A facile and smart strategy to enhance bone regeneration with efficient vitamin D3 delivery through sterosome technology.

The spontaneous healing of critical-sized bone defects is often limited, posing an increased risk of complications and suboptimal outcomes. Osteogenesis, a complex process central to bone formation, relies significantly on the pivotal role of osteoblasts. Despite the well-established osteogenic properties of vitamin D3 (VD3), its lipophilic nature confines administration to oral or muscle injection routes. Therefore, a strategic therapeutic approach involves designing a multifunctional carrier to enhance efficacy, potentially incorporating it into the delivery system. Here, we introduce an innovative sterosome-based delivery system, utilizing palmitic acid (PA) and VD3, aimed at promoting osteogenic differentiation and facilitating post-defect bone regeneration. The delivery system exhibited robust physical characteristics, including excellent stability, loading efficiency, sustained drug release and high cellular uptake efficiency. Furthermore, comprehensive investigations demonstrated outstanding biocompatibility and osteogenic potential in both 2D and 3D in vitro settings. A critical-sized calvarial defect model in mice recapitulated the notable osteogenic effects of the sterosomes in vivo. Collectively, our research proposes a clinically applicable strategy for bone healing, leveraging PA/VD3 sterosomes as an efficient carrier to deliver VD3 and enhance bone regenerative effects.

Biochemical changes in lumbar facet joint and disc degeneration by T2* mapping.

BACKGROUND: To investigate the biochemical changes in lumbar facet joint (LFJ) and intervertebral disc (IVD) with different degenerative grade by T2* mapping. METHODS: Sixty-eight patients with low back pain (study group) and 20 volunteers (control group) underwent standard MRI protocols and axial T2* mapping. Morphological evaluation of LFJ and IVD were performed on T2-weighted imaging according to Weishaupt and Pfirrmann grading system, respectively. T2* values of LFJ and of AF (anterior annulus fibrosus), NP (nucleus pulposus), and PF (posterior annulus fibrosus) in IVD were measured. Kruskal-Wallis test and Wilcoxon rank-sum test were used to compare T2* values of subjects with different degenerative grade. RESULTS: The mean T2* value of grade 0 LFJ (21.68[17.77,26.13]) was higher than those of grade I (18.42[15.68,21.8], p < 0.001), grade II (18.98[15.56,22.76], p = 0.011) and grade III (18.38[16.05,25.07], p = 0.575) LFJ in study group, and a moderate correlation was observed between T2* value and LFJ grade (rho=-0.304, p < 0.001) in control group. In the analysis of IVD, a moderate correlation was observed between AF T2* value and IVD grade (rho=-0.323, p < 0.001), and between NP T2* value and IVD grade (rho=-0.328, p < 0.001), while no significant difference was observed between the T2* values of PF in IVD of different grade in study group. CONCLUSIONS: Downward trend of T2* values can be found in LFJ, AF and NP as the degenerative grade rised. But in elderly patients with low back pain, no change trend was found in LFJ due to increased fluid accumulation in the joint space.

A novel classification predicts prognosis and drug sensitivity in osteosarcoma based on alterations in gene sets.

Osteosarcoma is a cancer originating in the bone cells, specifically in the osteoblasts. Previous studies mainly focused on particular molecules but the whole pathway network. We comprehensively analyzed the enrichment score of each signal pathway and identified a novel classification by 20 machine learning algorithms. Furthermore, differences in tumor immune infiltration cells and drug sensitivity were compared in low and high groups. We identified a model consisting of four signaling pathways that predict the prognosis and the immune status of the tumor microenvironment and drug sensitivity in osteosarcoma patients. The novel classification may be used in clinical applications to predict prognosis and drug sensitivity.

The most influential articles on stem cells in intervertebral disc degeneration.

