Nicotine: The link between cigarette smoking and kidney disease progression?January 30, 2007
The mechanisms by which cigarette smoke may accelerate some types of chronic kidney disease are currently unknown. A new study, being published by the American Physiological Society (http://www.the-aps.org/), demonstrates for the first time that human mesangial cells (MC) - cells in the blood vessels of the kidneys - are endowed with nicotinic receptors (nAChRs) Ã¡4, Ã¡5, Ã¡7, Ã¢2, Ã¢3, Ã¢4 and Ã¢5 (cells that interact with the nicotine in tobacco) and may play an active role in the development of certain kidney diseases.
The study, "Nicotine: The Link Between Cigarette Smoking and the Progression of Renal Injury?," was conducted by Edgar A. Jaimes, MD, Run-Xia Tian, MD, and Leopoldo Raij, MD, all of the Miller School of Medicine, University of Miami, Miami, FL. It appears in the Articles in Press Section of the American Journal of Physiology - Heart and Circulatory Physiology (http://ajpheart.physiology.org/), one of 11-peer reviewed journals published by the APS.
Overview of Methodology
Human mesangial cells were grown in CSC-Complete media, supplemented with 10 percent fetal calf serum. Cells were passed by trypsinization when confluent and used between the third and ninth passages. 3H-thymidine was used as an index of cell proliferation and cells were fasted for 72 hours in Maintenance Media and stimulated for 24 hours with nicotine (10-10 M to 10-7 M) or platelet derived growth factor.
Western blots were performed after the cells fasted and had been stimulated for 24 hours with nicotine (10-7). Cell homogenates were washed and thereafter centrifuged for 30 minutes. Blots were incubated overnight with one of nine antibodies, which included mouse anti-Ã¡2-nAChR mAb's, anti-Ã¡3-nAChR mAb's, or anti-Ã¡4-nAChR mAb's. Fibronectin mRNA expression was determined by real time PCR and protein expression was measured by western blot. Flow cytometry measurement was generated for reactive oxygen species.
Data were expressed as mean ± SEM. For statistical comparisons involving two groups, an unpaired Student t test was used. For comparisons involving more than two groups, ANOVA was used. Significance was considered when P<0.05.
Highlights of Results
Highlights of the results include the following:
- Human mesangial cells express nAChRs: The researchers were able to detect strong expression of several nAChRs subunits in the cultured human mesangial cells. They detected the presence of the nAChRs subunits Ã¡4, Ã¡5, Ã¡7, Ã¢2, Ã¢3, and Ã¢4 in these cells. They were not, however, able to detect significant expression of the Ã¡2 or Ã¡3 nAChR subunits.
- Nicotine increases mesangial cell proliferation via nAChRs activation: Nicotine stimulation of the cells resulted in a dose dependent increase in mesangial cell proliferation. One concentration found in the plasma of active smokers found that nicotine-induced MC proliferation was 1,328 for controls vs. 2,761 for nicotine.
- Nicotine increases fibronectin production: To determine whether transcriptional mechanisms were involved, the researchers measured the gene expression of fibronectin using real time exposure to nicotine. They found that nicotine induced a five-fold increase in fibronectin mRNA expression.
Summary and Conclusions
These studies are believed to be the first of their kind to:
(1) identify the presence of functionally active nAChRs in human mesangial cells; and
(2) demonstrate that nicotine, at concentrations similar to those found in the plasma of smokers, promotes mesangial cell proliferation and spurs on critical molecules that are involved in the extracellular matrix production.
Recent epidemiologic studies demonstrate that cigarette smoking increases the risk for progressive chronic kidney disease, but the role of smoking in primary renal diseases is less known. The results of this research, coupled with earlier findings, reveal previously unrecognized mechanisms showing nicotine - a component of cigarette smoke - as an agent that may accelerate and promote the progression of chronic kidney disease.
American Physiological Society
Related Cigarette Smoke Current Events and Cigarette Smoke News Articles
California's tobacco control efforts losing steam, finds UCSF report
California's position as a leader in tobacco control is under threat, according to a new report from the UC San Francisco Center for Tobacco Control Research and Education.
UTHealth researchers study impact of smoking ban in homeless shelter
Instituting a partial smoking ban at a homeless shelter can lead to a reduction in expired carbon monoxide levels, an indicator of exposure to cigarette smoke, and may have positive effects on shelter residents' health, according to new research.
Researchers demonstrate health risks posed by 'third hand' tobacco smoke
Research led by the University of York has highlighted the potential cancer risk in non-smokers - particularly young children - of tobacco smoke gases and particles deposited to surfaces and dust in the home.
NYU researchers find 18 percent of high school seniors smoke hookah
While cigarette use is declining precipitously among youth, evidence indicates that American adolescents are turning to ethnically-linked alternative tobacco products, such as hookahs, cigars, and various smokeless tobacco products, according to a recent report from the Centers for Disease Control and Prevention (CDC).
Scientists identify link between stem cell regulation and the development of lung cancer
UCLA researchers led by Dr. Brigitte Gomperts have discovered the inner workings of the process thought to be the first stage in the development of lung cancer.
Children exposed to secondhand tobacco or cooking smoke have very high rates of pain and complications after tonsillectomy
New research presented at this year's Euroanaesthesia meeting in Stockholm shows that children exposed to indoor coal-burning stoves and/or second-hand tobacco smoke are much more likely to suffer postoperative complications and excessive pain after tonsillectomies.
Toxins in the environment might make you older than your years
Why are some 75-year-olds downright spry while others can barely get around? Part of the explanation, say researchers writing in the Cell Press journal Trends in Molecular Medicine on May 28, is differences from one person to the next in exposure to harmful substances in the environment, chemicals such as benzene, cigarette smoke, and even stress.
E-cigarettes may boost resistance of drug-resistant pathogens
Despite being touted by their manufacturers as a healthy alternative to cigarettes, e-cigarettes appear in a laboratory study to increase the virulence of drug- resistant and potentially life-threatening bacteria, while decreasing the ability of human cells to kill these bacteria.
UTMB study discovers cause of many preterm births
A new study by researchers at the University of Texas Medical Branch at Galveston is the first to show that premature aging of the placenta due to oxidative stress is the cause of many preterm births. The study appears today in the American Journal of Pathology.
New research explores how smoking while pregnant leads to other diseases
While many parents-to-be are aware that the health of their baby starts before they've actually arrived into the world, recent research reveals that "harm" (i.e., tobacco smoke, dirty air, poor nutrition, even preeclampsia) may not present itself disease-wise until well into adulthood or when a second harmful "hit" triggers the individual's susceptibility.
More Cigarette Smoke Current Events and Cigarette Smoke News Articles