Expression Pattern Of Aquaporins Research Articles

Nano zinc oxide mediated resuscitation of aged Cajanus cajan via modulating aquaporin, cell cycle regulatory genes and hormonal responses.

Nanoparticle pretreatment improved the health ofaged Cajanus cajan seeds viz., regulation ofredox status, gene expression, andrestoration ofhormonal homeostasis. Ageing deteriorates the quality of seeds by lowering their vigor and viability, and terminating with loss of germination. These days, nanotechnology has been seen to revolutionize the agricultural sectors, and particularly nano zinc oxide (nZnO) has gained considerable interests due to its distinctive properties. The aim of the present work was to decipher the possibilities of using nZnO to rejuvenate accelerated aged (AA) seeds of Cajanus cajan. Both chemically (CnZnO) and green (GnZnO; synthesized using Moringa oleifera) fabricated nZnOs were characterized via standard techniques to interpret their purity, size, and shape. Experimental results revealed erratic germination with a decline in viability and membrane stability as outcomes of reactive oxygen intermediate (ROI) buildup in AA seeds. Application of nZnO substantially rebated the accrual of ROI, along with enhanced production of antioxidants, α-amylase activity, total sugar, protein and DNA content. Higher level of zinc was assessed qualitatively/ histologically and quantitatively in nZnO pulsed AA seeds, supporting germination without inducing toxicity. Meantime, augmentation in the gibberellic acid with a simultaneous reduction in the abscisic acid level were noted in nZnO invigorated seeds than that determined in the AA seeds, suggesting possible involvement of ROI in hormonal signalling. Furthermore, nZnO-subjected AA seeds unveiled differential expression of aquaporins and cell cycle regulatory genes. Summarizing, among CnZnO and GnZnO, later one holds better potential for a revival of AA seeds of Cajanus cajan by providing considerable tolerance against ageing-associated deterioration via recouping the cellular redox homeostasis, hormonal signaling, and alteration in expression patterns of aquaporin and cell cycle regulatory genes.

Comparative study of expression patterns of aquaporin (AQP) genes in apple fruits with contrasting ripening behavior

This research compared expression patterns of aquaporin (AQP) genes in two apple cultivars that exhibit contrasting ripening behavior. Commercially-mature apple fruits of cultivars ‘Golden Delicious’ and ‘Red Fuji’ were chosen as materials. The results showed that compared with ‘Red Fuji’, ‘Golden Delicious’ generally had higher rate of respiration, ethylene production, weight loss, dry matter concentration (DMC), titratable acidity (TA), total soluble solids (TSS) and soluble sugar contents during ripening. At 35 d, cells in ‘Golden Delicious’ were loosely arranged with larger intercellular space, while in ‘Red Fuji’, cells were still densely packed. A total of 20 AQPs were detected in both cultivars. Expression of these identified genes was in a tissue- and cultivar-specific manner during ripening. Generally, expression of MdAQPs was differentially induced at climacteric stage in peel and flesh tissues of ‘Golden Delicious’. In contrast, expression of most MdAQPs was differentially up-regulated at preclimacteric stage in peel and flesh tissues of ‘Red Fuji’. These results will be useful for further study the relationships between MdAQPs and storability of different apple cultivars.

Aquaporin-1 and Aquaporin-4 Expression in Ependyma, Choroid Plexus and Surrounding Transition Zones in the Human Brain.

