ABSTRACT
Tauopathies are age-associated neurodegenerative diseases whose mechanistic underpinnings remain elusive, partially due to a lack of appropriate human models. Here, we engineered human induced pluripotent stem cell (hiPSC)-derived neuronal lines to express 4R Tau and 4R Tau carrying the P301S MAPT mutation when differentiated into neurons. 4R-P301S neurons display progressive Tau inclusions upon seeding with Tau fibrils and recapitulate features of tauopathy phenotypes including shared transcriptomic signatures, autophagic body accumulation, and reduced neuronal activity. A CRISPRi screen of genes associated with Tau pathobiology identified over 500 genetic modifiers of seeding-induced Tau propagation, including retromer VPS29 and genes in the UFMylation cascade. In progressive supranuclear palsy (PSP) and Alzheimer's Disease (AD) brains, the UFMylation cascade is altered in neurofibrillary-tangle-bearing neurons. Inhibiting the UFMylation cascade in vitro and in vivo suppressed seeding-induced Tau propagation. This model provides a robust platform to identify novel therapeutic strategies for 4R tauopathy.
Subject(s)
Induced Pluripotent Stem Cells , Neurons , Tauopathies , tau Proteins , Humans , Induced Pluripotent Stem Cells/metabolism , tau Proteins/metabolism , Tauopathies/metabolism , Tauopathies/pathology , Neurons/metabolism , Neurons/pathology , Animals , Mice , Alzheimer Disease/metabolism , Alzheimer Disease/pathology , Alzheimer Disease/genetics , Brain/metabolism , Brain/pathology , Supranuclear Palsy, Progressive/metabolism , Supranuclear Palsy, Progressive/pathology , Supranuclear Palsy, Progressive/genetics , Cell Differentiation , Mutation , AutophagyABSTRACT
Tau (MAPT) drives neuronal dysfunction in Alzheimer disease (AD) and other tauopathies. To dissect the underlying mechanisms, we combined an engineered ascorbic acid peroxidase (APEX) approach with quantitative affinity purification mass spectrometry (AP-MS) followed by proximity ligation assay (PLA) to characterize Tau interactomes modified by neuronal activity and mutations that cause frontotemporal dementia (FTD) in human induced pluripotent stem cell (iPSC)-derived neurons. We established interactions of Tau with presynaptic vesicle proteins during activity-dependent Tau secretion and mapped the Tau-binding sites to the cytosolic domains of integral synaptic vesicle proteins. We showed that FTD mutations impair bioenergetics and markedly diminished Tau's interaction with mitochondria proteins, which were downregulated in AD brains of multiple cohorts and correlated with disease severity. These multimodal and dynamic Tau interactomes with exquisite spatial resolution shed light on Tau's role in neuronal function and disease and highlight potential therapeutic targets to block Tau-mediated pathogenesis.
Subject(s)
Mitochondria/metabolism , Nerve Degeneration/metabolism , Protein Interaction Maps , Synapses/metabolism , tau Proteins/metabolism , Alzheimer Disease/genetics , Amino Acids/metabolism , Biotinylation , Brain/metabolism , Brain/pathology , Cell Nucleus/metabolism , Disease Progression , Energy Metabolism , Frontotemporal Dementia/genetics , Humans , Induced Pluripotent Stem Cells/metabolism , Mutant Proteins/metabolism , Mutation/genetics , Nerve Degeneration/pathology , Neurons/metabolism , Protein Binding , Protein Domains , Proteomics , Severity of Illness Index , Subcellular Fractions/metabolism , Tauopathies/genetics , tau Proteins/chemistryABSTRACT
