Pharmacokinetic Model of Tenofovir and Emtricitabine and Their Intracellular Metabolites in Patients in the ANRS 134-COPHAR 3 Trial Using Dose Records.

Tenofovir (TFV) and emtricitabine (FTC) are part of the recommended highly active antiretroviral therapy (ART). Both molecules show a large interindividual pharmacokinetic (PK) variability. Here, we modeled the concentrations of plasma TFV and FTC and their intracellular metabolites (TFV diphosphate [TFV-DP] and FTC triphosphate [FTC-TP]) collected after 4 and 24 weeks of treatment in 34 patients from the ANRS 134-COPHAR 3 trial. These patients received daily (QD) atazanavir (300 mg), ritonavir (100 mg), and a fixed-dose combination of coformulated TFV disoproxil fumarate (300 mg) and FTC (200 mg). Dosing history was collected using a medication event monitoring system. A three-compartment model with absorption delay (Tlag) was selected to describe the PK of, respectively, TFV/TFV-DP and FTC/FTC-TP. TFV and FTC apparent clearances, 114 L/h (relative standard error [RSE] = 8%) and 18.1 L/h (RSE = 5%), respectively, were found to decrease with age. However, no significant association was found with the polymorphisms ABCC2 rs717620, ABCC4 rs1751034, and ABCB1 rs1045642. The model allows prediction of TFV-DP and FTC-TP concentrations at steady state with alternative regimens.

Dihydropyrimidinase protects from DNA replication stress caused by cytotoxic metabolites.

Imbalance in the level of the pyrimidine degradation products dihydrouracil and dihydrothymine is associated with cellular transformation and cancer progression. Dihydropyrimidines are degraded by dihydropyrimidinase (DHP), a zinc metalloenzyme that is upregulated in solid tumors but not in the corresponding normal tissues. How dihydropyrimidine metabolites affect cellular phenotypes remains elusive. Here we show that the accumulation of dihydropyrimidines induces the formation of DNA-protein crosslinks (DPCs) and causes DNA replication and transcriptional stress. We used Xenopus egg extracts to recapitulate DNA replication invitro. We found that dihydropyrimidines interfere directly with the replication of both plasmid and chromosomal DNA. Furthermore, we show that the plant flavonoid dihydromyricetin inhibits human DHP activity. Cellular exposure to dihydromyricetin triggered DPCs-dependent DNA replication stress in cancer cells. This study defines dihydropyrimidines as potentially cytotoxic metabolites that may offer an opportunity for therapeutic-targeting of DHP activity in solid tumors.

Microenvironment tailors nTreg structure and function.

Natural regulatory T cells (nTregs) ensure the control of self-tolerance and are currently used in clinical trials to alleviate autoimmune diseases and graft-versus-host disease after hematopoietic stem cell transfer. Based on CD39/CD26 markers, blood nTreg analysis revealed the presence of five different cell subsets, each representing a distinct stage of maturation. Ex vivo added microenvironmental factors, including IL-2, TGFß, and PGE2, direct the conversion from naive precursor to immature memory and finally from immature to mature memory cells, the latest being a no-return stage. Phenotypic and genetic characteristics of the subsets illustrate the structural parental maturation between subsets, which further correlates with the expression of regulatory factors. Regarding nTreg functional plasticity, both maturation stage and microenvironmental cytokines condition nTreg activities, which include blockade of autoreactive immune cells by cell-cell contact, Th17 and IL-10 Tr1-like activities, or activation of TCR-stimulating dendritic cell tolerization. Importantly, blood nTreg CD39/CD26 profile remained constant over a 2-y period in healthy persons but varied from person to person. Preliminary data on patients with autoimmune diseases or acute myelogenous leukemia illustrate the potential use of the nTreg CD39/CD26 profile as a blood biomarker to monitor chronic inflammatory diseases. Finally, we confirmed that naive conventional CD4 T cells, TCR-stimulated under a tolerogenic conditioned medium, could be ex vivo reprogrammed to FOXP3 lineage Tregs, and further found that these cells were exclusively committed to suppressive function under all microenvironmental contexts.

