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Current models to understand the onset and progression of scoliotic deformities in adolescent idiopathic scoliosis: a systematic review. Spine Deform 2022; 11:545-558. [PMID: 36454530 DOI: 10.1007/s43390-022-00618-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/20/2022] [Accepted: 11/12/2022] [Indexed: 12/05/2022]
Abstract
PURPOSE To create an updated and comprehensive overview of the modeling studies that have been done to understand the mechanics underlying deformities of adolescent idiopathic scoliosis (AIS), to predict the risk of curve progression and thereby substantiate etiopathogenetic theories. METHODS In this systematic review, an online search in Scopus and PubMed together with an analysis in secondary references was done, which yielded 86 studies. The modeling types were extracted and the studies were categorized accordingly. RESULTS Animal modeling, together with machine learning modeling, forms the category of black box models. This category is perceived as the most clinically relevant. While animal models provide a tangible idea of the biomechanical effects in scoliotic deformities, machine learning modeling was found to be the best curve-progression predictor. The second category, that of artificial models, has, just as animal modeling, a tangible model as a result, but focusses more on the biomechanical process of the scoliotic deformity. The third category is formed by computational models, which are very popular in etiopathogenetic parameter-based studies. They are also the best in calculating stresses and strains on vertebrae, intervertebral discs, and other surrounding tissues. CONCLUSION This study presents a comprehensive overview of the current modeling techniques to understand the mechanics of the scoliotic deformities, predict the risk of curve progression in AIS and thereby substantiate etiopathogenetic theories. Although AIS remains to be seen as a complex and multifactorial problem, the progression of its deformity can be predicted with good accuracy. Modeling of AIS develops rapidly and may lead to the identification of risk factors and mitigation strategies in the near future. The overview presented provides a basis to follow this development.
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The Role of Melatonin on Behavioral Changes and Concomitant Oxidative Stress in icvAβ 1-42 Rat Model with Pinealectomy. Int J Mol Sci 2021; 22:ijms222312763. [PMID: 34884567 PMCID: PMC8657444 DOI: 10.3390/ijms222312763] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2021] [Revised: 11/16/2021] [Accepted: 11/22/2021] [Indexed: 02/06/2023] Open
Abstract
One of the pathological hallmarks of Alzheimer’s disease (AD) associated with its progression that contributes to β-amyloid (Aβ) generation is oxidative stress (OS). Clinical data suggest that melatonin is a potent antioxidant that might be effective in the adjunctive therapy of this neurodegenerative disease. The present study aimed to explore the role of melatonin on behavioral changes and markers of OS in three rat models, namely, pinealectomy (pin) model of melatonin deficit, intracerebroventricular (icv)Aβ1-42 model of AD, and combination of both pin and Aβ1-42 model (pin+icvAβ1-42). The chronic injection with vehicle/melatonin (50 mg/kg, i.p. for 40 days) started on the same day of sham/pin and icv vehicle/Aβ1-42 infusion procedures. Anxiety in the open field and the elevated plus-maze test and cognitive responses in the object recognition test were tested between the 30th–35th day after the surgical procedures. Markers of OS in the frontal cortex (FC) and hippocampus were detected by the ELISA method. Melatonin treatment corrected the exacerbated anxiety response only in the pin+icvAβ1-42 model while it alleviated the cognitive impairment in the three models. Pinealectomy disturbed the antioxidant system via enhanced SOD activity and decreased GSH levels both in the FC and hippocampus. The Aβ1-42 model decreased the SOD activity in the FC and elevated the MDA level in the two brain structures. The pin+icvAβ1-42 model impaired the antioxidant system and elevated lipid peroxidation. Melatonin supplementation restored only the elevated MDA level of icvAβ1-42 and pin+icvAβ1-42 model in the hippocampus. In conclusion, our study reveals that the pin+icvAβ1-42 rat model triggers more pronounced anxiety and alterations in markers of OS that may be associated with melatonin deficit concomitant to icvAβ1-42-induced AD pathology.
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Lahmar S, Kessabi K, Messaoudi I. Aphanius fasciatus: a molecular model of scoliosis? Spine Deform 2021; 9:883-892. [PMID: 33512704 DOI: 10.1007/s43390-021-00291-w] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/13/2020] [Accepted: 01/15/2021] [Indexed: 11/25/2022]
Abstract
STUDY DESIGN Observational study of Killifish with spinal deformities OBJECTIVE: To evaluate the morphology and molecular biology of Aphanius fasciatus with severe spine deformities. Idiopathic Scoliosis affects 3% of the population and is an abnormal three-dimensional curvature of the spine with unknown cause. The lack of a model system with naturally occurring spinal curvatures has hindered research on the etiology of IS. METHODS The Mediterranean killifish Aphanius fasciatus, collected from the coast of Sfax (Tunisia), which has an inborn skeletal deformity was chosen. We used morphologic features to evaluate the severity of scoliosis according to the different types and performed a biochemical analysis using factors previously studied in humans (estradiol, melatonin and Insulin Growth Factor 1 "IGF-1"). RESULTS We have detected relevant molecular deviations that occur in Killifish deformities and the fish with severe scoliosis are smaller and less old than the ones with milder scolioses. Furthermore, a significant change in levels of ovarian estradiol, liver IGF-1 and brain melatonin was noted between deformed and normal fish. CONCLUSIONS Aphanius fasciatus could be used as a molecular model system to study the etiology of IS in humans as the characterization of the Aphanius fasciatus scoliosis syndrome has revealed morphological and biochemical parallels to IS. However, it is important to note the limitations of the proposed model, including the short lifespan of the fish. LEVEL OF EVIDENCE III.
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Affiliation(s)
- Samar Lahmar
- Université de Monastir, Institut Supérieur de Biotechnologie de Monastir, Laboratoire LR11ES41 Génétique Biodiversité et Valorisation des Bio-Ressources, 5000, Monastir, Tunisie.
| | - Kaouthar Kessabi
- Université de Monastir, Institut Supérieur de Biotechnologie de Monastir, Laboratoire LR11ES41 Génétique Biodiversité et Valorisation des Bio-Ressources, 5000, Monastir, Tunisie
| | - Imed Messaoudi
- Université de Monastir, Institut Supérieur de Biotechnologie de Monastir, Laboratoire LR11ES41 Génétique Biodiversité et Valorisation des Bio-Ressources, 5000, Monastir, Tunisie
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Zaydman AM, Strokova EL, Pahomova NY, Gusev AF, Mikhaylovskiy MV, Shevchenko AI, Zaidman MN, Shilo AR, Subbotin VM. Etiopathogenesis of adolescent idiopathic scoliosis: Review of the literature and new epigenetic hypothesis on altered neural crest cells migration in early embryogenesis as the key event. Med Hypotheses 2021; 151:110585. [PMID: 33932710 DOI: 10.1016/j.mehy.2021.110585] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2020] [Revised: 02/28/2021] [Accepted: 03/24/2021] [Indexed: 12/17/2022]
Abstract
Adolescent idiopathic scoliosis (AIS) affects 2-3% of children. Numerous hypotheses on etiologic/causal factors of AIS were investigated, but all failed to identify therapeutic targets and hence failed to offer a cure. Therefore, currently there are only two options to minimize morbidity of the patients suffering AIS: bracing and spinal surgery. From the beginning of 1960th, spinal surgery, both fusion and rod placement, became the standard of management for progressive adolescent idiopathic spine deformity. However, spinal surgery is often associated with complications. These circumstances motivate AIS scientific community to continue the search for new etiologic and causal factors of AIS. While the role of the genetic factors in AIS pathogenesis was investigated intensively and universally recognized, these studies failed to nominate mutation of a particular gene or genes combination responsible for AIS development. More recently epigenetic factors were suggested to play causal role in AIS pathogenesis. Sharing this new approach, we investigated scoliotic vertebral growth plates removed during vertebral fusion (anterior surgery) for AIS correction. In recent publications we showed that cells from the convex side of human scoliotic deformities undergo normal chondrogenic/osteogenic differentiation, while cells from the concave side acquire a neuronal phenotype. Based on these facts we hypothesized that altered neural crest cell migration in early embryogenesis can be the etiological factor of AIS. In particular, we suggested that neural crest cells failed to migrate through the anterior half of somites and became deposited in sclerotome, which in turn produced chondrogenic/osteogenic-insufficient vertebral growth plates. To test this hypothesis we conducted experiments on chicken embryos with arrest neural crest cell migration by inhibiting expression of Paired-box 3 (Pax3) gene, a known enhancer and promoter of neural crest cells migration and differentiation. The results showed that chicken embryos treated with Pax3 siRNA (microinjection into the neural tube, 44 h post-fertilization) progressively developed scoliotic deformity during maturation. Therefore, this analysis suggests that although adolescent idiopathic scoliosis manifests in children around puberty, the real onset of the disease is of epigenetic nature and takes place in early embryogenesis and involves altered neural crest cells migration. If these results confirmed and further elaborated, the hypothesis may shed new light on the etiology and pathogenesis of AIS.
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Affiliation(s)
- Alla M Zaydman
- Novosibirsk Research Institute of Traumatology and Orthopaedics named after Ya.L. Tsivyan, Novosibirsk, Russia
| | - Elena L Strokova
- Novosibirsk Research Institute of Traumatology and Orthopaedics named after Ya.L. Tsivyan, Novosibirsk, Russia
| | - Nataliya Y Pahomova
- Novosibirsk Research Institute of Traumatology and Orthopaedics named after Ya.L. Tsivyan, Novosibirsk, Russia
| | - Arkady F Gusev
- Novosibirsk Research Institute of Traumatology and Orthopaedics named after Ya.L. Tsivyan, Novosibirsk, Russia
| | - Mikhail V Mikhaylovskiy
- Novosibirsk Research Institute of Traumatology and Orthopaedics named after Ya.L. Tsivyan, Novosibirsk, Russia
| | - Alexander I Shevchenko
- Institute of Cytology and Genetics of the Siberian Branch of the Russian Academy of Sciences", Novosibirsk, Russia
| | | | - Andrey R Shilo
- Novosibirsk Zoo named after R.A. Shilo, Novosibirsk, Russia
| | - Vladimir M Subbotin
- Arrowhead Pharmaceuticals Inc., Madison WI, USA; University of Pittsburgh, Pittsburgh PA, USA; University of Wisconsin, Madison WI, USA.
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Low Body Mass Index for Early Screening of Adolescent Idiopathic Scoliosis: A Comparison Based on Standardized Body Mass Index Classifications. Asian Nurs Res (Korean Soc Nurs Sci) 2020; 14:24-29. [DOI: 10.1016/j.anr.2019.12.003] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2019] [Revised: 12/25/2019] [Accepted: 12/26/2019] [Indexed: 01/25/2023] Open
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Pasha S. 3D Deformation Patterns of S Shaped Elastic Rods as a Pathogenesis Model for Spinal Deformity in Adolescent Idiopathic Scoliosis. Sci Rep 2019; 9:16485. [PMID: 31712762 PMCID: PMC6848095 DOI: 10.1038/s41598-019-53068-7] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2019] [Accepted: 10/23/2019] [Indexed: 02/03/2023] Open
Abstract
Adolescent idiopathic scoliosis (AIS) is a three-dimensional (3D) deformity of the spinal column in pediatric population. The primary cause of scoliosis remains unknown. The lack of such understanding has hampered development of effective preventive methods for management of this disease. A long-held assumption in pathogenesis of AIS is that the upright spine in human plays an important role in induction of scoliosis. Here, the variations in the sagittal curve of the scoliotic and non-scoliotic pediatric spines were used to study whether specific sagittal curves, under physiological loadings, are prone to 3D deformation leading to scoliosis. To this end, finite element models of the S shaped elastic rods, which their curves were derived from the radiographs of 129 sagittal spinal curves of adolescents with and without scoliosis, were generated. Using the mechanics of deformation in elastic rods, this study showed that the 3D deformation patterns of the two-dimensional S shaped slender elastic rods mimics the 3D patterns of the spinal deformity in AIS patients with the same S shaped sagittal spinal curve. On the other hand, the rods representing the non-scoliotic sagittal spinal curves, under the same mechanical loading, did not twist thus did not lead to a 3D deformation. This study provided strong evidence that the shape of the sagittal profile in individuals can be a leading cause of the 3D spinal deformity as is observed in the AIS population.
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Affiliation(s)
- Saba Pasha
- Department of Orthopedic Surgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA. .,Division of Orthopedic Surgery, The Children's Hospital of Philadelphia, Philadelphia, PA, USA.
