The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform

A. S. Verkman - One of the best experts on this subject based on the ideXlab platform.

  • inhibition of Aquaporin 3 in macrophages by a monoclonal antibody as potential therapy for liver injury
    Nature Communications, 2020
    Co-Authors: Mariko Harachikuma, A. S. Verkman, Manami Tanaka, Masato Yasui
    Abstract:

    Aquaporin 3 (AQP3) is a transporter of water, glycerol and hydrogen peroxide (H2O2) that is expressed in various epithelial cells and in macrophages. Here, we developed an anti-AQP3 monoclonal antibody (mAb) that inhibited AQP3-facilitated H2O2 and glycerol transport, and prevented liver injury in experimental animal models. Using AQP3 knockout mice in a model of liver injury and fibrosis produced by CCl4, we obtained evidence for involvement of AQP3 expression in nuclear factor-κB (NF-κB) cell signaling, hepatic oxidative stress and inflammation in macrophages during liver injury. The activated macrophages caused stellate cell activation, leading to liver injury, by a mechanism involving AQP3-mediated H2O2 transport. Administration of an anti-AQP3 mAb, which targeted an extracellular epitope on AQP3, prevented liver injury by inhibition of AQP3-mediated H2O2 transport and macrophage activation. These findings implicate the involvement of macrophage AQP3 in liver injury, and provide evidence for mAb inhibition of AQP3-mediated H2O2 transport as therapy for macrophage-dependent liver injury.

  • Aquaporin 3 deficiency slows cyst enlargement in experimental mouse models of autosomal dominant polycystic kidney disease
    The FASEB Journal, 2019
    Co-Authors: A. S. Verkman, Lei Lei, Weiling Wang, Yingli Jia, Hong Zhou, Baoxue Yang, Xiaoqiang Geng
    Abstract:

    Human autosomal dominant polycystic kidney disease (ADPKD) is characterized by bilateral renal cysts that lead to a decline in kidney function. Previous studies reported Aquaporin (AQP)-3 expression in cysts derived from collecting ducts in ADPKD. To study the role of AQP3 in cyst development, we generated 2 polycystic kidney disease (PKD) mouse models: kidney-specific Pkd1 knockout mice and inducible Pkd1 knockout mice, each without and with AQP3 deletion. In both models, kidney sizes and cyst indexes were significantly reduced in AQP3-null PKD mice compared with AQP3-expressing PKD mice, with the difference seen mainly in collecting duct cysts. AQP3-deficient kidneys showed significantly reduced ATP content, increased phosphorylated (p)-AMPK, and decreased p-ERK and p-mammalian target of rapamycin (mTOR). In a matrix-grown Madin-Darby canine kidney cyst model, AQP3 expression promoted cyst enlargement and was associated with increased expression of hypoxia-inducible factor 1-α and glucose transporter 1 and increased glucose uptake. Our data suggest that the slowed renal cyst enlargement in AQP3 deficiency involves impaired energy metabolism in the kidney through AMPK and mTOR signaling and impaired cellular glucose uptake. These findings implicate AQP3 as a novel determinant of renal cyst enlargement and hence a potential drug target in ADPKD.-Wang, W., Geng, X., Lei, L., Jia, Y., Li, Y., Zhou, H., Verkman, A. S., Yang, B. Aquaporin-3 deficiency slows cyst enlargement in experimental mouse models of autosomal dominant polycystic kidney disease.

  • Aquaporin 3 deletion in mice results in renal collecting duct abnormalities and worsens ischemia reperfusion injury
    Biochimica et Biophysica Acta, 2017
    Co-Authors: Lei Lei, A. S. Verkman, Weiling Wang, Yingli Jia, Hong Zhou, Baoxue Yang
    Abstract:

