Background/aims: Cigarette smoking is a major risk factor of chronic obstructive pulmonary disease. This study aimed to examine the effects of cigarette smoke extract (CSE) on alveolar type II epithelial cells (AECII) and investigate the underlying mechanism.
Methods: Primary AECII were isolated from rat lung tissues and exposed to CSE. Apoptosis was detected by flow cytometry. Protein expression was detected by Western blot analysis.
Results: Primary rat AECII maintained morphological and physiological characteristic after 3 passages. CSE increased the expression of ER specific pro-apoptosis factors CHOP and caspase 12, and the phosphorylation of JNK in AECII. CSE activated ER stress signaling and increased the phosphorylation of PERK, eIF2α and IRE1. Furthermore, CSE induced the expression of Hrd1, a key factor of ER-associated degradation, in AECII. Knockdown of Hrd1 led to more than 2 fold increase of apoptosis, while overexpression of Hrd1 attenuated CSE induced apoptosis of AECII.
Conclusions: Our results suggest that ER stress induces HRD1 to protect alveolar type II epithelial cells from apoptosis induced by CSE.
Oxygen is a fundamental requirement for cellular metabolism. Hypoxia is a state of oxygen deprivation of the tissues. Cells develop numerous adaptive mechanisms to survive hypoxic insult.
Cellulose nanofibrils (CNFs) are advanced biomaterials valued for their strength, lightweight nature, and low thermal expansion, making them suitable for diverse industrial applications. However, their potential inhalation risks necessitate thorough safety evaluations. This study investigates the pulmonary inflammatory effects and retention of CNFs following intratracheal instillation in rats.
Acute lung injury (ALI) and its severe form, acute respiratory distress syndrome (ARDS), result from pulmonary edema and alveolar-capillary barrier disruption due to inflammation, often triggered by conditions like sepsis. Sepsis-induced ALI (SALI) involves extensive damage to vascular endothelium and alveolar epithelium, leading to respiratory failure. Our study explores ferroptosis, an iron-dependent cell death pathway, and calcium dysregulation in SALI.
Background: Bronchopulmonary dysplasia (BPD), a chronic lung disease prevalent among premature infants, significantly impacts lifelong respiratory health. Macrophages, as key components of the innate immune system, play a role in lung tissue inflammation and injury, exhibiting diverse and dynamic functionalities. The M4 macrophage, a distinctive subtype primarily triggered by chemokine (C-X-C motif) ligand 4 (CXCL4), has been implicated in pulmonary inflammatory and fibrotic processes.
Background: Sepsis is commonly associated with acute respiratory distress syndrome (ARDS). Although the exaggerated inflammation may damage intact lung tissues, a percentage of patients with ARDS are reportedly immunocompromised, with worse outcomes. Herein, using a murine sepsis model, time-course immune reprogramming after sepsis was evaluated to explore whether the host is immunocompromised.
