Comparing perioperative outcomes between regional anesthesia and general anesthesia in patients undergoing hip fracture surgery: a systematic review and meta-analysis.

PURPOSE: Nearly all patients with hip fractures undergo surgical treatment. The use of different anesthesia techniques during surgery may influence the clinical outcomes. The optimal anesthetic technique for patients undergoing hip fracture surgery is still controversial. We performed this updated systematic review and meta-analysis to compare clinical outcomes of patients undergoing hip fracture surgery with different anesthesia techniques. SOURCE: Articles published from 2000 to May 2023 were included from MEDLINE, Embase, Web of Science, and the Cochrane Library. We included randomized controlled trials and observational studies comparing general anesthesia (GA) with regional anesthesia (RA) for the outcomes of 30-day mortality, 90-day mortality, in-hospital mortality, perioperative complications, length of hospital stay, and length of surgery in patients undergoing hip fracture surgery. Subgroup analyses were performed for the outcomes based on study design (randomized controlled trials or observational studies). We used a random-effects model for all analyses. PRINCIPAL FINDINGS: In this meta-analysis, we included 12 randomized controlled trials. There was no difference in postoperative 30-day mortality between the two groups (odds ratio [OR], 0.88; 95% confidence interval [CI], 0.44 to 1.74; I2 = 0%). The incidence of intraoperative hypotension was lower in patients who received RA vs GA (OR, 0.52; 95% CI, 0.38 to 0.72; I2 = 0%). No significant differences were observed in 90-day mortality, in-hospital mortality, postoperative delirium, pneumonia, myocardial infarction, venous thromboembolism, length of surgery, and length of hospital stay. CONCLUSION: In this updated systematic review and meta-analysis, RA did not reduce postoperative 30-day mortality in hip fracture surgery patients compared to GA. Fewer patients receiving RA had intraoperative hypotension than those receiving GA did. Apart from intraoperative hypotension, the data showed no differences in complications between the two anesthetic techniques. STUDY REGISTRATION: PROSPERO (CRD42023411854); registered 7 April 2023.

RéSUMé: OBJECTIF: Presque toutes les personnes ayant subi une fracture de la hanche se font opérer. L'utilisation de différentes techniques d'anesthésie pendant la chirurgie peut influencer les issues cliniques. La technique d'anesthésie optimale pour la patientèle bénéficiant de chirurgie de fracture de la hanche est encore controversée. Nous avons réalisé cette mise à jour par revue systématique et méta-analyse pour comparer les issues cliniques des personnes bénéficiant d'une chirurgie de fracture de la hanche avec différentes techniques d'anesthésie. SOURCES: Les articles publiés de 2000 à mai 2023 ont été inclus à partir des bases de données MEDLINE, Embase, Web of Science et Cochrane Library. Nous avons inclus des études randomisées contrôlées et des études observationnelles comparant l'anesthésie générale (AG) à l'anesthésie régionale (AR) pour les issues de mortalité à 30 jours, de mortalité à 90 jours, de mortalité intrahospitalière, de complications périopératoires, de durée de séjour à l'hôpital et de durée de la chirurgie pour les personnes bénéficiant d'une chirurgie de fracture de la hanche. Des analyses de sous-groupes ont été réalisées pour les issues en fonction de la méthodologie utilisée (étude randomisée contrôlée ou étude observationnelle). Un modèle à effets aléatoires a été utilisé pour toutes les analyses. CONSTATATIONS PRINCIPALES: Dans cette méta-analyse, nous avons inclus 12 études randomisées contrôlées. Il n'y avait pas de différence dans la mortalité postopératoire à 30 jours entre les deux groupes (rapport de cotes [RC], 0,88; intervalle de confiance à 95 % [IC], 0,44 à 1,74; I2 = 0 %). L'incidence d'hypotension peropératoire était plus faible chez les patient·es ayant reçu une AR vs une AG (RC, 0,52; IC 95 %, 0,38 à 0,72; I2 = 0 %). Aucune différence significative n'a été observée dans les issues de mortalité à 90 jours, de mortalité intrahospitalière, de delirium postopératoire, de pneumonie, d'infarctus du myocarde, de thromboembolie veineuse, de durée de la chirurgie, et de durée du séjour à l'hôpital. CONCLUSION: Dans cette revue systématique avec méta-analyse, l'anesthésie régionale n'a pas réduit la mortalité postopératoire à 30 jours chez les personnes ayant bénéficié d'une chirurgie de fracture de la hanche par rapport à l'anesthésie générale. Une proportion moindre de patient·es ayant reçu une AR présentaient une hypotension peropératoire par rapport aux personnes ayant reçu une AG. En dehors de l'hypotension peropératoire, les données n'ont montré aucune différence dans les complications entre les deux techniques anesthésiques. ENREGISTREMENT DE L'éTUDE: PROSPERO (CRD42023411854); enregistrée le 7 avril 2023.

