title: Direct effect of streptozotocin on periodontal ligament cells through myeloid cell leukemia-1.
abstract: OBJECTIVE
  We hypothesized that streptozotocin (STZ) has a direct impact on periodontal ligament cell (PDL) damage as a potential direct inducer of periodontitis.
  
  
  BACKGROUND
  Since diabetes was accepted as one of the risk factors for the development of periodontal disease, various scientific studies have been undertaken in the STZ-induced periodontal disease models. STZ induces β-cell damage and subsequent diabetes development in vivo. Until now, assessment of the impacts of STZ-induced experimental diabetes on periodontitis has generally been conducted on the fundamental assumption that STZ have no direct action on PDL and its function. However, several recent studies suggest that STZ also directly affect many different biological functions in various tissues or organs.
  
  
  METHODS
  To assess the apoptotic effects of STZ on PDLs, they were treated with or without STZ at different concentrations. Qualitative estimation of apoptotic cell death was obtained by live/dead assay. The expression levels of apoptosis-related proteins were evaluated by western blot analysis.
  
  
  RESULTS
  STZ inhibits growth and induces apoptosis in PDLs in a dose-dependent manner. Furthermore, STZ dramatically induced Mcl-1 downregulation in a proteasome-dependent manner and thereby induced apoptosis of PDLs through the Bak/Bax apoptotic signaling pathway.
  
  
  CONCLUSIONS
  Our results support the hypothesis that suppression of the cellular Mcl-1 levels by STZ may be at least partly attributed to the development of periodontitis in STZ-induced diabetic animal models.
authors.affiliation: Department of Oral Pathology, School of Dentistry and Institute of Biodegradable Material, Institute of Oral Bioscience, Brain Korea 21 Project, Chonbuk National University, Jeon-ju, Korea.
authors.forename: J-A
authors.initials: JA
authors.lastname: Shin
authors.affiliation: Department of Molecular Medicine, School of Medicine, Gachon University, Incheon, South Korea.|Lee Gil Ya Cancer and Diabetes Institute, Incheon, South Korea.
authors.forename: I-S
authors.initials: IS
authors.lastname: Hong
authors.affiliation: Department of Oral Pathology, School of Dentistry and Institute of Biodegradable Material, Institute of Oral Bioscience, Brain Korea 21 Project, Chonbuk National University, Jeon-ju, Korea.
authors.forename: S
authors.initials: S
authors.lastname: Oh
authors.affiliation: Department of Oral Pathology, School of Dentistry and Institute of Biodegradable Material, Institute of Oral Bioscience, Brain Korea 21 Project, Chonbuk National University, Jeon-ju, Korea.
authors.forename: S-D
authors.initials: SD
authors.lastname: Cho
authors.affiliation: Department of Oral Medicine, School of Dentistry and Research Institute of Clinical Medicine of Chonbuk, National University, Biomedical Research Institute, Chonbuk National University Hospital, Jeonju, Korea.
authors.forename: K-E
authors.initials: KE
authors.lastname: Lee
mesh_terms: D000903:Antibiotics, Antineoplastic / Q000378:metabolism*; D017209:Apoptosis; D002460:Cell Line; D002470:Cell Survival / Q000187:drug effects; D005347:Fibroblasts / Q000187:drug effects* / Q000502:physiology*; D006801:Humans; D064549:Myeloid Cell Leukemia Sequence 1 Protein / Q000378:metabolism*; D010513:Periodontal Ligament / Q000166:cytology; D013311:Streptozocin / Q000378:metabolism*
chemical_list: D000903:Antibiotics, Antineoplastic; D064549:Myeloid Cell Leukemia Sequence 1 Protein; D013311:Streptozocin
keywords: apoptosis; diabetes; periodontitis; streptozotocin