391 research outputs found

    PNPLA porodica enzima ‚Äď karakterizacija i bioloŇ°ka uloga

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    This paper brings a brief review of the human patatin-like phospholipase domain-containing protein (PNPLA) family. Even though it consists of only nine members, their physiological roles and mechanisms of their catalytic activity are not fully understood. However, the results of a number of knock-out and gain- or loss-of-function research models suggest that these enzymes have an important role in maintaining the homeostasis and integrity of organelle membranes, in cell growth, signalling, cell death, and the metabolism of lipids such as triacylglycerol, phospholipids, ceramides, and retinyl esters. Research has also revealed a connection between PNPLA family member mutations or irregular catalytic activity and the development of various diseases. Here we summarise important findings published so far and discuss their structure, localisation in the cell, distribution in the tissues, specificity for substrates, and their potential physiological role, especially in view of their potential as drug targets.Ovaj revijalni rad donosi pregled dosadaŇ°njih spoznaja o porodici PNPLA (engl. patatin-like phospholipase domain-containing proteins) ljudskih enzima. Iako ovu porodicu ńćini samo 9 ńćlanova, najmanji sadrŇĺi 253 aminokiseline, a najveńái viŇ°e od 1360 aminokiselina, fizioloŇ°ka uloga i mehanizam katalitińćke aktivnosti nisu do sada potpuno razrijeŇ°eni niti za jednoga. MeńĎutim, rezultati brojnih tzv. knock-out, gain-of-function i loss-of-function modela istraŇĺivanja upuńáuju na vaŇĺnu ulogu ovih enzima u mnogim bioloŇ°kim procesima, ukljuńćujuńái odrŇĺavanje homeostaze i integriteta stanińćne membrane, rast stanice, stanińćnu signalizaciju, stanińćnu smrt i metabolizam lipida kao triacilglicerola, fosfolipida, ceramida i retinil estera. TakońĎer, rezultati istraŇĺivanja upozoravaju na povezanost mutacija i nepravilne aktivnosti pojedinih ńćlanova s razvojem raznih bolesti. Radi boljeg razumijevanja PNPLA porodice enzima i naglaska na njihov potencijal kao mete razvoja novih lijekova, donosimo sveobuhvatni pregled do sada poznatih spoznaja koje ukljuńćuju strukturu, lokalizaciju u stanici, distribuciju u tkivima, specifińćnost prema supstratima i potencijalnu fizioloŇ°ku ulogu

    Residual Neuropathy target esterase activity defines the PNPLA6 disorder spectrum

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    Biallelic pathogenic variants in the patatin like phospholipase domain containing 6 (PNPLA6) gene cause a spectrum of disorders including spastic paraplegia type 39, Gordon-Holmes, Boucher-Neuhäuser, Laurence-Moon, and Oliver-McFarlane syndromes. Patients display a pleiotropy of clinical characteristics that include vision loss, gait disturbance, anterior hypopituitarism, and hair anomalies. PNPLA6 encodes Neuropathy target esterase (NTE), an enzyme involved in phospholipid homeostasis and trafficking in the nervous system. Yet it remains unclear how variants in the PNPLA6 gene affect NTE that ultimately contributes to the observed spectrum of patient phenotypes.   Here, I undergo a clinical meta-analysis of 118 patients to uncover the genotype:phenotype correlations that underlie the PNPLA6 disorder spectrum. Analyses indicated that missense variants located within the enzymatic domain associate more with the severe forms of the disease, revealing a key role PNPLA6 enzymatic activity has on disease pathogenesis. Using an established NTE enzymatic assay to measure the esterase activity of 46 disease-associated and 20 benign variants observed across PNPLA6-associated clinical diagnoses resolved uncertainty in classification of all variants tested using the 2015 ACMG guidelines. Synthetically determining the overall NTE activity of affected individuals revealed a striking relationship between NTE activity and onset of clinical manifestations, where residual esterase activity in patients with retinopathy and endocrinopathy was significantly lower to those without reported visual or endocrinological symptoms. To study the effect of NTE dysfunction in vivo, I conditionally knocked out Pnpla6 in the developing mouse eye, where affected mice display signs of retinal degeneration through impaired visual function and retinal thinning via the outer nuclear layer and bipolar cells. This phenomenon was recaptured in a Pnpla6 murine allelic series, where mice with similar activities to patients with retinopathy experienced reduced visual function and retinal thickness compared to littermate controls and mice who had similar activities to patients without retinopathy. To uncover the full-length structure of NTE, I successfully expressed and purified full-length human NTE in human suspension cells that can be used for structural analyses in the future. Overall, our research has discovered a novel genotype:activity:phenotype relationship of the PNPLA6 disorder spectrum predicated on the residual activity of NTE

