Caffeine improves mitochondrial function in PINK1B9-null mutant Drosophila melanogaster.

Mitochondrial dysfunction plays a central role in Parkinson's disease (PD) and can be triggered by xenobiotics and mutations in mitochondrial quality control genes, such as the PINK1 gene. Caffeine has been proposed as a secondary treatment to relieve PD symptoms mainly by its antagonistic effects on adenosine receptors (ARs). Nonetheless, the potential protective effects of caffeine on mitochondrial dysfunction could be a strategy in PD treatment but need further investigation. In this study, we used high-resolution respirometry (HRR) to test caffeine's effects on mitochondrial dysfunction in PINK1B9-null mutants of Drosophila melanogaster. PINK1 loss-of-function induced mitochondrial dysfunction in PINK1B9-null flies observed by a decrease in O2 flux related to oxidative phosphorylation (OXPHOS) and electron transfer system (ETS), respiratory control ratio (RCR) and ATP synthesis compared to control flies. Caffeine treatment improved OXPHOS and ETS in PINKB9-null mutant flies, increasing the mitochondrial O2 flux compared to untreated PINKB9-null mutant flies. Moreover, caffeine treatment increased O2 flux coupled to ATP synthesis and mitochondrial respiratory control ratio (RCR) in PINK 1B9-null mutant flies. The effects of caffeine on respiratory parameters were abolished by rotenone co-treatment, suggesting that caffeine exerts its beneficial effects mainly by stimulating the mitochondrial complex I (CI). In conclusion, we demonstrate that caffeine may improve mitochondrial function by increasing mitochondrial OXPHOS and ETS respiration in the PD model using PINK1 loss-of-function mutant flies.

Mitochondrial function and cellular energy maintenance during aging in a Drosophila melanogaster model of Parkinson disease.

Parkinson's disease (PD) is a common neurodegenerative disease characterized by movement disorders as well as loss of dopaminergic neurons. Moreover, genes affecting mitochondrial function, such as SNCA, Parkin, PINK1, DJ-1 and LRRK2, were demonstrated to be associated with PD and other neurodegenerative disease. Additionally, mitochondrial dysfunction and cellular energy imbalance are common markers found in PD. In this study, we used the pink1 null mutants of Drosophila melanogaster as a Parkinson's disease model to investigate how the energetic pathways and mitochondrial functions change during aging in a PD model. In our study, the loss of the pink1 gene decreased the survival percent and the decreased climbing index during aging in pink1-/- flies. Furthermore, there was an impairment in mitochondrial function demonstrated by a decrease in OXPHOS CI&CII-Linked and ETS CI&CII-Linked in pink1-/- flies at 3, 15 and 30 days of life. Interestingly, OXPHOS CII-Linked and ETS CII-Linked presented decreases only at 15 days of life in pink1-/- flies. Moreover, there was an increase in peroxide (H2O2) levels in pink1-/- flies at 15 and 30 days of life. Loss of the pink1 gene also decreased the activity of citrate synthase (CS) and increased the activity of lactate dehydrogenase (LDH) in pink1-/- flies head. Our results demonstrate a metabolic shift in ATP production in pink1-/- flies, which changed from oxidative to glycolytic pathways from 15 days of age, and is apparently more pronounced in the central nervous system.

Antimicrobial and Toxicity Evaluation of Imidazolium-Based Dicationic Ionic Liquids with Dicarboxylate Anions.

Imidazolium-based dicationic ILs (DILs) presenting antimicrobial activity and relatively low toxicity are highly desirable and are envisioned for use in live tissue to prevent bacterial or fungal infections. In this context, we present here DILs with dicarboxylate anions [Cn(MIM)2[Cn(MIM)2][CO2-(CH2)mCO2], in which n = 4, 6, 8, and 10, and m = 0, 1, 2, 3, 4, and 5. The results showed that DILs with an alkyl chain spacer of ten carbons were active against yeasts and the bacterial strains tested. However, most of the DILs were cytotoxic and toxic at 1 mM. By contrast, DILs with alkyl chains possessing less than ten carbons were active against some specific Candidas and bacteria (mainly S. aureus), and they showed moderate cytotoxicity. The best activity against Gram-positive bacteria was observed for [C4(MIM)2][Pim] toward MRSA. For the DILs described herein, their level of toxicity against C. elegans was lower than that of most of the mono- and dicationic IL analogs with other anions. Our results showed that the presence of carboxylate anions reduces the toxicity of DILs compared to DILs containing halide anions, which is particularly significant to the means of designing biologically active compounds in antimicrobial formulations.

