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Published on: September 2, 2014
TMPRSS2 expression in oral mucosal cells induced by transfected double-stranded RNA and IL-1β
Misaki Akagi1, Kouji Ohta2, Miyuki Sakuma1
1Department of Oral and Maxillofacial Surgery, Graduate School of Biomedical and Health Sciences, Hiroshima University, 1-2-3 Kasumi, Minami-Ku, Hiroshima, 734-8553, Japan.
Objectives:
Transmembrane serine protease 2 (TMPRSS2) plays a key role in the entry of viruses such as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and influenza A into host cells, and its elevated expression is a risk factor for the spread of viral infection. However, TMPRSS2 expression and the factors related to its induction in oral keratinocytes and fibroblasts remain largely unknown. Here, we examined TMPRSS2 expression and factors related to its induction in oral mucosal cells.
Methods:
TMPRSS2 expression was examined in oral keratinocytes (RT7) and fibroblasts (GT1). Subsequently, TMPRSS2 induction in was analyzed in both cell types following transfection of nucleic acid and inflammatory cytokines, such as interleukin (IL)-1β. Finally, the effects of IL-1β on STAT1 activation related to double-stranded RNA (dsRNA)-induced TMPRSS2 expression were examined.
Results:
RT7 and GT1 cells exhibited constitutive TMPRSS2 mRNA and protein expression. Transfection with Poly(I:C) (as a dsRNA) and poly (dA:dT) (as a double-stranded DNA [dsDNA]) increased TMPRSS2 expression. TMPRSS2 expression was also increased by IL-1β, but not IFN-γ or TNF-α, while the combination of IL-1β and transfected Poly(I:C) caused a dramatic increase in TMPRSS2 expression as compared to each alone in both cell types. IL-1β also enhanced transfected Poly(I:C)-activated STAT1 related to TMPRSS2 expression.
Conclusions:
TMPRSS2-expressing oral keratinocytes and fibroblasts are targets of SARS-CoV-2 and influenza A virus. TMPRSS2 expression, in cooperation with IL-1β, plays an important role in promoting infection during virus invasion in oral mucosal cells.
Insights
Oral mucosal cells express Transmembrane serine protease 2 (TMPRSS2), a key factor in viral entry. Interleukin-1β (IL-1β) and viral nucleic acids significantly increase TMPRSS2 expression, promoting infection.
Area of Science:
- Virology
- Cell Biology
- Immunology
Background:
- Transmembrane serine protease 2 (TMPRSS2) is crucial for viral entry into host cells, including SARS-CoV-2 and influenza A.
- Elevated TMPRSS2 expression is a risk factor for viral infection spread.
- Understanding TMPRSS2 regulation in oral mucosal cells is vital for controlling viral infections.
Purpose of the Study:
- To investigate TMPRSS2 expression in oral keratinocytes and fibroblasts.
- To identify factors that induce TMPRSS2 expression in these oral mucosal cells.
- To elucidate the role of IL-1β and viral nucleic acids in TMPRSS2 induction.
Main Methods:
- Examined constitutive TMPRSS2 mRNA and protein expression in oral keratinocytes (RT7) and fibroblasts (GT1).
- Analyzed TMPRSS2 induction following transfection with nucleic acids (dsRNA, dsDNA) and inflammatory cytokines (IL-1β).
- Investigated the effect of IL-1β on STAT1 activation in relation to dsRNA-induced TMPRSS2 expression.
Main Results:
- Oral keratinocytes and fibroblasts constitutively express TMPRSS2.
- Double-stranded RNA (Poly(I:C)) and double-stranded DNA (poly(dA:dT)) increased TMPRSS2 expression.
- IL-1β significantly upregulated TMPRSS2, especially in combination with Poly(I:C), and enhanced Poly(I:C)-activated STAT1 signaling.
Conclusions:
- Oral keratinocytes and fibroblasts expressing TMPRSS2 are susceptible to SARS-CoV-2 and influenza A.
- IL-1β cooperates with viral components to enhance TMPRSS2 expression, facilitating viral invasion in oral mucosa.
- Targeting TMPRSS2 in oral mucosal cells could be a strategy to prevent viral infections.
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