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Introduction and Objective: The regulatory network of aquaporin (AQP) 1 and renin-angiotensin-aldosterone (ALDO) system are not quite clear in pulmonary arterial hypertension (PAH). Thus, we explored the role of AQP1, ALDO and spirolactone (SP) in the PAH animal model and pulmonary arterial smooth muscle cells (PASMCs). Method: PAH rat model was established by monocrotaline (MCT) via intraperitoneal in SD rat. Hemodynamic measurement was conducted via the external jugular vein cannula. PASMCs were extracted from normal SD rat and cultured in SmGM medium. α-Actin expression was identified by immunocytochemistry. Protein levels were assessed by Western blot. Cell viability was assayed using the MTT method. Apoptosis rate was evaluated by flow cytometry. ALDO level was measured by ELISA. Result: SP decreased AQP1 and β-catenin expressions in PAH rat model induced successfully by MCT. Moreover, ALDO increased AQP1 expression and cell viability in PASMCs, which were extracted from rat and identified by α-actin expression. AQP1 downregulation decreased β-catenin expression, and SP lowered AQP1 and β-catenin expressions elevated by ALDO in PASMCs. SP offset ALDO's effect on the upregulation of cell viability as well as AQP1 and β-catenin expressions in PASMCs. In addition, AQP1 downregulation and SP have a negative effect on Ki-67 and proliferating cell nuclear antigen expressions as well as cell viability after ALDO treatment in PASMCs. Conclusion: ALDO might contribute to PAH development via stimulating AQP1 expression and PASMCs proliferation. However, SP could be considered an effective drug regulating PASMCs proliferation through modulating AQP1 and β-catenin expressions in PAH. [ABSTRACT FROM AUTHOR]

Objective: We aimed to determine whether high‐dose nitroglycerin, a nitric oxide donor, preserves erythrocyte deformability during cardiopulmonary bypass and examines the signaling pathway of nitric oxide in erythrocytes. Methods: In a randomized and controlled fashion, forty‐two patients undergoing cardiac surgery with hypothermic cardiopulmonary bypass were allocated to high‐dose (N = 21) and low‐dose groups (N = 21). During rewarming period, patients were given intravenous nitroglycerin with an infusion rate 5 and 1 µg·kg−1·min−1 in high‐dose and low‐dose groups, respectively. Tyrosine phosphorylation level of non‐muscle myosin IIA in erythrocyte membrane was used as an index of erythrocyte deformability and analyzed using immunoblotting. Results: Tyrosine phosphorylation of non‐muscle myosin IIA was significantly enhanced after bypass in high‐dose group (3.729 ± 1.700 folds, P =.011) but not low‐dose group (1.545 ± 0.595 folds, P =.076). Phosphorylation of aquaporin 1, vasodilator‐stimulated phosphoprotein, and focal adhesion kinase in erythrocyte membrane was also upregulated in high‐dose group after bypass. Besides, plasma nitric oxide level was highly correlated with fold change of non‐muscle myosin IIA phosphorylation (Pearson's correlation coefficient.871). Conclusions: High‐dose nitroglycerin administered during cardiopulmonary bypass improves erythrocyte deformability through activating phosphorylation of aquaporin 1, vasodilator‐stimulated phosphoprotein, and focal adhesion kinase in erythrocytes. [ABSTRACT FROM AUTHOR]

Background: Lipopolysaccharide (LPS)-induced acute kidney injury (AKI) is associated with an abnormal immune response. Accumulating evidence has demonstrated that aquaporin 1 (AQP1) prevents kidney tissue injury in LPS-induced AKI by mediating immune response. However, the underlying mechanisms remain obscure. Macrophages as immune cells with multiple phenotypes are important mediators in tissue homeostasis and host defense. We propose that macrophage polarization is implicated in AQP1-mediated immune response. Methods: Herein we established sepsis-induced AKI model rats through intraperitoneal injection of LPS into Wistar rats to reveal immune mechanism of damage. We also used LPS-induced mouse RAW264.7 cells to elucidate the molecular mechanism of macropage polarization. Results: Histopathology showed that renal tubular epithelial cells in the model group were swollen, inflammatory exudation was obvious and the inflammatory factors, interleukin-6 (IL-6) and tumor necrosis factor α (TNF-α) were increased. Western blotting showed PI3K was upregulated in the model group. Serum creatinine and urea nitrogen increased after LPS injection. Renal AQP1 mRNA is downregulated and serum AQP1 protein increased first and then decreased in LPS-induced AKI rats. M2 macrophage markers (Arg-1, CD206) were increased in repair stage. In addition, treatment of murine macrophages (RAW264.7) with AQP1 siRNA resulted in decreased PI3K activation and M2 polarization, but increased IL-6 and TNF-α. Moreover, inhibiting PI3K with wortmannin imitated the results of AQP1 silencing. Conclusions: Macrophage M2 polarization is likely the cellular mechanism underlying the anti-AKI property of AQP1, and PI3K activation is involved in the AQP1-induced M2 phenotype switch. [ABSTRACT FROM AUTHOR]

