85 resultados para Mariner-like element
Resumo:
Aging is associated with an increased risk of depression in humans. To elucidate the underlying mechanisms of depression and its dependence on aging, here we study signs of depression in male SAMP8 mice. For this purpose, we used the forced swimming test (FST). The total floating time in the FST was greater in SAMP8 than in SAMR1 mice at 9 months of age; however, this difference was not observed in 12-month-old mice, when both strains are considered elderly. Of the two strains, only the SAMP8 animals responded to imipramine treatment. We also applied the dexamethasone suppression test (DST) and studied changes in the dopamine and serotonin (5-HT) uptake systems, the 5-HT2a/2c receptor density in the cortex, and levels of TPH2. The DST showed a significant difference between SAMR1 and SAMP8 mice at old age. SAMP8 exhibits an increase in 5-HT transporter density, with slight changes in 5-HT2a/2c receptor density. In conclusion, SAMP8 mice presented depression-like behavior that is dependent on senescence process, because it differs from SAMR1, senescence resistant strain.
Resumo:
Aging is associated with an increased risk of depression in humans. To elucidate the underlying mechanisms of depression and its dependence on aging, here we study signs of depression in male SAMP8 mice. For this purpose, we used the forced swimming test (FST). The total floating time in the FST was greater in SAMP8 than in SAMR1 mice at 9 months of age; however, this difference was not observed in 12-month-old mice, when both strains are considered elderly. Of the two strains, only the SAMP8 animals responded to imipramine treatment. We also applied the dexamethasone suppression test (DST) and studied changes in the dopamine and serotonin (5-HT) uptake systems, the 5-HT2a/2c receptor density in the cortex, and levels of TPH2. The DST showed a significant difference between SAMR1 and SAMP8 mice at old age. SAMP8 exhibits an increase in 5-HT transporter density, with slight changes in 5-HT2a/2c receptor density. In conclusion, SAMP8 mice presented depression-like behavior that is dependent on senescence process, because it differs from SAMR1, senescence resistant strain.
Resumo:
Aging is associated with an increased risk of depression in humans. To elucidate the underlying mechanisms of depression and its dependence on aging, here we study signs of depression in male SAMP8 mice. For this purpose, we used the forced swimming test (FST). The total floating time in the FST was greater in SAMP8 than in SAMR1 mice at 9 months of age; however, this difference was not observed in 12-month-old mice, when both strains are considered elderly. Of the two strains, only the SAMP8 animals responded to imipramine treatment. We also applied the dexamethasone suppression test (DST) and studied changes in the dopamine and serotonin (5-HT) uptake systems, the 5-HT2a/2c receptor density in the cortex, and levels of TPH2. The DST showed a significant difference between SAMR1 and SAMP8 mice at old age. SAMP8 exhibits an increase in 5-HT transporter density, with slight changes in 5-HT2a/2c receptor density. In conclusion, SAMP8 mice presented depression-like behavior that is dependent on senescence process, because it differs from SAMR1, senescence resistant strain.
Resumo:
Immunological pressure encountered by protozoan parasites drives the selection of strategies to modulate or avoid the immune responses of their hosts. Here we show that the parasite Entamoeba histolytica has evolved a chemokine that mimics the sequence, structure, and function of the human cytokine HsEMAPII (Homo sapiens endothelial monocyte activating polypeptide II). This Entamoeba EMAPII-like polypeptide (EELP) is translated as a domain attached to two different aminoacyl-tRNA synthetases (aaRS) that are overexpressed when parasites are exposed to inflammatory signals. EELP is dispensable for the tRNA aminoacylation activity of the enzymes that harbor it, and it is cleaved from them by Entamoeba proteases to generate a standalone cytokine. Isolated EELP acts as a chemoattractant for human cells, but its cell specificity is different from that of HsEMAPII. We show that cell specificity differences between HsEMAPII and EELP can be swapped by site directed mutagenesis of only two residues in the cytokines' signal sequence. Thus, Entamoeba has evolved a functional mimic of an aaRS-associated human cytokine with modified cell specificity.