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Fadzan M, Bettany-Saltikov J. Etiological Theories of Adolescent Idiopathic Scoliosis: Past and Present. Open Orthop J 2017; 11:1466-1489. [PMID: 29399224 PMCID: PMC5759107 DOI: 10.2174/1874325001711011466] [Citation(s) in RCA: 65] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/26/2017] [Revised: 09/01/2017] [Accepted: 09/11/2017] [Indexed: 12/11/2022] Open
Abstract
Adolescent idiopathic scoliosis is one of the most common spinal deformities, yet its cause is unknown. Various theories look to biomechanical, neuromuscular, genetic, and environmental origins, yet our understanding of scoliosis etiology is still limited. Determining the cause of a disease is crucial to developing the most effective treatment. Associations made with scoliosis do not necessarily point to causality, and it is difficult to determine whether said associations are primary (playing a role in development) or secondary (develop as a result of scoliosis). Scoliosis is a complex condition with highly variable expression, even among family members, and likely has many causes. These causes could be similar among homogenous groups of AIS patients, or they could be individual. Here, we review the most prevalent theories of scoliosis etiology and recent trends in research.
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Affiliation(s)
- Maja Fadzan
- Scoliosis 3DC, 3 Baldwin Green Common, Suite 204, Woburn, MA 01801, USA
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Latalski M, Danielewicz-Bromberek A, Fatyga M, Latalska M, Kröber M, Zwolak P. Current insights into the aetiology of adolescent idiopathic scoliosis. Arch Orthop Trauma Surg 2017; 137:1327-1333. [PMID: 28710669 PMCID: PMC5602042 DOI: 10.1007/s00402-017-2756-1] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/26/2017] [Indexed: 02/02/2023]
Abstract
Scoliosis occurs in about 0.2-0.6% of the general population. In the majority of cases the cause of this entity remains mostly unidentified. The search for the causes covers almost all aspects of its possible origin. We collected and systematised the contemporary theories and concepts concerning the aetiology of adolescent idiopathic scoliosis. Genetic and hereditary factors are commonly accepted as possible causes; however, the identification of the single gene responsible for the development of this condition seems impossible, which suggests multifactorial mechanism of its formation. Dysfunctions of the nervous system are recognised risks related to the development of scoliosis, but they are classified as belonging to a separate aetiological category. Scoliosis develops at the quickest rate during the child's growth spurt, which prompted the research on the role of the growth hormone in scoliosis aetiology. Melatonin is another hormone that is studied as a possible factor involved in development of this entity. In cases of progressive scoliosis, increased activity of calmodulin-a protein that regulates the levels of calcium ions-has been observed. The scientists have characterised numerous qualitative and quantitative changes in the composition of the tissue of intervertebral discs, spinal ligaments and paraspinal muscles. Some of the theories, explaining the nature of this entity, presented in this review seem to have only a purely theoretical value; their proliferation only confirms the fact that the actual nature of this condition has not been unveiled yet, and suggests its multifactorial aetiology.
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Affiliation(s)
- Michal Latalski
- Department of Paediatric Orthopaedics, Medical University of Lublin, ul. Gebali 6, 20-093, Lublin, Poland.
| | - A Danielewicz-Bromberek
- Department of Paediatric Orthopaedics, Medical University of Lublin, ul. Gebali 6, 20-093, Lublin, Poland
| | - M Fatyga
- Department of Paediatric Orthopaedics, Medical University of Lublin, ul. Gebali 6, 20-093, Lublin, Poland
| | - M Latalska
- Department of Vitreoretinal Surgery, Medical University of Lublin, ul. Chmielna 1, 20-079, Lublin, Poland
| | - M Kröber
- Department of Orthopaedics, Trauma und Spine Surgery, Asklepios Klinik Altona, Paul-Ehrlich-Strasse 1, 22763, Hamburg, Germany
| | - P Zwolak
- Department of Paediatric Orthopaedics, Medical University of Lublin, ul. Gebali 6, 20-093, Lublin, Poland
- Department of Orthopaedics, Trauma und Spine Surgery, Asklepios Klinik Altona, Paul-Ehrlich-Strasse 1, 22763, Hamburg, Germany
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Yang S, Zheng C, Jiang J, Lu F, Xia X, Zhu W, Jin X, Ma X. The value of applying a melatonin antagonist (Luzindole) in improving the success rate of the bipedal rat scoliosis model. BMC Musculoskelet Disord 2017; 18:137. [PMID: 28376758 PMCID: PMC5379722 DOI: 10.1186/s12891-017-1500-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/23/2017] [Accepted: 03/22/2017] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND An ideal animal model has always been the key to research the pathogenesis and treatment of adolescent idiopathic scoliosis (AIS), while available methods have obvious disadvantages. The deficiency of melatonin has been proved relating to AIS. In this research, we intended to apply Luzindole, the melatonin antagonist, in bipedal rat model, for the block of combination of melatonin and its receptor, to inhibit the melatonin effect, and then to understand whether this method can effectively improve the scoliosis rate of bipedal rat model, and investigate the role of melatonin in scoliosis. To investigate the feasibility of improving the success rate of bipedal rat scoliosis model via intraperitoneal injection of melatonin antagonist (Luzindole). METHODS A total of 60 3-weeks-old Sprague-Dawley rats were included in this study, and were divided into 3 groups (A, B and C). Each group included 20 rats. Osteotomy of the bilateral proximal humerus and proximal tailbone was performed in group A and group B; intraperitoneal injection of Luzindole (0.2 mg/kg) was performed in group A and group C. X-rays were taken before the surgery, 1 month after the surgery, 3 months after the surgery, and 6 months after the surgery, to calculate the Cobb's angle of the spine (>10° was considered scoliosis). The weight of every rat was also measured at the same time. Rats were euthanized 6 months after surgery to determine the calmodulin level in thrombocytes. RESULTS The rate of scoliosis in group A (14/20) was significantly higher than those in group B (6/20) and group C (0/20) (P < 0.05). The differences in the weights of the 3 groups were non-significant; as were differences in the calmodulin level in thrombocytes. CONCLUSION The application of the melatonin antagonist of Luzindole can improve the success rate of the bipedal rat scoliosis model. Meanwhile, this study indicates that a decreased melatonin level is not the primary cause of scoliosis, but that it may increase the likelihood and severity of scoliosis.
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Affiliation(s)
- Shuo Yang
- Department of Orthopedics, Huashan Hospital, Fudan University, No.12, Middle Wulumuqi Road, Shanghai, 200040, China
| | - Chaojun Zheng
- Department of Orthopedics, Huashan Hospital, Fudan University, No.12, Middle Wulumuqi Road, Shanghai, 200040, China
| | - Jianyuan Jiang
- Department of Orthopedics, Huashan Hospital, Fudan University, No.12, Middle Wulumuqi Road, Shanghai, 200040, China
| | - Feizhou Lu
- Department of Orthopedics, Huashan Hospital, Fudan University, No.12, Middle Wulumuqi Road, Shanghai, 200040, China.,Department of Orthopedics, The Fifth People's Hospital, Fudan University, No.128, Ruili Road, Shanghai, 200240, China
| | - Xinlei Xia
- Department of Orthopedics, Huashan Hospital, Fudan University, No.12, Middle Wulumuqi Road, Shanghai, 200040, China
| | - Wei Zhu
- Department of Orthopedics, Huashan Hospital, Fudan University, No.12, Middle Wulumuqi Road, Shanghai, 200040, China
| | - Xiang Jin
- Department of Orthopedics, Huashan Hospital, Fudan University, No.12, Middle Wulumuqi Road, Shanghai, 200040, China
| | - Xiaosheng Ma
- Department of Orthopedics, Huashan Hospital, Fudan University, No.12, Middle Wulumuqi Road, Shanghai, 200040, China.
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Bobyn JD, Little DG, Gray R, Schindeler A. Animal models of scoliosis. J Orthop Res 2015; 33:458-67. [PMID: 25492698 DOI: 10.1002/jor.22797] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/11/2014] [Accepted: 12/03/2014] [Indexed: 02/04/2023]
Abstract
Multiple techniques designed to induce scoliotic deformity have been applied across many animal species. We have undertaken a review of the literature regarding experimental models of scoliosis in animals to discuss their utility in comprehending disease aetiology and treatment. Models of scoliosis in animals can be broadly divided into quadrupedal and bipedal experiments. Quadrupedal models, in the absence of axial gravitation force, depend upon development of a mechanical asymmetry along the spine to initiate a scoliotic deformity. Bipedal models more accurately mimic human posture and consequently are subject to similar forces due to gravity, which have been long appreciated to be a contributing factor to the development of scoliosis. Many effective models of scoliosis in smaller animals have not been successfully translated to primates and humans. Though these models may not clarify the aetiology of human scoliosis, by providing a reliable and reproducible deformity in the spine they are a useful means with which to test interventions designed to correct and prevent deformity.
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Affiliation(s)
- Justin D Bobyn
- Orthopaedic Research & Biotechnology Unit, The Children's Hospital at Westmead, Sydney, Australia; Discipline of Paediatrics and Child Health, Faculty of Medicine, University of Sydney, Sydney, Australia
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Man GCW, Wai MGC, Wang WWJ, Jun WWW, Yim APY, Yee YAP, Wong JH, Ho WJ, Ng TB, Bun NT, Lam TP, Ping LT, Lee SKM, Man LSK, Ng BKW, Wah NBK, Wang CC, Chiu WC, Qiu Y, Yong Q, Cheng CY, Yiu CJC. A review of pinealectomy-induced melatonin-deficient animal models for the study of etiopathogenesis of adolescent idiopathic scoliosis. Int J Mol Sci 2014; 15:16484-99. [PMID: 25238413 PMCID: PMC4200812 DOI: 10.3390/ijms150916484] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2014] [Revised: 09/08/2014] [Accepted: 09/10/2014] [Indexed: 11/16/2022] Open
Abstract
Adolescent idiopathic scoliosis (AIS) is a common orthopedic disorder of unknown etiology and pathogenesis. Melatonin and melatonin pathway dysfunction has been widely suspected to play an important role in the pathogenesis. Many different types of animal models have been developed to induce experimental scoliosis mimicking the pathoanatomical features of idiopathic scoliosis in human. The scoliosis deformity was believed to be induced by pinealectomy and mediated through the resulting melatonin-deficiency. However, the lack of upright mechanical spinal loading and inherent rotational instability of the curvature render the similarity of these models to the human counterparts questionable. Different concerns have been raised challenging the scientific validity and limitations of each model. The objectives of this review follow the logical need to re-examine and compare the relevance and appropriateness of each of the animal models that have been used for studying the etiopathogenesis of adolescent idiopathic scoliosis in human in the past 15 to 20 years.
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Affiliation(s)
| | - Man Gene Chi Wai
- Department of Obstetrics and Gynaecology, Faculty of Medicine, the Chinese University of Hong Kong, Hong Kong, China.
| | | | - Wang William Wei Jun
- Department of Spine Surgery, Drum Tower Hospital, Nanjing University Medical School, Nanjing 210008, China.
| | | | - Yim Annie Po Yee
- Department of Orthopaedics & Traumatology, Faculty of Medicine, the Chinese University of Hong Kong, Hong Kong, China.
| | | | - Wong Jack Ho
- School of Biomedical Sciences, Faculty of Medicine, the Chinese University of Hong Kong, Hong Kong, China.
| | | | - Ng Tzi Bun
- School of Biomedical Sciences, Faculty of Medicine, the Chinese University of Hong Kong, Hong Kong, China.
| | | | - Lam Tsz Ping
- Department of Orthopaedics & Traumatology, Faculty of Medicine, the Chinese University of Hong Kong, Hong Kong, China.
| | | | - Lee Simon Kwong Man
- Lee Hysan Clinical Research Laboratory, Faculty of Medicine, the Chinese University of Hong Kong, Hong Kong, China.
| | | | - Ng Bobby Kin Wah
- Department of Orthopaedics & Traumatology, Faculty of Medicine, the Chinese University of Hong Kong, Hong Kong, China.
| | | | - Wang Chi Chiu
- Department of Obstetrics and Gynaecology, Faculty of Medicine, the Chinese University of Hong Kong, Hong Kong, China.
| | | | - Qiu Yong
- Department of Spine Surgery, Drum Tower Hospital, Nanjing University Medical School, Nanjing 210008, China.
| | | | - Cheng Jack Chun Yiu
- Joint Scoliosis Research Center of the Chinese University of Hong Kong and Nanjing University, Hong Kong, China.
