title: Carbocysteine counteracts the effects of cigarette smoke on cell growth and on the SIRT1/FoxO3 axis in bronchial epithelial cells.
abstract: Cigarette smoke may accelerate cellular senescence by increasing oxidative stress. Altered proliferation and altered expression of anti-aging factors, including SIRT1 and FoxO3, characterise cellular senescence. The effects of carbocysteine on the SIRT1/FoxO3 axis and on downstream molecular mechanisms in human bronchial epithelial cells exposed to cigarette smoke are largely unknown.
  
  
  
  Aim of this study was to explore whether carbocysteine modulated SIRT1/FoxO3 axis, and downstream molecular mechanisms associated to cellular senescence, in a bronchial epithelial cell line (16-HBE) exposed to cigarette smoke.
  
  
  
  16HBE cells were stimulated with/without cigarette smoke extracts (CSE) and carbocysteine. Flow cytometry and clonogenic assay were used to assess cell proliferation; western blot analysis was used for assessing nuclear expression of SIRT1 and FoxO3. The nuclear co-localization of SIRT1 and FoxO3 was assessed by fluorescence microscopy. Beta galactosidase (a senescence marker) and SIRT1 activity were assessed by specific staining and colorimetric assays, respectively. ChiP Assay and flow cytometry were used for assessing survivin gene regulation and protein expression, respectively.
  
  
  
  CSE decreased cell proliferation, the nuclear expression of SIRT1 and FoxO3 and increased beta galactosidase staining. CSE, reduced SIRT1 activity and FoxO3 localization on survivin promoter thus increasing survivin expression. In CSE stimulated bronchial epithelial cells carbocysteine reverted these phenomena by increasing cell proliferation, and SIRT1 and FoxO3 nuclear expression, and by reducing beta galactosidase staining and survivin expression.
  
  
  
  The study shows for the first time that carbocysteine may revert some senescence processes induced by oxidative stress due to cigarette smoke exposure.
authors.affiliation: Istituto di Biomedicina e Immunologia Molecolare, Consiglio Nazionale delle Ricerche, Palermo, Italy. Electronic address: pace@ibim.cnr.it.
authors.forename: E
authors.initials: E
authors.lastname: Pace
authors.affiliation: Istituto di Biomedicina e Immunologia Molecolare, Consiglio Nazionale delle Ricerche, Palermo, Italy.
authors.forename: S
authors.initials: S
authors.lastname: Di Vincenzo
authors.affiliation: Istituto di Biomedicina e Immunologia Molecolare, Consiglio Nazionale delle Ricerche, Palermo, Italy.
authors.forename: M
authors.initials: M
authors.lastname: Ferraro
authors.affiliation: Istituto di Biomedicina e Immunologia Molecolare, Consiglio Nazionale delle Ricerche, Palermo, Italy.
authors.forename: A
authors.initials: A
authors.lastname: Bruno
authors.affiliation: Istituto di Biomedicina e Immunologia Molecolare, Consiglio Nazionale delle Ricerche, Palermo, Italy.
authors.forename: P
authors.initials: P
authors.lastname: Dino
authors.affiliation: Dipartimento Biomedico di Medicina Interna e Specialistica (Di.Bi.M.I.S), University of Palermo, Palermo, Italy.
authors.forename: M R
authors.initials: MR
authors.lastname: Bonsignore
authors.affiliation: Dipartimento Biomedico di Medicina Interna e Specialistica (Di.Bi.M.I.S), University of Palermo, Palermo, Italy.
authors.forename: S
authors.initials: S
authors.lastname: Battaglia
authors.affiliation: Dompè Medical Affair, Milan, Italy.
authors.forename: F
authors.initials: F
authors.lastname: Saibene
authors.affiliation: Dompè Medical Affair, Milan, Italy.
authors.forename: L
authors.initials: L
authors.lastname: Lanata
authors.affiliation: Istituto di Biomedicina e Immunologia Molecolare, Consiglio Nazionale delle Ricerche, Palermo, Italy.
authors.forename: M
authors.initials: M
authors.lastname: Gjomarkaj
mesh_terms: D017209:Apoptosis / Q000187:drug effects; D002233:Carbocysteine / Q000494:pharmacology*; D002460:Cell Line; D049109:Cell Proliferation / Q000187:drug effects; D016922:Cellular Senescence / Q000187:drug effects; D004847:Epithelial Cells / Q000187:drug effects; D000071316:Forkhead Box Protein O3 / Q000187:drug effects / Q000378:metabolism*; D006801:Humans; D018384:Oxidative Stress / Q000187:drug effects; D056564:Sirtuin 1 / Q000187:drug effects / Q000378:metabolism*; D012906:Smoke / Q000009:adverse effects*; D014026:Nicotiana / Q000009:adverse effects*
chemical_list: C499517:FOXO3 protein, human; D000071316:Forkhead Box Protein O3; D012906:Smoke; D002233:Carbocysteine; C447939:SIRT1 protein, human; D056564:Sirtuin 1
keywords: Bronchial epithelial cells; Carbocysteine; Cigarette smoke; FoxO3; SIRT1