Mutations of WNK gene in patients with hypokalemic salt-losing tubulopathies / 上海交通大学学报（医学版）

Objective To explore the molecular mechanisms involved in hypokalemic salt-losing tubulopathies ( SLTs) through genetic screening of WNK gene in patients with SLTs. Methods Forty-four kindreds of SLTs were diagnosed Batter's syndrome or Gitelman's syndrome after CLCNKB and SLC12A3 sequencing and analysis, 8 of whose phenotype can not be simply attributed to CLCNKB or SLC12A3 mutations. Primers for PCR-amplified exons of WNK4 and WNK1 gene in genomic DNA were designed, and direct sequencing was performed to analyse the PCR products. Results Two missense mutations of WNK1, Ile~(1172)→ Met (I1172M) and Ser~(2047) → Asn (S2047N), were identified. Both of these 2 mutations segregated with the disease in SLTs kindred. Conclusion Two heterozygote missense mutations of WNK1 gene (I1172 M and S2047N) were found in 8 SLTs kindreds, indicating that WNK1 might be another gene responsible for hypokalemic salt-losing tubulopathies.

BMP-7 counteracts TGF0-?1-induced tubular epithelial-myofibroblast transdifferentiation of cultured renal tubular epithelial cells / 中华肾脏病杂志

Objective To study the possible role of bone morphogenetic protein 7(BMP 7) in the TGF ?1 induced tubular epithelial myofibroblast transdifferentiation (TEMT) of cultured renal tubular epithelial cells. Methods The normal rat kidney tubular epithelial cell line (HK 2) was cultured for three days on plastic plates in the presence or absence of recombinant TGF ?1 and BMP 7. The alterations in the phenotype were assessed by phase contrast microscopy. Transdifferentiation of tubular cells into myofibroblasts was assessed by immunofluorescence, with monoantibodies to alpha smooth muscle actin (? SMA), vimentin and cytokeratin respectively. The expression of ? SMA of HK 2 cells was measured by flowcytometry. The expression of ? SMA mRNA of HK 2 cells was assessed with reverse transcriptase polymerase chain reaction (RT PCR). Results Treatment of HK 2 cells with BMP 7(50 and 100 ng/ml) for 24～48 hours increased cellular proliferation. The culture of HK 2 cells in the presence of TGF ?1 induced a clear fibroblast like morphology, a loss of the epithelial marker cytokeratin and de novo expression of ? SMA and vimentin. Immunofluorescence staining showed the addition of various concentrations of BMP 7 to subconfluent cells for 24 and 48 hours, and the expression of ? SMA and vimentin was decreased. There was an increase in the percentage of cells expressing ? SMA with TGF ?1, which was completed inhibited by an addition of BMP 7(P