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Yee A, Song YQ, Chan D, Cheung KMC. Understanding the Basis of Genetic Studies: Adolescent Idiopathic Scoliosis as an Example. Spine Deform 2014; 2:1-9. [PMID: 27927437 DOI: 10.1016/j.jspd.2013.09.003] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/21/2013] [Revised: 08/24/2013] [Accepted: 09/01/2013] [Indexed: 12/31/2022]
Abstract
STUDY DESIGN A review of the general concepts of genetics studies with specific reference to adolescent idiopathic scoliosis (AIS). OBJECTIVES To equip the average spine surgeon with the vocabulary and understanding needed to understand the genetics of scoliosis and the approaches used to identify risk genes. SUMMARY OF BACKGROUND DATA Adolescent idiopathic scoliosis is a multifactorial disease. Increasing evidence from families and monozygotic twins suggests the involvement of genetic factors. An estimation of heritability also indicates a strong influence of genetics on the disease. Increasing focus has been placed on identifying genes and genetic variants associated with AIS. REVIEW This is a review of genes and genetic variations, the phenotype definition of AIS in genetics studies, concepts and approaches to identifying associated genes, and the evaluation of results. Different types of genetic variations are present in the genome. These variations may modulate the expression or function of protein products, which in turn alter individuals' susceptibility to disease. Identifying the variants related to AIS requires an objective and clearly defined phenotype, among which the Cobb angle is commonly used. The phenotype helps classify subjects into cases and controls. By selecting candidate genes of growth factors and hormonal receptors, which are speculated to be involved in the mechanism of disease, the variants within these genes were compared between cases and controls to identify any differences. Another approach was to use large families and inspect the co-segregation of variants and phenotypes. Recently, arrays covering the variants of the whole genome were developed and assist in high-throughput screening for associated genes. CONCLUSIONS Genetic factors have an important role in AIS. Deciphering the genes and genetic variants associated with AIS can improve our understanding of the mechanisms of the disease, as well as assist in designing treatment methods and preventive measures.
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Affiliation(s)
- Anita Yee
- Department of Biochemistry, University of Hong Kong, 3/F Laboratory Block, LKS Faculty of Medicine, 21 Sassoon Road, Pokfulam, Hong Kong, China
| | - You-Qiang Song
- Department of Biochemistry, University of Hong Kong, 3/F Laboratory Block, LKS Faculty of Medicine, 21 Sassoon Road, Pokfulam, Hong Kong, China
| | - Danny Chan
- Department of Biochemistry, University of Hong Kong, 3/F Laboratory Block, LKS Faculty of Medicine, 21 Sassoon Road, Pokfulam, Hong Kong, China
| | - Kenneth M C Cheung
- Department of Orthopaedics and Traumatology, 5/F Professorial Block, Queen Mary Hospital, University of Hong Kong, Pokfulam, Hong Kong, China.
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Aota Y, Terayama H, Saito T, Itoh M. Pinealectomy in a broiler chicken model impairs endochondral ossification and induces rapid cancellous bone loss. Spine J 2013; 13:1607-16. [PMID: 23791240 DOI: 10.1016/j.spinee.2013.05.017] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/26/2012] [Revised: 09/30/2012] [Accepted: 05/04/2013] [Indexed: 02/03/2023]
Abstract
BACKGROUND CONTEXT Adolescent idiopathic scoliosis (AIS) in humans is a lateral curvature of the spine often associated with osteopenia. It has recently been accepted that the development of AIS is closely associated with spinal overgrowth. Pinealectomy (PNX) in a chicken model consistently induces scoliosis with anatomic features similar to human AIS; however, the mechanism of PNX inducing scoliosis is poorly understood. PURPOSE This experimental study attempts to improve the understanding of the mechanisms underlying the onset of scoliosis in a PNX broiler chicken model. METHODS A histomorphometric study was performed to analyze longitudinal bone growth and cancellous bone remodeling before the development of scoliosis. Static and dynamic parameters in cancellous bone and chondro-osseous junction of the 7th thoracic vertebral body at 9 days after hatching were compared between PNX chickens (n=9) and control chickens with no surgery (n=5). RESULTS PNX resulted in a rapid and marked loss of cancellous bone volume (7.9±0.9% vs. 14.2±1.8%, mean±SD, p<.0005) and profoundly disrupted trabecular structure with increases in dynamic formative parameters, such as mineralizing surface, mineralization apposition rate, and adjusted appositional rate. In the chondro-osseous junction, activated osteoclasts phagocytized degenerating chondrocytes, leaving a minimal amount of cartilage matrix and activated osteoblasts, losing their scaffolding for bone formation, and directly covering the hypertrophic zone cells. The osteoid surface and thickness in the chondro-osseous junction were significantly increased in PNX chickens (43.1±14.2% vs. 11.6±5.7% and 4.1±0.2 μm vs. 2.9±0.4 μm). In the subjacent cartilage regions being protected from further resorption, abundant labeled cartilage remained with higher cellularity. CONCLUSIONS It is known that fast-growing birds have a unique paradigm of rapid bone elongation with minimal metaphyseal bone production. A bone-forming surface exists at the front of cartilage ossification in the growth plate; therefore, papillae of hypertrophic chondrocytes become included between the trabeculae of metaphyseal bone and the overall thickness of the growth plate increases considerably in addition to distal expansion. Our results indicate that the unique mechanism for rapid bone elongation in chicken is more pronounced after PNX. PNX also induces high turnover osteoporosis, which may also contribute to the development of scoliosis in the chicken.
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Affiliation(s)
- Yoichi Aota
- Department of Orthopaedic Surgery, Yokohama City University Hospital, 3-9 Fukuura, Kanazawa-ku, Yokohama City, Kanagawa Prefecture, Yokohama 236-0004, Japan.
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Restricted neural plasticity in vestibulospinal pathways after unilateral labyrinthectomy as the origin for scoliotic deformations. J Neurosci 2013; 33:6845-56. [PMID: 23595743 DOI: 10.1523/jneurosci.4842-12.2013] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Adolescent idiopathic scoliosis in humans is often associated with vestibulomotor deficits. Compatible with a vestibular origin, scoliotic deformations were provoked in adult Xenopus frogs by unilateral labyrinthectomy (UL) at larval stages. The aquatic ecophysiology and absence of body-weight-supporting limb proprioceptive signals in amphibian tadpoles as a potential sensory substitute after UL might be the cause for a persistent asymmetric descending vestibulospinal activity. Therefore, peripheral vestibular lesions in larval Xenopus were used to reveal the morphophysiological alterations at the cellular and network levels. As a result, spinal motor nerves that were modulated by the previously intact side before UL remained permanently silent during natural vestibular stimulation after the lesion. In addition, retrograde tracing of descending pathways revealed a loss of vestibular neurons on the ipsilesional side with crossed vestibulospinal projections. This loss facilitated a general mass imbalance in descending premotor activity and a permanent asymmetric motor drive to the axial musculature. Therefore, we propose that the persistent asymmetric contraction of trunk muscles exerts a constant, uncompensated differential mechanical pull on bilateral skeletal elements that enforces a distortion of the soft cartilaginous skeletal elements and bone shapes. This ultimately provokes severe scoliotic deformations during ontogenetic development similar to the human syndrome.
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Yim APY, Yeung HY, Sun G, Lee KM, Ng TB, Lam TP, Ng BKW, Qiu Y, Moreau A, Cheng JCY. Abnormal Skeletal Growth in Adolescent Idiopathic Scoliosis Is Associated with Abnormal Quantitative Expression of Melatonin Receptor, MT2. Int J Mol Sci 2013; 14:6345-58. [PMID: 23519105 PMCID: PMC3634428 DOI: 10.3390/ijms14036345] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2013] [Revised: 03/13/2013] [Accepted: 03/13/2013] [Indexed: 12/15/2022] Open
Abstract
The defect of the melatonin signaling pathway has been proposed to be one of the key etiopathogenic factors in adolescent idiopathic scoliosis (AIS). A previous report showed that melatonin receptor, MT2, was undetectable in some AIS girls. The present study aimed to investigate whether the abnormal MT2 expression in AIS is quantitative or qualitative. Cultured osteoblasts were obtained from 41 AIS girls and nine normal controls. Semi-quantification of protein expression by Western blot and mRNA expression by TaqMan real-time PCR for both MT1 and MT2 were performed. Anthropometric parameters were also compared and correlated with the protein expression and mRNA expression of the receptors. The results showed significantly lower protein and mRNA expression of MT2 in AIS girls compared with that in normal controls (p = 0.02 and p = 0.019, respectively). No differences were found in the expression of MT1. When dichotomizing the AIS girls according to their MT2 expression, the group with low expression was found to have a significantly longer arm span (p = 0.036). The results of this study showed for the first time a quantitative change of MT2 in AIS that was also correlated with abnormal arm span as part of abnormal systemic skeletal growth.
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Affiliation(s)
- Annie Po-yee Yim
- Department of Orthopaedics and Traumatology, The Chinese University of Hong Kong, Hong Kong, China; E-Mails: (A.P.Y.); (H.Y.); (G.S.); (T.L.); (B.K.N.)
| | - Hiu-yan Yeung
- Department of Orthopaedics and Traumatology, The Chinese University of Hong Kong, Hong Kong, China; E-Mails: (A.P.Y.); (H.Y.); (G.S.); (T.L.); (B.K.N.)
| | - Guangquan Sun
- Department of Orthopaedics and Traumatology, The Chinese University of Hong Kong, Hong Kong, China; E-Mails: (A.P.Y.); (H.Y.); (G.S.); (T.L.); (B.K.N.)
| | - Kwong-man Lee
- Lee Hysan clinical research laboratory, The Chinese University of Hong Kong, Hong Kong, China; E-Mail:
| | - Tzi-bun Ng
- School of Biomedical Science, The Chinese University of Hong Kong, Hong Kong, China; E-Mail:
| | - Tsz-ping Lam
- Department of Orthopaedics and Traumatology, The Chinese University of Hong Kong, Hong Kong, China; E-Mails: (A.P.Y.); (H.Y.); (G.S.); (T.L.); (B.K.N.)
| | - Bobby Kin-wah Ng
- Department of Orthopaedics and Traumatology, The Chinese University of Hong Kong, Hong Kong, China; E-Mails: (A.P.Y.); (H.Y.); (G.S.); (T.L.); (B.K.N.)
| | - Yong Qiu
- Spine Surgery, The Affiliated Drum Tower Hospital of Nanjing University Medical School, Nanjing 210000, China; E-Mail:
- The Joint Scoliosis Research Center of the Chinese University of Hong Kong and Nanjing University, Hong Kong, China
| | - Alain Moreau
- Research Center, Sainte-Justine Hospital, University of Montreal, Montreal, QC H3T 1C5, Canada; E-Mail:
| | - Jack Chun-yiu Cheng
- Department of Orthopaedics and Traumatology, The Chinese University of Hong Kong, Hong Kong, China; E-Mails: (A.P.Y.); (H.Y.); (G.S.); (T.L.); (B.K.N.)
- The Joint Scoliosis Research Center of the Chinese University of Hong Kong and Nanjing University, Hong Kong, China
- Author to whom correspondence should be addressed; E-Mail: ; Tel.: +852-26-098-631; Fax: +852-26-036-889
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Ouellet J, Odent T. Animal models for scoliosis research: state of the art, current concepts and future perspective applications. EUROPEAN SPINE JOURNAL : OFFICIAL PUBLICATION OF THE EUROPEAN SPINE SOCIETY, THE EUROPEAN SPINAL DEFORMITY SOCIETY, AND THE EUROPEAN SECTION OF THE CERVICAL SPINE RESEARCH SOCIETY 2013; 22 Suppl 2:S81-95. [PMID: 23099524 PMCID: PMC3616476 DOI: 10.1007/s00586-012-2396-7] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/09/2012] [Revised: 05/21/2012] [Accepted: 05/28/2012] [Indexed: 11/24/2022]
Abstract
PURPOSE The purpose of this study was to provide the readers with a reliable source of animal models currently being utilized to perform state-of-the-art scoliotic research. MATERIALS AND METHODS A comprehensive search was undertaken to review all publications on animal models for the study of scoliosis within the database from 1946 to January 2011. RESULTS The animal models have been grouped under specific headings reflecting the underlying pathophysiology behind the development of the spinal deformities produced in the animals: genetics, neuroendocrine, neuromuscular, external constraints, internal constraints with or without tissue injury, vertebral growth modulation and iatrogenic congenital malformations, in an attempt to organize and classify these multiple scoliotic animal models. As it stands, there are no animal models that mimic the human spinal anatomy with all its constraints and weaknesses, which puts it at risk of developing scoliosis. What we do have are a multitude of models, which produce spinal deformities that come close to the idiopathic scoliosis deformity. CONCLUSION All these different animal models compel us to believe that the clinical phenotype of what we call idiopathic scoliosis may well be caused by a variety of different underlying pathologies.