Maslinic acid alleviates intervertebral disc degeneration by inhibiting the PI3K/AKT and NF-κB signaling pathways.

Intervertebral disc degeneration (IDD) is the cause of low back pain (LBP), and recent research has suggested that inflammatory cytokines play a significant role in this process. Maslinic acid (MA), a natural compound found in olive plants ( Olea europaea), has anti-inflammatory properties, but its potential for treating IDD is unclear. The current study aims to investigate the effects of MA on TNFα-induced IDD in vitro and in other in vivo models. Our findings suggest that MA ameliorates the imbalance of the extracellular matrix (ECM) and mitigates senescence by upregulating aggrecan and collagen II levels as well as downregulating MMP and ADAMTS levels in nucleus pulposus cells (NPCs). It can also impede the progression of IDD in rats. We further find that MA significantly affects the PI3K/AKT and NF-κB pathways in TNFα-induced NPCs determined by RNA-seq and experimental verification, while the AKT agonist Sc-79 eliminates these signaling cascades. Furthermore, molecular docking simulation shows that MA directly binds to PI3K. Dysfunction of the PI3K/AKT pathway and ECM metabolism has also been confirmed in clinical specimens of degenerated nucleus pulposus. This study demonstrates that MA may hold promise as a therapeutic agent for alleviating ECM metabolism disorders and senescence to treat IDD.

Identifying the key genes regulating mesenchymal stem cells chondrogenic differentiation: an in vitro study.

BACKGROUND: Mesenchymal stem cells (MSCs) possess the potential to differentiate into chondrocytes, which makes them an ideal source for healing cartilage defects. Here, we seek to identify the essential genes participating in MSCs chondrogenesis. METHODS: Human MSCs were induced for chondrogenesis for 7, 14, and 21 days using a high-density micromass culture system, and RNA was extracted for RNA-seq. RESULTS: A total of 6247 differentially expressed genes (DEGs) were identified on day 7, and 85 DEGs were identified on day 14. However, no significant DEGs was identified on day 21. The top 30 DEGs at day 7, including COL9A3, COL10A1, and CILP2, are closely related to extracellular matrix organization. While the top 30 DEGs at day 14 revealed that inflammation-related genes were enriched, including CXCL8, TLR2, and CCL20. We also conducted protein-protein interaction (PPI) networks analysis using the search tool for the retrieval of interacting genes (STRING) database and identified key hub genes, including CXCL8, TLR2, CCL20, and MMP3. The transcriptional factors were also analyzed, identifying the top 5 TFs: LEF1, FOXO1, RORA, BHLHE41, and SOX5. We demonstrated one particular TF, RORA, in promoting early MSCs chondrogenesis. CONCLUSIONS: Taken together, our results suggested that these DEGs may have a complex effect on MSCs chondrogenesis both synergistically and solitarily.

Comparison of anterior or posterior approach in surgical treatment of thoracic and lumbar tuberculosis: a retrospective case-control study.

BACKGROUND: With the widespread use of the posterior surgery, more and more surgeons chose posterior surgery to treat thoracic and lumbar tuberculosis. But others still believed that the anterior surgery is more conducive to eradicating the lesions, and easier to place larger bone pieces for bone graft fusion. We compared the clinical and radiological outcomes of anterior and posterior surgical approaches and presented our views. METHODS: This study included 52 thoracic and lumbar tuberculosis patients at Sun Yat-sen Memorial Hospital from January 2010 to June 2018. All cases underwent radical debridement, nerve decompression, intervertebral bone graft fusion and internal fixation. Cases were divided into anterior group (24 cases) and posterior group (28 cases). Statistical analysis was used to compare the clinical effectiveness, radiological outcomes, complications and other related information. RESULTS: Patients in the anterior group and the posterior group were followed up for an average of 27.4 and 22.3 months, respectively. There were no statistically significant differences between groups in the preoperative, postoperative and last follow-up VAS score, ASIA grade and Cobb angle of local kyphosis. Moreover, there were no statistically significant differences in the improvement of neurological function, loss of kyphotic correction, total incidence of complications, operative time, intraoperative blood loss and hospital stay between the two groups (P > 0.05). But there was greater correction of kyphosis, earlier bone fusion, lower incidence of poor wound healing, less interference with the normal spine and less internal fixation consumables and medical cost in the anterior group (P < 0.05). CONCLUSIONS: Both anterior and posterior approaches are feasible for thoracic and lumbar tuberculosis. While for thoracic and lumbar tuberculosis patients with a single lesion limited in the anterior and middle columns of the spine without severe kyphosis, the anterior approach surgery may have greater advantages in kyphosis correction, bone fusion, wound healing, protection of the normal spine, and medical consumables and cost.

