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Penicillium chrysogenum as a model system for studying cellular effects of methylglyoxal.

Scheckhuber CQ - BMC Microbiol. (2015)

Bottom Line: The biologically most important compound of this class, methylglyoxal, results from spontaneous phosphate elimination from dihydroxyacetone phosphate and glyceraldehyde 3-phosphate which are intermediate glycolysis products.Methylglyoxal leads to growth rate reduction of this fungus so that the entry into the stationary phase is delayed.Furthermore, three proteins are identified that are present in lower abundance when methylglyoxal is added to the growth medium (aldo-keto reductase [Pc22g04850], 5-methyl-tetrahydropteroyl-triglutamate-homocysteine S-methyltransferase [Pc22g18630] and NAD-dependent formate dehydrogenase [Pc12g04310]).

View Article: PubMed Central - PubMed

Affiliation: Senckenberg Research Institute, LOEWE Excellence Cluster for Integrative Fungal Research (IPF), Georg-Voigt-Str. 14-16, D-60325, Frankfurt am Main, Germany. Christian.Scheckhuber@senckenberg.de.

ABSTRACT

Background: α-oxoaldehydes are formed as toxic by-products during metabolic activity. The biologically most important compound of this class, methylglyoxal, results from spontaneous phosphate elimination from dihydroxyacetone phosphate and glyceraldehyde 3-phosphate which are intermediate glycolysis products. Methylglyoxal-mediated modification of lipids, nucleic acids and proteins is known to lead to the formation of advanced glycation end products. These modifications contribute to the aetiology of severe diseases like diabetes and neurodegenerative disorders. By using simple model organisms it is possible to conveniently study the effects of methylglyoxal on cellular processes. Here, results are presented on the effects of methylglyoxal on mycelium growth, stationary phase entry (monitored by autophagy induction), mitochondrial morphology and protein composition in the filamentous fungus Penicillium chrysogenum.

Results: Methylglyoxal leads to growth rate reduction of this fungus so that the entry into the stationary phase is delayed. Mitochondrial morphology is not changed by methylglyoxal. However, rapamycin-mediated fragmentation of mitochondria is prevented by methylglyoxal. Furthermore, three proteins are identified that are present in lower abundance when methylglyoxal is added to the growth medium (aldo-keto reductase [Pc22g04850], 5-methyl-tetrahydropteroyl-triglutamate-homocysteine S-methyltransferase [Pc22g18630] and NAD-dependent formate dehydrogenase [Pc12g04310]).

Conclusions: The presented results contribute to the understanding of cellular pathways and mechanisms that are affected by the ubiquitous α-oxoaldehyde methylglyoxal.

No MeSH data available.


Related in: MedlinePlus

Analysis of mitochondrial morphology in Ws54-1255 treated with methylglyoxal and/or rapamycin. At the indicated times cultures grown on starvation pads supplemented with or without methylglyoxal and/or rapamycin were overlaid with a Mitotracker Green FM solution and analysed using fluorescence microscopy. Representative images are shown for each time point. a control; b + 0.05 % (v/v) methylglyoxal; c + 1 μM rapamycin; d + 0.05 % (v/v) methylglyoxal/+ 1 μM rapamycin. Corresponding bright field areas are shown below each fluorescence channel image. Scale bars: 10 μm
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Fig4: Analysis of mitochondrial morphology in Ws54-1255 treated with methylglyoxal and/or rapamycin. At the indicated times cultures grown on starvation pads supplemented with or without methylglyoxal and/or rapamycin were overlaid with a Mitotracker Green FM solution and analysed using fluorescence microscopy. Representative images are shown for each time point. a control; b + 0.05 % (v/v) methylglyoxal; c + 1 μM rapamycin; d + 0.05 % (v/v) methylglyoxal/+ 1 μM rapamycin. Corresponding bright field areas are shown below each fluorescence channel image. Scale bars: 10 μm

Mentions: Mitochondria display a strikingly dynamic morphology, ranging from small punctuate units to long thread-like structures. Their function depends on their morphology among other factors. ‘Healthy’ mitochondria, capable of synthesizing sufficient amounts of ATP, usually belong to the filamentous morphotype whereas spherical mitochondria are often an indication for cellular stress and death. It has been shown that mitochondrial morphology can be used as a fungal viability marker [30, 31]. In order to address the question whether methylglyoxal and/or rapamycin affect viability of Ws54-1255 mitochondrial morphotypes were determined (Fig. 4, Table 2). Control cultures displayed a filamentous mitochondrial morphology up to 60 h of growth on the starvation pad, indicating that Ws54-1255 is capable to tolerate this pronounced starvation without the induction of cell death (Fig. 4a; Table 2). Cultures growing in the presence of 0.05 % methylglyoxal exhibit a similar behaviour (Fig. 4b; Table 2). However, when cultures were subjected to 1 μM rapamycin, hyphae contained mostly round/spherical mitochondria after 40 and 60 h of cultivation (Fig. 4c; Table 2). Although not demonstrated experimentally, it is suggested that this phenotype might be due to the induction of autophagy (mitophagy) as it is known that mitophagy is correlated with mitochondrial fragmentation [32]. Interestingly, when both methylglyoxal and rapamycin are applied, mitochondrial morphology is mostly filamentous after 40 h of incubation (Fig. 4d; Table 2). This finding suggests that methylglyoxal is able to counteract rapamycin-mediated fragmentation of mitochondria. However, after 60 h of incubation hyphae contain mostly round (fragmented) mitochondria (Fig. 4d; Table 2).Fig. 4


Penicillium chrysogenum as a model system for studying cellular effects of methylglyoxal.