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Affiliation(s)
- Jean Ouellet
- />McGill Scoliosis and Spinal Research Chair, Deputy Chief Shriners Hospital, Montreal, Canada
- />Division of Orthopaedic Surgery, McGill University Health Hospital, Centre, Montreal Children Hospital, 2300 Tupper Street, Montreal, QC H3H 1P3 Canada
| | - Thierry Odent
- />Department of Orthopaedic Surgery, Hopital des Enfants Malade, Necker, Paris Descartes, France
- />Université Paris Descartes - Sorbonne Paris Cité - Service d’orthopédie pédiatrique - Hôpital Universitaire Necker - Enfants-Malades, Paris, France
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Zhong ZM, Li T, Xu ZX, Meng TT, Zeng JH, Zheng S, Ye WB, Wu Q, Chen JT. Effect of melatonin on the proliferation and differentiation of chondrocytes from rat vertebral body growth plate in vitro. Int J Med Sci 2013; 10:1392-8. [PMID: 23983601 PMCID: PMC3752726 DOI: 10.7150/ijms.5645] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/03/2012] [Accepted: 07/29/2013] [Indexed: 11/05/2022] Open
Abstract
PURPOSE Abnormal growth of vertebral body growth plate (VBGP) is considered as one of the etiologic factors in the adolescent idiopathic scoliosis (AIS). It was well-known that melatonin was correlated with the emergence and development of AIS. This study aimed to investigate the effect of melatonin on rat VBGP chondrocytes in vitro. METHODS Chondrocytes were isolated from rat VBGP, and treated with or without melatonin. Cell proliferation was measured by the Alamar Blue assay. Gene expression of collagen type II and aggrecan were evaluated by real-time PCR. Expression of the melatonin receptors (MT1, MT2), proliferating cell nuclear antigen (PCNA, a cell proliferation marker), Sox9 (a chondrocytic differentiation marker) and Smad4 (a common mediator in regulating the proliferation and differentiation of chondrocytes) were detected by Western blotting. RESULTS Expression of melatonin receptors (MT1, MT2) were detected in the rat VBGP chondrocytes. Melatonin, at 10 and 100 µg/mL concentration, significantly inhibited the proliferation of VBGP-chondrocytes and the gene expression of collagen type II and aggrecan, and down-regulated the protein expression of PCNA, Sox9 and Smad4. In addition, the inhibitory effect of melatonin was reversed by luzindole, a melatonin receptor antagonist. CONCLUSIONS These results suggest that melatonin at high concentrations can inhibit the proliferation and differentiation of VBGP chondrocytes, which might give some new insight into the pathogenic mechanism of AIS.
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Affiliation(s)
- Zhao-Ming Zhong
- Department of Spinal Surgery, Nanfang Hospital, Southern Medical University, China
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18
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The creation of scoliosis by scapula-to-contralateral ilium tethering procedure in bipedal rats: a kyphoscoliosis model. Spine (Phila Pa 1976) 2011; 36:1340-9. [PMID: 21224778 DOI: 10.1097/brs.0b013e3181f3d164] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
STUDY DESIGN Randomized trial. OBJECTIVE To create a new scoliotic model. SUMMARY OF BACKGROUND DATA Although there were a lot of modeling techniques producing scoliosis, failed was the creation of a scoliotic animal model all characterized by the evident axial rotation of vertebrae body, the simulation of the human erect posture, and avoiding direct traumas to the spine, the spinal cord, ribs, or glands in modeling techniques. METHODS A total of 45 4-week-old female wistar rats were randomly divided into three groups. Group 1 underwent subcutaneous left scapula-to-contralateral ilium tethering procedure with a nonadsorbable suture, which made the spine convex toward right side, and then removed forelimbs and tails of rats to create the bipedal rats. Tethering sutures were cut at postoperative eighth week, and the spines of rats were then observed during 2 weeks. Group 2 was the same as group 1 but in which scapula-to-ipsilateral ilium tethering procedure was performed. Group 3 was the same as group 1 except that the bipedal rats were not created. All postoperative rats were fed separately in special high cages for groups 1 and 2 or in standard cages for group 3. RESULTS At 2 weeks after tether release, the incidence of vertebral rotation was significantly higher in group 1 than in group 2 (P = 0.004). The differences in degrees of scoliosis and kyphosis between groups at the time of initial tethering were not found to be significant (P > 0.05), whereas those at 2 weeks after tether release were significantly larger in group 1 than in group 3 (P < 0.01). There were no significant differences in postoperative first food-taking duration, body weight, spinal relative length, modeling mortality, the incidences of reoperation, and scoliosis between groups (all P > 0.05). CONCLUSION The scoliotic model created by scapula-to-contralateral ilium tethering procedure in bipedal rats can preferably simulate the human scoliosis.
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19
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Janssen MMA, de Wilde RF, Kouwenhoven JWM, Castelein RM. Experimental animal models in scoliosis research: a review of the literature. Spine J 2011; 11:347-58. [PMID: 21474088 DOI: 10.1016/j.spinee.2011.03.010] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/03/2010] [Revised: 02/01/2011] [Accepted: 03/08/2011] [Indexed: 02/03/2023]
Abstract
BACKGROUND CONTEXT Many animal species and an overwhelming variety of procedures that produce an experimental scoliosis have been reported in the literature. However, varying results have been reported on identical procedures in different animal species. Furthermore, the relevance of experimental animal models for the understanding of human idiopathic scoliosis remains questionable. PURPOSE To give an overview of the procedures that have been performed in animals in an attempt to induce experimental scoliosis and discuss the characteristics and significance of various animal models. STUDY DESIGN Extensive review of the literature on experimental animal models in scoliosis research. METHODS MEDLINE electronic database was searched, focusing on parameters concerning experimental scoliosis in animal models. The search was limited to the English, French, and German languages. RESULTS The chicken appeared to be the most frequently used experimental animal followed by the rabbit and rat. Additionally, scoliosis has been induced in primates, goats, sheep, pigs, cows, dogs, and frogs. Procedures widely varied from systemic to local procedures. CONCLUSIONS Although it has been possible to induce scoliosis-like deformities in many animals through various ways, this always required drastic surgical or systemic interventions, thus making the relation to human idiopathic scoliosis unclear. The basic drawback of all used models remains that no animal resembles the upright biomechanical spinal loading condition of man, with its inherent rotational instability of certain spinal segments. The fundamental question remains what the significance of these animal models is to the understanding of human idiopathic scoliosis.
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Affiliation(s)
- Michiel M A Janssen
- Department of Orthopaedics, University Medical Centre Utrecht, Heidelberglaan 100, 3584 CX, Utrecht, The Netherlands
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Girardo M, Bettini N, Dema E, Cervellati S. The role of melatonin in the pathogenesis of adolescent idiopathic scoliosis (AIS). EUROPEAN SPINE JOURNAL : OFFICIAL PUBLICATION OF THE EUROPEAN SPINE SOCIETY, THE EUROPEAN SPINAL DEFORMITY SOCIETY, AND THE EUROPEAN SECTION OF THE CERVICAL SPINE RESEARCH SOCIETY 2011; 20 Suppl 1:S68-74. [PMID: 21416282 PMCID: PMC3087042 DOI: 10.1007/s00586-011-1750-5] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 03/02/2011] [Indexed: 12/15/2022]
Abstract
The cause of adolescent idiopathic scoliosis (AIS) in humans remains obscure and probably multifactorial. At present, there is no proven method or test available to identify children or adolescent at risk of developing AIS or identify which of the affected individuals are at risk of progression. Reported associations are linked in pathogenesis rather than etiologic factors. Melatonin may play a role in the pathogenesis of scoliosis (neuroendocrine hypothesis), but at present, the data available cannot clearly show the role of melatonin in producing scoliosis in humans. The data regarding human melatonin levels are mixed at best, and the melatonin deficiency as a causative factor in the etiology of scoliosis cannot be supported. It will be an important issue of future research to investigate the role of melatonin in human biology, the clinical efficacy, and safety of melatonin under different pathological situations. Research is needed to better define the role of all factors in AIS development.
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Affiliation(s)
- M Girardo
- Department of Spine Surgery, CTO/CRF/Maria Adelaide, Turin, Italy.
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Liu L, Zhu Y, Xu Y, Reiter RJ. Melatonin delays cell proliferation by inducing G1 and G2 /M phase arrest in a human osteoblastic cell line hFOB 1.19. J Pineal Res 2011; 50:222-31. [PMID: 21108658 DOI: 10.1111/j.1600-079x.2010.00832.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
A recent prospective study indicated that melatonin supplements may reduce the progression of idiopathic scoliosis, the most common deformity of the spine. This form of scoliosis occurs during rapid skeletal growth. To date, however, there is no direct evidence regarding an antiproliferative effect of melatonin at the level of osteoblasts. Herein, we investigated whether melatonin inhibits cell proliferation in a normal human fetal osteoblastic cell line hFOB 1.19. MTT staining showed that at 1 mm concentrations, melatonin significantly inhibited osteoblast proliferation in time-dependent manner. Flow cytometry demonstrated that melatonin significantly increased the fraction of cells in G(0) /G(1) phase of the cell cycle, while simultaneously reducing the proportion in the G(2) /M phase rather than the S phase. Western blot and real-time PCR analyses further confirmed that melatonin's inhibitory effect was possibly because of downregulation of cyclin D1 and CDK4, related to the G(1) phase, and of cyclin B1 and CDK1, related to the G(2) /M phase. There was no downregulation of cyclin E, CDK2, and cyclin A, which are related to G(1) /S transition and S phase. In addition, the trypan blue dye exclusion assay showed that cell viability was not changed by melatonin relative to control cells. These findings provide evidence that melatonin may significantly delay osteoblast proliferation in a time-dependent manner and this inhibition involves the downregulation of cyclin D1 and CDK4, related to the G(1) phase, and of cyclin B1 and CDK1, related to the G(2) /M phase.
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Affiliation(s)
- Lifeng Liu
- Department of Orthopaedics, First Hospital, China
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Evaluation of GPR50, hMel-1B, and ROR-alpha melatonin-related receptors and the etiology of adolescent idiopathic scoliosis. J Pediatr Orthop 2010; 30:539-43. [PMID: 20733416 PMCID: PMC2928583 DOI: 10.1097/bpo.0b013e3181e7902c] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
BACKGROUND Adolescent idiopathic scoliosis (AIS) is the most common spinal deformity in children. Studies have shown low melatonin levels resulting from pinealectomy in chickens and mice result in the development scoliosis, whereas supplementation with melatonin after the pinealectomy prevented it. The mere characterization of low melatonin levels is not sufficient to explain the development of idiopathic scoliosis in primates and humans, but we hypothesize that a mutation in melatonin-related receptors may be involved with the development of scoliosis. METHODS The coding, splice-site, and promoter regions of 3 melatonin-related receptors (hMel-1B, RORalpha, and GPR50) were evaluated by DNA sequencing for variants associated with the phenotype of adolescent idiopathic scoliosis. An initial screening of 50 scoliosis patients with adolescent idiopathic scoliosis was compared with 50 controls by DNA sequencing of the 3 receptors. Additional cases and controls were evaluated when genetic variants were observed (for a total of 885 individuals). RESULTS No significant differences were found in the hMel-1B and RORalpha receptors. We found 2 cSNPs in GPR50 (rs561077 and rs13440581) in the initial 50 patients. To evaluate the significance of these cSNPs, an additional 356 patients and 429 controls were analyzed. When the combined groups were analyzed, no significant associations were observed. CONCLUSIONS Despite the observed relationship between melatonin and scoliosis, there is no significant association between mutations found in any known melatonin-related receptors with adolescent idiopathic scoliosis. The strong evidence of a melatonin-related cause for the development of idiopathic scoliosis still encourages research into undiscovered melatonin-related receptors, melatonin-related hormones, and the catalytic enzymes for the serotonin-melatonin pathway. CLINICAL RELEVANCE This investigation is a genetic testing of the remaining currently known melatonin-related receptors that have not been analyzed earlier for association with AIS. Given the support in the literature of a relationship between melatonin and AIS, we have shown no mutations in any of the known melatonin-related receptor in patients with AIS.
