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Neurons exhibit a striking degree of functional diversity, each one tuned to the needs of the circuitry in which it is embedded. A fundamental functional dichotomy occurs in activity patterns, with some neurons firing at a relatively constant "tonic" rate, while others fire in bursts, a "phasic" pattern. Synapses formed by tonic versus phasic neurons are also functionally differentiated, yet the bases of their distinctive properties remain enigmatic. A major challenge toward illuminating the synaptic differences between tonic and phasic neurons is the difficulty in isolating their physiological properties. At the Drosophila neuromuscular junction, most muscle fibers are coinnervated by two motor neurons: the tonic "MN-Ib" and phasic "MN-Is." Here, we used selective expression of a newly developed botulinum neurotoxin transgene to silence tonic or phasic motor neurons in Drosophila larvae of either sex. This approach highlighted major differences in their neurotransmitter release properties, including probability, short-term plasticity, and vesicle pools. Furthermore, Ca2+ imaging demonstrated â¼2-fold greater Ca2+ influx at phasic neuron release sites relative to tonic, along with an enhanced synaptic vesicle coupling. Finally, confocal and super-resolution imaging revealed that phasic neuron release sites are organized in a more compact arrangement, with enhanced stoichiometry of voltage-gated Ca2+ channels relative to other active zone scaffolds. These data suggest that distinctions in active zone nano-architecture and Ca2+ influx collaborate to differentially tune glutamate release at tonic versus phasic synaptic subtypes.SIGNIFICANCE STATEMENT "Tonic" and "phasic" neuronal subtypes, based on differential firing properties, are common across many nervous systems. Using a recently developed approach to selectively silence transmission from one of these two neurons, we reveal specialized synaptic functional and structural properties that distinguish these specialized neurons. This study provides important insights into how input-specific synaptic diversity is achieved, which could have implications for neurologic disorders that involve changes in synaptic function.
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Junção Neuromuscular , Sinapses , Animais , Sinapses/fisiologia , Junção Neuromuscular/metabolismo , Vesículas Sinápticas/metabolismo , Neurônios Motores/fisiologia , DrosophilaRESUMO
Rhizopus microsporus often lives in association with bacterial and viral symbionts that alter its biology. This fungal model represents an example of the complex interactions established among diverse organisms in functional holobionts. We constructed a Genome-Scale Model (GSM) of the fungal-bacterial-viral holobiont (iHol). We employed a constraint-based method to calculate the metabolic fluxes to decipher the metabolic interactions of the symbionts with their host. Our computational analyses of iHol simulate the holobiont's growth and the production of the toxin rhizoxin. Analyses of the calculated fluxes between R. microsporus in symbiotic (iHol) versus asymbiotic conditions suggest that changes in the lipid and nucleotide metabolism of the host are necessary for the functionality of the holobiont. Glycerol plays a pivotal role in the fungal-bacterial metabolic interaction, as its production does not compromise fungal growth, and Mycetohabitans bacteria can efficiently consume it. Narnavirus RmNV-20S and RmNV-23S affected the nucleotide metabolism without impacting the fungal-bacterial symbiosis. Our analyses highlighted the metabolic stability of Mycetohabitans throughout its co-evolution with the fungal host. We also predicted changes in reactions of the bacterial metabolism required for the active production of rhizoxin. This iHol is the first GSM of a fungal holobiont.
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Macrolídeos , Rhizopus , Macrolídeos/metabolismo , Rhizopus/genética , Rhizopus/metabolismo , Bactérias/genética , Bactérias/metabolismo , Nucleotídeos/metabolismo , Simbiose/genéticaRESUMO
OBJECTIVE: This study assesses response to intravenous immunoglobulin (IVIG) in presumed autoimmune postural orthostatic tachycardia syndrome (POTS). BACKGROUND: POTS may be associated with autoimmune disorders, serum autoantibodies, or recent infection. Uncontrolled case studies suggest that IVIG is beneficial for treating autoimmune POTS. No previous randomized controlled trials have been conducted. METHODS: This single-site randomized controlled trial compared IVIG with intravenous albumin infusions. Albumin comparator ensured blinding and control for effects of volume expansion. Eligible patients with POTS had COMPASS-31 total weighted score ≥ 40 and met predetermined criteria suggesting autoimmunity. Over 12 weeks, participants received eight infusions (0.4 gm/kg each). Four infusions were given weekly followed by four infusions every other week. Primary outcome measure was improvement in COMPASS-31 2 weeks after final infusion. RESULTS: A total of 50 participants consented; 30 met inclusion criteria and received study drug (16 IVIG and 14 albumin; 29 female). Group baseline characteristics were well matched; 27 participants completed treatment protocol. Change in COMPASS-31 did not differ between groups (median change [IQR]; IVIG: -5.5 [-23.3, 2.5] versus albumin: -10.6 [-14.1, -4.7]; p-value = 0.629). The IVIG group had a higher response rate (46.7% versus 38.5%), but this was not statistically significant. Adverse events were common but usually mild and did not differ between treatment groups. CONCLUSIONS: This small randomized controlled trial of IVIG in POTS found no statistical difference in response compared with albumin infusion. Both groups showed improvement possibly related to volume expansion or other effects obscuring group differences. These findings inform development of future immunomodulatory clinical trials in POTS.
