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Das S, Das S, Rath PP, Banerjee A, Gourinath S, Mukhopadhyay AK, Maiti S. Hemolysin Coregulated Protein (HCP) from Vibrio Cholerae Interacts with the Host Cell Actin Cytoskeleton. ACS Infect Dis 2024; 10:2886-2898. [PMID: 39079033 DOI: 10.1021/acsinfecdis.4c00265] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/10/2024]
Abstract
Vibrio cholerae (V. cholerae), the etiological agent of cholera, employs various virulence factors to adapt and thrive within both aquatic and human host environments. Among these factors, the type VI secretion system (T6SS) stands out as one of the crucial determinants of its pathogenicity. Valine glycine repeat protein G1 (VgrG1) and hemolysin coregulated protein (HCP) are considered major effector molecules of T6SS. Previous studies have highlighted that VgrG1 interacts with HCP proteins. Additionally, it has been shown that VgrG1 possesses an actin cross-linking domain (ACD) with actin-binding activity. Interestingly, it was reported that purified HCP protein treatment increased the stress fibers within cells. Therefore, we hypothesize that HCP may interact with host cell actin, potentially playing a role in the cytoskeletal rearrangement during V. cholerae infection. To test this hypothesis, we characterized HCP from the V. cholerae O139 serotype and demonstrated its interaction with actin monomers. In silico analysis and experimental validation revealed the presence of an actin-binding site within HCP. Furthermore, overexpression of HCP resulted in its colocalization with actin stress fibers in host cells. Our findings establish HCP as an effector molecule for potent host cell actin cytoskeleton remodeling during V. cholerae infection, providing new insights into bacterial pathogenicity mechanisms. Understanding the interplay between bacterial effectors and host cell components is crucial for developing targeted therapeutic interventions against cholera and related infectious diseases.
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Affiliation(s)
- Shubham Das
- Department of Biological Sciences, Indian Institute of Science Education and Research Kolkata, Nadia, Mohanpur, West Bengal 741246, India
| | - Saikat Das
- Department of Biological Sciences, Indian Institute of Science Education and Research Kolkata, Nadia, Mohanpur, West Bengal 741246, India
| | | | - Aishwarya Banerjee
- Department of Biological Sciences, Indian Institute of Science Education and Research Kolkata, Nadia, Mohanpur, West Bengal 741246, India
| | - Samudrala Gourinath
- School of Life Sciences, Jawaharlal Nehru University, New Delhi 110067, India
| | | | - Sankar Maiti
- Department of Biological Sciences, Indian Institute of Science Education and Research Kolkata, Nadia, Mohanpur, West Bengal 741246, India
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Shubhrasmita Sahu S, Sarkar P, Chattopadhyay A. Quantitation of F-actin in cytoskeletal reorganization: Context, methodology and implications. Methods 2024; 230:44-58. [PMID: 39074540 DOI: 10.1016/j.ymeth.2024.07.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2024] [Revised: 07/08/2024] [Accepted: 07/17/2024] [Indexed: 07/31/2024] Open
Abstract
The actin cytoskeleton is involved in a large number of cellular signaling events in addition to providing structural integrity to the cell. Actin polymerization is a key event during cellular signaling. Although the role of actin cytoskeleton in cellular processes such as trafficking and motility has been extensively studied, the reorganization of the actin cytoskeleton upon signaling has been rarely explored due to lack of suitable assays. Keeping in mind this lacuna, we developed a confocal microscopy based approach that relies on high magnification imaging of cellular F-actin, followed by image reconstruction using commercially available software. In this review, we discuss the context and relevance of actin quantitation, followed by a detailed hands-on approach of the methodology involved with specific points on troubleshooting and useful precautions. In the latter part of the review, we elucidate the method by discussing applications of actin quantitation from our work in several important problems in contemporary membrane biology ranging from pathogen entry into host cells, to GPCR signaling and membrane-cytoskeleton interaction. We envision that future discovery of cell-permeable novel fluorescent probes, in combination with genetically encoded actin-binding reporters, would allow real-time visualization of actin cytoskeleton dynamics to gain deeper insights into active cellular processes in health and disease.
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Affiliation(s)
- Subhashree Shubhrasmita Sahu
- CSIR-Centre for Cellular and Molecular Biology, Uppal Road, Hyderabad 500 007, India; Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201 002, India
| | - Parijat Sarkar
- CSIR-Centre for Cellular and Molecular Biology, Uppal Road, Hyderabad 500 007, India; Department of Biochemistry, Stanford University, School of Medicine, Stanford, CA 94305, USA
| | - Amitabha Chattopadhyay
- CSIR-Centre for Cellular and Molecular Biology, Uppal Road, Hyderabad 500 007, India; Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201 002, India.
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3
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Koehler S, Huber TB, Denholm B. A protective role for <i>Drosophila</i> Filamin in nephrocytes via Yorkie mediated hypertrophy. Life Sci Alliance 2022; 5:e202101281. [PMID: 35922155 PMCID: PMC9351128 DOI: 10.26508/lsa.202101281] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2021] [Revised: 07/15/2022] [Accepted: 07/18/2022] [Indexed: 11/24/2022] Open
Abstract
Podocytes are specialized epithelial cells of the kidney glomerulus and are an essential part of the filtration barrier. Because of their position, they are exposed to constant biomechanical forces such as shear stress and hydrostatic pressure. These forces increase during disease, resulting in podocyte injury. It is likely podocytes have adaptative responses to help buffer against deleterious mechanical force and thus reduce injury. However, these responses remain largely unknown. Here, using the <i>Drosophila</i> model, we show the mechanosensor Cheerio (dFilamin) provides a key protective role in nephrocytes. We found expression of an activated mechanosensitive variant of Cheerio rescued filtration function and induced compensatory and hypertrophic growth in nephrocytes depleted of the nephrocyte diaphragm proteins Sns or Duf. Delineating the protective pathway downstream of Cheerio we found repression of the Hippo pathway induces nephrocyte hypertrophy, whereas Hippo activation reversed the Cheerio-mediated hypertrophy. Furthermore, we find Yorkie was activated upon expression of active Cheerio. Taken together, our data suggest that Cheerio acts via the Hippo pathway to induce hypertrophic growth, as a protective response in abnormal nephrocytes.
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Affiliation(s)
- Sybille Koehler
- Biomedical Sciences, University of Edinburgh, Edinburgh, UK
- III Department of Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Tobias B Huber
- III Department of Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Barry Denholm
- Biomedical Sciences, University of Edinburgh, Edinburgh, UK
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4
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Chi WY, Hsiao TH, Lee GH, Su IH, Chen BH, Tang MJ, Fu TF. The cooperative interplay among inflammation, necroptosis and YAP pathway contributes to the folate deficiency-induced liver cells enlargement. Cell Mol Life Sci 2022; 79:397. [PMID: 35790616 PMCID: PMC11073448 DOI: 10.1007/s00018-022-04425-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2022] [Revised: 06/10/2022] [Accepted: 06/13/2022] [Indexed: 11/03/2022]
Abstract
Change in cell size may bring in profound impact to cell function and survival, hence the integrity of the organs consisting of those cells. Nevertheless, how cell size is regulated remains incompletely understood. We used the fluorescent zebrafish transgenic line Tg-GGH/LR that displays inducible folate deficiency (FD) and hepatomegaly upon FD induction as in vivo model. We found that FD caused hepatocytes enlargement and increased liver stiffness, which could not be prevented by nucleotides supplementations. Both in vitro and in vivo studies indicated that RIPK3/MLKL-dependent necroptotic pathway and Hippo signaling interactively participated in this FD-induced hepatocytic enlargement in a dual chronological and cooperative manner. FD also induced hepatic inflammation, which convenes a dialog of positive feedback loop between necroptotic and Hippo pathways. The increased MMP13 expression in response to FD elevated TNFα level and further aggravated the hepatocyte enlargement. Meanwhile, F-actin was circumferentially re-allocated at the edge under cell membrane in response to FD. Our results substantiate the interplay among intracellular folate status, pathways regulation, inflammatory responses, actin cytoskeleton and cell volume control, which can be best observed with in vivo platform. Our data also support the use of this Tg-GGH/LR transgenic line for the mechanistical and therapeutic research for the pathologic conditions related to cell size alteration.
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Affiliation(s)
- Wan-Yu Chi
- The Institute of Basic Medical Science, College of Medicine, National Cheng Kung University, Tainan, Taiwan
| | - Tsun-Hsien Hsiao
- The Institute of Basic Medical Science, College of Medicine, National Cheng Kung University, Tainan, Taiwan
| | - Gang-Hui Lee
- International Center for Wound Repair and Regeneration, National Cheng Kung University, Tainan, Taiwan
| | - I-Hsiu Su
- International Center for Wound Repair and Regeneration, National Cheng Kung University, Tainan, Taiwan
| | - Bing-Hung Chen
- Department of Biotechnology, Kaohsiung Medical University, Kaohsiung, Taiwan
- Department of Medical Research, Kaohsiung Medical University Hospital, Kaohsiung, Taiwan
- Center for Biomarkers and Biotech Drugs, Kaohsiung Medical University, Kaohsiung, Taiwan
- Institute of Biomedical Sciences, National Sun Yat-Sen University, Kaohsiung, Taiwan
| | - Ming-Jer Tang
- International Center for Wound Repair and Regeneration, National Cheng Kung University, Tainan, Taiwan
- Department of Physiology, College of Medicine, National Cheng Kung University, Tainan, Taiwan
| | - Tzu-Fun Fu
- The Institute of Basic Medical Science, College of Medicine, National Cheng Kung University, Tainan, Taiwan.
- Department of Medical Laboratory Science and Biotechnology, College of Medicine, National Cheng Kung University, No. 1, University Rd., Tainan, 701, Taiwan.
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5
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Mechanisms of podocyte injury and implications for diabetic nephropathy. Clin Sci (Lond) 2022; 136:493-520. [PMID: 35415751 PMCID: PMC9008595 DOI: 10.1042/cs20210625] [Citation(s) in RCA: 47] [Impact Index Per Article: 23.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2021] [Revised: 02/25/2022] [Accepted: 03/25/2022] [Indexed: 02/06/2023]
Abstract
Albuminuria is the hallmark of both primary and secondary proteinuric glomerulopathies, including focal segmental glomerulosclerosis (FSGS), obesity-related nephropathy, and diabetic nephropathy (DN). Moreover, albuminuria is an important feature of all chronic kidney diseases (CKDs). Podocytes play a key role in maintaining the permselectivity of the glomerular filtration barrier (GFB) and injury of the podocyte, leading to foot process (FP) effacement and podocyte loss, the unifying underlying mechanism of proteinuric glomerulopathies. The metabolic insult of hyperglycemia is of paramount importance in the pathogenesis of DN, while insults leading to podocyte damage are poorly defined in other proteinuric glomerulopathies. However, shared mechanisms of podocyte damage have been identified. Herein, we will review the role of haemodynamic and oxidative stress, inflammation, lipotoxicity, endocannabinoid (EC) hypertone, and both mitochondrial and autophagic dysfunction in the pathogenesis of the podocyte damage, focussing particularly on their role in the pathogenesis of DN. Gaining a better insight into the mechanisms of podocyte injury may provide novel targets for treatment. Moreover, novel strategies for boosting podocyte repair may open the way to podocyte regenerative medicine.
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Caire R, Dalix E, Chafchafi M, Thomas M, Linossier MT, Normand M, Guignandon A, Vico L, Marotte H. YAP Transcriptional Activity Dictates Cell Response to TNF In Vitro. Front Immunol 2022; 13:856247. [PMID: 35401557 PMCID: PMC8989468 DOI: 10.3389/fimmu.2022.856247] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2022] [Accepted: 02/23/2022] [Indexed: 01/15/2023] Open
Abstract
YAP/TAZ are transcription co-factors recently described responsive to pro-inflammatory cytokines and involved in inflammatory-related disorders. However, the role of tumor necrosis factor (TNF), a major pro-inflammatory cytokine, on YAP signaling is not well understood and controversial. Here, we observe in vitro, using wild type and YAP knockout HEK293 cells, that TNF triggers YAP nuclear translocation and transcriptional activity, thus being dependent on Rho family of GTPases. In response to TNF, YAP transcriptional activity orientates cell fate toward survival. Transcriptional analysis with Nanostring technology reveals that YAP modulates TNF-induced increase in fibro-inflammatory pathways such as NF-κB, inflammasomes, cytokines or chemokines signaling and pro-fibrotic pathways involving TGF-β and extracellular matrix remodeling. Therefore, in response to TNF, YAP acts as a sustainer of the inflammatory response and as a molecular link between inflammation and fibrotic processes. This work identifies that YAP is critical to drive several biological effects of TNF which are involved in cancer and inflammatory disorders.