Valorization of the hemicellulose fraction of plant biomass is crucial for the sustainability of lignocellulosic biorefineries. The Cellulomonas genus comprises Gram-positive Actinobacteria that degrade cellulose and other polysaccharides by secreting a complex array of enzymes. In this work, we studied the specificity and synergy of two enzymes, CsXyn10A and CsAbf62A, which were identified as highly abundant in the extracellular proteome of Cellulomonas sp. B6 when grown on wheat bran. To explore their potential for bioprocessing, the recombinant enzymes were expressed and their activities were thoroughly characterized. rCsXyn10A is a GH10 endo-xylanase (EC 3.2.1.8), active across a broad pH range (5 to 9), at temperatures up to 55 °C. rCsAbf62A is an α-L-arabinofuranosidase (ABF) (EC 3.2.1.55) that specifically removes α-1,2 and α-1,3-L-arabinosyl substituents from arabino-xylo-oligosaccharides (AXOS), xylan, and arabinan backbones, but it cannot act on double-substituted residues. It also has activity on pNPA. No differences were observed regarding activity when CsAbf62A was expressed with its appended CBM13 module or only the catalytic domain. The amount of xylobiose released from either wheat arabinoxylan or arabino-xylo-oligosaccharides increased significantly when rCsXyn10A was supplemented with rCsAbf62A, indicating that the removal of arabinosyl residues by rCsAbf62A improved rCsXyn10A accessibility to ß-1,4-xylose linkages, but no synergism was observed in the deconstruction of wheat bran. These results contribute to designing tailor-made, substrate-specific, enzymatic cocktails for xylan valorization. KEY POINTS: ⢠rCsAbf62A removes α-1,2 and α-1,3-L-arabinosyl substituents from arabino-xylo-oligosaccharides, xylan, and arabinan backbones. ⢠The appended CBM13 of rCsAbf62A did not affect the specific activity of the enzyme. ⢠Supplementation of rCsXyn10A with rCsAbf62A improves the degradation of AXOS and xylan.
Subject(s)
Cellulomonas , Xylans , Cellulomonas/genetics , Cellulomonas/metabolism , Dietary Fiber , Endo-1,4-beta Xylanases/metabolism , Glycoside Hydrolases/metabolism , Hydrolysis , Oligosaccharides/metabolism , Substrate Specificity , Xylans/metabolismABSTRACT
Natural ponds in the Brazilian Cerrado harbor high biodiversity but are still poorly studied, especially their microbial assemblage. The characterization of the microbial community in aquatic environments is fundamental for understanding its functioning, particularly under the increasing pressure posed by land conversion and climate change. Here, we aim to characterize the structure (abundance, richness, and diversity) and composition of the Bacteria and Archaea in the sediment of two natural ponds belonging to different basins that primarily differ in size and depth in the Cerrado. Sediment samples were collected in the dry and rainy seasons and the transition periods between both. The structure and composition of Bacteria and Archaea were assessed by 16S rRNA gene pyrosequencing. We identified 45 bacterial and four archaeal groups. Proteobacteria and Acidobacteria dominated the bacterial community, while Euryarchaeota and Thaumarchaeota dominated the archaeal community. Seasonal fluctuations in the relative abundance of microbial taxa were observed, but pond characteristics were more determinant to community composition differences. Microbial communities are highly diverse, and local variability could partially explain the microbial structure's main differences. Functional predictions based in 16S rRNA gene accessed with Tax4Fun indicated an enriched abundance of predicted methane metabolism in the deeper pond, where higher abundance of methanogenic archaea Methanocella, Methanosaeta, and Methanomicrobiaceae was detected. Our dataset encompasses the more comprehensive survey of prokaryotic microbes in Cerrado's aquatic environments. Here, we present basic and essential information about composition and diversity, for initial insights into the ecology of Bacteria and Archaea in these environments.
