title: Midazolam suppresses osteogenic differentiation of human bone marrow-derived mesenchymal stem cells.
abstract: OBJECTIVE
  Previous study showed that peripheral-type benzodiazepine receptors (PBRs) are expressed in human mesenchymal stem cells (hMSCs) and diazepam was found to inhibit hMCSs viability in high concentration. Midazolam, a benzodiazepine derivative, is widely used as an intravenous sedative in hospital. Peripheral-type benzodiazepine receptors (PBRs) affect a broad spectrum of cellular functions. We tested the cell viability and osteogenic differentiation of hMSCs.
  
  
  METHODS
  Bone marrow was collected from 12 patients during the operation of spine internal fixation. Cultivated with basal medium, the hBMSCs were incubated with or without midazolam (0.1, 1, 5, 10, 15, 20 µM, respectively). Cell viability were tested with MTS assay after 2, 4, 6 hours respectively. Cell morphology was observed and recorded at 6 hour. After cultivated with osteogentic medium, the hBMSCs were incubated with or without midazolam (5, 10, 15, 20 µM, respectively). Alkaline phosphatase (ALP) activity and alizarin red S staining were measured. Cultivated with osteogentic medium with or without treatment of 15 µM midazolam, the mRNA expression of ALP, type 1 collagen (COL1), Runx2 and PPARγ was analyzed by real-time RT-PCR.
  
  
  RESULTS
  The treatments of midazolam inhibited cell viability to 85%-16% respectively (p < 0.05). Rounded up phenomenon with floating cells, Membrane-blebbed cells and cytoplasmic contraction were observed after 10, 15 or 20 µM midazolam treatment. The ALP activity and Calcium deposition of hBMSCs exposed to 15 and 20 µM midazolam was significantly inhibited at 7, 14 and 21 days (p < 0.05). And the mRNA expression of ALP, COL1 and PPARγ was significantly suppressed in the hBMSCs cultured with 15 µM midazolam (p < 0.05).
  
  
  CONCLUSIONS
  Midazolam exert negative effect on cell viability and osteogenic differentiation of cultured hBMSCs. During sedation in critical care, the use of midazolam may suppress activity of hBMSCs.
authors.affiliation: Department of Anesthesiology, the First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China. tougaosci@aliyun.com.
authors.forename: T
authors.initials: T
authors.lastname: Zhang
authors.forename: H
authors.initials: H
authors.lastname: Shao
authors.forename: K-q
authors.initials: KQ
authors.lastname: Xu
authors.forename: L-t
authors.initials: LT
authors.lastname: Kuang
authors.forename: R-f
authors.initials: RF
authors.lastname: Chen
authors.forename: H-h
authors.initials: HH
authors.lastname: Xiu
mesh_terms: D000328:Adult; D000469:Alkaline Phosphatase / Q000235:genetics / Q000378:metabolism; D001854:Bone Marrow Cells / Q000187:drug effects* / Q000378:metabolism; D002118:Calcium / Q000378:metabolism; D002454:Cell Differentiation / Q000187:drug effects*; D048430:Cell Shape / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D024042:Collagen Type I / Q000235:genetics / Q000378:metabolism; D050659:Core Binding Factor Alpha 1 Subunit / Q000235:genetics / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D005260:Female; D005786:Gene Expression Regulation; D006801:Humans; D006993:Hypnotics and Sedatives / Q000633:toxicity*; D008297:Male; D059630:Mesenchymal Stem Cells / Q000187:drug effects* / Q000378:metabolism; D008874:Midazolam / Q000633:toxicity*; D008875:Middle Aged; D010012:Osteogenesis / Q000187:drug effects*; D047495:PPAR gamma / Q000235:genetics / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D013997:Time Factors
chemical_list: D024042:Collagen Type I; D050659:Core Binding Factor Alpha 1 Subunit; D006993:Hypnotics and Sedatives; D047495:PPAR gamma; D012333:RNA, Messenger; C493709:RUNX2 protein, human; D000469:Alkaline Phosphatase; D008874:Midazolam; D002118:Calcium