Drosophila as a model system to investigate the effects of mitochondrial variation on innate immunity

Understanding why the response to infection varies between individuals remains one of the major challenges in immunology and infection biology. A substantial proportion of this heterogeneity can be explained by individual genetic differences which result in variable immune responses, and there are many examples of polymorphisms in nuclear-encoded genes that alter immunocompetence. However, how immunity is affected by genetic polymorphism in an additional genome, inherited maternally inside mitochondria (mtDNA), has been relatively understudied. Mitochondria are increasingly recognized as important mediators of innate immune responses, not only because they are the main source of energy required for costly immune responses, but also because by-products of mitochondrial metabolism, such as reactive oxygen species (ROS), may have direct microbicidal action. Yet, it is currently unclear how naturally occurring variation in mtDNA contributes to heterogeneity in infection outcomes. In this review article, we describe potential sources of variation in mitochondrial function that may arise due to mutations in vital nuclear and mitochondrial components of energy production or due to a disruption in mito-nuclear crosstalk. We then highlight how these changes in mitochondrial function can impact immune responses, focusing on their effects on ATP- and ROS-generating pathways, as well as immune signaling. Finally, we outline how being a powerful and genetically tractable model of infection, immunity and mitochondrial genetics makes the fruit fly Drosophila melanogaster ideally suited to dissect mitochondrial effects on innate immune responses to infection.publishedVersionPeer reviewe

On the impacts of working memory training on executive functioning

Recent studies have reported improvements in a variety of cognitive functions following sole working memory (WM) training. In spite of the emergence of several successful training paradigms, the scope of transfer effects has remained mixed. This is most likely due to the heterogeneity of cognitive functions that have been measured and tasks that have been applied. In the present study, we approached this issue systematically by investigating transfer effects from WM training to different aspects of executive functioning. Our training task was a demanding WM task that requires simultaneous performance of a visual and an auditory n-back task, while the transfer tasks tapped WM updating, coordination of the performance of multiple simultaneous tasks (i.e., dual-tasks) and sequential tasks (i.e., task switching), and the temporal distribution of attentional processing. Additionally, we examined whether WM training improves reasoning abilities; a hypothesis that has so far gained mixed support. Following training, participants showed improvements in the trained task as well as in the transfer WM updating task. As for the other executive functions, trained participants improved in a task switching situation and in attentional processing. There was no transfer to the dual-task situation or to reasoning skills. These results, therefore, confirm previous findings that WM can be trained, and additionally, they show that the training effects can generalize to various other tasks tapping on executive functions

Endogenous, cholesterol-activated ATP-dependent transport in membrane vesicles from Spodoptera frugiperda cells

Transport proteins of the ATP-binding cassette (ABC) family are found in all kingdoms of life. In humans, several ABC efflux transporters play a role in drug disposition and excretion. Therefore, in vitro methods have been developed to characterize the substrate and inhibitor properties of drugs with respect to these transporters. In the vesicular transport assay, transport is studied using inverted membrane vesicles produced from transporter overexpressing cell lines of both mammalian and insect origin. Insect cell expression systems benefit from a higher expression compared to background, but are not as well characterized as their mammalian counterparts regarding endogenous transport. Therefore, the contribution of this transport in the assay might be underappreciated. In this study, endogenous transport in membrane vesicles from Spodoptera frugiperda -derived Sf9 cells was characterized using four typical substrates of human ABC transporters: 5(6)-carboxy-2,′7′-dichlorofluorescein (CDCF), estradiol-17β-glucuronide, estrone sulfate and N-methyl-quinidine. Significant ATP-dependent transport was observed for three of the substrates with cholesterol-loading of the vesicles, which is sometimes used to improve the activity of human transporters expressed in Sf9 cells. The highest effect of cholesterol was on CDCF transport, and this transport in the cholesterol-loaded Sf9 vesicles was time and concentration dependent with a Km of 8.06 ± 1.11 μM. The observed CDCF transport was inhibited by known inhibitors of human ABCC transporters, but not by ABCB1 and ABCG2 inhibitors verapamil and Ko143, respectively. Two candidate genes for ABCC-type transporters in the S. frugiperda genome (SfABCC2 and SfABCC3) were identified based on sequence analysis as a hypothesis to explain the observed endogenous ABCC-type transport in Sf9 vesicles. Although further studies are needed to verify the role of SfABCC2 and SfABCC3 in Sf9 vesicles, the findings of this study highlight the need to carefully characterize background transport in Sf9 derived membrane vesicles to avoid false positive substrate findings for human ABC transporters studied with this overexpression system.Transport proteins of the ATP-binding cassette (ABC) family are found in all kingdoms of life. In humans, several ABC efflux transporters play a role in drug disposition and excretion. Therefore, in vitro methods have been developed to characterize the substrate and inhibitor properties of drugs with respect to these transporters. In the vesicular transport assay, transport is studied using inverted membrane vesicles produced from transporter overexpressing cell lines of both mammalian and insect origin. Insect cell expression systems benefit from a higher expression compared to background, but are not as well characterized as their mammalian counterparts regarding endogenous transport. Therefore, the contribution of this transport in the assay might be underappreciated. In this study, endogenous transport in membrane vesicles from Spodoptera frugiperda-derived Sf9 cells was characterized using four typical substrates of human ABC transporters: 5(6)-carboxy-2,' 7'-dichlorofluorescein (CDCF), estradiol-17 beta-glucuronide, estrone sulfate and N-methyl-quinidine. Significant ATP-dependent transport was observed for three of the substrates with cholesterol-loading of the vesicles, which is sometimes used to improve the activity of human transporters expressed in Sf9 cells. The highest effect of cholesterol was on CDCF transport, and this transport in the cholesterol-loaded Sf9 vesicles was time and concentration dependent with a Km of 8.06 +/- 1.11 mu M. The observed CDCF transport was inhibited by known inhibitors of human ABCC transporters, but not by ABCB1 and ABCG2 inhibitors verapamil and Ko143, respectively. Two candidate genes for ABCC-type transporters in the S. frugiperda genome (SfABCC2 and SfABCC3) were identified based on sequence analysis as a hypothesis to explain the observed endogenous ABCC-type transport in Sf9 vesicles. Although further studies are needed to verify the role of SfABCC2 and SfABCC3 in Sf9 vesicles, the findings of this study highlight the need to carefully characterize background transport in Sf9 derived membrane vesicles to avoid false positive substrate findings for human ABC transporters studied with this overexpression system.Peer reviewe

