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Luft FC. Calcineurin inhibition, cardiovascular consequences, vascular resistance, and potential responses. Acta Physiol (Oxf) 2024; 240:e14084. [PMID: 38214031 DOI: 10.1111/apha.14084] [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] [Received: 08/18/2023] [Revised: 10/20/2023] [Accepted: 01/01/2024] [Indexed: 01/13/2024]
Abstract
AIM To place the consequences of calcineurin inhibition in a cardiovascular context. METHODS Literature review coupled with personal encounters. RESULTS Calcineurin is a calcium-binding and calmodulin-binding protein that is conserved across evolution from yeast to mammals. The enzyme functions as a calcium-dependent, calmodulin-stimulated protein phosphatase. Its role in regulating physiology has largely been elucidated by observing calcineurin inhibition. Calcineurin inhibition transformed organ transplantation from an experiment into a therapy and made much of general immunotherapy possible. The function of this phosphatase and how its inhibition leads to toxicity concern us to this date. Initial research from patients and animal models implicated a panoply of factors contributing to hypertension and vasculopathy. Subsequently, the role of calcineurin in regulating the effective fluid volume, sodium reabsorption, and potassium and hydrogen ion excretion was elucidated by investigating calcineurin inhibition. Understanding the regulatory effects of calcineurin on endothelial and vascular smooth muscle cell function has also made substantial progress. However, precisely how the increase in systemic vascular resistance arises requires further mechanistic research. CONCLUSION Calcineurin inhibition continues to save lives; however, options to counteract the negative effects of calcineurin inhibition should be vigorously pursued.
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Affiliation(s)
- Friedrich C Luft
- Experimental and Clinical Research Center, a cooperation between the Max-Delbrück Center for Molecular Medicine and the Charité Medical Faculty, Berlin, Germany
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2
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Nolze A, Matern S, Grossmann C. Calcineurin Is a Universal Regulator of Vessel Function-Focus on Vascular Smooth Muscle Cells. Cells 2023; 12:2269. [PMID: 37759492 PMCID: PMC10528183 DOI: 10.3390/cells12182269] [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] [Received: 07/19/2023] [Revised: 09/05/2023] [Accepted: 09/08/2023] [Indexed: 09/29/2023] Open
Abstract
Calcineurin, a serine/threonine phosphatase regulating transcription factors like NFaT and CREB, is well known for its immune modulatory effects and role in cardiac hypertrophy. Results from experiments with calcineurin knockout animals and calcineurin inhibitors indicate that calcineurin also plays a crucial role in vascular function, especially in vascular smooth muscle cells (VSMCs). In the aorta, calcineurin stimulates the proliferation and migration of VSMCs in response to vascular injury or angiotensin II administration, leading to pathological vessel wall thickening. In the heart, calcineurin mediates coronary artery formation and VSMC differentiation, which are crucial for proper heart development. In pulmonary VSMCs, calcineurin/NFaT signaling regulates the release of Ca2+, resulting in increased vascular tone followed by pulmonary arterial hypertension. In renal VSMCs, calcineurin regulates extracellular matrix secretion promoting fibrosis development. In the mesenteric and cerebral arteries, calcineurin mediates a phenotypic switch of VSMCs leading to altered cell function. Gaining deeper insights into the underlying mechanisms of calcineurin signaling will help researchers to understand developmental and pathogenetical aspects of the vasculature. In this review, we provide an overview of the physiological function and pathophysiology of calcineurin in the vascular system with a focus on vascular smooth muscle cells in different organs. Overall, there are indications that under certain pathological settings reduced calcineurin activity seems to be beneficial for cardiovascular health.
