Impaired TLR4 and HIF expression in cystic fibrosis bronchial epithelial cells downregulates hemeoxygenase-1 and alters iron homeostasis in vitro

2014 ◽  
Vol 307 (10) ◽  
pp. L791-L799 ◽  
Author(s):  
Shashi Chillappagari ◽  
Shalini Venkatesan ◽  
Virajith Garapati ◽  
Poornima Mahavadi ◽  
Antje Munder ◽  
...  

Hemeoxygenase-1 (HO-1), an inducible heat shock protein, is upregulated in response to multiple cellular insults via oxidative stress, lipopolysaccharides (LPS), and hypoxia. In this study, we investigated in vitro the role of Toll-like receptor 4 (TLR4), hypoxia-inducible factor 1α (HIF-1α), and iron on HO-1 expression in cystic fibrosis (CF). Immunohistochemical analysis of TLR4, HO-1, ferritin, and HIF-1α were performed on lung sections of CFTR−/− and wild-type mice. CFBE41o- and 16HBE14o- cell lines were employed for in vitro analysis via immunoblotting, immunofluorescence, real-time PCR, luciferase reporter gene analysis, and iron quantification. We observed a reduced TLR4, HIF-1α, HO-1, and ferritin in CFBE41o- cell line and CF mice. Knockdown studies using TLR4-siRNA in 16HBE14o- revealed significant decrease of HO-1, confirming the role of TLR4 in HO-1 downregulation. Inhibition of HO-1 using tin protoporphyrin in 16HBE14o- cells resulted in increased iron levels, suggesting a probable role of HO-1 in iron accumulation. Additionally, sequestration of excess iron using iron chelators resulted in increased hypoxia response element response in CFBE41o- and 16HBE14o-, implicating a role of iron in HIF-1α stabilization and HO-1. To conclude, our in vitro results demonstrate that multiple regulatory factors, such as impaired TLR4 surface expression, increased intracellular iron, and decreased HIF-1α, downregulate HO-1 expression in CFBE41o- cells.

2021 ◽  
Vol 11 (12) ◽  
pp. 2478-2483
Author(s):  
Xiang Ji ◽  
Kai-Wen Zhou

Glaucoma is a leading cause of vision loss mainly due to retinal ganglion cells (RGC) loss. MicroRNAs (miRNAs) are highlighted as potential biomarkers in diseases. This study aims to investigate the role of miR-43 and BMSCs in the RGC apoptosis and glaucoma.RGCs were transfected with miR-43 inhibitors and mimics, and then co-cultured with BMSCs. RT-qPCR analysis was conducted to determine miR-43 expression, whilst Western blot, and flow cytometry were carried out to assess the role of miR-43 in apoptosis and inflammation. The interaction between miR-43 and BDNF, a neurotrophic factor, was detected by dual-luciferase reporter gene assay. Overexpression of miR-43 promoted RGC proliferation and decreased apoptosis. Furthermore, miR-43 overexpression diminished the contents of apoptosis- and inflammatory-related factors, and elevated the expression of BDNF. Down-regulation of BDNF exerted similar effect as down-regulation of miR-43, enhancing apoptosis and aggravating inflammation. Importantly, BMSC treatment reversed the in vitro inhibitory effect of si-BDNF on RGC with enhancement of miR-43 expression. Mechanically, miR-43 was indicated to target BDNF in glaucoma. Collectively, miR-43 delivered by BMSCs plays an important role in the inflammatory injury and abnormal apoptosis of RGC by regulating the expression of BDNF. These findings might help development of new treatment for glaucoma and provide a promising biomarker for diagnosis and treatment.


2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Zhao Guo ◽  
Wen-Shan Gao ◽  
Yun-Fei Wang ◽  
Fei Gao ◽  
Wei Wang ◽  
...  

