Search

Bisphenol (BP) structural analogues of BPA are widely used. Previous studies showed similar effects of BPA and BPS on reproduction in several species including human. We hypothesised that the similar effects of several bisphenols (BPs) could accumulate in granulosa cells (GCs) and affects steroidogenesis. This study investigated the effects of seven BP analogues and their equimolar cocktail on human granulosa cells (hGC) and assessed BPA, BPS, BPF and BPAF level exposures in the follicular fluid of 277 women undergoing Assisted Reproductive Technology. The hGCs were recovered after women oocyte punctures and treated with the seven BP analogues (BPS, BPA, BPAF, BPF, BPAP, BPE and BPB) or their equimolar cocktail of 7 × 1.43 or 7 × 7.14 μM for each of the seven BPs, the sum of BPs reaching 10 ("∑BPs 10 μM"), or 50 μM ("∑BPs 50 μM"), respectively. Oestradiol and progesterone secretion, cell proliferation, viability and expression of steroidogenic enzymes were investigated. Progesterone secretion was decreased by 6 BPs 10 μM and the cocktail "∑BPs 10 μM", (-17.8 to -41.3%) and by all seven BPs 50 μM and "∑BPs 50 μM" (-21.8 to -84.2%). Oestradiol secretion was decreased only by 50 μM BPAF and BPAP (-37.8% and -44%, respectively), with corresponding decreases in CYP17A1 and CYP19A1 gene expression. Cellular proliferation was decreased after treatment with 50 μM BPAF (-32.2%), BPAP (-29%), BPB (-24%) and the equimolar cocktail "∑BPs 50 μM" (-33.1%). BPB (50 μM) and the cocktail "∑BPs 50 μM" increased HSD3B2 mRNA expression. At least one BP was detected in 64 of 277 (23.1%) women follicular fluids. Similar effects of the seven BPs or their cocktail were observed on progesterone secretion and/or on cell proliferation, suggesting cumulative effects of BPs. Our results highlight the urge to consider all BPs simultaneously and to further investigate the potential additive or synergistic effects of several BPs., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Background: Ovarian granulosa cells (GC) are essential for the development and maturation of a proper oocyte. GC are sensitive to endocrine disruptors, including bisphenol A (BPA) and its analogue bisphenol S (BPS), plasticisers present in everyday consumer products. BPA exhibits greater binding affinity for the membrane oestrogen receptor (GPER) than for the nuclear oestrogen receptors (ERα and ERβ). Here, we analysed the effects of BPA and BPS on the steroidogenesis of ovine GC in vitro, as well as their early mechanisms of action, the ovine being a relevant model to study human reproductive impairment. Disruption of GC steroidogenesis might alter oocyte quality and consequently fertility rate. In addition, we compared the effects of a specific GPER agonist (G-1) and antagonist (G-15) to those of BPA and BPS. Ewe GC were cultured with BPA or BPS (10 or 50 µM) or G-1 (1 µM) and/or G-15 (10 µM) for 48 h to study steroidogenesis., Results: Both BPA and BPS (10 µM) altered the secretion of progesterone, however, only BPS (10 µM) affected oestradiol secretion. RNA-seq was performed on GC after 1 h of culture with BPA or BPS (50 µM) or G-1 (10 µM), followed by real-time PCR analyses of differentially expressed genes after 12, 24 and 48 h of culture. The absence of induced GPER target genes showed that BPA and BPS did not activate GPER in GC after 1 h of treatment. These molecules exhibited mainly independent early mechanisms of action. Gene ontology analysis showed that after 1 h of treatment, BPA mainly disrupted the expression of the genes involved in metabolism and transcription, while BPS had a smaller effect and impaired cellular communications. BPA had a transient effect on the expression of CHAC1 (NOTCH signalling and oxidative balance), JUN (linked to MAPK pathway), NR4A1 (oestradiol secretion inhibition), ARRDC4 (endocytose of GPCR) and KLF10 (cell growth, differentiation and apoptosis), while expression changes were maintained over time for the genes LSMEM1 (linked to MAPK pathway), TXNIP (oxidative stress) and LIF (cell cycle regulation) after 12 and 48 h, respectively., Conclusion: In conclusion, although they exhibited similar effects, BPA and BPS impaired different molecular pathways in GC in vitro. New investigations will be necessary to follow the temporal changes of these genes over time, as well as the biological processes involved., (© 2023. The Author(s).)