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Affiliation(s)
- Robin Caire
- INSERM, U1059-SAINBIOSE, Université de Lyon, Saint-Etienne, France
| | - Elisa Dalix
- INSERM, U1059-SAINBIOSE, Université de Lyon, Saint-Etienne, France
| | - Marwa Chafchafi
- INSERM, U1059-SAINBIOSE, Université de Lyon, Saint-Etienne, France
| | - Mireille Thomas
- INSERM, U1059-SAINBIOSE, Université de Lyon, Saint-Etienne, France
| | | | - Myriam Normand
- INSERM, U1059-SAINBIOSE, Université de Lyon, Saint-Etienne, France
| | - Alain Guignandon
- INSERM, U1059-SAINBIOSE, Université de Lyon, Saint-Etienne, France
| | - Laurence Vico
- INSERM, U1059-SAINBIOSE, Université de Lyon, Saint-Etienne, France
| | - Hubert Marotte
- INSERM, U1059-SAINBIOSE, Université de Lyon, Saint-Etienne, France.,Department of Rheumatology, Hôpital Nord, University Hospital Saint-Etienne, Saint-Etienne, France
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7
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Purohit S, Piani F, Ordoñez FA, de Lucas-Collantes C, Bauer C, Cara-Fuentes G. Molecular Mechanisms of Proteinuria in Minimal Change Disease. Front Med (Lausanne) 2022; 8:761600. [PMID: 35004732 PMCID: PMC8733331 DOI: 10.3389/fmed.2021.761600] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2021] [Accepted: 10/15/2021] [Indexed: 11/13/2022] Open
Abstract
Minimal change disease (MCD) is the most common type of idiopathic nephrotic syndrome in childhood and represents about 15% cases in adults. It is characterized by massive proteinuria, edema, hypoalbuminemia, and podocyte foot process effacement on electron microscopy. Clinical and experimental studies have shown an association between MCD and immune dysregulation. Given the lack of inflammatory changes or immunocomplex deposits in the kidney tissue, MCD has been traditionally thought to be mediated by an unknown circulating factor(s), probably released by T cells that directly target podocytes leading to podocyte ultrastructural changes and proteinuria. Not surprisingly, research efforts have focused on the role of T cells and podocytes in the disease process. Nevertheless, the pathogenesis of the disease remains a mystery. More recently, B cells have been postulated as an important player in the disease either by activating T cells or by releasing circulating autoantibodies against podocyte targets. There are also few reports of endothelial injury in MCD, but whether glomerular endothelial cells play a role in the disease remains unexplored. Genome-wide association studies are providing insights into the genetic susceptibility to develop the disease and found a link between MCD and certain human haplotype antigen variants. Altogether, these findings emphasize the complex interplay between the immune system, glomerular cells, and the genome, raising the possibility of distinct underlying triggers and/or mechanisms of proteinuria among patients with MCD. The heterogeneity of the disease and the lack of good animal models of MCD remain major obstacles in the understanding of MCD. In this study, we will review the most relevant candidate mediators and mechanisms of proteinuria involved in MCD and the current models of MCD-like injury.
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Affiliation(s)
- Shrey Purohit
- Division of Renal Diseases and Hypertension, Department of Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO, United States.,Department of Pediatrics, Section of Pediatric Nephrology, Children's Hospital Colorado, Aurora, CO, United States
| | - Federica Piani
- Division of Renal Diseases and Hypertension, Department of Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO, United States.,Department of Medicine and Surgery Sciences, Alma Mater Studiorum University of Bologna, Bologna, Italy
| | - Flor A Ordoñez
- Division of Pediatric Nephrology, Hospital Universitario Central de Asturias, Oviedo, Spain
| | | | - Colin Bauer
- Department of Pediatrics, Section of Pediatric Nephrology, Children's Hospital Colorado, Aurora, CO, United States
| | - Gabriel Cara-Fuentes
- Division of Renal Diseases and Hypertension, Department of Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO, United States.,Department of Pediatrics, Section of Pediatric Nephrology, Children's Hospital Colorado, Aurora, CO, United States
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8
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Thiebaut C, Vlaeminck-Guillem V, Trédan O, Poulard C, Le Romancer M. Non-genomic signaling of steroid receptors in cancer. Mol Cell Endocrinol 2021; 538:111453. [PMID: 34520815 DOI: 10.1016/j.mce.2021.111453] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/25/2021] [Revised: 09/03/2021] [Accepted: 09/05/2021] [Indexed: 12/21/2022]
Abstract
Steroid receptors (SRs) are members of the nuclear receptor family, which are ligand-activated transcription factors. SRs regulate many physiological functions including development and reproduction, though they can also be involved in several pathologies, especially cancer. Highly controlled cellular responses to steroids involve transcriptional regulation (genomic activity) combined with direct activation of signaling cascades (non-genomic activity). Non-genomic signaling has been extensively studied in cancer, mainly in breast cancer for ER and PR, and prostate cancer for AR. Even though most of the studies have been conducted in cells, some of them have been confirmed in vivo, highlighting the relevance of this pathway in cancer. This review provides an overview of the current and emerging knowledge on non-genomic signaling with a focus on breast and prostate cancers and its clinical relevance. A thorough understanding of ER, PR, AR and GR non-genomic pathways may open new perspectives for the development of therapeutic strategies.
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Affiliation(s)
- Charlène Thiebaut
- Université de Lyon, F-69000, Lyon, France; Inserm U1052, Centre de Recherche en Cancérologie de Lyon, F-69000, Lyon, France; CNRS UMR5286, Centre de Recherche en Cancérologie de Lyon, F-69000, Lyon, France
| | - Virginie Vlaeminck-Guillem
- Université de Lyon, F-69000, Lyon, France; Inserm U1052, Centre de Recherche en Cancérologie de Lyon, F-69000, Lyon, France; CNRS UMR5286, Centre de Recherche en Cancérologie de Lyon, F-69000, Lyon, France; Service de Biochimie Biologie Moléculaire Sud, Centre Hospitalier Lyon Sud, Hospices Civils de Lyon, F-69495, Pierre-Bénite, France
| | - Olivier Trédan
- Université de Lyon, F-69000, Lyon, France; Inserm U1052, Centre de Recherche en Cancérologie de Lyon, F-69000, Lyon, France; CNRS UMR5286, Centre de Recherche en Cancérologie de Lyon, F-69000, Lyon, France; Medical Oncology Department, Centre Léon Bérard, F-69000, Lyon, France
| | - Coralie Poulard
- Université de Lyon, F-69000, Lyon, France; Inserm U1052, Centre de Recherche en Cancérologie de Lyon, F-69000, Lyon, France; CNRS UMR5286, Centre de Recherche en Cancérologie de Lyon, F-69000, Lyon, France
| | - Muriel Le Romancer
- Université de Lyon, F-69000, Lyon, France; Inserm U1052, Centre de Recherche en Cancérologie de Lyon, F-69000, Lyon, France; CNRS UMR5286, Centre de Recherche en Cancérologie de Lyon, F-69000, Lyon, France.
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Abstract
Metastasis is the process of cancer cell dissemination from primary tumors to different organs being the bone the preferred site for metastatic homing of prostate cancer (PCa) cells. Prostate tumorigenesis is a multi-stage process that ultimately tends to advance to become metastatic PCa. Once PCa patients develop skeletal metastases, they eventually succumb to the disease. Therefore, it is imperative to identify essential molecular drivers of this process to develop new therapeutic alternatives for the treatment of this devastating disease. Here, we have identified MAP4K4 as a relevant gene for metastasis in PCa. Our work shows that genetic deletion of MAP4K4 or pharmacological inhibition of its encoded kinase, HGK, inhibits metastatic PCa cells migration and clonogenic properties. Hence, MAP4K4 might promote metastasis and tumor growth. Mechanistically, our results indicate that HGK depleted cells exhibit profound differences in F-actin organization, increasing cell spreading and focal adhesion stability. Additionally, HGK depleted cells fails to respond to TNF-α stimulation and chemoattractant action. Moreover, here we show that HGK upregulation in PCa samples from TCGA and other databases correlates with a poor prognosis of the disease. Hence, we suggest that it could be used as prognostic biomarker to predict the appearance of an aggressive phenotype of PCa tumors and ultimately, the appearance of metastasis. In summary, our results highlight an essential role for HGK in the dissemination of PCa cells and its potential use as prognostic biomarker.
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10
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Articular Chondrocyte Phenotype Regulation through the Cytoskeleton and the Signaling Processes That Originate from or Converge on the Cytoskeleton: Towards a Novel Understanding of the Intersection between Actin Dynamics and Chondrogenic Function. Int J Mol Sci 2021; 22:ijms22063279. [PMID: 33807043 PMCID: PMC8004672 DOI: 10.3390/ijms22063279] [Citation(s) in RCA: 35] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2021] [Revised: 03/16/2021] [Accepted: 03/17/2021] [Indexed: 02/08/2023] Open
Abstract
Numerous studies have assembled a complex picture, in which extracellular stimuli and intracellular signaling pathways modulate the chondrocyte phenotype. Because many diseases are mechanobiology-related, this review asked to what extent phenotype regulators control chondrocyte function through the cytoskeleton and cytoskeleton-regulating signaling processes. Such information would generate leverage for advanced articular cartilage repair. Serial passaging, pro-inflammatory cytokine signaling (TNF-α, IL-1α, IL-1β, IL-6, and IL-8), growth factors (TGF-α), and osteoarthritis not only induce dedifferentiation but also converge on RhoA/ROCK/Rac1/mDia1/mDia2/Cdc42 to promote actin polymerization/crosslinking for stress fiber (SF) formation. SF formation takes center stage in phenotype control, as both SF formation and SOX9 phosphorylation for COL2 expression are ROCK activity-dependent. Explaining how it is molecularly possible that dedifferentiation induces low COL2 expression but high SF formation, this review theorized that, in chondrocyte SOX9, phosphorylation by ROCK might effectively be sidelined in favor of other SF-promoting ROCK substrates, based on a differential ROCK affinity. In turn, actin depolymerization for redifferentiation would “free-up” ROCK to increase COL2 expression. Moreover, the actin cytoskeleton regulates COL1 expression, modulates COL2/aggrecan fragment generation, and mediates a fibrogenic/catabolic expression profile, highlighting that actin dynamics-regulating processes decisively control the chondrocyte phenotype. This suggests modulating the balance between actin polymerization/depolymerization for therapeutically controlling the chondrocyte phenotype.
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11
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Alauddin M, Okumura T, Rajaxavier J, Khozooei S, Pöschel S, Takeda S, Singh Y, Brucker SY, Wallwiener D, Koch A, Salker MS. Gut Bacterial Metabolite Urolithin A Decreases Actin Polymerization and Migration in Cancer Cells. Mol Nutr Food Res 2020; 64:e1900390. [PMID: 31976617 DOI: 10.1002/mnfr.201900390] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2019] [Revised: 12/11/2019] [Indexed: 12/12/2022]
Abstract
SCOPE Urolithin A (UA) is a gut-derived bacterial metabolite from ellagic acid found in pomegranates, berries, and nuts can downregulate cell proliferation and migration. Cell proliferation and cell motility require actin reorganization, which is under control of ras-related C3 botulinum toxin substrate 1 (Rac1) and p21 protein-activated kinase 1 (PAK1). The present study explores whether UA can modify actin cytoskeleton in cancer cells. METHODS The effect of UA on globular over filamentous actin ratio is determined utilizing Western blotting, immunofluorescence, and flow cytometry. Rac1 and PAK1 levels are measured by quantitative RT-PCR and immunoblotting. As a result, a 24 h treatment with UA (20 µm) significantly decreased Rac1 and PAK1 transcript levels and activity, depolymerized actin and wound healing. The effect of UA on actin polymerization is mimicked by pharmacological inhibition of Rac1 and PAK1. The effect is also mirrored by knock down using siRNA. CONCLUSION UA leads to disruption of Rac1 and Pak1 activity with subsequent actin depolymerization and migration. Thus, use of dietary UA in cancer prevention or as adjuvant therapy is promising.
