It is a recent discovery that coronavirus uses a protein CD147 also called EMMPRIN, to invade cells. (1) The amount of this protein is increased by mechanical ventilation according to experimental results. (2) For this reason mechanical ventilation may significantly enhance the virus infection of lung tissues.
By activating PPARgamma, a nuclear receptor, it is possible to decrease the amount of the protein EMMPRIN in macrophages, that are dysregulated in lung tissue. (3)
PPARgamma has potent anti inflammatory effect in microglia the resident immune cells of the brain and macrophages. (4)(5)
Proinsulin C-peptide may activate PPARgamma to achieve a twofold effect: the inhibition of the virus invasion of the cells and of inflammation. (6)
(1) https://www.biorxiv.org/content/10.1101/2020.03.14.988345v1.full.pdf
(2) https://pubmed.ncbi.nlm.nih.gov/11726397/?dopt=Abstract
(3) https://www.sciencedirect.com/science/article/abs/pii/S0167527306005845
(4) https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5949563/
(5) https://pubmed.ncbi.nlm.nih.gov/25134730/
(6) https://pubmed.ncbi.nlm.nih.gov/15375153/