Urinary Sediment mRNA Level of CREBBP and CYBA in Children With Steroid-Resistant Nephrotic Syndrome.

Background: This study aimed to evaluate gene expression patterns in urinary sediment samples of children with steroid-resistant nephrotic syndrome (SRNS). Methods: The messenger RNA (mRNA) levels of 770 immune-related genes were detected using a NanoString nCounter platform. To verify the NanoString results, quantitative analysis of nine gene mRNAs was performed using real-time RT-PCR in more samples. Results: Firstly, compared with the steroid-sensitive nephrotic syndrome (SSNS) group (n=3), significant changes were observed in the mRNA level of 70 genes, including MAP3K14, CYBA, SLC3A2, CREB-binding protein (CREBBP), CD68, forkhead box P1 (FOXP1), CD74, ITGB2, IFI30, and so forth, in the SRNS group (n=3). A total of 129 children with idiopathic nephrotic syndrome (INS), 15 with acute glomerulonephritis, and 6 with immunoglobulin A nephropathy (IgAN) were enrolled to verify the NanoString results. Compared with patients with IgAN, those with INS had significantly lower levels of FOXP1 (P=0.047) and higher levels of CREBBP (P=0.023). Among SSNS, the mRNA level of ITGB2 was significantly lower in the non-relapse group than in the non-frequent relapse and frequent-relapse groups (P=0.006). Compared with the SSNS group, CREBBP was significantly elevated in the SRNS group (P=0.02). Further, CYBA significantly decreased in the SRNS group (P=0.01). The area under the curve (AUC) for CREBBP and CYBA was 0.655 and 0.669, respectively. CREBBP had a sensitivity of 83.3% and a specificity of 49.4% and CYBA had a sensitivity of 58.3% and a specificity of 83.1% to rule out SSNS and SRNS. The diagnosis value was better for CREBBP+CYBA than for CREBBP or CYBA alone, indicating that the combination of CREBBP and CYBA was a more effective biomarker in predicting steroid resistance (AUC=0.666; sensitivity=63.9%; specificity=76.4%). Conclusions: This study was novel in investigating the urinary sediment mRNA level in children with INS using high-throughput NanoString nCounter technology, and 70 genes that may relate to SRNS were found. The results revealed that the urinary sediment mRNA level of ITGB2 was significantly lower in the non-relapse group than in the non-frequent relapse and frequent-relapse groups. Meanwhile, CREBBP was significantly elevated and CYBA was significantly lowered in the SRNS group compared with the SSNS group.

Hereditary deficiency of gp91(phox) is associated with enhanced arterial dilatation: results of a multicenter study.

BACKGROUND: NADPH oxidase is believed to modulate arterial tone, but its role in humans is still unclear. The objective of this study was to evaluate whether NADPH oxidase is involved in flow-mediated arterial dilation (FMD). METHODS AND RESULTS: Twenty-five patients with hereditary deficiency of gp91(phox), the catalytic core of NADPH oxidase, (X-CGD), 25 healthy subjects, and 25 obese patients matched for sex and age were recruited. FMD, platelet gp91(phox), serum levels of nitrite and nitrate as markers of nitric oxide generation, oxidized low-density lipoprotein, and urinary excretion of isoprostanes as markers of oxidative stress were determined. Platelet gp91(phox) expression was downregulated in X-CGD patients (1.0+/-0.8 mean fluorescence; P<0.001) and upregulated in obese patients (4.1+/-2.2 mean fluorescence; P=0.01) compared with healthy subjects (2.9+/-1.7 mean fluorescence). Urinary excretion of isoprostanes was reduced in X-CGD patients (41.7+/-33.3 pg/mg creatinine; P=0.04) and increased in obese patients (154.4+/-91 pg/mg creatinine; P<0.001) compared with healthy subjects (69.5+/-52.4 pg/mg creatinine). Obese patients had higher serum oxidized low-density lipoprotein than healthy subjects (35.3+/-6.7 versus 24.8+/-9.8 U/L; P<0.001) and X-CGD patients (28.5+/-7.2 U/L; P<0.001). X-CGD patients had significantly higher FMD (14.7+/-5.9%) compared with healthy subjects (7.9+/-2.5%; P<0.001); obese patients had lower FMD (5.3+/-3.0%; P=0.028) compared with healthy subjects. Serum nitrite and nitrate levels were significantly higher in patients with X-CGD (36.0+/-10.8 micromol/L; P=0.016) and lower in obese patients (9.3+/-11.0 micromol/L; P=0.001) compared with healthy subjects (27.1+/-19.1 micromol/L). Serum nitrite and nitrate levels significantly correlated with FMD (R(s)=0.403, P<0.001) and platelet gp91(phox) (R(s)=-0.515, P<0.001). FMD inversely correlated with platelet gp91(phox) (R(s)=-0.502, P<0.001) and isoprostanes (R(s)=-0.513, P<0.001). CONCLUSIONS: This study provides the first evidence that, in humans, gp91(phox) is implicated in the modulation of arterial tone.