Intervertebral disc degeneration (IVDD) is a common cause of low back pain. This study is aimed at investigating the role of microRNAs (miRNAs) in regulating human nucleus pulposus (NP) cell injury induced by tumor necrosis factor- (TNF-) α in IVDD. In this study, we induced NP cells with 20 ng/mL TNF-α in vitro, which promoted the obvious apoptosis of NP cells and the activation of nuclear transcription factor (NF)-κB. In contrast, using the specific NF-κB inhibitor BAY 11-7082 to treat cells greatly impaired the activation of NF-κB and increased the sensitivity of NP cells to TNF-α-induced apoptosis. Moreover, both TNF-α and BAY 11-7082 treatments were associated with marked miRNA dysregulation, with miR-502 being upregulated by TNF-α treatment and downregulated by BAY 11-7082 treatment, respectively. And the overexpression of miR-502 enhanced NF-κB activation and suppressed apoptosis of human NP cells induced by TNF-α, whereas the opposite was observed following miR-502 inhibition. Last, through bioinformatic analyses and luciferase reporter gene experiments, we identified TRAF2, an important activator of NF-κB, as a miR-502 target gene. Similarly, siRNA-mediated knockdown of the TRAF2 expression also suppressed TNF-α-induced apoptosis and enhanced NF-κB activation. Our findings provide evidence indicating that miR-502 is a key regulator of apoptosis of human NP cells induced by TNF-α by targeting TRAF2 and activating NF-κB.


2021 ◽  
Author(s):  
Zhang Jieling ◽  
Li Kai ◽  
Zheng Huifen ◽  
Zhu Yiping

Abstract Background: MicroRNAs play an important role in the genesis and progression of tumors, including colorectal cancer (CRC), which has a high morbidity and mortality rate. In this research, the role of miR-495-3p and HMGB1 in CRC was investigated.Methods: We performed qRT-PCR to detect the expression of miR-495-3p in colorectal cancer tissues and cell lines. Functional experiments such as CCK-8 assay, EDU assay, Transwell assay and apoptosis assay were conducted to explore the effects of miR-495-3p on the proliferation, migration and apoptosis of CRC cells in vitro. Then, the use of database prediction, dual-luciferase reporter gene assay and functional experiments verified the role of miR-495-3p target gene HMGB1 in CRC. Finally, rescue experiments was performed to investigate whether overexpression of HMGB1 could reverse the inhibitory effect of miR-495-3p on CRC cell proliferation in vivo and in vitro.Results: miR-495-3p was down-regulated in colorectal cancer tissues and cell lines, and could inhibit the proliferation and migration of colorectal cancer cells, and promote cell apoptosis. The database prediction and dual-luciferase reporter gene assay showed that HMGB1 was the downstream target gene of miR-495-3p. We finally demonstrated that miR-495-3p inhibited CRC cell proliferation by targeting HMGB1 in vitro and in vivo.Conclusion: Our research shows that miR-495-3p inhibits the progression of colorectal cancer by down-regulating the expression of HMGB1, which indicates that miR-495-3p may become a potential therapeutic target for colorectal cancer.


2017 ◽  
Vol 41 (1) ◽  
pp. 310-322 ◽  
Author(s):  
Ying Yang ◽  
Yanning Liu ◽  
Jihua Xue ◽  
Zhenggang Yang ◽  
Yu Shi ◽  
...  

