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Uçar MC, Hannezo E, Tiilikainen E, Liaqat I, Jakobsson E, Nurmi H, Vaahtomeri K. Self-organized and directed branching results in optimal coverage in developing dermal lymphatic networks. Nat Commun 2023; 14:5878. [PMID: 37735168 PMCID: PMC10514270 DOI: 10.1038/s41467-023-41456-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2022] [Accepted: 09/05/2023] [Indexed: 09/23/2023] Open
Abstract
Branching morphogenesis is a ubiquitous process that gives rise to high exchange surfaces in the vasculature and epithelial organs. Lymphatic capillaries form branched networks, which play a key role in the circulation of tissue fluid and immune cells. Although mouse models and correlative patient data indicate that the lymphatic capillary density directly correlates with functional output, i.e., tissue fluid drainage and trafficking efficiency of dendritic cells, the mechanisms ensuring efficient tissue coverage remain poorly understood. Here, we use the mouse ear pinna lymphatic vessel network as a model system and combine lineage-tracing, genetic perturbations, whole-organ reconstructions and theoretical modeling to show that the dermal lymphatic capillaries tile space in an optimal, space-filling manner. This coverage is achieved by two complementary mechanisms: initial tissue invasion provides a non-optimal global scaffold via self-organized branching morphogenesis, while VEGF-C dependent side-branching from existing capillaries rapidly optimizes local coverage by directionally targeting low-density regions. With these two ingredients, we show that a minimal biophysical model can reproduce quantitatively whole-network reconstructions, across development and perturbations. Our results show that lymphatic capillary networks can exploit local self-organizing mechanisms to achieve tissue-scale optimization.
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Affiliation(s)
- Mehmet Can Uçar
- Institute of Science and Technology Austria (IST Austria), Am Campus 1, 3400, Klosterneuburg, Austria
| | - Edouard Hannezo
- Institute of Science and Technology Austria (IST Austria), Am Campus 1, 3400, Klosterneuburg, Austria.
| | - Emmi Tiilikainen
- Translational Cancer Medicine Research Program, University of Helsinki, Biomedicum Helsinki, Haartmaninkatu 8, 00290, Helsinki, Finland
| | - Inam Liaqat
- Translational Cancer Medicine Research Program, University of Helsinki, Biomedicum Helsinki, Haartmaninkatu 8, 00290, Helsinki, Finland
| | - Emma Jakobsson
- Translational Cancer Medicine Research Program, University of Helsinki, Biomedicum Helsinki, Haartmaninkatu 8, 00290, Helsinki, Finland
| | - Harri Nurmi
- Translational Cancer Medicine Research Program, University of Helsinki, Biomedicum Helsinki, Haartmaninkatu 8, 00290, Helsinki, Finland
- Wihuri Research Institute, Biomedicum Helsinki, Haartmaninkatu 8, 00290, Helsinki, Finland
| | - Kari Vaahtomeri
- Translational Cancer Medicine Research Program, University of Helsinki, Biomedicum Helsinki, Haartmaninkatu 8, 00290, Helsinki, Finland.
- Wihuri Research Institute, Biomedicum Helsinki, Haartmaninkatu 8, 00290, Helsinki, Finland.
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Elhadad S, Redmond D, Huang J, Tan A, Laurence J. MASP2 inhibition by narsoplimab suppresses endotheliopathies characteristic of transplant-associated thrombotic microangiopathy: in vitro and ex vivo evidence. Clin Exp Immunol 2023; 213:252-264. [PMID: 37191586 PMCID: PMC10361744 DOI: 10.1093/cei/uxad055] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2023] [Revised: 04/17/2023] [Accepted: 05/15/2023] [Indexed: 05/17/2023] Open
Abstract
Transplant-associated thrombotic microangiopathy (TA-TMA) is an endotheliopathy complicating up to 30% of allogeneic hematopoietic stem cell transplants (alloHSCT). Positive feedback loops among complement, pro-inflammatory, pro-apoptotic, and coagulation cascade likely assume dominant roles at different disease stages. We hypothesized that mannose-binding lectin-associated serine protease 2 (MASP2), principal activator of the lectin complement system, is involved in the microvascular endothelial cell (MVEC) injury characteristic of TA-TMA through pathways that are susceptible to suppression by anti-MASP2 monoclonal antibody narsoplimab. Pre-treatment plasmas from 8 of 9 TA-TMA patients achieving a complete TMA response in a narsoplimab clinical trial activated caspase 8, the initial step in apoptotic injury, in human MVEC. This was reduced to control levels following narsoplimab treatment in 7 of the 8 subjects. Plasmas from 8 individuals in an observational TA-TMA study, but not 8 alloHSCT subjects without TMA, similarly activated caspase 8, which was blocked in vitro by narsoplimab. mRNA sequencing of MVEC exposed to TA-TMA or control plasmas with and without narsoplimab suggested potential mechanisms of action. The top 40 narsoplimab-affected transcripts included upregulation of SerpinB2, which blocks apoptosis by inactivating procaspase 3; CHAC1, which inhibits apoptosis in association with mitigation of oxidative stress responses; and pro-angiogenesis proteins TM4SF18, ASPM, and ESM1. Narsoplimab also suppressed transcripts encoding pro-apoptotic and pro-inflammatory proteins ZNF521, IL1R1, Fibulin-5, aggrecan, SLC14A1, and LOX1, and TMEM204, which disrupts vascular integrity. Our data suggest benefits to narsoplimab use in high-risk TA-TMA and provide a potential mechanistic basis for the clinical efficacy of narsoplimab in this disorder.
