Influence of QDPR expression on DHFR expression of NRK-52E cells in high gluoc se ambience / 医学研究生学报

ABSTRACT

Objective K93T point mutation exists in the quinoid dihydropteridine reductase ( QDPR) of OLEFT rats which catalyzes QDPR into tetrahydrobinopterin(BH4), while dihydrofolate reductase(DHFR) can reduce QDPR to BH4, which implies crosstalk between hydrobiopterin and folate metabolism.By investigating the influence of QDPR expression on DHFR expression of NRK-52E cells, the article aimed to find out the possible underlying mechanism of QDPR gene in diabetic nephropathy ( DN). Methods Western blot was performed to identify the expression level in NRK-52E cell under high glucose ambience and DHFR pro-tein expression of OLETF rats.NRK-52E cells were transfected by the lentivirus to establish no-load overexpression, overexpressed QDPR and knockdown QDPR models.Each group was given 5.4 mmol/L normal sugar medium and 30mmol/L in high glucose ambi-ence for 72 hours'cell cultivation to simulate DN model.Observation was made on the influence of QDPR gene expression levels on DHFR in high glucose ambience. Results The western blot analysis revealed that DHFR protein decreased in NHG group( [0.33 ± 0.16] vs [0.64 ±0.5], P<0.05) and OLETF rats cortex ([0.56 ±0.16] vs [1.03 ±0.12], P<0.01).In high glucose ambi-ence, compared with LV-OCON-HG group, the protein expression of DHFR was significantly decreased in LV-QDPR-HG group ([0.12 ±0.09] vs [0.63 ±0.08], P<0.01).No difference was found in the comparison of DHFR expression levels between LV-SHQDPR-HG and LV-SHCON-HG group. Conclusion DHFR protein expression decreases in NRK-52E cells of high glucose and LOLETF rat model, which suggests that DHFR protein plays an important role in the development of DN.QDPR overexpression leads to the decreased expression of DHFR, which implies that overexpressed QDPR influences the occurrence and process of DN by down-regulating DHFR expression level.