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[Background and Aims] NAFLD is the most common hepatic pathology in western countries and no treatment is currently available. NAFLD is characterized by the aberrant hepatocellular accumulation of fatty acids in the form of lipid droplets (LDs). Recently, it was shown that liver LD degradation occurs through a process termed lipophagy, a form of autophagy. However, the molecular mechanisms governing liver lipophagy are elusive. Here, we aimed to ascertain the key molecular players that regulate hepatic lipophagy and their importance in NAFLD., [Approach and Results] We analyzed the formation and degradation of LD in vitro (fibroblasts and primary mouse hepatocytes), in vivo and ex vivo (mouse and human liver slices) and focused on the role of the autophagy master regulator mammalian target of rapamycin complex (mTORC) 1 and the LD coating protein perilipin (Plin) 3 in these processes. We show that the autophagy machinery is recruited to the LD on hepatic overload of oleic acid in all experimental settings. This led to activation of lipophagy, a process that was abolished by Plin3 knockdown using RNA interference. Furthermore, Plin3 directly interacted with the autophagy proteins focal adhesion interaction protein 200 KDa and autophagy-related 16L, suggesting that Plin3 functions as a docking protein or is involved in autophagosome formation to activate lipophagy. Finally, we show that mTORC1 phosphorylated Plin3 to promote LD degradation., [Conclusions] These results reveal that mTORC1 regulates liver lipophagy through a mechanism dependent on Plin3 phosphorylation. We propose that stimulating this pathway can enhance lipophagy in hepatocytes to help protect the liver from lipid-mediated toxicity, thus offering a therapeutic strategy in NAFLD., Supported by C0120R3166, C0245R4032, and BH182173 from Newcastle University. M. G.-M. is a Sara Borrell Postdoctoral fellow (CD18/00203) from the Ministerio de Ciencia, Innovación y Universidades (Spain). J. P. B. is funded by the Agencia Estatal de Investigación, grants PID2019-105699RB-I00/AEI/10.13039/501100011033 and RED2018-102576-T, Instituto de Salud Carlos III (CB16/10/00282), Junta de Castilla y León (Escalera de Excelencia CLU-2017-03), Ayudas Equipos Investigación Biomedicina 2017 Fundación BBVA, and Fundación Ramón Areces. V. I. K. acknowledges support from Biotechnology and Biological Sciences Research Council (BB/M023389/1, BB/R008167/1, BB

Batten diseases (BDs) are a group of lysosomal storage disorders characterized by seizure, visual loss, and cognitive and motor deterioration. We discovered increased levels of globotriaosylceramide (Gb3) in cellular and murine models of CLN3 and CLN7 diseases and used fluorescent‐conjugated bacterial toxins to label Gb3 to develop a cell‐based high content imaging (HCI) screening assay for the repurposing of FDA‐approved compounds able to reduce this accumulation within BD cells. We found that tamoxifen reduced the lysosomal accumulation of Gb3 in CLN3 and CLN7 cell models, including neuronal progenitor cells (NPCs) from CLN7 patient‐derived induced pluripotent stem cells (iPSC). Here, tamoxifen exerts its action through a mechanism that involves activation of the transcription factor EB (TFEB), a master gene of lysosomal function and autophagy. In vivo administration of tamoxifen to the CLN7Δex2 mouse model reduced the accumulation of Gb3 and SCMAS, decreased neuroinflammation, and improved motor coordination. These data strongly suggest that tamoxifen may be a suitable drug to treat some types of Batten disease., The neuronal ceroid lipofuscinoses (NCL), commonly known as Batten disease (BD), are a group of recessively inherited fatal diseases of the nervous system that typically arise in childhood. There is neither cure nor drugs to revert the course of these diseases.

Precision cut liver slices (PCLSs) retain the structure and cellular composition of the native liver and represent an improved system to study liver fibrosis compared to two-dimensional mono- or co-cultures. The aim of this study was to develop a bioreactor system to increase the healthy life span of PCLSs and model fibrogenesis. PCLSs were generated from normal rat or human liver, or fibrotic rat liver, and cultured in our bioreactor. PCLS function was quantified by albumin enzyme-linked immunosorbent assay (ELISA). Fibrosis was induced in PCLSs by transforming growth factor beta 1 (TGFβ1) and platelet-derived growth factor (PDGFββ) stimulation ± therapy. Fibrosis was assessed by gene expression, picrosirius red, and α-smooth muscle actin staining, hydroxyproline assay, and soluble ELISAs. Bioreactor-cultured PCLSs are viable, maintaining tissue structure, metabolic activity, and stable albumin secretion for up to 6 days under normoxic culture conditions. Conversely, standard static transwell-cultured PCLSs rapidly deteriorate, and albumin secretion is significantly impaired by 48 hours. TGFβ1/PDGFββ stimulation of rat or human PCLSs induced fibrogenic gene expression, release of extracellular matrix proteins, activation of hepatic myofibroblasts, and histological fibrosis. Fibrogenesis slowly progresses over 6 days in cultured fibrotic rat PCLSs without exogenous challenge. Activin receptor-like kinase 5 (Alk5) inhibitor (Alk5i), nintedanib, and obeticholic acid therapy limited fibrogenesis in TGFβ1/PDGFββ-stimulated PCLSs, and Alk5i blunted progression of fibrosis in fibrotic PCLS. Conclusion: We describe a bioreactor technology that maintains functional PCLS cultures for 6 days. Bioreactor-cultured PCLSs can be successfully used to model fibrogenesis and demonstrate efficacy of antifibrotic therapies. ispartof: HEPATOLOGY vol:70 issue:4 pages:1377-1391 ispartof: location:United States status: published

