ABSTRACT
Mitochondrial carriers (MCs) belong to a eukaryotic protein family of transporters that in higher organisms is called the solute carrier family 25 (SLC25). All MCs have characteristic triplicated sequence repeats forming a 3-fold symmetrical structure of a six-transmembrane α-helix bundle with a centrally located substrate-binding site. Biochemical characterization has shown that MCs altogether transport a wide variety of substrates but can be divided into subfamilies, each transporting a few specific substrates. We have investigated the intron positions in the human MC genes and their orthologs of highly diversified organisms. The results demonstrate that several intron positions are present in numerous MC sequences at the same specific points, of which some are 3-fold symmetry related. Many of these frequent intron positions are also conserved in subfamilies or in groups of subfamilies transporting similar substrates. The analyses of the frequent and conserved intron positions in MCs suggest phylogenetic relationships not only between close but also distant homologs as well as a possible involvement of the intron positions in the evolution of the substrate specificity diversification of the MC family members.
Subject(s)
Membrane Transport Proteins , Mitochondria , Humans , Introns , Phylogeny , Mitochondria/genetics , Mitochondria/metabolism , Membrane Transport Proteins/genetics , Eukaryota/genetics , Evolution, Molecular , Conserved SequenceABSTRACT
In recent years, there has been considerable research showing that coffee consumption seems to be beneficial to human health, as it contains a mixture of different bioactive compounds such as chlorogenic acids, caffeic acid, alkaloids, diterpenes and polyphenols. Neurodegenerative diseases (NDs) are debilitating, and non-curable diseases associated with impaired central, peripheral and muscle nervous systems. Several studies demonstrate that neuroinflammation mediated by glial cells-such as microglia and astrocytes-is a critical factor contributing to neurodegeneration that causes the dysfunction of brain homeostasis, resulting in a progressive loss of structure, function, and number of neuronal cells. This happens over time and leads to brain damage and physical impairment. The most known chronic NDs are represented by Alzheimer's disease (AD), Parkinson's disease (PD), multiple sclerosis (MS), amyotrophic lateral sclerosis (ALS) and Huntington's disease (HD). According to epidemiological studies, regular coffee consumption is associated with a lower risk of neurodegenerative diseases. In this review, we summarize the latest research about the potential effects of caffeine in neurodegenerative disorders prevention and discuss the role of controlled caffeine delivery systems in maintaining high plasma caffeine concentrations for an extended time.
Subject(s)
Neurodegenerative Diseases , Humans , Caffeine/pharmacology , Coffee , Neurodegenerative Diseases/etiology , Neuroinflammatory DiseasesABSTRACT
Inflammaging is a term used to describe the tight relationship between low-grade chronic inflammation and aging that occurs during physiological aging in the absence of evident infection. This condition has been linked to a broad spectrum of age-related disorders in various organs including the brain. Inflammaging represents a highly significant risk factor for the development and progression of age-related conditions, including neurodegenerative diseases which are characterized by the progressive dysfunction and degeneration of neurons in the brain and peripheral nervous system. Curcumin is a widely studied polyphenol isolated from Curcuma longa with a variety of pharmacologic properties. It is well-known for its healing properties and has been extensively used in Asian medicine to treat a variety of illness conditions. The number of studies that suggest beneficial effects of curcumin on brain pathologies and age-related diseases is increasing. Curcumin is able to inhibit the formation of reactive-oxygen species and other pro-inflammatory mediators that are believed to play a pivotal role in many age-related diseases. Curcumin has been recently proposed as a potential useful remedy against neurodegenerative disorders and brain ageing. In light of this, our current review aims to discuss the potential positive effects of Curcumin on the possibility to control inflammaging emphasizing the possible modulation of inflammaging processes in neurodegenerative diseases.
