1
|
Brīvība M, Silamiķele L, Kalniņa I, Silamiķelis I, Birzniece L, Ansone L, Jagare L, Elbere I, Kloviņš J. Metformin targets intestinal immune system signaling pathways in a high-fat diet-induced mouse model of obesity and insulin resistance. Front Endocrinol (Lausanne) 2023; 14:1232143. [PMID: 37795356 PMCID: PMC10546317 DOI: 10.3389/fendo.2023.1232143] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/31/2023] [Accepted: 08/23/2023] [Indexed: 10/06/2023] Open
Abstract
Introduction Research findings of the past decade have highlighted the gut as the main site of action of the oral antihyperglycemic agent metformin despite its pharmacological role in the liver. Extensive evidence supports metformin's modulatory effect on the composition and function of gut microbiota, nevertheless, the underlying mechanisms of the host responses remain elusive. Our study aimed to evaluate metformin-induced alterations in the intestinal transcriptome profiles at different metabolic states. Methods The high-fat diet-induced mouse model of obesity and insulin resistance of both sexes was developed in a randomized block experiment and bulk RNA-Seq of the ileum tissue was the method of choice for comparative transcriptional profiling after metformin intervention for ten weeks. Results We found a prominent transcriptional effect of the diet itself with comparatively fewer genes responding to metformin intervention. The overrepresentation of immune-related genes was observed, including pronounced metformin-induced upregulation of immunoglobulin heavy-chain variable region coding Ighv1-7 gene in both high-fat diet and control diet-fed animals. Moreover, we provide evidence of the downregulation NF-kappa B signaling pathway in the small intestine of both obese and insulin-resistant animals as well as control animals after metformin treatment. Finally, our data pinpoint the gut microbiota as a crucial component in the metformin-mediated downregulation of NF-kappa B signaling evidenced by a positive correlation between the Rel and Rela gene expression levels and abundances of Parabacteroides distasonis, Bacteroides spp., and Lactobacillus spp. in the gut microbiota of the same animals. Discussion Our study supports the immunomodulatory effect of metformin in the ileum of obese and insulin-resistant C57BL/6N mice contributed by intestinal immunoglobulin responses, with a prominent emphasis on the downregulation of NF-kappa B signaling pathway, associated with alterations in the composition of the gut microbiome.
Collapse
Affiliation(s)
- Monta Brīvība
- Latvian Biomedical Research and Study Centre, Riga, Latvia
| | | | | | | | | | | | | | | | | |
Collapse
|
2
|
Xiong X, Zhang X, Yang M, Zhu Y, Yu H, Fei X, Mastuda F, Lan D, Xiong Y, Fu W, Yin S, Li J. Oocyte-Specific Knockout of Histone Lysine Demethylase KDM2a Compromises Fertility by Blocking the Development of Follicles and Oocytes. Int J Mol Sci 2022; 23:ijms231912008. [PMID: 36233308 PMCID: PMC9570323 DOI: 10.3390/ijms231912008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2022] [Revised: 10/07/2022] [Accepted: 10/07/2022] [Indexed: 11/05/2022] Open
Abstract
The methylation status of histones plays a crucial role in many cellular processes, including follicular and oocyte development. Lysine-specific demethylase 2a (KDM2a) has been reported to be closely associated with gametogenesis and reproductive performance, but the specific function and regulatory mechanism have been poorly characterized in vivo. We found KDM2a to be highly expressed in growing follicles and oocytes of mice in this study. To elucidate the physiological role of Kdm2a, the zona pellucida 3-Cre (Zp3-Cre)/LoxP system was used to generate an oocyte Kdm2a conditional knockout (Zp3-Cre; Kdm2aflox/flox, termed Kdm2a cKO) model. Our results showed that the number of pups was reduced by approximately 50% in adult Kdm2a cKO female mice mating with wildtype males than that of the control (Kdm2aflox/flox) group. To analyze the potential causes, the ovaries of Kdm2a cKO mice were subjected to histological examination, and results indicated an obvious difference in follicular development between Kdm2a cKO and control female mice and partial arrest at the primary antral follicle stage. The GVBD and matured rates of oocytes were also compromised after conditional knockout Kdm2a, and the morphological abnormal oocytes increased. Furthermore, the level of 17β-estradiol of Kdm2a cKO mice was only 60% of that in the counterparts, and hormone sensitivity decreased as the total number of ovulated and matured oocytes decreased after superovulation. After deletion of Kdm2a, the patterns of H3K36me2/3 in GVBD-stage oocytes were remarkedly changed. Transcriptome sequencing showed that the mRNA expression profiles in Kdm2a cKO oocytes were significantly different, and numerous differentially expressed genes were involved in pathways regulating follicular and oocyte development. Taken together, these results indicated that the oocyte-specific knockout Kdm2a gene led to female subfertility, suggesting the crucial role of Kdm2a in epigenetic modification and follicular and oocyte development.