Identification of key potential targets for TNF-α/TNFR1-related intervertebral disc degeneration by bioinformatics analysis.

BACKGROUND: Bioinformatics analysis was performed on gene expression profile microarray data to identify the key genes activated through the TNF-α/TNFR1 signaling pathway in intervertebral disc degeneration (IDD). The common differentially expressed genes (co-DEGs) were calculated in nucleus pulposus (NP) cells and annulus fibrosus (AF) cells under TNF-α treatment or TNFR1 knockdown, which reveals the potential mechanism of TNF-α involvement in IDD and may provide new therapeutic targets for IDD. METHODS: Differentially expressed genes (DEGs) in TNF-α-treated or TNFR1-knockdown NP cells and AF cells were identified. Further analysis of the gene ontology (GO), signaling pathways and interaction networks of the DEGs or co-DEGs were conducted using the Database for Annotation, Visualization and Integrated Discovery, STRING Database, and Cytoscape software. The relationship between genes and musculoskeletal diseases, including IDD, was assessed with the Comparative Toxicogenomics Database. The predicted microRNAs corresponding to the co-DEGs were also identified by microRNA Data Integration Portal. RESULTS: In NP cells, the DEGs (|log2FoldChange|>2, adj.P < 0.01) were identified including 48 DEGs by TNF-α treatment and 74 DEGs by TNFR1 knockdown; in AF cells, correspondingly, 105 DEGs were identified. The co-DEGs between NP cells and AF cells were calculated including CXCL8, ICAM1, BIRC3, RELB, NFKBIA, and TNFAIP3. They may be the hub genes that were significantly associated with both NP cells and AF cells through the TNF-α/TNFR1 signaling pathway. The co-DEGs and corresponding predicted miRNAs may be potential therapeutic targets for IDD. CONCLUSIONS: CXCL8, ICAM1, BIRC3, RELB, NFKBIA, and TNFAIP3 may have a synergistic effect on TNF-α-induced IDD development.Abbreviations: IDD: Intervertebral disc degeneration; NP: Nucleus pulposus; AF: Annulus fibrosus; co-DEG: Common differentially expressed gene; GO: Gene Ontology; KEGG: Kyoto Encyclopedia of Genes and Genomes; PPI: Protein-protein interaction.

Inverse Agonist of Retinoid-Related Orphan Receptor-Alpha Prevents Apoptosis and Degeneration in Nucleus Pulposus Cells via Upregulation of YAP.

Intervertebral disc degenerative disease (IDD) is the most common degenerative spine disease, which leads to chronic low back pain and symptoms in the lower extremities. In this study, we found that RORα, a member of the retinoid-related orphan receptor family, is significantly elevated in nucleus pulposus tissue in IDD patients. The elevation of RORα is associated with increased apoptosis of nucleus pulposus (NP) cells. Therefore, we applicated a well-established inverse agonist of RORα, SR3335, to investigate its role in regulating NP cell metabolism and apoptosis. To further investigate the mechanism that SR3335 regulates the pathogenesis of IDD in vitro, tumor necrosis factor alpha (TNF-α) stimulation was used in human NP cells to mimic the hostile environment that leads to degeneration. We found that SR3335 treatment reversed the trend of increased apoptosis in NP cells induced by TNF-α treatment. Next, TNF-α treatment upregulated the expression of type II collagen and aggrecan and downregulated MMP13 (matrix-degrading enzyme matrix metalloproteinase 13) and ADAMTS4 (a disintegrin and metalloproteinase with thrombospondin motifs 4). However, these effects were reversed after SR3335 treatment. Furthermore, we find that SR3335 mediated the effect in NP cells by regulating the YAP signaling pathway, especially by affecting the phosphorylation state of YAP. In conclusion, the reduction of matrix degradation enzymes and apoptosis upon SR3335 treatment suggests that SR3335 is a promising drug in reversing the deleterious microenvironment in IDD patients.

Bromodomain-containing protein 4 inhibition alleviates matrix degradation by enhancing autophagy and suppressing NLRP3 inflammasome activity in NP cells.