Subject(s)
Aging , Anti-Inflammatory Agents, Non-Steroidal/pharmacology , Brain/drug effects , Curcumin/pharmacology , Inflammation/drug therapy , Microglia/drug effects , Neurodegenerative Diseases/drug therapy , Animals , Brain/immunology , Brain/pathology , Humans , Inflammation/immunology , Inflammation/pathology , Microglia/immunology , Microglia/pathology , Neurodegenerative Diseases/immunology , Neurodegenerative Diseases/pathologyABSTRACT
The "canonical" introns begin by the dinucleotide GT and end by the dinucleotide AG. GT, together with a few downstream nucleotides, and AG, with a few of the immediately preceding nucleotides, are thought to be the strongest splicing signals (5'ss and 3'ss, respectively). We examined the composition of the intronic initial and terminal hexanucleotides of the mitochondrial solute carrier genes (SLC25A's) of zebrafish, chicken, mouse, and human. These genes are orthologous and we selected the transcripts in which the arrangement of exons and introns was superimposable in the species considered. Both 5'ss and 3'ss were highly polymorphic, with 104 and 126 different configurations, respectively, in our sample. In the line of evolution from zebrafish to chicken, as well as in that from zebrafish to mammals, the average nucleotide conservation in the four variable nucleotides was about 50 % at 5' and 40 % at 3'. In the divergent evolution of mouse and human, the conservation was about 80 % at 5' and 70 % at 3'. Despite these changes, the splicing signals remain strong enough to operate at the same site. At both 5' and 3', the frequency of a nucleotide at a given position in the zebrafish sequence is positively correlated with its conservation in chicken and mammals, suggesting that selection continued to operate in birds and mammals along similar lines.
Subject(s)
Anion Transport Proteins/genetics , RNA Splicing , Vertebrates/genetics , Animals , Base Sequence , Chickens , Consensus Sequence , Evolution, Molecular , Exons , Genes, Mitochondrial , Humans , Introns , Mice , Mitochondrial Proteins/genetics , Mutation , Nucleotides/genetics , RNA Splice Sites , ZebrafishABSTRACT
HHH syndrome is an autosomal recessive urea cycle disorder caused by alterations in the SLC25A15 gene encoding the mitochondrial ornithine carrier 1, which catalyzes the transport of cytosolic ornithine into the mitochondria in exchange for intramitochondrial citrulline. In this study the functional effects of several SLC25A15 missense mutations p.G27R, p.M37R, p.N74A, p.F188L, p.F188Y, p.S200K, p.R275Q and p.R275K have been tested by transport assays in reconstituted liposomes and complementation of Saccharomyces cerevisiae ORT1 null mutant in arginine-less synthetic complete medium. The HHH syndrome-causing mutations p.G27R, p.M37R, p.F188L and p.R275Q had impaired transport and did not complement ORT1∆ cells (except p.M37R slightly after 5 days in solid medium). The experimentally produced mutations p.N74A, p.S200K and p.R275K exhibited normal or considerable transport activity and complemented ORT1∆ cells after 3 days (p.N74A, p.S200K) or 5 days (p.R275K) incubation. Furthermore, the experimentally produced p.F188Y mutation displayed a substantial transport activity but did not complement the ORT1∆ cells in both liquid and solid media. In view of the disagreement in the results obtained between the two methods, it is recommended that the method of complementing the S. cerevisiae ORT1 knockout strain is used complimentary with the measurement of the catalytic activity, in order to distinguish HHH syndrome-causing mutations from isomorphisms.
Subject(s)
Amino Acid Transport Systems, Basic/genetics , Amino Acid Transport Systems, Basic/metabolism , Mitochondrial Membrane Transport Proteins/genetics , Saccharomyces cerevisiae Proteins/genetics , Saccharomyces cerevisiae/genetics , Arginine , Biological Transport , Culture Media , Escherichia coli/genetics , Genetic Complementation Test , Humans , Hyperammonemia/genetics , Liposomes/metabolism , Mutation, Missense , Ornithine/deficiency , Ornithine/genetics , Recombinant Proteins , Saccharomyces cerevisiae/growth & development , Urea Cycle Disorders, Inborn/geneticsABSTRACT
BACKGROUND/AIMS: Gastrointestinal damage (GD) is commonly associated with the inhibition of cyclooxygenase (COX)-1, one of the two known COXs, by traditional non-steroidal anti-inflammatory drugs. More recent evidences have proven that GD is caused by the simultaneous inhibition of the two COXs. This study was designed to evaluate the effect of the selective COX-1 inhibition on gastric integrity. METHODS: GD was evaluated in male CD1 mice. Drugs were administered by gastric gavage at a dose of 50 mg/kg (injection volume of 100 µl). Control mice received an equal volume of the vehicle (10% ethanol). Each mouse, in groups of at least 6 mice, received one dose/day for 5 days. RESULTS: In Western blot analysis, COX-1 expression levels were found to be significantly reduced in mice treated with 3-(5-chlorofuran-2-yl)-5-methyl-4-phenylisoxazole (P6) in comparison to mice pretreated with aspirin (ASA), which exhibited higher levels of COX-1, thus confirming the high selectivity of P6 towards COX-1 enzyme inhibition. Mucosal sections obtained from ASA-treated mice showed breaks in the epithelial barrier and a marked alteration of foveolae and gastric glands, whereas stomachs isolated from mice sacrificed after 5 days of chronic administration of P6 (at a dose of up to 50 mg/kg/day) showed sporadic transient mucosal hyperemia and did not seem to display any significant gastric damage. CONCLUSIONS: The selective COX-1 inhibition by P6 does not cause gastric damage in mice but preserves mucosal integrity.