Bisphenol S (BPS) affects terminal folliculogenesis by impairing steroidogenesis in granulosa cells from different species. Nevertheless, limited data are available on its effects during basal folliculogenesis. In this study, we evaluate in vitro the effects of a long-term BPS exposure on a model of basal follicular development in a mono-ovulatory species. We cultured ovine preantral follicles (180−240 μm, n = 168) with BPS (0.1 μM (possible human exposure dose) or 10 μM (high dose)) and monitored antrum appearance and follicular survival and growth for 15 days. We measured hormonal secretions (oestradiol (at day 13 [D13]), progesterone and anti-Müllerian hormone [D15]) and expression of key follicular development and redox status genes (D15) in medium and whole follicles, respectively. BPS (0.1 µM) decreased oestradiol secretion compared with the control (−48.8%, p < 0.001), without significantly impairing antrum appearance, follicular survival and growth, anti-Müllerian hormone and progesterone secretion and target gene expression. Thus, BPS could also impair oestradiol secretion during basal folliculogenesis as it is the case during terminal folliculogenesis. It questions the use of BPS as a safe BPA substitute in the human environment. More studies are required to elucidate mechanisms of action of BPS and its effects throughout basal follicular development.

Bisphenol A (BPA), a plasticizer and endocrine disruptor, has been substituted by bisphenol S (BPS), a structural analogue that had already shown adverse effects on granulosa cell steroidogenesis. The objective of this study was to assess the effect of chronic exposure to BPS, a possible endocrine disruptor, on steroid hormones in the ovary, oviduct and plasma using the ewe as a model. Given the interaction between steroidogenesis and the metabolic status, the BPS effect was tested according to two diet groups. Eighty adult ewes were allotted to restricted (R) and well-fed (WF) groups, that were further subdivided into two subgroups. Ewes were exposed to 50 µg BPS/kg/day in their diet (R50 and WF50 groups) or were unexposed controls (R0 and WF0 groups). After at least 3 months of BPS exposure, preovulatory follicular fluid, oviduct fluid and plasma were collected and steroid hormones were analyzed by gas chromatography coupled with tandem mass spectrometry (GC-MS/MS). A deleterious effect of restricted diet on the volume of oviduct fluid and numbers of pre-ovulatory follicles was observed. Exposure to BPS impaired estradiol concentrations in both follicular and oviduct fluids of well-fed ewes and progesterone, estradiol and estrone concentrations in plasma of restricted ewes. In addition, a significant interaction between metabolic status and BPS exposure was observed for seven steroids, including estradiol. In conclusion, BPS acts in ewes as an endocrine disruptor with differential actions according to metabolic status., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Téteau, Liere, Pianos, Desmarchais, Lasserre, Papillier, Vignault, Lebachelier de la Riviere, Maillard, Binet, Uzbekova, Saint-Dizier and Elis.)

Bisphenol A (BPA), an endocrine disruptor, has been replaced by structural analogues including bisphenol S (BPS). BPA and BPS exhibited similar effects regarding reproductive functions. Moreover, metabolic status and lipid metabolism are related to female fertility and could worsen BPS effects. The objective was to determine BPS in vivo effects on folliculogenesis and embryo production after chronic exposure through diet, and the influence of metabolic status in adult ewes. Sixty primiparous 2.5 year-old ewes, undergoing a restricted or well fed diet, were exposed to BPS (0, 4 or 50 µg/kg/day) for at least three months. After hormonal oestrus synchronisation and ovarian stimulation, ewes were subjected to ovum pick-up (OPU) procedures to collect immature oocytes, that underwent in vitro maturation, fertilisation and embryo production. Body weight, body condition score and plasma glucose were higher in well-fed compared to restricted ewes, while plasma NEFA was lower during the 4-5 months after the beginning of the diets. Plasma progesterone levels increased on day 5 before OPU session in well-fed compared to restricted ewes. No effect of BPS dose was observed on follicle population, plasma AMH levels and embryo production numbers and rates. However, a significant diet x BPS dose interaction was reported for cleaved embryos, > 4-cell embryos, blastocyst and early blastocyst numbers, and plasma triiodothyronine levels. Our study showed that a contrasted diet did not affect follicle population nor embryo production in adult ewes but could affect the quality and progesterone secretion of the corpus luteum. Chronic low BPS exposure had no effect on follicular population and oocyte competence. Nevertheless, the significant diet x dose interactions observed on embryo production suggest that BPS effect is modulated by metabolic status. Further studies are required to assess the risk of BPS exposure for public reproductive health., (Copyright © 2021. Published by Elsevier Inc.)

