title: Identification of Pathways Mediating Growth Differentiation Factor5-Induced Tenogenic Differentiation in Human Bone Marrow Stromal Cells.
abstract: To date, the molecular signalling mechanisms which regulate growth factors-induced MSCs tenogenic differentiation remain largely unknown. Therefore, a study to determine the global gene expression profile of tenogenic differentiation in human bone marrow stromal cells (hMSCs) using growth differentiation factor 5 (GDF5) was conducted. Microarray analyses were conducted on hMSCs cultures supplemented with 100 ng/ml of GDF5 and compared to undifferentiated hMSCs and adult tenocytes. Results of QuantiGene® Plex assay support the use and interpretation of the inferred gene expression profiles and pathways information. From the 27,216 genes assessed, 873 genes (3.21% of the overall human transcriptome) were significantly altered during the tenogenic differentiation process (corrected p<0.05). The genes identified as potentially associated with tenogenic differentiation were ARHGAP29, CCL2, integrin alpha 8 and neurofilament medium polypeptides. These genes, were mainly associated with cytoskeleton reorganization (stress fibers formation) signaling. Pathway analysis demonstrated the potential molecular pathways involved in tenogenic differentiation were: cytoskeleton reorganization related i.e. keratin filament signaling and activin A signaling; cell adhesion related i.e. chemokine and adhesion signaling; and extracellular matrix related i.e. arachidonic acid production signaling. Further investigation using atomic force microscopy and confocal laser scanning microscopy demonstrated apparent cytoskeleton reorganization in GDF5-induced hMSCs suggesting that cytoskeleton reorganization signaling is an important event involved in tenogenic differentiation. Besides, a reduced nucleostemin expression observed suggested a lower cell proliferation rate in hMSCs undergoing tenogenic differentiation. Understanding and elucidating the tenogenic differentiation signalling pathways are important for future optimization of tenogenic hMSCs for functional tendon cell-based therapy and tissue engineering.
authors.affiliation: Tissue Engineering Group (TEG), National Orthopaedic Centre of Excellence for Research and Learning (NOCERAL), Department of Orthopaedic Surgery, Faculty of Medicine, University of Malaya, Pantai Valley, Kuala Lumpur, 50603, Malaysia.
authors.forename: Sik-Loo
authors.initials: SL
authors.lastname: Tan
authors.affiliation: Tissue Engineering Group (TEG), National Orthopaedic Centre of Excellence for Research and Learning (NOCERAL), Department of Orthopaedic Surgery, Faculty of Medicine, University of Malaya, Pantai Valley, Kuala Lumpur, 50603, Malaysia.
authors.forename: Tunku Sara
authors.initials: TS
authors.lastname: Ahmad
authors.affiliation: Tissue Engineering Group (TEG), National Orthopaedic Centre of Excellence for Research and Learning (NOCERAL), Department of Orthopaedic Surgery, Faculty of Medicine, University of Malaya, Pantai Valley, Kuala Lumpur, 50603, Malaysia.
authors.forename: Wuey-Min
authors.initials: WM
authors.lastname: Ng
authors.affiliation: Tissue Engineering Group (TEG), National Orthopaedic Centre of Excellence for Research and Learning (NOCERAL), Department of Orthopaedic Surgery, Faculty of Medicine, University of Malaya, Pantai Valley, Kuala Lumpur, 50603, Malaysia.
authors.forename: Amir Abbas
authors.initials: AA
authors.lastname: Azlina
authors.affiliation: Tissue Engineering Group (TEG), National Orthopaedic Centre of Excellence for Research and Learning (NOCERAL), Department of Orthopaedic Surgery, Faculty of Medicine, University of Malaya, Pantai Valley, Kuala Lumpur, 50603, Malaysia.
authors.forename: Mahmood Merican
authors.initials: MM
authors.lastname: Azhar
authors.affiliation: School of Medicine & Health Sciences, Monash University, Sunway Campus, Selangor, Malaysia.
authors.forename: Lakshmi
authors.initials: L
authors.lastname: Selvaratnam
authors.affiliation: Tissue Engineering Group (TEG), National Orthopaedic Centre of Excellence for Research and Learning (NOCERAL), Department of Orthopaedic Surgery, Faculty of Medicine, University of Malaya, Pantai Valley, Kuala Lumpur, 50603, Malaysia.
authors.forename: Tunku
authors.initials: T
authors.lastname: Kamarul
mesh_terms: D001854:Bone Marrow Cells / Q000166:cytology*; D002454:Cell Differentiation / Q000187:drug effects*; D019070:Cell Lineage; D002478:Cells, Cultured; D018932:Chemokine CCL2 / Q000235:genetics / Q000378:metabolism; D003599:Cytoskeleton / Q000473:pathology; D020690:GTPase-Activating Proteins / Q000235:genetics / Q000378:metabolism; D055428:Growth Differentiation Factor 5 / Q000235:genetics / Q000378:metabolism / Q000494:pharmacology*; D006801:Humans; D039001:Integrin alpha Chains / Q000235:genetics / Q000378:metabolism; D059630:Mesenchymal Stem Cells / Q000166:cytology / Q000378:metabolism*; D018625:Microscopy, Atomic Force; D008856:Microscopy, Fluorescence; D020411:Oligonucleotide Array Sequence Analysis; D025341:Principal Component Analysis; D011994:Recombinant Proteins / Q000096:biosynthesis / Q000235:genetics / Q000494:pharmacology; D015398:Signal Transduction / Q000187:drug effects; D013710:Tendons / Q000166:cytology / Q000378:metabolism*; D059467:Transcriptome / Q000187:drug effects
chemical_list: C500429:ARHGAP29 protein, human; C111835:CCL2 protein, human; D018932:Chemokine CCL2; C525893:GDF5 protein, human; D020690:GTPase-Activating Proteins; D055428:Growth Differentiation Factor 5; D039001:Integrin alpha Chains; D011994:Recombinant Proteins; C093856:integrin alpha8