Tumor angiogenesis is an important therapeutic target in colorectal cancer (CRC). We aimed to identify novel genes associated with angiogenesis in CRC. Using RNA sequencing analysis in normal and tumor endothelial cells (TECs) isolated from primary CRC tissues, we detected frequent upregulation of adipocyte enhancer‐binding protein 1 (AEBP1) in TECs. Immunohistochemical analysis revealed that AEBP1 is upregulated in TECs and stromal cells in CRC tissues. Quantitative RT‐PCR analysis showed that there is little or no AEBP1 expression in CRC cell lines, but that AEBP1 is well expressed in vascular endothelial cells. Levels of AEBP1 expression in Human umbilical vein endothelial cells (HUVECs) were upregulated by tumor conditioned medium derived from CRC cells or by direct coculture with CRC cells. Knockdown of AEBP1 suppressed proliferation, migration, and in vitro tube formation by HUVECs. In xenograft experiments, AEBP1 knockdown suppressed tumorigenesis and microvessel formation. Depletion of AEBP1 in HUVECs downregulated a series of genes associated with angiogenesis or endothelial function, including aquaporin 1 (AQP1) and periostin (POSTN), suggesting that AEBP1 might promote angiogenesis through regulation of those genes. These results suggest that upregulation of AEBP1 contributes to tumor angiogenesis in CRC, which makes AEBP1 a potentially useful therapeutic target. [ABSTRACT FROM AUTHOR]

Background: The classical view of cerebrospinal fluid (CSF) production posits the choroid plexus as its major source. Although previous studies indicate that part of CSF production occurs in the subarachnoid space (SAS), the mechanisms underlying extra-choroidal CSF production remain elusive. We here investigated the distributions of aquaporin 1 (AQP1) and Na+/K+/2Cl− cotransporter 1 (NKCC1), key proteins for choroidal CSF production, in the adult rodent brain and spinal cord. Methods: We have accessed AQP1 distribution in the intact brain using uDISCO tissue clearing technique and by Western blot. AQP1 and NKCC1 cellular localization were accessed by immunohistochemistry in brain and spinal cord obtained from adult rodents. Imaging was performed using light-sheet, confocal and bright field light microscopy. Results: We determined that AQP1 is widely distributed in the leptomeningeal vasculature of the intact brain and that its glycosylated isoform is the most prominent in different brain regions. Moreover, AQP1 and NKCC1 show specific distributions in the smooth muscle cell layer of penetrating arterioles and veins in the brain and spinal cord, and in the endothelia of capillaries and venules, restricted to the SAS vasculature. Conclusions: Our results shed light on the molecular framework that may underlie extra-choroidal CSF production and we propose that AQP1 and NKCC1 within the leptomeningeal vasculature, specifically at the capillary level, are poised to play a role in CSF production throughout the central nervous system. [ABSTRACT FROM AUTHOR]

Background/Aims: Dachengqi decoction (DCQD) is a well-known traditional Chinese herbal drug with strong anti-inflammatory effects. Angiopoietin-1 (Ang-1) plays a vital role in maintaining the stability and integrity of the vascular wall and prevents vascular leakage due to inflammatory mediators. Our previous work found that DCQD protects against pancreatic injury in rats with severe acute pancreatitis (SAP). This study aims to investigate the effects of DCQD on intestinal endothelial damage in both damaged human umbilical vein endothelial cells (HUVECs) and SAP rats. Methods: HUVECs were randomly divided into four groups: control group, TNF-α group, TNF-α plus Ang-1 group (Ang-1 group), and TNF-α plus DCQD group (DCQD group). Cells were incubated for 6 h, 12 h, and 24 h, before collection. The treatment concentration of DCQD was decided based on a Cell Counting Kit-8 (CCK-8) assay. The monolayer permeability of the HUVECs was assessed by measuring the transendothelial electrical resistance (TEER). Apoptosis was analyzed by flow cytometry. mRNA and protein expression of aquaporin 1 (AQP-1), matrix metalloproteinase 9 (MMP9), and junctional adhesion molecule-C (JAM-C) was evaluated by RT-PCR, immunocytofluorescence, and western blot. Forty male Sprague-Dawley rats were randomized into a control group, SAP group, SAP plus Ang-1 group (Ang-1 group), and SAP plus DCQD group (DCQD group). SAP was induced by intraperitoneal injection of cerulein and lipopolysaccharide (LPS), while the control group received 0.9% saline solution. Evans blue was injected through the penile vein and the rats were then sacrificed 12 h after modeling. Levels of serum amylase, TNF-α, IL-1β, IL-2, and IL-6 were determined by using ELISA. Intestinal tissue was analysed by histology, and capillary permeability in the tissues was evaluated by Evans blue extravasation assay. Protein and mRNA expression of AQP-1, MMP9, and JAM-C were assessed by immunohistofluorescence, western blot, and RT-PCR. Results: DCQD reduced the permeability of HUVEC induced by TNF-α in vitro. Furthermore, DCQD altered the mRNA and protein levels of JAM-C, MMP9, and AQP-1 in HUVECs after TNF-α induction. SAP intestinal injury induced by cerulein combined with lipopolysaccharides was concomitant with increased expression of JAM-C and MMP9, and reduced expression of AQP-1 in intestinal tissue. Pretreatment with DCQD attenuated SAP intestinal injury and lowered the levels of serum amylase, TNF–α, IL-1β, IL-2, and IL-6 effectively. Our study demonstrated that DCQD decreased the expression of JAM-C and MMP9 and increased the expression of AQP-1 both in vitro and in vivo. Conclusion: DCQD can reduce capillary endothelial damage in acute pancreatitis-associated intestinal injury and the mechanism may be associated with the regulation of endothelial barrier function-associated proteins AQP-1, MMP9, and JAM-C.