Collapse
Affiliation(s)
- Xianrong Xiong
- Key Laboratory of Qinghai-Tibetan Plateau Animal Genetic Resource Reservation and Exploitation of Ministry of Education, Southwest Minzu University, Chengdu 610041, China
- Key Laboratory for Animal Science of National Ethnic Affairs Commission, Southwest Minzu University, Chengdu 610041, China
| | - Xiaojian Zhang
- Center for Assisted Reproduction, Sichuan Academy of Medical Science, Sichuan Provincial People’s Hospital, Chengdu 610072, China
| | - Manzhen Yang
- Key Laboratory for Animal Science of National Ethnic Affairs Commission, Southwest Minzu University, Chengdu 610041, China
| | - Yanjin Zhu
- Key Laboratory for Animal Science of National Ethnic Affairs Commission, Southwest Minzu University, Chengdu 610041, China
| | - Hailing Yu
- Key Laboratory of Qinghai-Tibetan Plateau Animal Genetic Resource Reservation and Exploitation of Ministry of Education, Southwest Minzu University, Chengdu 610041, China
| | - Xixi Fei
- Key Laboratory of Qinghai-Tibetan Plateau Animal Genetic Resource Reservation and Exploitation of Ministry of Education, Southwest Minzu University, Chengdu 610041, China
| | - Fuko Mastuda
- Laboratory of Theriogenology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo 113-8657, Japan
| | - Daoliang Lan
- Key Laboratory of Qinghai-Tibetan Plateau Animal Genetic Resource Reservation and Exploitation of Ministry of Education, Southwest Minzu University, Chengdu 610041, China
| | - Yan Xiong
- Key Laboratory of Qinghai-Tibetan Plateau Animal Genetic Resource Reservation and Exploitation of Ministry of Education, Southwest Minzu University, Chengdu 610041, China
| | - Wei Fu
- Key Laboratory of Qinghai-Tibetan Plateau Animal Genetic Resource Reservation and Exploitation of Ministry of Education, Southwest Minzu University, Chengdu 610041, China
| | - Shi Yin
- Key Laboratory of Qinghai-Tibetan Plateau Animal Genetic Resource Reservation and Exploitation of Ministry of Education, Southwest Minzu University, Chengdu 610041, China
| | - Jian Li
- Key Laboratory of Qinghai-Tibetan Plateau Animal Genetic Resource Reservation and Exploitation of Ministry of Education, Southwest Minzu University, Chengdu 610041, China
- Key Laboratory for Animal Science of National Ethnic Affairs Commission, Southwest Minzu University, Chengdu 610041, China
- Correspondence:
| |
Collapse
|
3
|
Li X, Ye Z, Guo Q, Wang E, Pan Y. PDTC ameliorates neuropathic pain by inhibiting microglial activation <em>via</em> blockage of the TNFα-CX3CR1 pathway. Eur J Histochem 2021; 65:3184. [PMID: 33728865 PMCID: PMC7970247 DOI: 10.4081/ejh.2021.3184] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Accepted: 01/18/2021] [Indexed: 11/22/2022] Open
Abstract
Previous studies have suggested that pyrrolidine dithiocarbamate (PDTC), a nuclear factor κB (NF-κB) inhibitor, play a role in deterring nerve injury-induced neuropathic pain (NP) The activation of NF-κB pathway may contribute to spinal microglial activation, CX3CR1 and tumor necrosis factor-alpha (TNF-a) up-regulation. The aim of this study was to clarify whether PDTC could inhibit the development of neuropathic pain via decreasing TNF-a-induced CX3CR1 up-regulation. Sprague-Dawley rats were randomly divided into sham group and NP group. Rats in each group were treated with intrathecal infusion of PDTC (100 or 1000 pmol/d) or