The choroid plexus (CP) is a structure in the brain ventricles that produces the main part of the cerebrospinal fluid (CSF). It is covered with specialized cells which show epithelial characteristics and are the site of the blood-CSF barrier. These cells form a contiguous cell sheet with ventricle-lining ependymal cells which are known to express aquaporin-4 (AQP4). In contrast, CP epithelial cells express aquaporin-1 (AQP1) apically. We investigated the expression patterns of aquaporins in the CP-ependyma transition from human body donors using immunofluorescence and electron microscopy. Ependymal cells and subependymal astrocytes at the base of the CP showed a particularly high AQP4 immunoreactivity. Astrocytic processes formed a dense meshwork or glial plate around the blood vessels entering the CP. Interestingly, some of these astrocytic processes were in direct contact with the CP stroma, which contains fenestrated blood vessels, separated only by a basal lamina. Electron microscopy confirmed the continuity of the subastrocytic basal lamina with the CP epithelium. We also probed for components of the AQP4 anchoring dystrophin-dystroglycan complex. Immunolabeling for dystrophin and AQP4 showed an overlapping staining pattern in the glial plate but not in previously reported AQP4-positive CP epithelial cells. In contrast, dystroglycan expression was associated with laminin staining in the glial plate and the CP epithelium. This suggests different mechanisms for AQP4 anchoring in the cell membrane. The high AQP4 density in the connecting glial plate might facilitate the transport of water in and out of the CP stroma and could possibly serve as a drainage and clearing pathway for metabolites.

Analysis of photosynthetic ability and related physiological traits in nodal leaves of grape

Fruiting shoots are comprised of leaves, fruits, and branches, which determine the grape yield and the quality of produce. Fruiting shoots are also the important structural unit for studying the relationship between the source and sink. The number of leaves, leaf area, photosynthetic activities, and density are directly or indirectly affecting the ability of the fruiting shoot to fix CO2 and provide a carbon source for the fruit growth and development. ‘Summer Black’ is used as the main test material and observed certain differences in appearance, microstructure, photosynthetic pigments, relative water content (RWC), organic acids, carbohydrates, mineral elements, and photosynthetic capacity at different nodal leaves. The net photosynthetic rate (A) was significantly positively correlated with leaf shape parameters (the ratio between branch point to lobe tip and distal sinus to petiolar junction), leaf structure thickness, RWC, carotenoids, soluble sugars, and organic acids, but it was significantly negatively correlated with intercellular CO2 concentration (Ci), Chlorophyll b and phosphorus content. The variations in magnesium, water, glucose, and fructose content in leaves matched the expression patterns of aquaporin, magnesium transporter, and sugar metabolism-related genes in various nodal leaves. In addition, the physiological traits and photosynthetic capacity at different nodal leaves of ‘Shine Muscat’ and ‘Kyoho’ were similar to those of ‘Summer Black’. The results of this study will provide a reference for the differences in leaf sink–source effects at different nodes and provide a basis for reasonably removing leaves.

Classical aquaporins from Pacific white shrimp (Litopenaeus vannamei): Molecular characterization and expression analysis in hypersalinity

Aquaporins (AQPs) are major intrinsic proteins that facilitate the transport of water, small solutes, and ions through membranes. In mammals, the classical aquaporin AQP4 plays a central role in the preservation of central nervous system (CNS) water homeostasis. Litopenaeus vannamei is a typical euryhaline crustacean, with a salinity tolerance range of 0.5–78. Compared to those reared at low-salinity, shrimps cultured at high-salinity have better taste and qualities, but slower growth, lower product yield, and higher mortality. Thus, there is an urgent need to research the osmoregulation of L. vannamei under high-salinity. Previous studies mainly focus on the osmoregulation of gill and hepatopancreas, whereas there is a lack of research on the osmoregulatory roles of CNS in L. vannamei. In the current study, we first presented another two classical AQPs from L. vannamei, of which the arthropod-specific big brain aquaporin (LvBib) was expressed as C-terminal splice variants (LvBib_L and LvBib_S), and the aquaporin-like protein (LvAqpl) was a new type of aquaporin in crustaceans. Tissue distribution revealed that LvAqp4, LvAqpl, and LvBib_L were mostly expressed in the CNS of brain and thoracic ganglion. Then, the expression pattern of aquaporins in brain and thoracic ganglion were examined under both acute and chronic high-salinity stresses. The LvAqpl was found to be down-regulated in both tissues in the two experiments; LvAqp4 was elevated in both tissues under acute stress, whereas it was decreased in the thoracic ganglion during early periods of adaption to high-salinity; LvBib_L was up-regulated in brain but down-regulated in thoracic ganglion under acute stress, whereas it showed the opposite expression pattern during chronic stress. The results suggest that these aquaporins have an important role in the CNS response to high-salinity challenge. Our study provides a base for future mechanistic studies on the role of classical aquaporins in osmoregulation.

