Reparative effects of chronic intermittent hypobaric hypoxia pre‑treatment on intervertebral disc degeneration in rats

The current insights of mitochondrial hormesis in the occurrence and treatment of bone and cartilage degeneration

It is widely acknowledged that aging, mitochondrial dysfunction, and cellular phenotypic abnormalities are intricately associated with the degeneration of bone and cartilage. Consequently, gaining a comprehensive understanding of the regulatory patterns governing mitochondrial function and its underlying mechanisms holds promise for mitigating the progression of osteoarthritis, intervertebral disc degeneration, and osteoporosis. Mitochondrial hormesis, referred to as mitohormesis, represents a cellular adaptive stress response mechanism wherein mitochondria restore homeostasis and augment resistance capabilities against stimuli by generating reactive oxygen species (ROS), orchestrating unfolded protein reactions (UPRmt), inducing mitochondrial-derived peptides (MDP), instigating mitochondrial dynamic changes, and activating mitophagy, all prompted by low doses of stressors. The varying nature, intensity, and duration of stimulus sources elicit divergent degrees of mitochondrial stress responses, subsequently activating one or more signaling pathways to initiate mitohormesis. This review focuses specifically on the effector molecules and regulatory networks associated with mitohormesis, while also scrutinizing extant mechanisms of mitochondrial dysfunction contributing to bone and cartilage degeneration through oxidative stress damage. Additionally, it underscores the potential of mechanical stimulation, intermittent dietary restrictions, hypoxic preconditioning, and low-dose toxic compounds to trigger mitohormesis, thereby alleviating bone and cartilage degeneration.

Is Obstructive Sleep Apnea-Associated Adenoid Hypertrophy Linked to Scoliotic Attitudes in Children?

Introduction Scoliosis, a multifaceted spinal deformity commonly affecting pediatric and adolescent populations, has spurred extensive scientific inquiry to understand its origins and impacts. Early-onset scoliosis (EOS), characterized by spinal curvature exceeding 10° before the age of 10, presents a unique challenge necessitating a comprehensive understanding of its etiological factors. Within this context, the potential role of hypoxia-induced by adenoid hypertrophy in contributing to the pathogenesis of EOS has emerged as an intriguing avenue of investigation. Materials and methods This retrospective study was conducted focusing on radiological and clinical data pertaining to children below 10 years of age who underwent isolated adenoidectomy for adenoid hypertrophy. Preoperative posteroanterior standing chest radiographs were utilized for scoliosis assessment, with Cobb angles serving as the primary measurement metric. To ensure accuracy and reliability, Cobb angle measurements were independently performed by two experienced observers. Statistical analyses encompassed the Mann-Whitney U test, Spearman correlation analysis, and intraclass correlation coefficient calculations to evaluate interobserver agreement. Results Among the cohort of 218 pediatric adenoidectomy patients, 177 individuals had radiographs suitable for EOS evaluation. The mean age of the participants was 5.72±2 years, with a nearly equal distribution of 52.5% male and 47.5% female patients. Strikingly, the study identified a 10.2% prevalence of coronal plane curvatures exceeding the critical threshold of 10°, indicative of EOS. The robust interobserver reliability was demonstrated by a commendable mean interclass correlation coefficient (ICC) value of 0.926, affirming consistent and accurate Cobb angle measurements between the observers. Conclusion In light of the heightened prevalence of EOS observed in children undergoing adenoidectomy, this study provides a compelling impetus for exploring the potential interrelationship between adenoid hypertrophy, hypoxia, and the emergence of early-onset scoliosis. The study underscores the importance of prospective research to elucidate the complex mechanisms connecting these factors, offering insights into potential risk factors and underlying pathogenic pathways associated with the development of early-onset scoliosis.

Pediatric Sleep Questionnaire for Sleep Apnea in Newly Diagnosed Adolescent Idiopathic Scoliosis Patients

Close association has been established between obstructive sleep apnea (OSA) and adolescent idiopathic scoliosis (AIS), with PSQ being employed as a screening method for OSA. A cross-sectional study was conducted among patients aged from 10 to 16 years who presented to a scoliosis outpatient clinic. Patient demographics, radiological assessments, and PSQ scores were gathered. A total of 299 patients were included in the study, with 28.7% males and 71.2% females. The average Cobb angle was 6.20°. PSQ scores revealed a prevalence of 33.4% for significant obstructive sleep apnea. Patients diagnosed with AIS exhibited a prevalence of 32.9% with positive PSQ results. Among those undergoing adenoid and/or tonsil surgery, 27% had positive PSQ scores. Factors such as genetics, abnormal biomechanical forces, environmental factors including melatonin, and intermittent hypoxia were explored for their potential contribution to AIS etiology. The aim of the study is to underscore the importance of early detection and intervention in OSA cases and highlights the effectiveness of the PSQ, as a screening tool in identifying sleep disorders. The findings underscore the complex relationship between OSA and AIS, and moreover any spinal curvature is in relation with OSA.