Subject(s)
Cyclooxygenase Inhibitors/pharmacology , Ethylene Glycols/pharmacology , Salicylates/pharmacology , Animals , Aspirin/toxicity , Cyclooxygenase 1/metabolism , Cyclooxygenase 2/metabolism , Dinoprostone/metabolism , Gastric Mucosa/drug effects , Gastric Mucosa/metabolism , Gastric Mucosa/pathology , Male , Membrane Proteins/metabolism , MiceABSTRACT
Inflammatory skin diseases include a series of disorders characterized by a strong activation of the innate and adaptive immune system in which proinflammatory cytokines play a fundamental role in supporting inflammation. Skin inflammation is a complex process influenced by various factors, including genetic and environmental factors, characterized by the dysfunction of both immune and non-immune cells. Psoriasis (PS) and atopic dermatitis (AD) are the most common chronic inflammatory conditions of the skin whose pathogeneses are very complex and multifactorial. Both diseases are characterized by an immunological dysfunction involving a predominance of Th1 and Th17 cells in PS and of Th2 cells in AD. Suppressor of cytokine signaling (SOCS) proteins are intracellular proteins that control inflammatory responses by regulating various signaling pathways activated by proinflammatory cytokines. SOCS signaling is involved in the regulation and progression of inflammatory responses in skin-resident and non-resident immune cells, and recent data suggest that these negative modulators are dysregulated in inflammatory skin diseases such as PS and AD. This review focuses on the current understanding about the role of SOCS proteins in modulating the activity of inflammatory mediators implicated in the pathogenesis of inflammatory skin diseases such as PS and AD.
Subject(s)
Dermatitis, Atopic , Psoriasis , Humans , Suppressor of Cytokine Signaling Proteins/genetics , Suppressor of Cytokine Signaling Proteins/metabolism , Signal Transduction/genetics , Cytokines/metabolism , InflammationABSTRACT
Key Clinical Message: Creutzfeldt-Jakob disease is a neurodegenerative disorder caused by brain accumulation of a misfolded form of the cellular prion protein, whose diagnosis is challenging, particularly in early stages, due to the variability and nonspecificity of the clinical and radiological features. 18F-fluorodeoxyglucose positron-emitted tomography has the potential to be considered a crucial investigation in these patients, revealing metabolic abnormalities earlier than the conventional neuroimaging analysis. Abstract: A 59-year-old man, the military officer, was referred to our Units for the onset of neurological symptoms rapidly evolving within a month, characterized by akinetic mutism, constructional apraxia, and disorders of spatial orientation. Brain 18F-fluorodeoxyglucose (18F-FDG) positron-emitted tomography (PET)/CT depicted an asymmetric hypometabolism in the left fronto-temporo-parietal cortex, as well as in the left thalamus and the right cerebellar hemisphere, while the glucose metabolism appears to be preserved in the somatosensory cortex and the basal ganglia. Laboratory routine analyses, cerebrospinal fluid routine, infective tests, electroencephalography (EEG), and brain magnetic resonance (MR) were all unremarkable. A positive RT-QuIC result on cerebro-spinal fluid (CSF) was subsequently shown, without any pathogenic gene mutations and, therefore, the result was consistent with a diagnosis of sporadic Creutzfeld-Jacob disease. The clinical evolution was quickly unfavorable, and the patient died about 4 months after hospital admission. FDG PET/computed tomography (CT) has the potential to be considered a crucial investigation in these patients, documenting metabolic changes long time before other diagnostic investigations such as CSF, EEG, brain CT, and brain MR, thus suggesting a greater sensitivity of glucose metabolic evaluation in the early stage of the disease in question.