Scheckhuber CQ - BMC Microbiol. (2015)

Analysis of mitochondrial morphology in Ws54-1255 treated with methylglyoxal and/or rapamycin. At the indicated times cultures grown on starvation pads supplemented with or without methylglyoxal and/or rapamycin were overlaid with a Mitotracker Green FM solution and analysed using fluorescence microscopy. Representative images are shown for each time point. a control; b + 0.05 % (v/v) methylglyoxal; c + 1 μM rapamycin; d + 0.05 % (v/v) methylglyoxal/+ 1 μM rapamycin. Corresponding bright field areas are shown below each fluorescence channel image. Scale bars: 10 μm
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4496818&req=5

Fig4: Analysis of mitochondrial morphology in Ws54-1255 treated with methylglyoxal and/or rapamycin. At the indicated times cultures grown on starvation pads supplemented with or without methylglyoxal and/or rapamycin were overlaid with a Mitotracker Green FM solution and analysed using fluorescence microscopy. Representative images are shown for each time point. a control; b + 0.05 % (v/v) methylglyoxal; c + 1 μM rapamycin; d + 0.05 % (v/v) methylglyoxal/+ 1 μM rapamycin. Corresponding bright field areas are shown below each fluorescence channel image. Scale bars: 10 μm
Mentions: Mitochondria display a strikingly dynamic morphology, ranging from small punctuate units to long thread-like structures. Their function depends on their morphology among other factors. ‘Healthy’ mitochondria, capable of synthesizing sufficient amounts of ATP, usually belong to the filamentous morphotype whereas spherical mitochondria are often an indication for cellular stress and death. It has been shown that mitochondrial morphology can be used as a fungal viability marker [30, 31]. In order to address the question whether methylglyoxal and/or rapamycin affect viability of Ws54-1255 mitochondrial morphotypes were determined (Fig. 4, Table 2). Control cultures displayed a filamentous mitochondrial morphology up to 60 h of growth on the starvation pad, indicating that Ws54-1255 is capable to tolerate this pronounced starvation without the induction of cell death (Fig. 4a; Table 2). Cultures growing in the presence of 0.05 % methylglyoxal exhibit a similar behaviour (Fig. 4b; Table 2). However, when cultures were subjected to 1 μM rapamycin, hyphae contained mostly round/spherical mitochondria after 40 and 60 h of cultivation (Fig. 4c; Table 2). Although not demonstrated experimentally, it is suggested that this phenotype might be due to the induction of autophagy (mitophagy) as it is known that mitophagy is correlated with mitochondrial fragmentation [32]. Interestingly, when both methylglyoxal and rapamycin are applied, mitochondrial morphology is mostly filamentous after 40 h of incubation (Fig. 4d; Table 2). This finding suggests that methylglyoxal is able to counteract rapamycin-mediated fragmentation of mitochondria. However, after 60 h of incubation hyphae contain mostly round (fragmented) mitochondria (Fig. 4d; Table 2).Fig. 4

Bottom Line: The biologically most important compound of this class, methylglyoxal, results from spontaneous phosphate elimination from dihydroxyacetone phosphate and glyceraldehyde 3-phosphate which are intermediate glycolysis products.Methylglyoxal leads to growth rate reduction of this fungus so that the entry into the stationary phase is delayed.Furthermore, three proteins are identified that are present in lower abundance when methylglyoxal is added to the growth medium (aldo-keto reductase [Pc22g04850], 5-methyl-tetrahydropteroyl-triglutamate-homocysteine S-methyltransferase [Pc22g18630] and NAD-dependent formate dehydrogenase [Pc12g04310]).

View Article: PubMed Central - PubMed

Affiliation: Senckenberg Research Institute, LOEWE Excellence Cluster for Integrative Fungal Research (IPF), Georg-Voigt-Str. 14-16, D-60325, Frankfurt am Main, Germany. Christian.Scheckhuber@senckenberg.de.

ABSTRACT

Background: α-oxoaldehydes are formed as toxic by-products during metabolic activity. The biologically most important compound of this class, methylglyoxal, results from spontaneous phosphate elimination from dihydroxyacetone phosphate and glyceraldehyde 3-phosphate which are intermediate glycolysis products. Methylglyoxal-mediated modification of lipids, nucleic acids and proteins is known to lead to the formation of advanced glycation end products. These modifications contribute to the aetiology of severe diseases like diabetes and neurodegenerative disorders. By using simple model organisms it is possible to conveniently study the effects of methylglyoxal on cellular processes. Here, results are presented on the effects of methylglyoxal on mycelium growth, stationary phase entry (monitored by autophagy induction), mitochondrial morphology and protein composition in the filamentous fungus Penicillium chrysogenum.

Results: Methylglyoxal leads to growth rate reduction of this fungus so that the entry into the stationary phase is delayed. Mitochondrial morphology is not changed by methylglyoxal. However, rapamycin-mediated fragmentation of mitochondria is prevented by methylglyoxal. Furthermore, three proteins are identified that are present in lower abundance when methylglyoxal is added to the growth medium (aldo-keto reductase [Pc22g04850], 5-methyl-tetrahydropteroyl-triglutamate-homocysteine S-methyltransferase [Pc22g18630] and NAD-dependent formate dehydrogenase [Pc12g04310]).

Conclusions: The presented results contribute to the understanding of cellular pathways and mechanisms that are affected by the ubiquitous α-oxoaldehyde methylglyoxal.

No MeSH data available.


Related in: MedlinePlus