Increased levels of circulating granulocytic myeloid‑derived suppressor cells in lumbar disc herniation

Myeloid-derived suppressor cells (MDSCs) expand when the body undergoes inflammatory diseases and chronic diseases. However, its role in intervertebral disc degeneration remains unclear. The present study aimed to characterize specific subsets of MDSCs as potential indicators of disease progression in patients with lumbar disc herniation (LDH). The Gene Expression Omnibus (GEO) database was used to analyze the changes in granulocyte MDSCs (G-MDSCs). Peripheral blood samples were collected from 40 patients with LDH and 15 healthy controls, and flow cytometry was used to characterize different subsets of MDSCs. All subjects underwent lumbar spine magnetic resonance imaging. Then, t-distributed stochastic neighborhood embedding and FlowSOM were used to analyze the data obtained by CytoFlex. The correlation between circulating MDSCs and the clinicopathological stage of LDH was then further analyzed. The GEO database predicted that G-MDSCs were highly expressed in patients with LDH. The frequency of circulating G-MDSCs increased with Pfirrmann stage III and IV, while the percentage of mononuclear MDSCs (M-MDSCs) only increased. Patient age and sex did not correlate with the frequency of circulating G-MDSCs and M-MDSCs. The results of the computer algorithm analysis were consistent with those of our manual gating. The present study showed that the occurrence of LDH led to changes in the MDSC subpopulation in the circulating peripheral blood of patients, and the frequency of circulating G-MDSCs in patients with clinical stage III and IV LDH increased with the degree of degeneration. The determination of G-MDSCs can be used as an auxiliary examination item for LDH.

Identification of SMIM1 and SEZ6L2 as Potential Biomarkers for Genes Associated with Intervertebral Disc Degeneration in Pyroptosis

Background. Inflammatory reactions and pyroptosis play an important role in the pathology of intervertebral disc degeneration (IDD). The aim of the present study was to investigate pyroptosis in the nucleus pulposus cells (NPCs) of inflammatory induced IDD by bioinformatic methods and to search for possible diagnostic biomarkers. Methods. Gene expression profiles related to IDD were downloaded from the GEO database to identify differentially expressed genes (DEGs) between inflammation-induced IDD and non-inflammatory intervention samples. Pyroptosis genes were then searched for, and their expression in IDD was analyzed. Weighted gene co-expression network analysis (WGCNA) was then used to search for modules of IDD genes associated with pyroptosis and intersected with DEGs to discover candidate genes that would be diagnostically valuable. A LASSO model was developed to screen for genes that met the requirements, and ROC curves were created to clarify the diagnostic value of the genetic markers. Ultimately, the screened genes were further validated, and their diagnostic value assessed by selecting gene sets from the GEO database. RT-PCR was used to assess the mRNA expression of diagnostic markers in the nucleus pulposus (NP). Pan-cancer analysis was applied to demonstrate the expression and prognostic value of the screened genes in various tumors. Results. A total of 733 DEGs were identified in GSE41883 and GSE27494, which were mainly enriched in transmembrane receptor protein serine/threonine, kinase signaling pathway, response to lipopolysaccharide, and other biological processes, and they were mainly related to TGF beta signaling pathway, toll-like receptor signaling pathway, and TNF signaling pathway. A total of 81 genes related to pyroptosis were identified in the literature, and eight genes related to IDD were identified in the Veen diagram, namely, IL1A, IL1B, NOD2, GBP1, IL6, AK1, EEF2K, and PYCARD. Eleven candidate genes were obtained after locating the intersection of pyroptosis-related module genes and DEGs according to WGCNA analysis. A total of six valid genes were obtained after constructing a machine learning model, and five key genes were finally identified after correlation analysis. GSE23132 and GSE56081 validated the candidate genes, and the final IDD-related diagnostic markers were obtained as SMIM1 and SEZ6L2. RT-PCR results indicated that the mRNA expression of both was significantly elevated in IDD. The pan-cancer analysis demonstrated that SMIM1 and SEZ6L2 have important roles in the expression and prognosis of various tumors. Conclusion. In conclusion, this research identifies SMIM1 and SEZ6L2 as important biomarkers of IDD associated with pyroptosis, which will help to unravel the development and pathogenesis of IDD and determine potential therapeutic targets.