Basal Respiratory Rate Research Articles

RETRACTED: dATP elevation induces myocardial metabolic remodeling to support improved cardiac function

Hallmark features of systolic heart failure are reduced contractility and impaired metabolic flexibility of the myocardium. Cardiomyocytes (CMs) with elevated deoxy ATP (dATP) via overexpression of ribonucleotide reductase (RNR) enzyme robustly improve contractility. However, the effect of dATP elevation on cardiac metabolism is unknown. Here, we developed proteolysis-resistant versions of RNR and demonstrate that elevation of dATP/ATP to ∼1% in CMs in a transgenic mouse (TgRRB) resulted in robust improvement of cardiac function. Pharmacological approaches showed that CMs with elevated dATP have greater basal respiratory rates by shifting myosin states to more active forms, independent of its isoform, in relaxed CMs. Targeted metabolomic profiling revealed a significant reprogramming towards oxidative phosphorylation in TgRRB-CMs. Higher cristae density and activity in the mitochondria of TgRRB-CMs improved respiratory capacity. Our results revealed a critical property of dATP to modulate myosin states to enhance contractility and induce metabolic flexibility to support improved function in CMs.

Inflammatory Milieu Induces Mitochondrial Alterations and Neuronal Activations in Hypothalamic POMC Neurons in a Time-Dependent Manner.

Inflammation has been associated with numerous neurological disorders. Inflammatory environments trigger a series of cellular and physiological alterations in the brain. However, how inflammatory milieu affects neuronal physiology and how neuronal alterations progress in the inflammatory environments are not fully understood. In this study, we examined the effects of pro-inflammatory milieu on mitochondrial functions and neuronal activities in the hypothalamic POMC neurons. Treating mHypoA-POMC/GFP1 with the conditioned medium collected from LPS activated macrophage were employed to mimic the inflammatory milieu during hypothalamic inflammation. After a 24-h treatment, intracellular ROS/RNS levels were elevated, and the antioxidant enzymes were reduced. Mitochondrial respiration and mitochondrial functions, including basal respiratory rate, spared respiration capacity, and maximal respiration, were all significantly compromised by inflammatory milieu. Moreover, pro-inflammatory cytokines altered mitochondrial dynamics in a time-dependent manner, resulting in the elongation of mitochondria in POMC neurons after a 24-h treatment. Additionally, the increase of C-Fos and Pomc genes expression indicated that the neurons were activated upon the stimulation of inflammatory environment. This neuronal activation of were confirmed on the LPS-challenged mice. Collectively, a short-term to midterm exposure to inflammatory milieu stimulated metabolic switch and neuronal activation, whereas chronic exposure triggered the elevation of oxidative stress, the decrease of the mitochondrial respiration, and the alterations of mitochondrial dynamics.

Environmental neurotoxic pesticide exposure induces gut inflammation and enteric neuronal degeneration by impairing enteric glial mitochondrial function in pesticide models of Parkinson's disease: Potential relevance to gut-brain axis inflammation in Parkinson's disease pathogenesis.

Despite the growing recognition that gastrointestinal (GI) dysfunction is prevalent in Parkinson's disease (PD) and occurs as a major prodromal symptom of PD, its cellular and molecular mechanisms remain largely unknown. Among the various types of GI cells, enteric glial cells (EGCs), which resemble astrocytes in structure and function, play a critical role in the pathophysiology of many GI diseases including PD. Thus, we investigated how EGCs respond to the environmental pesticides rotenone (Rot) and tebufenpyrad (Tebu) in cell and animal models to better understand the mechanism underlying GI abnormalities. Both Rot and Tebu induce dopaminergic neuronal cell death through complex 1 inhibition of the mitochondrial respiratory chain. We report that exposing a rat enteric glial cell model (CRL-2690 cells) to these pesticides increased mitochondrial fission and reduced mitochondrial fusion by impairing MFN2 function. Furthermore, they also increased mitochondrial superoxide generation and impaired mitochondrial ATP levels and basal respiratory rate. Measurement of LC3, p62 and lysosomal assays revealed impaired autolysosomal function in ECGs during mitochondrial stress. Consistent with our recent findings that mitochondrial dysfunction augments inflammation in astrocytes and microglia, we found that neurotoxic pesticide exposure also enhanced the production of pro-inflammatory factors in EGCs in direct correlation with the loss in mitochondrial mass. Finally, we show that pesticide-induced mitochondrial defects functionally impaired smooth muscle velocity, acceleration, and total kinetic energy in a mixed primary culture of the enteric nervous system (ENS). Collectively, our studies demonstrate for the first time that exposure to environmental neurotoxic pesticides impairs mitochondrial bioenergetics and activates inflammatory pathways in EGCs, further augmenting mitochondrial dysfunction and pro-inflammatory events to induce gut dysfunction. Our findings have major implications in understanding the GI-related pathogenesis and progression of environmentally linked PD.

