María Teresa Miras Portugal: a pioneer for vesicular nucleotide storage.

Chromaffin granules are secretory granules present in adrenal medulla chromaffin cells. They contain high contents of catecholamines and nucleotides and have been regarded as a model system for the study of vesicular transmitter uptake and release. In 1988, Dr. María Teresa Miras Portugal, when studying catecholamine biosynthesis, detected a novel group of nucleotides, the diadenosine polyphosphates, in the adrenal chromaffin granules. Based on this finding, she unraveled the existence of diadenosine polyphosphate-mediated chemical transmission, leading to a paradigm shift in the field of purinergic signaling. She is also a pioneer in the studies on vesicular nucleotide storage. First, María Teresa and her group characterized nucleotide transport in chromaffin granules and synaptic vesicles using fluorescent nucleotide derivatives such as 1, N6-ethenoadenosine triphosphates. Then, they revealed the presence of a hypothetical vesicular nucleotide transporter with unique properties in terms of substrate specificity. In this article, we will describe her contributions to vesicular nucleotide storage and the foundations she laid for future studies.

Quinacrine is not a vital fluorescent probe for vesicular ATP storage.

Quinacrine, a fluorescent amphipathic amine, has been used as a vital fluorescent probe to visualize vesicular storage of ATP in the field of purinergic signaling. However, the mechanism(s) by which quinacrine represents vesicular ATP storage remains to be clarified. The present study investigated the validity of the use of quinacrine as a vial fluorescent probe for ATP-storing organelles. Vesicular nucleotide transporter (VNUT), an essential component for vesicular storage and ATP release, is present in very low density lipoprotein (VLDL)-containing secretory vesicles in hepatocytes. VNUT gene knockout (Vnut-/-) or clodronate treatment, a VNUT inhibitor, disappeared vesicular ATP release (Tatsushima et al., Biochim Biophys Acta Molecular Basis of Disease 2021, e166013). Upon incubation of mice's primary hepatocytes, quinacrine accumulates in a granular pattern into the cytoplasm, sensitive to 0.1-µM bafilomycin A1, a vacuolar ATPase (V-ATPase) inhibitor. Neither Vnut-/- nor treatment of clodronate affected quinacrine granular accumulation. In vitro, quinacrine is accumulated into liposomes upon imposing inside acidic transmembranous pH gradient (∆pH) irrespective of the presence or absence of ATP. Neither ATP binding on VNUT nor VNUT-mediated uptake of ATP was affected by quinacrine. Consistently, VNUT-mediated uptake of quinacrine was negligible or under the detection limit. From these results, it is concluded that vesicular quinacrine accumulation is not due to a consequence of its interaction with ATP but due to ∆pH-driven concentration across the membranes as an amphipathic amine. Thus, quinacrine is not a vital fluorescent probe for vesicular ATP storage.

Achievement of live birth after overcoming two gynecological malignancies treated with radical trachelectomy and medroxyprogesterone acetate therapy.

Cervical cancer is a human papilloma virus-related disease, whereas endometrial cancer and atypical endometrial hyperplasia (AEH) are hormone-related diseases, so co-occurrence of the two is possible. However, scientific studies about such cases are rare. We encountered a case of cervical adenocarcinoma and AEH in a 33-year-old nulliparous woman. Two fertility-sparing treatments were performed, a radical trachelectomy for the cervical cancer and high-dose medroxyprogesterone acetate treatment for the AEH. After remission of the diseases, the patient became pregnant by in vitro fertilization and delivered a baby at 36 weeks' gestation by cesarean section. Although the patient had two uterine malignancies, proper evaluation of the diseases, consultation with the patient and her husband, and appropriate management led to fertility preservation, and live birth was achieved.

Dynamin-related protein 1 deficiency accelerates lipopolysaccharide-induced acute liver injury and inflammation in mice.

Mitochondrial fusion and fission, which are strongly related to normal mitochondrial function, are referred to as mitochondrial dynamics. Mitochondrial fusion defects in the liver cause a non-alcoholic steatohepatitis-like phenotype and liver cancer. However, whether mitochondrial fission defect directly impair liver function and stimulate liver disease progression, too, is unclear. Dynamin-related protein 1 (DRP1) is a key factor controlling mitochondrial fission. We hypothesized that DRP1 defects are a causal factor directly involved in liver disease development and stimulate liver disease progression. Drp1 defects directly promoted endoplasmic reticulum (ER) stress, hepatocyte death, and subsequently induced infiltration of inflammatory macrophages. Drp1 deletion increased the expression of numerous genes involved in the immune response and DNA damage in Drp1LiKO mouse primary hepatocytes. We administered lipopolysaccharide (LPS) to liver-specific Drp1-knockout (Drp1LiKO) mice and observed an increased inflammatory cytokine expression in the liver and serum caused by exaggerated ER stress and enhanced inflammasome activation. This study indicates that Drp1 defect-induced mitochondrial dynamics dysfunction directly regulates the fate and function of hepatocytes and enhances LPS-induced acute liver injury in vivo.