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Sánchez-Barceló EJ, Mediavilla MD, Tan DX, Reiter RJ. Scientific basis for the potential use of melatonin in bone diseases: osteoporosis and adolescent idiopathic scoliosis. J Osteoporos 2010; 2010:830231. [PMID: 20981336 PMCID: PMC2957228 DOI: 10.4061/2010/830231] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/25/2010] [Accepted: 03/03/2010] [Indexed: 11/20/2022] Open
Abstract
The objective of this paper was to analyze the data supporting the possible role of melatonin on bone metabolism and its repercussion in the etiology and treatment of bone pathologies such as the osteoporosis and the adolescent idiopathic scoliosis (AIS). Melatonin may prevent bone degradation and promote bone formation through mechanisms involving both melatonin receptor-mediated and receptor-independent actions. The three principal mechanisms of melatonin effects on bone function could be: (a) the promotion of the osteoblast differentiation and activity; (b) an increase in the osteoprotegerin expression by osteoblasts, thereby preventing the differentiation of osteoclasts; (c) scavenging of free radicals generated by osteoclast activity and responsible for bone resorption. A variety of in vitro and in vivo experimental studies, although with some controversial results, point toward a possible role of melatonin deficits in the etiology of osteoporosis and AIS and open a new field related to the possible therapeutic use of melatonin in these bone diseases.
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Affiliation(s)
- E. J. Sánchez-Barceló
- Department of Physiology & Pharmacology, School of Medicine, University of Cantabria, 39011 Santander, Spain,*E. J. Sánchez-Barceló:
| | - M. D. Mediavilla
- Department of Physiology & Pharmacology, School of Medicine, University of Cantabria, 39011 Santander, Spain
| | - D. X. Tan
- Department of Cellular & Structural Biology, University of Texas Health Science Center, San Antonio, TX 78229, USA
| | - R. J. Reiter
- Department of Cellular & Structural Biology, University of Texas Health Science Center, San Antonio, TX 78229, USA
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Vestibular asymmetry as the cause of idiopathic scoliosis: a possible answer from Xenopus. J Neurosci 2009; 29:12477-83. [PMID: 19812323 DOI: 10.1523/jneurosci.2583-09.2009] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Human idiopathic scoliosis is characterized by severe deformations of the spine and skeleton. The occurrence of vestibular-related deficits in these patients is well established but it is unclear whether a vestibular pathology is the common cause for the scoliotic syndrome and the gaze/posture deficits or if the latter behavioral deficits are a consequence of the scoliotic deformations. A possible vestibular origin was tested in the frog Xenopus laevis by unilateral removal of the labyrinthine endorgans at larval stages. After metamorphosis into young adult frogs, X-ray images and three-dimensional reconstructed micro-computer tomographic scans of the skeleton showed deformations similar to those of scoliotic patients. The skeletal distortions consisted of a curvature of the spine in the frontal and sagittal plane, a transverse rotation along the body axis and substantial deformations of all vertebrae. In terrestrial vertebrates, the initial postural syndrome after unilateral labyrinthectomy recovers over time and requires body weight-supporting limb proprioceptive information. In an aquatic environment, however, this information is absent. Hence, the lesion-induced asymmetric activity in descending spinal pathways and the resulting asymmetric muscular tonus persists. As a consequence the mostly cartilaginous skeleton of the frog tadpoles progressively deforms. Lack of limb proprioceptive signals in an aquatic environment is thus the element, which links the Xenopus model with human scoliosis because a comparable situation occurs during gestation in utero. A permanently imbalanced activity in descending locomotor/posture control pathways might be the common origin for the observed structural and behavioral deficits in humans as in the different animal models of scoliosis.
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[Molecular and genetic aspects of idiopathic scoliosis. Blood test for idiopathic scoliosis]. DER ORTHOPADE 2009; 38:114-6, 118-21. [PMID: 19212754 DOI: 10.1007/s00132-008-1362-x] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
Spinal deformities, and particularly scoliosis, are the most frequent forms of orthopedic deformities in children and adolescents. About 1-6% of the population has scoliosis. This disorder leads to severe spinal deformities and predominantly affects adolescent girls.Although the multifactorial origin of adolescent idiopathic scoliosis (AIS) is broadly recognized, the genetic causes of AIS are still largely unknown. Our previous studies suggested a generalized dysfunction of melatonin transduction (the hormone that is primarily produced in the brain and epiphysis). In the meantime we have demonstrated that such a defect of signal transduction is caused by chemical alterations, which inactivate the function of the inhibitory G protein-coupled melatonin receptors. This discovery has led to the development of the first blood test to detect children without symptoms who are at risk of developing scoliosis. Since a single function (cellular reaction to melatonin) is determined, the unique advantage of this test is that it can be performed without knowledge of mutations in defective genes that could provoke the onset of AIS.
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Fagan AB, Kennaway DJ, Oakley AP. Pinealectomy in the chicken: a good model of scoliosis? EUROPEAN SPINE JOURNAL : OFFICIAL PUBLICATION OF THE EUROPEAN SPINE SOCIETY, THE EUROPEAN SPINAL DEFORMITY SOCIETY, AND THE EUROPEAN SECTION OF THE CERVICAL SPINE RESEARCH SOCIETY 2009; 18:1154-9. [PMID: 19340465 DOI: 10.1007/s00586-009-0927-7] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/28/2007] [Revised: 01/18/2009] [Accepted: 02/23/2009] [Indexed: 11/25/2022]
Abstract
The phenomenon of spinal deformity in the pinealectomized chicken has led researchers to postulate a disturbance of melatonin activity as a potential cause of adolescent idiopathic scoliosis (AIS). More recently, structural differences between curves seen in this model and those seen in scoliosis have been highlighted suggesting the deformities observed are not as similar as first thought. We examined melatonin levels, and the radiological and histological characteristics of scoliosis after pinealectomy in chickens. They underwent pinealectomy (P) at 2 days of age, sham surgery (S) or served as controls (C). Mean melatonin levels were 32.9 pmol/L (P), 175 pmol/L (S) and 227.3 pmol/L (C). Scoliosis developed in 75% of chickens after pinealectomy and 38% after a sham procedure. Nineteen percent of unoperated controls also developed scoliosis. A lower melatonin level was associated with the development of scoliosis (p < or = 0.001), but exceptions were seen with levels up to 265 pmol/L observed in one case. Most of the curves occurring spontaneously and after sham surgery and almost half after pinealectomy were short angular curves: distinct from those resembling idiopathic scoliosis. These occur over one or two segments and are characterized by marked apical wedging, frequently associated with subluxation or dislocation. The intervertebral joint in the chicken is more like a synovial joint histologically than an intervertebral disc. This study highlights important differences between the chicken and the human, and between their respective spinal deformities. Caution is advised when drawing conclusions regarding the pathogenesis of AIS from this model.
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Affiliation(s)
- Andrew B Fagan
- Discipline of Orthopaedics and Trauma, The University of Adelaide, Royal Adelaide Hospital, Adelaide, SA, 5000, Australia.
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Abstract
STUDY DESIGN Review of the literature on the pathogenesis of adolescent idiopathic scoliosis (AIS). OBJECTIVE To discuss the different theories that have appeared on this subject. SUMMARY OF BACKGROUND DATA The pathogenesis of AIS, a condition exclusive to humans, has been the subject of many studies. Over the years, practically every structure of the body has been mentioned in the pathogenesis of AIS; however, the cause of this spinal deformity remains little understood. The pathogenesis of this condition is termed multifactorial. METHODS PubMed and Google Scholar electronic databases were searched focused on parameters concerning the pathogenesis of adolescent idiopathic scoliosis. The search was limited to the English language. RESULTS No single causative factor for the development of idiopathic scoliosis has been identified, it is thus termed multifactorial. AIS is a complex genetic disorder. The fully erect posture, which is unique to humans, seems to be a prerequisite for the development of AIS. CONCLUSION Although any or all of the mentioned factors in this review may play a certain role in the initiation and progression of AIS at a certain stage, the presented material suggests that in the observed deformation, genetics, and the unique mechanics of the fully upright human spine play a decisive role.
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Gorman KF, Breden F. Idiopathic-type scoliosis is not exclusive to bipedalism. Med Hypotheses 2008; 72:348-52. [PMID: 19070438 DOI: 10.1016/j.mehy.2008.09.052] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2008] [Revised: 09/12/2008] [Accepted: 09/12/2008] [Indexed: 12/11/2022]
Abstract
Human familial/idiopathic-type scoliosis (IS) is a complex genetic disorder for which the cause is unknown. The curve phenotype characteristically demonstrates pronounced morphological and developmental variability that is likely a consequence of biomechanical, environmental, and genetic differences between individuals. In addition, risk factors that affect the propensity for curves to progress to severity are unknown. Progress in understanding the fundamental biology of idiopathic-type scoliosis has been limited by the lack of a genetic/developmental animal model. Prior to consideration of teleosts, developmental idiopathic-type scoliosis has been considered to be exclusive to humans. Consequently, there is the notion that the syndrome is a result of bipedalism, and many studies try to explain the deformity from this anthrocentric viewpoint. This perspective has been reinforced by the choice of animals used for study, in that chickens and bipedal rats and mice demonstrate idiopathic-type curvature when made melatonin-deficient, but quadrupedal animals do not. Overlooked is the fact that teleosts also demonstrate similar curvature when made melatonin-deficient. Our characterization of the guppy curveback has demonstrated that non-induced idiopathic-type curvature is not exclusive to humans, nor bipedalism. We hypothesize that unique morphological, developmental and genetic parallels between the human and guppy syndromes are due to common molecular pathways involved in the etiopathogenesis of both phenotypes. We explore established gene conservation between human and teleost genomes that are in pathways hypothesized to be involved in the IS syndrome. We present non-induced vertebral wedging as a unique shared feature in IS and curveback that suggests a similar interaction between a molecular phenotype on the level of the vertebral anatomy, and biomechanics. We propose that rather than bipedalism per se, expression of idiopathic-type scoliosis is dependent on normal spinal loading applied along the cranio-caudal axis that interacts with an unknown factor causing the primary curve. In this regard, a comparative biological approach using a simplified teleost model will promote discovery of basic processes integral to idiopathic-type scoliosis in teleosts and humans, and highlight human-specific aspects of the deformity.
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Affiliation(s)
- Kristen F Gorman
- Department of Biological Sciences, Simon Fraser University, 8888 University Dr, Burnaby, BC, Canada V5A 1S6.
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Abstract
Adolescent idiopathic scoliosis (AIS) affects 1-3% of children in the at-risk population of those aged 10-16 years. The aetiopathogensis of this disorder remains unknown, with misinformation about its natural history. Non-surgical treatments are aimed to reduce the number of operations by preventing curve progression. Although bracing and physiotherapy are common treatments in much of the world, their effectiveness has never been rigorously assessed. Technological advances have much improved the ability of surgeons to safely correct the deformity while maintaining sagittal and coronal balance. However, we do not have long-term results of these changing surgical treatments. Much has yet to be learned about the general health, quality of life, and self-image of both treated and untreated patients with AIS.
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Affiliation(s)
- Stuart L Weinstein
- Department of Orthopaedic Surgery and Rehabilitation, University of Iowa, Iowa City, Iowa, IA 52242, USA.
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Day GA, McPhee IB, Tuffley J, Tomlinson F, Chaseling R, Kellie S, Torode I, Sherwood M, Cutbush K, Geddes AJ, Brankoff B. Idiopathic scoliosis and pineal lesions in Australian children. J Orthop Surg (Hong Kong) 2007; 15:327-33. [PMID: 18162681 DOI: 10.1177/230949900701500318] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
PURPOSE To determine whether treatment of pineal lesions in children is associated with development of idiopathic scoliosis. METHODS 38 boys and 10 girls with pineal lesions were identified. Their mean age at presentation was 10 years. The pineal pathology varied from cysts and epidermoid to teratoma, germinoma, pineocytoma, and glioblastoma. Treatment ranged from biopsy/extirpation to radiotherapy. RESULTS 12 patients died. No scoliosis was found in any females or any of the deceased. Two boys had scoliosis: one had a 12-degree right upper thoracic curve with 32-degree kyphosis and the other had a 60-degree right thoracolumbar idiopathic curve, requiring a 2-stage arthrodesis. CONCLUSION Pineal ablation is not related to the development of idiopathic scoliosis in humans.
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Affiliation(s)
- G A Day
- University of Queensland, Australia.