LDH-A-Modulation and the Variability of LDH Isoenzyme Profiles in Murine Gliomas: A Link with Metabolic and Growth Responses.

Simple SummaryThree different murine glioma cell lines were modified to downregulate the expression of the murine LDH-A gene using shRNA knock-down (KD), and compared to shRNA scrambled control (NC) cell lines. Successful LDH-A KD was confirmed by differences in the expression of LDH-A and LDH-B mRNA, protein and enzymatic activity, as well as their LDH isoenzyme profiles. mRNA expression data indicated that: (i) GL261 LDH-A KD cells may have an improved ability to metabolize lactate into the TCA cycle; and (ii) that GL261 LDH-A KD cells can upregulate lipid metabolism/fatty acid oxidation pathways, whereas the other glioma cell lines (CT2A, and ALTS1C1) do not have this capacity. The data suggest that GL261 LDH-A KD cells can develop/activate alternative metabolic pathways for enhanced survival in a nutrient-limited environment. Furthermore, LDH-A KD prolonged the doubling time of GL261 cells in culture and prevented the formation of subcutaneous flank tumors in immune-competent C57BL/6 mice. No differences between NC and KD cell proliferation (in vitro) or tumor growth in C57BL/6 mice (doubling time) were observed for CT2A and ALTS1C1 cells and tumors. Our results suggest that GL261 glioma cells (but not CT2A and ALTS1C1 cells) are pre-programmed with a capacity for activating different metabolic pathways with higher TCA cycle activity, and that this capacity is enhanced by LDH-A depletion, leading to a difference in growth and survival in an immune-competent environment.Three murine glioma cell lines (GL261, CT2A, and ALTS1C1) were modified to downregulate the expression of the murine LDH-A gene using shRNA, and compared to shRNA scrambled control (NC) cell lines. Differences in the expression of LDH-A and LDH-B mRNA, protein and enzymatic activity, as well as their LDH isoenzyme profiles, were observed in the six cell lines, and confirmed successful LDH-A KD. LDH-A KD (knock-down) resulted in metabolic changes in cells with a reduction in glycolysis (GlycoPER) and an increase in basal respiratory rate (mitoOCR). GL261 cells had a more limited ATP production capacity compared to CT2A and ALTS1C1 cells. An analysis of mRNA expression data indicated that: (i) GL261 LDH-A KD cells may have an improved ability to metabolize lactate into the TCA cycle; and (ii) that GL261 LDH-A KD cells can upregulate lipid metabolism/fatty acid oxidation pathways, whereas the other glioma cell lines do not have this capacity. These two observations suggest that GL261 LDH-A KD cells can develop/activate alternative metabolic pathways for enhanced survival in a nutrient-limited environment, and that specific nutrient limitations have a variable impact on tumor cell metabolism and proliferation. The phenotypic effects of LDH-A KD were compared to those in control (NC) cells and tumors. LDH-A KD prolonged the doubling time of GL261 cells in culture and prevented the formation of subcutaneous flank tumors in immune-competent C57BL/6 mice, whereas GL261 NC tumors had a prolonged growth delay in C57BL/6 mice. In nude mice, both LDH-A KD and NC GL261 tumors grew rapidly (more rapidly than GL261 NC tumors in C57BL/6 mice), demonstrating the impact of an intact immune system on GL261 tumor growth. No differences between NC and KD cell proliferation (in vitro) or tumor growth in C57BL/6 mice (doubling time) were observed for CT2A and ALTS1C1 cells and tumors, despite the small changes to their LDH isoenzyme profiles. These results suggest that GL261 glioma cells (but not CT2A and ALTS1C1 cells) are pre-programmed to have the capacity for activating different metabolic pathways with higher TCA cycle activity, and that this capacity is enhanced by LDH-A depletion. We observed that the combined impact of LDH-A depletion and the immune system had a significant impact on the growth of subcutaneous-located GL261 tumors.

