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1.
Brain ; 147(5): 1871-1886, 2024 May 03.
Artigo em Inglês | MEDLINE | ID: mdl-38128553

RESUMO

Multiple sclerosis is a chronic inflammatory disease in which disability results from the disruption of myelin and axons. During the initial stages of the disease, injured myelin is replaced by mature myelinating oligodendrocytes that differentiate from oligodendrocyte precursor cells. However, myelin repair fails in secondary and chronic progressive stages of the disease and with ageing, as the environment becomes progressively more hostile. This may be attributable to inhibitory molecules in the multiple sclerosis environment including activation of the p38MAPK family of kinases. We explored oligodendrocyte precursor cell differentiation and myelin repair using animals with conditional ablation of p38MAPKγ from oligodendrocyte precursors. We found that p38γMAPK ablation accelerated oligodendrocyte precursor cell differentiation and myelination. This resulted in an increase in both the total number of oligodendrocytes and the migration of progenitors ex vivo and faster remyelination in the cuprizone model of demyelination/remyelination. Consistent with its role as an inhibitor of myelination, p38γMAPK was significantly downregulated as oligodendrocyte precursor cells matured into oligodendrocytes. Notably, p38γMAPK was enriched in multiple sclerosis lesions from patients. Oligodendrocyte progenitors expressed high levels of p38γMAPK in areas of failed remyelination but did not express detectable levels of p38γMAPK in areas where remyelination was apparent. Our data suggest that p38γ could be targeted to improve myelin repair in multiple sclerosis.


Assuntos
Esclerose Múltipla , Bainha de Mielina , Oligodendroglia , Remielinização , Animais , Remielinização/fisiologia , Esclerose Múltipla/patologia , Esclerose Múltipla/metabolismo , Bainha de Mielina/metabolismo , Bainha de Mielina/patologia , Camundongos , Oligodendroglia/metabolismo , Oligodendroglia/patologia , Humanos , Proteína Quinase 12 Ativada por Mitógeno/metabolismo , Proteína Quinase 12 Ativada por Mitógeno/genética , Diferenciação Celular/fisiologia , Cuprizona/toxicidade , Camundongos Endogâmicos C57BL , Masculino , Feminino , Doenças Desmielinizantes/patologia , Doenças Desmielinizantes/metabolismo , Células Precursoras de Oligodendrócitos/metabolismo , Células Precursoras de Oligodendrócitos/patologia , Camundongos Transgênicos
2.
Arch Microbiol ; 203(7): 4209-4219, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34080042

RESUMO

Conjugated estrogens, such as 17ß-estradiol-3-sulfate (E2-3S), can be released into aquatic environments through wastewater treatment plants (WWTP). There, they are microbiologically degraded into free estrogens, which can have harmful effects on aquatic wildlife. Here, the degradation of E2-3S in environmental samples taken upstream, downstream and at the effluent of a WWTP was assessed. Sediment and biofilm samples were enriched for E2-3S-degrading microorganisms, yielding a broad diversity of bacterial isolates, including known and novel degraders of estrogens. Since E2-3S-degrading bacteria were also isolated in the sample upstream of the WWTP, the WWTP does not influence the ability of the microbial community to degrade E2-3S.


Assuntos
Bactérias , Biodiversidade , Biofilmes , Estradiol/análogos & derivados , Sedimentos Geológicos , Bactérias/classificação , Bactérias/genética , Estradiol/análise , Estradiol/metabolismo , Sedimentos Geológicos/microbiologia , Poluentes Químicos da Água/análise , Poluentes Químicos da Água/metabolismo , Purificação da Água
3.
PLoS Biol ; 14(4): e1002440, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-27070899

RESUMO

Microtubule-based kinesin motors have many cellular functions, including the transport of a variety of cargos. However, unconventional roles have recently emerged, and kinesins have also been reported to act as scaffolding proteins and signaling molecules. In this work, we further extend the notion of unconventional functions for kinesin motor proteins, and we propose that Kif13b kinesin acts as a signaling molecule regulating peripheral nervous system (PNS) and central nervous system (CNS) myelination. In this process, positive and negative signals must be tightly coordinated in time and space to orchestrate myelin biogenesis. Here, we report that in Schwann cells Kif13b positively regulates myelination by promoting p38γ mitogen-activated protein kinase (MAPK)-mediated phosphorylation and ubiquitination of Discs large 1 (Dlg1), a known brake on myelination, which downregulates the phosphatidylinositol 3-kinase (PI3K)/v-AKT murine thymoma viral oncogene homolog (AKT) pathway. Interestingly, Kif13b also negatively regulates Dlg1 stability in oligodendrocytes, in which Dlg1, in contrast to Schwann cells, enhances AKT activation and promotes myelination. Thus, our data indicate that Kif13b is a negative regulator of CNS myelination. In summary, we propose a novel function for the Kif13b kinesin in glial cells as a key component of the PI3K/AKT signaling pathway, which controls myelination in both PNS and CNS.