Neuromodulation and neuroprotective effects of chlorogenic acids in excitatory synapses of mouse hippocampal slices.

The increased healthspan afforded by coffee intake provides novel opportunities to identify new therapeutic strategies. Caffeine has been proposed to afford benefits through adenosine A2A receptors, which can control synaptic dysfunction underlying some brain disease. However, decaffeinated coffee and other main components of coffee such as chlorogenic acids, also attenuate brain dysfunction, although it is unknown if they control synaptic function. We now used electrophysiological recordings in mouse hippocampal slices to test if realistic concentrations of chlorogenic acids directly affect synaptic transmission and plasticity. 3-(3,4-dihydroxycinnamoyl)quinic acid (CA, 1-10 µM) and 5-O-(trans-3,4-dihydroxycinnamoyl)-D-quinic acid (NCA, 1-10 µM) were devoid of effect on synaptic transmission, paired-pulse facilitation or long-term potentiation (LTP) and long-term depression (LTD) in Schaffer collaterals-CA1 pyramidal synapses. However, CA and NCA increased the recovery of synaptic transmission upon re-oxygenation following 7 min of oxygen/glucose deprivation, an in vitro ischemia model. Also, CA and NCA attenuated the shift of LTD into LTP observed in hippocampal slices from animals with hippocampal-dependent memory deterioration after exposure to ß-amyloid 1-42 (2 nmol, icv), in the context of Alzheimer's disease. These findings show that chlorogenic acids do not directly affect synaptic transmission and plasticity but can indirectly affect other cellular targets to correct synaptic dysfunction. Unraveling the molecular mechanisms of action of chlorogenic acids will allow the design of hitherto unrecognized novel neuroprotective strategies.

Effects of caffeine on brain antioxidant status and mitochondrial respiration in acetaminophen-intoxicated mice.

Hepatic encephalopathy is a pathophysiological complication of acute liver failure, which may be triggered by hepatotoxic drugs such as acetaminophen (APAP). Although APAP is safe in therapeutic concentration, APAP overdose may induce neurotoxicity, which is mainly associated with oxidative stress. Caffeine is a compound widely found in numerous natural beverages. However, the neuroprotective effect of caffeine remains unclear during APAP intoxication. The present study aimed to investigate the possible modulatory effects of caffeine on brain after APAP intoxication. Mice received intraperitoneal injections of APAP (250 mg/kg) and/or caffeine (20 mg/kg) and, 4 h after APAP administration, samples of brain and blood were collected for the biochemical analysis. APAP enhanced the transaminase activity levels in plasma, increased oxidative stress biomarkers (lipid peroxidation and reactive oxygen species), promoted an imbalance in endogenous antioxidant system in brain homogenate and increased the mortality. In contrast, APAP did not induce dysfunction of the mitochondrial bioenergetics. Co-treatment with caffeine modulated the biomarkers of oxidative stress as well as antioxidant system in brain. Besides, survival assays demonstrated that caffeine protective effects could be dose- and time-dependent. In addition, caffeine promoted an increase of mitochondrial bioenergetics response in brain by the enhancement of the oxidative phosphorylation, which could promote a better energy supply necessary for brain recovery. In conclusion, caffeine prevented APAP-induced biochemical alterations in brain and reduced lethality in APAP-intoxicated mice, these effects may relate to the preservation of the cellular antioxidant status, and these therapeutic properties could be useful in the treatment of hepatic encephalopathy induced by APAP intoxication.

A single muscle contusion promotes an immediate alteration in mitochondrial bioenergetics response in skeletal muscle fibres with different metabolism.

