Pascal Reboul

Bryophytes produce rare and bioactive compounds with a broad range of therapeutic potential, and many species are reported in ethnomedicinal uses. However, only a few studies have investigated their potential as natural anti-inflammatory drug candidate compounds. The present study investigates the anti-inflammatory effects of thirty-two species of bryophytes, including mosses and liverworts, on Raw 264.7 murine macrophages stimulated with lipopolysaccharide (LPS) or recombinant human peroxiredoxin (hPrx1). The 70% ethanol extracts of bryophytes were screened for their potential to reduce the production of nitric oxide (NO), an important pro-inflammatory mediator. Among the analyzed extracts, two moss species significantly inhibited LPS-induced NO production without cytotoxic effects. The bioactive extracts of Dicranum majus and Thuidium delicatulum inhibited NO production in a concentration-dependent manner with IC₅₀ values of 1.04 and 1.54 µg/mL, respectively. The crude 70% ethanol and ethyl acetate extracts were then partitioned with different solvents in increasing order of polarity (n-hexane, diethyl ether, chloroform, ethyl acetate, and n-butanol). The fractions were screened for their inhibitory effects on NO production stimulated with LPS at 1 ng/mL or 10 ng/mL. The NO production levels were significantly affected by the fractions of decreasing polarity such as n-hexane and diethyl ether ones. Therefore, the potential of these extracts to inhibit the LPS-induced NO pathway suggests their effective properties in attenuating inflammation and could represent a perspective for the development of innovative therapeutic agents.

Mechanical overload and aging are the main risk factors of osteoarthritis (OA). Galectin 3 (GAL3) is important in the formation of primary cilia, organelles that are able to sense mechanical stress. The objectives were to evaluate the role of GAL3 in chondrocyte primary cilium formation and in OA in mice. Chondrocyte primary cilium was detected in vitro by confocal microscopy. OA was induced by aging and partial meniscectomy of wild-type (WT) and Gal3-null 129SvEV mice (Gal3^−/−). Primary chondrocytes were isolated from joints of new-born mice. Chondrocyte apoptosis was assessed by Terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL), caspase 3 activity and cytochrome c release. Gene expression was assessed by qRT-PCR. GAL3 was localized at the basal body of the chondrocyte primary cilium. Primary cilia of Gal3^−/− chondrocytes were frequently abnormal and misshapen. Deletion of Gal3 triggered premature OA during aging and exacerbated joint instability-induced OA. In both aging and surgery-induced OA cartilage, levels of chondrocyte catabolism and hypertrophy markers and apoptosis were more severe in Gal3^−/− than WT samples. In vitro, Gal3 knockout favored chondrocyte apoptosis via the mitochondrial pathway. GAL3 is a key regulator of cartilage homeostasis and chondrocyte primary cilium formation in mice. Gal3 deletion promotes OA development.

Dans le cadre du Cursus Master Ingénieur (CMI) de Biologie Santé Environnement (BSE) développé à l’Université de Lorraine en France, une équipe pluridisciplinaire propose aux étudiants de première année de cette formation une Activité de Mise en Situation (AMS). Par groupe de trois ou quatre, ils/elles doivent effectuer une recherche de documentation scientifique sur un sujet de société lié aux sciences pour ensuite élaborer un argumentaire pro- et anti- qui sera présenté oralement. L’équipe pédagogique accompagne les étudiants tout au long du processus, dans l’objectif de favoriser l’intégration et la réussite des nouveaux étudiants. Il s’agit aussi de renforcer des compétences construites au lycée, notamment des compétences informationnelles afin de faciliter l’appropriation de la littéracie universitaire. L’article examine la question des effets de ce dispositif d’accompagnement sur les étudiants et les accompagnants. L’analyse des résultats des étudiants, de leurs réponses à une enquête d’auto-évaluation, de celles des tuteurs lors d’entretiens semi-directifs indique que cette AMS contribue à l’acquisition de compétences et au développement de l’autonomie des étudiants. Les enseignants témoignent d’un changement de posture dans leur rôle d’accompagnant, changement qui transforme aussi leurs pratiques professionnelles dans d’autres cours.