In Vivo Sustained Release of the Retrograde Transport Inhibitor Retro-2.1 Formulated in a Thermosensitive Hydrogel.

A recently developed inhibitor of retrograde transport, namely Retro-2.1, proved to be a potent and broad-spectrum lead in vitro against intracellular pathogens, such as toxins, parasites, intracellular bacteria and viruses. To circumvent its low aqueous solubility, a formulation in poly(ethylene glycol)-block-poly(D,L)lactide micelle nanoparticles was developed. This formulation enabled the study of the pharmacokinetic parameters of Retro-2.1 in mice following intravenous and intraperitoneal injections, revealing a short blood circulation time, with an elimination half-life of 5 and 6.7 h, respectively. To explain the poor pharmacokinetic parameters, the metabolic stability of Retro-2.1 was studied in vitro and in vivo, revealing fast cytochrome-P-450-mediated metabolism into a less potent hydroxylated analogue. Subcutaneous injection of Retro-2.1 formulated in a biocompatible and bioresorbable polymer-based thermosensitive hydrogel allowed for sustained release of the drug, with an elimination half-life of 19 h, and better control of its metabolism. This study provides a guideline on how to administer this promising lead in vivo in order to study its efficacy.

An adamantamine derivative as a drug candidate for the treatment of visceral leishmaniasis.

BACKGROUND: This study aimed to investigate compounds acting on the host cell machinery to impair parasite installation with the possible advantage of limiting drug resistance. The strategy therefore consisted of selecting compounds that are poorly active on the axenic parasite, but very active on the intramacrophage form of Leishmania. OBJECTIVES: To identify a drug candidate from focused screening of adamantamine derivatives that can inhibit the development of Leishmania infantum in macrophages. METHODS: In vitro screening was performed on a library of 142 adamantamine derivatives with axenic and intramacrophage forms of L. infantum, as well as cytotoxicity assays, allowing selection of the most promising compound. Absorption, distribution, metabolism and excretion (ADME) experiments, including pharmacokinetics and microsomal stability, were performed and finally the physicochemical stability of the compound was investigated to assess its suitability for further drug development. RESULTS: VP343 was identified first in vitro, with a CC50 value of 63.7 µM and an IC50 value of 0.32 µM for L. infantum intramacrophage amastigotes and then in vivo, with a 59% reduction of the liver parasite burden after oral administration at 10 mg/kg/day for 5 days. In addition, the ADME data were compatible with moving this compound further through the antileishmanial drug candidate pipeline. CONCLUSIONS: VP343 has the properties of a good drug candidate and merits further investigations.

In the mouse, prostaglandin D2 signalling protects the endometrium against adenomyosis.

Adenomyosis is characterised by epithelial gland and mesenchymal stroma invasion of the uterine myometrium. Adenomyosis is an oestrogen-dependent gynaecological disease in which a number of factors, such as inflammatory molecules, prostaglandins (PGs), angiogenic factors, cell proliferation and extracellular matrix remodelling proteins, also play a role as key disease mediators. In this study, we used mice lacking both lipocalin and hematopoietic-PG D synthase (L- and H-Pgds) genes in which PGD2 is not produced to elucidate PGD2 roles in the uterus. Gene expression studied by real-time PCR and hormone dosages performed by ELISA or liquid chromatography tandem mass spectroscopy in mouse uterus samples showed that components of the PGD2 signalling pathway, both PGDS and PGD2-receptors, are expressed in the mouse endometrium throughout the oestrus cycle with some differences among uterine compartments. We showed that PGE2 production and the steroidogenic pathway are dysregulated in the absence of PGD2. Histological analysis of L/H-Pgds-/- uteri, and immunohistochemistry and immunofluorescence analyses of proliferation (Ki67), endothelial cell (CD31), epithelial cell (pan-cytokeratin), myofibroblast (α-SMA) and mesenchymal cell (vimentin) markers, identify that 6-month-old L/H-Pgds-/- animals developed adenomyotic lesions, and that disease severity increased with age. In conclusion, this study suggests that the PGD2 pathway has major roles in the uterus by protecting the endometrium against adenomyosis development. Additional experiments, using for instance transcriptomic approaches, are necessary to fully determine the molecular mechanisms that lead to adenomyosis in L/H-Pgds-/- mice and to confirm whether this strain is an appropriate model for studying the human disease.

