Efeitos da terapia fotodinâmica mediada por curcumina livre e associada a nanopartículas de ferro sobre Candida spp. e biofilmes de estomatite protética / Effects of curcumin-mediated photodynamic therapy, alone and combined with Iron nanoparticles, on Candida spp. and prosthetic stomatitis biofilms

A estomatite protética é uma doença oral que resulta em processo inflamatório crônico da mucosa de suporte de uma prótese dentária, frequentemente associada à infecção por Candida. O tratamento da estomatite protética é dificultado pelo desenvolvimento de resistência das cepas de Candida aos fármacos antifúngicos. Neste cenário, este estudo teve como objetivo avaliar o efeito da terapia fotodinâmica antimicrobiana (TFDa) mediada por curcumina livre (CUR) e nanopartículas de ferro revestidas de curcumina (NpFeCUR) sobre Candida spp. Para isso, o estudo foi dividido em 2 etapas. Na etapa 1, os efeitos da TFDa mediada por NpFeCUR foi estudado sobre células planctônicas e biofilmes monoespécie da cepa de C. albicans SC5314. Após o tratamento com TFDa, as células viáveis foram quantificadas por contagem de Unidades Formadoras de Colônias (UFC). Os resultados dessa etapa demonstraram que a TFDa mediada por NpFeCUR não foi capaz de reduzir a viabilidade fúngica em culturas planctônicas e em biofilmes. Na etapa 2, foi avaliado o efeito da TFDa mediada por CUR sobre biofilmes formados a partir de amostras clínicas de estomatite protética. Essas amostras foram coletadas de 5 pacientes com estomatite protética e analisadas quanto à presença de Candida spp. pelo método de Gram e semeadura em Chromagar Candida. As espécies de Candida foram identificadas por meio de espectrometria de massa (MALDI-TOF). A seguir, a TFDa foi testada sobre biofilmes monoespécies das espécies de Candida isoladas e sobre os biofilmes microcosmos. Após a TFDa, as células viáveis foram determinadas pela contagem de UFC em meios de cultura não seletivo e seletivos para leveduras, estreptococos, estafilococos e estreptococos do grupo mutans. Nos resultados da etapa 2, foi encontrada a presença de Candida nas amostras clínicas de 3 pacientes (P1, P2 e P3). Nas amostras P1 e P3, foi identificada a espécie C. dubliniensis, já na amostra P2 foi encontrada C. albicans. Os biofilmes monoespécies dessas cepas apresentaram redução em torno de 3,0 log10 UFC após o tratamento com TFDa. Para os biofilmes microcosmos, a redução do número de UFC causada pela TFDa variou entre as amostras dos pacientes e os meios de cultura, sendo capaz de inibir o crescimento de microrganismos totais, leveduras, estreptococos, estreptococos do grupo mutans e estafilococos. Conclui-se que a TFDa mediada por NpFeCUR não apresentou atividade antifúngica contra C. albicans. Já a TFDa mediada por CUR foi eficaz na redução das espécies de Candida e biofilmes provenientes de lesões de estomatite protética.(AU)

