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Biology subjects

Bernier, A.

Publications and source records attributed to Bernier, A..

4 recordsLinked to original sources

A cell-based method to assess the activity of the human sodium-coupled citrate transporter

Increasing evidence supports the human sodium-coupled citrate transporter (hNaCT) as a potential therapeutic target for metabolic syndrome, while genetic polymorphisms in hNaCT have been associated with neurological disorder. Isotopic tracers remain the primary method for evaluating citrate transport, which are labor-intensive, require dedicated equipment, and demand highly skilled personnel. Herein, we develop and validate a robust, live-cell-compatible fluorescent method to evaluate citrate transport activity mediated by hNaCT at single-cell and high-throughput levels. This method utilizes a baculoviral vector to modify HEK293 cells to co-express a genetically encoded citrate sensor (Citron1) and the hNaCT. This cell-based platform enabled real-time monitoring of citrate transport using fluorescent microscopy and standard multiwell plate reader. The present method enables the functional characterization of hNaCT gain- and loss-of-function mutation, as well as the evaluation of pharmacological inhibitors targeting citrate transport. These results demonstrate that the cell-based method reliably assesses citrate transport at a single-cell resolution and is compatible with high-throughput screening, to identify novel lead compounds for the therapeutic modulation of hNaCT.

cell biology↗

Cost-efficient whole genome-sequencing using novel mostly natural sequencing-by-synthesis chemistry and open fluidics platform

We introduce a massively parallel novel sequencing platform that combines an open flow cell design on a circular wafer with a large surface area and mostly natural nucleotides that allow optical end-point detection without reversible terminators. This platform enables sequencing billions of reads with longer read length ([~]300bp) and fast runs times (<20hrs) with high base accuracy (Q30 > 85%), at a low cost of $1/Gb. We establish system performance by whole-genome sequencing of the Genome-In-A-Bottle reference samples HG001-7, demonstrating high accuracy for SNPs (99.6%) and Indels in homopolymers up to length 10 (96.4%) across the vast majority (>98%) of the defined high-confidence regions of these samples. We demonstrate scalability of the whole-genome sequencing workflow by sequencing an additional 224 selected samples from the 1000 Genomes project achieving high concordance with reference data.

genomics↗

Transactional sex among men who have sex with men participating in the CohMSM prospective cohort study in West Africa

Men who have sex with men (MSM) are at much greater risk of HIV infection in Africa. Little is known about their involvement in transactional sex (TS). We aimed to characterize MSM reporting TS (MSM-TS) and to identify factors associated with their sexual practices using data from the prospective cohort study CohMSM conducted in Burkina Faso, Cote dIvoire, Mali and Togo. Our study focused on HIV-negative MSM, recruited between 06/2015 and 01/2018 by a team of trained peer educators. Scheduled study visits at 6, 12 and 18 months included medical examinations, HIV screening, risk-reduction counselling and face-to-face interviews to collect information on their sociodemographic characteristics, sexual behaviours, and HIV risk-reduction strategies. Three stigmatization sub-scores were constructed. The generalized estimating equation method was used for data analysis. Of the 630 HIV-negative participants recruited at baseline, 463, 410 and 244 had a follow-up visit at 6- and 12- and 18-months, respectively. Over a total of 1747 visits, 478 TS encounters were reported by 289 MSM-TS (45.9%). Of the latter, 91 participants reported systematic TS (31.5%), 55 (19.0 %) stopped reporting TS after baseline, and 53 (18.3%) reported TS after baseline. Ninety participants (31.1 %) reported occasional TS. After adjusting for country of study and follow-up visits, the following factors, reported for the previous 6 months, were associated with a greater likelihood of TS: younger age, an educational level <high-school diploma, satisfaction with current sex life, group sex with men, multiple male sexual partners, condomless anal sex, receptive or versatile anal sex with male sexual partners, giving benefits in exchange for sex with a man, alcohol consumption and drug use during sex, and experiencing stigmatization. The majority of MSM in this study who received benefits in exchange for sex had high-risk HIV infection exposure practices and were characterized by socioeconomic difficulties.

epidemiology↗

Male clients of male sex workers in West Africa: A neglected high risk population

Research on male clients of male sex workers (MCMSW) has been neglected for a long time globally. We aimed to characterize MCMSW and to identify factors associated with their sexual practices using data from the prospective cohort study CohMSM conducted in Burkina Faso, Cote dIvoire, Mali and Togo. Our study focused on HIV-negative men who have sex with other men (MSM) recruited between 06/2015 and 01/2018 by a team of trained peer educators. Scheduled study visits at 6, 12 and 18 months included medical examinations, HIV screening, risk-reduction counselling and face-to-face interviews to collect information on their sociodemographic characteristics, sexual behaviours, and HIV risk-reduction strategies (HIV-RRS). Three stigmatization sub-scores were constructed (experienced, perceived and internalized). Mixed-effects logistic regression was used for data analysis. Of the 280 participants recruited at baseline, 238, 211 and 118, respectively, had a follow-up visit at 6, 12 and 18 months. Over a total of 847 visits, 47 transactional sex (TS) encounters were reported by 38 MCMSW (13.6%). Of the latter, only one participant reported systematic TS (2.6%), 18 (47.4 %) stopped reporting TS after baseline, and 6 (15.8%) reported TS after baseline. Thirteen participants (34.2 %) reported occasional TS. After adjusting for country of study and age, the following self-reported factors were associated with a greater likelihood of being MCMSW: protected anal sex, exclusively insertive anal sex with male sexual partners, avoidance of sex after consuming psychoactive products and experiencing stigmatization (all during the previous 6 months). The majority of MCMSW in this study employed HIV-RRS with male sexual partners, including engaging in protected anal sex, avoidance of sex when consuming psychoactive products, and practising exclusively insertive anal sex.

epidemiology↗