5,306 research outputs found
Hemoglobin overexpression triggers neuronal cell death upon Parkinson’s disease mimicking insults
No full textTRAF6 promotes atypical ubiquitination of mutant DJ-1 and alpha-synuclein and is localized to Lewy bodies in sporadic Parkinson's disease brains
No full textParkinson’s disease (PD) is a neurodegenerative disorder characterized by loss of dopaminergic neurons in the Substantia Nigra and the formation of ubiquitin- and alpha-synuclein (aSYN)-positive cytoplasmic inclusions called Lewy bodies (LBs). Although most PD cases are sporadic, families with genetic mutations have been found. Mutations in PARK7/DJ-1 have been associated with autosomal recessive early-onset PD, while missense mutations or duplications of aSYN (PARK1, PARK4) have been linked to dominant forms of the disease. In this study, we identify the E3 ubiquitin ligase tumor necrosis factor-receptor associated factor 6 (TRAF6) as a common player in genetic and sporadic cases. TRAF6 binds misfolded mutant DJ-1 and aSYN. Both proteins are substrates of TRAF6 ligase activity in vivo. Interestingly, rather than conventional K63 assembly, TRAF6 promotes atypical ubiquitin linkage formation to both PD targets that share K6-, K27- and K29- mediated ubiquitination. Importantly, TRAF6 stimulates the accumulation of insoluble and polyubiquitinated mutant DJ-1 into cytoplasmic aggregates. In human post-mortem brains of PD patients, TRAF6 protein colocalizes with aSYN in LBs. These results reveal a novel role for TRAF6 and for atypical ubiquitination in PD pathogenesis
Expression of APE1 endonuclease in primarily cultured aortic valve interstitial cells undergoing spontaneous senescence
No full textApurinic/apyrimidinic endodeoxyribonuclease 1
(APE1) is the major enzyme involved in the base excision
repair pathway working on DNA damages mainly
caused by oxidative stress. Namely, APE1 hydrolyses
the phosphodiester bond at the abasic sites generated
by DNA glycosylases, creating the substrate for DNA
polymerase β and DNA ligase IIIa which terminate the
reparative process [1]. APE1 also seems to play a role in
cell senescence maintaining telomere stability and size
in interaction with specifi c telomere-protective proteins
[2]. Here, aortic valve interstitial cells (AVICs) isolated
from healthy bovine valve leafl ets were cultured under
normal conditions for up to 90 days to achieve spontaneous
cell senescence. Time-dependent increase in
β-galactosidase activity, a marker of cell senescence, was
paralleled by a remarkable decrease of APE1-expressing
AVICs starting from day 60, as immunocytochemically
revealed. Quantitative Western blot analyses also showed
a drop of APE1 protein content at day 60, whereas RTPCR
analyses revealed a mild increase of the enzyme
mRNA over time. Ultrastructurally, AVICs appeared
well preserved up to 30-day-long culturing. Conversely,
starting from day 60, cells showed non-lysosomal
autophagocytosis features mainly consisting of a hypertrophic
rough endoplasmic reticulum engulfi ng suff ering
mitochondria [3]. Cytoplasm vacuolization due to
large organelle degeneration was also clearly appreciable.