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Affiliation(s)
- Sonia Elhadad
- Department of Medicine, Division of Hematology and Medical Oncology, Weill Cornell Medicine, New York, NY, USA
| | - David Redmond
- Division of Regenerative Medicine, Hartman Institute for Therapeutic Organ Regeneration, Ansary Stem Cell Institute, New York, NY, USA
| | - Jenny Huang
- Division of Regenerative Medicine, Hartman Institute for Therapeutic Organ Regeneration, Ansary Stem Cell Institute, New York, NY, USA
| | - Adrian Tan
- Genomics Resources Core Facility, Weill Cornell Medicine, New York, NY, USA
| | - Jeffrey Laurence
- Department of Medicine, Division of Hematology and Medical Oncology, Weill Cornell Medicine, New York, NY, USA
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Schwensow N, Pederson S, Peacock D, Cooke B, Cassey P. Adaptive changes in the genomes of wild rabbits after 16 years of viral epidemics. Mol Ecol 2020; 29:3777-3794. [PMID: 32506669 DOI: 10.1111/mec.15498] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2018] [Revised: 05/20/2020] [Accepted: 05/29/2020] [Indexed: 01/01/2023]
Abstract
Since its introduction to control overabundant invasive European rabbits (Oryctolagus cuniculus), the highly virulent rabbit haemorrhagic disease virus (RHDV) has caused regular annual disease outbreaks in Australian rabbit populations. Although initially reducing rabbit abundance by 60%, continent-wide, experimental evidence has since indicated increased genetic resistance in wild rabbits that have experienced RHDV-driven selection. To identify genetic adaptations, which explain the increased resistance to this biocontrol virus, we investigated genome-wide SNP (single nucleotide polymorphism) allele frequency changes in a South Australian rabbit population that was sampled in 1996 (pre-RHD genomes) and after 16 years of RHDV outbreaks. We identified several SNPs with changed allele frequencies within or close to genes potentially important for increased RHD resistance. The identified genes are known to be involved in virus infections and immune reactions or had previously been identified as being differentially expressed in healthy versus acutely RHDV-infected rabbits. Furthermore, we show in a simulation study that the allele/genotype frequency changes cannot be explained by drift alone and that several candidate genes had also been identified as being associated with surviving RHD in a different Australian rabbit population. Our unique data set allowed us to identify candidate genes for RHDV resistance that have evolved under natural conditions, and over a time span that would not have been feasible in an experimental setting. Moreover, it provides a rare example of host genetic adaptations to virus-driven selection in response to a suddenly emerging infectious disease.
