La vision est considérée comme un des sens les plus importants, prenant en charge environ 80% des perceptions que nous recevons dans notre vie quotidienne. Les photorécepteurs de type cônes sont responsables de la vision centrale de haute résolution et en couleurs, et leur dégénérescence est souvent la cause de la perte de vision dans les maladies dégénératives rétiniennes (RDs). Les RDs sont un groupe hétérogène de maladies affectant des millions de personnes dans le monde, qui pour le moment sont pour la plupart sans aucune option thérapeutique. Les modèles animaux sont extrêmement utiles pour étudier le développement ou la dégénérescence de la rétine, ainsi que pour comprendre les mécanismes moléculaires des maladies génétiques héréditaires affectant les photorécepteurs. La modélisation des maladies dégénératives et du développement peut être particulièrement difficile, spécialement dans le cas de maladies humaines rares et complexes pour lesquelles aucun modèle animal exhaustif n'est disponible. De nos jours, la génération et le maintien de modèles de maladies humaines permettant une analyse approfondie du mécanisme moléculaire représente un grand défis . La technologie des cellules souches possède un grand potentiel dans la modélisation des maladies et représente un outil puissant pour générer des modèles évolutifs, sans l’utilisation d’animaux qui peuvent illustrer plus précisément les phénotypes cliniques de maladies humaines complexes. Nous avons développé un protocole pour différencier les cellules souches pluripotentes (PSCs) en feuillets rétiniens (RSs), qui sont des tissus polarisés et multicouches contenant des photorécepteurs cône et exprimant les marqueurs spécifiques du segment externe (OS), du cilium connecteur (CC) et du noyau. En utilisant à la fois des modèles de souris et des modèles humanisés à base de cellules souches, nous avons étudié le rôle de BMI1 dans les photorécepteurs matures. La protéine du groupe Polycomb Bmi1 est connue pour ses fonctions neuroprotectrices en contrôlant la sénescence et l'apoptose, et est exprimée à la fois dans le progéniteur rétinien et les neurones, mais on en sait peu sur son rôle spécifique dans la rétine adulte. Elle a été récemment associée à des troubles neurodégénératifs d'apparition tardive, et elle pourrait avoir un rôle dans la pathologie des RDs d'apparition tardive, comme la dégénérescence maculaire liée à l'âge (DMLA). Nous avons montré que les photorécepteurs cône et les neurones bipolaires sont générés normalement mais subissent ensuite une dégénérescence rapide chez les souris Bmi1-/- par nécroptose associée à Rip3. La dégénérescence était associée à des anomalies de compactage de la chromatine, à l'activation des répétitions en tandem et au stress oxydatif. De plus, nous montrons que BMI1 est préférentiellement exprimé dans les cônes au niveau des foyers hétérochromatiques dans la rétine humaine. Son inactivation dans les cellules souches embryonnaires humaines (hESCs) a altéré la différenciation terminale du cône et a entraîné des anomalies de compactage de la chromatine, l'activation des répétitions en tandem et l'induction de P53. Ces résultats fournissent un mécanisme expliquant comment une carence en Bmi1 conduit à la dégénérescence des cônes et révèlent des fonctions biologiques conservées et des différences pour Bmi1 dans la biologie des photorécepteurs entre la souris et l'homme. En utilisant un modèle humain basé sur les cellules souches pluripotentes induites (iPSCs), nous avons ensuite étudié le processus dégénératif chez les patients atteints de ciliopathies, un groupe de maladies génétiques hétérogènes affectant les protéines impliquées dans la structure et la fonction du cil primaire, qui sont fréquemment accompagnée d'une dégénérescence rétinienne. Nous générons des feuillets rétiniens dérivés d'iPSCs à partir de patients atteints de deux ciliopathies, les syndromes de Meckel-Gruber (MKS) et de Bardet-Biedl (BBS). Les photorécepteurs ciliopathiques présentaient des altérations communes significatives dans l'expression de centaines de gènes de développement. De plus, ils ont montré plusieurs anomalies dans la formation et le maintien du cilium interne, le positionnement du centriole mère, l'activation d'une réponse au stress aux protéines mal repliées, instabilités génomiques et l'accumulation de dommages à l'ADN. Cette étude révèle comment la combinaison des technologies de reprogrammation cellulaire et d'organogenèse avec le séquençage de nouvelle génération permet d'élucider les mécanismes moléculaires et cellulaires impliqués dans les troubles dégénératifs et développementaux de la rétine humaine. La même