BACKGROUND: Stem cell-related studies have been increasingly conducted to facilitate the regeneration of degenerative discs. However, analyses of high-impact articles focused on this topic are rare. This study aimed to determine and summarize the most-cited studies examining stem cells in the context of intervertebral disc degeneration (IDD). METHODS: We searched the Web of Science (WoS) database for stem cell-related articles in IDD, and the 50 highest-cited papers were summarized. A correlation analysis was conducted to determine the relationship among WoS citations, Altmetric Attention Score (AAS), and Dimensions. RESULTS: The number of citations of the top 50 manuscripts ranged from 92 to 370. The top three countries were the United States (14), China (10), and Japan (9). Spine (12) was the most prevalent journal, and this was followed by Biomaterials (6). Bone marrow-derived stem cells were the most common subject (38), and they were followed by nucleus pulposus-derived stem cells (4) and annulus fibrosus-derived stem cells (4). Humans were the most studied species (31), and the next most studied were rabbits (9) and rats (7). There was a very high correlation between WoS and Dimension citations (p < 0.001, r = 0.937). CONCLUSIONS: For the first time, the highest impact articles examining stem cells in the context of IDD were assessed together. The current study provides a deepened understanding of historical studies focused on stem cells in IDD and is beneficial for future studies in this field.

CD206+ M2-like macrophages protect against intervertebral disc degeneration partially by targeting R-spondin-2.

OBJECTIVE: This study aimed to explore the specific function of M2 macrophages in intervertebral disc degeneration (IDD). METHODS: Intervertebral disc (IVD) samples from normal (n = 4) and IDD (n = 6) patients were collected, and the expression of M2-polarized macrophage marker, CD206, was investigated using immunohistochemical staining. Nucleus pulposus cells (NPCs) in a TNF-α environment were obtained, and a mouse caudal IVD puncture model was established. Mice with Rheb deletions, specifically in the myeloid lineage, were generated and subjected to surgery-induced IDD. IDD-induced damage and cell apoptosis were measured using histological scoring, X-ray imaging, immunohistochemical staining, and TdT-mediated dUTP nick end labeling (TUNEL) assay. Finally, mice and NPCs were treated with R-spondin-2 (Rspo2) or anti-Rspo2 to investigate the role of Rspo2 in IDD. RESULTS: Accumulation of CD206 in human and mouse IDD tissues was detected. Rheb deletion in the myeloid lineage (RheBcKO) increased the number of CD206+ M2-like macrophages (mean difference 18.6% [15.7-21.6%], P < 0.001), decreased cell apoptosis (mean difference -15.6% [-8.9 to 22.2%], P = 0.001) and attenuated the IDD process in the mouse IDD model. NPCs treated with Rspo2 displayed increased extracellular matrix catabolism and apoptosis; co-culture with a conditioned medium derived from RheBcKO mice inhibited these changes. Anti-Rspo2 treatment in the mouse caudal IVD puncture model exerted protective effects against IDD. CONCLUSIONS: Promoting CD206+ M2-like macrophages could reduce Rspo2 secretion, thereby alleviating experimental IDD. Rheb deletion may help M2-polarized macrophages accumulate and attenuate experimental IDD partially by inhibiting Rspo2 production. Hence, M2-polarized macrophages and Rspo2 may serve as therapeutic targets for IDD.

LINC00891 Attenuates the Proliferation and Metastasis of Osteosarcoma Cells via miR-27a-3p/TET1 Axis.

Objective: There is currently no adequate treatment for osteosarcoma, a bone malignancy that poses a serious threat to adolescents and children. The dysregulation of long noncoding RNAs is associated with many cancers, including osteosarcoma. LINC00891 expression is aberrant in endometrial cancer, lung cancer, and thyroid cancer, and likely regulate the malignant behavior of cancer. However, the potential function and mechanisms of LINC00891 in osteosarcoma progression remain unclear. Materials and Methods: LINC00891, miR-27a-3p, and TET1 mRNA expression in osteosarcoma cells were analyzed using quantitative reverse transcription-polymerase chain reaction. CCK-8 and Transwell experiments were performed on osteosarcoma cells to investigate proliferation, migration, and invasion, respectively. Ten-eleven translocation 1 (TET1) protein was analyzed using western blotting. Luciferase experiment was performed to investigate the interactions between LINC00891 with miR-27a-3p, and miR-27a-3p with TET1. Results: LINC00891 expression was dramatically decreased in the five osteosarcoma cell lines examined, particularly in 143B and SaoS-2 cells. LINC00891 overexpression due to plasmid transfection sharply blocked the proliferation, migration, and invasion of osteosarcoma cells. Dual-luciferase reporter experiments found that LINC00891 sponges miR-27a-3p, and LINC00891 overexpression sharply decreases miR-27a-3p expression. Transfection with miR-27a-3p mimic accelerated the malignant behaviors in LINC00891 overexpressed-osteosarcoma cells. Moreover, TET1 was a novel targeted-gene of miR-27a-3p. TET1 protein was significantly impeded, whereas LINC00891 overexpression elevated TET1 mRNA and protein in osteosarcoma cells. MiR-27a-3p overexpression inhibited TET1 mRNA and protein in osteosarcoma cells. Conclusions: Our study verified that LINC00891 attenuates the proliferation and metastasis of osteosarcoma cells via the miR-27a-3p/TET1 axis. This study clarifies a new mechanism and therapeutic target for the development of osteosarcoma.