Background/Aims: About 400 million individuals are chronically infected with hepatitis B virus, at high risk of developing liver cirrhosis and hepatocellular carcinoma. Recent studies have demonstrated an interaction between hepatitis B virus replication and autophagy activity of hepatocytes. In the present study, we aimed to investigate the role of miR-141 in regulating autophagy and hepatitis B virus replication. Methods: The expression of HBV-DNA, miR-141 and Sirt1 mRNA was determined by quantitative real-time PCR analysis. The expression of HBsAg and HBeAg was determined by ELISA. Western blotting was performed to detect protein expression. The LC3 puncta was determined by immunofluorescence. To test whether miR-141 directly regulate the expression level of Sirt1 mRNA, dual-luciferase reporter gene assay was performed. Results: In vitro studies showed that miR-141 mimic inhibited the autophagic response, hepatitis B virus and the expression of Sirt1 in hepatocytes. And transfection with miR-141 inhibitor enhanced autophagic response and Sirt1 expression. The autophagy induced by overexpression of Sirt1 was inhibited by miR-141 mimic. In addition, miR-141 mimic also decreased the expression of Sirt1 mRNA. Sirt1 was predicted as a potential miR-141 target by bioinformatic analysis of its 3'-UTR, and confirmed by luciferase reporter assays which analyzing the interaction of miR-141 with the wild- type or the mutated Sirt1 3’-UTR. Conclusion: We have therefore demonstrated a role of miR-141 in regulating autophagy-mediated hepatitis B virus inhibition by targeting Sirt1, and may provide potential targets for drug development.


2020 ◽  
Author(s):  
Yubin Feng ◽  
shuang Hu ◽  
lanlan Li ◽  
xiaoqing Peng ◽  
Feihu Chen

Abstract BackgroundLong noncoding RNAs (lncRNAs) plays an important role in the development of physiology and pathology. Many reports have shown that LncRNA HOXA cluster antisense RNA 2 (HOXA-AS2) is a carcinogen and plays an important role in many tumors, but there are few reports on its role in Acute myeloid leukemia (AML). MethodsThe expression of HOXA-AS2 in AML cell line was detected by qRT-PCR. AML cases from the public database (GEPIA) were also included in this study. Cell counting kit-8 (CCK-8) assay, flow cytometry, immunofluorescence and Western blot were used to detect the role of HOXA-AS2 in AML cells. Luciferase reporter gene detection, RIP, RNA pull-down and RNA-ChIP detection were used to demonstrate the molecular biological mechanism of HOXA-AS2 in AML.ResultsOur results show that HOXA-AS2 was upregulated in AML cell lines and tissues, and the overexpression of HOXA-AS2 is negatively correlated with the survival of patients. Silencing HOXA-AS2 can inhibit the proliferation and induce differentiation of AML cells in vitro and in vivo. After overexpressing HOXA-AS2, it will show the opposite result. Moreover, more in-depth mechanism studies show that HOXA-AS2 exerts its carcinogenicity mainly by binding with the epigenetic inhibitor Enhancer of zeste homolog 2 (EZH2) and then inhibiting the expression of Large Tumor Suppressor 2 (LATS2). ConclusionsTaken together, our results highlight the important role of HOXA-AS2 in AML, suggesting that HOXA-AS2 may be an effective therapeutic target for patients with AML.


2021 ◽  
Vol 12 ◽  
Author(s):  
Elena Campione ◽  
Caterina Lanna ◽  
Terenzio Cosio ◽  
Luigi Rosa ◽  
Maria Pia Conte ◽  
...  

Lactoferrin (Lf) is a cationic glycoprotein synthetized by exocrine glands and is present in all human secretions. It is also secreted by neutrophils in infection and inflammation sites. This glycoprotein possesses antimicrobial activity due to its capability to chelate two ferric ions per molecule, as well as to interact with bacterial and viral anionic surface components. The cationic features of Lf bind to cells, protecting the host from bacterial and viral injuries. Its anti-inflammatory activity is mediated by the ability to enter inside the nucleus of host cells, thus inhibiting the synthesis of proinflammatory cytokine genes. In particular, Lf down-regulates the synthesis of IL-6, which is involved in iron homeostasis disorders and leads to intracellular iron overload, favoring viral replication and infection. The well-known antiviral activity of Lf has been demonstrated against DNA, RNA, and enveloped and naked viruses and, therefore, Lf could be efficient in counteracting also SARS-CoV-2 infection. For this purpose, we performed in vitro assays, proving that Lf exerts an antiviral activity against SARS-COV-2 through direct attachment to both SARS-CoV-2 and cell surface components. This activity varied according to concentration (100/500 μg/ml), multiplicity of infection (0.1/0.01), and cell type (Vero E6/Caco-2 cells). Interestingly, the in silico results strongly supported the hypothesis of a direct recognition between Lf and the spike S glycoprotein, which can thus hinder viral entry into the cells. These in vitro observations led us to speculate a potential supplementary role of Lf in the management of COVID-19 patients.