saline. The sciatic nerve chronic constriction injury (CCI) model was used to induce NP in rats. Mechanical stimuli and radiant heat were used to evaluate mechanical allodynia and thermal hyperalgesia. Spinal microglial marker OX42 and TNF-a were detected by immunohistochemistry. In vitro BV-2 microglia activation was induced by TNF-a incubation, and the levels of CX3CR1 were assessed by Western blot and reverse transcription-polymerase chain reaction. Pain behavior and immunohistochemistry results showed that intrathecal infusion of PDTC at 100 or 1000 pmol/d prevented the development of mechanical and thermal hyperalgesia, spinal microglial activation and TNF-a expression induced by sciatic nerve CCI in rats. In vitro experiment results showed that PDTC inhibited the TNF-a-induced CX3CR1 up-regulation in BV-2 microglial cells. In conclusion, intrathecal infusion of PDTC could attenuate the pain-related behaviors induced by sciatic nerve CCI through suppressing the spinal microglia activation and TNF-a up-regulation in rats. The NF-κB activation might be responsible for TNF-a-induced CX3CR1 up-regulation in microglia.
Collapse
Affiliation(s)
- Xilei Li
- Department of Anesthesiology, Xiangya Hospital, Central South University, Changsha; National Clinical Research Center for Geriatric Disorders, Central South University, Changsha, Hunan.
| | - Zhi Ye
- Department of Anesthesiology, Xiangya Hospital, Central South University, Changsha; National Clinical Research Center for Geriatric Disorders, Central South University, Changsha, Hunan.
| | - Qulian Guo
- Department of Anesthesiology, Xiangya Hospital, Central South University, Changsha; National Clinical Research Center for Geriatric Disorders, Central South University, Changsha, Hunan.
| | - E Wang
- Department of Anesthesiology, Xiangya Hospital, Central South University, Changsha; National Clinical Research Center for Geriatric Disorders, Central South University, Changsha, Hunan.
| | - Yundan Pan
- Department of Anesthesiology, Xiangya Hospital, Central South University, Changsha; National Clinical Research Center for Geriatric Disorders, Central South University, Changsha, Hunan.
| |
Collapse
|
4
|
Lambrou GI, Hatziagapiou K, Vlahopoulos S. Inflammation and tissue homeostasis: the NF-κB system in physiology and malignant progression. Mol Biol Rep 2020; 47:4047-4063. [PMID: 32239468 DOI: 10.1007/s11033-020-05410-w] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2020] [Accepted: 03/26/2020] [Indexed: 02/07/2023]
Abstract
Disruption of tissue function activates cellular stress which triggers a number of mechanisms that protect the tissue from further damage. These mechanisms involve a number of homeostatic modules, which are regulated at the level of gene expression by the transactivator NF-κB. This transcription factor shifts between activation and repression of discrete, cell-dependent gene expression clusters. Some of its target genes provide feedback to NF-κB itself, thereby strengthening the inflammatory response of the tissue and later terminating inflammation to facilitate restoration of tissue homeostasis. Disruption of key feedback modules for NF-κB in certain cell types facilitates the survival of clones with genomic aberrations, and protects them from being recognized and eliminated by the immune system, to enable thereby carcinogenesis.
