The expression of bradykinin and its receptors in spinal cord ischemia-reperfusion injury rat model

Acute spinal cord injury serum biomarkers in human and rat: a scoping systematic review

STUDY DESIGN

Scoping systematic review.

OBJECTIVES

To summarize the available experimental clinical and animal studies for the identification of all CSF and serum-derived biochemical markers in human and rat SCI models.

SETTING

Tehran, Iran.

METHODS

In this scoping article, we systematically reviewed the electronic databases of PubMed, Scopus, WOS, and CENTRAL to retrieve current literature assessing the levels of different biomarkers in human and rat SCI models.

RESULTS

A total of 19,589 articles were retrieved and 6897 duplicated titles were removed. The remaining 12,692 studies were screened by their title/abstract and 12,636 were removed. The remaining 56 were considered for full-text assessment, and 11 papers did not meet the criteria, and finally, 45 studies were included. 26 studies were human observational studies comprising 1630 patients, and 19 articles studied SCI models in rats, including 832 rats. Upon reviewing the literature, we encountered a remarkable heterogeneity in terms of selected biomarkers, timing, and method of measurement, studied models, extent, and mechanism of injury as well as outcome assessment measures.

CONCLUSIONS

The specific expression and distribution patterns of biomarkers in relation to spinal cord injury (SCI) phases, and their varied concentrations over time, suggest that cerebrospinal fluid (CSF) and blood biomarkers are effective measures for assessing the severity of SCI.

Umbilical mesenchymal stem cell-derived exosomes promote spinal cord functional recovery through the miR-146b/TLR4 -mediated NF-κB p65 signaling pathway in rats

Spinal cord injury (SCI) is an incurable central nervous system impairment that lack of efficient treatment. Exosomes derived from mesenchymal stem cells (MSCs) are widely applied in disease treatment. This work aimed to determine the promising therapeutic effects of MSC-derived exosomal miRNA146b on SCI. A rat spinal cord injury (SCI) model and lipopolysaccharide (LPS)-induced PC12 cell model were established. Exosomes were extracted from human umbilical cord mesenchymal stem cells (hUCMSCs). The identification of exosomes was performed by using transmission electronic microscope (TEM) and nanoparticle tracking analysis (NTA). Hematoxylin and eosin (HE) staining and TUNEL assay were performed to assess tissue damage and apoptosis, respectively. ELISA was performed to detect levels of inflammatory cytokines. Cell viability was checked by cell counting kit 8 (CCK-8). Gene expression and protein levels were detected by qPCR and western blotting assay. The interaction between miR-146 b and Toll-like receptor 4 (TLR4) was assessed by luciferase reporter gene assay. The hUCMSC-derived exosomes could notably alleviate the spinal cord injury and cell apoptosis. The exosomal miR-146 b treatment suppressed the release of IL-1 β, IL-6, and TNFα. The miR-146 b suppressed the expression of TLR4, directly interact with the 3'-untranslated region (3'UTR) of TLR4, and inactivated the nuclear factor κB (NF-κB) signaling. The hUCMSCs-derived exosomal miR-146 b protects neurons from spinal cord injury through targeting the TLR4 and inactivating the NF-κB signaling. Our findings supported the application of hUCMSCs-derived exosomal miR-146 b for the protection of SCI.

Bradykinin receptor participates in doxorubicin-induced cardiotoxicity by modulating iNOS signal pathway

Doxorubicin (DOX), an effective and broad-spectrum anthracycline antibiotic, is widely used in the treatment of numerous malignancies. However, dose-dependent cardiotoxicity limits the clinical application of DOX, and the molecular mechanisms are still unknown. In this study, we used the BK receptor B1/B2 double-knockout (B1B2 -/- ) mice to observe the role of BK receptor in cardiotoxicity induced by DOX and the underlying mechanisms. DOX induced myocardial injury with increased serum levels of AST, CK, and LDH, upregulated tissue expression of bradykinin B1/B2 receptor, FABP4 and iNOS, and downregulated expression of eNOS. However, these altered releases of myocardial enzyme and the expression level of iNOS were significantly prevented in the B1B2-/- mice. We concluded that the activation of both B1 and B2 receptors of BK were involved in the DOX-induced acute myocardial injury, possibly mediated through iNOS signaling pathways.

