番红O-固绿软骨染色液

Objectives To unravel the heterogeneity and function of microenvironmental neutrophils during intervertebral disc degeneration (IDD). Methods Single-cell RNA sequencing (scRNA-seq) was utilized to dissect the cellular landscape of neutrophils in intervertebral disc (IVD) tissues and their crosstalk with nucleus pulposus cells (NPCs). The expression levels of macrophage migration inhibitory factor (MIF) and ACKR3 in IVD tissues were detected. The MIF/ACKR3 axis was identified and its effects on IDD were investigated in vitro and in vivo . Results We sequenced here 71520 single cells from 5 control and 9 degenerated IVD samples using scRNA-seq. We identified a unique cluster of neutrophils abundant in degenerated IVD tissues that highly expressed MIF and was functionally enriched in extracellular matrix organization (ECMO). Cell-to-cell communication analyses showed that this ECMO-neutrophil subpopulation was closely interacted with an effector NPCs subtype, which displayed high expression of ACKR3. Further analyses revealed that MIF was positively correlated with ACKR3 and functioned via directly binding to ACKR3 on effector NPCs. MIF inhibition attenuated degenerative changes of NPCs and extracellular matrix, which could be partially reversed by ACKR3 overexpression. Clinically, a significant correlation of high MIF/ACKR3 expression with advanced IDD grade was observed. Furthermore, we also found a positive association between MIF + ECMO-neutrophil counts and ACKR3 + effector NPCs density as well as higher expression of the MIF/ACKR3 signaling in areas where these two cell types were neighbors. Conclusions These data suggest that ECMO-neutrophil promotes IDD progression by their communication with NPCs via the MIF/ACKR3 axis, which may shed light on therapeutic strategies.

Background Intervertebral disc (IVD) degeneration (IDD) represents a predominant origin of low back pain and disability, yet current therapeutic interventions remain suboptimal. Emerging evidence highlights autophagy activation as a therapeutic strategy against IDD. This study investigates the mechanistic interplay between N6-methyladenosine (m6A) modifications and autophagy dysregulation in IDD pathogenesis. Methods Bioinformatics analysis identified ring finger protein 41 ( RNF41 ) as a key autophagy-IDD intersection gene. Functional validation utilized tert-butyl hydroperoxide (TBHP)-treated human nucleus pulposus (NP) cells to assess RNF41’s effects on senescence (CDKN2A), autophagy (LC3-II/p62), apoptosis (TUNEL), inflammation (IL-18/IL-1β), and extracellular matrix (ECM) homeostasis (aggrecan/MMP). Key m6A regulators modulating autophagy were screened via correlation analysis. In vivo validation employed adeno-associated virus (AAV)-mediated methyltransferase-like 3 (METTL3)/RNF41 delivery in puncture-induced IDD rat models. Results RNF41 expression was downregulated in human IVD tissues. Overexpression of RNF41 mitigated TBHP-induced senescence, apoptosis, activated AMPK/mTOR-mediated autophagy, suppressed inflammation, and restored ECM balance. The autophagy inhibitor chloroquine (CQ) abolished the protective effects of RNF41 overexpression on degenerative NP cells. Mechanistically, METTL3/YTHDC1 co-regulation in degenerative NP cells mediated m6A hypermethylation of RNF41 mRNA, shortening its half-life via YTHDC1-dependent decay. Intradiscal METTL3-silencing AAV attenuated puncture-induced disc loss and histopathological degeneration, whereas RNF41-silencing AVV exacerbated ECM disruption and annular disorganization. Conclusion METTL3/YTHDC1-mediated m6A modification drives IDD progression by silencing RNF41 , thereby impairing autophagy and ECM integrity. Targeting this axis offers a clinically actionable strategy to delay disc degeneration, particularly in patients with early-stage IDD. This evidence establishes RNF41’s role as a theragnostic biomarker and therapeutic targe, enabling precision-guided interventional approaches.