Collapse
Affiliation(s)
- George I Lambrou
- First Department of Pediatrics, National and Kapodistrian University of Athens, Thivon & Levadeias 8, 11527, Goudi-Athens, Greece
| | - Kyriaki Hatziagapiou
- First Department of Pediatrics, National and Kapodistrian University of Athens, Thivon & Levadeias 8, 11527, Goudi-Athens, Greece
| | - Spiros Vlahopoulos
- First Department of Pediatrics, National and Kapodistrian University of Athens, Thivon & Levadeias 8, 11527, Goudi-Athens, Greece.
| |
Collapse
|
5
|
Tian B, Liu Z, Yang J, Sun H, Zhao Y, Wakamiya M, Chen H, Rytting E, Zhou J, Brasier AR. Selective Antagonists of the Bronchiolar Epithelial NF-κB-Bromodomain-Containing Protein 4 Pathway in Viral-Induced Airway Inflammation. Cell Rep 2019; 23:1138-1151. [PMID: 29694891 DOI: 10.1016/j.celrep.2018.03.106] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2017] [Revised: 02/11/2018] [Accepted: 03/22/2018] [Indexed: 11/25/2022] Open
Abstract
The mechanisms by which the mammalian airway detects invading viral pathogens to trigger protective innate neutrophilic inflammation are incompletely understood. We observe that innate activation of nuclear factor κB (NF-κB)/RelA transcription factor indirectly activates atypical BRD4 histone acetyltransferase (HAT) activity, RNA polymerase II (Pol II) phosphorylation, and secretion of neutrophilic chemokines. To study this pathway in vivo, we developed a conditional knockout of RelA in distal airway epithelial cells; these animals have reduced mucosal BRD4/Pol II activation and neutrophilic inflammation to viral patterns. To further understand the role of BRD4 in vivo, two potent, highly selective small-molecule BRD4 inhibitors were developed. These well-tolerated inhibitors disrupt the BRD4 complex with Pol II and histones, completely blocking inducible epithelial chemokine production and neutrophilia. We conclude that RelA-BRD4 signaling in distal tracheobronchiolar epithelial cells mediates acute inflammation in response to luminal viral patterns. These potent BRD4 antagonists are versatile pharmacological tools for investigating BRD4 functions in vivo.
Collapse
Affiliation(s)
- Bing Tian
- Department of Internal Medicine, University of Texas, Galveston, TX 77555, USA; Sealy Center for Molecular Medicine, University of Texas, Galveston, TX 77555, USA
| | - Zhiqing Liu
- Department of Pharmacology and Toxicology, University of Texas, Galveston, TX 77555, USA
| | - Jun Yang
- Department of Internal Medicine, University of Texas, Galveston, TX 77555, USA; Sealy Center for Molecular Medicine, University of Texas, Galveston, TX 77555, USA
| | - Hong Sun
- Department of Internal Medicine, University of Texas, Galveston, TX 77555, USA
| | - Yingxin Zhao
- Department of Internal Medicine, University of Texas, Galveston, TX 77555, USA; Sealy Center for Molecular Medicine, University of Texas, Galveston, TX 77555, USA; Institute for Translational Sciences, University of Texas, Galveston, TX 77555, USA
| | - Maki Wakamiya
- Institute for Translational Sciences, University of Texas, Galveston, TX 77555, USA
| | - Haiying Chen
- Department of Pharmacology and Toxicology, University of Texas, Galveston, TX 77555, USA
| | - Erik Rytting
- Department of Obstetrics and Gynecology, University of Texas, Galveston, TX 77555, USA
| | - Jia Zhou
- Sealy Center for Molecular Medicine, University of Texas, Galveston, TX 77555, USA; Department of Pharmacology and Toxicology, University of Texas, Galveston, TX 77555, USA; Institute for Translational Sciences, University of Texas, Galveston, TX 77555, USA
| | - Allan R Brasier
- School of Medicine and Public Health, University of Wisconsin, Madison, WI 53715, USA.
