Previous studies have analyzed paraspinal muscle imbalance in idiopathic scoliosis (IS) with methods including imaging, histology and electromyography. However, whether paraspinal muscle imbalance is the cause or the consequence of spinal deformities in IS remains unclear. Comparison of paraspinal muscle imbalance between IS and congenital scoliosis (CS) may shed some light on the causality of paraspinal muscle imbalance and IS. This study aimed to elucidate the generality and individuality of paraspinal muscle imbalance between IS and CS from gene expression.
Methods
Five pairs of surgical-treated IS and CS patients were matched. Bilateral paraspinal muscles at the apex were collected for transcriptome sequencing. Differentially expressed genes (DEGs) between the convexity and concavity in both IS and CS were identified. Comparison of DEGs between IS and CS was conducted to discriminate IS-specific DEGs from DEGs shared by both IS and CS. Bioinformatics analysis was performed. The top 10 hub genes in the protein–protein interaction (PPI) network of IS-specific DEGs were validated by quantitative PCR (qPCR) in 10 pairs of IS and CS patients.
Results
A total of 370 DEGs were identified in IS, whereas 380 DEGs were identified in CS. Comparison of DEGs between IS and CS identified 59 DEGs shared by IS and CS, along with 311 DEGs specific for IS. These IS-specific DEGs were enriched in response to external stimulus and signaling receptor binding in GO terms and calcium signaling pathway in KEGG pathways. The top 10 hub genes in the PPI network of IS-specific DEGs include BDKRB1, PRH1-TAS2R14, CNR2, NPY4R, HTR1E, CXCL3, ICAM1, ALB, ADIPOQ, and GCGR. Among these hub genes, the asymmetrical expression of PRH1-TAS2R14 and ADIPOQ in IS but not CS were validated by qPCR.
Conclusions
Transcriptomic differences in bilateral paraspinal muscles between the convexity and concavity in IS share few similarities with those in CS.
背景 以往的研究通过影像学、组织学和肌电图等方法分析了特发性脊柱侧弯症（IS）的脊柱旁肌肉失衡。然而，脊柱旁肌肉失衡是导致特发性脊柱侧弯症脊柱畸形的原因还是结果仍不清楚。比较IS和先天性脊柱侧弯症（CS）的脊柱旁肌肉失衡可能会对脊柱旁肌肉失衡和IS的因果关系有所启发。本研究旨在从基因表达的角度阐明IS和CS脊柱旁肌肉失衡的普遍性和个体性。 方法 对五对经过手术治疗的 IS 和 CS 患者进行配对。采集双侧脊柱旁顶点肌肉进行转录组测序。确定了IS和CS凸面和凹面之间的差异表达基因（DEGs）。对 IS 和 CS 的 DEGs 进行比较，以区分 IS 特异的 DEGs 和 IS 与 CS 共享的 DEGs。进行了生物信息学分析。在10对IS和CS患者中通过定量PCR（qPCR）验证了IS特异性DEGs的蛋白-蛋白相互作用（PPI）网络中的前10个枢纽基因。 结果 在 IS 中发现了 370 个 DEGs，而在 CS 中发现了 380 个 DEGs。通过比较 IS 和 CS 的 DEGs，发现 IS 和 CS 共有 59 个 DEGs，IS 特异的 DEGs 有 311 个。这些IS特异的DEGs在GO术语中富集于对外部刺激的反应和信号受体结合，在KEGG通路中富集于钙信号通路。在 IS 特异性 DEGs 的 PPI 网络中，前 10 个枢纽基因包括 BDKRB1、PRH1-TAS2R14、CNR2、NPY4R、HTR1E、CXCL3、ICAM1、ALB、ADIPOQ 和 GCGR。在这些枢纽基因中，通过 qPCR 验证了 PRH1-TAS2R14 和 ADIPOQ 在 IS 中的非对称表达，而在 CS 中则没有。 结论 IS 双侧脊柱旁肌肉凸面和凹面的转录组差异与 CS 几乎没有相似之处。
{"title":"Comparative analysis of paraspinal muscle imbalance between idiopathic scoliosis and congenital scoliosis from the transcriptome aspect","authors":"Zhen Wang, Junduo Zhao, Haining Tan, Yang Jiao, Xin Chen, Jianxiong Shen","doi":"10.1002/jsp2.1318","DOIUrl":"https://doi.org/10.1002/jsp2.1318","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Background</h3>\u0000 \u0000 <p>Previous studies have analyzed paraspinal muscle imbalance in idiopathic scoliosis (IS) with methods including imaging, histology and electromyography. However, whether paraspinal muscle imbalance is the cause or the consequence of spinal deformities in IS remains unclear. Comparison of paraspinal muscle imbalance between IS and congenital scoliosis (CS) may shed some light on the causality of paraspinal muscle imbalance and IS. This study aimed to elucidate the generality and individuality of paraspinal muscle imbalance between IS and CS from gene expression.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>Five pairs of surgical-treated IS and CS patients were matched. Bilateral paraspinal muscles at the apex were collected for transcriptome sequencing. Differentially expressed genes (DEGs) between the convexity and concavity in both IS and CS were identified. Comparison of DEGs between IS and CS was conducted to discriminate IS-specific DEGs from DEGs shared by both IS and CS. Bioinformatics analysis was performed. The top 10 hub genes in the protein–protein interaction (PPI) network of IS-specific DEGs were validated by quantitative PCR (qPCR) in 10 pairs of IS and CS patients.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>A total of 370 DEGs were identified in IS, whereas 380 DEGs were identified in CS. Comparison of DEGs between IS and CS identified 59 DEGs shared by IS and CS, along with 311 DEGs specific for IS. These IS-specific DEGs were enriched in response to external stimulus and signaling receptor binding in GO terms and calcium signaling pathway in KEGG pathways. The top 10 hub genes in the PPI network of IS-specific DEGs include <i>BDKRB1</i>, <i>PRH1-TAS2R14</i>, <i>CNR2</i>, <i>NPY4R</i>, <i>HTR1E</i>, <i>CXCL3</i>, <i>ICAM1</i>, <i>ALB</i>, <i>ADIPOQ</i>, and <i>GCGR</i>. Among these hub genes, the asymmetrical expression of <i>PRH1-TAS2R14</i> and <i>ADIPOQ</i> in IS but not CS were validated by qPCR.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>Transcriptomic differences in bilateral paraspinal muscles between the convexity and concavity in IS share few similarities with those in CS.</p>\u0000 </section>\u0000 </div>","PeriodicalId":14876,"journal":{"name":"JOR Spine","volume":"7 1","pages":""},"PeriodicalIF":3.7,"publicationDate":"2024-03-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/jsp2.1318","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140024742","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Intervertebral disc degeneration (IDD) and atherosclerosis are two common age-related conditions that can cause significant morbidity. While previous studies have suggested an association between the two conditions, the nature of this association remains unclear.