Orchestration of Tryptophan-Kynurenine Pathway, Acute Decompensation, and Acute-on-Chronic Liver Failure in Cirrhosis.

Systemic inflammation (SI) is involved in the pathogenesis of acute decompensation (AD) and acute-on-chronic liver failure (ACLF) in cirrhosis. In other diseases, SI activates tryptophan (Trp) degradation through the kynurenine pathway (KP), giving rise to metabolites that contribute to multiorgan/system damage and immunosuppression. In the current study, we aimed to characterize the KP in patients with cirrhosis, in whom this pathway is poorly known. The serum levels of Trp, key KP metabolites (kynurenine and kynurenic and quinolinic acids), and cytokines (SI markers) were measured at enrollment in 40 healthy subjects, 39 patients with compensated cirrhosis, 342 with AD (no ACLF) and 180 with ACLF, and repeated in 258 patients during the 28-day follow-up. Urine KP metabolites were measured in 50 patients with ACLF. Serum KP activity was normal in compensated cirrhosis, increased in AD and further increased in ACLF, in parallel with SI; it was remarkably higher in ACLF with kidney failure than in ACLF without kidney failure in the absence of differences in urine KP activity and fractional excretion of KP metabolites. The short-term course of AD and ACLF (worsening, improvement, stable) correlated closely with follow-up changes in serum KP activity. Among patients with AD at enrollment, those with the highest baseline KP activity developed ACLF during follow-up. Among patients who had ACLF at enrollment, those with immune suppression and the highest KP activity, both at baseline, developed nosocomial infections during follow-up. Finally, higher baseline KP activity independently predicted mortality in patients with AD and ACLF. Conclusion: Features of KP activation appear in patients with AD, culminate in patients with ACLF, and may be involved in the pathogenesis of ACLF, clinical course, and mortality.

Intergenerational effects on mouse sperm quality after in utero exposure to acetaminophen and ibuprofen.

Nonsteroidal antiinflammatory drugs and analgesic drugs, such as N-acetyl- p-aminophenol (APAP; acetaminophen, paracetamol), are widely used by pregnant women. Accumulating evidence has indicated that these molecules can favor genital malformations in newborn boys and reproductive disorders in adults. However, the consequences on postnatal testis development and adult reproductive health after exposure during early embryogenesis are still unknown. Using the mouse model, we show that in utero exposure to therapeutic doses of the widely used APAP-ibuprofen combination during the sex determination period leads to early differentiation and decreased proliferation of male embryonic germ cells, and early 5-methylcytosine and extracellular matrix protein deposition in 13.5 d postcoitum exposed testes. Consequently, in postnatal testes, Sertoli-cell maturation is delayed, the Leydig-cell compartment is hyperplasic, and the spermatogonia A pool is decreased. This results in a reduced production of testosterone and in epididymal sperm parameter defects. We observed a reduced sperm count (19%) in utero-exposed (F0) adult males and also a reduced sperm motility (40%) in their offspring (F1) when both parents were exposed, which leads to subfertility among the 6 mo old F1 animals. Our study suggests that the use of these drugs during the critical period of sex determination affects the germ-line development and leads to adverse effects that could be passed to the offspring.-Rossitto, M., Marchive, C., Pruvost, A., Sellem, E., Ghettas, A., Badiou, S., Sutra, T., Poulat, F., Philibert, P., Boizet-Bonhoure, B. Intergenerational effects on mouse sperm quality after in utero exposure to acetaminophen and ibuprofen.