    Aquaporin-3 (AQP3), a transporter of water, glycerol and H2O2, is expressed in basolateral membranes of principal cells in kidney collecting duct. Here, we report that AQP3 deletion in mice affects renal function and modulates renal injury. We found collecting duct hyperplasia and cell swelling in kidneys of adult AQP3 null mice. After mild renal ischemia-reperfusion (IR), AQP3 null mice had significantly greater blood urea nitrogen (57mg/dl) and creatinine (136μM) than wild-type mice (35mg/dl and 48μM, respectively), and showed renal morphological changes, including tubular dilatation, erythrocyte diapedesis and collecting duct incompletion. MPO, MDA and SOD following IR in AQP3 null mice were significantly different from that in wild-type mice (1.7U/g vs 0.8U/g, 3.9μM/g vs 2.4μM/g, 6.4U/mg vs 11U/mg, respectively). Following IR, AQP3 deletion inhibited activation of mitogen-activated protein kinase (MAPK) signaling and produced an increase in the ratios of Bax/Bcl-2, cleaved caspase-3/caspase-3 and p-p53/p53. Studies in transfected MDCK cells showed that AQP3 expression attenuated reduced cell viability following hypoxia-reoxygenation, with reduced apoptosis and increased MAPK signaling. Our results support a novel role for AQP3 in modulating renal injury and suggest the mechanisms involved in protection against hypoxic injury.

  • Aquaporin 3 mediates hydrogen peroxide dependent responses to environmental stress in colonic epithelia
    Proceedings of the National Academy of Sciences of the United States of America, 2017
    Co-Authors: Jay R Thiagarajah, A. S. Verkman, Jeffrey Chang, Jeremy A Goettel, Wayne I Lencer
    Abstract:

    The colonic epithelium provides an essential barrier against the environment that is critical for protecting the body and controlling inflammation. In response to injury or gut microbes, colonic epithelial cells produce extracellular hydrogen peroxide (H2O2), which acts as a potent signaling molecule affecting barrier function and host defense. In humans, impaired regulation of H2O2 in the intestine has been associated with early-onset inflammatory bowel disease and colon cancer. Here, we show that signal transduction by H2O2 depends on entry into the cell by transit through Aquaporin-3 (AQP3), a plasma membrane H2O2-conducting channel. In response to injury, AQP3-depleted colonic epithelial cells showed defective lamellipodia, focal adhesions, and repair after wounding, along with impaired H2O2 responses after exposure to the intestinal pathogen Citrobacter rodentium. Correspondingly, AQP3−/− mice showed impaired healing of superficial wounds in the colon and impaired mucosal innate immune responses against C. rodentium infection, manifested by reduced crypt hyperplasia, reduced epithelial expression of IL-6 and TNF-α, and impaired bacterial clearance. These results elucidate the signaling mechanism of extracellular H2O2 in the colonic epithelium and implicate AQP3 in innate immunity at mucosal surfaces.

  • Aquaporin 3 mediated hydrogen peroxide transport is required for nf κb signalling in keratinocytes and development of psoriasis
    Nature Communications, 2015
    Co-Authors: Mariko Harachikuma, Yoshiki Miyachi, Hiroki Satooka, Sachiko Watanabe, Tetsuya Honda, Takeshi Watanabe, A. S. Verkman
    Abstract:

    Aquaporin-3 (AQP3) mediates cellular uptake of water and hydrogen peroxide (H2O2). Here, the authors show that TNF-induced H2O2 enters keratinocytes via AQP3, eliciting NF-κB activation and the development of psoriasis, and identify AQP3 as a potential therapeutic target for this inflammatory immune-mediated disease.

Mariko Harachikuma - One of the best experts on this subject based on the ideXlab platform.

  • inhibition of Aquaporin 3 in macrophages by a monoclonal antibody as potential therapy for liver injury
    Nature Communications, 2020
    Co-Authors: Mariko Harachikuma, A. S. Verkman, Manami Tanaka, Masato Yasui
    Abstract:

    Aquaporin 3 (AQP3) is a transporter of water, glycerol and hydrogen peroxide (H2O2) that is expressed in various epithelial cells and in macrophages. Here, we developed an anti-AQP3 monoclonal antibody (mAb) that inhibited AQP3-facilitated H2O2 and glycerol transport, and prevented liver injury in experimental animal models. Using AQP3 knockout mice in a model of liver injury and fibrosis produced by CCl4, we obtained evidence for involvement of AQP3 expression in nuclear factor-κB (NF-κB) cell signaling, hepatic oxidative stress and inflammation in macrophages during liver injury. The activated macrophages caused stellate cell activation, leading to liver injury, by a mechanism involving AQP3-mediated H2O2 transport. Administration of an anti-AQP3 mAb, which targeted an extracellular epitope on AQP3, prevented liver injury by inhibition of AQP3-mediated H2O2 transport and macrophage activation. These findings implicate the involvement of macrophage AQP3 in liver injury, and provide evidence for mAb inhibition of AQP3-mediated H2O2 transport as therapy for macrophage-dependent liver injury.

