Apoptosis is of considerable importance in the pathogenesis of emphysema, and recent studies show that endoplasmic reticulum (ER) stress is involved in emphysema. In our research, we investigated the role of protein kinase RNA (PKR)-like ER kinase (PERK)/ eukaryotic initiation factor 2 alpha (eIF2α) pathway, the CCAAT enhancer-binding protein-homologous protein (CHOP) expression, caspase-12 activation and apoptosis in emphysema results from cigarette smoke (CS) exposure. Expression of phosphorylated-PERK (p-PERK), phospholated-eIF2α (p-eIF2α),CHOP and caspase-12 as well as the apoptosis rate are remarkably increased in rats after exposure to 2 months CS compared with control rats, significantly elevated in rats exposed to 4 months CS over rats exposed only to 2 months CS, and slightly decreased in ex-smoking rats in contrast to rats exposed to 4 months CS. Taken together, our results show that CS induces ER stress in lung epithelial cells, which may subsequently lead to lung injury in rats, and this might be a novel target for protection of pulmonary epithelial cells from ER stress injury in emphysema.
BackgroundNon–small cell lung cancer (NSCLC) is one of the leading malignant tumors worldwide. Aberrant gene promoter methylation contributes to NSCLC, and PRDM is a tumor suppressor gene family that possesses histone methyltransferase activity. This study aimed to investigate whether aberrant methylation of PRDM promoter is involved in NSCLC.Materials and methodsPrimary tumor tissues, adjacent nontumorous tissues, and distant lung tissues were collected from 75 NSCLC patients including 52 lung squamous cell carcinoma (LSCC) patients and 23 lung adenocarcinoma patients. The expression of PRDMs was detected by polymerase chain reaction (PCR), Western blot, and immunohistochemical analysis. The methylation of PRDM promoters was detected by methylation-specific PCR. The correlation of methylation and expression of PRDMs with clinicopathological characteristics of patients were analyzed.ResultsmRNA expression of PRDM2, PRDM5, and PRDM16 was low or absent in tumor tissues compared to distant lung tissues. The methylation frequencies of PRDM2, PRDM5, and PRDM16 in tumor tissues were significantly higher than those in distal lung tissues. In LSCC patients, methylation of PRDM2 and PRDM16 was correlated with smoking status and methylation of PRDM5 was correlated with tumor differentiation.ConclusionThe expression of PRDM2, PRDM5, and PRDM16 is low or absent in NSCLC, and this is mainly due to gene promoter methylation. Smoking may be an important cause of PRDM2 and PRDM16 methylation in NSCLC.
Rapid advances in the molecular genetics of Duchenne muscular dystrophy (DMD) and the discovery and localization of the gene product dystrophin has brought new hope that successful treatment for this disease may not be too far away. Dystrophin has been postulated to have a mechanical function, helping to resist stress associated with muscle contraction. The presence of dystrophin in low concentrations in muscle cells, its expression in nervous tissue and the observation that hypercontraction of the sarcomeres precedes membrane rupture make the hypothesis unlikely. On the basis of an analogy with a cytoskeletal protein ankyrin, which is associated with the sodium/potassium adenosine triphosphatase (ATPase) in the kidney, it is possible that dystrophin deficiency leads initially to an increased but inefficient calcium-ATPase activity, which pumps calcium out of the cell. Partial failure of the pump would result in intracellular accumulation of calcium, hypercontractions of the sarcomeres, rupture of the cell membrane, massive influx of calcium and cell necrosis.
Mantle cell lymphoma (MCL) is a rare type of B‐cell non‐Hodgkin’s lymphoma that commonly affects extranodal sites; however, tracheobronchial involvement is rare. We report the case of a 65‐year‐old male who presented with cough and dyspnoea. A chest computed tomography (CT) revealed irregular wall thickening of the trachea and bilateral bronchi and bilateral bronchiectasis. A bronchoscopy revealed a diffuse irregular surface of the tracheal and bilateral bronchial mucosa and polyposis‐like lesions. He was diagnosed with MCL based on an endobronchial biopsy, and then, the diagnosis was confirmed with a biopsy of the fluorodeoxyglucose (FDG)‐avid nasal mucosal soft tissue.
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