Impact of maternal hypertensive disorders of pregnancy on brain volumes at term-equivalent age in preterm infants: A voxel-based morphometry study.

OBJECTIVES: Infants born to mothers with hypertensive disorders of pregnancy (HDP) reportedly have negative behavioral and neurodevelopmental outcomes. However, the effects of maternal HDP on infant brain growth have not been fully evaluated. We aimed to evaluate brain volumes and brain injury in preterm infants born to mothers with HDP using magnetic resonance (MR) imaging at term-equivalent age. STUDY DESIGN: In this cohort study, MR imaging was performed for 94 preterm infants born before 34 weeks of gestation at Nagoya University Hospital between 2010 and 2018. Twenty infants were born to mothers with HDP and 74 to mothers without HDP. MAIN OUTCOME MEASURES: Total brain volumes and regional volumetric alterations were assessed by voxel-based morphometry, and brain injury was evaluated using the Kidokoro global brain abnormality score. Developmental quotient was assessed at a corrected age of 1.5 years in 59 infants (HDP, n = 11; non-HDP, n = 48). RESULTS: No significant differences were observed in the gray and white matter volumes of the two groups (HDP: 175 ± 24 mL, 137 ± 13 mL, respectively; non-HDP: 172 ± 24 mL, 142 ± 13 mL, respectively). Additionally, no regional volumetric alterations were observed between the two groups after covariate adjustment (gestational age and infant sex). The total Kidokoro score and developmental quotient were similar in both groups. CONCLUSIONS: No significant differences in the global and regional brain volumes were observed. Further research is needed to confirm our findings at different time points of MR imaging and in different populations.

Clodronate, an inhibitor of the vesicular nucleotide transporter, ameliorates steatohepatitis and acute liver injury.

The vesicular nucleotide transporter (VNUT) is responsible for the vesicular storage and release of ATP from various ATP-secreting cells, and it plays an essential role in purinergic signaling. Although extracellular ATP and its degradation products are known to mediate various inflammatory responses via purinoceptors, whether vesicular ATP release affects steatohepatitis and acute liver injury is far less understood. In the present study, we investigated the effects of clodronate, a potent and selective VNUT inhibitor, on acute and chronic liver inflammation in mice. In a model of methionine/choline-deficient diet-induced non-alcoholic steatohepatitis (NASH), the administration of clodronate reduced hepatic inflammation, fibrosis, and triglyceride accumulation. Clodronate also protected mice against high-fat/high-cholesterol diet-induced steatohepatitis. Moreover, prophylactic administration of clodronate prevented D-galactosamine and lipopolysaccharide-induced acute liver injury by reducing inflammatory cytokines and hepatocellular apoptosis. In vitro, clodronate inhibited glucose-induced vesicular ATP release mediated by VNUT and reduced the intracellular level and secretion of triglycerides in isolated hepatocytes. These results suggest that VNUT-dependent vesicular ATP release plays a crucial role in the recruitment of immune cells, cytokine production, and the aggravation of steatosis in the liver. Pharmacological inhibition of VNUT may provide therapeutic benefits in liver inflammatory disorders, including NASH and acute toxin-induced injury.

Reduced response to controlled ovarian stimulation after radical trachelectomy: A pitfall of fertility-sparing surgery for cervical cancer.

OBJECTIVE: To clarify the decrease in response to controlled ovarian stimulation in patients who receive in vitro fertilization treatment after radical trachelectomy. METHODS: The outcomes of ovarian stimulation were retrospectively evaluated and compared between patients who have undergone radical trachelectomy and control patients who had male factor infertility or unexplained infertility. RESULTS: A total of 30 ovarian stimulation cycles in 14 radical trachelectomy patients and 54 cycles in 30 control patients were reviewed. The median age at ovarian stimulation was 34.8 years in the radical trachelectomy group and 36.5 years in the control group. Compared with the control group, the radical trachelectomy group had significantly lower mean estradiol concentration (1461.7 pg/ml, SD 775.0 vs. 1950.9 pg/ml, SD 1057.3, P = 0.029) during controlled ovarian stimulation cycle and smaller median number of retrieved oocytes (5, range 1-14 vs. 8, range 1-19, P = 0.007), despite the higher use of gonadotropin (3527.5 IU, SD 1313.4 vs. 2670.8 IU, SD 905.1, P = 0.001). CONCLUSION: The response to controlled ovarian stimulation decreased after radical trachelectomy.