Objectives: The principal objective of our study was to document the short-term impact of the legalization of recreational cannabis on active cannabis use, cannabis use disorder, and various psychotic disorders., Methods: We carried out a retrospective observational study of patients who were at least 12 years old and who had visited a psychiatrist in the emergency unit of the Centre hospitalier universitaire de Sherbrooke (CHUS). We included all the consultations of this type over a 5-month period, immediately following the legalization of recreational cannabis in Canada. We then divided our population into an adult (over 18) and teenager group (12 to 17) compared the data to the data from consultations made 2 years earlier, using a generalized linear mixed model., Results: We examined consultations in patients over 18 years old in prelegalization ( n = 1,247) and postlegalization ( n = 1,368) groups. We observed a statistically significant increase in the use of cannabis (28.0% to 37.1%; odds ratio [ OR ] = 1.81 [1.34 to 2.44], P = 0.00011) as well as an increase in diagnoses of active cannabis use disorder (17.7% to 24.3%; OR = 1.53 [1.13 to 2.08], P = 0.0064). The increase in cannabis use disorder was more prominent among patients between 18 and 24 years old (17.3% to 25.9%; OR = 2.27 [1.17 to 4.40], P = 0.015). We observed no statistically significant difference in terms of psychotic disorder diagnoses (27.4% to 29.2%; OR = 1.17 [0.84 to 1.63], P = 0.35)]. Conversely, we identified a greater proportion of patients who had a personality disorder diagnosis in the postlegalization period (39.6% to 44.9%; OR = 1.35 [1.02 to 1.80], P = 0.038). Examination of pediatric (under 18 years old) consultations revealed no statistically significant differences., Conclusion: Although an affirmative conclusion is tentative, the current findings suggest a first link between the legalization of cannabis in Canada and increased diagnoses of cannabis use disorder, as well as cannabis use in general among patients in a university hospital psychiatric emergency department.

Study Question: Do plastic laboratory consumables and cell culture media used in ART contain bisphenols?, Summary Answer: The majority of human embryo culture media assessed contained bisphenol S close to the nanomolar concentration range, while no release of bisphenols by plastic consumables was detected under routine conditions., What Is Known Already: The deleterious effect of the endocrine disruptor bisphenol A (BPA) on female fertility raised concerns regarding ART outcome. BPA was detected neither in media nor in the majority of plastic consumables used in ART; however, it might have already been replaced by its structural analogs, including bisphenol S (BPS)., Study Design, Size, Duration: Seventeen plastic consumables and 18 cell culture and ART media were assessed for the presence of bisphenols., Participants/materials, Setting, Methods: Ten different bisphenols (bisphenol A, S, AF, AP, B, C, E, F, P and Z) were measured using an isotopic dilution according to an on-line solid phase extraction/liquid chromatography/mass spectrometry method., Main Results and the Role of Chance: While the plastic consumables did not release bisphenols under routine conditions, 16 of the 18 cell culture and ART media assessed contained BPS. Six media exhibited BPS concentrations higher than 1 nM and reached up to 6.7 nM (1693 ng/l)., Large Scale Data: N/A., Limitations, Reasons for Caution: Further studies are required to investigate a greater number of ART media to identify less potentially harmful ones, in terms of bisphenol content., Wider Implications of the Findings: As BPS has already been reported to impair oocyte quality at nanomolar concentrations, its presence in ART media, at a similar concentration range, could contribute to a decrease in the ART success rate. Thus far, there has been no regulation of these compounds in the ART context., Study Funding/competing Interests: This study was financially supported by the 'Centre-Val de Loire' Region (Bemol project, APR IR 2017), INRAE, BRGM, the French National Research Agency (project ANR-18-CE34-0011-01 MAMBO) and the BioMedicine Agency (Project 18AMP006 FertiPhenol). The authors declare that they have no conflict of interest that could be perceived as prejudicing the impartiality of the reported research., (© The Author(s) 2021. Published by Oxford University Press on behalf of European Society of Human Reproduction and Embryology.)

