Supervisors info:
Γεώργιος Λυρίτης, Ομότιμος Καθηγητής, Ιατρική, ΕΚΠΑ
Ισμήνη- Νίκη Δοντά, Καθηγήτρια, Ιατρική, ΕΚΠΑ
Ιωάννης Τριανταφυλλόπουλος, Επίκουρος Καθηγητής, Ιατρική, ΕΚΠΑ
Summary:
Genomic data from microarray studies that were available from GEO Database NCBI, were collected. The data included stromal cells, pre osteoblasts, osteoblasts, osteocytes and macrophage precursor cells from bone marrow cells that were cultured in space or ground based facilities under real or simulated microgravity, 1g or 2g gravity. Bioinformatics analysis revealed significant relation between stromal cells cultured for 192h and osteocytes cultured for 48h in 0g. Furthermore, osteocytes showed common expression pattern among 0g, 1g and 2g regardless of concomitant factors. All cell types presented an expression pattern amongst 0g, 1g and 2g gravity that moved on a certain level, thus affording predictive value. Genes that reached statistical significance were analyzed using Gene ontology and KEGG pathways, for their implication in metabolic pathways. The later, participated in MAPK signaling, osteoclast differentiation, neuronal intercommunication, purine and tryptophan metabolism, toxoplasmosis, cancer pathways, immune reactions and cytokine production. Tnfrs1a (Tumor necrosis factor receptor member 1), Il1r1 (Interleukin 1 receptor type 1), MAPK9 (mitogen-activated protein kinase 9), MAP2K7 (mitogen-activated protein kinase 7) were expressed in more than two of the aforementioned pathways. These genes are implicated in inflammatory responses, immune system activation (IgE mediated), osteoclast differentiation and MAPK signaling,, causing activation of NF kB transcription factor complex. Therefore, osteoclast activation is mediated directly or via inflammatory routes, resulting in osteolysis.
Keywords:
Osteoblasts, Microgravity, Osteocytes, Gene expression