    Alzheimer’s disease: the role of extrinsic factors in its development, an investigation of the environmental enigma

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    In the realm of Alzheimer’s disease, the most prevalent form of dementia, the impact of environmental factors has ignited intense curiosity due to its substantial burden on global health. Recent investigations have unveiled these environmental factors as key contributors, shedding new light on their profound influence. Notably, emerging evidence highlights the detrimental role of various environmental contaminants in the incidence and progression of Alzheimer’s disease. These contaminants encompass a broad spectrum, including air pollutants laden with ozone, neurotoxic metals like lead, aluminum, manganese, and cadmium, pesticides with their insidious effects, and the ubiquitous presence of plastics and microplastics. By meticulously delving into the intricate web connecting environmental pollutants and this devastating neurological disorder, this comprehensive chapter takes a deep dive into their involvement as significant risk factors for Alzheimer’s disease. Furthermore, it explores the underlying molecular mechanisms through which these contaminants exert their influence, aiming to unravel the complex interactions that drive the pathogenesis of the disease. Additionally, this chapter proposes potential strategies to mitigate the detrimental effects of these environmental contaminants on brain health, with the ultimate goal of restoring and preserving typical cognitive function. Through this comprehensive exploration, we aim to enhance our understanding of the multifaceted relationship between neurotoxins and Alzheimer’s disease, providing a solid foundation for developing innovative in-vivo models and advancing our knowledge of the intricate pathological processes underlying this debilitating condition

    Computational Modeling Study of the Binding of Aging and Non-Aging Inhibitors with Neuropathy Target Esterase

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    Neuropathy target esterase (NTE) is a serine hydrolase with phospholipase B activity, which is involved in maintaining the homeostasis of phospholipids. It can be inhibited by aging inhibitors such as some organophosphorus (OP) compounds, which leads to delayed neurotoxicity with distal degeneration of axons. However, the detailed binding conformation of aging and non-aging inhibitors with NTE is not known. In this study, new computational models were constructed by using MODELLER 10.3 and AlphaFold2 to further investigate the inhibition mechanism of aging and non-aging compounds using molecular docking. The results show that the non-aging compounds bind the hydrophobic pocket much deeper than aging compounds and form the hydrophobic interaction with Phe1066. Therefore, the unique binding conformation of non-aging compounds may prevent the aging reaction. These important differences of the binding conformations of aging and non-aging inhibitors with NTE may help explain their different inhibition mechanism and the protection of non-aging NTE inhibitors against delayed neuropathy

    Differentiated Neurons Are More Vulnerable to Organophosphate and Carbamate Neurotoxicity than Undifferentiated Neurons Due to the Induction of Redox Stress and Accumulate Oxidatively-Damaged Proteins

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    Organophosphate (OP) and carbamate pesticides are toxic to pests through targeted inhibition of acetylcholinesterase (AChE). However, OPs and carbamates may be harmful to non-target species including humans and could induce developmental neurotoxicity if differentiated or differentiating neurons are particularly vulnerable to neurotoxicant exposures. Hence, this study compared the neurotoxicity of OPs, chlorpyrifos-oxon (CPO), and azamethiphos (AZO) and the carbamate pesticide, aldicarb, to undifferentiated versus differentiated SH-SY5Y neuroblastoma cells. OP and carbamate concentration-response curves for cell viability were undertaken using 3-(4,5 dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide (MTT) and lactate dehydrogenase (LDH) assays and cellular bioenergetic capacity assessed via quantitation of cellular ATP levels. Concentration-response curves for inhibition of cellular AChE activity were also generated and the production of reactive oxygen species (ROS) was monitored using a 2‚Ä≤,7‚Ä≤-dichlorofluorescein diacetate (DCFDA) assay. The OPs and aldicarb reduced cell viability, cellular ATP levels, and neurite outgrowth in a concentration-dependent fashion, from a threshold concentration of ‚Č•10 ¬ĶM. Neurotoxic potency was in the order AZO > CPO > aldicarb for undifferentiated cells but CPO > AZO > aldicarb for differentiated cells and this toxic potency of CPO reflected its more extensive induction of reactive oxygen species (ROS) and generation of carbonylated proteins that were characterized by western blotting. Hence, the relative neurotoxicity of the OPs and aldicarb in part reflects non-cholinergic mechanisms that are likely to contribute to developmental neurotoxicity

