TRPM5-mediated calcium uptake regulates mucin secretion from human colon goblet cells

Mucin 5AC (MUC5AC) is secreted by goblet cells of the respiratory tract and, surprisingly, also expressed de novo in mucus secreting cancer lines. siRNA-mediated knockdown of 7343 human gene products in a human colonic cancer goblet cell line (HT29-18N2) revealed new proteins, including a Ca(2+)-activated channel TRPM5, for MUC5AC secretion. TRPM5 was required for PMA and ATP-induced secretion of MUC5AC from the post-Golgi secretory granules. Stable knockdown of TRPM5 reduced a TRPM5-like current and ATP-mediated Ca(2+) signal. ATP-induced MUC5AC secretion depended strongly on Ca(2+) influx, which was markedly reduced in TRPM5 knockdown cells. The difference in ATP-induced Ca(2+) entry between control and TRPM5 knockdown cells was abrogated in the absence of extracellular Ca(2+) and by inhibition of the Na(+)/Ca(2+) exchanger (NCX). Accordingly, MUC5AC secretion was reduced by inhibition of NCX. Thus TRPM5 activation by ATP couples TRPM5-mediated Na(+) entry to promote Ca(2+) uptake via an NCX to trigger MUC5AC secretion

Role of P-glycoprotein in the uptake/efflux transport of oral vitamin K antagonists and rivaroxaban through the Caco-2 cell model.

Vitamin K antagonists (VKAs) are prescribed worldwide and remain the oral anticoagulant of choice. These drugs are characterized by a narrow therapeutic index and a large inter- and intra-individual variability. P-glycoprotein could contribute to this variability. The aim of this study was to investigate the involvement of P-gp in the transport of acenocoumarol, phenprocoumon and warfarin using an in vitro Caco-2 cell monolayer model. These results were compared with those obtained with rivaroxaban, a new oral anticoagulant known to be a P-gp substrate. The transport of these four drugs was assessed at pH conditions 6.8/7.4 in the presence or absence of the P-gp inhibitor cyclosporine A (10 μM) and the more potent and specific P-gp inhibitor valspodar (5 μM). Analytical quantification was performed by LC/MS. With an efflux ratio of 1.7 and a significant decrease in the efflux (Papp B-A), in the presence of P-gp inhibitors at a concentration of 50 μM, acenocoumarol can be considered as a weak P-gp substrate. Concerning phenprocoumon, the results suggest that this molecule is a poor P-gp substrate. The P-gp inhibitors did not affect significantly the transport of warfarin. The efflux of rivaroxaban was strongly inhibited by the two P-gp inhibitors. In conclusion, none of the three VKAs tested are strong P-gp substrates. However, acenocoumarol can be considered as a weak P-gp substrate and phenprocoumon as a poor P-gp substrate.

Photodynamic therapy selectively enhances liposomal doxorubicin uptake in sarcoma tumors to rodent lungs.

BACKGROUND: In specific conditions, photodynamic therapy (PDT) can enhance the distribution of macromolecules across the endothelial barrier in solid tumors. It was recently postulated that tumor neovessels were more responsive to PDT than the normal vasculature. We hypothesized that Visudyne(R)-mediated PDT could selectively increase liposomal doxorubicin (Liporubicin) uptake in sarcoma tumors to rodent lungs while sparing the normal surrounding tissue. MATERIALS AND METHODS: Sarcoma tumors were generated subpleurally in the left lower lung lobe of 66 Fischer rats. Ten days following sarcoma implantation, tumors underwent different pre-treatment schemes: no PDT (controls), low-dose PDT (0.0625 mg/kg Visudyne(R), 10 J/cm(2) and 35 mW/cm(2)) and high-dose PDT (0.125 mg/kg Visudyne(R), 10 J/cm(2) and 35 mW/cm(2)). Liporubicin was then administered and allowed to circulate for 1, 3, or 6 hours. At the end of each treatment scheme, we assessed the uptake of Liporubicin in tumor and lung tissues by high-performance liquid chromatography and fluorescence microscopy. RESULTS: In all PDT-treated groups, there was a significant enhancement of Liporubicin uptake in tumors compared to controls after 3 and 6 hours of drug circulation. In addition, Liporubicin distribution within the normal lung tissue was not affected by PDT. Thus, PDT pre-treatment significantly enhanced the ratio of tumor-to-lung drug uptake compared to controls. Finally, fluorescence microscopy revealed a well-detectable Liporubicin signaling throughout PDT-treated tumors but not in controls. CONCLUSIONS: PDT is a tumor-specific enhancer of Liporubicin distribution in sarcoma lung tumors which may find a translation in clinics.

Tumor-necrosis factor can enhance radio-antibody uptake in human colon carcinoma xenografts by increasing vascular permeability.

