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1.
Chem Res Toxicol ; 37(5): 731-743, 2024 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-38634348

RESUMO

Acrylamide (ACR) is a common industrial contaminant with endocrine-disrupting toxicity. Numerous studies have indicated that females and diabetics are more sensitive to environmental contaminants. However, it remains unknown whether female diabetics are susceptible to ACR-induced toxicity and its potential mechanisms. Thus, the female ACR-exposure diabetic Balb/c mice model was established to address these issues. Results showed that ACR could induce liver injury in normal mice and cause more serious inflammatory cell infiltration, hepatocyte volume increase, and fusion in diabetic mice liver. Meanwhile, ACR could lead to exacerbation of diabetic symptoms in diabetic mice by disturbing the glucose and lipid metabolism in the liver, which mainly manifests as the accumulation of liver glycogen and liver lipids, the reduction of the activity/content of glycolytic and metabolizing enzyme as well as pentose phosphatase, upregulation of the gene expression in fatty acid transporter and gluconeogenesis, and downregulation of the gene expression in fatty acid synthesis and metabolism. Moreover, ACR exposure could induce oxidative stress, inflammation, and endoplasmic reticulum stress in the liver by a decrease in hepatic antioxidant enzyme activity and antioxidant content, an increase in inflammatory factor levels, and a change in the related protein expression of endoplasmic reticulum stress (ERS) and apoptosis-related pathways in diabetic mice. Statistical analysis results revealed that ACR-induced liver injury was highly correlated with inflammation and oxidative stress, and ERS and diabetic mice had a higher risk of liver injury than normal mice. Overall results suggested that female diabetic mice easily suffer from ACR-induced toxicity, and the reason was that ACR could induce further damage to the liver by worsening the condition of inflammation, oxidative stress, and ERS in the liver.


Assuntos
Acrilamida , Diabetes Mellitus Experimental , Estresse do Retículo Endoplasmático , Camundongos Endogâmicos BALB C , Animais , Feminino , Acrilamida/toxicidade , Estresse do Retículo Endoplasmático/efeitos dos fármacos , Camundongos , Diabetes Mellitus Experimental/metabolismo , Diabetes Mellitus Experimental/induzido quimicamente , Diabetes Mellitus Experimental/patologia , Fígado/efeitos dos fármacos , Fígado/metabolismo , Fígado/patologia , Doença Hepática Induzida por Substâncias e Drogas/metabolismo , Doença Hepática Induzida por Substâncias e Drogas/patologia , Estresse Oxidativo/efeitos dos fármacos
2.
Environ Res ; 243: 117870, 2024 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-38072111

RESUMO

The class of insecticides known as neonicotinoid insecticides has gained extensive application worldwide. Two characteristics of neonicotinoid pesticides are excellent insecticidal activity and a wide insecticidal spectrum for problematic insects. Neonicotinoid pesticides can also successfully manage pest insects that have developed resistance to other insecticide classes. Due to its powerful insecticidal properties and rapid plant absorption and translocation, dinotefuran, the most recent generation of neonicotinoid insecticides, has been widely used against biting and sucking insects. Dinotefuran has a wide range of potential applications and is often used globally. However, there is growing evidence that they negatively impact the biodiversity of organisms in agricultural settings as well as non-target organisms. The objective of this review is to present an updated summary of current understanding regarding the non-target effects of dinotefuran; we also enumerated nano- and bio-based mitigation and management strategies to reduce the impact of dinotefuran on non-target organisms and to pinpoint knowledge gaps. Finally, future study directions are suggested based on the limitations of the existing studies, with the goal of providing a scientific basis for risk assessment and the prudent use of these insecticides.


Assuntos
Guanidinas , Inseticidas , Animais , Inseticidas/toxicidade , Ecossistema , Neonicotinoides/toxicidade , Nitrocompostos/toxicidade , Insetos
3.
Gen Comp Endocrinol ; 350: 114469, 2024 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-38360373

