Evaluation of combination long-acting beta-2 agonists and inhaled glucocorticosteroids for treatment of asthma

β2-Adrenergic receptor agonists as a treatment for diabetic kidney disease

We have previously shown that the long-acting β2-adrenergic receptor (β2-AR) agonist formoterol induced recovery from acute kidney injury in mice. To determine whether formoterol protected against diabetic nephropathy, the most common cause of end-stage kidney disease (ESKD), we used a high-fat diet (HFD), a murine type 2 diabetes model, and streptozotocin, a murine type 1 diabetes model. Following formoterol treatment, there was a marked recovery from and reversal of diabetic nephropathy in HFD mice compared with those treated with vehicle alone at the ultrastructural, histological, and functional levels. Similar results were seen after formoterol treatment in mice receiving streptozotocin. To investigate effects in humans, we performed a competing risk regression analysis with death as a competing risk to examine the association between Veterans with chronic kidney disease (CKD) and chronic obstructive pulmonary disease (COPD), who use β2-AR agonists, and Veterans with CKD but no COPD, and progression to ESKD in a large national cohort of Veterans with stage 4 CKD between 2011 and 2013. Veterans were followed until 2016 or death. ESKD was defined as the initiation of dialysis and/or receipt of kidney transplant. We found that COPD was associated with a 25.6% reduction in progression from stage 4 CKD to ESKD compared with no COPD after adjusting for age, diabetes, sex, race-ethnicity, comorbidities, and medication use. Sensitivity analysis showed a 33.2% reduction in ESKD in Veterans with COPD taking long-acting formoterol and a 20.8% reduction in ESKD in Veterans taking other β2-AR agonists compared with those with no COPD. These data indicate that β2-AR agonists, especially formoterol, could be a treatment for diabetic nephropathy and perhaps other forms of CKD.NEW & NOTEWORTHY Diabetic nephropathy is the most common cause of ESKD. Formoterol, a long-acting β2-adrenergic receptor (β2-AR) agonist, reversed diabetic nephropathy in murine models of type 1 and 2 diabetes. In humans, there was an association with protection from progression of CKD in patients with COPD, by means of β2-AR agonist intake, compared with those without COPD. These data indicate that β2-AR agonists, especially formoterol, could be a new treatment for diabetic nephropathy and other forms of CKD.

Corticosteroid and long-acting ß-agonist therapy reduces epithelial goblet cell metaplasia

BACKGROUND

Bronchial epithelial goblet cell metaplasia (GCM) with hyperplasia is a prominent feature of asthma, but the effects of treatment with corticosteroids alone or in combination with a long-acting β₂ -adrenergic receptor agonist (LABA) on GCM in the bronchial epithelium are unknown.

OBJECTIVES

To determine whether corticosteroid alone or in combination with a LABA alters protein and gene expression pathways associated with IL-13-induced goblet cell metaplasia.

RESULTS

We evaluated the effects of fluticasone propionate (FP) and of salmeterol (SM), on the response of well-differentiated cultured bronchial epithelial cells to interleukin-13 (IL-13). Outcome measures included gene expression of SPDEF/FOXa2, gene expression and protein production of MUC5AC/MUC5B and morphologic appearance of cultured epithelial cell sheets. We additionally analysed expression of these genes in bronchial epithelial brushings from healthy, steroid-naïve asthmatic and steroid-treated asthmatic subjects. In cultured airway epithelial cells, FP treatment inhibited IL-13-induced suppression of FOXa2 gene expression and up-regulation of SPDEF, alterations in gene and protein measures of MUC5AC and MUC5B and induction of GCM. The addition of SM synergistically modified the effects of FP modestly-only for gel-forming mucin MUC5AC. In bronchial epithelial cells recovered from asthmatic vs healthy human subjects, we found FOXa2 and MUC5B gene expression to be reduced and SPDEF and MUC5AC gene expression to be increased; these alterations were not observed in bronchial epithelial cells recovered after treatment with inhaled corticosteroids.

CONCLUSION AND CLINICAL RELEVANCE

Corticosteroid treatment inhibits IL-13-induced GCM of the airways in asthma, possibly through its effects on SPDEF and FOXa2 regulation of mucin gene expression. These effects are modestly augmented by the addition of a long-acting ß-agonist. As we found evidence for drug treatment counteracting the effects of IL-13 on the epithelium, we conclude that further exploration into the mechanisms by which corticosteroids and long-acting β₂ -adrenergic agonists confer protection against pathologic airway changes is warranted.