University of Rennes

About: University of Rennes is a education organization based out in Rennes, France. It is known for research contribution in the topics: Population & Catalysis. The organization has 18404 authors who have published 40374 publications receiving 995327 citations.

Chiral transfer in coordination complexes: towards molecular materials

Abstract: In this critical review we present examples of coordination complexes with efficient chiral transfer determining stereochemistry at the metal centre and throughout the overall molecular assembly. The general features controlling the transmission of chirality are presented. The transfer of chirality are considered here with the special purpose of obtaining a molecular material displaying a particular property or function. Coordination complexes in fields as diverse as chiral luminescent materials, homochiral MOFs, chiral liquid crystals, enantioselective sensors, chiroptical switches, and magnetochiral compounds are presented (162 references).

The Sertoli-germ cell communication network in mammals.

Abstract: As soon as scientists began to study testicular structure and function, the concept emerged that SCs and GCs communicate We now know that the seminiferous epithelium is certainly one of the most complex tissues and that the structural and functional supports of SC-GC communication are extremely elaborate At all stages of sexual maturation, somatic cells and GCs have developed a formidable set of communication devices that are involved in attachment, displacement, cell shaping, and cell-cell transfer of molecules and cellular materials Some of the best morphologists since the nineteenth century have studied the anatomical basis of the SC-GC dialogue and have laid the foundations to the understanding of the spermatogenic process Further experimental efforts are still being made In particular, new data are emerging that have enabled scientists to go beyond the descriptional or deductive aspects and to tackle the mechanical aspects From the functional point of view, significant progress has been made in deciphering SC-GC cell language The unique strategic position of the SC allows this cell type to receive, integrate, and emit all the signals required for the spermatogenic process to or from the extratubular compartment (eg, FSH, testosterone), the peritubular cells (eg, P-Mod-S), and GCs themselves Its location also allows it to coordinate GC activity in both the transversal and the longitudinal axes of the seminiferous tubule The SC barrier and SC products create the physical and chemical microenvironments required for the completion of each of the different steps of spermatogenesis In addition to the tubule fluid, the SC products directly or indirectly implicated in GC control are proteins, peptides, and steroid(s) involved in germ cell proliferation, differentiation, and metabolism; transport/binding proteins; proteases; extracellular matrix components; energy metabolites; antiproteases; and various membrane components Sertoli cell polarization results from the existence of SC-SC occluding junctions The products required for the mitotic phase of spermatogenesis may principally be secreted basally, whereas those required for meiotic division, spermiogenesis, and sperm cells may preferentially be secreted apically The interaction between SC factors and GCs is mediated by GC membrane receptors and different endocytic processes The GC secondary pathway(s) involved in SC action remains a mystery Germ cell markers that would enable a precise assessment of SC influence are lacking Changes in the composition of the GC complement and in GC size and shape, as well as GC divisions and migration, profoundly affect SC morphology and function(ABSTRACT TRUNCATED AT 400 WORDS)

Single-Cell Analysis Reveals Fibroblast Clusters Linked to Immunotherapy Resistance in Cancer.

Abstract: A subset of cancer-associated fibroblasts (FAP+/CAF-S1) mediates immunosuppression in breast cancers, but its heterogeneity and its impact on immunotherapy response remain unknown. Here, we identify 8 CAF-S1 clusters by analyzing more than 19,000 single CAF-S1 fibroblasts from breast cancer. We validate the five most abundant clusters by flow cytometry and in silico analyses in other cancer types, highlighting their relevance. Myofibroblasts from clusters 0 and 3, characterized by extracellular matrix proteins and TGFβ signaling, respectively, are indicative of primary resistance to immunotherapies. Cluster 0/ecm-myCAF upregulates PD-1 and CTLA4 protein levels in regulatory T lymphocytes (Tregs), which, in turn, increases CAF-S1 cluster 3/TGFβ-myCAF cellular content. Thus, our study highlights a positive feedback loop between specific CAF-S1 clusters and Tregs and uncovers their role in immunotherapy resistance. SIGNIFICANCE: Our work provides a significant advance in characterizing and understanding FAP+ CAF in cancer. We reached a high resolution at single-cell level, which enabled us to identify specific clusters associated with immunosuppression and immunotherapy resistance. Identification of cluster-specific signatures paves the way for therapeutic options in combination with immunotherapies.This article is highlighted in the In This Issue feature, p. 1241.