Activity Of Enzyme Complex Research Articles

Structural, Characterization, Biological and Studying the Enzyme Activity of some transition metal complexes with 4- )(2- hydroxy phenyl imino) methyl) -2, 6-dimethoxy phenol

A new Schiff bases ligand 4- ((2-hyolroxy phenylimino) methyl) -2, 6-dimethoxyphenol derived from condensation of 2- amino phenol with 4-hydroxy -3, 5-dimethoxy benzaldehyde have been synthesized and characterized by spectroscopy, spectra, Mass spectrum and elemental microanalysis (C.H.N). Metal Complexes with ions have been also synthesized and characterized spectroscopic methods spectroscopy, flame atomic absorption, molar conductivity measurements and magnetic susceptibility. These studies indicate that the moler ratio for the complexes. The complexes showed characteristics octahedral geometry with the (O,N) ligand coordinated in bidentate mode while with showed square planer. The enzyme activity of the ligand and its metal complexes with esterase (AST) have also been studied . the study of enzyme activity indicates that the ligand its metal complexes revealed different inhibition behaviors. The synthesized ligands and their metal complexes have been tested against one type of fungi (candida albicans).

Mitochondrial complex I ROS production and redox signaling in hypoxia

Mitochondria are a main source of cellular energy. Oxidative phosphorylation (OXPHOS) is the major process of aerobic respiration. Enzyme complexes of the electron transport chain (ETC) pump protons to generate a protonmotive force (Δp) that drives OXPHOS. Complex I is an electron entry point into the ETC. Complex I oxidizes nicotinamide adenine dinucleotide (NADH) and transfers electrons to ubiquinone in a reaction coupled with proton pumping. Complex I also produces reactive oxygen species (ROS) under various conditions. The enzymatic activities of complex I can be regulated by metabolic conditions and serves as a regulatory node of the ETC. Complex I ROS plays diverse roles in cell metabolism ranging from physiologic to pathologic conditions. Progress in our understanding indicates that ROS release from complex I serves important signaling functions. Increasing evidence suggests that complex I ROS is important in signaling a mismatch in energy production and demand. In this article, we review the role of ROS from complex I in sensing acute hypoxia.

Sericin alleviates pentylenetetrazole kindling epilepsy and associated comorbidities via modulation of GABA-T enzyme and mitochondrial activity

Objective: To assess the effect of sericin against pentylenetetrazole (PTZ) kindling epilepsy and its associated comorbidities. Methods: Epilepsy was induced with PTZ at the dose of 30 mg/kg i.p. on alternative days for 25 days in rats. Sericin was administered orally at the doses of 250, 500, and 1000 mg/kg for 35 days. The behavioral activities were performed using an elevated plus maze, forced swim test, and Morris water maze test. A PTZ challenge test was conducted on day 32. On day 35, rats were sacrificed to perform oxidative stress, mitochondrial dysfunction, neuroinflammation, neurotransmitters, GABA-T activity, and histopathological analyses. Results: Sericin at 500 and 1000 mg/kg significantly reduced behavioral changes and neuroinflammatory cytokines, as well as improved oxidative stress, mitochondrial enzyme complex activity, neurotransmitter level, and GABA-T enzymatic activity (P<0.05). Moreover, sericin improved the neuronal survival altered by PTZ kindling in rat hippocampus. Conclusions: Sericin mitigates epilepsy-associated secondary complications possibly by the modulation of mitochondrial enzyme complexes and GABA-T enzymatic activity.

Investigation of mitochondrial oxidative phosforylation enzymes in hematological cancers

It is known that cancerous cells are different from normal cells in their structure and functions. It is aimed to determine whether there is a change in the activities of mitochondrial oxidative phosphorylation (OXPOS) respiratory enzymes, the main energy production site of cells, in various haematological cancers and to use the obtained data for therapeutic purposes. In this study, leukocyte mitochondria were isolated from blood samples obtained from patients with non-hodgkin lymphoma (NHL), hodgkin lemphoma (HL), chronic lymphocytic leukaemia (CLL), acute myelogenic leukaemia (AML), acute lymphocytic leukaemia (ALL), chronic myeloid leukaemia (CML), multiple myeloma and myelodysplastic syndrome (MDS) and controls. The enzyme activities of oxidative phosphorylation complexes I, II and IV were measured by spectrophotometric method. Enzyme activity results were statistically evaluated according to various criteria. Enzyme activities were evaluated according to gender, chemotherapy or not and disease groups. As a result of these statistical evaluations, no correlation was found between the type of haematological cancer and gender (p>0.05). The difference in mitochondrial oxidative complex enzyme activities between patients receiving chemotherapy and those not receiving chemotherapy was insignificant (p>0.05). When the enzyme activities of the control group and all haematological cancer cells studied were compared, the difference was found to be statistically significant (p<0.05). As a result, changes in the activities of OXPOS respiratory enzymes were found in various haematological cancers. The large number of therapies that specifically target mitochondria, the altered metabolic functions and dynamics of mitochondria in cancer cells make it a target for cancer therapeutics.