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Doenças Autoimunes , Síndrome da Taquicardia Postural Ortostática , Humanos , Feminino , Imunoglobulinas Intravenosas/uso terapêutico , Síndrome da Taquicardia Postural Ortostática/tratamento farmacológico , Autoimunidade , Albuminas , Ensaios Clínicos Controlados Aleatórios como AssuntoRESUMO
OBJECTIVES: Endovascular reperfusion therapy (EVT) for acute ischemic stroke (AIS) with large vessel occlusion (LVO) has resulted in increased patient transfers to comprehensive stroke centers (CSCs). Clinical outcomes including the financial impact of these transfers from geographically dispersed population are lacking. Hence, we studied outcomes and cost-effectiveness of stroke transfers from remote areas. MATERIALS AND METHODS: We used a 3-year cohort of AIS patients transferred from geographically dispersed counties (<100 mi., 101-200 mi., and >200 mi.). A 3-month modified Rankin scale (mRS) score of 0-2 defined a favorable clinical outcome. Cost-effectiveness is studied by calculating the incremental cost effectiveness ratio, using hospital costs reimbursed data and utility-weighted (UW)-mRS. RESULTS: Among 172 patients transferred for EVT, patients transferred from nearby counties were more likely to undergo intervention compared to other counties (56.9% vs. 36.7% vs. 49.2% pâ¯=â¯.11). Irrespective of proximity (in mi.) to CSC [21.5 (14-56.3)] vs. 185 (137-185) vs. 349 (325-355)], there was a similar delay (in min.) to arrival from all locations [321.5 (244-490), 366 (298-432), and 460 (385-554.5) respectively], but no statistically significant differences in favorable outcomes (18.0%, 34.1%, and 22.2%, respectively, pâ¯=â¯.41). Patients undergoing EVT had higher hospital costs reimbursed compared to non-EVT patients [$37,303 (25,745-40,658) vs. $14,008 (8,640-21,273) respectively, p < .001] and no statistically significant difference in UW-mRS [0.32 (0.06-0.56) vs. 0.06 (0-0.56), pâ¯=â¯.30]. CONCLUSIONS: Our study identifies a need for targeted interventions to improve community awareness and optimize systems of care to improve outcomes and cost-effectiveness of EVT.
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Trypanosoma cruzi is a parasitic protozoa causative of Chagas disease. As part of our interest in studying the basic biology of this microorganism, this work reports our observations related to the characterization of motifs and structural domains present in two fibrillarin isoforms (TcFib1 and TcFib2) that were found to be necessary for the nuclear targeting of these nucleolar proteins. Previous characterization of these proteins indicated that they share 68.67% of identical amino acids and are both expressed as nucleolar proteins in T. cruzi epimastigotes. Using an approach based on the transfection of recombinant genes encoding fluorescent fibrillarin-EGFP fusion proteins, this study found evidence for the presence of 4 motifs or protein domains that help target these proteins to the nucleus: The GAR domain and carboxyl terminus in both TcFibs, as well as two lysines and a computationally predicted cNLS in TcFib1. As a distinctive feature, the GAR domain of TcFib2 proved to be essential for the nuclear localization of this protein paralog. Such a difference between TcFib1 and Tcfib2 nuclear localization signals can be explained as the presence of two partially related nuclear import pathways for the two fibrillarin homologues in this organism.
