RESUMO
Background: The posterior procedure utilizing growth-friendly techniques is the golden standard for patients with early-onset scoliosis combined with thoracic insufficiency syndrome (EOS + TIS). Pulmonary hypoplasia is the main cause of dying prematurely in the EOS + TIS. This study assessed the therapeutic impact of a novel growth-friendly system on the pulmonary development of piglet's EOS + TIS model. Methods: The animal procedure period lasts 12 weeks, of which the construction of the EOS + TIS was performed at 0-8 weeks, and implantation of a novel growth-friendly system was applied at 8-12 weeks. During the animal procedure, X-rays and CT were performed to observe scoliosis, thorax, and lungs. After 12 weeks, pathological changes in lung tissue were assessed using HE and IHC staining. RNA-seq characterized novel growth-friendly system-associated differentially expressed genes (DEGs) and validated using RT-qPCR, western blotting, and IHC. Results: Implantation of the novel growth-friendly system increased body weight, body length, and total lung volume, as well as decreased the coronal and sagittal Cobb angles for the EOS + TIS model. It also ameliorated EOS + TIS-induced thickening of the alveolar wall, increased alveolar spaces, and decreased alveolar number and diameter. In lung tissue, a total of 790 novel growth-friendly system-associated DEGs were identified, and they were mainly involved in the regulation of immune, inflammatory, calcium transport, and vascular development. Among these DEGs, BDKRB1, THBS1, DUSP1, IDO1, and SPINK5 were hub genes, and their differential expression was consistent with RNA-seq results in lung tissues. Conclusion: The novel growth-friendly system has mitigated scoliosis and pulmonary hypoplasia in the EOS + TIS model. We further elucidate the molecular mechanisms underlying the amelioration of pulmonary hypoplasia.
RESUMO
BACKGROUND: Early-onset scoliosis (EOS) is a scoliosis deformity caused by various reasons before the age of 10 years and is often combined with thoracic insufficiency syndrome (TIS) causing patients with difficulty in securing lung growth in the thoracic cage. Currently, there is a shortage of effective large animal models for evaluating EOS + TIS in therapeutic studies. Consequently, we propose to construct a porcine EOS + TIS model and evaluate its transcriptome changes by RNA sequencing. METHODS: Piglets were constructed using unilateral posterior spine-tethering and ipsilateral rib-tethering in the EOS + TIS model, and X-ray and computed tomography (CT) were performed to assess growth changes in the spine, thoracic cage and lungs. The H&E and Masson staining was performed for pathological analysis of lung tissue. After RNA sequencing of lung tissues, data were analyzed for differential expression of mRNA, functional enrichment analysis (GO, KEGG and GSEA) and protein-protein interaction (PPI) network construction, and differential expression of hub gene was verified by RT-qPCR. RESULTS: In the model group, growth (body weight and length) of piglets was significantly delayed; fusion of ribs occurred and cobb angle changes in the coronal and sagittal planes were significantly enlarged; total lung volume (TLV) was significantly reduced, especially at the T7-T10 level. Pathological analysis revealed that, in the model lung tissue, the alveolar wall of was poorly perfused, the alveolar space was enlarged, the number and size of alveoli were significantly reduced, and it was accompanied by collagen fiber deposition. Moreover, a total of 432 differentially expressed mRNAs (DE-mRNAs) were identified in model lung tissues, which contained 262 down-regulated and 170 up-regulated DE-mRNAs, and they were mainly involved in the regulation of immunity, inflammation, cell cycle and extracellular matrix. A PPI network containing 71 nodes and 158 edges was constructed based on all DE-mRNAs, and JUN, CCL2, EGR1, ATF3, BTG2, DUSP1 and THBS1 etc. were hub gene. CONCLUSIONS: Overall, we constructed a porcine model that was capable of replicating the common clinical features of EOS + TIS such as rib fusion, asymmetric thoracic cage, increased cobb angle, decreased TLV, and pulmonary hypoplasia. Also, we revealed transcriptomic changes in the EOS + TIS model that may cause pulmonary hypoplasia.