Neuropharmacological Study on Capsaicin in Scopolamine-injected Mice.

To evaluate the potential beneficial role of Capsaicin in cognitive dysfunction, mitochondrial impairment, and oxidative damage induced by scopolamine in mice. Capsaicin is the chief phenolic component present in red chili and is responsible for its pungent and spicy flavor. It affects TRPV1 channels in nociceptive sensory neurons and is present in the hippocampus, and hypothalamus of the brains of rodents and humans. The main objective is to investigate the effective role of capsaicin in attenuating cognitive dysfunction, mitochondrial impairment, and oxidative damage induced by scopolamine in mice and examine the feasible mechanisms. Various doses of capsaicin (5, 10, and 20 mg/kg) were given orally to mice daily for 7 consecutive days after the administration of scopolamine. Various behavioral tests (motor coordination, locomotor counts, hole board test) and biochemical assay (Pro-inflammatory cytokines, catalase, lipid peroxidation, nitrite, reduced glutathione, and superoxide dismutase), mitochondrial complex (I, II, III, and IV) enzyme activities, and mitochondrial permeability transition were evaluated in the distinct regions of the brain. Scopolamine-treated mice showed a considerable reduction in the entries and duration in the light zone as well as in open arms of the elevated plus maze. Interestingly, capsaicin at different doses reversed the anxiety, depressive-like behaviors, and learning and memory impairment effects of scopolamine. Scopolamine-administered mice demonstrated substantially increased pro-inflammatory cytokines levels, impaired mitochondrial enzyme complex activities, and increased oxidative damage compared to the normal control group. Capsaicin treatment reinstated the reduced lipid peroxidation, nitric oxide, catalase, superoxide dismutase, reduced glutathione activity, decreasing pro-inflammatory cytokines and restoring mitochondrial complex enzyme activities (I, II, III, and IV) as well as mitochondrial permeability. Moreover, the IL-1β level was restored at a dose of capsaicin (10 and 20 mg/kg) only. Capsaicin reduced the scopolamine-induced acetylcholinesterase activity, thereby raising the acetylcholine concentration in the hippocampal tissues of mice. Preservation of neuronal cell morphology was also confirmed by capsaicin in histological studies. From the above experimental results, capsaicin at a dose of 10 mg/kg, p.o. for seven consecutive days was found to be the most effective dose. The experiential neuroprotective effect of capsaicin through the restoration of mitochondrial functions, antioxidant effects, and modulation of pro-inflammatory cytokines makes it a promising candidate for further drug development through clinical setup.

Dietary apple polyphenols enhance mitochondrial turnover and respiratory chain enzymes.

Previous studies have demonstrated the beneficial effects of apple polyphenol (AP) intake on muscle endurance. Since mitochondria are critical for muscle endurance, we investigated mitochondrial enzyme activity, biogenesis, degradation and protein quality control. Twenty-four Wistar rats were randomly fed a 5% AP diet (5% AP group, n=8), a 0.5% AP diet (0.5% AP group, n=8), or a control diet (control group, n=8). After a 4-week feeding period, the expression level of peroxisome proliferator-activated receptor γ coactivator-1α, a mitochondrial biosynthetic factor, did not increase, whereas that of transcription factor EB, another regulator of mitochondrial synthesis, significantly increased. Moreover, the mitochondrial count did not differ significantly between the groups. In contrast, mitophagy-related protein levels were significantly increased. The enzymatic activities of mitochondrial respiratory chain complexes II, III and IV were significantly higher in the AP intake group than in the control group. We conclude that AP feeding increases the activity of respiratory chain complex enzymes in rat skeletal muscles. Moreover, mitochondrial biosynthesis and degradation may have increased in AP-treated rats. NEW FINDINGS: What is the central question of this study? Does the administration of apple polyphenols (AP) affect mitochondrial respiratory chain complex enzyme activity, biogenesis, degradation and protein quality control in rat skeletal muscles? What is the main finding and its importance? AP feeding increases respiratory chain complex enzyme activity in rat skeletal muscle. Moreover, AP administration increases transcription factor EB activation, and mitophagy may be enhanced to promote degradation of dysfunctional mitochondria, but mitochondrial protein quality control was not affected.