approche, combinant la différenciation en RSs avec des techniques de séquençage du génome à large spectre, pourrait être appliquée pour modéliser de nombreuses maladies génétiques, développementales et dégénératives affectant les photorécepteurs. Il peut également aider à élucider les mécanismes moléculaires sous-jacents à ces maladies, au criblage de médicaments de composés ayant des effets thérapeutiques potentiels et à prédire les effets secondaires des médicaments. / Vision is considered the most important sense, taking on about 80% of the perceptions we receive in our everyday life. Cone-photoreceptors are responsible for high-resolution central vision and color discrimination, and their degeneration is frequently the cause of vision loss in retinal degenerative diseases (RDs). RDs are a heterogeneous group of diseases affecting millions of people worldwide, which at the moment are mostly without any therapeutic option. Animal models are extremely useful in studying the retina's development or degeneration and understanding the molecular mechanisms in inherited genetic disease affecting photoreceptors. Modeling human developmental and degenerative diseases can be particularly challenging, especially in the case of rare and complex diseases where no exhaustive animal models are available. Generation of sustainable human disease models that allow in-depth analysis of the molecular mechanism is one of the big challenges nowadays. Stem cell technology holds great potential in disease modeling and represents a new powerful tool for generating scalable and animal-free models that can more accurately illustrate clinical phenotypes of complex human diseases. We developed a protocol to differentiate pluripotent stem cells (PSCs) into retinal sheets (RSs), which are polarized, multi-layered tissues containing cone photoreceptors and expressing outer segment (OS), connecting cilium (CC), and nuclear specific markers. Using both mouse and stem cells-based humanized models, we first investigate the role of BMI1 in mature photoreceptors. The Polycomb group protein Bmi1 is known for its neuroprotective functions by controlling senescence and apoptosis and is expressed in both retinal progenitor and neurons, but little is known about its specific role in the adult retina. It has been recently linked to late-onset neurodegenerative disorders, and it could have a role in the pathology of late-onset RDs, such as Age-related Macular Degeneration (AMD). We showed that cone photoreceptors and bipolar neurons are generated normally but then undergo rapid degeneration in Bmi1-/- mice through Rip3-associated necroptosis. Degeneration was associated with chromatin compaction anomalies, activation of tandem-repeats, and oxidative stress. Furthermore, we show that BMI1 is preferentially expressed in cones at heterochromatic foci in the human retina. Its inactivation in human embryonic stem cells (hESCs) impaired cone terminal differentiation and resulted in chromatin compaction anomalies, activation of tandem-repeats, and P53 induction. These findings provide a mechanism explaining how Bmi1 deficiency leads to cone degeneration and reveal conserved biological functions and differences for Bmi1 in photoreceptor biology between mouse and man. Using an induced Pluripotent Stem Cells (iPSCs) based human model, we then investigate the degenerative process in patients with ciliopathies, a group of heterogeneous genetic diseases affecting proteins involved in primary cilium structure and function frequently accompanied by retinal degeneration. We generate iPSC-derived retinal sheets from patients affected by two ciliopathies, Meckel-Gruber (MKS) and Bardet-Biedl syndromes (BBS). Ciliopathic photoreceptors displayed significant common alterations in the expression of hundreds of developmental genes. Moreover, they showed several anomalies in the formation and maintenance of cilia, the mother centriole's positioning, the activation of a stress response to misfolded proteins, genomic instabilities, and DNA damage accumulation. This study reveals how combining cell reprogramming and organogenesis technologies with next-generation sequencing enables the elucidation of molecular and cellular mechanisms involved in human retinal degenerative and developmental disorders. The same approach, combining photoreceptor sheet differentiation and wide-genome expression profile, could be applied to model many genetic, developmental, and degenerative diseases affecting photoreceptors. It may help elucidate the molecular mechanisms underlining these diseases, drug screening of compounds with potential therapeutic effects, and predict drug side effects.