Opetussuunnitelmaosaaminen tulevien luokanopettajien kokemana

Suomessa luokanopettajankoulutuksen tavoitteena on luoda perusta opettajan korkeatasoisen osaamisen kehittymiselle. Tämän korkeatasoisen osaamisen ytimessä on muun muassa opetussuunnitelmaosaaminen, kun opetussuunnitelman katsotaan muodostavan peruskoulun opettajan pedagogisen ajattelun ja toiminnan sekä koulun kehittämisen viitekehyksen. Tässä tutkimuksessa tarkastellaan millaista maisterivaiheen luokanopettajaopiskelijoiden (n = 24) opetussuunnitelmaosaaminen on heidän itsensä kokemana. Opetussuunnitelmaosaamista tarkastellaan henkilökohtaisen mielensisäisen tiedon osatekijöiden eli teoreettisen, käytännöllisen ja itsesäätelytiedon näkökulmasta, sillä yksilön korkeatasoisen ammatillisen osaamisen perustan nähdään muodostuvan näiden osatekijöiden integroituessa.  Tutkimukseen osallistujat jäsensivät aluksi opetussuunnitelmaosaamistaan laatimalla aiheesta käsitekartan, minkä jälkeen toteutettiin yksilölliset haastattelut. Litteroitu aineisto analysoitiin teoriasidonnaisen sisällönanalyysin keinoin. Tulosten mukaan opiskelijoiden opetussuunnitelmaosaamisessa oli merkittäviä eroja. Parhaimmillaan koulutuksen aikaiset kokemukset oman toiminnan tietoisesta tarkastelusta ja säätelystä opetussuunnitelman tarkoitusten suunnassa auttoivat opiskelijoita rakentamaan asiantuntevaa ymmärrystä opetussuunnitelmasta opetus- ja kasvatustyön perustana. Koulutus ei kuitenkaan pystynyt tuottamaan kaikille tuleville opettajille samalla tavalla vahvaa opetussuunnitelmaosaamista eli rakentamaan tulevien opettajien korkeatasoista henkilökohtaista mielensisäistä tietoa opetussuunnitelman tarkoituksista.  </p

Validity and reliability of the Finnish version of the Functioning Assessment Short Test (FAST) in bipolar disorder

The Functioning Assessment Short Test (FAST) was developed for the clinical evaluation of functional impairment of patients suffering from bipolar disorder. The aim of this study was to validate the Finnish version of FAST.Peer reviewe

ER stress in Alzheimer's disease: a novel neuronal trigger for inflammation and Alzheimer's pathology

The endoplasmic reticulum (ER) is involved in several crucial cellular functions, e.g. protein folding and quality control, maintenance of Ca2+ balance, and cholesterol synthesis. Many genetic and environmental insults can disturb the function of ER and induce ER stress. ER contains three branches of stress sensors, i.e. IRE1, PERK and ATF6 transducers, which recognize the misfolding of proteins in ER and activate a complex signaling network to generate the unfolded protein response (UPR). Alzheimer's disease (AD) is a progressive neurodegenerative disorder involving misfolding and aggregation of proteins in conjunction with prolonged cellular stress, e.g. in redox regulation and Ca2+ homeostasis. Emerging evidence indicates that the UPR is activated in neurons but not in glial cells in AD brains. Neurons display pPERK, peIF2α and pIRE1α immunostaining along with abundant diffuse staining of phosphorylated tau protein. Recent studies have demonstrated that ER stress can also induce an inflammatory response via different UPR transducers. The most potent pathways are IRE1-TRAF2, PERK-eIF2α, PERK-GSK-3, ATF6-CREBH, as well as inflammatory caspase-induced signaling pathways. We will describe the mechanisms which could link the ER stress of neurons to the activation of the inflammatory response and the evolution of pathological changes in AD