Resumo:
Different vortex penetration regimes have been registered in the output voltage signal of a magnetometer when single microwave pulses are applied to an epitaxial overdoped La2− x Sr x CuO4 thin film in a perpendicular dc magnetic field. The onset of a significant variation in the sample magnetization which exists below threshold values of temperature, dc magnetic field, and pulse duration is interpreted as an avalanche-type flux penetration. The microwave contribution to the background electric field suggests that the nucleation of this fast vortex motion is of electric origin, which also guarantees the occurrence of vortex instabilities under adiabatic conditions via the enhancement of the flux flow resistivity. Flux creep phenomena and heat transfer effects act as stabilizing factors against the microwave-pulse-induced fast flux diffusion.
Resumo:
Background Chronic alcohol ingestion may cause severe biochemical and pathophysiological derangements to skeletal muscle. Unfortunately, these alcohol-induced events may also prime skeletal muscle for worsened, delayed, or possibly incomplete repair following acute injury. As alcoholics may be at increased risk for skeletal muscle injury, our goals were to identify the effects of chronic alcohol ingestion on components of skeletal muscle regeneration. To accomplish this, age- and gender-matched C57Bl/6 mice were provided normal drinking water or water that contained 20% alcohol (v/v) for 1820 wk. Subgroups of mice were injected with a 1.2% barium chloride (BaCl2) solution into the tibialis anterior (TA) muscle to initiate degeneration and regeneration processes. Body weights and voluntary wheel running distances were recorded during the course of recovery. Muscles were harvested at 2, 7 or 14 days post-injection and assessed for markers of inflammation and oxidant stress, fiber cross-sectional areas, levels of growth and fibrotic factors, and fibrosis. Results Body weights of injured, alcohol-fed mice were reduced during the first week of recovery. These mice also ran significantly shorter distances over the two weeks following injury compared to uninjured, alcoholics. Injured TA muscles from alcohol-fed mice had increased TNFα and IL6 gene levels compared to controls 2 days after injury. Total protein oxidant stress and alterations to glutathione homeostasis were also evident at 7 and 14 days after injury. Ciliary neurotrophic factor (CNTF) induction was delayed in injured muscles from alcohol-fed mice which may explain, in part, why fiber cross-sectional area failed to normalize 14 days following injury. Gene levels of TGFβ1 were induced early following injury before normalizing in muscle from alcohol-fed mice compared to controls. However, TGFβ1 protein content was consistently elevated in injured muscle regardless of diet. Fibrosis was increased in injured, muscle from alcohol-fed mice at 7 and 14 days of recovery compared to injured controls. Conclusions Chronic alcohol ingestion appears to delay the normal regenerative response following significant skeletal muscle injury. This is evidenced by reduced cross-sectional areas of regenerated fibers, increased fibrosis, and altered temporal expression of well-described growth and fibrotic factors.
Resumo:
In recent years, a number of zoonotic flaviviruses have emerged worldwide, and wild birds serve as their major reservoirs. Epidemiological surveys of bird populations at various geographical scales can clarify key aspects of the eco-epidemiology of these viruses. In this study, we aimed at exploring the presence of flaviviruses in the western Mediterranean by sampling breeding populations of the yellow-legged gull (Larus michahellis), a widely distributed, anthropophilic, and abundant seabird species. For 3 years, we sampled eggs from 19 breeding colonies in Spain, France, Algeria, and Tunisia. First, ELISAs were used to determine if the eggs contained antibodies against flaviviruses. Second, neutralization assays were used to identify the specific flaviviruses present. Finally, for colonies in which ELISA-positive eggs had been found, chick serum samples and potential vectors, culicid mosquitoes and soft ticks (Ornithodoros maritimus), were collected and analyzed using serology and PCR, respectively. The prevalence of flavivirus-specific antibodies in eggs was highly spatially heterogeneous. In northeastern Spain, on the Medes Islands and in the nearby village of L'Escala, 56% of eggs had antibodies against the flavivirus envelope protein, but were negative for neutralizing antibodies against three common flaviviruses: West Nile, Usutu, and tick-borne encephalitis viruses. Furthermore, little evidence of past flavivirus exposure was obtained for the other colonies. A subset of the Ornithodoros ticks from Medes screened for flaviviral RNA tested positive for a virus whose NS5 gene was 95% similar to that of Meaban virus, a flavivirus previously isolated from ticks of Larus argentatus in western France. All ELISA-positive samples subsequently tested positive for Meaban virus neutralizing antibodies. This study shows that gulls in the western Mediterranean Basin are exposed to a tick-borne Meaban-like virus, which underscores the need of exploring the spatial and temporal distribution of this flavivirus as well as its potential pathogenicity for animals and humans.