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Affiliation(s)
- Nina Schwensow
- Institute of Evolutionary Ecology and Conservation Genomics, University of Ulm, Ulm, Germany.,Centre for Applied Conservation Science, and School of Biological Sciences, University of Adelaide, SA, Australia
| | - Stephen Pederson
- Bioinformatics Hub, School of Biological Sciences, University of Adelaide, SA, Australia
| | - David Peacock
- Biosecurity SA, Adelaide, SA, Australia.,School of Animal and Veterinary Science, University of Adelaide, Roseworthy, SA, Australia
| | - Brian Cooke
- Institute for Applied Ecology, University of Canberra, Canberra, ACT, Australia
| | - Phillip Cassey
- Centre for Applied Conservation Science, and School of Biological Sciences, University of Adelaide, SA, Australia
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Ji D, Qiao M, Yao Y, Li M, Chen H, Dong Q, Jia J, Cui X, Li Z, Xia J, Gu J. Serum-based microRNA signature predicts relapse and therapeutic outcome of adjuvant chemotherapy in colorectal cancer patients. EBioMedicine 2018; 35:189-197. [PMID: 30166271 PMCID: PMC6156709 DOI: 10.1016/j.ebiom.2018.08.042] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2018] [Revised: 08/08/2018] [Accepted: 08/14/2018] [Indexed: 01/06/2023] Open
Abstract
Background Approximately 60% of patients with colorectal cancer (CRC) undergo either local recurrence or distant metastases after surgery. Current prognostic biomarkers are insufficient to predict recurrence of CRC and provide little forecast information about what patients are likely to receive benefit from the adjuvant chemotherapy. As microRNAs (miRNAs) constantly exist in human serum and being used to predict the prognosis of a various cancers, this study was designed to identify miRNA-based circulating biomarkers to predict clinical outcomes of CRC. Methods A serum-focused miRNA expression was used to investigate if miRNA expression profiles could predict the clinical outcomes of patients with CRC. We created miRNA signature profiles associated in the training set (n = 40), and further validated its prediction in two independent testing cohorts. Results Using Cox regression and risk-score analysis, we identified a four-miRNA signature (miR-652-3p, miR-342-3p, miR-501-3p and miR-328-3p) for the prediction of tumor relapse and the overall survival(OS) of patients with CRC in the training set (n = 40). This miRNA signature was further validated in a testing set (n = 226) and another independent cohort (n = 56). A high-risk signature score was significantly associated with CRC tumor recurrence and poor treatment outcome. Multivariable Cox regression models indicated that the risk score, based on the four-miRNA signature, was an independent prognostic classifier for patients with CRC. Conclusions The serum miRNA signature may serve as a minimally invasive predictor for tumor relapse and treatment outcome in patients with CRC and provide a useful reference for treatment selection.
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Affiliation(s)
- Dengbo Ji
- Key laboratory of Carcinogenesis and Translational Research(Ministry of Education), Department of Gastrointestinal Surgery III, Peking University Cancer Hospital & Institute, No. 52 Fucheng Rd., Haidian District, Beijing 100142, China
| | - Meng Qiao
- Key laboratory of Carcinogenesis and Translational Research(Ministry of Education), Department of Gastrointestinal Surgery III, Peking University Cancer Hospital & Institute, No. 52 Fucheng Rd., Haidian District, Beijing 100142, China
| | - Yunfeng Yao
- Key laboratory of Carcinogenesis and Translational Research(Ministry of Education), Department of Gastrointestinal Surgery III, Peking University Cancer Hospital & Institute, No. 52 Fucheng Rd., Haidian District, Beijing 100142, China
| | - Ming Li
- Key laboratory of Carcinogenesis and Translational Research(Ministry of Education), Department of Gastrointestinal Surgery III, Peking University Cancer Hospital & Institute, No. 52 Fucheng Rd., Haidian District, Beijing 100142, China
| | - Hailong Chen
- Cancer Institute (Key Laboratory of Cancer Prevention and Intervention, China National Ministry of Education, Key Laboratory of Molecular Biology in Medical Sciences, Zhejiang Province), The Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310009, China
| | - Qi Dong
- Cancer Institute (Key Laboratory of Cancer Prevention and Intervention, China National Ministry of Education, Key Laboratory of Molecular Biology in Medical Sciences, Zhejiang Province), The Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310009, China
| | - Jinying Jia
- Key laboratory of Carcinogenesis and Translational Research(Ministry of Education), Department of Gastrointestinal Surgery III, Peking University Cancer Hospital & Institute, No. 52 Fucheng Rd., Haidian District, Beijing 100142, China
| | - Xinxin Cui
- Key laboratory of Carcinogenesis and Translational Research(Ministry of Education), Department of Gastrointestinal Surgery III, Peking University Cancer Hospital & Institute, No. 52 Fucheng Rd., Haidian District, Beijing 100142, China
| | - Zhaowei Li
- Key laboratory of Carcinogenesis and Translational Research(Ministry of Education), Department of Gastrointestinal Surgery III, Peking University Cancer Hospital & Institute, No. 52 Fucheng Rd., Haidian District, Beijing 100142, China
| | - Jinhong Xia
- Key laboratory of Carcinogenesis and Translational Research(Ministry of Education), Department of Gastrointestinal Surgery III, Peking University Cancer Hospital & Institute, No. 52 Fucheng Rd., Haidian District, Beijing 100142, China
| | - Jin Gu
- Key laboratory of Carcinogenesis and Translational Research(Ministry of Education), Department of Gastrointestinal Surgery III, Peking University Cancer Hospital & Institute, No. 52 Fucheng Rd., Haidian District, Beijing 100142, China; Peking-Tsinghua Center for Life Sciences, China; Peking University S.G. Hospital, China.