Subject(s)
Archaea , Ponds , Archaea/genetics , Bacteria/genetics , Biodiversity , Geologic Sediments , Phylogeny , RNA, Ribosomal, 16S/geneticsABSTRACT
APOBEC3 proteins APOBEC3F (A3F), APOBEC3G (A3G), and APOBEC3H (A3H) are host restriction factors that inhibit HIV-1 through DNA cytidine deaminase-dependent and -independent mechanisms and have either one (A3H) or two (A3F and A3G) zinc-binding domains. A3H antiviral activity encompasses multiple molecular functions, all of which depend on recognition of RNA or DNA. A3H crystal structures revealed an unusual interaction with RNA wherein an RNA duplex mediates dimerization of two A3H proteins. In this study, we sought to determine the importance of RNA-binding amino acids in the antiviral and biochemical properties of A3H. We show that the wild-type A3H-RNA interaction is essential for A3H antiviral activity and for two deaminase-independent processes: encapsidation into viral particles and inhibition of reverse transcription. Furthermore, an extensive mutagenesis campaign revealed distinct roles for two groups of amino acids at the RNA binding interface. C-terminal helix residues exclusively bind RNA, and loop 1 residues play a dual role in recognition of DNA substrates and in RNA binding. Weakening the interface between A3H and RNA allows DNA substrates to bind with greater affinity and enhances deamination rates, suggesting that RNA binding must be disrupted to accommodate DNA. Intriguingly, we demonstrate that A3H can deaminate overhanging DNA strands of RNA/DNA heteroduplexes, which are early intermediates during reverse transcription and may represent natural A3H substrates. Overall, we present a mechanistic model of A3H restriction and a step-by-step elucidation of the roles of RNA-binding residues in A3H activity, particle incorporation, inhibition of reverse transcriptase inhibition, and DNA cytidine deamination.IMPORTANCE APOBEC3 proteins are host factors that protect the integrity of the host genome by inhibiting retroelements as well as retroviruses, such as HIV-1. To do this, the APOBEC3H protein has evolved unique interactions with structured RNAs. Here, we studied the importance of these interactions in driving antiviral activity of APOBEC3H. Our results provide a clear picture of how RNA binding drives the ability of APOBEC3H to infiltrate new viruses and prevent synthesis of viral DNA. We also explore how RNA binding by APOBEC3H influences recognition and deamination of viral DNA and describe two possible routes by which APOBEC3H might hypermutate the HIV-1 genome. These results highlight how one protein can sense many nucleic acid species for a variety of antiviral activities.
Subject(s)
Aminohydrolases/metabolism , Aminohydrolases/pharmacology , Antiviral Agents/pharmacology , HIV-1/drug effects , HIV-1/metabolism , APOBEC Deaminases/metabolism , Aminohydrolases/chemistry , Aminohydrolases/genetics , Cell Line , DNA, Viral/drug effects , DNA, Viral/metabolism , HIV-1/genetics , Humans , Models, Molecular , Protein Binding , Protein Conformation , RNA Recognition Motif Proteins , RNA-Binding Proteins/chemistry , Reverse Transcription , VirionABSTRACT
OBJECTIVE: To investigate what toxicological interactions occur when binary combinations of azamethiphos and botanical monoterpenes (eugenol, menthol or menthyl acetate) are applied to Triatoma infestans. METHODS: The toxicity of binary mixtures of azamethiphos and sublethal doses of a monoterpene (eugenol, menthol or menthyl acetate) was evaluated in nymphs of the first stage of T. infestans. Experiments using exposure to filter papers and topical application were carried out. Values of Lethal Concentration 50% (LC50) were calculated in the first case, and values of Lethal Dose 50% (LD50) in the second. RESULTS: The LC50 of azamethiphos applied on filter paper was 50.3 µg/cm2 . However, when it was simultaneously applied with a sublethal concentration of monoterpene, its toxicity increased (LC50 with eugenol = 11.20 µg/cm2 , LC50 with menthyl acetate = 5.30 µg/cm2 , LC50 with menthol = 7.26 µg/cm2 ). When applied topically, the LD50 of azamethiphos was 7.85 µg/insect, but its toxicity drastically increased when it was applied together with sublethal doses of menthol (LD50 = 0.00016 µg/insect) or menthyl acetate (LD50 = 0.00051 µg/insect). The simultaneous application with eugenol did not significantly change azamethiphos toxicity (LD50 = 12.79 µg/insect). CONCLUSIONS: The toxicity of azamethiphos in T. infestans was synergised when it was applied together with eugenol, menthol or menthyl acetate on a filter paper. However, only menthol and menthyl acetate synergysed azamethiphos when mixtures were topically applied. The drastic effects of menthol and menthyl acetate in topical application experiments should be further studied as they could be the basis for developing more efficient triatomicidal products with a lower content of conventional insecticides than those currently used for controlling T. infestans.