Assuntos
Sistema Nervoso Central/fisiologia , Cinesinas/fisiologia , Proteínas de Membrana/fisiologia , Bainha de Mielina/fisiologia , Proteínas do Tecido Nervoso/fisiologia , Sistema Nervoso Periférico/fisiologia , Animais , Proteína 1 Homóloga a Discs-Large , Camundongos , Camundongos Knockout , Oligodendroglia/metabolismo , Proteínas Associadas SAP90-PSD95 , Células de Schwann/metabolismo , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismo
4.
J Invertebr Pathol ; 120: 59-66, 2014 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-24907449

RESUMO

A potential Delia radicum biological control strategy involving cauliflower plantlet inoculation with various fungi was investigated in a series of laboratory and glasshouse experiments. In addition to entomopathogenic fungi, fungi with a high rhizosphere competence and fungi with the ability to survive as saprotrophs in soil were tested. The following fungal species were evaluated in the experiments: Trichoderma atroviride, T. koningiopsis, T. gamsii, Beauveria bassiana, Metharhizium anisopliae, M. brunneum and Clonostachys solani. A commercial carbosulfan-based insecticide was used as a positive control. Additionally, two commercial products, one based on B. bassiana (Naturalis) and one on Bacillus thuringiensis (Delfin) were used as reference biocontrol agents. The aims were (i) to assess the pathogenicity of the selected fungal isolates to Delia radicum, (ii) to evaluate the fungal isolates' rhizosphere competence, with the emphasis on the persistence of the original inoculum on the growing roots, (iii) to assess possible endophytic plant tissue colonization, and (iv) to evaluate potential plant growth stimulating effects of the added inoculi. Significant pathogenicity of tested fungi against Delia radicum was confirmed in in vitro and glasshouse experiments. All tested fungi persisted on cauliflower rhizoplane. More importantly, the added fungi were found on thoroughly washed roots outside the original point of inoculation. This provided us with evidence that our tested fungi could be transferred via or grow with the elongating roots. In addition to colonizing the rhizoplane, some fungi were found inside the plant root or stem tissue, thus exhibiting endophytic characteristics. The importance of fungal ecology as a criterion in appropriate biological control agent selection is discussed.


Assuntos
Brassica/microbiologia , Dípteros/microbiologia , Fungos , Larva/microbiologia , Controle Biológico de Vetores/métodos , Animais , Doenças das Plantas/microbiologia , Raízes de Plantas/crescimento & desenvolvimento , Raízes de Plantas/microbiologia
5.
J Asthma Allergy ; 15: 1593-1604, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36387835

RESUMO

Purpose: Benralizumab effectively reduces severe eosinophilic asthma (SEA) exacerbations in patients with a wide range of baseline blood eosinophil count (BEC). Patients included in real-world studies are often characterized by high mean/median BEC, while patients with BEC close to 300 cells/mm3 are poorly represented. This post hoc analysis from the Italian study ANANKE aims to define the clinical features and corroborate the efficacy of benralizumab in real world in the BEC 300-450 cells/mm3 subset of patients. Patients and Methods: Post hoc analysis of the Italian, multicenter, observational, retrospective real-life study ANANKE (NCT04272463). Baseline clinical and laboratory characteristics were collected in the 12 months prior to benralizumab treatment and presented for a BEC 300-450 cells/mm3 subgroup of patients. Change over time of BEC, annualized exacerbation rate (AER), asthma control (ACT), lung function and oral corticosteroid (OCS) use at 16, 24 and 48 weeks after benralizumab introduction were collected. Results: A total of 164 patients were analyzed, 34 of whom with a BEC of 300-450 cells/mm3. This subgroup was more likely to be female (64.7%), with lower rates of severe exacerbations at baseline when compared to the total population (0.69 vs 1.01). After 48 weeks of benralizumab treatment, the BEC 300-450 subset showed similar reductions in AER (-94.8% vs -92.2%) and OCS use (median dose reduction of 100% in both groups), as well as improvement in ACT score (median scores 22.5 vs 22) and lung function (pre-BD FEV1: +200 mL vs +300 mL) when compared to the total population. No discontinuations for safety reasons were registered. Conclusion: At baseline, apart from lower severe exacerbation rate, the BEC 300-450 cells/mm3 subset of patients is comparable to the total population prescribed with benralizumab. In this real-life study, benralizumab is as effective in BEC 300-450 patients as in the total population.

