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Background: After spinal cord injury (SCI), destructive immune cell subsets are dominant in the local microenvironment, which are the important mechanism of injury. Studies have shown that inflammasomes play an important role in the inflammation following SCI, and apoptosis-associated speck-like protein containing a card (ASC) is the adaptor protein shared by inflammasomes. Therefore, we speculated that inhibiting ASC may improve the local microenvironment of injured spinal cord. Here, CRID3, a blocker of ASC oligomerization, was used to study its effect on the local microenvironment and the possible role in neuroprotection following SCI., Methods: Murine SCI model was created using an Infinite Horizon impactor at T9 vertebral level with a force of 50 kdynes and CRID3 (50 mg/kg) was intraperitoneally injected following injury. ASC and its downstream molecules in inflammasome signaling pathway were measured by western blot. The immune cell subsets were detected by immunohistofluorescence (IHF) and flow cytometry (FCM). The spinal cord fibrosis area, neuron survival, myelin preservation, and functional recovery were assessed., Results: Following SCI, CRID3 administration inhibited inflammasome-related ASC and caspase-1, IL-1β, and IL-18 activation, which consequently suppressed M1 microglia, Th1 and Th1Th17 differentiation, and increased M2 microglia and Th2 differentiation. Accordingly, the improved histology and behavior have also been found., Conclusions: CRID3 may ameliorate murine SCI by inhibiting inflammasome activation, reducing proinflammatory factor production, restoring immune cell subset balance, and improving local immune microenvironment, and early administration may be a promising therapeutic strategy for SCI.

Interferon-induced transmembrane protein 1 (IFITM1) is a member of the IFITM family that is associated with some acute-phase cytokine-stimulated response. Recently, we demonstrated that IFITM1 was significantly upregulated in the injured spinal cords at the mRNA level. However, its expression and cellular localization at the protein level is still unclear. Here, a rat model of spinal cord injury (SCI) was performed to investigate the spatio-temporal expression of IFITM1 after SCI. IFITM1 mRNA and protein were assessed by quantitative reverse transcription-PCR and western blot, respectively. IHC was used to identify its cellular localization. We revealed that IFITM1 could be found in sham-opened spinal cords and gradually increased after SCI. It reached peak at 7 and 14 days postinjury (dpi) and still maintained at a relatively higher level at 28 dpi. IHC showed that IFITM1 expressed in GFAP + and APC + cells in sham-opened spinal cords. After SCI, in addition to the above-mentioned cells, it could also be found in CD45 + and CD68 + cells, and its expression in CD45 + , CD68 + , and GFAP + cells was increased significantly. These results demonstrate that IFITM1 is mainly expressed in astrocytes and oligodendroglia in normal spinal cords, and could rapidly increase in infiltrated leukocytes, activated microglia, and astrocytes after SCI.

Conditioned medium obtained from B104 neuroblastoma cells (B104CM) has been used widely for inducing oligodendrocyte progenitor cells (OPCs) from neural precursor cells (NPCs). Our previous studies have demonstrated that E16 rat spinal cord-derived NPCs could be induced to differentiate into OPCs using a combination of B104CM and basic fibroblast growth factor (bFGF). Here we report the development of a more efficient and reliable approach to generate large quantities of highly purified OPCs from spinal cord-derived NPCs using a combination of platelet derived growth factor (PDGF) and bFGF. We demonstrated that, after the two factors application, over 90% cells displayed typical bipolar or tripolar morphology and expressed markers for OPCs including A2B5 (90.36 +/- 4.59%), NG2 (93.63 +/- 3.37%) and platelet derived growth factor alpha receptor (PDGFR; 90.35 +/- 1.95%). Our results indicated that the PDGF/bFGF combination is more efficient in generating OPCs than the B104CM/bFGF. And it is a more potent combination of factors in promoting proliferation of OPCs.

The biological effects of interleukin (IL)-1 are mediated by two distinct receptors, the p80 or type I (IL-1RI) and p68 or type II (IL-1RII) receptors. Because IL-1RII has a short, 29-amino acid cytoplasmic domain which may not be sufficient for signaling, there is considerable evidence indicating that IL-1 may signal exclusively through the IL-1RI receptor. Here, we report the expression, distribution, and cellular localization of the IL-1RI protein in the adult rat spinal cord in vivo and embryonic spinal cord in vitro. We found that IL-1RI was expressed in both the gray and white matter throughout the entire length of the spinal cord and was localized in neurons of the anterior horn, astrocytes, oligodendrocytes, and central canal ependymal cells. Interestingly, resting microglia were negative for IL-1RI. In primary cultures obtained from the embryonic day (E) 15 rats, IL-1RI was expressed in neurons, astrocytes, and oligodendrocytes as well as microglia. These data provide both in vivo and in vitro evidence that neurons and glial cells express the IL-1RI proteins. The differential expression of IL-1RI in the developing, but not mature, microglia may indicate the difference of these cells in response to IL-1 stimuli during maturation. The distribution and cellular localization of IL-1RI proteins in the spinal cord provide a molecular basis for understanding the reciprocal interaction between the immune and the central nervous systems.