Distinct expression patterns of aquaporin 3 and 5 in ductal and alveolar epithelial cells in mouse mammary glands before and after parturition.

Milk osmolarity maintains an isotonic status for suckling infants during lactation. However, it remains unclear how the water content in milk is regulated in lactating mammary glands. In lactating mammary alveoli and ducts, mammary epithelial cells (MECs) are in direct contact with milk. In this study, we focus on two types of water channels, aquaporin 3 (AQP3) and AQP5, in alveolar and ductal MECs before and after parturition. AQP3 showed diffuse localization in the cytoplasm of ductal MECs but concentrated localization in the basolateral membrane of alveolar MECs during the late pregnancy and lactation periods. Translocation of AQP5 from the cytoplasm toward the apical membrane occurred in ductal MECs immediately before parturition. Subsequently, we examined the hormonal influences on the expression of AQP3 and AQP5 in cultured MECs in vitro. Progesterone and estrogen distinctly increased AQP3 and AQP5 in cultured MECs, respectively. Cotreatment with prolactin and dexamethasone significantly decreased both AQP3 and AQP5. Prolactin also facilitated the translocation of AQP5 into the apical membrane of MECs. In cultured MECs, AQP3 was homogeneously expressed in MECs, whereas AQP5 showed different expression levels between MECs regardless of the hormonal treatment. Different activation states of the prolactin/STAT5 pathway were also observed between ductal and alveolar MECs. These findings suggest that the expression pattern of AQP3 and AQP5 is distinctly regulated by lactogenic hormones in alveolar and ductal MECs before and after parturition. AQP5 expressed in ductal MECs may function as a water channel to regulate milk osmolarity in mice.

Aquaglyceroporins Are Differentially Expressed in Beige and White Adipocytes.

Browning of white adipocytes has been proposed as a powerful strategy to overcome metabolic complications, since brown adipocytes are more catabolic, expending energy as a heat form. However, the biological pathways involved in the browning process are still unclear. Aquaglyceroporins are a sub-class of aquaporin water channels that also permeate glycerol and are involved in body energy homeostasis. In the adipose tissue, aquaporin-7 (AQP7) is the most representative isoform, being crucial for white adipocyte fully differentiation and glycerol metabolism. The altered expression of AQP7 is involved in the onset of obesity and metabolic disorders. Herein, we investigated if aquaglyceroporins are implicated in beige adipocyte differentiation, similar to white cells. Thus, we optimized a protocol of murine 3T3-L1 preadipocytes browning that displayed increased beige and decreased white adipose tissue features at both gene and protein levels and evaluated aquaporin expression patterns along the differentiation process together with cellular lipid content. Our results revealed that AQP7 and aquaporin-9 (AQP9) expression was downregulated throughout beige adipocyte differentiation compared to white differentiation, which may be related to the beige physiological role of heat production from oxidative metabolism, contrasting with the anabolic/catabolic lipid metabolism requiring glycerol gateways occurring in white adipose cells.

The functional role of xylem parenchyma cells and aquaporins during recovery from severe water stress.

Xylem parenchyma cells [vessel associated cells (VACs)] constitute a significant fraction of the xylem in woody plants. These cells are often closely connected with xylem vessels or tracheids via simple pores (remnants of plasmodesmata fields). The close contact and biological activity of VACs during times of severe water stress and recovery from stress suggest that they are involved in the maintenance of xylem transport capacity and responsible for the restoration of vessel/tracheid functionality following embolism events. As recovery from embolism requires the transport of water across xylem parenchyma cell membranes, an understanding of stem-specific aquaporin expression patterns, localization and activity is a crucial part of any biological model dealing with embolism recovery processes in woody plants. In this review, we provide a short overview of xylem parenchyma cell biology with a special focus on aquaporins. In particular we address their distributions and activity during the development of drought stress, during the formation of embolism and the subsequent recovery from stress that may result in refilling. Complemented by the current biological model of parenchyma cell function during recovery from stress, this overview highlights recent breakthroughs on the unique ability of long-lived perennial plants to undergo cycles of embolism-recovery related to drought/rewetting or freeze/thaw events.