Trabajo presentado al 20th Biennial Meeting of The Society for Free Radical Research International (SFRR-I) del 15 al 18 de marzo de forma virtual, Neuronal ceroid lipofuscinoses (NCLs), known as Batten disease, are the most common of the rare neurodegenerative disorders in children. These disorders are grouped together based on clinical similarities and uniform neuropathological features, including accumulation of lipofuscin in lysosomes and widespread gliosis. CLN7 disease is one of these NCLs that present in late infancy and is caused by mutations in the CLN7/MFSD8 gene, which encodes a lysosomal membrane glycoprotein of unknown function, hence the biochemical processes affected by CLN7-loss of function are not understood. Here, we found in the Cln7Δex2 mouse model of CLN7 disease that failure in the autophagy-lysosomal pathway causes aberrant accumulation of reactive oxygen species (ROS)-producing brain mitochondria. Metabolic profile analysis of Cln7Δex2 neurons revealed a decrease in the basal oxygen consumption rate (OCR), ATP-linked and maximal OCR and proton leak, indicating bioenergetically impaired mitochondria. To assess the impact of ROS on CLN7 disease progression, Cln7Δex2 mice were crossed with mice expressing a mitochondrial-tagged form of catalase (mCAT) governed by a neuron-specific promoter (Cln7Δex2-CAMKIIaCre-mCAT). The increased mROS observed in Cln7Δex2 neurons was abolished in Cln7Δex2- CAMKIIaCre-mCAT neurons, verifying the efficacy of this approach. The brain mitochondrial swelling and mitochondrial cristae profile widening observed in Cln7Δex2 mice were abolished in Cln7Δex2-CAMKIIaCre-mCAT mice. Notably, Cln7Δex2 brain accumulation of subunit C-ATPase and lysosomal lipofuscin, as well as gliosis, which are hallmarks of the disease, were ameliorated in Cln7Δex2- CAMKIIaCre-mCAT mice. Altogether, these findings indicate that the generation of ROS by bioenergetically-impaired mitochondria in Cln7Δex2 neurons contributes to the histopathological symptoms of CLN7 disease.

The neuronal ceroid lipofuscinoses (NCLs) are a family of monogenic life-limiting pediatric neurodegenerative disorders collectively known as Batten disease1. Although genetically heterogeneous2, NCLs share several clinical symptoms and pathological hallmarks such as lysosomal accumulation of lipofuscin and astrogliosis2,3. CLN7 disease belongs to a group of NCLs that present in late infancy4–6 and, whereas CLN7/MFSD8 gene is known to encode a lysosomal membrane glycoprotein4,7–9, the biochemical processes affected by CLN7-loss of function are unexplored thus preventing development of potential treatments1,10. Here, we found in the Cln7Δex2 mouse model11 of CLN7 disease that failure in the autophagy-lysosomal pathway causes accumulation of structurally and bioenergetically impaired, reactive oxygen species (ROS)-producing neuronal mitochondria that contribute to CLN7 pathogenesis. Cln7Δex2 neurons exhibit a metabolic shift mediated by pro-glycolytic enzyme 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase-3 (PFKFB3). PFKFB3 inhibition in Cln7Δex2 mice in vivo and in CLN7 patients-derived cells rectified key disease hallmarks. Thus, specifically targeting glycolysis may alleviate CLN7 pathogenesis.

Resumen del trabajo presentado en la 20th Biennial Meeting of The Society for Free Radical Research International (SFRR-I) celebrado online del 15 al 18 de marzo de 2021, Our group is interested in understanding the mechanisms that contribute to the metabolic and redox coupling between astrocytes and neurons, as well as their implication in cognitive and motor functions. Neurons show a high dependence on mitochondrial oxidative phosphorylation for survival, whereas astrocytes resist to almost complete inhibition of mitochondrial respiration. A key factor in this process is PFKFB3, an enzyme that promotes glycolysis by activating its regulatory enzyme PFK1. We previously demonstrated that PFKFB3 is a substrate of the E3 ubiquitin ligase APC/C-Cdh1. By degrading PFKFB3, APC/C-Cdh1 ac- tivity shifts the equilibrium of glucose consumption from glycolysis towards pentose-phosphate pathway (PPP), thus regulating the redox status and survival of neurons. Conversely, APC/C-Cdh1 activity in astrocytes is very low, which accounts for the elevated PFKFB3 protein levels and glycolytic phenotype of these cells. However, the impact of PFKFB3 modulation in specific brain cells on cognitive and motor functions have not yet been explored. To address this, wgenerated a Cre recombinase inducible ROSA26-floxed knock-in mouse harboring the full-length PFKFB3 cDNA (PFKFB3LoxP/+) to specifically assess the impact of PFKFB3 expression in neurons in vivo. PFKFB3LoxP/+ mice were crossed with mice expressing Cre recombinase under the neuronal CAMKIIa promoter (CAMKIIa-Cre). We found that the resulting PFKFB3LoxP/+; CAMKIIa-Cre mice showed increased PFKFB3 protein levels in neurons in vivo and symptoms of cognitive decline and motor discoordination as from the 3 months of age. Interestingly, this PFKFB3-induced phenotype was rescued by in vivo coexpressing mitoCatalase (mCAT), i.e. the antioxidant enzyme catalase confined to neuronal mitochondria. These results indicate that aberrant enhancement of glycolysis in neurons causes behavioral impairment in mouse through a mitochondrial redox stress-mediated mechanism.

Correction to: Nature Metabolism https://doi.org/10.1038/s42255-020-00306-2, published online 9 November 2020. In the version of this article initially published, in the ×40 diseased human kidney images in Supplementary Fig. 1, the FSGS image duplicated the DN image. The error has been corrected in the HTML version of the article.

