Rare genetic forms of FSGS can be caused by mutations in TRPC6, which encodes a Ca<sup>2+</sup>-permeable cationic channel expressed in mesangial cells and podocytes; and NPHS2, which encodes podocin, a TRPC6-binding protein expressed in podocyte slit diaphragm domains.
Here we show that a large family with hereditary FSGS carries a missense mutation in the TRPC6 gene on chromosome 11q, encoding the ion-channel protein transient receptor potential cation channel 6 (TRPC6).
The Ca(2+)-permeable, nonselective cation channel TRPC6 is gated via phospholipase C-activating receptors and has recently been implicated in hypoxia-induced pulmonary vasoconstriction (HPV), idiopathic pulmonary hypertension and focal segmental glomerulosclerosis (FSGS).
Transient receptor potential cation channel-6 (TRPC6) is one of the proteins that plays a key role causing focal segmental glomerulosclerosis (FSGS) associated with the steroid-resistant nephritic syndrome (SRNS).
The recent discovery that gain-of-function mutations in Ca(2+)-permeable canonical transient receptor potential-6 channels (TRPC6) underlie a subset of familial forms of focal segmental glomerulosclerosis (FSGS) has focused attention on the basic cellular physiology of podocytes.
Mutations in canonical transient receptor potential channel 6 (TRPC6) have been identified as responsible for the development of focal segmental glomerulosclerosis, a proteinuric disease with steroid resistance and poor prognosis.
These results delineate the mechanism of TRPC6 activation regulated by tyrosine phosphorylation, and imply the cell type-specific regulation, which correlates the FSGS mutations with deregulated TRPC6 channel activity.
Together, these data suggest a dual and context dependent role of TRPC6 in podocytes where acute activation protects from complement-mediated damage, but chronic overactivation leads to focal segmental glomerulosclerosis.
Genomic DNA was extracted from peripheral blood cells, and Sanger sequencing was performed for all exons and exon-intron boundaries of TRPC6 and ACTN4 in the probands of all FSGS pedigrees enrolled in this study.
The canonical transient receptor potential 6 (TRPC6) ion channel is expressed in the podocyte, and mutations in its cytoplasmic domain cause FSGS in humans.
Recently, the podocyte has been identified as a primary target in both genetic and acquired glomerular disorders.Mutations discovered by Winn et al. and Reiser et al. in the gene encoding TRPC6, a non-selective cation channel of the TRP family expressed in podocyte foot processes, have been shown to cause focal segmental glomerulosclerosis.
Familial and genetic forms of focal segmental glomerulosclerosis (FSGS) are associated with six different mutations in genes affecting the podocyte (NPHS2, ACTN4, CD2AP, WT1, TRPC6, and PLCE1).
The latest advance in familial FSGS has been the discovery of a mutant form of canonical transient receptor potential cation channel 6 (TRPC6), which causes an increase in calcium transients and essentially a gain of function in this cation channel located on the podocyte cell membrane.
Here we show that a large family with hereditary FSGS carries a missense mutation in the TRPC6 gene on chromosome 11q, encoding the ion-channel protein transient receptor potential cation channel 6 (TRPC6).
Transient receptor potential cation channel 6 (TRPC6) has been identified as causing a familial form of progressive focal and segmental glomerulosclerosis.
Transient receptor potential cation channel, subfamily C, member 6 (TRPC6) in podocytes is involved in chronic proteinuric kidney disease, particularly in focal segmental glomerulosclerosis (FSGS).