Name: Murine Orthodontic Tooth Movement (OTM) Model
Uploaded: 2023-07-21T12:20:00
Description: Watch this Scientific Journal Video about Murine Orthodontic Tooth Movement OTM Model at JoVE.com

murine orthodontic tooth movement (otm) model

골격 기계 생물학을 탐구하기 위한 폐포골 리모델링 분석

It is generally known that bone is under constant reconstruction throughout life, in response to mechanical forces according to Wolff&#39;s law1,2. Appropriate mechanical stimulation, such as gravity and daily exercise, maintains bone mass and strength and prevents bone loss by stimulating both osteoblasts and osteoclasts. Osteoclasts, responsible for bone resorption3,4,5,6,7, and osteoblasts, responsible for bone formation8,9,10, maintain bone homeostasis and function jointly in the biological process of bone remodeling. In contrast, in the absence of loading stimuli, as in astronauts under long-term microgravity, bones suffer 10% bone mineral density loss, thus increasing the risk of osteoporosis11,12. Furthermore, noninvasive and convenient mechanical therapies, including orthodontics and distraction osteogenesis, have emerged as treatments for bone diseases13,14. All these have shown that mechanical force plays a critical role in maintaining bone quality and quantity. Recent studies generally analyzed bone remodeling in response to mechanical loading using time-consuming models such as running wheel and tail suspension tests, which usually took 4 weeks or more to simulate force loading or unloading15,16. Therefore, there is demand for a convenient and efficient animal model for studying bone remodeling driven by force loading.
The alveolar bone is the most active in terms of bone remodeling, with a high turnover rate17. Orthodontic tooth movement (OTM), a common treatment for malocclusion, is an artificial process of alveolar bone remodeling in response to mechanical force. However, OTM, which induces rapid bone remodeling18, is also a time-saving way to study the effects of mechanical force on bone remodeling compared with other models with a long experimental period. Therefore, OTM is an ideal model to study bone remodeling under mechanical stimuli. It is noteworthy that the mechanism of alveolar bone remodeling is often time-sensitive, and it is necessary to observe the changes in alveolar bone remodeling at certain time points after modeling. With the dual advantages of temporal and spatial control of DNA recombination and tissue specificity, an inducible conditional gene knockout mouse model is a suitable choice for OTM studies.
Conventionally, OTM-mediated alveolar bone remodeling has been divided into tension zones involving bone formation and pressure zones involving bone resorption19,20,21, which is more detailed but difficult to regulate. Furthermore, Yuri et al. reported that the time of bone formation in OTM differed on the tension and compression sides22. In addition, a previous study had demonstrated that the first molar could initiate wide remodeling of the maxillary alveolar bone under orthodontic force, which was not constrained to the tension and pressure zones23. Therefore, we selected the area located within three roots of M1 in the cross-section of the maxillary bone as the region of interest (ROI) and described methods to assess the activity of osteoblasts and osteoclasts in the same area to evaluate alveolar bone remodeling under OTM.
As a nuclear transcription factor, signal transducer and activator of transcription 3 (STAT3) has been proven critical in bone homeostasis24,25. Previous studies have reported low bone mineral density and recurrent pathological fractures in Stat3-mutant mice26,27. Our previous study demonstrated that deletion of Stat3 in Osx+ osteoblasts caused craniofacial malformation and osteoporosis, as well as spontaneous bone fracture28. Recently, we provided in vivo evidence with an inducible osteoblast-specific Stat3 deletion mouse model (Col1&#945;2CreERT2; Stat3fl/fl, hereafter called Stat3Col1&#945;2ERT2) that STAT3 is critical in mediating the effects of orthodontic force driving alveolar bone remodeling29. In this study, we provide methods and protocols for using inducible osteoblast lineage-specific Stat3 knockout mice to study bone remodeling under orthodontic force and describe methods for analyzing alveolar bone remodeling during OTM, thus shedding light on skeletal mechanical biology.

저자 스포트라이트: 폐포와 장골 리모델링을 비교하여 OTM 모델 잠재력 탐색 

유도 가능한 조골 계통 특이적 Stat3 녹아웃 마우스를 사용하여 교정 치아 운동 중 치조골 리모델링 연구

Our research focuses on the mechanism of bone remodeling under mechanical force, including alveolar bone and long bones. We try to answer how bones respond to mechanical stimuli to shed new light on skeletal mechanical biology for further clinical treatment. Currently, studies on OTM were limited to gene expression analysis in vivo or cellular function analysis in vitro.To this end, a challenge arose. How to trace and explore the function of specific genes in specific lineages during OTM in vivo? That's why we use inducible conditional knockout mice here.Orthodontic tooth movement, which induces rampant bone remodeling, is a time-saving method to study the effects of mechanical force on bone remodeling compared to other models that have a long experimental period. Our protocol also reveals dynamic alveolar bone remodeling at different time points with inducible gene-specific knockout mice. There are many important cell lineages in the alveolar bone.We aim to trace them and find out their underlying mechanisms during OTM. Furthermore, we will compare the mechanisms between alveolar bone and long bone remodeling to provide further clues for the potential of OTM model in biomechanical research.

Watch this Scientific Journal Video about Murine Orthodontic Tooth Movement OTM Model at JoVE.com

Murine Orthodontic Tooth Movement (OTM) Model  

Murine Orthodontic Tooth Movement(OTM) 모델

6주 된 수컷 쥐 10마리를 선택하여 WT와 CKO로 분류된 두 그룹으로 나누고 각 그룹에 5마리의 쥐를 배치하는 것으로 시작합니다. 일주일 동안 이틀에 한 번씩 모든 쥐에게 타목시펜을 투여합니다. 쥐를 고정시키기 위해 플라스틱 쥐 해부 플랫폼을 수술대로 준비합니다.사지 고정을 위해 각 고무 기둥에 탄성 밴드를 부착합니다. 금속 막대에 다른 실을 묶어 위쪽 앞니를 고정합니다. 마취된 쥐를 수술대의 앙와위 위치에 놓습니다.4개의 탄성 밴드를 사용하여 팔다리를 고정합니다. 위쪽 앞니를 고정하기 위해 금속 막대에 부착된 실 1개. 다음으로, 교정력 적용을 위해 닫힌 코일 스프링을 준비합니다.준비된 스프링의 한쪽 끝을 상악 왼쪽 첫 번째 어금니에 결찰합니다. 동력계로 측정하여 10g의 안정적인 힘을 보장합니다. 그런 다음 0.1mm 수지 강화 강철 합자 와이어를 사용하여 다른 쪽 끝을 중앙 앞니에 접합합니다.수술 후 마우스를 회수 케이지에 넣으십시오. 흉골 누움을 유지하기에 충분한 의식을 회복할 때까지 2-4시간 동안 쥐를 모니터링합니다. 부드러운 식단을 제공하고 합병증이 있는지 쥐를 정기적으로 관찰하고 필요에 따라 진통제를 투여하십시오.

Research

JoVE Journal

Medicine

Murine Orthodontic Tooth Movement (OTM) Model

Using Inducible Osteoblastic Lineage-Specific Stat3 Knockout Mice to Study Alveolar Bone Remodeling During Orthodontic Tooth Movement

The alveolar bone, with a high turnover rate, is the most actively-remodeling bone in the body. Orthodontic tooth movement (OTM) is a common artificial ...