Remodelling of the Mitochondrial Bioenergetic Pathways in Human Cultured Fibroblasts with Carbohydrates.

Mitochondrial oxidative phosphorylation defects underlie many neurological and neuromuscular diseases. Patients' primary dermal fibroblasts are one of the most commonly used in vitro models to study mitochondrial pathologies. However, fibroblasts tend to rely more on glycolysis than oxidative phosphorylation for their energy when cultivated in standard high-glucose medium, rendering it difficult to expose mitochondrial dysfunctions. This study aimed to systematically investigate to which extent the use of galactose- or fructose-based medium switches the fibroblasts' energy metabolism to a more oxidative state. Highly proliferative cells depend more on glycolysis than less proliferative cells. Therefore, we investigated two primary dermal fibroblast cultures from healthy subjects: a highly proliferative neonatal culture and a slower-growing adult culture. Cells were cultured with 25 mM glucose, galactose or fructose, and 4 mM glutamine as carbon sources. Compared to glucose, both galactose and fructose reduce the cellular proliferation rate, but the galactose-induced drop in proliferation is much more profound than the one observed in cells cultivated in fructose. Both galactose and fructose result in a modest increase in mitochondrial content, including mitochondrial DNA, and a disproportionate increase in protein levels, assembly, and activity of the oxidative phosphorylation enzyme complexes. Galactose- and fructose-based media induce a switch of the prevalent biochemical pathway in cultured fibroblasts, enhancing aerobic metabolism when compared to glucose-based medium. While both galactose and fructose stimulate oxidative phosphorylation to a comparable degree, galactose decreases the cellular proliferation rate more than fructose, suggesting that a fructose-based medium is a better choice when studying partial oxidative phosphorylation defects in patients' fibroblasts.

Impact of luminescent MoSe2 quantum dots on activity of trypsin under different pH environment

It is vital that a straightforward detection approach for trypsin should be developed as it is important diagnostic tool for a number of diseases. Herein, the impact of luminescent MoSe2 quantum dots on trypsin activity under different pH environment has been studied. Addition of trypsin to MoSe2 quantum dots enhanced the fluorescence of quantum dots whereas quantum dots resulted in quenching of fluorescence of trypsin. The quenching behavior at various pH and temperature was examined and revealed that the MoSe2-trypsin complex stabilized through the electrostatic interactions. The obtained negative values of zeta potential of the complex −0.11 mV, −0.30 mV and −0.59 mV for pH 6.0,7.6 and 9.0 respectively confirmed the stability of the complex. The separation between the donor and acceptor atoms in energy transfer mechanism was found to decrease (1.48 nm to 1.44 nm to 1.30 nm) with increasing value of pH. It was also evident that trypsin retained its enzyme activity in the trypsin-MoSe2 complex and under different pH environment. The Vant Hoff plot from quenching revealed 1 binding site for quantum dots by trypsin for all pH of buffer solution. The complex formation of trypsin-MoSe2 quantum dots was verified for the first time using fluorescence spectroscopy and it revealed that tryspin form complex with MoSe2 quantum dots through electrostatic interactions. Our results revealed that the MoSe2 quantum dots stabilized and sheltered the active sites of trypsin, which was likely the cause of the increased bioavailability of MoSe2 quantum dots in enzymes.

Antimicrobial mechanisms and secondary metabolite profiles of Streptomyces hygroscopicus subsp. hygroscopicus 5-4 against banana fusarium wilt disease using metabolomics.

