• Aquaporin-2 (AQP-2) is found in the apical cell membranes of the kidney's collecting duct principal cells and in intracellular vesicles located throughout the cell. (wikipedia.org)
  • This aquaporin is regulated in two ways by the peptide hormone vasopressin: short-term regulation (minutes) through trafficking of AQP2 vesicles to the apical region where they fuse with the apical plasma membrane long-term regulation (days) through an increase in AQP2 gene expression. (wikipedia.org)
  • In addition, quantitative immunoelectron microscopy of AQP2 labeling in the IMCD principal cells showed that there was a reduction in AQP2 in the apical plasma membrane, as well as in the basolateral plasma membrane and intracellular vesicles. (artscolumbia.org)
  • Thus reduction of AQP2 in both the apical and the basolateral plasma membrane may participate in the overall reduced water reabsorption (149). (artscolumbia.org)
  • However, treatment of lithium-diuretic rats with high doses of the specific V2-receptor agonist dDAVP was able to cause efficient delivery of AQP2 to the apical plasma membrane (a greater fraction of total AQP2 was found in the membrane than seen in control animals), but there was only a modest increase in AQP2 expression relative to animals treated with lithium alone. (artscolumbia.org)
  • On the contrary, thirsting of the rats for 2 days resulted in a much larger increase in AQP2 protein levels, but little targeting to the apical plasma membrane (a lot of AQP2 was found in intracellular domains, i. e. (artscolumbia.org)
  • When it is needed, vasopressin binds to the cell surface vasopressin receptor thereby activating a signaling pathway that causes the aquaporin 2 containing vesicles to fuse with the plasma membrane, so the aquaporin 2 can be used by the cell. (wikipedia.org)
  • The reduction in AQP2 (and AQP3) expression may be caused by a lithium-induced impairment in the production of cAMP in collecting duct principal cells (38, 39), indicating that inhibition of cAMP production may in part be responsible for the reduction in AQP2 expression as well as the inhibition of targeting to the plasma membrane in response to lithium treatment. (artscolumbia.org)
  • Detection of AQP2, RI and RII subunits of PKA in IMCD cells by immunofluorescence microscopy 47 2.5.4. (fu-berlin.de)
  • Selective activation of PKA type II is sufficient to elicit the AQP2 shuttle in renal principal cells 72 3.3.2. (fu-berlin.de)
  • It is encoded by the AQP2 gene. (wikipedia.org)
  • Lithium, which is often used to treat bipolar disorder, can cause acquired diabetes insipidus (characterized by the excretion of large volumes of dilute urine) by decreasing the expression of the AQP2 gene. (wikipedia.org)
  • The expression of the AQP2 gene is increased during conditions associated with water retention such as pregnancy and congestive heart failure. (wikipedia.org)
  • Consequently, this study showed that thirsting was a more potent stimulus for AQP2 expression than dDAVP administration in the present model and provided evidence for the presence of a vasopressin-independent regulation of AQP2 expression levels. (artscolumbia.org)
  • However, as is discussed, the degree of AQP2 downregulation as well as the intracellular localization of the protein differs significantly among the various conditions, suggesting that different mechanisms are responsible for AQP2 dysregulation in the various models. (artscolumbia.org)
  • As discussed below, a number of rat models with NDI have been evaluated, and common for all is a reduced expression of AQP2 in the principal cells of the collecting ducts. (artscolumbia.org)
  • The downregulation of AQP2 expression was paralleled by a progressive development of severe polyuria. (artscolumbia.org)
  • There was a very slow recovery in AQP2 expression and restoration of urinary concentration after cessation of lithium treatment (149) consistent with clinical findings. (artscolumbia.org)
  • Aquaporin 2 is in kidney epithelial cells and usually lies dormant in intracellular vesicle membranes. (wikipedia.org)
  • Extracellular vesicles (EVs) carry information inherited from parental cells, having significant potential for disease diagnosis. (harvard.edu)
  • In article Plasmon‐Enhanced Biosensing: Plasmon‐Enhanced Biosensing for Multiplexed Profiling of Extracellular Vesicles Hyungsoon Im and co‐workers label extracellular vesicles, which are nanoscale phospholipid vesicles secreted by cells, with fluorescently conjugated antibodies. (harvard.edu)
  • In addition to DI, a few other serious conditions are associated with reduced AQP2 levels and urinary concentrating defects (see Table 2). (artscolumbia.org)
  • AQP2 and AQP3 levels were progressively reduced to 5% of levels in control rats after 25 days of lithium treatment (129, 149). (artscolumbia.org)
  • Thus downregulation of both AQP2 and AQP3 appears to play a significant role in the development of lithium-induced polyuria. (artscolumbia.org)
  • Water reabsorption is regulated by AQP2 trafficking between intracellular storage vesicles and the apical membrane. (tcdb.org)
  • Water homeostasis in humans is regulated by vasopressin, which induces the translocation of homotetrameric aquaporin-2 (AQP2) water channels from intracellular vesicles to the apical membrane of renal principal cells. (nih.gov)
  • The AQP2 water channel translocates from intracellular vesicles to the apical membrane in response to an acute increase in circulating vasopressin. (centralparkcarriagesofficial.org)
  • Mutation or functional deficiency of AQP2 leads to severe nephrogenic diabetes insipidus, and inhibition of various aquaporins leads to many water-related diseases such as, edema, cardiac arrest, and stroke. (tcdb.org)
  • 10] "New mutations in the AQP2 gene in nephrogenic diabetes insipidus resulting in functional but misrouted water channels. (tcdb.org)
