scholarly journals Role of Human Antigen R (HuR) in the Regulation of Pulmonary ACE2 Expression

Cells ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 22
Author(s):  
Noof Aloufi ◽  
Zahraa Haidar ◽  
Jun Ding ◽  
Parameswaran Nair ◽  
Andrea Benedetti ◽  
...  
Keyword(s):  
Protein Expression ◽  
Lung Tissue ◽  
Cellular Localization ◽  
Rna Binding ◽  
Human Lung ◽  
Lung Fibroblasts ◽  
Severe Illness ◽  
Protein Levels ◽  
Human Lung Cells ◽  
Increased Risk

Patients with COPD may be at an increased risk for severe illness from COVID-19 because of ACE2 upregulation, the entry receptor for SARS-CoV-2. Chronic exposure to cigarette smoke, the main risk factor for COPD, increases pulmonary ACE2. How ACE2 expression is controlled is not known but may involve HuR, an RNA binding protein that increases protein expression by stabilizing mRNA. We hypothesized that HuR would increase ACE2 protein expression. We analyzed scRNA-seq data to profile ELAVL1 expression in distinct respiratory cell populations in COVID-19 and COPD patients. HuR expression and cellular localization was evaluated in COPD lung tissue by multiplex immunohistochemistry and in human lung cells by imaging flow cytometry. The regulation of ACE2 expression was evaluated using siRNA-mediated knockdown of HuR. There is a significant positive correlation between ELAVL1 and ACE2 in COPD cells. HuR cytoplasmic localization is higher in smoker and COPD lung tissue; there were also higher levels of cleaved HuR (CP-1). HuR binds to ACE2 mRNA but knockdown of HuR does not change ACE2 protein levels in primary human lung fibroblasts (HLFs). Our work is the first to investigate the association between ACE2 and HuR. Further investigation is needed to understand the mechanistic underpinning behind the regulation of ACE2 expression.

scholarly journals RBFOX3 regulates Claudin-1 expression in human lung tissue via attenuation of proteasomal degradation

2017 ◽  
Vol 37 (1) ◽  
Author(s):  
Yong-Eun Kim ◽  
Sunkyung Choi ◽  
Jong Ok Kim ◽  
Kee K. Kim
Keyword(s):  
Lung Tissue ◽  
Molecular Mechanisms ◽  
Neuronal Development ◽  
Rna Binding ◽  
Human Lung ◽  
Human Lung Cancer ◽  
Mrna Levels ◽  
Human Lung Tissue ◽  
Protein Levels ◽  
The Stability

RBFOX3, a nuclear RNA-binding protein, is well known as a regulator of alternative pre-mRNA splicing during neuronal development. However, other functions of RBFOX3 are poorly understood. Here, we investigated the function of RBFOX3 in the cytoplasm with respect to regulation of Claudin-1 expression. In human lung tissue, Claudin-1 is higher in RBFOX3-positive cells than in RBFOX3-negative cells. Immunostaining and mRNA quantification revealed that protein levels, but not mRNA levels, of Claudin-1 are increased by RBFOX3. In addition, cycloheximide treatment of human lung cancer cells revealed that RBFOX3 increases the stability of Claudin-1 through attenuation of its ubiquitination. Our study provides insights into the molecular mechanisms by which RBFOX3 regulates Claudin-1 expression in human lung tissue.

scholarly journals Reconstruction of the miR-506-Quaking axis in Idiopathic Pulmonary Fibrosis using integrative multi-source bioinformatics

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Stevan D. Stojanović ◽  
Maximilian Fuchs ◽  
Chunguang Liang ◽  
Kevin Schmidt ◽  
Ke Xiao ◽  
...  
Keyword(s):  
Data Mining ◽  
Idiopathic Pulmonary Fibrosis ◽  
Pulmonary Fibrosis ◽  
Rna Sequencing ◽  
In Silico ◽  
Rna Binding ◽  
Human Lung ◽  
Model Systems ◽  
Lung Fibroblasts ◽  
Sequencing Analysis

AbstractThe family of RNA-binding proteins (RBP) functions as a crucial regulator of multiple biological processes and diseases. However, RBP function in the clinical setting of idiopathic pulmonary fibrosis (IPF) is still unknown. We developed a practical in silico screening approach for the characterization of RBPs using multi-sources data information and comparative molecular network bioinformatics followed by wet-lab validation studies. Data mining of bulk RNA-Sequencing data of tissues of patients with IPF identified Quaking (QKI) as a significant downregulated RBP. Cell-type specific expression was confirmed by single-cell RNA-Sequencing analysis of IPF patient data. We systematically analyzed the molecular interaction network around QKI and its functional interplay with microRNAs (miRs) in human lung fibroblasts and discovered a novel regulatory miR-506-QKI axis contributing to the pathogenesis of IPF. The in silico results were validated by in-house experiments applying model systems of miR and lung biology. This study supports an understanding of the intrinsic molecular mechanisms of IPF regulated by the miR-506-QKI axis. Initially applied to human lung disease, the herein presented integrative in silico data mining approach can be adapted to other disease entities, underlining its practical relevance in RBP research.