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Affiliation(s)
- Md Alauddin
- Department of Women's Health, Eberhard Karls University of Tuebingen, Tübingen, 72076, Germany
| | - Toshiyuki Okumura
- Department of Women's Health, Eberhard Karls University of Tuebingen, Tübingen, 72076, Germany.,Department of Obstetrics and Gynecology, Juntendo University School of Medicine, Tokyo, 113-8421, Japan
| | - Janet Rajaxavier
- Department of Women's Health, Eberhard Karls University of Tuebingen, Tübingen, 72076, Germany
| | - Shayan Khozooei
- Department of Women's Health, Eberhard Karls University of Tuebingen, Tübingen, 72076, Germany
| | - Simone Pöschel
- Image Stream Core Facility, Eberhard Karls University of Tuebingen, Tübingen, 72076, Germany
| | - Satoru Takeda
- Department of Obstetrics and Gynecology, Juntendo University School of Medicine, Tokyo, 113-8421, Japan
| | - Yogesh Singh
- Institute of Medical Genetics and Applied Genomics, Eberhard Karls University of Tuebingen, Tübingen, 72076, Germany
| | - Sara Y Brucker
- Department of Women's Health, Eberhard Karls University of Tuebingen, Tübingen, 72076, Germany
| | - Diethelm Wallwiener
- Department of Women's Health, Eberhard Karls University of Tuebingen, Tübingen, 72076, Germany
| | - André Koch
- Department of Women's Health, Eberhard Karls University of Tuebingen, Tübingen, 72076, Germany
| | - Madhuri S Salker
- Department of Women's Health, Eberhard Karls University of Tuebingen, Tübingen, 72076, Germany
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12
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Teodori L, Costa A, Campanella L, Albertini MC. Skeletal Muscle Atrophy in Simulated Microgravity Might Be Triggered by Immune-Related microRNAs. Front Physiol 2019; 9:1926. [PMID: 30687129 PMCID: PMC6335973 DOI: 10.3389/fphys.2018.01926] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2018] [Accepted: 12/21/2018] [Indexed: 02/01/2023] Open
Abstract
Exposure to microgravity induces skeletal muscle disorders including atrophy, muscle force decrease, fiber-type shift. Microgravity also contributes to immune-function alterations and modifies microRNAs (miRs) expression. To understand the link between microgravity-induced skeletal muscle atrophy and immune function deregulation, a bioinformatics study was performed. The web platform MiRNet was used for miRs-targets interaction analysis from previous proteomic studies on human soleus (SOL) and vastus lateralis (VL) muscles. We predicted miRs targeting deregulated gene expression following bed rest as a model of microgravity exposure; namely, let-7a-5p, miR-125b-5p for over-expressed genes in SOL and VL; miR-1-3p, miR-125b-5p and miR-1-3p, miR-95-5p for down-expressed genes in VL and SOL. The predicted miRs have important immune functions, exhibiting a significant role on both inflammation and atrophy. Let-7a down-expression leads to proliferation pathways promotion and differentiation pathway inhibition, whereas miR-1-3p over-expression yields anti-proliferative effect, promoting early differentiation. Such conflicting signals could lead to impairment between proliferation and differentiation in skeletal muscles. Moreover, promotion of an M2-like macrophage phenotype (IL-13, IL-10) by let-7a down-regulation and simultaneous promotion of an M1-like macrophage (IL-6, TNF-α) phenotype through the over-expression of EEF2 lead to a deregulation between M1/M2 tuning, that is responsible for a first pro-inflammatory/proliferative phase followed by an anti-inflammatory pro-myogenic phase during skeletal muscle regeneration after injury. These observations are important to understand the mechanism by which inflammation may play a significant role in skeletal muscle dysfunction in spaceflights, providing new links between immune response and skeletal muscle deregulation, which may be useful to further investigate possible therapeutic intervention.
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Affiliation(s)
- Laura Teodori
- Diagnostic and Metrology Laboratory, TECFIS-FSN, ENEA, Frascati, Italy
| | - Alessandra Costa
- Diagnostic and Metrology Laboratory, TECFIS-FSN, ENEA, Frascati, Italy
| | - Luigi Campanella
- Department of Chemistry, Sapienza University of Rome, Rome, Italy
| | - Maria C Albertini
- Department of Biomolecular Sciences, University of Urbino Carlo Bo, Urbino, Italy
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13
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Mycoplasma hyopneumoniae resides intracellularly within porcine epithelial cells. Sci Rep 2018; 8:17697. [PMID: 30523267 PMCID: PMC6283846 DOI: 10.1038/s41598-018-36054-3] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2018] [Accepted: 11/09/2018] [Indexed: 12/18/2022] Open
Abstract
Enzootic pneumonia incurs major economic losses to pork production globally. The primary pathogen and causative agent, Mycoplasma hyopneumoniae, colonises ciliated epithelium and disrupts mucociliary function predisposing the upper respiratory tract to secondary pathogens. Alleviation of disease is reliant on antibiotics, vaccination, and sound animal husbandry, but none are effective at eliminating M. hyopneumoniae from large production systems. Sustainable pork production systems strive to lower reliance on antibiotics but lack of a detailed understanding of the pathobiology of M. hyopneumoniae has curtailed efforts to develop effective mitigation strategies. M. hyopneumoniae is considered an extracellular pathogen. Here we show that M. hyopneumoniae associates with integrin β1 on the surface of epithelial cells via interactions with surface-bound fibronectin and initiates signalling events that stimulate pathogen uptake into clathrin-coated vesicles (CCVs) and caveosomes. These early events allow M. hyopneumoniae to exploit an intracellular lifestyle by commandeering the endosomal pathway. Specifically, we show: (i) using a modified gentamicin protection assay that approximately 8% of M. hyopneumoniae cells reside intracellularly; (ii) integrin β1 expression specifically co-localises with the deposition of fibronectin precisely where M. hyopneumoniae cells assemble extracellularly; (iii) anti-integrin β1 antibodies block entry of M. hyopneumoniae into porcine cells; and (iv) M. hyopneumoniae survives phagolysosomal fusion, and resides within recycling endosomes that are trafficked to the cell membrane. Our data creates a paradigm shift by challenging the long-held view that M. hyopneumoniae is a strict extracellular pathogen and calls for in vivo studies to determine if M. hyopneumoniae can traffic to extrapulmonary sites in commercially-reared pigs.
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Collapsing glomerulonephritis with podocyte markers in hemophagocytic syndrome secondary to hepatosplenic T-cell lymphoma. BIOMEDICA 2018; 38:456-462. [PMID: 30653858 DOI: 10.7705/biomedica.v38i4.3893] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/02/2017] [Revised: 04/20/2018] [Indexed: 11/21/2022]
Abstract
The hemophagocytic syndrome is a serious clinical-histological entity secondary to different diseases. Collapsing glomerulonephritis is a proliferative podocytopathy that usually has an unfavorable renal prognosis. We present a case in which both entities were associated, which is an infrequent form of hepatosplenic T-cell lymphoma. In addition, we review the role of the markers of podocyte dedifferentiation in this glomerulopathy and its pathophysiology and treatment.
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15
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Zhang W, Xu Y, Chen G, Wang K, Shan W, Chen Y. Dynamic single-vesicle tracking of cell-bound membrane vesicles on resting, activated, and cytoskeleton-disrupted cells. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2018; 1861:26-33. [PMID: 30393161 DOI: 10.1016/j.bbamem.2018.10.013] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/11/2017] [Revised: 10/22/2018] [Accepted: 10/24/2018] [Indexed: 12/13/2022]
Abstract
The composition, structure, production, motion, fate, and functions of cell-bound membrane vesicles pre-existing in the plasma membrane of cells are poorly understood. Here, single-vesicle tracking of individual cell-bound membrane vesicles in the plasma membrane of endothelial cells treated with or without various reagents was performed to investigate the motion of cell-bound membrane vesicles. The efficacy of each of these reagents was confirmed prior to single-vesicle tracking. Via single-vesicle tracking, we found that oxLDL, TNF-α, and VEGFα significantly increased the average number of cell-bound membrane vesicles per cell, implying that cell activation by oxLDL, TNF-α, and VEGFα could trigger the production of cell-bound membrane vesicles. It was also found that oxLDL, TNF-α, VEGFα, LPS, and MβCD but not LDL could significantly affect the motion speed of cell-bound membrane whereas none of them could significantly influence the displacement (moving range) of cell-bound membrane vesicles. The single-vesicle tracking further revealed that the average number of cell-bound membrane vesicles per cell and the mean speed/displacement of individual cell-bound membrane vesicles could be dramatically altered by the cytoskeleton-disrupting reagents (cytochalasin D and nocodazole). The data imply that the production and movement of cell-bound membrane vesicles are probably controlled by intracellular cytoskeletons and capable of being affected by multiple conditions e.g. cell activation, membrane fluidity alteration, and others.
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Affiliation(s)
- Wendiao Zhang
- Nanoscale Science and Technology Laboratory, Institute for Advanced Study, Nanchang University, Nanchang, Jiangxi, PR China; School of Materials Science and Engineering, Nanchang University, Jiangxi 330031, PR China
| | - Ye Xu
- Nanoscale Science and Technology Laboratory, Institute for Advanced Study, Nanchang University, Nanchang, Jiangxi, PR China
| | - Guo Chen
- Nanoscale Science and Technology Laboratory, Institute for Advanced Study, Nanchang University, Nanchang, Jiangxi, PR China
| | - Kun Wang
- Nanoscale Science and Technology Laboratory, Institute for Advanced Study, Nanchang University, Nanchang, Jiangxi, PR China
| | - Wenzhe Shan
- Nanoscale Science and Technology Laboratory, Institute for Advanced Study, Nanchang University, Nanchang, Jiangxi, PR China.
| | - Yong Chen
- Nanoscale Science and Technology Laboratory, Institute for Advanced Study, Nanchang University, Nanchang, Jiangxi, PR China; School of Materials Science and Engineering, Nanchang University, Jiangxi 330031, PR China.
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16
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Van Itallie CM, Tietgens AJ, Aponte A, Gucek M, Cartagena-Rivera AX, Chadwick RS, Anderson JM. MARCKS-related protein regulates cytoskeletal organization at cell-cell and cell-substrate contacts in epithelial cells. J Cell Sci 2018; 131:jcs.210237. [PMID: 29222109 DOI: 10.1242/jcs.210237] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2017] [Accepted: 12/04/2017] [Indexed: 01/14/2023] Open
Abstract
Treatment of epithelial cells with interferon-γ and TNF-α (IFN/TNF) results in increased paracellular permeability. To identify relevant proteins mediating barrier disruption, we performed proximity-dependent biotinylation (BioID) of occludin and found that tagging of MARCKS-related protein (MRP; also known as MARCKSL1) increased ∼20-fold following IFN/TNF administration. GFP-MRP was focused at the lateral cell membrane and its overexpression potentiated the physiological response of the tight junction barrier to cytokines. However, deletion of MRP did not abrogate the cytokine responses, suggesting that MRP is not required in the occludin-dependent IFN/TNF response. Instead, our results reveal a key role for MRP in epithelial cells in control of multiple actin-based structures, likely by regulation of integrin signaling. Changes in focal adhesion organization and basal actin stress fibers in MRP-knockout (KO) cells were reminiscent of those seen in FAK-KO cells. In addition, we found alterations in cell-cell interactions in MRP-KO cells associated with increased junctional tension, suggesting that MRP may play a role in focal adhesion-adherens junction cross talk. Together, our results are consistent with a key role for MRP in cytoskeletal organization of cell contacts in epithelial cells.