Salivary glands are highly responsible for maintaining oral tissue homeostasis by secreting saliva. This study was designed to investigate aquaporin 1 and 4, oxidative stress, and autophagy in submandibular and parotid salivary glands of diabetic rats and the possible ameliorative effect of intermittent fasting on these changes. Fifty adult male rats were divided into control and experimental groups. Experimental diabetes was induced by a single intraperitoneal injection of streptozotocin. After induction of diabetics, the experimental group was divided into two groups (diabetic without intermittent fasting and diabetic with intermittent fasting). The animals were sacrificed two and four weeks after induction of diabetes. Intermittent fasting significantly decreased malondialdehyde and significantly elevated reduced glutathione (GSH) in the submandibular and parotid glands compared to those of diabetic rats. The salivary secretions were also significantly histologically spared in diabetics with intermittent fasting groups. Furthermore, intermittent fasting increased aquaporin 1 in both glands, while aquaporin 4 was only elevated in the submandibular gland. The immunolocalization and gene expression of Lc3-II was higher in the diabetic salivary glands than in the fasting glands. In conclusion, these findings highlight the pathological role of autophagy in diabetic submandibular and parotid glands and provide potential target for the therapeutic role of intermittent fasting to ameliorate the dysfunction of the submandibular and parotid glands in type I diabetes mellitus. • Intermittent fasting upregulated aquaporin 1 in both submandibular and parotid glands. • Intermittent fasting upregulated aquaporin 4 in submandibular gland. • Intermittent fasting improved the oxidative stress induced by diabetes. • The immunolocalization and gene expression of Lc3-II was higher in the diabetic salivary glands than in the fasting gland. [ABSTRACT FROM AUTHOR]

We previously showed that the water permeability of AQP0, the water channel of the lens, increases with acid pH and that His40 is required (Németh-Cahalan, K.L., and J.E. Hall. 2000. J. Biol. Chem. 275:6777-6782; Németh-Cahalan, K.L., K. Kalman, and J.E. Hall. 2004. J. Gen. Physiol. 123:573-580). We have now investigated the effect of zinc (and other transition metals) on the water permeability of AQP0 expressed in Xenopus oocytes and determined the amino acid residues that facilitate zinc modulation. Zinc (1 mM) increased AQP0 water permeability by a factor of two and prevented any additional increase induced by acid pH. Zinc had no effect on water permeability of AQP1, AQP4 or MIPfun (AQP0 from killifish), or on mutants of AQP1 and MIPfun with added external histidines. Nickel, but not copper, had the same effect on AQP0 water permeability as zinc. A fit of the concentration dependence of the zinc effect to the Hill equation gives a coefficient greater than three, suggesting that binding of more than one zinc ion is necessary to enhance water permeability. His40 and His122 are necessary for zinc modulation of AQP0 water permeability, implying structural constraints for zinc binding and functional modulation. The change in water permeability was highly sensitive to a coinjected zinc-insensitive mutant and a single insensitive monomer completely abolished zinc modulation. Our results suggest a model in which positive cooperativity among subunits of the AQP0 tetramer is required for zinc modulation, implying that the tetramer is the functional unit. The results also offer the possibility of a pharmacological approach to manipulate the water permeability and transparency of the lens.

Aquaporin (AQP) water channels are expressed in the eye at sites of aqueous fluid production and outflow: AQP1 and AQP4 in nonpigmented ciliary epithelium, and AQP1 in trabecular meshwork endothelium. Novel methods were developed to compare aqueous fluid dynamics in wild-type mice versus mice lacking AQP1 and/or AQP4. Aqueous fluid production was measured by in vivo confocal microscopy after transcorneal iontophoretic introduction of fluorescein. Intraocular pressure (IOP), outflow, and anterior chamber compliance were determined from pressure measurements in response to fluid infusions using micropipettes. Aqueous fluid volume and [Cl(-)] were assayed in samples withdrawn by micropipettes. In wild-type mice (CD1 genetic background, age 4-6 wk), IOP was 16.0 +/- 0.4 mmHg (SE), aqueous fluid volume 7.2 +/- 0.3 microl, fluid production 3.6 +/- 0.2 microl/h, fluid outflow 0.36 +/- 0.06 microl/h/mmHg, and compliance 0.036 +/- 0.006 microl/mmHg. IOP was significantly decreased by up to 1.8 mmHg (P < 0.002) and fluid production by up to 0.9 microl/h in age/litter-matched mice lacking AQP1 and/or AQP4 (outbred CD1 and inbred C57/bl6 genetic backgrounds). However, AQP deletion did not significantly affect outflow, [Cl(-)], volume, or compliance. These results provide evidence for the involvement of AQPs in intraocular pressure regulation by facilitating aqueous fluid secretion across the ciliary epithelium. AQP inhibition may thus provide a novel approach for the treatment of elevated IOP.

Acute appendicitis is the most common indication for pediatric abdominal emergency surgery. Determination of the severity of appendicitis on clinical grounds is challenging. Complicated appendicitis presenting with perforation, abscess or diffuse peritonitis is not uncommon. The question remains why and when acute appendicitis progresses to perforation. The aim of this study was to assess the impact of water permeability on the severity of appendicitis. We show that AQP1 expression and water permeability in appendicitis correlate with the stage of inflammation and systemic infection parameters, leading eventually to perforation of the appendix. AQP1 is also expressed within the ganglia of the enteric nervous system and ganglia count increases with inflammation. Severity of appendicitis can be correlated with water permeability measured by AQP1 protein expression and increase of ganglia count in a progressive manner. This introduces the question if regulation of water permeability can present novel curative or ameliorating therapeutic options.