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Affiliation(s)
| | | | - Claudia Grossmann
- Julius Bernstein Institute of Physiology, Martin Luther University Halle-Wittenberg, 06112 Halle (Saale), Germany
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3
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Tiwari D, Ahuja N, Kumar S, Kalra R, Nanduri R, Gupta S, Khare AK, Bhagyaraj E, Arora R, Gupta P. Nuclear receptor Nr1d1 alleviates asthma by abating GATA3 gene expression and Th2 cell differentiation. Cell Mol Life Sci 2022; 79:308. [PMID: 35596832 PMCID: PMC11073070 DOI: 10.1007/s00018-022-04323-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2021] [Revised: 03/30/2022] [Accepted: 04/21/2022] [Indexed: 11/03/2022]
Abstract
Nuclear receptors are a unique family of transcription factors that play cardinal roles in physiology and plethora of human diseases. The adopted orphan nuclear receptor Nr1d1 is a constitutive transcriptional repressor known to modulate several biological processes. In this study, we found that Nr1d1 plays a decisive role in T helper (Th)-cell polarization and transcriptionally impedes the formation of Th2 cells by directly binding to the promoter region of GATA binding protein 3 (GATA3) gene. Nr1d1 interacts with its cellular companion, the nuclear receptor corepressor and histone deacetylase 3 to form a stable repression complex on the GATA3 promoter. The presence of Nr1d1 also imparts protection against associated inflammatory responses in murine model of asthma and its ligand SR9011 eased disease severity by suppressing Th2 responses. Moreover, Chip-seq profiling uncovered Nr1d1 interactions with other gene subsets that impedes Th2-linked pathways and regulates metabolism, immunity and brain functions, therefore, providing empirical evidence regarding the genetic link between asthma and other comorbid conditions. Thus, Nr1d1 emerges as a molecular switch that could be targeted to subdue asthma.
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Affiliation(s)
- Drishti Tiwari
- Department of Molecular Immunology, Council of Scientific and Industrial Research, Institute of Microbial Technology, Sector 39A, Chandigarh, 160036, India.
| | - Nancy Ahuja
- Department of Molecular Immunology, Council of Scientific and Industrial Research, Institute of Microbial Technology, Sector 39A, Chandigarh, 160036, India
| | - Sumit Kumar
- Department of Molecular Immunology, Council of Scientific and Industrial Research, Institute of Microbial Technology, Sector 39A, Chandigarh, 160036, India
| | - Rashi Kalra
- Department of Molecular Immunology, Council of Scientific and Industrial Research, Institute of Microbial Technology, Sector 39A, Chandigarh, 160036, India
- Lester and Sue Smith Breast Center, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Ravikanth Nanduri
- Department of Molecular Immunology, Council of Scientific and Industrial Research, Institute of Microbial Technology, Sector 39A, Chandigarh, 160036, India
- Center for Cancer Research, National Cancer Institute, Bethesda, MD, 20892, USA
| | - Shalini Gupta
- Department of Molecular Immunology, Council of Scientific and Industrial Research, Institute of Microbial Technology, Sector 39A, Chandigarh, 160036, India
| | - Asheesh Kumar Khare
- Department of Molecular Immunology, Council of Scientific and Industrial Research, Institute of Microbial Technology, Sector 39A, Chandigarh, 160036, India
| | - Ella Bhagyaraj
- Department of Molecular Immunology, Council of Scientific and Industrial Research, Institute of Microbial Technology, Sector 39A, Chandigarh, 160036, India
- Department of Infectious Disease and Immunology, University of Florida, Gainesville, FL, USA
| | - Rashmi Arora
- Department of Molecular Immunology, Council of Scientific and Industrial Research, Institute of Microbial Technology, Sector 39A, Chandigarh, 160036, India
| | - Pawan Gupta
- Department of Molecular Immunology, Council of Scientific and Industrial Research, Institute of Microbial Technology, Sector 39A, Chandigarh, 160036, India.
