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Del Duca E, Dahabreh D, Kim M, Bar J, Da Rosa JC, Rabinowitz G, Facheris P, Gómez-Arias PJ, Chang A, Utti V, Chowdhury A, Liu Y, Estrada YD, Laculiceanu A, Agache I, Guttman-Yassky E. Transcriptomic evaluation of skin tape-strips in children with allergic asthma uncovers epidermal barrier dysfunction and asthma-associated biomarkers abnormalities. Allergy 2024; 79:1516-1530. [PMID: 38375886 PMCID: PMC11247382 DOI: 10.1111/all.16060] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2023] [Revised: 01/08/2024] [Accepted: 02/01/2024] [Indexed: 02/21/2024]
Abstract
INTRODUCTION Tape-strips, a minimally invasive method validated for the evaluation of several skin diseases, may help identify asthma-specific biomarkers in the skin of children with allergic asthma. METHODS Skin tape-strips were obtained and analyzed with RNA-Seq from children with moderate allergic asthma (MAA) (n = 11, mean age 7.00; SD = 1.67), severe allergic asthma (SAA) (n = 9, mean age 9.11; SD = 2.37), and healthy controls (HCs) (n = 12, mean age 7.36; SD = 2.03). Differentially expressed genes (DEGs) were identified by fold change ≥2 with a false discovery rate <0.05. Transcriptomic biomarkers were analyzed for their accuracy in distinguishing asthma from HCs, their relationships with asthma-related outcomes (exacerbation rate, lung function-FEV1, IOS-R5-20, and lung inflammation-FeNO), and their links to skin (barrier and immune response) and lung (remodeling, metabolism, aging) pathogenetic pathways. RESULTS RNA-Seq captured 1113 in MAA and 2117 DEGs in SAA. Epidermal transcriptomic biomarkers for terminal differentiation (FLG/filaggrin), cell adhesion (CDH19, JAM2), lipid biosynthesis/metabolism (ACOT2, LOXL2) were significantly downregulated. Gene set variation analysis revealed enrichment of Th1/IFNγ pathways (p < .01). MAA and SAA shared downregulation of G-protein-coupled receptor (OR4A16, TAS1R3), upregulation of TGF-β/ErbB signaling-related (ACVR1B, EGFR, ID1/2), and upregulation of mitochondrial-related (HIGD2A, VDAC3, NDUFB9) genes. Skin transcriptomic biomarkers correlated with the annualized exacerbation rate and with lung function parameters. A two-gene classifier (TSSC4-FAM212B) was able to differentiate asthma from HCs with 100% accuracy. CONCLUSION Tape-strips detected epithelial barrier and asthma-associated signatures in normal-appearing skin from children with allergic asthma and may serve as an alternative to invasive approaches for evaluating asthma endotypes.
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Affiliation(s)
- Ester Del Duca
- Department of Dermatology, Icahn School of Medicine at the Mount Sinai, New York, New York, USA
- Dermatology Clinic, Department of Clinical Internal, Anesthesiological and Cardiovascular Sciences, Sapienza University of Rome, Rome, Italy
| | - Dante Dahabreh
- Department of Dermatology, Icahn School of Medicine at the Mount Sinai, New York, New York, USA
| | - Madeline Kim
- Department of Dermatology, Icahn School of Medicine at the Mount Sinai, New York, New York, USA
| | - Jonathan Bar
- Department of Dermatology, Icahn School of Medicine at the Mount Sinai, New York, New York, USA
| | - Joel Correa Da Rosa
- Department of Dermatology, Icahn School of Medicine at the Mount Sinai, New York, New York, USA
| | - Grace Rabinowitz
- Department of Dermatology, Icahn School of Medicine at the Mount Sinai, New York, New York, USA
| | - Paola Facheris
- Department of Dermatology, Icahn School of Medicine at the Mount Sinai, New York, New York, USA
- Department of Dermatology, IRCCS Humanitas Research Hospital, Milan, Italy
| | - Pedro Jesús Gómez-Arias
- Department of Dermatology, Icahn School of Medicine at the Mount Sinai, New York, New York, USA
- Department of Dermatology, Reina Sofía University Hospital, Maimonides Biomedical Research Institute of Cordoba (IMIBIC), Cordoba, Spain
| | - Annie Chang
- Department of Dermatology, Icahn School of Medicine at the Mount Sinai, New York, New York, USA
| | - Vivian Utti
- Department of Dermatology, Icahn School of Medicine at the Mount Sinai, New York, New York, USA
| | - Amira Chowdhury
- Department of Dermatology, Icahn School of Medicine at the Mount Sinai, New York, New York, USA
| | - Ying Liu
- Department of Dermatology, Icahn School of Medicine at the Mount Sinai, New York, New York, USA
| | - Yeriel D Estrada
- Department of Dermatology, Icahn School of Medicine at the Mount Sinai, New York, New York, USA
| | - Alexandru Laculiceanu
- Department of Allergy and Clinical Immunology, Transylvania University, Brasov, Romania
| | - Ioana Agache
- Department of Allergy and Clinical Immunology, Transylvania University, Brasov, Romania
| | - Emma Guttman-Yassky
- Department of Dermatology, Icahn School of Medicine at the Mount Sinai, New York, New York, USA
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Abstract
RNA is not always a faithful copy of DNA. Advances in tools enabling the interrogation of the exact RNA sequence have permitted revision of how genetic information is transferred. We now know that RNA is a dynamic molecule, amenable to chemical modifications of its four canonical nucleotides by dedicated RNA-binding enzymes. The ever-expanding catalogue of identified RNA modifications in mammals has led to a burst of studies in the past 5 years that have explored the biological relevance of the RNA modifications, also known as epitranscriptome. These studies concluded that chemical modification of RNA nucleotides alters several properties of RNA molecules including sequence, secondary structure, RNA-protein interaction, localization and processing. Importantly, a plethora of cellular functions during development, homeostasis and disease are controlled by RNA modification enzymes. Understanding the regulatory interface between a single-nucleotide modification and cellular function will pave the way towards the development of novel diagnostic, prognostic and therapeutic tools for the management of diseases, including cardiovascular disease. In this Review, we use two well-studied and abundant RNA modifications - adenosine-to-inosine RNA editing and N6-methyladenosine RNA methylation - as examples on which to base the discussion about the current knowledge on installation or removal of RNA modifications, their effect on biological processes related to cardiovascular health and disease, and the potential for development and application of epitranscriptome-based prognostic, diagnostic and therapeutic tools for cardiovascular disease.