No description available.

Light and optical techniques have made a profound impact on modern medicine both in diagnostics and in therapy. Therapeutic action of light is based on photomechanical, photothermal, photochemical and photobiological interactions, depending on the wavelength, power density, exposure time and optical properties of tissue and cells. Last decade experienced a growing rise of commercial devices for management of hair growth, where all of them are based on low levels of light resulting into photobiological, non-thermal interaction of photons with cells, a process that recently has received an official term ‘photobiomodulation’. However, the design and analysis of the reported clinical studies are highly debated in a wider scientific community. The picture is further complicated by a virtual lack of proof about the exact molecular targets that mediate the physiological response of skin and hair follicles (HF) to low levels of light. The goal of this project was to investigate the expression of light-sensitive receptors in the human HF and to study the impact of UV-free blue light on hair growth ex vivo. The expression of Cryptochromes 1 and 2 (CRY1, 2), Opsin 2 and 3 (OPN2 and OPN3), but not other Opsins 1, 4 and 5 was detected in the distinct compartments of skin and anagen HF. Evaluation of the physiological role of detected light-sensitive receptors on hair growth was performed by the modulation of photoreceptors activity in HF ex vivo model. HFs treated with KL001, a stabilizer of CRY1 protein that lengthens the circadian period, delayed HF anagen-catagen transition; while silencing of CRY1 induced premature catagen development accompanied by reduced cell proliferation. Silencing of CRY1 in the HF outer root sheath (ORS) cells in vitro caused downregulation of ii genes involved in the control of proliferation; including the cyclin dependent kinase 6 (CDK6). OPN3 also had a positive effect on metabolic activity and proliferation of the ORS cells in vitro. OPN3 silencing resulted in the altered expression of genes involved in the control of proliferation and apoptosis. Investigated CRY1, OPN2 and 3 greatly absorb in the blue to green-region of the visible spectrum. This led us to investigate the effect of blue light on HF growth. Daily treatment with blue light (453 nm, 3.2 J/cm2, 16 nm full width half maximum) prolonged anagen phase in HF ex vivo that was associated with sustained proliferation. In addition, blue light (3.2 J/cm2) significantly stimulated proliferation of ORS cells in vitro. This effect was abrogated by silencing of OPN3. To summarize, CRY 1, OPN 2 and OPN 3 are expressed in the distinct compartments of the HF, including HF stem cells. Blue light (453 nm) at low radiant exposure exerts a positive effect on hair growth ex vivo, potentially via interaction with OPN3. The further research should be conducted to decipher interactions between blue light and the investigated receptors in the HFs. In addition, the beneficial effect of blue light at low radiant exposure on hair growth raises a possibility of increasing therapeutic efficacy when combined with topical chemistry used for management of hair growth.

No description available.