Fibrosis is a common pathological feature of chronic disease. Deletion of the NF-κB subunit c-Rel limits fibrosis in multiple organs, although the mechanistic nature of this protection is unresolved. Using cell-specific gene-targeting manipulations in mice undergoing liver damage, we elucidate a critical role for c-Rel in controlling metabolic changes required for inflammatory and fibrogenic activities of hepatocytes and macrophages and identify Pfkfb3 as the key downstream metabolic mediator of this response. Independent deletions of Rel in hepatocytes or macrophages suppressed liver fibrosis induced by carbon tetrachloride, while combined deletion had an additive anti-fibrogenic effect. In transforming growth factor-β1-induced hepatocytes, c-Rel regulates expression of a pro-fibrogenic secretome comprising inflammatory molecules and connective tissue growth factor, the latter promoting collagen secretion from HMs. Macrophages lacking c-Rel fail to polarize to M1 or M2 states, explaining reduced fibrosis in RelΔLysM mice. Pharmacological inhibition of c-Rel attenuated multi-organ fibrosis in both murine and human fibrosis. In conclusion, activation of c-Rel/Pfkfb3 in damaged tissue instigates a paracrine signalling network among epithelial, myeloid and mesenchymal cells to stimulate fibrogenesis. Targeting the c-Rel-Pfkfb3 axis has potential for therapeutic applications in fibrotic disease. ispartof: NATURE METABOLISM vol:2 issue:11 ispartof: location:Germany status: published

During postprandial state, the liver is exposed to high levels of dietary fatty acids (FAs) and carbohydrates. FAs are re-esterified into triglycerides, which can be stored in lipid droplets (LDs) in the liver. Aberrant accumulation of LDs can lead to diseases such as alcoholic liver disease and non-alcoholic fatty liver disease, the latter being the most common liver pathology in western countries. Improved understanding of LD biology has potential to unlock new treatments for these liver diseases. The Perilipin (Plin) family is the group of proteins that coat LDs, controlling their biogenesis, stabilization, and preventing their degradation. Recent studies have revealed that autophagy is involved in LD degradation and, therefore, may be crucial to avoid lipid accumulation. Here, we show that a phosphorylated form of Plin3 is required for selective degradation of LDs in fibroblasts, primary hepatocytes and human liver slices. We demonstrate that oleic acid treatment induces the recruitment of the autophagy machinery to the surface of LDs. When Plin3 is silenced, this recruitment is suppressed resulting in accumulation of lipid. Plin3 pulldowns revealed interactions with the autophagy initiator proteins Fip200 and Atg16L indicating that Plin3 may function as a docking protein involved in lipophagy activation. Of particular importance, we define Plin3 as a substrate for mTORC1-dependent phosphorylation and show that this event is decisive for lipophagy. Our study therefore reveals that Plin3, and its phosphorylation by mTORC1, is crucial for degradation of LDs by autophagy. We propose that stimulating this pathway to enhance LD autophagy in hepatocytes will help protect the liver from lipid-mediated toxicity thus offering new therapeutic opportunities in human steatotic liver diseases.

Sexual dimorphism has been reported in many processes. However, sexual bias in favour of the use of males is very present in science. One of the main reasons is that the impact of hormones in diverse pathways and processes such as autophagy have not been properly addressed in vivo. The Harderian gland is a perfect model to study autophagic modulation as it exhibits important changes during the oestrous cycle. The aim of this study is to identify the main processes behind Harderian gland differences under oestrous cycle and their modulator. In the present study we show that redox-sensitive transcription factors have an essential role: NF-κB may activate SQSTM1/p62 in oestrus, promoting selective types of autophagy: mitophagy and lipophagy. Nrf2 activation in dioestrus, leads the retrieval phase and restoration of mitochondrial homeostasis. Melatonin’s receptors show higher expression in dioestrus, leading to decreases in pro-inflammatory mediators and enhanced Nrf2 expression. Consequently, autophagy is blocked, and porphyrin release is reduced. All these results point to melatonin as one of the main modulators of the changes in autophagy during the oestrous cycle., This work was supported by FISS18-PI17/02009, C0120R3166, C0245R4032 and BH182173. MG-M has a postdoctoral fellowship from the Instituto de Salud Carlos III (ISCIII), Ministerio de Ciencia, Innovación y Universidades. Financial support from the University of Oviedo is also acknowledged.

Background & Aims Methyl-CpG binding protein 2, MECP2, which binds to methylated regions of DNA to regulate transcription, is expressed by hepatic stellate cells (HSCs) and is required for development of liver fibrosis in mice. We investigated the effects of MECP2 deletion from HSCs on their transcriptome and of phosphorylation of MECP2 on HSC phenotype and liver fibrosis. Methods We isolated HSCs from Mecp2–/y mice and wild-type (control) mice. HSCs were activated in culture and used in array analyses of messenger RNAs and long noncoding RNAs. Kyoto Encyclopedia of Genes and Genomes pathway analyses identified pathways regulated by MECP2. We studied mice that expressed a mutated form of Mecp2 that encodes the S80A substitution, MECP2S80, causing loss of MECP2 phosphorylation at serine 80. Liver fibrosis was induced in these mice by administration of carbon tetrachloride, and liver tissues and HSCs were collected and analyzed. Results MECP2 deletion altered expression of 284 messenger RNAs and 244 long noncoding RNAs, including those that regulate DNA replication; are members of the minichromosome maintenance protein complex family; or encode CDC7, HAS2, DNA2 (a DNA helicase), or RPA2 (a protein that binds single-stranded DNA). We found that MECP2 regulates the DNA repair Fanconi anemia pathway in HSCs. Phosphorylation of MECP2S80 and its putative kinase, HIPK2, were induced during transdifferentiation of HSCs. HSCs from MECP2S80 mice had reduced proliferation, and livers from these mice had reduced fibrosis after carbon tetrachloride administration. Conclusions In studies of mice with disruption of Mecp2 or that expressed a form of MECP2 that is not phosphorylated at S80, we found phosphorylation of MECP2 to be required for HSC proliferation and induction of fibrosis. In HSCs, MECP2 regulates expression of genes required for DNA replication and repair. Strategies to inhibit MECP2 phosphorylation at S80 might be developed for treatment of liver fibrosis.