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Affiliation(s)
- Christina M Van Itallie
- Laboratory of Tight Junction Structure and Function, National Institutes of Health, Building 50, Room 4525, 50 South Drive, Bethesda, MD 20892, USA
| | - Amber Jean Tietgens
- Laboratory of Tight Junction Structure and Function, National Institutes of Health, Building 50, Room 4525, 50 South Drive, Bethesda, MD 20892, USA
| | - Angel Aponte
- Proteomics Core, National Heart, Lung and Blood Institute, National Institutes of Health, Building 50, Room 4525, 50 South Drive, Bethesda, MD 20892, USA
| | - Marjan Gucek
- Proteomics Core, National Heart, Lung and Blood Institute, National Institutes of Health, Building 50, Room 4525, 50 South Drive, Bethesda, MD 20892, USA
| | - Alexander X Cartagena-Rivera
- Section on Auditory Mechanics, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Building 50, Room 4525, 50 South Drive, Bethesda, MD 20892, USA
| | - Richard S Chadwick
- Section on Auditory Mechanics, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Building 50, Room 4525, 50 South Drive, Bethesda, MD 20892, USA
| | - James M Anderson
- Laboratory of Tight Junction Structure and Function, National Institutes of Health, Building 50, Room 4525, 50 South Drive, Bethesda, MD 20892, USA
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17
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Interaction of CD80 with Neph1: a potential mechanism of podocyte injury. Clin Exp Nephrol 2017; 22:508-516. [PMID: 29022109 DOI: 10.1007/s10157-017-1489-3] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2017] [Accepted: 09/14/2017] [Indexed: 12/27/2022]
Abstract
BACKGROUND The induction of CD80 on podocytes has been shown in animal models of podocyte injury and in certain cases of nephrotic syndrome. In a lipopolysaccharide (LPS)-induced mouse model of albuminuria, we have recently shown a signalling axis of LPS-myeloid cell activation-TNFα production-podocyte CD80 induction-albuminuria. Therefore, in this report, we investigated the cellular and molecular consequences of TNFα addition and CD80 expression on cultured podocytes. METHODS A murine podocyte cell line was used for TNFα treatment and for over-expressing CD80. Expression and localization of various podocyte proteins was analysed by reverse transcriptase-polymerase chain reaction, western blotting and immunofluorescence. HEK293 cells were used to biochemically characterize interactions. RESULTS Podocytes treated with LPS in vitro did not cause CD80 upregulation but TNFα treatment was associated with an increase in CD80 levels, actin derangement and poor wound healing. Podocytes stably expressing CD80 showed actin derangement and co-localization with Neph1. CD80 and Neph1 interaction was confirmed by pull down assays of CD80 and Neph1 transfected in HEK293 cells. CONCLUSION Addition of TNFα to podocytes causes CD80 upregulation, actin reorganization and podocyte injury. Overexpressed CD80 and Neph1 interact via their extracellular domain. This interaction implies a mechanism of slit diaphragm disruption and possible use of small molecules that disrupt CD80-Neph1 interaction as a potential for treatment of nephrotic syndrome associated with CD80 upregulation.
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18
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Inyoo S, Suttitheptumrong A, Pattanakitsakul SN. Synergistic Effect of TNF-α and Dengue Virus Infection on Adhesion Molecule Reorganization in Human Endothelial Cells. Jpn J Infect Dis 2016; 70:186-191. [PMID: 27580574 DOI: 10.7883/yoken.jjid.2016.123] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Dengue hemorrhagic fever/dengue shock syndrome (DHF/DSS) is a severe pathological manifestation of dengue virus (DENV) infection. Enhanced production of cytokines in dengue patients is proposed to induce endothelial barrier instability resulting in increased vascular leakage. Tumor necrosis factor (TNF)-α is an inflammatory cytokine that activates endothelial cells and enhances vascular permeability and plasma leakage in DHF/DSS. The present study investigated the in vitro effect of TNF-α and DENV infection on the expression of adherence junction proteins, tight junction proteins, and membrane integrity of human endothelial cell lines. Immunofluorescence staining and western blot analysis demonstrated platelet endothelial cell adhesion molecule-1 (PECAM-1) reorganization and decreased levels of the tight junction protein occludin in human endothelial cells treated with TNF-α and DENV, compared to mock, DENV, or TNF-α-treated cells. Permeability assessed by FITC-dextran as a transport molecule was increased and correlated with the unusual reorganization of PECAM-1. The altered distribution of PECAM-1 and low occludin protein levels in human endothelial cells treated with TNF-α and DENV correlated with increased permeability. In conclusion, the synergistic effect of TNF-α and DENV induced permeability changes in endothelial cells. These results contribute to the understanding of the mechanisms underlying enhanced vascular permeability in DENV infection.
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Affiliation(s)
- Sivaporn Inyoo
- Division of Molecular Medicine, Office for Research and Development, Faculty of Medicine Siriraj Hospital, Mahidol University
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19
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LeftyA decreases Actin Polymerization and Stiffness in Human Endometrial Cancer Cells. Sci Rep 2016; 6:29370. [PMID: 27404958 PMCID: PMC4941646 DOI: 10.1038/srep29370] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2015] [Accepted: 06/16/2016] [Indexed: 12/27/2022] Open
Abstract
LeftyA, a cytokine regulating stemness and embryonic differentiation, down-regulates cell proliferation and migration. Cell proliferation and motility require actin reorganization, which is under control of ras-related C3 botulinum toxin substrate 1 (Rac1) and p21 protein-activated kinase 1 (PAK1). The present study explored whether LeftyA modifies actin cytoskeleton, shape and stiffness of Ishikawa cells, a well differentiated endometrial carcinoma cell line. The effect of LeftyA on globular over filamentous actin ratio was determined utilizing Western blotting and flow cytometry. Rac1 and PAK1 transcript levels were measured by qRT-PCR as well as active Rac1 and PAK1 by immunoblotting. Cell stiffness (quantified by the elastic modulus), cell surface area and cell volume were studied by atomic force microscopy (AFM). As a result, 2 hours treatment with LeftyA (25 ng/ml) significantly decreased Rac1 and PAK1 transcript levels and activity, depolymerized actin, and decreased cell stiffness, surface area and volume. The effect of LeftyA on actin polymerization was mimicked by pharmacological inhibition of Rac1 and PAK1. In the presence of the Rac1 or PAK1 inhibitor LeftyA did not lead to significant further actin depolymerization. In conclusion, LeftyA leads to disruption of Rac1 and Pak1 activity with subsequent actin depolymerization, cell softening and cell shrinkage.
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20
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Likhitpanichkul M, Torre OM, Gruen J, Walter BA, Hecht AC, Iatridis JC. Do mechanical strain and TNF-α interact to amplify pro-inflammatory cytokine production in human annulus fibrosus cells? J Biomech 2016; 49:1214-1220. [PMID: 26924657 DOI: 10.1016/j.jbiomech.2016.02.029] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2015] [Revised: 02/09/2016] [Accepted: 02/12/2016] [Indexed: 12/20/2022]
Abstract
During intervertebral disc (IVD) injury and degeneration, annulus fibrosus (AF) cells experience large mechanical strains in a pro-inflammatory milieu. We hypothesized that TNF-α, an initiator of IVD inflammation, modifies AF cell mechanobiology via cytoskeletal changes, and interacts with mechanical strain to enhance pro-inflammatory cytokine production. Human AF cells (N=5, Thompson grades 2-4) were stretched uniaxially on collagen-I coated chambers to 0%, 5% (physiological) or 15% (pathologic) strains at 0.5Hz for 24h under hypoxic conditions with or without TNF-α (10ng/mL). AF cells were treated with anti-TNF-α and anti-IL-6. ELISA assessed IL-1β, IL-6, and IL-8 production and immunocytochemistry measured F-actin, vinculin and α-tubulin in AF cells. TNF-α significantly increased AF cell pro-inflammatory cytokine production compared to basal conditions (IL-1β:2.0±1.4-84.0±77.3, IL-6:10.6±9.9-280.9±214.1, IL-8:23.9±26.0-5125.1±4170.8pg/ml for basal and TNF-α treatment, respectively) as expected, but mechanical strain did not. Pathologic strain in combination with TNF-α increased IL-1β, and IL-8 but not IL-6 production of AF cells. TNF-α treatment altered F-actin and α-tubulin in AF cells, suggestive of altered cytoskeletal stiffness. Anti-TNF-α (infliximab) significantly inhibited pro-inflammatory cytokine production while anti-IL-6 (atlizumab) did not. In conclusion, TNF-α altered AF cell mechanobiology with cytoskeletal remodeling that potentially sensitized AF cells to mechanical strain and increased TNF-α-induced pro-inflammatory cytokine production. Results suggest an interaction between TNF-α and mechanical strain and future mechanistic studies are required to validate these observations.
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Affiliation(s)
- Morakot Likhitpanichkul
- Leni and Peter W. May Department of Orthopedics, Icahn School of Medicine at Mount Sinai, Box 1188, New York, NY 10029, United States.
| | - Olivia M Torre
- Leni and Peter W. May Department of Orthopedics, Icahn School of Medicine at Mount Sinai, Box 1188, New York, NY 10029, United States.
| | - Jadry Gruen
- Leni and Peter W. May Department of Orthopedics, Icahn School of Medicine at Mount Sinai, Box 1188, New York, NY 10029, United States.
| | - Benjamin A Walter
- Leni and Peter W. May Department of Orthopedics, Icahn School of Medicine at Mount Sinai, Box 1188, New York, NY 10029, United States; Department of Biomedical Engineering, The City College of New York, New York, NY, United States.
| | - Andrew C Hecht
- Leni and Peter W. May Department of Orthopedics, Icahn School of Medicine at Mount Sinai, Box 1188, New York, NY 10029, United States.
| | - James C Iatridis
- Leni and Peter W. May Department of Orthopedics, Icahn School of Medicine at Mount Sinai, Box 1188, New York, NY 10029, United States.
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Abstract
Podocytes are highly specialized cells of the kidney glomerulus that wrap around capillaries and that neighbor cells of the Bowman’s capsule. When it comes to glomerular filtration, podocytes play an active role in preventing plasma proteins from entering the urinary ultrafiltrate by providing a barrier comprising filtration slits between foot processes, which in aggregate represent a dynamic network of cellular extensions. Foot processes interdigitate with foot processes from adjacent podocytes and form a network of narrow and rather uniform gaps. The fenestrated endothelial cells retain blood cells but permit passage of small solutes and an overlying basement membrane less permeable to macromolecules, in particular to albumin. The cytoskeletal dynamics and structural plasticity of podocytes as well as the signaling between each of these distinct layers are essential for an efficient glomerular filtration and thus for proper renal function. The genetic or acquired impairment of podocytes may lead to foot process effacement (podocyte fusion or retraction), a morphological hallmark of proteinuric renal diseases. Here, we briefly discuss aspects of a contemporary view of podocytes in glomerular filtration, the patterns of structural changes in podocytes associated with common glomerular diseases, and the current state of basic and clinical research.
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Affiliation(s)
- Jochen Reiser
- Department of Medicine, Rush University Medical Center, Chicago, IL, USA
| | - Mehmet M Altintas
- Department of Medicine, Rush University Medical Center, Chicago, IL, USA
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22
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Oliveira KC, Carvalho MLP, Bonatto JMC, Schechtman D, Verjovski-Almeida S. Human TNF-α induces differential protein phosphorylation in Schistosoma mansoni adult male worms. Parasitol Res 2015; 115:817-28. [PMID: 26547565 DOI: 10.1007/s00436-015-4812-5] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2015] [Accepted: 11/02/2015] [Indexed: 01/12/2023]
Abstract
Schistosoma mansoni and its vertebrate host have a complex and intimate connection in which several molecular stimuli are exchanged and affect both organisms. Human tumor necrosis factor alpha (hTNF-α), a pro-inflammatory cytokine, is known to induce large-scale gene expression changes in the parasite and to affect several parasite biological processes such as metabolism, egg laying, and worm development. Until now, the molecular mechanisms for TNF-α activity in worms are not completely understood. Here, we aimed at exploring the effect of hTNF-α on S. mansoni protein phosphorylation by 2D gel electrophoresis followed by a quantitative analysis of phosphoprotein staining and protein identification by mass spectrometry. We analyzed three biological replicates of adult male worms exposed to hTNF-α and successfully identified 32 protein spots with a statistically significant increase in phosphorylation upon in vitro exposure to hTNF-α. Among the differentially phosphorylated proteins, we found proteins involved in metabolism, such as glycolysis, galactose metabolism, urea cycle, and aldehyde metabolism, as well as proteins related to muscle contraction and to cytoskeleton remodeling. The most differentially phosphorylated protein (30-fold increase in phosphorylation) was 14-3-3, whose function is known to be modulated by phosphorylation, belonging to a signal transduction protein family that regulates a variety of processes in all eukaryotic cells. Further, 75% of the identified proteins are known in mammals to be related to TNF-α signaling, thus suggesting that TNF-α response may be conserved in the parasite. We propose that this work opens new perspectives to be explored in the study of the molecular crosstalk between host and pathogen.
