Explore the vast range of titles available.

Gap junctions establish direct pathways for cells to transfer metabolic and electrical messages. The local lipid environment is known to affect the structure, stability and intercellular channel activity of gap junctions; however, the molecular basis for these effects remains unknown. Here, we incorporate native connexin-46/50 (Cx46/50) intercellular channels into a dual lipid nanodisc system, mimicking a native cell-to-cell junction. Structural characterization by CryoEM reveals a lipid-induced stabilization to the channel, resulting in a 3D reconstruction at 1.9 Å resolution. Together with all-atom molecular dynamics simulations, it is shown that Cx46/50 in turn imparts long-range stabilization to the dynamic local lipid environment that is specific to the extracellular lipid leaflet. In addition, ~400 water molecules are resolved in the CryoEM map, localized throughout the intercellular permeation pathway and contributing to the channel architecture. These results illustrate how the aqueous-lipid environment is integrated with the architectural stability, structure and function of gap junction communication channels. The local lipid environment is known to affect the structure, stability and intercellular channel activity of gap junctions, however, the molecular basis for these effects remains unknown. Here authors report the CryoEM structure of Cx46/50 lipid-embedded channels, by which they reveal a lipid-induced stabilization to the channel.

Gap junctions establish direct pathways for cell-to-cell communication through the assembly of twelve connexin subunits that form intercellular channels connecting neighbouring cells. Co-assembly of different connexin isoforms produces channels with unique properties and enables communication across cell types. Here we used single-particle cryo-electron microscopy to investigate the structural basis of connexin co-assembly in native lens gap junction channels composed of connexin 46 and connexin 50 (Cx46/50). We provide the first comparative analysis to connexin 26 (Cx26), which—together with computational studies—elucidates key energetic features governing gap junction permselectivity. Cx46/50 adopts an open-state conformation that is distinct from the Cx26 crystal structure, yet it appears to be stabilized by a conserved set of hydrophobic anchoring residues. ‘Hot spots’ of genetic mutations linked to hereditary cataract formation map to the core structural–functional elements identified in Cx46/50, suggesting explanations for many of the disease-causing effects. Cryo-electron microscopy structures of connexin channels composed of connexin 46 and connexin 50 in an open-state reveal features that govern permselectivity and the location of mutated residues linked to herediatry cataracts.

The outstanding acuity of the mammalian ear relies on cochlear amplification, an active mechanism based on the electromotility (eM) of outer hair cells. eM is a piezoelectric mechanism generated by little-understood, voltage-induced conformational changes of the anion transporter homolog prestin (SLC26A5). We used a combination of molecular dynamics (MD) simulations and biophysical approaches to identify the structural dynamics of prestin that mediate eM. MD simulations showed that prestin samples a vast conformational landscape with expanded (ES) and compact (CS) states beyond previously reported prestin structures. Transition from CS to ES is dominated by the translational-rotational movement of prestin’s transport domain, akin to elevator-type substrate translocation by related solute carriers. Reversible transition between CS and ES states was supported experimentally by cysteine accessibility scanning, cysteine cross-linking between transport and scaffold domains, and voltage-clamp fluorometry (VCF). Our data demonstrate that prestin’s piezoelectric dynamics recapitulate essential steps of a structurally conserved ion transport cycle. Probing the molecular dynamics of the membrane motor, prestin, with biophysical measures and MD simulations, Kuwabara et al. find that an elevator-like domain movement across the membrane produces the unique piezoelectric behavior.