Prosthetic stomatitis is an oral disease that results in a chronic inflammatory process of the supporting mucosa of a dental prosthesis, often associated with Candida infection. The treatment of prosthetic stomatitis is complicated by the development of resistance in Candida strains to antifungal drugs. In this scenario, this study aimed to evaluate the effect of antimicrobial photodynamic therapy (aPDT) mediated by free curcumin (CUR) and curcumin-coated iron nanoparticles (FeCUR NPs) on Candida spp. For this purpose, the study was divided into 2 stages. In stage 1, the effects of aPDT mediated by FeCUR NPs were studied on planktonic cells and monospecies biofilms of the C. albicans SC5314 strain. After aPDT treatment, viable cells were quantified by Colony-Forming Units (CFU) counting. The results of this stage demonstrated that aPDT mediated by FeCUR NPs was unable to reduce fungal viability in planktonic cultures and biofilms. In stage 2, the effect of aPDT mediated by CUR on biofilms formed from clinical samples of prosthetic stomatitis was evaluated. These samples were collected from 5 patients with prosthetic stomatitis and analyzed for the presence of Candida spp. by Gram staining and seeding on Chromagar Candida. Candida species were identified using mass spectrometry (MALDI-TOF). Subsequently, aPDT was tested on monospecies biofilms of the isolated Candida species and on microcosm biofilms. After aPDT, viable cells were determined by CFU counting on non-selective and selective culture media for yeasts, streptococci, staphylococci, and mutans group streptococci. In the results of stage 2, Candida was found in clinical samples from 3 patients (P1, P2, and P3). In P1 and P3 samples, C. dubliniensis was identified, while C. albicans was found in the P2 sample. Monospecies biofilms of these strains showed a reduction of around 3.0 log10 CFU after aPDT treatment. For microcosm biofilms, the reduction in CFU caused by aPDT varied between patient samples and culture media, being able to inhibit the growth of total microorganisms, yeasts, streptococci, mutans group streptococci, and staphylococci. It is concluded that aPDT mediated by FeCUR NPs did not exhibit antifungal activity against C. albicans. On the other hand, aPDT mediated by CUR was effective in reducing Candida species and biofilms from prosthetic stomatitis lesions.(AU)

Influence of subacute physical exercise on medium- and long-chain fatty acid profile in serum of individuals with overweight.

OBJECTIVE: to test the hypothesis that acute physical exercise would change the fatty acids in the serum of individuals with increased body weight. METHOD: sixty-six sedentary women with excess weight were included in the sample (BMI = 29.6 ± 4.2). They were aged 24.4 ± 3.6 years and were randomly divided into control and exercise groups. After 12 hours fasting, basal blood collection was performed. Twelve hours after the first collection, the exercise group was submitted to a physical exercise session with energy expenditure of 250 kcal. The volunteers underwent a second blood collection 24 hours after the first one and dosed the fatty acids: pelargonic, azelaic, elaidic and oleic. RESULTS: physical exercise did not change the fatty acid profile response for both the intragroup analysis and intergroup analysis. Exercise group: pelargonic (before = 0.12 ± 0.06% vs after = 0.15 ± 0.14%, p = 0.507); azelaic (before = 20.3 ± 10.5% vs after = 27.7 ± 25.4%, p = 0.295); elaidic (before = 0.03 ± 0.01% vs after = 0.04 ± 0.01%, p = 0.328); oleic (before = 16.1 ± 7.4% vs after = 20.3 ± 14.6%, p = 0.236). CONTROL GROUP: pelargonic (before = 0.70 ± 0.45% vs after = 0.71 ± 0.51%, p = 0.776); azelaic (before = 62.1 ± 26% vs after = 57.1 ± 27%, p = 0.197); elaidic (before = 0.05 ± 0.02% mg/dl vs after = 0.05 ± 0.03%, p = 0.530); oleic (before = 26.8 ± 22.7% mg/dl vs after = 29.0 ± 22.4%, p = 0.525). CONCLUSION: in women with overweight, low intensity physical exercise is not capable of changing the medium-chain fatty acids in the first 12 hours.

Influence of subacute physical exercise on medium- and long-chain fatty acid profile in serum of individuals with overweight / Influencia del ejercicio físico subagudo en el perfil de ácidos grasos de cadena media y larga en individuos con sobrepeso

