Leucine-Rich Repeat Kinase-2 Controls the Differentiation and Maturation of Oligodendrocytes in Mice and Zebrafish

Leucine-rich repeat kinase-2 (LRRK2), a gene mutated in familial and sporadic Parkinson’s disease (PD), controls multiple cellular processes important for GLIA physiology. Interestingly, emerging studies report that LRRK2 is highly expressed in oligodendrocyte precursor cells (OPCs) compared to the pathophysiology of other brain cells and oligodendrocytes (OLs) in PD. Altogether, these observations suggest crucial function(s) of LRRK2 in OPCs/Ols, which would be interesting to explore. In this study, we investigated the role of LRRK2 in OLs. We showed that LRRK2 knock-out (KO) OPC cultures displayed defects in the transition of OPCs into OLs, suggesting a role of LRRK2 in OL differentiation. Consistently, we found an alteration of myelin basic protein (MBP) striosomes in LRRK2 KO mouse brains and reduced levels of oligodendrocyte transcription factor 2 (Olig2) and Mbp in olig2:EGFP and mbp:RFP transgenic zebrafish embryos injected with lrrk2 morpholino (MO). Moreover, lrrk2 knock-down zebrafish exhibited a lower amount of nerve growth factor (Ngf) compared to control embryos, which represents a potent regulator of oligodendrogenesis and myelination. Overall, our findings indicate that LRRK2 controls OL differentiation, affecting the number of mature OLs

Systematic Chromosomal Analysis of Cultured Mouse Neural Stem Cell Lines

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Metabolism of the EGFR tyrosin kinase inhibitor gefitinib by cytochrome P450 1A1 enzyme in EGFR-wild type non small cell lung cancer cell lines

<p>Abstract</p> <p>Background</p> <p>Gefitinib is a tyrosine kinase inhibitor (TKI) of the epidermal growth factor receptor (EGFR) especially effective in tumors with activating EGFR gene mutations while EGFR wild-type non small cell lung cancer (NSCLC) patients at present do not benefit from this treatment.</p> <p>The primary site of gefitinib metabolism is the liver, nevertheless tumor cell metabolism can significantly affect treatment effectiveness.</p> <p>Results</p> <p>In this study, we investigated the intracellular metabolism of gefitinib in a panel of EGFR wild-type gefitinib-sensitive and -resistant NSCLC cell lines, assessing the role of cytochrome P450 1A1 (CYP1A1) inhibition on gefitinib efficacy. Our results indicate that there is a significant difference in drug metabolism between gefitinib-sensitive and -resistant cell lines. Unexpectedly, only sensitive cells metabolized gefitinib, producing metabolites which were detected both inside and outside the cells. As a consequence of gefitinib metabolism, the intracellular level of gefitinib was markedly reduced after 12-24 h of treatment. Consistent with this observation, RT-PCR analysis and EROD assay showed that mRNA and activity of CYP1A1 were present at significant levels and were induced by gefitinib only in sensitive cells. Gefitinib metabolism was elevated in crowded cells, stimulated by exposure to cigarette smoke extract and prevented by hypoxic condition. It is worth noting that the metabolism of gefitinib in the sensitive cells is a consequence and not the cause of drug responsiveness, indeed treatment with a CYP1A1 inhibitor increased the efficacy of the drug because it prevented the fall in intracellular gefitinib level and significantly enhanced the inhibition of EGFR autophosphorylation, MAPK and PI3K/AKT/mTOR signalling pathways and cell proliferation.</p> <p>Conclusion</p> <p>Our findings suggest that gefitinib metabolism in lung cancer cells, elicited by CYP1A1 activity, might represent an early assessment of gefitinib responsiveness in NSCLC cells lacking activating mutations. On the other hand, in metabolizing cells, the inhibition of CYP1A1 might lead to increased local exposure to the active drug and thus increase gefitinib potency.</p

Duration of viremia and fecal shedding of the virus in hepatitis A infected children

