Integrin-linked kinase regulates tubular aquaporin-2 content and intracellular location: a link between the extracellular matrix and water reabsorption.
One of the clinical alterations observed in chronic renal disease (CRD) is the impaired urine concentration, known as diabetes insipidus (DI). Tubulointerstitial fibrosis of the kidney is also a pathological finding observed in CRD and involves composition of extracellular matrix (ECM). However, an association between these two events has not been elucidated. In this study, we showed that the extracellular-to-intracellular scaffold protein integrin-linked kinase (ILK) regulates expression of tubular water channel aquaporin-2 (AQP2) and its apical membrane presence in the renal tubule. Basally, polyuria and decreased urine osmolality were present in ILK conditional-knockdown (cKD-ILK) adult mice compared with nondepleted ILK littermates. No changes were observed in arginine-vasopressin (AVP) blood levels, renal receptor (V2R), or AQP3 expression. However, tubular AQP2 was decreased in expression and apical membrane presence in cKD-ILK mice, where the canonical V2R/cAMP axis activation is still functional, but independent of the absence of ILK. Thus, cKD-ILK constitutes a nephrogenic diabetes insipidus (NDI) model. AQP2 and ILK colocalize in cultured inner medullary collecting duct (mIMCD3) cells. Specific ILK siRNAs and collagen I (Col) decrease ILK and AQP2 levels and AQP2 presence on the membrane of tubular mIMCD3 cells, which impairs the capacity of the cells to transport water under hypotonic stress. The present work points to ILK as a therapeutic target in NDI.
Department of Systems Biology, Physiology Unit, Universidad de Alcalá, Alcalá de Henares, Madrid, Spain; Instituto Reina Sofia de Investigación Renal and Red de Investigación Renal (REDinREN), Instituto de Salud Carlos III, Madrid, Spain;
Jose Luis
JL
Cano-Peñalver
Department of Systems Biology, Physiology Unit, Universidad de Alcalá, Alcalá de Henares, Madrid, Spain; Instituto Reina Sofia de Investigación Renal and Red de Investigación Renal (REDinREN), Instituto de Salud Carlos III, Madrid, Spain;
Mercedes
M
Griera
Department of Integrative Oncology, British Columbia Cancer Research Center, Vancouver, British Columbia, Canada; and.
Isabel
I
Serrano
Instituto Reina Sofia de Investigación Renal and Red de Investigación Renal (REDinREN), Instituto de Salud Carlos III, Madrid, Spain; Biomedical Research Foundation and Department of Nephrology, Hospital Príncipe de Asturias, Alcalá de Henares, Madrid, Spain.
Diego
D
Rodríguez-Puyol
Department of Integrative Oncology, British Columbia Cancer Research Center, Vancouver, British Columbia, Canada; and.
Shoukat
S
Dedhar
Department of Systems Biology, Physiology Unit, Universidad de Alcalá, Alcalá de Henares, Madrid, Spain; Instituto Reina Sofia de Investigación Renal and Red de Investigación Renal (REDinREN), Instituto de Salud Carlos III, Madrid, Spain; sergio.frutos@uah.es.
Sergio
S
de Frutos
Department of Systems Biology, Physiology Unit, Universidad de Alcalá, Alcalá de Henares, Madrid, Spain; Instituto Reina Sofia de Investigación Renal and Red de Investigación Renal (REDinREN), Instituto de Salud Carlos III, Madrid, Spain;
Manuel
M
Rodríguez-Puyol
D000818:Animals; D051399:Aquaporin 2 / Q000096:biosynthesis / Q000235:genetics / Q000502:physiology*; D051400:Aquaporin 3 / Q000096:biosynthesis / Q000235:genetics; D001127:Arginine Vasopressin / Q000097:blood; D001693:Biological Transport, Active; D001834:Body Water / Q000378:metabolism*; D002462:Cell Membrane / Q000737:chemistry; D016764:Cell Polarity; D002478:Cells, Cultured; D024042:Collagen Type I / Q000494:pharmacology; D003894:Deamino Arginine Vasopressin / Q000494:pharmacology; D018500:Diabetes Insipidus, Nephrogenic / Q000378:metabolism; D004195:Disease Models, Animal; D016326:Extracellular Matrix Proteins / Q000502:physiology*; D007671:Kidney Concentrating Ability / Q000502:physiology*; D007685:Kidney Tubules, Collecting / Q000378:metabolism* / Q000648:ultrastructure; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D009994:Osmolar Concentration; D009997:Osmotic Pressure / Q000502:physiology; D010766:Phosphorylation; D011141:Polyuria / Q000235:genetics / Q000378:metabolism*; D011499:Protein Processing, Post-Translational; D017346:Protein Serine-Threonine Kinases / Q000172:deficiency / Q000235:genetics / Q000502:physiology*; D034622:RNA Interference; D034741:RNA, Small Interfering / Q000494:pharmacology; D017483:Receptors, Vasopressin / Q000096:biosynthesis / Q000235:genetics; D000099200:Scaffold Protein ILK
D051399:Aquaporin 2; D051400:Aquaporin 3; D001127:Arginine Vasopressin; D024042:Collagen Type I; D003894:Deamino Arginine Vasopressin; D016326:Extracellular Matrix Proteins; D017346:Protein Serine-Threonine Kinases; D034741:RNA, Small Interfering; D017483:Receptors, Vasopressin; D000099200:Scaffold Protein ILK; C496024:Aqp2 protein, mouse; C496028:Aqp3 protein, mouse
chronic renal disease; fibrosis; nephrogenic diabetes insipidus