Differential Gene Expression in Pain-Related Genes are not Affected by the Presence of Dementia.

BACKGROUND: Prior work has demonstrated differences in the transcriptome between those with and without chronic musculoskeletal pain. AIMS: The aim of this study was to explore whether pain-related gene expression is similar between individuals with and without dementia. DESIGN: This was a descriptive study using a one-time assessment. SETTINGS: PARTICIPANTS/SUBJECTS: A total of 20 older adults living in a continuing care retirement community, 50% of whom had dementia were inlcuded in this study. All were female and the mean age of participants was 89 (SD = 6). METHODS: Pain was evaluated based on the PROMIS Pain Intensity Short Form 3a. Whole blood was collected by venipuncture into Tempus vacutainer tubes (3 ml) and the RNA was extracted at the Translational Genomics Laboratory at the University of Maryland Baltimore. Analyses included a differential expression analysis, a weighted gene co-expression network analysis, and a pathway enrichment analysis. RESULTS: Eighty-three genes were differentially expressed between individuals with and without pain (p <.05). After normalizing gene counts and removing the low expressed genes, 18,028 genes were left in the final analysis. There was no clustering of the samples related to study variables of pain or dementia. CONCLUSION: The findings from this study provided some preliminary support that pain-related gene expression is similar between individuals with and without dementia.

Dissecting Genetic Mechanisms of Differential Locomotion, Depression, and Allodynia after Spinal Cord Injury in Three Mouse Strains.

Strain differences have been reported for motor behaviors, and only a subset of spinal cord injury (SCI) patients develop neuropathic pain, implicating genetic or genomic contribution to this condition. Here, we evaluated neuropsychiatric behaviors in A/J, BALB/c, and C57BL/6 male mice and tested genetic or genomic alterations following SCI. A/J and BALB/c naive mice showed significantly less locomotor activity and greater anxiety-like behavior than C57BL/6 mice. Although SCI elicited locomotor dysfunction, C57BL/6 and A/J mice showed the best and the worst post-traumatic recovery, respectively. Mild (m)-SCI mice showed deficits in gait dynamics. All moderate/severe SCI mice exhibited similar degrees of anxiety/depression. mSCI in BALB/c and A/J mice resulted in depression, whereas C57BL/6 mice did not exhibit depression. mSCI mice had significantly lower mechanical thresholds than their controls, indicating high cutaneous hypersensitivity. C57BL/6, but not A/J and BLAB/c mice, showed significantly lower heat thresholds than their controls. C57BL/6 mice exhibited spontaneous pain. RNAseq showed that genes in immune responses and wound healing were upregulated, although A/J mice showed the largest increase. The cell cycle and the truncated isoform of trkB genes were robustly elevated in SCI mice. Thus, different genomics are associated with post-traumatic recovery, underscoring the likely importance of genetic factors in SCI.