La infección por el virus de hepatitis A (HAV) es endémica en Argentina. El uso de técnicas moleculares permitió extender la detección del RNA del HAV en suero y heces en pacientes con diferentes presentaciones clínicas. Comparamos la sensibilidad del protocolo de RT-PCR que usamos con cebadores dirigidos a distintas regiones del genoma, resultando la detección de la región VP3 C terminal la más sensible. Se obtuvieron prospectivamente muestras de suero y materia fecal de 20 niños con hepatitis aguda autolimitada por HAV. El RNA del HAV fue detectado en 18/20 niños en muestras basales y en 19/20 sumando una muestra posterior. El RNA del HAV fue detectable en 9/20 pacientes hasta 30 días en suero; en materia fecal en 2/20 hasta 60 días y en 1/20 hasta 90 días. La secuencia genómica para la región VP1/2A en 8 muestras demostró que todas pertenecían al subgenotipo IA, aunque eran diferentes entre sí. Solo en 1/11 niños con falla hepática fulminante fue posible la detección del RNA del HAV utilizando la región VP3 C terminal y el genotipo fue I. La reciente introducción de la vacunación universal en niños de 1 año de edad en Argentina podría disminuir drásticamente la circulación del virus emergiendo nuevas fuentes de infección y permitiendo la introducción de nuevos genotipos. Las técnicas moleculares aplicadas al estudio de la historia natural de la infección y a la vigilancia epidemiológica contribuyen al control y la toma de decisiones eficientes en políticas de Salud Pública.Hepatitis A virus (HAV) infection is endemic in Argentina. Molecular tools have allowed HAV RNA detection to be extent to sera and feces from patients with different clinical backgrounds. We compare the sensitivity of the RT-PCR protocol we follow using primers targeting different genomic regions and VP3 C terminal was the most sensitive. Sequential sera and fecal samples were obtained from 20 children with acute self limited Hepatitis A. HAV RNA was detectable in 18/20 children if sera and stool specimens were collected at the onset of symptoms and in 19/20 if a later sample was considered. HAV RNA was detectable in serum from 9/20 patients until day 30 and in feces from 2 patients until day 60 and until day 90 in one. Genomic sequences from VP1/2A region in 8 samples showed they all belong to subgenotype IA although they were different between them. HAV RNA was detectable only in 1/11 sera from children with acute liver failure when VP3 C terminal fragment was searched and it belonged to genotype I. Universal vaccination in one year old children was recently implemented in Argentina and it will dramatically enable the decrease of the viral circulation, making new sources of infection emerge and allowing the introduction of new genotypes. The application of molecular tools to the study of the natural history of infection and to the epidemiologic surveillance may contribute to efficient control and lead to rational decisions in public health policies.Fil: Munné, María Silvina. ANLIS Dr.C.G.Malbrán. Instituto Nacional de Enfermedades Infecciosas. Laboratorio Nacional de Referencia de Hepatitis Virales; Argentina.Fil: Cañero Velasco, María C. Hospital Municipal del Niño de San Justo. Unidad de Gastroenterología y Hepatología; Argentina.Fil: Moreiro, Rita. Hospital Nacional de Pediatría J. P. Garrahan. Laboratorio; Argentina.Fil: Vladimirsky, Sara. ANLIS Dr.C.G.Malbrán. Instituto Nacional de Enfermedades Infecciosas. Laboratorio Nacional de Referencia de Hepatitis Virales; Argentina.Fil: Otegui, Lucio. ANLIS Dr.C.G.Malbrán. Instituto Nacional de Enfermedades Infecciosas. Laboratorio Nacional de Referencia de Hepatitis Virales; Argentina.Fil: Castro, Raúl. ANLIS Dr.C.G.Malbrán. Instituto Nacional de Enfermedades Infecciosas. Laboratorio Nacional de Referencia de Hepatitis Virales; Argentina.Fil: Brajterman, Leonardo. ANLIS Dr.C.G.Malbrán. Instituto Nacional de Enfermedades Infecciosas. Laboratorio Nacional de Referencia de Hepatitis Virales; Argentina.Fil: Soto, Sonia. ANLIS Dr.C.G.Malbrán. Instituto Nacional de Enfermedades Infecciosas. Laboratorio Nacional de Referencia de Hepatitis Virales; Argentina.Fil: Mutti, Jorge. Hospital Municipal del Niño de San Justo. Unidad de Gastroenterología y Hepatología; Argentina.Fil: Nucifora, Silvia. Hospital Municipal del Niño de San Justo. Unidad de Gastroenterología y Hepatología; Argentina.Fil: Lara, Elena. Hospital Municipal del Niño de San Justo. Laboratorio Central; Argentina.Fil: Sosa, Anibal. Hospital Municipal del Niño de San Justo. Laboratorio Central; Argentina.Fil: Godoy, Patricia. Hospital Municipal del Niño de San Justo. Unidad de Gastroenterología y Hepatología; Argentina.Fil: Ciocca, Mirta. Hospital Nacional de Pediatría J. P. Garrahan. Unidad de Hígado; Argentina.Fil: Cuarterolo, Miriam. Hospital Nacional de Pediatría J. P. Garrahan. Unidad de Hígado; Argentina.Fil: Quarleri, Jorge F. Facultad de Medicina. Centro Nacional de Referencia para el SIDA; Argentina.Fil: González, Jorge E. ANLIS Dr.C.G.Malbrán. Instituto Nacional de Enfermedades Infecciosas. Laboratorio Nacional de Referencia de Hepatitis Virales; Argentina