Indiana University-Purdue University Indianapolis (IUPUI) / The phototropin photoreceptors are important regulators of plant growth and development and can therefore affect the photosynthetic activity of plants. Phototropin1 and Phototropin2 are versatile protein kinases that become activated when exposed to blue light. Their photobiological actions are best understood in the model plant Arabidopsis thaliana, where they are known to trigger several responses to blue light, one of which is phototropism, the bending of plant organs towards light. Additionally, phot1 and phot2 drive stomatal opening, chloroplast arrangement in leaf cells, leaf expansion, and leaf orientation. The phot1-specific response is rapid inhibition of hypocotyl growth, leaf positioning and mRNA stability whereas phot2 mediates the chloroplast avoidance response to high light. These responses impact a plant’s ability to capture light for photosynthesis, therefore the phototropins play important roles in optimizing a plant’s photosynthetic activity. Soybean (Glycine max) is a very important crop plant in Indiana known for its nutritional versatility and is also utilized for biodiesel production.In spite of soybean being a key crop, there is currently no information about the functionality of soybean phototropins. Also, being a legume, soybean has many structural and functional features that are not present in Arabidopsis. Interestingly, PsPHOT1A (a photoreceptor from garden pea) was found to be a functional phototropin as it was able to complement the phot1 mutation in Arabidopsis. The roles of these proteins in soybean will be elucidated based on the hypothesis that soybean phototropins play essential roles in regulating photosynthetic activity as do the Arabidopsis phototropins. To date, five soybean phototropins, 3 PHOT1s and 2 PHOT2s, are believed to exist. These GmPHOT protein coding regions were amplified by RT-PCR and cloned into pCR8/TOPO or pENTR-D/TOPO vectors via TOPO cloning to utilize Gateway cloning technology to create plant transformation constructs subsequently. The cloned GmPHOT cDNAs from each of the 5 GmPHOTs were sequenced and compared to the GmPHOT sequences from the Phytozome database to assess the accuracy of the gene models. The gene models of all the GmPHOTs were found to be accurate except that of GmPHOT1B-2. The high level of sequence identity between the GmPHOTs and AtPHOTs and the conservation of LOV domains and catalytic domains indicate structural resemblance between them. This suggests that soybean phototropins should encode active photoreceptors. The cloned protein coding regions from soybean were then recombined into a plant expression vector via Gateway technology,which were then used for transformation of Agrobacterium tumefaciens. These plant expression constructs will be utilized in the future to determine the functionality of soybean phototropins in Arabidopsis.

The retina is the ocular tissue responsible for the detection of light. Its extensive demand for oxygen, coupled with a concomitant elevated supply, renders this tissue prone to both hypoxia and hyperoxia. In this thesis, we construct mathematical models of the retina, formulated as systems of reaction-diffusion equations, investigating its oxygen-related dynamics in healthy and diseased states. In the healthy state, we model the oxygen distribution across the human retina, examining the efficacy of the protein neuroglobin in the prevention of hypoxia. It has been suggested that neuroglobin could prevent hypoxia, either by transporting oxygen from regions where it is rich to those where it is poor, or by storing oxygen during periods of diminished supply or increased uptake. Numerical solutions demonstrate that neuroglobin may be effective in preventing or alleviating hypoxia via oxygen transport, but that its capacity for oxygen storage is essentially negligible, whilst asymptotic analysis reveals that, contrary to the prevailing assumption, neuroglobin's oxygen affinity is near optimal for oxygen transport. A further asymptotic analysis justifies the common approximation of a piecewise constant oxygen uptake across the retina, placing existing models upon a stronger theoretical foundation. In the diseased state, we explore the effect of hyperoxia upon the progression of the inherited retinal diseases, known collectively as retinitis pigmentosa. Both numerical solutions and asymptotic analyses show that this mechanism may replicate many of the patterns of retinal degeneration seen in vivo, but that others are inaccessible to it, demonstrating both the strengths and weaknesses of the oxygen toxicity hypothesis. It is shown that the wave speed of hyperoxic degeneration is negatively correlated with the local photoreceptor density, high density regions acting as a barrier to the spread of photoreceptor loss. The effects of capillary degeneration and treatment with antioxidants or trophic factors are also investigated, demonstrating that each has the potential to delay, halt or partially reverse photoreceptor loss. In addition to answering questions that are not accessible to experimental investigation, these models generate a number of experimentally testable predictions, forming the first loop in what has the potential to be a fruitful experimental/modelling cycle.

