Objective·To investigate the differential gene expression of microglia in the gray and white matter of multiple sclerosis(MS)using single-nucleus transcriptomic analysis,aiming to explore their roles in disease progression,and identify key transcriptional regulatory networks associated with the disease.Methods·snRNA-seq data of frozen human brain tissue samples from MS patients and control individuals were obtained from the Gene Expression Omnibus(GEO)database.R language,along with R packages such as Seurat,was employed to identify cell types based on specific cell markers.Microglia were extracted from the identified cell populations and classified based on their anatomical origin,either gray matter or white matter.Dimensionality reduction and clustering techniques were utilized to identify distinct microglial subpopulations with differential characteristics.Differentially expressed genes(DEGs)between the MS and control groups at the subpopulation level were analyzed by using the Seurat package.Gene set enrichment analysis of Gene Ontology(GO)and Kyoto Encyclopedia of Genes and Genomes(KEGG)was conducted on the DEGs to further explore the biological significance of these differences.Monocle3 was used for pseudotime analysis to study dynamic changes in microglia subpopulations during disease progression.Single cell regulatory network inference and clustering(SCENIC)method was applied to analyze transcription factor(TF)regulatory networks,aiming to identify key transcription factors potentially involved in MS regulation.Results·After quality control,a total of 149 062 nuclei were retained for analysis.Following dimensional reduction and clustering,12 238 microglia were identified by using key markers,including DOCK8,CSF1R,P2RY12,and CD74.The results of GO and KEGG pathway analysis showed that in gray matter microglia,functions such as endocytosis,ion homeostasis,and lipid localization were downregulated during disease progression,while in white matter microglia,functions such as protein folding,cytoplasmic translation,and response to thermal stimuli were upregulated.SCENIC analysis revealed that the expression of transcription factors such as FLI1,MITF,and FOXP1 was upregulated in MS.Conclusion·Microglia play a critical role in MS,with white matter microglia being more significantly impacted by MS than their gray matter counterparts.Transcription factors such as FLI1,MITF,and FOXP1 are identified as key regulators involved in disease modulation,with their associated transcriptional regulatory networks playing a central role in disease modulation.

Objective·To investigate the differential gene expression of microglia in the gray and white matter of multiple sclerosis(MS)using single-nucleus transcriptomic analysis,aiming to explore their roles in disease progression,and identify key transcriptional regulatory networks associated with the disease.Methods·snRNA-seq data of frozen human brain tissue samples from MS patients and control individuals were obtained from the Gene Expression Omnibus(GEO)database.R language,along with R packages such as Seurat,was employed to identify cell types based on specific cell markers.Microglia were extracted from the identified cell populations and classified based on their anatomical origin,either gray matter or white matter.Dimensionality reduction and clustering techniques were utilized to identify distinct microglial subpopulations with differential characteristics.Differentially expressed genes(DEGs)between the MS and control groups at the subpopulation level were analyzed by using the Seurat package.Gene set enrichment analysis of Gene Ontology(GO)and Kyoto Encyclopedia of Genes and Genomes(KEGG)was conducted on the DEGs to further explore the biological significance of these differences.Monocle3 was used for pseudotime analysis to study dynamic changes in microglia subpopulations during disease progression.Single cell regulatory network inference and clustering(SCENIC)method was applied to analyze transcription factor(TF)regulatory networks,aiming to identify key transcription factors potentially involved in MS regulation.Results·After quality control,a total of 149 062 nuclei were retained for analysis.Following dimensional reduction and clustering,12 238 microglia were identified by using key markers,including DOCK8,CSF1R,P2RY12,and CD74.The results of GO and KEGG pathway analysis showed that in gray matter microglia,functions such as endocytosis,ion homeostasis,and lipid localization were downregulated during disease progression,while in white matter microglia,functions such as protein folding,cytoplasmic translation,and response to thermal stimuli were upregulated.SCENIC analysis revealed that the expression of transcription factors such as FLI1,MITF,and FOXP1 was upregulated in MS.Conclusion·Microglia play a critical role in MS,with white matter microglia being more significantly impacted by MS than their gray matter counterparts.Transcription factors such as FLI1,MITF,and FOXP1 are identified as key regulators involved in disease modulation,with their associated transcriptional regulatory networks playing a central role in disease modulation.

Objective To investigate the role of spinal cord TNF-a in the development of bone cancer pain in mice. Methods Seventy-two 4-6 week old C3H/He mice weighing 18-25 g were randomly divided into 3 groups (n = 24 each) : group I sham operation (group S) ; group II bone cancer pain (group BCP) and group Ⅲ etanercept (group E). Bone cancer pain was induced by implantation of osteosarcoma NCTC 2472 cells into the intramedullary space of right femur in group II and Ⅲ . Group Ⅲ received intraperitoneal etanercept 100 μg at 3 days before and immediately before and day 3 and 6 after tumor cell inoculation. In group S culture medium α-MEM containing no cancer cell was injected instead. The paw withdrawal threshold to mechanical stimuli (PWMT) and paw withdrawal latency to thermal stimuli ( PWTL) were measured before inoculation (baseline) and at day 3, 5,7, 10, 14 after inoculation respectively. Eight animals were killed on the 7th, 10th, and 14th day after inoculation in each group. The spinal cords were removed and TNF-α mRNA expression in the spinal cord was determined by RT-PCR. Results Cancer pain was significantly attenuated by pretreatment with etanercept. The TNF-α mRNA expression in the spinal cord was significantly increased after inoculation and was significantly attenuated by pretreatment with etanercept in group Ⅲ . Conclusion Spinal cord TNF-a is involved in the development of bone cancer pain in mice.