The expression patterns of aquaporin 9, vacuolar H+-ATPase, and cytokeratin 5 in the epididymis of the common vampire bat.

Desmodus rotundus is a vampire bat species that inhabits Latin America. Some basic aspects of this species' biology are still unknown, as the histophysiological characteristics of the male reproductive tract. Our study has focused on its epididymis, which is an important organ for performing a variety of functions, especially the sperm maturation and storage. The aim of this study was to identify principal, narrow, clear, and basal cells using cell-specific markers such as aquaporin 9 (AQP9), vacuolar H+-ATPase (V-ATPase), and cytokeratin 5 (KRT5). Principal cells were labeled by AQP9 from initial segment to cauda region in their stereocilia. They were shown with a columnar shape, whereas V-ATPase-rich cells were identified with a goblet-shaped body along the entire epididymis, including the initial segment, which were named as clear cells. Pencil-shaped V-ATPase-rich cells (narrow cells) were not detected in the initial segment of the bat epididymis, unlike in the rodent. Basal cells were labeled by KRT5 and were located at the basal portion of the epithelium forming a dense network. However, no basal cells with a luminal-reaching body extension were observed in the bat epididymis. In summary, epithelial cells were identified by their specific markers in the vampire bat epididymis. Principal and basal cells were labeled by AQP9 and KRT5, respectively. Narrow cells were not observed in the vampire bat epididymis, whereas clear cells were identified by V-ATPase labeling along the entire duct in a goblet-shaped body. In addition, no luminal-reaching basal cells were observed in the vampire bat epididymis.

Expression pattern of aquaporins in patients with primary nephrotic syndrome with edema.

The association between the expression of aquaporins (AQPs) in kidney tissues and the occurrence of edema in nephrotic syndrome (NS) remains unclear. The current study aimed to investigate this association. A total of 54 patients with primary glomerular disease, diagnosed by renal biopsy, were divided into three groups: Control, NS without edema and NS with edema. The expression of AQP1, AQP2, AQP3 and AQP4 in kidney tissues from these patients was assessed using immunohistochemistry, and urinary AQP concentrations were quantified by ELISA. Comparison of the three groups was conducted using one way analysis of variance, independent samples t-test or the Chi-square test. AQP1 was strongly expressed in the proximal tubules. The proportion of the AQP1-positive area in kidney tissues from patients with NS with edema was significantly reduced, in comparison with the other two groups. By contrast, the proportion of the AQP2-positive area in the NS with edema group was significantly higher than that of the other two groups; significant differences were also observed between the control and NS without edema groups for this parameter. Urinary AQP2 concentrations in patients with NS (with and without edema) were significantly higher than that of the control group, and exhibited a significant positive correlation with kidney tissue AQP2 concentrations. The present study demonstrated the abnormal expression pattern of AQP1-AQP4 in the kidney tissues of patients with NS, providing a basis for an improved understanding of the role of AQP in the pathogenesis of NS.

Water Channels Aquaporin 4 and -1 Expression in Subependymoma Depends on the Localization of the Tumors.

BackgroundWe analyzed aquaporin 4 and -1 expression in subependymomas, benign and slow growing brain tumors WHO grade I. Ten subependymoma cases were investigated, five of the fossa inferior and five of the fossa superior.Methods and ResultsUsing immunohistochemistry, we observed different aquaporin expression patterns depending on localization: aquaporin 4 and -1 were detected in infratentorial subependymomas in the entire tumor tissue. In contrast, supratentorial subependymomas revealed aquaporin 4 and -1 expression only in border areas of the tumor. PCR analyses however showed no difference in aquaporin 4 expression between all subependymomas independent of localization but at higher levels than in normal brain. In contrast, aquaporin 1 RNA levels were found to be higher only in infratentorial samples compared to supratentorial and normal brain samples. The reason for the different distribution pattern of aquaporin 4 in subependymomas still remains unclear. On the cellular level, aquaporin 4 was redistributed on the surface of the tumor cells, and in freeze fracture replicas no orthogonal arrays of particles were found. This was similar to our previous findings in malignant glioblastomas. From these studies, we know that extracellular matrix molecules within the tumor like agrin and its receptor alpha-dystroglycan are involved in forming orthogonal arrays of particles. In subependymomas neither agrin nor alpha-dystroglycan were detected around blood vessels.ConclusionsTaken together, we show in this study that in the benign subependymomas aquaporins 1 and 4 are dramatically redistributed and upregulated. We speculate that extracellular environments of infra- and supratentorial subependymomas are different and lead to different distribution patterns of aquaporin 4 and -1.