Methods
We used Mendelian randomization (MR) to investigate the causal relationship between IDD and atherosclerosis. We identified genetic variants associated with IDD using summary statistics from a large genome-wide association study (GWAS). These variants were then used as instrumental variables to infer causal relationships with atherosclerosis in summary statistics from a separate GWAS.
Results
Our MR analysis provided evidence for a causal relationship between IDD and atherosclerosis. We found that the genetic predisposition to atherosclerosis was associated with a higher risk of IDD (odds ratio [OR] = 3.55, 95% confidence interval [CI]: 1.07–11.74, p = 0.04). The IVW estimates were consistent with the observational findings and other robust MR methods. Sensitivity analyses suggested that our findings were robust to potential sources of bias.
Conclusions
Our study provides evidence for a causal link between IDD and atherosclerosis, suggesting that interventions targeting atherosclerosis could have potential benefits for reducing the risk of IDD. Further research is needed to explore the underlying mechanisms that link these two conditions and to investigate potential therapeutic interventions.
{"title":"Evaluating the causal effect of atherosclerosis on the risk of intervertebral disc degeneration","authors":"Yang-Ting Cai, Xian-Xing Zhong, Ling Mo, Rui-Ze Huang, Qiang Lin, Cai-Jun Liu, Shun-Cong Zhang","doi":"10.1002/jsp2.1319","DOIUrl":"https://doi.org/10.1002/jsp2.1319","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Background</h3>\u0000 \u0000 <p>Intervertebral disc degeneration (IDD) and atherosclerosis are two common age-related conditions that can cause significant morbidity. While previous studies have suggested an association between the two conditions, the nature of this association remains unclear.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>We used Mendelian randomization (MR) to investigate the causal relationship between IDD and atherosclerosis. We identified genetic variants associated with IDD using summary statistics from a large genome-wide association study (GWAS). These variants were then used as instrumental variables to infer causal relationships with atherosclerosis in summary statistics from a separate GWAS.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>Our MR analysis provided evidence for a causal relationship between IDD and atherosclerosis. We found that the genetic predisposition to atherosclerosis was associated with a higher risk of IDD (odds ratio [OR] = 3.55, 95% confidence interval [CI]: 1.07–11.74, <i>p</i> = 0.04). The IVW estimates were consistent with the observational findings and other robust MR methods. Sensitivity analyses suggested that our findings were robust to potential sources of bias.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>Our study provides evidence for a causal link between IDD and atherosclerosis, suggesting that interventions targeting atherosclerosis could have potential benefits for reducing the risk of IDD. Further research is needed to explore the underlying mechanisms that link these two conditions and to investigate potential therapeutic interventions.</p>\u0000 </section>\u0000 </div>","PeriodicalId":14876,"journal":{"name":"JOR Spine","volume":"7 1","pages":""},"PeriodicalIF":3.7,"publicationDate":"2024-03-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/jsp2.1319","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140031862","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Irina Heggli, Graciosa Q. Teixeira, James C. Iatridis, Cornelia Neidlinger-Wilke, Stefan Dudli
Disc degeneration and vertebral endplate bone marrow lesions called Modic changes are prevalent spinal pathologies found in chronic low back pain patients. Their pathomechanisms are complex and not fully understood. Recent studies have revealed that complement system proteins and interactors are dysregulated in disc degeneration and Modic changes. The complement system is part of the innate immune system and plays a critical role in tissue homeostasis. However, its dysregulation has also been associated with various pathological conditions such as rheumatoid arthritis and osteoarthritis. Here, we review the evidence for the involvement of the complement system in intervertebral disc degeneration and Modic changes. We found that only a handful of studies reported on complement factors in Modic changes and disc degeneration. Therefore, the level of evidence for the involvement of the complement system is currently low. Nevertheless, the complement system is tightly intertwined with processes known to occur during disc degeneration and Modic changes, such as increased cell death, autoantibody production, bacterial defense processes, neutrophil activation, and osteoclast formation, indicating a contribution of the complement system to these spinal pathologies. Based on these mechanisms, we propose a model how the complement system could contribute to the vicious cycle of tissue damage and chronic inflammation in disc degeneration and Modic changes. With this review, we aim to highlight a currently understudied but potentially important inflammatory pathomechanism of disc degeneration and Modic changes that may be a novel therapeutic target.