Objectives To review the known impacts of recreational cannabis legalization on mental health and substance use, in the context of recent changes in the status of cannabis laws in Canada. Methods PubMed database was systematically searched using various terms regarding mental health and cannabis legalization. Two independent investigators then assessed a total of 272 titles and abstracts and 11 articles were ultimately found eligible for review. Results Most studies measuring the impact of legalization on cannabis use showed an increase in cannabis use after the legalization. Moreover, no study demonstrated a reduction of cannabis use after legalization of recreational cannabis. All three studies regarding health care contacts demonstrated an increase in the number of cannabis-related emergency department visits after cannabis legalization. Two studies revealed reduction of perceived risks associated with cannabis after legalization, while another study offered opposite results. To interpret these observational results accurately, we also need to consider the long-term trends that prevailed before the changes in cannabis laws. Conclusions The quantity of evidence on the impacts of recreational cannabis legalization on mental health and substance use is limited. Further research is needed to strengthen these results and explore the effects of cannabis legalization on other mental health issues such as psychosis.

Juvenile xanthogranuloma (JXG) is the most frequent form of non-Langerhans cell histiocytosis. We present a case of giant congenital JXG in a 7-week-old boy, who had a firm and incompressible lesion, measuring 3 × 4 cm in diameter, on his right flank. The clinical appearance of the lesion and the ultrasound results suggested a vascular tumor, such as a hemangioma. Histology confirmed a JXG, although there was an absence of Touton cells, which are usually pathognomonic of JXG. In light of these findings, it would be important to include JXG in the differential diagnosis of congenital tumours, particularly vascular lesions.

Aims: This study aimed at describing adalimumab pharmacokinetics (PK) and the concentration-effect relationship of adalimumab using pharmacokinetic-pharmacodynamic (PK-PD) modelling in patients with rheumatoid arthritis (RA)., Methods: Adalimumab PK and PK-PD data were obtained from a multicentric observational study. Adalimumab (40 mg) was administered subcutaneously every other week, and its pharmacokinetics was described using a one-compartment model. The relationship between adalimumab concentration and C-reactive protein (CRP) concentration was described using an indirect response model with inhibition of CRP input, whereas the relationship between adalimumab concentration and disease activity score in 28 joints (DAS28) was described using a direct inhibition model. Dose regimens that included a loading dose of adalimumab were simulated., Results: Thirty patients treated for RA were analysed. The following pharmacokinetic and PK-PD parameters were estimated (interidividual coefficient of variation): apparent volume of distribution (Vd /F) = 10.8 l (92%); apparent clearance (CL/F) = 0.32 l day(-1) (17%); first-order absorption rate (ka ) = 0.28 day(-1) ; CRP input (kin ) = 22.0 mg l(-1)  day(-1) (65%); adalimumab concentration leading to a 50% decrease in kin (C50 ) = 3.6 mg l(-1) (88%); baseline DAS28 (DAS0 ) = 5.5 mg l(-1) (11%); and adalimumab concentration leading to 50% decrease of DAS0 (IC50 ) = 11.0 mg l(-1) (71%). Simulations showed that a 160 mg loading dose should reduce the time to reach efficacy in terms of both CRP and DAS28 after the first injection., Conclusions: This is the first study to describe adalimumab pharmacokinetics and the concentration-effect relationship in RA. A 160 mg loading dose may lead to an increased benefit from treatment in RA patients., (© 2014 The British Pharmacological Society.)

Introduction: Hereditary hemorrhagic telangiectasia (HHT) is a genetic disorder associated with abnormal angiogenesis and disabling epistaxis, for which bevacizumab is reported to be a new therapeutic option. In the present study, bevacizumab transport in porcine nasal mucosa was investigated to determine antibody bioavailability., Material and Methods: Transmucosal absorption of bevacizumab was examined by using nasal mucosa specimens mounted onto static vertical diffusion cells then treated with bevacizumab solution (25 mg mL(-1), 500 μg) for 2.5h. Bevacizumab concentrations were measured by enzyme-linked immunosorbent assays. Mucosal integrity was examined by histological examination of treated mucosa., Results: Transmucosal transport of bevacizumab followed a Fickian diffusion process (permeability coefficient: [0.63 ± 22]× 10(-6) cm s(-1); and steady-state flux: 56.4 ± 19.6 μg cm(-2)h(-1)). Total recovery of bevacizumab throughout the 2.5h experiment was 83% of the initial dose distributed (i) at the mucosal surface (263 ± 73 μg; ∼53%) and (ii) into (95 ± 14 μg; ∼19%) and through (56 ± 26 μg; ∼11%) the mucosa. There was no evidence of any noticeable histological effects, confirming the harmlessness of nasal bevacizumab delivery., Conclusion: In the present study, absorption of bevacizumab into nasal mucosa was demonstrated, providing new fundamentals that are mandatory for further clinical trials in HHT patients., (Copyright © 2011 Elsevier Ltd. All rights reserved.)