Cold-induced RNA-binding protein (CIRBP) regulates the expression of Src-associated during mitosis of 68 kDa (Sam68) and extracellular signal-regulated kinases (ERK) during heat stress-induced testicular injury

2020 ◽  
Vol 32 (18) ◽  
pp. 1357
Author(s):  
Chengcheng Xu ◽  
Dandan Ke ◽  
Liping Zou ◽  
Nianyu Li ◽  
Yingying Wang ◽  
...  
Keyword(s):  
Gene Expression ◽  
Heat Stress ◽  
Protein Expression ◽  
Rna Binding ◽  
Cell Model ◽  
Binding Protein ◽  
Rna Binding Protein ◽  
Protein Levels ◽  
Extracellular Signal ◽  
Testicular Injury

In this study, the ability of cold-induced RNA-binding protein (CIRBP) to regulate the expression of Src-associated during mitosis of 68 kDa (Sam68) and extracellular signal-regulated kinases (ERK) in the mouse testis and mouse primary spermatocytes (GC-2spd cell line) before and after heat stress was examined to explore the molecular mechanism by which CIRBP decreases testicular injury. A mouse testicular hyperthermia model, a mouse primary spermatocyte hyperthermia model and a low CIRBP gene-expression cell model were constructed and their relevant parameters were analysed. The mRNA and protein levels of CIRBP and Sam68 were significantly decreased in the 3-h and 12-h testicular heat-stress groups, extracellular signal-regulated kinase 1/2 (ERK1/2) protein expression was not significantly affected but phospho-ERK1/2 protein levels were significantly decreased. GC-2spd cellular heat-stress results showed that the mRNA and protein concentrations of CIRBP and Sam68 were reduced 48h after heat stress. In the low CIRBP gene-expression cell model, CIRBP protein expression was significantly decreased. Sam68 mRNA expression was significantly decreased only at the maximum transfection concentration of 50nM and Sam68 protein expression was not significantly affected. These findings suggest that CIRBP may regulate the expression of Sam68 at the transcriptional level and the expression of phospho-ERK1/2 protein, both of which protect against heat-stress-induced testicular injury in mice.

scholarly journals Discrepancy between Jun/Fos Proto-Oncogene mRNA and Protein Expression in the Rheumatoid Arthritis Synovial Membrane

J ◽  
2020 ◽  
Vol 3 (2) ◽  
pp. 181-194 ◽  
Author(s):  
René Huber ◽  
Bruno Stuhlmüller ◽  
Elke Kunisch ◽  
Raimund W. Kinne
Keyword(s):  
Rheumatoid Arthritis ◽  
Protein Expression ◽  
Synovial Membrane ◽  
Rna Binding ◽  
Mrna Level ◽  
Joint Disease ◽  
Protein Levels ◽  
Modifying Factors ◽  
Mrna And Protein Expression ◽  
Joint Trauma

Rheumatoid arthritis (RA) is a chronic inflammatory and destructive joint disease characterized by overexpression of pro-inflammatory/pro-destructive mediators, whose regulation has been the focus of our previous studies. Since the expression of these proteins commonly depends on AP-1, the expression of the AP-1-forming subunits cJun, JunB, JunD, and cFos was assessed in synovial membrane (SM) samples of RA, osteoarthritis (OA), joint trauma (JT), and normal controls (NC) using ELISA and qRT-PCR. With respect to an observed discrepancy between mRNA and protein levels, the expression of the mRNA stability-modifying factors AU-rich element RNA-binding protein (AUF)-1, tristetraprolin (TTP), and human antigen R (HuR) was measured. JunB and JunD protein expression was significantly higher in RA-SM compared to OA and/or NC. By contrast, jun/fos mRNA expression was significantly (cjun) or numerically decreased (junB, junD, cfos) in RA and OA compared to JT and/or NC. Remarkably, TTP and HuR were also affected by discrepancies between their mRNA and protein levels, since they were significantly decreased at the mRNA level in RA versus NC, but significantly or numerically increased at the protein level when compared to JT and NC. Discrepancies between the mRNA and protein expression for Jun/Fos and TTP/HuR suggest broad alterations of post-transcriptional processes in the RA-SM. In this context, increased levels of mRNA-destabilizing TTP may contribute to the low levels of jun/fos and ttp/hur mRNA, whereas abundant mRNA-stabilizing HuR may augment translation of the remaining mRNA into protein with potential consequences for the composition of the resulting AP-1 complexes and the expression of AP-1-dependent genes in RA.

scholarly journals Trypanosoma brucei RNA Binding Proteins p34 and p37 Mediate NOPP44/46 Cellular Localization via the Exportin 1 Nuclear Export Pathway