OBJECTIF: Etudier les interactions toxicologiques qui se produisent lorsque des combinaisons binaires d'azaméthiphos et de monoterpènes botaniques (eugénol, menthol ou acétate de menthyle) sont appliquées à Triatoma infestans. MÉTHODES: La toxicité de mélanges binaires d'azaméthiphos et de doses sublétales d'un monoterpène (eugénol, menthol ou acétate de menthyle) a été évaluée sur les nymphes du premier stade de T. infestans. Des expériences utilisant une exposition à des papiers filtres et une application topique ont été réalisées. Les valeurs de concentration létale à 50% (CL50) ont été calculées dans le premier cas et les valeurs de dose létale à 50% (DL50) dans le second. RÉSULTATS: La CL50 de l'azaméthiphos appliqué sur papier filtre était de 50,3 µg/cm2 . Cependant, lorsqu'il était appliqué simultanément avec une concentration sublétale de monoterpène, sa toxicité augmentait (CL50 avec eugénol = 11,20 µg/cm2 , CL50 avec acétate de menthyle = 5,30 µg/cm2 , CL50 avec menthol = 7,26 µg/cm2 ). Lorsqu'il était appliqué localement, la DL50 de l'azaméthiphos était de 7,85 µg/insecte, mais sa toxicité augmentait considérablement lorsqu'il était appliqué avec des doses sublétales de menthol (DL50 = 0,00016 µg/insecte) ou d' acétate de menthyle (DL50 = 0,00051 µg/insecte). L'application simultanée d'eugénol n'a pas modifié de manière significative la toxicité de l'azaméthiphos (DL50 = 12,79 µg/insecte). CONCLUSIONS: La toxicité de l'azaméthiphos chez T. infestans a été mise en synergie lorsqu'il a été appliqué avec de l'eugénol, du menthol ou de l' acétate de menthyle sur un papier filtre. Cependant, seuls le menthol et l' acétate de menthyle ont eu un effet synergique avec l'azaméthiphos lorsque les mélanges étaient appliqués localement. Les effets drastiques du menthol et de l' acétate de menthyle dans les expériences d'application topique devraient être plus étudiés car ils pourraient être la base du développement de produits triatomicides plus efficaces avec une teneur inférieure en insecticides conventionnels que ceux actuellement utilisés pour lutter contre T. infestans.
Subject(s)
Insect Repellents/pharmacology , Insect Vectors/drug effects , Plant Oils/pharmacology , Triatoma/drug effects , Animals , Chagas Disease/parasitology , Insect Control/methods , Insect Repellents/chemistry , Lethal Dose 50 , Monoterpenes/chemistry , Monoterpenes/pharmacology , Nymph/drug effects , Organothiophosphates/pharmacology , Plant Oils/chemistryABSTRACT
Woody biomass represents an important source of carbon on earth, and its global recycling is highly dependent on Agaricomycetes fungi. White-rot Basidiomycetes are a very important group in this regard, as they possess a large and diverse enzymatic repertoire for biomass decomposition. Among these enzymes, the recently discovered lytic polysaccharide monooxygenases (LPMOs) have revolutionized biomass processing with their novel oxidative mechanism of action. The strikingly high representation of LPMOs in fungal genomes raises the question of their functional versatility. In this work, we studied an AA9 LPMO from the white-rot basidiomycete Pycnoporus sanguineus, PsAA9A. Successfully produced as a recombinant secreted protein in Pichia pastoris, PsAA9A was found to be a C1-specific LPMO active on cellulosic substrates, generating native and oxidized cello-oligosaccharides in the presence of an external electron donor. PsAA9A boosted cellulolytic activity of glysoside hydrolases from families GH1, GH5, and GH6.This study serves as a starting point towards understanding the functional versatility and biotechnological potential of this enzymatic family, highly represented in wood decay fungi, in Pycnoporus genus. KEY POINTS: ⢠PsAA9A is the first AA9 from P. sanguineus to be characterized. ⢠PsAA9A has activity on cellulose, producing C1-oxidized cello-oligosaccharides. ⢠Boosting activity with GH1, GH5, and GH6 was proven.
