Cellular source and proinflammatory roles of high-mobility group box 1 in surgically injured rat vocal folds

Abstract

Objectives High mobility group box 1 (HMGB1) is a chromatin-binding protein located in the cell nucleus. Following injury, immunocompetent cells secrete HMGB1 to the extracellular milieu under the stimulation of pro-inflammatory cytokines. Extracellular HMGB1 acts a “danger signal” that instigates the innate immunity and tissue repair. We previously reported HMGB1 in the vocal fold extracellular compartment between Day 3 and Day 7 following surgical injury. In this study, we further investigated the cell source of HMGB1 and the relationship of pro-inflammatory cytokine expression and HMGB1 translocation in wounded vocal folds. Study Design Prospective animal study. Methods Bilateral vocal fold injury was performed on 122 Sprague-Dawley rats. An additional 18 rats served as uninjured controls. Animals were sacrificed at multiple time points up to 4 weeks after surgery. Immunohistochemistry co-staining was performed to identify the cell source of HMGB1. Cell markers, ED1, fibroblast-specific protein 1 (FSP1), and alpha smooth muscle actin (α-SMA) were used to identify macrophages, fibroblasts and myofibroblasts respectively. Enzyme-linked immunosorbent assays were performed to measure cytokine levels of interleukin-1beta (IL-1β) and tumor necrosis factor-alpha (TNF-α) in vocal fold tissue. Results Co-staining of HMGB1 was strong with ED1 and FSP1 but was minimal with α-SMA in injured vocal folds. Compared to uninjured controls, IL-1β and TNF-α expression increased significantly the first two days after injury. Conclusions Macrophages and fibroblasts were a major cell source of vocal fold HMGB1. Translocation of HMGB1 may be an active response to the early accumulation of IL-1β and TNF-α in the wounded vocal folds.

Towards a Physiological Scale of Vocal Fold Agent-Based Models of Surgical Injury and Repair: Sensitivity Analysis, Calibration and Verification

“…Further, fibroblasts remain the dominant cell type at Day 1 (53.81%) and Day 2 (29.37%) despite the infiltration of neutrophils and macrophages into the acute wound environment. Previous work showed that both macrophages and fibroblasts were the major cell source of damage-associated molecular patterns (DAMP), namely high mobility group box-1, in modulating the inflammatory cytokine production in acute vocal fold injury [67,109]. Our data and others collectively suggest immunological and repair functions of fibroblasts that are unique in vocal fold microenvironment [110,111].…”

A paper-based microfluidic platform with shape-memory-polymer-actuated fluid valves for automated multi-step immunoassays

“…Dysregulation of TNF-α has been associated with multiple physiological dysfunctions and diseases such as cancer 33 , Alzheimer's disease 34 , major depression 35 , and inflammatory bowel disease 36 . To demonstrate the potential clinical application of our platform, protein samples extracted from surgically injured rat vocal fold tissues 37 were subjected to both conventional and μPAD-based ELISAs for evaluation.…”

“…Finally, we conducted sandwich ELISA for detection of TNF-α in protein extractions from injured rat vocal folds 2 days ( n = 4) and 4 weeks ( n = 5) following surgery 37 . We also benchmarked our platform through testing the same samples using a commercial ELISA kit (ab100785, Abcam) on a 96-well plate.…”

High-Performance Agent-Based Modeling Applied to Vocal Fold Inflammation and Repair

“…Ongoing work on parallelizable calibration automation is being developed to refine the parameter values of the VF-ABM with additional vocal fold data collected in our laboratory (Li et al, 2012 ; Heris et al, 2015 ; Latifi et al, 2016 ; Li-Jessen et al, 2017 ) and others (King et al, 2015 ; Kishimoto et al, 2016 ). Those works are necessary to improve the biological representation of the VF-ABM for the ultimate clinical application.…”