Aims: Infliximab, an anti-tumour necrosis factor α monoclonal antibody, has profoundly modified the treatment of several inflammatory diseases. The objective was to assess the influence of methotrexate on the variability of infliximab pharmacokinetics and concentration-effect relationship in axial ankylosing spondylitis (AAS) patients., Methods: Twenty-six patients with AAS were included in a prospective study. They were treated by infliximab 5 mg kg⁻¹ infusions at weeks 0, 2, 6, 12 and 18. Infliximab concentrations were measured before, and 2 and 4 h after each infusion, and at each intermediate visit (weeks 1, 3, 4, 5, 8, 10 and 14). Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) was measured at each visit. Infliximab pharmacokinetics was described using a two-compartment model with first-order distribution and elimination constants. A population approach was used. Infliximab pharmacodynamics was described using the area under the BASDAI curve., Results: A total of 507 blood samples and 329 BASDAI measurements were collected. The following pharmacokinetic parameters were obtained (interindividual coefficient of variation): volumes of distribution for the central compartment = 2.4 l (9.6%) and peripheral compartment = 1.8 l (26%), systemic clearance = 0.23 l day⁻¹ (22%) and intercompartment clearance = 2.3 l day⁻¹. Methotrexate influenced neither pharmacokinetic nor BASDAI variability., Conclusions: Using the present dosage, the clinical efficacy of infliximab is only weakly influenced by its serum concentrations. The results do not support the combination of methotrexate with infliximab in ankylosing spondylitis., (© 2011 The Authors. British Journal of Clinical Pharmacology © 2011 The British Pharmacological Society.)

Purpose: An ancillary phase II study was conducted to study interindividual variability in cetuximab pharmacokinetics and its influence on progression-free survival (PFS) in metastatic colorectal cancer patients cotreated with irinotecan and 5-fluorouracil., Experimental Design: Ninety-six patients received cetuximab as an infusion loading dose of 400 mg/m(2) followed by weekly infusions of 250 mg/m(2). Doses of irinotecan and 5-fluorouracil were adjusted individually. Cetuximab concentrations were measured by ELISA. Compartmental pharmacokinetic parameters were estimated by a population approach, and PFS was analyzed using a Cox model., Results: Cetuximab pharmacokinetics was best described using a two-compartment model with both first-order and saturable (zero-order) elimination. Estimated pharmacokinetic parameters (% standard error) were as follows: central volume of distribution V(1) = 2.96 L (4%), peripheral volume of distribution V(2) = 4.65 L (6%), elimination clearance CL = 0.497 L/d (4%), distribution clearance Q = 0.836 L/d (8%), and zero-order elimination rate k(0) = 8.71 mg/d (10%). Body surface area influenced V(1), V(2), and k(0). Pretreatment serum albumin influenced CL. Risk of disease progression decreased with cetuximab global clearance (cumulative dose/cumulative area under the concentration versus time curve; P = 0.00016). Median PFS of patients with a cetuximab residual concentration on day 14 below median value was 3.3 months as compared with 7.8 months for the other patients (P = 0.004)., Conclusions: Cetuximab pharmacokinetics in colorectal cancer patients can be described using a model combining linear and nonlinear elimination rates. PFS is influenced by global clearance of cetuximab, a parameter that can be estimated using cetuximab residual concentration on day 14., (©2011 AACR)

