SARS-CoV-2-Induced PAPOLG Contributes to Inflammation Response by Stabilizing NF-κB mRNA

J Med Virol. 2025 Jul;97(7):e70478. doi: 10.1002/jmv.70478.

Abstract

One of the unknowns related to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection is the mechanism underlying the inflammatory response induced by the virus. Poly(A) polymerase gamma (PAPOLG) was previously shown to be upregulated during SARS-CoV-2 infection. The present study explored how PAPOLG affects the inflammatory reaction triggered by SARS-CoV-2. PAPOLG was knocked down or overexpressed in THP-1 macrophages. Target pathways were identified using RNA sequencing and bioinformatics analysis. The levels of PAPOLG, transcriptional regulator nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB), and cytokines TNF-α and IL-6 were measured, along with an assessment of NF-κB mRNA stability. PAPOLG was significantly upregulated in SARS-CoV-2-infected THP-1 macrophages. Genes subjected to alternative polyadenylation were enriched in immune pathways, and NF-κB emerged as a key regulator. Knockdown of PAPOLG promoted NF-κB mRNA degradation, while decreasing the levels of tumor necrosis factor-alpha (TNF-α) and interleukin-6 (IL6). Conversely, overexpression of PAPOLG stabilized NF-κB mRNA and enhanced TNF-α and IL-6 expression. PAPOLG contributes to the inflammatory response in SARS-CoV-2-infected macrophages by stabilizing NF-κB mRNA. Thus, PAPOLG may be targeted to control COVID-19-related inflammation.

Keywords: NF‐κB; PAPOLG; SARS‐CoV‐2; cytokine storm; inflammation.

MeSH terms

  • COVID-19* / genetics
  • COVID-19* / immunology
  • COVID-19* / metabolism
  • COVID-19* / virology
  • Humans
  • Inflammation* / genetics
  • Inflammation* / metabolism
  • Inflammation* / virology
  • Interleukin-6 / genetics
  • Interleukin-6 / metabolism
  • Macrophages / immunology
  • Macrophages / metabolism
  • Macrophages / virology
  • NF-kappa B* / genetics
  • NF-kappa B* / metabolism
  • Polynucleotide Adenylyltransferase* / genetics
  • Polynucleotide Adenylyltransferase* / metabolism
  • RNA Stability
  • RNA, Messenger* / genetics
  • RNA, Messenger* / metabolism
  • SARS-CoV-2*
  • THP-1 Cells
  • Tumor Necrosis Factor-alpha / genetics
  • Tumor Necrosis Factor-alpha / metabolism

Substances

  • NF-kappa B
  • RNA, Messenger
  • Tumor Necrosis Factor-alpha
  • Interleukin-6
  • Polynucleotide Adenylyltransferase
  • IL6 protein, human