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Mosaddeghzadeh N, Nouri K, Krumbach OHF, Amin E, Dvorsky R, Ahmadian MR. Selectivity Determinants of RHO GTPase Binding to IQGAPs. Int J Mol Sci 2021; 22:12596. [PMID: 34830479 PMCID: PMC8625570 DOI: 10.3390/ijms222212596] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2021] [Revised: 11/16/2021] [Accepted: 11/19/2021] [Indexed: 12/13/2022] Open
Abstract
IQ motif-containing GTPase-activating proteins (IQGAPs) modulate a wide range of cellular processes by acting as scaffolds and driving protein components into distinct signaling networks. Their functional states have been proposed to be controlled by members of the RHO family of GTPases, among other regulators. In this study, we show that IQGAP1 and IQGAP2 can associate with CDC42 and RAC1-like proteins but not with RIF, RHOD, or RHO-like proteins, including RHOA. This seems to be based on the distribution of charged surface residues, which varies significantly among RHO GTPases despite their high sequence homology. Although effector proteins bind first to the highly flexible switch regions of RHO GTPases, additional contacts outside are required for effector activation. Sequence alignment and structural, mutational, and competitive biochemical analyses revealed that RHO GTPases possess paralog-specific residues outside the two highly conserved switch regions that essentially determine the selectivity of RHO GTPase binding to IQGAPs. Amino acid substitution of these specific residues in RHOA to the corresponding residues in RAC1 resulted in RHOA association with IQGAP1. Thus, electrostatics most likely plays a decisive role in these interactions.
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Affiliation(s)
- Niloufar Mosaddeghzadeh
- Medical Faculty, Institute of Biochemistry and Molecular Biology II, University Hospital Düsseldorf, Heinrich Heine University Düsseldorf, 40225 Düsseldorf, Germany; (N.M.); (K.N.); (O.H.F.K.); (E.A.); (R.D.)
| | - Kazem Nouri
- Medical Faculty, Institute of Biochemistry and Molecular Biology II, University Hospital Düsseldorf, Heinrich Heine University Düsseldorf, 40225 Düsseldorf, Germany; (N.M.); (K.N.); (O.H.F.K.); (E.A.); (R.D.)
- Department of Pathology and Molecular Medicine, McMaster University, Hamilton, ON L8S 4L8, Canada
| | - Oliver H. F. Krumbach
- Medical Faculty, Institute of Biochemistry and Molecular Biology II, University Hospital Düsseldorf, Heinrich Heine University Düsseldorf, 40225 Düsseldorf, Germany; (N.M.); (K.N.); (O.H.F.K.); (E.A.); (R.D.)
| | - Ehsan Amin
- Medical Faculty, Institute of Biochemistry and Molecular Biology II, University Hospital Düsseldorf, Heinrich Heine University Düsseldorf, 40225 Düsseldorf, Germany; (N.M.); (K.N.); (O.H.F.K.); (E.A.); (R.D.)
- Medical Faculty, Institute of Neural and Sensory Physiology, University Hospital Düsseldorf, Heinrich Heine University, 40225 Düsseldorf, Germany
| | - Radovan Dvorsky
- Medical Faculty, Institute of Biochemistry and Molecular Biology II, University Hospital Düsseldorf, Heinrich Heine University Düsseldorf, 40225 Düsseldorf, Germany; (N.M.); (K.N.); (O.H.F.K.); (E.A.); (R.D.)
| | - Mohammad R. Ahmadian
- Medical Faculty, Institute of Biochemistry and Molecular Biology II, University Hospital Düsseldorf, Heinrich Heine University Düsseldorf, 40225 Düsseldorf, Germany; (N.M.); (K.N.); (O.H.F.K.); (E.A.); (R.D.)
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Peng X, Wang T, Gao H, Yue X, Bian W, Mei J, Zhang Y. The interplay between IQGAP1 and small GTPases in cancer metastasis. Biomed Pharmacother 2021; 135:111243. [PMID: 33434854 DOI: 10.1016/j.biopha.2021.111243] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2020] [Revised: 12/27/2020] [Accepted: 12/31/2020] [Indexed: 01/07/2023] Open
Abstract
The metastatic spread of tumor cells to distant anatomical locations is a critical cause for disease progression and leads to more than 90 % of cancer-related deaths. IQ motif-containing GTPase-activating protein 1 (IQGAP1), a prominent regulator in the cancer metastasis process, is a scaffold protein that interacts with components of the cytoskeleton. As a critical node within the small GTPase network, IQGAP1 acts as a binding partner of several small GTPases, which in turn function as molecular switches to control most cellular processes, including cell migration and invasion. Given the significant interaction between IQGAP1 and small GTPases in cancer metastasis, we briefly elucidate the role of IQGAP1 in regulating cancer metastasis and the varied interactions existing between IQGAP1 and small GTPases. In addition, the potential regulators for IQGAP1 activity and its interaction with small GTPases are also incorporated in this review. Overall, we comprehensively summarize the role of IQGAP1 in cancer tumorigenicity and metastasis, which may be a potential anti-tumor target to restrain cancer progression.
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Affiliation(s)
- Xiafeng Peng
- Department of Gynecology and Obstetrics, Wuxi Maternal and Child Health Hospital, the Affiliated Hospital to Nanjing Medical University, Wuxi, 214023, China; First Clinical Medicine College, Nanjing Medical University, Nanjing, 211166, China.
| | - Tiejun Wang
- Department of Gynecology and Obstetrics, Wuxi Maternal and Child Health Hospital, the Affiliated Hospital to Nanjing Medical University, Wuxi, 214023, China.
| | - Han Gao
- School of Medicine, Jiangnan University, Wuxi, 214122, China.
| | - Xin Yue
- First Clinical Medicine College, Nanjing Medical University, Nanjing, 211166, China.
| | - Weiqi Bian
- First Clinical Medicine College, Nanjing Medical University, Nanjing, 211166, China.
| | - Jie Mei
- Department of Gynecology and Obstetrics, Wuxi Maternal and Child Health Hospital, the Affiliated Hospital to Nanjing Medical University, Wuxi, 214023, China; Wuxi Clinical Medical College, Nanjing Medical University, Wuxi, 214023, China.
| | - Yan Zhang
- Department of Gynecology and Obstetrics, Wuxi Maternal and Child Health Hospital, the Affiliated Hospital to Nanjing Medical University, Wuxi, 214023, China.
