Exosomes are extracellular vesicles formed by various donor cells that regulate gene expression and cellular function in recipient cells. Exosomes derived from mesenchymal stem cells (MSC-Exos) perform the regulatory function of stem cells by transporting proteins, nucleic acids, and lipids. Intervertebral disc degeneration (IDD) is one of the main causes of low back pain, and it is characterized by a decreased number of nucleus pulposus cells, extracellular matrix decomposition, aging of the annulus fibrosus, and cartilage endplate calcification. Besides, nutrient transport and structural repair of intervertebral discs depend on bone and cartilage and are closely related to the state of the bone. Trauma, disease and aging can all cause bone injury. However, there is a lack of effective drugs against IDD and bone injury. Recent MSC-Exos fine tuning has led to significant progress in the IDD treatment and bone repair and regeneration. In this review, we looked at the uniqueness of MSC-Exos, and the potential treatment mechanisms of MSC-Exos with respect to IDD, bone defects and injuries.

Distraction spinal cord injuries (DSCIs) often occur as the neurological complication of distraction forces following the implantation of internal fixation devices during scoliosis correction surgery. However, the underlying mechanism behind these injuries remains unclear. The present study aimed to explore the activation of microglia and macrophages, as well as changes in TLR4-mediated NF-κB and MAPK pathway activity after DSCIs in Bama miniature pigs. Prior to surgical intervention, the pigs were randomly divided into three groups: the sham group, the complete distraction spinal cord injury (CDSCI) group, and the incomplete distraction spinal cord injury (IDSCI) group. After surgery, the Tarlov scale and individual limb motor scale (ILMS) were used to evaluate changes in the pigs’ behavior. All pigs were euthanized 7 days after surgery, and histopathological examinations of the spinal cord tissues were performed. Immunohistochemistry was used to detect Caspase-3 expression in the anterior horn of spinal gray matter tissues. Immunofluorescence staining was utilized to assess the M1/M2 phenotype changes in microglia/macrophages and NF-κB P65 expression in central DSCI lesions, while western blotting was performed to determine the expression of TLR4/NF-κB/MAPK pathway-related proteins. The results of the present study showed that the Tarlov and ILMS scores decreased significantly in the two DSCI groups compared with the sham group. Hematoxylin and eosin (HE) and Nissl staining revealed that the tissue structure and nerve fiber tracts in the distracted spinal cord tissues were destroyed. Both DSCI groups showed the number of survived neurons decreased and the Caspase-3 expression increased. The results of the immunofluorescence staining indicated that the CD16 and CD206 expression in the microglia/macrophages increased. Between the two DSCI groups, the CDSCI group showed increased CD16 and decreased CD206 expression levels. The intensity of the fluorescence of NF-κB P65 was found to be significantly enhanced in pigs with DSCIs. Moreover, western blot results revealed that the expression of TLR4, p-IκBα, NF-κB P65, p-JNK, p-ERK, and p-P38 proteins increased in spinal cord tissues following DSCI. The present study was based on a porcine DSCI model that closely mimicked clinical DSCIs while clarifying DSCI-associated neuroinflammation mechanisms, in turn providing evidence for identifying potential anti-inflammatory targets.

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Study Design. Systematic review and meta-analysis.Objective. This study aimed to compare the radiographical and clinical outcomes between anterior spinal fusion (ASF) and posterior spinal fusion (PSF) in Lenke type 5 adolescence idiopathic scoliosis. Summary of Background Data. PSF has been the standard operation for adolescence idiopathic scoliosis. ASF can also achieve a good curve correction effect with fewer fusion segments and minor invasion of paraspinal structures. Materials and Methods. A systematic literature research was conducted in PubMed, Embase, Cochrane Library, and Web of Science. Use meta-analysis to compare the changes of thoracolumbar/ lumbar and thoracic curves and other important outcomes between ASF and PSF. Results. A total of 427 ASF and 392 PSF patients from 12 studies were included. There was no significant difference in the correction degree of thoracolumbar/lumbar and thoracic curve between ASF and PSF (P > 0.05), except for PSF had more compensatory correction degree of thoracic curve at postoperation (P < 0.05). Besides, the loss of correction in thoracic curve in PSF at the last follow-up was significantly less than that in ASF (P < 0.05). PSF presented larger change values of thoracic kyphosis and lumbar lordosis at the last follow-up (P < 0.05). PSF showed a better effect in correcting trunk shift distance at the postoperation (P < 0.05) but less trunk shift distance correction from postoperation to last follow-up (P < 0.05). There was no significant difference in the incidence of proximal junctional kyphosis and estimated blood loss between the two approaches (P > 0.05). Moreover, ASF showed fewer fusion segments, but longer operation and hospital stay time (P < 0.05). Conclusion. ASF is capable of achieving similar correction in coronal curve and balance as PSF with fewer fusion segments. Spine surgeons should select an appropriate approach tailored to individual patients needs while considering procedural risks and benefits.