RESUMO

Tetrabromobisphenol A bis(2-hydroxyethyl) ether (TBBPA-DHEE) is the major TBBPA derivative. It has been detected in different environmental samples. Previous studies show that TBBPA-DHEE caused neurotoxicity in rats. In this study, juvenile zebrafish were exposed to various concentrations of TBBPA-DHEE to ascertain the potential neurotoxicity of TBBPA-DHEE, the chemical, and its possible molecular mechanism of action. Behavioral analysis revealed that TBBPA-DHEE could significantly increase the swimming distance and speed in the 1.5 mg/L group compared to the control. In contrast, the swimming distance and speed were significantly reduced in the 0.05 and 0.3 mg/L groups, affecting learning, memory, and neurodevelopment. Similarly, TBBPA-DHEE exposure caused a concentration-dependent significant increase in the levels of excitatory neurotransmitters, namely, dopamine, norepinephrine, and epinephrine, which could be attributed to the change observed in zebrafish behavior. This demonstrates the neurotoxicity of TBBPA-DHEE on juvenile zebrafish. The concentration-dependent increase in the IBR value revealed by the IBR index reveals the noticeable neurotoxic effect of TBBPA-DHEE. Transcriptomic analysis shows that TBBPA-DHEE exposure activated the PPAR signaling pathways, resulting in a disturbance of fatty acid (FA) metabolism and changes in the transcript levels of genes involved in these pathways, which could lead to lipotoxicity and hepatotoxicity. Our findings demonstrate a distinct endocrine-disrupting response to TBBPA-DHEE exposure, possibly contributing to abnormal behavioral alterations. This study provides novel insights into underlying the mechanisms and effects of TBBPA-DHEE on aquatic organisms, which may be helpful forenvironmental/human health risk assessments of the emerging pollutant.


Assuntos
Retardadores de Chama , Peixe-Zebra , Humanos , Ratos , Animais , Peixe-Zebra/metabolismo , Éteres/análise , Éteres/metabolismo , Análise de Sequência de RNA , Retardadores de Chama/toxicidade , Retardadores de Chama/análise , Retardadores de Chama/metabolismo
4.
Pestic Biochem Physiol ; 204: 106098, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-39277407

RESUMO

Fenitrothion (FNT) is a common organophosphorus pesticide that is widely used in both agricultural and domestic pest control. FNT has been frequently detected in various environmental media, including the human body, and is a notable contaminant. Epidemiological investigations have recently shown the implications of exposure to FNT in the incidence of various metabolic diseases, such as diabetes mellitus in humans, indicating that FNT may be a potential endocrine disruptor. However, the effects of FNT exposure on glucose homeostasis and their underlying mechanisms in model organisms remain largely unknown, which may limit our understanding of the health risks of FNT. In this study, FNT (4 5, 90, 180, and 4 50 µM) exposure model of rat hepatocytes (Buffalo Rat Liver, BRL cells) was established to investigate the effects and potential mechanisms of its toxicity on glucose metabolism. Several key processes of glucose metabolism were detected in this study. The results showed significantly increased glucose levels in the culture medium and decreased glycogen content in the FNT-exposed BRL cells. The results of quantitative real-time PCR and enzymology showed the abnormal expression of genes and activity/content of glucose metabolic enzymes involved in glucose metabolism, which might promote gluconeogenesis and inhibit glucose uptake, glycolysis, and glycogenesis. Furthermore, gluconeogenesis and glycolytic were carried out in the mitochondrial membrane. The abnormal of mitochondrial membrane potential may be a potential mechanism underlying FNT-induced glucose metabolism disorder. In addition, the mRNA and protein expression implicated that FNT may disrupt glucose metabolism by inhibiting the AMPKα and IRS1/PI3K/AKT signaling pathways. In conclusion, results provide in vitro evidence that FNT can cause glucose metabolism disorder, which emphasizes the potential health risks of exposure to FNT in inducing diabetes mellitus.


Assuntos
Proteínas Quinases Ativadas por AMP , Fenitrotion , Glucose , Proteínas Substratos do Receptor de Insulina , Fosfatidilinositol 3-Quinases , Proteínas Proto-Oncogênicas c-akt , Transdução de Sinais , Animais , Ratos , Fenitrotion/toxicidade , Proteínas Proto-Oncogênicas c-akt/metabolismo , Proteínas Substratos do Receptor de Insulina/metabolismo , Transdução de Sinais/efeitos dos fármacos , Proteínas Quinases Ativadas por AMP/metabolismo , Fosfatidilinositol 3-Quinases/metabolismo , Glucose/metabolismo , Fígado/efeitos dos fármacos , Fígado/metabolismo , Hepatócitos/efeitos dos fármacos , Hepatócitos/metabolismo , Transtornos do Metabolismo de Glucose/induzido quimicamente , Transtornos do Metabolismo de Glucose/metabolismo , Inseticidas/toxicidade
5.
Environ Toxicol ; 39(9): 4397-4416, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-38808594