Skeletal muscle is the most abundant tissue in the human body and mechanical injuries are common; these are frequently of mechanical origins, such as contusion. However, the immediate mitochondrial response to injury and energetic substrate utilisation is still unclear. We evaluated the acute response in mitochondrial function after a single muscle contusion, either in fast twitch fibres (glycolytic metabolism), fast and slow twitch (oxidative and glycolytic metabolism), or slow twitch fibres (oxidative metabolism). Rats were assigned to two groups: control and Lesion (muscle contusion). We collected the gastrocnemius and soleus muscles. The fibres were analysed for mitochondrial respiration, lactate dehydrogenase (LDH), citrate synthase (CS) activity, Ca2+ uptake, and H2O2 production. We found that muscle injury was able to increase ATP synthesis-dependent and OXPHOS oxygen flux in the oxidative fibres when stimulated by complex I + II substrates. On the other hand, the muscle injury increased hydrogen peroxide (H2O2) production when compared to control fibres, and reduced citrate synthase activity; however, it did not change Ca2+ uptake. Surprisingly, injury in mixed fibres increased the OXPHOS and ATP synthesis oxygen consumption, and H2O2 production, but it reduced Ca2+ uptake. The injury in glycolytic fibres did not affect oxygen flux coupled to ATP synthesis, citrate synthase, and lactate dehydrogenase activity, but did reduce Ca2+ uptake. Finally, we demonstrated distinct mitochondrial responses between the different muscle fibres, indicating that the mitochondrial dynamics is related to flexibilities in metabolism, and that reactive oxygen species directly affect physiology and normal function.

MPMT-OX up-regulates GABAergic transmission and protects against seizure-like behavior in Caenorhabditis elegans.

The signal transmission in the nervous system operates through a sensitive balance between excitatory (E) inputs and inhibitory (I) responses. Imbalances in this system contribute to the development of pathologies such as seizures. In Caenorhabditis elegans, the locomotor circuit operates via the coordinated activity of cholinergic excitatory (E) and GABAergic inhibitory (I) transmission. Changes in E/I inputs can cause uncontrolled electrical discharges, mimicking the physiology of seizures. Molecules derived from 1,3,4-oxadiazole have been found to exhibit diverse biological activities, including anticonvulsant effect. In this work, we study the activity of the compound 2-[(4-methoxyphenylselenyl)methylthio]-5-phenyl-1,3,4-oxadiazole (MPMT-OX) in the GABAergic and cholinergic systems. We demonstrate that MPMT-OX reduced the locomotor activity of C. elegans with a normal balance between the E/I systems and increased the resistance to paralysis in worms exposed to pentylenetetrazol and aldicarb. MPMT-OX increased seizure resistance and assisted in the recovery of locomotor activity in worms with deletions in the genes unc-46, which regulates the transport of GABA into vesicles, and unc-49, which encodes the GABAA receptor. C. elegans with deletions in the unc-25 and unc-47 genes did not respond to treatment. Therefore, we suggest that the compound MPMT-OX upregulates GABAergic signaling in a manner dependent on the unc-25 gene, which is responsible for GABA synthesis, and unc-47, which encodes the vesicular GABA transporter.

A1 rather than A2A adenosine receptor as a possible target of Guanosine effects on mitochondrial dysfunction following Traumatic Brain Injury in rats.

Traumatic brain injury (TBI) represents one of the leading causes of death worldwide. Its pathophysiology involves several neurochemical events including mitochondrial dysfunction. Since mitochondrial respiration plays a key role in cell survival, pharmacological interventions targeting mitochondrial function have been highlighted as a powerful tool against the neurodegenerative process triggered by TBI. Guanosine (GUO), a neuroprotective molecule in different neurological disorders involving neurotoxicity, has shown protective properties after TBI, however its mechanism of action is not well understood in the central nervous system (CNS). Therefore, the aim of this study is to evaluate the possible target receptor involved in the protective GUO effects on TBI-induced mitochondrial dysfunction in the cerebral cortex of rats. Results show that a single dose of GUO (7.5 mg/kg) injected 40 min after a fluid percussion injury (FPI) protects against loss of mitochondrial membrane potential and increase of reactive oxygen species 8 h post-TBI. These effects were specifically blocked by a pretreatment (10 min after TBI) with an A1 adenosine receptor antagonist (DPCPX 1 mg/kg). In contrast, pretreatment with an A2A adenosine receptor antagonist (SCH 58261 0.05 mg/kg) did not alter GUO effects. These findings suggest that acute GUO neuroprotection following TBI involves the modulation of the adenosinergic system, especially A1 adenosine receptor.

