@article{NowotnyCastroHugoetal.2018,
  author    = {Nowotny, Kerstin and Castro, Jose Pedro and Hugo, Martin and Braune, Sabine and Weber, Daniela and Pignitter, Marc and Somoza, Veronika and Bornhorst, Julia and Schwerdtle, Tanja and Grune, Tilman},
  title     = {Oxidants produced by methylglyoxal-modified collagen trigger ER stress and apoptosis in skin fibroblasts},
  series = {Free radical biology and medicine : the official journal of the Oxygen Society, a constituent member of the International Society for Free Radical Research},
  volume    = {120},
  journal   = {Free radical biology and medicine : the official journal of the Oxygen Society, a constituent member of the International Society for Free Radical Research},
  publisher = {Elsevier},
  address   = {New York},
  issn      = {0891-5849},
  doi       = {10.1016/j.freeradbiomed.2018.03.022},
  pages     = {102 -- 113},
  year      = {2018},
  abstract  = {Methylglyoxal (MG), a highly reactive dicarbonyl, interacts with proteins to form advanced glycation end products (AGEs). AGEs include a variety of compounds which were shown to have damaging potential and to accumulate in the course of different conditions such as diabetes mellitus and aging. After confirming collagen as a main target for MG modifications in vivo within the extracellular matrix, we show here that MG-collagen disrupts fibroblast redox homeostasis and induces endoplasmic reticulum (ER) stress and apoptosis. In particular, MG-collagen-induced apoptosis is associated with the activation of the PERK-eIF2 alpha pathway and caspase-12. MG-collagen contributes to altered redox homeostasis by directly generating hydrogen peroxide and oxygen-derived free radicals. The induction of ER stress in human fibroblasts was confirmed using collagen extracts isolated from old mice in which MG-derived AGEs were enriched. In conclusion, MG-derived AGEs represent one factor contributing to diminished fibroblast function during aging.},
  language  = {en}
}
@article{CastroWardelmannGruneetal.2018,
  author    = {Castro, Jose Pedro and Wardelmann, Kristina and Grune, Tilman and Kleinridders, Andre},
  title     = {Mitochondrial Chaperones in the Brain},
  series = {Frontiers in Endocrinology},
  volume    = {9},
  journal   = {Frontiers in Endocrinology},
  publisher = {Frontiers Research Foundation},
  address   = {Lausanne},
  issn      = {1664-2392},
  doi       = {10.3389/fendo.2018.00196},
  pages     = {13},
  year      = {2018},
  abstract  = {The brain orchestrates organ function and regulates whole body metabolism by the concerted action of neurons and glia cells in the central nervous system. To do so, the brain has tremendously high energy consumption and relies mainly on glucose utilization and mitochondrial function in order to exert its function. As a consequence of high rate metabolism, mitochondria in the brain accumulate errors over time, such as mitochondrial DNA (mtDNA) mutations, reactive oxygen species, and misfolded and aggregated proteins. Thus, mitochondria need to employ specific mechanisms to avoid or ameliorate the rise of damaged proteins that contribute to aberrant mitochondrial function and oxidative stress. To maintain mitochondria homeostasis (mitostasis), cells evolved molecular chaperones that shuttle, refold, or in coordination with proteolytic systems, help to maintain a low steady-state level of misfolded/aggregated proteins. Their importance is exemplified by the occurrence of various brain diseases which exhibit reduced action of chaperones. Chaperone loss (expression and/or function) has been observed during aging, metabolic diseases such as type 2 diabetes and in neurode-generative diseases such as Alzheimer's (AD), Parkinson's (PD) or even Huntington's (HD) diseases, where the accumulation of damage proteins is evidenced. Within this perspective, we propose that proper brain function is maintained by the joint action of mitochondrial chaperones to ensure and maintain mitostasis contributing to brain health, and that upon failure, alter brain function which can cause metabolic diseases.},
  language  = {en}
}
@article{FernandoDrescherDeubeletal.2018,
  author    = {Fernando, Raquel and Drescher, Cathleen and Deubel, Stefanie and Jung, Tobias and Ost, Mario and Klaus, Susanne and Grune, Tilman and Castro, Jose Pedro},
  title     = {Low proteasomal activity in fast skeletal muscle fibers is not associated with increased age-related oxidative damage},
  series = {Experimental gerontology},
  volume    = {117},
  journal   = {Experimental gerontology},
  publisher = {Elsevier},
  address   = {Oxford},
  issn      = {0531-5565},
  doi       = {10.1016/j.exger.2018.10.018},
  pages     = {45 -- 52},
  year      = {2018},
  abstract  = {The skeletal muscle is a crucial tissue for maintaining whole body homeostasis. Aging seems to have a disruptive effect on skeletal muscle homeostasis including proteostasis. However, how aging specifically impacts slow and fast twitch fiber types remains elusive. Muscle proteostasis is largely maintained by the proteasomal system. Here we characterized the proteasomal system in two different fiber types, using a non-sarcopenic aging model. By analyzing the proteasomal activity and amount, as well as the polyubiquitinated proteins and the level of protein oxidation in Musculus soleus (Sol) and Musculus extensor digitorum longus (EDL), we found that the slow twitch Sol muscle shows an overall higher respiratory and proteasomal activity in young and old animals. However, especially during aging the fast twitch EDL muscle reduces protein oxidation by an increase of antioxidant capacity. Thus, under adaptive non-sarcopenic conditions, the two fibers types seem to have different strategies to avoid age-related changes.},
  language  = {en}
}
@article{FernandoDrescherNowotnyetal.2018,
  author    = {Fernando, Raquel and Drescher, Cathleen and Nowotny, Kerstin and Grune, Tilman and Castro, Jose Pedro},
  title     = {Impaired proteostasis during skeletal muscle aging},
  series = {Free radical biology and medicine : the official journal of the Oxygen Society, a constituent member of the International Society for Free Radical Research},
  volume    = {132},
  journal   = {Free radical biology and medicine : the official journal of the Oxygen Society, a constituent member of the International Society for Free Radical Research},
  publisher = {Elsevier},
  address   = {New York},
  issn      = {0891-5849},
  doi       = {10.1016/j.freeradbiomed.2018.08.037},
  pages     = {58 -- 66},
  year      = {2018},
  abstract  = {Aging is a complex phenomenon that has detrimental effects on tissue homeostasis. The skeletal muscle is one of the earliest tissues to be affected and to manifest age-related changes such as functional impairment and the loss of mass. Common to these alterations and to most of tissues during aging is the disruption of the proteostasis network by detrimental changes in the ubiquitin-proteasomal system (UPS) and the autophagy-lysosomal system (ALS). In fact, during aging the accumulation of protein aggregates, a process mainly driven by increased levels of oxidative stress, has been observed, clearly demonstrating UPS and ALS dysregulation. Since the UPS and ALS are the two most important pathways for the removal of misfolded and aggregated proteins and also of damaged organelles, we provide here an overview on the current knowledge regarding the connection between the loss of proteostasis and skeletal muscle functional impairment and also how redox regulation can play a role during aging. Therefore, this review serves for a better understanding of skeletal muscle aging in regard to the loss of proteostasis and how redox regulation can impact its function and maintenance.},
  language  = {en}
}