Four Decades of Foot and Ankle Research Activity: A Scientometric study of Subspecialty Foot and Ankle Journals.

Objectives: To evaluate foot and ankle documents using scientometric methods and provide insight into global research activities. Methods: This scientometric study was conducted at the Department of Spine Surgery, Ganzhou People's Hospital, China. Documents on foot and ankle from 1980 to 2019 were retrieved from the Scopus database. The number of documents, year of publication, journal, country, institution, author, h-index, and top-cited documents were analyzed. Results: In total, 11313 documents were retrieved. The annual research output on foot and ankle showed a dramatic increase over the past four decades, especially in the past decade (p = 0.000). Foot & Ankle International published the biggest number of documents (44.48%). The United States contributed more than half (52.17%) of the global production, followed by the United Kingdom (11.39%), and Germany (3.62%). The United States had the highest h-index (109). The Hospital for Special Surgery (1.87%) ranked first in terms of productivity, followed by Union Memorial Hospital (1.37%), and Duke University Medical Center (1.24%). The most productive author was Myerson MS (1.25%), followed by Schon LC (0.77%), and Hyer CF (0.74%). Conclusion: Research on foot and ankle has thrived rapidly over the past four decades, particularly in the last decade. The United States contributes the most to the quantity and quality of foot and ankle documents.

lncRNA MEG3 Promotes PDK4/GSK-3ß/ß-Catenin Axis in MEFs by Targeting miR-532-5p.

Studies reported the positive and negative osteogenic effects of MEG3 in mesenchymal stem cells (MSCs). This study aims at clarifying the osteogenic potential of MEG3 and the underlying mechanism. Bone morphogenetic protein 9- (BMP9-) transfected MSCs were recruited as an osteogenic model in vitro, and ectopic bone formation were used in vivo to explore the effect of MEG3 on osteogenesis. We found that overexpression of MEG3 facilitated BMP9-induced osteogenic markers, ALP activities, and matrix mineralization. However, knockdown of MEG3 attenuated BMP9-induced osteogenic markers. MEG3 increased the phosphorylation of GSK-3ß and the protein level of ß-catenin. Pyruvate dehydrogenase kinase 4 (PDK4) can also combine with GSK-3ß and increase the latter phosphorylation. Moreover, MEG3 increased the mRNA level of PDK4. The ceRNA analysis showed that MEG3 may regulate the expression of PDK4 via microRNA 532-5p (miR-532-5p). The MEG3-enhanced GSK-3ß/ß-catenin axis can be attenuated by miR-532-5p, and miR-532-5p inhibitor partly rescued endogenous PDK4 and MEG3-mediated expression of PDK4. MEG3 may potentiate PDK4 and GSK-3ß/ß-catenin by inhibiting miR-532-5p.

Citation analysis of the most influential publications on whiplash injury: A STROBE-compliant study.