Subject(s)
Fungal Proteins , Mixed Function Oxygenases , Fungal Proteins/genetics , Humans , Mixed Function Oxygenases/genetics , Polyporaceae , Polysaccharides , SaccharomycetalesABSTRACT
The Toluca valley, located in central Mexico, is thought to be the center of origin of the potato late blight pathogen Phytophthora infestans. We characterized over 500 individuals of P. infestans sampled from populations with a geographical distance of more than 400 km in six regions adjacent to the Toluca valley in three states including Michoacán, Mexico, and Tlaxcala. Our sampling occurred on a predominant east to west gradient and showed significant genetic differentiation. The most western sampling location found in Michoacán was most differentiated from the other populations. Populations from San Gerónimo, Juchitepec, and Tlaxcala clustered together and appeared to be in linkage equilibrium. This work provides a finer understanding of gradients of genetic diversity in populations of P. infestans at the center of origin.
Subject(s)
DNA, Fungal/genetics , Genetic Variation , Microsatellite Repeats/genetics , Phytophthora infestans/genetics , Genetics, Population/methods , Genotype , Geography , Mexico , Phytophthora infestans/classification , Phytophthora infestans/physiology , Plant Diseases/microbiology , Solanum tuberosum/microbiology , Species SpecificityABSTRACT
Tauopathies are age-associated neurodegenerative diseases whose mechanistic underpinnings remain elusive, partially due to lack of appropriate human models. Current human induced pluripotent stem cell (hiPSC)-derived neurons express very low levels of 4-repeat (4R)-tau isoforms that are normally expressed in adult brain. Here, we engineered new iPSC lines to express 4R-tau and 4R-tau carrying the P301S MAPT mutation when differentiated into neurons. 4R-P301S neurons display progressive Tau inclusions upon seeding with Tau fibrils and recapitulate features of tauopathy phenotypes, including shared transcriptomic signatures, autophagic body accumulation, and impaired neuronal activity. A CRISPRi screen of genes associated with Tau pathobiology identified over 500 genetic modifiers of Tau-seeding-induced Tau propagation, including retromer VPS29 and the UFMylation cascade as top modifiers. In AD brains, the UFMylation cascade is altered in neurofibrillary-tangle-bearing neurons. Inhibiting the UFMylation cascade suppressed seeding-induced Tau propagation. This model provides a powerful platform to identify novel therapeutic strategies for 4R tauopathy.
ABSTRACT
Elucidating the complex relationship between plants and endophytic fungi is very important in order to understand the maintenance of biodiversity, equity, stability, and ecosystem functioning. However, knowledge about the diversity of endophytic fungi from species of the native Brazilian Cerrado biome is poorly documented and remains largely unknown. These gaps led us to characterize the diversity of Cerrado endophytic foliar fungi associated with six woody species (Caryocar brasiliense, Dalbergia miscolobium, Leptolobium dasycarpum, Qualea parviflora, Ouratea hexasperma, and Styrax ferrugineus). Additionally, we investigated the influence of host plant identities on the structure of fungal communities. Culture-dependent methods coupled with DNA metabarcoding were employed. Irrespective of the approach, the phylum Ascomycota and the classes Dothideomycetes and Sordariomycetes were dominant. Using the cultivation-dependent method, 114 isolates were recovered from all the host species and classified into more than 20 genera and 50 species. Over 50 of the isolates belonged to the genus Diaporthe, and were distributed into more than 20 species. Metabarcoding revealed the phyla Chytridiomycota, Glomeromycota, Monoblepharomycota, Mortierellomycota, Olpidiomycota, Rozellomycota, and Zoopagomycota. These groups are reported for the first time as components of the endophytic mycobiome of Cerrado plant species. In total, 400 genera were found in all host species. A unique leaf endophytic mycobiome was identified in each host species, which differed not only by the distribution of fungal species, but also by the abundance of shared species. These findings highlight the importance of the Brazilian Cerrado as a reservoir of microbial species, and emphasize how endophytic fungal communities are diversified and adapted.
ABSTRACT
The fatty acids profile has been playing a decisive role in recent years, thanks to technological, sensory and health demands from producers and consumers. The application of NIRS technique on fat tissues, could lead to more efficient, practical, and economical in the quality control. The study aim was to assess the accuracy of Fourier Transformed Near Infrared Spectroscopy technique to determine fatty acids composition in fat of 12 European local pig breeds. A total of 439 spectra of backfat were collected both in intact and minced tissue and then were analyzed using gas chromatographic analysis. Predictive equations were developed using the 80% of samples for the calibration, followed by full cross validation, and the remaining 20% for the external validation test. NIRS analysis of minced samples allowed a better response for fatty acid families, n6 PUFA, it is promising both for n3 PUFA quantification and for the screening (high, low value) of the major fatty acids. Intact fat prediction, although with a lower predictive ability, seems suitable for PUFA and n6 PUFA while for other families allows only a discrimination between high and low values.