Marked differences in the tumor uptake of a 125I-labeled monoclonal antibody (MAb) directed against carcinoembryonic antigen (CEA) were observed in 4 serially transplanted human colorectal carcinomas in nude mice. A comparative study showed that elevated values of measurable tumor vascular parameters, such as permeability, blood flow and blood volume, correlated better with high MAb tumor uptake than the concentration of target antigen in the tumor. In an attempt to modify the vascular parameters and to determine if this could increase antibody uptake by the tumor, rhTNF alpha (TNF) was injected i.t. or i.v. and antibody localization experiments were performed immediately thereafter. Results showed that the permeability of the tumor vessels increased 8 to 10 fold 1 hr after i.t. injection of TNF as compared to control tumors injected with saline. Tumor uptake of 125I-labeled anti-CEA MAb, was 3 times higher 2 hr after i.v. injection and still 27% higher 22 hr later, as compared to results from controls. Intravenous injection of TNF simultaneously with the 125I-labeled anti-CEA MAb also resulted in a 2-fold increase in tumor uptake 4 hr after injection, but the increase was no longer significant 24 hr after injection. Interestingly after i.v. injection of TNF, the MAb concentration in the blood and other normal tissues, such as liver, kidneys, lungs and heart was decreased, resulting in significantly higher ratios of tumor to normal tissue. Taken together the results demonstrate that injection of TNF can increase tumor vascular permeability and improve radio-antibody uptake. This raises the possibility of increasing the radiation dose delivered by antibody to the tumor in the course of radioimmunotherapy.

Effect of water velocity on the uptake of polychlorinatedd biphenyls (PCBs) by silicone rubber (SR) and low-density polyethylene (LDPE) passive samplers: an assessment of the efficiency of performance reference compounds (PRCs) in river-like flow conditions

One aim of this study is to determine the impact of water velocity on the uptake of indicator polychlorinated biphenyls (iPCBs) by silicone rubber (SR) and low-density polyethylene (LDPE) passive samplers. A second aim is to assess the efficiency of performance reference compounds (PRCs) to correct for the impact of water velocity. SR and LDPE samplers were spiked with 11 or 12 PRCs and exposed for 6 weeks to four different velocities (in the range of 1.6 to 37.7 cm s−1) in river-like flow conditions using a channel system supplied with river water. A relationship between velocity and the uptakewas found for each iPCB and enables to determine expected changes in the uptake due to velocity variations. For both samplers, velocity increases from 2 to 10 cm s−1, 30 cm s−1 (interpolated data) and 100 cm s−1 (extrapolated data) lead to increases of the uptake which do not exceed a factor of 2, 3 and 4.5, respectively. Results also showed that the influence of velocity decreased with increasing the octanol-water coefficient partition (log Kow) of iPCBs when SR is used whereas the opposite effect was observed for LDPE. Time-weighted average (TWA) concentrations of iPCBs in water were calculated from iPCB uptake and PRC release. These calculations were performed using either a single PRC or all the PRCs. The efficiency of PRCs to correct the impact of velocity was assessed by comparing the TWA concentrations obtained at the four tested velocities. For SR, a good agreement was found among the four TWA concentrations with both methods (average RSD b 10%). Also for LDPE, PRCs offered a good correction of the impact of water velocity (average RSD of about 10 to 20%). These results contribute to the process of acceptance of passive sampling in routine regulatory monitoring programs.

Incident Hepatitis C Virus Infections in the Swiss HIV Cohort Study : changes in treatment uptake and outcomes between 1991 and 2013

Background: The hepatitis C virus (HCV) epidemic is evolving rapidly in patients infected with human immunodeficiency virus (HIV). We aimed to describe changes in treatment uptake and outcomes of incident HCV infections before and after 2006, the time-point at which major changes in HCV epidemic became apparent. Methods.  We included all adults with an incident HCV infection before June 2012 in the Swiss HIV Cohort Study, a prospective nationwide representative cohort of individuals infected with HIV. We assessed the following outcomes by time period: the proportion of patients starting an HCV therapy, the proportion of treated patients achieving a sustained virological response (SVR), and the proportion of patients with persistent HCV infection during follow-up. Results.  Of 193 patients with an HCV seroconversion, 106 were diagnosed before and 87 after January 2006. The proportion of men who have sex with men increased from 24% before to 85% after 2006 (P < .001). Hepatitis C virus treatment uptake increased from 33% before 2006 to 77% after 2006 (P < .001). Treatment was started during early infection in 22% of patients before and 91% after 2006 (P < .001). An SVR was achieved in 78% and 29% (P = .01) of patients treated during early and chronic HCV infection. The probability of having a detectable viral load 5 years after diagnosis was 0.67 (95% confidence interval [CI], 0.58-0.77) in the group diagnosed before 2006 and 0.24 (95% CI, 0.16-0.35) in the other group (P < .001). Conclusions. In recent years, increased uptake and earlier initiation of HCV therapy among patients with incident infections significantly reduced the proportion of patients with replicating HCV.

