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Background: Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a debilitating chronic disease that lacks known pathogenesis, distinctive diagnostic criteria, and effective treatment options. Understanding the genetic (and other) risk factors associated with the disease would begin to help to alleviate some of these issues for patients., Methods: We applied both GWAS and the PrecisionLife combinatorial analytics platform to analyze ME/CFS cohorts from UK Biobank, including the Pain Questionnaire cohort, in a case-control design with 1000 cycles of fully random permutation. Results from this study were supported by a series of replication and cohort comparison experiments, including use of disjoint Verbal Interview CFS, post-viral fatigue syndrome and fibromyalgia cohorts also derived from UK Biobank, and compared results for overlap and reproducibility., Results: Combinatorial analysis revealed 199 SNPs mapping to 14 genes that were significantly associated with 91% of the cases in the ME/CFS population. These SNPs were found to stratify by shared cases into 15 clusters (communities) made up of 84 high-order combinations of between 3 and 5 SNPs. p-values for these communities range from 2.3 × 10 -10 to 1.6 × 10 -72 . Many of the genes identified are linked to the key cellular mechanisms hypothesized to underpin ME/CFS, including vulnerabilities to stress and/or infection, mitochondrial dysfunction, sleep disturbance and autoimmune development. We identified 3 of the critical SNPs replicated in the post-viral fatigue syndrome cohort and 2 SNPs replicated in the fibromyalgia cohort. We also noted similarities with genes associated with multiple sclerosis and long COVID, which share some symptoms and potentially a viral infection trigger with ME/CFS., Conclusions: This study provides the first detailed genetic insights into the pathophysiological mechanisms underpinning ME/CFS and offers new approaches for better diagnosis and treatment of patients., (© 2022. The Author(s).)

A comprehensive repertoire of human microRNAs (miRNAs) that could be involved in early melanoma invasion into the dermis remains unknown. To this end, we sequenced small RNAs (18-30 nucleotides) isolated from an annotated series of invasive melanomas (average invasive depth, 2.0 mm), common melanocytic nevi, and matched normal skin (n=28). Our previously established bioinformatics pipeline identified 765 distinct mature known miRNAs and defined a set of top 40 list that clearly segregated melanomas into thin (0.75 mm) and thick (2.7 mm) groups. Among the top, miR-21-5p, let-7b-5p, let-7a-5p, miR-424-5p, miR-423-5p, miR-21-3p, miR-199b-5p, miR-182-5p, and miR-205-5p were differentially expressed between thin and thick melanomas. In a validation cohort (n=167), measured expression of miR-21-5p and miR-424-5p, not previously reported in melanoma, were significantly increased in invasive compared with in situ melanomas (P<0.0001). Increased miR-21-5p levels were significantly associated with invasive depth (P=0.038), tumor mitotic index (P=0.038), lymphovascular invasion (P=0.0036), and AJCC stage (P=0.038). In contrast, let-7b levels were significantly decreased in invasive and in situ melanomas compared with common and dysplastic nevi (P<0.0001). Decreased let-7b levels were significantly associated with invasive depth (P=0.011), Clark's level (P=0.013), ulceration (P=0.0043), and AJCC stage (P=0.011). These results define a distinct set of miRNAs associated with invasive and aggressive melanoma phenotype.

γδ T cells are a subset of lymphocytes specialized in protecting the host against pathogens and tumours. Here we describe a subset of regulatory γδ T cells that express the latency-associated peptide (LAP), a membrane-bound TGF-β1. Thymic CD27+IFN-γ+CCR9+α4β7+TCRγδ+ cells migrate to the periphery, particularly to Peyer's patches and small intestine lamina propria, where they upregulate LAP, downregulate IFN-γ via ATF-3 expression and acquire a regulatory phenotype. TCRγδ+LAP+ cells express antigen presentation molecules and function as antigen presenting cells that induce CD4+Foxp3+ regulatory T cells, although TCRγδ+LAP+ cells do not themselves express Foxp3. Identification of TCRγδ+LAP+ regulatory cells provides an avenue for understanding immune regulation and biologic processes linked to intestinal function and disease.

Importance: Recent large-scale genome-wide association studies have discovered several genetic variants associated with Alzheimer disease (AD); however, the extent to which DNA methylation in these AD loci contributes to the disease susceptibility remains unknown., Objective: To examine the association of brain DNA methylation in 28 reported AD loci with AD pathologies., Design, Setting, and Participants: Ongoing community-based clinical pathological cohort studies of aging and dementia (the Religious Orders Study and the Rush Memory and Aging Project) among 740 autopsied participants 66.0 to 108.3 years old., Exposures: DNA methylation levels at individual CpG sites generated from dorsolateral prefrontal cortex tissue using a bead assay., Main Outcomes and Measures: Pathological diagnosis of AD by National Institute on Aging-Reagan criteria following a standard postmortem examination., Results: Overall, 447 participants (60.4%) met the criteria for pathological diagnosis of AD. Brain DNA methylation in SORL1, ABCA7, HLA-DRB5, SLC24A4, and BIN1 was associated with pathological AD. The association was robustly retained after replacing the binary trait of pathological AD with 2 quantitative and molecular specific hallmarks of AD, namely, Aβ load and paired helical filament tau tangle density. Furthermore, RNA expression of transcripts of SORL1 and ABCA7 was associated with paired helical filament tau tangle density, and the expression of BIN1 was associated with Aβ load., Conclusions and Relevance: Brain DNA methylation in multiple AD loci is associated with AD pathologies. The results provide further evidence that disruption of DNA methylation is involved in the pathological process of AD.

The full repertoire of human microRNAs (miRNAs) that could distinguish common (benign) nevi from cutaneous (malignant) melanomas remains to be established. In an effort to gain further insight into the role of miRNAs in melanoma, we applied Illumina next-generation sequencing (NGS) platform to carry out an in-depth analysis of miRNA transcriptome in biopsies of nevi, thick primary (>4.0 mm) and metastatic melanomas with matched normal skin in parallel to melanocytes and melanoma cell lines (both primary and metastatic) (n=28). From this data representing 698 known miRNAs, we defined a set of top-40 list, which properly classified normal from cancer; also confirming 23 (58%) previously discovered miRNAs while introducing an additional 17 (42%) known and top-15 putative novel candidate miRNAs deregulated during melanoma progression. Surprisingly, the miRNA signature distinguishing specimens of melanoma from nevus was significantly different than that of melanoma cell lines from melanocytes. Among the top list, miR-203, miR-204-5p, miR-205-5p, miR-211-5p, miR-23b-3p, miR-26a-5p and miR-26b-5p were decreased in melanomas vs. nevi. In a validation cohort (n=101), we verified the NGS results by qRT-PCR and showed that receiver-operating characteristic curves for miR-211-5p expression accurately discriminated invasive melanoma (AUC=0.933), melanoma in situ (AUC=0.933) and dysplastic (atypical) nevi (AUC=0.951) from common nevi. Target prediction analysis of co-transcribed miRNAs showed a cooperative regulation of key elements in the MAPK signaling pathway. Furthermore, we found extensive sequence variations (isomiRs) and other non-coding small RNAs revealing a complex melanoma transcriptome. Deep-sequencing small RNAs directly from clinically defined specimens provides a robust strategy to improve melanoma diagnostics.