Multimodal Single‐Cell Analyses Outline the Immune Microenvironment and Therapeutic Effectors of Interstitial Cystitis/Bladder Pain Syndrome

Abstract

Interstitial cystitis/bladder pain syndrome (IC/BPS) has a significant impact on quality of life, but the etiopathogenesis remains largely unknown. The bladder microenvironment of patients with IC/BPS to obtain biological evidence supporting diagnosis and novel therapy is systematically characterized. Single-cell RNA sequencing (scRNA-seq) and image mass cytometry (IMC) are applied to bladder biopsies of the IC/BPS cohort. A total of 42 distinct cell clusters are identified from different groups. The increased hyperactivated Th1-biased response, but not Th2-biased response, and decreased immunosuppressive Treg are elucidated in the bladder microenvironment of non-Hunner-type IC (NHIC)/Hunner-type IC (HIC). M2/M2-like macrophage extends in the HIC and M1-like macrophage extends in NHIC, all of which secrete a range of chemokines with different pattern. The pro-inflammatory mediators, TNF-𝜶, produced by tissue-resident macrophages and IL6, by the inflammatory fibroblasts are identified as key mediators of IC/BPS pathogenesis. Additionally, a regulatory network between different cell types is observed as a shift from structural cell communication in unaffected normal bladder to a Macrophage-Endothelial-dominated interactome in NHIC/HIC. The results demonstrate the high heterogeneity in NHIC/HIC, and provide an essential resource for diagnosis, and treatment of IC/BPS in the future by highlighting the importance of the microenvironment of bladder mucosa.

Comprehensive transcriptome profiling of urothelial cells following TNFα stimulation in an in vitro interstitial cystitis/bladder pain syndrome model

“…IC/BPS patients have altered urothelial cell expression of proinflammatory cytokines and chemokines, including IL1b, and TNFa (14,43), while urine samples from IC/BPS patients contain elevated levels of IL1b, IL8, CXCL1, CXCL10 (44)(45)(46)(47), possibly derived from urothelial cells, as observed in our study, where significantly higher concentration of these cytokines and chemokines was determined in TNFa-stimulated cells. Abnormalities in specific proinflammatory signaling networks that contribute to alterations in bladder immune and structural cell phenotypes were recently uncovered by Su et al (40), who performed single cell RNA seq in bladder tissues of patients with IC/BPS. They have also shown that immune response during IC/BPS is characterized by extensive infiltration of TNFa-producing neutrophil granulocytes and macrophages in bladder tissue (40).…”

“…Abnormalities in specific proinflammatory signaling networks that contribute to alterations in bladder immune and structural cell phenotypes were recently uncovered by Su et al (40), who performed single cell RNA seq in bladder tissues of patients with IC/BPS. They have also shown that immune response during IC/BPS is characterized by extensive infiltration of TNFa-producing neutrophil granulocytes and macrophages in bladder tissue (40). Their observations go hand in hand with our findings suggesting an active role of urothelial cells in shaping the bladder immunity through altered proinflammatory cytokine and…”

“…The two most frequently cited in vitro IC/BPS models include LPS‐ and TNFα-induced inflammation of cancer RT4 and T24 urothelial cells ( 39 ). While LPS-induced model of inflammation is less appropriate since exclusion of bacterial infection is one of the criteria for the diagnosis of IC/BPS ( 1 ), TNFα, on the other hand, has been recognized as one of the most important proinflammatory cytokines involved in the pathophysiological process of IC/BPS ( 40 , 41 ) and was therefore used as an inflammatory trigger in the current study.…”

“…( 40 ), who performed single cell RNA seq in bladder tissues of patients with IC/BPS. They have also shown that immune response during IC/BPS is characterized by extensive infiltration of TNFα-producing neutrophil granulocytes and macrophages in bladder tissue ( 40 ). Their observations go hand in hand with our findings suggesting an active role of urothelial cells in shaping the bladder immunity through altered proinflammatory cytokine and chemokine signaling pathways.…”

A novel strategy to dissect multifaceted macrophage function in human diseases

“…MacSpectrum and AtheroSpectrum have been published both as free web tools and as R packages (https://macspectrum.uconn.edu), and they have since been used to further evaluate macrophages in a number of disease conditions, including obesity, 79,80 diabetes, 81 pulmonary fibrosis, 82 liver disease, 83,84 cancer, 85,86 and interstitial cystitis 87 in addition to our own work on CVD 58 and adipose tissue thermogenesis. 88 In the future, we hope that these tools are applied to characterize macrophage functions in additional pathologies.…”