatric neurology and medical genetics, Hospital Necker-Enfants Malades, Université Paris Cité, F-75015, Paris France
| | - Marianne Alison
- Department of pediatric radiology, Hospital Robert Debré, Université Paris Cité, F-75015, Paris France
| | - Isabelle Desguerre
- Departments of pediatric neurology and medical genetics, Hospital Necker-Enfants Malades, Université Paris Cité, F-75015, Paris France
| | - Arnold Munnich
- INSERM UMR1163, Institut Imagine, Université Paris Cité, F-75015, Paris France.,Departments of pediatric neurology and medical genetics, Hospital Necker-Enfants Malades, Université Paris Cité, F-75015, Paris France
| | - Matthew Campbell
- Smurfit Institute of Genetics, Trinity College Dublin, Dublin 2, Ireland
| |
Collapse
|
5
|
Hempel C, Rosenthal R, Fromm A, Krug SM, Fromm M, Günzel D, Piontek J. Tight junction channels claudin-10b and claudin-15: Functional mapping of pore-lining residues. Ann N Y Acad Sci 2022; 1515:129-142. [PMID: 35650657 DOI: 10.1111/nyas.14794] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Although functional and structural models for paracellular channels formed by claudins have been reported, mechanisms regulating charge and size selectivity of these channels are unknown in detail. Here, claudin-15 and claudin-10b cation channels showing high-sequence similarity but differing channel properties were analyzed. Mutants of pore-lining residues were expressed in MDCK-C7 cells. In claudin-15, proposed ion interaction sites (D55 and E64) conserved between both claudins were neutralized. D55N and E64Q substitutions decreased ion permeabilities, and D55N/E64Q had partly additive effects. D55N increased cation dehydration capability and decreased pore diameter. Additionally, residues differing between claudin-15 and -10b close to pore center were analyzed. Claudin-10b-mimicking W63K affected neither assembly nor function of claudin-15 channels. In contrast, in claudin-10b, corresponding (claudin-15b-mimicking) K64W and K64M substitutions disturbed integration into tight junction and slightly altered relative permeabilities for differently sized monovalent cations. Removal of claudin-10b-specific negative charge (D36A substitution) was without effect. The data suggest that a common tetra-aspartate ring (D55/D56) in pore center of claudin-15/-10b channels directly attracts cations, while E64/D65 may be at least partly shielded by W63/K64. Charge at position W63/K64 affects assembly and properties for claudin-10b but not for claudin-15 channels. Our findings add to the mechanistic understanding of the determinants of paracellular cation permeability.
Collapse
Affiliation(s)
- Caroline Hempel
- Clinical Physiology/Nutritional Medicine, Medizinische Klinik für Gastroenterologie, Infektiologie und Rheumatologie, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Rita Rosenthal
- Clinical Physiology/Nutritional Medicine, Medizinische Klinik für Gastroenterologie, Infektiologie und Rheumatologie, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Anja Fromm
- Clinical Physiology/Nutritional Medicine, Medizinische Klinik für Gastroenterologie, Infektiologie und Rheumatologie, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Susanne M Krug
- Clinical Physiology/Nutritional Medicine, Medizinische Klinik für Gastroenterologie, Infektiologie und Rheumatologie, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Michael Fromm
- Clinical Physiology/Nutritional Medicine, Medizinische Klinik für Gastroenterologie, Infektiologie und Rheumatologie, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Dorothee Günzel
- Clinical Physiology/Nutritional Medicine, Medizinische Klinik für Gastroenterologie, Infektiologie und Rheumatologie, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Jörg Piontek
- Clinical Physiology/Nutritional Medicine, Medizinische Klinik für Gastroenterologie, Infektiologie und Rheumatologie, Charité - Universitätsmedizin Berlin, Berlin, Germany
| |
Collapse
|
6
|
Claudin-17 Deficiency in Mice Results in Kidney Injury Due to Electrolyte Imbalance and Oxidative Stress. Cells 2022; 11:cells11111782. [PMID: 35681477 PMCID: PMC9180152 DOI: 10.3390/cells11111782] [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: 03/25/2022] [Revised: 05/18/2022] [Accepted: 05/24/2022] [Indexed: 11/17/2022] Open
Abstract
The multi-gene claudin (CLDN) family of tight junction proteins have isoform-specific roles in blood–tissue barrier regulation. CLDN17, a putative anion pore-forming CLDN based on its structural characterization, is assumed to regulate anion balance across the blood-tissue barriers. However, our knowledge about CLDN17 in physiology and pathology is limited. The current study investigated how Cldn17 deficiency in mice affects blood electrolytes and kidney structure. Cldn17−/− mice revealed no breeding abnormalities, but the newborn pups exhibited delayed growth. Adult Cldn17−/− mice displayed electrolyte imbalance, oxidative stress, and injury to the kidneys. Ingenuity pathway analysis followed by RNA-sequencing revealed hyperactivation of signaling pathways and downregulation of SOD1 expression in kidneys associated with inflammation and reactive oxygen species generation, demonstrating the importance of Cldn17 in the maintenance of electrolytes and reactive oxygen species across the blood-tissue barrier.