An imbalance between matrix synthesis and degradation is the hallmark of intervertebral disc degeneration while inflammatory cytokines contribute to the imbalance. Bromodomain and extra-terminal domain (BET) family is associated with the pathogenesis of inflammation, and inhibition of BRD4, a vital member of BET family, plays an anti-inflammatory role in many diseases. However, it remains elusive whether BRD4 plays a similar role in nucleus pulposus (NP) cells and participates in the pathogenesis of intervertebral disc degeneration. The present study aims to observe whether BRD4 inhibition regulates matrix metabolism by controlling autophagy and NLRP3 inflammasome activity. Besides, the relationship was investigated among nuclear factor κB (NF-κB) signaling, autophagy and NLRP3 inflammasome in NP cells. Here, real-time polymerase chain reaction, western blot analysis and adenoviral GFP-LC3 vector transduction in vitro were used, and it was revealed that BRD4 inhibition alleviated the matrix degradation and increased autophagy in the presence or absence of tumor necrosis factor α. Moreover, p65 knockdown or treatment with JQ1 and Bay11-7082 demonstrated that BRD4 inhibition attenuated NLRP3 inflammasome activity through NF-κB signaling, while autophagy inhibition by bafilomycin A1 promoted matrix degradation and NLRP3 inflammasome activity in NP cells. In addition, analysis of BRD4 messenger RNA expression in human NP tissues further verified the destructive function of BRD4. Simply, BRD4 inhibition alleviates matrix degradation by enhancing autophagy and suppressing NLRP3 inflammasome activity through NF-κB signaling in NP cells.

Melatonin prevents bone destruction in mice with retinoic acid-induced osteoporosis.

BACKGROUND: The protective effect of melatonin against bone metabolism imbalance in osteoporosis (OP) induced by drugs such as retinoic acid (RA) is unclear. The aim of this study was to explore the role of melatonin in bone destruction based on a mouse model. METHODS: RA-induced OP model mice were established. To assess the effect of melatonin on these mice, micro-CT was used to characterize the trabecular structure of normal mice and those treated with RA (model), RA + low-dose melatonin (Mlt-L), RA + high-dose melatonin (Mlt-H), and RA + alendronate sodium (positive control). The shape of the trabecular bone, the length and diameter of the femoral head and the height and diameter of vertebra(L1) of each group were also measured and the number of osteoclasts was determined by Tartrate-resistant acid phosphatase (TRACP) staining. Meanwhile, the expression of alkaline phosphatase (ALP) was evaluated by immunohistochemistry assays. The differences between groups in terms of liver and kidney oxidation-related indexes and serum and urinary indicators related to bone metabolism were also analyzed. Furthermore, qRT-PCR and western blotting were used to evaluate the effect of melatonin on osteogenic and osteoclastic differentiation in MC3T3-E1 and RAW264.7 cells, respectively. RESULTS: RA induction led to a decrease in the amount and density of trabecular bone, a decrease in the length and diameter of the femur and height, diameter of the vertebra (L1), a decrease in bone mass and density and the expression of ALP, and an increase in the number of osteoclasts. Melatonin treatment alleviated these effects induced by RA, increasing the amount of trabecular bone in OP mice, improving the microstructure of the femur and vertebra(L1) and increasing bone mass bone density and the expression of ALP, as well as decreasing the number of osteoclasts. Additionally, blood and urinary bone metabolism-related indicators showed that melatonin promoted bone formation and inhibited bone resorption. Determination of oxidant and antioxidant biomarkers in the livers and kidneys of the mice revealed that melatonin promoted the antioxidant level and suppressed the level of oxidant molecules in these organs. In vitro, RA promoted osteoclasts and inhibit osteogenesis by increasing oxidative stress levels in the RAW264.7 and MC3T3-E1 cells, but melatonin reversed this effect. Melatonin may, therefore, play a role in the ERK/SMAD and NF-κB pathways. CONCLUSIONS: Melatonin can alleviate bone loss in RA-induced OP model mice, repair the trabecular microstructure, and promote bone formation. These effects may be related to reducing oxidation levels in vivo and vitro through the ERK/SMAD and NF-κB pathways.

MicroRNA-155 suppresses the catabolic effect induced by TNF-α and IL-1ß by targeting C/EBPß in rat nucleus pulposus cells.