Sex-Specific Response of Caenorhabditis elegans to Methylmercury Toxicity.

Methylmercury (MeHg), an abundant environmental pollutant, has long been known to adversely affect neurodevelopment in both animals and humans. Several reports from epidemiological studies, as well as experimental data indicate sex-specific susceptibility to this neurotoxicant; however, the molecular bases of this process are still not clear. In the present study, we used Caenorhabditis elegans (C. elegans), to investigate sex differences in response to MeHg toxicity during development. Worms at different developmental stage (L1, L4, and adult) were treated with MeHg for 1 h. Lethality assays revealed that male worms exhibited significantly higher resistance to MeHg than hermaphrodites, when at L4 stage or adults. However, the number of worms with degenerated neurons was unaffected by MeHg, both in males and hermaphrodites. Lower susceptibility of males was not related to changes in mercury (Hg) accumulation, which was analogous for both wild-type (wt) and male-rich him-8 strain. Total glutathione (GSH) levels decreased upon MeHg in him-8, but not in wt. Moreover, the sex-dependent response of the cytoplasmic thioredoxin system was observed-males exhibited significantly higher expression of thioredoxin TRX-1, and thioredoxin reductase TRXR-1 expression was downregulated upon MeHg treatment only in hermaphrodites. These outcomes indicate that the redox status is an important contributor to sex-specific sensitivity to MeHg in C. elegans.

Guanosine Attenuates Behavioral Deficits After Traumatic Brain Injury by Modulation of Adenosinergic Receptors.

Traumatic brain injury (TBI) is a leading cause of disability worldwide, triggering chronic neurodegeneration underlying cognitive and mood disorder still without therapeutic prospects. Based on our previous observations that guanosine (GUO) attenuates short-term neurochemical alterations caused by TBI, this study investigated the effects of chronical GUO treatment in behavioral, molecular, and morphological disturbances 21 days after trauma. Rats subject to TBI displayed mood (anxiety-like) and memory dysfunction. This was accompanied by a decreased expression of both synaptic (synaptophysin) and plasticity proteins (BDNF and CREB), a loss of cresyl violet-stained neurons, and increased astrogliosis and microgliosis in the hippocampus. Notably, chronic GUO treatment (7.5 mg/kg i.p. daily starting 1 h after TBI) prevented all these TBI-induced long-term behavioral, neurochemical, and morphological modifications. This neuroprotective effect of GUO was abrogated in the presence of the adenosine A1 receptor antagonist DPCPX (1 mg/kg) but unaltered by the adenosine A2A receptor antagonist SCH58261 (0.05 mg/kg). These findings show that a chronic GUO treatment prevents the long-term mood and memory dysfunction triggered by TBI, which involves adenosinergic receptors.

6-Hydroxydopamine induces different mitochondrial bioenergetics response in brain regions of rat.

Mitochondrial dysfunction has been demonstrated to have a central role in Parkinson Disease (PD) pathophysiology. Some studies have indicated that PD causes an impairment in mitochondrial bioenergetics; however, the effects of PD on brain-region specific bioenergetics was never investigated before. This study aimed to evaluate mitochondrial bioenergetics in different rat brain structures in an in vitro model of PD using 6-OHDA. Rat brain slices of hippocampus, striatum, and cortex were exposed to 6-OHDA (100 µM) for 1 h and mitochondrial bioenergetic parameters, peroxide production, lactate dehydrogenase (LDH) and citrate synthase (CS) activities were analyzed. Hippocampus slices exposed to 6-OHDA presented increased peroxide production but, no mitochondrial adaptive response against 6-OHDA damage. Cortex slices exposed to 6-OHDA presented increased oxygen flux related to oxidative phosphorylation and energetic pathways exchange demonstrated by the increase in LDH activity, suggesting a mitochondrial compensatory response. Striatum slices exposed to 6-OHDA presented a decrease of oxidative phosphorylation and decrease of oxygen flux related to ATP-synthase indicating an impairment in the respiratory chain. The co-incubation of 6-OHDA with n-acetylcysteine (NAC) abolished the effects of 6-OHDA on mitochondrial function in all brain regions tested, indicating that the increased reactive oxygen species (ROS) production is responsible for the alterations observed in mitochondrial bioenergetics. The present results indicate a brain-region specific response against 6-OHDA, providing new insights into brain mitochondrial bioenergetic function in PD. These findings may contribute to the development of future therapies with a target on energy metabolism.