2003 ◽  
Vol 77 (9) ◽  
pp. 5152-5166 ◽  
Author(s):  
Jiang Yin ◽  
Aniko V. Paul ◽  
Eckard Wimmer ◽  
Elizabeth Rieder

ABSTRACT The role of the cis replication element (cre) in the 2CATPase coding region of the poliovirus (PV) genome has been studied with a series of mutants derived from either a PV1 full-length genome or a replicon (P/L) containing the firefly luciferase reporter gene in place of the capsid region. Using the P/L replicon we have inserted cre elements at three different locations in the genome including the 5′ nontranslated region and within the open reading frame. The successful recovery of replication of a nonviable P/L (A5C) mutant replicon with an artificial cre element as “rescuer,” in addition to the results of site-directed mutagenesis and experiments with truncated forms of PV-cre(2C), indicated that (i) the sequence within the upper stem and loop regions contains the minimal cre RNA required for VPg uridylylation in vitro, (ii) the location of the cre RNA in the poliovirus genome is not relevant to RNA infectivity, and (iii) specific binding of 3CDpro to PV-cre(2C) occurs within the upper stem region and probably involves several contact residues. The role of a 14-nucleotide conserved “core” sequence among known cre structures in picornaviruses was examined by site-directed mutagenesis of individual nucleotides. In addition to a conserved AAA (4472 to 4474) triplet previously shown to be the primary RNA template for VPg uridylylation by the PV RNA polymerase 3Dpol (E. Rieder, A. V. Paul, D. W. Kim, J. H. van Boom, and E. Wimmer, J. Virol. 74:10371-10380, 2000), we have now shown that important residues (G4468 and A4481) are contained in a predicted internal bulge at the upper stem-loop of PV-cre(2C). We have further demonstrated that the viral proteins 3CDpro and 3Cpro form stable complexes with a transcript PV-cre(2C) RNA that can be considered critical for VPg uridylylation.


2021 ◽  
Author(s):  
Hua Gao ◽  
Yang Zhongjin ◽  
Li Zhenye ◽  
Li Zhenzong

Abstract Background: ADP-ribosylation-like factor4C (ARL4C) is overexpressed in several cancer tissues and is involved in cancer development. Increasing evidence reveals that aberrant microRNAs (miRNAs) expression play a crucial role in the tumorigenesis of cancers. Nevertheless, the exact mechanism that regulates ARL4C expression in glioma has not been fully elucidated. The aim of this study was to investigate expression and significance of miR-654-3p/ARL4C in glioma.Methods: CGGA and TCGA databases were used to study the prognosis role of miR-654-3p, ARL4C and the relationship between ARL4C and pathological grade in gliomas. Real-time quantitative PCR was performed to detect the levels of miR-654-3p and ARL4C in glioma tissues. CCK-8 and colony formation experiments were used to observe the effects of miR-654-3p and ARL4C on the proliferation of U87 cells.Results: CGGA database and TCGA database both showed that the level of ARL4C was increased along with the WHO grades of glioma, and patients with high ARL4C had lower IDH mutation ratio, older age and poor overall survival (OS) compared with patients with low ARL4C. The clinical features in patients with high miR-654-3p showed the opposite trend compared with patients with high ARL4C. In vitro experiments showed that overexpression of ARL4C promoted cell proliferation in U87 cells. Dual-luciferase reporter gene assays showed that ARL4C was the target gene of miR-654-3p, and miR-654-3p mimics could inhibit the cell proliferation of U87 cells, and ARL4C partly counteracted the role of miR-654-3p in U87 cells.Conclusions: miR-654-3p/ARL4C is associated with pathological grade of glioma, and patients with high ARL4C or low miR-654-3p have shorter OS. miR-654-3p/ARL4C may serve as a prognostic factor in patients with glioma and new potential therapeutic target.