Reducing C-terminal truncation mitigates synucleinopathy and neurodegeneration in a transgenic model of multiple system atrophy.

Multiple system atrophy (MSA) is a sporadic orphan neurodegenerative disorder. No treatment is currently available to slow down the aggressive neurodegenerative process, and patients die within a few years after disease onset. The cytopathological hallmark of MSA is the accumulation of alpha-synuclein (α-syn) aggregates in affected oligodendrocytes. Several studies point to α-syn oligomerization and aggregation as a mediator of neurotoxicity in synucleinopathies including MSA. C-terminal truncation by the inflammatory protease caspase-1 has recently been implicated in the mechanisms that promote aggregation of α-syn in vitro and in neuronal cell models of α-syn toxicity. We present here an in vivo proof of concept of the ability of the caspase-1 inhibitor prodrug VX-765 to mitigate α-syn pathology and to mediate neuroprotection in proteolipid protein α-syn (PLP-SYN) mice, a transgenic mouse model of MSA. PLP-SYN and age-matched wild-type mice were treated for a period of 11 wk with VX-765 or placebo. VX-765 prevented motor deficits in PLP-SYN mice compared with placebo controls. More importantly, VX-765 was able to limit the progressive toxicity of α-syn aggregation by reducing its load in the striatum of PLP-SYN mice. Not only did VX-765 reduce truncated α-syn, but it also decreased its monomeric and oligomeric forms. Finally, VX-765 showed neuroprotective effects by preserving tyrosine hydroxylase-positive neurons in the substantia nigra of PLP-SYN mice. In conclusion, our results suggest that VX-765, a drug that was well tolerated in a 6 wk-long phase II trial in patients with epilepsy, is a promising candidate to achieve disease modification in synucleinopathies by limiting α-syn accumulation.

Methotrexate and BAFF interaction prevents immunization against TNF inhibitors.

OBJECTIVES: TNF inhibitors (TNFi) can induce anti-drug antibodies (ADA) in patients with autoimmune diseases (AID) leading to clinical resistance. We explored a new way of using methotrexate (MTX) to decrease this risk of immunisation. METHODS: We treated BAFF transgenic (BAFFtg) mice, a model of AID in which immunisation against biologic drugs is high, with different TNFi. We investigated the effect of a single course of MTX during the first exposure to TNFi. Wild-type (WT) and BAFFtg mice were compared for B-Cell surface markers involved in MTX-related purinergic metabolism, adenosine production and regulatory B-cells (Bregs).We translated the study to macaques and patients with rheumatoid arthritis from the ABIRISK cohort to determine if there was an interaction between serum BAFF levels and MTX that prevented immuniation. RESULTS: In BAFFtg but not in WT mice or macaques, a single course of MTX prevented immunisation against TNFi and maintained drug concentration for over 52 weeks. BAFFtg mice B-cells expressed more CD73 and CD39 compared to WT mice. MTX induced adenosine release from B cells and increased Bregs and precursors. Use of CD73 blocking antibodies reversed MTX-induced tolerance. In patients from the ABIRISK cohort treated with TNFi for chronic inflammatory diseases, high BAFF serum level correlated with absence of ADA to TNFi only in patients cotreated with MTX but not in patients on TNFi monotherapy. CONCLUSION: MTX and BAFF interact in mice where CD73, adenosine and regulatory B cells were identified as key actors in this phenomenon. MTX and BAFF also interact in patients to prevent ADA formation.

Activity of Bisnaphthalimidopropyl Derivatives against Trypanosoma brucei.

