Publications by authors named "Denzil P Mathew"

3 Publications

  • Page 1 of 1

Cigarette smoking causes epigenetic changes associated with cardiorenal fibrosis.

Physiol Genomics 2016 12 27;48(12):950-960. Epub 2016 Oct 27.

College of Medicine and Life Sciences, Department of Medicine, Division of Cardiovascular Medicine and Center for Hypertension and Personalized Medicine, University of Toledo, Toledo, Ohio.

Clinical studies indicate that smoking combustible cigarettes promotes progression of renal and cardiac injury, leading to functional decline in the setting of chronic kidney disease (CKD). However, basic studies using in vivo small animal models that mimic clinical pathology of CKD are lacking. To address this issue, we evaluated renal and cardiac injury progression and functional changes induced by 4 wk of daily combustible cigarette smoke exposure in the 5/6th partial nephrectomy (PNx) CKD model. Molecular evaluations revealed that cigarette smoke significantly (P < 0.05) decreased renal and cardiac expression of the antifibrotic microRNA miR-29b-3 and increased expression of molecular fibrosis markers. In terms of cardiac and renal organ structure and function, exposure to cigarette smoke led to significantly increased systolic blood pressure, cardiac hypertrophy, cardiac and renal fibrosis, and decreased renal function. These data indicate that decreased expression of miR-29b-3p is a novel mechanism wherein cigarette smoke promotes accelerated cardiac and renal tissue injury in CKD. (155 words).
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http://dx.doi.org/10.1152/physiolgenomics.00070.2016DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5206391PMC
December 2016

Electronic cigarette inhalation alters innate immunity and airway cytokines while increasing the virulence of colonizing bacteria.

J Mol Med (Berl) 2016 06 25;94(6):667-79. Epub 2016 Jan 25.

Pulmonary and Critical Care Section, VA San Diego Healthcare System, 3350 La Jolla Village Dr, MC 111J, San Diego, CA, 92161, USA.

Unlabelled: Electronic (e)-cigarette use is rapidly rising, with 20 % of Americans ages 25-44 now using these drug delivery devices. E-cigarette users expose their airways, cells of host defense, and colonizing bacteria to e-cigarette vapor (EV). Here, we report that exposure of human epithelial cells at the air-liquid interface to fresh EV (vaped from an e-cigarette device) resulted in dose-dependent cell death. After exposure to EV, cells of host defense-epithelial cells, alveolar macrophages, and neutrophils-had reduced antimicrobial activity against Staphylococcus aureus (SA). Mouse inhalation of EV for 1 h daily for 4 weeks led to alterations in inflammatory markers within the airways and elevation of an acute phase reactant in serum. Upon exposure to e-cigarette vapor extract (EVE), airway colonizer SA had increased biofilm formation, adherence and invasion of epithelial cells, resistance to human antimicrobial peptide LL-37, and up-regulation of virulence genes. EVE-exposed SA were more virulent in a mouse model of pneumonia. These data suggest that e-cigarettes may be toxic to airway cells, suppress host defenses, and promote inflammation over time, while also promoting virulence of colonizing bacteria.

Key Message: Acute exposure to e-cigarette vapor (EV) is cytotoxic to airway cells in vitro. Acute exposure to EV decreases macrophage and neutrophil antimicrobial function. Inhalation of EV alters immunomodulating cytokines in the airways of mice. Inhalation of EV leads to increased markers of inflammation in BAL and serum. Staphylococcus aureus become more virulent when exposed to EV.
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http://dx.doi.org/10.1007/s00109-016-1378-3DOI Listing
June 2016

Analysis of the effects of cigarette smoke on staphylococcal virulence phenotypes.

Infect Immun 2015 Jun 30;83(6):2443-52. Epub 2015 Mar 30.

Medicine Service, Veterans Affairs San Diego Healthcare System, San Diego, California, USA Department of Medicine, University of California, San Diego, California, USA

Cigarette smoking is the leading preventable cause of death, disease, and disability worldwide. It is well established that cigarette smoke provokes inflammatory activation and impairs antimicrobial functions of human immune cells. Here we explore whether cigarette smoke likewise affects the virulence properties of an important human pathogen, Staphylococcus aureus, and in particular methicillin-resistant S. aureus (MRSA), one of the leading causes of invasive bacterial infections. MRSA colonizes the nasopharynx and is thus exposed to inhalants, including cigarette smoke. MRSA exposed to cigarette smoke extract (CSE-MRSA) was more resistant to macrophage killing (4-fold higher survival; P < 0.0001). CSE-MRSA demonstrated reduced susceptibility to cell lysis (1.78-fold; P = 0.032) and antimicrobial peptide (AMP) (LL-37) killing (MIC, 8 μM versus 4 μM). CSE modified the surface charge of MRSA in a dose-dependent fashion, impairing the binding of particles with charge similar to that of AMPs by 90% (P < 0.0001). These changes persisted for 24 h postexposure, suggesting heritable modifications. CSE exposure increased hydrophobicity by 55% (P < 0.0001), which complemented findings of increased MRSA adherence and invasion of epithelial cells. CSE induced upregulation of mprF, consistent with increased MRSA AMP resistance. S. aureus without mprF had no change in surface charge upon exposure to CSE. In vivo, CSE-MRSA pneumonia induced higher mouse mortality (40% versus 10%) and increased bacterial burden at 8 and 20 h postinfection compared to control MRSA-infected mice (P < 0.01). We conclude that cigarette smoke-induced immune resistance phenotypes in MRSA may be an additional factor contributing to susceptibility to infectious disease in cigarette smokers.
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http://dx.doi.org/10.1128/IAI.00303-15DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4432760PMC
June 2015
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