IntroductionIt has been reported that pregnant women used more cosmetics daily than non-pregnant women. Phenoxyacetic acid is the main metabolite of phenoxyethanol, the most frequent preservative in cosmetics used in Europe, previously associated with reproductive effects (longer time to conception, endocrine disruptors in newborns and poorer verbal comprehension in children). In France, specialised platforms (PREVention ENvIronment Reproduction (PREVENIR)) in university hospital maternity wards are dedicated to evaluating environmental and occupational exposures in patients with pregnancy-related pathologies and supporting targeted prevention efforts. These platforms are composed of occupational health physicians, obstetrician-gynaecologists, midwives, occupational health nurses, and occupational health and environmental engineers. To assess the efficacy of these platforms, we developed a randomised clinical trial, the protocol for which is presented in this paper. The primary objective of the PREVENIR-G Study is to compare the change in urinary phenoxyacetic acid concentrations from baseline to 3 months postintervention between an intervention group and a control group. To date, the intervention has been integrated into routine care in certain facilities; however, its efficacy remains unproven. It is therefore essential to assess the relevance of this intervention, considering both its potential benefits and any adverse effects, such as increased stress or anxiety.Methods and analysisThis study is an unblinded, randomised clinical superiority trial with two parallel groups (intervention vs no intervention) in four university maternity hospitals in France. We will include 300 pregnant women (aged 18 years or older) who are under 24 weeks of gestation (150 per group) referred to the participating PREVENIR platforms for management. The intervention will consist of clinical prevention management through the PREVENIR platforms, involving a consultation with an environmental health expert for an assessment of environmental and occupational exposures. During the consultation, targeted prevention messages will be provided based on identified exposures. The no intervention comparator will be a waiting-list control group. At the inclusion visit, patients will receive urine collection vials for samples to be collected at baseline and again at 3 months. Urine samples will be collected twice in a single day, on three separate days, during the collection week at home. In the week following the urine collection period, only participants in the intervention group will engage with the PREVENIR platforms. The primary outcome will be the difference in the urinary phenoxyacetic acid concentration between baseline and 3 months postintervention, compared between the intervention and control groups.Ethics and disseminationThe study has been approved by the hospital ethics committee (CCP Ouest 2, no. 2023-A00941-44). All participants will provide written informed consent. Results will be shared through presentations and publications.Trial registration numberNCT06642818

Introduction: The P2X3 receptor (P2X3R), an ATP-gated non-selective cation channel of the P2X receptor family, is expressed in sensory neurons and involved in nociception. P2X3R inhibition was shown to reduce chronic and neuropathic pain. In a previous screening of 2000 approved drugs, natural products, and bioactive substances, various non-steroidal anti-inflammatory drugs (NSAIDs) were found to inhibit P2X3R-mediated currents. Methods: To investigate whether the inhibition of P2X receptors contributes to the analgesic effect of NSAIDs, we characterized the potency and selectivity of various NSAIDs at P2X3R and other P2XR subtypes using two-electrode voltage clamp electrophysiology. Results: We identified diclofenac as a hP2X3R and hP2X2/3R antagonist with micromolar potency (with IC 50 values of 138.2 and 76.7 µM, respectively). A weaker inhibition of hP2X1R, hP2X4R, and hP2X7R by diclofenac was determined. Flufenamic acid (FFA) inhibited hP2X3R, rP2X3R, and hP2X7R (IC 50 values of 221 µM, 264.1 µM, and ∼900 µM, respectively), calling into question its use as a non-selective ion channel blocker, when P2XR-mediated currents are under study. Inhibition of hP2X3R or hP2X2/3R by diclofenac could be overcome by prolonged ATP application or increasing concentrations of the agonist α,β-meATP, respectively, indicating competition of diclofenac and the agonists. Molecular dynamics simulation showed that diclofenac largely overlaps with ATP bound to the open state of the hP2X3R. Our results suggest a competitive antagonism through which diclofenac, by interacting with residues of the ATP-binding site, left flipper, and dorsal fin domains, inhibits the gating of P2X3R by conformational fixation of the left flipper and dorsal fin domains. In summary, we demonstrate the inhibition of the human P2X3 receptor by various NSAIDs. Diclofenac proved to be the most effective antagonist with a strong inhibition of hP2X3R and hP2X2/3R and a weaker inhibition of hP2X1R, hP2X4R, and hP2X7R. Discussion: Considering their involvement in nociception, inhibition of hP2X3R and hP2X2/3R by micromolar concentrations of diclofenac, which are rarely reached in the therapeutic range, may play a minor role in analgesia compared to the high-potency cyclooxygenase inhibition but may explain the known side effect of taste disturbances caused by diclofenac.

To determine risk factors of superimposed preeclampsia in women with essential chronic hypertension receiving antihypertensive therapy prior to conception. A retrospective study of 211 patients that analyzed risk factors of superimposed preeclampsia at first prenatal visit. Variables with a p<.1 at univariate analysis were included in a logistic regression analysis. P<.05 was considered as significant. Superimposed preeclampsia occurred in 49 (23.2%) women. In logistic regression analysis, previous preeclampsia [OR: 4.05 (1.61-10.16)], and mean arterial blood pressure of 95 mmHg or higher [OR: 4.60 (1.94-10.93)] were associated with increased risk of superimposed preeclampsia. When both variables were present, sensitivity, specificity, positive predictive value, negative predictive value, and likelihood ratio for superimposed preeclampsia were 43%, 94%, 70%, 85%, and 7.71 (95% CI: 3.20-18.57), respectively. In essential chronic hypertensive women, previous preeclampsia and mean arterial blood pressure of 95 mmHg or higher are associated with increased risks of superimposed preeclampsia.