ABSTRACT
BACKGROUND: The prolonged activation of microglia and excessive production of pro-inflammatory cytokines can lead to chronic neuroinflammation, which is an important pathological feature of Parkinson's disease (PD). We have previously reported the protective effect of Vitamin C (Vit C) on a mouse model of PD. However, its effect on microglial functions in neuroinflammation remains to be clarified. Glycogen synthase kinase 3ß (GSK3ß) is a serine/threonine kinase having a role in driving inflammatory responses, making GSK3ß inhibitors a promising target for anti-inflammatory research. METHODS: In this study, we investigated the possible involvement of GSK3ß in Vit C neuroprotective effects by using a well-known 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced animal model of PD and a cellular model of neuroinflammation, represented by Lipopolysaccharide (LPS)-activated BV-2 microglial cells. RESULTS: We demonstrated the ability of Vit C to decrease the expression of different mediators involved in the inflammatory responses, such as TLR4, p-IKBα, and the phosphorylated forms of p38 and AKT. In addition, we demonstrated for the first time that Vit C promotes the GSK3ß inhibition by stimulating its phosphorylation at Ser9. CONCLUSION: This study evidenced that Vit C exerts an anti-inflammatory function in microglia, promoting the upregulation of the M2 phenotype through the activation of the Wnt/ß-catenin signaling pathway.
Subject(s)
Anti-Inflammatory Agents , Ascorbic Acid , Neuroinflammatory Diseases , Neuroprotective Agents , Animals , Male , Mice , Anti-Inflammatory Agents/pharmacology , Ascorbic Acid/pharmacology , Cell Line , Disease Models, Animal , Glycogen Synthase Kinase 3 beta/metabolism , Lipopolysaccharides , Mice, Inbred C57BL , Microglia/drug effects , Microglia/metabolism , Neuroinflammatory Diseases/drug therapy , Neuroprotective Agents/pharmacology , Parkinson Disease/drug therapy , Parkinson Disease/metabolism , Phosphorylation/drug effects , Serine/metabolismABSTRACT
Resveratrol is a polyphenol that acts as antioxidants do, protecting the body against diseases, such as diabetes, cancer, heart disease, and neurodegenerative disorders, such as Alzheimer's (AD) and Parkinson's diseases (PD). In the present study, we report that the treatment of activated microglia with resveratrol after prolonged exposure to lipopolysaccharide is not only able to modulate pro-inflammatory responses, but it also up-regulates the expression of decoy receptors, IL-1R2 and ACKR2 (atypical chemokine receptors), also known as negative regulatory receptors, which are able to reduce the functional responses promoting the resolution of inflammation. This result might constitute a hitherto unknown anti-inflammatory mechanism exerted by resveratrol on activated microglia.
Subject(s)
Lipopolysaccharides , Microglia , Resveratrol/metabolism , Lipopolysaccharides/metabolism , Microglia/metabolism , Cytokines/metabolism , Anti-Inflammatory Agents/metabolismABSTRACT
COX-1 plays a previously unrecognized part in the neuroinflammation. Genetic ablation or pharmacological inhibition of COX-1 activity attenuates the inflammatory response and neuronal loss. In this context, the effects of selective COX-1 inhibitors (P6, P10, SC-560, aspirin) and coxibs (celecoxib and etoricoxib) on LPS-stimulated microglial cell function (a worldwide accepted neuroinflammation model) were investigated, and the effects on COX-1/COX-2, cPGES mRNA and iNOS expression, PGE(2) and NO production and NF-κB activation by IκBα phosphorylation were evaluated. The total suppression of the expression of both COX-1 and COX-2 by their respective selective inhibitors occurred. NF-κB remained almost completely inactive in the presence of coxibs, as expected, and totally inactive in the presence of P6. P6 also markedly counteracted LPS enhancing cPGES mRNA expression and PGE(2) production. Since COX-1 is predominantly localized in microglia, its high selective inhibition rather than COX-2 (by coxibs) is more likely to reduce neuroinflammation and has been further investigated as a potential therapeutic approach and prevention in neurodegenerative diseases with a marked inflammatory component.