AIM: miR-155 is a pro-inflammatory or anti-inflammatory factor depending on the cell type in which it is expressed. miR-155 controls apoptosis and matrix degradation in nucleus pulposus (NP) cells in vitro. The aim of this study is to explore the effect of miR-155 in vivo and further investigate the mechanism of miR-155 in vitro. METHODS: MRI, hematoxylin-eosin staining, or Collagen-II immunochemistry were performed to observe intervertebral disk degeneration in conditional miR-155 overexpression mice and miR-155 knockout mice. In vitro, a dual luciferase reporter assay, real-time PCR and western blot experiments were performed to demonstrate the effect of miR-155 on the expression of catabolic genes induced by inflammatory cytokines and determine the role of ß-catenin and C/EBPß in the miR-155-mediated modulation of the expression of catabolic genes. RESULTS: Degeneration was observed in the lumbar disks of 1-year-old miR-155 knockout mice but not in the conditional miR-155 overexpression mice. miR-155 overexpression repressed the catabolic effect induced by TNF-α or IL-1ß in vitro. Furthermore, specifically in NP cells, miR-155 overexpression suppressed the expression of C/EBPß but not of ß-catenin. Additionally, in the loss-of-function experiments using C/EBPß siRNA, C/EBPß knockdown repressed the expression of catabolic genes induced by TNF-α and IL-1ß, which is consistent with the miR-155 results. CONCLUSION: miR-155 is a sustainable factor for intervertebral disk and suppresses the expression of catabolic genes induced by TNF-α and IL-1ß by targeting C/EBPß in rat NP cells.

Melatonin-mediated miR-526b-3p and miR-590-5p upregulation promotes chondrogenic differentiation of human mesenchymal stem cells.

Bone marrow-derived mesenchymal stem cells (BMSCs), with inherent chondrogenic differentiation potential appear to be ideally suited for therapeutic use in cartilage regeneration. Accumulating evidence has demonstrated that melatonin can promote chondrogenic differentiation in human BMSCs. However, little is known about the mechanism. MicroRNAs (miRNAs) have been shown to regulate the differentiation of BMSCs, but their roles in melatonin-promoted chondrogenic differentiation have not been characterized. Here, we demonstrate that melatonin promoted chondrogenic differentiation of human BMSCs via upregulation of miR-526b-3p and miR-590-5p. Mechanistically, the elevated miR-526b-3p and miR-590-5p enhanced SMAD1 phosphorylation by targeting SMAD7. Additionally, administration of miR-526b-3p mimics or miR-590-5p mimics successfully promoted the chondrogenic differentiation of human BMSCs. Collectively, our study suggests that modification of BMSCs using melatonin or miRNA transduction could be an effective therapy for cartilage damage and degeneration.

Regulation of a disintegrins and metalloproteinase with thrombospondin motifs 7 during inflammation in nucleus pulposus (NP) cells: role of AP-1, Sp1 and NF-κB signaling.

AIM: The objective of this study is to explore the effect of inflammatory cytokines on a disintegrins and metalloproteinase with thrombospondin motifs 7 (ADAMTS7) and to demonstrate the role of Sp1, AP-1 and NF-κB signaling on the ADAMTS7 regulation during inflammation in NP cells. METHODS: Real-time PCR was to detect the effect of ADAMTS7 knockdown on the expression of catabolic enzymes during inflammatory condition in NP cells. Real-time PCR, western blot, immunofluorescence and transfection experiments were used to observe the effect of tumor necrosis factor-α (TNF-α) or interleukin-1ß on the expression and the activity of ADAMTS7, and demonstrated the role to Sp1, AP-1 and NF-κB in the regulation of ADAMTS7 during inflammation. RESULTS: As other cells, ADAMTS7 knockdown suppressed the mRNA expression of catabolic factors during inflammation in human NP cells. However, the expression of ADAMTS7 mRNA and protein and the activity of ADAMTS7 promoter were refractory to inflammatory cytokines. In addition, Sp1, AP-1, not NF-κB signaling sustained the expression of ADAMTS7 mRNA, protein, as well as promoter activity during inflammation in NP cells. CONCLUSION: ADAMTS7 played a crucial role in the expression of catabolic genes in the presence of TNF-α and AP-1, Sp1, not NF-κB signaling were critical for the maintenance of ADAMTS7 expression during inflammation in NP cells.

SIRT1 expression is refractory to hypoxia and inflammatory cytokines in nucleus pulposus cells: Novel regulation by HIF-1α and NF-κB signaling.

Hypoxia and a marked increase in inflammatory cytokines are common hallmarks of intervertebral disc degeneration; these events disrupt the normal balance between extracellular matrix (ECM) degradation and synthesis in degenerative intervertebral discs. SIRT1, one of the NAD+-dependent class III histone deacetylases, controls cellular processes and is regulated by hypoxia and inflammatory cytokines in a cell-type-dependent manner. SIRT1 protects degenerative human nucleus pulposus cells against apoptosis. However, the role of SIRT1 in inflammation in intervertebral discs is still unclear. The current study showed that in rat NP cells, as in other cells, SIRT1 suppressed the induction of the mRNA expression of proteases that degrade ECM induced by TNF-α. Moreover, real-time PCR, transfection, and loss- and gain-of-function experiments revealed that SIRT1 mRNA and protein expression were refractory to hypoxia and HIF-1α. Additionally, SIRT1 mRNA and protein expression and the activity of the SIRT1 promoter were not affected by inflammatory cytokines but were sustained by NF-κB signaling in the presence or absence of TNF-α. In summary, the present study suggested that SIRT1 is not affected by hypoxia and inflammatory cytokines in rat intervertebral discs. Moreover, not HIF-1α but NF-κB signaling is critical for the maintenance of SIRT1 expression in NP cells under physiologic and pathophysiologic conditions.