{"title":"The role of the complement system in disc degeneration and Modic changes","authors":"Irina Heggli, Graciosa Q. Teixeira, James C. Iatridis, Cornelia Neidlinger-Wilke, Stefan Dudli","doi":"10.1002/jsp2.1312","DOIUrl":"https://doi.org/10.1002/jsp2.1312","url":null,"abstract":"<p>Disc degeneration and vertebral endplate bone marrow lesions called Modic changes are prevalent spinal pathologies found in chronic low back pain patients. Their pathomechanisms are complex and not fully understood. Recent studies have revealed that complement system proteins and interactors are dysregulated in disc degeneration and Modic changes. The complement system is part of the innate immune system and plays a critical role in tissue homeostasis. However, its dysregulation has also been associated with various pathological conditions such as rheumatoid arthritis and osteoarthritis. Here, we review the evidence for the involvement of the complement system in intervertebral disc degeneration and Modic changes. We found that only a handful of studies reported on complement factors in Modic changes and disc degeneration. Therefore, the level of evidence for the involvement of the complement system is currently low. Nevertheless, the complement system is tightly intertwined with processes known to occur during disc degeneration and Modic changes, such as increased cell death, autoantibody production, bacterial defense processes, neutrophil activation, and osteoclast formation, indicating a contribution of the complement system to these spinal pathologies. Based on these mechanisms, we propose a model how the complement system could contribute to the vicious cycle of tissue damage and chronic inflammation in disc degeneration and Modic changes. With this review, we aim to highlight a currently understudied but potentially important inflammatory pathomechanism of disc degeneration and Modic changes that may be a novel therapeutic target.</p>","PeriodicalId":14876,"journal":{"name":"JOR Spine","volume":"7 1","pages":""},"PeriodicalIF":3.7,"publicationDate":"2024-02-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/jsp2.1312","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139676714","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Zhen-zhong Zheng, Jing-hong Xu, Jia-lin Chen, Bin Jiang, Hong Ma, Lei Li, Ya-wei Li, Yu-liang Dai, Bing Wang
Background
Marfan syndrome (MFS) is a rare genetic disorder caused by mutations in the Fibrillin-1 gene (FBN1) with significant clinical features in the skeletal, cardiopulmonary, and ocular systems. To gain deeper insights into the contribution of epigenetics in the variability of phenotypes observed in MFS, we undertook the first analysis of integrating DNA methylation and gene expression profiles in whole blood from MFS and healthy controls (HCs).
Methods
The Illumina 850K (EPIC) DNA methylation array was used to detect DNA methylation changes on peripheral blood samples of seven patients with MFS and five HCs. Associations between methylation levels and clinical features of MFS were analyzed. Subsequently, we conducted an integrated analysis of the outcomes of the transcriptome data to analyze the correlation between differentially methylated positions (DMPs) and differentially expressed genes (DEGs) and explore the potential role of methylation-regulated DEGs (MeDEGs) in MFS scoliosis. The weighted gene co-expression network analysis was used to find gene modules with the highest correlation coefficient with target MeDEGs to annotate their functions in MFS.
Results
Our study identified 1253 DMPs annotated to 236 genes that were primarily associated with scoliosis, cardiomyopathy, and vital capacity. These conditions are typically associated with reduced lifespan in untreated MFS. We calculated correlations between DMPs and clinical features, such as cobb angle to evaluate scoliosis and FEV1% to assess pulmonary function. Notably, cg20223687 (PTPRN2) exhibited a positive correlation with cobb angle of scoliosis, potentially playing a role in ERKs inactivation.
Conclusions
Taken together, our systems-level approach sheds light on the contribution of epigenetics to MFS and offers a plausible explanation for the complex phenotypes that are linked to reduced lifespan in untreated MFS patients.
{"title":"Integrated DNA methylation analysis reveals a potential role for PTPRN2 in Marfan syndrome scoliosis","authors":"Zhen-zhong Zheng, Jing-hong Xu, Jia-lin Chen, Bin Jiang, Hong Ma, Lei Li, Ya-wei Li, Yu-liang Dai, Bing Wang","doi":"10.1002/jsp2.1304","DOIUrl":"10.1002/jsp2.1304","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Background</h3>\u0000 \u0000 <p>Marfan syndrome (MFS) is a rare genetic disorder caused by mutations in the Fibrillin-1 gene (FBN1) with significant clinical features in the skeletal, cardiopulmonary, and ocular systems. To gain deeper insights into the contribution of epigenetics in the variability of phenotypes observed in MFS, we undertook the first analysis of integrating DNA methylation and gene expression profiles in whole blood from MFS and healthy controls (HCs).</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>The Illumina 850K (EPIC) DNA methylation array was used to detect DNA methylation changes on peripheral blood samples of seven patients with MFS and five HCs. Associations between methylation levels and clinical features of MFS were analyzed. Subsequently, we conducted an integrated analysis of the outcomes of the transcriptome data to analyze the correlation between differentially methylated positions (DMPs) and differentially expressed genes (DEGs) and explore the potential role of methylation-regulated DEGs (MeDEGs) in MFS scoliosis. The weighted gene co-expression network analysis was used to find gene modules with the highest correlation coefficient with target MeDEGs to annotate their functions in MFS.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>Our study identified 1253 DMPs annotated to 236 genes that were primarily associated with scoliosis, cardiomyopathy, and vital capacity. These conditions are typically associated with reduced lifespan in untreated MFS. We calculated correlations between DMPs and clinical features, such as cobb angle to evaluate scoliosis and FEV1% to assess pulmonary function. Notably, cg20223687 (PTPRN2) exhibited a positive correlation with cobb angle of scoliosis, potentially playing a role in ERKs inactivation.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>Taken together, our systems-level approach sheds light on the contribution of epigenetics to MFS and offers a plausible explanation for the complex phenotypes that are linked to reduced lifespan in untreated MFS patients.</p>\u0000 </section>\u0000 </div>","PeriodicalId":14876,"journal":{"name":"JOR Spine","volume":"7 1","pages":""},"PeriodicalIF":3.7,"publicationDate":"2024-01-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10831201/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139671803","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Libangxi Liu, Hong Sun, Yang Zhang, Chang Liu, Yong Zhuang, Miao Liu, Xuezheng Ai, Dan Long, Bo Huang, Changqing Li, Yue Zhou, Shiwu Dong, Chencheng Feng
Background
The N6-methyladenosine (m6A) dynamics in the progression of intervertebral disc (IVD) aging remain largely unknown. This study aimed to explore the distribution and pattern of m6A modification in nucleus pulpous (NP) tissues of rats at different ages.