Respiratory Functional and Neuroanatomical Changes in 6‐OHDA Model of Parkinson’s Disease Require Tumor Necrosis Factor Alpha Receptor 1

Most deaths of Parkinson’s Disease (PD) patients are due to respiratory complications which appears in the late stages of this disease. Previous studies have shown brainstem degeneration which is probably linked to respiratory function impairment in a rat model of PD induced by 6‐hydroxydopamine (6‐OHDA) injection in caudate‐putamen (CPu). One of the hypotheses that explains why neurons die in this PD model is neuroinflammation mediated by a cytokine called tumor necrosis factor alpha (TNF‐α). So, this study aims to investigate the role of TNF‐α in respiratory functional and neuroanatomical deficits in the animal model of PD induced by 6‐OHDA. C57BL/6 or TNF‐α receptor 1 knockout mice (TNFR1‐/‐) were anesthetized with isoflurane 2.5% and received bilateral injection of 6‐OHDA (10 µg/µl) or vehicle in CPu through stereotaxic surgery. 20 days after surgery, mice were submitted to whole body plethysmography under normal and hypercapnic conditions (7% CO2). Animals were perfused and the brains were removed to neuroanatomical analysis. 6‐OHDA destroyed TH+ neurons in Substantia nigra (SNc) in all groups analyzed (6‐OHDA WT: 77%; 6‐OHDA TNFR1‐/‐: 79%). Degeneration was observed in preBötzinger complex (preBötC) and in retrotrapezoid nucleus (RTN) in 6‐OHDA WT group, but not in 6‐OHDA TNFR1‐/‐ group (preBötC: 6‐OHDA WT: 43%, 6‐OHDA TNFR1‐/‐: 22%; RTN: 6‐OHDA WT: 52%; 6‐OHDA TNFR1‐/‐: 15%). Astrocyte’s density in SNc is enhanced in 6‐OHDA WT group but not in 6‐OHDA TNFR1‐/‐ group (6‐OHDA WT: 122%) and is reduced in preBötC in all groups analyzed (p<0.05), while in RTN, no change was observed. Microglia analysis indicates neuroinflammation in SNc and RTN in all groups. Respiratory assessment reveals reduction in basal respiratory rate in 6‐OHDA WT group but not in 6‐OHDA TNFR1‐/‐ group (6‐OHDA WT: 25%; 6‐OHDA TNFR1‐/‐: 17%). No change was observed between groups in respiratory parameters under hypercapnia. Considering all results presented here we can state that in this model of PD, respiratory deficits are associated with neurodegeneration in respiratory brainstem areas. Abolishing TNF‐α inflammation pathway, reduction in respiratory rate and degeneration of brainstem areas involved with neural control of breathing are prevented indicating the involvement of this pathway in the respiratory changes found in the 6‐OHDA model of PD.

Reversal of SARS-CoV2-Induced Hypoxia by Nebulized Sodium Ibuprofenate in a Compassionate Use Program.

IntroductionSodium ibuprofenate in hypertonic saline (NaIHS) administered directly to the lungs by nebulization and inhalation has antibacterial and anti-inflammatory effects, with the potential to deliver these benefits to hypoxic patients. We describe a compassionate use program that offered this therapy to hospitalized COVID-19 patients.MethodsNaIHS (50 mg ibuprofen, tid) was provided in addition to standard of care (SOC) to hospitalized COVID-19 patients until oxygen saturation levels of > 94% were achieved on ambient air. Patients wore a containment hood to diminish aerosolization. Outcome data from participating patients treated at multiple hospitals in Argentina between April 4 and October 31, 2020, are summarized. Results were compared with a retrospective contemporaneous control (CC) group of hospitalized COVID-19 patients with SOC alone during the same time frame from a subset of participating hospitals from Córdoba and Buenos Aires.ResultsThe evolution of 383 patients treated with SOC + NaIHS [56 on mechanical ventilation (MV) at baseline] and 195 CC (21 on MV at baseline) are summarized. At baseline, NaIHS-treated patients had basal oxygen saturation of 90.7 ± 0.2% (74.3% were on supplemental oxygen at baseline) and a basal respiratory rate of 22.7 ± 0.3 breath/min. In the CC group, basal oxygen saturation was 92.6 ± 0.4% (52.1% were on oxygen supplementation at baseline) and respiratory rate was 19.3 ± 0.3 breath/min. Despite greater pulmonary compromise at baseline in the NaIHS-treated group, the length of treatment (LOT) was 9.1 ± 0.2 gs with an average length of stay (ALOS) of 11.5 ± 0.3 days, in comparison with an ALOS of 13.3 ± 0.9 days in the CC group. In patients on MV who received NaIHS, the ALOS was lower than in the CC group. In both NaIHS-treated groups, a rapid reversal of deterioration in oxygenation and NEWS2 scores was observed acutely after initiation of NaIHS therapy. No serious adverse events were considered related to ibuprofen therapy. Mortality was lower in both NaIHS groups compared with CC groups.ConclusionsTreatment of COVID-19 pneumonitis with inhalational nebulized NaIHS was associated with rapid improvement in hypoxia and vital signs, with no serious adverse events attributed to therapy. Nebulized NaIHS s worthy of further study in randomized, placebo-controlled trials (ClinicalTrials.gov: NCT04382768).Supplementary InformationThe online version contains supplementary material available at 10.1007/s40121-021-00527-2.

