AUTHOR=Maremanda Krishna P. , Sundar Isaac K. , Li Dongmei , Rahman Irfan 

TITLE=Age-Dependent Assessment of Genes Involved in Cellular Senescence, Telomere, and Mitochondrial Pathways in Human Lung Tissue of Smokers, COPD, and IPF: Associations With SARS-CoV-2 COVID-19 ACE2-TMPRSS2-Furin-DPP4 Axis

JOURNAL=Frontiers in Pharmacology

VOLUME=11

YEAR=2020

URL=https://www.frontiersin.org/journals/pharmacology/articles/10.3389/fphar.2020.584637

DOI=10.3389/fphar.2020.584637

ISSN=1663-9812

ABSTRACT=<sec><title>Background</title><p>Aging is one of the key contributing factors for chronic obstructive pulmonary diseases (COPD) and other chronic inflammatory lung diseases. Here, we determined how aging contributes to the altered gene expression related to mitochondrial function, cellular senescence, and telomeric length processes that play an important role in the progression of COPD and idiopathic pulmonary fibrosis (IPF).</p></sec><sec><title>Methods</title><p>Total RNA from the human lung tissues of non-smokers, smokers, and patients with COPD and IPF were processed and analyzed using a Nanostring platform based on their ages (younger: &lt;55 years and older: &gt;55 years).</p></sec><sec><title>Results</title><p>Several genes were differentially expressed in younger and older smokers, and patients with COPD and IPF compared to non-smokers which were part of the mitochondrial biogenesis/function (<italic>HSPD1</italic>, <italic>FEN1</italic>, <italic>COX18</italic>, <italic>COX10</italic>, <italic>UCP2 &amp; 3</italic>), cellular senescence (<italic>PCNA</italic>, <italic>PTEN</italic>, <italic>KLOTHO</italic>, <italic>CDKN1C</italic>, <italic>TNKS2</italic>, <italic>NFATC1 &amp; 2</italic>, <italic>GADD45A</italic>), and telomere replication/maintenance (<italic>PARP1</italic>, <italic>SIRT6</italic>, <italic>NBN</italic>, <italic>TERT</italic>, <italic>RAD17</italic>, <italic>SLX4</italic>, <italic>HAT1</italic>) target genes. Interestingly, <italic>NOX4</italic> and <italic>TNKS2</italic> were increased in the young IPF as compared to the young COPD patients. Genes in the mitochondrial dynamics and quality control mechanisms like <italic>FIS1</italic> and <italic>RHOT2</italic> were decreased in young IPF compared to their age matched COPD subjects. ERCC1 and <italic>GADD45B</italic> were higher in young COPD as compared to IPF. Aging plays an important role in various infectious diseases including the SARS-CoV-2 infection. Lung immunoblot analysis of smokers, COPD and IPF subjects revealed increased abundance of proteases and receptor/spike protein like TMPRSS2, furin, and DPP4 in association with a slight increase in severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) receptor ACE2 levels.</p></sec><sec><title>Conclusions</title><p>Overall, these findings suggest that altered transcription of target genes that regulate mitochondrial function, cellular senescence, and telomere attrition in the pathobiology of lung aging in COPD and IPF is associated with alterations in SARS-CoV-2 ACE2-TMPRSS2-Furin-DPP4 axis as pharmacological targets for COVID-19.</p></sec>