Probes for INS

the increased expression of 18kDa Translocator protein (TSPO) is one of the few available biomarkers of neuroinflammation that can be assessed in humans in vivo by positron emission tomography (PET). TSPO PET imaging of the central nervous system (CNS) has been widely undertaken, but to date no clear consensus has been reached about its utility in brain disorders. One reason for this could be because the interpretation of TSPO PET signal remains challenging, given the cellular heterogeneity and ubiquity of TSPO in the brain. the aim of the current study was to ascertain if TSPO PET imaging can be used to detect neuroinflammation induced by a peripheral treatment with endotoxin lipopolysaccharide (LPS) in a rat model (ip LPS), and investigate the origin of TSPO signal changes in terms of their cellular sources and regional distribution. An initial pilot study utilising both [18F]DPA-714 and [11C]PK11195 demonstrated [18F]DPA-714 to exhibit a significantly higher lesion-related signal in the intracerebral LPS rat model (ic LPS) than [11C]PK11195. Subsequently, [18F]DPA-714 was selected for use in the ip LPS study. twenty-four hours after ip LPS, there was an increased uptake of [18F]DPA-714 across the whole brain. Further analyses of regions of interest, using immunohistochemistry and RNAscope Multiplex fluorescence V2 in situ hybridization technology, showed TSPO expression in microglia, monocyte derived-macrophages, astrocytes, neurons and endothelial cells. The expression of TSPO was significantly increased after ip LPS in a region-dependent manner; with microglia, monocyte-derived macrophages and astrocytes in the substantia nigra, in contrast to the hippocampus where TSPO was mostly confined to microglia and astrocytes. in summary, our data demonstrate the robust detection of peripherally-induced neuroinflammation in the CNS utilizing the TSPO radioligand [18F]DPA-714, and importantly, confirm that the TSPO signal increase arises mostly from a combination of microglia, astrocytes and monocyte-derived macrophages.

Detection of individual cytokines in routine biopsies from patients with inflammatory skin diseases has the potential to personalize diagnosis and treatment selection, but this approach has been limited by technical feasibility. We evaluate whether a chromogen-based RNA in situ hybridization approach can be used to detect druggable cytokines in psoriasis and atopic dermatitis. A series of psoriasis (n = 20) and atopic dermatitis (n = 26) biopsies were stained using RNA in situ hybridization for IL4, IL12B (IL-12/23 p40), IL13, IL17A, IL17F, IL22, IL23A (IL-23 p19), IL31, and TNF (TNF-α). NOS2 and IFNG, canonical psoriasis biomarkers, were also included. All 20 of the psoriasis cases were positive for IL17A, which tended to be the predominant cytokine, although some cases had relatively higher levels of IL12B, IL17F, or IL23A. The majority of cytokine expression in psoriasis was epidermal. A total of 22 of 26 atopic dermatitis cases were positive for IL13, also at varying levels; a subset of cases had significant IL4, IL22, or IL31 expression. Patterns were validated in independent bulk RNA-sequencing and single-cell RNA-sequencing datasets. Overall, RNA in situ hybridization for cytokines appears highly specific with virtually no background staining and may allow for individualized evaluation of treatment-relevant cytokine targets in biopsies from patients with inflammatory skin disorders.

The sequence of pathological events in feline hypertrophic cardiomyopathy (fHCM) is still largely unknown, although we know that fHCM is characterized by interstitial remodeling in a macrophage-driven pro-inflammatory environment and that myocardial ischemia might contribute to its progression. This study aimed to gain further insights into the structural changes associated with interstitial remodeling in fHCM with special focus on the myocardial microvasculature and the phenotype of the interstitial cells. Twenty-eight hearts (16 hearts with fHCM and 12 without cardiac disease) were evaluated in the current study, with immunohistochemistry, RNA-in situ hybridization, and transmission electron microscopy. Morphometrical evaluations revealed a statistically significant lower microvascular density in fHCM. This was associated with structural alterations in capillaries that go along with a widening of the interstitium due to the accumulation of edema fluid, collagen fibers, and mononuclear cells that also proliferated locally. The interstitial cells were mainly of fibroblastic or vascular phenotype, with a substantial contribution of predominantly resident macrophages. A large proportion expressed CD34 mRNA, which suggests a progenitor cell potential. Our results indicate that microvascular alterations are key events in the pathogenesis of fHCM and that myocardial interstitial cell populations with CD34+ phenotype play a role in the pathogenesis of the disease.