Background: The first line treatment for cutaneous leishmaniasis is pentavalent antimony such as sodium stibogluconate (pentostam) and meglumine antimonite (glucantime). One of the most important ways to uptake the drug is by a transmembrane protein, called aquaglyceroporin encoded by Aquaglyceroprotein1 (LmAQP1). In this study, molecular characterization of LmAQP1 was reported. Methods: Leishmania major (MRHO/IR/75/ER) promastigotes were cultured, and then DNA extraction and RNA extraction were done and followed by cDNA synthesis. Amplicons resulted from PCR and RT-PCR using specific primers were purified and sequenced. Molecular characterization was done by bioinformatically software such as BLST, ClustalW2, and RMSD. Results: Amplicons resulted from PCR and RT-PCR showed equal size in length. BLASTn analysis showed a point nucleotide change in LmAQP1 gene that encoded 282-amino-acid long protein with a mutation at position 154 including replacement of alanine by threonine. The observed mutation in the interested gene was assessed using the above-mentioned software. The mentioned gene was submitted at GenBank, NCBI with accession number of KU514052. Conclusion: The functional prediction of the protein encoded from LmAQP1 showed that the mentioned mutation could not affect the three-dimension structure, but it may modify the drug uptake potential of this important channel. Based on from LmAQP1 role, it seems to be an appropriate candidate for drug development. According to search through internet, this is the first report of LmAQP1 from L. major (MRHO/IR/75/ER).

Rheumatoid arthritis (RA) is an autoimmune inflammatory disease affecting approximately 1% of the global population, with a higher prevalence in women than in men. Chronic inflammation and oxidative stress play pivotal roles in the pathogenesis of RA. Anethole, a prominent compound derived from fennel (Foeniculum vulgare), possesses a spectrum of therapeutic properties, including anti-arthritic, anti-inflammatory, antioxidant, and tumor-suppressive effects. However, its specific impact on RA remains underexplored. This study sought to uncover the potential therapeutic value of anethole in treating RA by employing an H 2 O 2 -induced inflammation model with HIG-82 synovial cells. Our results demonstrated that exposure to H 2 O 2 induced the inflammation and apoptosis in these cells. Remarkably, anethole treatment effectively countered these inflammatory and apoptotic processes triggered by H 2 O 2 . Moreover, we identified the aquaporin 1 (AQP1) and protein kinase A (PKA) pathway as critical regulators of inflammation and apoptosis. H 2 O 2 stimulation led to an increase in the AQP1 expression and a decrease in p-PKA-C, contributing to cartilage degradation. Conversely, anethole not only downregulated the AQP1 expression but also activated the PKA pathway, effectively suppressing cell inflammation and apoptosis. Furthermore, anethole also inhibited the enzymes responsible for cartilage degradation. In summary, our findings highlight the potential of anethole as a therapeutic agent for mitigating H 2 O 2 -induced inflammation and apoptosis in synovial cells, offering promising prospects for future RA treatments., (© 2023 Wiley Periodicals LLC.)

Vascular changes represent a characteristic feature of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection leading to a breakdown of the vascular barrier and subsequent edema formation. The aim of this study was to provide a detailed characterization of the vascular alterations during SARS-CoV-2 infection and to evaluate the impaired vascular integrity. Groups of ten golden Syrian hamsters were infected intranasally with SARS-CoV-2 or phosphate-buffered saline (mock infection). Necropsies were performed at 1, 3, 6, and 14 days post-infection (dpi). Lung samples were investigated using hematoxylin and eosin, alcian blue, immunohistochemistry targeting aquaporin 1, CD3, CD204, CD31, laminin, myeloperoxidase, SARS-CoV-2 nucleoprotein, and transmission electron microscopy. SARS-CoV-2 infected animals showed endothelial hypertrophy, endothelialitis, and vasculitis. Inflammation mainly consisted of macrophages and lower numbers of T-lymphocytes and neutrophils/heterophils infiltrating the vascular walls as well as the perivascular region at 3 and 6 dpi. Affected vessels showed edema formation in association with loss of aquaporin 1 on endothelial cells. In addition, an ultrastructural investigation revealed disruption of the endothelium. Summarized, the presented findings indicate that loss of aquaporin 1 entails the loss of intercellular junctions resulting in paracellular leakage of edema as a key pathogenic mechanism in SARS-CoV-2 triggered pulmonary lesions.

Background. Mutations of the β-catenin gene (CTNNB1), leading to aberrant immunohistochemical expression of β-catenin, represent a key mechanism of WNT/β-catenin pathway alteration in ovarian cancer. Aquaporin 1 (AQP1), as component of transmembrane-water-channel family proteins, has been documented in different human tumors and, recently, also in ovarian carcinoma. Only few studies have investigated the pathogenetic and prognostic role of β-catenin and AQP1 in ovarian carcinoma. Methods. We evaluated the expression of β-catenin and AQP1 in the preoperative peritoneal biopsies of 32 patients with peritoneal carcinosis, in which a histological diagnosis of high grade serous ovarian carcinoma was made. Furthermore, we have investigated their potential association with chemotherapeutic response evaluated at the omental site, as well as with clinico-pathological parameters. Results. Sixteen cases showed an aberrant membranous and cytoplasmic β-catenin staining pattern. The remaining 16 cases showed a preserved β-catenin expression localized only in cell membranes; 20 cases showed positive membranous staining (AQP1+), while 12 cases were considered negative (AQP1–). In the AQP+ group, we detected a significant association of AQP1 expression with poor chemotherapy response in omental tissues complete response score (CRS) 1-2, while a CRS 3 was never observed in all positive cases. Conclusions. Our findings suggest that β-catenin and AQP1 are expressed in a sub-group of ovarian tumors and play important roles in carcinogenesis. Patients affected by high grade serous carcinoma could be categorized in two different predictive groups: as AQP+ and AQP–. AQP+ cases may represent a subset of poor responders who could be considered more eligible for cytoreductive surgery rather than for neoadjuvant chemotherapy.

