Sympathetic Nerve Mediated Spinal Glia Activation Underlies Itch in a Cutaneous T-Cell Lymphoma Model.
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ABSTRACT:
SUBMITTER: Tong F
PROVIDER: S-EPMC9068854 | biostudies-literature | 2022 Apr
REPOSITORIES: biostudies-literature
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Sympathetic Nerve Mediated Spinal Glia Activation Underlies Itch in a Cutaneous T-Cell Lymphoma Model.
Tong Fang F He Qianru Q Du Wan-Jie WJ Yang Huan H Du Dongping D Pu Shaofeng S Han Qingjian Q
Neuroscience bulletin 20211206 4
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Project description:BackgroundCutaneous T-cell lymphoma (CTCL) is a chronic and progressive disease that has a major impact on quality of life (QoL).ObjectivesTo describe the impact of the different stages of disease in patients with classical mycosis fungoides, folliculotropic mycosis fungoides, and Sézary syndrome on generic- and dermatology-specific QoL and the relation with itch.MethodsA cross-sectional cohort study of patients with classical mycosis fungoides, folliculotropic mycosis fungoides, and Sézary syndrome was performed. Outcomes were the Skindex-29 score, Impact of Chronic Skin Disease on Daily Life which includes a visual analogue scale itch, and RAND-12.ResultsOne hundred six patients with CTCL were included. Compared to the total mycosis fungoides group, patients with Sézary syndrome had significantly worse Skindex-29 scores. Patients with advanced disease had statistically higher scores for the symptom (P = .007), functioning (P = .002), and total score (P = .012). The degree of itching was strongly correlated with the total Skindex-29 score (R = 0.713, P < .001).ConclusionThe different stages of CTCL can have a significant effect on multiple domains of generic- and dermatology-specific QoL. Itch was strongly correlated with QoL and therefore can be used as an overall QoL indicator. The effect on QoL, even in patients with early-stage disease, should not be underestimated.
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Project description:MicroRNA (miRNA) dysregulation is a hallmark of cutaneous T-cell lymphoma (CTCL), an often-fatal malignancy of skin-homing CD4+ T cells for which there are few effective therapies. The role of microRNAs (miRs) in controlling epigenetic modifier-dependent transcriptional regulation in CTCL is unknown. In this study, we characterize a novel miR dysregulation that contributes to overexpression of the epigenetic reader bromodomain-containing protein 4 (BRD4). We used patient CD4+ T cells to show diminished levels of miR-29b compared with healthy donor cells. Patient cells and miR-29b-/- mouse cells revealed an inverse relationship between miR-29b and BRD4, the latter of which is overexpressed in these cells. Chromatin immunoprecipitation and sequencing analysis revealed increased genome-wide BRD4 occupancy at promoter and enhancer regions in CD4+ T cells from CTCL patients. The cumulative result of BRD4 binding was increased expression of tumor-associated genes such as NOTCH1 and RBPJ, as well as the interleukin-15 (IL-15) receptor complex, the latter enhancing IL-15 autocrine signaling. Furthermore, we confirm the in vivo relevance of this pathway in our IL-15 transgenic mouse model of CTCL by showing that interference with BRD4-mediated pathogenesis, either by restoring miR-29b levels via bortezomib treatment or by directly inhibiting BRD4 binding via JQ1 treatment, prevents progression of CTCL. We describe a novel oncogenic pathway featuring IL-15, miR-29b, and BRD4 in CTCL and suggest targeting of these components as a potentially effective therapy for CTCL patients.
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Project description:Itch is a sensation that promotes the desire to scratch, which can be evoked by mechanical and chemical stimuli. In the spinal cord, neurons expressing the gastrin-releasing peptide receptor (GRPR) have been identified as specific mediators of itch. However, our understanding of the GRPR population in the spinal cord, and thus how these neurons exercise their functions, is limited. For this purpose, we constructed a Cre line designed to target the GRPR population of neurons (Grpr-Cre). Our analysis revealed that Grpr-Cre cells in the spinal cord are predominantly excitatory interneurons that are found in the dorsal lamina, especially in laminae II-IV. Application of the specific agonist gastrin-releasing peptide induced spike responses in 43.3% of the patched Grpr-Cre neurons, where the majority of the cells displayed a tonic firing property. Additionally, our analysis showed that the Grpr-Cre population expresses Vglut2 mRNA, and mice ablated of Vglut2 in Grpr-Cre cells (Vglut2-lox;Grpr-Cre mice) displayed less spontaneous itch and attenuated responses to both histaminergic and nonhistaminergic agents. We could also show that application of the itch-inducing peptide, natriuretic polypeptide B, induces calcium influx in a subpopulation of Grpr-Cre neurons. To summarize, our data indicate that the Grpr-Cre spinal cord neural population is composed of interneurons that use VGLUT2-mediated signaling for transmitting chemical and spontaneous itch stimuli to the next, currently unknown, neurons in the labeled line of itch.
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