Subject(s)
Fatty Acids, Omega-3 , Fatty Acids , Animals , Swine , Fatty Acids/analysis , Spectroscopy, Near-Infrared/methods , Adipose Tissue/chemistry , Spectrophotometry, Infrared , Fatty Acids, Omega-3/analysisABSTRACT
Brugia malayi is a human filarial nematode responsible for elephantiasis, a debilitating condition that is part of a broader spectrum of diseases called filariasis, including lymphatic filariasis and river blindness. Almost all filarial nematode species infecting humans live in mutualism with Wolbachia endosymbionts, present in somatic hypodermal tissues but also in the female germline which ensures their vertical transmission to the nematode progeny. These α-proteobacteria potentially provision their host with essential metabolites and protect the parasite against the vertebrate immune response. In the absence of Wolbachia wBm, B. malayi females become sterile, and the filarial nematode lifespan is greatly reduced. In order to better comprehend this symbiosis, we investigated the adaptation of wBm to the host nematode soma and germline, and we characterized these cellular environments to highlight their specificities. Dual RNAseq experiments were performed at the tissue-specific and ovarian developmental stage levels, reaching the resolution of the germline mitotic proliferation and meiotic differentiation stages. We found that most wBm genes, including putative effectors, are not differentially regulated between infected tissues. However, two wBm genes involved in stress responses are upregulated in the hypodermal chords compared to the germline, indicating that this somatic tissue represents a harsh environment to which wBm have adapted. A comparison of the B. malayi and C. elegans germline transcriptomes reveals a poor conservation of genes involved in the production of oocytes, with the filarial germline proliferative zone relying on a majority of genes absent from C. elegans. The first orthology map of the B. malayi genome presented here, together with tissue-specific expression enrichment analyses, indicate that the early steps of oogenesis are a developmental process involving genes specific to filarial nematodes, that likely result from evolutionary innovations supporting the filarial parasitic lifestyle.
Subject(s)
Biological Evolution , Brugia malayi/genetics , Carisoprodol , Elephantiasis/genetics , Germ Cells , Animals , Caenorhabditis elegans , Elephantiasis, Filarial/genetics , Female , Gene Expression , Genome , Humans , Oogenesis , Sequence Analysis, RNA , Symbiosis , Wolbachia/physiologyABSTRACT
Biological nitrogen fixation (BNF) represents the main input source of N in tropical savannas. BNF could be particularly important for Brazilian savannas (known as Cerrado) that show a highly conservative N cycle. We evaluated the effects of seasonal precipitation and nutrient additions on the nifH gene abundance in soils from a long-term fertilization experiment in a Cerrado's native area. The experiment consists of five treatments: (1) control, (2) liming, (3) nitrogen (N), (4) nitrogen + phosphorus (NP), and (5) phosphorus (P) additions. The nifH gene sequence was related to Bradyrhizobium members. Seasonal effects on N-fixing potential were observed by a decrease in the nifH relative abundance from rainy to dry season in control, N, and NP treatments. A significant reduction in nifH abundance was found in the liming treatment in both seasons. The findings evidenced the multiple factors controlling the potential N-fixing by free-living diazotrophs in these nutrient-limited and seasonally dry ecosystems.
ABSTRACT
Age-related Macular Degeneration (AMD), a blinding eye disease, is characterized by pathological protein- and lipid-rich drusen deposits underneath the retinal pigment epithelium (RPE) and atrophy of the RPE monolayer in advanced disease stages - leading to photoreceptor cell death and vision loss. Currently, there are no drugs that stop drusen formation or RPE atrophy in AMD. Here we provide an iPSC-RPE AMD model that recapitulates drusen and RPE atrophy. Drusen deposition is dependent on AMD-risk-allele CFH(H/H) and anaphylatoxin triggered alternate complement signaling via the activation of NF-κB and downregulation of autophagy pathways. Through high-throughput screening we identify two drugs, L-745,870, a dopamine receptor antagonist, and aminocaproic acid, a protease inhibitor that reduce drusen deposits and restore RPE epithelial phenotype in anaphylatoxin challenged iPSC-RPE with or without the CFH(H/H) genotype. This comprehensive iPSC-RPE model replicates key AMD phenotypes, provides molecular insight into the role of CFH(H/H) risk-allele in AMD, and discovers two candidate drugs to treat AMD.