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Affiliation(s)
- Katia C Oliveira
- Núcleo de Enteroparasitas, Centro de Parasitologia e Micologia, Instituto Adolfo Lutz, 01614-000, São Paulo, SP, Brazil.,Disciplina de Parasitologia, Departamento de Microbiologia, Imunologia e Parasitologia, Universidade Federal de São Paulo, São Paulo, Brazil
| | - Mariana L P Carvalho
- Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, 05508-900, São Paulo, SP, Brazil
| | - José Matheus C Bonatto
- Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, 05508-900, São Paulo, SP, Brazil
| | - Debora Schechtman
- Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, 05508-900, São Paulo, SP, Brazil
| | - Sergio Verjovski-Almeida
- Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, 05508-900, São Paulo, SP, Brazil. .,Instituto Butantan, 05503-900, São Paulo, SP, Brazil.
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Ford AJ, Jain G, Rajagopalan P. Designing a fibrotic microenvironment to investigate changes in human liver sinusoidal endothelial cell function. Acta Biomater 2015; 24:220-7. [PMID: 26117313 DOI: 10.1016/j.actbio.2015.06.028] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2014] [Revised: 06/08/2015] [Accepted: 06/23/2015] [Indexed: 02/08/2023]
Abstract
The deposition of extracellular matrix (ECM) proteins by hepatic cells during fibrosis leads to the stiffening of the organ and perturbed cellular functions. Changes in the elasticity of liver tissue are manifested by altered phenotype in hepatic cells. We have investigated changes in human liver sinusoidal endothelial cells (hLSECs) that occur as the elastic modulus of their matrix transitions from healthy (6kPa) to fibrotic (36kPa) conditions. We have also investigated the role played by Kupffer cells in the dedifferentiation of hLSECs. We report the complete loss of fenestrae and the expression of CD31 at the surface as a result of increasing elastic moduli. LSECs exhibited a greater number of actin stress fibers and vinculin focal adhesion on the stiffer substrate, as well. A novel finding is that these identical trends can be obtained on soft (6kPa) substrates by introducing an inflamed microenvironment through the addition of Kupffer cells. hLSEC monocultures on 6kPa gels exhibited fenestrae that were 140.7±52.6nm in diameter as well as a lack of surface CD31 expression. Co-culturing hLSECs with rat Kupffer cells (rKCs) on 6kPa substrates, resulted in the complete loss of fenestrae, an increase in CD31 expression and in a well-organized cytoskeleton. These results demonstrate that the increasing stiffness of liver matrices does not solely result in changes in hLSEC phenotype. Even on soft substrates, culturing hLSECs in an inflamed microenvironment can result in their dedifferentiation. Our findings demonstrate the interplay between matrix elasticity and inflammation in the progression of hepatic fibrosis.
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Esmaili H, Mostafidi E, Mehramuz B, Ardalan M, Mohajel-Shoja M. An update on renal involvement in hemophagocytic syndrome (macrophage activation syndrome). J Nephropathol 2015; 5:8-14. [PMID: 27047804 PMCID: PMC4790190 DOI: 10.15171/jnp.2016.02] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2015] [Accepted: 07/03/2015] [Indexed: 12/16/2022] Open
Abstract
Context: Hemophagocytic syndrome (HPS) is mainly characterized by massive infiltration of bone marrow by activated macrophages and often presents with pancytopenia. Thrombotic microangiopathy (TMA) is also present with thrombocytopenia and renal involvement. Both conditions could coexist with each other and complicate the condition.
Evidence Acquisition: Directory of Open Access Journals (DOAJ), EMBASE, Google Scholar, PubMed, EBSCO, and Web of Science with keywords relevant to; Hemophagocytic syndrome, macrophage activation syndrome, interferon-gamma and thrombotic microangiopathy, have been searched.
Results: Viral infection, rheumatologic disease and malignancies are the main underlying causes for secondary HPS. calcineurin inhibitors and viral infections are also the main underlying causes of TMA in transplant recipients. In this review, we discussed a 39-year-old male who presented with pancytopenia and renal allograft dysfunction. With the diagnosis of HPS induced TMA his renal condition and pancytopenia improved after receiving intravenous immunoglobulin (IVIG) and plasmapheresis therapy.
Conclusions: HPS is an increasingly recognized disorder in the realm of different medical specialties. Renal involvement complicates the clinical picture of the disease, and this condition even is more complex in renal transplant recipients. We should consider the possibility of HPS in any renal transplant recipient with pancytopenia and allograft dysfunction. The combination of HPS with TMA future increases the complexity of the situation.
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Affiliation(s)
- Haydarali Esmaili
- Department of Pathology, Al-Zahra Hospital, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Elmira Mostafidi
- Department of Pathology, Al-Zahra Hospital, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Bahareh Mehramuz
- Department of Pathology, Al-Zahra Hospital, Tabriz University of Medical Sciences, Tabriz, Iran
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Barutta F, Bruno G, Grimaldi S, Gruden G. Inflammation in diabetic nephropathy: moving toward clinical biomarkers and targets for treatment. Endocrine 2015; 48:730-42. [PMID: 25273317 DOI: 10.1007/s12020-014-0437-1] [Citation(s) in RCA: 88] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/16/2014] [Accepted: 09/21/2014] [Indexed: 12/13/2022]
Abstract
Diabetic nephropathy (DN) is a leading cause of end stage renal failure and there is an urgent need to identify new clinical biomarkers and targets for treatment to effectively prevent and slow the progression of the complication. Many lines of evidence show that inflammation is a cardinal pathogenetic mechanism in DN. Studies in animal models of experimental diabetes have demonstrated that there is a low-grade inflammation in the diabetic kidney. Both pharmacological and genetic strategies targeting inflammatory molecules have been shown to be beneficial in experimental DN. In vitro studies have cast light on the cellular mechanisms whereby diabetes triggers inflammation and in turn inflammation magnifies the kidney injury. Translation of this basic science knowledge into potential practical clinical applications is matter of great interest for researchers today. This review focuses on key pro-inflammatory systems implicated in the development of DN: the tumor necrosis factor(TNF)-α/TNF-α receptor system, the monocyte chemoattractant protein-1/CC-chemokine receptor-2 system, and the Endocannabinoid system that have been selected as they appear particularly promising for future clinical applications.
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Affiliation(s)
- Federica Barutta
- Department of Medical Sciences, University of Turin, C/so AM Dogliotti 14, Turin, Italy
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26
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Gu S, Kounenidakis M, Schmidt EM, Deshpande D, Alkahtani S, Alarifi S, Föller M, Alevizopoulos K, Lang F, Stournaras C. Rapid activation of FAK/mTOR/p70S6K/PAK1-signaling controls the early testosterone-induced actin reorganization in colon cancer cells. Cell Signal 2013; 25:66-73. [DOI: 10.1016/j.cellsig.2012.08.005] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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27
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TNFα pathway blockade ameliorates toxic effects of FSGS plasma on podocyte cytoskeleton and β3 integrin activation. Pediatr Nephrol 2012; 27:2217-26. [PMID: 22538781 DOI: 10.1007/s00467-012-2163-3] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/12/2012] [Revised: 03/06/2012] [Accepted: 03/07/2012] [Indexed: 12/17/2022]
Abstract
BACKGROUND In the absence of mutant genes encoding components of the podocyte slit diaphragm, about 30-50 % of children with primary glucocorticoid-resistant focal segmental glomerulosclerosis (FSGS) develop recurrent proteinuria and slowly progressive FSGS lesions following renal transplantation. Recurrence of FSGS in the allograft strongly suggests a circulating factor that disturbs normal podocyte biology. To date, the nature of the circulating factor is unclear, and there is no cure for the recurrent form of FSGS (R-FSGS). METHODS Cultured differentiated human podocytes were exposed to the plasmapheresis effluent or blood plasma samples from pediatric patients with recurrent or primary FSGS; in some cases, podocytes were pre-incubated with specific antibodies to block the tumor necrosis factor-alpha (TNFα) signaling pathway. Integrity of focal adhesion complexes and actin cytoskeleton were investigated by immunofluorescent microscopy. RESULTS Plasmapheresis effluent from an R-FSGS child or fresh plasma from two children with primary FSGS rapidly disturbed the cytoskeleton of normal human podocytes in vitro. Plasma from a child with R-FSGS also activated β3 integrin and dispersed focal adhesion complexes. The effects were reversed by pre-incubation with antibodies against TNFα or either of the two TNFα receptors. When our patient with R-FSGS became resistant to plasmapheresis, we initiated treatment with twice weekly etanercept injections and then infliximab. Within 3 weeks of regular anti-TNFα therapy, the patient achieved sustained partial remission of proteinuria, allowing us to wean her off plasmapheresis completely. CONCLUSIONS We suggest that in some FSGS patients, disruption of the podocyte cytoskeleton and β3 integrin-mediated podocyte attachment are driven by the TNFα pathway.
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Koya M, Pichler R, Jefferson JA. Minimal-change disease secondary to etanercept. Clin Kidney J 2012; 5:420-3. [PMID: 26019819 PMCID: PMC4432405 DOI: 10.1093/ckj/sfs081] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2012] [Accepted: 06/18/2012] [Indexed: 01/15/2023] Open
Abstract
Etanercept is a soluble tumor necrosis factor alpha (TNFα) receptor which is widely used in the treatment of rheumatoid arthritis, psoriasis and other autoimmune inflammatory disorders. It is known for its relative lack of nephrotoxicity; however, there are reports on the development of nephrotic syndrome associated with the treatment with TNFα antagonists. Here, we describe a patient with psoriasis who developed biopsy-proven minimal-change disease (MCD) shortly after initiating etanercept. Our case is unique in that the MCD resolved after discontinuation of this medication, notably without the use of corticosteroids, strongly suggesting a drug-related phenomenon.
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Affiliation(s)
- Mariko Koya
- Department of Internal Medicine , University of Washington , Seattle, WA , USA
| | - Raimund Pichler
- Department of Nephrology , University of Washington , Seattle, WA , USA
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Saito M, Katsuno T, Nakagawa T, Sato T, Noguchi Y, Sazuka S, Saito K, Arai M, Yokote K, Yokosuka O. Intestinal epithelial cells with impaired autophagy lose their adhesive capacity in the presence of TNF-α. Dig Dis Sci 2012; 57:2022-30. [PMID: 22466076 DOI: 10.1007/s10620-012-2133-4] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/01/2011] [Accepted: 03/02/2012] [Indexed: 12/19/2022]
Abstract
BACKGROUND AND OBJECTIVES Genome-wide association studies have revealed a link between autophagy-related (ATG) genes and susceptibility to Crohn's disease. This suggests underlying involvement of autophagy impairment in the pathogenesis of Crohn's disease. This study was performed to investigate the pathophysiological importance of autophagy impairment in intestinal epithelial cells exposed to TNF-α. METHODS Human colonic epithelial cells (HT-29) and rat small intestinal epithelial cells (IEC-18) were used. Formation of phosphatidylethanolamine-conjugated microtubule-associated protein light chain 3 (LC3-II) was monitored as a marker of autophagy. Autophagy was inhibited using 3-methyladenine or short interfering RNA targeting ATG5 and ATG16L1. RESULTS TNF-α treatment elicited a significant dose-dependent increase in LC3-II protein levels, thus autophagy is induced in the presence of TNF-α. Combined autophagy inhibition and TNF-α treatment induced a marked increase in the number of detached cells and a decrease in activated integrin β1 protein levels. Trypan blue staining indicated 70-80 % of the detached cells were alive, suggesting that these cells became detached not because they were killed but because of dysfunction of cellular adhesion. CONCLUSIONS This is the first study indicating that intestinal epithelial cells with impaired autophagy lose their adhesive capacity in the presence of TNF-α. These observations indicate that impairment of autophagy leads to disruption of the intestinal epithelial cell layers in TNF-α-rich environments.