Collapse
|
7
|
Jo CH, Kim S, Kim GH. Claudins in kidney health and disease. Kidney Res Clin Pract 2022; 41:275-287. [PMID: 35354245 PMCID: PMC9184838 DOI: 10.23876/j.krcp.21.279] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2021] [Accepted: 12/29/2021] [Indexed: 11/04/2022] Open
Abstract
Claudins are strategically located to exert their physiologic actions along with the nephron segments from the glomerulus. Claudin-1 is normally located in the Bowman’s capsule, but its overexpression can reach the podocytes and lead to albuminuria. In the proximal tubule (PT), claudin-2 forms paracellular channels selective for water, Na+, K+, and Ca2+. Claudin-2 gene mutations are associated with hypercalciuria and kidney stones. Claudin-10 has two splice variants, -10a and -10b; Claudin-10a acts as an anion-selective channel in the PT, and claudin-10b functions as a cation-selective pore in the thick ascending limb (TAL). Claudin-16 and claudin-19 mediate paracellular transport of Na+, Ca2+, and Mg2+ in the TAL, where the expression of claudin-3/16/19 and claudin-10b are mutually exclusive. The claudin-16 or -19 mutation causes familial hypomagnesemia with hypercalciuria and nephrocalcinosis. Claudin-14 polymorphisms have been linked to increased risk of hypercalciuria. Claudin-10b mutations produce HELIX syndrome, which encompasses hypohidrosis, electrolyte imbalance, lacrimal gland dysfunction, ichthyosis, and xerostomia. Hypercalciuria and magnesuria in metabolic acidosis are related to downregulation of PT and TAL claudins. In the TAL, stimulation of calcium-sensing receptors upregulates claudin-14 and negatively acts on the claudin-16/19 complex. Claudin-3 acts as a general barrier to ions in the collecting duct. If this barrier is disturbed, urine acidification might be impaired. Claudin-7 forms a nonselective paracellular channel facilitating Cl– and Na+ reabsorption in the collecting ducts. Claudin-4 and -8 serve as anion channels and mediate paracellular Cl– transport; their upregulation may contribute to pseudohypoaldosteronism II and salt-sensitive hypertension.
Collapse
Affiliation(s)
- Chor ho Jo
- Hanyang Biomedical Research Institute, Hanyang University College of Medicine, Seoul, Republic of Korea
| | - Sua Kim
- Hanyang Biomedical Research Institute, Hanyang University College of Medicine, Seoul, Republic of Korea
| | - Gheun-Ho Kim
- Hanyang Biomedical Research Institute, Hanyang University College of Medicine, Seoul, Republic of Korea
- Department of Internal Medicine, Hanyang University College of Medicine, Seoul, Republic of Korea
- Correspondence: Gheun-Ho Kim Department of Internal Medicine, Hanyang University College of Medicine, 222-1 Wangsimni-ro, Seongdong-gu, Seoul 04763, Republic of Korea. E-mail:
| |
Collapse
|
8
|
Kava R, Peripolli E, Berton MP, Lemos M, Lobo RB, Stafuzza NB, Pereira AS, Baldi F. Genome-wide structural variations in Brazilian Senepol cattle, a tropically adapted taurine breed. Livest Sci 2021. [DOI: 10.1016/j.livsci.2021.104708] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
|
9
|
Tight junction protein CLDN17 serves as a tumor suppressor to reduce the invasion and migration of oral cancer cells by inhibiting epithelial-mesenchymal transition. Arch Oral Biol 2021; 133:105301. [PMID: 34781072 DOI: 10.1016/j.archoralbio.2021.105301] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2021] [Revised: 10/25/2021] [Accepted: 10/27/2021] [Indexed: 12/11/2022]
Abstract
OBJECTIVE To investigate claudin-17 (CLDN17) expression in oral cancer and its effect on epithelial-mesenchymal transition (EMT), invasion and migration in oral cancer cells. METHODS The GEO2R tool was used to analyze gene expression in two microarray datasets (GSE74530 and GSE146483) derived from the Gene Expression Omnibus (GEO) database. Gene Expression Profiling Interactive Analysis (GEPIA) verified CLDN17 expression in head and neck squamous cell carcinoma (HNSC) patients. Moreover, oral cancer cells were transfected with CLDN17 overexpression plasmid or CLDN17 shRNA to evaluate cell invasion and migration. Gene and protein expression was detected by qRT-PCR, immunohistochemistry and western blotting. RESULTS CLDN17 was one of the top 200 differentially expressed genes in the GSE74530 and GSE146483 datasets and was downregulated in oral cancer. CLDN17 expression was higher in HNSC tissues, and it was related to TNM staging. In HNSC tumors, CLDN17 expression was positively correlated with CDH1 but negatively related to VIM, SNAIL1, SNAIL2, and TWIST1. Meanwhile, we found that CLDN17 expression was lower in oral cancer tissues; it declined with higher T status, N status, M status and staging, lower differentiation grade, and a worse prognosis. Upregulation of CLDN17 inhibited the invasion and migration of oral cancer cells, with elevated CDH1 and reduced VIM, SNAIL1, SNAIL2, and TWIST1, while CLDN17 downregulation had the opposite effects. CONCLUSION CLDN17 may serve as a tumor suppressor in oral cancer since it could reduce the invasion and migration of cells by inhibiting the EMT process, thus becoming a potential therapeutic target in oral cancer.