Objective: to test the hypothesis that acute physical exercise would change the fatty acids in the serum of individuals with increased body weight. Method: sixty-six sedentary women with excess weight were included in the sample (BMI = 29.6 ± 4.2). They were aged 24.4 ± 3.6 years and were randomly divided into control and exercise groups. After 12 hours fasting, basal blood collection was performed. Twelve hours after the first collection, the exercise group was submitted to a physical exercise session with energy expenditure of 250 kcal. The volunteers underwent a second blood collection 24 hours after the first one and dosed the fatty acids: pelargonic, azelaic, elaidic and oleic. Results: physical exercise did not change the fatty acid profile response for both the intragroup analysis and intergroup analysis. Exercise group: pelargonic (before = 0.12 ± 0.06% vs after = 0.15 ± 0.14%, p = 0.507); azelaic (before = 20.3 ± 10.5% vs after = 27.7 ± 25.4%, p = 0.295); elaidic (before = 0.03 ± 0.01% vs after = 0.04 ± 0.01%, p = 0.328); oleic (before = 16.1 ± 7.4% vs after = 20.3 ± 14.6%, p = 0.236). Control group: pelargonic (before = 0.70 ± 0.45% vs after = 0.71 ± 0.51%, p = 0.776); azelaic (before = 62.1 ± 26% vs after = 57.1 ± 27%, p = 0.197); elaidic (before = 0.05 ± 0.02% mg/dl vs after = 0.05 ± 0.03%, p = 0.530); oleic (before = 26.8 ± 22.7% mg/dl vs after = 29.0 ± 22.4%, p = 0.525). Conclusion: in women with overweight, low intensity physical exercise is not capable of changing the medium-chain fatty acids in the first 12 hours

Objetivo: probar la hipótesis de que ejercicio físico agudo cambiaría los ácidos grasos en el suero de las personas con mayor peso corporal. Método: se incluyeron en la muestra sesenta y seis mujeres sedentarias con exceso de peso (IMC = 29.6 ± 4.2). Tenían una edad de 24,4 ± 3,6 años y se dividieron aleatoriamente en grupos de control y ejercicio. Después de 12 horas de ayuno, se realizó la extracción de sangre basal. Doce horas después de la primera extracción, el grupo de ejercicio se sometió a una sesión de ejercicio físico con un gasto de energía de 250 kcal. Los voluntarios se sometieron a una segunda extracción de sangre 24 horas después de la primera con dosificación de los ácidos grasos: pelargónico, azelaico, elaídico y oleico. Resultados: el ejercicio físico no modificó la respuesta del perfil de ácidos grasos para el análisis intragrupo y el análisis intergrupo. Ejercicio grupo: pelargónico (antes = 0,12 ± 0,06% vs después = 0,15 ± 0,14%, p = 0,507); azelaico (antes = 20,3 ± 10,5% vs después = 27,7 ± 25,4%, p = 0,295); elaídico (antes = 0,03 ± 0,01% vs después = 0,04 ± 0,01%, p = 0,328); oleico (antes = 16,1 ± 7,4% vs después = 20,3 ± 14,6%, p = 0,236). Grupo de control: pelargónico (antes = 0,70 ± 0,45% vs después = 0,71 ± 0,51%, p = 0,776); azelaico (antes = 62,1 ± 26% vs después = 57,1 ± 27%, p = 0,197); elaídico (antes = 0,05 ± 0,02% mg/dl vs después = 0,05 ± 0,03%, p = 0,530); oleico (antes = 26.8 ± 22,7% mg/dl vs después = 29,0 ± 22,4%, p = 0,525). Conclusión: en mujeres con sobrepeso, el ejercicio físico de baja intensidad no produce ningún cambio en los ácidos grasos de cadena media en las primeras 12 horas

Efeito do treinamento intervalado de alta intensidade versus treinamento contínuo na composição corporal: uma revisão sistemática com meta-análise / Effect of high-intensity interval training versus continuous training on body composition: A systematic review with meta-analysis

A Obesidade é um fator de risco para doenças cardiovasculares e a sua prevalência cresce a cada ano atingindo mais de 2 bilhões de adultos no mundo. As principais recomendações para perda de gordura concentram-se em exercícios de estados estacionários de intensidades moderadas. Entretanto, essas diretrizes não conseguem ser atendidas pela maior parte da população adulta. Sendo assim, novas modalidades ou intensidades de exercícios vem sendo propostas na tentativa de promover perdas mais significativas da gordura corporal. Foi realizado uma revisão sistemática com meta-análise com o objetivo de comparar os efeitos do treinamento intervalado de alta intensidade (HIIT) e do treinamento contínuo nos desfechos: massa corporal total, percentual de gordura, índice de massa corporal e circunferência de cintura de indivíduos com sobrepeso e/ou obesidade. As buscas foram realizadas nas bases de dados Pubmed, Science Direct, PEDro, Scielo e Cochrane Library. A análise foi restrita a ensaios clínicos randomizados em adultos com 18 anos de idade ou mais e com excesso de peso corporal. As meta-análises foram conduzidas utilizando o software Review Manager para modelos de efeitos aleatórios com o método do inverso da variância para os dados contínuos, os dados foram apresentados por diferença da média e IC95%. Quatorze estudos foram incluídos para a análise meta-analítica, houve redução significativa para o grupo CONT para circunferência de cintura (1,19 cm; IC95%: 0,34­2,04; p= 0,006; I²= 0%). Em conclusão, o HIIT não se mostrou melhor estatisticamente em relação ao CONT para alterar os marcadores da composição corporal.