Mortality and neurological outcomes in extremely and very preterm infants born to mothers with hypertensive disorders of pregnancy.

To evaluate the impact of maternal hypertensive disorders of pregnancy (HDP) on mortality and neurological outcomes in extremely and very preterm infants using a nationwide neonatal database in Japan. This population-based retrospective study was based on an analysis of data collected by the Neonatal Research Network of Japan from 2003 to 2015 of neonates weighing 1,500 g or less at birth, between 22 and 31 weeks' gestation. A total of 21,659 infants were randomly divided into two groups, HDP (n = 4,584) and non-HDP (n = 4,584), at a ratio of 1:1 after stratification by four factors including maternal age, parity, weeks of gestation, and year of delivery. Short-term (neonatal period) and medium-term (3 years of age) mortality and neurological outcomes were compared between the two groups by logistic regression analyses. In univariate analysis, HDP was associated with an increased risk for in-hospital death (crude odds ratio [OR], 1.31; 95% confidence interval, 1.04-1.63) and a decreased risk for severe intraventricular haemorrhage (0.68; 0.53-0.87) and periventricular leukomalacia (0.60; 0.48-0.77). In multivariate analysis, HDP was significantly associated with a lower risk for in-hospital death (adjusted OR, 0.61; 0.47-0.80), severe intraventricular haemorrhage (0.47; 0.35-0.63), periventricular leukomalacia (0.59; 0.45-0.78), neonatal seizures (0.40; 0.28-0.57) and cerebral palsy (0.70; 0.52-0.95) at 3 years after adjustment for covariates including birth weight. These results were consistent with those of additional analyses, which excluded cases with histological chorioamnionitis and which divided the infants into two subgroups (22-27 gestational weeks and 28-31 gestational weeks). Maternal HDP was associated with an increased risk for in-hospital death without adjusting for covariates, but it was also associated with a lower risk for mortality and adverse neurological outcomes in extremely and very preterm infants if all covariates except HDP were identical.

Vesicular ATP release from hepatocytes plays a role in the progression of nonalcoholic steatohepatitis.

Non-alcoholic steatohepatitis (NASH) is becoming a growing public health problem along with the increase of metabolic syndrome worldwide. Extracellular nucleotides are known to serve as a danger signal by initiating purinergic signaling in many inflammatory disorders, although the role of purinergic signaling in the progression of NASH remains to be clarified. Vesicular nucleotide transporter (VNUT) is a key molecule responsible for vesicular ATP release to initiate purinergic signaling. Here, we studied the role of VNUT in the progression of nonalcoholic steatohepatitis. VNUT was expressed in mouse hepatocytes and associated, at least in part, with apolipoprotein B (apoB)-containing vesicles. High glucose stimulation evoked release of appreciable amount of ATP from hepatocytes, which disappeared in hepatocytes of Vnut knockout (Vnut-/-) mice. Glucose treatment also stimulated triglyceride secretion from hepatocytes, which was inhibited by PPADS and MRS211, antagonists of P2Y receptors, and clodronate, a VNUT inhibitor, and was significantly reduced in Vnut-/- mice. In vivo, postprandial secretion of triglyceride from hepatocytes was observed, while the serum triglyceride level was significantly reduced in Vnut-/- mice. On a high-fat diet, the liver of wild type mice exhibited severe inflammation, fibrosis, and macrophage infiltration, which is similar to NASH in humans, while this NASH pathology was not observed in Vnut-/- mice. These results suggest that VNUT-mediated vesicular ATP release regulates triglyceride secretion and involves in chronic inflammation in hepatocytes. Since blockade of vesicular ATP release protects against progression of steatohepatitis, VNUT may be a pharmacological target for NASH.

Physiopathological roles of vesicular nucleotide transporter (VNUT), an essential component for vesicular ATP release.

