Nephrogenic diabetes insipidus associated with mutations of vasopressin V2 receptors and aquaporin-2

摘要

Nephrogenic diabetes insipidus has two types of X-linked and autosomal recessive inheritance. The former is the mutations of arginine vasopressin (AVP) V2 receptors that have had 155 mutations in 239 families in the literature. The latter is the mutations of aquaporin-2(AQP-2) water channel, which have had 11 mutations. The functional analysis of V2 receptor mutations has resulted in two abnormalities. The mutated receptors retain in cytoplasma and can not fold into plasma membrane in most of AVP V2 receptor mutations. The other is that the mutated receptors, localized in plasma membrane, can not either bind to its ligand AVP or transduce its signal to the post-receptor pathway. Also, the mutated AQP-2 is functionally divided into two types of abnormality. In 10 out of 11 mutations, the mutated AQP-2 is located in endoplasmic reticulum or Golgi apparatus, and can not be translocated into apical plasma membrane. The mutated AQP-2 should functionally produce water permeability, if it could be routed intoplasma membrane. Only one mutation of AQP-2 (T125M and G175R) can be folded in apical membrane, but it does not produce water permeability. Recently, the experimental trials have been begun for rescuing the mutated AVP V2 receptors or AQP-2.