Ontogeny of the mammalian kidney: expression of aquaporins 1, 2, 3, and 4

Abstract

Further studies investigating the regulation of AQPs during kidney development may provide insights into normal water-handling mechanisms and the pathophysiology of fetal kidneys, which may determine new directions for the clinical treatment of kidney diseases.

Age-related changes in renal AQP3 and AQP4 expression in Sprague Dawley rats

“…A similar pattern of AQP3 expression has been found by other investigators, who reported that AQP3 could be detected in ureteric buds of the rat kidney as early as embryonic day 18 (Baum et al, 1998). Interestingly, Lee et al (1997) reported that AQP3 mRNA could be detected at birth and that levels were stable after birth throughout life (Yamamoto et al, 1997;Xing et al, 2014) AQP4 mRNA was barely detectable in fetal rat kidneys, whereas it was detected after birth and was maintained at stable levels throughout life (Xing et al, 2014). Another study reported low levels of AQP4 mRNA expression in the kidneys from birth to 6-months of age, which were minimal at 12 months (Yamamoto et al, 1997).…”

“…Decreased renal function and increased susceptibility to chronic kidney diseases are observed in aging kidneys, primarily due to glomerulosclerosis, tubular atrophy, interstitial fibrosis, and loss of functional renal mass (Martin and Sheaff, 2007;Silva et al, 2010) Aquaporins (AQPs) are a family of small membrane proteins of approximately 30 kDa that serve as semi-permeable channels. AQPs are also called major intrinsic proteins, which facilitate water transport across biological membranes (Xing et al, 2014), and are involved in diverse physiological functions including brain water balance, cell migration, cell proliferation, neuro-excitation, fat metabolism, and epidermal hydration (Tradtrantip et al, 2009). To date, 13 members of the AQP family belonging to three groups have been identified: water-selective channels; aquaglyceroporins, which transport water, glycerol, as well as urea; and unorthodox channels (Poling et al, 2014).…”

“…AQP2 is the main target of vasopressin (AVP), which regulates water permeability in the collecting duct (Nejsum et al, 2001;BonillaFelix, 2004). AVP regulates AQP2 via short-term and long-term regulatory mechanisms, which are fundamentally different (Nielsen and Agre, 1995;Poulsen et al, 2013) AQP2 null mice fail to thrive and die postnatally as a result of excessive extracellular fluid loss, indicating that the concentration of urine is dependent on the presence of AQP2 (Tamma et al, 2012;Xing et al, 2014). AQP3 and AQP4 are localized to the basolateral plasma membranes of principal cells in the connecting tubule and collecting duct (Murillo-Carretero et al, 1999;Nielsen et al, 1999;Tamma et al, 2012;Kortenoeven and Fenton, 2014) and provide potential pathways of water reabsorption via AQP2 (Wang et al, 2002;Nishimura and Yang, 2013;Koetenoeven and Fenton, 2014;Marlar et al, 2014).…”

“…AQP3 and AQP4 are localized to the basolateral plasma membranes of principal cells in the connecting tubule and collecting duct (Murillo-Carretero et al, 1999;Nielsen et al, 1999;Tamma et al, 2012;Kortenoeven and Fenton, 2014) and provide potential pathways of water reabsorption via AQP2 (Wang et al, 2002;Nishimura and Yang, 2013;Koetenoeven and Fenton, 2014;Marlar et al, 2014). AQP3 is located in the cortical and outer medullary collecting ducts and AQP4 is located in the inner medullary collecting duct membrane (Terris et al, 1995;Verkman, 1998;Nielsen et al, 2002;Kim et al, 2005;Verkman, 2006;Nishimura and Yang, 2013) AQP3 is regulated by long-term AVP stimulation (Terris et al, 1995;Yang et al, 2013;Xing et al, 2014) and extracellular pH (Zelenina et al, 2003;Castle, 2005). In addition to water, AQP3 also transports glycerol and urea (King and Agre, 1996;Lee et al, 1997;Kuwahara et al, 1997) AQP4 enables water permeation in the basolateral plasma membrane of the rat inner medullary collecting duct (Ma et al, 2000).…”

How impaired efficacy happened between Gancao and Yuanhua: Compounds, targets and pathways

“…They exist in every organ of mammalians for water metabolism, especially in the kidney 22, 23 . At least 8 kinds of AQPs exist in the epithelium cells of kidney tubules among which AQP 1, 2, 3, and 4 play the major role in the reabsorption of primary urine.…”