Resumo:
Emerging evidence suggests that the hypocretinergic system is involved in addictive behavior. In this study, we investigated the role of these hypothalamic neuropeptides in anxiety-like responses of nicotine and stress-induced reinstatement of nicotine-seeking behavior. Acute nicotine (0.8 mg/kg, s.c.) induced anxiogenic-like effects in the elevated plus-maze and activated the paraventricular nucleus of thehypothalamus (PVN) as revealed by c-Fos expression. Pretreatment with the hypocretin receptor 1 (Hcrtr-1) antagonist SB334867 orpreprohypocretin gene deletion blocked both nicotine effects. In the PVN, SB334867 also prevented the activation of corticotrophinreleasing factor (CRF) and arginine-vasopressin (AVP) neurons, which expressed Hcrtr-1. In addition, an increase of the percentage of c-Fos-positive hypocretin cells in the perifornical and dorsomedial hypothalamic (PFA/DMH) areas was found after nicotine (0.8 mg/kg,s.c.) administration. Intracerebroventricular infusion of hypocretin-1 (Hcrt-1) (0.75 nmol/1 l) or footshock stress reinstated a previouslyextinguished nicotine-seeking behavior. The effects of Hcrt-1 were blocked by SB334867, but not by the CRF1 receptor antagonistantalarmin. Moreover, SB334867 did not block CRF-dependent footshock-induced reinstatement of nicotine-seeking while antalarmin was effective in preventing this nicotine motivational response. Therefore, the Hcrt system interacts with CRF and AVP neurons in the PVN and modulates the anxiogenic-like effects of nicotine whereas Hcrt and CRF play a different role in the reinstatement of nicotineseeking.Indeed, Hcrt-1 reinstates nicotine-seeking through a mechanism independent of CRF activation whereas CRF mediates the reinstatement induced by stress.
Resumo:
Aging is associated with an increased risk of depression in humans. To elucidate the underlying mechanisms of depression and its dependence on aging, here we study signs of depression in male SAMP8 mice. For this purpose, we used the forced swimming test (FST). The total floating time in the FST was greater in SAMP8 than in SAMR1 mice at 9 months of age; however, this difference was not observed in 12-month-old mice, when both strains are considered elderly. Of the two strains, only the SAMP8 animals responded to imipramine treatment. We also applied the dexamethasone suppression test (DST) and studied changes in the dopamine and serotonin (5-HT) uptake systems, the 5-HT2a/2c receptor density in the cortex, and levels of TPH2. The DST showed a significant difference between SAMR1 and SAMP8 mice at old age. SAMP8 exhibits an increase in 5-HT transporter density, with slight changes in 5-HT2a/2c receptor density. In conclusion, SAMP8 mice presented depression-like behavior that is dependent on senescence process, because it differs from SAMR1, senescence resistant strain.
Resumo:
En este trabajo se describe una base de conocimiento de las ALU humanas. La ontología incorpora términos SO y GO y está orientada a describir el contexto genómico del conjunto de ALU. Para cada elemento ALU se almacenan el gen y transcrito más cercanos, así como su anotación funcional de acuerdo a GO, el estado de la cromatina circundante y los factores de transcripción presentes en la ALU. Se han incorporado reglas semánticas para facilitar el almacenamiento, consulta e integración de la información. La ontología de ALU es plenamente analizable mediante razonadores como Pellet y está parcialmente transferida a una wiki semántica.
