Altered expression of SARS-CoV-2 entry and processing genes by Porphyromonas gingivalis-derived lipopolysaccharide, inflammatory cytokines and prostaglandin E2 in human gingival fibroblasts

Abstract

Objective: The aim of this in vitro study was to investigate the expression of SARS-CoV-2 entry and processing genes in human gingival fibroblasts (HGnF) following treatment with Porphyromonas gingivalis-derived lipopolysaccharide (PgLPS) or inflammatory cytokines/mediators.

Design: We assessed the expression of SARS-CoV-2 entry and processing genes; angiotensin-converting enzyme 2 (ACE2), cellular serine proteases transmembrane serine protease 2 (TMPRSS2), Furin, and basigin (BSG) in HGnF by real-time PCR. To further asses the contribution of PgLPS and inflammatory cytokines/mediators to proliferation and SARS-CoV-2 entry and processing gene expression, HGnF were treated with PgLPS, IL1β, TNFα, and PGE₂.

Results: The expression for ACE2 in HGnF was significantly elevated after PgLPS or IL1β, TNFα, PGE₂ treatment. The expression of TMPRSS2 was increased by PgLPS, IL1β, or PGE₂ while BSG was elevated by PgLPS and IL1β. The expression of BSG and FURIN decreased after TNFα treatment.

Conclusion: SARS-CoV-2 entry and processing genes are expressed in human gingival fibroblasts and their expressions are altered by PgLPS, IL1β, TNFα and PGE₂ treatment.

Keywords: Angiotensin-converting enzyme 2; Basigin; COVID-19; Furin; Transmembrane serine protease 2.

Fig. 1

Effect of PgLPS, IL1β, TNFα and PGE₂ on HGnF cell proliferation. Cell numbers were analyzed after treatment with (A) PgLPS (0, 0.1, 1, 10 μg/mL), (B) IL1β (0, 0.01, 0.1, 1 ng/mL), (C) TNFα (0, 1, 10, 100 ng/mL) or (D) PGE₂ (0, 1, 10, 100, 1000 nM) for 24 h. Data are presented as dot plots. Values are shown as mean ± SD. n = 5. O.D., optical density.

Fig. 2

Effect of PgLPS, IL1β, TNFα, and PGE₂ on expression of ACE2. Expression level of ACE2 mRNA was analyzed after treatment with (A) PgLPS (0, 0.1, 1, 10 μg/mL), (B) IL1β (0, 0.01, 0.1, 1 ng/mL), (C) TNFα (0, 1, 10, 100 ng/mL) or (D) PGE₂ (0, 1, 10, 100, 1000 nM) for 24 h. Data are presented as dot plots. Values are shown as mean ± SD. n = 3-8. *P < 0.05, **P < 0.01, ***P < 0.001, ****P < 0.0001.

Fig. 3

Effect of PgLPS, IL1β, TNFα, and PGE₂ on expression of TMPRSS2. Expression level of TMPRSS2 mRNA was analyzed after treatment with (A) PgLPS (0, 0.1, 1, 10 μg/mL), (B) IL1β (0, 0.01, 0.1, 1 ng/mL), (C) TNFα (0, 1, 10, 100 ng/mL) or (D) PGE₂ (0, 1, 10, 100, 1000 nM) for 24 h. Data are presented as dot plots. Values are shown as mean ± SD. n = 3-4. **P < 0.01, ***P < 0.001, ****P < 0.0001.

Fig. 4

Effect of PgLPS, IL1β, TNFα, and PGE₂ on expression of BSG. Expression level of BSG mRNA was analyzed after treatment with (A) PgLPS (0, 0.1, 1, 10 μg/mL), (B) IL1β (0, 0.01, 0.1, 1 ng/mL), (C) TNFα (0, 1, 10, 100 ng/mL) or (D) PGE₂ (0, 1, 10, 100, 1000 nM) for 24 h. Data are presented as dot plots. Values are shown as mean ± SD. n = 3. *P < 0.05, **P < 0.01, ****P < 0.0001.

Fig. 5

Effect of PgLPS, IL1β, TNFα, and PGE₂ on expression of FURIN. Expression level of FURIN mRNA was analyzed after treatment with (A) PgLPS (0, 0.1, 1, 10 μg/mL), (B) IL1β (0, 0.01, 0.1, 1 ng/mL), (C) TNFα (0, 1, 10, 100 ng/mL) or (D) PGE₂ (0, 1, 10, 100, 1000 nM) for 24 h. Data are presented as dot plots. Values are shown as mean ± SD. n = 3. ****P < 0.0001.