Transcription factor NF-κB promotes acute lung injury via microRNA-99b-mediated PRDM1 down-regulation
2020; Elsevier BV; Volume: 295; Issue: 52 Linguagem: Inglês
10.1074/jbc.ra120.014861
ISSN1083-351X
AutoresJie Zhao, Fei Xie, Ruidong Chen, Zhen Zhang, Rujun Dai, Na Zhao, Rongxin Wang, Yanhong Sun, Yue Chen,
Tópico(s)NF-κB Signaling Pathways
ResumoAcute lung injury (ALI), is a rapidly progressing heterogenous pulmonary disorder that possesses a high risk of mortality. Accumulating evidence has implicated the activation of the p65 subunit of NF-κB [NF-κB(p65)] activation in the pathological process of ALI. microRNAs (miRNAs), a group of small RNA molecules, have emerged as major governors due to their post-transcriptional regulation of gene expression in a wide array of pathological processes, including ALI. The dysregulation of miRNAs and NF-κB activation has been implicated in human diseases. In the current study, we set out to decipher the convergence of miR-99b and p65 NF-κB activation in ALI pathology. We measured the release of pro-inflammatory cytokines (IL-1β, IL-6, and TNFα) in bronchoalveolar lavage fluid using ELISA. MH-S cells were cultured and their viability were detected with cell counting kit 8 (CCK8) assays. The results showed that miR-99b was up-regulated, while PRDM1 was down-regulated in a lipopolysaccharide (LPS)-induced murine model of ALI. Mechanistic investigations showed that NF-κB(p65) was enriched at the miR-99b promoter region, and further promoted its transcriptional activity. Furthermore, miR-99b targeted PRDM1 by binding to its 3'UTR, causing its down-regulation. This in-creased lung injury, as evidenced by increased wet/dry ratio of mouse lung, myeloperoxidase activity and pro-inflammatory cytokine secretion, and enhanced infiltration of inflammatory cells in lung tissues. Together, our findings indicate that NF-κB(p65) promotion of miR-99b can aggravate ALI in mice by down-regulating the expression of PRDM1. Acute lung injury (ALI), is a rapidly progressing heterogenous pulmonary disorder that possesses a high risk of mortality. Accumulating evidence has implicated the activation of the p65 subunit of NF-κB [NF-κB(p65)] activation in the pathological process of ALI. microRNAs (miRNAs), a group of small RNA molecules, have emerged as major governors due to their post-transcriptional regulation of gene expression in a wide array of pathological processes, including ALI. The dysregulation of miRNAs and NF-κB activation has been implicated in human diseases. In the current study, we set out to decipher the convergence of miR-99b and p65 NF-κB activation in ALI pathology. We measured the release of pro-inflammatory cytokines (IL-1β, IL-6, and TNFα) in bronchoalveolar lavage fluid using ELISA. MH-S cells were cultured and their viability were detected with cell counting kit 8 (CCK8) assays. The results showed that miR-99b was up-regulated, while PRDM1 was down-regulated in a lipopolysaccharide (LPS)-induced murine model of ALI. Mechanistic investigations showed that NF-κB(p65) was enriched at the miR-99b promoter region, and further promoted its transcriptional activity. Furthermore, miR-99b targeted PRDM1 by binding to its 3'UTR, causing its down-regulation. This in-creased lung injury, as evidenced by increased wet/dry ratio of mouse lung, myeloperoxidase activity and pro-inflammatory cytokine secretion, and enhanced infiltration of inflammatory cells in lung tissues. Together, our findings indicate that NF-κB(p65) promotion of miR-99b can aggravate ALI in mice by down-regulating the expression of PRDM1. Acute lung injury (ALI) is a prevalent disease with exceedingly-high rates of morbidity and mortality. ALI can often predispose patients to acute respiratory distress syndrome (ARDS) (1Rubenfeld G.D. Caldwell E. Peabody E. Weaver J. Martin D.P. Neff M. Stern E.J. Hudson L.D. Incidence and outcomes of acute lung injury.N. Engl. J. 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Once the organs fail to burden much inflammasome activity, the human body elicits a severe immune response that stimulates excessive release of pro-inflammatory cytokines, thus prompting some inflammatory diseases including ALI (12Davis B.K. Wen H. Ting J.P. The inflammasome NLRs in immunity, inflammation, and associated diseases.Annu. Rev. Immunol. 