Laryngeal widening and adequate ventilation by expiratory pressure load training improve aerobic capacity in COPD: a randomised controlled trial

RATIONALE

Despite strategies acting on peripheral airway obstruction in chronic obstructive pulmonary disease (COPD), exercise intolerance remains inadequately improved. We hypothesised that laryngeal narrowing is a potential treatment target of expiratory pressure load training (EPT) to improve exercise intolerance in COPD.

METHODS

The effect of 3-month EPT was assessed in 47 patients with COPD divided into Global Initiative for Chronic Obstructive Lung Disease (GOLD) mild-to-moderate (I-II) and severe-to-very severe (III-IV), randomly allocating 1:1 to EPT or control groups. The primary outcome was endurance time in the constant work rate exercise test in GOLD III-IV patients.

RESULTS

Compared with controls, EPT increased: (1) endurance time, with estimated treatment effect: +703 (95% CI: 379 to 1031) s, p=0.0008 (GOLD I-II); +390 (95% CI: 205 to 574) s, p=0.0006 (GOLD III-IV); (2) peak oxygen uptake (p=0.0086 in GOLD I-II; p=0.0004 in GOLD III-IV); (3) glottic dilatation ratio at maximum collapse on laryngoscopy in the submaximal exercise (p=0.0062 in GOLD I-II; p=0.0001 in GOLD III-IV); and (4) the inflection point of expiratory tidal volume relative to minute ventilation during the incremental exercise (p=0.0015 in GOLD I-II; p=0.0075 in GOLD III-IV). Across GOLD grades, the responses of glottic dilatation ratio at maximum collapse and the expiratory tidal volume at the inflection point were selected as more influential variables correlating with the improvement in peak oxygen uptake and endurance time, respectively.

CONCLUSION

These results show that EPT improved aerobic capacity and endurance time with larger laryngeal widening and adequate ventilation despite advanced COPD.

TRIAL REGISTRATION NUMBER

UMIN000041250.

Ezrin Modulates the Cell Surface Expression of Programmed Cell Death Ligand-1 in Human Cervical Adenocarcinoma Cells

Cancer cells employ programmed cell death ligand-1 (PD-L1), an immune checkpoint protein that binds to programmed cell death-1 (PD-1) and is highly expressed in various cancers, including cervical carcinoma, to abolish T-cell-mediated immunosurveillance. Despite a key role of PD-L1 in various cancer cell types, the regulatory mechanism for PD-L1 expression is largely unknown. Understanding this mechanism could provide a novel strategy for cervical cancer therapy. Here, we investigated the influence of ezrin/radixin/moesin (ERM) family scaffold proteins, crosslinking the actin cytoskeleton and certain plasma membrane proteins, on the expression of PD-L1 in HeLa cells. Our results showed that all proteins were expressed at mRNA and protein levels and that all ERM proteins were highly colocalized with PD-L1 in the plasma membrane. Interestingly, immunoprecipitation assay results demonstrated that PD-L1 interacted with ERM as well as actin cytoskeleton proteins. Furthermore, gene silencing of ezrin, but not radixin and moesin, remarkably decreased the protein expression of PD-L1 without affecting its mRNA expression. In conclusion, ezrin may function as a scaffold protein for PD-L1; regulate PD-L1 protein expression, possibly via post-translational modification in HeLa cells; and serve as a potential therapeutic target for cervical cancer, improving the current immune checkpoint blockade therapy.