Fermentative 2‐carbon metabolism produces carcinogenic levels of acetaldehyde in Candida albicans. (28th February 2013)

• Record Type: Journal Article
• Authors: Marttila, E.; Bowyer, P.; Sanglard, D.; Uittamo, J.; Kaihovaara, P.; Salaspuro, M.; Richardson, M.; Rautemaa, R.
• Is Part Of: Molecular oral microbiology. Volume 28:Number 4(2013:Aug.)
• Page Start: 281
• Page End: 291
• Publication Date: 2013-02-28
• Subjects: Mouth -- Microbiology -- Periodicals; Respiratory infections -- Microbiology -- Periodicals; Mouth -- Diseases -- Immunological aspects -- Periodicals; 617.522
• DOI: 10.1111/omi.12024
• Languages: English
• ISSNs: 2041-1006

Abstract

<abstract abstract-type="main" id="omi12024-abs-0001"> <title>Summary</title> <p>Acetaldehyde is a carcinogenic product of alcohol fermentation and metabolism in microbes associated with cancers of the upper digestive tract. In yeast acetaldehyde is a by‐product of the pyruvate bypass that converts pyruvate into acetyl‐Coenzyme A (CoA) during fermentation. The aims of our study were: (i) to determine the levels of acetaldehyde produced by <italic>Candida albicans</italic> in the presence of glucose in low oxygen tension <italic>in vitro</italic>; (ii) to analyse the expression levels of genes involved in the pyruvate‐bypass and acetaldehyde production; and (iii) to analyse whether any correlations exist between acetaldehyde levels, alcohol dehydrogenase enzyme activity or expression of the genes involved in the pyruvate‐bypass. <italic>Candida albicans</italic> strains were isolated from patients with oral squamous cell carcinoma (<italic>n</italic> = 5), autoimmune polyendocrinopathy–candidiasis–ectodermal dystrophy (APECED) patients with chronic oral candidosis (<italic>n</italic> = 5), and control patients (<italic>n</italic> = 5). The acetaldehyde and ethanol production by these isolates grown under low oxygen tension in the presence of glucose was determined, and the expression of alcohol dehydrogenase (<italic>ADH1</italic> and <italic>ADH2</italic>), pyruvate decarboxylase (<italic>PDC11</italic>), aldehyde dehydrogenase (<italic>ALD6</italic>) and acetyl‐CoA synthetase (<italic>ACS1</italic> and <italic>ACS2</italic>) and Adh enzyme activity were analysed. The <italic>C. albicans</italic> isolates produced high levels of acetaldehyde from glucose under low oxygen tension. The acetaldehyde levels did not correlate with the expression of <italic>ADH1</italic>, <italic> ADH2</italic> or <italic>PDC11</italic> but correlated with the expression of down‐stream genes <italic>ALD6</italic> and <italic>ACS1</italic>. Significant differences in the gene expressions were measured between strains isolated from different patient groups. Under low oxygen tension <italic>ALD6</italic> and <italic>ACS1</italic>, instead of <italic>ADH1</italic> or <italic>ADH2</italic>, appear the most reliable indicators of candidal acetaldehyde production from glucose.</p> </abstract>