    Influence of prenatal chlorpyrifos exposure, APOE genotype and sex on neurodevelopmental disorders: behavioral and biochemical abnormalities in mice

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    L'√ļs massiu del pesticida clorpirif√≥s (CPF) pot desencadenar efectes perjudicials sobre la salut, en particular, en la poblaci√≥ en desenvolupament. En els darrers anys, s'ha associat l'increment en el diagn√≤stic dels trastorns de l'espectre autista (TEA) amb l'exposici√≥ a t√≤xics. D'altra banda, existeixen polimorfismes gen√®tics com el de l'apolipoproteina E (APOE) que influeixen en la resposta a factors ambientals. En aquesta tesis s'ha avaluat com l'exposici√≥ prenatal a CPF i el gentotip APOE contribueixen en les alteracions conductuals i bioqu√≠miques observades en els trastorns del neurodesenvolupament. Les femelles C57BL/6J i homozig√≤tiques pels al¬∑lels humans e3 i e4 es van exposar a trav√©s de la dieta a 0 o 1 mg/kg/dia de CPF des de el dia gestacional (DG) 12 al 18. A m√©s, un grup de femelles C57BL/6J es va exposar a 300 mg/kg/dia d'√†cid valporic (AVP) els DG 12 i 13, per mitj√† d'una injecci√≥ subcut√†nea. Un altre grup de C57BL/6J va ser exposar per v√≠a oral a 0 o 1 mg/kg/dia de CPF del dia postnatal 10 al 15. En els individus exposats prenatalment es va avaluar la cura de les cries i la qualitat del niu en les mares. Les habilitats comunicatives i el desenvolupament f√≠sic i motor durant el per√≠ode de lact√†ncia, i les conductes d'ansietat durant l'adolesc√®ncia, aix√≠ com l'expressi√≥ d'elements involucrats en el sistema GABAergic i glutamatergic. Les conductes socials es van avaluar en els ratolins adolescents exposats pre o postnatalment a CPF. En l'avaluaci√≥ de les habilitats comunicatives dels ratolins C57BL/6J, vam observar que els efectes provocats per l'exposici√≥ a CPF eren oposats als observats en l'exposici√≥ a AVP, per√≤ els dos tractaments van produir un retard en el desenvolupament f√≠sic, alteracions en les conductes socials i canvis en l'expressi√≥ d'elements GABAergics i glutamat√®rgics de manera dependent del sexe. A m√©s. al llarg de l'estudi es van observar diferencies del genotip APOE, a excepci√≥ de les conductes socials on ambd√≥s genotips van mostrar una fectaci√≥ del tractament de manera dependent del sexe. En general aquesta tesis q√ľestiona l'associaci√≥ entre el CPF i el TEA, i suggereix que les diferents isoformes d'apoE (apoE3 i apoE4) no s√≥n un factor de risc pel desenvolupament del trastorn.El uso masivo del pesticida clorpirifos (CPF) puede desencadenar efectos perjudiciales sobre la salud, en particular, en la poblaci√≥n en desarrollo. En los √ļltimos a√Īos, se ha asociado el incremento en el diagn√≥stico de los trastornos del espectro autista (TEA) con la exposici√≥n a t√≥xicos. Por otra parte, existen polimorfismos gen√©ticos como el de la apolipoprote√≠na E (APOE) que influyen en la respuesta a factores ambientales. En esta tesis se ha evaluado c√≥mo la exposici√≥n prenatal a CPF y el genotipo APOE contribuyen en las alteraciones conductuales y bioqu√≠micas observadas en los trastornos del neurodesarrollo. Las hembras C57BL/6J y homocig√≥ticas por los alelos humanos e3 y e4 se expusieron a trav√©s de la dieta a 0 o 1 mg/kg/d√≠a de CPF des de el d√≠a gestacional (DG) 12 al 18. Adem√°s, un grupo de hembras C57BL/6J se expusieron a 300 mg/kg/d√≠a de √°cido valproico (AVP) los DG 12 y 13, por medio de una inyecci√≥n subcut√°nea. Otro grupo de C57BL/6J se expuso por via oral a 0 o 1 mg/kg/d√≠a de CPF del d√≠a postnatal 10 a 15. En los individuos expuestos prenatalmente se evalu√≥ el cuidado de las cr√≠as y la calidad del nido en las madres. Las habilidades comunicativas y el desarrollo f√≠sico y motor durante el per√≠odo de lactancia, y las conductas de ansiedad durante la asolescencia, as√≠ como la expresi√≥n de elementos involucrados en el sistema GABAergico y glutamat√©rgico. Las conductas sociales se evaluaron en los ratones adolescentes expuestos pre o postnatalmente a CPF. En la evaluaci√≥n de las habilidades comunicativas de los ratones C57BL/6J observamos que los efectos provocados por la exposici√≥n a CPF eran opuestos a los observados en la exposici√≥n a AVP, pero ambos tratamientos produjeron un retraso en el desarrollo f√≠sico, alteraciones en las conductas sociales y cambios en la expressi√≥n de elementos GABAergicos y glutamat√©rgico de forma dependiente del sexo. Adem√°s, a lo largo del estudio, se observaron diferencias del genotipo APOE, a excepci√≥n de las conductas sociales donde ambos genotipos mostraron una afectaci√≥n del tratamiento de forma dependiente del sexo. En general, esta tesis cuestiona la asociaci√≥n entre el CPF y el TEA, y sugiere que las distintas isoformas de apoE (apoE3 y apoE4) no son un factor de riesgo para el desarrollo del trastorno.The massive use of the pesticide chlorpyrifos (CPF) can trigger detrimental health effects, specially, in the developing population. In recent years, the increase in the diagnosis of autism spectrum disorder (ASD) has been associated with exposure to toxics. On the other hand, there are genetic polymorphism such as that of apolipoprotein E (APOE) that influence the response to environmental factors. In this thesis we have evalauted how prenatal exposure to CPF and the APOE genotype contribute to the behavioral and biochemical alterations observed in neurodevelopmental disorders. Females C57BL/6J and homozygous for the human e3 and e4 alleles were exposed trough the diet to 0 or 1 mg/kg/day of CPF from gestational day (GD) 12 to 18. In addition, a group of C57BL/6J females were exposed to 300 mg/kg/day of valproic acid (VPA) on GD 12 and 13, by a subcutaneous injection. Another group of C57BL/6J mice was orally exposed to 0 or 1 mg/kg/day of CPF from postnatal day 10 to 15. Dams of mice prenatally exposed were evaluated in maternal care and nest quality. Communication skills and physical and motor development were evalauted during lactation period, and anxiety behavior during adolescence, as well as the expression of elements involved in the GABAergic and glutamatergic system. Social behavior was assessed in adolescent mice exposed pre or postnatally to CPF. The effects induced in communication skills by prenatal CPF exposure were opposite to those observed with VPA in C57BL/6J mice, but both treatments delayed physical development, altered social behavior and changed the expression of some GABAergic and glutamatergic elements in a sex-dependent manner. Moreover, throughout the study, we observed differences between APOE genotype, except for social behavior, where both genotypes showed an affectation of the treatment depending on sex. In general, this thesis questions the association between CPF and ASD, and suggests that the different apoE isoforms (apoE3 and apoE4) are not a risk factor for the development of the disorder