Obesity is a risk factor for cardiovascular disease and its prevalence grows each year reaching more than 2 billion adults worldwide. The main recommendations for fat loss are concentrated in steady-state exercises of moderate intensity. However, these guidelines cannot be met by most of the adult population. Thus, new modalities or exercise intensities are being proposed in an attempt to promote weight or fat loss. A systematic review with meta-analysis was conducted to compare the effects of high-intensity interval training (HIIT) and continuous training on outcomes: total body mass (TBM), fat percentage (%F), body mass index (BMI), and waist circumference ( WC) of overweight and / or obesity. Searches were conducted in Pubmed, Science Direct, PEDro, Scielo and Cochrane Library. The analysis was restricted to randomized clinical trials in adults 18 years of age or older and overweight. Meta-analyses were conducted using Review Manager software for random effects models with the inverse variance method for continuous data, and results were pre-sented by mean difference and 95%CI. Fourteen studies were included for the meta-analytic analysis, there was a significant reduction for the CONT group for CC (1.19 cm; 95%CI: 0,34­2,04; p= 0,006; I²= 0%). In conclusion, HIIT was not statistically better in relation to CONT to alter the markers of body composition.

Metabolic Reponses to a physical exercise session in women with excess body mass: randomized clinical trial.

BACKGROUND: There are various factors that influence the effect of physical exercise on the lipid profile, among them the body mass index and calorie expenditure of the exercise are some of the main factors. To test the hypothesis that a physical exercise session based on caloric expenditure may acutely modify the glycemia and lipid values of women with excess body mass. METHODS: The study included 66 women, randomly divided into two groups, control and experimental, with BMI of 29 ± 4.4 kg/m2 vs 29 ± 4.3 kg/m2 (p = 0.45) sedentary and aged 23 ± 3.8 vs 24 ± 3.5 years, respectively (p = 0.25). After 12 h fasting, the volunteers underwent the first blood collection. The experimental group was submitted to a physical exercise session corresponding to energy expenditure of 250Kcal, of light intensity based the Borg Rating of Perceived Exertion (RPE), 12 h after the first blood collection. The control and experimental group volunteers underwent a second blood collection 24 h after the first. Glycemia, insulin status and lipid profile were measured and Homa IR and Homa-beta were calculated. The t-test for independent and dependent samples was used, and a level of significance of 5% was adopted. RESULTS: Physical exercise changed the glycemic response in both the intragroup analysis (before = 96 ± 6.6 mg/dL vs after = 92 ± 6.6 mg/dL), (p = 0.01), and in the intergroup analysis (control = Δ 0.9 ± 6.1 vs experimental = Δ -4.1 ± 6.3) (p = 0.02). No changes were shown for the Homa IR, Homa Beta and Insulin indexes. When the lipid profiles were evaluated, differences in HDL were shown in the intragroup analysis (before = 89 ± 10.5 mg/dL vs. after = 91 ± 10.3 mg/dL) (p = 0.04). For the other parameters (LDL, TG, Total Cholesterol, TG/HDL), no changes were shown. CONCLUSION: In women with excess body weight, a low intensity exercise session diminished the glycemia, but did not change the lipid response. TRIAL REGISTRATION: NCT03170973 . Retrospectively registered.