Whiplash injury is a common diagnosis and causes substantial economic burden. Numerous papers have been published to provide new insights into whiplash injury. However, so far there has not been a comprehensive analysis of the most influential publications on whiplash injury. This study aimed to determine the 100 most cited publications on whiplash injury and analyze their characteristics. A keyword search was conducted using the Web of Science database. The top 100 cited publications relevant to whiplash injury were gathered. The main characteristics including title, year of publication, citation, authorship, journal, country, institution, and topic were generated. The number of citations of the top 100 cited publications ranged from 82 to 777. Fifteen countries contributed the top 100 publications. Australia had the largest number of publications (26), followed by the United States (21), and Canada (12). The majority of the publications were from Europe (40) and North America (33). A total of 19 institutions and 17 authors published more than one publication. The University of Queensland (16) and the author Sterling M (7) had the leading publication record. This is the first citation analysis to identify and characterize the highest impact researches on whiplash injury. The present analysis provides the most influential studies on whiplash injury, and reveals the leading journals, counties, institutions, and authors with special contributions in this filed. The list may serve as an archive of historical development of whiplash injury and a basis for further research.

MiR-702-5p ameliorates diabetic encephalopathy in db/db mice by regulating 12/15-LOX.

The purpose of this study was to investigate the effect of miR-702-5p on diabetic encephalopathy (DE) and the interaction of miR-702-5p/12/15-LOX in the central nervous system (CNS). In this study, db/db mice were used as DE animal model and HT22 cells were treated with high-glucose (HG). Based on the bioinformatics prediction of possible binding sites between miR-702-5p and 12/15-LOX, we found that the expression of miR-702-5p was significantly down-regulated while 12/15-LOX up-regulated in vivo and in vitro, and the expression changes were inversely correlated. In vivo, diabetic mice with cognitive dysfunction and hippocampal neuronal damage had a concomitant increase in amyloid precursor protein (APP), amyloid beta(Aß), tau, BAX protein expressions; by contrast, Bcl-2 protein expression was significantly decreased. Overexpression of miR-702-5p significantly reduced the histopathological damage of the hippocampus, improved the learning and memory function of db/db mice, down-regulated 12/15-LOX, APP, Aß, tau, BAX protein expressions significantly and up-regulated the expression of Bcl-2. In vitro, miR-702-5p mimic reversed the decline in cell viability and the increase in cell apoptosis induced by HG. Simultaneously, reduced 12/15-LOX, APP, Aß, BAX protein expressions, and increased Bcl-2 protein expression were detected in the miR-702-5p mimic group. Moreover, combined administration of miR-702-5p mimic and 12/15-LOX overexpression lentivirus significantly reversed the protective effect of up-regulation of miR-702-5p. In conclusion, miR-702-5p has a neuroprotective effect on DE, and this effect was achieved by inhibiting 12/15-LOX. However, miR-702-5p had an endogenous regulatory effect on 12/15-LOX rather than a direct targeting relationship.

LINC01140 regulates osteosarcoma proliferation and invasion by targeting the miR-139-5p/HOXA9 axis.

Osteosarcoma is one of the commonest metastatic tumor in children and teenagers, and has a hopeless, prognosis. Long non-coding RNA (lncRNA) acts momentous roles as a regulator on the proliferation and migration of cancer. Here, we performed GEO database analysis and qPCR to identify differentially expressed lncRNAs in osteosarcoma cells. Knockdown of lncRNA LINC01140 was used to detect the effect of LINC01140 on the proliferation, invasion, and epithelial-mesenchymal transition (EMT) of osteosarcoma cells. Bioinformatics analysis and qPCR identified the LINC01140/miR-139-5p/Homeobox A9 (HOXA9) regulatory axis. RNA immunoprecipitation assay, Dual-luciferase assay, and rescue experiments confirmed the interaction of LINC01140/miR-139-5p/HOXA9 in osteosarcoma. LINC01140 was overexpressed in osteosarcoma and knocking down LINC01140 restrained the proliferation and invasion of osteosarcoma cells and EMT. In Saos2 and MG63 cells, LINC01140 sponged miR-139-5p, and a miR-139-5p inhibitor overturned the suppression of LINC01140 knockdown on the proliferation and migration of osteosarcoma cells. Moreover, miR-139-5p depressed the invasion, proliferation, and EMT of osteosarcoma cells via targeting HOXA9. Our results indicate that LINC01140 downregulation inhibits the invasion, proliferation, and EMT in osteosarcoma cells through targeting the miR-139-5p/HOXA9 axis. Therefore, LINC01140 is a potential therapeutic target for osteosarcoma.