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Affiliation(s)
- Masaya Saito
- Department of Medicine and Clinical Oncology (K1), Graduate School of Medicine, Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba-shi 260-8670, Japan
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Contreras-Ruiz L, Schulze U, García-Posadas L, Arranz-Valsero I, López-García A, Paulsen F, Diebold Y. Structural and functional alteration of corneal epithelial barrier under inflammatory conditions. Curr Eye Res 2012; 37:971-81. [PMID: 22738643 DOI: 10.3109/02713683.2012.700756] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
PURPOSE The aim of the study was to determine the effect of inflammatory conditions on the expression of tight junction (TJ) and adherens junction (AJ) proteins between human corneal epithelial cells and, consequently, on corneal epithelial barrier integrity. MATERIALS AND METHODS Zonula occludens proteins ZO-1 and ZO-2, claudin-1 and -2 (CLDN-1 and CLDN-2), occludin (OCLN) as well as E-cadherin (E-cad) expression were analyzed in a human corneal epithelial cell line (HCE) at basal conditions and after stimulation with inflammatory cytokines (TNFα, TGFβ, IL-10, IL-13, IL-17, IL-6), using real time RT-PCR, Western blotting and immunofluorescence. Actin cytoskeleton staining was performed after all stimulations. Transepithelial electrical resistance (TER) and fluorescein transepithelial permeability (TEP) were measured as barrier integrity functional assays. RESULTS ZO-1, ZO-2, CLDN-1, CLDN-2, OCLN and E-cad were detected in HCE cell membranes at basal conditions. Cytokine stimulation resulted in significant changes in the expression of TJ and AJ proteins, both at mRNA and protein level, a remarkable change in their localization pattern, as well as a reorganization of actin cytoskeleton. Pro-inflammatory cytokines TNFα, TGFβ, IL-13, IL-17 and IL-6 induced a structural and functional disruption of the epithelial barrier, while IL-10 showed a barrier protective effect. CONCLUSION Simulated inflammatory conditions lead to an alteration of corneal barrier integrity by modulating TJ, and to a lesser extent also AJ, protein composition, at least In Vitro. The observed barrier protective effects of IL-10 support its well-known anti-inflammatory functions and highlight a potential therapeutic perspective.
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Ranzinger J, Rustom A, Abel M, Leyh J, Kihm L, Witkowski M, Scheurich P, Zeier M, Schwenger V. Nanotube action between human mesothelial cells reveals novel aspects of inflammatory responses. PLoS One 2011; 6:e29537. [PMID: 22216308 PMCID: PMC3246504 DOI: 10.1371/journal.pone.0029537] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2011] [Accepted: 11/30/2011] [Indexed: 12/12/2022] Open
Abstract
A well-known role of human peritoneal mesothelial cells (HPMCs), the resident cells of the peritoneal cavity, is the generation of an immune response during peritonitis by activation of T-cells via antigen presentation. Recent findings have shown that intercellular nanotubes (NTs) mediate functional connectivity between various cell types including immune cells - such as T-cells, natural killer (NK) cells or macrophages - by facilitating a spectrum of long range cell-cell interactions. Although of medical interest, the relevance of NT-related findings for human medical conditions and treatment, e.g. in relation to inflammatory processes, remains elusive, particularly due to a lack of appropriate in vivo data. Here, we show for the first time that primary cultures of patient derived HPMCs are functionally connected via membranous nanotubes. NT formation appears to be actin cytoskeleton dependent, mediated by the action of filopodia. Importantly, significant variances in NT numbers between different donors as a consequence of pathophysiological alterations were observable. Furthermore, we show that TNF-α induces nanotube formation and demonstrate a strong correlation of NT connectivity in accordance with the cellular cholesterol level and distribution, pointing to a complex involvement of NTs in inflammatory processes with potential impact for clinical treatment.
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Affiliation(s)
- Julia Ranzinger
- Department of Nephrology, University of Heidelberg, Heidelberg, Germany.
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Gordon J, Kopp JB. Off the beaten renin-angiotensin-aldosterone system pathway: new perspectives on antiproteinuric therapy. Adv Chronic Kidney Dis 2011; 18:300-11. [PMID: 21782136 DOI: 10.1053/j.ackd.2011.06.002] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2011] [Revised: 05/31/2011] [Accepted: 06/01/2011] [Indexed: 01/23/2023]
Abstract
CKD is a major public health problem in the developed and the developing world. The degree of proteinuria associated with renal failure is a generally well accepted marker of disease severity. Agents with direct antiproteinuric effects are highly desirable therapeutic strategies for slowing, or even halting, progressive loss of kidney function. We review progress on therapies acting further downstream of the renin-angiotensin-aldosterone system pathway (e.g., transforming growth factor-beta antagonism, endothelin antagonism) and on those acting independent of the renin-angiotensin-aldosterone system pathway. In all, we discuss 26 therapeutic targets or compounds and 2 lifestyle changes (dietary modification and weight loss) that have been used clinically for diabetic or nondiabetic kidney disease. These therapies include endogenous molecules (estrogens, isotretinoin), biologic antagonists (monoclonal antibodies, soluble receptors), and small molecules. Where mechanistic data are available, these therapies have been shown to exert favorable effects on glomerular cell phenotype. In some cases, recent work has indicated surprising new molecular pathways for some therapies, such as direct effects on the podocyte by glucocorticoids, rituximab, and erythropoietin. It is hoped that recent advances in the basic science of kidney injury will prompt development of more effective pharmaceutical and biologic therapies for proteinuria.
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Abstract
The development of proliferative podocytopathies has been linked to ligation of tumor necrosis factor receptor 2 (TNFR2) expressed on the renal parenchyma; however, the TNFR2-positive cells within the kidney responsible for podocyte injury are unknown. We detected de novo expression of TNFR2 on podocytes before hyperplastic injury in crescentic glomerulonephritis of mice with nephrotoxic nephritis, and in collapsing glomerulopathy of Tg26(HIV/nl) mice, kd/kd mice, and human beings. We further found that serum levels of soluble TNF-α and TNFR2 correlated significantly with renal injury in Tg26(HIV/nl) mice. Thus, we asked whether ligand binding of TNFR2 on podocytes ex vivo precipitates the characteristic proliferative and pro-inflammatory diseased podocyte phenotypes. Soluble TNF-α activated NF-κB and dose-dependently induced podocyte proliferation, marked by the expression of the podocyte G(1) cyclin and NF-κB target gene, cyclin D1. Microarray gene and chemokine protein expression profiling showed a marked pro-inflammatory NF-κB signature, and activated podocytes secreting CCL2- and CCL5-induced macrophage migration in transwell assays. Neutralization of TNFR2 on podocytes with blocking antibodies abrogated NF-κB activation and the induction of cyclin D1 by TNF-α, and identified TNFR2 as the primary receptor that induced IκBα degradation, the initiating event in NF-κB activation. These results suggest that TNFR2 expressed on podocytes and its canonical NF-κB signaling may directly interpose the compound pathogenic responses by podocytes to TNF-α, in the absence of other TNFR2-positive renal cell types in proliferative podocytopathies.
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Inhibition of GGTase-I and FTase disrupts cytoskeletal organization of human PC-3 prostate cancer cells. Cell Biol Int 2010; 34:815-26. [PMID: 20446922 DOI: 10.1042/cbi20090288] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
The mevalonate synthesis pathway produces intermediates for isoprenylation of small GTPases, which are involved in the regulation of actin cytoskeleton and cell motility. Here, we investigated the role of the prenylation transferases in the regulation of the cytoskeletal organization and motility of PC-3 prostate cancer cells. This was done by using FTI-277, GGTI-298 or NE-10790, the specific inhibitors of FTase (farnesyltransferase), GGTase (geranylgeranyltransferase)-I and -II, respectively. Treatment of PC-3 cells with GGTI-298 and FTI-277 inhibited migration and invasion in a time- and dose-dependent manner. This was associated with disruption of F-actin organization and decreased recovery of GFP-actin. Immunoblot analysis of various cytoskeleton-associated proteins showed that the most striking change in GGTI-298- and FTI-277-treated cells was a markedly decreased level of total and phosphorylated cofilin, whereas the level of cofilin mRNA was not decreased. The treatment of PC-3 cells with GGTI-298 also affected the dynamics of GFP-paxillin and decreased the levels of total and phosphorylated paxillin. The levels of phosphorylated FAK (focal adhesion kinase) and PAK (p-21-associated kinase)-2 were also lowered by GGTI-298, but levels of paxillin or FAK mRNAs were not affected. In addition, GGTI-298 had a minor effect on the activity of MMP-9. RNAi knockdown of GGTase-Ibeta inhibited invasion, disrupted F-actin organization and decreased the level of cofilin in PC-3 cells. NE-10790 did not have any effect on PC-3 prostate cancer cell motility or on the organization of the cytoskeleton. In conclusion, our results demonstrate the involvement of GGTase-I- and FTase-catalysed prenylation reactions in the regulation of cytoskeletal integrity and motility of prostate cancer cells and suggest them as interesting drug targets for development of inhibitors of prostate cancer metastasis.
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Kim DM, Chung KS, Choi SJ, Jung YJ, Park SK, Han GH, Ha JS, Song KB, Choi NS, Kim HM, Won M, Seo YS. RhoB induces apoptosis via direct interaction with TNFAIP1 in HeLa cells. Int J Cancer 2009; 125:2520-7. [PMID: 19637314 DOI: 10.1002/ijc.24617] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
RhoB, a tumor suppressor, has emerged as an interesting cancer target, and extensive studies aimed at understanding its role in apoptosis have been performed. In our study, we investigated the involvement of RhoB-interacting molecules in apoptosis. To identify RhoB-interacting proteins, we performed yeast-two hybrid screening assays using RhoB as a bait and isolated TNFAIP1, a TNFalpha-induced protein containing the BTB/POZ domain. The interaction between RhoB and TNFAIP1 was demonstrated in vivo through coimmunoprecipitation studies and in vitro binding assays. RFP-TNFAIP1 was found to be partially colocalized with EGFP-RhoB. The partial colocalization of RhoB and TNFAIP1 in endosomes suggests that RhoB-TNFAIP1 interactions may have a functional role in apoptosis. TNFAIP1 elicited proapoptotic activity, while simultaneous expression of RhoB and TNFAIP1 resulted in a dramatic increase in apoptosis in HeLa cells. Furthermore, knockdown of RhoB using siRNA clearly rescued cells from apoptosis induced by TNFAIP1. This finding suggests that interactions between RhoB and TNFAIP1 are crucial for induction of apoptosis in HeLa cells. The observation of increased SAPK/JNK phosphorylation in apoptotic cells and the finding that a JNK inhibitor suppressed apoptosis indicates that SAPK/JNK signaling may be involved in apoptosis induced by RhoB-TNFAIP1 interactions. In conclusion, we found that RhoB interacts with TNFAIP1 to regulate apoptosis via a SAPK/JNK-mediated signal transduction mechanism.
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Affiliation(s)
- Dong-Myung Kim
- Department of Biological Science, KAIST, Daejeon 305-701, Korea
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Abstract
Remarkable advances have been made in the past decade in understanding the pathophysiology of idiopathic nephrotic syndrome. Although the initiating events leading to the onset of proteinuria still are not well defined, it has become increasingly clear that many glomerular diseases can be classified as podocytopathies, with injury to the podocyte playing a major role in the development and progression of disease. A complex interaction of immune system mediators, slit diaphragm signal transduction, podocyte injury and conformational change, and mediators of apoptosis and fibrosis determine the extent and nature of proteinuria and progression of glomerulosclerosis. New insights into the pathogenesis of idiopathic nephrotic syndrome likely will lead to innovative therapies and new approaches to management and prevention.
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Mathew SJ, Haubert D, Krönke M, Leptin M. Looking beyond death: a morphogenetic role for the TNF signalling pathway. J Cell Sci 2009; 122:1939-46. [PMID: 19494121 DOI: 10.1242/jcs.044487] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Tumour necrosis factor alpha (TNFalpha) is a pro-inflammatory mediator with the capacity to induce apoptosis. An integral part of its apoptotic and inflammatory programmes is the control of cell shape through modulation of the cytoskeleton, but it is now becoming apparent that this morphogenetic function of TNF signalling is also employed outside inflammatory responses and is shared by the signalling pathways of other members of the TNF-receptor superfamily. Some proteins that are homologous to the components of the TNF signalling pathway, such as the adaptor TNF-receptor-associated factor 4 and the ectodysplasin A receptor (and its ligand and adaptors), have dedicated morphogenetic roles. The mechanism by which TNF signalling affects cell shape is not yet fully understood, but Rho-family GTPases have a central role. The fact that the components of the TNF signalling pathway are evolutionarily old suggests that an ancestral cassette from unicellular organisms has diversified its functions into partly overlapping morphogenetic, inflammatory and apoptotic roles in multicellular higher organisms.