The integrative physiology of inter-organ communication in lipophagy regulation is not well understood. Lipophagy and the cytosolic lipases ATGL and HSL contribute to lipid droplet (LD) mobilization; however, whether autophagy proteins engage with lipases to promote lipid utilization remains unknown. Here, we show that cold induces autophagy in proopiomelanocortin (POMC) neurons and activates lipophagy in brown adipose tissue (BAT) and liver in mice. Targeted activation of autophagy in POMC neurons via intra-hypothalamic rapamycin is sufficient to trigger lipid utilization in room temperature-housed mice. Conversely, inhibiting autophagy in POMC neurons or in peripheral tissues or denervating BAT blocks lipid utilization. Unexpectedly, the autophagosome marker LC3 is mechanistically coupled to ATGL-mediated lipolysis. ATGL exhibits LC3-interacting region (LIR) motifs, and mutating a single LIR motif on ATGL displaces ATGL from LD and disrupts lipolysis. Thus, cold-induced activation of central autophagy activates lipophagy and cytosolic lipases in a complementary manner to mediate lipolysis in peripheral tissues.

During skeletal morphogenesis diverse mechanisms are used to support bone formation. This can be seen in the bones that require a cartilage template for their development. In mammals the cartilage template is removed, but in zebrafish the cartilage template persists and the bone mineralizes around the cartilage scaffold. Remodeling of unmineralized cartilage occurs via planar cell polarity (PCP) mediated cell rearrangements that contribute to lengthening of elements; however, the mechanisms that maintain the chondrocyte template that supports perichondral ossification remain unclear. We report double mutants disrupting two zebrafish kinesin-I genes (hereafter kif5Blof) that we generated using CRISPR/Cas9 mutagenesis. We show that zygotic Kif5Bs have a conserved function in maintaining muscle integrity, and are required for cartilage remodeling and maintenance during craniofacial morphogenesis by a PCP-distinct mechanism. Further, kif5Blof does not activate ER stress response genes, but instead disrupts lysosomal function, matrix secretion, and causes deregulated autophagic markers and eventual chondrocyte apoptosis. Ultrastructural and transplantation analysis reveal neighboring cells engulfing extruded kif5Blof chondrocytes. Initial cartilage specification is intact; however, during remodeling, kif5Blof chondrocytes die and the cartilage matrix devoid of hypertrophic chondrocytes remains and impedes normal ossification. Chimeric and mosaic analyses indicate that Kif5B functions cell-autonomously in secretion, nuclear position, cell elongation and maintenance of hypertrophic chondrocytes. Interestingly, large groups of wild-type cells can support elongation of neighboring mutant cells. Finally, mosaic expression of kif5Ba, but not kif5Aa in cartilage rescues the chondrocyte phenotype, further supporting a specific requirement for Kif5B. Cumulatively, we show essential Kif5B functions in promoting cartilage remodeling and chondrocyte maintenance during zebrafish craniofacial morphogenesis., Author summary During skeletal morphogenesis diverse mechanisms are used to support bone formation, for example some bones require a cartilage template. In mammals the cartilage template is removed, but in zebrafish the cartilage template persists and the bone mineralizes around the cartilage scaffold. Remodeling of unmineralized cartilage occurs via planar cell polarity (PCP) mediated cell rearrangements that contribute to lengthening of elements. We identified a conserved role for the Kinesin-1 heavy chain, kif5B, in maintaining muscle integrity and a novel role in cartilage development during craniofacial morphogenesis. In chondrogenesis Kif5B acts by a distinct mechanism from PCP signaling and does not activate the ER stress response genes, but instead involves regulation of lysosomal function, matrix secretion, and autophagy. When kif5B is lost, autophagic markers are deregulated leading to eventual chondrocyte apoptosis. Chimeric and mosaic analyses indicate that Kif5B functions cell-autonomously in secretion, nuclear position, cell elongation and maintenance. Interestingly, large groups of wild-type cells, likely via their matrix, support elongation of neighboring mutant cells. Cumulatively, our study reveals Kif5B’s essential role in promoting cartilage remodeling and chondrocyte maintenance during craniofacial morphogenesis.

During skeletal morphogenesis diverse mechanisms are used to support bone formation. This can be seen in the bones that require a cartilage template for their development. In mammals the cartilage template is removed, but in zebrafish the cartilage template persists and the bone mineralizes around the cartilage scaffold. Remodeling of unmineralized cartilage occurs via planar cell polarity (PCP) mediated cell rearrangements that contribute to lengthening of elements; however, the mechanisms that maintain the chondrocyte template that supports perichondral ossification remain unclear. We report double mutants disrupting two zebrafish kinesin-I genes (hereafter kif5Blof) that we generated using CRISPR/Cas9 mutagenesis. We show that zygotic Kif5Bs have a conserved function in maintaining muscle integrity, and are required for cartilage remodeling and maintenance during craniofacial morphogenesis by a PCP-distinct mechanism. Further, kif5Blof does not activate ER stress response genes, but instead disrupts lysosomal function, matrix secretion, and causes deregulated autophagic markers and eventual chondrocyte apoptosis. Ultrastructural and transplantation analysis reveal neighboring cells engulfing extruded kif5Blof chondrocytes. Initial cartilage specification is intact; however, during remodeling, kif5Blof chondrocytes die and the cartilage matrix devoid of hypertrophic chondrocytes remains and impedes normal ossification. Chimeric and mosaic analyses indicate that Kif5B functions cell-autonomously in secretion, nuclear position, cell elongation and maintenance of hypertrophic chondrocytes. Interestingly, large groups of wild-type cells can support elongation of neighboring mutant cells. Finally, mosaic expression of kif5Ba, but not kif5Aa in cartilage rescues the chondrocyte phenotype, further supporting a specific requirement for Kif5B. Cumulatively, we show essential Kif5B functions in promoting cartilage remodeling and chondrocyte maintenance during zebrafish craniofacial morphogenesis.