Impact of Anions on the Partition Constant, Self-Diffusion, Thermal Stability, and Toxicity of Dicationic Ionic Liquids.

Partition constants (KD°), molecular dynamics (T1, T2, and DOSY measurements), thermal stability, and toxicity of dicationic ionic liquids (ILs) were determined. The dicationic ILs derived from 1,n-bis(3-methylimidazolim-1-yl)octane, [BisOct(MIM)2][2X] (in which X = Cl, Br, NO3, SCN, BF4, and NTf2), were evaluated to verify the influence of anion structure on the IL properties. A monocationic IL [Oct(MIM)][Br] was also monitored for comparison. In general, the solubility of the ILs followed the anion free energy of hydration (ΔG°hyd). The thermokinetic and thermodynamic functions of activation of the ILs were determined via thermogravimetric data, and it was observed that polyatomic anions influence the decomposition mechanism of these IL structures. Furthermore, [Oct(MIM)][Br] had a decomposition rate greater than that of the dicationic analogue, and the thermodynamic parameters of activation data corroborate these results. Finally, the dicationic ILs did not indicate toxic effects (LD50 > 40 mM).

Metabolic effects of manganese in the nematode Caenorhabditis elegans through DAergic pathway and transcription factors activation.

Manganese (Mn) is an essential trace element for physiological functions since it acts as an enzymatic co-factor. Nevertheless, overexposure to Mn has been associated with a pathologic condition called manganism. Furthermore, Mn has been reported to affect lipid metabolism by mechanisms which have yet to be established. Herein, we used the nematode Caenorhabditis elegans to examine Mn's effects on the dopaminergic (DAergic) system and determine which transcription factors that regulate with lipid metabolism are affected by it. Worms were exposed to Mn for four hours in the presence of bacteria and in a liquid medium (85 mM NaCl). Mn increased fat storage as evidenced both by Oil Red O accumulation and triglyceride levels. In addition, metabolic activity was reduced as a reflection of decreased oxygen consumption caused by Mn. Mn also affected feeding behavior as evidenced by decreased pharyngeal pumping rate. DAergic neurons viability were not altered by Mn, however the dopamine levels were significantly reduced following Mn exposure. Furthermore, the expression of sbp-1 transcription factor and let-363 protein kinase responsible for lipid accumulation control was increased and decreased, respectively, by Mn. Altogether, our data suggest that Mn increases the fat storage in C. elegans, secondary to DAergic system alterations, under the control of SBP-1 and LET-363 proteins.

Caffeine and acetaminophen association: Effects on mitochondrial bioenergetics.

AIMS: Many studies have been demonstrating the role of mitochondrial function in acetaminophen (APAP) hepatotoxicity. Since APAP is commonly consumed with caffeine, this work evaluated the effects of the combination of APAP and caffeine on hepatic mitochondrial bioenergetic function in mice. MAIN METHODS: Mice were treated with caffeine (20mg/kg, intraperitoneal (i.p.)) or its vehicle and, after 30minutes, APAP (250mg/kg, i.p.) or its vehicle. Four hours later, livers were removed, and the parameters associated with mitochondrial function and oxidative stress were evaluated. Hepatic cellular oxygen consumption was evaluated by high-resolution respirometry (HRR). KEY FINDINGS: APAP treatment decreased cellular oxygen consumption and mitochondrial complex activities in the livers of mice. Additionally, treatment with APAP increased swelling of isolated mitochondria from mice livers. On the other hand, caffeine administered with APAP was able to improve hepatic mitochondrial bioenergetic function. Treatment with APAP increased lipid peroxidation and reactive oxygen species (ROS) production and decreased glutathione levels in the livers of mice. Caffeine administered with APAP was able to prevent lipid peroxidation and the ROS production in mice livers, which may be associated with the improvement of mitochondrial function caused by caffeine treatment. SIGNIFICANCE: We suggest that the antioxidant effects of caffeine and/or its interactions with mitochondrial bioenergetics may be involved in its beneficial effects against APAP hepatotoxicity.