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Jang HW, Kim SW, Cho YJ, Heo K, Lee BI, Lee SK, Jang IJ, Lee MG, Kim WJ, Lee JH. GWAS identifies two susceptibility loci for lamotrigine-induced skin rash in patients with epilepsy. Epilepsy Res 2015. [PMID: 26220383 DOI: 10.1016/j.eplepsyres.2015.05.014] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
PURPOSE Lamotrigine (LTG)-induced maculopapular eruption (MPE) often causes treatment discontinuation and rising burdens on current healthcare systems. We conducted a genome-wide association study to identify novel susceptibility loci associated with LTG-induced MPE in patients with epilepsy. MATERIALS AND METHODS We enrolled patients with LTG-induced MPE (n=34) and utilized the Korea Association Resource project cohort as a control group (n=1214). We explored associations between LTG-induced MPE and single nucleotide polymorphisms (SNPs) through imputation and replicated these associations in samples from 59 LTG-induced MPE cases and 98 LTG tolerant-controls. RESULTS We found two novel SNPs associated with LTG-induced MPE: rs12668095 near CRAMP1L/TMEM204/IFT140/HN1L (P=4.89×10(-7)) and rs79007183 near TNS3 (P=3.15×10(-10)), both of which were replicated in an independent cohort. CONCLUSION These two validated SNPs may be good candidate markers for predicting LTG-induced MPE in epilepsy patients, although further experimental validation is needed.
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Affiliation(s)
- Hui Won Jang
- Department of Pharmacology, Yonsei University College of Medicine, Seoul, Republic of Korea
| | - So Won Kim
- Department of Pharmacology, Yonsei University College of Medicine, Seoul, Republic of Korea
| | - Yang-Je Cho
- Department of Neurology, Yonsei University College of Medicine, Seoul, Republic of Korea
| | - Kyoung Heo
- Department of Neurology, Yonsei University College of Medicine, Seoul, Republic of Korea
| | - Byung In Lee
- Department of Neurology, Yonsei University College of Medicine, Seoul, Republic of Korea
| | - Sang Kun Lee
- Department of Neurology, Seoul National University College of Medicine, Seoul, Republic of Korea
| | - In-Jin Jang
- Department of Clinical Pharmacology and Therapeutics, Seoul National University College of Medicine, Seoul, Republic of Korea
| | - Min Goo Lee
- Department of Pharmacology, Yonsei University College of Medicine, Seoul, Republic of Korea
| | - Won-Joo Kim
- Department of Neurology, Yonsei University College of Medicine, Seoul, Republic of Korea.
| | - Ji Hyun Lee
- Department of Oral Biology, Yonsei University College of Dentistry, Seoul, Republic of Korea.
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Murphy SK, Yang H, Moylan CA, Pang H, Dellinger A, Abdelmalek MF, Garrett ME, Ashley-Koch A, Suzuki A, Tillmann HL, Hauser MA, Mae Diehl A. Relationship between methylome and transcriptome in patients with nonalcoholic fatty liver disease. Gastroenterology 2013; 145:1076-87. [PMID: 23916847 PMCID: PMC3805742 DOI: 10.1053/j.gastro.2013.07.047] [Citation(s) in RCA: 285] [Impact Index Per Article: 25.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/22/2013] [Revised: 07/25/2013] [Accepted: 07/26/2013] [Indexed: 02/07/2023]
Abstract
BACKGROUND & AIMS Cirrhosis and liver cancer are potential outcomes of advanced nonalcoholic fatty liver disease (NAFLD). It is not clear what factors determine whether patients will develop advanced or mild NAFLD, limiting noninvasive diagnosis and treatment before clinical sequelae emerge. We investigated whether DNA methylation profiles can distinguish patients with mild disease from those with advanced NAFLD, and how these patterns are functionally related to hepatic gene expression. METHODS We collected frozen liver biopsies and clinical data from patients with biopsy-proven NAFLD (56 in the discovery cohort and 34 in the replication cohort). Samples were divided into groups based on histologic severity of fibrosis: F0-1 (mild) and F3-4 (advanced). DNA methylation profiles were determined and coupled with gene expression data from the same biopsies; differential methylation was validated in subsets of the discovery and replication cohorts. We then analyzed interactions between the methylome and transcriptome. RESULTS Clinical features did not differ between patients known to have mild or advanced fibrosis based on biopsy analysis. There were 69,247 differentially methylated CpG sites (76% hypomethylated, 24% hypermethylated) in patients with advanced vs mild NAFLD (P < .05). Methylation at fibroblast growth factor receptor 2, methionine adenosyl methyltransferase 1A, and caspase 1 was validated by bisulfite pyrosequencing and the findings were reproduced in the replication cohort. Methylation correlated with gene transcript levels for 7% of differentially methylated CpG sites, indicating that differential methylation contributes to differences in expression. In samples with advanced NAFLD, many tissue repair genes were hypomethylated and overexpressed, and genes in certain metabolic pathways, including 1-carbon metabolism, were hypermethylated and underexpressed. CONCLUSIONS Functionally relevant differences in methylation can distinguish patients with advanced vs mild NAFLD. Altered methylation of genes that regulate processes such as steatohepatitis, fibrosis, and carcinogenesis indicate the role of DNA methylation in progression of NAFLD.