Methods
Histological staining and MRI were performed to evaluate the degeneration of IVD. The expression of m6A modifiers was analyzed using qRT-PCR and western blot. Subsequently, methylated RNA immunoprecipitation next generation sequencing and RNA-seq were conducted to identify differences in m6A methylome and transcriptome of NP tissues.
Results
Compared to 2-month-old rats, we found significant changes in the global m6A level and the expression of Mettl3 and FTO in NP tissues from 20-month-old rats. During the progression of NP aging, there were 1126 persistently differentially m6A peaks within 931 genes, and 51 persistently differentially expressed genes. GO and KEGG analyses showed that these m6A peaks and m6A modified genes were mainly engaged in the biological processes and pathways of intervertebral disc degermation (IDD), such as extracellular matrix metabolism, angiogenesis, inflammatory response, mTOR and AMPK signaling pathways. Meanwhile, conjoint analyses and Venn diagram revealed a total of 405 aging related genes contained significant methylation and expression levels in 20-month-old rats in contrast to 2-month-old and 10-month-old rats. Moreover, it was found that four aging related genes with hypermethylated modification including BUB1, CA12, Adamts1, and Adamts4 depicted differentially expressed at protein level, of which BUB1 and CA12 were decreased, while Adamts1 and Adamts4 were increased during the progression of NP aging.
Conclusion
Collectively, this study elucidated the distribution and pattern of m6A modification during the aging of IVD. Furthermore, the m6A modified genes were involved in the IDD related biological processes and pathways. These findings may provide novel insights into the mechanisms and therapies of IDD from the perspective of aging.
{"title":"Dynamics of N6-methyladenosine modification during aging and their potential roles in the degeneration of intervertebral disc","authors":"Libangxi Liu, Hong Sun, Yang Zhang, Chang Liu, Yong Zhuang, Miao Liu, Xuezheng Ai, Dan Long, Bo Huang, Changqing Li, Yue Zhou, Shiwu Dong, Chencheng Feng","doi":"10.1002/jsp2.1316","DOIUrl":"10.1002/jsp2.1316","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Background</h3>\u0000 \u0000 <p>The N6-methyladenosine (m6A) dynamics in the progression of intervertebral disc (IVD) aging remain largely unknown. This study aimed to explore the distribution and pattern of m<sup>6</sup>A modification in nucleus pulpous (NP) tissues of rats at different ages.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>Histological staining and MRI were performed to evaluate the degeneration of IVD. The expression of m6A modifiers was analyzed using qRT-PCR and western blot. Subsequently, methylated RNA immunoprecipitation next generation sequencing and RNA-seq were conducted to identify differences in m6A methylome and transcriptome of NP tissues.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>Compared to 2-month-old rats, we found significant changes in the global m6A level and the expression of Mettl3 and FTO in NP tissues from 20-month-old rats. During the progression of NP aging, there were 1126 persistently differentially m6A peaks within 931 genes, and 51 persistently differentially expressed genes. GO and KEGG analyses showed that these m6A peaks and m6A modified genes were mainly engaged in the biological processes and pathways of intervertebral disc degermation (IDD), such as extracellular matrix metabolism, angiogenesis, inflammatory response, mTOR and AMPK signaling pathways. Meanwhile, conjoint analyses and Venn diagram revealed a total of 405 aging related genes contained significant methylation and expression levels in 20-month-old rats in contrast to 2-month-old and 10-month-old rats. Moreover, it was found that four aging related genes with hypermethylated modification including BUB1, CA12, Adamts1, and Adamts4 depicted differentially expressed at protein level, of which BUB1 and CA12 were decreased, while Adamts1 and Adamts4 were increased during the progression of NP aging.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusion</h3>\u0000 \u0000 <p>Collectively, this study elucidated the distribution and pattern of m6A modification during the aging of IVD. Furthermore, the m6A modified genes were involved in the IDD related biological processes and pathways. These findings may provide novel insights into the mechanisms and therapies of IDD from the perspective of aging.</p>\u0000 </section>\u0000 </div>","PeriodicalId":14876,"journal":{"name":"JOR Spine","volume":"7 1","pages":""},"PeriodicalIF":3.7,"publicationDate":"2024-01-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10810761/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139569693","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Ana P. Peredo, Tonia K. Tsinman, Edward D. Bonnevie, Xi Jiang, Harvey E. Smith, Sarah E. Gullbrand, Nathaniel A. Dyment, Robert L. Mauck
<div> <section> <h3> Introduction</h3> <p>Therapeutic interventions for intervertebral disc herniation remain scarce due to the inability of endogenous annulus fibrosus (AF) cells to respond to injury and drive tissue regeneration. Unlike other orthopedic tissues, such as cartilage, delivery of exogenous cells to the site of annular injury remains underdeveloped, largely due to a lack of an ideal cell source and the invasive nature of cell isolation. Human induced pluripotent stem cells (iPSCs) can be differentiated to specific cell fates using biochemical factors and are, therefore, an invaluable tool for cell therapy approaches. While differentiation protocols have been developed for cartilage and fibrous connective tissues (e.g., tendon), the signals that regulate the induction and differentiation of human iPSCs toward the AF fate remain unknown.