Au cours de l’évolution, les plantes ont développé des mécanismes pour percevoir et s'adapter aux conditions de stress. Les formes actives de l'oxygène (FAO) sont des facteurs importants de l'état redox cellulaire et sont impliquées dans ces réponses. Le peroxyde d'hydrogène (H2O2), une FAO majeure des voies de signalisation oxydative, peut être produit rapidement dans la photorespiration. Chez Arabidopsis, le H2O2 produit dans la photorespiration est métabolisé notamment par la CATALASE2 (CAT2). Dans le contexte du mutant cat2 déficient pour cette catalase, les réponses au stress oxydatif induit par la production conditionnelle du H2O2 sont fortement dépendante de la photopériode. En particulier, la formation de lésions, accompagnée de réponses similaires à celles d' attaques pathogènes, sont spécifiques des conditions de culture en jours longs (JL). Ces effets ne sont pas observés en jours courts (JC) malgré un stress oxydant qui semble être aussi prononcé qu’en JL. Une approche transcriptomique globale a été utilisée pour explorer les patterns d’expression génique associées à ces effets. Elle a permis de mettre en évidence des interactions entre photopériode et H2O2 ou entre photopériode et CO2. En particulier, la majorité des gènes répondant à l' H2O2 dans le mutant cat2 sont induits lorsque les plantes sont cultivées en JC alors que un plus petit nombre sont induits par l’ H2O2 spécifiquement en JL. De façon générale, ces analyses ont mis en évidence des relations étroites entre les ressources carbonées, la lumière et l'état redox cellulaire dans les réponses aux changements environnementaux. Un gène induit par le H2O2 spécifiquement en JL, l’AZELAIC ACID INDUCED 1 (AZI1), a été sélectionné pour des analyses fonctionnelles à l’aide d’approches génétique, biochimique et transcriptomique. L’analyse de mutants cat2 azi1 a révélé que AZI1 ne semble pas jouer un rôle majeur dans les réponses des plantes à un stress oxydatif durable. Cependant, ce gène semble jouer un rôle important lorsque le stress oxydatif est déclenchée de façon abrupte par le transfert des plantes de conditions de culture en fort CO2 vers l'air ambiant. De plus, cette étude montre que la communication de feuille à feuille est impliquée dans la régulation de l'expansion de la mort cellulaire en réponse a l'H2O2 issue de la photorespiration. Dans la régulation de l'expansion des lésions, nous proposons que AZI1 agirait d'une part localement pour induire la mort cellulaire et d'autre en inhibant la mort cellulaire d'une façon systémique. Dans des fonds génétiques sauvage Col-0 ou mutant cat2, l’analyse comparative de mutants d'insertion ADN-T pour les principaux photochromes (phyA , phyB) et cryptochromes (cry1, cry2) a permis d'étudier les interactions entre les stress et les fonctions des photorécepteurs. Il est apparu que, la mutation des gènes PHY comme CRY conduit a une stimulation de l’accumulation de glutathion H2O2 dépendante. En revanche, dans le fond génétique cat2 contrairement à la perte des fonctions PHY, la mutation des gènes cry conduit a une modulation du profil transcritomique induit par l’ H2O2. De plus, un criblage de conditions de stress sur les simples mutants cry a révélé une plus forte sensibilité de ces génotypes au stress osmotique, a l’ H2O2 et au paraquat. Globalement, ces données indiquent que l’ensemble des photorécepteurs et plus particulièrement les cryptochromes peuvent jouer un rôle dans la réponse à l’ H2O2 intracellulaire suggérant ainsi l’existence d’un réseau complexe permettant l’intégration de conditions environnementales et la détermination de réponses appropriées au stress. / During evolution, plants have developed mechanisms to perceive and respond to stress conditions. Reactive oxygen species (ROS) are important components of cell redox state that have been implicated in these responses. H2O2, an important ROS molecule in oxidative signalling, can be produced rapidly in photorespiration. In Arabidopsis, photorespiratory H2O2 is notably metabolized by CATALASE2 (CAT2). Responses to oxidative stress induced conditionally by photorespiratory H2O2 in the catalase-deficient mutant, cat2, are highly determined by growth daylength. In particular, lesion formation, accompanied