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4
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Williams RB, Johnson CN. A Review of Calcineurin Biophysics with Implications for Cardiac Physiology. Int J Mol Sci 2021; 22:ijms222111565. [PMID: 34768996 PMCID: PMC8583826 DOI: 10.3390/ijms222111565] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2021] [Revised: 10/20/2021] [Accepted: 10/21/2021] [Indexed: 12/20/2022] Open
Abstract
Calcineurin, also known as protein phosphatase 2B, is a heterodimeric serine threonine phosphatase involved in numerous signaling pathways. During the past 50 years, calcineurin has been the subject of extensive investigation. Many of its cellular and physiological functions have been described, and the underlying biophysical mechanisms are the subject of active investigation. With the abundance of techniques and experimental designs utilized to study calcineurin and its numerous substrates, it is difficult to reconcile the available information. There have been a plethora of reports describing the role of calcineurin in cardiac disease. However, a physiological role of calcineurin in healthy cardiomyocyte function requires clarification. Here, we review the seminal biophysical and structural details that are responsible for the molecular function and inhibition of calcineurin. We then focus on literature describing the roles of calcineurin in cardiomyocyte physiology and disease.
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Affiliation(s)
- Ryan B. Williams
- Department of Chemistry, Mississippi State University, Starkville, MS 39759, USA;
| | - Christopher N. Johnson
- Department of Chemistry, Mississippi State University, Starkville, MS 39759, USA;
- Center for Arrhythmia Research and Therapeutics, Vanderbilt University Medical Center, Nashville, TN 37232, USA
- Correspondence:
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5
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Sagar S, Kapoor H, Chaudhary N, Roy SS. Cellular and mitochondrial calcium communication in obstructive lung disorders. Mitochondrion 2021; 58:184-199. [PMID: 33766748 DOI: 10.1016/j.mito.2021.03.005] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2020] [Revised: 03/03/2021] [Accepted: 03/15/2021] [Indexed: 12/14/2022]
Abstract
Calcium (Ca2+) signalling is well known to dictate cellular functioning and fate. In recent years, the accumulation of Ca2+ in the mitochondria has emerged as an important factor in Chronic Respiratory Diseases (CRD) such as Asthma and Chronic Obstructive Pulmonary Disease (COPD). Various reports underline an aberrant increase in the intracellular Ca2+, leading to mitochondrial ROS generation, and further activation of the apoptotic pathway in these diseases. Mitochondria contribute to Ca2+ buffering which in turn regulates mitochondrial metabolism and ATP production. Disruption of this Ca2+ balance leads to impaired cellular processes like apoptosis or necrosis and thus contributes to the pathophysiology of airway diseases. This review highlights the key role of cytoplasmic and mitochondrial Ca2+ signalling in regulating CRD, such as asthma and COPD. A better understanding of the dysregulation of mitochondrial Ca2+ homeostasis in these diseases could provide cues for the development of advanced therapeutic interventions in these diseases.
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Affiliation(s)
- Shakti Sagar
- CSIR-Institute of Genomics & Integrative Biology, New Delhi, India; Academy of Scientific & Innovative Research (AcSIR), Ghaziabad 201002, India
| | - Himanshi Kapoor
- CSIR-Institute of Genomics & Integrative Biology, New Delhi, India
| | - Nisha Chaudhary
- Multidisciplinary Center for Advanced Research and Studies, Jamia Millia Islamia, New Delhi, India
| | - Soumya Sinha Roy
- CSIR-Institute of Genomics & Integrative Biology, New Delhi, India; Academy of Scientific & Innovative Research (AcSIR), Ghaziabad 201002, India.
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6
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Du X, Zhi J, Yang D, Wang Q, Luo X, Deng X. Research progress in the mechanism of calcium ion on contraction and relaxation of airway smooth muscle cells. J Recept Signal Transduct Res 2020; 41:117-122. [PMID: 32808844 DOI: 10.1080/10799893.2020.1806315] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
lntracellular calcium ion is the key secondary messenger system of the cellular processes in airway smooth muscle cells(ASMc). The treatment and regulation of Ca2+ in airway smooth muscle (ASM) is, in part, to associated with many airway diseases such as asthma, COPD and pulmonary fibrosis. The mechanism of contraction and relaxation of ASM is a concerned aspect in airway diseases. This review emphasizes established and recent discoveries whice show the research progress of Ca2+ on cell contraction and relaxation in ASM in recent years, to provide theoretical support and new targets for clinical prevention and treatment of perioperative bronchospasm and variousrespiratory related diseases.