| |
Collapse
|
6
|
Wang P, Liu Z, Zhang X, Li J, Sun L, Ju Z, Li J, Chan P, Liu GH, Zhang W, Song M, Qu J. CRISPR/Cas9-mediated gene knockout reveals a guardian role of NF-κB/RelA in maintaining the homeostasis of human vascular cells. Protein Cell 2018; 9:945-965. [PMID: 29968158 PMCID: PMC6208479 DOI: 10.1007/s13238-018-0560-5] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2018] [Accepted: 06/08/2018] [Indexed: 12/12/2022] Open
Abstract
Vascular cell functionality is critical to blood vessel homeostasis. Constitutive NF-κB activation in vascular cells results in chronic vascular inflammation, leading to various cardiovascular diseases. However, how NF-κB regulates human blood vessel homeostasis remains largely elusive. Here, using CRISPR/Cas9-mediated gene editing, we generated RelA knockout human embryonic stem cells (hESCs) and differentiated them into various vascular cell derivatives to study how NF-κB modulates human vascular cells under basal and inflammatory conditions. Multi-dimensional phenotypic assessments and transcriptomic analyses revealed that RelA deficiency affected vascular cells via modulating inflammation, survival, vasculogenesis, cell differentiation and extracellular matrix organization in a cell type-specific manner under basal condition, and that RelA protected vascular cells against apoptosis and modulated vascular inflammatory response upon tumor necrosis factor α (TNFα) stimulation. Lastly, further evaluation of gene expression patterns in IκBα knockout vascular cells demonstrated that IκBα acted largely independent of RelA signaling. Taken together, our data reveal a protective role of NF-κB/RelA in modulating human blood vessel homeostasis and map the human vascular transcriptomic landscapes for the discovery of novel therapeutic targets.
Collapse
Affiliation(s)
- Ping Wang
- National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, 100101, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Zunpeng Liu
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, 100101, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Xiaoqian Zhang
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, 100101, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Jingyi Li
- National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, 100101, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
- National Clinical Research Center for Geriatric Disorders, Xuanwu Hospital of Capital Medical University, Beijing, 100053, China
| | - Liang Sun
- The MOH Key Laboratory of Geriatrics, Beijing Hospital, National Center of Gerontology, Beijing, 100730, China
| | - Zhenyu Ju
- Key Laboratory of Regenerative Medicine of Ministry of Education, Institute of Aging and Regenerative Medicine, Jinan University, Guangzhou, 510632, China
| | - Jian Li
- The MOH Key Laboratory of Geriatrics, Beijing Hospital, National Center of Gerontology, Beijing, 100730, China
| | - Piu Chan
- National Clinical Research Center for Geriatric Disorders, Xuanwu Hospital of Capital Medical University, Beijing, 100053, China
| | - Guang-Hui Liu
- National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, 100101, China.
- University of Chinese Academy of Sciences, Beijing, 100049, China.
- National Clinical Research Center for Geriatric Disorders, Xuanwu Hospital of Capital Medical University, Beijing, 100053, China.
- Institute of Stem cell and Regeneration, Chinese Academy of Sciences, Beijing, 100101, China.
- Key Laboratory of Regenerative Medicine of Ministry of Education, Institute of Aging and Regenerative Medicine, Jinan University, Guangzhou, 510632, China.
| | - Weiqi Zhang
- National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, 100101, China.
- University of Chinese Academy of Sciences, Beijing, 100049, China.
- National Clinical Research Center for Geriatric Disorders, Xuanwu Hospital of Capital Medical University, Beijing, 100053, China.
| | - Moshi Song
- State Key Laboratory of Membrane Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, 100101, China.
- University of Chinese Academy of Sciences, Beijing, 100049, China.
- Institute of Stem cell and Regeneration, Chinese Academy of Sciences, Beijing, 100101, China.
| | - Jing Qu
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, 100101, China.
- University of Chinese Academy of Sciences, Beijing, 100049, China.
- Institute of Stem cell and Regeneration, Chinese Academy of Sciences, Beijing, 100101, China.