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Doença de Chagas , Trypanosoma cruzi , Humanos , Trypanosoma cruzi/genética , Trypanosoma cruzi/metabolismo , Transporte Ativo do Núcleo Celular , Proteínas Cromossômicas não Histona/metabolismo , Sinais de Localização Nuclear/genética , Sinais de Localização Nuclear/metabolismo , Proteínas Nucleares/genética , Proteínas Nucleares/metabolismo , Nucléolo Celular/metabolismoRESUMO
INTRODUCTION: Pulmonary arterial hypertension (PAH) is characterised by loss of microvessels. The Wnt pathways control pulmonary angiogenesis but their role in PAH is incompletely understood. We hypothesised that Wnt activation in pulmonary microvascular endothelial cells (PMVECs) is required for pulmonary angiogenesis, and its loss contributes to PAH. METHODS: Lung tissue and PMVECs from healthy and PAH patients were screened for Wnt production. Global and endothelial-specific Wnt7a -/- mice were generated and exposed to chronic hypoxia and Sugen-hypoxia (SuHx). RESULTS: Healthy PMVECs demonstrated >6-fold Wnt7a expression during angiogenesis that was absent in PAH PMVECs and lungs. Wnt7a expression correlated with the formation of tip cells, a migratory endothelial phenotype critical for angiogenesis. PAH PMVECs demonstrated reduced vascular endothelial growth factor (VEGF)-induced tip cell formation as evidenced by reduced filopodia formation and motility, which was partially rescued by recombinant Wnt7a. We discovered that Wnt7a promotes VEGF signalling by facilitating Y1175 tyrosine phosphorylation in vascular endothelial growth factor receptor 2 (VEGFR2) through receptor tyrosine kinase-like orphan receptor 2 (ROR2), a Wnt-specific receptor. We found that ROR2 knockdown mimics Wnt7a insufficiency and prevents recovery of tip cell formation with Wnt7a stimulation. While there was no difference between wild-type and endothelial-specific Wnt7a -/- mice under either chronic hypoxia or SuHx, global Wnt7a +/- mice in hypoxia demonstrated higher pulmonary pressures and severe right ventricular and lung vascular remodelling. Similar to PAH, Wnt7a +/- PMVECs exhibited an insufficient angiogenic response to VEGF-A that improved with Wnt7a. CONCLUSIONS: Wnt7a promotes VEGF signalling in lung PMVECs and its loss is associated with an insufficient VEGF-A angiogenic response. We propose that Wnt7a deficiency contributes to progressive small vessel loss in PAH.
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Hipertensão Arterial Pulmonar , Camundongos , Animais , Hipertensão Arterial Pulmonar/complicações , Fator A de Crescimento do Endotélio Vascular/metabolismo , Células Endoteliais/metabolismo , Hipertensão Pulmonar Primária Familiar/metabolismo , Hipóxia/metabolismoRESUMO
Trypanosoma cruzi is the causative agent of American trypanosomiasis, which mainly affects populations in Latin America. Benznidazole is used to control the disease, with severe effects in patients receiving this chemotherapy. Previous studies have demonstrated the inhibition of triosephosphate isomerase from T. cruzi, but cellular enzyme inhibition has yet to be established. This study demonstrates that rabeprazole inhibits both cell viability and triosephosphate isomerase activity in T. cruzi epimastigotes. Our results show that rabeprazole has an IC50 of 0.4 µM, which is 14.5 times more effective than benznidazole. Additionally, we observed increased levels of methyl-glyoxal and advanced glycation end products after the inhibition of cellular triosephosphate isomerase by rabeprazole. Finally, we demonstrate that the inactivation mechanisms of rabeprazole on triosephosphate isomerase of T. cruzi can be achieved through the derivatization of three of its four cysteine residues. These results indicate that rabeprazole is a promising candidate against American trypanosomiasis.