Collapse
|
10
|
Ferreira PG, van Megen WH, Tan R, Lee CHL, Svenningsen P, Alexander RT, Dimke H. Renal claudin-14 expression is not required for regulating Mg 2+ balance in mice. Am J Physiol Renal Physiol 2021; 320:F897-F907. [PMID: 33818126 DOI: 10.1152/ajprenal.00590.2020] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The kidneys play a crucial role in maintaining Ca2+ and Mg2+ homeostasis by regulating these minerals' reabsorption. In the thick ascending limb of Henle's loop (TAL), Ca2+ and Mg2+ are reabsorbed through the tight junctions by a shared paracellular pathway formed by claudin-16 and claudin-19. Hypercalcemia activates the Ca2+-sensing receptor (CaSR) in the TAL, causing upregulation of pore-blocking claudin-14 (CLDN14), which reduces Ca2+ and Mg2+ reabsorption from this segment. In addition, a high-Mg2+ diet is known to increase both urinary Mg2+ and Ca2+ excretion. Since Mg2+ may also activate CaSR, we aimed to investigate whether CaSR-dependent increases in CLDN14 expression also regulate urinary Mg2+ excretion in response to hypermagnesemia. Here, we show that a Mg2+-enriched diet increased urinary Mg2+ and Ca2+ excretion in mice; however, this occurred without detectable changes in renal CLDN14 expression. The administration of a high-Mg2+ diet to Cldn14-/- mice did not cause more pronounced hypermagnesemia or significantly alter urinary Mg2+ excretion. Finally, in vitro evaluation of CaSR-driven Cldn14 promoter activity in response to increasing Mg2+ concentrations revealed that Cldn14 expression only increases at supraphysiological extracellular Mg2+ levels. Together, these results suggest that CLDN14 is not involved in regulating extracellular Mg2+ balance following high dietary Mg2+ intake.NEW & NOTEWORTHY Using transgenic models and in vitro assays, this study examined the effect of Mg2+ on regulating urinary excretion of Ca2+ and Mg2+ via activation of the Ca2+-sensing receptor-claudin 14 (CLDN14) pathway. The study suggests that CLDN14 is unlikely to play a significant role in the compensatory response to hypermagnesemia.
Collapse
Affiliation(s)
- Patrícia G Ferreira
- Department of Cardiovascular and Renal Research, Institute of Molecular Medicine, University of Southern Denmark, Odense, Denmark
| | - Wouter H van Megen
- Department of Cardiovascular and Renal Research, Institute of Molecular Medicine, University of Southern Denmark, Odense, Denmark
| | - Rebecca Tan
- Department of Physiology, The University of Alberta, Edmonton, Alberta, Canada
| | - Christy H L Lee
- Department of Physiology, The University of Alberta, Edmonton, Alberta, Canada
| | - Per Svenningsen
- Department of Cardiovascular and Renal Research, Institute of Molecular Medicine, University of Southern Denmark, Odense, Denmark
| | - R Todd Alexander
- Department of Pediatrics, The University of Alberta, Edmonton, Alberta, Canada.,Membrane Protein Disease Research Group, The University of Alberta, Edmonton, Alberta, Canada
| | - Henrik Dimke
- Department of Cardiovascular and Renal Research, Institute of Molecular Medicine, University of Southern Denmark, Odense, Denmark.,Department of Nephrology, Odense University Hospital, Odense, Denmark
| |
Collapse
|
11
|
Adil MS, Narayanan SP, Somanath PR. Cell-cell junctions: structure and regulation in physiology and pathology. Tissue Barriers 2020; 9:1848212. [PMID: 33300427 DOI: 10.1080/21688370.2020.1848212] [Citation(s) in RCA: 49] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Epithelial and endothelial cell-cell contacts are established and maintained by several intercellular junctional complexes. These structurally and biochemically differentiated regions on the plasma membrane primarily include tight junctions (TJs), and anchoring junctions. While the adherens junctions (AJs) provide essential adhesive and mechanical properties, TJs hold the cells together and form a near leak-proof intercellular seal by the fusion of adjacent cell membranes. AJs and TJs play essential roles in vascular permeability. Considering their involvement in several key cellular functions such as barrier formation, proliferation, migration, survival, and differentiation, further research is warranted on the composition and signaling pathways regulating cell-cell junctions to develop novel therapeutics for diseases such as organ injuries. The current review article presents our current state of knowledge on various cell-cell junctions, their molecular composition, and mechanisms regulating their expression and function in endothelial and epithelial cells.
Collapse
Affiliation(s)
- Mir S Adil
- Clinical and Experimental Therapeutics, University of Georgia and Charlie Norwood VA Medical Center , Augusta, GA, USA
| | - S Priya Narayanan
- Clinical and Experimental Therapeutics, University of Georgia and Charlie Norwood VA Medical Center , Augusta, GA, USA
| | - Payaningal R Somanath
- Clinical and Experimental Therapeutics, University of Georgia and Charlie Norwood VA Medical Center , Augusta, GA, USA
| |
Collapse
|
12
|
Meoli L, Günzel D. Channel functions of claudins in the organization of biological systems. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2020; 1862:183344. [PMID: 32442419 DOI: 10.1016/j.bbamem.2020.183344] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/17/2019] [Revised: 04/27/2020] [Accepted: 05/05/2020] [Indexed: 02/07/2023]
Abstract
Claudins are tight junction proteins mostly appreciated in their function of paracellular barrier-formation. Compared to a virtual absence of any tight junctions, their paracellular sealing role certainly stands out. Yet, it was recognized immediately after the discovery of the first claudins, that some members of the claudin protein family were able to convey size and charge selectivity to the paracellular pathway. Thus, paracellular permeability can be fine-tuned according to the physiological needs of a tissue by inserting these channel-forming claudins into tight junction strands. Precise permeability adjustment is further suggested by the presence of numerous isoforms of channel-forming claudins (claudin-10b-, -15-, -16-like isoforms) in various vertebrate taxa. Moreover, their expression and localization are controlled by multiple transcriptional and posttranslational mechanisms. Consequently, mutation or dysregulation of channel-forming claudins can cause severe diseases. The present review therefore aims at providing an up-to-date report of the current research on these aspects of channel-forming claudins and their possible implications on future developments.