The effects of ammonia and glutamine on mitochondrial respiration of rat pancreatic acinar cells

During glutamine catabolism is produced ammonia, which can be toxic to cells. In hepatic encephalopathy neuron mitochondria ammonia causes the formation of free radicals, the opening of the mitochondrial permeability transition pore, oxidative phosphorylation disruption and swelling. It is still unknown whether the utilization of glutamine in the mitochondria of acinar cells of the pancreas produces toxic concentrations of ammonia. The experiments were performed on male Wistar rats weighing 250–300 g. Pancreatic acini were isolated using collagenase. Cells were incubated for 30 min with glucose (10 mM) in the control and additionally NH4Cl (5 mM) or glutamine (2 mM) in the experiment. Acetylcholine (10 μM) or cholecystokinin (0.1 nM) was used to stimulate secretion. Respiration rate of isolated rat pancreatic acini was measured using a Clark electrode. Maximum respiration rate was stimulated by addition to the FCCP. Statistical significance (P) of difference between the groups was determined with two-way repeated-measures ANOVA followed by a Holm-Bonferroni corrected post-hoc t tests. The secretagogues acetylcholine and cholecystokinin did not affect basal and FCCP-stimulated respiratory rate. The basal respiratory rate of pancreatic acinar cells decreased with NH4Cl compared to the basal respiratory rate with glucose oxidation, and this decrease was observed both at normal condition and under the action of secretagogues. Glutamine did not affect basal respiratory rate. During glutamine oxidation, the maximum respiratory rate increased compared to the control, regardless of the effect of acetylcholine or cholecystokinin. NH4Cl reduced the maximum rate of FCCP-stimulated respiration in rest or upon stimulation with secretagogues compared to glucose control. Therefore, NH4Cl causes a negative effect mitochondrial respiration regardless of secretory stimulation with acetylcholine or cholecystokinin. The toxic amount of ammonia required for inhibition of mitochondrial respiration is apparently not formed due to glutamine oxidation even when stimulated by acinar cells by secretagogues.

Nucleoredoxin Knockdown in SH-SY5Y Cells Promotes Cell Renewal.

Nucleoredoxin (NXN) is a redox regulator of Disheveled and thereby of WNT signaling. Deficiency in mice leads to cranial dysmorphisms and defects of heart, brain, and bone, suggesting defects of cell fate determination. We used shRNA-mediated knockdown of NXN in SH-SY5Y neuroblastoma cells to study its impact on neuronal cells. We expected that shNXN cells would easily succumb to redox stress, but there were no differences in viability on stimulation with hydrogen peroxide. Instead, the proliferation of naïve shNXN cells was increased with a higher rate of mitotic cells in cell cycle analyses. In addition, basal respiratory rates were higher, whereas the relative change in oxygen consumption upon mitochondrial stressors was similar to control cells. shNXN cells had an increased expression of redox-sensitive heat shock proteins, Hsc70/HSPA8 and HSP90, and autophagy markers suggested an increase in autophagosome formation upon stimulation with bafilomycin and higher flux under low dose rapamycin. A high rate of self-renewal, autophagy, and upregulation of redox-sensitive chaperones appears to be an attractive anti-aging combination if it were to occur in neurons in vivo for which SH-SY5Y cells are a model.

20(s)‑ginseonside‑Rg3 modulation of AMPK/FoxO3 signaling to attenuate mitochondrial dysfunction in a dexamethasone‑injured C2C12 myotube‑based model of skeletal atrophy invitro.