Current treatments for African trypanosomiasis are either toxic, costly, difficult to administer, or prone to elicit resistance. This study evaluated the activity of bisnaphthalimidopropyl (BNIP) derivatives againstTrypanosoma brucei BNIPDiaminobutane (BNIPDabut), the most active of these compounds, showedin vitroinhibition in the single-unit nanomolar range, similar to the activity in the reference drug pentamidine, and presented low toxicity and adequate metabolic stability. Additionally, using a murine model of acute infection and live imaging, a significant decrease in parasite load in BNIPDabut-treated mice was observed. However, cure was not achieved. BNIPDabut constitutes a new scaffold for antitrypanosomal drugs that deserves further consideration.

A limited sampling strategy based on maximum a posteriori Bayesian estimation for a five-probe phenotyping cocktail.

PURPOSE: Cocktail approach using a combination of probes to phenotype several cytochromes P450 or transporters is of high interest in anticipating drug­drug interactions and personalized medicine. Its clinical use remains however limited by the intensive sampling scheme required to obtain phenotyping indexes (PI) which consists in calculating the area under the concentration­time curves. We proposed to use maximum a posteriori Bayesian estimation (MAPBE) that incorporates available information from the whole population to derive PI from a few individual observations. The performance of a limited sampling strategy (LSS) based on MAPBE was evaluated for a five-probe cocktail. METHODS: The studied cocktail included midazolam, tolbutamide, caffeine, dextromethorphan, omeprazole and their relevant metabolites. Prior information for MAPBE was obtained by nonlinear mixed-effect modelling of data from a pilot study. Sampling times were chosen based on optimal design theory using the Bayesian Fisher information matrix. Through a simulation study, we investigated the predicted PI in terms of bias and imprecision for varying number and timing of samples. RESULTS: Some three-point Bayesian designs gave mean prediction errors in [−5 %, 5 %], root mean square errors below 30 % for all probes, except dextromethorphan whose model should be consolidated further with additional data. This approach gave overall less outlier predicted values than single-point metrics and was more flexible to the timing of the latest sampling. CONCLUSIONS: MAPBE is accurate for predicting simultaneously several PI while being flexible in terms of integrating clinical constraints. Therefore, LSS based on MAPBE could help reduce the time of presence in hospital for individuals to be phenotyped.

Pre-clinical development of a combination microbicide vaginal ring containing dapivirine and darunavir.

OBJECTIVES: Combination microbicide vaginal rings may be more effective than single microbicide rings at reducing/preventing sexual transmission of HIV. Here, we report the pre-clinical development and macaque pharmacokinetics of matrix-type silicone elastomer vaginal rings containing dapivirine and darunavir. METHODS: Macaque rings containing 25 mg dapivirine, 100 mg dapivirine, 300 mg darunavir or 100 mg dapivirine+300 mg darunavir were manufactured and characterized by differential scanning calorimetry. In vitro release was assessed into isopropanol/water and simulated vaginal fluid. Macaque vaginal fluid and blood serum concentrations for both antiretrovirals were measured during 28 day ring use. Tissue levels were measured on day 28. Ex vivo challenge studies were performed on vaginal fluid samples and IC50 values were calculated. RESULTS: Darunavir caused a concentration-dependent reduction in the dapivirine melting temperature in both solid drug mixes and in the combination ring. In vitro release from rings was dependent on drug loading, the number of drugs present and the release medium. In macaques, serum concentrations of both microbicides were maintained between 10(1) and 10(2) pg/mL. Vaginal fluid levels ranged between 10(3) and 10(4) ng/g and between 10(4) and 10(5) ng/g for dapivirine and darunavir, respectively. Both dapivirine and darunavir showed very similar concentrations in each tissue type; the range of drug tissue concentrations followed the general rank order: vagina (1.8 × 10(3)-3.8 × 10(3) ng/g)  > cervix (9.4 × 10(1)-3.9 × 10(2) ng/g)  > uterus (0-108 ng/g)  > rectum (0-40 ng/g). Measured IC50 values were >2 ng/mL for both compounds. CONCLUSIONS: Based on these results, and in light of recent clinical progress of the 25 mg dapivirine ring, a combination vaginal ring containing dapivirine and darunavir is a viable second-generation HIV microbicide candidate.