  • Aquaporin 3 potentiates murine asthma through mediating t cell trafficking and chemokine production
    European Respiratory Journal, 2016
    Co-Authors: Kohei Ikezoe, Mariko Harachikuma, Tetsuya Honda, Toru Oga, Tatsuaki Tsuruyama, Kazuko Uno, Jun Ichi Fuchikami, Kiminobu Tanizawa, Tomohiro Handa, Yoshio Taguchi
    Abstract:

    Background: Oxidative stress plays a pivotal role in the pathogenesis of asthma. Aquaporin-3 (AQP3) is a small integral membrane protein, and facilitates the membrane uptake of hydrogen peroxide (H 2 O 2 ). Objective: We investigated the contribution of AQP3 to the pathogenesis of asthma through regulating the amount of cellular H 2 O 2 . Methods: Wild-type and AQP3 deficient (AQP3 -/- ) mice were sensitized to ovalbumin (OVA) and subsequently challenged with aerosolized OVA. We then investigated airway inflammation and airway hyperresponsiveness and assessed the functions of T cells and alveolar macrophages (AMs) through AQP3 expression. Results: AQP3 -/- mice exhibited significantly reduced airway inflammation and airway hyperresponsiveness compared to wild-type mice in OVA-induced asthma. Adoptive transfer experiments showed that airway eosinophilic inflammation was reduced in mice receiving OVA-sensitized splenocytes from AQP3 -/- mice than from wild-type mice during the elicitation phase, and that fewer CD4 + T cells from AQP3 -/- mice migrated to thoracic lymph nodes and lungs than from wild-type mice. Additionally, in vivo and vitro experiments indicated that AQP3 induced the production of some chemokines such as CCL24 and CCL22 through regulating the amount of cellular H 2 O 2 in M2 polarized AMs. Conclusions: AQP3 expression was involved in OVA-induced asthma model by mediating T cell trafficking and chemokine production from M2 polarized AMs partly via the regulation of the amount of cellular H 2 O 2 . These results imply a critical role of AQP3 in asthma, and AQP3 may be a novel therapeutic target.

  • Aquaporin 3 potentiates allergic airway inflammation in ovalbumin induced murine asthma
    Scientific Reports, 2016
    Co-Authors: Kohei Ikezoe, Mariko Harachikuma, Tetsuya Honda, Toru Oga, Tatsuaki Tsuruyama, Kazuko Uno, Jun Ichi Fuchikami, Kiminobu Tanizawa, Tomohiro Handa, Yoshio Taguchi
    Abstract:

    Oxidative stress plays a pivotal role in the pathogenesis of asthma. Aquaporin-3 (AQP3) is a small transmembrane water/glycerol channel that may facilitate the membrane uptake of hydrogen peroxide (H2O2). Here we report that AQP3 potentiates ovalbumin (OVA)-induced murine asthma by mediating both chemokine production from alveolar macrophages and T cell trafficking. AQP3 deficient (AQP3(-/-)) mice exhibited significantly reduced airway inflammation compared to wild-type mice. Adoptive transfer experiments showed reduced airway eosinophilic inflammation in mice receiving OVA-sensitized splenocytes from AQP3(-/-) mice compared with wild-type mice after OVA challenge, consistently with fewer CD4(+) T cells from AQP3(-/-) mice migrating to the lung than from wild-type mice. Additionally, in vivo and vitro experiments indicated that AQP3 induced the production of some chemokines such as CCL24 and CCL22 through regulating the amount of cellular H2O2 in M2 polarized alveolar macrophages. These results imply a critical role of AQP3 in asthma, and AQP3 may be a novel therapeutic target.

  • Aquaporin 3 controls breast cancer cell migration by regulating hydrogen peroxide transport and its downstream cell signaling
    Molecular and Cellular Biology, 2016
    Co-Authors: Hiroki Satooka, Mariko Harachikuma
    Abstract:

    Most breast cancer mortality is due to clinical relapse associated with metastasis. CXCL12/CXCR4-dependent cell migration is a critical process in breast cancer progression; however, its underlying mechanism remains to be elucidated. Here, we show that the water/glycerol channel protein Aquaporin-3 (AQP3) is required for CXCL12/CXCR4-dependent breast cancer cell migration through a mechanism involving its hydrogen peroxide (H2O2) transport function. Extracellular H2O2, produced by CXCL12-activated membrane NADPH oxidase 2 (Nox2), was transported into breast cancer cells via AQP3. Transient H2O2 accumulation was observed around the membrane during CXCL12-induced migration, which may be facilitated by the association of AQP3 with Nox2. Intracellular H2O2 then oxidized PTEN and protein tyrosine phosphatase 1B (PTP1B) followed by activation of the Akt pathway. This contributed to directional cell migration. The expression level of AQP3 in breast cancer cells was related to their migration ability both in vitro and in vivo through CXCL12/CXCR4- or H2O2-dependent pathways. Coincidentally, spontaneous metastasis of orthotopic xenografts to the lung was reduced upon AQP3 knockdown. These findings underscore the importance of AQP3-transported H2O2 in CXCL12/CXCR4-dependent signaling and migration in breast cancer cells and suggest that AQP3 has potential as a therapeutic target for breast cancer.

  • involvement of Aquaporin 3 in epidermal growth factor receptor signaling via hydrogen peroxide transport in cancer cells
    Biochemical and Biophysical Research Communications, 2016
    Co-Authors: Mariko Harachikuma, Sachiko Watanabe, Hiroki Satooka
    Abstract:

    Aquaporin 3 (AQP3), a water/glycerol channel protein, is capable of transporting hydrogen peroxide (H2O2). Here, we show that AQP3-mediated intracellular H2O2 is involved in epidermal growth factor (EGF)-induced cell signaling and its dependent cell function in the EGF receptor (EGFR)-positive cancer cell lines A431 and H1666. AQP3 knockdown suppressed the transport into the cells of extracellular H2O2 produced in response to EGF in A431 and H1666 cells. EGF-induced Erk and Akt activation, which occurred through SHP2 and/or PTEN modulation, was impaired by AQP3 knockdown. Cell growth and migration induced by EGF stimulation were attenuated in AQP3 knockdown cells compared with those in control cells. Coincidentally, tumor growth of A431 cell xenografts in immunodeficient mice was decreased by AQP3 knockdown. Accordingly, a xenograft with AQP3 knockdown A431 cells significantly enhanced the survival of recipient mice compared with the transplantation with control cells. In addition, AQP3 associated with EGFR and NADPH oxidase 2, which we propose is linked to AQP3 producing a localized increase in intracellular H2O2 to function as a second messenger during EGFR cell signaling. Therefore, our findings suggest that AQP3 is required for EGF-EGFR cell signaling in cancer cells and is a therapeutic target for cancer progression.

Wendy B Bollag - One of the best experts on this subject based on the ideXlab platform.

  • Aquaporin 3 in keratinocytes and skin its role and interaction with phospholipase d2
    Archives of Biochemistry and Biophysics, 2011
    Co-Authors: Haixia Qin, Xiangjian Zheng, Wendy B Bollag, Xiaofeng Zhong, Anita K Shetty, Peter M Elias
    Abstract:

    Aquaporin 3 (AQP3) is an aquaglyceroporin that transports water and glycerol and is expressed in the epidermis, among other epithelial tissues. We have recently shown that there is an association between this glycerol channel and phospholipase D2 (PLD2) in caveolin-rich membrane microdomains. While PLD2 is able to hydrolyze membrane phospholipids to generate phosphatidic acid, this enzyme also catalyzes, in the presence of primary alcohols, a transphosphatidylation reaction to produce a phosphatidylalcohol. We have proposed that AQP3 associated with PLD2 provides the physiological primary alcohol glycerol to PLD2 for use in the transphosphatidylation reaction to generate phosphatidylglycerol (PG). Further, we have proposed that PG functions as a signaling molecule to mediate early epidermal keratinocyte differentiation, and manipulation of this signaling module inhibits keratinocyte proliferation and enhances differentiation. In contrast, other investigators have suggested a proliferative role for AQP3 in keratinocytes. In addition, AQP3 knockout mice exhibit an epidermal phenotype, characterized by dry skin, decreased elasticity and delayed barrier repair and wound healing, which can be corrected by glycerol but not other humectants. AQP3 levels have also been found to be altered in human skin diseases. In this article the evidence supporting a role for AQP3 in the epidermis will be discussed.