SIAH1 promotes senescence and apoptosis of nucleus pulposus cells to exacerbate disc degeneration through ubiquitinating XIAP.

BACKGROUND: Using clinical samples and database analysis, this study aimed to investigate the signaling pathways that mediated degeneration of nucleus pulposus cells (NPCs) in patients with intervertebral disc degeneration (IDD). METHODS: NPCs were extracted from enucleated intervertebral discs of IDD patients, and the senescence, apoptosis, and extracellular matrix (ECM) synthesis levels of cells were confirmed by ß-galactosidase (SA-ß-gal), Western blot, and measurement of superoxide dismutase (SOD), malondialdehyde (MDA) and glutathione (GSH). The microarray expression profile of GSE56081 was downloaded to screen differentially expressed mRNAs. CO-IP and ubiquitination assays were used to determine the targeted regulation of XIAP by SIAH1. Methylation of mRNA was verified by m6A RIP and actinomycin D assays. RESULTS: NPCs extracted from the enucleated intervertebral discs of IDD patients exhibited marked senescence, apoptosis, elevated levels of inflammation, and decreased ECM synthesis. The expression of SIAH1 was significantly elevated in NPCs of IDD patients, and SIAH1 knockdown reversed senescence, apoptosis, elevated levels of inflammation, and decreased ECM synthesis in NPCs of IDD patients. CO-IP and ubiquitination assays indicated that SIAH1 can target and ubiquitinate XIAP. Besides, MeRIP-qPCR and actinomycin experiments showed that METTL3-mediated m6A can methylate SIAH1 mRNA. CONCLUSION: In IDD patients, SIAH1 can target and ubiquitinate XIAP, thereby mediating senescence, apoptosis, increased inflammation, and decreased ECM synthesis of NPCs, while METTL3-mediated m6A can methylate SIAH1 mRNA, producing harmful effects.

miR-204-5p is sponged by TUG1 to aggravate neuron damage induced by focal cerebral ischemia and reperfusion injury through upregulating COX2.

Studies have reported that miR-204-5p is involved in multiple biological processes. However, little is known about the expression and mechanism of miR-204-5p in cerebral ischemia and reperfusion injury. This study found that miR-204-5p expression was significantly downregulated in the blood of patients with ischemic stroke, MCAO/R rat brains, and OGD/R neurons. Overexpression of miR-204-5p markedly reduced infarct volume and neurological impairment and alleviated the inflammatory response in vivo. miR-204-5p promoted neuronal viability and reduced apoptotic cells in vitro. Mechanically, miR-204-5p was negatively regulated by the expression lncRNA TUG1 upstream and down-regulated COX2 expression downstream. Therefore, the TUG1/miR-204-5p/COX2 axis was involved in ischemia and reperfusion-induced neuronal damage. This finding may provide a novel strategy for the treatment of cerebral ischemia and reperfusion injury.

miR-637 Inhibits Osteogenic Differentiation of Human Intervertebral Disc Cartilage Endplate Stem Cells by Targeting WNT5A.

Background: Degenerative disk disease (DDD) remains the leading incentive of severe lumbago. DDD is mainly caused by degeneration of cartilage endplate (CEP). Cartilage endplate stem cells (CESCs) are essential in chondrogenesis and osteogenesis of CEP. This study investigated the mechanism of miR-637 inhibiting osteogenic differentiation of human CESC by regulating WNT5A.Methods: The degenerative CEP (N = 10) and non-degenerative CEP (N = 6) were obtained from patients undergoing disk fusion surgery. CESCs were examined for surface stem cell markers, alkaline phosphatase (ALP) levels, osteogenic differentiation, osteogenic genes (Runx2, COL1), and chondrogenic gene (COL2). The miR-637 expression in CESCs was detected. The targeting relationship of miR-637 and WNT5A was confirmed. After miR-637 overexpression/WNT5A down-regulation, the action of miR-637/WNT5A on osteogenic differentiation of CESCs was evaluated. After simultaneous overexpression of miR-637/WNT5A, the effect of miR-637 on osteogenic differentiation of CESCs was assessed.Results: miR-637 was down-expressed in degenerative CESCs (D-CESCs), and miR-637 overexpression inhibited the osteogenic differentiation of D-CESCs, while inhibition of miR-637 promoted the osteogenic differentiation ability of D-CESCs. miR-637 targeted WNT5A and down-regulation of WNT5A inhibited the osteogenic differentiation of D-CESCs. Up-regulated WNT5A partially annulled the inhibitory action of miR-637 overexpression on osteogenic differentiation of D-CESCs.Conclusion: miR-637 inhibited osteogenic differentiation of D-CESCs via targeting WNT5A.