6.
Neurosci Lett ; 753: 135868, 2021 05 14.
Artigo em Inglês | MEDLINE | ID: mdl-33812927

RESUMO

Small Rho GTPases such as Cdc42 and Rac1 regulate peripheral myelination during development. Deletion of Rac1 in Schwann cell conditional knockout mice causes a delay in the process of radial sorting, followed by hypomyelination as well as defective PAK1 activation and high number of immature Oct6+ Schwann cells. Rac3 has been shown to have redundant, specific and even opposite functions to Rac1 depending on the cell type, age and other factors. In neuronal cells, evidence suggests that Rac3 may oppose Rac1 by disrupting PAK1-GIT1-Paxillin signaling thus preventing cell differentiation and extension of lamellipodia. Therefore, we tested if these Rho GTPases have similar or opposite functions in Schwann cells, by deleting the genes for both proteins in mice during peripheral myelination. At P30, global deletion of Rac3 alleviates the developmental defects on axonal sorting and hypomyelination that are caused by Schwann cell conditional ablation of Rac1. Moreover, Rac3 deletion also reverses the arrest of Schwann cells at the Oct6+ stage and ameliorates the defects in PAK1 phosphorylation observed in Rac1 deficient mice. This partial rescue of the phenotype declines later on with aging. Since double transgenic animals showed dysmyelination without axonal degeneration at P60, we postulate that this deterioration is not likely due to loss of Rac3 in neurons, but it seems to be a Schwann cell-specific defect in the maintenance of myelin.


Assuntos
Bainha de Mielina/metabolismo , Neuropeptídeos/metabolismo , Células de Schwann/fisiologia , Proteínas rac de Ligação ao GTP/metabolismo , Proteínas rac1 de Ligação ao GTP/metabolismo , Animais , Axônios/metabolismo , Diferenciação Celular , Camundongos , Camundongos Knockout , Neuropeptídeos/genética , Fosforilação , Quinases Ativadas por p21/metabolismo , Proteínas rac1 de Ligação ao GTP/genética
7.
PLoS One ; 14(6): e0218166, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31188879

RESUMO

OBJECTIVE: Non-invasive prenatal testing (NIPT) based on cell-free fetal DNA (cffDNA) is highly accurate in the detection of common fetal autosomal trisomies. Aim of this project was to investigate short-term costs and clinical outcomes of the contingent use of cffDNA for prenatal screening of trisomies 21, 18, 13 within a national health service (NHS). METHODS: An economic analysis was developed from the perspective of the Italian NHS to compare two possible scenarios for managing pregnant women: women managed according to the Standard of Care screening (SoC) vs a cffDNA scenario, where Harmony Prenatal Test was introduced as a second line screening choice for women with an "at risk" result from SoC screening. RESULTS: The introduction of cffDNA as a second line screening test, conditional to a risk ≥ 1:1,000 from SoC screening, showed a 3% increase in the detection of trisomies, with a 71% decrease in the number of invasive tests performed. Total short-term costs (pregnancy management until childbirth) decreased by € 19 million (from € 84.5 to 65.5 million). CONCLUSION: The adoption of the Harmony Prenatal Test in women resulting at risk from SoC screening, implied a greater number of trisomies detection, together with a reduction of the healthcare costs.


Assuntos
Ácidos Nucleicos Livres/economia , DNA/economia , Síndrome de Down/economia , Diagnóstico Pré-Natal/economia , Síndrome da Trissomia do Cromossomo 13/economia , Síndrome da Trissomía do Cromossomo 18/economia , Orçamentos/métodos , Ácidos Nucleicos Livres/genética , DNA/genética , Síndrome de Down/diagnóstico , Síndrome de Down/genética , Feminino , Testes Genéticos/economia , Custos de Cuidados de Saúde , Humanos , Gravidez , Síndrome da Trissomia do Cromossomo 13/diagnóstico , Síndrome da Trissomia do Cromossomo 13/genética , Síndrome da Trissomía do Cromossomo 18/diagnóstico , Síndrome da Trissomía do Cromossomo 18/genética
8.
Nat Neurosci ; 19(7): 879-87, 2016 07.
Artigo em Inglês | MEDLINE | ID: mdl-27273766

