Quercetin treatment changes fluxes in the primary metabolism and increases culture longevity and recombinant α1-antitrypsin production in human AGE1.HN cells

Abstract

Addition of the flavonoid quercetin to cultivations of the α(1)-antitrypsin (A1AT) producing human AGE1.HN.AAT cell line resulted in alterations of the cellular physiology and a remarkable improvement of the overall performance of these cells. In a first screening in 96-well plate format, toxicity and the effect of quercetin on the lactate/glucose ratio was analyzed. It was found that quercetin treatment reduced the lactate/glucose ratio dose dependently. An increase in culture longevity, viable cell density (160% of control), and A1AT concentration (from 0.39 g/L in the control to 0.76 g/L with quercetin, i.e., 195% of the control) was observed in batch cultivation with 10 μM quercetin compared to the control. A detailed analysis of quercetin effects on primary metabolism revealed dose-dependent alterations in metabolic fluxes. Quercetin addition resulted in an improved channeling of pyruvate into the mitochondria accompanied by reduced waste product formation and stimulation of TCA cycle activity. The observed changes in cellular physiology can be explained by different properties of quercetin and its metabolites, e.g., inhibition of specific enzymes, stimulation of oxidation of cytoplasmic, and mitochondrial NADH resulting in reduced NADH/NAD(+) ratio, and cytoprotective activity. The present study shows that the addition of specific effectors to the culture medium represents a promising strategy to improve the cellular metabolic phenotype and the production of biopharmaceuticals. The provided results contribute, additionally, to an improved understanding of quercetin action on the metabolism of human cells in a general physiological context.

Quercetin-Induced Lifespan Extension in Podospora anserina Requires Methylation of the Flavonoid by the O-Methyltransferase PaMTH1

“…In rats, this percentage (86%) was even higher ( Morand et al, 1998 ; Manach et al, 1999 ). In line with our findings and with findings from other organisms, Niklas et al (2012) exhibited an increased longevity in human cell cultures by quercetin treatment. In contrast to our study, this lifespan increasing effect was not linked to methylated derivative of quercetin.…”

“…For instance, the anti-oxidative capacity of quercetin can be linked to lifespan extension in C. elegans , S. cerevisiae , and D. melanogaster ( Belinha et al, 2007 ; Kampkötter et al, 2008 ; Saul et al, 2008 ; Pietsch et al, 2009 ). Furthermore, Niklas et al (2012) first reported an increased longevity in human cell cultures by quercetin treatment. Beside the anti-oxidative capacity, studies with cell cultures and rats identified a pro-oxidative effect of quercetin ( Laughton et al, 1989 ; Metodiewa et al, 1999 ; Robaszkiewicz et al, 2007 ).…”

Isotope labeling experiments in metabolomics and fluxomics

“…On the basis of these findings it was possible to redesign cultivation in two ways to increase the production of human α 1 ‐antitrypsin. The first was to limit glucose supply by controlled feeding and the second to add quercitin, an inhibitor for glucose uptake, to the culture 82,83. This example shows that a thorough fluxomic analysis directly leads to ideas for the improvement of production processes.…”

Quercetin promotes the osteogenic differentiation of rat mesenchymal stem cells via mitogen-activated protein kinase signaling

“…MSCs were seeded in 96-well plates at a density of 1.0x10 8 cells/l and cultured in an incubator at 37˚C under conditions of 5% CO 2 until they reached 80% confluence. After 24 h, the MSCs were divided into a control group and different concentration quercetin treatment groups (0.01, 0.1, 1, 10 or 100 µmol/l), with six replicates in each group.…”

“…Quercetin is one of the most ubiquitous bioflavonoids, occurring widely in plants in the form of glycosides or aglycone, which exert a number of pharmacological effects, functioning as antioxidants (5), anti-inflammatory agents (6), antitumor agents (7) and metabolic regulators (8). Quercetin has also been shown to exert a positive pharmacological effect on bone metabolism (9)(10)(11), although the underlying mechanism of action is yet to be fully elucidated.…”