Feron, F. | bioRxiv Science

bioRxiv2021

A comparative in vitro and in vivo study of osteogenicity by using two biomaterials and two human mesenchymal stem cell subtypes

Bone repair induced by stem cells and biomaterials may represent an alternative to autologous bone grafting. Here, we compared the efficiency of two biomaterials - biphasic calcium phosphate (BCP) and bioactive glass (BG) - when loaded with either adult bone marrow mesenchymal stem cells (BM-MSCs) or newborn nasal ecto-mesenchymal stem cells (NE-MSCs), the latter being collected for further repair of lip cleft-associated bone loss. Both cell types display the typical stem cell surface markers CD73+/CD90+/CD105+/nestin, and exhibit the MSC-associated osteogenic, chondrogenic and adipogenic multipotency. NE-MSCs produce less collagen and alkaline phosphatase than BM-MSCs. At the transcript level, NE-MSCs express more abundantly three genes coding for bone sialoprotein, osteocalcin and osteopontin, while BM-MSCs produce extra copies of RUNX2. BM-MSCs and NE-MSCs adhere and survive on BCP and BG. In vivo experiments reveal that bone formation is only observed with BM-MSCs transplanted on BCP biomaterial.

bioengineering↗

bioRxiv2021

Epigenetic regulation clocks the multigenerational olfactory imprinting in C. elegans

Imprinting is an early sensory life experience that induces adult behaviours, such as mother recognition or homing. In a previous study, we demonstrated a striking olfactory imprinting in C. elegans that can be inherited over generations. When exposed to specific odorants during a timely controlled post-hatch period, C. elegans worms display during adulthood an enhanced migration towards these molecules. In order to unveil some of the genetic and epigenetic factors that are responsible for such a behavioural plasticity, we assessed the role of heterochronic genes using a candidate gene approach. We report here that translation of the Hunchback-Like 1 (HBL1) transcription factor in the sensory processing interneuron AIY, is a determining factor for olfactory plasticity timing in C.elegans. HBL1 may associate to the SPR1/CoREST co-repressor, the lysine demethylase SPR5/LSD1 and the histone deacetylase HDA3 to lengthen the plasticity period, whereas the translation initiation factor IFE-4 and the histone deacetylase HDA2 abridge it. We also observed that lengthened plasticity periods allow proportionally faster stable behavioral adaptation of C. elegans populations. We conclude that plasticity timing is a key factor, not only to transiently adapt individuals but also to stably adapt animal populations via multigenerational accumulation of experience.

animal behavior and cognition↗