RESUMO

Myelination is essential for nervous system function. Schwann cells interact with neurons and the basal lamina to myelinate axons using known receptors, signals and transcription factors. In contrast, the transcriptional control of axonal sorting and the role of mechanotransduction in myelination are largely unknown. Yap and Taz are effectors of the Hippo pathway that integrate chemical and mechanical signals in cells. We describe a previously unknown role for the Hippo pathway in myelination. Using conditional mutagenesis in mice, we show that Taz is required in Schwann cells for radial sorting and myelination and that Yap is redundant with Taz. Yap and Taz are activated in Schwann cells by mechanical stimuli and regulate Schwann cell proliferation and transcription of basal lamina receptor genes, both necessary for radial sorting of axons and subsequent myelination. These data link transcriptional effectors of the Hippo pathway and of mechanotransduction to myelin formation in Schwann cells.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Movimento Celular/fisiologia , Proliferação de Células/fisiologia , Bainha de Mielina/metabolismo , Fosfoproteínas/metabolismo , Células de Schwann/metabolismo , Fatores de Transcrição/metabolismo , Aciltransferases , Animais , Axônios/fisiologia , Axônios/ultraestrutura , Proteínas de Ciclo Celular , Células Cultivadas , Mecanotransdução Celular/fisiologia , Camundongos Endogâmicos C57BL , Neurogênese/fisiologia , Receptores de Laminina/metabolismo , Células de Schwann/citologia , Proteínas de Sinalização YAP
9.
J Cell Biol ; 208(3): 313-29, 2015 Feb 02.
Artigo em Inglês | MEDLINE | ID: mdl-25646087

RESUMO

Fast neural conduction requires accumulation of Na(+) channels at nodes of Ranvier. Dedicated adhesion molecules on myelinating cells and axons govern node organization. Among those, specific laminins and dystroglycan complexes contribute to Na(+) channel clustering at peripheral nodes by unknown mechanisms. We show that in addition to facing the basal lamina, dystroglycan is found near the nodal matrix around axons, binds matrix components, and participates in initial events of nodogenesis. We identify the dystroglycan-ligand perlecan as a novel nodal component and show that dystroglycan is required for the selective accumulation of perlecan at nodes. Perlecan binds the clustering molecule gliomedin and enhances clustering of node of Ranvier components. These data show that proteoglycans have specific roles in peripheral nodes and indicate that peripheral and central axons use similar strategies but different molecules to form nodes of Ranvier. Further, our data indicate that dystroglycan binds free matrix that is not organized in a basal lamina.


Assuntos
Moléculas de Adesão Celular Neuronais/metabolismo , Proteoglicanas de Heparan Sulfato/metabolismo , Nós Neurofibrosos/metabolismo , Animais , Células Cultivadas , Técnicas de Cocultura , Distroglicanas/metabolismo , Matriz Extracelular/metabolismo , Humanos , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos DBA , Camundongos Transgênicos , Microvilosidades/metabolismo , Ligação Proteica , Transporte Proteico , Proteólise , Canais de Sódio/metabolismo
10.
PLoS One ; 9(7): e100592, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24984037

RESUMO

X-ray diffraction has provided extensive information about the arrangement of lipids and proteins in multilamellar myelin. This information has been limited to the abundant inter-nodal regions of the sheath because these regions dominate the scattering when x-ray beams of 100 µm diameter or more are used. Here, we used a 1 µm beam, raster-scanned across a single nerve fiber, to obtain detailed information about the molecular architecture in the nodal, paranodal, and juxtaparanodal regions. Orientation of the lamellar membrane stacks and membrane periodicity varied spatially. In the juxtaparanode-internode, 198-202 Å-period membrane arrays oriented normal to the nerve fiber axis predominated, whereas in the paranode-node, 205-208 Å-period arrays oriented along the fiber direction predominated. In parts of the sheath distal to the node, multiple sets of lamellar reflections were observed at angles to one another, suggesting that the myelin multilayers are deformed at the Schmidt-Lanterman incisures. The calculated electron density of myelin in the different regions exhibited membrane bilayer profiles with varied electron densities at the polar head groups, likely due to different amounts of major myelin proteins (P0 glycoprotein and myelin basic protein). Scattering from the center of the nerve fibers, where the x-rays are incident en face (perpendicular) to the membrane planes, provided information about the lateral distribution of protein. By underscoring the heterogeneity of membrane packing, microdiffraction analysis suggests a powerful new strategy for understanding the underlying molecular foundation of a broad spectrum of myelinopathies dependent on local specializations of myelin structure in both the PNS and CNS.


Assuntos
Membrana Celular/química , Proteína Básica da Mielina/química , Proteína P0 da Mielina/química , Bainha de Mielina/química , Difração de Raios X , Animais , Membrana Celular/metabolismo , Camundongos , Proteína Básica da Mielina/metabolismo , Proteína P0 da Mielina/metabolismo , Bainha de Mielina/metabolismo
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