Vesicular nucleotide transporter (VNUT) is the last identified member of the SLC17 organic anion transporter family, which plays a central role in vesicular storage in ATP-secreting cells. The discovery of VNUT demonstrated that, despite having been neglected for a long time, vesicular ATP release represents a major pathway for purinergic chemical transmission, which had been mainly attributed to ATP permeation channels. This article summarizes recent advances in our understanding of the mechanism of VNUT and its physiopathological roles as well as the development of inhibitors. Regulating the activity and/or the expression of VNUT represents a new and promising therapeutic strategy for the treatment of multiple diseases.

Antenatal Corticosteroids and Outcomes in Preterm Twins.

OBJECTIVE: To estimate whether improvement in outcomes from antenatal corticosteroid treatment in extremely and very preterm twins is similar to that observed in singletons, and to investigate whether antenatal corticosteroid treatment has different effects according to chorionicity or birth order. METHODS: This population-based study was based on an analysis of data collected by the Neonatal Research Network of Japan from 2003 to 2015 of neonates weighing 1,500 g or less at birth, from gestational ages of 24 0/7 to 31 6/7 weeks of gestation. After propensity score matching, univariate logistic and interaction analyses were performed to compare short-term (neonatal period) and medium-term (3 years of age) outcomes of the children of mothers who received antenatal corticosteroids with those of children of mothers who did not receive antenatal corticosteroids. We focused on differences between singletons and twins, between monochorionic and dichorionic twins and between the first and second twin. RESULTS: The study comprised 23,502 singletons and 6,546 twins. Antenatal corticosteroid treatment was associated with significant decreased short-term neurologic outcomes in both singletons and twins. However, antenatal corticosteroid treatment was associated with significantly decreased mortality (odds ratio [OR] 0.61; 95% CI 0.53-0.70), respiratory distress syndrome (OR 0.71, 95% CI 0.67-0.76), and cerebral palsy (OR 0.85, 95% CI 0.72-0.99) in singletons but not in twins (OR 0.89, 95% CI 0.68-1.17; OR 0.99, 95% CI 0.87-1.12; and OR 0.82, 95% CI 0.61-1.11, respectively). No association was found between chorionicity and the efficacy of antenatal corticosteroid treatment on outcomes. Further, no association was found between birth order and the efficacy of antenatal corticosteroid treatment on outcomes, except for periventricular leukomalacia and necrotizing enterocolitis (interaction: P=.02 and P=.04, respectively). CONCLUSION: Antenatal corticosteroid treatment in twins was associated with a beneficial effect on short-term neurologic outcomes only, without improvement in other short-term and medium-term outcomes. There was no difference related to chorionicity.

Outcome of cesarean scar pregnancy treated with local methotrexate injection.

Local injection of methotrexate (MTX) has been widely used for caesarean scar pregnancy (CSP), but the optimal candidate remains undetermined. The aim of this study is to determine the risk factors associated with treatment failure among patients who received a single dose of local MTX. This is a retrospective cohort study. Clinical information was compared between treatment success vs. failure groups. Risk factors related to treatment failure were also investigated with multivariate analysis. Of 47 patients diagnosed with CSP, 30 received local MTX injection. The initial serum ß- human chorionic gonadotropin (hCG) level in the failure group was significantly higher than in the success group (p = 0.048), and the cut-off value was 47,000 mIU/ml. The rate of type 2 position of the gestational sac in the failure group was significantly higher than in the treatment success group (p = 0.031). A high initial serum ß-hCG level (≥ 47,000 mIU/ml) was identified as the independent risk factor for treatment failure (adjusted odds ratio = 21.9; 95% confidence interval = 1.3-383.1). Type 2 gestational sac position and a higher level of ß-hCG at diagnosis appear to be associated with poor outcomes after local injection of a single dose of MTX.

Ovarian cancer-associated mesothelial cells induce acquired platinum-resistance in peritoneal metastasis via the FN1/Akt signaling pathway.

Peritoneal dissemination of ovarian cancer (OvCa) arises from the surface of the peritoneum, covered by monolayer of mesothelial cells (MCs). Given that both OvCa cells and MCs are present in the same peritoneal metastatic microenvironment, they may establish cell-to-cell crosstalk or phenotypic alterations including the acquisition of platinum-resistance in OvCa cells. Herein, we report how OvCa-associated mesothelial cells (OCAMs) induce platinum-resistance in OvCa cells through direct cell-to-cell crosstalk. We evaluated mutual associations between OvCa cells and human primary MCs with in vitro coculturing experimental models and in silico omics data analysis. The role of OCAMs was also investigated using clinical samples and in vivo mice models. Results of in vitro experiments show that mesenchymal transition is induced in OCAMs primarily by TGF-ß1 stimulation. Furthermore, OCAMs influence the behavior of OvCa cells as a component of the tumor microenvironment of peritoneal metastasis. Mechanistically, OCAMs can induce decreased platinum-sensitivity in OvCa cells via induction of the FN1/Akt signaling pathway via cell-to-cell interactions. Histological analysis of OvCa peritoneal metastasis also illustrated FN1 expression in stromal cells that are supposed to originate from MCs. Further, we also confirmed the activation of Akt signaling in OvCa cells in contact with TGF-ß1 stimulated peritoneum, using an in vivo mice model. Our results suggest that the tumor microenvironment, enhanced by direct cell-to-cell crosstalk between OvCa cells and OCAMs, induces acquisition of platinum-resistance in OvCa cells, which may serve as a novel therapeutic target for prevention of OvCa peritoneal dissemination.