| |
Collapse
|
7
|
Central Role of the NF-κB Pathway in the Scgb1a1-Expressing Epithelium in Mediating Respiratory Syncytial Virus-Induced Airway Inflammation. J Virol 2018; 92:JVI.00441-18. [PMID: 29593031 DOI: 10.1128/jvi.00441-18] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2018] [Accepted: 03/20/2018] [Indexed: 12/24/2022] Open
Abstract
Lower respiratory tract infection with respiratory syncytial virus (RSV) produces profound inflammation. Despite an understanding of the role of adaptive immunity in RSV infection, the identity of the major sentinel cells initially triggering inflammation is controversial. Here we evaluate the role of nonciliated secretoglobin (Scgb1a1)-expressing bronchiolar epithelial cells in RSV infection. Mice expressing a tamoxifen (TMX)-inducible Cre recombinase-estrogen receptor fusion protein (CreERTM) knocked into the Scgb1a1 locus were crossed with mice that harbor a RelA conditional allele (RelAfl ), with loxP sites flanking exons 5 to 8 of the Rel homology domain. The Scgb1a1CreERTM/+ × RelAfl/fl mouse is a RelA conditional knockout (RelACKO) of a nonciliated epithelial cell population enriched in the small bronchioles. TMX-treated RelACKO mice have reduced pulmonary neutrophilic infiltration and impaired expression and secretion of NF-κB-dependent cytokines in response to RSV. In addition, RelACKO mice had reduced expression levels of interferon (IFN) regulatory factor 1/7 (IRF1/7) and retinoic acid-inducible gene I (RIG-I), components of the mucosal IFN positive-feedback loop. We demonstrate that RSV replication induces RelA to complex with bromodomain-containing protein 4 (BRD4), a cofactor required for RNA polymerase II (Pol II) phosphorylation, activating the atypical histone acetyltransferase (HAT) activity of BRD4 required for phospho-Ser2 Pol II formation, histone H3K122 acetylation, and cytokine secretion in vitro and in vivo TMX-treated RelACKO mice have less weight loss and reduced airway obstruction/hyperreactivity yet similar levels of IFN-γ production despite higher levels of virus production. These data indicate that the nonciliated Scgb1a1-expressing epithelium is a major innate sensor for restricting RSV infection by mediating neutrophilic inflammation and chemokine and mucosal IFN production via the RelA-BRD4 pathway.IMPORTANCE RSV infection is the most common cause of infant hospitalizations in the United States, resulting in 2.1 million children annually requiring medical attention. RSV primarily infects nasal epithelial cells, spreading distally to produce severe lower respiratory tract infections. Our study examines the role of a nonciliated respiratory epithelial cell population in RSV infection. We genetically engineered a mouse that can be selectively depleted of the NF-κB/RelA transcription factor in this subset of epithelial cells. These mice show an impaired activation of the bromodomain-containing protein 4 (BRD4) coactivator, resulting in reduced cytokine expression and neutrophilic inflammation. During the course of RSV infection, epithelial RelA-depleted mice have reduced disease scores and airway hyperreactivity yet increased levels of virus replication. We conclude that RelA-BRD4 signaling in nonciliated bronchiolar epithelial cells mediates neutrophilic airway inflammation and disease severity. This complex is an attractive target to reduce the severity of infection.
Collapse
|
8
|
Ijaz T, Sun H, Pinchuk IV, Milewicz DM, Tilton RG, Brasier AR. Deletion of NF-κB/RelA in Angiotensin II-Sensitive Mesenchymal Cells Blocks Aortic Vascular Inflammation and Abdominal Aortic Aneurysm Formation. Arterioscler Thromb Vasc Biol 2017; 37:1881-1890. [PMID: 28818856 DOI: 10.1161/atvbaha.117.309863] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2016] [Accepted: 08/07/2017] [Indexed: 11/16/2022]
Abstract
OBJECTIVE Infusion of angiotensin II (Ang II) induces extracellular matrix remodeling and inflammation resulting in abdominal aortic aneurysms (AAAs) in normolipidemic mice. Although Ang II activates mesenchymal cells in the media and adventitia to become fibrogenic, the sentinel role of this mesenchymal population in modulating the inflammatory response and aneurysms is not known. We test the hypothesis that these fibrogenic mesenchymal cells play a critical role in Ang II-induced aortic wall vascular inflammation and AAA formation. APPROACH AND RESULTS Ang II infusion increased phospho-Ser536-RelA and interleukin (IL)-6 immunostaining in the abdominal aorta. In addition, aortic mRNA transcripts of RelA-dependent cytokines IL-6 and IL-1β were significantly elevated suggesting that Ang II functionally activates RelA signaling. To test the role of mesenchymal RelA in AAA formation, we generated RelA-CKO mice by administering tamoxifen to double transgenic mice harboring RelA-flox alleles and tamoxifen-inducible Col1a2 promoter-driven Cre recombinase (Col1a2-CreERT). Tamoxifen administration to Col1a2-CreERT•mT/mG mice induced Cre expression and RelA depletion in aortic smooth muscle cells and fibroblasts but not in endothelial cells. Infusion of Ang II significantly increased abdominal aortic diameter and the incidence of AAA in RelA wild-type but not in RelA-CKO mice, independent of changes in systolic blood pressure. Furthermore, mesenchymal cell-specific RelA-CKO mice exhibited decreased expression of IL-6 and IL-1β cytokines and decreased recruitment of C68+ and F4/80lo•Ly6Chi monocytes during Ang II infusion. CONCLUSIONS Fibrogenic mesenchymal RelA plays a causal role in Ang II-induced vascular inflammation and AAA in normolipidemic mice.
