•A new method for preparing high-quality single-cell nuclear suspension of frozen spinal cord issue.•Tissue beating method breaks the colloidal scar and facilitates full grinding.•Two density ...gradient centrifugation were performed to remove impurities.
Recently, microRNAs (miRNAs) have been identified as key regulators of the proliferation and differentiation of mesenchymal stem cells (MSCs). Our previous in vivo study and other in vitro studies ...using miRNA microarrays suggest that miR-424 is involved in the regulation of bone formation. However, the role and mechanism of miR-424 in bone formation still remain unknown. Here, we identified that the downregulation of miR-424 mediates bone formation under oxidative stress, and we explored its underlying mechanism. Our results showed that miR-424 was significantly downregulated in an anterior lumbar interbody fusion model of pigs and in a cell model of oxidative stress induced by H
O
. The overexpression of miR-424 inhibited proliferation and osteogenic differentiation shown by a decrease in alkaline phosphatase (ALP) activity, mineralization and osteogenic markers, including RUNX2 and ALP, whereas the knockdown of miR-424 led to the opposite results. Moreover, miR-424 exerts its effects by targeting FGF2. Furthermore, we found that FOXO1 suppressed miR-424 expression and bound to its promoter region. FOXO1 enhanced proliferation and osteogenic differentiation in part through the miR-424/FGF2 pathway. These results indicated that FOXO1-suppressed miR-424 regulates both the proliferation and osteogenic differentiation of MSCs via targeting FGF2, suggesting that miR-424 might be a potential novel therapeutic strategy for promoting bone formation.
•This review summarizes the important roles of hypoxic stress and oxidative stress and their regulation in the bone repair process.•This review presents the classic anti-hypoxic stress and ...anti-oxidative stress bone materials reported in previous studies in separate categories.•This review proposes the concept of novel smart anti-stress bone repair materials based on epigenetic regulation.
Tissue engineering aims to offer large-scale replacement of damaged organs using implants with the combination of cells, growth factors and scaffolds. However, the intra/peri‑implant region is exposed to severe hypoxic stress and oxidative stress during the early stage of implantation with bone graft materials, which endangers the survival, proliferation and differentiation of seed cells within the implants as well as the host cells surrounding the implants. If the bone graft material could spontaneously and intelligently regulate the hypoxic stress and oxidative stress to a moderate level, it will facilitate the vascularization of the implants and the rapid regeneration of the bone tissue. In this review, we will first introduce the signaling pathways of cellular response under hypoxic stress and oxidative stress, then present the classical material designs and examples in response to hypoxic stress and oxidative stress. And finally, we will address the important role of epigenetic mechanisms in the regulation of hypoxic stress and oxidative stress and describe the potential applications and prospective smart bone graft materials based on novel epigenetic factors against hypoxic stress and oxidative stress in bone repair. The main content of this review is summarized in the following graphical abstract.
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Whether modified laminoplasty is better than conventional laminoplasty is unclear. Thus, a meta-analysis comparing the outcomes of preserving or repairing the posterior deep extensor insertion to C2 ...in laminoplasty was conducted for patients with multilevel cervical spondylotic myelopathy (MCSM).
Several electronic databases were chosen to search for relevant studies. The primary indices included preoperative and postoperative Japanese Orthopaedic Association (JOA) scores, JOA recovery rate, muscle atrophy rate, preoperative and postoperative range of motion (ROM), ROM decrease rate, and incidence of axial pain. Results are expressed as odds ratios with 95% confidence intervals for the dichotomous outcomes and mean differences for continuous outcomes.
Eight studies involving 763 patients were included in this study. The postoperative cervical ROM was significantly higher in the modified group (P = 0.01, MD = 3.0 0.66, 5.35), as was the cervical posterior muscle volume (P = 0.02, MD = 28.28 4.42, 52.3) and the operation time (MD = −45.04, 95% CI −49.79, −40.29; P < 0.01). The incidence of axial symptoms in the modified group was lower than that in the conventional group (P < 0.01, OR 0.28 0.17, 0.46), as was the rate of decrease of cervical ROM (P = 0.004, MD = −6.72 −11.25, 2.19). There was no significant difference (P > 0.05) between the groups in blood loss, preoperative and postoperative JOA score, or JOA recovery rate.
Modified laminoplasty had shorter operation times, a lower incidence of axial pain, a higher cervical ROM, and a lower atrophy rate compared with conventional laminoplasty. The clinical and radiologic results of modified laminoplasty have been partly superior to those of conventional laminoplasty to date.
