Aquaporin Expression in Developing Human Teeth and Selected Orofacial Tissues

Abstract

The aquaporin (AQP) family of membrane channel proteins function as selective pores through which water, glycerol, and other small solutes cross the cell plasma membrane. To date, 11 members of this transporter family, designated AQP0-10, have been cloned and characterized in humans. The AQPs are differentially expressed in temporospatial patterns, where different AQPs demonstrate distinct tissue distributions that may reflect differing cell membrane transport functions. The purpose of this study was to evaluate AQP expression in the developing human teeth by RT-PCR and Western blot analysis. To access the generality of AQP expression, selected other orofacial tissues were studied by RT-PCR. The presence of all eleven human AQPs was screened in each tissue by RT-PCR. Positive amplification products were verified by direct DNA sequencing. AQPs 1, 3, 4, 5, 6, and 10 were identified by RT-PCR in developing teeth, and AQP1, 3, 5, and 6 were confirmed by Western blot analysis. AQP 4 was not detected by Western blot analysis, and we were unable to test for the recently identified AQP10 due to unavailability of antibodies. AQPs detected in other orofacial tissues by RT-PCR included gingiva (AQP3, 7, 10); Meckel's cartilage (AQP1, 3, 4, 5, 6); submandibular gland (AQP1, 3, 4, 5, 6, 7); masseter muscle (AQP1, 3, 4, 7, 8, 9,10); and infrahyoid muscle (AQP1, 3, 4,10). These results demonstrate that multiple aquaporins are expressed in developing teeth and in selected orofacial tissues.

The role of water channel aquaporin 3 in the mechanism of TNF‐α‐mediated proinflammatory events: Implication in periodontal inflammation

“…Numerous studies have demonstrated altered AQP3 expression during normal (Roudier et al, 1998;Wang et al, 2003) and various pathological states of impaired water regulation such as in the occurrence of diarrhea and skin inflammation (Hamabata et al, 2002;Marchini et al, 2003;Guttman et al, 2007;Parker et al, 2007), however, no studies to date have revealed the expression of AQP3 in periodontal inflammation. In the present study, peak AQP3 mRNA and protein expression were found within 4 and 6 h of TNF-a stimulation, respectively ( Fig.…”

Effect of aquaporin 1 and 4 on masticatory muscles degeneration as a result of aging

“…Aquaporins act as selective pores that provide bidirectional water-passage through biological membranes, and thereby they allow the regulation of osmotic homeostasis in relation to the movement of melted material and extracellular medium (2). In particular, aquaporin 4 (AQP4) is the water channel that is found in mammalian skeletal muscle in vivo (11).…”

“…The members of Group 1 (AQP 0-2, 4-6 and 8) are primarily water selective channels. The members of Group 2 (AQP 3, 7, 9, and 10) are permeable to water as well as neutral soluble substances, including glycerol and urea (2).…”

The role of AQP1 in knee Osteoarthritis (OA): A contemporary review

“…AQPs expression has been studied in various tissues and organs such as kidney, respiratory tract, brain, eye and gastrointestinal tract 7 . In addition, very recent evidence from studies in developing orofacial tissues confirm that AQP1 is expressed in human Meckel's cartilage along with several other members of the AQP gene family 8 . Expression of AQP1, 2 and 3 has been investigated in chondrocyte-like cells in the adult human intervertebral disc, which suggested a significant role for transmembrane water and solute transporters in cell volume control in the hyperosmotic environment of this fibrocartilage tissue 9 .…”