[Analysis of the molecular pathogenesis of hereditary protein C deficiency due to a p.Gly86Asp variant of the PROC gene].

OBJECTIVE: To explore the molecular pathogenesis of hereditary protein C (PC) deficiency due to a p.Gly86Asp variant of the PROC gene through in vitro expression experiment. METHODS: Wild type and Gly86Asp mutant expression plasmids of PC were constructed and respectively transfected into HEK 293FT cells. Total RNA was extracted from the transfected cells, and the expression of PROC gene was determined by quantitative real-time PCR (qRT-PCR). PC antigen (PC:Ag) in the supernatant of cell culture and cell lysate was determined by enzyme-linked immunosorbent assay (ELISA), and the level of PC protein was detected by Western blotting. RESULTS: qRT-PCR has detected no significant difference in the transcription level of wild-type and mutant-type PC. Compared with the wild type, the level of mutant PC:Ag in the supernatant and cell lysate were 81.3%±2.6% and 110.0%±2.8%, respectively. No difference was detected in the molecular weight between the wild-type and mutant-type PC by Western blotting. The PC content of mutant type was higher than wild-type in cell lysate, while the opposite was found with the cell culture supernatant. CONCLUSION: The impaired secretion by mutant PC may be the molecular mechanism of PC deficiency caused by the p.Gly86Asp variant.