It is well known that aging induces a progressive decline in the proliferation and neural differentiation of radial glial cells (RGCs) in the hippocampal dentate gyrus (DG). The function of ...miR-144/451 is to activate stress-regulated molecular gene expression switches for cell proliferation and differentiation. We found that the miR-144/451 expression in the hippocampus was significantly reduced in aged mice compared to adult mice. Furthermore, the proliferation and neural differentiation of RGCs in the mouse hippocampal DG was decreased by miR-144/451 knockout (miR-144/451–/–). Antioxidant agents, superoxide dismutases (SODs) and catalase, and the expression of melatonin’s receptor in the hippocampus were decreased in the miR-144/451–/– mice. In addition, the (protein kinase B) AKT/(glycogen synthase kinase 3β) GSK3β/(catenin beta-1) β-catenin signaling pathway was weakly activated in the hippocampus of miR-144/451–/– mice, which was related to brain neurogenesis. Melatonin treatment improved the expression of miR-144/451 and antioxidant enzymes and activated the AKT/GSK3β/β-catenin pathway in the hippocampus of miR-144/451–/– mice. When the AKT pathway was inhibited by LY294002, the neurogenerative and antioxidant effects of melatonin were significantly limited in the hippocampus of miR-144/451–/– mice. In brief, our results indicated that miR-144/451 plays crucial roles in the proliferation and neural differentiation of RGCs via the regulation of the antioxidant and AKT/GSK3β/β-catenin pathways.
Animal experimental study.
To establish a slowly progressive and reproducible intervertebral disc degeneration model and determine the performance of T1ρ magnetic resonance imaging in the evaluation ...of disc degeneration.
Recently, one of the hotspots of research efforts was related to management of early stage of disc degeneration. To our knowledge, a functional animal model that mimics ischemic and slowly progressive disc degeneration of humans does not exist.
The subchondral bone adjacent to the lumbar intervertebral discs (from L3-L4 to L6-L7) of 8 rhesus monkeys was randomly injected with 4 mL of Pingyangmycin (PYM) solution (1.5 mg/mL, PYM), or 4 mL of phosphate buffered saline (Vehicle control), or exteriorized but not injected anything (Sham), respectively. The degenerative process was investigated by using radiography and T1ρ magnetic resonance imaging at 1, 3, 6, 9, 12, and 15 months postoperatively. Histological scoring, immunohistochemistry, and real-time polymerase chain reaction were performed at 15 months.
The mean T1ρ values of nucleus pulposus and annulus fibrosus in the PYM group significantly decreased after 3 and 6 months, respectively, followed by slow decrease, and the histological score was significantly higher at 15 months, compared with the control groups. The results of molecular analysis revealed a significant increase matrix metalloprotease-3, A disintegrin and metalloproteinase with thrombospondin motifs -5, tumor necrosis factor α, interleukin-1β, interleukin-6 expressions, and marked reduction in aggrecan, type II collagen, von Willebrand factor expressions at the messenger RNA levels in the PYM group. Spearman correlation analysis of Pfirrmann grades showed significantly inverse correlation with T1ρ values of nucleus pulposus and annulus fibrosus (r = -0.634, -0.617, respectively, P < 0.01).
Injection of PYM into the subchondral bone adjacent to the lumbar intervertebral discs of rhesus monkeys can results in mild, slowly progressive disc degeneration, which mimics the onset of human disc degeneration, and the T1ρ magnetic resonance imaging is suited for evaluating intervertebral disc degeneration.
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•The ultimate way to build organoid tissue for regeneration is to enable the cells to take the initiative to build suitable functions.•Mechanical irritation should be a necessary factor in the ...construction of musculoskeletal organoids for regeneration.•The construction of the organoids for regeneration should be stimulated by the suitable environment, such as light stimulation for the retinal organoid, sound wave stimulation for cochlear organoid, etc.
It has always been a dream to construct tissues and even organs for transplantation to replace those with defects caused by diseases or injuries. Tissue engineering is another milestone in the developmental history of life science after cellular and molecular bioscience. Nevertheless, despite decades of rapid development, tissue-engineered biomaterials have not been widely used clinically. Biomaterials constructed by physical and chemical methods have lots of difficulty in precisely mimicking the macroscopic and microscopic structures of human tissues. The ultimate way to build organoid tissue for regeneration is to enable the cells to take the initiative and build suitable functions. Based on the thoughts of tissue engineering, organoid technology holds great potential as a research tool for a wide range of fields, including developmental biology, disease pathology, cell biology, precision medicine, and drug toxicity and efficacy testing. This technology also holds tremendous potential for regenerative medicine, as organoids present the possibility for autologous and allogeneic cell therapy through the replacement of damaged or diseased tissues with organoid-propagated tissue or stem cell populations. In this review work, we briefly outlook the development history of organoid technology, summarize the current bottlenecks and the underlying reasons, and propose the unified term “function-oriented design in tissue engineering”, a new topic that may provide a solution to overcome these bottlenecks.
