Biology subjects

Parthasarathy, V.

Publications and source records attributed to Parthasarathy, V..

3 recordsLinked to original sources

bioRxiv2023

Single-cell RNA sequencing reveals dysregulated fibroblast subclusters in prurigo nodularis

Prurigo nodularis (PN) is an intensely pruritic, chronic inflammatory skin disease that disproportionately affects black patients. However, the pathogenesis of PN is poorly understood. We performed single-cell transcriptomic profiling, ligand receptor analysis and cell trajectory analysis of 28,695 lesional and non-lesional PN skin cells to uncover disease-identifying cell compositions and genetic characteristics. We uncovered a dysregulated role for fibroblasts (FBs) and myofibroblasts as a key pathogenic element in PN, which were significantly increased in PN lesional skin. We defined seven unique subclusters of FBs in PN skin and observed a shift of PN lesional FBs towards a cancer-associated fibroblast (CAF)-like phenotype, with WNT5A+ CAFs increased in the skin of PN patients and similarly so in squamous cell carcinoma (SCC). A multi-center PN cohort study subsequently revealed an increased risk of SCC as well as additional CAF-associated malignancies in PN patients, including breast and colorectal cancers. Systemic fibroproliferative diseases were also upregulated in PN patients, including renal sclerosis and idiopathic pulmonary fibrosis. Ligand receptor analyses demonstrated increased FB1-derived WNT5A and periostin interactions with neuronal receptors MCAM and ITGAV, suggesting a fibroblast-neuronal axis in PN. Type I IFN responses in immune cells and increased angiogenesis/permeability in endothelial cells were also observed. As compared to atopic dermatitis (AD) and psoriasis (PSO) patients, increased mesenchymal dysregulation is unique to PN with an intermediate Th2/Th17 phenotype between atopic dermatitis and psoriasis. These findings identify a pathogenic role for CAFs in PN, including a novel targetable WNT5A+ fibroblast subpopulation and CAF-associated malignancies in PN patients.

bioinformatics↗

bioRxiv2022

Dermal nerve growth factor is increased in prurigo nodularis compared to atopic dermatitis

BackgroundPrurigo nodularis (PN) is a chronic, pruritic, inflammatory skin disease characterized by hyperkeratotic nodules on the trunk and extremities. While there is growing research on the immunological basis of PN, the neuropathic and structural components of PN lesions are unknown. ObjectiveTo determine the inflammatory, neuropathic, and structural pathways in PN compared to atopic dermatitis (AD). MethodsLesional and non-lesional skin biopsies were collected from 13 PN and 6 AD patients. mRNA and protein expression in biopsies was determined using RNA-Sequencing and immunohistochemistry (IHC), respectively. Differentially expressed genes (DEGs) were identified using the DESeq2 R package and pathway level enrichment was determined using Gene Set Enrichment Analysis. IHC expression was quantified with QuPath followed by statistical comparison with the Students t-test and Mann-Whitney U. ResultsCompared to lesional AD, lesional PN had greater mRNA expression of MMPs, OSM, NGF, IL1{beta}, CXCL2, CXCL5, CXCL8, and insulin-like growth factors, and lower expression of CCL13, CCL26, EPHB1, and collagens. Compared to non-lesional AD, non-lesional PN showed upregulation of keratin-family genes. GSEA revealed that lesional PN had greater keratinization, cornified envelope, myelin sheath, TGF-beta signaling, extracellular matrix disassembly, metalloendopeptidase activity, and neutrotrophin-TRK receptor signaling, while non-lesional PN had higher keratin filament, extracellular structure organization, extracellular matrix disassembly, and angiogenesis. IHC showed increased dermal nerve growth factor (NGF) expression in lesional PN compared to lesional AD (p=0.038), and greater epidermal NGF compared to dermal NGF in non-lesional PN (p=0.014). LimitationsSingle, tertiary care center. ConclusionsPN demonstrated increased neurotrophic and extracellular matrix (ECM) remodeling signatures compared to AD, possibly explaining the morphological differences in their lesions. These signatures may therefore be important components of the PN pathogenesis and may serve as therapeutic targets.

pathology↗

bioRxiv2022

Circulating plasma IL-13 and periostin are dysregulated type 2 inflammatory biomarkers in prurigo nodularis: a cluster analysis

BackgroundPrurigo nodularis (PN) is a chronic inflammatory skin disease characterized by severe pruritus and notable disease heterogeneity. There is evidence of systemic inflammation in PN, including dysregulation observed in type 2 inflammation in subsets of patients. We aimed to elucidate which components of type 2 inflammation are dysregulated in PN patients using plasma immunoassay cytokine profiling. Materials and MethodsWhole blood was obtained from PN patients with uncontrolled disease and control patients without pruritus. Plasma samples were isolated from whole blood and assayed for IL-4, IL-5, IL-13, IgE, and periostin. For statistical analysis, ANOVA was utilized to compare PN and control patients. For multiple hypothesis, adjusted p-value was calculated with a Benjamini-Hochberg procedure with the significance threshold at 0.05. Clustering was performed using K-means clustering in R version 4.0.3. ResultsSingle-plex assays of the Th2 biomarkers demonstrated significantly elevated circulating plasma IL-13 (0.13 vs. 0.006 pg/mL, p=0.0008) and periostin (80.3 vs. 60.2 ng/mL, p=0.012) in PN patients compared to controls. IL-4 (0.11 vs. 0.02 pg/mL, p=0.30) and IL-5 (0.75 vs. 0.40 pg/mL, p=0.10) were not significantly elevated, while IgE approached significance in PN (1202.0 vs. 432.7 ng/mL, p=0.08). Clustering of PN and control patients together revealed mean silhouette maximization at two clusters. Cluster 1 (n=36) consisted of 18 PN patients and 18 controls. Cluster 2 (n=11) consisted entirely of PN patients (p<0.01) (Figure 1b). When comparing the two clusters, cluster 2 had higher levels of IL-13 (0.33 vs. 0.008 pg/mL, p=0.0001) and IL-5 (1.22 vs. 0.43 pg/mL, p=0.03) compared to cluster 1. There were no significant differences in any of the biomarkers between PN patients from cluster 1 and the healthy control patients in this cluster. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=167 SRC="FIGDIR/small/495051v1_fig1.gif" ALT="Figure 1"> View larger version (29K): org.highwire.dtl.DTLVardef@101432dorg.highwire.dtl.DTLVardef@1e16d01org.highwire.dtl.DTLVardef@bb8edborg.highwire.dtl.DTLVardef@19fd785_HPS_FORMAT_FIGEXP M_FIG O_FLOATNOFigure 1.C_FLOATNO Single-plex plasma immunoassays of prurigo nodularis vs. controls (a) Plasma single-plex immunoassays (b) Heatmap of Z-scored biomarker levels for each patient, delineated by cluster. PN, prurigo nodularis; HC, healthy control C_FIG ConclusionsThis study demonstrates elevation of IL-13 and periostin in PN patients with distinct clusters with varying degrees of type 2 inflammation. Given this heterogeneity, further biomarker studies with single-cell resolution will provide better guidance towards future precision medicine approaches in the treatment of PN.

immunology↗