2021 ◽  
Author(s):  
Xian Zhao ◽  
Xiaojing Xu ◽  
Qiong Wang ◽  
Xiaofei Wu

Abstract Background: Majority of cancer related deaths in males are attributed to prostate cancer (PRAD) throughout the world. Recently, the role of long non-coding RNAs (lncRNAs) in the pathogenesis of cancer has been widely explored. In this study, we investigated the role of lncRNA LINC01213 (LINC01213) in tumorigenesis of prostate cancer (PRAD).Methods: PRAD and adjacent tissue samples were collected from cancer patients. Survival rate among these patients was compared by Kaplan–Meier analysis. PRAD cells viability was estimated by CCK-8 method while AnnexinV/PI cytometry assay was used to determine the percent of apoptotic cells. qRT-PCR and western blot assay were used to determine the mRNA and protein expressions, respectively. Interaction between LINC01213 and corresponding miRNA as well as between miRNA and mRNA was confirmed by dual luciferase reporter gene assay. PRAD cells were also injected subcutaneously in nude mice to support in vitro findings.Results: It was observed that LINC01213 was highly expressed in PRAD samples and cell lines. Down-regulation of LINC01213 in PRAD cells decreased cell viability and inhibited proliferation. Luciferase reporter gene assay and RNA pull-down confirmed that LINC01213 targeted miR-597-3p. Increased expression of miR-597-3p resulted in decreased BCL2L2 expression in vitro. Inhibitory effects of miR-597-3p on PRAD cells’ survival and growth were diminished after LINC01213 overexpression which was also associated with alteration in the protein expression of BCL-xL, BCL-2 as well as caspase 3 and caspase 9.Conclusion: Taken together, our findings suggest that LINC01213 plays its role in PRAD tumorigenesis through miR-597-3p/ BCL2L2 dependent pathway with associated modulation of genes involved in cell survival and apoptosis.


2020 ◽  
Author(s):  
Yubin Feng ◽  
Shuang Hu ◽  
Lanlan Li ◽  
Xiaoqing Peng ◽  
Feihu Chen

Abstract BackgroundLong noncoding RNAs (lncRNAs) plays an important role in the development of physiology and pathology. Many reports have shown that lncRNA HOXA cluster antisense RNA 2 (HOXA-AS2) is a carcinogen and plays an important role in many tumors, but little is known about its role in Acute myeloid leukemia (AML). MethodsThe expression of HOXA-AS2 in AML cell line was detected by qRT-PCR. AML cases from the public database (GEPIA) were also included in this study. Cell counting kit-8 (CCK-8) assay, flow cytometry, immunofluorescence and Western blot were used to detect the role of HOXA-AS2 in AML cells. Luciferase reporter gene detection, RIP, RNA pull-down and RNA-ChIP detection were used to demonstrate the molecular biological mechanism of HOXA-AS2 in AML.ResultsHOXA-AS2 was upregulated in AML cell lines and tissues, and the overexpression of HOXA-AS2 is negatively correlated with the survival of patients. Silencing HOXA-AS2 can inhibit the proliferation and induce differentiation of AML cells in vitro and in vivo. Overexpressing HOXA-AS2 showed the opposite result. Moreover, more in-depth mechanism studies showed that carcinogenicity of HOXA-AS2 exerted mainly through binding with the epigenetic inhibitor Enhancer of zeste homolog 2 (EZH2) and then inhibiting the expression of Large Tumor Suppressor 2 (LATS2). ConclusionsTaken together, our findings highlight the important role of HOXA-AS2 in AML, suggesting that HOXA-AS2 may be an effective therapeutic target for patients with AML.


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