Resumo:
Background Transketolase-like 1 (TKTL1) induces glucose degradation through anaerobic pathways, even in presence of oxygen, favoring the malignant aerobic glycolytic phenotype characteristic of tumor cells. As TKTL1 appears to be a valid biomarker for cancer prognosis, the aim of the current study was to correlate its expression with tumor stage, probability of tumor recurrence and survival, in a series of colorectal cancer patients. Methodolody/Principal Findings Tumor tissues from 63 patients diagnosed with colorectal cancer at different stages of progression were analyzed for TKTL1 by immunohistochemistry. Staining was quantified by computational image analysis, and correlations between enzyme expression, local growth, lymph-node involvement and metastasis were assessed. The highest values for TKTL1 expression were detected in the group of stage III tumors, which showed significant differences from the other groups (Kruskal-Wallis test, P = 0.000008). Deeper analyses of T, N and M classifications revealed a weak correlation between local tumor growth and enzyme expression (Mann-Whitney test, P = 0.029), a significant association of the enzyme expression with lymph-node involvement (Mann-Whitney test, P = 0.0014) and a significant decrease in TKTL1 expression associated with metastasis (Mann-Whitney test, P = 0.0004). Conclusions/Significance To our knowledge, few studies have explored the association between variations in TKTL1 expression in the primary tumor and metastasis formation. Here we report downregulation of enzyme expression when metastasis appears, and a correlation between enzyme expression and regional lymph-node involvement in colon cancer. This finding may improve our understanding of metastasis and lead to new and more efficient therapies against cancer.
Resumo:
This study explored the evolutionary mechanism by which the clinical isolate PA110514 yields the imipenemresistant derivative PA116136. Both isolates were examined by PFGE and SDS-PAGE, which led to the identification of a new insertion sequence, ISPa133. This element was shown to have distinct chromosomal locations in each of the original isolates that appeared to explain the differences in imipenem susceptibilty. In strain PA110514, ISPa133 is located 56 nucleotides upstream of the translational start codon, which has no effect on expression of the porin OprD. However, in strain PA116136 ISPa133 it is located in front of nucleotide 696 and, by interrupting the coding region, causes a loss of OprD expression, thus conferring imipenem resistance. In vitro experiments mimicking the natural conditions of selective pressure yielded imipenem-resistant strains in which ISPa133 similarly interrupted oprD. A mechanism is proposed whereby ISPa133 acts as a mobile switch, with its position in oprD depending on the degree of selective pressure exerted by imipenem
Resumo:
This study explored the evolutionary mechanism by which the clinical isolate PA110514 yields the imipenemresistant derivative PA116136. Both isolates were examined by PFGE and SDS-PAGE, which led to the identification of a new insertion sequence, ISPa133. This element was shown to have distinct chromosomal locations in each of the original isolates that appeared to explain the differences in imipenem susceptibilty. In strain PA110514, ISPa133 is located 56 nucleotides upstream of the translational start codon, which has no effect on expression of the porin OprD. However, in strain PA116136 ISPa133 it is located in front of nucleotide 696 and, by interrupting the coding region, causes a loss of OprD expression, thus conferring imipenem resistance. In vitro experiments mimicking the natural conditions of selective pressure yielded imipenem-resistant strains in which ISPa133 similarly interrupted oprD. A mechanism is proposed whereby ISPa133 acts as a mobile switch, with its position in oprD depending on the degree of selective pressure exerted by imipenem
Resumo:
This study explored the evolutionary mechanism by which the clinical isolate PA110514 yields the imipenemresistant derivative PA116136. Both isolates were examined by PFGE and SDS-PAGE, which led to the identification of a new insertion sequence, ISPa133. This element was shown to have distinct chromosomal locations in each of the original isolates that appeared to explain the differences in imipenem susceptibilty. In strain PA110514, ISPa133 is located 56 nucleotides upstream of the translational start codon, which has no effect on expression of the porin OprD. However, in strain PA116136 ISPa133 it is located in front of nucleotide 696 and, by interrupting the coding region, causes a loss of OprD expression, thus conferring imipenem resistance. In vitro experiments mimicking the natural conditions of selective pressure yielded imipenem-resistant strains in which ISPa133 similarly interrupted oprD. A mechanism is proposed whereby ISPa133 acts as a mobile switch, with its position in oprD depending on the degree of selective pressure exerted by imipenem