Collapse
Affiliation(s)
- Luca Meoli
- Institute of Clinical Physiology/Nutritional Medicine, Medical Department, Division of Gastroenterology, Infectiology, Rheumatology, Charité - Universitätsmedizin Berlin, 12203 Berlin, Germany
| | - Dorothee Günzel
- Institute of Clinical Physiology/Nutritional Medicine, Medical Department, Division of Gastroenterology, Infectiology, Rheumatology, Charité - Universitätsmedizin Berlin, 12203 Berlin, Germany.
| |
Collapse
|
13
|
Piontek J, Krug SM, Protze J, Krause G, Fromm M. Molecular architecture and assembly of the tight junction backbone. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2020; 1862:183279. [PMID: 32224152 DOI: 10.1016/j.bbamem.2020.183279] [Citation(s) in RCA: 54] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/23/2019] [Revised: 03/16/2020] [Accepted: 03/19/2020] [Indexed: 12/18/2022]
Abstract
The functional and structural concept of tight junctions has developed after discovery of claudin and TAMP proteins. Many of these proteins contribute to epi- and endothelial barrier but some, in contrast, form paracellular channels. Claudins form the backbone of tight junction (TJ) strands whereas other proteins regulate TJ dynamics. The current joined double-row model of TJ strands and channels is crucially based on the linear alignment of claudin-15 in the crystal. Molecular dynamics simulations, protein docking, mutagenesis, cellular TJ reconstitution, and electron microscopy studies largely support stability and functionality of the model. Here, we summarize in silico and in vitro data about TJ strand assembly including comparison of claudin crystal structures and alternative models. Sequence comparisons, experimental and structural data substantiate differentiation of classic and non-classic claudins differing in motifs related to strand assembly. Classic claudins seem to share a similar mechanism of strand formation. Interface variations likely contribute to TJ strand flexibility. Combined in vitro/in silico studies are expected to elucidate mechanistic keys determining TJ regulation.
Collapse
Affiliation(s)
- Jörg Piontek
- Institute of Clinical Physiology/Nutritional Medicine, Medical Department, Division of Gastroenterology, Infectiology, Rheumatology, Charité - Universitätsmedizin Berlin, 12203 Berlin, Germany
| | - Susanne M Krug
- Institute of Clinical Physiology/Nutritional Medicine, Medical Department, Division of Gastroenterology, Infectiology, Rheumatology, Charité - Universitätsmedizin Berlin, 12203 Berlin, Germany
| | - Jonas Protze
- Leibniz-Institut für Molekulare Pharmakologie (FMP), 13125 Berlin, Germany
| | - Gerd Krause
- Leibniz-Institut für Molekulare Pharmakologie (FMP), 13125 Berlin, Germany
| | - Michael Fromm
- Institute of Clinical Physiology/Nutritional Medicine, Medical Department, Division of Gastroenterology, Infectiology, Rheumatology, Charité - Universitätsmedizin Berlin, 12203 Berlin, Germany.
| |
Collapse
|
14
|
Fuladi S, Jannat RW, Shen L, Weber CR, Khalili-Araghi F. Computational Modeling of Claudin Structure and Function. Int J Mol Sci 2020; 21:ijms21030742. [PMID: 31979311 PMCID: PMC7037046 DOI: 10.3390/ijms21030742] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2019] [Revised: 01/16/2020] [Accepted: 01/16/2020] [Indexed: 12/18/2022] Open
Abstract
Tight junctions form a barrier to control passive transport of ions and small molecules across epithelia and endothelia. In addition to forming a barrier, some of claudins control transport properties of tight junctions by forming charge- and size-selective ion channels. It has been suggested claudin monomers can form or incorporate into tight junction strands to form channels. Resolving the crystallographic structure of several claudins in recent years has provided an opportunity to examine structural basis of claudins in tight junctions. Computational and theoretical modeling relying on atomic description of the pore have contributed significantly to our understanding of claudin pores and paracellular transport. In this paper, we review recent computational and mathematical modeling of claudin barrier function. We focus on dynamic modeling of global epithelial barrier function as a function of claudin pores and molecular dynamics studies of claudins leading to a functional model of claudin channels.
Collapse
Affiliation(s)
- Shadi Fuladi
- Department of Physics, University of Illinois at Chicago, Chicago, IL 60607, USA; (S.F.); (R.-W.J.)
| | - Ridaka-Wal Jannat
- Department of Physics, University of Illinois at Chicago, Chicago, IL 60607, USA; (S.F.); (R.-W.J.)
| | - Le Shen
- Department of Pathology, University of Chicago, Chicago, IL 60637, USA;
- Department of Surgery, University of Chicago, Chicago, IL 60637, USA
| | - Christopher R. Weber
- Department of Pathology, University of Chicago, Chicago, IL 60637, USA;
- Correspondence: (C.R.W.); (F.K.-A.)
| | - Fatemeh Khalili-Araghi
- Department of Physics, University of Illinois at Chicago, Chicago, IL 60607, USA; (S.F.); (R.-W.J.)
