To determine the expression level and role of PYCARD [PYRIN-PAAD-DAPIN domain (PYD) and a C-terminal caspase recruitment domain (CARD), PYCARD] gene and its transcript variant mRNA in peripheral blood mononuclear cells (PBMCs) of patients with primary gout (PG).
PYCARD gene and its transcript variant mRNA were measured using reverse transcription-polymerase chain reaction (RT-PCR) in PBMCs. The expression of PYCARD gene and PYCARD-1,-2 mRNA in PBMCs was compared between the patients with acute phase PG (APPG) (n=44), non-acute phase PG (NAPPG) (n= 51) and healthy controls (HC) (n=87). PYCARD and NF-kappaB (p105/p50) protein expressions were measured using Western blot in the PBMCs of participants in the PG and HC groups. Routine blood tests and blood uric acid test were undertaken in all participants. Differences in the indicators were examined among the three groups. Correlations between the expression of PYCARD gene and PYCARD-1,-2 mRNA and other indicators were analyzed.
The expression level of PYCARD gene, PYCARD-1,-2 mRNA was significantly higher in the APPG and NAPPG group than in the HC group (P<0.01). The NAPPG group had significantly higher levels of PYCARD gene transcript variant 2x mRNA and 2y mRNA in the HC and APPG groups (P<0.05). The expression of PYCARD and NF-kappaB (p105/p50) protein was significantly higher in the PG group compared with the HC group [(4.900 +/- 1.324) vs. (3.975 +/- 0.210) and (0.263 +/- 0.106) vs. (0.127 +/- 0.008), respectively P<0.05]. The expression level of PYCARD-2 mRNA and granulocyte were positively correlated in the NAPPG group.
Abnormal expression of PYCARD gene and its transcript variant and PYCARD protein in PG patients suggests that PYCARD gene and its transcript variant may play an important role in regulating the inflammatory response of PG patients.