Biology subjects

Soheilmoghaddam, F.

Publications and source records attributed to Soheilmoghaddam, F..

3 recordsLinked to original sources

bioRxiv2023

Rapamycin mitigates Valproic Acid-induced teratogenicity in human and animal models by suppressing AP-1-mediated senescence

Valproic acid (VPA) is an effective and widely used anti-seizure medication but is teratogenic when used during pregnancy, affecting brain and spinal cord development for reasons that remain largely unclear. Here we designed a genetic recombinase-based SOX10 reporter system in human pluripotent stem cells that enables tracking and lineage tracing of Neural Crest cells (NCCs) in a human organoid model of the developing neural tube. We found that VPA induces extensive cellular senescence and promotes mesenchymal differentiation of human NCCs at the expense of neural lineages. We next show that the clinically-approved drug, Rapamycin, inhibits AP1-mediated senescence and restores aberrant NCC differentiation trajectory in human organoids exposed to VPA. Notably, in vivo validation in developing zebrafish highlighted the therapeutic promise of this approach. Collectively our data identifies a novel mechanism for VPA-associated neurodevelopmental teratogenicity and a potential pharmacological preventative strategy. The results exemplify the power of genetically modified human stem cell-derived organoid models for drug discovery and safety testing.

neuroscience↗

bioRxiv2022

Driving Osteocytogenesis from Mesenchymal Stem Cells in Osteon-like Biomimetic Nanofibrous Scaffolds

The repair of critical-sized bone defects, resulting from tumor resection, skeletal trauma or infection, remains a significant clinical problem. A potential solution is a tissue-engineered approach that utilises the combination of human mesenchymal stem cells (hMSCs) with synthetic biomaterial scaffolds, mimicking many of the biochemical and biophysical cues present within the native bone. Unfortunately, osteocyte cells, the orchestrators of bone maturation and homeostasis, are rarely produced within such MSC-seeded scaffolds, limiting the formation of true mature cortical bone from these synthetic implants. In this contribution, a bone morphogenic protein-6 (BMP6)-presenting osteon-like scaffolds based on electrospun poly(lactic-co-glycolic acid) (PLGA) fibrous scaffolds and poly(ethylene glycol) (PEG) based-hydrogels is reported. BMP6 peptide is shown to drive higher levels of SMAD signalling than the full-length protein counterpart. Osteon-mimetic scaffolds promoted the formation of osteocyte-like cells displaying multi-dendritic morphology and osteocyte-specific marker, E11/gp38 (E11), along with significant production of dentin matrix protein 1 (DMP1), confirming maturation of the ososteocyte-like cells. These results demonstrate that osteon-like scaffolds presenting chemo-topographical cues can drive the formation of mature osteocyte-like cells from hMSCs, without the need for osteogenic factor media supplements, providing a novel ex vivo production platform for osteocyte-like cells from human MSCs in cortical bone mimics.

bioengineering↗

bioRxiv2022

Deconstructing replicative senescence heterogeneity of human mesenchymal stem cells at single cell resolution reveals therapeutically targetable senescent cell sub-populations

Cellular senescence is characterised by a state of permanent cell cycle arrest. It is accompanied by often variable release of the so-called senescence-associated secretory phenotype (SASP) factors, and occurs in response to a variety of triggers such as persistent DNA damage, telomere dysfunction, or oncogene activation. While cellular senescence is a recognised driver of organismal ageing, the extent of heterogeneity within and between different senescent cell populations remains largely unclear. Elucidating the drivers and extent of variability in cellular senescence states is important for discovering novel targeted seno-therapeutics and for overcoming cell expansion constraints in the cell therapy industry. Here we combine cell biological and single cell RNA-sequencing approaches to investigate heterogeneity of replicative senescence in human ESC-derived mesenchymal stem cells (esMSCs) as MSCs are the cell type of choice for the majority of current stem cell therapies and senescence of MSC is a recognized driver of organismal ageing. Our data identify three senescent subpopulations in the senescing esMSC population that differ in SASP, oncogene expression, and escape from senescence. Uncovering and defining this heterogeneity of senescence states in cultured human esMSCs allowed us to identify potential drug targets that may delay the emergence of senescent MSCs in vitro and perhaps in vivo in the future.

bioinformatics↗