2011; 29 (21219188): 707-73510.1146/annurev-immunol-031210-101405Crossref PubMed Scopus (1041) Google Scholar, 13Bauer C. Duewell P. Mayer C. Lehr H.A. Fitzgerald K.A. Dauer M. Tschopp J. Endres S. Latz E. Schnurr M. Colitis induced in mice with dextran sulfate sodium (DSS) is mediated by the NLRP3 inflammasome.Gut. 2010; 59 (20442201): 1192-119910.1136/gut.2009.197822Crossref PubMed Scopus (447) Google Scholar). MicroRNAs (miRNAs), 21–23 nucleotides in length, possess the ability to negatively regulate gene expression by repression of mRNA translation repression or promotion of mRNA degradation (14Yekta S. Shih I.H. Bartel D.P. 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Overexpression of miR-125a in myelodysplastic syndrome CD34+ cells modulates NF-kappaB activation and enhances erythroid differentiation arrest.PLoS ONE. 2014; 9 (24690917)e9340410.1371/journal.pone.0093404Crossref PubMed Scopus (36) Google Scholar), which regulates the expressions of a large variety of genes that are involved in numerous processes like inflammatory and immune responses of the cell, cell growth, and development (20Napetschnig J. Wu H. Molecular basis of NF-kappaB signaling.Annu. Rev. Biophys. 2013; 42 (23495970): 443-46810.1146/annurev-biophys-083012-130338Crossref PubMed Scopus (545) Google Scholar). Moreover, transcriptional repressor PR (PRDI-BF1-RIZ) domain zinc finger protein 1 (PRDM1) has also been identified to be a downstream effector of the NF-κB (21Romagnoli M. Belguise K. Yu Z. Wang X. Landesman-Bollag E. Seldin D.C. Chalbos D. Barille-Nion S. Jezequel P. Seldin M.L. Sonenshein G.E. Epithelial-to-mesenchymal transition induced by TGF-beta1 is mediated by Blimp-1-dependent repression of BMP-5.Cancer Res. 2012; 72 (23054396): 6268-627810.1158/0008-5472.CAN-12-2270Crossref PubMed Scopus (65) Google Scholar). PRDM1 (also referred to as Blimp-1) was originally identified as a post-inductive silencer of interferon beta (IFN-β) gene expression and controls cell fate decisions in multiple tissue contexts (22Elias S. Robertson E.J. Bikoff E.K. Mould A.W. Blimp-1/PRDM1 is a critical regulator of Type III Interferon responses in mammary epithelial cells.Sci. Rep. 2018; 8 (29321612): 23710.1038/s41598-017-18652-9Crossref PubMed Scopus (6) Google Scholar). However, the mechanism underlying the role of miR-99b and NF-κB in ALI remains unclear. In the current study, we performed experiments using ALI mouse models, and found miR-99b expression was increased in the lung tissues. In addition, we observed that NF-κB could increase miR-99b expression and deteriorate ALI of mice induced by LPS. As a result, we speculated whether the miR-99b/PRDM1 axis regulated the development of ALI. Therefore, we set out to elucidate the mechanism by which miR-99b affects the processes of ALI by means of LPS-induced MH-S cells and a murine model of LPS-induced ALI. Firstl the results of hematoxylin-eosin (HE) staining illustrated disordered alveolar structure, thickened alveolar wall, obvious alveolar septum, interstitial edema and inflammatory cell infiltration in the lung tissues of mice in the ALI group compared with the control group (Fig. 1A). The dry/wet weight (W/D) ratio of the mice in the ALI group was elevated relative to the control group (Fig. 1B). Myeloperoxidase (MPO) activity was elevated in mice after ALI treatment (Fig. 1C). ELISA (ELISA) was further employed to detect the expression patterns of inflammatory factor tumor necrosis factor-α (TNFα), IL-6, and IL-1β in the BALF, and the results showed that LPS treatment led to elevated TNFα, IL-6, and IL-1β in the BALF of mice (Fig. 1D). Subsequently, the expression patterns of miR-99b in lung tissues were detected with reverse transcription quantitative PCR (RT-qPCR), and the results showed a significant elevation in miR-99b expression levels in the lung tissues of mice of the ALI group compared with the control group (Fig. 1E). Additionally, immunofluorescence staining analysis revealed a significant increase in the number of macrophages in