Fusarium wilt of bananas (FWB) is seriously affecting the sustainable development of the banana industry and is caused by the devastating soil-borne fungus Fusarium oxysporum f. sp. cubense tropical race 4 (Foc TR4). Biological control is a promising strategy for controlling Fusarium wilt in bananas. We previously identified Streptomyces hygroscopicus subsp. hygroscopicus 5-4 with strong antifungal activity against the FWB. The most possible antimicrobial mechanism of strain 5-4 was explored using the metabolomics approach, light microscopy imaging, and transmission electron microscopy (TEM). The membrane integrity and ultrastructure of Foc TR4 was damaged after extract treatment, which was supported by the degradation of mycelium, soluble protein content, extracellular reducing sugar content, NADH oxidase activity, malondialdehyde content, mitochondrial membrane potential, and mitochondrial respiratory chain complex enzyme activity. The extracts of strain 5-4 cultivated at different times were characterized by a liquid chromatography-mass spectrometer (LC-MS). 647 known metabolites were detected in the extracts of strains 5-4. Hygromycin B, gluten exorphin B4, torvoside G, (z)-8-tetradecenal, piperitoside, sarmentosin, pubescenol, and other compounds were the main differential metabolites on fermentation culture for 7 days. Compared with strain 5-4 extracts, hygromycin B inhibited the mycelial growth of Foc TR4, and the EC50 concentration was 7.4 μg/mL. These results showed that strain 5-4 could destroy the cell membrane of Foc TR4 to inhibit the mycelial growth, and hygromycin B may be the key antimicrobial active metabolite. Streptomyces hygroscopicus subsp. hygroscopicus 5-4 might be a promising candidate strain to control the FWB and provide a scientific basis for the practical application of hygromycin B as a biological control agent.

Effects and mechanism of perinatal nonylphenol exposure on cardiac function and myocardial mitochondria in neonatal rats

BackgroundNonylphenol (NP) is a common environmental endocrine disruptor that is associated with the development of cardiovascular disease. However, the toxic effect of NP on mitochondria in the heart of offspring to exposed individuals remains exclusive. ObjectiveTo investigate whether perinatal NP exposure causes mitochondrial damage in the hearts of offspring of exposed individuals and determine its mechanism of action through both animal and cell experiments. Methods and resultsFor the in vivo experiment, pregnant rats were randomly divided into four groups: the control group (corn oil, C), low dose group (2.5 mg/kg/day, L-NP group), medium dose group (50 mg/kg/day, M-NP group), and high dose group (100 mg/kg/day, H-NP group), with 12 rats in each group. The NP concentration in the hearts of offspring at PND21 and PND90 increased with the increase of the NP dose. Perinatal NP exposure induced a gradual increase in systolic blood pressure in offspring at PND90. In the H-NP group, there was a high degree of inflammatory cell infiltration, myofibril breaks, inconspicuous or absent nuclei, and pink collagen deposition. At PND90, the membrane integrity of mitochondria in the H-NP group was disrupted, the cristae disorder was aggravated, and there was internal lysis with vacuolation. Compared to the control group, the mitochondrial membrane potential of offspring at PND21 and PND90 was decreased in each of the NP exposure groups. NP exposure decreased the activity of mitochondrial respiratory enzyme complex I (CI) and increased the activity of mitochondrial respiratory enzyme complex IV (CIV) in the offspring. At PND21 and PND90, the mRNA and protein expression levels of cardiac mitochondrial PGC-1α, NRF-1, and TFAM decreased with increasing NP dose in a dose-dependent manner. In the in vitro experiment, H9C2 cells were divided into the following four groups: the blank group, RSV group (15 μg/ml), RSV + NP group (15 μg/ml RSV + 120 mmol/L NP), and NP group (120 mmol/L). With increasing NP concentration, the cell survival rate gradually decreased. Compared to the control, the membrane potential was significantly decreased in the NP group; the protein expression levels of SIRT1, PGC-1α, NRF-1, and TFAM in the NP group were significantly lower. ConclusionPerinatal NP exposure caused mitochondrial damage and dysfunction in the offspring of exposed individuals in a dose-dependent manner. This toxic effect may be related to NP-induced mitochondrial pathology in the offspring and the inhibition of both gene and protein expression involved in the PGC-1α/NRF-1/TFAM mitochondrial biogenesis signaling pathway following NP exposure.