Objectives: Study of aquaporin 1 (AQP1) and aquaporin 3 (AQP3) expression to understand its potential role in the pathophysiology of skin cancer.Methods: Analysis of AQP1 and AQP3 expression by immunohistochemistry of 72 skin biopsy specimens from melanocytic skin tumors, nonmelanocytic tumors, or healthy samples.Results: AQP1 showed strong labeling in 100% of benign common melanocytic nevi. Small blood vessels, stroma, and melanophages surrounding different types of melanomas tumors also were positive. Tumoral melanocytes in atypical nevi and melanomas were negative for AQP1. AQP3 showed strong labeling in 100% of melanocytic nevi, 100% of atypical melanocytic nevi, and 100% of melanomas. In all basal cell carcinomas and squamous cell carcinomas, staining for AQP3 was positive.Conclusions: To our knowledge, this work represents the first demonstration of AQP1/AQP3 expression in human melanocytic skin tumors. More studies are needed to understand the underlying molecular mechanisms of expression of both AQPs in melanocytic tumors and their potential as molecular therapeutic targets. [ABSTRACT FROM AUTHOR]

Aquaporin 1 (AQP1) plays an important role in endothelial functions and is regulated by MEF2C. However, how AQP1 level is stabilized to maintain endothelial water homeostasis is still not clear. Here, we show that AQP1 expression is significantly upregulated by MEF2C transcriptionally and inhibited by miR‐133a‐3p.1 post‐transcriptionally. Meanwhile, MEF2C activates the expression of miR‐133a1. Simultaneous overexpression of MEF2C and miR‐133a‐3p.1 suppresses the aptitude of changes in AQP1 expression caused by either MEF2C or miR‐133a‐3p.1. Accordingly, the changes in migration and tube formation of human umbilical vein endothelial cells (HUVECs) caused by MEF2C or miR133a‐3p.1 are blunted by coexpression of both of them. These data demonstrate that the homeostasis and physiological function of AQP1 in endothelial health are maintained by the MEF2C and miR‐133a‐3p.1 regulatory circuit. [ABSTRACT FROM AUTHOR]

Background: The first line treatment for cutaneous leishmaniasis is pentavalent antimony such as sodium stibogluconate (pentostam) and meglumine antimonite (glucantime). One of the most important ways to uptake the drug is by a trans-membrane protein, called aquaglyceroporin encoded by Aquaglyceroprotein1 (LmAQP1). In this study, molecular characterization of LmAQP1 was reported. Methods: Leishmania major (MRHO/IR/75/ER) promastigotes were cultured, and then DNA extraction and RNA extraction were done and followed by cDNA synthesis. Amplicons resulted from PCR and RT-PCR using specific primers were purified and sequenced. Molecular characterization was done by bioinformatically software such as BLST, ClustalW2, and RMSD. Results: Amplicons resulted from PCR and RT-PCR showed equal size in length. BLASTn analysis showed a point nucleotide change in LmAQP1 gene that encoded 282-amino-acid long protein with a mutation at position 154 including replacement of alanine by threonine. The observed mutation in the interested gene was assessed using the above-mentioned software. The mentioned gene was submitted at GenBank, NCBI with accession number of KU514052. Conclusion: The functional prediction of the protein encoded from LmAQP1 showed that the mentioned mutation could not affect the three-dimension structure, but it may modify the drug uptake potential of this important channel. Based on from LmAQP1 role, it seems to be an appropriate candidate for drug development. According to search through internet, this is the first report of LmAQP1 from L. major (MRHO/IR/75/ER). [ABSTRACT FROM AUTHOR]

Background: Aquaporins (AQPs) are a family of integral membrane channel proteins that facilitate the transport of water and other small solutes across cell membranes. AQPs appear to play crucial roles in parasite survival and represent possible drug targets for novel intervention strategy. In this work, we investigated the tissue distribution and biological roles of an aquaporin TcAQP1 in the neglected parasitic nematode Toxocara canis. Methods: Recombinant C-terminal hydrophilic domain of AQP1 of T. canis (rTcAQP1c) and polyclonal antibody against rTcAQP1c were produced to analyse the tissue expression of native TcAQP1 in adult (female and male) worms using an immunohistochemical approach. RNA interference (RNAi), quantitative real-time PCR (qRT-PCR) and nematocidal assays were performed to investigate the functional roles of TcAQP1 in the adult stage of T. canis. Results: Immunofluorescence analysis showed that TcAQP1 was localised predominantly in the epithelial linings of the reproductive tract and basolateral membrane of the intestine in the adult stage (female and male) of T. canis, indicating important roles in reproduction, nutrient absorption and/or osmoregulation. Treatment with silencing RNA for 24 h resulted in a significant reduction of Tc-aqp-1 mRNA level in adult T. canis, though no phenotypical change was observed. The efficient gene knockdown compromised the nematocidal activity of albendazole in vitro, suggesting the role of TcAQP1 in drug uptake. Conclusions: The findings of this study provide important information about tissue expression and functional roles of TcAQP1 protein in adult T. canis. Understanding the biological functions of this protein in other developmental stages of T. canis and related parasitic nematodes would contribute to the discovery of novel diagnostic or anthelmintic targets. [ABSTRACT FROM AUTHOR]