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Affiliation(s)
- Xiyu Du
- Department of Anesthesiology, Plastic Surgery Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Juan Zhi
- Department of Anesthesiology, Plastic Surgery Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Dong Yang
- Department of Anesthesiology, Plastic Surgery Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Qianyu Wang
- Department of Anesthesiology, Plastic Surgery Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Xiang Luo
- Department of Anesthesiology, Plastic Surgery Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Xiaoming Deng
- Department of Anesthesiology, Plastic Surgery Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
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7
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Shi R, Xu JW, Xiao ZT, Chen RF, Zhang YL, Lin JB, Cheng KL, Wei GY, Li PB, Zhou WL, Su WW. Naringin and Naringenin Relax Rat Tracheal Smooth by Regulating BK Ca Activation. J Med Food 2019; 22:963-970. [PMID: 31259654 DOI: 10.1089/jmf.2018.4364] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Naringin and its aglycone, naringenin, occur naturally in our regular diet and traditional Chinese medicines. This study aimed to detect an effective therapeutic approach for cough variant asthma (CVA) through evaluating the relaxant effect of these two bioactive herbal monomers as antitussive and antiasthmatic on rat tracheal smooth muscle. The relaxant effect was determined by measuring muscular tension with a mechanical recording system in rat tracheal rings. Cytosolic Ca2+ concentration was measured using a confocal imaging system in primary cultured tracheal smooth muscle cells. In rat tracheal rings, addition of both naringin and naringenin could concentration dependently relax carbachol (CCh)-evoked tonic contraction. This epithelium-independent relaxation could be suppressed by BaCl2, tetraethylammonium, and iberiotoxin (IbTX), but not by glibenclamide. After stimulating primary cultured tracheal smooth muscle cells by CCh or high KCl, the intracellular Ca2+ increase could be inhibited by both naringin and naringenin, respectively. This reaction was also suppressed by IbTX. These results demonstrate that both naringin and naringenin can relax tracheal smooth muscle through opening big conductance Ca2+-activated K+ channel, which mediates plasma membrane hyperpolarization and reduces Ca2+ influx. Our data indicate a potentially effective therapeutic approach of naringin and naringenin for CVA.
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Affiliation(s)
- Rui Shi
- Guangdong Engineering and Technology Research Center for Quality and Efficacy Reevaluation of Postmarket Traditional Chinese Medicine, School of Life Sciences, Sun Yat-sen University, Guangzhou, China.,State Key Laboratory of Biocontrol and Guangdong Provincial Key Laboratory of Plant Resources, School of Life Sciences, Sun Yat-sen University, Guangzhou, China.,School of Life Sciences, Sun Yat-sen University, Guangzhou, China
| | - Jia-Wen Xu
- School of Life Sciences, Sun Yat-sen University, Guangzhou, China
| | - Zi-Ting Xiao
- Guangdong Engineering and Technology Research Center for Quality and Efficacy Reevaluation of Postmarket Traditional Chinese Medicine, School of Life Sciences, Sun Yat-sen University, Guangzhou, China.,State Key Laboratory of Biocontrol and Guangdong Provincial Key Laboratory of Plant Resources, School of Life Sciences, Sun Yat-sen University, Guangzhou, China.,School of Life Sciences, Sun Yat-sen University, Guangzhou, China
| | - Ruo-Fei Chen
- School of Life Sciences, Sun Yat-sen University, Guangzhou, China
| | - Yi-Lin Zhang
- School of Life Sciences, Sun Yat-sen University, Guangzhou, China
| | - Jia-Bi Lin
- Guangdong Engineering and Technology Research Center for Quality and Efficacy Reevaluation of Postmarket Traditional Chinese Medicine, School of Life Sciences, Sun Yat-sen University, Guangzhou, China.,State Key Laboratory of Biocontrol and Guangdong Provincial Key Laboratory of Plant Resources, School of Life Sciences, Sun Yat-sen University, Guangzhou, China.,School of Life Sciences, Sun Yat-sen University, Guangzhou, China