POTENTIATION OF PROBIOTIC ACTIVITY BY SIMULTANEOUS USE OF AEROCOCCUS VIRIDANS AND MYCOBACTERIUM VACCAE

In modern animal husbandry, progressive intensive technologies for keeping animals and the productive exploitation of animals are economically efficient, but they deplete the physiological reserves of the body and lead to undesirable pathophysiological changes of a complex nature. The immune-reactive potential of the integral and censoring systems of the macroorganism decreases, the metabolic activity of enzyme complexes at the level of cells and organs changes, antimicrobial resistance decreases, and the quantitative and qualitative composition of the normal flora of the covering tissues and hollow organs is disturbed. The stress of debilitating technological leads to systemic pathologies of infectious and non-infectious origin and deterioration of the health and well-being of the animals.
 One of the physiological ways of correcting the systemic pathology based on damage to the native bioprotective mechanisms of the macroorganism is the use of resident prokaryotes of the microbiome artificially cultivated and given per os as a feed dietary supplement. In our research, we isolated probiotic cultures of A. viridans and M. vaccae from healthy broiler chickens, studied their biological properties, established their biosafety for other animals, and determined probiotic potencies when used monovalently and in association. It was shown that the combined use of probiotic prokaryotes significantly improves the stimulation of the immune-reactive potential of the macroorganism and, in association, increases the colonization capabilities of indigenous prokaryotes. Isolated probiotic cultures of the resident microbiota are suitable for the production of probiotics and symbiotics for farm and domestic animals and for prophylactic and therapeutic use both in monoculture and in association. Simultaneous use of probiotic associations is more effective than monocultures.

The mitochondrial BCKD complex interacts with hepatic apolipoprotein E in cultured cells in vitro and mouse livers in vivo

Background and aimsApolipoprotein E (APOE) is known for its role in lipid metabolism and its association with age-related disease pathology. The aim of the present work was to identify previously unknown functions of APOE based on the detection of novel APOE protein–protein interaction candidates.Approach and resultsAPOE targeted replacement mice and transfected cultured hepatocytes expressing the human isoforms APOE3 and APOE4 were used. For 7 months, APOE3 and APOE4 mice were fed a high-fat and high-sugar diet to induce obesity, while a subgroup was subjected to 30% dietary restriction. Proteomic analysis of coimmunoprecipitation products from APOE mouse liver extracts revealed 28 APOE-interacting candidate proteins, including branched-chain alpha-keto acid dehydrogenase (BCKD) complex subunit alpha (BCKDHA) and voltage-dependent anion-selective channel 1 (VDAC1). The binding of APOE and BCKDHA was verified in situ by proximity ligation assay in cultured cells. The activity of the BCKD enzyme complex was significantly higher in obese APOE4 mice than in APOE3 mice, while the plasma levels of branched-chain amino acids and mTOR signalling proteins were not different. However, the protein–protein interaction with VDAC1 was strongly induced in APOE3 and APOE4 mice upon dietary restriction, suggesting a prominent role of APOE in mitochondrial function.ConclusionsThe protein–protein interactions of APOE with BCKDHA and VDAC1 appear to be of physiological relevance and are modulated upon dietary restriction. Because these are mitochondrial proteins, it may be suggested that APOE is involved in mitochondria-related processes and adaptation to hepatic energy demands.

Control of cascade reaction by proximity of enzymes.

A proximity of enzymes into a cytoplasm causes efficient cascade reactions of enzymes. Therefore, efficiencies of enzyme reactions in vitro will be improved by a local increase in concentration of enzyme. In a previous study, two different types of enzymes were placed in close proximity using synthetic polymer. However, it is difficult to reversibly control proximity and dispersion of enzymes. In this study, we attempt to closely assemble three enzymes using 3-way junction DNA in order to create an efficient and controllable bioreactor emulating the proximity of enzymes into a cytoplasm. The methods for constructions of three-enzyme complexes show the following steps. First, we designed single stranded DNAs (ssDNAs) which can form the triply-branched structure by a hybridization reaction. The ssDNA with amino group at terminal was conjugated to NHS ester-PEG4-maleimide. Next, a sulfhydryl group of primary amines of three enzymes (horseradish peroxidase, glucose oxidase and β-galactosidase) was reacted with maleimide of ssDNA-PEG4-maleimide. To obtain ssDNA-PEG4-Protein, three types of thiolated enzymes were conjugated with three different ssDNA-PEG4-maleimide, correspondingly. The products were purified and characterized by native PAGE and UV-Vis spectroscopy. The absorbance intensity of UV-Vis spectra of the purified ssDNA-PEG4-Protein at 260 nm for the ssDNA depended on the number of ssDNAs in a protein. Finally, three-enzyme complexes were assembled. The enzyme activity of three-enzyme complexes was compared with that of the free enzyme mixture. The cascade reaction is involving β-Gal-catalyzed hydrolysis of lactose, GOx-catalyzed oxidation of glucose to gluconolactone and hydrogen peroxide, and HRP-catalyzed oxidation of Amplex Red to resorufin with hydrogen peroxide. Assembling of three-enzyme complexes using 3-way junction DNA enhanced the cascade reaction activity under a dilute condition compared with the free enzymes. Therefore, this enzyme assembly system will contribute to emulations efficient reactions into the biological cells.