Efeito do exercício sobre os níveis de hdl-c: uma revisão sistemática de metanálises / Effect of exercise on hdl-c levels: a systematic review of meta-analyses / Efecto del ejercicio sobre los niveles de hdl-c: una revisión sistemática de metaanálisis

RESUMO A elevação de 1% no HDL-C associa-se à redução de 3% nas taxas de mortalidade cardiovascular. Contudo, praticar exercícios a ponto de gerar alterações benéficas do HDL-C ainda é controverso. Portanto, o objetivo deste estudo foi avaliar se existe benefício do exercício físico sobre os níveis de HDL-C. Trata-se de uma revisão sistemática de metanálises, de artigos indexados ao PubMed/MEDLINE, SciELO e LILACS. Utilizaram-se os termos, Lipoproteins, Cholesterol, HDL, Exercise and Resistance Training. Critérios de inclusão: metanálises publicadas até 22 de janeiro de 2015, com o exercício como forma de intervenção e com desfecho no HDL-C. Critérios de exclusão: Não citação de efeitos de confusão, avaliação do HDL-C como desfecho secundário ou intervenção dietética. Com relação ao resultado do treinamento aeróbico, avaliamos oito estudos. Quatro foram significantes para aumento de HDL-C. Destes, a menor duração em semanas foi 21,8 ± 19,5 e a maior foi 35,3 ± 31,8; a menor frequência foi 3,5 ± 1,0 e a maior, 4,0 ± 1,1; a menor intensidade/%VO2máx foi 64,8% e a maior, 69,2 ± 10,1. Quatro estudos não foram significantes, sendo a menor duração em semanas 10,7 ± 3,2 e a maior, 23,19 ± 17,7; a menor frequência foi 3,7 ± 0,8 e a maior foi 4,75 ± 2,5; a menor intensidade/%VO2máx foi 64,2 ± 9,4 e a maior, 74,7 ± 11,8. Treinamento resistido: Nenhum dos três estudos foi significante. Treinamento combinado: Um único estudo apresentou aumento dos níveis de HDL-C (diferença média [IC 95%]: 0,08 (IC 95%, 0,05-0,12 mmol/l]). Concluímos que não é possível afirmar que o treinamento aeróbico, resistido ou combinado, proporcionam aumentos significantes nos níveis de HDL-C, o que limita sua prescrição como terapia eficiente para aumento de HDL-C.

ABSTRACT The 1% increase in HDL-C is associated with a 3% reduction in cardiovascular mortality rates. However, exercising to the point of generating beneficial changes in HDL-C is still controversial. Therefore, the objective of this study was to evaluate whether there is a benefit of physical exercise on HDL-C levels. This is a systematic review of meta-analyses in articles indexed to PubMed/MEDLINE, SciELO and LILACS. We used the terms Lipoproteins, Cholesterol, HDL, Exercise and Resistance Training. Inclusion criteria: Meta-analyses published until January 22, 2015, with exercise as an intervention and with HDL-C endpoint. Exclusion criteria: No citation of confounding effects, assessment of HDL-C as a secondary endpoint, or dietary intervention. Regarding the aerobic training results, we evaluated eight studies. Four were significant for increased HDL-C. Of these the shortest duration in weeks was 21.8±19.5 and the highest was 35.3±31.8; the lowest frequency was 3.5±1.0 and the highest 4.0±1.1; the lowest intensity/%VO 2max was 64.8% and the highest 69.2±10.1. Four studies were not significant, being the shortest duration in weeks: 10.7±3.2 and the highest 23.19±17.7; the lowest frequency was 3.7±0.8 and the highest was 4.75±2.5; the lowest intensity/%VO 2maxwas 64.2±9.4 and the highest 74.7 ± 11.8. Resistance training: None of the three studies was significant. Combined training: A single study showed an increase in HDL-C levels (mean difference [95% CI]: 0.08 [95% CI, 0.05 -0.12 mmol/L]).We concluded that it is not possible to state that aerobic training, resisted or combined, provides significant increases in HDL-C levels, which limits its prescription as an efficient therapy for HDL-C increase.