| | - Ke-Ling Cheng
- Guangdong Engineering and Technology Research Center for Quality and Efficacy Reevaluation of Postmarket Traditional Chinese Medicine, School of Life Sciences, Sun Yat-sen University, Guangzhou, China.,State Key Laboratory of Biocontrol and Guangdong Provincial Key Laboratory of Plant Resources, School of Life Sciences, Sun Yat-sen University, Guangzhou, China.,School of Life Sciences, Sun Yat-sen University, Guangzhou, China
| | - Gu-Yi Wei
- Guangdong Engineering and Technology Research Center for Quality and Efficacy Reevaluation of Postmarket Traditional Chinese Medicine, School of Life Sciences, Sun Yat-sen University, Guangzhou, China.,State Key Laboratory of Biocontrol and Guangdong Provincial Key Laboratory of Plant Resources, School of Life Sciences, Sun Yat-sen University, Guangzhou, China.,School of Life Sciences, Sun Yat-sen University, Guangzhou, China
| | - Pei-Bo Li
- Guangdong Engineering and Technology Research Center for Quality and Efficacy Reevaluation of Postmarket Traditional Chinese Medicine, School of Life Sciences, Sun Yat-sen University, Guangzhou, China.,State Key Laboratory of Biocontrol and Guangdong Provincial Key Laboratory of Plant Resources, School of Life Sciences, Sun Yat-sen University, Guangzhou, China.,School of Life Sciences, Sun Yat-sen University, Guangzhou, China
| | - Wen-Liang Zhou
- School of Life Sciences, Sun Yat-sen University, Guangzhou, China
| | - Wei-Wei Su
- Guangdong Engineering and Technology Research Center for Quality and Efficacy Reevaluation of Postmarket Traditional Chinese Medicine, School of Life Sciences, Sun Yat-sen University, Guangzhou, China.,State Key Laboratory of Biocontrol and Guangdong Provincial Key Laboratory of Plant Resources, School of Life Sciences, Sun Yat-sen University, Guangzhou, China.,School of Life Sciences, Sun Yat-sen University, Guangzhou, China
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8
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Tykocki NR, Boerman EM, Jackson WF. Smooth Muscle Ion Channels and Regulation of Vascular Tone in Resistance Arteries and Arterioles. Compr Physiol 2017; 7:485-581. [PMID: 28333380 DOI: 10.1002/cphy.c160011] [Citation(s) in RCA: 212] [Impact Index Per Article: 30.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Vascular tone of resistance arteries and arterioles determines peripheral vascular resistance, contributing to the regulation of blood pressure and blood flow to, and within the body's tissues and organs. Ion channels in the plasma membrane and endoplasmic reticulum of vascular smooth muscle cells (SMCs) in these blood vessels importantly contribute to the regulation of intracellular Ca2+ concentration, the primary determinant of SMC contractile activity and vascular tone. Ion channels provide the main source of activator Ca2+ that determines vascular tone, and strongly contribute to setting and regulating membrane potential, which, in turn, regulates the open-state-probability of voltage gated Ca2+ channels (VGCCs), the primary source of Ca2+ in resistance artery and arteriolar SMCs. Ion channel function is also modulated by vasoconstrictors and vasodilators, contributing to all aspects of the regulation of vascular tone. This review will focus on the physiology of VGCCs, voltage-gated K+ (KV) channels, large-conductance Ca2+-activated K+ (BKCa) channels, strong-inward-rectifier K+ (KIR) channels, ATP-sensitive K+ (KATP) channels, ryanodine receptors (RyRs), inositol 1,4,5-trisphosphate receptors (IP3Rs), and a variety of transient receptor potential (TRP) channels that contribute to pressure-induced myogenic tone in resistance arteries and arterioles, the modulation of the function of these ion channels by vasoconstrictors and vasodilators, their role in the functional regulation of tissue blood flow and their dysfunction in diseases such as hypertension, obesity, and diabetes. © 2017 American Physiological Society. Compr Physiol 7:485-581, 2017.