Background: Inflammatory reactions induced by spinal cord injury (SCI) are essential for recovery after SCI. Atractylenolide III (ATL‐III) is a natural monomeric herbal bioactive compound that is mainly derived in Atractylodes macrocephala Koidz and has anti‐inflammatory and neuroprotective effects. Objective: Here, we speculated that ATL‐III may ameliorate SCI by modulating microglial/macrophage polarization. In the present research, we focused on investigating the role of ATL‐III on SCI in rats and explored the potential mechanism. Methods: The protective and anti‐inflammatory effects of ATL‐III on neuronal cells were examined in a rat SCI model and lipopolysaccharide (LPS)‐stimulated BV2 microglial line. The spinal cord lesion area, myelin integrity, and surviving neurons were assessed by specific staining. Locomotor function was evaluated by the Basso, Beattie, and Bresnahan (BBB) scale, grid walk test, and footprint test. The activation and polarization of microglia/macrophages were assessed by immunohistofluorescence and flow cytometry. The expression of corresponding inflammatory factors from M1/M2 and the activation of relevant signaling pathways were assessed by Western blotting. Results: ATL‐III effectively improved histological and functional recovery in SCI rats. Furthermore, ATL‐III promoted the transformation of M1 into M2 and attenuated the activation of microglia/macrophages, further suppressing the expression of corresponding inflammatory mediators. This effect may be partly mediated by inhibition of neuroinflammation through the NF‐κB, JNK MAPK, p38 MAPK, and Akt pathways. Conclusion: This study reveals a novel effect of ATL‐III in the regulation of microglial/macrophage polarization and provides initial evidence that ATL‐III has potential therapeutic benefits in SCI rats. [ABSTRACT FROM AUTHOR]

Inflammation is one of the key injury factors for spinal cord injury (SCI). Exosomes (Exos) derived from M2 macrophages have been shown to inhibit inflammation and be beneficial in SCI animal models. However, lacking targetability restricts their application prospects. Considering that chemokine receptors increase dramatically after SCI, viral macrophage inflammatory protein II (vMIP-II) is a broad-spectrum chemokine receptor binding peptide, and lysosomal associated membrane protein 2b (Lamp2b) is the key membrane component of Exos, we speculated that vMIP-II-Lamp2b gene-modified M2 macrophage-derived Exos (vMIP-II-Lamp2b-M2-Exo) not only have anti-inflammatory properties, but also can target the injured area by vMIP-II. In this study, using a murine contusive SCI model, we revealed that vMIP-II-Lamp2b-M2-Exo could target the chemokine receptors which highly expressed in the injured spinal cords, inhibit some key chemokine receptor signaling pathways (such as MAPK and Akt), further inhibit proinflammatory factors (such as IL-1β, IL-6, IL-17, IL-18, TNF-α, and iNOS), and promote anti-inflammatory factors (such as IL-4 and Arg1) productions, and the transformation of microglia/macrophages from M1 into M2. Moreover, the improved histological and functional recoveries were also found. Collectively, our results suggest that vMIP-II-Lamp2b-M2-Exo may provide neuroprotection by targeting the injured spinal cord, inhibiting some chemokine signals, reducing proinflammatory factor production and modulating microglia/macrophage polarization. [Display omitted] • vMIP-II-Lamp2b-M2-Exo can target the injured spinal cord by vMIP-II. • vMIP-II-Lamp2b-M2-Exo can inhibit MAPK and AKT signaling pathways. • vMIP-II-Lamp2b-M2-Exo can reduce proinflammatory factor production. • vMIP-II-Lamp2b-M2-Exo can inhibit M1 microglia/macrophage polarization. • The early administration of vMIP-II-Lamp2b-M2-Exo is a promising strategy for SCI. [ABSTRACT FROM AUTHOR]

MicroRNAs (miRNAs) are involved in a series of pathology of spinal cord injury (SCI). Although, locally expressed miRNAs have advantages in studying the pathological mechanism, they cannot be used as biomarkers. The "free circulation" miRNAs can be used as biomarkers, but they have low concentration and poor stability in body fluids. Exosomal miRNAs in body fluids have many advantages comparing with free miRNAs. Therefore, we hypothesized that the specific miRNAs in the central nervous system might be transported to the peripheral circulation and concentrated in exosomes after injury. Using next-generation sequencing, miRNA profiles in serum exosomes of sham and subactue SCI rats were analyzed. The results showed that SCI can lead to changes of serum exosomal miRNAs. These changed miRNAs and their associated signaling pathways may explain the pathological mechanism of suacute SCI. More importantly, we found some valuable serum exosomal miRNAs for diagnosis and prognosis of SCI. • Serum exosomes of sham and subactue SCI rats were isolated and identified. • Serum exosomal microRNA transcriptome profiling in subacute spinal cord injured rats is investigated. • The changed miRNAs and their associated signaling pathways have been systematically determined. • Our results will provide a basis for the pathological mechanism, diagnosis and prognosis of SCI. [ABSTRACT FROM AUTHOR]

• The results of RNA-seq confirmed the anti-inflammatory and anti-apoptotic effects of morroniside on injured SC tissues. • Some key signal pathways and molecules may be involved in the SC protection of morroniside. • The data provided the basis for further studying the mechanism of the protective effects of morroniside on SCI. We have previously reported that morroniside promoted motor activity after spinal cord injury (SCI) in rats. However, the mechanism by which morroniside induces recovery of injured spinal cord (SC) remains unknown. In the current study, RNA sequencing (RNA-seq) was employed to evaluate changes of gene expressions at the transcriptional level of the injured spinal cords in morroniside-administrated rats. Principal component analysis, analysis of enriched Gene Ontology (GO), enrichment analyses Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway, and other bioinformatics analyses were executed to distinguish differentially expressed genes (DEGs). The results of RNA-seq confirmed the anti-inflammatory and anti-apoptotic effects of morroniside on injured SC tissues, and provided the basis for additional research of the mechanisms involving the protective effects of morroniside on SCI. [ABSTRACT FROM AUTHOR]