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Guo F. RhoA and Cdc42 in T cells: Are they targetable for T cell-mediated inflammatory diseases? PRECISION CLINICAL MEDICINE 2021; 4:56-61. [PMID: 33842837 PMCID: PMC8023016 DOI: 10.1093/pcmedi/pbaa039] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2020] [Revised: 12/01/2020] [Accepted: 12/10/2020] [Indexed: 12/12/2022] Open
Abstract
Many inflammatory diseases are not curable, necessitating a better understanding of their pathobiology that may help identify novel biological targets. RhoA and Cdc42 of Rho family small GTPases regulate a variety of cellular functions such as actin cytoskeletal organization, cell adhesion, migration, proliferation, and survival. Recent characterization of mouse models of conditional gene knockout of RhoA and Cdc42 has revealed their physiological and cell type-specific roles in a number of cell types. In T lymphocytes, which play an important role in the pathogenesis of most, if not all, of the inflammatory diseases, we and others have investigated the effects of T cell-specific knockout of RhoA and Cdc42 on T cell development in the thymus, peripheral T cell homeostasis, activation, and differentiation to effector and regulatory T cells, and on T cell-mediated allergic airway inflammation and colitis. Here we highlight the phenotypes resulting from RhoA and Cdc42 deletion in T cells and discuss whether pharmacological targeting of RhoA and Cdc42 is feasible in treating asthma that is driven by allergic airway inflammation and colitis.
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Affiliation(s)
- Fukun Guo
- Division of Experimental Hematology and Cancer Biology, Children's Hospital Medical Center, Cincinnati, OH 45229, USA
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Zhang X, Wu D, Wang C, Luo Y, Ding X, Yang X, Silva F, Arenas S, Weaver JM, Mandell M, Deretic V, Liu M. Sustained activation of autophagy suppresses adipocyte maturation via a lipolysis-dependent mechanism. Autophagy 2020; 16:1668-1682. [PMID: 31840569 PMCID: PMC8386625 DOI: 10.1080/15548627.2019.1703355] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Dysregulation of macroautophagy/autophagy is implicated in obesity and insulin resistance. However, it remains poorly defined how autophagy regulates adipocyte development. Using adipose-specific rptor/raptor knockout (KO), atg7 KO and atg7 rptor double-KO mice, we show that inhibiting MTORC1 by RPTOR deficiency led to autophagic sequestration of lipid droplets, formation of LD-containing lysosomes, and elevation of basal and isoproterenol-induced lipolysis in vivo and in primary adipocytes. Despite normal differentiation at an early phase, progressive degradation and shrinkage of cellular LDs and downregulation of adipogenic markers PPARG and PLIN1 occurred in terminal differentiation of rptor KO adipocytes, which was rescued by inhibiting lipolysis or lysosome. In contrast, inactivating autophagy by depletion of ATG7 protected adipocytes against RPTOR deficiency-induced formation of LD-containing lysosomes, LD degradation, and downregulation of adipogenic markers in vitro. Ultimately, atg7 rptor double-KO mice displayed decreased lipolysis, restored adipose tissue development, and upregulated thermogenic gene expression in brown and inguinal adipose tissue compared to RPTOR-deficient mice in vivo. Collectively, our study demonstrates that autophagy plays an important role in regulating adipocyte maturation via a lipophagy and lipolysis-dependent mechanism. ABBREVIATIONS ATG7: autophagy related 7; BAT: brown adipose tissue; CEBPB/C/EBPβ: CCAAT enhancer binding protein beta; DGAT1: diacylglycerol O-acyltransferase 1; eWAT: epididymal white adipose tissue; iWAT: inguinal white adipose tissue; KO: knockout; LD: lipid droplet; MAP1LC3/LC3: microtubule-associated protein 1 light chain 3; MTOR: mechanistic target of rapamycin kinase; MTORC1: mechanistic target of rapamycin kinase complex 1; PLIN1: perepilin 1; PNPLA2/ATGL: patatin-like phospholipase domain containing 2; PPARG/PPARγ: peroxisome proliferator activated receptor gamma; RPTOR: regulatory associated protein of MTOR complex1; TG: triglyceride; ULK1: unc-51 like kinase 1; UCP1: uncoupling protein 1; WAT: white adipose tissue.
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Affiliation(s)
- Xing Zhang
- Department of Biochemistry and Molecular Biology, University of New Mexico Health Sciences Center, Albuquerque, New Mexico, USA
| | - Dandan Wu
- Department of Biochemistry and Molecular Biology, University of New Mexico Health Sciences Center, Albuquerque, New Mexico, USA
| | - Chunqing Wang
- Department of Biochemistry and Molecular Biology, University of New Mexico Health Sciences Center, Albuquerque, New Mexico, USA
| | - Yan Luo
- Department of Biochemistry and Molecular Biology, University of New Mexico Health Sciences Center, Albuquerque, New Mexico, USA
| | - Xiaofeng Ding
- Department of Biochemistry and Molecular Biology, University of New Mexico Health Sciences Center, Albuquerque, New Mexico, USA
| | - Xin Yang
- Department of Biochemistry and Molecular Biology, University of New Mexico Health Sciences Center, Albuquerque, New Mexico, USA
| | - Floyd Silva
- Department of Biochemistry and Molecular Biology, University of New Mexico Health Sciences Center, Albuquerque, New Mexico, USA
| | - Sara Arenas
- Department of Biochemistry and Molecular Biology, University of New Mexico Health Sciences Center, Albuquerque, New Mexico, USA
| | - John Michael Weaver
- Autophagy Inflammation and Metabolism Center for Biomedical Research Excellence, University of New Mexico Health Sciences Center, Albuquerque, New Mexico, USA
| | - Michael Mandell
- Autophagy Inflammation and Metabolism Center for Biomedical Research Excellence, University of New Mexico Health Sciences Center, Albuquerque, New Mexico, USA,Department of Molecular Genetics and Microbiology, University of New Mexico Health Sciences Center, Albuquerque, New Mexico, USA
| | - Vojo Deretic
- Autophagy Inflammation and Metabolism Center for Biomedical Research Excellence, University of New Mexico Health Sciences Center, Albuquerque, New Mexico, USA,Department of Molecular Genetics and Microbiology, University of New Mexico Health Sciences Center, Albuquerque, New Mexico, USA
| | - Meilian Liu
- Department of Biochemistry and Molecular Biology, University of New Mexico Health Sciences Center, Albuquerque, New Mexico, USA,CONTACT Meilian Liu Department of Biochemistry and Molecular Biology, University of New Mexico Health Sciences Center, Albuquerque, USA
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Humphries BA, Wang Z, Yang C. MicroRNA Regulation of the Small Rho GTPase Regulators-Complexities and Opportunities in Targeting Cancer Metastasis. Cancers (Basel) 2020; 12:E1092. [PMID: 32353968 PMCID: PMC7281527 DOI: 10.3390/cancers12051092] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2020] [Revised: 04/24/2020] [Accepted: 04/25/2020] [Indexed: 02/07/2023] Open
Abstract
The small Rho GTPases regulate important cellular processes that affect cancer metastasis, such as cell survival and proliferation, actin dynamics, adhesion, migration, invasion and transcriptional activation. The Rho GTPases function as molecular switches cycling between an active GTP-bound and inactive guanosine diphosphate (GDP)-bound conformation. It is known that Rho GTPase activities are mainly regulated by guanine nucleotide exchange factors (RhoGEFs), GTPase-activating proteins (RhoGAPs), GDP dissociation inhibitors (RhoGDIs) and guanine nucleotide exchange modifiers (GEMs). These Rho GTPase regulators are often dysregulated in cancer; however, the underlying mechanisms are not well understood. MicroRNAs (miRNAs), a large family of small non-coding RNAs that negatively regulate protein-coding gene expression, have been shown to play important roles in cancer metastasis. Recent studies showed that miRNAs are capable of directly targeting RhoGAPs, RhoGEFs, and RhoGDIs, and regulate the activities of Rho GTPases. This not only provides new evidence for the critical role of miRNA dysregulation in cancer metastasis, it also reveals novel mechanisms for Rho GTPase regulation. This review summarizes recent exciting findings showing that miRNAs play important roles in regulating Rho GTPase regulators (RhoGEFs, RhoGAPs, RhoGDIs), thus affecting Rho GTPase activities and cancer metastasis. The potential opportunities and challenges for targeting miRNAs and Rho GTPase regulators in treating cancer metastasis are also discussed. A comprehensive list of the currently validated miRNA-targeting of small Rho GTPase regulators is presented as a reference resource.