Melatonin reversed tumor necrosis factor-alpha-inhibited osteogenesis of human mesenchymal stem cells by stabilizing SMAD1 protein.

Tumor necrosis factor-alpha (TNFα) plays a pivotal role in inflammation-related osteoporosis through the promotion of bone resorption and suppression of bone formation. Numerous drugs have been produced to treat osteoporosis by inhibiting bone resorption, but they offer few benefits to bone formation, which is what is needed by patients with severe bone loss. Melatonin, which can exert both anti-inflammatory and pro-osteogenic effects, shows promise in overcoming TNFα-inhibited osteogenesis and deserves further research. This study demonstrated that melatonin rescued TNFα-inhibited osteogenesis of human mesenchymal stem cells and that the interactions between SMURF1 and SMAD1 mediated the crosstalk between melatonin signaling and TNFα signaling. Additionally, melatonin treatment was found to downregulate TNFα-induced SMURF1 expression and then decrease SMURF1-mediated ubiquitination and degradation of SMAD1 protein, leading to steady bone morphogenetic protein-SMAD1 signaling activity and restoration of TNFα-impaired osteogenesis. Thus, melatonin has prospects for treating osteoporosis caused by inflammatory factors due to its multifaceted functions on regulation of bone formation, bone resorption, and inflammation. Further studies will focus on unveiling the specific mechanisms by which melatonin downregulates SMURF1 expression and confirming the clinical therapeutic value of melatonin in the prevention and therapy of bone loss associated with inflammation.

Melatonin enhances chondrogenic differentiation of human mesenchymal stem cells.

Intramembranous ossification and endochondral ossification are two ways through which bone formation and fracture healing occur. Accumulating amounts of evidence suggests that melatonin affects osteoblast differentiation, but little is known about the effects of melatonin on the process of chondrogenic differentiation. In this study, the effects of melatonin on human mesenchymal stem cells (MSCs) undergoing chondrogenic differentiation were investigated. Cells were induced along chondrogenic differentiation via high-density micromass culture in chondrogenic medium containing vehicle or 50 nm melatonin. Histological study and quantitative analysis of glycosaminoglycan (GAG) showed induced cartilage tissues to be larger and richer in GAG, collagen type II and collagen type X in the melatonin group than in the untreated controls. Real-time RT-PCR analysis demonstrated that melatonin treatment significantly up-regulated the expression of the genes involved in chondrogenic differentiation, including aggrecan (ACAN), collagen type II (COL2A1), collagen type X (COL10A1), SRY (sex-determining region Y)-box 9 (SOX9), runt-related transcription factor 2 (RUNX2) and the potent inducer of chondrogenic differentiation, bone morphogenetic protein 2 (BMP2). And the expression of melatonin membrane receptors (MT) MT1 and MT2 were detected in the chondrogenic-induced-MSCs by immunofluorescence staining. Luzindole, a melatonin receptor antagonist, was found to partially block the ability of melatonin to increase the size and GAG synthesis of the induced cartilage tissues, as well as to completely reverse the effect of melatonin on the gene expression of ACAN, COL2A1, COL10A1, SOX9 and BMP2 after 7 days of differentiation. These findings demonstrate that melatonin enhances chondrogenic differentiation of human MSCs at least partially through melatonin receptors.

Facet joint tropism, pelvic incidence and intervertebral height index: associations with facet joint osteoarthritis in lumbar spinal stenosis.