Adverse effects of endometriosis on pregnancy: a case-control study.

BACKGROUND: Endometriosis is a common disease occurring in 1-2% of all women of reproductive age. Although there is increasing evidence on the association between endometriosis and adverse perinatal outcomes, little is known about the effect of pre-pregnancy treatments for endometriosis on subsequent perinatal outcomes. Thus, this study aimed to evaluate maternal and neonatal outcomes in pregnant women with endometriosis and to investigate whether pre-pregnancy surgical treatment would affect these outcomes. METHODS: This case-control study included 2769 patients who gave birth at Nagoya University Hospital located in Japan between 2010 and 2017. Maternal and neonatal outcomes were compared between the endometriosis group (n = 80) and the control group (n = 2689). The endometriosis group was further divided into two groups: patients with a history of surgical treatment such as cystectomy for ovarian endometriosis, ablation or excision of endometriotic implants, or adhesiolysis (surgical treatment group, n = 49) and those treated with only medications or without any treatment (non-surgical treatment group, n = 31). RESULTS: In the univariate analysis, placenta previa and postpartum hemorrhage were significantly increased in the endometriosis group compared to the control group (12.5% vs. 4.1%, p <  0.01 and 27.5% vs. 18.2%, p = 0.04, respectively). In the multivariate analysis, endometriosis significantly increased the odds ratio (OR) for placenta previa (adjusted OR, 3.19; 95% confidence interval [CI], 1.56-6.50, p <  0.01) but not for postpartum hemorrhage (adjusted OR, 1.14; 95% CI, 0.66-1.98, p = 0.64). Other maternal and neonatal outcomes were similar between the two groups. In patients with endometriosis, patients in the surgical treatment group were significantly associated with an increased risk of placenta previa (OR. 4.62; 95% CI, 2.11-10.10, p <  0.01); however, patients in the non-surgical treatment group were not associated with a high risk (OR, 1.63; 95% CI, 0.19-6.59, p = 0.36). Additionally, other maternal and neonatal outcomes were similar between the two groups. CONCLUSION: Women who have had surgical treatment for their endometriosis appear to have a higher risk for placenta previa. This may be due to the more severe stage of endometriosis often found in these patients. However, clinicians should be alert to this potential increased risk and manage these patients accordingly.

Relationship between preexisting mental disorders and prognosis of gynecologic cancers: A case-control study.

AIM: Cancer treatment involves long-term therapy and follow-up, with mental disorders (MD) often affecting the treatment process. Hence, in this study, we retrospectively analyze cases involving gynecologic cancer with MD and clarify the relationship between psychosis and cancer prognosis. METHODS: Patients with both gynecologic cancer and MD from January 2003 to August 2016 were recruited in this study. Cases were limited to those whose MD had been diagnosed before their cancer. Control patients without MD were also analyzed. Both cases and controls were adjusted for age, cancer type, and cancer stage. RESULTS: A total of 54 patients with gynecologic cancer and MD, as well as 108 controls without MD, were included. The median age of the patients was 52 years. Details regarding cancer type were as follows: 11 ovarian cancers, 26 uterine corpus cancers and 17 cervical cancers. Among these, 25 schizophrenia cases, 15 depressive disorders, 4 bipolar disorders and 10 other MD were recorded. No significant differences in the 5-year survival rate were found between patients and controls. In advanced-stage cervical cancer, however, the prognosis was significantly poor given the low rate of initial treatment completion. Moreover, patients with advanced-stage cervical cancer had significantly lower chemotherapy completion rates compared to those with other gynecologic malignancies. CONCLUSION: Mental disorders do not affect the prognosis of gynecologic cancers, except for advanced cervical cancer. Accordingly, improving the low rate of initial treatment completion seems to be a focal point for better prognosis in advanced cervical cancer.