The role of aquaporin 4 (AQP4) in spinal cord injury.

Aquaporin-4 (AQP-4) is an aquaporin composed of six helical transmembrane domains and two highly conserved ASN-pro-ALA (NPA) motifs. It is strongly expressed in rodent and human spinal cord tissues and plays a key role in the pathological process after SCI. After SCI, edema, glial scarring, and inflammation can accelerate the progression of injury and lead to deterioration of function. Many studies have reported that AQP-4 plays an important role in SCI. In particular, it plays an important role in secondary pathological processes (spinal cord edema, glial scar formation, and inflammatory response) after SCI. Loss of AQP-4 has been associated with reduced spinal edema and improved prognosis after SCI in mice. In addition, downregulation of AQP-4 reduces glial scar formation and the inflammatory response after SCI. There is a consensus from numerous studies that AQP-4 may be a potential target for SCI therapy, which guides the ongoing investigation for molecular therapy of SCI. Here, we review the structure of AQP-4, its expression in normal and damaged spinal cord, and its role in SCI, as well as discuss the theoretical basis for the treatment of SCI.

Efficacy and safety of tolperisone versus baclofen among Chinese patients with spasticity associated with spinal cord injury: a non-randomized retrospective study.

There are many medications available to treat spasticity, but the tolerability of medications is the main issue for choosing the best treatment. The objectives of this study were to compare the efficacy and adverse effects of tolperisone compared to baclofen among patients with spasticity associated with spinal cord injury. Patients received baclofen plus physical therapy (BAF+PT, n=135) or tolperisone plus physical therapy (TOL+PT, n=116), or physical therapy alone (PT, n=180). The modified Ashworth scale score, the modified Medical Research Council score, the Barthel Index score, and the Disability Assessment scale score were improved (P<0.05 for all) in all the patients at the end of 6 weeks compared to before interventions. After 6 weeks, the overall coefficient of efficacy of the intervention(s) in the BAF+PT, TOL+PT, and PT groups were 1.15, 0.45, and 0.05, respectively. The patients of the BAF+PT group reported asthenia, drowsiness, and sleepiness and those of the TOL+PT group reported dyspepsia and epigastric pain as adverse effects. When comparing drug interventions to physical therapy alone, both baclofen plus physical therapy and tolperisone plus physical therapy played a significant role in the improvement of daily activities of patients. Nonetheless, baclofen plus physical therapy was tentatively effective. Tolperisone plus physical therapy was slightly effective. In addition, baclofen caused adverse effects related to the sedative manifestation (Level of Evidence: III; Technical Efficacy Stage: 4).

LncRNA LINC00324 is upregulated in intervertebral disk degeneration and upregulates FasL in nucleus pulposus cells.

BACKGROUND: It has been reported that long intergenic non-protein-coding RNA 324 (LINC00324) promotes liver cancer by upregulating Fas ligand (FasL), which is a major player in intervertebral disk degeneration (IDD), indicating the involvement of LINC00324 in IDD. This study was carried out to investigate the interaction between LINC00324 and FasL in IDD. METHODS: Plasma samples were collected from both IDD (n = 60) and healthy controls (n = 60). The expression of LINC00324 and FasL in plasma was determined by RT-qPCR. The interactions between LINC00324 and FasL in nucleus pulposus (NP) cells were analyzed by overexpression experiments. RESULTS: LINC00324 and FasL were upregulated in IDD patients, and they were positively correlated. After treatment, the expression levels of FasL and LINC00324 were significantly decreased. In NP cells, overexpression of LINC00324 increased the expression of FasL at both mRNA and protein levels, while overexpression of FasL did not affect the expression of LINC00324. CONCLUSION: LINC00324 may upregulate FasL in IDD to promote disease progression.