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Lafortune P, Aubin CÉ, Boulanger H, Villemure I, Bagnall KM, Moreau A. Biomechanical simulations of the scoliotic deformation process in the pinealectomized chicken: a preliminary study. SCOLIOSIS 2007; 2:16. [PMID: 17996083 PMCID: PMC2200637 DOI: 10.1186/1748-7161-2-16] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/26/2007] [Accepted: 11/09/2007] [Indexed: 11/10/2022]
Abstract
BACKGROUND The basic mechanisms whereby mechanical factors modulate the metabolism of the growing spine remain poorly understood, especially the role of growth adaptation in spinal disorders like in adolescent idiopathic scoliosis (AIS). This paper presents a finite element model (FEM) that was developed to simulate early stages of scoliotic deformities progression using a pinealectomized chicken as animal model. METHODS The FEM includes basic growth and growth modulation created by the muscle force imbalance. The experimental data were used to adapt a FEM previously developed to simulate the scoliosis deformation process in human. The simulations of the spine deformation process are compared with the results of an experimental study including a group of pinealectomized chickens. RESULTS The comparison of the simulation results of the spine deformation process (Cobb angle of 37 degrees ) is in agreement with experimental scoliotic deformities of two representative cases (Cobb angle of 41 degrees and 30 degrees ). For the vertebral wedging, a good agreement is also observed between the calculated (28 degrees ) and the observed (25 degrees - 30 degrees ) values. CONCLUSION The proposed biomechanical model presents a novel approach to realistically simulate the scoliotic deformation process in pinealectomized chickens and investigate different parameters influencing the progression of scoliosis.
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Affiliation(s)
- Pierre Lafortune
- Department of Mechanical Engineering, Ecole Polytechnique, University of Montreal, P.O. Box 6079, Station Centre-ville, Montreal, Quebec, H3C 3A7, Canada
- Research Centre, Sainte-Justine University Hospital Centre, University of Montreal, Montreal, Quebec, Canada
| | - Carl-Éric Aubin
- Department of Mechanical Engineering, Ecole Polytechnique, University of Montreal, P.O. Box 6079, Station Centre-ville, Montreal, Quebec, H3C 3A7, Canada
- Research Centre, Sainte-Justine University Hospital Centre, University of Montreal, Montreal, Quebec, Canada
| | - Hugo Boulanger
- Research Centre, Sainte-Justine University Hospital Centre, University of Montreal, Montreal, Quebec, Canada
| | - Isabelle Villemure
- Department of Mechanical Engineering, Ecole Polytechnique, University of Montreal, P.O. Box 6079, Station Centre-ville, Montreal, Quebec, H3C 3A7, Canada
- Research Centre, Sainte-Justine University Hospital Centre, University of Montreal, Montreal, Quebec, Canada
| | - Keith M Bagnall
- Division of Anatomy/Department of Surgery, University of Alberta, Edmonton, Alberta, Canada
| | - Alain Moreau
- Research Centre, Sainte-Justine University Hospital Centre, University of Montreal, Montreal, Quebec, Canada
- Department of Biochemistry, Faculty of Medicine, University of Montreal, Montreal, Quebec, Canada
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Alini M, Eisenstein SM, Ito K, Little C, Kettler AA, Masuda K, Melrose J, Ralphs J, Stokes I, Wilke HJ. Are animal models useful for studying human disc disorders/degeneration? EUROPEAN SPINE JOURNAL : OFFICIAL PUBLICATION OF THE EUROPEAN SPINE SOCIETY, THE EUROPEAN SPINAL DEFORMITY SOCIETY, AND THE EUROPEAN SECTION OF THE CERVICAL SPINE RESEARCH SOCIETY 2007; 17:2-19. [PMID: 17632738 PMCID: PMC2365516 DOI: 10.1007/s00586-007-0414-y] [Citation(s) in RCA: 488] [Impact Index Per Article: 28.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/03/2006] [Revised: 04/24/2007] [Accepted: 05/28/2007] [Indexed: 12/11/2022]
Abstract
Intervertebral disc (IVD) degeneration is an often investigated pathophysiological condition because of its implication in causing low back pain. As human material for such studies is difficult to obtain because of ethical and government regulatory restriction, animal tissue, organs and in vivo models have often been used for this purpose. However, there are many differences in cell population, tissue composition, disc and spine anatomy, development, physiology and mechanical properties, between animal species and human. Both naturally occurring and induced degenerative changes may differ significantly from those seen in humans. This paper reviews the many animal models developed for the study of IVD degeneration aetiopathogenesis and treatments thereof. In particular, the limitations and relevance of these models to the human condition are examined, and some general consensus guidelines are presented. Although animal models are invaluable to increase our understanding of disc biology, because of the differences between species, care must be taken when used to study human disc degeneration and much more effort is needed to facilitate research on human disc material.
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Affiliation(s)
- Mauro Alini
- AO Research Institute, Clavadelerstrasse, 7270 Davos, Switzerland
| | | | - Keita Ito
- AO Research Institute, Clavadelerstrasse, 7270 Davos, Switzerland
| | - Christopher Little
- Raymond Purves Lab, Institute of Bone and Joint Research, Kolling Institute of Medical Research, University of Sydney at the Royal North Shore Hospital, St. Leonards, NSW Australia
| | - A. Annette Kettler
- Institute of Orthopaedic Research and Biomechanics, University of Ulm, Ulm, Germany
| | - Koichi Masuda
- Department of Orthopedic Surgery, Rush Medical College at Rush University Medical Center, Chicago, IL USA
| | - James Melrose
- Raymond Purves Lab, Institute of Bone and Joint Research, Kolling Institute of Medical Research, University of Sydney at the Royal North Shore Hospital, St. Leonards, NSW Australia
| | - Jim Ralphs
- School of Bioscience, Cardiff University, Cardiff, UK
| | - Ian Stokes
- Department of Orthopaedics and Rehabilitation, University of Vermont, Burlington, VA USA
| | - Hans Joachim Wilke
- Institute of Orthopaedic Research and Biomechanics, University of Ulm, Ulm, Germany
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Cheung KMC, Wang T, Qiu GX, Luk KDK. Recent advances in the aetiology of adolescent idiopathic scoliosis. INTERNATIONAL ORTHOPAEDICS 2007; 32:729-34. [PMID: 17572891 PMCID: PMC2898941 DOI: 10.1007/s00264-007-0393-y] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/30/2007] [Revised: 05/06/2007] [Accepted: 05/07/2007] [Indexed: 12/24/2022]
Abstract
The aetiology of adolescent idiopathic scoliosis (AIS) is still unknown despite many years of research effort. Theories on AIS's aetiology have included mechanical, hormonal, metabolic, neuromuscular, growth, and genetic abnormalities. Amongst these, some factors may be epiphenomena rather than the cause itself. Other factors may even contribute to curve progression, rather than curve initiation. Current views maintain that AIS is a multifactorial disease with genetic predisposing factors [Lowe et al. in J Bone Joint Surg [Am] 82:1157-1168, 2000]. With improvements in diagnostic methods, imaging and genomics, there has been considerable recent work on aetiology. This review aims to bring readers up-to-date with the latest developments in scoliosis research.
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Affiliation(s)
- Kenneth M C Cheung
- Department of Orthopaedics and Traumatology, Queen Mary Hospital, The University of Hong Kong, Pokfulam, Hong Kong, China.
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Gorman KF, Tredwell SJ, Breden F. The mutant guppy syndrome curveback as a model for human heritable spinal curvature. Spine (Phila Pa 1976) 2007; 32:735-41. [PMID: 17414906 DOI: 10.1097/01.brs.0000259081.40354.e2] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
STUDY DESIGN This study investigated the morphology, pathogenesis, and inheritance of idiopathic-like spinal curvature in the guppy syndrome, curveback. OBJECTIVE To determine whether curveback could be applied as a model for the primary factors that contribute to heritable spinal curvature in humans, specifically, the etiopathogenesis of human familial idiopathic scoliosis. SUMMARY OF BACKGROUND DATA Although a genetic basis is accepted, phenotypic complexity and the lack of an animal model with noninduced curvature have made identification of idiopathic scoliosis etiology difficult. It is well established that humans and fish share many genes with similar tissue and temporal expression characteristics, and comparisons between human and fish genomes have proven to be valuable for understanding the genetics of diseases affecting humans. METHODS The curveback lineage of guppies was constructed from a single curved male crossed to a normal female. Offspring (103) from the original cross were scored from birth until death for the presence and magnitude of spinal curvature. Genetic architecture was investigated through selective inbreeding, analysis of the distribution of curve magnitude in the mature population, and assessment of curve dynamics during development. Computed tomography assessed vertebral detail. RESULTS Computed tomography reveals that vertebral breakage or fusion is not associated with the curveback syndrome. Inbreeding demonstrates a strong genetic influence on curveback, and the distribution of curve magnitude among adult fish suggests polygenic inheritance. There is a female bias for curves of high magnitude and curves that resolve before maturity. There is developmental variability for the age of curve onset, curve progression, and final curve magnitude. CONCLUSIONS Observed parallels between the curveback syndrome and human idiopathic scoliosis suggest that the guppy model is an unexploited resource for the identification of primary etiological factors involved in curvature. As models for biomedical research, teleosts offer great potential regarding spinal stability and deformity.
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Affiliation(s)
- Kristen F Gorman
- Department of Biological Sciences, Simon Fraser University, Burnaby, British Columbia, Canada.
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Gorman KF, Breden F. Teleosts as models for human vertebral stability and deformity. Comp Biochem Physiol C Toxicol Pharmacol 2007; 145:28-38. [PMID: 17240199 DOI: 10.1016/j.cbpc.2006.10.004] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/01/2006] [Revised: 10/12/2006] [Accepted: 10/12/2006] [Indexed: 11/17/2022]
Abstract
Vertebral development is a dynamic and complicated process, and defects can be caused by a variety of influences. Spinal curvature with no known cause (idiopathic scoliosis) affects 2-3% of the human population. In order to understand the etiology and pathogenesis of complex human skeletal defects such as idiopathic scoliosis, multiple models must be used to study all of the factors affecting vertebral stability and deformity. Although fish and humans have many of the same types of offenses to vertebral integrity, they have been overlooked as a resource for study. The most common morphological deformity reported for fish are those that occur during the development of the spinal system, and as with humans, curvature is a common morphological consequence. Here we review spinal curvature in teleosts and suggest that they are an unexploited resource for understanding the basic elements of vertebral stability, deformity, development and genetics. Fish can be a value to vertebral research because they are tractable, have a diversity of non-induced vertebral deformities, and substantial genomic resources. Current animal models lack non-induced deformities and the experimental tractability necessary for genetic studies. The fact that fish are free of an appendicular skeleton should allow for analysis of basic spinal integrity without the biomechanical constraints observed in quadrupedal and bipedal models. To illustrate the point we review human idiopathic scoliosis and the potential contribution teleosts can make for the identification of causes, risk factors, and treatment options.
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Affiliation(s)
- Kristen F Gorman
- Department of Biological Sciences, Simon Fraser University, Burnaby, BC, Canada.
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Machida M, Dubousset J, Yamada T, Kimura J, Saito M, Shiraishi T, Yamagishi M. Experimental scoliosis in melatonin-deficient C57BL/6J mice without pinealectomy. J Pineal Res 2006; 41:1-7. [PMID: 16842534 DOI: 10.1111/j.1600-079x.2005.00312.x] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The etiology of idiopathic scoliosis is unknown. Scoliosis with many characteristics closely resembling those seen in idiopathic scoliosis has been produced in young chickens and bipedal rats after pinealectomy. In this study, we induced experimental scoliosis in C57BL/6J mice without pinealectomy and melatonin treatment suppressed the development of scoliosis. A total of 100 mice were divided into four groups: 20 quadrupedal mice served as controls; 30 mice underwent resection of two forelegs and tail at 3 wk of age (bipedal mice); the remaining 20 quadrupedal and 30 bipedal mice received intraperitoneal melatonin (8 mg/kg BW) at 19:00 hr daily. Before killing, blood samples were collected in the middle of dark cycle and melatonin levels were measured by radioimmunoassay. Spine X-ray and helical 3D-CT were examined after killing at 5 months of age. The bipedal mice without a tail were able to walk with standing posture, whereas the quadrupedal mice did not walk with standing posture. In C57BL/6J mice, the serum melatonin was reduced to nearly zero; however, the normal level was restored in both bipedal and quadrupedal mice after the injection of melatonin. Scoliosis with rib humps developed in 29 of 30 bipedal and in five quadrupedal mice. None of mice with melatonin treatment developed scoliosis. The results suggest that melatonin deficiency in bipedal mice appears to play crucial role for development of scoliosis. Also the restoration of melatonin levels prevents the development of scoliosis.