the lung tissues of mice from the ALI group when compared with the control group (Fig. 1F). These findings indicated that miR-99b was highly-expressed in mice with ALI. To further explore the involvement of miR-99b in regulating ALI, the status of lung injury in mice was examined by treating ALI mice with miR-99b antagomir. RT-qPCR results revealed a significant decrease in the expression levels of miR-99b in the lung tissues of mice in the ALI + miR-99b antagomir group relative to the ALI + antagomir negative control (NC) group (Fig. 2A), indicating successful silencing of miR-99b in ALI mice. Meanwhile, HE staining demonstrated that inflammatory cell infiltration was reduced in the lung tissues of mice in the ALI + miR-99b antagomir group compared with the ALI + antagomir NC group, in addition to marked improvements in alveolar septum and pulmonary interstitial edema (Fig. 2B). In addition, decreased lung W/D ratio (Fig. 2C), MPO activity (Fig. 2D), and TNFα, IL-6, and IL-1β expression levels were observed in the BALF (Fig. 2E) in mice in the ALI + miR-99b antagomir group compared with the ALI + antagomir NC group. Taken together, these findings indicate that silencing miR-99b could relieve lung injury in ALI mice. Additionally, MH-S cell models of ALI were simulated by LPS treatment to further study the mechanism of miR-99b in ALI regulation. RT-qPCR was then applied to detect the expression patterns of miR-99b in the cells following treatment with different concentrations of LPS, and the results showed that miR-99b expression was elevated in the cells following escalating concentration of LPS treatment (Fig. 3A). Subsequently, miR-99b was silenced in the LPS-stimulated cells, and RT-qPCR results revealed a decrease in miR-99b expression upon miR-99b inhibitor introduction (Fig. 3B). The results of cell counting kit 8 (CCK8) and ELISA experiments showed that LPS treatment repressed MH-S cell viability and enhanced TNFα, IL-6 and IL-1β levels. However, compared with the LPS + inhibitor NC group, cell viability was promoted, whereas the expression levels of TNFα, IL-6 and IL-1β were all decreased in the LPS + miR-99b inhibitor group (Fig. 3C, D). The expression levels of NF-κB(p-p65) in the cells were detected using nucleocytoplasmic separation experimentation, and it was found that the expression of NF-κB(p-p65) in the nucleus was markedly elevated with the increase of LPS concentration (Fig. 3E). Immunofluorescence was then employed to detect the treatment of LPS on p-p65 expression levels, and the results indicated that LPS treatment promoted NF-κB(p-p65) nucleation (Fig. 3F). The TRANSFAC database was retrieved to predict the NF-κB(p65) binding sites with the miR-99b promoter region (Fig. 3G). Results of ChIP (ChIP) assay revealed a promoted NF-κB(p65) enrichment at the miR-99b promoter region following LPS treatment (Fig. 3H). NF-κB inhibitor (10 μm BAY11-7082 and 100 μm SATM) was used to treat MH-S macrophages, and the expression levels of NF-κB(p-p65) were detected by Western-blot. The results showed a significant decrease in NF-κB(p65) and NF-κB(p-p65) expression levels (Fig. 3I). RT-qPCR was then applied to detect the miR-99b expression patterns, and it was found that miR-99b expression was inhibited in the presence of NF-κB inhibitor (Fig. 3J). Macrophages p65 was further silenced by shRNA transfection, and the expression levels of p65 and miR-99b were detected using Western-blot and RT-qPCR. The results illustrated a decline in p65 and miR-99b expression once NF-κB was silenced (Fig. 3K). Cell viability of LPS-stimulated MH-S was observed to be promoted upon NF-κB knockdown, while concurrent transfection of miR-99b mimic inhibited the viability (Fig. 3L). The above results suggested that NF-κB(p65) was enriched at the miR-99b promoter region, and promoted its transcriptional activity, thus accelerating inflammatory damage to the cells. The downstream target genes of miR-99b were predicted using starBase (http://starbase.sysu.edu.cn/), miRDB (http://mirdb.org/index.html) and microRNA databases (http://www.microrna.org/microrna/getMirnaForm.do). Following diagram analysis of the predicted miRNAs (Fig. 4A), 