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Affiliation(s)
- Brock A. Humphries
- Center for Molecular Imaging, Department of Radiology, University of Michigan, 109 Zina Pitcher Place, Ann Arbor, MI 48109, USA
| | - Zhishan Wang
- Department of Toxicology and Cancer Biology, College of Medicine, University of Kentucky, 1095 V A Drive, Lexington, KY 40536, USA;
| | - Chengfeng Yang
- Department of Toxicology and Cancer Biology, College of Medicine, University of Kentucky, 1095 V A Drive, Lexington, KY 40536, USA;
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Xu C, Wu X, Lu M, Tang L, Yao H, Wang J, Ji X, Hussain M, Wu J, Wu X. Protein tyrosine phosphatase 11 acts through RhoA/ROCK to regulate eosinophil accumulation in the allergic airway. FASEB J 2019; 33:11706-11720. [PMID: 31361966 PMCID: PMC6902720 DOI: 10.1096/fj.201900698r] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Src homology domain 2-containing protein tyrosine phosphatase 2 (SHP2) participates in multiple cell functions including cell shape, movement, and differentiation. Therefore, we investigated the potential role of SHP2 in eosinophil recruitment into lungs in allergic airway inflammation and explored the underlying mechanism. Both SHP2 and Ras homolog family member A (RhoA) kinase were robustly activated in the airway eosinophils of children with allergic asthma and of a mouse model with allergic airway inflammation. Moreover, inhibition of SHP2 activity by its specific inhibitors reverses the dephosphorylation of p190-A Rho GTPase-activating protein and in turn attenuates RhoA/Rho-associated protein kinase (ROCK) signaling, resulting in the attenuation of eosinophil migration in response to platelet-activating factor stimulation. Specifically, SHP2 deletion in myeloid cells did not affect the number and classification of circulating leukocytes but significantly attenuated the allergen-induced inflammatory cell, especially eosinophil, infiltration into lungs, and airway hyperreactivity. Notably, genetic interaction between RhoA and SHP2 indicated that RhoA inactivation and SHP2 deletion synergistically attenuated the allergen-induced eosinophil infiltration into lungs and airway hyperreactivity, whereas overexpression of active RhoA robustly restored the SHP2 deletion-resultant attenuation of allergen-induced eosinophil recruitment into lungs and airway hyperreactivity as well. Thus, this study demonstrates that SHP2 via RhoA/ROCK signaling regulates eosinophil recruitment in allergic airway inflammation and possibly in allergic asthma.-Xu, C., Wu, X., Lu, M., Tang, L., Yao, H., Wang, J., Ji, X., Hussain, M., Wu, J., Wu, X. Protein tyrosine phosphatase 11 acts through RhoA/ROCK to regulate eosinophil accumulation in the allergic airway.
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Affiliation(s)
- Chengyun Xu
- Department of Pharmacology, School of Medicine, Zhejiang University, Hangzhou, China
| | - Xiling Wu
- Department of Respiratory Medicine, The Affiliated Children's Hospital, School of Medicine, Zhejiang University, Hangzhou, China
| | - Meiping Lu
- Department of Respiratory Medicine, The Affiliated Children's Hospital, School of Medicine, Zhejiang University, Hangzhou, China
| | - Lanfang Tang
- Department of Respiratory Medicine, The Affiliated Children's Hospital, School of Medicine, Zhejiang University, Hangzhou, China
| | - Hongyi Yao
- Department of Pharmacy, The Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China
| | - Jirong Wang
- Department of Pharmacology, School of Medicine, Zhejiang University, Hangzhou, China
| | - Xing Ji
- Department of Pharmacology, School of Medicine, Zhejiang University, Hangzhou, China
| | - Musaddique Hussain
- Department of Pharmacology, School of Medicine, Zhejiang University, Hangzhou, China
| | - Junsong Wu
- Department of Orthopedic Surgery, The First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China
| | - Ximei Wu
- Department of Pharmacology, School of Medicine, Zhejiang University, Hangzhou, China
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Morgan CJ, Hedman AC, Li Z, Sacks DB. Endogenous IQGAP1 and IQGAP3 do not functionally interact with Ras. Sci Rep 2019; 9:11057. [PMID: 31363101 PMCID: PMC6667474 DOI: 10.1038/s41598-019-46677-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2019] [Accepted: 06/28/2019] [Indexed: 02/07/2023] Open
Abstract
The Ras family of small GTPases modulates numerous essential processes. Activating Ras mutations result in hyper-activation of selected signaling cascades, which leads to human diseases. The high frequency of Ras mutations in human malignant neoplasms has led to Ras being a desirable chemotherapeutic target. The IQGAP family of scaffold proteins binds to and regulates multiple signaling molecules, including the Rho family GTPases Rac1 and Cdc42. There are conflicting data in the published literature regarding interactions between IQGAP and Ras proteins. Initial reports showed no binding, but subsequent studies claim associations of IQGAP1 and IQGAP3 with K-Ras and H-Ras, respectively. Therefore, we set out to resolve this controversy. Here we demonstrate that neither endogenous IQGAP1 nor endogenous IQGAP3 binds to the major Ras isoforms, namely H-, K-, and N-Ras. Importantly, Ras activation by epidermal growth factor is not altered when IQGAP1 or IQGAP3 proteins are depleted from cells. These data strongly suggest that IQGAP proteins are not functional interactors of H-, K-, or N-Ras and challenge the rationale for targeting the interaction of Ras with IQGAP for the development of therapeutic agents.