RESUMO

Decabrominated diphenyl ether (BDE-209) is a typical persistent organic pollutant that can cross the placental barrier, increasing the exposure risk for offspring. Norepinephrine (NE) from nerve terminals and acetylcholine (Ach) can bind to specific receptors on immune cells, inhibit the immune function of the body then cause immunotoxicity. However, whether maternal exposure to BDE-209 could lead to immunotoxicity in the offspring by acting on the sympathetic and parasympathetic nervous systems remains unclear. In view of this, the pregnancy and lactation rat BDE-209 exposure model was established and the results demonstrated that pregnancy and lactation BDE-209 exposure could induce immunotoxicity to female offspring via affecting immunopathology (hematological and biochemical parameters, organ indices, and spleen histopathological), decreasing humoral immunity (serum hemolysin, immunoglobulins, and cytokine productions), damaging cellular immunity (splenic lymphocytes and spleen cytokine productions), and restraining nonspecific immunity. Moreover, a dramatically significant correlation was observed between spleen nerve indices and immunity indices. Additionally, the mechanism revealed that maternal BDE-209 exposure caused offspring immunotoxicity through (1) activating MHC/PKCθ/NF-κB pathway; (2) promoting sympathetic nervous pathway, by upregulating the expression of ß2AR protein, which in turn elevating cAMP, following activate PKA and phosphorylate CREB, ultimately leading to immunotoxicity;(3) activating parasympathetic nerve pathway by reducing the binding with Ach and α7nAchR, upregulating the expression of JAK2 and phosphorylating STAT3, induced immunotoxicity of female offspring.


Assuntos
Éteres Difenil Halogenados , Exposição Materna , Efeitos Tardios da Exposição Pré-Natal , Animais , Feminino , Gravidez , Éteres Difenil Halogenados/toxicidade , Exposição Materna/efeitos adversos , Efeitos Tardios da Exposição Pré-Natal/imunologia , Efeitos Tardios da Exposição Pré-Natal/induzido quimicamente , Ratos , Baço/efeitos dos fármacos , Baço/imunologia , Sistema Nervoso Autônomo/efeitos dos fármacos , Ratos Sprague-Dawley , Poluentes Ambientais/toxicidade , Masculino , Citocinas/metabolismo
6.
J Environ Manage ; 354: 120312, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38340667

RESUMO

The increased use of antibiotics by humans for various purposes has left the environment polluted. Antibiotic pollution remediation is challenging because antibiotics exist in trace amounts and only highly sensitive detection techniques could be used to quantify them. Nevertheless, their trace quantity is not a hindrance to their transfer along the food chain, causing sensitization and the development of antibiotic resistance. Despite an increase in the literature on antibiotic pollution and the development and transfer of antibiotic-resistant genes (ARGs), little attention has been given to the behavior of antibiotics at the soil-solution interface and how this affects antibiotic adsorption-desorption interactions and subsequent uptake and transformation by plants. Thus, this review critically examines the interactions and possible degradation mechanisms of antibiotics in soil and the link between antibiotic soil-solution chemistry and uptake by plants. Also, different factors influencing antibiotic mobility in soil and the transfer of ARGs from one organism to another were considered. The mechanistic and critical analyses revealed that: (a) the charge characteristics of antibiotics at the soil-root interface determine whether they are adsorbed to soil or taken up by plants; (b) antibiotics that avoid soil colloids and reach soil pore water can be absorbed by plant roots, but their translocation to the stem and leaves depends on the ionic state of the molecule; (c) few studies have explored how plants adapt to antibiotic pollution and the transformation of antibiotics in plants; and (d) the persistence of antibiotics in cropland soils can be influenced by the content of soil organic matter, coexisting ions, and fertilization practices. Future research should focus on the soil/solution-antibiotic-plant interactions to reveal detailed mechanisms of antibiotic transformation by plants and whether plant-transformed antibiotics could be of environmental risk.


Assuntos
Antibacterianos , Poluentes do Solo , Humanos , Antibacterianos/metabolismo , Solo , Poluentes do Solo/química , Plantas/metabolismo , Poluição Ambiental/análise
7.
Environ Res ; 231(Pt 2): 115989, 2023 08 15.
Artigo em Inglês | MEDLINE | ID: mdl-37119838

RESUMO

In conjunction with global climate change, progressive ocean warming, and acclivity in pollution and anthropogenic eutrophication, the incidence of harmful algal blooms (HABs) and cyanobacterial harmful algal blooms (CHABs) continue to expand in distribution, frequency, and magnitude. Algal bloom-related toxins have been implicated in human health disorders and ecological dysfunction and are detrimental to the national and global economy. Biomonitoring programs based on traditional monitoring protocols were characterised by some limitations that can be efficiently overdone using the CRISPR/Cas technology. In the present review, the potential and challenges of exploiting the Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR)-Cas technology for early detection of HABs and CHABs-associated toxigenic species were analysed. Based on more than 30 scientific papers, the main results indicate the great potential of CRISPR/Cas technology for this issue, even if the high sensitivity detected for the Cas12 and Cas13 platforms represents a possible interference risk.