27 mRNAs were found at the intersection. Subsequently, ALI mRNA expression data set GSE2368 was obtained from the Gene Expression Omnibus (GEO) database (https://www.ncbi.nlm.nih.gov/geo/), which comprised of 2 normal samples and 2 lung injury samples, and a set of three candidate mRNAs were yielded. PRDM1 was the only overlapping gene with the predicted 27 mRNAs in the aforementioned three databases. Meanwhile, previous literature has shown that deletion of PRDM1 (Blimp1) in T cells decreased the expression levels of Foxp3 and CTLA-4, while increasing those of proinflammatory cytokines and the production of autoantibodies, including the increase of IgE (23Shen E. Rabe H. Luo L. Wang L. Wang Q. Yin J. Yang X. Liu W. Sido J.M. Nakagawa H. Ao L. Kim H.J. Cantor H. Leavenworth J.W. Control of Germinal Center Localization and Lineage Stability of Follicular Regulatory T Cells by the Blimp1 Transcription Factor.Cell Rep. 2019; 29 (31722202): 1848-186110.1016/j.celrep.2019.10.012Abstract Full Text Full Text PDF PubMed Scopus (13) Google Scholar). Therefore, it was hypothesized that the PRDM1 gene was involved in the regulation of ALI, and thus, was selected for further experimentation. The results further revealed that miR-99b-5p targeted the PRDM1 gene (Fig. 4B), and the PRDM1 expression in the GSE2368 data set was much lower in the lung injury samples relative to normal samples (Fig. 4C). The results of dual-luciferase reporter gene assay demonstrated that over-expression of miR-99b inhibited the luciferase activity of WT (WT)-PRDM1-3'UTR, while exerting no effects on the luciferase activity of mutant (Mut)-PRDM1-3'UTR in HEK293 cells (Fig. 4D). The results of RT-qPCR and Western-blot showed that the mRNA and protein expression levels of PRDM1 were inhibited in miR-99b over-expressed MH-S cells (Fig. 4E). PRDM1 expression patterns were also detected in MH-S cells following p65 over-expression or in combination with miR-99b inhibition, the results of which showed that the PRDM1 levels were inhibited by over-expression (oe)-p65 compared with the oe-NC, and compared with oe-p65 + inhibitor NC, the PRDM1 levels were restored by oe-p65 + miR-99b inhibition (Fig. 4F). These further demonstrated that the PRDM1 gene may be involved in the regulation of lung injury via p65/miR-99b expression levels. Subsequently, immunohistochemical detection was performed to examine the PRDM1 expression patterns in ALI mouse lung tissues, and a significant decrease in the PRDM1 expression was observed compared with the control group (Fig. 4G). Western-blot results showed a concentration-dependent decline of PRDM1 expression in MH-S cells after LPS stimulation (Fig. 4H). PRDM1 over-expression was then achieved by lentivirus (Fig. 4I). CCK8 assay revealed PRDM1 overexpression increased cell viability of MH-S cells after LPS stimulation (Fig. 4J). Collectively, these findings revealed that miR-99b targeted PRDM1 and inhibited its expression to increase the severity of LPS induced cell injury. To further verify whether PRDM1 regulates ALI in mice, the extent of lung injury was examined by injecting lentivirus expressing oe-PRDM1 into ALI mice. The expression patterns of PRDM1 in lung tissues were first examined by immunohistochemistry after 28 days of injection. ALI mice presented an increase in PRDM1 expression in the lung tissues following infection of lentivirus expressing oe-PRDM1 (Fig. 5A). Western-blot yielded similar results regarding the protein expressions of PRDM1 to that of immunohistochemistry (Fig. 5B). HE staining was further applied to examine lung tissue damage, and it was observed that inflammatory cell infiltration and interstitial edema were decreased in mice of the ALI + oe-PRDM1 group compared with the ALI + oe-NC group (Fig. 5C). Moreover, the ALI + oe-PRDM1 group demonstrated decreased ratio of lung W/D (Fig. 5D), decreased MPO activity (Fig. 5E), and expression levels of inflammatory factor TNFα, IL-6, and IL-1β in BALF (Fig. 5F) compared with the ALI + oe-NC group. In a word, PRDM1 over-expression inhibited lung injury in ALI mice. RT-qPCR findings showed that, compared with the ALI + DMSO group, the expression levels of