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Affiliation(s)
- Chase J Morgan
- From the Department of Laboratory Medicine, National Institutes of Health, 10 Center Drive, Bethesda, Maryland, 20892, USA
| | - Andrew C Hedman
- From the Department of Laboratory Medicine, National Institutes of Health, 10 Center Drive, Bethesda, Maryland, 20892, USA
| | - Zhigang Li
- From the Department of Laboratory Medicine, National Institutes of Health, 10 Center Drive, Bethesda, Maryland, 20892, USA
| | - David B Sacks
- From the Department of Laboratory Medicine, National Institutes of Health, 10 Center Drive, Bethesda, Maryland, 20892, USA.
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Yang JQ, Kalim KW, Li Y, Zheng Y, Guo F. Ablation of RhoA impairs Th17 cell differentiation and alleviates house dust mite-triggered allergic airway inflammation. J Leukoc Biol 2019; 106:1139-1151. [PMID: 31260596 DOI: 10.1002/jlb.3a0119-025rrr] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2019] [Revised: 06/17/2019] [Accepted: 06/18/2019] [Indexed: 01/10/2023] Open
Abstract
Asthma is a heterogeneous chronic airway inflammation in which Th2 and Th17 cells are key players in its pathogenesis. We have reported that RhoA of Rho GTPases orchestrated glycolysis for Th2 cell differentiation and allergic airway inflammation by the use of a conditional RhoA-deficient mouse line. However, the role of RhoA in Th17 cells remains to be elucidated. In this study, we investigated the effects of RhoA deficiency on Th17 cells in the context of ex vivo cell culture systems and an in vivo house dust mites (HDM)-induced allergic airway inflammation. We found that RhoA deficiency inhibited Th17 differentiation and effector cytokine secretion, which was associated with the downregulations of Stat3 and Rorγt, key Th17 transcription factors. Furthermore, loss of RhoA markedly suppressed Th17 and neutrophil-involved airway inflammation induced by HDM in mice. The infiltrating inflammatory cells in the lungs and bronchoalveolar lavage (BAL) fluids were dramatically reduced in conditional RhoA-deficient mice. Th17 as well as Th2 effector cytokines were suppressed in the airways at both protein and mRNA levels. Interestingly, Y16, a specific RhoA inhibitor, was able to recapitulate the most phenotypes of RhoA genetic deletion in Th17 differentiation and allergic airway inflammation. Our data demonstrate that RhoA is a key regulator of Th17 cell differentiation and function. RhoA might serve as a potential novel therapeutic target for asthma and other inflammatory disorders.
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Affiliation(s)
- Jun-Qi Yang
- Division of Experimental Hematology and Cancer Biology, Children's Hospital Medical Center, and Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, Ohio, USA.,Key Laboratory of National Health Commission on Parasitic Disease Control and Prevention, Jiangsu Provincial Key Laboratory on Parasitic and Vector Control, Jiangsu Institute of Parasitic Diseases and Public Health Research Center, Jiangnan University, Wuxi, Jiangsu, China
| | - Khalid W Kalim
- Division of Experimental Hematology and Cancer Biology, Children's Hospital Medical Center, and Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, Ohio, USA
| | - Yuan Li
- Division of Experimental Hematology and Cancer Biology, Children's Hospital Medical Center, and Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, Ohio, USA
| | - Yi Zheng
- Division of Experimental Hematology and Cancer Biology, Children's Hospital Medical Center, and Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, Ohio, USA
| | - Fukun Guo
- Division of Experimental Hematology and Cancer Biology, Children's Hospital Medical Center, and Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, Ohio, USA
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11
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Wang P, Gong X, Guan P, Ji D, Du L, Xu D, Liu Y. Site-specific expression of IQGAP1 in human nephrons. J Mol Histol 2019; 50:119-127. [PMID: 30659402 DOI: 10.1007/s10735-019-09811-5] [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: 10/28/2018] [Accepted: 01/06/2019] [Indexed: 11/30/2022]
Abstract
IQGAP1 is a multifunctional, 190-kDa scaffolding protein that plays an important role in the regulation of cell adhesion, migration, proliferation, differentiation, polarization and cytoskeletal remodeling. IQGAP1 is ubiquitously expressed in human organs and is highly expressed in the kidney. Currently, the site-specific expression of IQGAP1 in the human nephrons is unclear. We performed Western blotting analysis, immunohistochemistry and double-immunolabeling confocal microscopic analysis of IQGAP1 with specific biomarkers of each nephron segment to study the expression and distribution of IQGAP1 in human nephrons. We found that IQGAP1 was strongly expressed in human podocytes and glomerular endothelial cells, but weakly expressed in glomerular mesangial cells. In human renal tubules, IQGAP1 was strongly expressed in the collecting duct, moderately expressed in the proximal tubule, medullary loop, distal convoluted tubule and connecting tubule. IQGAP1 staining was much stronger in the apical membrane in the proximal tubule, thick descending limb and thick ascending limb of medullary loop and collecting duct. However, the expression of IQGAP1 was mainly in the basolateral membrane of the connecting tubule, and diffusely in the thin limb of medullary loop and distal convoluted tubule. The interaction between IQGAP1 and F-actin suggested that cytoskeleton regulation may be the underlying mechanism mediating the effect of IQGAP1 in human nephrons. To the best of our knowledge, this is the first report of specific expression and differential subcellular location of IQGAP1 in human nephrons. The site-specific expression pattern of IQGAP1 suggests that IQGAP1 may play diverse roles in various human nephron segments.
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Affiliation(s)
- Ping Wang
- Department of Nephrology, Shandong Provincial Qianfoshan Hospital, Shandong University, No.16766, Jingshi Road, Jinan, 250014, China
| | - Xiaojie Gong
- Department of Nephrology, Shandong Provincial Qianfoshan Hospital, Shandong University, No.16766, Jingshi Road, Jinan, 250014, China
| | - Peizhong Guan
- Department of Nephrology, YEDA Hospital, Yantai, 264000, China
| | - Dong Ji
- Department of Dialysis, Huimin County People's Hospital, Binzhou, 251700, China
| | - Linna Du
- Department of Nephrology, Shandong Provincial Qianfoshan Hospital, Shandong University, No.16766, Jingshi Road, Jinan, 250014, China
| | - Dongmei Xu
- Department of Nephrology, Shandong Provincial Qianfoshan Hospital, Shandong University, No.16766, Jingshi Road, Jinan, 250014, China
| | - Yipeng Liu
- Department of Nephrology, Shandong Provincial Qianfoshan Hospital, Shandong University, No.16766, Jingshi Road, Jinan, 250014, China.