BACKGROUND CONTEXT: Facet joint osteoarthritis (FJOA) is associated with lumbar disc degeneration and has a significant role in the development of lumbar spinal stenosis (LSS). The relationship between various radiographic parameters and the grade of FJOA is not well understood. PURPOSE: To explore radiographical parameters associated with FJOA in LSS without lumbar dynamic instability. STUDY DESIGN: Retrospective study analysis. PATIENT SAMPLE: A total of 122 patients diagnosed with LSS who visited our hospital between January 2015 and July 2022. OUTCOME MEASURES: We evaluated radiographic parameters of patients at L4-5 including lumbar lordosis (LL), pelvic incidence (PI), pelvic tilt (PT), sacral slope (SS), grades of FJOA, facet joint orientation (FO), facet joint tropism (FT), intervertebral height index (IHI) and the relative cross-sectional area (RCSA) of paraspinal muscles. METHODS: Patients diagnosed with LSS between January 2015 and July 2022 were enrolled. Demographic characteristics and radiographic parameters were collected. Spinopelvic parameters were measured through the preoperative lateral image of the whole spine, including LL, PI, pelvic tilt, and sacral slope. Lumbar computed tomography scan and magnetic resonance imaging were collected to measure the FO, FT, IHI, and the RCSA of paraspinal muscles respectively. Patients were divided into three groups according to the severity of FJOA graded by the Weishaupt classification: grade 0 and grade 1 were group A, grade 2 were group B, and grade 3 were group C. All variables were compared among the three groups, while the relationship between parameters and grades of FJOA were also analyzed. RESULTS: A total of 122 patients were included. PI was significantly greater in group C compared to group A (p = 0.025) and group B (p=0.022). FT was significantly greater in group C compared to group A (p<.001) and group B (p<.001). The RCSA of multifidus in group A were significantly greater than that in group B (p=0.02) and C (p=0.002). Additionally, FO in group C were significantly lower than group A (p<.001) and group B (p=0.028). The IHI in group C was significantly lower than group A (p=0.017). The correlation analysis indicated that grades of FJOA was positively related to Age, BMI (body mass index), PI, LL and FT, while negatively related to IHI, FO, RCSA of multifidus and RCSA of psoas major. Furthermore, the logistics regression showed that FT, PI, and IHI were important influence factors for FJOA. CONCLUSIONS: The current study confirmed that FT, PI and IHI were significantly associated with grades of FJOA at L4-5. Additionally, longitudinal studies are needed to understand the causal relationship between these parameters and FJOA.

Increased macroautophagy in the pathological process of intervertebral disc degeneration in rats.

OBJECTIVE: Macroautophagy increases with age in rat intervertebral discs; however, the effect of macroautophagy on the process of intervertebral disc degeneration (IVDD) is still unclear. The aim of this study was to examine the presence of autophagosome, as well as the levels of Beclin-1 and LC3 proteins, in vivo. Additionally, in vitro evidence of macroautophagy and GRP78 and GADD153 protein levels were investigated to explore the mechanism of macroautophagy in the process of IVDD. METHODS: Male Sprague-Dawley rats, aged 2 months, were randomly divided into six groups (three control and three model groups, n = 8 per group). At the 6-, 12-, and 18-week time points, autophagosomes in nucleus pulposus cells were detected with transmission electron microscope (TEM). Expression of Beclin-1 and LC3 protein levels within intervertebral disc was detected using Western blotting analysis. Then, the rat annulus fibrosus cells were isolated and cultured with Earle's balanced salt solution. At 1, 2, and 3 hr of culture, autophagosomes were detected using monodansylcadaverine assay, and LC3, Beclin-1, GRP78, and GADD153 protein levels were detected using Western blotting analysis. RESULTS: Transmission electron microscopy revealed autophagosomes within nucleus pulposus cells in both the control and model groups. At 6-, 12-, and 18-week posttreatments, the levels of Beclin-1 and the LC3-II/LC3-I protein ratio in the model groups were higher than those in the control groups (p < 0.05). Compared with the control rats, amino acid starvation increased the number of monodansylcadaverine-positive cells and the LC3-II/LC3-I protein ratio in the model rats. Moreover, the in vitro levels of Beclin-1, GRP78, and GADD153 proteins were increased with the prolongation of amino acid starvation (p < 0.05). CONCLUSIONS: Macroautophagy was present and was associated with increased pathological process of IVDD in rats. Macroautophagy of intervertebral disc cells is possibly secondary to endoplasmic reticulum stress.

Sustained release of melatonin from poly (lactic-co-glycolic acid) (PLGA) microspheres to induce osteogenesis of human mesenchymal stem cells in vitro.