RESUMEN Un aumento de 1% en el HDL-C se asocia con una reducción del 3% en las tasas de mortalidad cardiovascular. Sin embargo, el ejercicio hasta el punto de generar cambios beneficiosos en el HDL-C sigue siendo controvertido. Por lo tanto, el objetivo de este estudio fue evaluar si existe un beneficio del ejercicio sobre los niveles de HDL-C. Se trata de una revisión sistemática de los metaanálisis de artículos indexados a PubMed/MEDLINE, SciELO y LILACS. Utilizamos los términos Lipoproteins, Cholesterol, HDL, Exercise and Resistance Training. Criterios de inclusión: metaanálisis publicados hasta el 22 de enero de 2015, con el ejercicio como una intervención y el resultado de HDL-C. Criterios de exclusión: No se mencionan los efectos de confusión, la evaluación de HDL-C como criterio secundario de valoración o intervención dietética. Como resultado del entrenamiento aeróbico, se evaluaron ocho estudios. Cuatro fueron significativos en relación al aumento de HDL-C. De estos, el tiempo más corto en semanas fue de 21,8 ± 19,5 y el más largo fue de 35,3 ± 31,8; la frecuencia más baja fue de 3,5 ± 1,0 y la más alta fue de 4,0 ± 1,1, la intensidad/%VO 2máx más baja fue 64,8% y la más alta fue 69,2 ± 10.1 Cuatro estudios no fueron significativos, siendo la menor duración en semanas de 10,7 ± 3,2, y la más grande de 23,19 ± 17,7; la frecuencia más baja fue de 3,7 ± 0,8 y la más alta fue 4,75 ± 2,5; la intensidad/%VO 2máxmás baja fue de 64,2 ± 9,4 y la más alta fue 74,7 ± 11.8. Entrenamiento de resistencia: Ninguno de los tres estudios fue significativo. Entrenamiento combinado: Un único estudio presentó un aumento de los niveles de HDL-C (diferencia promedio [IC 95%]: 0,08 [IC 95%, 0,05-0,12 mmol/l]). Llegamos a la conclusión de que no es posible decir que el entrenamiento aeróbico, de resistencia o combinado, proporciona un aumento significativo de los niveles de HDL-C, lo que limita su prescripción como terapia efectiva para aumentar el HDL-C.

The embryogenesis of the tick Rhipicephalus (Boophilus) microplus: the establishment of a new chelicerate model system.

Chelicerates, which include spiders, ticks, mites, scorpions, and horseshoe crabs, are members of the phylum Arthropoda. In recent years, several molecular experimental studies of chelicerates have examined the embryology of spiders; however, the embryology of other groups, such as ticks (Acari: Parasitiformes), has been largely neglected. Ticks and mites are believed to constitute a monophyletic group, the Acari. Due to their blood-sucking activities, ticks are also known to be vectors of several diseases. In this study, we analyzed the embryonic development of the cattle tick, Rhipicephalus (Boophilus) microplus (Acari: Ixodidae). First, we developed an embryonic staging system consisting of 14 embryonic stages. Second, histological analysis and antibody staining unexpectedly revealed the presence of a population of tick cells with similar characteristics to the spider cumulus. Cumulus cell populations also exist in other chelicerates; these cells are responsible for the breaking of radial symmetry through bone morphogenetic protein signaling. Third, it was determined that the posterior (opisthosomal) embryonic region of R. microplus is segmented. Finally, we identified the presence of a transient ventral midline furrow and the formation and regression of a fourth leg pair; these features may be regarded as hallmarks of late tick embryogenesis. Importantly, most of the aforementioned features are absent from mite embryos, suggesting that mites and ticks do not constitute a monophyletic group or that mites have lost these features. Taken together, our findings provide fundamental common ground for improving knowledge regarding tick embryonic development, thereby facilitating the establishment of a new chelicerate model system.

Inorganic polyphosphates regulate hexokinase activity and reactive oxygen species generation in mitochondria of Rhipicephalus (Boophilus) microplus embryo.