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12
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Jain M, Mann TD, Stulić M, Rao SP, Kirsch A, Pullirsch D, Strobl X, Rath C, Reissig L, Moreth K, Klein-Rodewald T, Bekeredjian R, Gailus-Durner V, Fuchs H, Hrabě de Angelis M, Pablik E, Cimatti L, Martin D, Zinnanti J, Graier WF, Sibilia M, Frank S, Levanon EY, Jantsch MF. RNA editing of Filamin A pre-mRNA regulates vascular contraction and diastolic blood pressure. EMBO J 2018; 37:e94813. [PMID: 30087110 PMCID: PMC6166124 DOI: 10.15252/embj.201694813] [Citation(s) in RCA: 60] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2016] [Revised: 06/25/2018] [Accepted: 06/27/2018] [Indexed: 12/26/2022] Open
Abstract
Epitranscriptomic events such as adenosine-to-inosine (A-to-I) RNA editing by ADAR can recode mRNAs to translate novel proteins. Editing of the mRNA that encodes actin crosslinking protein Filamin A (FLNA) mediates a Q-to-R transition in the interactive C-terminal region. While FLNA editing is conserved among vertebrates, its physiological function remains unclear. Here, we show that cardiovascular tissues in humans and mice show massive editing and that FLNA RNA is the most prominent substrate. Patient-derived RNA-Seq data demonstrate a significant drop in FLNA editing associated with cardiovascular diseases. Using mice with only impaired FLNA editing, we observed increased vascular contraction and diastolic hypertension accompanied by increased myosin light chain phosphorylation, arterial remodeling, and left ventricular wall thickening, which eventually causes cardiac remodeling and reduced systolic output. These results demonstrate a causal relationship between RNA editing and the development of cardiovascular disease indicating that a single epitranscriptomic RNA modification can maintain cardiovascular health.
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Affiliation(s)
- Mamta Jain
- Division of Cell Biology, Center for Anatomy and Cell Biology, Medical University of Vienna, Vienna, Austria
| | - Tomer D Mann
- The Mina and Everard Goodman Faculty of Life Sciences, Bar Ilan University, Ramat-Gan, Israel
- Tel Aviv Sourasky Medical Center, Tel Aviv, Israel
| | - Maja Stulić
- Division of Cell Biology, Center for Anatomy and Cell Biology, Medical University of Vienna, Vienna, Austria
| | - Shailaja P Rao
- Center of Molecular Medicine, Institute of Molecular Biology and Biochemistry, Medical University of Graz, Graz, Austria
| | - Andrijana Kirsch
- Center of Molecular Medicine, Institute of Molecular Biology and Biochemistry, Medical University of Graz, Graz, Austria
| | - Dieter Pullirsch
- Division of Cell Biology, Center for Anatomy and Cell Biology, Medical University of Vienna, Vienna, Austria
| | - Xué Strobl
- Division of Cell Biology, Center for Anatomy and Cell Biology, Medical University of Vienna, Vienna, Austria
| | - Claus Rath
- Division of Anatomy, Center for Anatomy and Cell Biology, Medical University of Vienna, Vienna, Austria
| | - Lukas Reissig
- Division of Anatomy, Center for Anatomy and Cell Biology, Medical University of Vienna, Vienna, Austria
| | - Kristin Moreth
- German Mouse Clinic, Institute of Experimental Genetics, Helmholtz Zentrum München, Neuherberg, Germany
| | - Tanja Klein-Rodewald
- German Mouse Clinic, Institute of Experimental Genetics, Helmholtz Zentrum München, Neuherberg, Germany
- Institute of Pathology, Helmholtz Zentrum München, Neuherberg, Germany
| | - Raffi Bekeredjian
- Department of Cardiology, University of Heidelberg, Heidelberg, Germany
| | - Valerie Gailus-Durner
- German Mouse Clinic, Institute of Experimental Genetics, Helmholtz Zentrum München, Neuherberg, Germany
| | - Helmut Fuchs
- German Mouse Clinic, Institute of Experimental Genetics, Helmholtz Zentrum München, Neuherberg, Germany
| | - Martin Hrabě de Angelis
- German Mouse Clinic, Institute of Experimental Genetics, Helmholtz Zentrum München, Neuherberg, Germany
- Department of Experimental Genetics, Center of Life and Food Sciences Weihenstephan, Technische Universität München, Freising-Weihenstephan, Germany
- German Center for Diabetes Research (DZD), Neuherberg, Germany
| | - Eleonore Pablik
- Section for Medical Statistics, CeMSIIS, Medical University of Vienna, Vienna, Austria
| | - Laura Cimatti
- Division of Cell Biology, Center for Anatomy and Cell Biology, Medical University of Vienna, Vienna, Austria
| | - David Martin
- Division of Cell Biology, Center for Anatomy and Cell Biology, Medical University of Vienna, Vienna, Austria
| | | | - Wolfgang F Graier
- Center of Molecular Medicine, Institute of Molecular Biology and Biochemistry, Medical University of Graz, Graz, Austria
| | - Maria Sibilia
- Department of Medicine I, Comprehensive Cancer Center, Institute for Cancer Research, Medical University of Vienna, Vienna, Austria
| | - Saša Frank
- Center of Molecular Medicine, Institute of Molecular Biology and Biochemistry, Medical University of Graz, Graz, Austria
| | - Erez Y Levanon
- The Mina and Everard Goodman Faculty of Life Sciences, Bar Ilan University, Ramat-Gan, Israel
| | - Michael F Jantsch
- Division of Cell Biology, Center for Anatomy and Cell Biology, Medical University of Vienna, Vienna, Austria
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13
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Determinants of Divergent Adaptive Immune Responses after Airway Sensitization with Ligands of Toll-Like Receptor 5 or Toll-Like Receptor 9. PLoS One 2016; 11:e0167693. [PMID: 27977701 PMCID: PMC5157987 DOI: 10.1371/journal.pone.0167693] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2016] [Accepted: 10/22/2016] [Indexed: 01/09/2023] Open
Abstract
Excessive type 2 helper T cell responses to environmental antigens can cause immunopathology such as asthma and allergy, but how such immune responses are induced remains unclear. We studied this process in the airways by immunizing mice intranasally with the antigen ovalbumin together with either of two Toll-like receptor (TLR) ligands. We found the TLR5 ligand flagellin promoted a type 2 helper T cell response, whereas, a TLR9 ligand CpG oligodeoxyribonucleotide (ODN) promoted a type 1 helper T cell response. CpG ODN induced mRNA encoding interleukin (IL)-12 p40, whereas, flagellin caused IL-33 secretion and induced mRNAs encoding IL-1 and thymic stromal lymphopoietin (TSLP). By using mice deficient in the TLR and IL-1R signaling molecule, myeloid differentiation primary response 88 (MyD88), in conventional dendritic cells (cDCs) and alveolar macrophages (AMs), and by cell sorting different lung populations after 2 hours of in vivo stimulation, we characterized the cell types that rapidly produced inflammatory cytokines in response to TLR stimulation. CpG ODN was likely recognized by TLR9 on cDCs and AMs, which made mRNA encoding IL-12. IL-12 was necessary for the subsequent innate and adaptive interferon-γ production. In contrast, flagellin stimulated multiple cells of hematopoietic and non-hematopoietic origin, including AMs, DCs, monocytes, and lung epithelial cells. AMs were largely responsible for IL-1α, whereas lung epithelial cells made TSLP. Multiple hematopoietic cells, including AMs, DCs, and monocytes contributed to other cytokines, including IL-1β and TNFα. MyD88-dependent signals, likely through IL-1R and IL-33R, and MyD88-independent signals, likely from TSLP, were necessary in cDCs for promotion of the early IL-4 response by CD4 T cells in the draining lymph node. Thus, the cell types that responded to TLR ligands were a critical determinant of the innate cytokines produced and the character of the resulting adaptive immune response in the airways.