In grapevine (Vitis vinifera), as in many crops, soluble sugar content is a major component of yield and economical value. This paper identifies and characterizes a Glycogen Synthase Kinase3 protein kinase, cloned from a cDNA library of grape Cabernet Sauvignon berries harvested at the ripening stage. This gene, called VvSK1, was mainly expressed in flowers, berries, and roots. In the berries, it was strongly expressed at postvéraison, when the berries accumulate glucose, fructose, and abscisic acid. In grapevine cell suspensions, VvSK1 transcript abundance is increased by sugars and abscisic acid. In transgenic grapevine cells overexpressing VvSK1, the expression of four monosaccharide transporters (VvHT3, VvHT4, VvHT5, and VvHT6) was up-regulated, the rate of glucose uptake was increased 3- to 5-fold, and the amount of glucose and sucrose accumulation was more than doubled, while the starch amount was not affected. This work provides, to our knowledge, the first example of the control of sugar uptake and accumulation by a sugar-inducible protein kinase.

Background: During grape berry ripening, the vacuoles accumulate water, sugars and secondary metabolites, causing great impact in plant productivity and wine quality. However, the molecular basis of these compartmentation processes is still poorly understood. As in many species, the major bottleneck to study these aspects in grapevine is to obtain highly purified vacuoles with a good yield. The present paper describes an isolation method of protoplasts and intact vacuoles from grape berry cells and their functional characterization by transport and cytometric assays., Findings: Protoplasts were prepared by enzymatic digestion of grape cells, and vacuoles were released and purified by a Ficoll step gradient centrifugation. The tonoplast stained strongly with the fluorescent dye FM1-43 and most vacuoles maintained an internal acidic pH, as assessed by Neutral Red. Flow cytometry analysis of vacuole samples incubated with the calcium-sensitive fluorescent probe Fluo-4 AM revealed a well-defined sub-population of intact vacuoles. As assessed by the pH-sensitive probe ACMA, intact vacuoles generated and maintained a pH gradient through the activity of V-ATPase and V-PPase and were able to transport Ca2+ via a proton-dependent transport system., Conclusions: Highly pure, intact and functional protoplast and vacuole populations from grape cells were obtained with the present method, which revealed to be fast and efficient. The capacity of the vacuole population to sequester protons and accumulate Ca2+ strongly suggests the intactness and physiological integrity of these extremely fragile organelles. Grapevine protoplasts and vacuoles may be used as models for both basic research and biotechnological approaches, such as proteomics, solute uptake and compartmentation, toxicological assessments and breeding programs.

Five hundred and six EST-derived markers, 313 SSR markers and 26 BAC end-derived or SCAR markers were anchored by PCR on a subset of a Cabernet Sauvignon BAC library representing six genome equivalents pooled in three dimensions. In parallel, the 12,351 EST clusters of the grapevine UniGene set (build #11) from NCBI were used to design 12,125 primers pairs and perform electronic PCR on 67,543 nonredundant BAC-end sequences. This in silico experiment yielded 1,140 positive results concerning 638 different markers, among which 602 had not been already anchored by PCR. The data obtained will provide an easier access to the regulatory sequences surrounding important genes (represented by ESTs). In total, 1,731 islands of BAC clones (set of overlapping BAC clones containing at least one common marker) were obtained and 226 of them contained at least one genetically mapped anchor. These assigned islands are very useful because they will link the genetic map and the future fingerprint-based physical map and because they allowed us to indirectly place 93 ESTs on the genetic map. The islands containing two or more mapped SSR markers were also used to assess the quality of the integrated genetic map of the grapevine genome.

The accumulation of sugars in grape berries requires the co-ordinate expression of sucrose transporters, invertases, and monosaccharide transporters. A monosaccharide transporter homologue (VvHT1, Vitis vinifera hexose transporter 1) has previously been isolated from grape berries at the veraison stage, and its expression was shown to be regulated by sugars and abscisic acid. The present work investigates the function and localization of VvHT1. Heterologous expression in yeast indicates that VvHT1 encodes a monosaccharide transporter with maximal activity at acidic pH (pH 4.5) and high affinity for glucose (K(m)=70 muM). Fructose, mannose, sorbitol, and mannitol are not transported by VvHT1. In situ hybridization shows that VvHT1 transcripts are primarily found in the phloem region of the conducting bundles. Immunofluorescence and immunogold labelling experiments localized VvHT1 in the plasma membrane of the sieve element/companion cell interface and of the flesh cells. The expression and functional properties of VvHT1 suggests that it retrieves the monosaccharides needed to provide the energy necessary for cell division and cell growth at an early stage of berry development.