Sarcoidosis is an idiopathic inflammatory disorder that is commonly treated with glucocorticoids. An imprecise understanding of the immunologic changes underlying sarcoidosis has limited therapeutic progress. Here in this open-label trial (NCT03910543), 10 patients with cutaneous sarcoidosis are treated with tofacitinib, a Janus kinase inhibitor. The primary outcome is the change in the cutaneous sarcoidosis activity and morphology instrument (CSAMI) activity score after 6 months of treatment. Secondary outcomes included change in internal organ involvement, molecular parameters, and safety. All patients experience improvement in their skin with 6 patients showing a complete response. Improvement in internal organ involvement is also observed. CD4+ T cell-derived IFN-γ is identified as a central cytokine mediator of macrophage activation in sarcoidosis. Additional type 1 cytokines produced by distinct cell types, including IL-6, IL-12, IL-15 and GM-CSF, also associate with pathogenesis. Suppression of the activity of these cytokines, especially IFN-γ, correlates with clinical improvement. Our results thus show that tofacitinib treatment is associated with improved sarcoidosis symptoms, and predominantly acts by inhibiting type 1 immunity.

Acral dermatoses, including hyperkeratotic palmoplantar eczema (HPE), palmoplantar psoriasis (PP), and mycosis fungoides palmaris et plantaris (MFPP), can be challenging to diagnose clinically and histopathologically. In this setting, cytokine biomarkers may be able to help provide diagnostic clarity. We therefore evaluated interleukin (IL)-17A, interferon gamma (IFN-γ), and IL-13 expression in PP, HPE, and MFPP and compared their expression profiles to non-acral sites. We utilized biopsy specimens from the Yale Dermatopathology database, selecting cases of HPE (n=12), PP (n=8), MFPP (n=8), normal acral skin (n=9), non-acral eczema (n=10), and non-acral psoriasis (n=10) with classic clinical and histopathologic features. IL17A mRNA expression by RNA in situ hybridization differentiated PP (median score 63.1 [IQR 9.4-104.1]) from HPE (0.8 [0-6.0]; P = .003), MFPP (0.6 [0-2.6]; P = .003), and normal acral skin (0 [0-0]; P < .001). Unexpectedly, both PP and HPE demonstrated co-expression of IFNG and IL13 mRNA. In contrast, non-acral psoriasis and eczema demonstrated divergent patterns of IFNG and IL13 mRNA expression. Taken together, we show that IL17A mRNA expression may be a useful biomarker of PP, and we further demonstrate that acral dermatoses exhibit unique immunology compared to non-acral sites, with implications for clinical management.

METHODS : Retinal, optic nerve head (ONH) and distal optic nerve (ON) tissues from 8 juvenile 10-12 week-old cats (4 males and 4 females) with feline congenital glaucoma (FCG) and 5 age-matched normal control cats (3 males and 2 females) were used. Data for weekly intraocular pressure (IOP) and optic nerve axon counts were available for all subjects. Protein and gene expression in tissue cryosections were examined by immunofluorescence labeling (IF) and RNAscope in situ hybridization (ISH), respectively. Retinal tissue was IF labeled for myeloid cell marker, IBA-1 and flat-mounted. ISH for markers of infiltrating monocytes/macrophages (_CCR2_) and proinflammatory cytokines (_IL1A_, _C1QA_, _TNF_) was performed. Microglia were identified by IF of homeostatic microglial marker, P2RY12. Microscopy images wereanalyzed using Image J, QuPath and Imaris. Two-tailed unpaired t-test or Mann-Whitney test or ANOVA were used for between-group comparisons (p

Nonalcoholic fatty liver disease (NAFLD) is a global health-care problem with limited therapeutic options. To obtain a cellular resolution of pathogenesis, 82,168 single-cell transcriptomes (scRNA-seq) across different NAFLD stages were profiled, identifying hepatocytes and 12 other non-parenchymal cell (NPC) types. scRNA-seq revealed insights into the cellular and molecular mechanisms of the disease. We discovered a dual role for hepatic stellate cells in gene expression regulation and in the potential to trans-differentiate into myofibroblasts. We uncovered distinct expression profiles of Kupffer cells versus monocyte-derived macrophages during NAFLD progression. Kupffer cells showed stronger immune responses, while monocyte-derived macrophages demonstrated a capability for differentiation. Three chimeric NPCs were identified including endothelial-chimeric stellate cells, hepatocyte-chimeric endothelial cells, and endothelial-chimeric Kupffer cells. Our work identified unanticipated aspects of mouse with NAFLD at the single-cell level and advanced the understanding of cellular heterogeneity in NAFLD livers.