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Affiliation(s)
- Susan K. Murphy
- Department of Obstetrics and Gynecology, Duke University, Durham, NC
| | - Hyuna Yang
- Department of Bioinformatics and Biostatistics, Duke University, Durham, NC
| | - Cynthia A. Moylan
- Division of Gastroenterology and Hepatology, Duke University, Durham, NC
| | - Herbert Pang
- Department of Bioinformatics and Biostatistics, Duke University, Durham, NC
| | - Andrew Dellinger
- Department of Bioinformatics and Biostatistics, Duke University, Durham, NC
| | | | | | | | - Ayako Suzuki
- Division of Gastroenterology and Hepatology, Duke University, Durham, NC
| | - Hans L. Tillmann
- Section of Medical Genetics, Department of Medicine, Duke University, Durham, NC
| | | | - Anna Mae Diehl
- Division of Gastroenterology and Hepatology, Duke University, Durham, NC
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Integrative genome-wide gene expression profiling of clear cell renal cell carcinoma in Czech Republic and in the United States. PLoS One 2013; 8:e57886. [PMID: 23526956 PMCID: PMC3589490 DOI: 10.1371/journal.pone.0057886] [Citation(s) in RCA: 89] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2012] [Accepted: 01/28/2013] [Indexed: 12/17/2022] Open
Abstract
Gene expression microarray and next generation sequencing efforts on conventional, clear cell renal cell carcinoma (ccRCC) have been mostly performed in North American and Western European populations, while the highest incidence rates are found in Central/Eastern Europe. We conducted whole-genome expression profiling on 101 pairs of ccRCC tumours and adjacent non-tumour renal tissue from Czech patients recruited within the "K2 Study", using the Illumina HumanHT-12 v4 Expression BeadChips to explore the molecular variations underlying the biological and clinical heterogeneity of this cancer. Differential expression analysis identified 1650 significant probes (fold change ≥2 and false discovery rate <0.05) mapping to 630 up- and 720 down-regulated unique genes. We performed similar statistical analysis on the RNA sequencing data of 65 ccRCC cases from the Cancer Genome Atlas (TCGA) project and identified 60% (402) of the downregulated and 74% (469) of the upregulated genes found in the K2 series. The biological characterization of the significantly deregulated genes demonstrated involvement of downregulated genes in metabolic and catabolic processes, excretion, oxidation reduction, ion transport and response to chemical stimulus, while simultaneously upregulated genes were associated with immune and inflammatory responses, response to hypoxia, stress, wounding, vasculature development and cell activation. Furthermore, genome-wide DNA methylation analysis of 317 TCGA ccRCC/adjacent non-tumour renal tissue pairs indicated that deregulation of approximately 7% of genes could be explained by epigenetic changes. Finally, survival analysis conducted on 89 K2 and 464 TCGA cases identified 8 genes associated with differential prognostic outcomes. In conclusion, a large proportion of ccRCC molecular characteristics were common to the two populations and several may have clinical implications when validated further through large clinical cohorts.
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Abstract
Claudins are tight junction membrane proteins that regulate paracellular permeability of renal epithelia to small ions, solutes, and water. Claudins interact within the cell membrane and between neighboring cells to form tight junction strands and constitute both the paracellular barrier and the pore. The first extracellular domain of claudins is thought to be the pore-lining domain and contains the determinants of charge selectivity. Multiple claudins are expressed in different nephron segments; such differential expression likely determines the permeability properties of each segment. Recent evidence has identified claudin-2 as constituting the cation-reabsorptive pathway in the proximal tubule; claudin-14, -16, and -19 as forming a complex that regulates calcium transport in the thick ascending limb of the loop of Henle; and claudin-4, -7, and -8 as determinants of collecting duct chloride permeability. Mutations in claudin-16 and -19 cause familial hypercalciuric hypomagnesemia with nephrocalcinosis. The roles of other claudins in kidney diseases remain to be fully elucidated.
