- Email: [email protected]
Lipofuscin effects in Caenorhabditis elegans ageing model
S48
D. Rossin et al. / Free Radical Biology and Medicine 108 (2017) S18–S107
P-089
NRF2/KEAP1-mediated antioxidant defence pathway regulates skeletal muscle circadian clock function Niamh S Horton 1, Ian M Copple 2, Aphrodite Vasilaki 1, Malcolm J Jackson 1, Anne McArdle 1, Vanja Pekovic-Vaughan 1 1
Musculoskeletal Biology, Institute of Ageing and Chronic Disease, University of Liverpool, UK and MRC-Arthritis Research UK Centre for Integrated Research into Musculoskeletal Ageing (CIMA) 2 Institute of Translational Medicine, University of Liverpool, UK Keywords: NRF2; Circadian; FDB; muscle; COPD
The circadian clock is an intrinsic timing mechanism which regulates most physiological processes within the body. Disruption of circadian rhythms has been identified as a risk factor for several chronic diseases with altered redox control. We investigated the hypothesis that NRF2, a master regulator of antioxidant defence, is a clock-controlled gene in skeletal muscle, which can modulate the circadian clock function. Using genetic, pharmacological and realtime imaging approaches, we identified a feedback mechanism between the circadian clock machinery and the NRF2/KEAP1 antioxidant pathway. Pharmacological manipulation of NRF2 exerted robust effects on both the amplitude and periodicity of circadian clock oscillations. Moreover, single muscle fibre isolation has confirmed cell-autonomous changes in core clock gene expression in fibres from Nrf2 KO mice. Interestingly, similar effects on clock gene expression were also evident in muscle fibres isolated from old wild-type mice. Loss of Nrf2, or ageing led to diminished clock gene cycles but activated rhythmic gene cycles of genes involved in inflammation and stress resistance. All together, these findings implicate NRF2 as an important therapeutic target which may be utilised in future to reset or re-align disrupted circadian rhythms seen in several chronic diseases associated with muscle wasting including COPD and sarcopenia. E-mail address: [email protected] (N. Horton) Acknowledgements
Funding was provided by University of Liverpool- Crossley Barnes Studentship. http://dx.doi.org/10.1016/j.freeradbiomed.2017.04.174
age pigments being such molecules. The “age pigment” lipofuscin is naturally produced throughout the life of an organism and it is aggregated in post-mitotic cells as ageing progresses resulting in age-dependent degeneration of various cellular systems. Lipofuscin is non-degradable and consists of oxidized, cross-linked proteins, lipids and saccharides. Its accumulation seems to be associated with the cellular proteolytic mechanisms inability to degrade it during ageing. Lipofuscin accumulation promotes ageing as it acts as proteasome inhibitor by directly binding on proteasome complexes. Our aim is to study the effects of lifelong exposure to lipofuscin on organismal lifespan and physiology by exploiting the ageing model of Caenorhabditis elegans. Our preliminary results demonstrated that the nematode lifespan is altered upon treatment with artificial lipofuscin and that the two major cellular degradation mechanisms (proteasome and autophagy) are affected. Detailed analysis of the involved antioxidant mechanisms and metabolic pathways has been performed and additional experimentation will elucidate the molecular and biochemical basis of the above-mentioned effects. E-mail address: [email protected] (N. Papaevgeniou) http://dx.doi.org/10.1016/j.freeradbiomed.2017.04.175
P-091
N-acetylcysteine, an antioxidant with anti-adipogenic effect on adipocytes Azul Pieralisi 1, Daniela Soto 1, Matias Gabrielli 2, Claudia N Martini 1, Virginia E Diz 3, Federico Rovner 3, Maria C Vila 2, Juan C Calvo 1,4, Liliana N Guerra 1,2,5 1
Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Departamento de Quimica Biologica, Buenos Aires, Argentine Republic 2 CONICET - Universidad de Buenos Aires, IQUIBICEN, Buenos Aires, Argentine Republic 3 Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Departamento de Quimica Inorganica, Analitica y Fisica, Buenos Aires, Argentine Republic 4 CONICET, IBYME, Buenos Aires, Argentine Republic 5 Universidad Nacional de Lujan, Departamento de Ciencias Basicas, Buenos Aires, Argentine Republic Keywords: N-Acetylcysteine; Obesity; Triglyceride; Adipogenic factor
