[Clinical and pathological features and mutational types of WT1 mutation-associated nephropathy]

Objective: To explore the clinical and pathological features and mutational types and their relations with WT1 mutation-associated nephropathy (WT1MAN). Methods: The clinical and pathological data and the results of WT1 mutation analysis of the cases from Nanfang Hospital of Southern Medical University, Sun Yat-sen Memorial Hospital and The First Affiliated Hospital of Sun Yat-sen University whom we recruited recently and reported during the last ten years were analyzed. Results: Totally, 20 cases (6 males and 14 females), included 5 newly diagnosed cases, were recruited. (1) Ten children were diagnosed with Denys-Drash syndrome (DDS): The median onset age of proteinuria was 1 year and 7 months. Diffuse mesangial sclerosis (DMS) were revealed in 3 cases, minimal lesions (MCD) in 4 cases, and focal segmental glomerulosclerosis (FSGS) in 1 case; renal pathology was not available in the other 2 cases. Glomerular basement membrane (GBM) thickening was observed in 2 cases. Calcineurin inhibitors (CNIs) were administered in 5 cases, complete remission of proteinuria was observed in 3 cases, partial remission in the other 2 cases. Genetic analysis revealed that six cases had WT1 missense mutation, 3 had nonsense mutation, and 1 had frameshift mutation. (2) Two cases were diagnosed with Frasier syndrome (FS): proteinuria was observed at 1 year and 1 month of age and 1 year and 9 months of age, respectively. FSGS with GBM layering were observed in both cases. They progressed to ESRD at 1 year and 6 months of age and 6 years and 6 months of age, respectively. CNI was tried in 1 case with partial proteinuria remission. Both patients were detected to have WT1 splice mutation. (3) Isolated nephropathy (IN) was observed in 8 cases: three had splice mutation, 5 had missense mutation. Of the 3 patients with splice mutation, one was found to have nephropathy and renal failure at the age of 5 months. The other two cases (1 was FSGS and another MCD), both had GBM layering. CNIs were tried on both of them, one got partial remission with normal renal function at the age of fourteen years, the other one had no response and entered ESRD at the age of 6 years and 9 months. Of the 5 cases with missense mutation, 3 had DMS, 2 of them entered ESRD within 6 months of age, another case had DMS entered ESRD at 9 years of age. One case with FSGS, was treated with CNIs and got complete remission. Conclusions: Slow progression (7/10) nephropathy was observed in DDS patients. Missense mutation (11/20) was the most common type of WT1 variants, followed by splice mutation (5/20) in this group of patients. Early onset nephropathy (4/5), rapid progression (4/5) and GBM layering (4/4) wereobserved in patients with splice mutation. CNI was effective in reducing or even eliminating proteinuria in WT1 MAN patients (8/9).

[Clinical features and gene mutation analysis of 13 Chinese juvenile patients with nephronophthisis]

Objective: To explore the clinical features and pathogenic gene mutation of juvenile nephronophthisis (NPHP) in Chinese patients. Method: Clinical data and blood samples of 27 juvenile NPHP patients from 25 families who were initially clinically diagnosed in six hospitals in Guangdong province were collected. NPHP1 homozygous deletions were detected in all patients. Sequencing of NPHP1 gene was performed when homozygous deletions were not found in patients without eye involvement. In patients with eye involvement, NPHP5 sequencing was carried out initially and subsequently NPHP10 gene and NPHP1 when there were no NPHP5 gene mutation found. Result: Diagnosis was confirmed in 13 patients by renal pathology and (or) gene sequencing, including four boys and nine girls with a median onset age of 8.5(0.1-12.8) years. Seven of the 13 patients had a normal routine urine test and six patients had mild to moderate proteinuria. None had persistent hematuria. The estimated glomerular filtration rate of the 13 patients was (12.7±10.7) ml/(min·1.73 m²) at the time of diagnosis. Renal cysts were found in only five patients by iconography. Decreased renal size was observed in nine cases and normal renal size in four patients. Renal pathology was available in five patients, renal cysts formation at the cortical-medullar area, thickening and laying tubular basement membrane, were observed. Two of the thirteen children had eye involvement, one had liver impairment and one had growth retardation. NPHP1 gene defects were detected in seven patients with a mutation rate of 25.9%, and large homozygous deletions were observed in three patients. Four patients had single point mutations, i. e. compound heterozygous mutations (c.13 C>T and c. 1520+ 5 G>A) in one patient; homozygous mutation in three patients, two patients were siblings from the same pedigree harbored c. 1756 C>T and the other one harbored c. 1298delA. NPHP5 gene homozygous mutation was found in one pedigree. The fourteen children without renal pathology and whose genetic tests were negative shared similar clinical features with the thirteen patients whose diagnosis were confirmed by gene mutation and (or) renal pathology. Conclusion: The onset of juvenile NPHP is insidious. Urine and renal iconography changes are mild or negative. The ratio of NPHP1 mutant patient is similar with previous reports, but the proportion of NPHP1 gene homozygous deletions is much lower and all of the NPHP1 gene single point mutations detected in this research were novel, which indicates a genetic discrepancy existed between Chinese NPHP patients and the western ones.

Hsp110 expression changes in rat primary myocardial cells exposed to heat stress in vitro

We investigated and described the kinetics of heat shock protein (Hsp) 110 expression and distribution in rat primary myocardial cells exposed to heat stress in vitro. After incubation at 37°C for 72 h, myocardial cells were heat stressed at 42°C for 0, 10, 20, 40, 60, 120, 240, 360, and 480 min. Significant increases in aspartate transaminase, lactate dehydrogenase, and creatine kinase enzymatic activities in the myocardial cell culture media were observed during heat stress, suggesting that the integrity of the myocardial cells was altered. Immunocytochemical analysis revealed that the expressed Hsp110 was constitutively localized in the cytoplasm and in the nuclei in small amounts characterized by a granular pattern. Nuclear Hsp110 levels increased significantly after 240 min of heat stress compared with levels in the control. The overall levels of Hsp110 expression increased significantly after 20 min. After 240 min, Hsp110 levels were approximately 1.2-fold higher than those in the control. Increasing levels of hsp110 messenger RNA detected using real-time quantitative polymerase chain reaction were observed after 20 min of heat stress, and the levels peaked with a 10-fold increase after 240 min of heat stress. These results indicate that the expression of Hsp110 in primary myocardial cells in vitro is sensitive to hyperthermic stress and that Hsp110 is involved in the potential acquisition of thermotolerance after heat stress. Therefore, Hsp110 might play a fundamental role in opposing and alleviating heat-induced damage caused by hyperthermic stress in primary myocardial cells.