Subject(s)
Cyclooxygenase Inhibitors/pharmacology , Inflammation Mediators/metabolism , Lipopolysaccharides/pharmacology , Membrane Proteins/antagonists & inhibitors , Microglia/drug effects , Animals , Aspirin/pharmacology , Celecoxib , Cell Line , Cell Survival/drug effects , Cyclooxygenase 1/metabolism , Cyclooxygenase 2/metabolism , Cyclooxygenase 2 Inhibitors/pharmacology , Dinoprostone/metabolism , Dose-Response Relationship, Drug , Down-Regulation , Etoricoxib , I-kappa B Proteins/metabolism , Intramolecular Oxidoreductases/genetics , Intramolecular Oxidoreductases/metabolism , Membrane Proteins/metabolism , Mice , Microglia/enzymology , Microglia/immunology , NF-KappaB Inhibitor alpha , NF-kappa B/metabolism , Nitric Oxide/metabolism , Nitric Oxide Synthase Type II/metabolism , Phosphorylation , Prostaglandin-E Synthases , Pyrazoles/pharmacology , Pyridines/pharmacology , RNA, Messenger/metabolism , Sulfonamides/pharmacology , Sulfones/pharmacologyABSTRACT
The mitochondrial CIC (citrate carrier) catalyses the efflux of citrate from the mitochondrial matrix in exchange for cytosolic malate. In the present paper we show that CIC mRNA and protein markedly increase in lipopolysaccharide-activated immune cells. Moreover, CIC gene silencing and CIC activity inhibition significantly reduce production of NO, reactive oxygen species and prostaglandins. These results demonstrate for the first time that CIC has a critical role in inflammation.
Subject(s)
Carrier Proteins/physiology , Inflammation Mediators/metabolism , Mitochondrial Proteins/physiology , Carrier Proteins/antagonists & inhibitors , Carrier Proteins/genetics , Cells, Cultured , Cytosol/metabolism , Gene Silencing , Humans , Mitochondria/metabolism , Mitochondrial Proteins/antagonists & inhibitors , Mitochondrial Proteins/genetics , Nitric Oxide/metabolism , RNA, Messenger/metabolism , Up-RegulationABSTRACT
Upregulation of inflammatory responses in the brain is associated with a number of neurodegenerative diseases. Microglia are activated in neurodegenerative diseases, producing pro-inflammatory mediators. Critically, lipopolysaccharide (LPS)-induced microglial activation causes dopaminergic neurodegeneration in vitro and in vivo. The signaling mechanisms triggered by LPS to stimulate the release of pro-inflammatory mediators in microglial cells are still incompletely understood. To further explore the mechanisms of LPS-mediated inflammatory response of microglial cells, we studied the role of phosphatidylinositol 3-kinase (PI3K)/Akt signal transduction pathways known to be activated by toll-like receptor-4 signaling through LPS. In the current study, we report that the activation profile of LPS-induced pAkt activation preceded those of LPS-induced NF-κB activation, suggesting a role for PI3K/Akt in the pathway activation of NF-κB-dependent inflammatory responses of activated microglia. These results, providing the first evidence that PI3K dependent signaling is involved in the inflammatory responses of microglial cells following LPS stimulation, may be useful in preventing inflammatory based neurodegenerative processes.