Autophagy failure is associated with metabolic insufficiency. Although caloric restriction (CR) extends healthspan, its adherence in humans is poor. We established an isocaloric twice-a-day (ITAD) feeding model wherein ITAD-fed mice consume the same food amount as ad libitum controls but at two short windows early and late in the diurnal cycle. We hypothesized that ITAD feeding will provide two intervals of intermeal fasting per circadian period and induce autophagy. We show that ITAD feeding modifies circadian autophagy and glucose/lipid metabolism that correlate with feeding-driven changes in circulating insulin. ITAD feeding decreases adiposity and, unlike CR, enhances muscle mass. ITAD feeding drives energy expenditure, lowers lipid levels, suppresses gluconeogenesis, and prevents age/obesity-associated metabolic defects. Using liver-, adipose-, myogenic-, and proopiomelanocortin neuron-specific autophagy-null mice, we mapped the contribution of tissue-specific autophagy to system-wide benefits of ITAD feeding. Our studies suggest that consuming two meals a day without CR could prevent the metabolic syndrome. Our studies suggest that consuming two meals a day with complete food restriction in between the meals is sufficient to lower blood glucose and lipid levels. This simple dietary approach activates a cell “cleansing system“ called autophagy in liver, fat, brain, and muscle that helps prevent obesity and diabetes.

Background Systemic low-grade inflammation is thought to be associated with an increased risk of adverse clinical outcomes in elderly population. We tested this notion with the goal of identifying useful potential biomarkers of 1-year hospitalization and mortality in the elderly population. Design A total of 120 institutionalized older subjects were enrolled as participants in this study, including 90 women and 30 men (ranging in age from 68 to 105 years), selected from Santa Teresa nursing home (Oviedo, Spain). We studied functional status, morbidity, socio-demographic characteristics and several inflammation and inflammation-related markers. Results The study included 95 non-hospitalized participants and 23 participants with at least one hospitalization during 1 year (19% of subjects). The study also included 100 survivors and 19 participants who died during the 1-year study (16% of subjects). In logistic regression models adjusted by age, sex, anti-inflammatory drug use and morbid conditions, high levels of interleukin 1 receptor antagonist (IL-1ra) and red blood cell distribution width (RDW) were associated with hospitalization and death at 1 year. Elevated levels of tumour necrosis factor a (TNF-a) were also associated with an increased risk of death at 1 year after adjusting for the same potential confounders. Multivariate logistic regression models showed that elevated serum levels of IL-1ra were intimately associated with 1-year subsequent hospitalization and mortality in aged subjects after adjusting for age, sex, anti-inflammatory drug use and morbid conditions. Conclusions Current data suggest that IL-1ra is a predictor of 1-year hospitalization and mortality in the elderly population.

BACKGROUND: The objective of this work was to study the post-mortem evolution of potential biomarkers (µ-calpain activity and proteolytic profile) of meat tenderisation in bovine longissimus dorsi (LD) muscle from several biotypes coming from two beef breeds (‘Asturiana de los Valles’ and ‘Asturiana de la Montana’) and showing different levels of muscular hypertrophy (mh/mh, mh/+, + /+). RESULTS: LD samples were taken at 2, 12, 24 and 48 h and 3, 7, 14 and 21 days post-mortem. The presence of muscular hypertrophy produced a faster rate of pH decline, faster exhaustion of µ-calpain activity and earlier occurrence of proteolytic changes. Changes in the electrophoretic pattern of some peptides from sarcoplasmic (glyceraldehyde-3-phosphate dehydrogenase) and myofibrillar (troponin T and troponin I) muscle extracts within the first 24 h significantly correlated with meat toughness and allowed accurate discrimination of meat products into two groups: (1) fast tenderising meat, coming from mh-biotypes, and (2) late tenderising meat, from normal (+/+) biotypes. CONCLUSION: Early monitoring (within 24 h after slaughter) of selected biomarkers in LD muscle allowed accurate prediction of ultimate meat toughness and could be used in the meat industry as a tool for early classification of beef into fast and late tenderising meat. Copyright © 2012 Society of Chemical Industry

Background. Studies of the role of oxidative stress in functional dependence among the aging population are limited. In this report, we address this situation through an analysis of a large panel of blood oxidative biomarkers in elderly population. Because the analysis of multiple biomarkers increases the complexity of data interpretation, this investigation has utilized both an analysis of single biomarkers in addition to employment of the statistical data reduction tool principal component analysis that might allow for a clearer description of redox status as compared with a single measure alone. Methods. We studied three groups of participants older than 65 years based on their Barthel Index: an independent group (100-95), a moderately dependent group (94-60), and a severely dependent group (59-0). Results. We observed a significant increase in circulating protein carbonyl levels in the severely dependent group as compared with the independent and moderately dependent groups. Using principal component analysis, we found at least three factors (an erythrocyte-related component, a protein damage–related component, and a plasma-related component) that could be used to assess the different oxidative parameters in our population. We discovered a significant association of higher levels of the protein damage–related component with the severely dependent group. Conclusions. Protein damage levels could be assessed in clinical use as a biomarker of severe dependence. Furthermore, our results support the hypothesis that functional decline could be associated in part due to oxidative stress. Finally, we show that principal component analysis could be a useful statistical tool in the analysis of age-related decline.