Subject(s)
Aminocaproic Acid/pharmacology , Induced Pluripotent Stem Cells/drug effects , Macular Degeneration/drug therapy , Pyridines/pharmacology , Pyrroles/pharmacology , Retinal Pigment Epithelium/drug effects , Alleles , Complement Factor H/genetics , Complement Factor H/metabolism , Drug Evaluation, Preclinical , Humans , Induced Pluripotent Stem Cells/metabolism , Macular Degeneration/genetics , Macular Degeneration/metabolism , Models, Biological , Phenotype , Retinal Pigment Epithelium/metabolismABSTRACT
Fibromyalgia is a complex syndrome characterized by widespread chronic pain, without any obvious etiology, and it is often accompanied by a constellation of symptoms such as fatigue, sleep disturbances and cognitive dysfunction, to name a few. The syndrome may be associated with a variety of autoimmune and psychiatric conditions. Fibromyalgia can occur with other musculoskeletal pathologies and its symptoms can overlap with other chronic painful conditions such as chronic myofascial pain syndromes seen in cervical and lumbar spinal osteoarthritis and degenerative disc disease. Gene polymorphisms have been related to a decreased pain threshold and an increased susceptibility to disorders associated with chronic pain. Some of those genetic variants might trigger the onset of fibromyalgia. Researchers are looking into the possible factors that might contribute to its pathophysiology. It is important to study the connections between pro-inflammatory cytokines and genetic variants in pain-related genes and their roles in predisposition and development of fibromyalgia. The objective of this review article is to provide a brief overview of the pro-inflammatory cytokines commonly associated with fibromyalgia, as well as to look into the genes that have shown some level of involvement in the development of fibromyalgia and its symptomatology.
ABSTRACT
Atrial fibrillation (AF) is a common arrhythmia, and gastroesophageal reflux disease (GERD) is a common gastroenterology disease; both are highly encountered daily in clinical practice. Since both share common predisposing factors, we can conclude that there is a link between them. To date, the precise mechanism of reflux disease as a possible cause of atrial fibrillation remains uncertain. However, some possibilities can be postulated, such as the inflammation process, and sympathovagal imbalance represents the main factors for how GERD can initiate AF. Vigorous aerobic exercise in healthy people can bring about acidic esophageal reflux, which is a common risk factor for AF. Various inflammatory markers such as C-reaction protein (CRP) and interleukins have been a central role in initiating AF. A large hiatal hernia (HH) can cause direct compression on the left atrium that is possibly predisposing to atrial arrhythmogenesis. It has been sporadically reported that using a proton pump inhibitor to treat GERD in patients with coexisting AF has a noticeable effect on decreasing symptoms of AF and recurrence with less cost and side effects.
ABSTRACT
Posterior reversible encephalopathy syndrome (PRES) is an entity which is characterized by acute to subacute onset of neurological symptoms like altered mental status, seizures, headaches and other focal neurological deficits. It is diagnosed with the help of MRI findings which typically involve the subcortical white matter of parieto-occipital lobes. In this review, we will discuss the various etiologies and risk factors including some of the most common chemotherapeutic agents and immunosuppressant agents associated with this disorder. We will discuss the mechanism of actions and side effect profiles of a few drugs and their role in causation of PRES. This review article discusses if there is any difference in presentation and imaging findings of PRES caused by cytotoxic agents versus caused by other etiologies. It also highlights the difficulty in management of PRES caused by cytotoxic agents as the discontinuation of these drugs could be life-threatening due to graft rejections or graft versus host disease.