Hypertrophy training improves glycaemic and inflammatory parameters in men with risk factors / El entrenamiento de hipertrofia mejora los parámetros glucémicos e inflamatorios en hombres con factores de riesgo

Background and aims: A close link between metabolic syndrome (MS), insulin resistance, chronic low-grade inflammation and cardiovascular diseases has been highlighted in the literature. However, resistance training (RT) has shown interesting results on inflammatory mediators, adipokines, and insulin-related parameters in this population, although results are still contradictory. This study aimed to investigate the effects of hypertrophy RT on glycaemic, cytokines and adipokines levels in men with MS risk factors. Methods: Twenty-one untrained men (57.8 +/- 7.74 years old) underwent a RT for 15 weeks (3 times per week), comprised of nine exercises performed predominantly in the hypertrophy zone. Blood samples were drawn for analysis of glycaemic, inflammatory and hormonal parameters. Subjects were encouraged to maintain their habitual dietary intake during the intervention and dual-energy X-ray absorptiometry was used to assess body composition. Results: Levels of interleukin-1 beta (IL-1beta), interleukin-6 (IL-6), interleukin-18 (IL-18), tumor necrosis factor alpha (TNF-alfa), interferon-gamma (IFN-gama), resistin, ghrelin and leptin decreased, while interleukin-10 (IL-10) and adiponectin concentrations increased after RT. Moreover, the intervention improved glycaemic and insulinemic parameters, besides body composition. Body mass, abdominal and waist circumferences, besides total cholesterol and triglycerides levels remained unaltered. Conclusion: Positive modulation of glycaemic, insulinemic and inflammatory parameters are found in men with MS risk factors after 15 weeks of hypertrophy resistance training, parallel with improvements on body composition and independent of weight loss. Strategies to reduce pre-competition body weight in mixed martial arts

Antecedentes y objetivos: Se ha destacado en la literatura un estrecho vínculo entre el síndrome metabólico (SM), la resistencia a la insulina, la inflamación crónica de bajo grado y las enfermedades cardiovasculares. Además de varios beneficios, el entrenamiento de resistencia (ER) ha producido resultados contradictorios en citoquinas, citoquinas derivadas de tejido adiposo y niveles de parámetros relacionados con la insulina. Este estudio tuvo como objetivo investigar los efectos del ER de hipertrofia como una sola intervención en los niveles de glucemia, citoquinas y adipoquinas en hombres con factores de riesgo de SM. Métodos: Veintiún hombres sedentarios (57,8 +/- 7,74 años) se sometieron a ER durante 15 semanas (3 veces por semana), compuesto de nueve ejercicios realizados predominantemente en la zona de hipertrofia. Se tomaron muestras de sangre para el análisis de parámetros glucémicos, inflamatorios y hormonales. Los sujetos fueron alentados a mantener su ingesta dietética habitual durante la intervención y se utilizó la absorciometria de rayos X de energía dual para evaluar la composición corporal. Resultados: Los niveles de interleucina-1 beta (IL-1beta), interleucina-6 (IL-6), interleucina-18 (IL-18), necrosis tumoral alfa (TNF-alfa), interferón gamma (IFN-gama), resistina, grelina y leptina disminuyeron, mientras que las concentraciones de interleucina-10 (IL-10) y adiponectina aumentaron después del ER. También, la intervención mejoro los parámetros glicemico e insulinemico, además de la composición corporal. La masa corporal, la circunferencia abdominal y la cintura, además del colesterol total y los triglicéridos permanecieron inalterados. Conclusión: La modulación significativa y positiva en los parámetros sistémicos glicémicos, insulinemicos e inflamatorios ha sido encontrada en los hombres con factores de riesgo de SM después de 15 semanas de entrenamiento de resistencia a la hipertrofia, paralelamente con mejoras en la composición corporal e independiente de la pérdida de peso

Brain infusion of α-synuclein oligomers induces motor and non-motor Parkinson's disease-like symptoms in mice.