- Correspondence: (C.R.W.); (F.K.-A.)
| |
Collapse
|
15
|
Rosenthal R, Günzel D, Piontek J, Krug SM, Ayala‐Torres C, Hempel C, Theune D, Fromm M. Claudin-15 forms a water channel through the tight junction with distinct function compared to claudin-2. Acta Physiol (Oxf) 2020; 228:e13334. [PMID: 31188544 DOI: 10.1111/apha.13334] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2018] [Revised: 06/06/2019] [Accepted: 06/07/2019] [Indexed: 12/18/2022]
Abstract
AIM Claudin-15 is mainly expressed in the small intestine and indirectly involved in glucose absorption. Similar to claudin-2 and -10b, claudin-15 is known to form a paracellular channel for small cations. Claudin-2, but not claudin-10b, also forms water channels. Here we experimentally tested whether claudin-15 also mediates water transport and if yes, whether water transport is Na+ -coupled, as seen for claudin-2. METHODS MDCK C7 cells were stably transfected with claudin-15. Ion and water permeability were investigated in confluent monolayers of control and claudin-15-expressing cells. Water flux was induced by an osmotic or ionic gradient. RESULTS Expression of claudin-15 in MDCK cells strongly increased cation permeability. The permeability ratios for monovalent cations indicated a passage of partially hydrated ions through the claudin-15 pore. Accordingly, its pore diameter was determined to be larger than that of claudin-2 and claudin-10b. Mannitol-induced water flux was elevated in claudin-15-expressing cells compared to control cells. In contrast to the Na+ -coupled water flux of claudin-2 channels, claudin-15-mediated water flux was inhibited by Na+ flux. Consequently, water flux was increased in Na+ -free solution. Likewise, Na+ flux was decreased after induction of water flux through claudin-15. CONCLUSION Claudin-15, similar to claudin-2, forms a paracellular cation and water channel. In functional contrast to claudin-2, water and Na+ fluxes through claudin-15 inhibit each other. Claudin-15 allows Na+ to retain part of its hydration shell within the pore. This then reduces the simultaneous passage of additional water through the pore.
Collapse
Affiliation(s)
- Rita Rosenthal
- Department of Gastroenterology, Rheumatology and Infectious Diseases, Institute of Clinical Physiology/Nutritional Medicine Charité – Universitätsmedizin Berlin Berlin Germany
| | - Dorothee Günzel
- Department of Gastroenterology, Rheumatology and Infectious Diseases, Institute of Clinical Physiology/Nutritional Medicine Charité – Universitätsmedizin Berlin Berlin Germany
| | - Jörg Piontek
- Department of Gastroenterology, Rheumatology and Infectious Diseases, Institute of Clinical Physiology/Nutritional Medicine Charité – Universitätsmedizin Berlin Berlin Germany
| | - Susanne M. Krug
- Department of Gastroenterology, Rheumatology and Infectious Diseases, Institute of Clinical Physiology/Nutritional Medicine Charité – Universitätsmedizin Berlin Berlin Germany
| | - Carlos Ayala‐Torres
- Department of Gastroenterology, Rheumatology and Infectious Diseases, Institute of Clinical Physiology/Nutritional Medicine Charité – Universitätsmedizin Berlin Berlin Germany
| | - Caroline Hempel
- Department of Gastroenterology, Rheumatology and Infectious Diseases, Institute of Clinical Physiology/Nutritional Medicine Charité – Universitätsmedizin Berlin Berlin Germany
| | - Dian Theune
- Department of Gastroenterology, Rheumatology and Infectious Diseases, Institute of Clinical Physiology/Nutritional Medicine Charité – Universitätsmedizin Berlin Berlin Germany
| | - Michael Fromm
- Department of Gastroenterology, Rheumatology and Infectious Diseases, Institute of Clinical Physiology/Nutritional Medicine Charité – Universitätsmedizin Berlin Berlin Germany
| |
Collapse
|
16
|
Tervonen A, Ihalainen TO, Nymark S, Hyttinen J. Structural dynamics of tight junctions modulate the properties of the epithelial barrier. PLoS One 2019; 14:e0214876. [PMID: 30964903 PMCID: PMC6456171 DOI: 10.1371/journal.pone.0214876] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2018] [Accepted: 03/21/2019] [Indexed: 01/09/2023] Open
Abstract
Tight junctions are dynamic structures that are crucial in establishing the diffusion and electrical barrier of epithelial monolayers. Dysfunctions in the tight junctions can impede this barrier function and lead to many pathological conditions. Unfortunately, detailed understanding of the non-specific permeation pathway through the tight junctions, the so-called leak pathway, is lacking. We created computational models of the leak pathway to describe the two main barrier measures, molecular permeability and transepithelial electric resistance while using common structural dynamics. Our results showed that the proposed alternatives for the leak pathway, the bicellular strand opening dynamics and the tricellular pores, contribute together with distinct degrees, depending on the epithelium. The models can also capture changes in the tight junction barrier caused by changes in tight junction protein composition. In addition, we observed that the molecular permeability was markedly more sensitive to changes in the tight junction structure and strand dynamics compared with transepithelial electric resistance. The results highlight that our model creates a good methodological framework to integrate knowledge on the tight junction structure as well as to provide insights and tools to advance tight junction research.