Muscle atrophy, a side effect from administration of the anti-inflammatory medication dexamethasone (DEX), is preventable by concomitant administration of the major monomeric constituent of Panax ginseng C.A. Meyer, 20(S)-ginsenoside Rg3 (S-Rg3). Putative S-Rg3-associated prevention of DEX-induced muscle atrophy may involve S-Rg3 mitigation of DEX-induced mitochondrial dysfunction. In the present study, MTT assays revealed enhanced cell viability following S-Rg3 treatment of DEX-injured C2C12 myotubes. Subsequent PCR and western blotting results demonstrated S-Rg3-induced reduction of expression of muscle atrophy F-box protein (atrogin-1) and muscle RING-finger protein-1, proteins previously linked to muscle atrophy. Additionally, S-Rg3 treatment of DEX-injured myotubes led to aggregation of Rg3 monomers in cells and dose-dependent increases in cellular mitochondrial basal respiratory oxygen consumption rate and intracellular ATP levels compared with their levels in untreated DEX-injured myotubes. In addition, S-Rg3 treatment significantly reversed DEX-induced reductions of expression of key mitochondrial respiratory electron transport chain subunits of protein complexes II, III and V in DEX-injured myotube cells. Furthermore, S-Rg3 alleviation of mitochondrial dysfunction associated with DEX-induced injury of C2C12 myotubes was linked to S-Rg3-associated decreases in both forkhead box O3 (FoxO3) protein expression and phosphorylation of AMP-activated protein kinase (AMPK). Collectively, these results implicate S-Rg3 modulation of signaling within the AMPK-FoxO3 pathway as a putative mechanism underlying S-Rg3 alleviation of DEX-induced muscle atrophy.

Mitochondrial P2X7 Receptor Localization Modulates Energy Metabolism Enhancing Physical Performance.

Basal expression of the P2X7 receptor (P2X7R) improves mitochondrial metabolism, Adenosine 5′-triphosphate (ATP) synthesis, and overall fitness of immune and non-immune cells. We investigated P2X7R contribution to energy metabolism and subcellular localization in fibroblasts (mouse embryo fibroblasts and HEK293 human fibroblasts), mouse microglia (primary brain microglia, and the N13 microglia cell line), and heart tissue. The P2X7R localizes to mitochondria, and its lack (1) decreases basal respiratory rate, ATP-coupled respiration, maximal uncoupled respiration, resting mitochondrial potential, mitochondrial matrix Ca2+ level, (2) modifies expression pattern of oxidative phosphorylation enzymes, and (3) severely affects cardiac performance. Hearts from P2rx7-deleted versus wild-type mice are larger, heart mitochondria smaller, and stroke volume, ejection fraction, fractional shortening, and cardiac output, are significantly decreased. Accordingly, the physical fitness of P2X7R-null mice is severely reduced. Thus, the P2X7R is a key modulator of mitochondrial energy metabolism and a determinant of physical fitness.

Effects of psychoactive drugs on cellular bioenergetic pathways

Objectives To investigate the actions of lithium, valproate, lamotrigine and quetiapine on bioenergetic pathways in cultured NT2-N neuronal-like cells and C8-B4 microglial cells. Methods NT2-N and C8-B4 cells were cultured and treated with lithium (2.5 mM), valproate (0.5 mM), quetiapine (0.05 mM) or lamotrigine (0.05 mM) for 24 hours. Gene expression and the mitochondrial bioenergetic profile were measured in both cell lines. Results In NT2-N cells, valproate increased oxidative phosphorylation (OXPHOS) gene expression, mitochondrial uncoupling and maximal respiratory capacity, while quetiapine decreased OXPHOS gene expression and respiration linked to ATP turnover, as well as decreasing the expression of genes in the citric acid cycle. Lamotrigine decreased OXPHOS gene expression but had no effect on respiration, while lithium reduced the expression of genes in the citric acid cycle. In C8-B4 cells, valproate and lithium increased OXPHOS gene expression, and valproate increased basal respiratory rate and maximal and spare respiratory capacities. In contrast, quetiapine significantly reduced basal respiratory rate and maximal and spare respiratory capacities. Conclusions Overall our data suggest that some drugs used to treat neuropsychiatric and affective disorders have actions on a range of cellular bioenergetic processes, which could impact their effects in patients.