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Affiliation(s)
- Masafumi Machida
- Department of Orthopaedic Surgery, National Hospital Organization, Murayama Medical Center, Tokyo, Japan.
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Routh RH, Rumancik S, Pathak RD, Burshell AL, Nauman EA. The relationship between bone mineral density and biomechanics in patients with osteoporosis and scoliosis. Osteoporos Int 2005; 16:1857-63. [PMID: 15999291 DOI: 10.1007/s00198-005-1951-z] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/30/2004] [Accepted: 05/12/2005] [Indexed: 11/28/2022]
Abstract
Nearly one-third of all women and one-sixth of all men over age 65 have osteoporosis, and this condition is often accompanied by lumbar scoliosis. Previous work has shown that, in a group of postmenopausal women with scoliosis and osteoporosis, both the bone mineral content (BMC) and bone mineral density (BMD) were greater on the concave side than the convex side. The goal of this study was to examine the structure-function relationships in the spines of patients with low bone mass and scoliosis using a patient-specific biomechanical model. We compared the percent change in BMC and the percent change in BMD with axial force, F(a), shear force, F(s), moment, M, local curvature, theta(rel), and the patient's age, A. We found that the percent change in BMC depended on the applied moment and the local curvature. The same dependence was observed for the percent change in BMD, but in this case, the shear force was also significantly inversely correlated. A population with femoral neck BMD with a T-score greater than -2.0 was similarly evaluated and yielded similar results. The percent change in BMD was related to M, theta(rel), A and negatively to the shear force. These results indicate that the osteoporotic spine is still able to respond to changes in the mechanical environment and provides a useful comparison between patients with osteoporosis and those with normal bone mass. In addition, this model may be a useful tool for the in vivo assessment of bone density changes in response to mechanical stimuli and drug treatments.
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Affiliation(s)
- R Hank Routh
- Department of Endocrinology, Ochsner Hospital, New Orleans, LA, USA
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Yoshihara H, Kawakami N, Matsuyama Y, Inoh H, Imagama S, Ishiguro N. A histomorphologic study of scoliosis in pinealectomized chickens. Spine (Phila Pa 1976) 2005; 30:2244-51. [PMID: 16227885 DOI: 10.1097/01.brs.0000182095.00577.ee] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
STUDY DESIGN Pinealectomy was used to induce scoliosis in Broiler chickens, and a histologic investigation of the pinealectomized chickens was performed. OBJECTIVES To investigate the incidence of scoliosis in pinealectomized Broiler chickens and to determine histologic changes in vertebrae in the pinealectomized chickens before the occurrence of a secondary vertebral wedging deformity due to scoliosis. SUMMARY OF BACKGROUND DATA White Leghorn chickens have previously been used as an experimental model of scoliosis, but the occurrence of scoliosis in these chickens following pinealectomy has varied in different reports and is not always high. It is accepted that the development of scoliosis has a close association with growth, but the etiology and mechanism of the disease remain unknown. Histologic findings in vertebrae after the occurrence of scoliosis include those caused by secondary changes due to mechanical compression, and no histologic data for the period before the occurrence of scoliosis are available. METHODS Study 1. A total of 100 female "Broiler" chickens were pinealectomized, and the frequency with which scoliosis occurred was investigated. Study 2. Sixty female Broiler chickens were divided into three groups: the control group (Group C, n = 20), the sham operation group (Group S, n = 20), and the pinealectomy group (Group P, n = 20). Each group was then subdivided into two groups according to the time of death: 3 days after the operation (Group 3-C, 3-S, 3-P, n = 10), and 6 days after the operation (Group 6-C, 6-S, 6-P, n = 10). Decalcified thin sagittal sections were made using a tartrate-resistant acid phosphatase (TRAP) stain. Histologic examinations of the growth plate, trabecular structure, and osteoclast number were performed. RESULTS The incidence of scoliosis in the pinealectomized Broiler chickens was 93.6%. Nine of the 10 chickens in Group 6-P showed scoliosis deformity, while the presence of scoliosis was unclear in chickens in Group 3-P. The osteoclast number increased significantly in Group 3-P, compared with Groups 3-C and 3-S, and the trabecular thickness was greater in Group 3-P than in Groups 3-C and 3-S. There was no significant change in the growth plate or in other aspects of the trabecular structure, except for trabecular thickness, in any of the groups. CONCLUSIONS The results show that the incidence of scoliosis using pinealectomized Broiler chickens is sufficient to study histologic changes of the vertebral body before onset of scoliosis. We found that the osteoclast number and trabecular thickness increased in pinealectomized chickens after 3 days after surgery, just before scoliosis began to develop, and that no change in the growth plate occurred. This suggests that there is no association between changes in the growth plate and the development of scoliosis. However, the change in osteoclast number may have an association with the development of scoliosis, through changes in bone modeling.
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Affiliation(s)
- Hisatake Yoshihara
- Department of Orthopaedic Surgery, Nagoya University School of Medicine, Nagoya, Japan.
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Cheung KMC, Wang T, Poon AMS, Carl A, Tranmer B, Hu Y, Luk KDK, Leong JCY. The effect of pinealectomy on scoliosis development in young nonhuman primates. Spine (Phila Pa 1976) 2005; 30:2009-13. [PMID: 16166887 DOI: 10.1097/01.brs.0000179087.38730.5d] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
STUDY DESIGN Prospective study on pinealectomy in primates. OBJECTIVE To evaluate whether pinealectomy in a bipedal nonhuman primate model will result in the development of scoliosis. SUMMARY OF BACKGROUND DATA Pinealectomy in newborn chickens consistently resulted in scoliosis development. Published data suggest that the surgical removal of the pineal, loss of melatonin secretion, and a bipedal posture are important elements in the development of scoliosis in lower animal models. METHOD There were 18 rhesus monkeys between 8 and 11 months old that underwent pineal excision. All monkeys were kept in a regulated 12-hour light-dark cycle. Monthly radiographs assessed scoliosis development. Completeness of pineal excision was assessed by measurement of a major metabolite of melatonin in the urine, 6-sulfatoxymelatonin, using an enzyme-linked immunosorbent assay assessed. RESULTS Mean follow-up was 28 months (range 10-41). Seven monkeys died prematurely, and 11 survived to date; the data from those that died could still be used, although follow-up was shortened. At the latest follow-up or death, scoliosis did not develop in any of the monkeys. Urinary 6-sulfatoxymelatonin measurements revealed 3 patterns. Group 1 consisted of 10 monkeys, which showed definite evidence of complete pineal excision. Group 2 consisted of an uncertain group of 2 monkeys in which the nighttime melatonin level is slightly high. Group 3 consisted of 6 monkeys that had incomplete pineal excision or ectopic melatonin production. CONCLUSIONS To our knowledge, this is the first report of pinealectomy in nonhuman primates. Of the 18 monkeys, 10 had a loss of melatonin secretion, for a mean of 29 months after surgery. Because none of the monkeys had scoliosis develop, this study strongly suggests that the possible etiologic factors producing idiopathic scoliosis in lower animals are different from primates, and findings in lower animals cannot necessarily be extrapolated to human beings.
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Affiliation(s)
- Kenneth M C Cheung
- Department of Orthopaedics and Traumatology, University of Hong Kong, Hong Kong, China.
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Machida M, Saito M, Dubousset J, Yamada T, Kimura J, Shibasaki K. Pathological mechanism of idiopathic scoliosis: experimental scoliosis in pinealectomized rats. EUROPEAN SPINE JOURNAL : OFFICIAL PUBLICATION OF THE EUROPEAN SPINE SOCIETY, THE EUROPEAN SPINAL DEFORMITY SOCIETY, AND THE EUROPEAN SECTION OF THE CERVICAL SPINE RESEARCH SOCIETY 2005; 14:843-8. [PMID: 15864672 DOI: 10.1007/s00586-004-0806-1] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/15/2003] [Accepted: 07/30/2004] [Indexed: 11/24/2022]
Abstract
The pathological mechanism of curve progression in idiopathic scoliosis is still obscure. In this study we investigated the pathological mechanism of idiopathic scoliosis in experimentally induced scoliosis in rats. A total 30 rats were divided into three groups: ten bipedal rats with a sham operation, which served as the control; ten quadrupedal rats with pinealectomy; and ten bipedal rats with pinealectomy. Scoliosis developed only in pinealectomized bipedal rats and not in pinealectomized quadrupedal rats. Cervicothoracic lordosis developed in bipedal rats with or without pinealectomy. These deformities of lordoscoliosis in pinealectomized bipedal rats were similar to human idiopathic scoliosis. Lordosis or lordotic tendency was sufficient to cause the spine to rotate to the side. Rotational instability of the spine with rotation of lordotic segment appears to produce a characteristic scoliotic deformity as a secondary phenomenon. Our findings suggest that lordosis may develop in bipedal rats, but pinealectomy is required for the development of lordoscoliosis. Balanced muscle tone controlled by the postural reflex is important to maintain normal posture with a straight spine in the bipedal condition. The disturbance of equilibrium and other postural mechanisms secondary to a deficiency of melatonin after pinealectomy may promote development of lordoscoliosis with vertebral rotation especially in the bipedal posture.
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Affiliation(s)
- Masafumi Machida
- Department of Orthopaedic Surgery, Nihon University School of Medicine, Tokyo, Japan.
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Bashiardes S, Veile R, Allen M, Wise CA, Dobbs M, Morcuende JA, Szappanos L, Herring JA, Bowcock AM, Lovett M. SNTG1, the gene encoding gamma1-syntrophin: a candidate gene for idiopathic scoliosis. Hum Genet 2004; 115:81-9. [PMID: 15088139 DOI: 10.1007/s00439-004-1121-y] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2004] [Accepted: 03/18/2004] [Indexed: 10/26/2022]
Abstract
Idiopathic scoliosis (IS) affects approximately 2%-3% of the population and has a heritable component. The genetics of this disorder are complex. Here, we describe a family in which a pericentric inversion of chromosome 8 co-segregates with IS. We have used fluorescence in situ hybridization to identify cloned DNAs that span the breakpoints on the two arms of the chromosome. We have identified a bacterial artificial chromosome (BAC) of 150 kb that crosses the q-arm breakpoint and a BAC of 120 kb that crosses the p-arm breakpoint. The complete genomic DNA sequence of these BACs has been analyzed to identify candidate genes and to localize further the precise breakpoints. This has revealed that the p-arm break does not interrupt any known gene and occurs in a region of highly repetitive sequence elements. On the q-arm, the break occurs between exons 10 and 11 of the gamma-1 syntrophin (SNTG1) gene. Syntrophins are a group of cytoplasmic peripheral membrane proteins that associate directly with dystrophin, the Duchenne muscular dystrophy gene; gamma1-syntrophin has been shown to be a neuronal cell-specific protein. Mutational analysis of SNTG1 exons in 152 sporadic IS patients has revealed a 6-bp deletion in exon 10 of SNTG1 in one patient and a 2-bp insertion/deletion mutation occurring in a polypyrimidine tract of intronic sequence 20 bases upstream of the SNTG1 exon 5 splice site in two patients. These changes were not seen in a screen of 480 control chromosomes. Genomic DNAs from seven affected individuals within the family of a patient carrying the 6-bp deletion were typed to determine whether the alteration co-segregated with IS. The deletion was only observed in five out of these seven individuals. Thus, although genetic heterogeneity or multiple alleles cannot be ruled out, the 6-bp deletion does not consistently co-segregate with the disease in this family.