Bone is the most common metastatic site for breast cancer. Estrogen-related-receptor alpha (ERRα) has been implicated in cancer cell invasiveness. Here, we established that ERRα promotes spontaneous metastatic dissemination of breast cancer cells from primary mammary tumors to the skeleton. We carried out cohort studies, pharmacological inhibition, gain-of-function analyses in vivo and cellular and molecular studies in vitro to identify new biomarkers in breast cancer metastases. Meta-analysis of human primary breast tumors revealed that high ERRα expression levels were associated with bone but not lung metastases. ERRα expression was also detected in circulating tumor cells from metastatic breast cancer patients. ERRα overexpression in murine 4T1 breast cancer cells promoted spontaneous bone micro-metastases formation when tumor cells were inoculated orthotopically, whereas lung metastases occurred irrespective of ERRα expression level. In vivo, Rank was identified as a target for ERRα. That was confirmed in vitro in Rankl stimulated tumor cell invasion, in mTOR/pS6K phosphorylation, by transactivation assay, ChIP and bioinformatics analyses. Moreover, pharmacological inhibition of ERRα reduced primary tumor growth, bone micro-metastases formation and Rank expression in vitro and in vivo. Transcriptomic studies and meta-analysis confirmed a positive association between metastases and ERRα/RANK in breast cancer patients and also revealed a positive correlation between ERRα and BRCA1^mut carriers. Taken together, our results reveal a novel ERRα/RANK axis by which ERRα in primary breast cancer promotes early dissemination of cancer cells to bone. These findings suggest that ERRα may be a useful therapeutic target to prevent bone metastases.

Purification of recombinant proteins remains a bottleneck for downstream processing. The authors engineered a new galectin 3 truncated form (CRD_SAT), functionally and structurally characterized, with preserved solubility and lectinic activity. Taking advantage of these properties, the authors designed an expression vector (pCARGHO), suitable for CRD_SAT‐tagged protein expression in prokaryotes. CRD_SAT binds to lactose‐Sepharose with a high specificity and facilitates solubilization of fusion proteins. This tag is structurally stable and can be easily removed from fusion proteins using TEV protease. Furthermore, due to their basic isoelectric point (pI), CRD_SAT, and TEV are efficiently eliminated using cationic exchange chromatography. When pI of the protein of interest (POI) and CRD_SAT are close, other chromatographic methods are successfully tested. Using CRD_SAT tag, the authors purified several proteins from prokaryote and eukaryote origin and demonstrated as examples, the preservation of both Escherichia coli Thioredoxin 1 and human CDC25B_cd activities. Overall, yields of proteins obtained after tag removal are about 5–50 mg per litre of bacterial culture. Our purification method displays various advantages described herein that may greatly interest academic laboratories, biotechnology, and pharmaceutical companies.

Based on a novel approach suggesting a role of adipose tissue in osteoarthritis (OA), we aimed to determine whether the infrapatellar fat pad (IFP) may affect joint cell functions through adipokines. The conditioned media of IFP and subcutaneous adipose tissue from OA patients were used to determine the production of leptin and adiponectin, and to stimulate chondrocytes and fibroblast-like synoviocytes (FLS). Blocking experiments were carried out to evaluate the contribution of adipokines to IFP effects. The gene expression of inflammatory and degradative proteins, growth factors and components of the extracellular matrix, and the production of inflammatory mediators and metalloproteases were determined to evaluate cell response to fat-conditioned media. IFP releases elevated amounts of leptin and adiponectin independently of the body mass index and the gender. The conditioned media from IFP strongly induce the expression of inflammatory genes in both articular cells and the expression of degradative genes in chondrocytes, but remain ineffective in regulating the expression of aggrecan, type 2 collagen or growth factors. Blocking leptin or adiponectin does not change the cell response to IFP. A great variability between patients is found when compared the inflammatory activity of paired samples of IFP and subcutaneous adipose tissue. IFP may trigger both cartilage destruction and inflammation of the synovium, but not through leptin or adiponectin. The data suggest also that IFP may have specific inflammatory phenotypic features independent from the general phenotype found in obesity.