Intranasal premedication with dexmedetomidine versus midazolam for pediatric patients in ophthalmic surgery: a randomized controlled study

Background Excessive anxiety has a bad implication on anesthetic practice in pediatric anesthesia; therefore, decreasing anxiety by premedication is an important issue. Intranasal administration of various drugs is an easy route with rapid onset of action allowing administration of variable drugs such as midazolam and dexmedetomidine used in pediatric preoperative sedation. Patients and methods A total of 64 pediatric patients who were subjected to elective ophthalmic surgeries received either 0.5 mg/kg midazolam or 1 μg/kg dexmedetomidine intranasally. Basal heart and respiratory rate, blood pressure, sedation score, and oxygen saturation were recorded initially and every 5 min till the transfer to the operating room. Sedation score was also assessed at 30 min after drug administration. Postoperative monitoring was continued, and any postoperative complications were recorded. Results Oxygen saturation, heart rate, systolic blood pressure, and respiratory rate values showed insignificant differences when both groups were compared together but showed significance differences when compared with the basal value in each group separately after 30 min. Sedation score was faster and child–parents separation score was higher in dexmedetomidine group when compared with midazolam group, and also both groups showed significant sedation score less than 3 when compared with the basal value at 15, 20, 25, and 30 min. Conclusion Midazolam and dexmedetomidine were nearly equally effective as intranasal premedication for pediatric patients subjected to elective ophthalmic surgery with minimal adverse effects, and we recommend the use of midazolam owing to its safety, effectiveness, and lower cost.

Plasma amyloid beta levels and platelet mitochondrial respiration in patients with Alzheimer's disease

ObjectivesAltered amyloid metabolism and mitochondrial dysfunction play key roles in the development of Alzheimer's disease (AD). We asked whether an association exists between disturbed platelet mitochondrial respiration and the plasma concentrations of Aβ40 and Aβ42 in patients with AD. Design and methodsPlasma Aβ40 and Aβ42 concentrations and mitochondrial respiration in intact and permeabilized platelets were measured in 50 patients with AD, 15 patients with vascular dementia and 25 control subjects. A pilot longitudinal study was performed to monitor the progression of AD in a subgroup 11 patients with AD. ResultsThe mean Aβ40, Aβ42 and Aβ42/Aβ40 levels were not significantly altered in patients with AD compared with controls. The mitochondrial respiratory rate in intact platelets was significantly reduced in patients with AD compared to controls, particularly the basal respiratory rate, maximum respiratory capacity, and respiratory reserve; however, the flux control ratio for basal respiration was increased. A correlation between the plasma Aβ42 concentration and mitochondrial respiration in both intact and permeabilized platelets differs in controls and patients with AD. ConclusionsBased on our data, (1) mitochondrial respiration in intact platelets, but not the Aβ level itself, may be included in a panel of biomarkers for AD; (2) dysfunctional mitochondrial respiration in platelets is not explained by changes in plasma Aβ concentrations; and (3) the association between mitochondrial respiration in platelets and plasma Aβ levels differs in patients with AD and controls. The results supported the hypothesis that mitochondrial dysfunction is the primary factor contributing to the development of AD.

Manganese activates NLRP3 inflammasome signaling and propagates exosomal release of ASC in microglial cells.

Chronic, sustained inflammation underlies many pathological conditions, including neurodegenerative diseases. Divalent manganese (Mn2+) exposure can stimulate neurotoxicity by increasing inflammation. In this study, we examined whether Mn2+ activates the multiprotein NLRP3 inflammasome complex to promote neuroinflammation. Exposing activated mouse microglial cells to Mn2+ substantially augmented NLRP3 abundance, caspase-1 cleavage, and maturation of the inflammatory cytokine interleukin-1β (IL-1β). Exposure of mice to Mn2+ had similar effects in brain microglial cells. Furthermore, Mn2+ impaired mitochondrial ATP generation, basal respiratory rate, and spare capacity in microglial cells. These data suggest that Mn-induced mitochondrial defects drove the inflammasome signal amplification. We found that Mn induced cell-to-cell transfer of the inflammasome adaptor protein ASC in exosomes. Furthermore, primed microglial cells exposed to exosomes from Mn-treated mice released more IL-1β than did cells exposed to exosomes from control-treated animals. We also observed that welders exposed to manganese-containing fumes had plasma exosomes that contained more ASC than did those from a matched control group. Together, these results suggest that the divalent metal manganese acts as a key amplifier of NLRP3 inflammasome signaling and exosomal ASC release.

