Fig. 2

Protective model of a “second hit” during distant organ injury. The schematic cells represent proximal tubule cells of kidney. It has been shown in the Human Protein Atlas that ACE2 and TMPRSS2 are co-expressed in proximal tubules, especially in its microvilli (https://www.proteinatlas.org/ENSG00000130234-ACE2/tissue/kidney and https://www.proteinatlas.org/ENSG00000184012-TMPRSS2/tissue/kidney). The virus invasion flow was adopted from Parmar et al. [12]. The proposed model demonstrates that with increased time after the initial injury it becomes more difficult for SARS-CoV-2 to enter the injured lung or kidney cell. 6 h after the injury the both targets of SARS-CoV-2 (ACE2 and TMPRSS2) are downregulated. 36 h after the injury, while the expression of TMPRSS2 is recovered, the expression of ACE2 is downregulated even more than after 6 h