Duration of viremia and fecal shedding of the virus in hepatitis A infected children

La infección por el virus de hepatitis A (HAV) es endémica en Argentina. El uso de técnicas moleculares permitió extender la detección del RNA del HAV en suero y heces en pacientes con diferentes presentaciones clínicas. Comparamos la sensibilidad del protocolo de RT-PCR que usamos con cebadores dirigidos a distintas regiones del genoma, resultando la detección de la región VP3 C terminal la más sensible. Se obtuvieron prospectivamente muestras de suero y materia fecal de 20 niños con hepatitis aguda autolimitada por HAV. El RNA del HAV fue detectado en 18/20 niños en muestras basales y en 19/20 sumando una muestra posterior. El RNA del HAV fue detectable en 9/20 pacientes hasta 30 días en suero; en materia fecal en 2/20 hasta 60 días y en 1/20 hasta 90 días. La secuencia genómica para la región VP1/2A en 8 muestras demostró que todas pertenecían al subgenotipo IA, aunque eran diferentes entre sí. Solo en 1/11 niños con falla hepática fulminante fue posible la detección del RNA del HAV utilizando la región VP3 C terminal y el genotipo fue I. La reciente introducción de la vacunación universal en niños de 1 año de edad en Argentina podría disminuir drásticamente la circulación del virus emergiendo nuevas fuentes de infección y permitiendo la introducción de nuevos genotipos. Las técnicas moleculares aplicadas al estudio de la historia natural de la infección y a la vigilancia epidemiológica contribuyen al control y la toma de decisiones eficientes en políticas de Salud Pública.Hepatitis A virus (HAV) infection is endemic in Argentina. Molecular tools have allowed HAV RNA detection to be extent to sera and feces from patients with different clinical backgrounds. We compare the sensitivity of the RT-PCR protocol we follow using primers targeting different genomic regions and VP3 C terminal was the most sensitive. Sequential sera and fecal samples were obtained from 20 children with acute self limited Hepatitis A. HAV RNA was detectable in 18/20 children if sera and stool specimens were collected at the onset of symptoms and in 19/20 if a later sample was considered. HAV RNA was detectable in serum from 9/20 patients until day 30 and in feces from 2 patients until day 60 and until day 90 in one. Genomic sequences from VP1/2A region in 8 samples showed they all belong to subgenotype IA although they were different between them. HAV RNA was detectable only in 1/11 sera from children with acute liver failure when VP3 C terminal fragment was searched and it belonged to genotype I. Universal vaccination in one year old children was recently implemented in Argentina and it will dramatically enable the decrease of the viral circulation, making new sources of infection emerge and allowing the introduction of new genotypes. The application of molecular tools to the study of the natural history of infection and to the epidemiologic surveillance may contribute to efficient control and lead to rational decisions in public health policies.Fil: Munné, María Silvina. ANLIS Dr.C.G.Malbrán. Instituto Nacional de Enfermedades Infecciosas. Laboratorio Nacional de Referencia de Hepatitis Virales; Argentina.Fil: Cañero Velasco, María C. Hospital Municipal del Niño de San Justo. Unidad de Gastroenterología y Hepatología; Argentina.Fil: Moreiro, Rita. Hospital Nacional de Pediatría J. P. Garrahan. Laboratorio; Argentina.Fil: Vladimirsky, Sara. ANLIS Dr.C.G.Malbrán. Instituto Nacional de Enfermedades Infecciosas. Laboratorio Nacional de Referencia de Hepatitis Virales; Argentina.Fil: Otegui, Lucio. ANLIS Dr.C.G.Malbrán. Instituto Nacional de Enfermedades Infecciosas. Laboratorio Nacional de Referencia de Hepatitis Virales; Argentina.Fil: Castro, Raúl. ANLIS Dr.C.G.Malbrán. Instituto Nacional de Enfermedades Infecciosas. Laboratorio Nacional de Referencia de Hepatitis Virales; Argentina.Fil: Brajterman, Leonardo. ANLIS Dr.C.G.Malbrán. Instituto Nacional de Enfermedades Infecciosas. Laboratorio Nacional de Referencia de Hepatitis Virales; Argentina.Fil: Soto, Sonia. ANLIS Dr.C.G.Malbrán. Instituto Nacional de Enfermedades Infecciosas. Laboratorio Nacional de Referencia de Hepatitis Virales; Argentina.Fil: Mutti, Jorge. Hospital Municipal del Niño de San Justo. Unidad de Gastroenterología y Hepatología; Argentina.Fil: Nucifora, Silvia. Hospital Municipal del Niño de San Justo. Unidad de Gastroenterología y Hepatología; Argentina.Fil: Lara, Elena. Hospital Municipal del Niño de San Justo. Laboratorio Central; Argentina.Fil: Sosa, Anibal. Hospital Municipal del Niño de San Justo. Laboratorio Central; Argentina.Fil: Godoy, Patricia. Hospital Municipal del Niño de San Justo. Unidad de Gastroenterología y Hepatología; Argentina.Fil: Ciocca, Mirta. Hospital Nacional de Pediatría J. P. Garrahan. Unidad de Hígado; Argentina.Fil: Cuarterolo, Miriam. Hospital Nacional de Pediatría J. P. Garrahan. Unidad de Hígado; Argentina.Fil: Quarleri, Jorge F. Facultad de Medicina. Centro Nacional de Referencia para el SIDA; Argentina.Fil: González, Jorge E. ANLIS Dr.C.G.Malbrán. Instituto Nacional de Enfermedades Infecciosas. Laboratorio Nacional de Referencia de Hepatitis Virales; Argentina