</p> </section> <section> <h3> Methods</h3> <p>iPSC-derived sclerotome cells were treated with various combinations of developmental signals including transforming growth factor beta 3 (TGF-β3), connective tissue growth factor (CTGF), platelet derived growth factor BB (PDGF-BB), insulin-like growth factor 1 (IGF-1), or the Hedgehog pathway activator, Purmorphamine, and gene expression changes in major AF-associated ECM genes were assessed. The top performing combination treatments were further validated by using three distinct iPSC lines and by assessing the production of upregulated ECM proteins of interest. To conduct a broader analysis of the transcriptomic shifts elicited by each factor combination, and to compare genetic profiles of treated cells to mature human AF cells, a 96.96 Fluidigm gene expression array was applied, and principal component analysis was employed to identify the transcriptional signatures of each cell population and treatment group in comparison to native AF cells.</p> </section> <section> <h3> Results</h3> <p>TGF-β3, in combination with PDGF-BB, CTGF, or IGF-1, induced an upregulation of key AF ECM genes in iPSC-derived sclerotome cells. In particular, treatment with a combination of TGF-β3 with PDGF-BB for 14 days significantly increased gene expression of collagen II and aggrecan and increased protein deposition of collagen I and elastin compared to other treatment groups. Assessment of genes uniquely highly expressed by AF cells or SCL cells, respectively, revealed a shift toward the genetic profile of AF cells with the addition of TGF-β3 and PDGF-BB for 14 days.</p> </section> <section> <h3> Discussion</h3> <p>These findings represent an initial approach to guide human ind
导言：由于内源性纤维环（AF）细胞无法对损伤做出反应并驱动组织再生，因此治疗椎间盘突出症的干预措施仍然很少。与软骨等其他骨科组织不同，将外源性细胞输送到椎间盘环损伤部位的技术仍不发达，这主要是由于缺乏理想的细胞来源以及细胞分离的侵入性。人类诱导多能干细胞（iPSC）可利用生化因子分化为特定的细胞命运，因此是细胞疗法的宝贵工具。虽然已开发出软骨和纤维结缔组织（如肌腱）的分化方案，但调节软骨和纤维结缔组织分化的信号还不明确、肌腱）的分化方案，但调节人类 iPSCs 向房颤命运诱导和分化的信号仍然未知。方法：用各种发育信号组合处理 iPSC 衍生的硬骨细胞，包括转化生长因子 beta 3（TGF-β3）、结缔组织生长因子（CTGF）、血小板衍生生长因子 BB（PDGF-BB）、胰岛素样生长因子 1（IGF-1）或刺猬通路激活剂 Purmorphamine，并评估主要 AF 相关 ECM 基因的基因表达变化。通过使用三种不同的 iPSC 株系和评估上调的相关 ECM 蛋白的生成情况，进一步验证了表现最佳的组合疗法。为了对每种因子组合引起的转录组变化进行更广泛的分析，并将处理过的细胞的基因图谱与成熟的人类房颤细胞进行比较，应用了96.96 Fluidigm基因表达阵列，并采用主成分分析法确定了每个细胞群和处理组与原生房颤细胞相比的转录特征：结果：TGF-β3 与 PDGF-BB、CTGF 或 IGF-1 结合使用可诱导 iPSC 衍生的硬骨体细胞中的关键 AF ECM 基因上调。特别是，与其他处理组相比，TGF-β3 与 PDGF-BB 联合处理 14 天可显著增加胶原蛋白 II 和凝集素的基因表达，并增加胶原蛋白 I 和弹性蛋白的蛋白质沉积。对AF细胞或SCL细胞分别表达的独特高表达基因的评估显示，在添加TGF-β3和PDGF-BB 14天后，AF细胞的基因特征发生了转变：这些发现代表了一种引导人类诱导多能干细胞向AF样命运转变的初步方法，可用于细胞递送策略。
{"title":"Developmental morphogens direct human induced pluripotent stem cells toward an annulus fibrosus-like cell phenotype","authors":"Ana P. Peredo, Tonia K. Tsinman, Edward D. Bonnevie, Xi Jiang, Harvey E. Smith, Sarah E. Gullbrand, Nathaniel A. Dyment, Robert L. Mauck","doi":"10.1002/jsp2.1313","DOIUrl":"10.1002/jsp2.1313","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Introduction</h3>\u0000 \u0000 <p>Therapeutic interventions for intervertebral disc herniation remain scarce due to the inability of endogenous annulus fibrosus (AF) cells to respond to injury and drive tissue regeneration. Unlike other orthopedic tissues, such as cartilage, delivery of exogenous cells to the site of annular injury remains underdeveloped, largely due to a lack of an ideal cell source and the invasive nature of cell isolation. Human induced pluripotent stem cells (iPSCs) can be differentiated to specific cell fates using biochemical factors and are, therefore, an invaluable tool for cell therapy approaches. While differentiation protocols have been developed for cartilage and fibrous connective tissues (e.g., tendon), the signals that regulate the induction and differentiation of human iPSCs toward the AF fate remain unknown.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>iPSC-derived sclerotome cells were treated with various combinations of developmental signals including transforming growth factor beta 3 (TGF-β3), connective tissue growth factor (CTGF), platelet derived growth factor BB (PDGF-BB), insulin-like growth factor 1 (IGF-1), or the Hedgehog pathway activator, Purmorphamine, and gene expression changes in major AF-associated ECM genes were assessed. The top performing combination treatments were further validated by using three distinct iPSC lines and by assessing the production of upregulated ECM proteins of interest. To conduct a broader analysis of the transcriptomic shifts elicited by each factor combination, and to compare genetic profiles of treated cells to mature human AF cells, a 96.96 Fluidigm gene expression array was applied, and principal component analysis was employed to identify the transcriptional signatures of each cell population and treatment group in comparison to native AF cells.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>TGF-β3, in combination with PDGF-BB, CTGF, or IGF-1, induced an upregulation of key AF ECM genes in iPSC-derived sclerotome cells. In particular, treatment with a combination of TGF-β3 with PDGF-BB for 14 days significantly increased gene expression of collagen II and aggrecan and increased protein deposition of collagen I and elastin compared to other treatment groups. Assessment of genes uniquely highly expressed by AF cells or SCL cells, respectively, revealed a shift toward the genetic profile of AF cells with the addition of TGF-β3 and PDGF-BB for 14 days.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Discussion</h3>\u0000 \u0000 <p>These findings represent an initial approach to guide human ind","PeriodicalId":14876,"journal":{"name":"JOR Spine","volume":"7 1","pages":""},"PeriodicalIF":3.7,"publicationDate":"2024-01-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10810760/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139569689","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Hamish T. J. Gilbert, Francis E. J. Wignall, Leo Zeef, Judith A. Hoyland, Stephen M. Richardson
Background
Stem cell-based therapies show promise as a means of repairing the degenerate intervertebral disc, with growth factors often used alongside cells to help direct differentiation toward a nucleus pulposus (NP)-like phenotype. We previously demonstrated adipose-derived stem cell (ASC) differentiation with GDF6 as optimal for generating NP-like cells through evaluating end-stage differentiation parameters. Here we conducted a time-resolved transcriptomic characterization of ASCs response to GDF6 stimulation to understand the early drivers of differentiation to NP-like cells.