A serous membrane covering the liver and the hepatic parenchyma, consists of hepatocytes, arteries, veins, hepatic sinusoids and biliary ductuli. There are erythrocytes, thrombocytes, melanin particles and Kupffer cell in the hepatic sinusoids and the blood vessels. The gall bladder wall consists of a mucous layer a muscle layer and a serous layer. The bottom of the epithelium abounds with round or oval secretory. In liver, immunohistochemistry results show that AQP1 have intense reaction in hepatic lobule, Kupffer cells (Macrophagocytus stellatus), hepatocytes, portal tract, blood islands ,vein and artery, but almost no reaction of AQP2 was detected. In gallbladder, mucous epithelium, endothelial cells from vein and artery all have strong AQP1 expression, AQP2 showed minor diffused positive reaction in gallbladder, which suggesting that AQP1 may have the main role in the absorption and transportation of fluid in hepatobiliary system of Qinghai Lizard. [ABSTRACT FROM AUTHOR]

Objective: To evaluate the role of urine aquaporin 1 and perilipin 2 as biomarkers adjunct to renal mass biopsy in guiding the management of patients with small renal masses. Methods: Preoperative aquaporin 1 and perilipin 2 levels in 57 patients with small renal masses undergoing partial nephrectomy were analyzed and compared with postoperative tumor histology. An algorithm was created utilizing aquaporin 1 and perilipin 2 in conjunction with renal mass biopsy. Cut‐off values were implemented to maximize biomarker sensitivity and specificity. Renal mass biopsy utilization and intervention were then compared with rates in traditional renal mass biopsy algorithms. Results: All clear cell and papillary renal cell carcinomas were correctly identified and assigned to the treatment path. All benign lesions were correctly sorted to a confirmatory renal mass biopsy path. Two chromophobe masses did not have elevated aquaporin 1 and perilipin 2, and would require renal mass biopsy. Compared with protocols that call for all small renal masses to be biopsied, confirmatory renal mass biopsy could have been safely avoided in 74% of patients with elevated aquaporin 1 and perilipin 2. Compared with protocols that do not utilize renal mass biopsy, surgical intervention would have been avoided in 23% of patients with benign masses. Conclusions: Aquaporin 1 and perilipin 2 possess high sensitivity and specificity for detecting clear cell and papillary renal cell carcinoma. Use of these markers might compliment renal mass biopsy in the characterization of small renal masses. [ABSTRACT FROM AUTHOR]

Abstract Background Aquaporin-1 (AQP1), a water channel protein controlling the water contents of cells and tissues, exerts pleiotropic effects on various biological activities, including inflammation, angiogenesis, and extracellular matrix remodeling, by regulating cell behaviors and tissue water balance. Objective To investigate AQP1 roles in systemic sclerosis (SSc) which is characterized by autoimmune inflammation, vasculopathy, and tissue fibrosis. Methods AQP1 expression was evaluated by immunohistochemistry and quantitative reverse transcription PCR in skin samples from human and animal models and by immunoblotting in cultured cells. Fli1 binding to the AQP1 promoter was evaluated by chromatin immunoprecipitation. Cell migration was assessed by scratch assay. Results Dermal fibroblasts and endothelial cells highly expressed AQP1 in SSc lesional skin, and AQP1 expression in dermal fibroblasts and endothelial cells positively correlated with the degrees of tissue fibrosis and edema, respectively. Consistently, SSc dermal fibroblasts up-regulated AQP1 compared with normal dermal fibroblasts in vitro. Furthermore, TGF-β stimulation induced AQP1 expression in normal dermal fibroblasts, while TGF-β1 antisense oligonucleotide suppressed AQP1 expression in SSc dermal fibroblasts. In endothelial cells, Fli1 deficiency resulted in AQP1 up-regulation in vivo and in vitro and Fli1 bound to the AQP1 promoter. Importantly, SSc dermal fibroblasts and FLI1 siRNA-treated endothelial cells had a pro-migratory property, which was remarkably diminished by gene silencing of AQP1. Conclusion AQP1 is up-regulated in SSc dermal fibroblasts and SSc endothelial cells at least partially due to autocrine TGF-β stimulation and Fli1 deficiency, respectively, possibly contributing to inflammation, vasculopathy, and tissue fibrosis by regulating tissue edema and cell migration. [ABSTRACT FROM AUTHOR]

Neuroblastoma is a biologically very heterogeneous tumor with its clinical manifestation ranging from spontaneous regression to highly aggressive metastatic disease. Several adverse factors have been linked to oncogenesis, tumor progression and metastases of neuroblastoma including NMYC amplification, the neural adhesion molecule NCAM, as well as CXCR4 as a promoter of metastases. In this study, we investigate to what extent the expression of AQP1 in neuroblastoma correlates with changing cellular factors such as the hypoxic status, differentiation, expression of known adverse factors such as NMYC and NCAM, and CXCR4-related metastatic spread. Our results show that while AQP1 expression leads to an increased migratory behavior of neuroblastoma cells under hypoxic conditions, we find that hypoxia is associated with a reduction of NMYC in the same cells. A similar effect can be observed when using the tetracycline driven mechanism of SH-EP/Tet cells. When NMYC is not expressed, the expression of AQP1 is increased together with an increased expression of HIF-1α and HIF-2α. We furthermore show that when growing cells in different cell densities, they express AQP1, HIF-1α, HIF-2α, NMYC and NCAM to different degrees. AQP1 expression correlates with a hypoxic profile of these cells with increased HIF-1α and HIF-2α expression, as well as with NMYC and NCAM expression in two out of three neuroblastoma cell lines. When investigating cell properties of the cells that actually migrate, we find that the increased APQ1 expression in the migrated cells correlates with an increased NMYC and NCAM expression again in two out of three cell lines. Expression of the tumor cell homing marker CXCR4 varies between different tumor areas and between cell lines. While some migrated tumor cells highly express CXCR4, cells of other origin do not. In the initial phase of migration, we determined a dominant role of AQP1 expression of migrating cells in the scratch assay.

