Background: DNA methylation dynamics in the brain are associated with normal development and neuropsychiatric disease and differ across functionally distinct brain regions. Previous studies of genome-wide methylation differences among human brain regions focus on limited numbers of individuals and one to two brain regions.Results: Using GTEx samples, we generate a resource of DNA methylation in purified neuronal nuclei from 8 brain regions as well as lung and thyroid tissues from 12 to 23 donors. We identify differentially methylated regions between brain regions among neuronal nuclei in both CpG (181,146) and non-CpG (264,868) contexts, few of which were unique to a single pairwise comparison. This significantly expands the knowledge of differential methylation across the brain by 10-fold. In addition, we present the first differential methylation analysis among neuronal nuclei from basal ganglia tissues and identify unique CpG differentially methylated regions, many associated with ion transport. We also identify 81,130 regions of variably CpG methylated regions, i.e., variable methylation among individuals in the same brain region, which are enriched in regulatory regions and in CpG differentially methylated regions. Many variably methylated regions are unique to a specific brain region, with only 202 common across all brain regions, as well as lung and thyroid. Variably methylated regions identified in the amygdala, anterior cingulate cortex, and hippocampus are enriched for heritability of schizophrenia.Conclusions: These data suggest that epigenetic variation in these particular human brain regions could be associated with the risk for this neuropsychiatric disorder.
26 January 2022 in Advances in Biological Regulation
Background: Efforts to understand genetic variability involved in an individual’s susceptibility to chronic pain support a role for upstream regulation by epigenetic mechanisms. Methods: To examine the transcriptomic and epigenetic basis of chronic pain that resides in the peripheral nervous system, we used RNA-seq and ATAC-seq of the rat dorsal root ganglion (DRG) to identify novel molecular pathways associated with pain hypersensitivity in two well-studied persistent pain models induced by chronic constriction injury (CCI) of the sciatic nerve and intra-plantar injection of complete Freund’s adjuvant (CFA) in rats. Results: Our RNA-seq studies identify a variety of biological process related to synapse organization, membrane potential, transmembrane transport, and ion binding. Interestingly, genes that encode transcriptional regulators were disproportionately downregulated in both models. Our ATAC-seq data provide a comprehensive map of chromatin accessibility changes in the DRG. A total of 1123 regions showed changes in chromatin accessibility in one or both models when compared to the naïve and 31 shared differentially accessible regions (DAR)s. Functional annotation of the DARs identified disparate molecular functions enriched for each pain model which suggests that chromatin structure may be altered differently following sciatic nerve injury and hind paw inflammation. Motif analysis identified 17 DNA sequences known to bind transcription factors in the CCI DARs and 33 in the CFA DARs. Two motifs were significantly enriched in both models. Conclusions: Our improved understanding of the changes in chromatin accessibility that occur in chronic pain states may identify regulatory genomic elements that play essential roles in modulating gene expression in the DRG.
The human gut microbiota is composed of bacteria (microbiota or microbiome), fungi (mycobiome), viruses, and archaea, but most of the research is primarily focused on the bacterial component of this ecosystem. Besides bacteria, fungi have been shown to play a role in host health and physiologic functions. However, studies on mycobiota composition during infancy, the factors that might shape infant gut mycobiota, and implications to child health and development are limited. In this review, we discuss the factors likely shaping gut mycobiota, interkingdom interactions, and associations with child health outcomes and highlight the gaps in our current knowledge of this ecosystem.
21 February 2024 in Regional Anesthesia & Pain Medicine
Introduction Significant interindividual variability in spinal cord stimulation (SCS) outcomes exists. Due to its high cost and risks of complications, criteria to guide patient selection for SCS trials and their outcomes would be helpful. With increased focus on the use of patient-reported outcomes to improve care, we aim to evaluate the National Institute of Health Patient Reported Outcome Measurement Information System measures for an association with successful SCS trials in patients with persistent pain. Methods Our prospective, observational study enrolled 60 patients with persistent pain who underwent an SCS trial. Patients completed demographic and Patient Reported Outcome Measurement Information System computer adaptive test (PROMIS CAT) assessments to measure self-reported pain interference, depression, anxiety, physical functioning, and sleep disturbance at the time they presented for placement of their trial device. Results Of the 58 patients who underwent successful electrode placement, 11 had an unsuccessful trial. There were no differences in patient demographics between patients with a successful and an unsuccessful trial. Patients who had a successful SCS trial reported lower pre-trial levels of anxiety, depression, and sleep disturbance and decreased post-trial levels of depression, sleep disturbance, and pain interference. Conclusions We found that patients with high levels of depression, anxiety, and sleep disturbance using the PROMIS CAT were predictive of unsuccessful trials. In addition, we found that patients with successful SCS trials reported lower levels of these domains on PROMIS CAT administered at the end of the trial.
6 June 2024 in Regional Anesthesia & Pain Medicine
Background Taxanes such as paclitaxel (PTX) induce dose-dependent chemotherapy-induced peripheral neuropathy (CIPN), which is associated with debilitating chronic pain and gait impairment. Increased macrophage-related proinflammatory activities have been reported to mediate the development and maintenance of neuropathic pain. While spinal cord stimulation (SCS) has been used for a number of pain conditions, the mechanisms supporting its use for CIPN remain to be elucidated. Thus, we aimed to examine whether SCS can attenuate Schwann cell-mediated and macrophage-mediated neuroinflammation in the sciatic nerve of Rowlette Nude (RNU) rats with PTX-induced gait impairment and mechanical hypersensitivity. Methods Adult male tumor-bearing RNU rats were used for this study examining PTX treatment and SCS. Gait and mechanical hypersensitivity were assessed weekly. Cytokines, gene expression, macrophage infiltration and polarisation, nerve morphology and Schwann cells were examined in sciatic nerves using multiplex immunoassay, bulk RNA sequencing, histochemistry and immunohistochemistry techniques. Results SCS (50 Hz, 0.2 milliseconds, 80% motor threshold) attenuated the development of mechanical hypersensitivity (20.93±0.80 vs 12.23±2.71 grams, p<0.0096) and temporal gait impairment [swing (90.41±7.03 vs 117.27±9.71%, p<0.0076), and single stance times (94.92±3.62 vs 112.75±7.27%, p<0.0245)] induced by PTX (SCS+PTX+Tumor vs Sham SCS+PTX+Tumor). SCS also attenuated the reduction in Schwann cells, myelin thickness and increased the concentration of anti-inflammatory cytokine interleukin (IL)−10. Bulk RNA sequencing revealed differential gene expression after SCS, with 607 (59.2%) genes upregulated while 418 (40.8%) genes were downregulated. Notably, genes related to anti-inflammatory cytokines and neuronal growth were upregulated, while genes related to proinflammatory-promoting genes, increased M2γ polarisation and decreased macrophage infiltration and Schwann cell loss were downregulated. Conclusion SCS may attenuate PTX-induced pain and temporal gait impairment, which may be partly attributed to decreases in Schwann cell loss and macrophage-mediated neuroinflammation in sciatic nerves.