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Doença de Chagas , Tripanossomicidas , Trypanosoma cruzi , Humanos , Triose-Fosfato Isomerase/química , Triose-Fosfato Isomerase/farmacologia , Rabeprazol/farmacologia , Rabeprazol/uso terapêutico , Reposicionamento de Medicamentos , Doença de Chagas/tratamento farmacológico , Tripanossomicidas/farmacologiaRESUMO
THEORY: Cultural competence and humility are core elements of medical education in a diverse society. Language is inseparable from culture, as language informs, indexes, frames, and encodes both culture and worldview. Spanish is the most common non-English language taught in U.S. medical schools, yet medical Spanish courses tend to artificially separate language from culture. It is unknown to what extent medical Spanish courses advance students' sociocultural knowledge or patient care skills. HYPOTHESES: Based on current predominant pedagogy, medical Spanish classes may not adequately integrate sociocultural issues relevant to Hispanic/Latinx health. We hypothesized that students who completed a medical Spanish course would not demonstrate significant gains in sociocultural skills following the educational intervention. METHOD: An interprofessional team developed a sociocultural questionnaire, and 15 medical schools invited their students to complete the questionnaire before and after completing a medical Spanish course. Of participating schools, 12 implemented a standardized medical Spanish course and three served as control sites. Survey data were analyzed regarding: (1) perceived sociocultural competence (recognition of common cultural beliefs, recognition of culturally normative non-verbal cues, gestures, and social behaviors, ability to address sociocultural issues in healthcare context, and knowledge of health disparities); (2) application of sociocultural knowledge; and (3) demographic factors and self-rated language proficiency (Poor, Fair, Good, Very Good, or Excellent) on the Interagency Language Roundtable scale for healthcare (ILR-H). RESULTS: Overall, 610 students participated in sociocultural questionnaire between January 2020 and January 2022. After the course, participants reported an increased understanding of cultural aspects of communication with Spanish-speaking patients and the ability to apply sociocultural knowledge to patient care (all p < 0.001). When analyzed by demographic factors, students who identified as Hispanic/Latinx or as heritage speakers of Spanish tended to report increased sociocultural knowledge/skills following the course. When examined by Spanish proficiency, preliminary trends showed that students at both ILR-H Poor and Excellent levels did not demonstrate gains in sociocultural knowledge or ability to apply sociocultural skills. Students at sites with a standardized course were likely to improve sociocultural skills in mental health conversations (p < 0.001) while students at control sites were not (p = 0.05). CONCLUSIONS: Medical Spanish educators may benefit from additional guidance on teaching sociocultural aspects of communication. Our findings support that students at ILR-H levels of Fair, Good, and Very Good are particularly well-suited for gaining sociocultural skills in current medical Spanish courses. Future studies should explore potential metrics to evaluate cultural humility/competence within actual interactions with patients.
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INTRODUCTION: Cerebrovascular pathology is an early and causal hallmark of Alzheimer's disease (AD), in need of effective therapies. METHODS: Based on the success of our previous in vitro studies, we tested for the first time in a model of AD and cerebral amyloid angiopathy (CAA), the carbonic anhydrase inhibitors (CAIs) methazolamide and acetazolamide, Food and Drug Administration-approved against glaucoma and high-altitude sickness. RESULTS: Both CAIs reduced cerebral, vascular, and glial amyloid beta (Aß) accumulation and caspase activation, diminished gliosis, and ameliorated cognition in TgSwDI mice. The CAIs also improved microvascular fitness and induced protective glial pro-clearance pathways, resulting in the reduction of Aß deposition. Notably, we unveiled that the mitochondrial carbonic anhydrase-VB (CA-VB) is upregulated in TgSwDI brains, CAA and AD+CAA human subjects, and in endothelial cells upon Aß treatment. Strikingly, CA-VB silencing specifically reduces Aß-mediated endothelial apoptosis. DISCUSSION: This work substantiates the potential application of CAIs in clinical trials for AD and CAA.
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Doença de Alzheimer , Angiopatia Amiloide Cerebral , Estados Unidos , Humanos , Camundongos , Animais , Peptídeos beta-Amiloides/metabolismo , Inibidores da Anidrase Carbônica/farmacologia , Inibidores da Anidrase Carbônica/uso terapêutico , Células Endoteliais/metabolismo , Células Endoteliais/patologia , Angiopatia Amiloide Cerebral/tratamento farmacológico , Angiopatia Amiloide Cerebral/patologia , Doença de Alzheimer/patologia , CogniçãoRESUMO
Varroa destructor is a damaging mite of Western honey bees (Apis mellifera). Genetic variability of the mite in different regions of the world could be related to the movement of infested bees or other factors, such as climate. In this study, V. destructor samples were collected from tropical and temperate climate regions of Mexico, and a humid continental climate region of Canada. COX-1 AFLPs showed that all the mites were the Korean haplotype. Four microsatellites revealed nine haplogroups from the continental climate region of Canada, compared to three haplogroups from the tropical and temperate climate regions of Mexico. CytII-ATP sequences showed seven haplogroups from the humid continental climate region vs. two haplogroups from the temperate region and one haplogroup from the tropical region. CytB sequences revealed seven haplogroups from Canada vs. three from Mexico. A comparison of the cytB sequences of the samples from Canada and Mexico to those from a worldwide collection showed that one sequence, designated the cytB1 type, predominated, comprising 57% of the 86 sequences; it clustered with similar sequences that comprised 80% of the sequences, designated family A. CytB1 was predominant in Mexico, but not in Canada. The other 20% of sequences were in families B and C, and all those samples originated from East and Southeast Asia. The microsatellite, cytII-ATP, and cytB markers, all showed higher variability in mites collected in Canada than in Mexico, which could be related to the cooler climate or an earlier invasion and/or multiple mite invasions in Canada.