P-090
Lipofuscin effects in Caenorhabditis elegans ageing model Nikoletta Papaevgeniou 1,2, Annika Hoehn 2, Tilman Grune 2, Niki Chondrogianni 1 1
Department of Cellular and Molecular Ageing, Institute of Biology, Medicinal Chemistry and Biotechnology, National Hellenic Research Foundation, Athens, Greece 2 Department of Molecular Toxicology (ΜΤΟΧ), German Institute of Human Nutrition (DIfE), Potsdam-Rehbruecke, Germany Keywords: Ageing; Lipofuscin; Proteostasis; Caenorhabditis elegans
Ageing is a multidimensional process involving many variables that affect all levels of life. Upon ageing a significant increase of damaged biomolecules, such as accumulated proteins occurs with
Reports about antioxidant effect in obesity are contradictory. We showed that N-acetylcysteine (NAC) inhibits cellular lipid accumulation during adipocyte differentiation, through the inhibition of adipogenic transcriptor factors expression, such as PPARγ and, MAPKs phosphorylation (Pieralisi et al.,Redox Biol 2016; Soto el al, Redox Rep 2016). Here we evaluated NAC on fully differentiated cells (3T3-L1 adipocytes: AC). Treatments with 0.01 to 5 mM NAC, included in culture media for 5 days, were not toxic. 5 mM NAC treatment on AC (ACN) provoked a decrease of 60% in cellular Triglycerides (Tg) content (1.22+0.09 gTg/g protein [AC] vs 0.49+0.03 gTg/g protein [ACN], po0.05). We evaluated Oil-Red-O stained lipids content in ACN comparing to AC, which is set to 100 (100+4 [AC] vs 80+2 [ACN] arbitrary units (AU), po 0.05), lipid protein perilipin (Pl) mRNA levels (Pl/ Rplp0:100+13 [AC] vs 72+9 [ACN] AU, po 0.05) and PPARγ: protein expression (PPARγ/GAPDH:100+6 [AC] vs 70+4 [ACN] AU; po 0.05) and mRNA levels (PPARγ/ Rplp0:100+7 [AC] vs 74+14 [ACN] AU, po0.05). These NAC treatments produced a decrease of 20 – 30%, suggesting that NAC could
D. Rossin et al. / Free Radical Biology and Medicine 108 (2017) S18–S107
P-089
NRF2/KEAP1-mediated antioxidant defence pathway regulates skeletal muscle circadian clock function Niamh S Horton 1, Ian M Copple 2, Aphrodite Vasilaki 1, Malcolm J Jackson 1, Anne McArdle 1, Vanja Pekovic-Vaughan 1 1
Musculoskeletal Biology, Institute of Ageing and Chronic Disease, University of Liverpool, UK and MRC-Arthritis Research UK Centre for Integrated Research into Musculoskeletal Ageing (CIMA) 2 Institute of Translational Medicine, University of Liverpool, UK Keywords: NRF2; Circadian; FDB; muscle; COPD
The circadian clock is an intrinsic timing mechanism which regulates most physiological processes within the body. Disruption of circadian rhythms has been identified as a risk factor for several chronic diseases with altered redox control. We investigated the hypothesis that NRF2, a master regulator of antioxidant defence, is a clock-controlled gene in skeletal muscle, which can modulate the circadian clock function. Using genetic, pharmacological and realtime imaging approaches, we identified a feedback mechanism between the circadian clock machinery and the NRF2/KEAP1 antioxidant pathway. Pharmacological manipulation of NRF2 exerted robust effects on both the amplitude and periodicity of circadian clock oscillations. Moreover, single muscle fibre isolation has confirmed cell-autonomous changes in core clock gene expression in fibres from Nrf2 KO mice. Interestingly, similar effects on clock gene expression were also evident in muscle fibres isolated from old wild-type mice. Loss of Nrf2, or ageing led to diminished clock gene cycles but activated rhythmic gene cycles of genes involved in inflammation and stress resistance. All together, these findings implicate NRF2 as an important therapeutic target which may be utilised in future to reset or re-align disrupted circadian rhythms seen in several chronic diseases associated with muscle wasting including COPD and sarcopenia. E-mail address: [email protected] (N. Horton) Acknowledgements