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Affiliation(s)
- Stavros Bashiardes
- Department of Genetics, Washington University School of Medicine, St. Louis, MO, USA
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Morcuende JA, Minhas R, Dolan L, Stevens J, Beck J, Wang K, Weinstein SL, Sheffield V. Allelic variants of human melatonin 1A receptor in patients with familial adolescent idiopathic scoliosis. Spine (Phila Pa 1976) 2003; 28:2025-8; discussion 2029. [PMID: 12973153 DOI: 10.1097/01.brs.0000083235.74593.49] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
STUDY DESIGN A genetic study of patients with familial adolescent idiopathic scoliosis. OBJECTIVES The purpose of this study was to evaluate the evidence for linkage on chromosome 4q and determine whether mutations in the gene coding for melatonin receptor are present. SUMMARY OF BACKGROUND DATA Adolescent idiopathic scoliosis is the most common spine deformity arising during childhood, but its cause remains unknown. The fact that adolescent idiopathic scoliosis is often seen in several members of the same family strongly suggests a genetic factor. Recent work by Wise et al provides evidence for linkage of adolescent idiopathic scoliosis at several different chromosome sites, including 4q. In addition, there is some evidence that adolescent idiopathic scoliosis may be related to a disturbance in melatonin metabolism, and the human melatonin-1A receptor is known to be located on chromosome 4q. METHODS Probands having clinically relevant idiopathic scoliosis (Cobb angle >30 degrees) and their relatives were identified. Radiographic confirmation was required for a positive diagnosis. Linkage analysis was performed with 15 microsatellite markers of chromosome 4q spaced at approximately 10-cM resolution and 5 microsatellite markers surrounding the site for human melatonin receptor. The gene for human melatonin receptor was screened for mutations in the coding region using genomic DNA samples by single-strand conformational polymorphism analysis. Amplimers showing a band shift were reamplified and sequenced bidirectionally. RESULTS There was no evidence for linkage at chromosome 4q in this study population. Twenty-nine individuals demonstrated aberrant single-strand conformation polymorphism band patterns, and sequence evaluation demonstrated six genetic polymorphisms for the gene for human melatonin receptor. These genetic variations were found in both affected and nonaffected individuals, and there was no correlation between gene variants and the phenotype for adolescent idiopathic scoliosis. CONCLUSIONS The results of this study demonstrated no evidence of linkage to chromosome 4q and no mutations in the coding region of the gene for human melatonin receptor. The identification of variants in the human melatonin receptor could provide a useful tool for testing the gene in the predisposition to various other melatonin-related disorders and for clarifying the role of melatonin in adolescent idiopathic scoliosis.
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Affiliation(s)
- Jose A Morcuende
- Department of Orthopaedic Surgery, University of Iowa, Iowa City, Iowa, USA.
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Elastic Strapping Orthosis for Adolescent Idiopathic Scoliosis: A Preliminary Report and Initial Clinical Observations. ACTA ACUST UNITED AC 2002. [DOI: 10.1097/00008526-200203000-00005] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Machida M, Dubousset J, Satoh T, Murai I, Wood KB, Yamada T, Ryu J. Pathologic mechanism of experimental scoliosis in pinealectomized chickens. Spine (Phila Pa 1976) 2001; 26:E385-91. [PMID: 11568714 DOI: 10.1097/00007632-200109010-00006] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
STUDY DESIGN This study was designed to investigate the pathologic mechanisms of idiopathic scoliosis using experimentally induced scoliosis in chickens. OBJECTIVE To understand the process of producing a scoliotic deformity in pinealectomized chickens. SUMMARY OF BACKGROUND DATA Pinealectomy in chickens consistently produces scoliosis with anatomic characteristics similar to those of human idiopathic scoliosis. Pinealectomized chickens are an important animal model for the study of idiopathic scoliosis. METHODS In this study, 40 chickens were divided into two groups; 20 chickens treated with pinealectomy and 20 with a sham operation as control subjects on the second after hatching. The chickens in both groups then were killed at intervals ranging from 1 to 20 weeks after surgery. Their spines were examined visually and radiologically for the presence of a scoliotic curve and vertebral deformities. RESULTS Rotational lordoscoliosis developed in pinealectomized chickens. The chickens with severe scoliosis were characterized by apically wedge-shaped vertebrae. In contrast, no scoliosis with any vertebral deformity developed in any of the chickens that received a sham operation. CONCLUSIONS Because there normally is evidence of lordosis in the thoracic spine of chickens, the rotational instability of the spine induced by pinealectomy may produce a scoliotic deformity as a secondary phenomenon. Pinealectomy in chickens consistently produces scoliosis with anatomic characteristics similar to those of human idiopathic scoliosis. The authors believe that disturbance of the equilibrium and the posture mechanism associated with a defect in melatonin synthesis after pinealectomy may promote the development of rotational lordoscoliosis.
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Affiliation(s)
- M Machida
- Department of Orthopaedic Surgery and Biochemistry, Nihon University School of Medicine, Tokyo, Japan
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Inoh H, Kawakami N, Matsuyama Y, Aoki T, Kanemura T, Natsume N, Iwata H. Correlation between the age of pinealectomy and the development of scoliosis in chickens. Spine (Phila Pa 1976) 2001; 26:1014-21. [PMID: 11337619 DOI: 10.1097/00007632-200105010-00006] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
STUDY DESIGN Pinealectomy induces experimental scoliosis in chickens. This study analyzed the correlation between the age at which pinealectomy was performed and the development of scoliosis in chickens. OBJECTIVE To investigate the differences in the rate or magnitude of scoliosis and the type of curvature in chickens pinealectomized at different times after hatching. SUMMARY OF BACKGROUND DATA Scoliosis develops in almost all chickens pinealectomized within 3 days after hatching, but there are no data on whether the condition will develop in chickens pinealectomized earlier or later after hatching. METHODS In this study, 106 female white leghorn chickens were divided into six groups: four pinealectomy groups (pinealectomy was performed 2, 4, 11, or 18 days after hatching in Groups P-2, P-4, P-11, and P-18, respectively), a control group (Group C), and a sham operation group (Group S). Ventrodorsal radiographs of the spine were taken at 4-week intervals until the age of 12 weeks. At 12 weeks, a 1-mL sample of blood was taken from the heart at the middle of the dark cycle, and the serum melatonin concentration was measured by radioimmunoassay. RESULTS At the age of 12 weeks, scoliosis was present in 63.6% of the chickens in Group P-2, 72.7% in Group P-4, 81% in Group P-11, and 70% in Group P-18, and the Cobb angles in the scoliotic chickens averaged 32.6, 29.8, 23.8, and 22.3 degrees in the respective groups. There were no significant differences in the rate or magnitude of scoliosis and the type of curvature among the pinealectomy groups at the age of 12 weeks. At the age of 12 weeks, the serum melatonin levels at the middle of the dark cycle in the pinealectomized chickens were significantly lower than those of chickens in Groups C and S. However, there were no differences in the serum melatonin levels between scoliotic and nonscoliotic pinealectomized chickens. CONCLUSIONS Findings from this study show that scoliosis develops in 60% to 80% of chickens pinealectomized within 18 days after hatching, and that scoliotic development is not influenced by the age at which pinealectomy is performed. However, this study suggests that melatonin plays a complicated role in spinal development, inasmuch as the serum melatonin levels after pinealectomy approximated zero. Yet scoliosis did not develop in all pinealectomized chickens.
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Affiliation(s)
- H Inoh
- Department of Orthopaedic Surgery, Nagoya Daiichi Red Cross Hospital, Nagoya, Japan.
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Bagnall KM, Beuerlein M, Johnson P, Wilson J, Raso VJ, Moreau M. Pineal transplantation after pinealectomy in young chickens has no effect on the development of scoliosis. Spine (Phila Pa 1976) 2001; 26:1022-7. [PMID: 11337620 DOI: 10.1097/00007632-200105010-00007] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
STUDY DESIGN Three experimental groups and one control group of chickens underwent different surgical procedures to determine the effects of pineal gland transplantation on the development of scoliosis. OBJECTIVE To determine whether transplantation of the pineal gland to the body wall musculature maintains serum melatonin levels at normal values and prevents the development of scoliosis. SUMMARY OF BACKGROUND DATA Scoliosis occurs consistently after pinealectomy in young chickens. Many characteristics of this scoliosis are similar to those seen in patients with adolescent idiopathic scoliosis. It is not clear whether the underlying mechanism is dependent on reduced levels of serum melatonin or some other aspect of the extensive surgery. METHODS Four groups of chickens were selected: normal chickens, pinealectomized chickens, chickens that underwent simple cutting of the pineal stalk, and chickens that underwent transplantation of the pineal gland into the body wall. Development of scoliosis was determined from measurement of the Cobb angle from weekly radiographs. RESULTS All of the experimental groups showed the same levels of incidence and the same patterns of scoliosis development. Serum melatonin levels were reduced to nearly zero in all the experimental groups for the duration of the experiment. Scoliosis developed in none of the normal chickens. CONCLUSIONS Neither transplantation of the pineal gland into the body wall musculature nor simple cutting of the pineal stalk was able to maintain normal levels of serum melatonin because both procedures reduced levels to nearly zero. The incidence and pattern of scoliosis development in these groups were the same as those for the pinealectomized group. Reduction of serum melatonin levels remains a prerequisite for scoliosis development in young chickens.
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Affiliation(s)
- K M Bagnall
- Department of Surgery, University of Alberta, Edmonton, Alberta, Canada.
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Beuerlein M, Wang X, Moreau M, Raso J, Mahood J, Bagnall K. Development of scoliosis following pinealectomy in young chickens is not the result of an artifact of the surgical procedure. Microsc Res Tech 2001; 53:81-6. [PMID: 11279673 DOI: 10.1002/jemt.1071] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Pinealectomy in young chickens consistently results in scoliosis, which has many characteristics similar to those seen in adolescent idiopathic scoliosis. The mechanism underlying this phenomenon remains a mystery and it is not yet entirely clear whether some unidentified aspect of the extensive surgery is the major factor rather than the removal of the pineal gland. Four different types of pinealectomy surgery were performed on young chickens as well as deliberate damage to the cerebral cortex which simulated the extreme of any accidental damage that might occur during surgery. Scoliosis was assessed from weekly radiographs. No differences in incidence of scoliosis, degree of severity, or pattern of curve development were observed for any of the experimental groups when compared with controls. In all groups approximately 55% of the chickens developed scoliosis that progressed rapidly. Different pinealectomy procedures and deliberate damage to the cerebral cortex produce scoliosis in young chickens with the same incidence and characteristics. This suggests strongly that the mechanism behind the phenomenon is due to the removal of the pineal gland and not some artifact of the extensive surgery. The pinealectomy model in young chickens is proving to be a good model for studying AIS in humans. An understanding of the mechanism underlying this phenomenon has the potential to provide further insights into the etiology of AIS and can lead to the development of novel treatment methods.
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Affiliation(s)
- M Beuerlein
- Division of Anatomy, University of Alberta, Edmonton, Alberta T6G 2H7, Canada
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Beuerlein M, Wilson J, Moreau M, Raso VJ, Mahood J, Wang X, Greenhill B, Bagnall KM. The critical stage of pinealectomy surgery after which scoliosis is produced in young chickens. Spine (Phila Pa 1976) 2001; 26:237-40. [PMID: 11224858 DOI: 10.1097/00007632-200102010-00007] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
STUDY DESIGN Stages of the surgical procedure for pinealectomy in chickens were identified. Groups of chickens were selected for each stage. Scoliosis development was identified from radiographs. OBJECTIVES To determine the critical stage of surgery for pinealectomy after which scoliosis develops in young chickens. SUMMARY OF BACKGROUND DATA Pinealectomy in young chickens consistently produces scoliosis in young chickens that has many characteristics similar to those seen in patients with adolescent idiopathic scoliosis. The mechanism behind this phenomenon remains unknown. METHODS Five distinct stages in the pinealectomy surgery were identified. Groups of chickens were selected to undergo surgery to represent these five stages. Scoliosis was determined from weekly radiographs. RESULTS Cutting the pineal stalk was identified as the critical stage in the surgery after which scoliosis developed. The incidence of scoliosis did not increase after more extensive surgery in which the pineal bulb was removed from the skull. This stage was also correlated with a significant reduction of serum melatonin levels. CONCLUSIONS Cutting the pineal stalk was identified as the critical stage of pinealectomy surgery after which scoliosis may develop. This stage was also correlated with the significant reduction of average serum melatonin levels. These results allow the focus of attention into the mechanism behind this phenomenon to center on the consequences of cutting the pineal stalk rather than total removal of the pineal gland.
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Affiliation(s)
- M Beuerlein
- Division of Anatomy, University of Alberta, Edmonton, Alberta, Canada
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Abstract
This review discusses the development of melatonin rhythmicity in humans and the factors that may alter the appearance of melatonin rhythms. The literature on the possible consequences of disordered melatonin production in relation to Sudden Infant Death Syndrome, fetal origins of adult disease, and scoliosis is critically reviewed. Finally, the emerging use of melatonin to correct sleep disorders in infants and children is reviewed.
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Affiliation(s)
- D J Kennaway
- Department of Obstetrics and Gynaecology, University of Adelaide, South Australia
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