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Affiliation(s)
- Jianghui Hou
- Renal Division, Washington University, St. Louis, Missouri 63110, USA
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Abstract
The early blood vessels of the embryo and yolk sac in mammals develop by aggregation of de novo-forming angioblasts into a primitive vascular plexus, which then undergoes a complex remodeling process. Angiogenesis is also important for disease progression in the adult. However, the precise molecular mechanism of vascular development remains unclear. It is therefore of great interest to determine which genes are specifically expressed in developing endothelial cells (ECs). Here, we used Flk1-deficient mouse embryos, which lack ECs, to perform a genome-wide survey for genes related to vascular development. We identified 184 genes that are highly enriched in developing ECs. The human orthologs of most of these genes were also expressed in HUVECs, and small interfering RNA knockdown experiments on 22 human orthologs showed that 6 of these genes play a role in tube formation by HUVECs. In addition, we created Arhgef15 knockout and RhoJ knockout mice by a gene-targeting method and found that Arhgef15 and RhoJ were important for neonatal retinal vascularization. Thus, the genes identified in our survey show high expression in ECs; further analysis of these genes should facilitate our understanding of the molecular mechanisms of vascular development in the mouse.
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Stefaniuk M, Lukasiuk K. Cloning of expressed sequence tags (ESTs) representing putative epileptogenesis-related genes and the localization of their expression in the normal brain. Neurosci Lett 2010; 482:230-4. [DOI: 10.1016/j.neulet.2010.07.045] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2010] [Revised: 07/13/2010] [Accepted: 07/19/2010] [Indexed: 11/29/2022]
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Anderson JM, Van Itallie CM. Physiology and function of the tight junction. Cold Spring Harb Perspect Biol 2010; 1:a002584. [PMID: 20066090 DOI: 10.1101/cshperspect.a002584] [Citation(s) in RCA: 726] [Impact Index Per Article: 51.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Understanding of tight junctions has evolved from their historical perception as inert solute barriers to recognition of their physiological and biochemical complexity. Many proteins are specifically localized to tight junctions, including cytoplasmic actin-binding proteins and adhesive transmembrane proteins. Among the latter are claudins, which are critical barrier proteins. Current information suggests that the paracellular barrier is most usefully modeled as having two physiologic components: a system of charge-selective small pores, 4 A in radius, and a second pathway created by larger discontinuities in the barrier, lacking charge or size discrimination. The first pathway is influenced by claudin expression patterns and the second is likely controlled by different proteins and signals. Recent information on claudin function and disease-causing mutations have led to a more complete understanding of their role in barrier formation, but progress is impeded by lack of high resolution structural information.
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Affiliation(s)
- James M Anderson
- Department of Cell and Molecular Physiology, University of North Carolina at Chapel Hill, 6312 MBRB, Chapel Hill, North Carolina 27599-7545, USA.
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Saharinen P, Helotera H, Miettinen J, Norrmen C, D'Amico G, Jeltsch M, Langenberg T, Vandevelde W, Ny A, Dewerchin M, Carmeliet P, Alitalo K. Claudin-like protein 24 interacts with the VEGFR-2 and VEGFR-3 pathways and regulates lymphatic vessel development. Genes Dev 2010; 24:875-80. [PMID: 20439428 DOI: 10.1101/gad.565010] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
The Claudin-like protein of 24 kDa (CLP24) is a hypoxia-regulated transmembrane protein of unknown function. We show here that clp24 knockdown in Danio rerio and Xenopus laevis results in defective lymphatic development. Targeted disruption of Clp24 in mice led to enlarged lymphatic vessels having an abnormal smooth muscle cell coating. We also show that the Clp24(-/-) phenotype was further aggravated in the Vegfr2(+/LacZ) or Vegfr3(+/LacZ) backgrounds and that CLP24 interacts with vascular endothelial growth factor receptor-2 (VEGFR-2) and VEGFR-3 and attenuates the transcription factor CREB phosphorylation via these receptors. Our results indicate that CLP24 is a novel regulator of VEGFR-2 and VEGFR-3 signaling pathways and of normal lymphatic vessel structure.