Subject(s)
Lipopolysaccharides/toxicity , Microglia/metabolism , Phosphatidylinositol 3-Kinases/metabolism , Proto-Oncogene Proteins c-akt/metabolism , Signal Transduction/drug effects , Animals , Cells, Cultured , Chick Embryo , Microglia/pathology , NF-kappa B/metabolism , Neurodegenerative Diseases/metabolism , Toll-Like Receptor 4/metabolismABSTRACT
Intron evolution may be readily imaged through the combined use of the "dot plot" function of the NCBI BLAST, aligning two sequences at a time, and the Vertebrate "Multiz" alignment and conservation tool of the UCSC Genome Browser. With the NCBI BLAST, an ideal alignment of two highly conserved sequences generates a diagonal straight line in the plot from the lower left corner to the upper right corner. Gaps in this line correspond to non-conserved sections. In addition, the dot plot of the alignment of a sequence with the same sequence after the removal of the Transposable Elements (TEs) can be observed along the diagonal gaps that correspond to the sites of TE insertion. The UCSC Genome Browser can graph, along the entire sequence of a single gene, the level of overall conservation in vertebrates. This level can be compared with the conservation level of the gene in one or more selected vertebrate species. As an example, we show the graphic analysis of the intron conservation in two genes: the mitochondrial solute carrier 21 (SLC25A21) and the growth hormone receptor (GHR), whose coding sequences are conserved through vertebrates, while their introns show dramatic changes in nucleotide composition and even length. In the SLC25A21, a few short but significant nucleotide sequences are conserved in zebrafish, Xenopus and humans, and the rate of conservation steadily increases from chicken/human to mouse/human alignments. In the GHR, a less conserved gene, the earlier indication of intron conservation is a small signal in chicken/human alignment. The UCSC tool may simultaneously display the conservation level of a gene in different vertebrates, with reference to the level of overall conservation in Vertebrates. It is shown that, at least in SLC25A21, the sites of higher conservation are not always coincident in chicken and zebrafish nor are the sites of higher vertebrate conservation.
ABSTRACT
A number of proteins which are needed for the building of new immunodeficiency virus type 1 virions can only be translated from unspliced virus-derived pre-mRNAs. These unspliced mRNAs are shuttled through the nuclear pores reaching the cytosol when bound to the viral protein Rev. However, as a cellular co-factor Rev requires a Rev-binding protein of the AGFG family (nucleoporin-related Arf-GAP domain and FG repeats-containing proteins). In this article we address the evolution of the AGFGs by analyzing the first section of the coding mRNAs. This contains a "core module" which can be traced from Drosophilae to fish, amphibia, birds, and mammals, including man. In the subfamily of AGFG1 molecules the estimated conservation from Drosophilae to primates is 67% (with limited gaps). In some Drosophilae the core module is preceded by a long stretch of more than 300 coding nucleotides, but this additional module is absent in other Drosophilae and in all AGFG1s of other species. The AGFG2 molecules emerged later in evolution, possibly deriving from a duplication of AGFG1s. AGFG2s, present in mammals only, exhibit an additional module of about 50 coding nucleotides ahead of the core module, which is significantly less conserved (54%, with more remarkable gaps). This additional module does not seem to have homologies with the additional module of Drosophilae nor with the precoding section of AGFG1s. Interestingly, in birds a highly re-edited form of the AGFG1 core module (Gallus gallus, Galliformes) coexists with a typical form of the AGFG1 core module (Taeniopygia guttata, Passeriformes).
Subject(s)
Evolution, Molecular , Genes, rev , HIV-1/genetics , Nuclear Pore Complex Proteins/genetics , RNA-Binding Proteins/genetics , rev Gene Products, Human Immunodeficiency Virus/genetics , 5' Untranslated Regions/genetics , Animals , Base Sequence , Humans , Molecular Sequence Data , Nucleic Acid Conformation , RNA, Messenger/genetics , RNA, Viral/genetics , Sequence Alignment , Sequence Homology, Nucleic Acid , Species SpecificityABSTRACT
Both mouse and human chemokine receptor CXC motif 5 (CXCR5) genes exhibit one single intron interrupting the coding sequence. The mouse intron is 12053 nucleotides (nt) long; the human intron is 9603 nt long. Sections of the mouse intron significantly align plus/plus with sections of the human intron; the aligned segments are in the same order in mouse as in man and overall cover 13% of the mouse sequence and 17% of the human sequence. The human CXCR5 intron harbors sequences derived from retroviruses (human endogenous retroviruses). The mouse intron comprises very similar sequences. About 70% of the mouse intron sequence is 'specific' to this gene, while sequences in the rest of the intron are shared with many other genes located on different chromosomes. In the human the coverage by specific sequences is about 87%. Thus, the contribution of transposable elements is significantly higher in mouse (30%) than in man (13%). Intra-intronic plus/minus alignments exist in mouse (10 couples) and man (two couples): these may form stem and loop structures determining the secondary structure of the corresponding pre-mRNAs.