Effects of BA and TDZ on postharvest quality and expression of laccase and aquaporin genes in cut rose ‘Sparkle’

This experiment was conducted to study the effects of BA and TDZ on postharvest quality of cut rose ‘Sparkle’ and expression of Laccase and Aquaporine genes. The concentrations of TDZ at 25 and 75μM and BA at 150 and 300μM were applied for 24h as pulsing, while control cut roses received neither TDZ nor BA. TDZ with 25 and 75μM increased the longevity of flowers 1 and 2.8days respectively, compared to control. Furthermore, TDZ in both concentrations showed significant difference in flower quality. 150μM BA showed less adverse effects on display quality than 300μM BA. In fact, applying 300μM BA resulted in early petal senescence and bent neck. Expression patterns of Aquaporin (RhTIP), and Laccase (RhLAC) genes were investigated in leaves received 75μM TDZ and 150μM BA, as well as control treatment. The result showed that 150μM BA induced the expression of RhLAC gene, while TDZ had no significant impact on RhLAC transcription expression level. Expression of RhTIP was neither affected by BA nor by TDZ. These results suggest that decline of postharvest quality and increase in the expression of RhLAC under BA treatment could be related to BA-induced stress affecting the endogenous ethylene production in cut rose cv. Sparkle. In contrast to TDZ which prolonged postharvest quality of cut rose cv. Sparkle, BA decreased the longevity of flowers concomitantly with appearing necrosis symptom on petals.

Co-expression of AQP3 and AQP5 in esophageal squamous cell carcinoma correlates with aggressive tumor progression and poor prognosis

To investigate the expression patterns of aquaporin 3 (AQP) 3 and AQP5, to evaluate their relationships with clinicopathological characteristics, and to determine their correlations with survival in esophageal squamous cell carcinoma (ESCC) patients, expression levels of AQP3 and AQP5 proteins in 126 ESCC patients were detected by immunohistochemistry. Then, paired Student's t-test, chi-square test, Spearman's rank correlation, Kaplan-Meier plots, and Cox proportional hazards regression model were used to analyze their associations with clinicopathological characteristics and survivals of ESCC patients. Both AQP3 and AQP5 proteins were localized on the cell membrane of tumor cells in ESCC tissues. The expression levels of two proteins in ESCC tissues were significantly higher than those in adjacent normal tissues (both P<0.001). Additionally, high expression of AQP3 and AQP5 was both correlated with advanced invasion depth (both P=0.01), aggressive lymph node status (P=0.02 and 0.01, respectively), and positive distant metastasis (both P=0.01). However, the overexpression of AQP3 and AQP5 alone did not influence the prognosis. Furthermore, ESCC patients with the co-expression of AQP3 and AQP5 showed the poorest prognosis in overall (P=0.002) and disease-free survival (P<0.001). Multivariate analysis showed that the co-expression of AQP3 and AQP5 was an independent prognostic factors of overall (P=0.01) and disease-free survival (P=0.01) in ESCC. Our data demonstrate for the first time that high expression of both AQP3 and AQP5, not each alone, is an independent poor prognostic factor in ESCC patients. Combined detection of the two proteins' expression may help to predict the progression and the prognosis of ESCC patients.