A pitfall in diagnosing fetal abdominal lymphangioma: A report of two cases.

Typical ultrasound findings of fetal abdominal lymphangioma include thick-walled, multiseptated anechoic masses. Although a majority of cases can be suspected promptly by ultrasound examination, the two cases presented herein did not meet the standard criteria and were misleading. Both cases involved unilocular cysts without clear septations, but in retrospect were atypical findings of fetal abdominal lymphangioma. A few reports of misleading cases have been described previously; however, the precise characteristics have not been reported in detail. Therefore, in this case report, we focused predominantly upon the difficulties encountered in the prenatal diagnosis of abdominal lymphangioma based on ultrasound morphology alone.

Structures suggest a mechanism for energy coupling by a family of organic anion transporters.

Members of the solute carrier 17 (SLC17) family use divergent mechanisms to concentrate organic anions. Membrane potential drives uptake of the principal excitatory neurotransmitter glutamate into synaptic vesicles, whereas closely related proteins use proton cotransport to drive efflux from the lysosome. To delineate the divergent features of ionic coupling by the SLC17 family, we determined the structure of Escherichia coli D-galactonate/H+ symporter D-galactonate transporter (DgoT) in 2 states: one open to the cytoplasmic side and the other open to the periplasmic side with substrate bound. The structures suggest a mechanism that couples H+ flux to substrate recognition. A transition in the role of H+ from flux coupling to allostery may confer regulation by trafficking to and from the plasma membrane.

Possible Association between Cathepsin V and the Development of Placenta Accreta Spectrum Disorders.

BACKGROUND/AIMS: The study aimed to evaluate molecular changes related to trophoblast adhesion in placenta accreta spectrum (PAS) disorders. METHODS: A retrospective analysis of 10 PAS cases in which both the trophoblast adherent site and the non-adherent site were identified was performed in April 2010 and March 2013. Microarray analysis and reverse transcription polymerase chain reaction (RT-PCR) analyses were performed to extract upregulated genes in the adherent site. Gene expression changes were examined by immunohistochemistry. RESULTS: Microarray analysis showed that 157 transcripts were > 3-fold upregulated, including the following: a disintegrin and metalloproteinase-28 (ADAM28), 3.10-fold; cathepsin V (CTSV), 3.73-fold; cathepsin S (CTSS), 3.46-fold; and matrix metalloproteinase-19 (MMP19), 3.41-fold. RT-PCR showed relatively high mRNA expressions. On immunohistochemistry, extravillous trophoblast (EVT) at the non-adherent site showed weak or no CTSV expression, whereas EVT that invaded myometrium at the adherent site showed strong expression (histological score, median [min-max], 115.6 [37.6-153.6] vs. 184.8 [56.4-222.8], p < 0.05). MMP19 showed moderate staining, with no difference between the adherent and non-adherent sites. ADAM28 and CTSS showed weak or no staining. DISCUSSION: This limited study suggests that CTSV may be involved in the pathogenesis of PAS.

Involvement of VNUT-exocytosis in transient receptor potential vanilloid 4-dependent ATP release from gastrointestinal epithelium.

Adenosine triphosphate (ATP) modulates mechanosensitive vagal afferent nerves in the gastrointestinal tract. ATP is stored in secretory vesicles via the ATP transporter VNUT. Recently, the bisphosphate clodronate was reported to inhibit VNUT and was suggested to be a safe potent therapeutic option for chronic pain. Transient receptor potential vanilloid 4 (TRPV4) is activated by mechanical stimuli and some epoxyeicosatrienoic acids and becomes sensitized under inflammatory conditions. We have previously reported that TRPV4 and VNUT are expressed in mouse esophageal keratinocytes and that TRPV4 activation induces ATP release in gastric epithelial cells. Here we show the expression of TRPV4 and VNUT in normal human gastrointestinal cell derived cell lines (GES-1 and CCD 841) and in tissues from normal and VNUT-KO mice. TRPV4 agonists (GSK101 or 8,9-EET) induced an increase in cytosolic Ca2+ and/or current responses in mouse primary colonic epithelial cells and CCD 841 cells, but not in cells isolated from TRPV4-KO mice. TRPV4 agonists (GSK101 or 5.6-EET) also induced ATP release in GES-1 and CCD 841 cells, which could be blocked by the VNUT inhibitor, clodronate. Thus, VNUT inhibition with clodronate could represent a novel therapeutic option for visceral pain.