Assuntos
Monitoramento Biológico , Cianobactérias , Humanos , Sistemas CRISPR-Cas , Proliferação Nociva de Algas , Cianobactérias/genética , Poluição Ambiental
8.
Environ Res ; 206: 112594, 2022 04 15.
Artigo em Inglês | MEDLINE | ID: mdl-34973196

RESUMO

BFRs (brominated flame retardants) are a class of compounds that are added to or applied to polymeric materials to avoid or reduce the spread of fire. Tetrabromobisphenol A (TBBPA) is one of the known BFR used many in industries today. Due to its wide application as an additive flame retardant in commodities, TBBPA has become a common indoor contaminant. Recent researches have raised concerns about the possible hazardous effect of exposure to TBBPA and its derivatives in humans and wildlife. This review gives a thorough assessment of the literature on TBBPA and its derivatives, as well as environmental levels and human exposure. Several analytical techniques/methods have been developed for sensitive and accurate analysis of TBBPA and its derivatives in different compartments. These chemicals have been detected in practically every environmental compartment globally, making them a ubiquitous pollutant. TBBPA may be subject to adsorption, biological degradation or photolysis, photolysis after being released into the environment. Treatment of TBBPA-containing waste, as well as manufacturing and usage regulations, can limit the release of these chemicals to the environment and the health hazards associated with its exposure. Several methods have been successfully employed for the treatment of TBBPA including but not limited to adsorption, ozonation, oxidation and anaerobic degradation. Previous studies have shown that TBBPA and its derivative cause a lot of toxic effects. Diet and dust ingestion and have been identified as the main routes of TBBPA exposure in the general population, according to human exposure studies. Toddlers are more vulnerable than adults to be exposed to indoor dust through inadvertent ingestion. Furthermore, TBBP-A exposure can occur during pregnancy and through breast milk. This review will go a long way in closing up the knowledge gap on the silent and over ignored deadly effects of TBBPA and its derivatives and their attendant consequences.


Assuntos
Poluentes Ambientais , Retardadores de Chama , Bifenil Polibromatos , Adulto , Poeira/análise , Poluentes Ambientais/análise , Poluentes Ambientais/toxicidade , Retardadores de Chama/análise , Retardadores de Chama/toxicidade , Humanos , Bifenil Polibromatos/análise , Bifenil Polibromatos/toxicidade
9.
J Environ Manage ; 322: 116123, 2022 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-36063698

RESUMO

Marine oil spills emanating from wells, pipelines, freighters, tankers, and storage facilities draw public attention and necessitate quick and environmentally friendly response measures. It is sometimes feasible to contain the oil with booms and collect it with skimmers or burn it, but this is impracticable in many circumstances, and all that can be done without causing further environmental damage is adopting natural attenuation, particularly through microbial biodegradation. Biodegradation can be aided by carefully supplying biologically accessible nitrogen and phosphorus to alleviate some of the microbial growth constraints at the shoreline. This review discussed the characteristics of oil spills, origin, ecotoxicology, health impact of marine oils spills, and responses, including the variety of remedies and responses to oil spills using biological techniques. The different bioremediation and bio-dispersant treatment technologies are then described, with a focus on the use of green surfactants and their advances, benefits/drawbacks. These technologies were thoroughly explained, with a timeline of research and recent studies. Finally, the hurdles that persist as a result of spills are explored, as well as the measures that must be taken and the potential for the development of existing treatment technologies, all of which must be linked to the application of integrated procedures.


Assuntos
Poluição por Petróleo , Petróleo , Poluentes Químicos da Água , Biodegradação Ambiental , Nitrogênio , Óleos , Petróleo/metabolismo , Poluição por Petróleo/análise , Fósforo , Água do Mar , Tensoativos , Poluentes Químicos da Água/análise
10.
J Sci Food Agric ; 102(6): 2526-2537, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-34676564