Hypoxia-treated umbilical mesenchymal stem cell alleviates spinal cord ischemia-reperfusion injury in SCI by circular RNA circOXNAD1/ miR-29a-3p/ FOXO3a axis

Spinal cord ischemia reperfusion (SCIR) injury leads to spinal cord function injury, neural dysfunction and sometimes paralysis or even paraplegia, which severely impair the physical and mental health of individuals. Mesenchymal stem cells (MSCs) are a group of stem cells that have been widely studied for treatment of various diseases. This work aimed to study the therapeutic potential of hypoxia-induced exosomal circular RNA OXNAD1 from human umbilical cord mesenchymal stem cells (HucMSCs) against SCIR. We established an in vivo rat spinal cord injury (SCI) model and conducted treatment with exosomes that isolated from hypoxia-HucMSCs. Hypoxia-HucMSCs-derived exosomal circOXNAD1 alleviated the spinal cord tissue injury in SCI, improved limb motor function, decreased production of inflammatory factors including the IL-1 β, IL-6, and TNF-α. The in vitro hypoxia and reoxygenation (H/R) model demonstrated that Hypoxia-HucMSCs-derived exosomal circOXNAD1 improved neuron proliferation and alleviated apoptosis. Mechanistically, circOXNAD1 directly interact with miR-29a-3p and miR-29a-3p targets the 3'UTR of FOXO3a in neurons. Inhibition of miR-29a-3p and overexpression of FOXO3a reversed the effects of circOXNAD1 depletion in PC12 cell phenotypes. In conclusion, Hypoxia elevated the level circOXNAD1 in exosomes that derived from HuMSCs. The exosomal circOXNAD1 alleviated SCI through sponging miR-29a-3p and consequently elevated the FOXO3a expression. Our findings provided novel evidence for MSC-derived exosomal circOXNAD1in the treatment of SCI.

Bradykinin Activates the Bradykinin B2 Receptor to Ameliorate Neuronal Injury in a Rat Model of Spinal Cord Ischemia-Reperfusion Injury

Bradykinin and bradykinin B2 receptors (B2R) play important roles in both the peripheral and central nervous systems. The aim of this study was to explore the changes of bradykinin and B2R in spinal cord ischemic injury (SCII) and whether bradykinin treatment would improve the neurologic function of SCII rats. The rats were divided into the sham group, the SCII group, and three doses of bradykinin (50, 100, 150 μg/kg) groups. The neurologic function was assessed by the Basso, Beattie, and Bresnahan (BBB) score at -1, 1, 3, 5, and 7 days postsurgery. Bradykinin concentration in serum and IL-6, TNF-α, and MCP-1 levels in the spinal cord were detected by ELISA. The mRNA expressions of B2R, IL-6, TNF-α, MCP-1, COX-2, and iNOS in the spinal cord were determined by RT-PCR. The protein expressions of B2R, COX-2, iNOS, p65, and p-p65 were detected by Western blot. Immunohistochemical staining was used to examine B2R expression in the L4-6 segments of the spinal cord. Bradykinin levels in serum and B2R expression in the spinal cord were downregulated in SCII rats. Bradykinin treatment significantly improved the hind limb motor function of SCII rats and increased B2R expression, inhibiting COX-2, iNOS, and p-p65 expression in the spinal cord of SCII rats together with a decrease of the inflammatory mediators of IL-6, TNF-α, and MCP-1 levels. Bradykinin administration activated B2R in the spinal cord of SCII rats, which may improve hind limb locomotor recovery by regulating the NF-κB signaling pathway to inhibit the inflammatory response. These findings may provide a theoretical basis for the clinical application of bradykinin in SCII.

Degenerative Cervical Myelopathy: Insights into Its Pathobiology and Molecular Mechanisms

Degenerative cervical myelopathy (DCM), earlier referred to as cervical spondylotic myelopathy (CSM), is the most common and serious neurological disorder in the elderly population caused by chronic progressive compression or irritation of the spinal cord in the neck. The clinical features of DCM include localised neck pain and functional impairment of motor function in the arms, fingers and hands. If left untreated, this can lead to significant and permanent nerve damage including paralysis and death. Despite recent advancements in understanding the DCM pathology, prognosis remains poor and little is known about the molecular mechanisms underlying its pathogenesis. Moreover, there is scant evidence for the best treatment suitable for DCM patients. Decompressive surgery remains the most effective long-term treatment for this pathology, although the decision of when to perform such a procedure remains challenging. Given the fact that the aged population in the world is continuously increasing, DCM is posing a formidable challenge that needs urgent attention. Here, in this comprehensive review, we discuss the current knowledge of DCM pathology, including epidemiology, diagnosis, natural history, pathophysiology, risk factors, molecular features and treatment options. In addition to describing different scoring and classification systems used by clinicians in diagnosing DCM, we also highlight how advanced imaging techniques are being used to study the disease process. Last but not the least, we discuss several molecular underpinnings of DCM aetiology, including the cells involved and the pathways and molecules that are hallmarks of this disease.