Aumento acentuado da leucina como fator de mau prognóstico na doença da urina de xarope de bordo - relato de caso

INTRODUCTION: Leucinosis or Maple Syrup Disease (MSD) is an innate metabolism error caused by a deficiency in the activity of the alpha-keto acid-dehydrogenase enzyme complex, which leads to the accumulation of essential branched-chain amino acids (leucine, valine, and isoleucine), leucine is particularly toxic to the central nervous system (CNS). OBJECTIVES: Report a case of maple syrup disease in a 10-day-old newborn (NB), born to consanguineous parents, with late diagnosis, with high levels of leucine, with an unfavorable prognosis. COMMENTS: MSD is a rare condition, of autosomal recessive origin, which occurs due to the accumulation of essential branched-chain amino acids in tissues(leucine, valine, and isoleucine). The accumulation of amino acids mainly affects the CNS. Studies have shown that the elevated leucine concentration decreases the serum sodium concentration and increases intracellular water, causing cerebral edema. Neurological damage will depend on the degree and time of tissue exposure to metabolites. Despite the unfavorable outcome of the case presented, the prognosis of MSD can be modified with strict diet control and early and aggressive management of metabolic crisis.

M6A-related bioinformatics analysis and functional characterization reveals that METTL3-mediated NPC1L1 mRNA hypermethylation facilitates progression of atherosclerosis via inactivation of the MAPK pathway.

Accumulating evidence has demonstrated that N6-methyladenosine (m6A) plays important roles in many major diseases, including atherosclerosis (AS). In the present study, we aimed to explore the transcriptomic m6A landscape of endothelial function-associated genes and identify potential regulators in AS progression. The GEO data (GSE142386) from MeRIP-seq in human umbilical vein endothelial cells (HUVECs) with METTL3 knocked down or not were analyzed. RNA-seq was performed to identify differences in gene expression. Gene ontology (GO) functional and Kyoto encyclopedia of genes and genomes (KEGG) pathway analyses were conducted to evaluate the potential functions of the differentially expressed genes. MeRIP-qPCR was used to measure the m6A and mRNA levels of the top 8 downregulated genes, and NPC1L1 was selected as the candidate gene. Oxidized low-density lipoprotein (ox-LDL) was used to stimulate HUVECs, and METTL3 or NPC1L1 was silenced in ox-LDL-treated cells. And Transwell, ELISA, and cell apoptosis assays were performed to assess cell functional injury. ApoE-/- mice were fed with high-fat diet for 8 weeks to establish an AS model, and adenovirus-mediated NPC1L1 shRNA or NC shRNA was injected into the mice through the tail vein. Mouse aortic tissue damage and plaque deposition were evaluated by H&E, Oil Red O, and TUNEL staining. One hundred and ninety-four hypermethylated m6A peaks and 222 hypomethylated peaks were detected in response to knockdown of METTL3. Genes with altered m6A peaks were significantly involved in the histone modification, enzyme activity, and formation of multiple complexes and were predominantly enriched in the MAPK pathway. NPC1L1 was a most significantly downregulated transcript in response to knockdown of METTL3. Moreover, knockdown of NPC1L1 or de-m6A (METTL3 knockdown)-mediated downregulation of NPC1L1 could improve ox-LDL-induced dysfunction of HUVECs in vitro and high-fat diet-induced atherosclerotic plaque in vivo, which was associated with the inactivation of the MAPK pathway. METTL3-mediated NPC1L1 mRNA hypermethylation facilitates AS progression by regulating the MAPK pathway, and NPC1L1 may be a novel target for the treatment of AS.

Double dicyanamide decorated double phenoxide bridged MnIII dimer with single-molecule magnetic behaviour and bio-catalytic activity

