Airway epithelial dysfunction and mesenchymal transition in chronic obstructive pulmonary disease: Role of Oct-4.

The airway epithelium is a dynamic tissue that undergoes slow but constant renewal. Dysregulation of airway epithelial function related to cigarette smoke exposure plays an important role in the pathophysiology of COPD. Oct4 is a transcription factor responsible for maintaining cellular self-renewal and regeneration, and CD146 and CD105/Endoglin are adhesion molecules involved in cell proliferation, differentiation, epithelial-mesenchymal-transition and tissue remodeling. Bronchial biopsy specimens (BBs) were obtained from 7 healthy controls (HC) and 10 COPD and subjected to paraffin embedding; BBs from HC were also used for epithelial cell expansion and pHBEC/ALI (air-liquid interface) culture. pHBEC/ALI were exposed to cigarette smoke extract (CSE) for 7, 14 and 21 days. In BBs, Oct4, CD146 and CD105 were evaluated by immunohistochemistry. In pHBEC/ALI, the expression of Oct4, CD146, CD105 and acetyl-αtubulin was evaluated by Western Blot, MUC5AC and IL-8 measurements by ELISA. The Oct4 epithelial immunoreactivity was lower in COPD than in HC, whilst CD146 and CD105 expression was higher in COPD than in HC. In pHBEC/ALI, Transepithelial Electrical Resistance values, measured over 7 to 21 days of differentiation, decreased by 18% (2.5% CSE) and 29% (5% CSE) compared to untreated samples. Oct4 and acetyl-αtubulin were induced after one-week differentiation and downregulated by CSE in reconstituted epithelium; CD146, CD105, MUC5AC and IL-8 were increased by CSE. Oct4 de-regulation and CD146 and CD105 overexpression, induced by cigarette smoke exposure, might play a role in airway epithelial dysfunction by causing changes in self-renewal and mesenchymal transition mechanisms, leading to alteration of epithelium homeostasis and abnormal tissue remodeling involved in progression of COPD.

PBDEs affect inflammatory and oncosuppressive mechanisms via the EZH2 methyltransferase in airway epithelial cells.

AIMS: We aimed to investigate the effect of PBDEs (47, 99, 209) on cellular events involved in epigenetic modification, inflammation, and epithelial mesenchymal transition (EMT). MATERIALS AND METHODS: We studied: 1) ERK1/2 phosphorylation; 2) Enhancer of Zester Homolog 2 (EZH2); 3) Histone H3 tri-methylated in lysine 27 (H3K27me3); 4) K-RAS; 5) silencing disabled homolog 2-interacting protein gene (DAB2IP), 6) let-7a; 7) Muc5AC/Muc5B, and 8) IL-8 in a 3D in vitro model of epithelium obtained with primary Normal Human Bronchial Epithelial cells (pNHBEs) or A549 cell line, chronically exposed to PBDEs (47, 99, 209). KEY FINDINGS: PBDEs (10 nM, 100 nM and 1 µM) increased ERK1/2 phosphorylation, and EZH2, H3K27me3, and K-RAS protein expression, while decreased DAB2IP and Let-7a transcripts in pNHBEs ALI culture. Furthermore PBDEs (47, 99) (100 nM) increased Muc5AC and Muc5B mRNA, and PBDE 47 (100 nM) IL-8 mRNA via EZH2 in pNHBEs. Finally, PBDEs (100 nM) affected EZH2, H3K27me3, K-RAS protein expression, and DAB2IP, Let-7a transcripts and cell invasion in A549 cells. Gsk343 (methyltransferase EZH2 inhibitor) (1 mM) and U0126 (inhibitor of MEK1/2) (10 µM) were used to show the specific effect of PBDEs. SIGNIFICANCE: PBDE inhalation might promote inflammation/cancer via EZH2 methyltransferase activity and H3K27me3, k-RAS and ERk1/2 involvement, generating adverse health outcomes of the human lung.

Is nasobiliary tube really safe? A case report.

A case of esophageal ulcer caused by nasobiliary tube is described. This tool is not routinely considered to be a cause of major complications in the literature and to our knowledge, this is the first report of this kind of complication in nasobiliary tube placement. A 72-year-old patient presented with Charcot's triad and was demonstrated to have cholangitis with multiple biliary stones in the common bile duct. Biliary drainage was achieved through endoscopic retrograde cholangiography, endoscopic sphincterotomy, biliary tree drainage and nasobiliary tube with double pigtail. The patient presented odynophagia, dysphagia and retrosternal pain 12 h after the procedure and upper endoscopy revealed a long esophageal ulcer, which was treated conservatively. This report provides corroboration of evidence that nasobiliary tube placement has potential complications related to pressure sores. In our opinion this is a possibility to consider in informed consent forms.

Surgical treatment of coledochal cyst associated with an aberrant posterior hepatic duct: report of a case and brief literature review.

Choledochal cysts (CCs) are rare congenital cystic or fusiform dilatations of the biliary tree that can involve the extrahepatic and/or intrahepatic biliary tree. We report a case of huge type I CC associated with an aberrant posterior hepatic duct. A 52-year-old man presented with a 3-week history of upper right abdominal pain and jaundice and serologic sign of obstructive jaundice. Ultrasonography (US), magnetic resonance cholangiopancreatography and endoscopic retrograde cholangiopancreatography were performed with the diagnosis of CC type I according to the classification of Alonso-Lej and Todani-Watanabe. The indication for surgical resection was posed. The cyst was completely resected and the biliary tract was reconstructed with a double hepatico-jejunostomy using the same Roux limb, since during the surgical dissection a before unrecognized anatomical variation of the right biliary tree (aberrant posterior hepatic duct at VI-VII segment) was identified. The diagnosis of CC is often difficult and US and magnetic resonance cholangiopancreatography are necessary to definite biliary dilatation. Endoscopic retrograde cholangiopancreatography should be the most definitive and reliable procedure for the diagnosis and treatment of bilio-pancreatic disorders. Gold standard treatment is surgery (bilio-jejunostomy) and frozen-section histology should be performed to rule out the presence of cancer. In conclusion, surgery is the gold standard for the treatment of CC type I and does not depend on the age of patients, based on a substantial lifetime risk of developing cholangiocarcinoma. Preoperative study is mandatory to assess the biliary tree morphology and to research any anatomical variation.