ABSTRACT
Cardiac involvement in amyloidosis and sarcoidosis is poorly understood, and is associated with high morbidity and mortality. Atrial and ventricular arrhythmias, along with conduction defects, are frequent in cardiac amyloidosis and sarcoidosis. Atrial dysfunction in cardiac amyloidosis may result in atrial fibrillation and increases the risk of stroke, making anticoagulation significant and challenging. Ventricular arrhythmia and conduction defects are more common in AL amyloidosis and cardiac sarcoidosis. Premature ventricular contractions (PVCs) from Purkinje fibers trigger ventricular arrhythmias in cardiac amyloidosis, while the inflammation and scarring leading to the reentrant process is the cause in cardiac sarcoidosis. The typical treatment modalities include Class II and III antiarrhythmic drugs and ablation techniques, while corticosteroids and immunosuppressants are indicated in cardiac sarcoidosis to reduce the burden of the disease and arrhythmias. Sudden cardiac death can be a manifestation of both disorders that can be prevented by the Implantable cardioverter-defibrillator (ICD), although the predictive risk factors for primary prevention remain uncertain. In this review, we addressed the current understanding of the pathways involved in inducing arrhythmias in cardiac amyloidosis and sarcoidosis-also, the complications including sudden death and stroke associated with arrhythmia in both diseases. We have discussed other preventive steps needed to minimize arrhythmias to provide symptomatic relief and palliation to patients.
ABSTRACT
Eusocial animals, such as the termites, often build a nest-like structure called a mound that provides shelter with stable internal conditions and protection against predators. Termites are important components of the Brazilian Cerrado biota. This study aimed to investigate the bacterial community composition and diversity of the Syntermes wheeleri termite-mound soil using culture-independent approaches. We considered the vertical profile by comparing two different mound depths (mound surface and 60 cm) and seasonality with samplings during the rainy and dry seasons. We compared the mound soil microbiota to the adjacent soil without the influence of the mound to test the hypothesis that the Cerrado soil bacterial community was more diverse and more susceptible to seasonality than the mound soil microbiota. The results support the hypothesis that the Cerrado soil bacterial community is more diverse than the mound soil and also has a higher variability among seasons. The number of observed OTUs (Operational Taxonomic Units) was used to express bacterial richness, and it indicates that soil moisture has an effect on the community distribution and richness of the Cerrado samples in comparison to mound samples, which remain stable across seasons. This could be a consequence of the protective role of the mound for the termite colony. The overall community taxonomic profile was similar between soil samples, especially when compared to the taxonomic composition of the Syntermes wheeleri termite's gut, which might be explained by the different characteristics and functionality between the soil and the gut microbial community.
ABSTRACT
In previous studies we have found that blockade of NMDA (N-Methyl-D-Aspartic-Acid)-type glutamatergic receptor with intracerebroventricular (ICV) selective drugs induces an inhibition of lordosis in ovariectomized (OVX) estrogen primed rats receiving progesterone or luteinizing hormone releasing hormone (LHRH). By the opposite way, stimulation with NMDA in OVX estrogen primed rats induced a significant increase of lordosis. In the present study the action of an alpha1-noradrenergic antagonist, HEAT (BE 2254/2-beta-4-Hydroxyphenyl-Ethyl-Aminomethyl-1-Tetralone), and Metoprolol, a beta-noradrenergic antagonist, were studied injecting them ICV previously to NMDA administration in treated OVX estrogen primed rats. In experiment 1, the enhancing effect on lordosis induced by NMDA at high dose (1 microg) was abolished by HEAT administration (P < 0.001 for 3 and 6 microg), and the LH plasma levels were decreased only with the higher dose (P < 0.05), suggesting that behavioral effects are quite more sensitive to the alpha-blockade than hormonal effects. In experiment 2, enhancing effects on lordosis behavior were not observed with neither the NMDA at low dose (0.5 microg) nor the metoprolol alone (5.71 microg), but a synergism was observed when both were simultaneously administered (P < 0.001). The LH plasma levels were increased by Metoprolol alone (P < 0.05), and powered by the combination with NMDA at low dose (P < 0.01 vs. SAL and NMDA alone); no differences were observed with Metoprolol. LH increase was observed with Metoprolol even without behavioural modifications. These findings strongly suggest that facilitatory and inhibitory effects of NMDA in this model are mediated by alpha- and beta-adrenergic transmission in both, behavioral and hormonal effects.