Funding was provided by University of Liverpool- Crossley Barnes Studentship. http://dx.doi.org/10.1016/j.freeradbiomed.2017.04.174
age pigments being such molecules. The “age pigment” lipofuscin is naturally produced throughout the life of an organism and it is aggregated in post-mitotic cells as ageing progresses resulting in age-dependent degeneration of various cellular systems. Lipofuscin is non-degradable and consists of oxidized, cross-linked proteins, lipids and saccharides. Its accumulation seems to be associated with the cellular proteolytic mechanisms inability to degrade it during ageing. Lipofuscin accumulation promotes ageing as it acts as proteasome inhibitor by directly binding on proteasome complexes. Our aim is to study the effects of lifelong exposure to lipofuscin on organismal lifespan and physiology by exploiting the ageing model of Caenorhabditis elegans. Our preliminary results demonstrated that the nematode lifespan is altered upon treatment with artificial lipofuscin and that the two major cellular degradation mechanisms (proteasome and autophagy) are affected. Detailed analysis of the involved antioxidant mechanisms and metabolic pathways has been performed and additional experimentation will elucidate the molecular and biochemical basis of the above-mentioned effects. E-mail address: [email protected] (N. Papaevgeniou) http://dx.doi.org/10.1016/j.freeradbiomed.2017.04.175
P-091
N-acetylcysteine, an antioxidant with anti-adipogenic effect on adipocytes Azul Pieralisi 1, Daniela Soto 1, Matias Gabrielli 2, Claudia N Martini 1, Virginia E Diz 3, Federico Rovner 3, Maria C Vila 2, Juan C Calvo 1,4, Liliana N Guerra 1,2,5 1
Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Departamento de Quimica Biologica, Buenos Aires, Argentine Republic 2 CONICET - Universidad de Buenos Aires, IQUIBICEN, Buenos Aires, Argentine Republic 3 Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Departamento de Quimica Inorganica, Analitica y Fisica, Buenos Aires, Argentine Republic 4 CONICET, IBYME, Buenos Aires, Argentine Republic 5 Universidad Nacional de Lujan, Departamento de Ciencias Basicas, Buenos Aires, Argentine Republic Keywords: N-Acetylcysteine; Obesity; Triglyceride; Adipogenic factor
P-090
Lipofuscin effects in Caenorhabditis elegans ageing model Nikoletta Papaevgeniou 1,2, Annika Hoehn 2, Tilman Grune 2, Niki Chondrogianni 1 1
Department of Cellular and Molecular Ageing, Institute of Biology, Medicinal Chemistry and Biotechnology, National Hellenic Research Foundation, Athens, Greece 2 Department of Molecular Toxicology (ΜΤΟΧ), German Institute of Human Nutrition (DIfE), Potsdam-Rehbruecke, Germany Keywords: Ageing; Lipofuscin; Proteostasis; Caenorhabditis elegans
Ageing is a multidimensional process involving many variables that affect all levels of life. Upon ageing a significant increase of damaged biomolecules, such as accumulated proteins occurs with
Reports about antioxidant effect in obesity are contradictory. We showed that N-acetylcysteine (NAC) inhibits cellular lipid accumulation during adipocyte differentiation, through the inhibition of adipogenic transcriptor factors expression, such as PPARγ and, MAPKs phosphorylation (Pieralisi et al.,Redox Biol 2016; Soto el al, Redox Rep 2016). Here we evaluated NAC on fully differentiated cells (3T3-L1 adipocytes: AC). Treatments with 0.01 to 5 mM NAC, included in culture media for 5 days, were not toxic. 5 mM NAC treatment on AC (ACN) provoked a decrease of 60% in cellular Triglycerides (Tg) content (1.22+0.09 gTg/g protein [AC] vs 0.49+0.03 gTg/g protein [ACN], po0.05). We evaluated Oil-Red-O stained lipids content in ACN comparing to AC, which is set to 100 (100+4 [AC] vs 80+2 [ACN] arbitrary units (AU), po 0.05), lipid protein perilipin (Pl) mRNA levels (Pl/ Rplp0:100+13 [AC] vs 72+9 [ACN] AU, po 0.05) and PPARγ: protein expression (PPARγ/GAPDH:100+6 [AC] vs 70+4 [ACN] AU; po 0.05) and mRNA levels (PPARγ/ Rplp0:100+7 [AC] vs 74+14 [ACN] AU, po0.05). These NAC treatments produced a decrease of 20 – 30%, suggesting that NAC could