Melatonin promotes bone formation and prevents bone degradation via receptor-dependent or receptor-independent actions. The aim of this study is to encapsulate melatonin into poly (lactic-co-glycolic acid) (PLGA) microspheres (PLGA-MEL-MS) and create a melatonin sustained release system, then to evaluate its effect on the osteogenesis of human mesenchymal stem cells (hMSCs) in vitro. PLGA-MEL-MS were prepared by single emulsion solvent evaporation technique. Scanning electron microscopy demonstrated the incorporation of melatonin did not disturb the conventional generation of PLGA microspheres in size and morphology. In vitro drug release assay showed that PLGA-MEL-MS exhibited a biphasic drug release pattern: a low initial burst release effect with approximately 40% drug release at the first 3 days and a relatively retarded and continuous release with about 85% drug release over the 25 days. Cell proliferation assay demonstrated that PLGA-MEL-MS had no apparent effect on proliferation of human MSCs. In an osteogenesis assay, PLGA-MEL-MS obviously enhanced alkaline phosphatase (ALP) mRNA expression and increased ALP activity compared to that in the control group. Meanwhile, several markers of osteoblast differentiation were also significantly upregulated, including runx2, osteopontin, and osteocalcin. Furthermore, quantificational alizarin red-based assay demonstrated that PLGA-MEL-MS significantly enhanced calcium deposit of hMSCs compared to the controls. Therefore, this simple melatonin sustained release system can control released melatonin to generate a microenvironment with a relatively stable concentration of melatonin for a period of time to support osteogenic differentiation of hMSCs in vitro. This suggests that this system may be used as bone growth stimulator in bone healing in vivo.

Inhibition of the PI3K/AKT pathway reduces tumor necrosis factor-alpha production in the cellular response to wear particles in vitro.

Joint replacement is the most effective treatment for end-stage osteoarticular disease. However, macrophage-mediated aseptic loosening of joint prosthesis severely hampers the clinical effects of joint replacement. Until now, the mechanism by which macrophages regulate the secretion of inflammatory cytokines after particle stimulation is not clear. It is well known that the PI3K/AKT pathway participates in multiple cellular processes, including cell growth, survival, and inflammation. However, whether the PI3K/AKT pathway participates in the proinflammatory response of macrophages after particle stimulation and secondary aseptic loosening is still unknown. In this study, ceramic and titanium particles of different sizes were prepared to stimulate macrophages. LY294002, a specific inhibitor of PI3K, was pretreated prior to particle stimulation. The expression of tumor necrosis factor-alpha (TNF-α) and all the subunits of PI3K and AKT were detected by real-time polymerase chain reaction, enzyme-linked immunosorbent assay, and Western blot. The result showed that LY294002 could suppress the RNA and protein expression of TNF-α in RAW264.7 cells after stimulation of different particles. The subunits of PI3K (p110ß and p85ß), followed by activation of phosphor-AKT (Ser473), participated in the regulation of activating macrophages by wear particles, ultimately resulting in the secretion of TNF-α.

Correlation analysis of surgical outcomes and spino-pelvic parameters in patients with degenerative lumbar scoliosis.

Objectives: The study aims to analyze factors that affect the postoperative health-related quality of life (HRQOL) of degenerative lumbar scoliosis (DLS) patients and explore the appropriate pelvic incidence minus lumbar lordosis (PI-LL) value for Chinese DLS patients. Methods: DLS patients who met the inclusion and exclusion criteria were included in this study. General information, spino-pelvic parameters, and HRQOL were collected. Correlation analysis was used to explore the spino-pelvic parameters that affect the postoperative HRQOL. Thresholds of each parameter were obtained using the receiver operating characteristic (ROC) curve. Regardless of the effect of age, DLS patients were classified into three groups according to the SRS-Schwab classification: group 0 means PI-LL < 10°, group+means PI-LL = 10-20°, and group ++ means PI-LL > 20°. Postoperative HRQOL was analyzed using variance methods. The ROC curve was used to measure the appropriate PI-LL threshold. When considering the effect of age, the patients with Oswestry Disability Index (ODI) < 75% percentile were considered to have a satisfactory clinical outcome, which was drawn to an equation between PI-LL, age, and PI by multiple linear regression equation. Results: A total of 71 patients were included. Compared with the control group, there were significant differences in both postoperative ODI and Scoliosis Research Society 22 (SRS-22) scores when the postoperative Cobb angle ≤11°, postoperative lumbar lordosis index (LLI) > 0.8, postoperative sagittal vertical axis (SVA) ≤ 5 cm, postoperative T1 pelvic angle (TPA) ≤ 16° and postoperative global tilt (GT) ≤ 22°, respectively. Regardless of the effect of age, there was a statistical difference in postoperative HRQOL between group 0 and group ++. The PI-LL threshold derived from the ROC curve was 14.4°. Compared with the PI-LL > 14° group, the PI-LL ≤ 14° group achieved a lower postoperative ODI score and a higher postoperative SRS-22 score. Considering the influence of age, the equation for ideal PI-LL was PI-LL = 0.52age + 0.38PI-39.4 (R = 0.509, p = 0.001). Conclusions: PI-LL was an important parameter that affects the postoperative HRQOL of DLS patients. Sufficient LL should be restored during the operation (LL ≥ PI-14°). The appropriate PI-LL value was affected by age. Smaller LL needed to be restored as the age increased.