Background: Intervertebral disc degeneration (IDD) significantly contributes to low back pain (LBP), yet effective treatment options are scarce. BSHXF, a classical traditional Chinese medicine formula, demonstrates dual pharmacological actions: tonifying kidneys, strengthening bones, activating blood circulation, and resolving stasis. It has been widely used in IDD management. Given its potential, combining BSHXF with miRNA regulation and stem cell therapy may enhance therapeutic outcomes by targeting molecular and cellular pathways underlying IDD pathogenesis.Aim of the study: IDD is recognized as one of the primary causes of low back pain, yet effective therapeutic interventions for this condition remain limited. This study explores the role of BSHXF drug-containing serum combined with adipose-derived stem cells (ADSCs) in slowing IDD progression via the miR-199a-3p/TGF-β/Smad signaling pathway. By comprehensively investigating the synergistic effects of this combination therapy, we aim to propose a novel multi-target strategy that addresses the complex pathogenesis of IDD.Materials and Methods: This study employed a combination of in vivo and in vitro models. An IDD model was induced in rat caudal intervertebral discs through needle puncture, while an oxidative stress-induced ADSCs injury model was created in vitro using tert-butyl hydroperoxide (T-BHP). Cell viability was measured with the CCK-8 assay. Cell cycle distribution and mitochondrial reactive oxygen species (ROS) levels were assessed using flow cytometry. Cellular senescence was assessed using SA-β-galactosidase staining. Lactate dehydrogenase (LDH) activity was quantified to evaluate cellular damage. Differentiation into nucleus pulposus-like cells was assessed using immunofluorescence double staining for CD73 and COL2A1. ELISA was used to measure inflammatory cytokines (TNF-α, IL-1β, IL-4, IL-10) in cell supernatants. miR-199a-3p expression was determined using RT-qPCR. Western blotting was employed to quantify COL2A1, SOX9, and ACAN protein levels, reflecting nucleus pulposus-like differentiation and extracellular matrix (ECM) synthesis capacity. Western blotting was employed to assess pathway activity by analyzing the protein expressions of TGF-β1, Smad2, Smad3, and their phosphorylated forms, P-Smad2 and P-Smad3. In vivo experiments assessed histopathological degeneration through hematoxylin-eosin (HE) and Safranin O-Fast Green staining. Immunohistochemistry (IHC) analyzed COL1A1 and COL2A1 expression levels. RT-qPCR quantified miR-199a-3p expression. Western blotting was employed to assess the expression levels of TGF-β1, Smad2, Smad3, P-Smad2, and P-Smad3 for pathway regulation evaluation.Results: Our experimental results demonstrated that serum containing BSHXF significantly alleviated T-BHP-induced oxidative stress, improved the cellular microenvironment, promoted ADSCs proliferation, and decelerated cellular senescence. Further mechanistic analysis revealed that BSHXF significantly activated the TGF-β/Smad signaling pathway, driving the differentiation of ADSCs into nucleus pulposus-like cells and restoring normal cell cycle progression. Overexpression of miR-199a-3p inhibited the TGF-β/Smad pathway, leading to ECM degradation and elevated expression of inflammatory factors (TNF-α, IL-1β). In contrast, BSHXF restored TGF-β/Smad pathway activity by downregulating miR-199a-3p expression. In vivo experiments demonstrated that miR-199a-3p overexpression exacerbated IDD, characterized by reduced COL2A1 expression, elevated COL1A1 levels, and increased disc fibrosis. BSHXF intervention markedly attenuated IDD progression by downregulating miR-199a-3p expression, reducing disc fibrosis, and effectively restoring collagen expression.Conclusion: BSHXF activated the TGF-β/Smad pathway to promote the differentiation of ADSCs into nucleus pulposus-like cells. It exerted protective effects by alleviating oxidative stress damage, improving the microenvironment, delaying senescence, and enhancing cellular functions. This study is the first to reveal that miR-199a-3p overexpression exacerbates intervertebral disc fibrosis and degeneration. BSHXF restored TGF-β/Smad pathway activity by downregulating miR-199a-3p expression, thereby improving disc structure and function. This integrated approach offers a novel multi-target intervention strategy for IDD, demonstrating significant therapeutic potential.