Age-related changes of aquaporin expression patterns in the postnatal rat retina

Previous studies revealed that the rat retina contains numerous membrane-located water channels, the aquaporins (AQPs). Protein expression patterns of AQP1–4, 6 and 9 were examined by immunohistochemistry. In the present study, we investigated the immunolocalization of AQP1–4, 6 and 9 during postnatal development in the rat retina and examined the effect of age on the tissue distribution of these channels. AQP1, 3, 4, 6 and 9 showed gradually increased expression in rat retinas from postnatal week 1 to week 12, and decreased in the 40-week-old rat retinas. AQP2 expression was barely seen in the first week in rat retinas and displayed a significant increase from week 1 to week 4, however no significant alteration of AQP2 was observed after 4weeks of development. AQP1 and 4 immunoreactivities were present in the inner limiting membrane (ILM), the ganglion cell layer (GCL), inner nuclear layer (INL) and retinal pigment epithelium (RPE) in the 4-, 12- and 40-week-old rat retinas. The RPE, OLM and ILM showed a remarkable expression of AQP1–4, 6 and 9 in the 4, 12 and 40-week-old rat retinas. The reduced expression of AQPs in aged rat retinas may indicate the involvement of AQPs in the pathogenesis of age-related retinal diseases.

Expression of aquaporin water channels in canine fetal adnexa in respect to the regulation of amniotic fluid production and absorption

Amniotic fluid (AF) is created by the flow of fluid from the fetal lung and bladder and reabsorbed in part by fetal swallowing and partly by the transfer across the amnion to the fetal circulation. Placental water flux is an important factor in determining AF volume and fetal hydration. In addition the fetal membranes might be involved in the regulation of fluid composition. To understand the mechanisms responsible for maintaining a correct balance of AF volume we evaluated the expression of aquaporins (AQPs) in canine fetal adnexa. AQPs are a family of integral membrane proteins permitting passive but physiologically rapid transcellular water movement. The presence of AQP1, 3, 5, 8 and −9 was immunohistochemically assessed in canine fetal adnexa, collected in early, middle and late-gestation during ovario-hysterectomies performed with fully informed owners' consent. Changes in AF volume and biochemical composition were also evaluated throughout pregnancy. Our results show distinct aquaporin expression patterns in maternal and extraembryonic tissues in relation to pregnancy period. AQP1 was localized in placental endothelia, allantochorion, amnion, allantois and yolk sac. AQP3 was present in the placental labyrinth, amnion, allantois and yolk sac. AQP8 was especially evident on the epithelia lining the glandular chambers, the amniotic and allantois sacs. AQP9, a channel highly permeable to water and urea, was observed in epithelia of amnion, allantois and yolk sac. In summary, AQP1, 3, 5, 8 and −9 have distinct expression patterns in canine fetal membranes and placenta in relation to pregnancy period, suggesting an involvement in mediating the AF changes during gestation.

Aquaporin 1 expression in human temporomandibular disc

Aquaporins (AQPs) are a family of hydrophobic membrane channel proteins. The expression of several AQP isoforms has been investigated in different human tissues, including the orofacial region. However, information on the role and localization of AQP1 in joints is limited, and no data are available on aquaporins in the normal temporomandibular joint (TMJ) disc. Sixteen human TMJ discs without degenerative changes were taken from fresh cadavers to investigate the presence and distribution of AQP1 by immunohistochemistry. The aim of the study was to gain additional insights into the biomolecular composition of aquaporins and their role in homeostasis of the TMJ. Porcine TMJ discs were also studied by Western blotting for comparison. Scattered AQP1 immunoexpression was detected in human disc cells, documenting its constitutive expression, but differences amongst the three disc regions were not significant. AQP1 expression was demonstrated in porcine TMJ disc by Western blotting. Our findings suggest that AQP1 is normally expressed in the TMJ disc and confirm a role for it in the maintenance of TMJ homeostasis. Further studies are needed to elucidate expression patterns of aquaporins in diseased TMJ discs.

