To elucidate the molecular mechanisms underlying the up-regulation of aldose reductase observed in many cancer cells, we investigated the signal transduction pathways mediating induction of aldose reductase gene expression by 12-O-tetradecanoylphorbol-13-acetate, a potent tumor promoter. A maximum of four-fold induction in aldose reductase mRNA was demonstrated in HeLa cells treated with 12-O-tetradecanoylphorbol-13-acetate. The increased level of aldose reductase transcript was accompanied by the elevated level of enzyme activity, and completely abolished in the presence of actinomycin D. Inhibitors of protein kinase C, bisindolylmaleimide I and calphostin C, as well as inhibitors of tyrosine kinase, genistein and tyrphostin A23, significantly attenuated 12-O-tetradecanoylphorbol-13-acetate-induced increase in aldose reductase mRNA. Blockade of the p38 mitogen-activated protein kinase pathway by SB203580 also suppressed 12-O-tetradecanoylphorbol-13-acetate-induced aldose reductase expression. The promoter activity of aldose reductase gene was significantly augmented in the cells treated with 12-O-tetradecanoylphorbol-13-acetate, but attenuated in the presence of bisindolylmaleimide I, tyrphostin A23 or SB203580. Pyrrolidinedithiocarbamate, a nuclear factor kappaB inhibitor, dose-dependently suppressed 12-O-tetradecanoylphorbol-13-acetate-induced increase in aldose reductase mRNA. 12-O-tetradecanoylphorbol-13-acetate augmented the DNA binding activity of nuclear factor kappaB and nuclear factor kappaB-dependent gene transcription, and these effects were attenuated by bisindolylmaleimide I or tyrphostin A23, but not by SB203580. Taken together, activation of protein kinase C and tyrosine kinase by 12-O-tetradecanoylphorbol-13-acetate elicits increased promoter activity of aldose reductase gene via nuclear factor kappaB. A p38 mitogen-activated protein kinase pathway, distinct from the tyrosine kinase pathway, may also take part in 12-O-tetradecanoylphorbol-13-acetate-induced increase in aldose reductase gene expression.
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http://dx.doi.org/10.1016/j.biocel.2005.04.016 | DOI Listing |
CNS Neurol Disord Drug Targets
March 2025
University Institute of Chemical Technology, KBC North Maharashtra University, Jalgaon 425001, MS, India.
Introduction: The polyol pathway is responsible for the metabolism of almost one-third of the total glucose in people with chronic diabetes. Moreover, it causes complications in organs that rely on aldose reductase (AR) as an enzyme. The purpose of this research was to examine the in vitro and in vivo effects of a flavonoid-rich ethyl acetate fraction of a methanolic extract of Ficus carica Lam.
View Article and Find Full Text PDFACS Omega
March 2025
Pharmacogenetics Research Lab, Department of Pharmacy, COMSATS University Islamabad, Abbottabad Campus, Abbottabad 22060, Pakistan.
Hyperlipidemia, a condition characterized by elevated lipid levels, presents significant cardiovascular risks. Syringaldehyde (SA), a phenolic aldehyde derived from plants, exhibits antioxidant, antihyperglycemic, and anti-inflammatory properties. However, its potential toxicity and effects on hyperlipidemia have not been studied.
View Article and Find Full Text PDFBiophys Physicobiol
January 2025
Department of Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo, Tokyo 153-8902, Japan.
Cyanobacteria can produce alkanes equivalent to diesel fuels through a two-step enzymatic process involving acyl-(acyl carrier protein) reductase (AAR) and aldehyde deformylating oxygenase (ADO), providing a potential renewable biofuel source. AAR binds to ADO for efficient delivery of an aldehyde substrate and they have been proposed to dissociate when the alkane product is released from the same site as the substrate entrance of ADO. However, the dynamics of the substrate and product in ADO during substrate entry and product release are poorly understood.
View Article and Find Full Text PDFBiochem J
March 2025
Department of Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, U.S.A.
There is an increasing interest in the role of fructose as a major driver of non-alcoholic fatty liver disease (NAFLD), and it is linked closely with the intake of sugar. However, there has also been the recognition that fructose can be produced directly from intracellular glucose via the evolutionarily conserved polyol pathway whose access is governed by aldose reductase (AR). The purpose of this article is to review the biochemistry of AR and the role of the polyol pathway in opening fructose metabolism.
View Article and Find Full Text PDFEcotoxicol Environ Saf
March 2025
College of Animal Science and Technology, Shihezi University, Shihezi, Xinjiang 832000, China. Electronic address:
Cottonseed meal is widely used as an alternative source of protein in the animal feed industry. However, the presence of toxic gossypol limits its use in livestock production. In order to reduce gossypol toxicity, microbial degradation is generally considered to be an environmentally friendly and cost-effective strategy.
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