Proteolytically Stable Diaza-Peptide Foldamers Mimic Helical Hot Spots of Protein-Protein Interactions and Act as Natural Chaperones.

A novel class of peptidomimetic foldamers based on diaza-peptide units are reported. Circular dichroism, attenuated total reflection -Fourier transform infrared, NMR, and molecular dynamics studies demonstrate that unlike the natural parent nonapeptide, the specific incorporation of one diaza-peptide unit at the N-terminus allows helical folding in water, which is further reinforced by the introduction of a second unit at the C-terminus. The ability of these foldamers to resist proteolysis, to mimic the small helical hot spot of transthyretin-amyloid ß (Aß) cross-interaction, and to decrease pathological Aß aggregation demonstrates that the introduction of diaza-peptide units is a valid approach for designing mimics or inhibitors of protein-protein interaction and other therapeutic peptidomimetics. This study also reveals that small peptide foldamers can play the same role as physiological chaperone proteins and opens a new way to design inhibitors of amyloid protein aggregation, a hallmark of more than 20 serious human diseases such as Alzheimer's disease.

Intergenerational effects on fertility in male and female mice after chronic exposure to environmental doses of NSAIDs and 17α-ethinylestradiol mixtures.

Non-steroidal anti-inflammatory drugs (NSAIDs) and 17α-ethinylestradiol (EE2) are extensively used in human and veterinary medicine. Due to their partial removal by wastewater treatment plants, they are frequent environmental contaminants, particularly in drinking water. Here, we investigated the adverse outcomes of chronic exposure to mixtures of NSAIDs (ibuprofen, 2hydroxy-ibuprofen, diclofenac) and EE2 at two environmentally relevant doses in drinking water, on the reproductive organ development and fertility in F1-exposed male and female mice and in their F2 offspring. In male and female F1 mice, which were exposed to these mixtures, reproductive organ maturation, estrous cyclicity, and spermiogenesis were altered. These defects were observed also in F2 animals, in addition to some specific sperm parameter alterations in F2 males. Transcriptomic analysis revealed significant changes in gene expression patterns and associated pathways implicated in testis and ovarian physiology. Chronic exposure of mice to NSAID and EE2 mixtures at environmental doses intergenerationally affected male and female fertility (i.e. total number of pups and time between litters). Our study provides new insights into the adverse effects of these pharmaceuticals on the reproductive health and will facilitate the implementation of a future regulatory environmental risk assessment of NSAIDs and EE2 for human health.

Structure-Based Design of a Lead Compound Derived from Natural Schweinfurthins with Antitumor Properties That Target Oxysterol-Binding Protein.

Schweinfurthins (SWs) are naturally occurring prenylated stilbenes with promising anticancer properties. They act through a novel mechanism of action similar to that of other families of natural compounds. Their known target, oxysterol-binding protein (OSBP), plays a crucial role in controlling the intracellular distribution of cholesterol. We synthesized 15 analogues of SWs and demonstrated for the first time that their cytotoxicity as well as that of natural derivatives correlates with their affinity for OSBP. Through this extensive SAR study, we selected one synthetic analogue obtained in one step from SW-G. Using its fluorescence properties, we showed that this compound recapitulates the effect of natural SW-G in cells and confirmed that it leads to cell death via the same mechanism. Finally, after pilot PK experiments, we provided the first evidence of its in vivo efficacy in combination with temozolomide in a patient-derived glioblastoma xenograft model.

Evaluation of a six-probe cocktail (caffeine, tolbutamide, omeprazole, dextromethorphan, midazolam, and digoxin) approach to estimate hepatic drug detoxification capability and dosage requirements after a single oral dosing in healthy Chinese volunteers.