Collapse
Affiliation(s)
- Aapo Tervonen
- Faculty of Medicine and Health Technology and BioMediTech Institute, Tampere University, Tampere, Finland
- * E-mail:
| | - Teemu O. Ihalainen
- Faculty of Medicine and Health Technology and BioMediTech Institute, Tampere University, Tampere, Finland
| | - Soile Nymark
- Faculty of Medicine and Health Technology and BioMediTech Institute, Tampere University, Tampere, Finland
| | - Jari Hyttinen
- Faculty of Medicine and Health Technology and BioMediTech Institute, Tampere University, Tampere, Finland
| |
Collapse
|
17
|
Tsukita S, Tanaka H, Tamura A. The Claudins: From Tight Junctions to Biological Systems. Trends Biochem Sci 2019; 44:141-152. [DOI: 10.1016/j.tibs.2018.09.008] [Citation(s) in RCA: 127] [Impact Index Per Article: 25.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2018] [Revised: 09/17/2018] [Accepted: 09/19/2018] [Indexed: 01/04/2023]
|
18
|
Samanta P, Wang Y, Fuladi S, Zou J, Li Y, Shen L, Weber C, Khalili-Araghi F. Molecular determination of claudin-15 organization and channel selectivity. J Gen Physiol 2018; 150:949-968. [PMID: 29915162 PMCID: PMC6028499 DOI: 10.1085/jgp.201711868] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2017] [Revised: 03/08/2018] [Accepted: 05/04/2018] [Indexed: 12/28/2022] Open
Abstract
Members of the claudin family form tight junctions between adjacent epithelial and endothelial cells. Samanta et al. build an atomic model of claudin-15 using molecular dynamics simulations and conclude that four claudin-15 molecules each contribute an aspartic acid residue to form a selectivity filter. Tight junctions are macromolecular structures that traverse the space between adjacent cells in epithelia and endothelia. Members of the claudin family are known to determine tight junction permeability in a charge- and size-selective manner. Here, we use molecular dynamics simulations to build and refine an atomic model of claudin-15 channels and study its transport properties. Our simulations indicate that claudin-15 forms well-defined channels for ions and molecules and otherwise “seals” the paracellular space through hydrophobic interactions. Ionic currents, calculated from simulation trajectories of wild-type as well as mutant channels, reflect in vitro measurements. The simulations suggest that the selectivity filter is formed by a cage of four aspartic acid residues (D55), contributed by four claudin-15 molecules, which creates a negative electrostatic potential to favor cation flux over anion flux. Charge reversal or charge ablation mutations of D55 significantly reduce cation permeability in silico and in vitro, whereas mutations of other negatively charged pore amino acid residues have a significantly smaller impact on channel permeability and selectivity. The simulations also indicate that water and small ions can pass through the channel, but larger cations, such as tetramethylammonium, do not traverse the pore. Thus, our model provides an atomic view of claudin channels, their transport function, and a potential three-dimensional organization of its selectivity filter.
Collapse
Affiliation(s)
| | - Yitang Wang
- Department of Pathology, The University of Chicago, Chicago, IL.,Department of Surgery, The University of Chicago, Chicago, IL
| | - Shadi Fuladi
- Department of Physics, University of Illinois, Chicago, IL
| | - Jinjing Zou
- Department of Pathology, The University of Chicago, Chicago, IL
| | - Ye Li
- Department of Pathology, The University of Chicago, Chicago, IL
| | - Le Shen
- Department of Pathology, The University of Chicago, Chicago, IL .,Department of Surgery, The University of Chicago, Chicago, IL
| | | | | |
Collapse
|
19
|
Marshall WS, Breves JP, Doohan EM, Tipsmark CK, Kelly SP, Robertson GN, Schulte PM. claudin-10 isoform expression and cation selectivity change with salinity in salt-secreting epithelia of Fundulusheteroclitus. ACTA ACUST UNITED AC 2018; 221:jeb.168906. [PMID: 29150449 DOI: 10.1242/jeb.168906] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2017] [Accepted: 11/13/2017] [Indexed: 12/11/2022]
Abstract
To provide insight into claudin (Cldn) tight junction (TJ) protein contributions to branchial salt secretion in marine teleost fishes, this study examined cldn-10 TJ protein isoforms of a euryhaline teleost (mummichog; Fundulus heteroclitus) in association with salinity change and measurements of transepithelial cation selectivity. Mummichogs were transferred from freshwater (FW) to seawater (SW, 35‰) and from SW to hypersaline SW (2SW, 60‰) in a time course with transfer control groups (FW to FW, and SW to SW). FW to SW transfer increased mRNA abundance of cldn-10d and cldn-10e twofold, whilst cldn-10c and cldn-10f transcripts were unchanged. Transfer from SW to 2SW did not alter cldn-10d, and transiently altered cldn-10e abundance, but increased cldn-10c and cldn-10f fourfold. This was coincident with an increased number of single-stranded junctions (observed by transmission electron microscopy). For both salinity transfers, (1) cldn-10e mRNA was acutely responsive (i.e. after 24 h), (2) other responsive cldn-10 isoforms increased later (3-7 days), and (3) cystic fibrosis transmembrane conductance regulator (cftr) mRNA was elevated in accordance with established changes in transcellular Cl- movement. Changes in mRNA encoding cldn-10c and -10f appeared linked, consistent with the tandem repeat locus in the Fundulus genome, whereas mRNA for tandem cldn-10d and cldn-10e seemed independent of each other. Cation selectivity sequence measured by voltage and conductance responses to artificial SW revealed Eisenman sequence VII: Na+>K+>Rb+∼Cs+>Li+ Collectively, these data support the idea that Cldn-10 TJ proteins create and maintain cation-selective pore junctions in salt-secreting tissues of teleost fishes.
