BMP4 localization and PCNA expression during distraction osteogenesis of the porcine mandible

• Published in: International journal of oral and maxillofacial surgery 2012-07, Vol.41 (7), p.867-873
• Main Authors: Hansen, G.M, Lawler, M.E, Williams, W.B, Troulis, M.J, Kaban, L.B
• Format: Article
• Language: English
• Subjects: Animals; Biological and medical sciences; BMP4; Bone Morphogenetic Protein 4 - analysis; Cell physiology; Cell Proliferation; Coloring Agents; Dentistry; Female; Fundamental and applied biological sciences. Psychology; Immunohistochemistry; Internal Fixators; Mandible - pathology; Mandible - surgery; mandibular distraction osteogenesis; Medical sciences; Mineralization, calcification; Molecular and cellular biology; Osteoblasts - pathology; Osteogenesis, Distraction - instrumentation; Osteogenesis, Distraction - methods; Otorhinolaryngology. Stomatology; PCNA; Periosteum - pathology; Periosteum - surgery; Proliferating Cell Nuclear Antigen - analysis; Random Allocation; Skeleton and joints; Stem Cells - pathology; Surgery; Swine; Swine, Miniature; Time Factors; Vertebrates: osteoarticular system, musculoskeletal system
• ISSN: 0901-5027; 1399-0020
• DOI: 10.1016/j.ijom.2011.12.032

AbstractThis study characterized sequential molecular and cellular events in the porcine mandibular distraction osteogenesis (DO) wound. Nineteen Yucatan minipigs were divided into three treatment groups: Group A, unilateral mandibular distraction with 0 day latency, 1 mm/day rate for 12 days, 24 days fixation ( n= 16); Group B, acute lengthening 12 mm ( n= 2); Group C, sham control ( n= 1). Group A was further divided by death date: mid-DO ( n= 5), end-DO ( n= 4), mid-fixation ( n= 5) and end-fixation ( n= 2). Groups B and C were killed on postoperative day 36, corresponding to end-fixation. Specimens were stained for proliferating cell nuclear antigen (PCNA) and bone morphogenetic protein-4 (BMP4). Cellular proliferation (PCNA) was assessed quantitatively and BMP4 staining was assessed on a semi-quantitative scale. Progenitor cell proliferation was greatest during mid-DO and decreased from end-DO through end-fixation. Proliferation in the acute lengthening group was elevated relative to sham control and comparable to end-DO. BMP4 staining intensity (localized to the periosteal cambium layer) was greatest during mid- and end-DO, decreased at mid-fixation and was undetectable at end-fixation. Progenitor cell proliferation and BMP4 expression are greatest during mid-DO and decrease progressively thereafter. At the time of death of the acute lengthening group, only increased cell proliferation was demonstrated.