by induction of a range of pathogenesis responses, is specific to the long day (LD) photoperiod: these responses are not observed in short days (SD), even though oxidative stress seems to be as marked as in LD. A whole-genome transcriptomics approach was used to explore gene expression patterns underlying these effects, and identified interactions between daylength and H2O2 and between daylength and CO2. In particular, the majority of H2O2-responsive genes in cat2 were up-regulated more strongly in SD air, though a subset of H2O2-induced genes showed a LD-specific response. Overall, this analysis indicates close networking between carbon status, light, and redox state in environmental responses. The most strongly H2O2-induced gene in LD was azelaic acid induced 1 (AZI1) and this gene was chosen for functional analysis using a genetic, biochemical and transcript profiling approach. Analysis of cat2 azi1 mutants revealed that AZI1 does not seem to play an important role in the plant response to sustained, continuous oxidative stress, but is influential when oxidative stress is abruptly induced, in this case, by transferring plants from high CO2 to air. Moreover, this study provided evidence that leaf-to-leaf communication is involved in regulating cell death spread in response to photorespiratory H2O2. In the regulation of this lesion spread, it is proposed that AZI1 acts both locally to promote cell death as well as systemically to inhibit it. Using a comparative analysis of T-DNA insertion mutants for the major phytochromes (phyA, phyB) and cryptochromes (cry1, cry2) introduced into the Col-0 or cat2 background, interactions between stress and photoreceptor function were analyzed. A stimulatory effect of both phy and cry mutations on H2O2-triggered glutathione accumulation was apparent. In contrast to loss of PHY function, both cry mutations modulated daylength-dependent H2O2-triggered transcriptome profiles in cat2. In addition, stress screening of single cry mutants revealed effects on osmotic, H2O2 and paraquat sensitivity. Overall, these data show that both kinds of photoreceptor, but particularly cryptochromes, can play a role in the response to intracellular H2O2, suggesting that there is an intricate network allowing integration of environmental information to determine appropriate responses to stress.

Zusätzlich zu der eubakteriellen RNA-Polymerase (RNAP) der Plastiden sind im Zellkern von Arabidopsis thaliana drei weitere, phagentypische RNAP kodiert, die jeweils aus nur einer Einheit aufgebaut sind. Die Enzyme RpoTp und RpoTm werden in die Plastiden, bzw. die Mitochondrien transportiert, während RpoTmp in beiden Organellen zu finden ist. Um die Lichtabhängigkeit der RpoT-Gene zu untersuchen, wurde die lichtinduzierte Akkumulation ihrer Transkripte in 7-Tage alten Keimlingen, sowie 3- bzw. 9-Wochen alten Rosettenblättern mittels quantitativer real-time PCR ermittelt. Die entwicklungsabhängige Regulation der RpoT-Transkript-Akkumulation wurde außerdem während der Blattentwicklung analysiert. Zusätzlich wurde der Einfluss des circadianen Rhythmus untersucht. Es stellte sich heraus, dass die Transkriptakkumulation aller drei RpoT-Gene stark lichtinduziert war und nur marginalen circadianen Schwankungen unterlag. In weiteren Versuchen mit verschiedenen Lichtrezeptor-Mutanten und unterschiedlichen Lichtqualitäten wurde der Einfluss multipler Rezeptoren auf den Prozess der Lichtinduktion gezeigt. In den Zellen höherer Pflanzen finden sich drei Genome. Die Biogenese von Chloroplasten und Mitochondrien, sowie lebenswichtige Prozesse, wie Atmung und Photosynthese setzen oftmals die Aktivität von Genen auf mindestens zwei dieser Genome voraus. Eine intrazelluläre Kommunikation zwischen den verschiedenen Genomen ist daher unumgänglich für einen funktionierenden Stoffwechsel der Pflanze. In dieser Arbeit wurde herausgestellt, dass die Zahl mitochondrialer Genkopien in photosynthetisch inaktiven Arabidopsis-Keimlingen drastisch erhöht ist. Bei der Untersuchung des DNA-Gehaltes in Proben, die Altersstufen von 2-Tage alten Keimblättern bis hin zu 37-Tage alten, seneszenten Rosettenblättern umfassten, fand sich ein deutlicher Anstieg der Kopienzahlen in älteren