miR-99b were inhibited and those of PRDM1 were enhanced in the ALI + BAY11-7082 group. Silencing of NF-κB(p65) led to an inhibited miR-99b expression with an elevated PRDM1 expression. Meanwhile, miR-99b expression levels were promoted, while those of PRDM1 were reduced in the ALI + sh-NF-κB(p65) + miR-99b agomir group compared with the ALI + sh-NF-κB(p65) + agomir NC group (Fig. 6A). Western-blot findings were consistent with RT-qPCR results (Fig. 6B). In addition, HE staining illustrated an obvious decrease in the infiltration of inflammatory cells, edema of lung tissues (Fig. 6C), ratio of lung W/D (Fig. 6D), MPO activity in the BALF (Fig. 6E) and the secretion of pro-inflammatory factors in the lung tissues (Fig. 6F) of the ALI + BAY11-7082 group compared with the ALI + DMSO group. ALI + sh-NF-κB (p65) treatment brought about consistent results with those of the ALI + BAY11-7082 treatment. Meanwhile, the infiltration of inflammatory cells in lung tissues was increased (Fig. 6C), the ratio of lung W/D was elevated (Fig. 6D), MPO activity in BALF was elevated (Fig. 6E), and the concentration of inflammatory factor TNFα, IL-6, and IL-1β in lung tissues were all markedly increased (Fig. 6F) in the ALI + sh-NF-κB(p65) + miR-99b agomir group in contrast to the ALI + sh-NF-κB(p65) + agomir NC group. Collectively, these findings indicate that NF-κB(p65) promoted the progression of ALI in mice via miR-99b up-regulation to inhibit the PRDM1. So far, ALI still presents with enormous fatality and morbidity rates (24Cross L.J. Matthay M.A. Biomarkers in acute lung injury: insights into the pathogenesis of acute lung injury.Crit. Care Clin. 2011; 27 (21440206): 355-37710.1016/j.ccc.2010.12.005Abstract Full Text Full Text PDF PubMed Scopus (148) Google Scholar). In this work, we demonstrated NF-κB(p65) promotion of miR-99b can affects the processes of ALI in LPS-induced MH-S cells and a murine model of LPS-induced ALI by down-regulating the expression of PRDM1. Initially, our findings indicated that miR-99b was highly expressed in the LPS-induced mouse ALI models. Similarly, up-regulated levels of miR-99a have been previously identified in rat models of acute respiratory distress syndrome (25Huang C. Xiao X. Chintagari N.R. Breshears M. Wang Y. Liu L. MicroRNA and mRNA expression profiling in rat acute respiratory distress syndrome.BMC Med. Genomics. 2014; 7 (25070658): 4610.1186/1755-8794-7-46Crossref PubMed Scopus (53) Google Scholar). We found that lung injury was increased in the ALI mouse models as evidenced by up-regulated W/D ratio, MPO activity and the concentration of TNFα, IL-6, and IL-1β, while the infiltration of inflammatory cells was reduced in the lung tissues, whereas all the aforementioned could be countered by the addition of miR-99b antagomir, which is very much in line with the previous data. Moreover, it has been documented that over-expression of miR-99b-5p brings about elevations in the expression levels of proinflammatory cytokines (IL-2, IL-6, TNFα, and IFN-γ), thus promoting the pathogenesis of rheumatoid arthritis (26Zhu X. Wu L. Mo X. Xia W. Guo Y. Wang M. Zeng K. Wu J. Qiu Y. Lin X. Lu X. Deng F. Lei S. Identification of PBMC-expressed miRNAs for rheumatoid arthritis.Epigenetics. 2020; 15: 386-39710.1080/15592294.2019.1676613Crossref PubMed Scopus (4) Google Scholar). Additionally, we uncovered the targeting relationship between miR-99b and PRDM1, and found that miR-99b interacted with the 3'UTR of PRDM1 mRNA, consequently inhibiting its expression. Indeed, miRNAs possess the ability to inhibit mRNA degradation or translation by interacting with the 3'UTR of specific target mRNAs (27Ivey K.N. Srivastava D. microRNAs as Developmental Regulators.Cold Spring Harb. Perspect. Biol. 2015; 7 (26134312)a00814410.1101/cshperspect.a008144Crossref PubMed Scopus (120) Google Scholar). More in line with our findings, miR-125a (the miR-125a cluster on chromosome 19 in humans includes miR-99b) has been previously predicted to be able to bind to PRDM1 (28Gururajan M. Haga C.L. Das S. Leu C.M. Hodson D. Josson S. Turner M. Cooper M.D. MicroRNA 125b inhibition of B cell differentiation in germinal centers.Int. Immunol. 