Relationship of aquaporin 1, 3, and 5 expression in lung cancer cells to cellular differentiation, invasive growth, and metastasis potential

An oncogenic capacity of aquaporins, transmembrane channels for water, was recently proposed. This study seeks to elucidate the involvement of aquaporin 1, 3, and 5 in the development and progression of lung cancer. Expression of aquaporin 1, 3, and 5 was examined by immunohistochemistry, Western blot, and laser-captured microdissection/real-time reverse transcription polymerase chain reaction in 160 lung cancers of various histologic subtypes; and its correlation with clinicopathological factors and survival was analyzed. Aquaporin 1, 3, and 5 were expressed in tumor cells in 71%, 40%, and 56% of lung cancers, respectively. Aquaporin expressions were frequent in adenocarcinomas, whereas aquaporin 1 and 5 were negative in squamous cell carcinomas. Bronchioloalveolar carcinoma cells exhibited an apicolateral aquaporin 1 and apicolateral or basolateral aquaporin 3 localization in nonmucinous type, and apical aquaporin 1 and 5 and basolateral aquaporin 3 expression in mucinous type, which corresponded to aquaporins expression of nonneoplastic lung tissue. Basolateral aquaporin 5 expression was acquired during tumorigenesis of nonmucinous bronchioloalveolar carcinoma. In contrast, invasive adenocarcinoma tumor cells overexpressed aquaporin 1 and 5 with loss of subcellular polarization and with an intracytoplasmic distribution. Overexpression of aquaporin 1 correlated with high postoperative adenocarcinoma metastasis ratios and unfavorable disease-free survival rates (P = .031). We conclude that expression patterns of aquaporin 1, 3, and 5 in lung cancer cells are mostly associated with cellular differentiation. However, the expression of aquaporin 1 and 5 is up-regulated in invading lung cancer cells, particularly in adenocarcinomas; and the overexpression of aquaporin 1 with loss of subcellular polarization is suggested to be involved in their invasive and metastatic potential.

Expression pattern of aquaporin 4 and 5 in the middle ear of guinea pigs with secretory otitis media

Conclusions: Our study suggests that aquaporins 4 and 5 (AQP4 and AQP5) in the middle ear cavity may play a vital role in the homeostasis of the tubotympanum and in the course of the accumulation of the effusion in secretory otitis media (SOM). Objective: To explore the pathological change in water homeostasis in the middle ear in SOM and to observe the expression and regulation of AQP4 and AQP5 in the middle ear cavity in SOM. Materials and methods: Reverse transcriptase polymerase chain reaction (RT-PCR) and Western blotting were used to detect AQP4 and AQP5 in the bullae of animal models of SOM and normal animals. The expression patterns of AQP4 and AQP5 in the SOM group were compared with those in the normal group. Results: RT-PCR and immunoblot analyses revealed that mRNAs encoding AQP4 and AQP5 were expressed in the middle ear membrane of the guinea pigs in both groups; AQP4 was also detected as 33 kDa protein in both groups. Quantitative analysis of RT-PCR and Western blotting revealed that expression of AQP4 and AQP5 was higher in the SOM group than in the control group.

Aquaporin expression patterns in the developing mouse salivary gland

Little is known about the presence of the various membrane-located water channels, aquaporins (AQP), during the prenatal and postnatal development of the mouse submandibular salivary gland (SMG). To learn more about AQPs in the developing aspect of salivary glands, we investigated trends in the expression patterns of several AQPs using the embryonic, early postnatal, and young adult mouse SMGs as models. We have chosen AQPs previously found in salivary glands in other animals. Transcripts of AQPs 1, 3, 4, 5, and 8 were detected by reverse transcription-polymerase chain reaction (RT-PCR) and quantified. Aquaporin proteins 1, 3, 4, and 5, but not AQP protein 8, were detected and quantified using western blotting. The various AQPs showed distinct transcript and protein-expression patterns. The change in trends may indicate that the importance of the various AQPs varies throughout the developmental stages in the mouse SMG. Their presence might be related to cell adhesion, migration, proliferation, apoptosis, transepithelial transport, osmosensing, or cell volume regulation; all roles that in the literature are linked to the various AQPs. Overall, this study demonstrates that AQP presentation varies and has a specific expression pattern during the development of mouse SMG. This feature may be important for glandular anatomical and physiological development.

Expression pattern of aquaporin 4 and 5 in the middle ear of guinea pigs with secretory otitis media

Expression pattern of aquaporin 4 and 5 in the middle ear of guinea pigs with secretory otitis media