Subject(s)
Introns/genetics , Receptors, CXCR5/genetics , Animals , Base Sequence , Humans , Mice , Molecular Sequence Data , Sequence Homology, Nucleic Acid , Species SpecificityABSTRACT
In this work, we examine the effects of lipopolysaccharide (LPS) treatment on nerve cells of chick embryo used as a universal avian model. We demonstrate that LPS leads to a dramatic cell loss in primary cultures of both glia and neurons, isolated from chick embryos. Toxic effects appear to be mediated by the Toll-like receptor (TLR)-4 complex, expressed in both glial and neuronal cells, since after TLR-4 silencing by RNA interference experiments LPS-induced cytotoxicity was prevented. The role of nitric oxide in LPS-induced cell damage has also been investigated. These results demonstrate, for the first time in avian nerve cells, the surface expression of TLR-4 and its role as a pattern recognition receptor involved in LPS-induced cell responses in a similar manner to that observed in mammals.
Subject(s)
Brain/metabolism , Lipopolysaccharides/toxicity , Toll-Like Receptor 4/biosynthesis , Animals , Blotting, Western , Brain/drug effects , Brain/embryology , Cell Culture Techniques , Cell Survival/drug effects , Cells, Cultured , Chick Embryo , Electrophoresis, Polyacrylamide Gel , Microscopy, Confocal , Neuroglia/drug effects , Neuroglia/immunology , Neuroglia/metabolism , Neurons/drug effects , Neurons/immunology , Neurons/metabolism , Nitric Oxide/biosynthesis , Nitric Oxide Synthase Type II/genetics , Reverse Transcriptase Polymerase Chain Reaction , Toll-Like Receptor 4/geneticsABSTRACT
The human chemokine receptor (CKR) genes CCR2, CCR6, CCR7, CCR9, CCR10, CXCR4, and CXCR5 harbor one or two introns. CCR7, CCR9, CCR10, and CXCR5 introns, (but not CCR2, CCR6, and CXCR4 introns) encompass retrovirus-like inserts with the characteristics of SINEs (short interspersed nuclear elements) up to 300 nucleotides (nt) long. Other characteristic elements of the retroviral genome, such as long terminal repeats and gag, pol, and env genes, are lacking. The inserts likely derived from one (or more) of the following retroviruses: XA34 (NCBI GenBank Nucleotides, U29659), HERV-P-T47D (AF087913), ERV FTD (U27241), HERV-K (Y17832), HML6p (U86698), HERV-H/env60 (AJ289710), XA38 (U37066). Virus-like inserts are remarkably homogeneous in all CKR introns, with nt identities of about 80%. Percentages of nt identities between the CKR inserts and the corresponding viral sequences are also about 80%. With reference to the CKR sequence, the viral sequence aligns in some instances Plus/Plus (XA34, HML6p, HERV-H/env60, and XA38) and in other instances Plus/Minus (HERV-P-T47D, ERV FTD, and HERV-K). Some aspects of the evolution of retroviruses and CKRs as well as hypotheses on the biological significance of the SINE inserts are discussed.
Subject(s)
Endogenous Retroviruses/genetics , Evolution, Molecular , Introns/genetics , Receptors, Chemokine/genetics , Base Sequence , Endogenous Retroviruses/immunology , Humans , Molecular Sequence Data , Receptors, Chemokine/physiology , Sequence Homology, Nucleic Acid , Virus Activation/immunologyABSTRACT
Among therapeutic approaches that have been investigated, targeting of receptors implicated in managing neuroinflammation has been described. One such family of receptors comprises the formyl peptide receptors (FPRs) whose ligands could play a role in host defense. The murine FPR gene family includes at least six members while in humans there are only three. The two most important members are the Fpr1 and Fpr2. Fpr1encodes murine FPR1, which is considered the murine orthologue of human FPR. Resveratrol, a non-flavonoid polyphenol rich in red wine and grapes, apart from its beneficial health effects and anti-inflammatory properties, has been reported to reduce neuroinflammation in different neurodegenerative disease models. Resveratrol anti-inflammatory responses involve the activation of the protein deacetylase sirtuin 1 (SIRT1) gene. In this work we have investigated in an LPS-based murine model of neuroinflammation the role of FPR1, examining not only if this receptor undergoes a reduction of its expression during neuroinflammation, but also whether treatment with resveratrol was able to modulate its expression leading to an amelioration of neuroinflammatory picture in a murine model of neuroinflammation. Results of this work showed that FPR1 together with SIRT1 resulted upregulated by resveratrol treatment and that this increase is associated with an amelioration of the neuroinflammatory picture, as demonstrated by the induction of IL-10 and IL1-RA expression and the downregulation of proinflammatory mediators, such as TNF-α and IL-1ß. The expression and the modulation of FPR1 by resveratrol may be evaluated in order to propose a novel anti-inflammatory and pro-resolving therapeutic approach for the reduction of the detrimental effects associated with neuro-inflammation based neurodegenerative diseases and also as a promising strategy to promote human health by a diet rich in antioxidative bioactive compounds.