Changes in gene expression linked with adult reproductive diapause in a northern malt fly species: a candidate gene microarray study

<p>Abstract</p> <p>Background</p> <p>Insect diapause is an important biological process which involves many life-history parameters important for survival and reproductive fitness at both individual and population level. <it>Drosophila montana</it>, a species of <it>D. virilis </it>group, has a profound photoperiodic reproductive diapause that enables the adult flies to survive through the harsh winter conditions of high latitudes and altitudes. We created a custom-made microarray for <it>D. montana </it>with 101 genes known to affect traits important in diapause, photoperiodism, reproductive behaviour, circadian clock and stress tolerance in model Drosophila species. This array gave us a chance to filter out genes showing expression changes during photoperiodic reproductive diapause in a species adapted to live in northern latitudes with high seasonal changes in environmental conditions.</p> <p>Results</p> <p>Comparisons among diapausing, reproducing and young <it>D. montana </it>females revealed expression changes in 24 genes on microarray; for example in comparison between diapausing and reproducing females one gene (<it>Drosophila cold acclimation gene, Dca</it>) showed up-regulation and 15 genes showed down-regulation in diapausing females. Down-regulation of seven of these genes was specific to diapause state while in five genes the expression changes were linked with the age of the females rather than with their reproductive status. Also, qRT-PCR experiments confirmed <it>couch potato </it>(<it>cpo</it>) gene to be involved in diapause of <it>D. montana</it>.</p> <p>Conclusions</p> <p>A candidate gene microarray proved to offer a practical and cost-effective way to trace genes that are likely to play an important role in photoperiodic reproductive diapause and further in adaptation to seasonally varying environmental conditions. The present study revealed two genes, <it>Dca </it>and <it>cpo</it>, whose role in photoperiodic diapause in <it>D. montana </it>is worth of studying in more details. Also, further studies using the candidate gene microarray with more specific experimental designs and target tissues may reveal additional genes with more restricted expression patterns.</p

A refined in vitro model to study inflammatory responses in organotypic membrane culture of postnatal rat hippocampal slices

BACKGROUND: Propagated tissue degeneration, especially during aging, has been shown to be enhanced through potentiation of innate immune responses. Neurodegenerative diseases and a wide variety of inflammatory conditions are linked together and several anti-inflammatory compounds considered as having therapeutic potential for example in Alzheimer's disease (AD). In vitro brain slice techniques have been widely used to unravel the complexity of neuroinflammation, but rarely, has the power of the model itself been reported. Our aim was to gain a more detailed insight and understanding of the behaviour of hippocampus tissue slices in serum-free, interface culture per se and after exposure to different pro- and anti-inflammatory compounds. METHODS: The responses of the slices to pro- and anti-inflammatory stimuli were monitored at various time points by measuring the leakage of lactate dehydrogenase (LDH) and the release of cytokines interleukin 6 (IL-6) and tumour necrosis factor alpha (TNF-α) and nitric oxide (NO) from the culture media. Histological methods were applied to reveal the morphological status after exposure to stimuli and during the time course of the culture period. Statistical power analysis were made with nQuery Advisor(®), version 5.0, (Statistical Solutions, Saugus, MA) computer program for Wilcoxon (Mann-Whitney) rank-sum test. RESULTS: By using the interface membrane culture technique, the hippocampal slices largely recover from the trauma caused by cutting after 4–5 days in vitro. Furthermore, the cultures remain stable and retain their responsiveness to inflammatory stimuli for at least 3 weeks. During this time period, cultures are susceptible to modification by inflammatory stimuli as assessed by quantitative biochemical assays and morphological characterizations. CONCLUSION: The present report outlines the techniques for studying immune responses using a serum-free slice culture model. Statistically powerful data under controlled culture conditions and with ethically justified use of animals can be obtained as soon as after 4–5 DIV. The model is most probably suitable also for studies of chronic inflammation

Kouluhyvinvointi syntyy vain yhteistyöllä

Lapsi- ja perhepalveluiden muutosohjelman (LAPE) mukaan hyvinvoiva lapsi oppii ja kasvaa. Edessä olevan kouluvuoden alussa onkin hyvä pysähtyä miettimään mitä kouluhyvinvointi on ja miten voimme edistää sitä yhdessä.</p