RESUMO

BACKGROUND: Selenium (Se)-enriched glycoproteins have been a research highlight for the role of both Se and glycoproteins in immunoregulation. Arsenic (As) is a toxicant that is potentially toxic to the immune function and consequently to human health. Several reports suggested that Se could reduce the toxicity of heavy metals. Moreover, more and more nutrients in food had been applied to relieve As-induced toxicity. Hence glycoproteins were isolated and purified from Se-enriched Grifola frondosa, and their preliminary characteristics as well as amelioration effect and mechanism on As3+ -induced immune toxicity were evaluated. RESULTS: Four factions, namely Se-GPr11 (electrophoresis analysis exhibited one band: 14.32 kDa), Se-GPr22 (two bands: 20.57 and 31.12 kDa), Se-GPr33 (three bands: 15.08, 20.57 and 32.78 kDa) and Se-GPr44 (three bands: 16.73, 32.78 and 42.46 kDa), were obtained from Se-enriched G. frondosa via DEAE-52 and Sephacryl S-400 column. In addition, Se-GPr11 and Se-GPr44 are ideal proteins that contain high amounts of almost all essential amino acids. Thereafter, the RAW264.7 macrophage model was adopted to estimate the effect of Se-GPr11 and Se-GPr44 on As3+ -induced immune toxicity. The results showed that the pre-intervention method was the best consequent and the potential mechanisms were, first, by improving the oxidative stress state (enhancing the activity of superoxide dismutase and glutathione peroxidase, decreasing the levels of reactive oxygen species and malondialdehyde); secondly, through nuclear factor-κB and mitogen-activated protein kinase-mediated upregulation cytokines (interleukin-2 and interferon-γ) secretion induced by As3+ . CONCLUSION: The results suggested Se-enriched G. frondosa may be a feasible supplement to improve health level of the As3+ pollution population. © 2021 Society of Chemical Industry.


Assuntos
Arsênio , Grifola , Selênio , Glutationa Peroxidase/metabolismo , Glicoproteínas/farmacologia , Grifola/química , Grifola/metabolismo , Humanos , Selênio/metabolismo
11.
J Environ Manage ; 292: 112758, 2021 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-34030015

RESUMO

This paper presents a review of synthetic polymer (notably plastic) wastes profiles in Africa, their current management status, and better options. Data revealed that of the approximated 86.14 million metric tonnes and 31.5 million metric tonnes of primary polymers and plastics, respectively, and an estimated 230 million metric tonnes of plastic components imported between 1990 and 2017, about 17 million metric tonnes are mismanaged. Leading African nations on the plastic wastes generator table in increasing order are Tunisia (6.9%), Morocco (9.6%), Algeria (11.2%), South Africa (11.6%), Nigeria (16.9%), and the chief is Egypt (18.4%). The volume of plastic wastes generated in Africa directly correlates with her increasing population status, however, the current treatment options have major drawbacks (high energy and technological input, high demand for space, and creation of obnoxious by-products). Ineffective regulations, poor monitoring, and slow adoption of veritable practices by governments are responsible for the steady increase in plastic volume in the African landscapes and environments. In Nigeria, only about 9% and 12% of the total generated wastes are recycled and incinerated. The remainder bulk is either discarded into waste dumps (and a few available landfills) or natural environments. There is a paucity of standard plastic biodegradative work by African scientists, and only a few works show detection of competent synthetic plastic degrading microbes globally. Asides from the ills of possible omission of core degraders, there is a need for researchers to follow standard degradation procedures to arrive at efficient, reproducible, and generally accepted outcomes utilizable on a larger scale. Thus, metagenomic search on the vast African urban and rural plastisphere is the best isolation option.


Assuntos
Plásticos , Gerenciamento de Resíduos , Egito , Marrocos , Nigéria , África do Sul , Tunísia
12.
Biochem J ; 473(6): 757-67, 2016 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-26759379

RESUMO

Disconnection of a cell from its epithelial neighbours and the formation of a mesenchymal phenotype are associated with profound changes in the distribution of cellular components and the formation of new cellular polarity. We observed a dramatic redistribution of inositol trisphosphate receptors (IP3Rs) and stromal interaction molecule 1 (STIM1)-competent endoplasmic reticulum-plasma membrane junctions (ER-PM junctions) when pancreatic ductal adenocarcinoma (PDAC) cells disconnect from their neighbours and undergo individual migration. In cellular monolayers IP3Rs are juxtaposed with tight junctions. When individual cells migrate away from their neighbours IP3Rs preferentially accumulate at the leading edge where they surround focal adhesions. Uncaging of inositol trisphosphate (IP3) resulted in prominent accumulation of paxillin in focal adhesions, highlighting important functional implications of the observed novel structural relationships. ER-PM junctions and STIM1 proteins also migrate to the leading edge and position closely behind the IP3Rs, creating a stratified distribution of Ca(2+) signalling complexes in this region. Importantly, migration of PDAC cells was strongly suppressed by selective inhibition of IP3Rs and store-operated Ca(2+) entry (SOCE), indicating that these mechanisms are functionally required for migration.