Hydrogel injection has been recently proposed as a novel therapy for disc degenerative diseases, with the potential to restore the spine motion and the intervertebral disc height. However, it remains ...unknown whether the new technique could also maintain the shock absorbing property of the treated intervertebral disc. In this study, 18 porcine lumbar bone-disc-bone specimens were collected and randomly divided into three groups: the normal with intact intervertebral discs, the mimic for the injection of disulfide cross-linked hyaluronan hydrogels following discectomy, and the control disc with discectomy only. In the static compression test, specimens in the mimic group exhibited displacements similar to those in the normal discs, whereas the control group showed a significantly larger displacement range in the first two steps (P<0.05). With the frequency increasing, all specimens generally displayed an increasing storage modulus, decreasing loss modulus, and tanδ. At any frequency point, the control group exhibited the largest value in all the three parameters among three groups while the normal group was the lowest, with the mimic group being mostly close to the normal group. Therefore, the hydrogel injection into the intervertebral discs greatly restored their shock absorbing function, suggesting that the technique could serve as an effective approach to maintaining biomechanical properties of the degenerative intervertebral disc.
N6-methyladenosine (m6A) has been implicated in the progression of several diseases, and the role of epigenetic regulation in immunity is emerging, particularly for RNA m6A modification. However, it ...is unclear how m6A-related genes affect the immune microenvironment of ligamentum flavum hyperplasia (LFH). Therefore, we aimed to investigate the effect of m6A modification on the LFH immune microenvironment.
The GSE113212 dataset was downloaded from the Gene Expression Omnibus (GEO) database. We systematically analyzed m6A regulators in eight patient samples and the corresponding clinical information of the samples. Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG), Gene Set Enrichment Analysis (GSEA) and protein-protein interactions (PPIs) were used to explore the correlation of m6A clusters with the immune microenvironment in LFH. A least absolute shrinkage and selection operator (Lasso) regression was then used to further explore the m6A prognostic signature in LFH. The relative abundance of immune cell types was quantified using a single-sample Gene Set Enrichment Analysis (ssGSEA) algorithm. We explored the relationship between hub genes and small molecule drug sensitivity by clustering hub gene-based samples. In addition, Real-Time quantitative PCR (RT-qPCR) as well as western blotting (WB) were used to validate the gene expression of the differentially expressed genes.
A total of 1259 differentially expressed genes were identified, of which 471 were upregulated and 788 were downregulated. A total of three genes showed significant differences (METTL16, PCIF1, and FTO). According to the enrichment analysis, immune factors may play a key role in LFH. ssGSEA was used to cluster the immune infiltration score, construct the hub gene diagnosis model, and screen a total of 6 LFH immune-related prediction model genes. The predictive diagnostic model of LFH was further constructed, revealing that METTL16, PCIF1, FTO and ALKBH5 had superior diagnostic efficiency. RT-qPCR results showed that 6 genes (METTL16, PCIF1, POSTN, TNNC1, MMP1 and ACTA1; P < 0.05) exhibited expression consistent with the results of the bioinformatics analysis of the mRNA microarray. Up-regulated METTL16, PCIF1, and ALKBH5 levels in LFH were validated by western blotting.
Diversity and complexity of LFH's immune microenvironment are influenced by M6A modification, and our study provides strong evidence for predicting the diagnosis and prognosis of LFH.
Electroencephalography (EEG) microstates are used to study cognitive processes and brain disease-related changes. However, dysfunctional patterns of microstate dynamics in Alzheimer's disease (AD) ...remain uncertain. To investigate microstate changes in AD using EEG and assess their association with cognitive function and pathological changes in cerebrospinal fluid (CSF). We enrolled 56 patients with AD and 38 age- and sex-matched healthy controls (HC). All participants underwent various neuropsychological assessments and resting-state EEG recordings. Patients with AD also underwent CSF examinations to assess biomarkers related to the disease. Stepwise regression was used to analyze the relationship between changes in microstate patterns and CSF biomarkers. Receiver operating characteristics analysis was used to assess the potential of these microstate patterns as diagnostic predictors for AD. Compared with HC, patients with AD exhibited longer durations of microstates C and D, along with a decreased occurrence of microstate B. These microstate pattern changes were associated with Stroop Color Word Test and Activities of Daily Living scale scores (all P < 0.05). Mean duration, occurrences of microstate B, and mean occurrence were correlated with CSF Aβ
levels, while duration of microstate C was correlated with CSF Aβ
levels in AD (all P < 0.05). EEG microstates are used to predict AD classification with moderate accuracy. Changes in EEG microstate patterns in patients with AD correlate with cognition and disease severity, relate to Aβ deposition, and may be useful predictors for disease classification.
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