2007 ◽  
Vol 6 (12) ◽  
pp. 2206-2213 ◽  
Author(s):  
Kristina Hellman ◽  
Kimberly Prohaska ◽  
Noreen Williams
Keyword(s):  
Amino Acid ◽  
Trypanosoma Brucei ◽  
Nuclear Export ◽  
Cellular Localization ◽  
Binding Proteins ◽  
Rna Binding ◽  
Rna Binding Proteins ◽  
Nuclear Export Signal ◽  
Amino Acid Sequences ◽  
Protein Levels

ABSTRACT We have previously identified and characterized two novel nuclear RNA binding proteins, p34 and p37, which have been shown to interact with a family of nucleolar phosphoproteins, NOPP44/46, in Trypanosoma brucei. These proteins are nearly identical, the major difference being an 18-amino-acid insert in the N terminus of p37. In order to characterize the interaction between p34 and p37 and NOPP44/46, we have utilized an RNA interference (RNAi) cell line that specifically targets p34 and p37. Within these RNAi cells, we detected a disruption of a higher-molecular-weight complex containing NOPP44/46, as well as a dramatic increase in nuclear NOPP44/46 protein levels. We demonstrated that no change occurred in NOPP44/46 mRNA steady-state levels or stability, nor was there a change in cellular protein levels. These results led us to investigate whether p34 and p37 regulate NOPP44/46 cellular localization. Examination of the p34 and p37 amino acid sequences revealed a leucine-rich nuclear export signal, which interacts with the nuclear export factor exportin 1. Immune capture experiments demonstrated that p34, p37, and NOPP44/46 associate with exportin 1. When these experiments were performed with p34/p37 RNAi cells, NOPP44/46 no longer associated with exportin 1. Sequential immune capture experiments demonstrated that p34, p37, NOPP44/46, and exportin 1 exist in a common complex. Inhibiting exportin 1-mediated nuclear export led to an increase in nuclear NOPP44/46 proteins, indicating that they are exported from the nucleus via this pathway. Together, our results demonstrate that p34 and p37 regulate NOPP44/46 cellular localization by facilitating their association with exportin 1.

scholarly journals Increased expression of ACE2, the SARS-CoV-2 entry receptor, in alveolar and bronchial epithelium of smokers and COPD subjects

2020 ◽  
Author(s):  
Merel Jacobs ◽  
Hannelore P Van Eeckhoutte ◽  
Sara RA Wijnant ◽  
Wim Janssens ◽  
Guy F Joos ◽  
...  
Keyword(s):  
Mrna Expression ◽  
Cigarette Smoke ◽  
Lung Tissue ◽  
Bronchial Epithelium ◽  
Chronic Obstructive ◽  
Protein Levels ◽  
Populations At Risk ◽  
Increased Risk ◽  
Entry Receptor ◽  
Severe Copd

ABSTRACTRationaleSmokers and patients with chronic obstructive pulmonary disease (COPD) are at increased risk for severe Coronavirus Disease 2019 (COVID-19).ObjectivesWe investigated the expression of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) entry receptor ACE2 and the protease TMPRSS2 in lung tissue from never smokers and smokers with and without COPD.MethodsIn a cross-sectional, observational study we measured mRNA expression of ACE2 and TMPRSS2 by RT-PCR in lung tissue samples from 120 well phenotyped subjects. Next, protein levels of ACE2 were visualized by immunohistochemistry on paraffin sections from 87 subjects and quantified in alveolar and bronchial epithelium. Finally, primary human bronchial epithelial cells (HBECs) were cultured at air liquid interface and exposed to air or cigarette smoke.ResultsACE2 mRNA expression was significantly higher in lung tissue from current smokers and subjects with moderate to very severe COPD and correlated with physiological parameters of airway obstruction and emphysema. Pulmonary expression levels of TMPRSS2 were significantly higher in patients with (very) severe COPD and correlated significantly with ACE2 expression. Importantly, protein levels of ACE2 were elevated in both alveolar and bronchial epithelium of current smokers and subjects with moderate to very severe COPD. Finally, TMPRSS2 mRNA expression increased in in vitro cultured HBECs upon acute exposure to cigarette smoke.ConclusionsWe demonstrate increased expression of ACE2 in lungs of smokers and COPD subjects, which might facilitate host cell entry of SARS-CoV-2. These findings help identifying populations at risk for severe COVID-19.

Cytokines increase B1 bradykinin receptor mRNA and protein levels in human lung fibroblasts

1997 ◽  
Vol 25 (1) ◽  
pp. 43S-43S ◽  
Author(s):  
STEPHEN B. PHAGOO ◽  
MOHAMMED YAQOOB ◽  
PETER McINTYRE ◽  
CAROLINE JONES ◽  
GILLIAN M. BURGESS
Keyword(s):  
Human Lung ◽  
Lung Fibroblasts ◽  
Human Lung Fibroblasts ◽  
Protein Levels ◽  
Receptor Mrna ◽  
Bradykinin Receptor
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