Methods
Human ASCs were treated with recombinant human GDF6 for 2, 6, and 12 h. RNA sequencing and detailed bioinformatic analysis were used to assess differential gene expression, gene ontology (GO), and transcription factor involvement during early differentiation. Quantitative polymerase chain reaction (qPCR) was used to validate RNA sequencing findings and inhibitors used to interrogate Smad and Erk signaling pathways, as well as identify primary and secondary response genes.
Results
The transcriptomic response of ASCs to GDF6 stimulation was time-resolved and highly structured, with “cell differentiation” “developmental processes,” and “response to stimulus” identified as key biological process GO terms. The transcription factor ERG1 was identified as a key early response gene. Temporal cluster analysis of differentiation genes identified positive regulation NP cell differentiation, as well as inhibition of osteogenesis and adipogenesis. A role for Smad and Erk signaling in the regulation of GDF6-induced early gene expression response was observed and both primary and secondary response genes were identified.
Conclusions
This study identifies a multifactorial early gene response that contributes to lineage commitment, with the identification of a number of potentially useful early markers of differentiation of ASCs to NP cells. This detailed insight into the molecular processes in response to GDF6 stimulation of ASCs is important for the development of an efficient and efficacious cell-based therapy for intervertebral disc degeneration-associated back pain.
{"title":"Transcriptomic profiling reveals key early response genes during GDF6-mediated differentiation of human adipose-derived stem cells to nucleus pulposus cells","authors":"Hamish T. J. Gilbert, Francis E. J. Wignall, Leo Zeef, Judith A. Hoyland, Stephen M. Richardson","doi":"10.1002/jsp2.1315","DOIUrl":"https://doi.org/10.1002/jsp2.1315","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Background</h3>\u0000 \u0000 <p>Stem cell-based therapies show promise as a means of repairing the degenerate intervertebral disc, with growth factors often used alongside cells to help direct differentiation toward a nucleus pulposus (NP)-like phenotype. We previously demonstrated adipose-derived stem cell (ASC) differentiation with GDF6 as optimal for generating NP-like cells through evaluating end-stage differentiation parameters. Here we conducted a time-resolved transcriptomic characterization of ASCs response to GDF6 stimulation to understand the early drivers of differentiation to NP-like cells.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>Human ASCs were treated with recombinant human GDF6 for 2, 6, and 12 h. RNA sequencing and detailed bioinformatic analysis were used to assess differential gene expression, gene ontology (GO), and transcription factor involvement during early differentiation. Quantitative polymerase chain reaction (qPCR) was used to validate RNA sequencing findings and inhibitors used to interrogate Smad and Erk signaling pathways, as well as identify primary and secondary response genes.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>The transcriptomic response of ASCs to GDF6 stimulation was time-resolved and highly structured, with “cell differentiation” “developmental processes,” and “response to stimulus” identified as key biological process GO terms. The transcription factor ERG1 was identified as a key early response gene. Temporal cluster analysis of differentiation genes identified positive regulation NP cell differentiation, as well as inhibition of osteogenesis and adipogenesis. A role for Smad and Erk signaling in the regulation of GDF6-induced early gene expression response was observed and both primary and secondary response genes were identified.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>This study identifies a multifactorial early gene response that contributes to lineage commitment, with the identification of a number of potentially useful early markers of differentiation of ASCs to NP cells. This detailed insight into the molecular processes in response to GDF6 stimulation of ASCs is important for the development of an efficient and efficacious cell-based therapy for intervertebral disc degeneration-associated back pain.</p>\u0000 </section>\u0000 </div>","PeriodicalId":14876,"journal":{"name":"JOR Spine","volume":"7 1","pages":""},"PeriodicalIF":3.7,"publicationDate":"2024-01-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/jsp2.1315","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139494423","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Jiaxiang Zhou, Jianmin Wang, Jianfeng Li, Zhengya Zhu, Zhongyuan He, Junhong Li, Tao Tang, Hongkun Chen, Yukun Du, Zhen Li, Manman Gao, Zhiyu Zhou, Yongming Xi
Background
Disc degeneration is associated with repetitive violent injuries. This study aims to explore the impact of repetitive strikes loading on the biology and biomechanics of intervertebral discs (IVDs) using an organ culture model.
Methods
IVDs from the bovine tail were isolated and cultured in a bioreactor, with exposure to various loading conditions. The control group was subjected to physiological loading, while the model group was exposed to either one strike loading (compression at 38% of IVD height) or repetitive one strike loading (compression at 38% of IVD height). Disc height and dynamic compressive stiffness were measured after overnight swelling and loading. Furthermore, histological morphology, cell viability, and gene expression were analyzed on Day 32. Glycosaminoglycan (GAG) and nitric oxide (NO) release in conditioned medium were also analyzed.