BackgroundNucleus pulposus cell (NPC) senescence in intervertebral disc (IVD) tissue is the major pathological cause during intervertebral disc degeneration (IDD). N6-methyladenosine (m6A) methylation and gut microbiota play important roles in the progression of IDD. This study investigated whether methyltransferase-like 3 (METTL3) regulates TLR2 m6A modification and gut microbiota to influence NPC senescence.MethodsAn IDD rat model was established by lumbar intervertebral disc puncture and NPCs were challenged with IL-1β to mimic IVD injury. IDD rats and IL-1β-exposed NPCs were treated with METTL3-interfering lentivirus and the TLR2 agonist Pam3CSK4. Compositional changes in the rat gut microbiota were analyzed and fecal microbiota transplantation procedures were used. NPC senescence, cell cycle and the expression of senescence-associated secretory phenotype (SASP) factors were assessed. The m6A enrichment of TLR2 and the binding of IGF2BP1 to TLR2 mRNA were examined.ResultsMETTL3 and TLR2 were highly expressed in IDD rats. METTL3 silencing attenuated senescent phenotypes and reduced secretion of SASP factors. Pam3CSK4 reversed the beneficial effects of METTL3 silencing on NPC senescence and IVD injury. METTL3 stabilized TLR2 mRNA in an IGF2BP1-dependent manner. METTL3 silencing restored specific gut microbiota levels in IDD rats, which was further reversed by administration of Pam3CSK4. Fecal microbiota from METTL3 silenced IDD rats altered the pathological phenotypes of IDD rats.ConclusionsThese results demonstrate the beneficial effects of METTL3 silencing on NPC senescence and amelioration of IVD injury, involving modulation of TLR2 m6A modification and gut microbiota. These findings support METTL3 silencing as a potential therapeutic target for IDD.

Astragalus polysaccharides (APS) are a crucial bioactive component known for their various pharmacological properties. Abnormal O‐linked β‐N‐acetylglucosamine modification (O‐GlcNAcylation) is noted in cases of intervertebral disc degeneration (IVDD). Nonetheless, it remains uncertain whether APS regulates the process of O‐GlcNAcylation associated with IVDD. We employed molecular docking, cycloheximide chase assay, immunohistochemistry, and immunoprecipitation to investigate APS‐mediated OGT/O‐GlcNAcylation regulation of Nrf2. The effects of APS and its role in promoting the O‐GlcNAcylation of Nrf2 in IVDD through both in vivo and in vitro studies are discussed. In vitro investigations demonstrated an increase in the levels of OGT and O‐GlcNAcylation in nucleus pulposus cells (NPCs) following exposure to tert‐butyl hydroperoxide (TBHP). APS further facilitated improvements in OGT expression and O‐GlcNAcylation processes, restoring the viability of NPCs inhibited by TBHP and promoting the synthesis of collagen II and aggrecan, while reducing apoptosis. Mechanistically, APS promotes the expression of OGT by targeting it. Furthermore, O‐GlcNAcylation mediated by OGT stabilizes the expression of Nrf2 via the ubiquitin‐proteasome pathway. Rescue experiments indicated that the disruption of either OGT or Nrf2 expression negated the protective role of APS on NPCs. Ultimately, both in vitro and in vivo studies indicated that APS significantly enhanced OGT expression and O‐GlcNAcylation, which subsequently improved Nrf2 expression and contributed to the alleviation of IVDD in rats. APS promotes O‐GlcNAcylation through OGT, thereby stabilizing the expression of Nrf2, which in turn contributes to the improvement of IVDD.

Background Bone fracture healing is a multifaceted process that involves different stages and intercellular interactions. In this study, we aimed to investigate the effect of Taohong Siwu decoction (TSD) on bone fracture healing and the underlying mechanisms. Methods First, a mouse model of femur fracture was constructed, and TSD intervention was administered for durations of 7, 14, and 21 days. Following this, immunofluorescence (IF) was employed to evaluate the expression of CD90 (a marker for mesenchymal stem cells [MSCs]), endomucin (Emcn), and CD31. We also treated MSCs with normal serum and 10% TSD-containing serum to investigate the effects of TSD. Molecular docking was applied to verify the binding of active compounds in TSD to pVon Hippel–Lindau (VHL). Additionally, MSCs were treated with paeoniflorin and 2-methoxyestradiol (2-ME2) to explore the effects of paeoniflorin. Subsequently, mouse aortic endothelial cells were extracted and identified. Furthermore, normally cultured MSCs were cocultured with endothelial cells. MSCs were exposed to control serum, 10% TSD-containing serum, and a combination of 10% TSD-containing serum with 2-ME2. Finally, we administered a combination of 2-ME2 over 21 days to evaluate its effects on the fractured mice. Results TSD significantly influenced H-type angiogenesis during the healing process of fractured mice. Compared to the sham group, the model group exhibited lower levels of Emcn, CD90, hypoxia-inducible factor-1 alpha (HIF-1α), and vascular endothelial growth factor (VEGF), while there was an increase in pVHL expression. After 7, 14, and 21 days of TSD intervention, the levels of Emcn, CD90, HIF-1α, VEGF, and pVHL gradually increased, whereas HIF-1α expression decreased. In vitro experiments revealed that TSD enhanced the proliferation and migration of MSCs while inhibiting the ubiquitination of pVHL/HIF-1α. Moreover, ferulic acid, amygdalin, hydroxysafflor yellow A, and paeoniflorin demonstrated a strong affinity for binding with pVHL. Notably, paeoniflorin promoted the proliferation and migration of MSCs through the pVHL/HIF-1α pathway to promote angiogenesis. Furthermore, TSD was found to enhance endothelial angiogenesis in MSCs. In summary, TSD affects H-type angiogenesis and MSCs homing during the healing process of fractured mice through the HIF-1α axis. Conclusions TSD regulated MSC-mediated H-type angiogenesis to accelerate fracture healing through VHL/HIF-1α ubiquitination.