“Cardio - respiratory effects in children aged 6-12 years in their first dental visit

Objetive: A descriptive, cross-sectional studywas performed to determine the cardiorespiratoryeffects in child’s first dental visit to thePediatric Dental Clinic at Alas Peruanas University,without the presence of any pre-existingcondition, such as pain, previous traumatic dentalvisits, use of medications and systemic diseases.
 Material and méthodos: To accomplish this, heart rate, oxygen saturation, blood pressure,body temperature and respiratory rate were recordedon 70 children before (waiting room) andafter first dental visit (operating room) using afinger pulse oximeter, digital sphygmomanometer,thermometer and a wristwatch. 
 Results:showed basal and postoperative body temperatureregistered 36° C and 36.1° C, respectively.Basal systolic blood pressure registered 96 mmHg and postoperative 93 mm Hg, and basaldiastolic blood pressure registered 63 mm Hgand postoperative 63 mm Hg. Basal oxygen saturationregistered 96% and postoperative 93%.Basal heart rate registered 88 bpm and postoperative85 bpm. Basal respiratory rate registered20 bpm and postoperative 20 bpm. The authorconcluded that significant cardiorespiratorychanges exist during first dental visit, existingsignificant differences in oxygen saturation andrespiratory rate recorded before and after dentalcare.

The APPswe/PS1A246E mutations in an astrocytic cell line leads to increased vulnerability to oxygen and glucose deprivation, Ca2+ dysregulation, and mitochondrial abnormalities

Growing evidence suggests a close relationship between Alzheimer's Disease (AD) and cerebral hypoxia. Astrocytes play a key role in brain homeostasis and disease states, while some of the earliest changes in AD occur in astrocytes. We have therefore investigated whether mutations associated with AD increase astrocyte vulnerability to ischemia. Two astroglioma cell lines derived from APPSWE /PS1A246E (APP, amyloid precursor protein; PS1, presenilin 1) transgenic mice and controls from normal mice were subjected to oxygen and glucose deprivation (OGD), an invitro model of ischemia. Cell death was increased in the APPSWE /PS1A246E line compared to the control. Increasing extracellular calcium concentration ([Ca2+ ]) exacerbated cell death in the mutant but not in the control cells. In order to explore cellular Ca2+ homeostasis, the cells were challenged with ATP or thapsigargin and [Ca2+ ] was measured by fluorescence microscopy. Changes in cytosolic Ca2+ concentration ([Ca2+ ]c ) were potentiated in the APPSWE /PS1A246E transgenic line. Mitochondrial function was also altered in the APPSWE /PS1A246E astroglioma cells; mitochondrial membrane potential and production of reactive oxygen species were increased, while mitochondrial basal respiratory rate and ATP production were decreased compared to control astroglioma cells. These results suggest that AD mutations in astrocytes make them more sensitive to ischemia; Ca2+ dysregulation and mitochondrial dysfunction may contribute to this increased vulnerability. Our results also highlight the role of astrocyte dyshomeostasis in the pathophysiology of neurodegenerative brain disorders.

Anaesthetic Effect of Propofol on Rainbow Trout (Oncorhynchus Mykiss) in Two Different Concentrations

Objective- The study aims to determine efficacy of propofol as an inmersion agent to induce anesthesia in rainbow trout (Oncorhynchus mykiss). Design- Experimental study. Animals- 36 healthy rainbow trout Procedure- Trouts were sorted ramdomly in two groups, 18 fish each one. Both groups were anesthesized by bath, one of them with 2,5 mg/l, the other one at 5 mg/l concentration. During the experiment, basal respiratory rate, partial and total equilibrium loss, time to anesthesia, anaesthesia respiratory rate and manipulation response were recorded. Results and Conclusion- Induction and recovery times as well as behavioural response were recorded, being significantly affected by propofol concentration (P <0.01). After exposure to 2,5 and 5 mg/l, fishes reached stage 3 anaesthesia in 4,99 ± 1,07 and 2,81 ± 0,71 minutes respectively. Recovery time were 3,59 ± 1,44 for 2,5 mg/l and 7,49 ± 3,02 minutes for 5 mg/l. After the experiment, the fish remained for 48 hours in a pond attached to the unit, without any death. This study, showed the behavioural response of rainbow trout to anaesthesia as well effectiveness of propofol as anaesthetic. Propofol induce safe dose dependent anaesthesia, being useful for different tasks related to the management of culture trout, as it meets the criteria established in aquaculture use. Clinical relevance- The results of the present work provide data to be used in surgical procedures and containment maneuvers in the different practices performed in fish farming.