Results
The repetitive one strike group exhibited early disc degeneration, characterized by decreased dynamic compression stiffness, the presence of annulus fibrosus clefts, and degradation of the extracellular matrix. Additionally, this group demonstrated significantly higher levels of cell death (p < 0.05) and glycosaminoglycan (GAG) release (p < 0.05) compared to the control group. Furthermore, upregulation of MMP1, MMP13, and ADAMTS5 was observed in both nucleus pulposus (NP) and annulus fibrosus (AF) tissues of the repetitive one strike group (p < 0.05). The one strike group exhibited annulus fibrosus clefts but showed no gene expression changes compared to the control group.
Conclusions
This study shows that repetitive violent injuries lead to the degeneration of a healthy bovine IVDs, thereby providing new insights into early-stage disc degeneration.
{"title":"Repetitive strikes loading organ culture model to investigate the biological and biomechanical responses of the intervertebral disc","authors":"Jiaxiang Zhou, Jianmin Wang, Jianfeng Li, Zhengya Zhu, Zhongyuan He, Junhong Li, Tao Tang, Hongkun Chen, Yukun Du, Zhen Li, Manman Gao, Zhiyu Zhou, Yongming Xi","doi":"10.1002/jsp2.1314","DOIUrl":"https://doi.org/10.1002/jsp2.1314","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Background</h3>\u0000 \u0000 <p>Disc degeneration is associated with repetitive violent injuries. This study aims to explore the impact of repetitive strikes loading on the biology and biomechanics of intervertebral discs (IVDs) using an organ culture model.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>IVDs from the bovine tail were isolated and cultured in a bioreactor, with exposure to various loading conditions. The control group was subjected to physiological loading, while the model group was exposed to either one strike loading (compression at 38% of IVD height) or repetitive one strike loading (compression at 38% of IVD height). Disc height and dynamic compressive stiffness were measured after overnight swelling and loading. Furthermore, histological morphology, cell viability, and gene expression were analyzed on Day 32. Glycosaminoglycan (GAG) and nitric oxide (NO) release in conditioned medium were also analyzed.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>The repetitive one strike group exhibited early disc degeneration, characterized by decreased dynamic compression stiffness, the presence of annulus fibrosus clefts, and degradation of the extracellular matrix. Additionally, this group demonstrated significantly higher levels of cell death (<i>p</i> < 0.05) and glycosaminoglycan (GAG) release (<i>p</i> < 0.05) compared to the control group. Furthermore, upregulation of MMP1, MMP13, and ADAMTS5 was observed in both nucleus pulposus (NP) and annulus fibrosus (AF) tissues of the repetitive one strike group (<i>p</i> < 0.05). The one strike group exhibited annulus fibrosus clefts but showed no gene expression changes compared to the control group.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>This study shows that repetitive violent injuries lead to the degeneration of a healthy bovine IVDs, thereby providing new insights into early-stage disc degeneration.</p>\u0000 </section>\u0000 </div>","PeriodicalId":14876,"journal":{"name":"JOR Spine","volume":"7 1","pages":""},"PeriodicalIF":3.7,"publicationDate":"2024-01-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/jsp2.1314","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139494424","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Takashi Yurube, William J. Buchser, Zhongying Zhang, Prashanta Silwal, Michael T. Lotze, James D. Kang, Gwendolyn A. Sowa, Nam V. Vo
Background
Low back pain is a global health problem that originated mainly from intervertebral disc degeneration (IDD). Autophagy, negatively regulated by the phosphatidylinositol 3-kinase (PI3K)/Akt/mammalian target of rapamycin (mTOR) signaling pathway, prevents metabolic and degenerative diseases by removing and recycling damaged cellular components. Despite growing evidence that autophagy occurs in the intervertebral disc, the regulation of disc cellular autophagy is still poorly understood.
Methods
Annulus fibrosus (rAF) cell cultures derived from healthy female rabbit discs were used to test the effect of autophagy inhibition or activation on disc cell fate and matrix homeostasis. Specifically, different chemical inhibitors including rapamycin, 3-methyladenine, MK-2206, and PP242 were used to modulate activities of different proteins in the PI3K/Akt/mTOR signaling pathway to assess IL-1β-induced cellular senescence, apoptosis, and matrix homeostasis in rAF cells grown under nutrient-poor culture condition.
Results
Rapamycin, an inhibitor of mTOR complex 1 (mTORC1), reduced the phosphorylation of mTOR and its effector p70/S6K in rAF cell cultures. Rapamycin also induced autophagic flux as measured by increased expression of key autophagy markers, including LC3 puncta number, LC3-II expression, and cytoplasmic HMGB1 intensity and decreased p62/SQSTM1 expression. As expected, IL-1β stimulation promoted rAF cellular senescence, apoptosis, and matrix homeostatic imbalance with enhanced aggrecanolysis and MMP-3 and MMP-13 expression. Rapamycin treatment effectively mitigated IL-1β-mediated inflammatory stress changes, but these alleviating effects of rapamycin were abrogated by chemical inhibition of Akt and mTOR complex 2 (mTORC2).
Conclusions
These findings suggest that rapamycin blunts adverse effects of inflammation on disc cells by inhibiting mTORC1 to induce autophagy through the PI3K/Akt/mTOR pathway that is dependent on Akt and mTORC2 activities. Hence, our findings identify autophagy, rapamycin, and PI3K/Akt/mTOR signaling as potential therapeutic targets for IDD treatment.