We aim to explore the key metabolic components and underlying mechanisms of the Bushen Huoxue Formula (BH) in treating Osteoarthritis (OA). The mouse knee OA model was constructed using the destabilization of the medial meniscus method. OA mice were orally administered the BH. Mouse cartilage damage was assessed. High performance liquid chromatography-tandem mass spectrometry (HPLC-MS), network pharmacology analysis and molecular docking were employed to analyze the serum metabolite components and target protein of BH. After lipopolysaccharide (LPS) treatment, different concentrations of β-Estradiol 3-acetate were added to primary chondrocytes. Flow cytometry was utilized for detecting cell apoptosis. The Ubiquitin-Specific Protease 13 (USP13)/Toll-like Receptor 4 (TLR4)/Myeloid Differentiation Primary Response Protein 88 (MYD88)/NF-κB pathway and the TLR4 ubiquitination levels were assessed using immunological quantification and biochemical methods. Relative to normal mice, OA mice exhibited decreased knee joint cartilage thickness and increased inflammatory damage. BH treatment reversed these effects. Furthermore, BH enhanced TLR4 ubiquitination. Estradiol acetate was identified as the metabolic component of BH that alleviates OA. Estradiol acetate and its subtype molecule β-Estradiol 3-acetate could bind to the USP13 protein. The β-Estradiol 3-acetate concentration-dependently decreased the elevated levels of USP13, TLR4, MYD88, p-p65/p65 in chondrocytes induced by LPS, while increasing the TLR4 ubiquitination. β-Estradiol 3-acetate reversed LPS-induced chondrocyte apoptosis and elevation of inflammatory factors. Moreover, USP13 overexpression abolished the protective effects of BH and β-Estradiol 3-acetate against LPS-induced chondrocytes. In Conclusion, the BH metabolite β-Estradiol 3-acetate promotes TLR4 ubiquitination to relieve inflammation and apoptosis in OA chondrocytes by inhibiting USP13.