Neuromyelitis optica (NMO) is an autoimmune disease of the central nervous system (CNS) which primarily involves the optic nerve and spinal cord. Aquaporin 4 (AQP4) is the main objective antigen, and its specific antibody was NMO-IgG. It was found in clinic that most of NMO-IgG-positive patients were female, whose clinical symptoms were more severe, bilateral optic neuritis (BON) or optic neuritis (ON) and myelitis were more likely to appear at the same time, and involved spinal segments were longer. Recent studies discovered that anti-aquaporin 1 (AQP1) and anti-myelin oligodendrocyte glycoprotein (MOG) antibodies existed in the serum of patients with NMO-IgG-negative. It was discovered that low proportions of women, more cases of long-segment spinal cord lesion, and rare cases of ON appeared in anti-AQP1 antibody-positive patients. Most of anti-MOG antibody-positive patients were male. ON was common, especially bilateral optic nerves involved at the same time, and thoracolumbar involvement was common. DOI: 10.3969/j.issn.1672-6731.2016.10.004

Background: Aquaporin 1 (AQP1) overexpression has been shown to be associated with uncontrolled cell replication, invasion, migration, and tumor metastasis. We aimed to evaluate AQP1 expression in lung adenocarcinomas and to examine its association with clinicopathological features and prognostic significance. We also investigated the association between AQP1 overexpression and epithelial-mesenchymal transition (EMT) markers. Methods: We examined AQP1 expression in 505 cases of surgically resected lung adenocarcinomas acquired at the Seoul National University Bundang Hospital from 2003 to 2012. Expression of AQP1 and EMT-related markers, including Ecadherin and vimentin, were analyzed by immunohistochemistry and tissue microarray. Results: AQP1 overexpression was associated with several aggressive pathological parameters, including venous invasion, lymphatic invasion, and tumor recurrence. AQP1 overexpression tended to be associated with higher histological grade, advanced pathological stage, and anaplastic lymphoma kinase (ALK) translocation; however, these differences were not statistically significant. In addition, AQP1 overexpression positively correlated with loss of E-cadherin expression and acquired expression of vimentin. Lung adenocarcinoma patients with AQP1 overexpression showed shorter progression-free survival (PFS, 46.1 months vs. 56.2 months) compared to patients without AQP1 overexpression. Multivariate analysis confirmed that AQP1 overexpression was significantly associated with shorter PFS (hazard ratio, 1.429; 95% confidence interval, 1.033 to 1.977; p=.031). Conclusions: AQP1 overexpression was thereby concluded to be an independent factor of poor prognosis associated with shorter PFS in lung adenocarcinoma. These results suggested that AQP1 overexpression might be considered as a prognostic biomarker of lung adenocarcinoma.

Xingsi Liang,1,2,* Bin Zhang,3,* Quan Chen,4,* Jing Zhang,1,5 Biao Lei,1,5 Bo Li,5 Yangchao Wei,1,5 Run Zhai,1,5 Zhiqing Liang,2 Songqing He,1,5 Bo Tang1,5 1Laboratory of Liver Injury and Repair Molecular Medicine, Guilin Medical University, 2Department of Infectious Diseases, Guilin Medical University, Affiliated Hospital, Guilin, Guangxi, 3Department of Oncology, The First Affiliated Hospital of Dalian Medical University, Dalian, Liaoning, 4Department of Anesthesiology, The First Affiliated Hospital of Liaoning Medical University, Jinzhou, Liaoning, 5Department of Hepatobiliary Surgery, Guilin Medical University, Affiliated Hospital, Guilin, Guangxi, People’s Republic of China *These authors contributed equally to this work Abstract: Characterized by its acute onset, critical condition, poor prognosis, and high mortality rate, severe acute pancreatitis (SAP) can cause multiple organ failure at its early stage, particularly acute lung injury (ALI). The pathogenesis of ALI is diffuse alveolar damage, including an increase in pulmonary microvascular permeability, a decrease in compliance, and invasion of many inflammatory cells. Corticosteroids are the main treatment method for ALI; however, the associated high toxicity and side effects induce pain in patients. Recent studies show that the effective components in many traditional Chinese medicines can effectively inhibit inflammation with few side effects, which can decrease the complications caused by steroid consumption. Based on these observations, the main objective of the current study is to investigate the effect of alpinetin, which is a flavonoid extracted from Alpinia katsumadai Hayata, on treating lung injury induced by SAP and to explore the mechanism underlying the alpinetin-mediated decrease in the extent of ALI. In this study, we have shown through in vitro experiments that a therapeutic dose of alpinetin can promote human pulmonary microvascular endothelial cell proliferation. We have also shown via in vitro and in vivo experiments that alpinetin upregulates aquaporin-1 and, thereby, inhibits tumor necrosis factor-α expression as well as reduces the degree of lung injury. Overall, our study shows that alpinetin alleviates SAP-induced ALI. The likely molecular mechanism includes upregulated aquaporin expression, which inhibits tumor necrosis factor-α and, thus, alleviates SAP-induced ALI. Keywords: alpinetin, aquaporin-1, severe acute pancreatitis, acute lung injury, HPMVEC, tumor necrosis factor-α

