RESUMEN
BACKGROUND:Neuroinflammation is an important factor leading to secondary spinal cord injury,and microglia/macrophage pyroptosis is a significant part of post-spinal cord injury neuroinflammation.Studies have shown that microglia/macrophage undergoes pyroptosis after spinal cord injury,but the regulatory mechanism of circular RNA(circRNA)in microglia/macrophage pyroptosis after spinal cord injury remains unclear. OBJECTIVE:To investigate the role and mechanism of circRNA0005512 in regulating microglia/macrophage pyroptosis after spinal cord injury. METHODS:Female Wistar rats were divided into sham group and spinal cord injury group.Motor function was evaluated using the Basso,Beattie,and Bresnahan(BBB)scale.Cavity volume was assessed by hematoxylin-eosin staining.Differential expression of circRNA in spinal cord tissue was screened using RNA-sequencing and circ0005512 was validated by real-time PCR.Immunofluorescence,western blot assay,ELISA,and real-time PCR were performed to detect cell pyroptosis in the rats and lipopolysaccharide-induced microglial cell line HAPI cell models.Gene knockdown was used to confirm the regulatory role of circRNA0005512 in microglia/macrophage pyroptosis. RESULTS AND CONCLUSION:(1)Seven days after spinal cord injury,evident cavities were observed at the injury site.Immediately after spinal cord injury,the motor function of rats was completely lost.Over time,the motor function of rats in the spinal cord injury group gradually partially recovered,and there was a significant difference in BBB scores compared to the sham group.(2)Circ0005512 was significantly upregulated according to the results of the RNA-sequencing and confirmed in both the animal and cell models.(3)Immunofluorescence,western blot assay,real-time PCR,and ELISA confirmed the significant upregulation of cell pyroptosis markers(NLRP3,GSDMD,and caspase-1)in spinal cord injury tissue and lipopolysaccharide-induced HAPI cells.(4)In the cell model,knockdown of circ0005512 resulted in significantly decreased levels of cell pyroptosis marker-NLRP3.(5)The results above indicate that circ0005512 promotes pyroptosis in microglia/macrophages after spinal cord injury.
RESUMEN
@#Objective To explore the physiological characteristics of synaptic transmission of anterior horn early development in thorac-ic spinal cord mediated byα-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptors in rats. Methods 36 Wistar rats were divided into embryonic 17 days group (E17, n=12), embryonic 20 days group (E20, n=12) and postnatal 7 days group (P7, n=12). Immuno-fluorescent staining of calmodulin-dependent protein kinaseⅡ(CaMKⅡ) was used to test the distribution of AMPA receptors. Multi-elec-trode array technique (MED-64 system) was used to test the changes of field excitatory post-synaptic potential (fEPSP) of synaptic transmis-sion mediated by AMPA receptor. Results There was small amount of CaMKⅡ-positive neurons existing in gray matter of spinal cord at E17, CaMKⅡ-positive neurons migrated to the center, and the number of neurons became more and more in E20 and P7 rats. The number of evoked fEPSP gradually increased in rats from E17 to P7, and could be blocked by 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX). The range of synaptic connection in spinal cord gray matter significantly reduced (P<0.001). Conclusion AMPA receptors participate in the early development of spinal cord in rats and act as the main excitatory receptor of functional synaptic connection in neural network of ventricornu.