Assuntos
Sinalização do Cálcio/fisiologia , Membrana Celular/fisiologia , Movimento Celular/fisiologia , Retículo Endoplasmático/fisiologia , Transição Epitelial-Mesenquimal/fisiologia , Receptores de Inositol 1,4,5-Trifosfato/metabolismo , Animais , Canais de Cálcio/genética , Canais de Cálcio/metabolismo , Adesão Celular , Linhagem Celular Tumoral , Regulação da Expressão Gênica/fisiologia , Técnicas de Silenciamento de Genes , Transporte Proteico , Molécula 1 de Interação Estromal
13.
Adv Exp Med Biol ; 993: 217-237, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28900917

RESUMO

The junctions between the endoplasmic reticulum and the plasma membrane are essential platforms for the activation of store-operated Ca2+ influx. These junctions have specific dimensions and are nonuniformly distributed in polarized cells. The mechanisms involved in the formation of the junctions are currently undergoing vigorous investigation, and significant progress was attained in this research area during the last 10 years. Some cell types display stationary junctions, while in other cells, new junctions can form rapidly following cytosolic Ca2+ signals and/or the reduction of the Ca2+ concentration in the lumen of the endoplasmic reticulum; furthermore, in moving cells, junctions can undergo saltatory formation, long distance sliding, and dissolution. The proteins involved in the activation of the Ca2+ influx could be also involved in the formation of the junctions. The architecture, dynamics, and localization of the junctions are important for the regulation of Ca2+ signaling cascades and their downstream events.


Assuntos
Canais de Cálcio/metabolismo , Sinalização do Cálcio/fisiologia , Cálcio/metabolismo , Membrana Celular/metabolismo , Retículo Endoplasmático/metabolismo , Junções Intercelulares/metabolismo , Animais , Humanos
14.
J Physiol ; 594(11): 2837-47, 2016 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-26939537

RESUMO

Endoplasmic reticulum (ER)-plasma membrane (PM) junctions are contact sites between the ER and the PM; the distance between the two organelles in the junctions is below 40 nm and the membranes are connected by protein tethers. A number of molecular tools and technical approaches have been recently developed to visualise, modify and characterise properties of ER-PM junctions. The junctions serve as the platforms for lipid exchange between the organelles and for cell signalling, notably Ca(2+) and cAMP signalling. Vice versa, signalling events regulate the development and properties of the junctions. Two Ca(2+) -dependent mechanisms of de novo formation of ER-PM junctions have been recently described and characterised. The junction-forming proteins and lipids are currently the focus of vigorous investigation. Junctions can be relatively short-lived and simple structures, forming and dissolving on the time scale of a few minutes. However, complex, sophisticated and multifunctional ER-PM junctions, capable of attracting numerous protein residents and other cellular organelles, have been described in some cell types. The road from simplicity to complexity, i.e. the transformation from simple 'nascent' ER-PM junctions to advanced stable multiorganellar complexes, is likely to become an attractive research avenue for current and future junctologists. Another area of considerable research interest is the downstream cellular processes that can be activated by specific local signalling events in the ER-PM junctions. Studies of the cell physiology and indeed pathophysiology of ER-PM junctions have already produced some surprising discoveries, likely to expand with advances in our understanding of these remarkable organellar contact sites.


Assuntos
Membrana Celular/química , Membrana Celular/fisiologia , Retículo Endoplasmático/química , Retículo Endoplasmático/fisiologia , Junções Intercelulares/química , Junções Intercelulares/fisiologia , Animais , Humanos
15.
Proc Natl Acad Sci U S A ; 109(17): 6572-7, 2012 Apr 24.
Artigo em Inglês | MEDLINE | ID: mdl-22493256