Objective This study explores LncRNA TM1-3P effects on the proliferation, apoptosis, and inflammatory response of fibroblasts in osteoarthritis (OA) and its underlying mechanism. Methods Bioinformatics was performed to analyze OA disease-related genes, miRNA profiles, and function. The targeted regulation of LncRNA TM1-3P and miR-144-3p, ONECUT2 and miR-144-3p were analyzed by dual luciferase reporter gene assay, RNA Binding Protein Immunoprecipitation (RIP), and RNA pull down. Histopathological morphology of the knee joint was observed by hematoxylin–eosin (HE) and Annona Red O/Fast Green. The expressions of mRNAs and proteins were detected by RT-qPCR, Western blot, and immunohistochemistry. Unpaired T test was used between groups, and the one-way analysis of variance of repeated measurement data was applied for multi-group comparison, following Tukey's post-test. Results ONECUT2 and Smurf2 genes were significantly elevated in the osteoarthritis group compared with the normal group ( P < 0.001, P < 0.001). Expressions of ONECUT2 and LncRNA TM1-3P were increased, and expression of miR-144-3p was decreased in interleukin (IL)-1β-induced human fibroblast synovial cells (hFSCs) (mRNA: 1.06 ± 0.24 vs. 3.29 ± 0.73, proteins: 0.22 ± 0.03 vs. 0.46 ± 0.22, 1.23 ± 0.22 vs. 3.76 ± 0.73, 1.06 ± 0.25 vs. 0.37 ± 0.13, P < 0.01, P < 0.001, P < 0.01, P < 0.05). Overexpression of miR-144-3p down-regulated the ONECUT2 expression, reduced cell proliferation, promoted apoptosis in hFSCs induced by IL-1β (mRNA: 0.89 ± 0.14 vs. 0.15 ± 0.01, P < 0.05; proteins: 0.46 ± 0.01 vs. 0.23 ± 0.01, P < 0.001; CCK8: 1.88 ± 0.07 vs. 1.65 ± 0.07; P < 0.05; EDU: 55.82 ± 1.44 vs 40.57 ± 2.24, P < 0.05; apoptosis: 10.57 ± 0.79 vs 16.36 ± 0.35, P < 0.0001). Overexpression of LncRNA TM1-3P up-regulated the expression of ONECUT2, promoted cell proliferation, and inhibited apoptosis (mRNA: 0.9 ± 0.09 vs 1.94 ± 0.12, P < 0.05; proteins: 0.61 ± 0.05 vs 0.76 ± 0.03, P > 0.05; CCK8: 2.07 ± 0.05 vs 2.47 ± 0.06; P < 0.01; EDU: 52.67 ± 1.17 vs 60.06 ± 3.24, P < 0.05; apoptosis: 10.57 ± 0.79 vs 16.36 ± 0.35, P < 0.001), which were reversed by the overexpression of miR-144-3p treatment (mRNA: 1.82 ± 0.07 vs 0.31 ± 0.07, P < 0.0001; proteins: 0.74 ± 0.02 vs 0.35 ± 0.01, P < 0.01; CCK8: 2.41 ± 0.01 vs 1.67 ± 0.02; P < 0.0001; EDU: 66.85 ± 2.86 vs 44.68 ± 1.97, P < 0.0001; apoptosis: 7.19 ± 0.19 vs 13.36 ± 0.53, P < 0.0001). Silencing LncRNA TM1-3P attenuated the injury of knee joint tissue, down-regulated the expression of ONECUT2, Smurf2, IL-1β, IL-6, TNF-α, and improved the expression of Rap1 in rats (0.71 ± 0.04 vs 0.48 ± 0.02, 0.68 ± 0.06 vs 0.36 ± 0.02, 0.74 ± 0.03 vs 0.49 ± 0.04, 0.78 ± 0.01 vs 0.54 ± 0.03, 0.68 ± 0.02 vs 0.4 ± 0.04, 0.24 ± 0.01 vs 0.4 ± 0.03, P < 0.05, P < 0.05, P < 0.05, P < 0.01, P < 0.01, P < 0.05). Conclusion LncRNA TM1-3P improved inflammation and damage of knee joints in OA rats through miR-144-3p/ONECUT2 axis, providing a new theoretical basis for gene therapy of OA.

Osteoporotic osteoarthritis (OPOA) is a specific phenotype of OA with high incidence and severe cartilage damage. This study aimed to explore the protective efficacy of PEMF on the progression of OPOA and observed the effects of PEMF on PPARγ, autophagy- and apoptosis-related proteins in OPOA rats. Rats were randomly divided into three groups: control group, OPOA group, and PEMF group (n = 6). One week after surgery, the rats in PEMF group were subjected to PEMF (3.82 mT, 8 Hz, 40 min/day and 5 day/week) for 12 weeks. Results showed that PEMF retarded cartilage degeneration and bone loss, as evidenced by pathological staining image, decreased MMP-13 expression and increased bone mineral density. PEMF inhibited the serum levels of inflammatory cytokines, and the expressions of caspase-3 and caspase-8, while upregulated the expression of PPARγ. Moreover, PEMF significantly improved the autophagy disorders, represented by decrease expressions of Beclin-1, P62, and LC3B. The research demonstrates that PEMF can effectively prevent cartilage and subchondral bone destruction in OPOA rats. The potential mechanism may be related to upregulation of PPARγ, inhibition of chondrocyte apoptosis and inflammation, and improvement of autophagy disorder. PEMF therapy thus shows promising application prospects in the treatment of postmenopausal OA.