RESUMEN
Cigarette smoke (CS) is a prevalent chemical indoor air contaminant known to be the primary cause of EMT during airway remodeling in COPD. While some evidence indicates the involvement of SMAD4 in EMT across certain diseases, its specific role in CS-induced EMT in airway remodeling associated with COPD is not established. In our research, we observed a substantial upregulation in SMAD4 expression, O-GlcNAcylation and EMT in patients with COPD, as well as in vitro and in vivo COPD models induced by CS, than those of the controls. Downregulation of SMAD4 resulted in a reduction in CS-induced EMT in vitro and in vivo. As a post-translational modification of proteins, O-GlcNAcylation is dynamically controlled by the duo of enzymes: O-linked N-acetylglucosamine (O-GlcNAc) transferase (OGT) and O-GlcNAcase (OGA). We further discovered the enhancement of O-GlcNAcylation levels induced by CS was due to an elevated OGT expression, as the expression of OGA remained unchanged. Using an OGT inhibitor (OSMI-1) counteracted the effects of SMAD4 on EMT. Whereas, overexpressing OGT increased SMAD4 expression and promoted EMT. OGT-mediated SMAD4 O-GlcNAcylation shielded SMAD4 from proteasomal degradation by reducing its ubiquitination, thereby aiding in SMAD4 stabilization in response to EMT induced by CS. Overall, this research uncovers a fresh pathway for CS-induced EMT in the airway remodeling of COPD and offers valuable insights.
RESUMEN
INTRODUCTION: Segmentectomy and lobectomy are the main surgical procedures for early-stage lung cancer. However, few studies have analysed patient-reported outcomes after segmentectomy versus lobectomy. This study aims to compare patient-reported outcomes-such as symptoms, daily functioning and quality of life-between thoracoscopic segmentectomy and lobectomy for early-stage lung cancer during the 1 year after surgery. METHODS AND ANALYSIS: Overall, 788 newly diagnosed patients with early-stage lung cancer (tumour size ≤2 cm), who are scheduled to undergo thoracoscopic segmentectomy or lobectomy, will be recruited in this multicentre, prospective cohort study. The patients will receive standardised care after surgery. The Perioperative Symptom Assessment for Lung Surgery-a validated lung cancer surgery-specific scale-will be used to assess the symptoms and functions at baseline, at discharge and monthly after discharge for 1 year. The European Organization for Research and Treatment of Cancer Quality of Life Questionnaire Core 30 and Lung Cancer module 29 will be used to assess the patients' quality of life at the same time points. The primary outcome will be the shortness of breath scores during the first year after thoracoscopic segmentectomy and lobectomy and will be compared using mixed-effects models. The secondary outcomes will include other symptoms, indicators of daily functioning, quality of life scores and traditional clinical outcomes. These will be compared using mixed-effects models and the Student's t-test, non-parametric test or Χ2 test. Propensity score matching will be used to ensure an even distribution of known confounders between the groups. ETHICS AND DISSEMINATION: The Ethics Committee for Medical Research and New Medical Technology of Sichuan Cancer Hospital approved this study (approval number: SCCHEC-02-2022-002). All participants will be instructed to provide informed consent. The manuscript is based on protocol version 3.0. The study results will be presented at medical conferences and published in peer-reviewed journals. TRIAL REGISTRATION NUMBER: ChiCTR2200060753.