    Albumin Is a Component of the Esterase Status of Human Blood Plasma

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    open access articleThe esterase status of blood plasma can claim to be one of the universal markers of various diseases; therefore, it deserves attention when searching for markers of the severity of COVID-19 and other infectious and non-infectious pathologies. When analyzing the esterase status of blood plasma, the esterase activity of serum albumin, which is the major protein in the blood of mammals, should not be ignored. The purpose of this study is to expand understanding of the esterase status of blood plasma and to evaluate the relationship of the esterase status, which includes information on the amount and enzymatic activity of human serum albumin (HSA), with other biochemical parameters of human blood, using the example of surviving and deceased patients with confirmed COVID-19. In experiments in vitro and in silico, the activity of human plasma and pure HSA towards various substrates was studied, and the effect of various inhibitors on this activity was tested. Then, a comparative analysis of the esterase status and a number of basic biochemical parameters of the blood plasma of healthy subjects and patients with confirmed COVID-19 was performed. Statistically significant differences have been found in esterase status and biochemical indices (including albumin levels) between healthy subjects and patients with COVID-19, as well as between surviving and deceased patients. Additional evidence has been obtained for the importance of albumin as a diagnostic marker. Of particular interest is a new index, [Urea] x [MDA] x 1000/(BChEb x [ALB]), which in the group of deceased patients was 10 times higher than in the group of survivors and 26 times higher than the value in the group of apparently healthy elderly subjects
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