Disease relevance of Bsnd

• Recently, mutations in barttin, a protein not related to any known ion transporter or channel, were described in BSND, a variant of Bartter syndrome associated with sensorineural deafness [1].

High impact information on Bsnd

• To further confirm that changes were specific for THP and not merely the consequence of reduced kidney growth, the abundance of barttin, another distal tubular protein related to chloride transport, was tested as well [2].
• Under furosemide treatment barttin mRNA was regulated in parallel with ClC-K1 mRNA [3].
• Parallel down-regulation of chloride channel CLC-K1 and barttin mRNA in the thin ascending limb of the rat nephron by furosemide [3].
• Our findings imply that during furosemide treatment selective down-regulation of ClC-K1 and barttin mRNAs in thin limb plays a role in maintaining salt and water homeostasis [3].
• Here we show that barttin functions as an activator of ClC-K chloride channels [1].

Biological context of Bsnd

• The aim of the present study was to investigate the influence of the loop diuretic furosemide on the gene expression of the kidney chloride channel ClC-K1 and its recently described functional subunit barttin [3].

Associations of Bsnd with chemical compounds

• Microdissection of the inner medullary collecting duct and thin limb of Henle's loop followed by real-time PCR revealed that CLC-K1 and barttin mRNA regulation in inner medulla was limited to the thin limb; mRNA levels in collecting ducts were not affected by furosemide treatment [3].

Other interactions of Bsnd

• Localisation and regulation of ClC-K1 and barttin mRNA was analysed by RNase protection and in situ hybridisation [3].

Analytical, diagnostic and therapeutic context of Bsnd

• Co-immunoprecipitation revealed a direct interaction of barttin with ClC-K [1].
• We performed in situ hybridization on rat kidney slices and RT-PCR analysis on microdissected nephron segments to prove co-expression of barttin, ClC-K1 and ClC-K2 along the distal nephron [1].

References