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Affiliation(s)
- Pipsa Saharinen
- Molecular/Cancer Biology Program, Biomedicum Helsinki, University of Helsinki, Helsinki FIN-00014, Finland
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Longo-Guess CM, Gagnon LH, Fritzsch B, Johnson KR. Targeted knockout and lacZ reporter expression of the mouse Tmhs deafness gene and characterization of the hscy-2J mutation. Mamm Genome 2007; 18:646-56. [PMID: 17876667 PMCID: PMC2613174 DOI: 10.1007/s00335-007-9049-x] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2007] [Accepted: 06/14/2007] [Indexed: 01/03/2023]
Abstract
The Tmhs gene codes for a tetraspan transmembrane protein that is expressed in hair cell stereocilia. We previously showed that a spontaneous missense mutation of Tmhs underlies deafness and vestibular dysfunction in the hurry-scurry (hscy) mouse. Subsequently, mutations in the human TMHS gene were shown to be responsible for DFNB67, an autosomal recessive nonsyndromic deafness locus. Here we describe a genetically engineered null mutation of the mouse Tmhs gene (Tmhs ( tm1Kjn )) and show that its phenotype is identical to that of the hscy missense mutation, confirming the deleterious nature of the hscy cysteine-to-phenylalanine substitution. In the targeted null allele, the Tmhs promoter drives expression of a lacZ reporter gene. Visualization of beta-galactosidase activity in Tmhs ( tm1Kjn ) heterozygous mice indicates that Tmhs is highly expressed in the cochlear and vestibular hair cells of the inner ear. Expression is first detectable at E15.5, peaks around P0, decreases slightly at P6, and is absent by P15, a duration that supports the involvement of Tmhs in stereocilia development. Tmhs reporter gene expression also was detected in several cranial and cervical sensory ganglia, but not in the vestibular or spiral ganglia. We also describe a new nontargeted mutation of the Tmhs gene, hscy-2J, that causes abnormal splicing from a cryptic splice site within exon 2 and is predicted to produce a functionally null protein lacking 51 amino acids of the wild-type sequence.
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Koto T, Takubo K, Ishida S, Shinoda H, Inoue M, Tsubota K, Okada Y, Ikeda E. Hypoxia disrupts the barrier function of neural blood vessels through changes in the expression of claudin-5 in endothelial cells. THE AMERICAN JOURNAL OF PATHOLOGY 2007; 170:1389-97. [PMID: 17392177 PMCID: PMC1829471 DOI: 10.2353/ajpath.2007.060693] [Citation(s) in RCA: 184] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
The mechanisms underlying the hypoxia-induced disruption of the barrier function of neural vasculature were analyzed with reference to the expression of claudin-5, a component of tight junctions between neural endothelial cells. The movement of claudin-5 from the cytoplasm to the plasma membrane of cultured confluent brain-derived endothelial (bEND.3) cells was closely correlated with the increase in the transendothelial electrical resistance. Inhibition of the expression of claudin-5 by RNAi resulted in a reduction of transendothelial electrical resistance, indicating a critical role of claudin-5 in the barrier property. Hypoxia (1% O(2)) altered the location of claudin-5 in the plasma membrane and the level of claudin-5 protein in bEND.3 cells, and these changes were accompanied by a decrease in the transendothelial electrical resistance. In vivo the claudin-5 molecules were expressed under normoxia in the plasma membrane of retinal microvascular endothelial cells but were significantly reduced under hypoxic conditions. Tracer experiments revealed that the barrier function of hypoxic retinal vasculature with depressed claudin-5 expression was selectively disrupted against small molecules, which is very similar to the phenotype of claudin-5-deficient mice. These in vitro and in vivo data indicate that claudin-5 is a target molecule of hypoxia leading to the disruption of the barrier function of neural vasculature.
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Affiliation(s)
- Takashi Koto
- Department of Pathology, School of Medicine, Keio University, 35 Shinanomachi, Shinjuku-ku, Tokyo 160-8582, Japan.
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Isolation and Characterization of a Novel Four-Transmembrane Protein PMP22CD Specifically Expressed in the Testis. Int J Mol Sci 2006. [DOI: 10.3390/i7100425] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
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Wu J, Helftenbein G, Koslowski M, Sahin U, Tureci O. Identification of new claudin family members by a novel PSI-BLAST based approach with enhanced specificity. Proteins 2006; 65:808-15. [PMID: 17022085 DOI: 10.1002/prot.21218] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
In an attempt to develop a novel strategy for the identification of new members of protein families by in silico approaches, we have developed a semi-automated procedure of consecutive PSI-BLAST (Position-Specific-Iterated Basic Local Alignment Search Tool) searches incorporating identificiation as well as subsequent validation of putative candidates. For a proof of concept study we chose the search for novel members of the claudin family. The initial step was an iterated PSI-BLAST search starting with the PMP22_Claudin domain of each known member of the claudin family against the human part of the RefSeq Database. Putative new claudin domains derived from the converged list were evaluated by a validating PSI-BLAST in which each sequence was assessed for finding back the starting set of known claudin domains. The local PSI-BLAST searches and validation were automated by a set of PERL scripts. With this strategy a total of three additional putative claudin domains in three different proteins were identified. One of them was subjected to further characterization and was shown to exhibit claudin-like features in terms of protein structure and expression pattern. The strategy we present is an efficient and versatile tool to identify novel members of domain-sharing protein families. Low rates of false positives achieved by inclusion of a validation step into the in silico procedure make this strategy particularly attractive to select candidates for subsequent labor-intensive wet bench characterization.