In conclusion, decreasing APE1 expression over time
is supposed to contribute to AVIC decay in a model of
spontaneous cell senescence
Hemoglobin is present as a canonical α2β2 tetramer in dopaminergic neurons
No full textAbstractHemoglobin is the oxygen carrier in blood erythrocytes. Oxygen coordination is mediated by α2β2 tetrameric structure via binding of the ligand to the heme iron atom. This structure is essential for hemoglobin function in the blood. In the last few years, expression of hemoglobin has been found in atypical sites, including the brain. Transcripts for α and β chains of hemoglobin as well as hemoglobin immunoreactivity have been shown in mesencephalic A9 dopaminergic neurons, whose selective degeneration leads to Parkinson's disease. To gain further insights into the roles of hemoglobin in the brain, we examined its quaternary structure in dopaminergic neurons in vitro and in vivo. Our results indicate that (i) in mouse dopaminergic cell line stably over-expressing α and β chains, hemoglobin exists as an α2β2 tetramer; (ii) similarly to the over-expressed protein, endogenous hemoglobin forms a tetramer of 64kDa; (iii) hemoglobin also forms high molecular weight insoluble aggregates; and (iv) endogenous hemoglobin retains its tetrameric structure in mouse mesencephalon in vivo. In conclusion, these results suggest that neuronal hemoglobin may be endowed with some of the biochemical activities and biological function associated to its role in erythroid cells. This article is part of a Special Issue entitled: Oxygen Binding and Sensing Proteins
Design and advanced characterization of quercetin-loaded nano-liposomes prepared by high-pressure homogenization
No full textParkinson's disease DJ-1 L166P alters rRNA biogenesis by exclusion of TTRAP from the nucleolus and sequestration into cytoplasmic aggregates via TRAF6
No full textMutations in PARK7/DJ-1 gene are associated to autosomal recessive early onset forms of Parkinson"s disease (PD). Although large gene deletions have been linked to a loss-of-function phenotype, the pathogenic mechanism of missense mutations is less clear. The L166P mutation causes misfolding of DJ-1 protein and its degradation. L166P protein may also accumulate into insoluble cytoplasmic aggregates with a mechanism facilitated by the E3 ligase TNF receptor associated factor 6 (TRAF6). Upon proteasome impairment L166P activates the JNK/p38 MAPK apoptotic pathway by its interaction with TRAF and TNF Receptor Associated Protein (TTRAP). When proteasome activity is blocked in the presence of wild-type DJ-1, TTRAP forms aggregates that are localized to the cytoplasm or associated to nucleolar cavities, where it is required for a correct rRNA biogenesis. In this study we show that in post-mortem brains of sporadic PD patients TTRAP is associated to the nucleolus and to Lewy Bodies, cytoplasmic aggregates considered the hallmark of the disease. In SH-SY5Y neuroblastoma cells, misfolded mutant DJ-1 L166P alters rRNA biogenesis inhibiting TTRAP localization to the nucleolus and enhancing its recruitment into cytoplasmic aggregates with a mechanism that depends in part on TRAF6 activity. This work suggests that TTRAP plays a role in the molecular mechanisms of both sporadic and familial PD. Furthermore, it unveils the existence of an interplay between cytoplasmic and nucleolar aggregates that impacts rRNA biogenesis and involves TRAF
Stages for the More Sustainable Farm
No full textCurrently, agricultural farm units are faced with a double and most times contradictory challenge, in order to be successful: on the one hand the invested capital has to be profitable and the economic performance has to be maximised. On the other hand, given the socio-environmental situation, it is necessary to preserve and to protect the environment and natural resources. Given the potential conflict of the two aims, since the satisfaction of one implies the underperformance of the other (and vice versa), the question then is: which is the solution to choose? We intend, in this work, to formulate a farm plan with the purpose of reconciling the criteria of environmental sustainability with that of economic competitiveness. For this achievement we proceed to the comparative study of sustainability of different groups of farms identified in the study area (first evaluation cycle) through MESMIS (“Marco para la Evaluación de Sistemas de Manejo de Recursos Naturales Mediante Indicadores de Sustentabilidad” - Framework for Evaluation of Natural-Resource Systems Handling through Sustainability Indicators) methodology, that allowed to select the more sustainable group of farms. Based on the found potentialities and weakness on these production systems, we stepped to the planning of a production unit of bovine meat, which obeys simultaneously to economic and environmental objectives, using Multicriteria Decision. We finished the work with the sustainability evaluation between groups of farms identified previously and the planned farms (second evaluation cycle), based, again, in the MESMIS methodology, to confirm (or not) the greatest sustainability of the last ones. Analyses of the results allow us to confirm the greatest relative sustainability of the planned farm, for the diverse traced scenarios.Decision taking, planning, sustainability, Environmental Economics and Policy, Farm Management,