Herein, we report the magnetic properties and bio-catalytic activity of a flying bee-like double phenoxido bridged dinuclear MnIII-Schiff base complex decorated with double dicyanamide (dca−) ligands and formulated as: [Mn2(L)2(dca)2] (1) (where H2L = 2,2′-((1E,1′E)-(ethane-1,2-diylbis(azanylylidene))-bis(ethan-1-yl-ylidene))diphenol). The complex has been synthesised by one-pot stepwise reaction of the tetradentate Schiff’s base ligand H2L with MnCl2 and dca− at 1:1:2 ratio under aerobic conditions. It has been characterized by single crystal X-ray diffraction (SC-XRD) and spectroscopic techniques. Complex 1 contains two MnIII ions connected by a double phenoxido bridge in an octahedral geometry and terminal dca− ligands. The dimers are connected to other dimers through both hydrogen bonding and π-interactions to form an extended supramolecular network. The present study reveals that in presence of tetradentate Schiff base ligands, the use of a 1:2 Mn:dca− ratio leads to formation of a dimeric MnIII complex in contrast to the discrete mononuclear complexes or 1D structures previously obtained for the Mn:dca− ratio of 1:1. The magnetic study indicates that the dimeric MnIII complex shows a negligible MnIII–MnIII interaction and a large anisotropy. The AC susceptibility measurements indicate that complex 1 behaves as a field-induced single-molecule magnet (SMM), with a high energy barrier of 73(4)K. The study of model catechol oxidase-like enzyme activity of complex 1 indicates that the dimeric MnIII complex acts as an active catalyst (kcat = 34.94 h−1) in the oxidation of 3,5-di-tert-butylcatechol (3,5-DTBC) in presence of aerial O2 in acetonitrile medium.

Eradication of HCV by direct antiviral agents restores mitochondrial function and energy homeostasis in peripheral blood mononuclear cells.

Hepatitis C virus (HCV) adopts several immune evasion mechanisms such as interfering with innate immunity or promoting T-cell exhaustion. However, the recent direct-antiviral agents (DAAs) rapidly eliminate the virus, and the repercussions in terms of immune system balance are unknown. Here we compared the PBMCs transcriptomic profile of patients with HCV chronic infection at baseline (T0) and 12 weeks after the end of the therapy (SVR12) with DAAs. 3862 genes were differently modulated, identifying oxidative phosphorylation as the top canonical pathway differentially activated. Therefore, we dissected PBMCs bioenergetic profile by analyzing mitochondrial respiration and glycolysis at 4 timepoints: T0, 4 weeks of therapy, end of therapy (EoT), and SVR12. Maximal and reserve respiratory capacity considerably increased at EoT, persisting until SVR12. Notably, over time a significant increase was observed in respiratory chain (RC) complexes protein levels and the enzymatic activity of complexes I, II, and IV. Mitochondrial-DNA integrity improved over time, and the expression of mitochondrial biogenesis key regulators such as TFAM, Nrf-1, and PPARGC1A significantly increased at SVR12; hence, RC complexes synthesis and mitochondrial respiration were supported after treatment. HCV clearance with DAAS profoundly changed PBMCs bioenergetic profile, suggesting the immunometabolism study as a new approach to the understanding of viral immune evasion mechanisms and host adaptations during infections and therapies.

Melatonin Protects Against Titanium Oxide-Induced Neurotoxicity: Neurochemical, Neurobehavioral, and Histopathological Evidences.

titania (titanium dioxide, TiO2) is known to induce neurotoxicity and CNS dysfunctions. Numerous studies have explored the neuroprotective effects of melatonin against neurotoxicity. This study evaluates the potential of melatonin to protect against titania-induced neurotoxicity and the role of the Keap1/Nrf2/ARE signaling pathway. One group of animals were treated with Titania (0.045 and 0.075g/rat) alone while the other with added melatonin (1mg/kg and 3mg/kg) and behavioral alterations were assessed using OFT (open field test). Neurochemical and histopathological changes were also studied in the hippocampus by analyzing kelch ECH associating protein 1 (Keap1), nuclear factor erythroid 2-related factor 2 (Nrf2), and antioxidant response element (ARE). It was seen that the animals with added Melatonin had improved behavioral scores in the OFT, like anxiety and motor dysfunction triggered by TiO2. Melatonin also reduced lipid peroxidation, ROS, GSSG, IL1β, TNFα, Bax, and Keap1 levels, but boosted GSH, GPx, GR, SOD,IL10,IL4, Bcl2, Nrf2, and ARE levels and improved quadruple mitochondrial enzyme complex activity in titania-treated animals. Histopathological examination showed melatonin induced cytoprotection against vacuolization and necrosis in granular cells of DG and pyramidal cells of CA1 area of the hippocampus. In our study, pretreatment with melatonin reduced titania-induced neurotoxicity in the hippocampus through a mechanism potentially mediated by the Keap-1/Nrf2/ARE pathway.

