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Biology subjects

Feron, F.

Publications and source records attributed to Feron, F..

4 recordsLinked to original sources

Human nasal olfactory stem cell-derived extracellular vesicles improve the repair of rat nerves

Damage to the peripheral nerve impairs quality of life. Despite the advances in surgery to facilitate nerve regeneration, complete recovery remains elusive. Human olfactory ecto-mesenchymal stem cells (OEMSC) have potential for the treatment of peripheral nerve injury through the release of extracellular vesicles (EV). The current research investigates the therapeutic effects of a venous bridge, filled with freshly purified or cryoconserved OEMSC-derived EVs after a peroneal nerve loss of substance. Injured peroneal nerve was bridged with a vein into which freshly purified or cryoconserved EVs were injected or not. Nerve repair was analyzed by measuring locomotor function, muscle mechanical properties, muscle mass, axon number, and myelination. The EVs significantly increased locomotor recovery, maintained the contractile phenotype of the target muscle, and augmented the number of growing axons. These results demonstrate that EVs display a positive effect on peripheral nerve regeneration, representing an alternative to cellular therapies for peripheral nerve repair.

neuroscience↗

Culture of human nasal olfactory stem cells and their extracellular vesicles as advanced therapy medicinal products

The olfactory ecto-mesenchymal stem cell (OE-MSC) are mesenchymal stem cells originating from the lamina propria of the nasal mucosa. They have neurogenic and immune-modulatory properties and showed therapeutic potential in animal models of spinal cord trauma, hearing loss, Parkinsonss disease, amnesia, and peripheral nerve injury. In this paper we designed a protocol that meet the requirements set by human health agencies to manufacture these stem cells for clinical applications. Once purified, OE-MSCs can be used per se or expanded in order to get the extracellular vesicles (EV) they secrete. A protocol for the extraction of these vesicles was validated and the EV from the OE-MSC were functionally tested on an in vitro model. Nasal mucosa biopsies from three donors were used to validate the manufacturing process of clinical grade OE-MSC. All stages were performed by expert staff of the cell therapy laboratory according to aseptic handling manipulations, requiring grade A laminar airflow. Enzymatic digestion provides more rapidly a high number of cells and is less likely to be contaminated. Foetal calf serum was replaced with human platelet lysate and allowed stronger cell proliferation, with the optimal percentage of platelet lysate being 10%. Cultivated OE-MSCs are sterile, highly proliferative (percentage of CFU-F progenitors was 15,5%) and their maintenance does not induce chromosomal rearrangement (karyotyping and chromosomal microarray analysis were normal). These cells express the usual phenotypic markers of OE-MSC. Purification of the EVs was performed with ultracentrifugation and size exclusion chromatography. Purified vesicles expressed the recognized markers of EVs (Minimal Information for Studies of Extracellular Vesicles ("MISEV") guidelines) and promoted cell differentiation and neurite elongation in a model of neuroblastoma Neuro2a cell line. We developed a safer and more efficient manufacturing process for clinical-grade olfactory stem cells, these cells can now be used in humans. A phase I clinical trial will begin soon.An efficient protocol for the purification of the OE-MSC EVs have been validated. These EVs exert neurogenic properties in vitro. More studies are needed to understand the exact mechanisms of action of these EVs and prove their efficacy and safety in animal models.

neuroscience↗

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↗

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↗