Mechanical strain delivers anti-apoptotic and proliferative signals to gingival fibroblasts.
Physical forces play a critical role in the survival and proliferation of many cell types, including fibroblasts. Gingival fibroblasts are exposed to mechanical stress during mastication, orthodontic tooth movement, and wound healing following periodontal surgery. The aim of this study was to examine the effect of mechanical strain on human gingival fibroblasts (hGF). Cells were subjected to short-term (up to 60 min) and long-term (up to 48 hrs) 20% average elongation at 0.1 Hz. We monitored survival signaling by evaluating the phosphorylation status and localization of Forkhead box (FoxO) family members, which are mediators of apoptosis. We also examined strain-induced proliferation by measuring the level of proliferating cell nuclear antigen (PCNA). We observed that cyclic strain caused the phosphorylation and retention in the cytoplasm of FoxO family members. Moreover, mechanical strain resulted in increased ERK kinase phosphorylation and PCNA expression. In conclusion, cyclic strain delivers anti-apoptotic and proliferative stimuli to hGF.
Enders Research Laboratories, Rm 1150.2, Children's Hospital, 300 Longwood Avenue, Boston, MA 02115, USA. Theodora.Danciu@tch.harvard.edu
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Danciu
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Gagari
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Adam
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Damoulis
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Freeman
D017209:Apoptosis / Q000502:physiology; D002455:Cell Division / Q000502:physiology; D048429:Cell Size / Q000502:physiology; D002478:Cells, Cultured; D004268:DNA-Binding Proteins / Q000378:metabolism*; D005347:Fibroblasts / Q000378:metabolism*; D000071161:Forkhead Box Protein O1; D051858:Forkhead Transcription Factors; D005881:Gingiva / Q000166:cytology / Q000378:metabolism*; D006801:Humans; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism; D018809:Proliferating Cell Nuclear Antigen / Q000378:metabolism*; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism; D011518:Proto-Oncogene Proteins / Q000378:metabolism; D051057:Proto-Oncogene Proteins c-akt; D015398:Signal Transduction / Q000502:physiology*; D013314:Stress, Mechanical; D013997:Time Factors; D014157:Transcription Factors / Q000378:metabolism*; D014178:Translocation, Genetic
D004268:DNA-Binding Proteins; C085126:FOXO1 protein, human; D000071161:Forkhead Box Protein O1; D051858:Forkhead Transcription Factors; D018809:Proliferating Cell Nuclear Antigen; D011518:Proto-Oncogene Proteins; D014157:Transcription Factors; D017346:Protein Serine-Threonine Kinases; D051057:Proto-Oncogene Proteins c-akt; D020928:Mitogen-Activated Protein Kinases