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Affiliation(s)
- Nathan R Tykocki
- Department of Pharmacology, University of Vermont, Burlington, Vermont, USA
| | - Erika M Boerman
- Department of Medical Pharmacology and Physiology, University of Missouri, Columbia, Missouri, USA
| | - William F Jackson
- Department of Pharmacology and Toxicology, Michigan State University, East Lansing, Michigan, USA
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9
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Prakash YS. Emerging concepts in smooth muscle contributions to airway structure and function: implications for health and disease. Am J Physiol Lung Cell Mol Physiol 2016; 311:L1113-L1140. [PMID: 27742732 DOI: 10.1152/ajplung.00370.2016] [Citation(s) in RCA: 99] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2016] [Accepted: 10/06/2016] [Indexed: 12/15/2022] Open
Abstract
Airway structure and function are key aspects of normal lung development, growth, and aging, as well as of lung responses to the environment and the pathophysiology of important diseases such as asthma, chronic obstructive pulmonary disease, and fibrosis. In this regard, the contributions of airway smooth muscle (ASM) are both functional, in the context of airway contractility and relaxation, as well as synthetic, involving production and modulation of extracellular components, modulation of the local immune environment, cellular contribution to airway structure, and, finally, interactions with other airway cell types such as epithelium, fibroblasts, and nerves. These ASM contributions are now found to be critical in airway hyperresponsiveness and remodeling that occur in lung diseases. This review emphasizes established and recent discoveries that underline the central role of ASM and sets the stage for future research toward understanding how ASM plays a central role by being both upstream and downstream in the many interactive processes that determine airway structure and function in health and disease.
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Affiliation(s)
- Y S Prakash
- Departments of Anesthesiology, and Physiology & Biomedical Engineering, Mayo Clinic, Rochester, Minnesota
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Liachko NF, Saxton AD, McMillan PJ, Strovas TJ, Currey HN, Taylor LM, Wheeler JM, Oblak AL, Ghetti B, Montine TJ, Keene CD, Raskind MA, Bird TD, Kraemer BC. The phosphatase calcineurin regulates pathological TDP-43 phosphorylation. Acta Neuropathol 2016; 132:545-61. [PMID: 27473149 DOI: 10.1007/s00401-016-1600-y] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2016] [Revised: 07/20/2016] [Accepted: 07/21/2016] [Indexed: 12/12/2022]
Abstract
Detergent insoluble inclusions of TDP-43 protein are hallmarks of the neuropathology in over 90 % of amyotrophic lateral sclerosis (ALS) cases and approximately half of frontotemporal dementia (FTLD-TDP) cases. In TDP-43 proteinopathy disorders, lesions containing aggregated TDP-43 protein are extensively post-translationally modified, with phosphorylated TDP-43 (pTDP) being the most consistent and robust marker of pathological TDP-43 deposition. Abnormally phosphorylated TDP-43 has been hypothesized to mediate TDP-43 toxicity in many neurodegenerative disease models. To date, several different kinases have been implicated in the genesis of pTDP, but no phosphatases have been shown to reverse pathological TDP-43 phosphorylation. We have identified the phosphatase calcineurin as an enzyme binding to and catalyzing the removal of pathological C-terminal phosphorylation of TDP-43 in vitro. In C. elegans models of TDP-43 proteinopathy, genetic elimination of calcineurin results in accumulation of excess pTDP, exacerbated motor dysfunction, and accelerated neurodegenerative changes. In cultured human cells, treatment with FK506 (tacrolimus), a calcineurin inhibitor, results in accumulation of pTDP species. Lastly, calcineurin co-localizes with pTDP in degenerating areas of the central nervous system in subjects with FTLD-TDP and ALS. Taken together, these findings suggest calcineurin acts on pTDP as a phosphatase in neurons. Furthermore, patient treatment with calcineurin inhibitors may have unappreciated adverse neuropathological consequences.
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