Spinal cord injury (SCI) is lead to locomotor impairment because of neurological damage after following trauma. Quercetin (Que) has been confirmed to have a neuro-protective effect during nerve damage processes. The purpose of this study was to determine the roles of Que in functional recovery, cavity formation, astrocyte activation, and nerve regeneration following SCI. Sprague-Dawley rats were randomly divided into three groups: Sham group, SCI group, and Que + SCI group. A rat model of SCI was made at T10 using the modified Allen's method. In the Que + SCI group, animals underwent laminectomy and were then intraperitoneally injected with 20 mg/kg Que for 7 days. Locomotor function was determined with the Basso, Beattie, Bresnahan (BBB) scores at 1, 3, 5, and 7 days post-injury. At 7 days post-injury, somatosensory evoked potentials (SEPs) and motor evoked potentials (MEPs) were recorded. Hematoxylin-Eosin (HE) staining was used to investigate cavity formation. Astrocyte activation was assayed by immunohistochemistry staining with an antibody specific for glial fibrillary acidic protein (GFAP), as well as the expression of GFAP and S100β. Axons were stained using an antibody specific for neurofilament 200 (NF200) and 5-hydroxytryptamine (5-HT). In addition, the protein level of BDNF, p-JNK2, and p-STAT3 was detected using Western blot. Que promoted locomotor function and electrophysiological recovery, reduced cavity formation, contributed to astrocyte activation and axonal regeneration after acute SCI. Moreover, Que up-regulated the expression of BDNF, but reduced p-JNK2 and p-STAT3 expression after acute SCI. Taken together, Que promoted locomotor and electrophysiological functional recovery, astrocyte activation and axonal regeneration after acute SCI, possibly through BDNF and JAK2/STAT3 signaling pathways.

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Introduction: Quercetin was recently reported to help protect against osteoarthritis (OA) progression, but the molecular mechanism for that protective affect remains unclear. Methods: Here, OA model rats were intraperitoneally injected with quercetin, and the severity of cartilage damage in the rats was evaluated by H&E, Safranin O, and Toluidine blue, as well as by using the Osteoarthritis Research Society International (OARSI) Scoring System. Additionally, rat chondrocytes were treated with quercetin and then stimulated with IL-1β. The levels of pro-inflammatory cytokines (IL-1β, IL-18, and TNF-α) were detected by ELISA.Cell apoptosis was evaluated by flow cytometry and Hoechst staining. ROS levels were measured using a DCFH-DA probe. Protein expression was evaluated by Western blotting, immunohistochemical staining, and immunofluorescence. Results: Our data showed that quercetin attenuated the degeneration and erosion of articular cartilage, suppressed inflammation and apoptosis, and downregulated the levels of IRAK1, NLRP3, and caspase-3 expression. In vitro data showed that overexpression of NLRP3 could reverse the suppressive effect of quercetin on IL-1β-induced rat chondrocyte injuries. Importantly, rescue experiments confirmed that quercetin inhibited IL-1β-induced rat chondrocyte injuries in vitro by suppressing the IRAK1/NLRP3 signaling pathway. Conclusion:Our study indicated that quercetin inhibits IL-1β-induced inflammation and cartilage degradation by suppressing the IRAK1/NLRP3 signaling pathway.

Background: The therapeutic effects of adipose-derived mesenchymal stem cell (ADSC) transplantation have been demonstrated in several models of central nervous system (CNS) injury and are thought to involve the modulation of the inflammatory response. However, the exact underlying molecular mechanism is poorly understood. Activation of the Jagged1/Notch signaling pathway is thought to involve inflammatory and gliotic events in the CNS. Here, we elucidated the effect of ADSC transplantation on the inflammatory reaction after spinal cord injury (SCI) and the potential mechanism mediated by Jagged1/Notch signaling pathway suppression. Methods: To evaluate the therapeutic effects of ADSC treatment and the potential inhibitory effects of ADSCs on Notch signaling, mice were subjected to contusion SCI, and GFP-labeled ADSCs were injected into the lesion site immediately after the injury. Locomotor function, spinal cord tissue morphology, and the levels of Notch-related proteins and proinflammatory transcripts were compared between groups. To validate the hypothesis that the therapeutic effects of ADSCs are partly due to Notch1 signaling inhibition, a Jagged1 small interfering RNA (siRNA) was injected into the spinal cord to knock down Jagged1/Notch signaling. Neuronal staining and analyses of microglia/macrophage activation and signaling pathways were performed.

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Background and aim: Traumatic spinal cord injury (SCI) is a common and devastating central nervous disease, the treatment of which faces many challenges to the medical community and society as a whole. Treatment measures based on oxidative stress of spinal motor neurons during SCI are expected to help restore biological functions of neurons under injury conditions. However, to date, there are no systematic reports regarding oxidative stress on spinal motor neuron injury. Our aim is to better understand and explain the influences and mechanisms of oxidative stress on spinal motor neurons during SCI. Methods:We first exposed VSC4.1 motor neurons to hydrogen peroxide (H 2 O 2 ) and evaluated the effects on cell viability, morphology, cycling, and apoptosis, with an emphasis on the changes to the cytoskeleton and the effect of N-acetyl-Lcysteine (NAC) on these changes. Then, we investigated the effects of NAC on these cytoskeletal changes in vitro and in vivo. Results:We found that H 2 O 2 caused severe damage to the normal cytoskeleton, leading to a reduction in neurite length and number, rearrangement of the actin cytoskeleton, and disorder of the microtubules and neurofilaments in VSC4.1. Importantly, NAC attenuated the oxidative damage of spinal motor neurons in vitro and in vivo, promoting the recovery of hindlimb motor ability in mice with SCI at the early stage of injury.

Background Improved chondrogenic differentiation of mesenchymal stem cells (MSCs) by genetic regulation is a potential method for regenerating articular cartilage. MiR-127-5p has been reported to promote cartilage differentiation of rat bone marrow MSCs (rMSCs); however, the regulatory mechanisms underlying hypoxia-stimulated chondrogenic differentiation remain unknown. Methods rMSCs were induced to undergo chondrogenic differentiation under normoxic or hypoxic conditions. Expression of lncRNA DNM3OS, miR-127-5p, and GREM2 was detected by quantitative real-time PCR. Proteoglycans were detected by Alcian blue staining. Western blot assays were performed to examine the relative levels of GREM2 and chondrogenic differentiation related proteins. Luciferase reporter assays were performed to assess the association among DNM3OS, miR-127-5p, and GREM2. Results MiR-127-5p levels were upregulated, while DNM3OS and GREM2 levels were downregulated in rMSCs induced to undergo chondrogenic differentiation, and those changes were attenuated by hypoxic conditions (1% O2). Further in vitro experiments revealed that downregulation of miR-127-5p reduced the production of proteoglycans and expression of chondrogenic differentiation markers (COL1A1, COL2A1, SOX9, and ACAN) and osteo/chondrogenic markers (BMP-2, p-SMAD1/2). MiR-127-5p overexpression produced the opposite results in rMSCs induced to undergo chondrogenic differentiation under hypoxic conditions. GREM2 was found to be a direct target of miR-127-5p, which was suppressed in rMSCs undergoing chondrogenic differentiation. Moreover, DNM3OS could directly bind to miR-127-5p and inhibit chondrogenic differentiation of rMSCs via regulating GREM2. Conclusions Our study revealed a novel molecular pathway (DNM3OS/miR-127-5p/GREM2) that may be involved in hypoxic chondrogenic differentiation.

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