Water uptake by Annona diversifolia Saff. and A. purpurea Moc. & sessé ex dunal seeds (Annonaceae)

Annonaceae seeds are known by presenting dormancy mechanisms, whose reports ranging from coating impermeable to the physiological dormancy. By this way, the present study aimed to evaluate water uptake in Annona diversifolia Saff and Annona purpurea Moc & Sessé ex Dunal seeds. For this study, seeds were placed under immersion in distilled water, and used four replicates of 25 seeds of each species, which were weighed during the 480 hours that were immersed. To determine the place of purchase of water, Annona diversifolia seeds were sealed with paraffin at different locations. Based on the results, seeds from both species reached the phases I and II of water uptake, which indicates they are not hard; however, germination (Phase III) was not reached. Annona diversifolia seeds completed Phase I with, 50h and Annona purpurea with 70h from imbibitions begin, which shows that even slowly, water is acquire.

High hepatic and extrahepatic mortality and low treatment uptake in HCV-coinfected persons in the Swiss HIV cohort study between 2001 and 2013.

BACKGROUND & AIMS: The landscape of HCV treatments is changing dramatically. At the beginning of this new era, we highlight the challenges for HCV therapy by assessing the long-term epidemiological trends in treatment uptake, efficacy and mortality among HIV/HCV-coinfected people since the availability of HCV therapy. METHODS: We included all SHCS participants with detectable HCV RNA between 2001 and 2013. To identify predictors for treatment uptake uni- and multivariable Poisson regression models were applied. We further used survival analyses with Kaplan-Meier curves and Cox regression with drop-out as competing risk. RESULTS: Of 12,401 participants 2107 (17%) were HCV RNA positive. Of those, 636 (30%) started treatment with an incidence of 5.8/100 person years (PY) (95% CI 5.3-6.2). Sustained virological response (SVR) with pegylated interferon/ribavirin was achieved in 50% of treated patients, representing 15% of all participants with replicating HCV-infection. 344 of 2107 (16%) HCV RNA positive persons died, 59% from extrahepatic causes. Mortality/100 PY was 2.9 (95% CI 2.6-3.2) in untreated patients, 1.3 (1.0-1.8) in those treated with failure, and 0.6 (0.4-1.0) in patients with SVR. In 2013, 869/2107 (41%) participants remained HCV RNA positive. CONCLUSIONS: Over the last 13years HCV treatment uptake was low and by the end of 2013, a large number of persons remain to be treated. Mortality was high, particularly in untreated patients, and mainly due to non-liver-related causes. Accordingly, in HIV/HCV-coinfected patients, integrative care including the diagnosis and therapy of somatic and psychiatric disorders is important to achieve mortality rates similar to HIV-monoinfected patients.

Protease inhibitors to treat hepatitis C in the Swiss HIV Cohort Study: high efficacy but low treatment uptake.

OBJECTIVES: Direct-acting antiviral agents (DAAs) have become the standard of care for the treatment of chronic hepatitis C virus (HCV) infection. We aimed to assess treatment uptake and efficacy in routine clinical settings among HIV/HCV coinfected patients after the introduction of the first generation DAAs. METHODS: Data on all Swiss HIV Cohort Study (SHCS) participants starting HCV protease inhibitor (PI) treatment between September 2011 and August 2013 were collected prospectively. The uptake and efficacy of HCV therapy were compared with those in the time period before the availability of PIs. RESULTS: Upon approval of PI treatment in Switzerland in September 2011, 516 SHCS participants had chronic HCV genotype 1 infection. Of these, 57 (11%) started HCV treatment during the following 2 years with either telaprevir, faldaprevir or boceprevir. Twenty-seven (47%) patients were treatment-naïve, nine (16%) were patients with relapse and 21 (37%) were partial or null responders. Twenty-nine (57%) had advanced fibrosis and 15 (29%) had cirrhosis. End-of-treatment virological response was 84% in treatment-naïve patients, 88% in patients with relapse and 62% in previous nonresponders. Sustained virological response was 78%, 86% and 40% in treatment-naïve patients, patients with relapse and nonresponders, respectively. Treatment uptake was similar before (3.8 per 100 patient-years) and after (6.1 per 100 patient-years) the introduction of PIs, while treatment efficacy increased considerably after the introduction of PIs. CONCLUSIONS: The introduction of PI-based HCV treatment in HIV/HCV-coinfected patients improved virological response rates, while treatment uptake remained low. Therefore, the introduction of PIs into the clinical routine was beneficial at the individual level, but had only a modest effect on the burden of HCV infection at the population level.

Cadmium uptake and induction of metallothionein synthesis in a renal epithelial cell line (LLC-PK1).

LLC-PK1 cells, an established cell line from pig kidney with proximal tubule properties, were cultivated in vitro at confluence on plastic dishes. They were then exposed (apical side) to inorganic cadmium (CdCl2, 5 microM) for periods ranging between 1 to 24 h. Analysis of the cell supernatant after homogenisation and ultracentrifugation indicated that Cd taken up in the first 3 h was bound to cytosolic high molecular weight proteins, but was redistributed to low molecular weight proteins at later stages. Induction of Cd-metallothionein (Cd-Mt) synthesis, as judged from Cd-Mt binding to a specific anti-Cd-Mt antibody and from the rate of 35S-cys incorporation into a specific protein fraction, was apparent 3-6 h after the addition of Cd to the incubation medium.