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14
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Nouri K, Fansa EK, Amin E, Dvorsky R, Gremer L, Willbold D, Schmitt L, Timson DJ, Ahmadian MR. IQGAP1 Interaction with RHO Family Proteins Revisited: KINETIC AND EQUILIBRIUM EVIDENCE FOR MULTIPLE DISTINCT BINDING SITES. J Biol Chem 2016; 291:26364-26376. [PMID: 27815503 PMCID: PMC5159498 DOI: 10.1074/jbc.m116.752121] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2016] [Revised: 10/27/2016] [Indexed: 11/16/2022] Open
Abstract
IQ motif-containing GTPase activating protein 1 (IQGAP1) plays a central role in the physical assembly of relevant signaling networks that are responsible for various cellular processes, including cell adhesion, polarity, and transmigration. The RHO family proteins CDC42 and RAC1 have been shown to mainly interact with the GAP-related domain (GRD) of IQGAP1. However, the role of its RASGAP C-terminal (RGCT) and C-terminal domains in the interactions with RHO proteins has remained obscure. Here, we demonstrate that IQGAP1 interactions with RHO proteins underlie a multiple-step binding mechanism: (i) a high affinity, GTP-dependent binding of RGCT to the switch regions of CDC42 or RAC1 and (ii) a very low affinity binding of GRD and a C terminus adjacent to the switch regions. These data were confirmed by phosphomimetic mutation of serine 1443 to glutamate within RGCT, which led to a significant reduction of IQGAP1 affinity for CDC42 and RAC1, clearly disclosing the critical role of RGCT for these interactions. Unlike CDC42, an extremely low affinity was determined for the RAC1-GRD interaction, suggesting that the molecular nature of IQGAP1 interaction with CDC42 partially differs from that of RAC1. Our study provides new insights into the interaction characteristics of IQGAP1 with RHO family proteins and highlights the complementary importance of kinetic and equilibrium analyses. We propose that the ability of IQGAP1 to interact with RHO proteins is based on a multiple-step binding process, which is a prerequisite for the dynamic functions of IQGAP1 as a scaffolding protein and a critical mechanism in temporal regulation and integration of IQGAP1-mediated cellular responses.
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Affiliation(s)
- Kazem Nouri
- From the Institute of Biochemistry and Molecular Biology II, Medical Faculty of the Heinrich-Heine University, 40225 Düsseldorf, Germany
| | - Eyad K Fansa
- From the Institute of Biochemistry and Molecular Biology II, Medical Faculty of the Heinrich-Heine University, 40225 Düsseldorf, Germany
| | - Ehsan Amin
- From the Institute of Biochemistry and Molecular Biology II, Medical Faculty of the Heinrich-Heine University, 40225 Düsseldorf, Germany
| | - Radovan Dvorsky
- From the Institute of Biochemistry and Molecular Biology II, Medical Faculty of the Heinrich-Heine University, 40225 Düsseldorf, Germany
| | - Lothar Gremer
- the Institute of Physical Biology, Heinrich-Heine University, 40225 Düsseldorf, Germany.,Forschungszentrum Jülich, ICS-6, 52428 Jülich, Germany
| | - Dieter Willbold
- the Institute of Physical Biology, Heinrich-Heine University, 40225 Düsseldorf, Germany.,Forschungszentrum Jülich, ICS-6, 52428 Jülich, Germany
| | - Lutz Schmitt
- the Institute of Biochemistry, Heinrich-Heine University, 40225 Düsseldorf, Germany, and
| | - David J Timson
- the School of Pharmacy and Biomolecular Sciences, University of Brighton, Huxley Building, Lewes Road, Brighton BN2 4GJ, United Kingdom
| | - Mohammad R Ahmadian
- From the Institute of Biochemistry and Molecular Biology II, Medical Faculty of the Heinrich-Heine University, 40225 Düsseldorf, Germany,
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15
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Khalifeh-Soltani A, Ha A, Podolsky MJ, McCarthy DA, McKleroy W, Azary S, Sakuma S, Tharp KM, Wu N, Yokosaki Y, Hart D, Stahl A, Atabai K. α8β1 integrin regulates nutrient absorption through an Mfge8-PTEN dependent mechanism. eLife 2016; 5. [PMID: 27092791 PMCID: PMC4868538 DOI: 10.7554/elife.13063] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2015] [Accepted: 04/18/2016] [Indexed: 12/25/2022] Open
Abstract
Coordinated gastrointestinal smooth muscle contraction is critical for proper nutrient absorption and is altered in a number of medical disorders. In this work, we demonstrate a critical role for the RGD-binding integrin α8β1 in promoting nutrient absorption through regulation of gastrointestinal motility. Smooth muscle-specific deletion and antibody blockade of α8 in mice result in enhanced gastric antral smooth muscle contraction, more rapid gastric emptying, and more rapid transit of food through the small intestine leading to malabsorption of dietary fats and carbohydrates as well as protection from weight gain in a diet-induced model of obesity. Mechanistically, ligation of α8β1 by the milk protein Mfge8 reduces antral smooth muscle contractile force by preventing RhoA activation through a PTEN-dependent mechanism. Collectively, our results identify a role for α8β1 in regulating gastrointestinal motility and identify α8 as a potential target for disorders characterized by hypo- or hyper-motility. DOI:http://dx.doi.org/10.7554/eLife.13063.001 Animals absorb nutrients from the food they eat in a complicated process that involves multiple steps. In the mouth, teeth break down the food into smaller chunks. Then the food passes through the stomach and small intestine, where enzymes break it down into individual molecules that are small enough to be absorbed by cells that line the small intestine. These cells then package the molecules and release them into the bloodstream so that they can be distributed to the rest of the body. Muscles in the wall of the small intestine control how quickly food travels through this part of the gut. If food moves too quickly, the cells that line the intestine have less time to absorb the food molecules and may fail to absorb enough nutrients. If the food moves too slowly, an individual may experience nausea or vomiting, or the contents of their stomach may spill into their lungs. In 2014, researchers reported that a protein in breast milk called Mfge8 helps to boost the number of fat molecules absorbed from food. Now, Khalifeh-Soltani et al. – including some of the same researchers involved in the earlier work – show that Mfge8 also slows the rate at which food travels through the small intestine in mice. Mfge8 binds to another protein called integrin α8β1 to control how often the intestine muscles contract. Genetically engineered mice that lacked integrin α8β1 developed diarrhea and food passed through their intestines more quickly than in normal mice. Furthermore, these mice did not gain as much weight as normal mice when they were fed a high-fat diet. Khalifeh-Soltani et al.’s findings show that Mfge8 has a dual role in controlling the absorption of food molecules in the small intestine. The next challenge is to find out whether drugs that alter the activity of integrin α8β1 could be used to help treat patients with diseases in which food moves too quickly, or too slowly, through the gut. DOI:http://dx.doi.org/10.7554/eLife.13063.002