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Affiliation(s)
- Sam J Mathew
- Institute for Genetics, University of Cologne, Zülpicher Strasse 47, D-50674 Köln, Germany
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Abstract
Hemophagocytic syndrome (HPs) is a rare but distinct condition caused by inappropriate and dysregulated activation of the immune system. HPs is characterized by febrile hepatosplenomegaly, pancytopenia, hypofibrinemia and liver dysfunction; these changes are associated with the infiltration of bone marrow and organs by nonmalignant macrophages that phagocytose blood cells. Primary HPs is linked to inherited immune dysregulation, whereas secondary HPs tends to be triggered by an infectious or neoplastic disease. Multiorgan failure can complicate this life-threatening condition and renal involvement has frequently been reported; however, precise descriptions of the renal manifestations of HPs are lacking. Acute kidney injury due to tubular necrosis is the most common renal presentation, but nephrotic syndrome can also occur. HPs can be observed in immunocompromised patients and nephrologists must be aware that this condition can occur in renal transplant recipients. Mortality in patients with HPs can be as high as 50%. Despite considerable advances in the treatment of familial HPs, no specific therapy has demonstrated a consistent capacity to control reactive HPs when combined with suppression of the triggering factor. This review summarizes the presentation, causes, pathophysiology and renal features of HPs for the benefit of the practicing nephrologist.
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Ikezumi Y, Suzuki T, Karasawa T, Kawachi H, Nikolic-Paterson DJ, Uchiyama M. Activated macrophages down-regulate podocyte nephrin and podocin expression via stress-activated protein kinases. Biochem Biophys Res Commun 2008; 376:706-11. [PMID: 18809387 DOI: 10.1016/j.bbrc.2008.09.049] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2008] [Accepted: 09/11/2008] [Indexed: 10/25/2022]
Abstract
The development of proteinuria and glomerulosclerosis in kidney disease is associated with podocyte damage, including down-regulation of nephrin and podocin. Macrophages are known to induce renal injury, but the mechanisms involved are not fully understood. This study examined macrophage-mediated podocyte damage. Conditioned media (CM) from activated macrophages caused a 50-60% reduction in nephrin and podocin mRNA and protein expression in cultured mouse podocytes and rat glomeruli. This was abolished by a neutralizing anti-TNFalpha antibody. The addition of recombinant TNFalpha to podocytes or glomeruli caused a comparable reduction in podocyte nephrin and podocin expression to that of macrophage CM. Inhibition of c-Jun amino terminal kinase (JNK) or p38 kinase abolished the TNFalpha-induced reduction in nephrin and podocin expression. This study demonstrates that activated macrophages can induce podocyte injury via a TNFalpha-JNK/p38-dependent mechanism. This may explain, in part, the protective effects of JNK and p38 blockade in experimental kidney disease.
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Affiliation(s)
- Yohei Ikezumi
- Department of Pediatrics, Niigata University Medical and Dental Hospital, 1-757 Asahimachi-dori, Chuo-ku, Asahimachi-dori, Niigata 951-8510, Japan.
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40
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Papakonstanti EA, Stournaras C. Cell responses regulated by early reorganization of actin cytoskeleton. FEBS Lett 2008; 582:2120-7. [PMID: 18325339 DOI: 10.1016/j.febslet.2008.02.064] [Citation(s) in RCA: 114] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2008] [Accepted: 02/21/2008] [Indexed: 01/20/2023]
Abstract
Microfilaments exist in a dynamic equilibrium between monomeric and polymerized actin and the ratio of monomers to polymeric forms is influenced by a variety of extracellular stimuli. The polymerization, depolymerization and redistribution of actin filaments are modulated by several actin-binding proteins, which are regulated by upstream signalling molecules. Actin cytoskeleton is involved in diverse cellular functions including migration, ion channels activity, secretion, apoptosis and cell survival. In this review we have outlined the role of actin dynamics in representative cell functions induced by the early response to extracellular stimuli.
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Affiliation(s)
- E A Papakonstanti
- Department of Biochemistry, Medical School, University of Crete, GR-71110, Heraklion-Voutes, Greece.
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Treede I, Braun A, Sparla R, Kühnel M, Giese T, Turner JR, Anes E, Kulaksiz H, Füllekrug J, Stremmel W, Griffiths G, Ehehalt R. Anti-inflammatory effects of phosphatidylcholine. J Biol Chem 2007; 282:27155-27164. [PMID: 17636253 PMCID: PMC2693065 DOI: 10.1074/jbc.m704408200] [Citation(s) in RCA: 202] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
We recently showed that mucus from patients with ulcerative colitis, a chronic inflammatory disorder of the colon, is characterized by a low level of phosphatidylcholine (PC) while clinical studies reveal that therapeutic addition of PC using slow release preparations is beneficial. The positive role of PC in this disease is still elusive. Here we tested the hypothesis that exogenous application of PC has anti-inflammatory properties using three model systems. First, human Caco-2 cells were treated with tumor necrosis factor-alpha (TNF-alpha) to induce a pro-inflammatory response via activation of NF-kappaB. Second, latex bead phagosomes were analyzed for their ability to assemble actin in vitro, a process linked to pro-inflammatory signaling and correlating with the growth versus killing of mycobacteria in macrophages. The third system used was the rapid assembly of plasma membrane actin in macrophages in response to sphingosine 1-phosphate. TNF-alpha induced a pro-inflammatory response in Caco-2 cells, including 1) assembly of plasma membrane actin; 2) activation of both MAPKs ERK and p38; 3) transport of NF-kappaB subunits to the nucleus; and 4) subsequent up-regulation of the synthesis of pro-inflammatory gene products. Exogenous addition of most PCs tested significantly inhibited these processes. Other phospholipids like sphingomyelin or phosphatidylethanolamine showed no effects in these assays. PC also inhibited latex bead phagosome actin assembly, the killing of Mycobacterium tuberculosis in macrophages, and the sphingosine 1-phosphate-induced actin assembly in macrophages. TNF-alpha induces the activation of signaling molecules and the reorganization of the actin cytoskeleton in human intestinal cells. Exogenous application of PC blocks pro-inflammatory signaling in Caco-2 cells, in phagosomes in vitro and facilitates intracellular survival of mycobacteria. We provide further evidence that actin assembly by membranes is part of the pro-inflammatory response. Collectively, these results provide a molecular foundation for the clinical studies showing a beneficial effect of PC therapy in ulcerative colitis.
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Affiliation(s)
- Irina Treede
- Department of Gastroenterology, University Hospital Heidelberg, INF 345, Heidelberg 69120, Germany, the; Cell Biology Program, European Molecular Biology Laboratory, Postfach 102209, Heidelberg 69117, Germany, the
| | - Annika Braun
- Department of Gastroenterology, University Hospital Heidelberg, INF 345, Heidelberg 69120, Germany, the
| | - Richard Sparla
- Department of Gastroenterology, University Hospital Heidelberg, INF 345, Heidelberg 69120, Germany, the
| | - Mark Kühnel
- Cell Biology Program, European Molecular Biology Laboratory, Postfach 102209, Heidelberg 69117, Germany, the
| | - Thomas Giese
- Institute of Immunology, University of Heidelberg, Im Neuenheimer Feld 305, Heidelberg 69120, Germany, the
| | - Jerrold R Turner
- Department of Pathology, University of Chicago, MC-1089, 60637 Chicago, Illinois
| | - Elsa Anes
- Unidade dos Retrovirus e Infeccdoas Associades(URIA)-Molecular Pathogenesis Centre, Faculty of Pharmacy, University of Lisbon, av. das Forcas Armadas, Lisbon 1600-083, Portugal, and the
| | - Hasan Kulaksiz
- Department of Gastroenterology, University Hospital Heidelberg, INF 345, Heidelberg 69120, Germany, the
| | - Joachim Füllekrug
- Department of Gastroenterology, University Hospital Heidelberg, INF 345, Heidelberg 69120, Germany, the
| | - Wolfgang Stremmel
- Department of Gastroenterology, University Hospital Heidelberg, INF 345, Heidelberg 69120, Germany, the
| | - Gareth Griffiths
- Cell Biology Program, European Molecular Biology Laboratory, Postfach 102209, Heidelberg 69117, Germany, the
| | - Robert Ehehalt
- Department of Gastroenterology, University Hospital Heidelberg, INF 345, Heidelberg 69120, Germany, the.
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Kallergi G, Mavroudis D, Georgoulias V, Stournaras C. Phosphorylation of FAK, PI-3K, and impaired actin organization in CK-positive micrometastatic breast cancer cells. Mol Med 2007; 13:79-88. [PMID: 17515959 PMCID: PMC1869618 DOI: 10.2119/2006-00083.kallergi] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2006] [Accepted: 12/12/2006] [Indexed: 12/12/2022] Open
Abstract
Several markers have been used to detect circulating tumor cells (CTC) in the peripheral blood of patients with breast cancer. However, analysis of activated signaling kinases in CTC implicated in cellular transformation, migration, and survival has not been addressed so far. In the present study, we focused on the phenotypic profile of micrometastatic cells in peripheral blood mononuclear cells (PBMC) preparations from 45 breast cancer patients. PBMC cytospins from 28 cytokeratin (CK)-positive and 17 CK-negative samples were assessed for the expression of phosphorylated FAK (p-FAK), phosphorylated PI-3 kinase (p-PI-3K), and HER2 using confocal laser scanning microscopy. The expression of p-FAK was documented in all 28 CK-positive samples, while all 17 CK-negative samples were tested negative for p-FAK. Immunomagnetic separation using EpCAM antibody fully confirmed these findings, implying a sound correlation for the co-expression of the two molecules. Interestingly, 15 of 28 CK- and p-FAK-positive samples also expressed the HER2 oncoprotein. p-PI-3K was documented in 15 of 17 CK- and p-FAK-positive samples. Immunoblot analysis of micrometastatic cells in co-culture with PBMC confirmed the specific expression of both p-FAK and p-PI-3K. Finally, impaired actin organization was apparent in CK- and p-FAK/p-PI-3K-positive samples, comparable to that observed in MCF-7 human breast cancer cells. Our findings provide strong evidence that micrometastatic cells express activated signaling kinases, which may regulate migration mechanisms, supporting the presumption of their malignant and metastatic nature.
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Affiliation(s)
- Galatea Kallergi
- Department of Biochemistry, University of Crete Medical School and
| | - Dimitris Mavroudis
- Department of Medical Oncology, University Hospital of Heraklion, Heraklion, 71110, Greece
| | - Vassilis Georgoulias
- Department of Medical Oncology, University Hospital of Heraklion, Heraklion, 71110, Greece
| | - Christos Stournaras
- Department of Biochemistry, University of Crete Medical School and
- Address correspondence and reprint requests to Christos Stournaras, Department of Biochemistry, University of Crete Medical School, GR-71110 Heraklion Voutes. Phone: +30-2810-394563; Fax: +30-2810-394530; E-mail:
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Abstract
Since the early days of cell volume regulation research, the role of actin cytoskeleton organization and rearrangement has attracted specific interest. Rapid modifications in actin dynamics and architecture have been described. They were shown to regulate cell volume changes, as well as regulatory volume decrease in a large variety of cell types, including hepatocytes, lymphocytes, fibroblasts, myocytes, and various tumor cells. Using microscopic and biochemical analyses, modifications of actin organization and polymerization dynamics were studied. This chapter summarizes the molecular approaches applied so far for the quantitative assessment of actin cytoskeleton dynamics in the various cell types. It demonstrates that rapid modifications of actin cytoskeleton dynamics regulated by specific signaling pathways play a functional role in cell volume regulation. It is concluded that studying actin polymerization dynamics and signaling represents a challenging tool for the understanding of osmosensing and osmosignaling regulation in cellular physiology.