Parkinson's disease (PD) is characterized by motor dysfunction, which is preceded by a number of non-motor symptoms including olfactory deficits. Aggregation of α-synuclein (α-syn) gives rise to Lewy bodies in dopaminergic neurons and is thought to play a central role in PD pathology. However, whether amyloid fibrils or soluble oligomers of α-syn are the main neurotoxic species in PD remains controversial. Here, we performed a single intracerebroventricular (i.c.v.) infusion of α-syn oligomers (α-SYOs) in mice and evaluated motor and non-motor symptoms. Familiar bedding and vanillin essence discrimination tasks showed that α-SYOs impaired olfactory performance of mice, and decreased TH and dopamine levels in the olfactory bulb early after infusion. The olfactory deficit persisted until 45days post-infusion (dpi). α- SYO-infused mice behaved normally in the object recognition and forced swim tests, but showed increased anxiety-like behavior in the open field and elevated plus maze tests 20 dpi. Finally, administration of α-SYOs induced late motor impairment in the pole test and rotarod paradigms, along with reduced TH and dopamine content in the caudate putamen, 45 dpi. Reduced number of TH-positive cells was also seen in the substantia nigra of α-SYO-injected mice compared to control. In conclusion, i.c.v. infusion of α-SYOs recapitulated some of PD-associated non-motor symptoms, such as increased anxiety and olfactory dysfunction, but failed to recapitulate memory impairment and depressive-like behavior typical of the disease. Moreover, α-SYOs i.c.v. administration induced motor deficits and loss of TH and dopamine levels, key features of PD. Results point to α-syn oligomers as the proximal neurotoxins responsible for early non-motor and motor deficits in PD and suggest that the i.c.v. infusion model characterized here may comprise a useful tool for identification of PD novel therapeutic targets and drug screening.

Reversal of bioenergetics dysfunction by diphenyl diselenide is critical to protection against the acetaminophen-induced acute liver failure.

Physiopathological conditions such as acute liver failure (ALF) induced by acetaminophen (APAP) can often impair the mitochondrial bioenergetics. Diphenyl diselenide [(PhSe)2] has been shown protects against APAP-induced ALF. The present study aimed to clarify the signaling mechanism involved in the protection of bioenergetics dysfunction associated with ALF-induced by APAP overdose. Mice received APAP (600mg/kg) or (PhSe)2 (15.6mg/kg) alone, or APAP+(PhSe)2, all the solutions were administered by the intraperitoneal (i.p.). Samples of liver, blood and liver mitochondria were collected at 2 and 4h after APAP administration. APAP-induced ALF was able to induce ALF by means of alteration on liver injury biomarkers, increased Nitrite and Nitrate levels and the impairment of oxidative phosphorylation capacity (OXPHOS). In parallel, APAP overdose promoted activation of nuclear factor erythroid 2-related factor 2 (Nrf2) and Heat shock protein 70 (HSP70) expression. (PhSe)2 was able to abolish the APAP-induced decline of OXPHOS and changes on the Nrf2-ARE pathway. In addition, (PhSe)2 elevated the levels of peroxisome proliferator-activated receptor-γ coactivator (PGC-1α), helping to restore the levels of nuclear respiratory factor 1 (NRF1) associated with mitochondrial biogenesis. In summary, the treatment with (PhSe)2 maintained mitochondrial function, promoted genes related to mitochondrial dynamic and demonstrating to play critical role in the modulation of cellular protective responses during ALF.

(p-ClPhSe)2 Reduces Hepatotoxicity Induced by Monosodium Glutamate by Improving Mitochondrial Function in Rats.

