P0024TRIPARTITE MOTIF-CONTAINING 55 (TRIM55) PARTICIPATES IN THE IMMUNE RESPONSE IN THE EXPERIMENTAL ANTI-THY1 GLOMERULONEPHRITIS

Background and Aims Mesangial proliferative glomerulonephritis (MsPGN) is considered as an immune- related disease. In the previous study, tripartite motif family was reported to be closely related to immune regulation. Therefore, we performed a series of experiments in vivo and vitro to investigate the role of tripartite motif-containing 55 (TRIM55), a member of tripartite motif family, in the progression of MsPGN. Method 36 male SD rats were randomly divided into 6 groups to induce anti-Thy1 nephritis. Specimens of the negative control group were collected at 0d after the injection, while those of other groups were collected at 1d, 2d, 3d, 4d, 5d after the injection, respectively. Renal cortex slices were obtained for histological and immunohistochemistry assessmen of CD68. qPCR analysis of glomerulus was performed to examine the expression of TRIM55 . Primary RMCs with overexpression of TRIM55 were obtained through plasmid transfection. In addition, si-RNA tranfection was used to knock down the expression of TRIM55 in primary RMCs. qPCR analysis was conducted to detect the level of cytokines, such as TNF-α, CCL2, CXCL6, CXCL10, and IL-6. Results PAS staining results indicated mesangial dissolution occurred since 1d, followed by inflammatory cell infiltration. CD68 immunohistochemical staining results showed that macrophages infiltration peaked at 1d and then decreased gradually. The expression of TRIM55 mRNA also peaked at 1d and decreased gradually, which was consistent with the trend of macrophages infiltration. In primary RMCs, knockdown of TRIM55 led to down-regulation of the expression of cytokines (TNF-α, CCL2, CXCL6, CXCL10 and IL-6). On the other hand, the expression of those cytokines(TNF-α, CCL2, CXCL6, CXCL10 and IL-6) significantly increased in TRIM55-overexpressed primary RMCs. Conclusion The above results indicate that TRIM55 participates in the immune response in experimental anti-Thy1 glomerulonephritis by regulating the production of cytokines. We duce TRIM55 may be a promising therapeutic intervention to ameliorate leukocyte infiltration in MsPGN.

Mouse Corticospinal System Comprises Different Functional Neuronal Ensembles Depending On Their Hodology

Background: Movement performance depends on the synaptic interactions generated by coherent parallel sensorimotor cortical outputs to different downstream targets. The major outputs of the neocortex to subcortical structures are driven by pyramidal tract neurons (PTNs) located in layer 5B. One of the main targets of PTNs is the spinal cord through the corticospinal (CS) system, which is formed by a complex collection of distinct CS circuits. However, little is known about intracortical synaptic interactions that originate CS commands and how different populations of CS neurons are functionally organized. To further understand the functional organization of the CS system, we analyzed the activity of unambiguously identified CS neurons projecting to different zones of the same spinal cord segment using two-photon calcium imaging and retrograde neuronal tracers. Results: Sensorimotor cortex slices obtained from transgenic mice expressing GCaMP6 funder the Thy1 promoter were used to analyze the spontaneous calcium transients in layer 5 pyramidal neurons. Distinct subgroups of CS neurons projecting to dorsal horn and ventral areas of the same segment show more synchronous activity between them than with other subgroups. Conclusions: The results indicate that CS neurons projecting to different spinal cord zones segregated into functional ensembles depending on their hodology, suggesting that a modular organization of CS outputs controls sensorimotor behaviors in a coordinated manner.

Mouse corticospinal system comprises different functional neuronal ensembles depending on their hodology

Background Movement performance depends on the synaptic interactions generated by coherent parallel sensorimotor cortical outputs to different downstream targets. The major outputs of the neocortex to subcortical structures are driven by pyramidal tract neurons (PTNs) located in layer 5B. One of the main targets of PTNs is the spinal cord through the corticospinal (CS) system, which is formed by a complex collection of distinct CS circuits. However, little is known about intracortical synaptic interactions that originate CS commands and how different populations of CS neurons are functionally organized. To further understand the functional organization of the CS system, we analyzed the activity of unambiguously identified CS neurons projecting to different zones of the same spinal cord segment using two-photon calcium imaging and retrograde neuronal tracers. Results Sensorimotor cortex slices obtained from transgenic mice expressing GCaMP6 funder the Thy1 promoter were used to analyze the spontaneous calcium transients in layer 5 pyramidal neurons. Distinct subgroups of CS neurons projecting to dorsal horn and ventral areas of the same segment show more synchronous activity between them than with other subgroups. Conclusions The results indicate that CS neurons projecting to different spinal cord zones segregated into functional ensembles depending on their hodology, suggesting that a modular organization of CS outputs controls sensorimotor behaviors in a coordinated manner.

MOUSE CORTICOSPINAL SYSTEM COMPRISES DIFFERENT FUNCTIONAL NEURONAL ENSEMBLES DEPENDING ON THEIR HODOLOGY

Background: Movement performance depends on the synaptic interactions generated by coherent parallel sensorimotor cortical outputs to different downstream targets. The major outputs of the neocortex to subcortical structures are driven by pyramidal tract neurons (PTNs) located in layer 5B. One of the main targets of PTNs is the spinal cord through the corticospinal (CS) system, which is formed by a complex collection of distinct CS circuits. However, little is known about intracortical synaptic interactions that originate CS commands and how different populations of CS neurons are functionally organized. To further understand the functional organization of the CS system, we analyzed the activity of unambiguously identified CS neurons projecting to different zones of the same spinal cord segment using two-photon calcium imaging and retrograde neuronal tracers. Results: Sensorimotor cortex slices obtained from transgenic mice expressing GCaMP6f under the Thy1 promoter were used to analyze the spontaneous calcium transients in layer 5 pyramidal neurons. Distinct subgroups of CS neurons projecting to dorsal horn and ventral areas of the same segment show more synchronous activity between them than with other subgroups. Conclusions: The results indicate that CS neurons projecting to different spinal cord zones segregated into functional ensembles depending on their hodology, suggesting that a modular organization of CS outputs controls sensorimotor behaviors in a coordinated manner.