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Thaunat O, Delahousse M, Fakhouri F, Martinez F, Stephan JL, Noël LH, Karras A. Nephrotic syndrome associated with hemophagocytic syndrome. Kidney Int 2006; 69:1892-8. [PMID: 16557222 DOI: 10.1038/sj.ki.5000352] [Citation(s) in RCA: 96] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Hemophagocytic syndrome (HPS) is defined by bone marrow and organ infiltration by activated, nonmalignant macrophages, which phagocytose blood cells. The clinical spectrum of HPS is broad, but renal involvement has rarely been investigated. We report a previously unknown renal manifestation of HPS: nephrotic syndrome. This multicentric retrospective study included patients fulfilling the following criteria: (i) no history of nephropathy; (ii) HPS diagnosis with histologic evidence of hemophagocytosis; (iii) occurrence of nephrotic syndrome during HPS; and (iv) available renal histology. Using the same criteria, we also searched the literature for additional cases. We identified nine patients retrospectively and found two additional cases in the literature (five males and six females, whose mean age was 34 +/- 27 years). Black African patients predominated (63.6%). HPS was due to lymphoma (six cases), infectious disease (three cases), and autoimmune disease (one case), and was primary in one patient. Acute renal failure was associated with nephrotic syndrome in 10/11 cases. Renal histology showed acute tubular necrosis associated with collapsing glomerulopathy in five patients (all Africans with negative human immunodeficiency virus serology), minimal change glomerulopathy in four, and thrombotic-microangiopathy with abnormal podocytes in two. Death occurred in seven cases. Nephrotic syndrome should be included among the renal complications of HPS with acute renal failure. We postulate that abnormal T-cell activation and/or high pro-inflammatory cytokine levels during HPS might cause podocyte injuries, especially among African patients with a susceptible genetic background.
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Affiliation(s)
- O Thaunat
- Department of Nephrology, Hôpital Necker-Enfants Malades, Paris, France.
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Patrick DM, Leone AK, Shellenberger JJ, Dudowicz KA, King JM. Proinflammatory cytokines tumor necrosis factor-alpha and interferon-gamma modulate epithelial barrier function in Madin-Darby canine kidney cells through mitogen activated protein kinase signaling. BMC PHYSIOLOGY 2006; 6:2. [PMID: 16504032 PMCID: PMC1402323 DOI: 10.1186/1472-6793-6-2] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/25/2005] [Accepted: 02/21/2006] [Indexed: 01/21/2023]
Abstract
Background The tight junction is a dynamic structure that is regulated by a number of cellular signaling processes. Occludin, claudin-1, claudin-2 and claudin-3 are integral membrane proteins found in the tight junction of MDCK cells. These proteins are restricted to this region of the membrane by a complex array of intracellular proteins which are tethered to the cytoskeleton. Alteration of these tight junction protein complexes during pathological events leads to impaired epithelial barrier function that perturbs water and electrolyte homeostasis. We examined MDCK cell barrier function in response to challenge by the proinflammatory cytokines tumor necrosis factor-α (TNFα) and interferon-γ (IFNγ). Results Exposure of MDCK cells to TNFα/IFNγ resulted in a marked sustained elevation of transepithelial electrical resistance (TER) as well as elevated paracellular permeability. We demonstrate that the combination of TNFα/IFNγ at doses used in this study do not significantly induce MDCK cell apoptosis. We observed significant alterations in occludin, claudin-1 and claudin-2 protein expression, junctional localization and substantial cytoskeletal reorganization. Pharmacological inhibition of ERK1/2 and p38 signaling blocked the deleterious effects of the proinflammatory cytokines on barrier function. Conclusion These data strongly suggest that downstream effectors of MAP kinase signaling pathways mediate the TNFα/IFNγ-induced junctional reorganization that modulates MDCK cell barrier function.
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Affiliation(s)
- David M Patrick
- Southwestern Graduate School of Biomedical Sciences, UT Southwestern Medical Center, 5323 Harry Hines Blvd., Dallas, TX 75390-9004, USA
| | - Amanda K Leone
- Southwestern Graduate School of Biomedical Sciences, UT Southwestern Medical Center, 5323 Harry Hines Blvd., Dallas, TX 75390-9004, USA
| | | | - Kara A Dudowicz
- Trinity University, Biology Department, One Trinity Place, San Antonio, TX 78212, USA
| | - Jonathan M King
- Trinity University, Biology Department, One Trinity Place, San Antonio, TX 78212, USA
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The Functional Role of Actin Cytoskeleton Dynamics and Signaling. ACTA ACUST UNITED AC 2006. [DOI: 10.1016/s1569-2558(06)37009-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
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Zheng L, Sinniah R, Hsu SIH. In situ glomerular expression of activated NF-kappaB in human lupus nephritis and other non-proliferative proteinuric glomerulopathy. Virchows Arch 2005; 448:172-83. [PMID: 16205945 DOI: 10.1007/s00428-005-0061-9] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2005] [Accepted: 08/03/2005] [Indexed: 01/18/2023]
Abstract
Nuclear Factor-kappaB (NF-kappaB) has been suggested to play a role in the cellular and molecular mechanisms underlying glomerular injury. We investigated the potential role of NF-kappaB activation in the pathogenesis of glomerular injury in 31 patients with class III-V lupus nephritis (LN), 14 patients with non-proliferative proteinuric glomerulopathy and six normal controls. The expression of NF-kappaB subunits p65 and p50, and the NF-kappaB regulated proinflammatory mediators tumor necrosis factor-alpha (TNF-alpha), interleukin-1beta (IL-1beta), interleukin-6 (IL-6) and intercellular adhesion molecule-1 (ICAM-1) as well as CD68 and synaptopodin was examined by Southwestern histochemistry (SWH) or immunohistochemistry. In contrast to non-proliferative glomerulopathy and normal controls, NF-kappaB activation (both p65 and p50) was enhanced in glomerular endothelial, mesangial cells or infiltrating cells in class IV LN, along with upregulation of TNF-alpha, IL-1beta, IL-6 and ICAM-1 expression. Glomerular endothelial and mesangial activation of NF-kappaB and mesangial ICAM-1 expression correlated with disease activity and the level of glomerular macrophage infiltration. Podocyte NF-kappaB overactivation (predominantly p65) paralleled podocyte expression of TNF-alpha and IL-1beta in patients with LN and non-proliferative glomerulopathy. Podocyte staining scores of NF-kappaB and p65 were positively correlated with the severity of proteinuria in LN and non-proliferative glomerulopathy. These results suggest a pathogenic role for NF-kappaB in glomerular injury by multiple mechanisms.
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Affiliation(s)
- Ling Zheng
- Department of Pathology, National University of Singapore, Singapore, Singapore
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Sasaki S, Nishihira J, Ishibashi T, Yamasaki Y, Obikane K, Echigoya M, Sado Y, Ninomiya Y, Kobayashi K. Transgene of MIF induces podocyte injury and progressive mesangial sclerosis in the mouse kidney. Kidney Int 2004; 65:469-81. [PMID: 14717917 DOI: 10.1111/j.1523-1755.2004.00394.x] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
BACKGROUND Recent evidence suggests that macrophage migration inhibitory factor (MIF) is a proinflammatory cytokine that plays a pathogenic role in glomerulonephritis. Renal expression of MIF is up-regulated in infiltrating and intrinsic renal cells, which include glomerular epithelial cells. The aim of the current study was to further clarify the role of MIF produced by podocytes in the process of renal disease. METHODS We generated transgenic mice carrying a murine MIF cDNA driven by cytomegalovirus enhancer and beta-actin/beta-globin promoter, a hybrid promoter transactivated in podocytes in vivo. RESULTS MIF expression was markedly up-regulated in podocytes in neonatal and adult transgenic kidneys. A longitudinal study of the MIF transgenic mice demonstrated a progressive matrix increase in mesangium accompanied by collagen IV accumulation, representing no significant glomerular cell hypercellularity. The glomeruli in transgenic kidney were not accompanied by influx of macrophages and T cells at the early stage of disease progression. Although a significant number of the mice showing higher expression of MIF died from renal failure at 8 weeks, most of them survived with significant proteinuria and progressive renal failure. Podocytes of transgenic mice frequently underwent characteristic ultrastructural changes, such as cell flattening, contracted foot processes, and villous transformation. In addition, immunohistochemical expression of synaptopodin, an actin-associated protein distributed in differentiated podocyte foot process, was significantly attenuated in transgenic kidney. CONCLUSION Our results indicate that podocyte-expressed MIF could induce an injury of podocytes themselves, thereby accelerating the progression of glomerulosclerosis and leading to end-stage renal failure.
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Affiliation(s)
- Satoshi Sasaki
- Department of Pediatrics, Hokkaido University Graduate School of Medicine, Sapporo, Japan.
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van den Berg JG, Weening JJ. Role of the immune system in the pathogenesis of idiopathic nephrotic syndrome. Clin Sci (Lond) 2004; 107:125-36. [PMID: 15157184 DOI: 10.1042/cs20040095] [Citation(s) in RCA: 79] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2004] [Revised: 05/11/2004] [Accepted: 05/25/2004] [Indexed: 12/19/2022]
Abstract
Idiopathic NS (nephrotic syndrome) is characterized by massive proteinuria, due to a leak in the glomerular barrier to proteins. Genetic defects that affect the function and the composition of the glomerular capillary wall, in particular of the visceral epithelial cells, have recently been recognized as the cause of familial forms of NS. MCNS (minimal change NS) and FSGS (focal and segmental glomerulosclerosis) are common non-familial forms of NS in which the causative defect has not yet been identified. Several studies have shown that non-familial NS is associated with the presence of circulating permeability factors and with complex disturbances in the immune system. Thus far, there is no direct evidence that these factors directly alter glomerular permeability to proteins, and some of these factors may be a consequence, rather than a cause, of NS. In this review, we will briefly highlight the mechanisms that underlie proteinuria in general and focus on the immunological disturbances associated with idiopathic NS, with attention to potential mechanisms whereby the immune system may directly act on the glomerular capillary filter.
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Affiliation(s)
- José G van den Berg
- Department of Pathology, Academic Medical Center, University of Amsterdam, Meibergdreef 9, 1105 AZ Amsterdam, The Netherlands.
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Abstract
BACKGROUND Leukocyte dysfunction contributes to the pathogenesis of diabetic vascular complications. Neutrophils adhere to the endothelium through the beta(2)integrin CD11b/CD18. In Type 2 diabetes, neutrophil surface CD11b expression is increased and is associated with impaired actin polymerization. This study aimed to determine whether increasing neutrophil actin polymerization could correct the defect in CD11b exposure. DESIGN Neutrophil actin polymerization was stimulated with the tyrosine phosphatase inhibitor phenylarsine oxide (PAO), and cytoskeletal phosphotyrosine was monitored by immunoblotting Triton X-100 insoluble fractions of cells. Neutrophil F-actin was measured with phalloidin-FITC staining, and surface CD11b expression was determined with anti-CD11b-PE before analysis with flow cytometry. RESULTS Phenylarsine oxide caused an increase in phosphotyrosine in neutrophils from both patients with Type 2 diabetes (DM) and controls (NC) (-fold increase: NC, 1.43 +/- 0.16; DM, 1.46 +/- 0.10). The response to PAO in terms of phalloidin-binding was impaired in neutrophils from patients [phalloidin-FITC MFI area under the curve, NC 200 +/- 5 (x 10(3)), DM 124 +/- 9 (x 10(3)), P < 0.0001]. Phenylarsine oxide at concentrations < 10 micro mol L(-1) also caused loss of CD11b from neutrophil surfaces that was impaired in samples from patients [CD11b sites area under the curve NC 90 +/- 6 (x 10(3)), DM 121 +/- 9 (x 10(3)), P < 0.002]. However, in neutrophils from patients, incubation with PAO at a concentration of > 10 micro mol L(-1) caused a significant increase in intracellular F-actin and CD11b down-regulation equivalent to that observed in controls. CONCLUSION In Type 2 diabetes, impaired neutrophil actin polymerization even in response to increasing cytoskeletal phophotyrosine suggests a downstream defect. Furthermore, increasing actin polymerization, above a minimum threshold level, corrects the defect in integrin exposure. Correction of the actin polymerization defect in Type 2 diabetes could improve the prognosis of diabetic vascular complications.
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Affiliation(s)
- A Advani
- Department of Medicine, University of Newcastle Upon Tyne, Newcastle Upon Tyne, UK.
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