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Varroidae , Humanos , Animais , Abelhas/genética , Varroidae/genética , México , Clima Tropical , Canadá , Trifosfato de AdenosinaRESUMO
We tested 294 domestic pet dogs in Mexico for neutralizing antibodies for mosquito-borne flaviviruses. We found high (42.6%) exposure to West Nile virus in Reynosa (northern Mexico) and low (1.2%) exposure in Tuxtla Gutierrez (southern Mexico) but very limited exposure to Aedes-borne flaviviruses. Domestic dogs may be useful sentinels for West Nile virus.
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Aedes , Culicidae , Flavivirus , Febre do Nilo Ocidental , Vírus do Nilo Ocidental , Animais , Anticorpos Neutralizantes , Cães , México/epidemiologia , Febre do Nilo Ocidental/epidemiologia , Febre do Nilo Ocidental/veterináriaRESUMO
Immunoparesis is the suppression of normal polyclonal immunoglobulins and is present in most patients with newly diagnosed multiple myeloma (MM). The association of immunoparesis at diagnosis, and particularly its recovery along with treatment, with survival in patients ineligible for autologous stem-cell transplantation (ASCT) has not been well established. This retrospective study evaluated the impact of immunoparesis in 431 patients diagnosed with MM, ineligible for ASCT, with a median overall survival of 36 months [95% confidence interval (CI): 31-40]. Immunoparesis was present in 81.2% of patients at diagnosis and was associated with a trend to a worse overall response rate (ORR: 84.8% vs. 74.9%; OR 1.88 (95% CI: 0.97-3.63), shorter progression-free survival (PFS) [22.0 vs. 18.2 months; hazard ratio (HR) 0.775; 95%CI: 0.590-1.018; p = 0.066], and overall survival (OS) (45.9 vs. 34.2 months; HR 0.746; 95% CI: 0.551-1.010; p = 0.057). Twenty-four per cent of patients who had immunoparesis at diagnosis recovered polyclonal immunoglobulins in the follow-up period. Interestingly, these patients had a better ORR (96.3% vs. 68.2%; OR 12.29 (95% CI: 3.77-40.06), PFS (HR 0.703; 95CI%: 0.526-0.941; p = 0.018) and OS (HR 0.678; 95 CI%: 0.503-0.913; p = 0.011) than patients who did not recover it. In summary, restoring a healthy immune system along with first-line treatment in patients with MM, not receiving ASCT, is associated with better outcomes.
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Transplante de Células-Tronco Hematopoéticas , Mieloma Múltiplo , Intervalo Livre de Doença , Humanos , Imunoglobulinas , Mieloma Múltiplo/diagnóstico , Prognóstico , Intervalo Livre de Progressão , Estudos Retrospectivos , Transplante AutólogoRESUMO
At chemical synapses, synaptic vesicles release their acidic contents into the cleft, leading to the expectation that the cleft should acidify. However, fluorescent pH probes targeted to the cleft of conventional glutamatergic synapses in both fruit flies and mice reveal cleft alkalinization rather than acidification. Here, using a reaction-diffusion scheme, we modeled pH dynamics at the Drosophila neuromuscular junction as glutamate, ATP, and protons (H+) were released into the cleft. The model incorporates bicarbonate and phosphate buffering systems as well as plasma membrane calcium-ATPase activity and predicts substantial cleft acidification but only for fractions of a millisecond after neurotransmitter release. Thereafter, the cleft rapidly alkalinizes and remains alkaline for over 100 ms because the plasma membrane calcium-ATPase removes H+ from the cleft in exchange for calcium ions from adjacent pre- and postsynaptic compartments, thus recapitulating the empirical data. The extent of synaptic vesicle loading and time course of exocytosis have little influence on the magnitude of acidification. Phosphate but not bicarbonate buffering is effective at suppressing the magnitude and time course of the acid spike, whereas both buffering systems are effective at suppressing cleft alkalinization. The small volume of the cleft levies a powerful influence on the magnitude of alkalinization and its time course. Structural features that open the cleft to adjacent spaces appear to be essential for alleviating the extent of pH transients accompanying neurotransmission.