  • abnormal Aquaporin 3 protein expression in hyperproliferative skin disorders
    Archives of Dermatological Research, 2011
    Co-Authors: Kristen E Voss, Wendy B Bollag, Roni J Bollag, Nicole Fussell, Daniel J Sheehan
    Abstract:

    Non-melanoma skin cancers (NMSCs) and psoriasis represent common hyperproliferative skin disorders, with approximately one million new NMSC diagnoses each year in the United States alone and a psoriasis prevalence of about 2% worldwide. We recently demonstrated that the glycerol channel, Aquaporin-3 (AQP3) and the enzyme phospholipase D2 (PLD2) interact functionally in epidermal keratinocytes of the skin to inhibit their proliferation. However, others have suggested that AQP3 is pro-proliferative in keratinocytes and is upregulated in the NMSC, squamous cell carcinoma (SCC). To evaluate the AQP3/PLD2 signaling module in skin diseases, we determined their levels in SCC, basal cell carcinoma (BCC) and psoriasis as compared to normal epidermis. Skin biopsies with the appropriate diagnoses (10 normal, 5 SCC, 13 BCC and 10 plaque psoriasis samples) were obtained from the pathology archives and examined by immunohistochemistry using antibodies recognizing AQP3 and PLD2. In normal epidermis AQP3, an integral membrane protein, was localized mainly to the plasma membrane and PLD2 to the cell periphery, particularly in suprabasal layers. In BCC, AQP3 and PLD2 levels were reduced as compared to the normal-appearing overlying epidermis. In SCC, AQP3 staining was "patchy," with areas of reduced AQP3 immunoreactivity exhibiting positivity for Ki67, a marker of proliferation. PLD2 staining was unchanged in SCC. In psoriasis, AQP3 staining was usually observed in the cytoplasm rather than in the membrane. Also, in the majority of psoriatic samples, PLD2 showed weak immunoreactivity or aberrant localization. These results suggest that abnormalities in the AQP3/PLD2 signaling module correlate with hyperproliferation in psoriasis and the NMSCs.

  • a potential role for the phospholipase d2 Aquaporin 3 signaling module in early keratinocyte differentiation production of a phosphatidylglycerol signaling lipid
    Journal of Investigative Dermatology, 2007
    Co-Authors: Wendy B Bollag, Xiangjian Zheng, Ding Xie, Xiaofeng Zhong
    Abstract:

    In keratinocytes Aquaporin-3 (AQP3), an efficient glycerol transporter, is associated with phospholipase D2 (PLD2) in caveolin-rich membrane microdomains. PLD catalyzes both phospholipid hydrolysis to produce phosphatidate and a transphosphatidylation reaction using primary alcohols to generate phosphatidylalcohols. As PLD2 can utilize the physiological alcohol glycerol to form phosphatidylglycerol (PG), we hypothesized that AQP3 provides glycerol to PLD2 for PG synthesis, which then modulates keratinocyte function. Acidic medium inhibits AQP3 transport activity; both glycerol uptake and PG synthesis were inhibited by low versus physiological pH. Co-transfection experiments were performed in which AQP3 or empty vector was introduced into keratinocytes simultaneously with reporter constructs in which differentiation or proliferation promoters directed expression of a luciferase reporter gene. AQP3 coexpression decreased the promoter activity of keratin 5, increased that of keratin 10 and enhanced the effect of a differentiating agent on the promoter activity of involucrin, consistent with promotion of early differentiation. Glycerol inhibited DNA synthesis, whereas equivalent concentrations of xylitol or sorbitol, as osmotic controls, had no effect. Direct provision of PG, but not phosphatidylpropanol, inhibited DNA synthesis in proliferative cells. Thus, our results support the idea that AQP3 supplies PLD2 with glycerol for synthesizing PG, a lipid signal that promotes early keratinocyte differentiation.

  • Aquaporin 3 colocates with phospholipase d2 in caveolin rich membrane microdomains and is downregulated upon keratinocyte differentiation
    Journal of Investigative Dermatology, 2003
    Co-Authors: Xiangjian Zheng, Wendy B Bollag
    Abstract:

    Aquaporin 3 is a channel that transports both water and glycerol. Aquaporin 3-deficient mice exhibit skin defects, including decreased glycerol content and impairment of water holding capacity, barrier recovery, and wound healing. Whether Aquaporin 3 and its glycerol transporting capacity are involved in regulating keratinocyte function, we have previously shown that phospholipase D2 can metabolize phospholipids in the presence of glycerol to yield phosphatidylglycerol. We hypothesized that Aquaporin 3 is involved in the regulation of keratinocyte function by a mechanism involving the interaction between Aquaporin 3 and phospholipase D. Using sucrose gradient centrifugation, immunoprecipitation analysis, and confocal microscopy, we found that Aquaporin 3 and phospholipase D2 colocalized in caveolin-rich membrane microdomains. In addition, Aquaporin 3 expression was downregulated at the transcriptional level and glycerol uptake was reduced upon primary mouse keratinocytes to differentiation in response to an elevated extracellular calcium concentration or 1,25-dihydroxyvitamin D3. Our results suggest that Aquaporin 3 and phospholipase D2 form a signaling module in lipid rafts, where Aquaporin 3 transports glycerol to phospholipase D2 for the synthesis of phosphatidylglycerol. Phosphatidylglycerol, as a bioactive lipid, could potentially mediate the effects of the Aquaporin 3-phospholipase D2 signaling module, with Aquaporin 3 as a modulatory unit, in the regulation of keratinocyte function.

Yoshiki Miyachi - One of the best experts on this subject based on the ideXlab platform.

  • Aquaporin 3 mediated hydrogen peroxide transport is required for nf κb signalling in keratinocytes and development of psoriasis
    Nature Communications, 2015
    Co-Authors: Mariko Harachikuma, Yoshiki Miyachi, Hiroki Satooka, Sachiko Watanabe, Tetsuya Honda, Takeshi Watanabe, A. S. Verkman
    Abstract:

    Aquaporin-3 (AQP3) mediates cellular uptake of water and hydrogen peroxide (H2O2). Here, the authors show that TNF-induced H2O2 enters keratinocytes via AQP3, eliciting NF-κB activation and the development of psoriasis, and identify AQP3 as a potential therapeutic target for this inflammatory immune-mediated disease.

  • Chemokine-dependent T cell migration requires Aquaporin-3-mediated hydrogen peroxide uptake.
    The Journal of experimental medicine, 2012
    Co-Authors: Mariko Hara-chikuma, Shunsuke Chikuma, Yoshinori Sugiyama, Kenji Kabashima, Shintaro Inoue, Yoshiki Miyachi
    Abstract:

    Chemokine-dependent trafficking is indispensable for the effector function of antigen-experienced T cells during immune responses. In this study, we report that the water/glycerol channel Aquaporin-3 (AQP3) is expressed on T cells and regulates their trafficking in cutaneous immune reactions. T cell migration toward chemokines is dependent on AQP3-mediated hydrogen peroxide (H2O2) uptake but not the canonical water/glycerol transport. AQP3-mediated H2O2 transport is essential for the activation of the Rho family GTPase Cdc42 and the subsequent actin dynamics. Coincidentally, AQP3-deficient mice are defective in the development of hapten-induced contact hypersensitivity, which is attributed to the impaired trafficking of antigen-primed T cells to the hapten-challenged skin. We therefore suggest that AQP3-mediated H2O2 uptake is required for chemokine-dependent T cell migration in sufficient immune response.

  • upregulation of Aquaporin 3 is involved in keratinocyte proliferation and epidermal hyperplasia
    Journal of Investigative Dermatology, 2011
    Co-Authors: Kyoko Nakahigashi, A. S. Verkman, Kenji Kabashima, Yoshiki Miyachi, Akihiko Ikoma, Mariko Harachikuma
    Abstract:

    Aquaporin-3 (AQP3) is a water/glycerol-transporting protein expressed in keratinocytes of the epidermis. We previously showed that AQP3-mediated transport of water and glycerol is involved in keratinocyte migration and proliferation, respectively. However, the involvement of AQP3 in epidermal hyperplasia in skin diseases, such as atopic dermatitis (AD), is unknown. In this study, we found significantly increased AQP3 transcript and protein expression in the epidermis of human AD lesions. The upregulation of AQP3 expression in human keratinocytes by transfection with human AQP3 DNA plasmid was associated with increased cellular glycerol and ATP, as well as increased cell proliferation. Among several cytokines and chemokines produced in the skin, CCL17, which is highly expressed in AD, was found to be a strong inducer of AQP3 expression and enhanced keratinocyte proliferation. In mouse AD models, AQP3 was strongly overexpressed in the epidermis in wild-type mice. Epidermal hyperplasia was reduced in AQP3-deficient mice, with a decreased number of proliferating keratinocytes. These results suggest the involvement of AQP3 in epidermal hyperplasia by a mechanism involving upregulated AQP3 expression and consequent enhancement of keratinocyte proliferation.