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Affiliation(s)
- Amin Khalifeh-Soltani
- Cardiovascular Research Institute, University of California, San Francisco, San Francisco, United States.,Department of Medicine, University of California, San Francisco, San Francisco, United States
| | - Arnold Ha
- Cardiovascular Research Institute, University of California, San Francisco, San Francisco, United States
| | - Michael J Podolsky
- Cardiovascular Research Institute, University of California, San Francisco, San Francisco, United States.,Department of Medicine, University of California, San Francisco, San Francisco, United States
| | - Donald A McCarthy
- Cardiovascular Research Institute, University of California, San Francisco, San Francisco, United States
| | - William McKleroy
- Cardiovascular Research Institute, University of California, San Francisco, San Francisco, United States
| | - Saeedeh Azary
- Cardiovascular Research Institute, University of California, San Francisco, San Francisco, United States
| | - Stephen Sakuma
- Cardiovascular Research Institute, University of California, San Francisco, San Francisco, United States
| | - Kevin M Tharp
- Metabolic Biology, University of California, Berkeley, Berkeley, United States.,Department of Nutritional Sciences and Toxicology, University of California, Berkeley, Berkeley, United States
| | - Nanyan Wu
- Lung Biology Center, University of California, San Francisco, San Francisco, United States
| | - Yasuyuki Yokosaki
- Cell-Matrix Frontier Laboratory, Biomedical Research Unit, Health Administration Center, Hiroshima University, Hiroshima, Japan
| | - Daniel Hart
- Cardiovascular Research Institute, University of California, San Francisco, San Francisco, United States
| | - Andreas Stahl
- Metabolic Biology, University of California, Berkeley, Berkeley, United States.,Department of Nutritional Sciences and Toxicology, University of California, Berkeley, Berkeley, United States
| | - Kamran Atabai
- Cardiovascular Research Institute, University of California, San Francisco, San Francisco, United States.,Department of Medicine, University of California, San Francisco, San Francisco, United States.,Lung Biology Center, University of California, San Francisco, San Francisco, United States
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16
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Abstract
Glucocorticoids are the most effective treatment for asthma. However, their clinical applications are limited by low efficacy in severe asthma and by undesired side effects associated with high dose or prolonged use. The most successful approach to overcome these limitations has been the development of highly potent glucocorticoids that can be delivered to the lungs by inhalation to achieve local efficacy with minimal systemic effects. On the basis of our previous structural studies, we designed and developed a highly potent glucocorticoid, VSGC12, which showed an improved anti-inflammation activity in both cell-based reporter assays and cytokine inhibition experiments, as well as in a gene expression profiling of mouse macrophage RAW264.7 cells. In a mouse asthma model, VSGC12 delivered a higher efficacy than fluticasone furoate, a leading clinical compound, in many categories including histology and the number of differentiated immune cells. VSGC12 also showed a higher potency than fluticasone furoate in repressing most asthma symptoms. Finally, VSGC12 showed a better side effect profile than fluticasone furoate at their respective effective doses, including better insulin response and less bone loss in an animal model. The excellent therapeutic and side effect properties of VSGC12 provide a promising perspective for developing this potent glucocorticoid as a new effective drug for asthma.
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17
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Hedman AC, Smith JM, Sacks DB. The biology of IQGAP proteins: beyond the cytoskeleton. EMBO Rep 2015; 16:427-46. [PMID: 25722290 DOI: 10.15252/embr.201439834] [Citation(s) in RCA: 145] [Impact Index Per Article: 16.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2014] [Accepted: 01/07/2015] [Indexed: 01/02/2023] Open
Abstract
IQGAP scaffold proteins are evolutionarily conserved in eukaryotes and facilitate the formation of complexes that regulate cytoskeletal dynamics, intracellular signaling, and intercellular interactions. Fungal and mammalian IQGAPs are implicated in cytokinesis. IQGAP1, IQGAP2, and IQGAP3 have diverse roles in vertebrate physiology, operating in the kidney, nervous system, cardio-vascular system, pancreas, and lung. The functions of IQGAPs can be corrupted during oncogenesis and are usurped by microbial pathogens. Therefore, IQGAPs represent intriguing candidates for novel therapeutic agents. While modulation of the cytoskeletal architecture was initially thought to be the primary function of IQGAPs, it is now clear that they have roles beyond the cytoskeleton. This review describes contributions of IQGAPs to physiology at the organism level.
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Affiliation(s)
- Andrew C Hedman
- Department of Laboratory Medicine, National Institutes of Health, Bethesda, MD, USA
| | - Jessica M Smith
- Department of Laboratory Medicine, National Institutes of Health, Bethesda, MD, USA
| | - David B Sacks
- Department of Laboratory Medicine, National Institutes of Health, Bethesda, MD, USA
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