Collapse
Affiliation(s)
- William S Marshall
- Department of Biology, St Francis Xavier University, Antigonish, NS, Canada B2G 2W5
| | - Jason P Breves
- Department of Biology, Skidmore College, Saratoga Springs, NY 12866, USA
| | - Ellen M Doohan
- Department of Biology, St Francis Xavier University, Antigonish, NS, Canada B2G 2W5
| | - Christian K Tipsmark
- Department of Biological Sciences, University of Arkansas, Fayetteville, AK 72701, USA
| | - Scott P Kelly
- Department of Biology, York University, Toronto, ON, Canada M3J 1P3
| | - George N Robertson
- Department of Biology, St Francis Xavier University, Antigonish, NS, Canada B2G 2W5
| | - Patricia M Schulte
- Department of Zoology, University of British Columbia, Vancouver, BC, Canada V6T 1Z4
| |
Collapse
|
20
|
Rosenthal R, Günzel D, Theune D, Czichos C, Schulzke JD, Fromm M. Water channels and barriers formed by claudins. Ann N Y Acad Sci 2017. [PMID: 28636801 DOI: 10.1111/nyas.13383] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Physiological studies in leaky epithelia, like kidney proximal tubules and the small intestine, have documented water transport via both transcellular and paracellular pathways. The discovery of aquaporin water channels provided a molecular basis for transcellular water movement. In contrast, the contribution, or even existence, of a specific paracellular water pathway has been disputed for a long time, until the cation channel-forming tight junction protein claudin-2 was shown to also permit the paracellular passage of water through its pore. In proximal kidney tubules, claudin-2-based water transport contributes 23-30% of the total water transport. Other paracellular ion channels (claudin-10a, -10b, and -17) proved to be impermeable to water, although their pore size would be sufficient for water molecules to pass. Studies of barrier-forming claudins, like claudin-1 and claudin-3, which tighten the paracellular pathway against ions and larger solutes, indicate that changes in the expression of these sealing claudins do not influence transepithelial water permeability. The present genetic, molecular, computational, and physiological studies are just now beginning to probe the mechanisms and regulation of paracellular permeation.
Collapse
Affiliation(s)
- Rita Rosenthal
- Institute of Clinical Physiology, Department of Gastroenterology, Rheumatology and Infectious Diseases, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Dorothee Günzel
- Institute of Clinical Physiology, Department of Gastroenterology, Rheumatology and Infectious Diseases, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Dian Theune
- Institute of Clinical Physiology, Department of Gastroenterology, Rheumatology and Infectious Diseases, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Carolina Czichos
- Institute of Clinical Physiology, Department of Gastroenterology, Rheumatology and Infectious Diseases, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Jörg-Dieter Schulzke
- Institute of Clinical Physiology, Department of Gastroenterology, Rheumatology and Infectious Diseases, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Michael Fromm
- Institute of Clinical Physiology, Department of Gastroenterology, Rheumatology and Infectious Diseases, Charité - Universitätsmedizin Berlin, Berlin, Germany
| |
Collapse
|
21
|
Tight junctions of the proximal tubule and their channel proteins. Pflugers Arch 2017; 469:877-887. [DOI: 10.1007/s00424-017-2001-3] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2017] [Revised: 05/13/2017] [Accepted: 05/16/2017] [Indexed: 12/20/2022]
|
22
|
Baumgartner HK, Rudolph MC, Ramanathan P, Burns V, Webb P, Bitler BG, Stein T, Kobayashi K, Neville MC. Developmental Expression of Claudins in the Mammary Gland. J Mammary Gland Biol Neoplasia 2017; 22:141-157. [PMID: 28455726 PMCID: PMC5488167 DOI: 10.1007/s10911-017-9379-6] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/20/2016] [Accepted: 04/17/2017] [Indexed: 02/06/2023] Open
Abstract
Claudins are a large family of membrane proteins whose classic function is to regulate the permeability of tight junctions in epithelia. They are tetraspanins, with four alpha-helices crossing the membrane, two extracellular loops, a short cytoplasmic N-terminus and a longer and more variable C-terminus. The extracellular ends of the helices are known to undergo side-to-side (cis) interactions that allow the formation of claudin polymers in the plane of the membrane. The extracellular loops also engage in head-to-head (trans) interactions thought to mediate the formation of tight junctions. However, claudins are also present in intracellular structures, thought to be vesicles, with less well-characterized functions. Here, we briefly review our current understanding of claudin structure and function followed by an examination of changes in claudin mRNA and protein expression and localization through mammary gland development. Claudins-1, 3, 4, 7, and 8 are the five most prominent members of the claudin family in the mouse mammary gland, with varied abundance and intracellular localization during the different stages of post-pubertal development. Claudin-1 is clearly localized to tight junctions in mammary ducts in non-pregnant non-lactating animals. Cytoplasmic puncta that stain for claudin-7 are present throughout development. During pregnancy claudin-3 is localized both to the tight junction and basolaterally while claudin-4 is found only in sparse puncta. In the lactating mouse both claudin-3 and claudin-8 are localized at the tight junction where they may be important in forming the paracellular barrier. At involution and under challenge by lipopolysaccharide claudins -1, -3, and -4 are significantly upregulated. Claudin-3 is still colocalized with tight junction molecules but is also distributed through the cytoplasm as is claudin-4. These largely descriptive data provide the essential framework for future mechanistic studies of the function and regulation of mammary epithelial cell claudins.