The Syrian hamster Harderian gland exhibits sexually dimorphic porphyrin biosynthesis, wherein the female glands display an extraordinarily high concentration of porphyrins. Damage derived from this production of porphyrins, mediated by reactive oxygen species, causes the glands to develop autophagic processes, which culminate in detachment-derived cell death; these cells normally play a central role in the secretory activity of the gland. The main aim of this study was to analyze how a change in the redox state impacts autophagy. Female Syrian hamsters were treated daily with melatonin (25 μg, subcutaneously) at ZT 10 for 1-2 months (N-acetyl-5-methoxytryptamine), an endogenous antioxidant that ameliorates the deleterious effects of free radicals via a variety of mechanisms. The length of treatment affected the redox balance, the autophagy machinery, and the activation of p53 and NF-κB. One-month treatment displaces redox balance to the antioxidant side, promotes autophagy through a p53-mediated mechanism, and increases cell detachment. Meanwhile, 2-month treatment restores redox balance to the oxidant side, activates NF-κB reducing autophagy to basal levels, increases number of type II cells, and reduces number of detached cells. Our results conclude that the redox state can modulate autophagy through redox-sensitive transcriptions factors. Additionally, these findings support a hypothesis that ascribes differences in the autophagic-lysosomal pathway to epithelial cell types, thereby restricting detachment-induced autophagic cell death to epithelial cell type I.

The objective of the present study was to investigate the changes in a large panel of emergent geriatric biomarkers in long-term trained elderly men to analyze the effects of long-term exercise on an aged population. We collected blood samples from two groups of male volunteers older than 65 years who maintain a measure of functional independence: one group of sedentary subjects without a history of regular physical activity and the other of subjects who have sustained training, starting during adulthood (mean training time = 49 ± 8 years). We studied morbidity, polypharmacy, cellular and serological inflammatory parameters, and endocrine mediators. After adjusting for confounding factors, we observed reduced medication intake per subject and lower number of diseases per subject with statistical differences nearly significant in the long-term exercise group. We showed that long-term training was associated with lower levels of white blood cell counts, neutrophil counts, interleukin-6, interleukin-10, interleukin-1 receptor antagonist, and soluble TNF receptor-I. Furthermore, we noted an increase in the concentrations of insulin-like growth factor-1 and dehydroepiandrosterone in the long-term training group. We concluded that long-term exercise training from adulthood to old age is clearly associated with a healthy profile of emergent geriatric biomarkers. Long-term training could improve the inflammatory–endocrine imbalance associated with disease, frailty, functional decline, and mortality in elderly men. Our results point to the benefits of prolonged exercise from adulthood to old age.

Aging is commonly defined as a physiological phenomenon associated with morphological and functional deleterious changes in which oxidative stress has a fundamental impact; therefore, readjusting the oxidative balance should have beneficial effects. In our study, we tested the antioxidant melatonin in old mouse brains and showed positive effects at the cellular and mitochondrial levels. Melatonin attenuated β-amyloid protein expression and α-synuclein deposits in the brain compared to aged group. Furthermore, oxidative stress was increased by aging and induced the nuclear translocation of nuclear factor-kappa B (NF-κB), which was suppressed by melatonin treatment. The antioxidant mitochondrial expression, superoxide dismutase 2 (SOD2), was increased in both control and melatonin-treated old mice, despite the different activation states of the NF-κB pathway. The NF-κB pathway was activated in the old mice, which may be explained by this group’s response to the increased oxidative insult; this insult was inhibited in melatonin-treated animals, showing this group an increase in active mitochondria population that was not observed in old group. We also report that melatonin is capable of restoring the mitochondrial potential of age-damaged neurons. In conclusion, melatonin’s beneficial effects on brain aging are linked to the increase in mitochondrial membrane potential and SOD2 expression, which probably reduces the mitochondrial contribution to the oxidative stress imbalance.

Oxidative stress has been reported to increase during aging and conditions of hypoxia. Although low oxygen saturation has a key role in the development of several age-related diseases, the underlying mechanisms are still unknown. We analyzed the relationship between aging and hypoxia by examining oxidative stress and inflammation-related cytokines. We collected blood samples from three volunteer experimental groups, consisting of one group of normoxic middle-aged people and two groups of individuals older than 75 years, which comprised a subgroup of normoxic subjects and another with oxyhemoglobin saturation lower than 95% (hypoxic). Our results showed a fall in antioxidant defenses in older people with hypoxia. TNF-alpha, the first element in the cytokine cascade, was significantly increased in the aged population, implying that aging is accompanied by a gradual increase in this inflammatory biomarker. IL-6 was not associated with aging, but it was highly elevated under hypoxia conditions in elderly subjects. Thus, these parameters could be used as biological markers of different inflammatory processes triggered by oxidative stress induced by a decrease in antioxidant defenses in the elderly population, with TNF-alpha as an indicator of chronic processes, such as aging, and IL-6 as a marker for acute responses, such as hypoxia.

Introduction Obesity and type 2 diabetes are growing health problems worldwide. The three principal diabetogenic factors are adiposity, insulin resistance in skeletal muscle, and decreased insulin production by pancreatic β cells. During recent years, macroautophagy (hereafter autophagy) - sequestration and lysosomal degradation of cellular components - has emerged as an important player in these processes, playing a protective role against development of insulin resistance and diabetes. Of particular importance is the removal of dysfunctional mitochondria via mitophagy, a form of macroautophagy selective for mitochondria. Both muscle insulin resistance and β-cell dysfunction largely depend on metabolic overload of mitochondria, which results in incomplete β-oxidation, oxidative stress, accumulation of toxic lipid intermediates, and mitochondrial damage. Mitophagy eliminates this vicious cycle of oxidative stress and mitochondrial damage, and thus counteracts pathogenic processes. Autophagy also mediates exercise-induced increases in muscle glucose uptake and protects β cells against ER stress in diabetogenic conditions. On the other hand, adipose tissue autophagy promotes adipocyte differentiation, possibly through its role in mitochondrial clearance. Being involved in many aspects, autophagy appears to be an attractive target for therapeutic interventions against obesity and diabetes. Conclusion Here we explore the connections of autophagy with mitochondria in obesity and type 2 diabetes, and discuss its roles in diabetic complications. Understanding how autophagy protects against diabetes could help design new strategies against this growing epidemic.