2010; 22 (20497960): 583-59210.1093/intimm/dxq042Crossref PubMed Scopus (122) Google Scholar). Moreover, down-regulated levels of PRDM1 have been found in lung cancer cells, wherein these decreased expressions promoted cell invasion in vitro and lung metastasis in vivo (29Zhu Z. Wang H. Wei Y. Meng F. Liu Z. Zhang Z. Downregulation of PRDM1 promotes cellular invasion and lung cancer metastasis.Tumour Biol. 2017; 39 (28378641)101042831769592910.1177/1010428317695929Crossref Scopus (14) Google Scholar). Furthermore, over-expression of PRDM1 is known to suppress the release of IFN-γ, TNFα, and TNF-β by direct binding to multiple conserved regulatory regions in human natural killer cells (30Smith M.A. Maurin M. Cho H.I. Becknell B. Freud A.G. Yu J. Wei S. Djeu J. Celis E. Caligiuri M.A. Wright K.L. PRDM1/Blimp-1 controls effector cytokine production in human NK cells.J. Immunol. 2010; 185 (20944005): 6058-606710.4049/jimmunol.1001682Crossref PubMed Scopus (58) Google Scholar). As a result, we concur that miR-99b targeted PRDM1 expression to augment the state of LPS-induced cell injury. ALI is characterized by inflammatory cell infiltration, pro-inflammatory cytokine generation (3Grommes J. Soehnlein O. Contribution of neutrophils to acute lung injury.Mol. Med. 2011; 17 (21046059): 293-30710.2119/molmed.2010.00138Crossref PubMed Scopus (782) Google Scholar, 31Matute-Bello G. Frevert C.W. Martin T.R. Animal models of acute lung injury.Am. J. Physiol. Lung Cell Mol Physiol. 2008; 295 (18621912): L379-L39910.1152/ajplung.00010.2008Crossref PubMed Scopus (1024) Google Scholar), along with ROS generation in the lungs (32Chung I.S. Kim J.A. Kim J.A. Choi H.S. Lee J.J. Yang M. Ahn H.J. Lee S.M. Reactive oxygen species by isoflurane mediates inhibition of nuclear factor kappaB activation in lipopolysaccharide-induced acute inflammation of the lung.Anesth. Analg. 2013; 116 (23302986): 327-33510.1213/ANE.0b013e31827aec06Crossref PubMed Scopus (30) Google Scholar). It has been reported that LPS treatment leads to ROS production and NF-κB activation (33Cho R.L. Yang C.C. Lee I.T. Lin C.C. Chi P.L. Hsiao L.D. Yang C.M. Lipopolysaccharide induces ICAM-1 expression via a c-Src/NADPH oxidase/ROS-dependent NF-kappaB pathway in human pulmonary alveolar epithelial cells.Am. J. Physiol. Lung Cell Mol Physiol. 2016; 310: L639-L65710.1152/ajplung.00109.2014Crossref PubMed Scopus (46) Google Scholar), whereas these results hold true of our experimentation with MH-S cell models of ALI, wherein the expression levels of NF-κB (p-p65) in the nucleus were elevated, These aberrant levels of NF-κB(p-p65) were accompanied by increases in LPS concentration and NF-κB (p-p65) nucleation, while enrichment in the miR-99b promoter region was promoted by LPS treatment, which indicted that NF-κB (p65) was recruited to the miR-99b promoter region to promote inflammatory damage in its transcriptional regulatory cells. Existing data further reveals that NF-κB could promote the transcription of miR-99a by binding to the -1643 to -1652 region of the miR-99a promoter (34Bao M.H. Li J.M. Luo H.Q. Tang L. Lv Q.L. Li G.Y. Zhou H.H. NF-kappaB-regulated miR-99a modulates endothelial cell inflammation.Mediators Inflamm. 2016; 2016 (27403035)530817010.1155/2016/5308170Crossref PubMed Scopus (28) Google Scholar). In addition, one study suggested that NF-κB might be negatively-correlated with PRDM1 during the process of B-cell differentiation (35Piccaluga P.P. Agostinelli C. Fuligni F. Righi S. Tripodo C. Re M.C. Clo A. Miserocchi A. Morini S. Gariglio M. Ferri G.G. Rinaldi-Ceroni A. Piccin O. De Andrea M. Pileri S.A. et al.IFI16 expression is related to selected transcription factors during B-cell differentiation.J. Immunol. Res. 2015; 2015 (26185770)74764510.1155/2015/747645Crossref PubMed Scopus (12) Google Scholar). These results collectively highlight the promoting effect of NF-κB on ALI via miR-99b-mediated PRDM1 inhibition. In conclusion, the current study revealed that NF-κB(p65) promoted the miR-99b expression by enriching the miR-99b promoter region. miR-99b was highly-expressed in ALI mouse lung tissues and
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