Collapse
Affiliation(s)
- Talha Ijaz
- From the Department of Biochemistry and Molecular Biology (T.I.), MD-PhD Program (T.I.), Division of Gasteroenterology, Department of Internal Medicine (I.V.P.), Division of Endocrinology, Department of Internal Medicine (H.S., R.G.T., A.R.B.), Institute for Translational Sciences (R.G.T., A.R.B.), Sealy Center for Molecular Medicine (R.G.T., A.R.B.), University of Texas Medical Branch, Galveston; and Department of Internal Medicine, University of Texas Health Science Center at Houston (D.M.M.)
| | - Hong Sun
- From the Department of Biochemistry and Molecular Biology (T.I.), MD-PhD Program (T.I.), Division of Gasteroenterology, Department of Internal Medicine (I.V.P.), Division of Endocrinology, Department of Internal Medicine (H.S., R.G.T., A.R.B.), Institute for Translational Sciences (R.G.T., A.R.B.), Sealy Center for Molecular Medicine (R.G.T., A.R.B.), University of Texas Medical Branch, Galveston; and Department of Internal Medicine, University of Texas Health Science Center at Houston (D.M.M.)
| | - Irina V Pinchuk
- From the Department of Biochemistry and Molecular Biology (T.I.), MD-PhD Program (T.I.), Division of Gasteroenterology, Department of Internal Medicine (I.V.P.), Division of Endocrinology, Department of Internal Medicine (H.S., R.G.T., A.R.B.), Institute for Translational Sciences (R.G.T., A.R.B.), Sealy Center for Molecular Medicine (R.G.T., A.R.B.), University of Texas Medical Branch, Galveston; and Department of Internal Medicine, University of Texas Health Science Center at Houston (D.M.M.)
| | - Dianna M Milewicz
- From the Department of Biochemistry and Molecular Biology (T.I.), MD-PhD Program (T.I.), Division of Gasteroenterology, Department of Internal Medicine (I.V.P.), Division of Endocrinology, Department of Internal Medicine (H.S., R.G.T., A.R.B.), Institute for Translational Sciences (R.G.T., A.R.B.), Sealy Center for Molecular Medicine (R.G.T., A.R.B.), University of Texas Medical Branch, Galveston; and Department of Internal Medicine, University of Texas Health Science Center at Houston (D.M.M.)
| | - Ronald G Tilton
- From the Department of Biochemistry and Molecular Biology (T.I.), MD-PhD Program (T.I.), Division of Gasteroenterology, Department of Internal Medicine (I.V.P.), Division of Endocrinology, Department of Internal Medicine (H.S., R.G.T., A.R.B.), Institute for Translational Sciences (R.G.T., A.R.B.), Sealy Center for Molecular Medicine (R.G.T., A.R.B.), University of Texas Medical Branch, Galveston; and Department of Internal Medicine, University of Texas Health Science Center at Houston (D.M.M.)
| | - Allan R Brasier
- From the Department of Biochemistry and Molecular Biology (T.I.), MD-PhD Program (T.I.), Division of Gasteroenterology, Department of Internal Medicine (I.V.P.), Division of Endocrinology, Department of Internal Medicine (H.S., R.G.T., A.R.B.), Institute for Translational Sciences (R.G.T., A.R.B.), Sealy Center for Molecular Medicine (R.G.T., A.R.B.), University of Texas Medical Branch, Galveston; and Department of Internal Medicine, University of Texas Health Science Center at Houston (D.M.M.).
| |
Collapse
|