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Inhibitory Effect of Luteolin on Spike S1 Glycoprotein-Induced Inflammation in THP-1 Cells Via the ER Stress-Inducing Calcium/CHOP/MAPK Pathway

Overview
Publisher MDPI
Specialty Chemistry
Date 2024 Oct 26
PMID 39459041
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Abstract

Background/objectives: The global SARS-CoV-2 outbreak has escalated into a critical public health emergency, with the spike glycoprotein S1 subunit of SARS-CoV-2 (spike-S1) linked to inflammation in lung tissue and immune cells. Luteolin, a flavone with anti-inflammatory properties, shows promise, but research on its effectiveness against long-COVID-related inflammation and spike protein-induced responses remains limited. This study aims to elucidate the underlying mechanisms of inflammation in THP-1 cells induced by the spike-S1. Additionally, it seeks to assess the potential of luteolin in mitigating inflammatory responses induced by the spike-S1 in a THP-1 macrophage model.

Methods: The gene expression profiles of spike-S1 in THP-1 cells were analyzed by transcriptome sequencing. The inhibitory effect of luteolin on ER stress and inflammation in spike-S1-induced THP-1 cells was investigated using Western blotting, RT-PCR, and ELISA.

Results: The candidate genes (, , , , , , and ) were upregulated in the spike-S1-induced THP-1 group compared to the control group. Among these, calcium/calmodulin-dependent protein kinase II alpha (CAMK2A) was identified as the most promising molecule in spike-S1-induced THP-1 cells. Our results indicate that the spike S1 significantly increased the expression of ER-stress markers at both gene and protein levels. Luteolin significantly reduced ER stress by decreasing the expression of ER-stress marker genes and ER-stress marker proteins ( < 0.01). Additionally, luteolin exhibited anti-inflammatory properties upon spike S1-induction in THP-1 cells by significantly suppressing IL-6, IL-8, and IL-1β cytokine secretion in a dose-dependent manner ( < 0.05). Furthermore, our results revealed that luteolin exhibited the downregulation of the MAPK pathway, as evidenced by modulating the phosphorylation of p-ERK1/2, p-JNK and p-p38 proteins ( < 0.05).

Conclusions: The results from this study elucidate the mechanisms by which the spike S1 induces inflammation in THP-1 cells and supports the use of naturally occurring bioactive compounds, like luteolin, against inflammation-related SARS-CoV-2 infection.

References
1.
Liskova A, Samec M, Koklesova L, Samuel S, Zhai K, Al-Ishaq R . Flavonoids against the SARS-CoV-2 induced inflammatory storm. Biomed Pharmacother. 2021; 138:111430. PMC: 7906511. DOI: 10.1016/j.biopha.2021.111430. View

2.
Bracken C, Beauverger P, Duclos O, Russo R, Rogers K, Husson H . CaMKII as a pathological mediator of ER stress, oxidative stress, and mitochondrial dysfunction in a murine model of nephronophthisis. Am J Physiol Renal Physiol. 2016; 310(11):F1414-22. DOI: 10.1152/ajprenal.00426.2015. View

3.
Wang Y, Liu L, Zhong B, Liu T, Li Y, Yang Y . WDR5 is essential for assembly of the VISA-associated signaling complex and virus-triggered IRF3 and NF-kappaB activation. Proc Natl Acad Sci U S A. 2010; 107(2):815-20. PMC: 2818949. DOI: 10.1073/pnas.0908967107. View

4.
Lu M, Berglund E, Larsson C, Hoog A, Farnebo L, Branstrom R . Calmodulin and calmodulin-dependent protein kinase II inhibit hormone secretion in human parathyroid adenoma. J Endocrinol. 2010; 208(1):31-9. DOI: 10.1677/JOE-10-0123. View

5.
Lopez-Lazaro M . Distribution and biological activities of the flavonoid luteolin. Mini Rev Med Chem. 2009; 9(1):31-59. DOI: 10.2174/138955709787001712. View