The physiological roles of polyphosphates (poly P) recently found in arthropod mitochondria remain obscure. Here, the possible involvement of poly P with reactive oxygen species generation in mitochondria of Rhipicephalus microplus embryos was investigated. Mitochondrial hexokinase and scavenger antioxidant enzymes, such as superoxide dismutase, catalase, and glutathione reductase were assayed during embryogenesis of R. microplus. The influence of poly P3 and poly P15 were analyzed during the period of higher enzymatic activity during embryogenesis. Both poly Ps inhibited hexokinase activity by up to 90% and, interestingly, the mitochondrial membrane exopolyphosphatase activity was stimulated by the hexokinase reaction product, glucose-6-phosphate. Poly P increased hydrogen peroxide generation in mitochondria in a situation where mitochondrial hexokinase is also active. The superoxide dismutase, catalase and glutathione reductase activities were higher during embryo cellularization, at the end of embryogenesis and during embryo segmentation, respectively. All of the enzymes were stimulated by poly P3. However, superoxide dismutase was not affected by poly P15, catalase activity was stimulated only at high concentrations and glutathione reductase was the only enzyme that was stimulated in the same way by both poly Ps. Altogether, our results indicate that inorganic polyphosphate and mitochondrial membrane exopolyphosphatase regulation can be correlated with the generation of reactive oxygen species in the mitochondria of R. microplus embryos.

Glycogen and glucose metabolism are essential for early embryonic development of the red flour beetle Tribolium castaneum.

Control of energy metabolism is an essential process for life. In insects, egg formation (oogenesis) and embryogenesis is dependent on stored molecules deposited by the mother or transcribed later by the zygote. In oviparous insects the egg becomes an isolated system after egg laying with all energy conversion taking place during embryogenesis. Previous studies in a few vector species showed a strong correlation of key morphogenetic events and changes in glucose metabolism. Here, we investigate glycogen and glucose metabolism in the red flour beetle Tribolium castaneum, an insect amenable to functional genomic studies. To examine the role of the key enzymes on glycogen and glucose regulation we cloned and analyzed the function of glycogen synthase kinase 3 (GSK-3) and hexokinase (HexA) genes during T. castaneum embryogenesis. Expression analysis via in situ hybridization shows that both genes are expressed only in the embryonic tissue, suggesting that embryonic and extra-embryonic cells display different metabolic activities. dsRNA adult female injection (parental RNAi) of both genes lead a reduction in egg laying and to embryonic lethality. Morphological analysis via DAPI stainings indicates that early development is impaired in Tc-GSK-3 and Tc-HexA1 RNAi embryos. Importantly, glycogen levels are upregulated after Tc-GSK-3 RNAi and glucose levels are upregulated after Tc-HexA1 RNAi, indicating that both genes control metabolism during embryogenesis and oogenesis, respectively. Altogether our results show that T. castaneum embryogenesis depends on the proper control of glucose and glycogen.

A mitochondrial membrane exopolyphosphatase is modulated by, and plays a role in, the energy metabolism of hard tick Rhipicephalus (Boophilus) microplus embryos.

The physiological roles of polyphosphates (polyP) recently found in arthropod mitochondria remain obscure. Here, the relationship between the mitochondrial membrane exopolyphosphatase (PPX) and the energy metabolism of hard tick Rhipicephalus microplus embryos are investigated. Mitochondrial respiration was activated by adenosine diphosphate using polyP as the only source of inorganic phosphate (P(i)) and this activation was much greater using polyP(3) than polyP(15). After mitochondrial subfractionation, most of the PPX activity was recovered in the membrane fraction and its kinetic analysis revealed that the affinity for polyP(3) was 10 times stronger than that for polyP(15). Membrane PPX activity was also increased in the presence of the respiratory substrate pyruvic acid and after addition of the protonophore carbonyl cyanide-p-trifluoromethoxyphenylhydrazone. Furthermore, these stimulatory effects disappeared upon addition of the cytochrome oxidase inhibitor potassium cyanide and the activity was completely inhibited by 20 µg/mL heparin. The activity was either increased or decreased by 50% upon addition of dithiothreitol or hydrogen peroxide, respectively, suggesting redox regulation. These results indicate a PPX activity that is regulated during mitochondrial respiration and that plays a role in adenosine-5'-triphosphate synthesis in hard tick embryos.