Background The most appropriate management for patients with stage IV ovarian cancer remains unclear. Our objective was to understand the main determinants associated with survival and to discuss best surgical management. Methods Data of 1038 patients with confirmed ovarian cancer treated between 1996 and 2016 were extracted from maintained databases of 7 French referral gynecologic oncology institutions. Patients with stage IV diseases were selected for further analysis. The Kaplan–Meier method was used to estimate the survival distribution. A Cox proportional hazards model including all the parameters statistically significant in univariable analysis, was used to account for the influence of multiple variables. Results Two hundred and eight patients met our inclusion criteria: 65 (31.3%) never underwent debulking surgery, 52 (25%) underwent primary debulking surgery (PDS) and 91 (43.8%) neoadjuvant chemotherapy and interval debulking surgery (NACT-IDS). Patients not operated had a significantly worse overall survival than patients that underwent PDS or NACT–IDS (p < 0.001). In multivariable analysis, three factors were independent predictors of survival: upfront surgery (HR 0.32 95% CI 0.14–0.71, p = 0.005), postoperative residual disease = 0 (HR 0.37 95% CI 0.18–0.75, p = 0.006) and association of Carboplatin and Paclitaxel regimen (HR 0.45 95% CI 0.25–0.80, p = 0.007). Conclusions Presence of distant metastases should not refrain surgeons from performing radical procedures, whenever the patient is able to tolerate. Maximal surgical efforts should be done to minimize residual disease as it is the main determinant of survival.

[This corrects the article DOI: 10.3389/fphar.2023.1120360.].

Background Recent studies have challenged radical procedures for less extensive surgery in selected patients with early-stage cervical cancer at low risk of parametrial invasion. Our objective was to identify a subgroup of patients at low risk of parametrial invasion among women having undergone surgical treatment. Methods Data of 1447 patients with cervical cancer treated between 1996 and 2016 were extracted from maintained databases of 10 French University hospitals. Patients with early-stage (IA2–IIA) disease treated by radical surgery including hysterectomy and trachelectomy, were selected for further analysis. The Kaplan–Meier method was used to estimate the survival distribution. A Cox proportional hazards model including all the parameters statistically significant in univariate analysis, was used to account for the influence of multiple variables. Results Out of the 263 patients included for analysis, on final pathology analysis 28 (10.6%) had parametrial invasion and 235 (89.4%) did not. Factors significantly associated with parametrial invasion on multivariate analysis were: age > 65 years, tumor > 30 mm in diameter measured by MRI, lymphovascular space invasion (LVSI) on pathologic analysis. Among the 235 patients with negative pelvic lymph nodes, parametrial disease was seen in only 7.6% compared with 30.8% of those with positive pelvic nodes (p < 0.001). In a subgroup of patients presenting tumors < 30 mm, negative pelvic status and no LVSI, the risk of parametrial invasion fell to 0.6% (1/173 patients). Conclusion Our analysis suggests that there is a subgroup of patients at very low risk of parametrial invasion, potentially eligible for less radical procedures.

Background The prognostic impact of surgical paraaortic staging remains unclear in patients with locally advanced cervical cancer (LACC). The objective of our study was to evaluate the survival impact of surgical staging in patients with LACC and no evidence of paraaortic lymph node (PALN) metastasis on pre-operative imaging work-up. Methods Data of 1447 patients with cervical cancer treated between 1996 and 2016 were extracted from maintained databases of 10 French University hospitals. Patients with locally advanced disease (IB2 or more) treated by concurrent chemoradiation therapy (CRT) and no evidence of paraaortic metastasis on pre-operative imaging work-up were selected for further analysis. The Kaplan–Meier method was used to estimate the survival distribution. A Cox proportional hazards model was used to account for the influence of multiple variables. Results Six hundred and forty-seven patients were included, 377 (58.3%) with surgical staging and 270 (41.7%) without, with a mean follow up of 38.1 months (QI 13.0–56.0). Pathologic analysis revealed positive lymph nodes in 47 patients (12.5%). In multivariate model analysis, surgical staging remained an independent prognostic factor for DFS (OR 0.64, CI 95% 0.46–0.89, p = 0.008) and OS (OR 0.43, CI 95% 0.27–0.68, p < 0.001). The other significant parameter in multivariate analysis for both DFS and OS was treatment by intracavitary brachytherapy (OR respectively of 0.7 (0.5–1.0) and 0.6 (0.4–0.9), p < 0.05). Conclusion Nodal surgical staging had an independent positive impact on survival in patients with LACC treated with CRT with no evidence of metastatic PALN on imaging.