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Affiliation(s)
- Jun Wu
- Ganymed-Pharmaceuticlas AG, Freiligrathstrasse 12, 55131 Mainz, Germany
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17
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Abstract
Tight junctions restrict the flow of ions and aqueous molecules between cells by forming a selective barrier to the paracellular pathway. Permeability of the tight junction barrier is determined by a class of transmembrane proteins known as claudins. The relationship between claudins and paracellular permeability is complex and determined not only by the profile of claudin expression but also by the arrangement of claudins and other proteins into tight junction strands. This review summarizes progress in understanding how claudins are assembled into tight junctions and how they interact with other tight junction proteins.
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Affiliation(s)
- Michael Koval
- Division of Pulmonary, Allergy and Critical Care Medicine, Department of Medicine, Emory University School of Medicine, Atlanta, Georgia 30322, USA.
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18
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Abstract
Tight junctions form continuous intercellular contacts controlling solute movement through the paracellular pathway across epithelia. Paracellular barriers vary among epithelia in electrical resistance and behave as if they are lined with pores that have charge and size selectivity. Recent evidence shows that claudins, a large family (at least 24 members) of intercellular adhesion molecules, form the seal and its variable pore-like properties. This evidence comes from the study of claudins expressed in cultured epithelial cell models, genetically altered mice, and human mutants. We review information on the structure, function, and transcriptional and posttranslational regulation of the claudin family as well as of their evolutionarily distant relatives called the PMP22/EMP/MP20/claudin, or pfam00822, superfamily.
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Affiliation(s)
- Christina M Van Itallie
- Department of Medicine, Division of Gastroenterology and Hepatology, University of North Carolina, Chapel Hill, North Carolina 27599-7545, USA.
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Longo-Guess CM, Gagnon LH, Cook SA, Wu J, Zheng QY, Johnson KR. A missense mutation in the previously undescribed gene Tmhs underlies deafness in hurry-scurry (hscy) mice. Proc Natl Acad Sci U S A 2005; 102:7894-9. [PMID: 15905332 PMCID: PMC1142366 DOI: 10.1073/pnas.0500760102] [Citation(s) in RCA: 80] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Mouse deafness mutations provide valuable models of human hearing disorders and entry points into molecular pathways important to the hearing process. A newly discovered mouse mutation named hurry-scurry (hscy) causes deafness and vestibular dysfunction. Scanning electron microscopy of cochleae from 8-day-old mutants revealed disorganized hair bundles, and by 50 days of age, many hair cells are missing. To positionally clone hscy, 1,160 F(2) mice were produced from an intercross of (C57BL/6-hscy x CAST/EiJ) F(1) hybrids, and the mutation was localized to a 182-kb region of chromosome 17. A missense mutation causing a critical cysteine to phenylalanine codon change was discovered in a previously undescribed gene within this candidate interval. The gene is predicted to encode an integral membrane protein with four transmembrane helices. A synthetic peptide designed from the predicted protein was used to produce specific polyclonal antibodies, and strong immunoreactivity was observed on hair bundles of both inner and outer hair cells in cochleae of newborn +/+ controls and +/hscy heterozygotes but was absent in hscy/hscy mutants. Accordingly, the gene was given the name "tetraspan membrane protein of hair cell stereocilia," symbol Tmhs. Two related proteins (>60% amino acid identity) are encoded by genes on mouse chromosomes 5 and 6 and, together with the Tmhs-encoded protein (TMHS), comprise a distinct tetraspan subfamily. Our localization of TMHS to the apical membrane of inner ear hair cells during the period of stereocilia formation suggests a function in hair bundle morphogenesis.
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MESH Headings
- Animals
- Base Sequence
- Blotting, Northern
- Chromosome Mapping
- Cluster Analysis
- Crosses, Genetic
- DNA, Complementary/genetics
- Deafness/genetics
- Gene Components
- Gene Expression
- Hair Cells, Auditory/metabolism
- Hair Cells, Auditory/ultrastructure
- Histological Techniques
- Immunohistochemistry
- Membrane Proteins/genetics
- Membrane Proteins/metabolism
- Mice/genetics
- Mice, Mutant Strains
- Microscopy, Electron, Scanning
- Molecular Sequence Data
- Mutation, Missense/genetics
- Sequence Analysis, DNA
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Abstract
Tight junctions form selective barriers that regulate paracellular transport across epithelia. A large family of tetraspanning cell-cell adhesion proteins called claudins create the barrier and regulate electrical resistance, size, and ionic charge selectivity. Study of inherited human claudin diseases and the outcome of the genetic manupulation of claudins in mice, Drosophila, and Caenorhabditis elegans are furthering our understanding of paracellular physiology.
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Affiliation(s)
- Christina M Van Itallie
- Department of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA.
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