Background and objective: Polycystic liver disease (PCLD) represents a group of genetic disorders that include autosomal dominant polycystic kidney disease (ADPKD) and isolated polycystic liver disease (iPCLD). There is currently no definitive treatment except for liver transplantation. The aim of this study was to assess the expression level of aquaporin 1 (AQP1) on the PCLD cysts with different sizes and provide the potential therapeutic target. Methods: We collected 3 normal bile ducts, and recruited 8 patients with simple liver cyst disease, 24 patients with ADPKD, and 17 patients with iPCLD. AQP1 expression in different types of cyst walls and in normal bile ducts was detected using real time quantitative PCR, western blot and immunofluorescence staining. We also compared AQP1 expression levels in cysts of different sizes. Besides, ionic concentrations, pH and osmolality of cyst fluid were analyzed. Results: The results showed that AQP1 expression in PCLD cysts was significantly higher than that in simple liver cysts and the normal bile ducts. In addition, a comparable increasing trend was found in cysts of smaller sizes to cysts of larger sizes. pH values, the sodium and chloride concentrations were higher in cyst fluid than that in the serum. Conclusions: AQP1 was overexpressed in cystic cholangiocytes. A tendency of increased AQP1 protein expression in correlation with the cyst size was also found. These observations offered a direction into the molecular mechanisms of cyst expansion and maybe provide new treatment strategies to reduce fluid secretion into liver cysts.

CHIP28 is a 28-kD hydrophobic integral membrane protein that functions as a water channel in erythrocytes and renal tubule epithelial cell membranes. We examined the transmembrane topology of CHIP28 in the ER by engineering a reporter of translocation (derived from bovine prolactin) into nine sequential sites in the CHIP28 coding region. The resulting chimeras were expressed in Xenopus oocytes, and the topology of the reporter with respect to the ER membrane was determined by protease sensitivity. We found that although hydropathy analysis predicted up to seven potential transmembrane regions, CHIP28 spanned the membrane only four times. Two putative transmembrane helices, residues 52-68 and 143-157, reside on the lumenal and cytosolic surfaces of the ER membrane, respectively. Topology derived from these chimeric proteins was supported by cell-free translation of five truncated CHIP28 cDNAs, by N-linked glycosylation at an engineered consensus site in native CHIP28 (residue His69), and by epitope tagging of the CHIP28 amino terminus. Defined protein chimeras were used to identify internal sequences that direct events of CHIP28 topogenesis. A signal sequence located within the first 52 residues initiated nascent chain translocation into the ER lumen. A stop transfer sequence located in the hydrophobic region from residues 90-120 terminated ongoing translocation. A second internal signal sequence, residues 155-186, reinitiated translocation of a COOH-terminal domain (residues 186-210) into the ER lumen. Integration of the nascent chain into the ER membrane occurred after synthesis of 107 residues and required the presence of two membrane-spanning regions. From this data, we propose a structural model for CHIP28 at the ER membrane in which four membrane-spanning alpha-helices form a central aqueous channel through the lipid bilayer and create a pathway for water transport.

The localization and transporting properties of a kidney protein homologous to human erythrocyte protein CHIP28 was evaluated. The cDNA encoding rat kidney protein CHIP28k was isolated from a rat renal cortex cDNA library. A 2.8-kb cDNA was identified which contained an 807 bp open reading frame encoding a 28.8 kD protein with 94% amino acid identity to CHIP28. in vitro translation of CHIP28k cDNA in rabbit reticulocyte lysate generated a 28-kD protein; addition of ER-derived microsomes gave a 32-kD transmembrane glycoprotein. Translation of truncated RNA demonstrated glycosylation of residue Asn42 which is predicted to lie between the first and second transmembrane domains. Expression of in vitro transcribed mRNA encoding CHIP28k in Xenopus oocytes increased oocyte osmotic water permeability (Pf) from (4 +/- 1) x 10(-4) to (33 +/- 4) x 10(-4) cm/s at 10 degrees C; the increase in oocyte Pf was weakly temperature dependent and inhibited by HgCl2. Two-electrode voltage clamp measurements indicated that CHIP28k was not permeable to ions. Oocyte Pf also increased with expression of total mRNA from kidney cortex and papilla; the increase in Pf with mRNA from cortex, but not kidney papilla, was blocked by coinjection with excess antisense CHIP28k cRNA. In situ hybridization of a 150 base cRNA antisense probe to tissue sections from rat kidney showed selective CHIP28k localization to epithelial cells in proximal tubule and thin descending limb of Henle. Pf in purified apical membrane vesicles from rat and human proximal tubule, and in proteoliposomes reconstituted with purified protein, was very high and inhibited by HgCl2; stripping of apical vesicles with N-lauroylsarcosine enriched a 28-kD protein by 25-fold and yielded a vesicle population with high water, but low urea and proton permeabilities. CHIP28k identity was confirmed by NH2-terminus sequence analysis. These results indicate that CHIP28k is a major and highly selective water transporting protein in the kidney proximal tubule and thin descending limb of Henle, but not collecting duct.

Purpose: It is suggested that caveolin and aquaporin might be closely associated with bladder signal activity. We investigated the effect of the deletion of caveolin 1, using caveolin 1 knockout mice, on the expression of aquaporin 1 in order to identify their relation in the urothelium of the urinary bladder. Methods: The cellular localization and expressions of aquaporin 1 and caveolin 1, in the wild type and caveolin 1 knockout mice urinary bladder, were examined by Western blot and immunofluorescence techniques. Results: Aquaporin 1 and caveolin 1 were coexpressed in the arterioles, venules, and capillaries of the suburothelial layer in the wild type controls. Aquaporin 1 protein expression was significantly higher in the caveolin 1 knockout mice than in the wild type controls (P