The Syrian hamster Harderian gland (HG) is an organ that undergoes physiological autophagy in response to oxidative stress induced by porphyrin production. Porphyrin production in the HG has marked sex differences and is closely linked to reproductive function. In the present study, we observed that the estrous cycle and associated estrogen variations may affect oxidative-stress-induced proteolytic processes. In particular, significant changes in autophagic activity were detected during the estrous cycle. Notably, increased activation of macroautophagy as well as chaperone-mediated autophagy in the estrus phase coincided with a minimal antioxidant capability and the highest protein damage levels. By contrast, autophagic machinery was found to be blocked in the diestrus phase, likely due to mammalian target of rapamycin activation, which could be corroborated by the subsequent pS6K activation. Analogous results were observed regarding proteasome activity, which also showed maximal activity in the estrus phase. Interestingly, all these mechanisms were associated with important morphological changes in the HG during the estrous cycle. We observed statistically significant increases in Type II cells, which may be related to extensive autophagy in the estrus phase. Physiologically, this would result in a significant release of porphyrins specifically when females are more receptive. These data support the role of porphyrins as pheromones, as other authors have previously suggested, thus making the HG a scent organ. In addition, these results suggest a porphyrin-based approach to the treatment of porphyria during pregnancy, a condition for which no treatment is currently known.

The conversion of muscle into meat is a complex process of major concern for meat scientists due to its influence on the final meat quality. The aim of this study was to investigate the occurrence of autophagic processes in the conversion of muscle into meat. Our findings demonstrated, for the first time, the occurrence of autophagic processes in the muscle tissue at early postmortem period (2 h to 24 h) in both beef breeds studied (Asturiana de los Valles and Asturiana de la Montana) showing significant time-scale differences between breeds, which could indicate a role of this process in meat maturation. These breeds have different physiological features: while Asturiana de los Valles is a meat-specialized breed showing high growth rate, an elevated proportion of white fibers in the muscle and low intramuscular fat level, Asturiana de la Montana is a small- to medium-sized rustic breed adapted to less-favored areas, showing more red fibers in the muscle and a high intramuscular fat content.

The Syrian hamster Harderian gland (HG) has a marked sexual dimorphism and exhibits an extraordinary rate of porphyrinogenesis. The physiological oxidative stress, derived from constant porphyrin production, is so high that the HG needs additional survival autophagic mechanisms to fight against this chronic exposure, provoking the triggering of a holocrine secretion in female glands that forms two types of secretory masses: intra-tubular-syncytial and inter-tubular-syncytial masses. The aim of this work was to study the development of this inter-tubular holocrine secretion. To approach this task, we have considered that the steps developed during the formation of the so-called invasive masses consist of the growth of epithelial cells, cell detachment from the basal lamina and invasion of surrounding tissues. The presence of these masses, particularly in the female HG, are closely linked to sexual dimorphism in redox balance and to alterations in the expression of certain factors such as cytokeratins, P-cadherin, matrix metalloproteinases, cathepsin H, proliferating cell nuclear antigen, p53, CD-31 and vascular endothelial growth factor, which seem to be involved in tissue remodeling. The results document unusual mechanisms of secretion in Syrian hamster HG: an extraordinary system of massive secretion through the conjunctive tissue, disrupting the branched structure of the gland.

Systemic low-grade inflammation is thought to be associated with an increased risk of adverse clinical outcomes in elderly population. We tested this notion with the goal of identifying useful potential biomarkers of 1-year hospitalization and mortality in the elderly population.A total of 120 institutionalized older subjects were enrolled as participants in this study, including 90 women and 30 men (ranging in age from 68 to 105 years), selected from Santa Teresa nursing home (Oviedo, Spain). We studied functional status, morbidity, socio-demographic characteristics and several inflammation and inflammation-related markers.The study included 95 non-hospitalized participants and 23 participants with at least one hospitalization during 1 year (19% of subjects). The study also included 100 survivors and 19 participants who died during the 1-year study (16% of subjects). In logistic regression models adjusted by age, sex, anti-inflammatory drug use and morbid conditions, high levels of interleukin 1 receptor antagonist (IL-1ra) and red blood cell distribution width (RDW) were associated with hospitalization and death at 1 year. Elevated levels of tumour necrosis factor α (TNF-α) were also associated with an increased risk of death at 1 year after adjusting for the same potential confounders. Multivariate logistic regression models showed that elevated serum levels of IL-1ra were intimately associated with 1-year subsequent hospitalization and mortality in aged subjects after adjusting for age, sex, anti-inflammatory drug use and morbid conditions.Current data suggest that IL-1ra is a predictor of 1-year hospitalization and mortality in the elderly population.

In the present investigation we have analyzed the association between functional dependence and inflammatory biomarkers using the Barthel Index (BI) and the Katz Index (KI). This analysis may contribute to translational medicine by incorporating the clinical and laboratory data to better understand the relationship between chronic inflammation and functional dependence in the elderly population. The ultimate goal of this study was to identify possible useful biomarkers of functional dependence in the elderly. Participants in this study consisted of 120 older subjects (90 women and 30 men; range 68–105 years) who were selected from the Santa Teresa nursing home (Oviedo, Spain). We studied functional status using the following tools to diagnose the functional dependence by clinicians: BI and KI for activities of daily living. We analyzed morbidity, sociodemographic characteristics and a panel of inflammatory and inflammatory-related markers. In linear regression models adjusted by age, sex, anti-inflammatory drug use and morbid conditions high levels of interleukin 6 (IL-6) and soluble TNF receptor-I (sTNF-RI) were associated with functional dependence as measured using BI and KI. Elevated levels of red blood cell distribution width (RDW) were also associated with functional dependence measured using the KI after adjusting for the same potential confounders. The current results suggest that high IL-6, sTNF-RI and RDW levels are associated with the functional dependence in the elderly population. The results are consistent with the presumed underlying biological mechanism, in which the up-regulation of inflammatory mediators is associated with functional dependence in elderly subjects.