Subject(s)
Astrocytes/pathology , Inflammation/metabolism , Inflammation/pathology , Microglia/pathology , Receptors, Formyl Peptide/metabolism , Resveratrol/pharmacology , Animals , Anti-Inflammatory Agents/pharmacology , Astrocytes/drug effects , Astrocytes/metabolism , Calcium-Binding Proteins/genetics , Calcium-Binding Proteins/metabolism , Disease Models, Animal , Glial Fibrillary Acidic Protein/metabolism , Inflammation/chemically induced , Inflammation Mediators/metabolism , Interleukin 1 Receptor Antagonist Protein/metabolism , Lipopolysaccharides , Male , Mice , Microfilament Proteins/genetics , Microfilament Proteins/metabolism , Microglia/drug effects , Microglia/metabolism , Models, Biological , RNA, Messenger/genetics , RNA, Messenger/metabolism , Signal Transduction , Sirtuin 1/genetics , Sirtuin 1/metabolism , Tumor Necrosis Factor-alpha/genetics , Tumor Necrosis Factor-alpha/metabolismABSTRACT
Vitamin C (Vit C) is anutrient present in many foods, particularly citrus fruits, green vegetables, tomatoes, and potatoes. Vit C is studied for its applications in the prevention and management of different pathologies, including neurodegenerative diseases. Neuroinflammation is a defense mechanism activated by a stimulus or an insult that is aimed at the preservation of the brain by promoting tissue repair and removing cellular debris; however, persistent inflammatory responses are detrimental and may lead to the pathogenesis and progression of neurodegenerative diseases like Parkinson's disease (PD) and Alzheimer's disease. PD is one of the most common chronic progressive neurodegenerative disorders, and oxidative stress is one of the most important factors involved in its pathogenesis and progression.Due to this, research on antioxidant and anti-inflammatory compounds is an important target for counteracting neurodegenerative diseases, including PD. In the central nervous system, the presence of Vit C in the brain is higher than in other body districts, but why and how this occurs is still unknown. In this research, Vit C, with its anti-inflammatory and anti-oxidative properties, is studied to better understand its contribution to brain protection; in particular, we have investigated the neuroprotective effects of Vit C in the 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced animal model of PD and its role in the modulation of neuroinflammation. First, we observed that Vit C significantly decreased the MPTP-induced loss of tyrosine hydroxylase (TH)-positive dopaminergic neuronal cells in the substantia nigra, as well as microglial cell activation and astrogliosis. Furthermore, gait and spontaneous locomotor activity, evaluated by an automated treadmill and the Open Field test, respectively, were partially ameliorated by Vit C treatment in MPTP-intoxicated animals. In relation to neuroinflammation, results show that Vit C reduced the protein and mRNA expression of inflammatory cytokines such as IL-6, TLR4, TNF-α, iNOS, and CD40, while anti-inflammatory proteins such as IL-10, CD163, TGF-ß, and IL-4 increased. Interestingly, we show for the first time that Vit C reduces neuroinflammation by modulating microglial polarization and astrocyte activation. Moreover, Vit C was able to reduce NLRP3 activation, which is linked to the pathogenesis of many inflammatory diseases, including neuroinflammatory disorders. In conclusion, our study provides evidence that Vit C may represent a new promising dietary supplement for the prevention and alleviation of the inflammatory cascade of PD, thus contributing to neuroprotection.