It takes two peroxisome proliferator-activated receptors (PPAR-β/δ and PPAR-γ) to tango idiopathic pulmonary fibrosis.

Background: Idiopathic pulmonary fibrosis (IPF) is characterized by aberrant lung epithelial phenotypes, fibroblast activation, and increased extracellular matrix deposition. Transforming growth factor-beta (TGF-β)1-induced Smad signaling and downregulation of peroxisomal genes are involved in the pathogenesis and can be inhibited by peroxisome proliferator-activated receptor (PPAR)-α activation. However, the three PPARs, that is PPAR-α, PPAR-β/δ, and PPAR-γ, are known to interact in a complex crosstalk.

Adenomatous hyperplasia induced by chronic cherry pit retention mimicking an endobronchial tumor-case series and systematic review of literature.

Introduction: Endobronchial foreign body aspiration is not common in adults, but it is a life-threatening event. Recurrent pneumonias by chronic retention of foreign body often lead to initial medical presentation of the patient. However, lymphoplasmacellular bronchitis with adenomatous hyperplasia and squamous epithelium metaplasia with complete or partial blockage of lobar bronchus mimicking lung tumor is rare in literature, and this particular condition is often misdiagnosed.

Transforming Growth Factor-β1 Regulates Peroxisomal Genes/Proteins via Smad Signaling in Idiopathic Pulmonary Fibrosis Fibroblasts and Transgenic Mouse Models.

Idiopathic pulmonary fibrosis (IPF) is a chronic human disease with persistent destruction of lung parenchyma. Transforming growth factor-β1 (TGF-β1) signaling plays a pivotal role in the initiation and pathogenesis of IPF. As shown herein, TGF-β1 signaling down-regulated not only peroxisome biogenesis but also the metabolism of these organelles in human IPF fibroblasts.

PPARα-mediated peroxisome induction compensates PPARγ-deficiency in bronchiolar club cells.

Despite the important functions of PPARγ in various cell types of the lung, PPARγ-deficiency in club cells induces only mild emphysema. Peroxisomes are distributed in a similar way as PPARγ in the lung and are mainly enriched in club and AECII cells. To date, the effects of PPARγ-deficiency on the overall peroxisomal compartment and its metabolic alterations in pulmonary club cells are unknown.

Postnatal development of the bronchiolar club cells of distal airways in the mouse lung: stereological and molecular biological studies.

Club (Clara) cells are nonciliated secretory epithelial cells present in bronchioles of distal pulmonary airways. So far, no information is available on the postnatal differentiation of club cells by a combination of molecular biological, biochemical, and stereological approaches in the murine lung. Therefore, the present study was designed to investigate the changes in the club cell secretory proteins (CC10, surfactant proteins A, B and D) and club cell abundance within the epithelium of bronchioles of distal airways during the postnatal development of the mouse lung.

C22-bronchial and T7-alveolar epithelial cell lines of the immortomouse are excellent murine cell culture model systems to study pulmonary peroxisome biology and metabolism.

In pulmonary research, temperature-sensitive immortalized cell lines derived from the lung of the "immortomouse" (H-2k(b)-tsA58 transgenic mouse), such as C22 club cells and T7 alveolar epithelial cells type II (AECII), are frequently used cell culture models to study CC10 metabolism and surfactant synthesis. Even though peroxisomes are highly abundant in club cells and AECII and might fulfill important metabolic functions therein, these organelles have never been investigated in C22 and T7 cells. Therefore, we have characterized the peroxisomal compartment and its associated gene transcription in these cell lines.

Compromised peroxisomes in idiopathic pulmonary fibrosis, a vicious cycle inducing a higher fibrotic response via TGF-β signaling.

Idiopathic pulmonary fibrosis (IPF) is a devastating disease, and its pathogenic mechanisms remain incompletely understood. Peroxisomes are known to be important in ROS and proinflammatory lipid degradation, and their deficiency induces liver fibrosis. However, altered peroxisome functions in IPF pathogenesis have never been investigated.