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Sinapses , Vesículas Sinápticas , Animais , Simulação por Computador , Ácido Glutâmico/metabolismo , Camundongos , Sinapses/metabolismo , Transmissão Sináptica , Vesículas Sinápticas/metabolismoRESUMO
FlhDC is a heterohexameric complex that acts as a master regulator of flagellar biosynthesis genes in numerous bacteria. Previous studies have identified a single flhDC operon encoding this complex. However, we found that two flhDC loci are present throughout Paraburkholderia, and two additional flhC copies are also present in Paraburkholderia unamae. Systematic deletion analysis in P. unamae of the different flhDC copies showed that one of the operons, flhDC1, plays the predominant role, with deletion of its genes resulting in a severe inhibition of motility and biofilm formation. Expression analysis using promoter-lacZ fusions and real-time quantitative PCR support the primary role of flhDC1 in flagellar gene regulation, with flhDC2 a secondary contributor. Phylogenetic analysis shows the presence of the flhDC1 and flhDC2 operons throughout Paraburkholderia. In contrast, Burkholderia and other bacteria only carry the copy syntenous with flhDC2. The variations in impact each copy of flhDC has on downstream processes indicate that regulation of FlhDC in P. unamae, and likely other Paraburkholderia species, is regulated at least in part by the presence of multiple copies of these genes. IMPORTANCE Motility is important in the colonization of plant roots by beneficial and pathogenic bacteria, with flagella playing essential roles in host cell adhesion, entrance, and biofilm formation. Flagellar biosynthesis is energetically expensive. Its complex regulation by the FlhDC master regulator is well studied in peritrichous flagella expressing enterics. We report the unique presence throughout Paraburkholderia of multiple copies of flhDC. In P. unamae, the flhDC1 copy showed higher expression and a greater effect on swim motility, flagellar development, and regulation of downstream genes, than the flhDC2 copy that is syntenous to flhDC in Escherichia coli and pathogenic Burkholderia spp. The flhDC genes have evolved differently in these plant-growth-promoting bacteria, giving an additional layer of complexity in gene regulation by FlhDC.
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Proteínas de Bactérias/metabolismo , Burkholderiaceae/metabolismo , Flagelos/metabolismo , Regulação Bacteriana da Expressão Gênica/fisiologia , Movimento/fisiologia , Transativadores/metabolismo , Proteínas de Bactérias/genética , Biofilmes/crescimento & desenvolvimento , Burkholderiaceae/genética , Flagelos/genética , Dosagem de Genes , Transativadores/genéticaRESUMO
The dogma that the synaptic cleft acidifies during neurotransmission is based on the corelease of neurotransmitters and protons from synaptic vesicles, and is supported by direct data from sensory ribbon-type synapses. However, it is unclear whether acidification occurs at non-ribbon-type synapses. Here we used genetically encoded fluorescent pH indicators to examine cleft pH at conventional neuronal synapses. At the neuromuscular junction of female Drosophila larvae, we observed alkaline spikes of over 1 log unit during fictive locomotion in vivo. Ex vivo, single action potentials evoked alkalinizing pH transients of only â¼0.01 log unit, but these transients summated rapidly during burst firing. A chemical pH indicator targeted to the cleft corroborated these findings. Cleft pH transients were dependent on Ca2+ movement across the postsynaptic membrane, rather than neurotransmitter release per se, a result consistent with cleft alkalinization being driven by the Ca2+/H+ antiporting activity of the plasma membrane Ca2+-ATPase at the postsynaptic membrane. Targeting the pH indicators to the microenvironment of the presynaptic voltage gated Ca2+ channels revealed that alkalinization also occurred within the cleft proper at the active zone and not just within extrasynaptic regions. Application of the pH indicators at the mouse calyx of Held, a mammalian central synapse, similarly revealed cleft alkalinization during burst firing in both males and females. These findings, made at two quite different non-ribbon type synapses, suggest that cleft alkalinization during neurotransmission, rather than acidification, is a generalizable phenomenon across conventional neuronal synapses.SIGNIFICANCE STATEMENT Neurotransmission is highly sensitive to the pH of the extracellular milieu. This is readily evident in the neurological symptoms that accompany systemic acid/base imbalances. Imaging data from sensory ribbon-type synapses show that neurotransmission itself can acidify the synaptic cleft, likely due to the corelease of protons and glutamate. It is not clear whether the same phenomenon occurs at conventional neuronal synapses due to the difficulties in collecting such data. If it does occur, it would provide for an additional layer of activity-dependent modulation of neurotransmission. Our findings of alkalinization, rather than acidification, within the cleft of two different neuronal synapses encourages a reassessment of the scope of activity-dependent pH influences on neurotransmission and short-term synaptic plasticity.