Complementary ACSL isoforms contribute to a non-Warburg advantageous energetic status characterizing invasive colon cancer cells

Metabolic reprogramming is one of cancer hallmarks. Here, we focus on functional differences and individual contribution of acyl coA synthetases (ACSL) isoforms to the previously described ACSL/stearoyl-CoA desaturase (ACSL1/ACSL4/SCD) metabolic network causing invasion and poor prognosis in colorectal cancer (CRC). ACSL4 fuels proliferation and migration accompanied by a more glycolytic phenotype. Conversely, ACSL1 stimulates invasion displaying a lower basal respiratory rate. Acylcarnitines elevation, polyunsaturated fatty acids (PUFA) lower levels, and monounsaturated fatty acids (MUFA) upregulation characterize the individual overexpression of ACSL1, ACSL4 and SCD, respectively. However, the three enzymes simultaneous overexpression results in upregulated phospholipids and urea cycle derived metabolites. Thus, the metabolic effects caused by the network are far from being caused by the individual contributions of each enzyme. Furthermore, ACSL/SCD network produces more energetically efficient cells with lower basal respiration levels and upregulated creatine pathway. These features characterize other invasive CRC cells, thus, ACSL/SCD network exemplifies specific metabolic adaptations for invasive cancer cells.

Gangliosides GM1 and GD1a normalize respiratory rates of rat brain mitochondria reduced by tert-butyl hydroperoxide

The rate of oxygen consumption by glutamate- and malate-energized rat brain mitochondria, which was stimulated by an uncoupler 2,4-dinitrophenol (DNP), declined in the presence of a prooxidant tert-butyl hydroperoxide. Preincubation with gangliosides GM1 or GD1a at micromolar (but not nanomolar) concentrations significantly slowed down this decline in the mitochondrial respiration, as shown by measuring absolute respiratory rates and ratios of the mitochondrial respiratory rate in the presence of DNP to the basal respiratory rate (V DNP/V 0). Gangliosides GM1 and GD1a also slowed down a decline in the DNP-stimulated mitochondrial respiration induced by long-term incubation (“aging”) of mitochondria on ice. The data obtained are likely to reflect a prooxidant-induced reduction in the activity of enzymes of the mitochondrial respiratory chain as well as a GM1- and GD1a-induced decrease in the degree of their inactivation. Interestingly, in the presence of the Trk receptor tyrosine kinase inhibitor (K252a) this effect of gangliosides was not manifested in any way. Our data suggest that the direct impact of gangliosides on mitochondrial signaling pathways, specifically on the Trk receptor tyrosine kinase, plays a certain role in the mechanism of their protective effect on cerebral neurons and, probably, neuroglia.

Lack of β, β-carotene-9', 10'-oxygenase 2 leads to hepatic mitochondrial dysfunction and cellular oxidative stress in mice.

β,β-Carotene-9',10'-dioxygenase 2 (BCO2) is a carotenoid cleavage enzyme localized to the inner mitochondrial membrane in mammals. This study was aimed to assess the impact of genetic ablation of BCO2 on hepatic oxidative stress through mitochondrial function in mice. Liver samples from 6-wk-old male BCO2-/- knockout (KO) and isogenic wild-type (WT) mice were subjected to proteomics and functional activity assays. Compared to the WT, KO mice consumed more food (by 18%) yet displayed significantly lower body weight (by 12%). Mitochondrial proteomic results demonstrated that loss of BCO2 was associated with quantitative changes of the mitochondrial proteome mainly shown by suppressed expression of enzymes and/or proteins involved in fatty acid β-oxidation, the tricarboxylic acid cycle, and the electron transport chain. The mitochondrial basal respiratory rate, proton leak, and electron transport chain complex II capacity were significantly elevated in the livers of KO compared to WT mice. Moreover, elevated reactive oxygen species and increased mitochondrial protein carbonylation were also demonstrated in liver of KO mice. Loss of BCO2 induces mitochondrial hyperactivation, mitochondrial stress, and changes of the mitochondrial proteome, leading to mitochondrial energy insufficiency. BCO2 appears to be critical for proper hepatic mitochondrial function.