  • The expression of differentiation markers in Aquaporin-3 deficient epidermis
    Archives of Dermatological Research, 2009
    Co-Authors: Mariko Hara-chikuma, A. S. Verkman, Shunsuke Chikuma, Kenzo Takahashi, Yoshiki Miyachi
    Abstract:

    Aquaporin-3 (AQP3) is a water/glycerol transporting protein expressed strongly at the plasma membrane of keratinocytes. There is evidence for involvement of AQP3-facilitated water and glycerol transport in keratinocyte migration and proliferation, respectively. Here, we investigated the involvement of AQP3 in keratinocyte differentiation. Studies were done using AQP3 knockout mice, primary cultures of mouse keratinocytes (AQP3 knockout), neonatal human keratinocytes (AQP3 knockdown), and human skin. Cells were cultured with high Ca^2+ or 1α,25-dihydroxyvitamin D_3 (VD_3) to induce differentiation. The expression of differentiation marker proteins and differentiating responses were comparable in control and AQP3-knockout or knockdown keratinocytes. Topical application of all-trans retinoic acid (RA), a known regulator of keratinocyte differentiation and proliferation, induced comparable expression of differentiation marker proteins in wildtype and AQP3 null epidermis, though with impaired RA-induced proliferation in AQP3 null mice. Immunostaining of human and mouse epidermis showed greater AQP3 expression in cells undergoing proliferation than differentiation. Our results showed little influence of AQP3 on keratinocyte differentiation, and provide further support for the proposed involvement of AQP3-facilitated cell proliferation.

Mariko Hara - One of the best experts on this subject based on the ideXlab platform.

  • Glycerol replacement corrects defective skin hydration, elasticity, and barrier function in Aquaporin-3-deficient mice.
    Proceedings of the National Academy of Sciences of the United States of America, 2003
    Co-Authors: Mariko Hara
    Abstract:

    Mice deficient in the epidermal water/glycerol transporter Aquaporin-3 (AQP3) have reduced stratum corneum (SC) hydration and skin elasticity, and impaired barrier recovery after SC removal. SC glycerol content is reduced 3-fold in AQP3 null mice, whereas SC structure, protein/lipid composition, and ion/osmolyte content are not changed. We show here that glycerol replacement corrects each of the defects in AQP3 null mice. SC water content, measured by skin conductance and 3H2O accumulation, was 3-fold lower in AQP3 null vs. wild-type mice, but became similar after topical or systemic administration of glycerol in quantities that normalized SC glycerol content. SC water content was not corrected by glycerol-like osmolytes such as xylitol, erythritol, and propanediol. Orally administered glycerol fully corrected the reduced skin elasticity in AQP3 null mice as measured by the kinetics of skin displacement after suction, and the delayed barrier recovery as measured by transepidermal water loss after tape-stripping. Analysis of [14C]glycerol kinetics indicated reduced blood-to-SC transport of glycerol in AQP3 null mice, resulting in slowed lipid biosynthesis. These data provide functional evidence for a physiological role of glycerol transport by an aquaglyceroporin, and indicate that glycerol is a major determinant of SC water retention, and mechanical and biosynthetic functions. Our findings establish a scientific basis for the >200-yr-old empirical practice of including glycerol in cosmetic and medicinal skin formulations.

  • selectively reduced glycerol in skin of Aquaporin 3 deficient mice may account for impaired skin hydration elasticity and barrier recovery
    Journal of Biological Chemistry, 2002
    Co-Authors: Mariko Hara, A. S. Verkman
    Abstract:

    Deletion of the epidermal water/glycerol transporter Aquaporin-3 (AQP3) in mice reduced superficial skin conductance by ∼2-fold (Ma, T., Hara, M., Sougrat, R., Verbavatz, J. M., and Verkman, A. S. (2002) J. Biol. Chem. 277, 17147–17153), suggesting defective stratum corneum (SC) hydration. Here, we demonstrate significant impairment of skin hydration, elasticity, barrier recovery, and wound healing in AQP3 null mice in a hairless (SKH1) genetic background and investigate the cause of the functional defects by analysis of SC morphology and composition. Utilizing a novel 3H2O distribution method, SC water content was reduced by ∼50% in AQP3 null mice. Skin elasticity measured by cutometry was significantly reduced in AQP3 null mice with ∼50% reductions in elasticity parameters Uf, Ue, and Ur. Although basal skin barrier function was not impaired, AQP3 deletion produced an ∼2-fold delay in recovery of barrier function as measured by transepidermal water loss after tape stripping. Another biosynthetic skin function, wound healing, was also ∼2-fold delayed by AQP3 deletion. By electron microscopy AQP3 deletion did not affect the structure of the unperturbed SC. The SC content of ions (Na+, K+, Ca2+, Mg2+) and small solutes (urea, lactic acid, glucose) was not affected by AQP3 deletion nor was the absolute amount or profile of lipids and free amino acids. However, AQP3 deletion produced significant reductions in glycerol content in SC and epidermis (in nmol/μg protein: 5.5 ± 0.4 versus 2.3 ± 0.7 in SC; 0.037 ± 0.007versus 0.022 ± 0.005 in epidermis) but not in dermis or blood. These results establish hydration, mechanical, and biosynthetic defects in skin of AQP3-deficient mice. The selective reduction in epidermal and SC glycerol content in AQP3 null mice may account for these defects, providing the first functional evidence for physiologically important glycerol transport by an Aquaporin.

  • impaired stratum corneum hydration in mice lacking epidermal water channel Aquaporin 3
    Journal of Biological Chemistry, 2002
    Co-Authors: Mariko Hara, Jeanmarc Verbavatz, Rachid Sougrat, A. S. Verkman
    Abstract:

    The water and solute transporting properties of the epidermis have been proposed to be important determinants of skin moisture content and barrier properties. The water/small solute-transporting protein Aquaporin-3 (AQP3) was found by immunofluorescence and immunogold electron microscopy to be expressed at the plasma membrane of epidermal keratinocytes in mouse skin. We studied the role of AQP3 in stratum corneum (SC) hydration by comparative measurements in wild-type and AQP3 null mice generated in a hairless SKH1 genetic background. The hairless AQP3 null mice had normal perinatal survival, growth, and serum chemistries but were polyuric because of defective urinary concentrating ability. AQP3 deletion resulted in a > 4-fold reduced osmotic water permeability and > 2-fold reduced glycerol permeability in epidermis. Epidermal, dermal, and SC thickness and morphology were not grossly affected by AQP3 deletion. Surface conductance measurements showed remarkably reduced SC water content in AQP3 null mice in the hairless genetic background (165 +/- 10 versus 269 +/- 12 microsiemens (microS), p < 0.001), as well as in a CD1 genetic background (209 +/- 21 versus 469 +/- 11 microS). Reduced SC hydration was seen from 3 days after birth. SC hydration in hairless wild-type and AQP3 null mice was reduced to comparable levels (90-100 microS) after a 24-h exposure to a dry atmosphere, but the difference was increased when surface evaporation was prevented by occlusion or exposure to a humidified atmosphere (179 +/- 13 versus 441 +/- 34 microS). Conductance measurements after serial tape stripping suggested reduced water content throughout the SC in AQP3 null mice. Water sorption-desorption experiments indicated reduced water holding capacity in the SC of AQP3 null mice. The impaired skin hydration in AQP3 null mice provides the first functional evidence for the involvement of AQP3 in skin physiology. Modulation of AQP3 expression or function may thus alter epidermal moisture content and water loss in skin diseases.

  • osmotic stress up regulates Aquaporin 3 gene expression in cultured human keratinocytes
    Biochimica et Biophysica Acta, 2001
    Co-Authors: Yoshinori Sugiyama, Mariko Hara, Yukiko Ota, Shintaro Inoue
    Abstract:

    Of ten members of the Aquaporin family (AQP), the mRNA expression and regulation of AQP1, AQP3, AQP4 and AQP9 in cultured human keratinocytes were examined by an RNase protection assay. AQP3 mRNA was expressed in growing and differentiating cells, while AQP9 mRNA was only detected in differentiating cells. The epidermis in skin-equivalent cultures expressed both AQP3 and AQP9 mRNA. However, neither AQP1 nor AQP4 mRNA was detectable in either monolayer or skin-equivalent cultures. Incubation of keratinocytes in sorbitol-added hypertonic medium increased AQP3 mRNA expression. This was confirmed using other solutes such as NaCl, mannitol, glucose and sucrose. The effect of sorbitol was reversible, dose-dependent and maximal at 24 h after addition. However, AQP1, AQP4 and AQP9 mRNA expression were unchanged under any of the hypertonic conditions examined. These findings indicated that osmotic stress up-regulates AQP3 gene expression in cultured keratinocytes.