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Ácido Glutâmico/metabolismo , Junção Neuromuscular/metabolismo , Neurônios/metabolismo , Transmissão Sináptica/fisiologia , Animais , Drosophila , Feminino , Concentração de Íons de Hidrogênio , Plasticidade Neuronal/fisiologia , Vesículas Sinápticas/metabolismoRESUMO
Deletion of the long arm of chromosome 6 (del6q) is the most frequent cytogenetic abnormality in Waldenström macroglobulinaemia (WM), occurring in approximately 50% of patients. Its effect on patient outcome has not been completely established. We used fluorescence in situ hybridisation to analyse the prevalence of del6q in selected CD19+ bone marrow cells of 225 patients with newly diagnosed immunoglobulin M (IgM) monoclonal gammopathies. Del6q was identified in one of 27 (4%) cases of IgM-monoclonal gammopathy of undetermined significance, nine of 105 (9%) of asymptomatic WM (aWM), and 28/93 (30%) of symptomatic WM (sWM), and was associated with adverse prognostic features and higher International Prognostic Scoring System for WM (IPSSWM) score. Asymptomatic patients with del6q ultimately required therapy more often and had a shorter time to transformation (TT) to symptomatic disease (median TT, 30 months vs. 199 months, respectively, P < 0·001). When treatment was required, 6q-deleted patients had shorter progression-free survival (median 20 vs. 47 months, P < 0·001). The presence of del6q translated into shorter overall survival (OS), irrespective of the initial diagnosis, with a median OS of 90 compared with 131 months in non-del6q patients (P = 0·01). In summary, our study shows that del6q in IgM gammopathy is associated with symptomatic disease, need for treatment and poorer clinical outcomes.
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Transformação Celular Neoplásica/genética , Macroglobulinemia de Waldenstrom/genética , Idoso , Doenças Assintomáticas , Células da Medula Óssea/química , Células da Medula Óssea/ultraestrutura , Deleção Cromossômica , Cromossomos Humanos Par 6/genética , Feminino , Humanos , Imunoglobulina M/sangue , Imunofenotipagem , Hibridização in Situ Fluorescente , Masculino , Pessoa de Meia-Idade , Gamopatia Monoclonal de Significância Indeterminada/genética , Paraproteínas/análise , Prognóstico , Intervalo Livre de Progressão , Medição de Risco , Análise de Sobrevida , Fatores de Tempo , Resultado do Tratamento , Macroglobulinemia de Waldenstrom/patologiaRESUMO
PURPOSE: Exosomes are extracellular vesicles secreted by cells, which can transport different molecules, including nucleic acids. Dietary habits may induce gene regulation through the modulation of exosomal RNAs. We aimed at characterizing exosomal lncRNAs, mRNA and miRNAs modulation after a 1-year adherence to a low-fat diet (LFD) or to Mediterranean-based diets enriched in extra-virgin olive oil (MedDiet + EVOO) or in a mixture of nuts (MedDiet + Nuts). METHODS: Plasma samples were collected, at baseline and after 1 year of dietary interventions, from 150 participants included in the PREDIMED study (Reus Center). LncRNAs, mRNAs and miRNAs were isolated from plasma exosomes and screened. RT-qPCR validation was performed for miRNAs. RESULTS: Compared with LFD, 413 lncRNAs and 188 mRNAs, and 476 lncRNAs and 235 mRNAs were differentially modulated in response to the MedDiet + EVOO and MedDiet + Nuts interventions, respectively. In addition, after 1 year of dietary interventions, 26 circulating miRNAs were identified as differentially expressed between groups. After 1 year of intervention, 11 miRNAs significantly changed in LFD group, while 8 and 21 were modulated in response to the MedDiet enriched with EVOO or nuts, respectively. Bioinformatic analyses of differentially expressed miRNAs and their validated target genes suggest certain metabolic pathways are modulated by LFD (PI3K-Akt and AMPK), MedDiet + EVOO (PI3K-Akt, NF-kappa B, HIF-1, and insulin resistance), and MedDiet-Nuts (FoxO, PI3K-Akt, AMPK, p53 and HIF-1) interventions. CONCLUSION: Results show that 1-year MedDiet + Nuts and MedDiet + EVOO dietary interventions modulate exosomal RNA content, with the former affecting a higher number of miRNAs. The modulation of exosomal RNAs could help explain how the adherence to a Mediterranean diet may lead to beneficial effects and deserves further investigation.