Collapse
Affiliation(s)
- Heidi K. Baumgartner
- Department of Obstetrics and Gynecology, University of Colorado Denver, Aurora, CO 80045 USA
| | - Michael C. Rudolph
- Division of Endocrinology, Metabolism & Diabetes, University of Colorado Denver, Aurora, CO 80045 USA
| | - Palaniappian Ramanathan
- Department of Pathology, University of Texas Medical Branch at Galveston, Galveston, TX 77555 USA
| | - Valerie Burns
- Department of Physiology and Biophysics, Anschutz Medical Center, University of Colorado Denver, Aurora, CO 80045 USA
| | - Patricia Webb
- Department of Obstetrics and Gynecology, University of Colorado Denver, Aurora, CO 80045 USA
| | - Benjamin G. Bitler
- Department of Obstetrics and Gynecology, University of Colorado Denver, Aurora, CO 80045 USA
| | - Torsten Stein
- College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
| | - Ken Kobayashi
- Research Faculty of Agriculture, Hokkaido University, Sapporo, 060-8589 Japan
| | - Margaret C. Neville
- Department of Obstetrics and Gynecology, University of Colorado Denver, Aurora, CO 80045 USA
- Department of Physiology and Biophysics, Anschutz Medical Center, University of Colorado Denver, Aurora, CO 80045 USA
- 6561 Glencoe St., Centennial, CO 80121 USA
| |
Collapse
|
23
|
Piontek A, Rossa J, Protze J, Wolburg H, Hempel C, Günzel D, Krause G, Piontek J. Polar and charged extracellular residues conserved among barrier-forming claudins contribute to tight junction strand formation. Ann N Y Acad Sci 2017; 1397:143-156. [DOI: 10.1111/nyas.13341] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2017] [Revised: 02/26/2017] [Accepted: 03/01/2017] [Indexed: 01/09/2023]
Affiliation(s)
- Anna Piontek
- Leibniz-Institut für Molekulare Pharmakologie (FMP); Berlin Germany
| | - Jan Rossa
- Leibniz-Institut für Molekulare Pharmakologie (FMP); Berlin Germany
| | - Jonas Protze
- Leibniz-Institut für Molekulare Pharmakologie (FMP); Berlin Germany
| | - Hartwig Wolburg
- Institute of Pathology and Neuropathology; University of Tübingen; Tübingen Germany
| | - Caroline Hempel
- Institute of Clinical Physiology; Charité - Universitätsmedizin Berlin; Berlin Germany
| | - Dorothee Günzel
- Institute of Clinical Physiology; Charité - Universitätsmedizin Berlin; Berlin Germany
| | - Gerd Krause
- Leibniz-Institut für Molekulare Pharmakologie (FMP); Berlin Germany
| | - Jörg Piontek
- Institute of Clinical Physiology; Charité - Universitätsmedizin Berlin; Berlin Germany
| |
Collapse
|
24
|
Muto S. Physiological roles of claudins in kidney tubule paracellular transport. Am J Physiol Renal Physiol 2017; 312:F9-F24. [DOI: 10.1152/ajprenal.00204.2016] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2016] [Revised: 10/24/2016] [Accepted: 10/25/2016] [Indexed: 12/30/2022] Open
Abstract
The paracellular pathways in renal tubular epithelia such as the proximal tubules, which reabsorb the largest fraction of filtered solutes and water and are leaky epithelia, are important routes for transepithelial transport of solutes and water. Movement occurs passively via an extracellular route through the tight junction between cells. The characteristics of paracellular transport vary among different nephron segments with leaky or tighter epithelia. Claudins expressed at tight junctions form pores and barriers for paracellular transport. Claudins are from a multigene family, comprising at least 27 members in mammals. Multiple claudins are expressed at tight junctions of individual nephron segments in a nephron segment-specific manner. Over the last decade, there have been advances in our understanding of the structure and functions of claudins. This paper is a review of our current knowledge of claudins, with special emphasis on their physiological roles in proximal tubule paracellular solute and water transport.
Collapse
Affiliation(s)
- Shigeaki Muto
- Division of Nephrology, Department of Internal Medicine, Jichi Medical University, Shimotsuke, Tochigi, Japan
| |
Collapse
|
25
|
Milatz S, Breiderhoff T. One gene, two paracellular ion channels—claudin-10 in the kidney. Pflugers Arch 2016; 469:115-121. [DOI: 10.1007/s00424-016-1921-7] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2016] [Revised: 11/23/2016] [Accepted: 11/27/2016] [Indexed: 11/29/2022]
|
26
|
Zhou L, Zeng Y, Baker LA, Hou J. A proposed route to independent measurements of tight junction conductance at discrete cell junctions. Tissue Barriers 2015; 3:e1105907. [PMID: 26716077 DOI: 10.1080/21688370.2015.1105907] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2015] [Revised: 10/01/2015] [Accepted: 10/05/2015] [Indexed: 01/15/2023] Open
Abstract
Direct recording of tight junction permeability is of pivotal importance to many biologic fields. Previous approaches bear an intrinsic disadvantage due to the difficulty of separating tight junction conductance from nearby membrane conductance. Here, we propose the design of Double whole-cell Voltage Clamp - Ion Conductance Microscopy (DVC-ICM) based on previously demonstrated potentiometric scanning of local conductive pathways. As proposed, DVC-ICM utilizes two coordinated whole-cell patch-clamps to neutralize the apical membrane current during potentiometric scanning, which in models described here will profoundly enhance the specificity of tight junction recording. Several potential pitfalls are considered, evaluated and addressed with alternative countermeasures.
Collapse
Affiliation(s)
- Lushan Zhou
- Department of Chemistry; Indiana University ; Bloomington, IN USA
| | - Yuhan Zeng
- Department of Chemistry; Indiana University ; Bloomington, IN USA
| | - Lane A Baker
- Department of Chemistry; Indiana University ; Bloomington, IN USA
| | - Jianghui Hou
- Department of Internal Medicine - Renal Division ; St. Louis, MO USA ; Center for Investigation of Membrane Excitability Diseases; Washington University Medical School ; St. Louis, MO USA
| |
Collapse
|