Effects of PBMC mitochondrial autophagy on exercise energy consumption and mitochondrial respiratory chain complex enzyme activity in high altitude migrants

目的: 探究高原移居中青年男性走、跑状态运动能耗及外周血单个核细胞(PBMC)线粒体自噬标志物变化特征。方法: 招募152名受试者,根据移居高原年限分为高原移居Ⅰ组(HM1)、高原移居Ⅱ组(HM2)、高原移居Ⅲ组(HM3)、世居高原组(Con)。检测受试者3.0 km/h 、4.5 km/h、6.0 km/h及7.5 km/h条件下运动能耗;ELISA检测受试者PBMC线粒体NADH-Q氧化还原酶、琥珀酸-Q氧化还原酶、UQ-细胞色素C氧化还原酶、细胞色素C氧化酶水平;RT-PCR和Western blot检测受试者PBMC线粒体Parkin、PINK3、LC3A、LC3B mRNA及蛋白表达水平。结果: 与Con组比较,HM1、HM2组3 km/h步行能耗显著上升(P＜ 0.05);与HM1组比较,HM2组显著降低(P＜0.05) 。与Con组比较,HM1组4.5 km/h、6 km/h及7.5 km/h走、跑能耗均显著上升(P＜0.05) 。与Con组比较,HM1、HM2和HM3组复合物Ⅰ、复合物Ⅱ及复合物Ⅲ水平均显著降低(P＜0.05) ;与HM1组和HM2组比较,HM3组显著上升(P＜0.05) ;与HM1组比较,HM2组显著上升(P＜0.05) 。与Con组比较,HM1、HM2组复合物Ⅳ水平显著降低(P＜0.05) ;与HM1组和HM2组比较,HM3组显著上升(P＜0.05) 。与Con组比较,HM1、HM2和HM3组Parkin mRNA表达显著上升(P＜0.05) ,HM1、HM2组高于HM3组(P＜0.05) ;与Con组比较,HM1、HM2和HM3组PINK3 mRNA表达显著降低(P＜0.05) ,HM1组显著低于HM2、HM3组(P＜0.05) ;与Con组比较,HM1、HM2和HM3组LC3A mRNA表达显著降低(P＜0.05) ,HM1组和HM2组显著低于HM3组,HM1组显著低于HM2组(P＜0.05) ;与Con组比较,HM1、HM2和HM3组LC3B mRNA和LC3B蛋白表达显著上升(P＜0.05) ,HM1组和HM2组显著高于HM3组,HM1组显著低于HM2组(P＜0.05) 。与Con组比较,HM1、HM2组Parkin蛋白表达显著上升(P＜0.05) ,HM1组、HM2组显著高于HM3组(P＜0.05) ;与Con组比较,HM1、HM2组PINK3和LC3A蛋白表达显著降低(P＜0.05) ,HM1组、HM2组显著低于HM3组(P＜0.05) 。结论: 高原移居者随高原移居时间延长,PBMC线粒体自噬水平逐步下降,PBMC线粒体呼吸酶活性逐渐增殖;高原定量负荷运动能量消耗逐渐降低。.

Biochemical characterization of mitochondria from adult worms and plerocercoid larvae of Spirometra mansoni shows mixed populations of anaerobic and aerobic mitochondria

The mitochondria of adult and plerocercoid Spirometra mansoni were characterized in isolated mitochondria and in situ by electron microscopic histochemistry with special attention to the respiratory chain. Although the specific activities of the constituent enzyme complexes of succinate oxidase are fairly similar in adult and plerocercoid mitochondria, those of succinate oxidase and NADH-FRD are approximately 4- and 25-fold higher in adult mitochondria than in plerocercoid mitochondria, respectively. Quinone analysis by high performance liquid chromatography and mass spectrometry showed that adult and plerocercoid mitochondria contained both rhodoquinone-10 and ubiquinone-10 at concentrations of 4.98 and 0.106 nmol mg−1 for adult, and 0.677 and 0.137 nmol mg−1 for plerocercoid, respectively. Inhibition studies on the succinate-oxidase system of adult mitochondria showed that they possessed both cyanide-sensitive and -insensitive succinate oxidases, the latter of which produces hydrogen peroxide. Adult mitochondria, when NADH was used as a substrate, were shown to produce hydrogen peroxide, and the production of hydrogen peroxide decreased to undetectable levels in the presence of fumarate. The specific activities of NADH-fumarate reductase and cytochrome c oxidase were significantly higher in mature proglottids than in immature and gravid proglottids. Isopycnic density-gradient centrifugation analyses and in situ electron microscopic histochemistry revealed that both adult and plerocercoid mitochondria were heterogeneous in terms of respiratory function and physicochemical properties. The physiological significance of adult and plerocercoid mitochondria is discussed in relation to the oxygen tension of their parasitic habitats.