isolation-quantitative-evaluation-brush-cells-from-mouse

Isolation and Quantitative Evaluation of Brush Cells from Mouse Tracheas

Tracheal brush cells are cholinergic chemosensory epithelial cells poised to transmit signals from the airway lumen to the immune and nervous systems. ...

Harvard Medical School

Cysteinyl leukotrienes (cysLTs), leukotriene C4 (LTC4), LTD4, and LTE4 are proinflammatory lipid mediators with pathobiologic function in asthma. LTE4, the stable cysLT, is a weak agonist for the type 1 and type 2 cysLT receptors (CysLTRs), which constrict airway smooth muscle, but elicits airflow obstruction and pulmonary inflammation in patients with asthma. We recently identified GPR99 as a high-affinity receptor for LTE4 that mediates cutaneous vascular permeability. Here we demonstrate that a single intranasal exposure to extract from the respiratory pathogen Alternaria alternata elicits profound epithelial cell (EpC) mucin release and submucosal swelling in the nasal mucosa of mice that depends on cysLTs, as it is absent in mice deficient in the terminal enzyme for cysLT biosynthesis, LTC4 synthase (LTC4S). These mucosal changes are associated with mast cell (MC) activation and absent in MC-deficient mice, suggesting a role for MCs in control of EpC function. Of the three CysLTRs, only GPR99-deficient mice are fully protected from EpC mucin release and swelling elicited by Alternaria or by intranasal LTE4 GPR99 expression is detected on lung and nasal EpCs, which release mucin to doses of LTE4 one log lower than that required to elicit submucosal swelling. Finally, mice deficient in MCs, LTC4S, or GPR99 have reduced baseline numbers of goblet cells, indicating an additional function in regulating EpC homeostasis. These results demonstrate a novel role for GPR99 among CysLTRs in control of respiratory EpC function and suggest that inhibition of LTE4 and of GPR99 may have therapeutic benefits in asthma.

Leukotriene E4 elicits respiratory epithelial cell mucin release through the G-protein-coupled receptor, GPR99.

A new spin on mast cells and cysteinyl leukotrienes: Leukotriene E activates mast cells in vivo.

Respiratory epithelial cells (EpCs) orchestrate airway mucosal inflammation in response to diverse environmental stimuli, but how distinct EpC programs are regulated remains poorly understood. Here, we report that inhalation of aeroallergens leads to expansion of airway brush cells (BrCs), specialized chemosensory EpCs and the dominant epithelial source of interleukin-25 (IL-25). BrC expansion was attenuated in mice lacking either LTC synthase, the biosynthetic enzyme required for cysteinyl leukotriene (CysLT) generation, or the EpC receptor for leukotriene E (LTE), CysLTR. LTE inhalation was sufficient to elicit CysLTR-dependent BrC expansion in the murine airway through an IL-25-dependent but STAT6-independent signaling pathway. Last, blockade of IL-25 attenuated both aeroallergen and LTE-elicited CysLTR-dependent type 2 lung inflammation. These results demonstrate that CysLTR senses the endogenously generated lipid ligand LTE and regulates airway BrC number and function.

Lora G. Bankova

Division of Rheumatology,
Allergy and Immunology,
Brigham and Women's Hospital,
Division of Rheumatology, Allergy and Immunology, Brigham and Women's Hospital

Harvard Medical School

Isolation and Quantitative Evaluation of Brush Cells from Mouse Tracheas

Lora G. Bankova

.css-o250i3{font-size:18px;font-family:Open Sans,sans-serif;line-height:21.6px;}Division of Rheumatology,Allergy and Immunology,Brigham and Women's Hospital,Division of Rheumatology, Allergy and Immunology, Brigham and Women's Hospital

Harvard Medical School

Isolation and Quantitative Evaluation of Brush Cells from Mouse Tracheas

Division of Rheumatology,
Allergy and Immunology,
Brigham and Women's Hospital,
Division of Rheumatology, Allergy and Immunology, Brigham and Women's Hospital