Table 2.
Hypothesized correlations between expression patterns of MASPs other than TMPRSS2 and pathological observations in COVID-19 patients
| Putative priming MASP | Relevant expression organ/tissue | Likely relevance for SARS-CoV-2 infection and COVID-19 pathology |
|---|---|---|
| TMPRSS12, PRSS21 (testisin), PRSS41 (TESSP-1), and PRSS55 (T-SP1)a + TMPRSS6 (matriptase-2) + TMPRSS7 (matriptase-3) | Male reproductive organs (prostate, testis) | Possible viral reservoir. More severe complications of COVID-19 in male patients, leading to significantly higher mortality rates. |
| Airway trypsin-like proteases TMPRSS11A (HATL1), TMPRSS11D (HAT), TMPRSS11E (DESC1), and TMPRSS11F (HATL4) + TMPRSS4 + TMPRSS7 (matriptase-3) + TMPRSS14 (matriptase) + PRSS8 (prostasin) | At highest levels in the esophagus and minor salivary gland, but also expressed in the bronchi, trachea, and lungs | Alternative entry portals for SARS-CoV-2. Might contribute to and/or worsen lung infection/pneumonia. |
| TMPRSS5 (spinesin) + TMPRSS7 (matriptase-3) |
Brain/tibial nerve | Might explain the neurological complications reported for some patients, as well as impaired motor functions. |
| TMPRSS6 (matriptase-2) + TMPRSS1 (hepsin) |
Liver | Might contribute to liver damage. |
| TMPRSS10 (corin) | Cardiomyocytes | Might be responsible for heart damage. Might indirectly contribute to thrombotic complications through dysregulation of blood pressure. |
| TMPRSS1 (hepsin) + TMPRSS4 + TMPRSS14 (matriptase) + PRSS8 (prostasin) | Kidney | Might contribute to acute kidney injury (AKI). |
| TMPRSS14 (matriptase) + PRSS8 (prostasin) | Ubiquitously expressed in epithelial cells. | Involved in u-PA activation. Might be linked to thrombotic complications. Might also be linked to intestinal infection. |
a
Note that both PRSS41 and PRSS55 are termed “testis serine protease 1”.