It is has been demonstrated that mitochondrial dysfunction, oxidative stress, and chronic inflammatory process are associated with progress of morbid obesity in human patients. For this reason, the searching for safe and effective antiobesity drugs has been the subject of intense research. In this context, the organic selenium compounds have attracted much attention due to their pharmacological properties, such as antihyperglycemic, antioxidant, and anti-inflammatory. The aim of this study was to evaluate the hepatoprotective action of p-chloro-diphenyl diselenide (p-ClPhSe)2 , an organic selenium compound, in a model of obesity induced by monosodium glutamate (MSG) administration in rats. Wistar rats were treated during the first ten postnatal days with MSG (4 g/kg by subcutaneous injections) and received (p-ClPhSe)2 (10 mg/kg, intragastrically) from 90th to 97th postnatal day. Mitochondrial function, purine content and the levels of proteins involved in apoptotic (poly [ADP-ribose] polymerase [PARP]) and inflammatory processes (inducible nitric oxide synthases [iNOS] and p38) were determined in the liver of rats. The present study, demonstrated that postnatal administration of MSG to male rats induced a mitochondrial dysfunction, accompanied by oxidative stress and an increase in the ADP levels, without altering the efficiency of phosphorylation in the liver of adult rats. Furthermore, the MSG administration also induces hepatotoxicity, through an increase in PARP, iNOS, and p38 levels. (p-ClPhSe)2 treatment had beneficial effects against mitochondrial dysfunction, oxidative stress, and modulated protein markers of apoptosis and inflammation in the liver of MSG-treated rats. J. Cell. Biochem. 118: 2877-2886, 2017. © 2017 Wiley Periodicals, Inc.

Guanosine Protects Against Traumatic Brain Injury-Induced Functional Impairments and Neuronal Loss by Modulating Excitotoxicity, Mitochondrial Dysfunction, and Inflammation.

Traumatic brain injury (TBI) is one of the most common types of brain injuries that cause death or persistent neurological disturbances in survivors. Most of the promising experimental drugs were not effective in clinical trials; therefore, the development of TBI drugs represents a huge unmet need. Guanosine, an endogenous neuroprotective nucleoside, has not been evaluated in TBI to the best of our knowledge. Therefore, the present study evaluated the effect of guanosine on TBI-induced neurological damage. Our findings showed that a single dose of guanosine (7.5 mg/kg, intraperitoneally (i.p.) injected 40 min after fluid percussion injury (FPI) in rats protected against locomotor and exploratory impairments 8 h after injury. The treatment also protected against neurochemical damage to the ipsilateral cortex, glutamate uptake, Na+/K+-ATPase, glutamine synthetase activity, and alterations in mitochondrial function. The inflammatory response and brain edema were also reduced by this nucleoside. In addition, guanosine protected against neuronal death and caspase 3 activation. Therefore, this study suggests that guanosine plays a neuroprotective role in TBI and can be exploited as a new pharmacological strategy.

Reversible reprotoxic effects of manganese through DAF-16 transcription factor activation and vitellogenin downregulation in Caenorhabditis elegans.

AIMS: Vitellogenesis is the yolk production process which provides the essential nutrients for the developing embryos. Yolk is a lipoprotein particle that presents lipids and lipid-binding proteins, referred to as vitellogenins (VIT). The Caenorhabditis elegans nematode has six genes encoding VIT lipoproteins. Several pathways are known to regulate vitellogenesis, including the DAF-16 transcription factor. Some reports have shown that heavy metals, such as manganese (Mn), impair brood size in C. elegans; however the mechanisms associated with this effect have yet to be identified. Our aim was to evaluate Mn's effects on C. elegans reproduction and better understand the pathways related to these effects. MAIN METHODS: Young adult larval stage worms were treated for 4h with Mn in 85mM NaCl and Escherichia coli OP50 medium. KEY FINDINGS: Mn reduced egg-production and egg-laying during the first 24h after the treatment, although the total number of progenies were indistinguishable from the control group levels. This delay may have occurred due to DAF-16 activation, which was noted only after the treatment and was not apparent 24h later. Moreover, the expression, protein levels and green fluorescent protein (GFP) fluorescence associated with VIT were decreased soon after Mn treatment and recovered after 24h. SIGNIFICANCE: Combined, these data suggest that the delay in egg-production is likely regulated by DAF-16 and followed by the inhibition of VIT transport activity. Further studies are needed to clarify the mechanisms associated with Mn-induced DAF-16 activation.