Rosettenblättern. Außerdem unterschieden sich die Kopienzahlen der untersuchten Gene zum Teil erheblich voneinander. / In addition to eubacterial-like multi-subunit RNA polymerases (RNAP) localized in plastids and the nucleus, Arabidopsis thaliana contains three phage-like single-unit, nuclear-encoded, organellar RNAPs. The enzymes RpoTp and RpoTm are imported into plastids and mitochondria, respectively, whereas RpoTmp shows dual targeting properties into both organelles. To investigate if expression of the RpoT genes is light-dependent, light-induced transcript accumulation of RpoTm, RpoTp and RpoTmp was analyzed using quantitative real-time-PCR in 7-day-old seedlings as well as in 3- and 9-week-old rosette leaves. To address the question whether RpoT transcript accumulation is regulated differentially during plant development transcript abundance was measured during leaf development. Additionally, effects of the plants circadian rhythm on RpoT transcript accumulation were analyzed. Transcripts of all three RpoT genes were found to be strongly light-induced even in senescent leaves and only marginally influenced by the circadian clock. Further analyses employing different photoreceptor mutants and light qualities revealed the involvement of multiple receptors in the light-induction process. The biogenesis of mitochondria and chloroplasts as well as processes like respiration and photosynthesis require the activity of genes residing in at least two distinct genomes. There have to be ways of intracellular communication between different genomes to control gene activities in response to developmental and metabolic needs of the plant. In this study, it was shown that gene copy numbers drastically increased in photosynthetically inactive Arabidopsis seedlings. Mitochondrial DNA contents in cotyledons and leaves ranging in age from 2-day-old cotyledons to 37-day-old senescent rosette leaves were examined. A common increase in senescing rosette leaves and drastic differences between individual genes were found, revealing the importance of an integrative chondriome in higher plant cells.

O decorim e o biglicam são membros da família dos pequenos proteoglicanos ricos em leucina e possuem importantes funções no controle da proliferação, migração e invasão do citotrofoblasto extraviloso (TEV). O objetivo deste trabalho foi de caracterizar a expressão diferencial e a imunolocalização de decorim e biglicam em placentas humanas normais a termo (PNT), na placenta acreta (PA), na mola invasora (MI) e no coriocarcinoma (CO). Na PNT, as células deciduais apresentaram positividade para o decorim, enquanto o TEV foi negativo. O decorim foi fracamente expresso na matriz endometrial, mas negativo no fibrinoide do tipo matriz, enquanto foi positivo para biglicam. Na PA e na MI, o TEV mostrou positividade para decorim e biglicam. No CO, somente o citotrofoblasto foi positivo para ambos proteoglicanos. Portanto, o decorim e o biglicam são expressos diferencialmente em placentas normais e patológicas, sugerindo que os padrões de expressão desses proteoglicanos nas patologias estudadas indicam um papel na modulação da migração e da invasão do trofoblasto. / Decorin and biglycan are family members of the small leucine-rich proteoglycans family, and they have many functions as controlling proliferation, migration and invasion of extravillous trophoblast cells (EVT). The aim of this study was to characterize decorin and biglycan differential expression and immunolocalization in human normal term placenta (NTP), in placenta accreta (PA), in invasive mole (IM), and in choriocarcinoma (CH) samples. In PNT, deciduas cells were positive to decorin whereas EVT was negative. Decorin was faintly stained at endometrial matrix, but negative at matrix-type fibrinoid, although it was positive for biglycan. In PA and IM, the EVT was positive for decorin and biglycan. In CH, only cytotrophoblast cells were positive for both proteoglycans. Therefore, decorin and biglycan are differentially expressed in normal placenta and in placenta pathologies, suggesting that the expression patterns of the proteoglycans in studied pathologies indicate a role in modulating trophoblast migration and invasion.

No description available.