RESUMO

A long-standing paradigm in cell biology is the shutdown of endocytosis during mitosis. There is consensus that transferrin uptake is inhibited after entry into prophase and that it resumes in telophase. A recent study proposed that endocytosis is continuous throughout the cell cycle and that the observed inhibition of transferrin uptake is due to a decrease in available transferrin receptor at the cell surface, and not to a shutdown of endocytosis. This challenge to the established view is gradually becoming accepted. Because of this controversy, we revisited the question of endocytic activity during mitosis. Using an antibody uptake assay and controlling for potential changes in surface receptor density, we demonstrate the strong inhibition of endocytosis in mitosis of CD8 chimeras containing any of the three major internalization motifs for clathrin-mediated endocytosis (YXXΦ, [DE]XXXL[LI], or FXNPXY) or a CD8 protein with the cytoplasmic tail of the cation-independent mannose 6-phosphate receptor. The shutdown is not gradual: We describe a binary switch from endocytosis being "on" in interphase to "off" in mitosis as cells traverse the G(2)/M checkpoint. In addition, we show that the inhibition of transferrin uptake in mitosis occurs despite abundant transferrin receptor at the surface of HeLa cells. Our study finds no support for the recent idea that endocytosis continues during mitosis, and we conclude that endocytosis is temporarily shutdown during early mitosis.


Assuntos
Clatrina/fisiologia , Endocitose/fisiologia , Mitose/fisiologia , Citometria de Fluxo , Imunofluorescência , Células HeLa , Humanos , Microscopia de Fluorescência , Receptores da Transferrina/metabolismo
16.
Biochem J ; 451(1): 25-32, 2013 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-23323887

RESUMO

We demonstrated three novel forms of dynamic behaviour of junctions between the ER (endoplasmic reticulum) and the PM (plasma membrane) in migrating cancer cells: saltatory formation, long-distance sliding and dissolution. The individual ER-PM junctions formed near the leading edge of migrating cells (usually within 0.5 µm of polymerized actin and close to focal adhesions) and appeared suddenly without sliding from the interior of the cell. The long distance sliding and dissolution of ER-PM junctions accompanied the tail withdrawal.


Assuntos
Membrana Celular/metabolismo , Movimento Celular , Retículo Endoplasmático/metabolismo , Adesões Focais/metabolismo , Neoplasias/metabolismo , Linhagem Celular Tumoral , Membrana Celular/patologia , Retículo Endoplasmático/patologia , Adesões Focais/patologia , Humanos , Neoplasias/patologia
17.
Toxicology ; 506: 153848, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38825032

RESUMO

Polybrominated diphenyl ethers (PBDEs) are persistent contaminants used as flame retardants in electronic products. PBDEs are contaminants of concern due to leaching and recalcitrance conferred by the stable and hydrophobic bromide residues. The near absence of legislatures and conscious initiatives to tackle the challenges of PBDEs in Africa has allowed for the indiscriminate use and consequent environmental degradation. Presently, the incidence, ecotoxicity, and remediation of PBDEs in Africa are poorly elucidated. Here, we present a position on the level of contamination, ecotoxicity, and management strategies for PBDEs with regard to Africa. Our review shows that Africa is inundated with PBDEs from the proliferation of e-waste due to factors like the increasing growth in the IT sector worsened by the procurement of second-hand gadgets. An evaluation of the fate of PBDEs in the African environment reveals that the environment is adequately contaminated, although reported in only a few countries like Nigeria and Ghana. Ultrasound-assisted extraction, microwave-assisted extraction, and Soxhlet extraction coupled with specific chromatographic techniques are used in the detection and quantification of PBDEs. Enormous exposure pathways in humans were highlighted with health implications. In terms of the removal of PBDEs, we found a gap in efforts in this direction, as not much success has been reported in Africa. However, we outline eco-friendly methods used elsewhere, including microbial degradation, zerovalent iron, supercritical fluid, and reduce, reuse, recycle, and recovery methods. The need for Africa to make and implement legislatures against PBDEs holds the key to reduced effect on the continent.


Assuntos
Resíduo Eletrônico , Éteres Difenil Halogenados , Éteres Difenil Halogenados/toxicidade , Éteres Difenil Halogenados/análise , África , Humanos , Retardadores de Chama/toxicidade , Poluentes Ambientais/toxicidade , Animais , Monitoramento Ambiental/métodos , Ecotoxicologia/métodos
18.
Sci Total Environ ; 927: 172308, 2024 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-38599396