{"title":"Rapamycin mitigates inflammation-mediated disc matrix homeostatic imbalance by inhibiting mTORC1 and inducing autophagy through Akt activation","authors":"Takashi Yurube, William J. Buchser, Zhongying Zhang, Prashanta Silwal, Michael T. Lotze, James D. Kang, Gwendolyn A. Sowa, Nam V. Vo","doi":"10.1002/jsp2.1303","DOIUrl":"10.1002/jsp2.1303","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Background</h3>\u0000 \u0000 <p>Low back pain is a global health problem that originated mainly from intervertebral disc degeneration (IDD). Autophagy, negatively regulated by the phosphatidylinositol 3-kinase (PI3K)/Akt/mammalian target of rapamycin (mTOR) signaling pathway, prevents metabolic and degenerative diseases by removing and recycling damaged cellular components. Despite growing evidence that autophagy occurs in the intervertebral disc, the regulation of disc cellular autophagy is still poorly understood.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>Annulus fibrosus (rAF) cell cultures derived from healthy female rabbit discs were used to test the effect of autophagy inhibition or activation on disc cell fate and matrix homeostasis. Specifically, different chemical inhibitors including rapamycin, 3-methyladenine, MK-2206, and PP242 were used to modulate activities of different proteins in the PI3K/Akt/mTOR signaling pathway to assess IL-1β-induced cellular senescence, apoptosis, and matrix homeostasis in rAF cells grown under nutrient-poor culture condition.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>Rapamycin, an inhibitor of mTOR complex 1 (mTORC1), reduced the phosphorylation of mTOR and its effector p70/S6K in rAF cell cultures. Rapamycin also induced autophagic flux as measured by increased expression of key autophagy markers, including LC3 puncta number, LC3-II expression, and cytoplasmic HMGB1 intensity and decreased p62/SQSTM1 expression. As expected, IL-1β stimulation promoted rAF cellular senescence, apoptosis, and matrix homeostatic imbalance with enhanced aggrecanolysis and MMP-3 and MMP-13 expression. Rapamycin treatment effectively mitigated IL-1β-mediated inflammatory stress changes, but these alleviating effects of rapamycin were abrogated by chemical inhibition of Akt and mTOR complex 2 (mTORC2).</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>These findings suggest that rapamycin blunts adverse effects of inflammation on disc cells by inhibiting mTORC1 to induce autophagy through the PI3K/Akt/mTOR pathway that is dependent on Akt and mTORC2 activities. Hence, our findings identify autophagy, rapamycin, and PI3K/Akt/mTOR signaling as potential therapeutic targets for IDD treatment.</p>\u0000 </section>\u0000 </div>","PeriodicalId":14876,"journal":{"name":"JOR Spine","volume":"7 1","pages":""},"PeriodicalIF":3.7,"publicationDate":"2024-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/jsp2.1303","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139390513","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Maho Koga, Byumsu Kim, Marianne Lintz, Sertaç Kirnaz, Jacob L. Goldberg, Ibrahim Hussain, Branden Medary, Kathleen N. Meyers, Suzanne A. Maher, Roger Härtl, Lawrence J. Bonassar
Background
Tissue-engineered intervertebral disc (TE-IVD) constructs are an attractive therapy for treating degenerative disc disease and have previously been investigated in vivo in both large and small animal models. The mechanical environment of the spine is notably challenging, in part due to its complex anatomy, and implants may require additional mechanical support to avoid failure in the early stages of implantation. As such, the design of suitable support implants requires rigorous validation.
Methods
We created a FE model to simulate the behavior of the IVD cages under compression specific to the anatomy of the porcine cervical spine, validated the FE model using an animal model, and predicted the effects of implant location and vertebral angle of the motion segment on implant behavior. Specifically, we tested anatomical positioning of the superior vertebra and placement of the implant. We analyzed corresponding stress and strain distributions.
Results
Results demonstrated that the anatomical geometry of the porcine cervical spine led to concentrated stress and strain on the posterior side of the cage. This stress concentration was associated with the location of failure of the cages reported in vivo, despite superior mechanical properties of the implant. Furthermore, placement of the cage was found to have profound effects on migration, while the angle of the superior vertebra affected stress concentration of the cage.
Conclusions
This model can be utilized both to inform surgical procedures and provide insight on future cage designs and can be adopted to models without the use of in vivo animal models.
{"title":"Finite element modeling to predict the influence of anatomic variation and implant placement on performance of biological intervertebral disc implants","authors":"Maho Koga, Byumsu Kim, Marianne Lintz, Sertaç Kirnaz, Jacob L. Goldberg, Ibrahim Hussain, Branden Medary, Kathleen N. Meyers, Suzanne A. Maher, Roger Härtl, Lawrence J. Bonassar","doi":"10.1002/jsp2.1307","DOIUrl":"https://doi.org/10.1002/jsp2.1307","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Background</h3>\u0000 \u0000 <p>Tissue-engineered intervertebral disc (TE-IVD) constructs are an attractive therapy for treating degenerative disc disease and have previously been investigated in vivo in both large and small animal models. The mechanical environment of the spine is notably challenging, in part due to its complex anatomy, and implants may require additional mechanical support to avoid failure in the early stages of implantation. As such, the design of suitable support implants requires rigorous validation.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>We created a FE model to simulate the behavior of the IVD cages under compression specific to the anatomy of the porcine cervical spine, validated the FE model using an animal model, and predicted the effects of implant location and vertebral angle of the motion segment on implant behavior. Specifically, we tested anatomical positioning of the superior vertebra and placement of the implant. We analyzed corresponding stress and strain distributions.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>Results demonstrated that the anatomical geometry of the porcine cervical spine led to concentrated stress and strain on the posterior side of the cage. This stress concentration was associated with the location of failure of the cages reported in vivo, despite superior mechanical properties of the implant. Furthermore, placement of the cage was found to have profound effects on migration, while the angle of the superior vertebra affected stress concentration of the cage.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>This model can be utilized both to inform surgical procedures and provide insight on future cage designs and can be adopted to models without the use of in vivo animal models.</p>\u0000 </section>\u0000 </div>","PeriodicalId":14876,"journal":{"name":"JOR Spine","volume":"6 4","pages":""},"PeriodicalIF":3.7,"publicationDate":"2023-12-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/jsp2.1307","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139047542","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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