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Dieta Mediterrânea , MicroRNAs , Dieta com Restrição de Gorduras , Humanos , MicroRNAs/genética , Nozes , Azeite de Oliva , Fosfatidilinositol 3-QuinasesRESUMO
INTRODUCTION: The only curative treatment for severe aplastic anemia in children is an allogeneic stem cell transplant; however, few patients have a matched related or unrelated donor. Haploidentical stem cell transplantation (haplo-SCT) using bone marrow (BM) and peripheral blood stem cells (PBSC) has been recently described as effective and safe. In this study, we retrospectively report the outcome of twelve pediatric patients who underwent haplo-SCT using only PBSC. METHODS: The conditioning regimen consisted on rabbit anti-thymocyte globulin (r-ATG) 2.5 mg/kg/d on days -7, -6,-5, and -4, and cyclophosphamide (Cy) 50 mg/kg/d on days -3 and -2. We used Cy 50 mg/kg/d on days +3 and +4, tacrolimus and mycophenolic acid as graft versus host disease (GVHD) prophylaxis. RESULTS: The median follow-up was 1,099 days (45-1258 days). The overall survival rate up-to-date is 83.3%. In 10 of the 12 patients, a sustained graft was achieved. None of the patients had acute or chronic GVHD. CONCLUSIONS: Haplo-SCT could be established as a first-line treatment when there is no matched related or unrelated donor. According to this short sample and previous reports, PBSC are a feasible option effectively used as the sole source of stem cells. Additionally, post-transplant cyclophosphamide remains a good strategy for GVHD prevention.
Assuntos
Anemia Aplástica/terapia , Antígenos CD34 , Transplante de Células-Tronco Hematopoéticas , Transplante Haploidêntico , Adolescente , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Masculino , México , Estudos Retrospectivos , Condicionamento Pré-TransplanteRESUMO
Current treatments for Chagas disease have a limited impact during the chronic stage and trigger severe side effects. Treatments target Trypanosoma cruzi, the etiological agent of the disease. The aims of this study were to evaluate the trypanocidal activity of four 2-phenylbenzothiazole derivatives (BZT1-4) in vitro by using the infectious and non-infectious forms of T. cruzi (trypomastigotes and epimastigotes, respectively) and to test the most promising compound (BZT4) in vivo in mice. Additionally, the toxicological profile and possible neuronal damage were examined. In relation to trypomastigotes, BZT4 was more selective and effective than the reference drug (benznidazole) during this infective stage, apparently due to the synergistic action of the CF3 and COOH substituents in the molecule. During the first few hours post-administration of BZT4, parasitemia decreased by 40% in an in vivo model of short-term treatment, but parasite levels later returned to the basal state. In the long-term assessment, the compound did not produce a significant antiparasitic effect, only attaining a 30% reduction in parasitemia by day 20 with the dose of 16 mg/kg. The toxicity test was based on repeated dosing of BZT4 (administered orally) during 21 days, which did not cause liver damage. However, the compound altered the concentration of proteins and the proteinic profile of neuronal cells in vitro, perhaps leading to an effect on the central nervous system. Further research on the low trypanocidal activity in vivo compared to the better in vitro effect could possibly facilitate molecular redesign to improve trypanocidal activity.
Assuntos
Doença de Chagas , Nitroimidazóis , Tiazóis , Tripanossomicidas , Trypanosoma cruzi , Animais , Doença de Chagas/tratamento farmacológico , Camundongos , Nitroimidazóis/uso terapêutico , Nitroimidazóis/toxicidade , Tiazóis/uso terapêutico , Tiazóis/toxicidade , Testes de Toxicidade , Tripanossomicidas/uso terapêutico , Tripanossomicidas/toxicidade , Trypanosoma cruzi/efeitos dos fármacosRESUMO
Overfishing of sea cucumber Isostichopus badionotus from Yucatan has led to a major population decline. They are being captured as an alternative to traditional species despite a paucity of information about their health-promoting properties. The transcriptome of the body wall of wild and farmed I. badionotus has now been studied for the first time by an RNA-Seq approach. The functional profile of wild I. badionotus was comparable with data in the literature for other regularly captured species. In contrast, the metabolism of first generation farmed I. badionotus was impaired. This had multiple possible causes including a sub-optimal growth environment and impaired nutrient utilization. Several key metabolic pathways that are important in effective handling and accretion of nutrients and energy, or clearance of harmful cellular metabolites, were disrupted or dysregulated. For instance, collagen mRNAs were greatly reduced and deposition of collagen proteins impaired. Wild I. badionotus is, therefore, a suitable alternative to other widely used species but, at present, the potential of farmed I. badionotus is unclear. The environmental or nutritional factors responsible for their impaired function in culture remain unknown, but the present data gives useful pointers to the underlying problems associated with their aquaculture.