Mast cells-intestinal cancer cells crosstalk is mediated by TNF-alpha and sustained by the IL-33/ST2 axis
No full textAbstract It is common knowledge that mast cells (MCs) exert different roles in the gastrointestinal tract, from the maintenance of homeostasis to the onset and propagation of different gut diseases such as food allergies, infections, inflammation, and cancer. However, the mechanisms through which MCs dialog and influence the intestinal tissue are not completely known. To get insight into the bidirectional crosstalk between MCs and the intestinal microenvironment, both in homeostatic and pathological settings, colon organoids from intestinal epithelium of healthy mice and adenomas from AOM/DSS-treated mice have been exploited and co-cultured with MCs. The influence of MCs on organoid architecture and the effect of healthy and tumoral organoids on the phenotype and responsiveness of MCs have been addressed. We observed that MCs interact with intestinal organoids and contribute to the differentiation of healthy organoids by upregulating the expression of mucin-2, chromogranin A, cadherin-1, and claudin 4. On the contrary, in co-culture with tumoral organoids a decrease in cell proliferation, chromogranin A, and lysozyme expression was observed. Tumoral organoids have been shown to activate MCs via the IL-33/ST2 axis leading to increased release of TNF-α which in turn was responsible for the observed effects on tumoral organoids. Our results indicate that MCs are important mediators of intestinal tissue homeostasis and that a different environment can shape and direct MCs toward the dampening or propagation of the inflammatory response. Ultimately, our MC-organoid co-cultures represent a valid in vitro tool to investigate the role of MCs in the gut
Neuronal hemoglobin affects dopaminergic cells' response to stress
No full textHemoglobin (Hb) is the major protein in erythrocytes and carries oxygen (O2) throughout the body. Recently, Hb has been found synthesized in atypical sites, including the brain. Hb is highly expressed in A9 dopaminergic (DA) neurons of the substantia nigra (SN), whose selective degeneration leads to Parkinson's disease (PD). Here we show that Hb confers DA cells' susceptibility to 1-methyl-4-phenylpyridinium (MPP+) and rotenone, neurochemical cellular models of PD. The toxic property of Hb does not depend on O2 binding and is associated with insoluble aggregate formation in the nucleolus. Neurochemical stress induces epigenetic modifications, nucleolar alterations and autophagy inhibition that depend on Hb expression. When adeno-associated viruses carrying α- and β-chains of Hb are stereotaxically injected into mouse SN, Hb forms aggregates and causes motor learning impairment. These results position Hb as a potential player in DA cells' homeostasis and dysfunction in PD
Parole d'artiste : Marta Cuscunà
No full textInternational audienceModeration of the interview with Marta Cuscunà, an Italian performer, director, puppeteer and author. In 2009, she was awarded the Premio Scenario per Ustica for E bello vivere liberi!, first show of a trilogy on female resistance, followed by La semplicità ingannata (2012) and Sorry, boys (2015). These three texts are published in Resistenze femminili (Udine: Forum, 2019). In 2018 she created Il canto della caduta. Earthbound (2021) is her last devised show, which brings in the themes of ecofeminism, taking cues from the theories of Donna Haraway and Bruno Latour. In 2021 she became associate artist at the Piccolo Teatro in Milan. In 2023, she is guest of honor at the 11th Biennale internationale des arts de la marionette in Paris. She was awarded the prizes Rete Critica (2017), Premio della Critica – ANCT (2018) and Premio Hystrio - Altre Muse (2019).Animation de la discussion avec Marta Cuscunà, performeuse, metteuse en scène, marionnettiste et autrice italienne. En 2009, elle a remporté le prix Premio Scenario per Ustica pour È bello vivere liberi !, premier spectacle d’une trilogie sur les résistances féminines, suivi par La semplicità ingannata (2012) et Sorry, boys (2015). Ces trois textes ont été réunis dans Resistenze femminili (Udine : Forum, 2019). En 2018, elle a créé Il canto della caduta. Son dernier spectacle, Earthbound (2021), traite de l’écoféminisme en s’inspirant des théories de Donna Haraway et de Bruno Latour. En 2021, elle devient artiste associée au Piccolo Teatro de Milan. En 2023, elle est invitée d’honneur à la Biennale Internationale des Arts de la Marionnette à Paris. Elle a obtenu les prix Premio Rete Critica (2017), Premio della Critica – ANCT (2018) et Premio Hystrio - Altre Muse (2019)
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