  • Mutations in the AQP2 gene cause recessive and dominant nephrogenic diabetes insipidus (NDI), a disease in which the kidney is unable to concentrate urine in response to vasopressin. (nih.gov)
  • The purpose of their 2017 study was to investigate whether Aliskiren regulates AQP2 expression in the collecting duct principal cells and whether Aliskiren treatment attenuates lithium-induced nephrogenic diabetes insipidus (NDI). (inhn.org)
  • Dysregulation of AQP2 plays a fundamental role in acquired forms of nephrogenic diabetes insipidus, e.g., sustained lithium intake, which are associated with depletion of AQP2 protein from the collecting ducts and a defect in urinary concentration. (inhn.org)
  • In conclusion, the direct renin inhibitor Aliskiren upregulates AQP2 protein expression in inner medullary collecting duct principal cells and prevents lithium-induced nephrogenic diabetes insipidus likely via cAMP-PROTEIN KINASE A pathways. (inhn.org)
  • Moreover, intracellular trafficking of AQP3 after TAM treatment was investigated in Madin-Darby Canine Kidney (MDCK) cells stably expressing AQP3. (bvsalud.org)
  • These findings suggest that TAM attenuates the downregulation of AQP3 in a UUO model and a lithium-induced NDI model and affects the intracellular localization in the collecting ducts. (bvsalud.org)
  • Aquaporin-2 (AQP-2) is found in the apical cell membranes of the kidney's collecting duct principal cells and in intracellular vesicles located throughout the cell. (wikipedia.org)
  • Aquaporin 2 is in kidney epithelial cells and usually lies dormant in intracellular vesicle membranes. (wikipedia.org)
  • Arginine-vasopressin (AVP) facilitates water reabsorption in renal collecting duct principal cells through regulation of the water channel aquaporin-2 (AQP2). (mdpi.com)
  • Human aquaporin 2 (AQP2) is a water channel found in the kidney collecting duct, where it plays a key role in concentrating urine. (nih.gov)
  • Large scale protein identification in intracellular aquaporin-2 vesicles from renal inner medullary collecting duct. (nih.gov)
  • Nephron and collecting duct-specific deletion of the prorenin receptor is associated with polyuria and impaired countercurrent multiplication, accompanied by reduced levels of medullary aquaporin-2 (AQP2) and Na- K-2CI cotransporter. (inhn.org)
  • The locations of several NDI-causing mutations can be observed in the AQP2 structure, primarily situated within transmembrane domains and the majority of which cause misfolding and ER retention. (nih.gov)
  • These observations provide a framework for understanding why mutations in AQP2 cause NDI as well as structural insights into AQP2 interactions that may govern its trafficking. (nih.gov)
  • Here, a family in which dominant NDI was caused by an exchange of arginine 254 by leucine in the intracellular C terminus of AQP2 (AQP2-R254L), which destroys the protein kinase A consensus site, was identified. (nih.gov)
  • The C terminus of AQP2 displays multiple conformations with the C-terminal α-helix of one protomer interacting with the cytoplasmic surface of a symmetry-related AQP2 molecule, suggesting potential protein-protein interactions involved in cellular sorting of AQP2. (nih.gov)
  • reported on the molecular mechanisms of mycotoxin (citrinin, ochratoxin-A, and T-2 mycotoxin) inhibition of AQP2 and arginine vasopressin receptor 2 (AVPR2). (tcdb.org)
  • Here we present the X-ray structure of human AQP2 at 2.75 Å resolution. (nih.gov)
  • The primary lens fiber cells result from differentiation of the cells in the posterior half of the lens vesicle while secondary fiber cells differentiate from lens epithelial cells displaced toward the equator by lens epithelial cell proliferation. (molvis.org)
  • The expression and function of AQP2 are regulated by a series of transcriptional factors and post-transcriptional phosphorylation, ubiquitination, and glycosylation ( He and Yang 2019 ). (tcdb.org)
  • Overall, our results demonstrate that FBEVs foster MM angiogenesis through dual time-related uptake-independent and uptake-dependent mechanisms that activate different intracellular pathways and transcriptional programs, providing the rationale for designing novel anti-angiogenic strategies. (bvsalud.org)
  • For this process, phosphorylation of AQP2 at S256 by cAMP-dependent protein kinase A is thought to be essential. (nih.gov)
  • The net result of the cascade involving a G protein (guanyl-nucleotide regulatory protein) and adenylate cyclase is an increase in the intracellular cyclic adenosine monophosphate (cAMP) level, which can play a dual role in antidiuresis regulation. (medscape.com)
  • Aliskiren treatment improved urinary concentrating defect in lithium-treated mice and partially prevented the decrease of AQP2 and pS256-AQP2 protein abundance in the inner medulla of the kidney. (inhn.org)
  • The direct reininhibitor Aliskiren increased the collecting duct AQP2 expression and partially improved the urine concentration defect in lithium-treated mice, likely by directly activating the cAMP-PROTEIN KINASE A pathway in the principal cells. (inhn.org)
  • 2006 ). AQP2 is critical in regulating urine concentrating ability. (tcdb.org)
  • Expressed in oocytes, AQP2-R254L appeared to be a functional water channel but was impaired in its transport to the cell surface to the same degree as AQP2-S256A, which mimics nonphosphorylated AQP2. (nih.gov)
  • Aliskiren treatment was associated with ~20% reduction of prorenin receptor in inner medulla compared with the lithium group, accompanied by increased AQP2 expression and improved polyuria. (inhn.org)
  • Myometrial smooth muscle contractility is regulated by both intracellular calcium concentration ([Ca 2+ ] i ) and by the calcium sensitivity of myofilaments [ 1 ]. (biomedcentral.com)
  • Meniere's disease is affected by dexamethasone which is a direct modulator of AQP2. (tcdb.org)