The primary objectives of this study were to investigate the suitability of a 6-probe cocktail (caffeine, tolbutamide, omeprazole, dextromethorphan, midazolam, and digoxin) to be used as a tool for assessing the activity of drug metabolizing enzymes and transporters, and examine differences in the way drugs are handled among groups with different genetic regulation of these processes. This was a single-center, open-label, phase I clinical study involving 20 young, healthy Chinese volunteers (equal gender distribution). The subjects were administered a single, oral dose of the 6-probe cocktail and serum samples were collected to assess the disposition of the different probe substrates and produced metabolites. The serum samples were analyzed using ultra-performance liquid chromatography-electrospray ionization-tandem mass spectrometry technology. The DNA samples were subjected to whole exome sequencing. Nineteen healthy volunteers completed the study. The 6-probe cocktail was safe and well-tolerated by all the subjects. The parent substrates and metabolites-caffeine (paraxanthine), dextromethorphan (dextrorphan), digoxin, midazolam (1-hydroxy-midazolam), omeprazole (5-hydroxy-omeprazole), and tolbutamide (4-hydroxy-tolbutamide)-were within the detectable window. Genetic variations known to alter drug metabolism (CYP2D6*10, CYP2C19*2, CYP2C19*3, and CYP2C9*3) were identified and generally correlated with phenotypic status. The 6-probe cocktail appeared to be suitable for assessing drug metabolizing activities. This, in conjunction with individual genetics, will pave the way for the implementation of personalized medicine in clinical practice. This will hopefully improve efficacy and reduce the incidence of adverse drug reactions.

Biological Investigation of a Water-Soluble Isoginkgetin-Phosphate Analogue, Targeting the Spliceosome with In Vivo Antitumor Activity.

The first total synthesis of the natural product Isoginkgetin as well as four water-soluble Isoginkgetin-phosphate analogues is reported herein. Moreover, the full study of the IP2 phosphate analogue with respect to pharmacological properties (metabolic and plasmatic stabilities, pharmacokinetic, off-target, etc.) as well as in vitro and in vivo biological activities are disclosed herein.

TRIM28-dependent SUMOylation protects the adult ovary from activation of the testicular pathway.

Gonadal sexual fate in mammals is determined during embryonic development and must be actively maintained in adulthood. In the mouse ovary, oestrogen receptors and FOXL2 protect ovarian granulosa cells from transdifferentiation into Sertoli cells, their testicular counterpart. However, the mechanism underlying their protective effect is unknown. Here, we show that TRIM28 is required to prevent female-to-male sex reversal of the mouse ovary after birth. We found that upon loss of Trim28, ovarian granulosa cells transdifferentiate to Sertoli cells through an intermediate cell type, different from gonadal embryonic progenitors. TRIM28 is recruited on chromatin in the proximity of FOXL2 to maintain the ovarian pathway and to repress testicular-specific genes. The role of TRIM28 in ovarian maintenance depends on its E3-SUMO ligase activity that regulates the sex-specific SUMOylation profile of ovarian-specific genes. Our study identifies TRIM28 as a key factor in protecting the adult ovary from the testicular pathway.

Concentrations of tenofovir and emtricitabine in breast milk of HIV-1-infected women in Abidjan, Cote d'Ivoire, in the ANRS 12109 TEmAA Study, Step 2.

The aim was to evaluate emtricitabine (FTC) and tenofovir (TFV) neonatal ingestion through breast milk. Median TFV and FTC breast milk doses represented 0.03% and 2%, respectively, of the proposed oral infant doses. Neonatal simulated plasma concentrations were extremely low for TFV but between the half-maximal inhibitory concentration and the adult minimal expected concentration for FTC. The rare children who will acquire HIV despite TDF-FTC therapy will need to be monitored for viral resistance acquisition.