Neuro&ndash;Immune Interactions in Severe COVID-19 Infection

SARS-CoV-2 is a new coronavirus that has affected the world since 2019. Interstitial pneumonia is the most common clinical presentation, but additional symptoms have been reported, including neurological manifestations. Severe forms of infection, especially in elderly patients, present as an excessive inflammatory response called &ldquo;cytokine storm&rdquo;, which can lead to acute respiratory distress syndrome (ARDS), multiorgan failure and death. Little is known about the relationship between symptoms and clinical outcomes or the characteristics of virus&ndash;host interactions. The aim of this narrative review is to highlight possible links between neurological involvement and respiratory damage mediated by pathological inflammatory pathways in SARS-CoV-2 infection. We will focus on neuro&ndash;immune interactions and age-related immunity decline and discuss some pathological mechanisms that contribute to negative outcomes in COVID-19 patients. Furthermore, we will describe available therapeutic strategies and their effects on COVID-19 neurological symptoms

Maximal load of the vitamin B12 transport system: a study on mice treated for four weeks with high-dose vitamin B12 or cobinamide.

Several studies suggest that the vitamin B12 (B12) transport system can be used for the cellular delivery of B12-conjugated drugs, also in long-term treatment Whether this strategy will affect the endogenous metabolism of B12 is not known. To study the effect of treatment with excess B12 or an inert derivative, we established a mouse model using implanted osmotic minipumps to deliver saline, cobinamide (Cbi) (4.25 nmol/h), or B12 (1.75 nmol/h) for 27 days (n = 7 in each group). B12 content and markers of B12 metabolism were analysed in plasma, urine, kidney, liver, and salivary glands. Both Cbi and B12 treatment saturated the transcobalamin protein in mouse plasma. Cbi decreased the content of B12 in tissues to 33-50% of the level in control animals but did not influence any of the markers examined. B12 treatment increased the tissue B12 level up to 350%. In addition, the transcript levels for methylenetetrahydrofolate reductase in kidneys and for transcobalamin and transcobalamin receptor in the salivary glands were reduced. Our study confirms the feasibility of delivering drugs through the B12 transport system but emphasises that B12 status should be monitored because there is a risk of decreasing the transport of endogenous B12. This risk may lead to B12 deficiency during prolonged treatment

Maximal Load of the Vitamin B12 Transport System: A Study on Mice Treated for Four Weeks with High-Dose

Several studies suggest that the vitamin B12 (B12) transport system can be used for the cellular delivery of B12-conjugated drugs, also in long-term treatment Whether this strategy will affect the endogenous metabolism of B12 is not known. To study the effect of treatment with excess B12 or an inert derivative, we established a mouse model using implanted osmotic minipumps to deliver saline, cobinamide (Cbi) (4.25 nmol/h), or B12 (1.75 nmol/h) for 27 days (n = 7 in each group). B12 content and markers of B12 metabolism were analysed in plasma, urine, kidney, liver, and salivary glands. Both Cbi and B12 treatment saturated the transcobalamin protein in mouse plasma. Cbi decreased the content of B12 in tissues to 33–50 % of the level in control animals but did not influence any of the markers examined. B12 treatment increased the tissue B12 level up to 350%. In addition, the transcript levels for methylenetetrahydrofolate reductase in kidneys and for transcobalamin and transcobalamin receptor in the salivary glands were reduced. Our study confirms the feasibility of delivering drugs through the B12 transport system but emphasises that B12 status should be monitored because there is a risk of decreasing the transport of endogenous B12. This risk may lead to B12 deficiency during prolonged treatment