The objective of the present study was to investigate a large panel of oxidative stress biomarkers in long-term trained elderly men to analyse the effects of chronic training on an aged population. We collected blood samples from two groups of male volunteers older than 65 years who maintain a measure of functional independence: one group of sedentary subjects without a history of regular physical activity and the other of subjects who have sustained training, starting during middle age (mean training time = 49 ± 8 years). We studied morbidity and polypharmacy, as well as haematological parameters including red cell count, haemoglobin concentration, haematocrit, mean corpuscular volume, red cell distribution width and several oxidative biomarkers including protein carbonyl content and lipid peroxidation in plasma and erythrocytes, red blood cell H2O2-induced haemolysis test, plasma total antioxidant activity and the main antioxidant enzymes of erythrocytes: superoxide dismutase, catalase, glutathione peroxidase, glutathione reductase and glutathione-S-transferase. After adjusting for confounding factors, we observed an increase in all oxidative damage biomarkers in the plasma and erythrocytes of the long-term exercise group. However, we reported a decrease in the number of diseases per subject with statistical differences nearly significant (p = 0.061), reduced intake of medications per subject and lower levels of red cell distribution width in the chronic exercise group. These results indicate that chronic exercise from middle age to old age increases oxidative damage; however, chronic exercise appears to be an effective strategy to attenuate the age-related decline in the elderly.

The present study investigated the changes in several erythrocyte oxidative stress biomarkers in hypoxic elderly individuals to analyze the deleterious effects of low oxyhemoglobin saturation in an elderly population. We collected blood samples from one normoxic middle-aged group and two groups composed of individuals older than 75 years of age: one normoxic group and one hypoxic group. Aging appeared to provoke a defective erythrocyte antioxidant defense associated with increased oxidative damage in the elderly population. Acute hypoxia activated an insufficient antioxidant defense response as suggested by the oxidative damage observed. The oxidative imbalance presented in older participants and increased in hypoxia participants had a direct effect on glyceraldehyde-3-phosphate dehydrogenase cell distribution. Oxidative stress levels altered Band 3 protein and mediated caspase-3 activation in erythrocyte from the aged group although it was not extended to hypoxic individuals. Therefore, aged participants appeared to activate an insufficient antioxidant response against hypoxia-related oxidative stress. Language: en

Aging is commonly defined as a physiological phenomenon associated with morphological and functional deleterious changes in which oxidative stress has a fundamental impact; therefore, readjusting the oxidative balance should have beneficial effects. In our study, we tested the antioxidant melatonin in old mouse brains and showed positive effects at the cellular and mitochondrial levels. Melatonin attenuated β-amyloid protein expression and α-synuclein deposits in the brain compared to aged group. Furthermore, oxidative stress was increased by aging and induced the nuclear translocation of nuclear factor-kappa B (NF-κB), which was suppressed by melatonin treatment. The antioxidant mitochondrial expression, superoxide dismutase 2 (SOD2), was increased in both control and melatonin-treated old mice, despite the different activation states of the NF-κB pathway. The NF-κB pathway was activated in the old mice, which may be explained by this group's response to the increased oxidative insult; this insult was inhibited in melatonin-treated animals, showing this group an increase in active mitochondria population that was not observed in old group. We also report that melatonin is capable of restoring the mitochondrial potential of age-damaged neurons. In conclusion, melatonin's beneficial effects on brain aging are linked to the increase in mitochondrial membrane potential and SOD2 expression, which probably reduces the mitochondrial contribution to the oxidative stress imbalance.

The Syrian hamster Harderian gland (HG) has a large porphyrin metabolism with a sexual dimorphism, showing male HGs much lower porphyrin concentrations than female glands. Damage derived from this production of porphyrins, displayed by reactive oxygen species, forces the gland to develop morphological changes that must have a physiological significance. Thus, oxidative stress is present in two states: mild oxidative stress in male HGs and extreme oxidative stress in female HGs. Cathepsins data gave indirect indications about the presence of programmed cell death affecting the lysosomal pathway, especially in female HGs, which showed an accumulation of autophagic bodies. Our results showed different degrees of autophagy in Syrian hamster HGs depending on sex and probably controlled by the redox-sensitive transcription factors: NFkappaB and p53. The discovery of these sexual dimorphisms in redox signaling and in autophagy corroborates previous findings and underlines the key role of reactive oxygen species in the regulation of autophagy. In addition, in this paper we propose a physiological significance for these phenomena: male HGs develop a survival autophagy, while in female HGs, autophagy culminates in a detachment-derived cell death that plays a central role in its secretory activity, leading to a massive glandular secretion.

Purpose The aim of this investigation was to analyze whether the following platelet indices are useful markers for functional dependence and 1-year all-cause hospitalization and mortality in the elderly population: platelet count (PLT), platelet distribution width (PDW), mean platelet volume (MPV), and platelet–large cell ratio (P-LCR). Methods The 119 participants in this study were 90 women and 29 men between the ages of 68 and 105 years who were selected from the Santa Teresa nursing home (Oviedo, Spain). We studied morbidity, sociodemographic characteristics, and functional status using the Barthel Index (BI) and Katz Index (KI) for activities of daily living. Results In logistic regression models adjusted for age, sex, and anti-inflammatory drug use, low levels of PDW were associated with death at 1 year. When we applied logistic regression models adjusted for morbid conditions as well as age, sex, and anti-inflammatory drug use, the PDW remained statistically significant. No relation between PLT, MPV, or P-LCR and mortality was found. No statistical associations between the platelet indices studied and functional dependence or hospitalization were observed. Conclusion Our data suggest that the PDW could be a predictor of 1-year mortality in the elderly population and may therefore serve as a useful tool for identifying individuals with a high risk of mortality who may benefit from preventative care or early-stage strategies.