Nunthawan Nowwarote1,2,3, Thanaphum Osathanon1, Benjamin P J Fournier2,3, Thanakorn Theerapanon4, Somchai Yodsanga5, Paksinee Kamolratanakul6, Thantrira Porntaveetus4, Vorasuk Shotelersuk7,8. 1. Dental Stem Cell Biology Research Unit and Department of Anatomy, Faculty of Dentistry, Chulalongkorn University, Bangkok, Thailand. 2. Centre de Recherche des Cordeliers, Universite de Paris, Sorbonne Universite, Paris, France. 3. Dental Faculty Garanciere, Oral Biology Department, Universite de Paris, Paris, France. 4. Center of Excellence in Genomics and Precision Dentistry, Department of Physiology, Faculty of Dentistry, Chulalongkorn University, Bangkok, Thailand. 5. Department of Oral Pathology, Faculty of Dentistry, Chulalongkorn University, Bangkok, Thailand. 6. Department of Oral and Maxillofacial Surgery, Faculty of Dentistry, Chulalongkorn University, Bangkok, Thailand. 7. Center of Excellence for Medical Genomics, Medical Genomics Cluster, Department of Pediatrics, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand. 8. Excellence Center for Genomics and Precision Medicine, King Chulalongkorn Memorial Hospital, The Thai Red Cross Society, Bangkok, Thailand.
Abstract
OBJECTIVE: To investigate the role of phosphatase and tensin homolog (PTEN) in dental pulp cells (hDPs) and adipose-derived mesenchymal stem cells (hADSCs). MATERIALS AND METHODS: Genetic variant was identified with exome sequencing. The hDPs isolated from a patient with Cowden syndrome were investigated for their proliferation, osteogenesis, adipogenesis, and gene expression compared with controls. The normal hDPs and hADSCs were treated with the PTEN inhibitor, VO-OHpic trihydrate (VOT), to investigate the effect of PTEN inhibition. RESULTS: A heterozygous nonsense PTEN variant, c.289C>T (p.Gln97*), was identified in the Cowden patient's blood and intraoral lipomas. The mutated hDPs showed significantly decreased proliferation, but significantly upregulated RUNX2 and OSX expression and mineralization, indicating enhanced osteogenic ability in mutated cells. The normal hDPs treated with VOT showed the decreases in proliferation, colony formation, osteogenic marker genes, alkaline phosphatase activity, and mineral deposition, suggesting that PTEN inhibition diminishes proliferation and osteogenic potential of hDPs. Regarding adipogenesis, the VOT-treated hADSCs showed a reduced number of cells containing lipid droplets, suggesting that PTEN inhibition might compromise adipogenic ability of hADSCs. CONCLUSIONS: PTEN regulates proliferation, enhances osteogenesis of hDPs, and induces adipogenesis of hADSCs. The gain-of-function PTEN variant, p.Gln97*, enhances osteogenic ability of PTEN in hDPs.
OBJECTIVE: To investigate the role of phosphatase and tensin homolog (PTEN) in dental pulp cells (hDPs) and adipose-derived mesenchymal stem cells (hADSCs). MATERIALS AND METHODS: Genetic variant was identified with exome sequencing. The hDPs isolated from a patient with Cowden syndrome were investigated for their proliferation, osteogenesis, adipogenesis, and gene expression compared with controls. The normal hDPs and hADSCs were treated with the PTEN inhibitor, VO-OHpic trihydrate (VOT), to investigate the effect of PTEN inhibition. RESULTS: A heterozygous nonsense PTEN variant, c.289C>T (p.Gln97*), was identified in the Cowden patient's blood and intraoral lipomas. The mutated hDPs showed significantly decreased proliferation, but significantly upregulated RUNX2 and OSX expression and mineralization, indicating enhanced osteogenic ability in mutated cells. The normal hDPs treated with VOT showed the decreases in proliferation, colony formation, osteogenic marker genes, alkaline phosphatase activity, and mineral deposition, suggesting that PTEN inhibition diminishes proliferation and osteogenic potential of hDPs. Regarding adipogenesis, the VOT-treated hADSCs showed a reduced number of cells containing lipid droplets, suggesting that PTEN inhibition might compromise adipogenic ability of hADSCs. CONCLUSIONS: PTEN regulates proliferation, enhances osteogenesis of hDPs, and induces adipogenesis of hADSCs. The gain-of-function PTEN variant, p.Gln97*, enhances osteogenic ability of PTEN in hDPs.