RESUMO

Despite the diverse research into the environmental impact of plastics, several stones have yet to be unraveled in terms of their ecotoxicological potential. Moreover, their detrimental impacts have become terrifying in recent years as the understanding of their tendency to associate and form cohorts with other emerging contaminants grew. Despite the hypothesis that microplastics may potentially adsorb organic pollutants, sequestering and making them not bioavailable for enhanced toxicity, evidence with pollutants such as Tetrabromobisphenol A (TBBPA) defers this assertion. TBBPA, one of the most widely used brominated flame retardants, has been enlisted as an emerging contaminant of serious environmental and human health concerns. Being also an additive to plasticware, it is not far to suspect that TBBPA could be found in association with micro/nanoplastics in our environment. Several pieces of evidence from recent studies have confirmed the micro/nanoplastics-TBBPA association and have exposed their compounded detrimental impacts on the environment and human health. This study, therefore, presents a comprehensive and up-to-date review of recent findings regarding their occurrence, factors that foster their association, including their sorption kinetics and isotherms, and their impacts on aquatic/agroecosystem and human health. The way forward and prospects for future studies were presented. This research is believed to be of significant interest to the readership due to its relevance to current environmental challenges posed by plastics and TBBPA. The study not only contributes valuable insights into the specific interaction between micro/nanoplastics and TBBPA but also suggests the way forward and prospects for future studies in this field.


Assuntos
Ecotoxicologia , Poluentes Ambientais , Microplásticos , Bifenil Polibromatos , Humanos , Monitoramento Ambiental , Retardadores de Chama
19.
Chemosphere ; 364: 143168, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-39181463

RESUMO

Per- and polyfluoroalkyl substances (PFAS) are rampant, toxic contaminants from anthropogenic sources, called forever chemicals for their recalcitrance. Although banned in several parts of the world for public health implications, including liver, kidney, and testicular diseases, PFAS are abundant in water sources due to easy dispersion. With chemical properties resulting from strong hydrophobic bonds, they defile many physicochemical removal methods. Though adsorption processes such as granular activated carbon (GAC) are widely used, they are marred by several limitations, including cost and secondary contamination. Thus, eco-friendly methods involving a synergy of the removal principles have been preferred for ease of use, cost-effectiveness, and near-zero effect on the environment. We present novel eco-friendly methods as the solution to PFAS remediation towards environmental sustainability. Current eco-friendly methods of PFAS removal from water sources, including electrocoagulation, membrane/filtration, adsorption, and phytoremediation methods, were highlighted, although with limitations. Novel eco-friendly methods such as microbial fuel cells, photoelectrical cells, and plasma treatment offer solutions to PFAS remediation and are quite efficient in terms of cost, result, and environmental sustainability. Overall, the successful integration of eco-friendly techniques in a seamless manner ensures the desired result. We also present a balanced position on the ecosystem impact of these ecofriendly methods, noting the successes towards environmental sustainability while exposing the gaps for further research.


Assuntos
Fluorocarbonos , Águas Residuárias , Poluentes Químicos da Água , Poluentes Químicos da Água/análise , Poluentes Químicos da Água/química , Águas Residuárias/química , Fluorocarbonos/química , Fluorocarbonos/análise , Purificação da Água/métodos , Adsorção , Biodegradação Ambiental , Recuperação e Remediação Ambiental/métodos
20.
Heliyon ; 10(11): e32673, 2024 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-38912509

RESUMO

Protein engineering mechanisms can be an efficient approach to enhance the biochemical properties of various biocatalysts. Immobilization of biocatalysts and the introduction of new-to-nature chemical reactivities are also possible through the same mechanism. Discovering new protocols that enhance the catalytic active protein that possesses novelty in terms of being stable, active, and, stereoselectivity with functions could be identified as essential areas in terms of concurrent bioorganic chemistry (synergistic relationship between organic chemistry and biochemistry in the context of enzyme engineering). However, with our current level of knowledge about protein folding and its correlation with protein conformation and activities, it is almost impossible to design proteins with specific biological and physical properties. Hence, contemporary protein engineering typically involves reprogramming existing enzymes by mutagenesis to generate new phenotypes with desired properties. These processes ensure that limitations of naturally occurring enzymes are not encountered. For example, researchers have engineered cellulases and hemicellulases to withstand harsh conditions encountered during biomass pretreatment, such as high temperatures and acidic environments. By enhancing the activity and robustness of these enzymes, biofuel production becomes more economically viable and environmentally sustainable. Recent trends in enzyme engineering have enabled the development of tailored biocatalysts for pharmaceutical applications. For instance, researchers have engineered enzymes such as cytochrome P450s and amine oxidases to catalyze challenging reactions involved in drug synthesis. In addition to conventional methods, there has been an increasing application of machine learning techniques to identify patterns in data. These patterns are then used to predict protein structures, enhance enzyme solubility, stability, and function, forecast substrate specificity, and assist in rational protein design. In this review, we discussed recent trends in enzyme engineering to optimize the biochemical properties of various biocatalysts. Using examples relevant to biotechnology in engineering enzymes, we try to expatiate the significance of enzyme engineering with how these methods could be applied to optimize the biochemical properties of a naturally occurring enzyme.

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