Darbo tikslas - Įvertinti su amžiumi susijusius struktūrinius žmogaus pamatinės arterijos sienelės pokyčius. Darbo uždaviniai: 1. Ištirti pamatinės arterijos medijos kolageninių skaidulų kiekybinius pokyčius; 2. Nustatyti pamatinės arterijos sienelės medijos raumeninių ląstelių kiekybinius pokyčius; 3. Ištirti pamatinės arterijos sienelės medijoje esančių elastinių skaidulų kiekybinius pokyčius; 4. Ištirti pamatinės arterijos sienelės medijos storio pokyčius; 5. Nustatyti žmogaus pamatinės arterijos intimos, vidinės elastinės membranos struktūrinius pokyčius; 6. Įvertinti kiekybinių histologinių pokyčių tarpusavio priklausomybę bei sąsają su amžiumi. Mokslinis naujumas Galvos smegenų kraujotakos sutrikimai yra viena iš priežasčių, lemiančių didžiausią mirtingumą ir neįgalumą. Epidemiologiniai tyrimai rodo, kad sergamumas ir mirtingumas dėl galvos smegenų kraujotakos sutrikimų tarp vyresnio amžiaus asmenų turi tendenciją sparčiai didėti. Šiame darbe žmogaus galvos smegenų pamatinės arterijos sienelės struktūros pokyčiai vertinti amžiniu aspektu. Histomorfometriškai analizuota medžiaga leido įvertinti bendruosius pamatinės smegenų arterijos sienelės ypatumus, susijusius su amžiumi. Histomorfometriškai įvertinome pamatinės arterijos medijos elastinių ir kolageninių skaidulų bei raumeninių ląstelių kiekybinius pokyčius susijusius su amžiumi skirtingose amžiaus grupėse. Tyrimo metu nagrinėjome ne tik elastinių skaidulų ir kolageno tinklo plotą, bet apskaičiavome ir skaidulų... [toliau žr. visą tekstą] / The aim of the investigation was to examine and evaluate age-related structural changes in media of human basilar artery The main objectives of the thesis were as follows: 1. To examine the quantitative changes in the collagen fibres in media of basilar artery; 2. To evaluate the quantitative changes in muscular cells in the media of basilar artery; 3. To evaluate the quantitative changes in the elastic fibres in the media of basilar artery; 4. To evaluate the changes in the thickness of the tunica media; 5. To examine the structural changes in the human basilar artery intima and internal elastic membrane; 6. To assess the relation of different quantitative histological changes and to determine their correlation with age. Academic novelity of the investigation Cerebrovascular diseases cause huge mortality and disablement. Epidemiologic research has revealed that the morbidity and mortality rates due to cerebrovascular diseases tend to increase. We evaluated basilar artery wall structural changes occuring while ageing. Histomorphometrically analysed material enabled to evaluate general cerebral artery wall peculiarities related to age. We evaluated histomorphometrically quantitative changes of elastic and collagen fibres, muscular cells in ageing in different age groups. We also made analysis not only of elastic and collagen fibres area, but also of perimeter and number of fibres. We analyzed the changes in the thickness of the tunica media. We examined the structural... [to full text]

In Europa leiden etwa 120 Millionen aller 18- bis 80-jährigen an einer Hörbehinderung (16% Prävalenz). Die altersassoziierte Innenohrschwerhörigkeit (Age related hearing impairment, ARHI) hat damit Anschluss gefunden an die großen Volkskrankheiten: Ischämische Herzerkrankungen (5,9 %), Demenz (5,8 %), Diabetes mellitus und Cerebralen Erkrankungen (je 5,5 %). Der erste Teil der Arbeit befasst sich mit der Theorie des Hörens und seinen Störungen, der cochleären Durchblutung, den metabolischen Risikofaktoren, der Molekularbiologie und Epigenetik des Innenohres. Obwohl in der Literatur weitgehend Konsens über den Einfluss exogener Faktoren auf ARHI herrscht, wie Diabetes mellitus, Herz-Kreislauferkrankungen (Framingham Studie und CVD), Hypertonie, Rauchen, Body mass index (BMI) und genderspezifische hormonelle Einflüsse, gibt es kaum HNO-ärztliche Studien dazu. Der zweite Teil geht in einer Praxis-Fallstudie an 202 Patienten folgenden Fragen nach: 1. Gibt es zwischen metabolischen Erkrankungen, wie Adipositas, Störungen des Fett- und Glucosestoffwechsels, der Hypertonie und der Zunahme von Innenohrschwerhörigkeiten im Erwachsenenalter klinische Zusammenhänge? 2. Könnte eine erste Ohrsymptomatik Prädikator einer okkulten pathologischen Stoffwechselveränderung sein? 3. Gibt es Möglichkeiten einer Prävention? Im Ergebnis zeigten sich bei Patienten mit ARHI im Verhältnis Männer/Frauen: Störung des Glukosestoffwechsels bei 97 %/84 %, Lipidstoffwechselstörungen bei 76 %/85 %, eine Homocysteinämien bei 70 %/62 %, ein Anstieg des Plasminogen-Aktivator-Inhibitors (PAI) bei 65 %/38 % und eine Harnsäureerhöhung bei 48 %/15 %. Auch bei ersten Ohrsymptomen (Ohrdruck, Tinnitus, einzelne Frequenzsenken) fanden sich in jedem einzelnen Fall metabolische Veränderungen, die entweder allein oder in unterschiedlichen Kombinationen vorlagen. Männern mit metabolisch initiierten KHK-Erkrankung haben als Prädikator häufig eine erektile Dysfunktion. Erste auditorische Symptomen könnten Prädikator okkulter metabolischer Störungen bei Männern und Frauen sein. Anamnestisch unklare Innenohrprobleme sollten daher auf Stoffwechselstörungen untersucht werden, da diese Risikofaktoren darstellen, die leitlinienbasiert zu therapieren sind. Eine Prognose ist in keinem Einzelfall möglich, da die Folgen auf die molekularbiologischen Prozesse im Innenohres individuell nicht erkennbar sind. Doch sahen wir bei einigen Patienten deutliche Verbesserungen der Symptome und einen Hörschwellenanstieg. Andere Patienten zeigten innerhalb des Beobachtungszeitraums keine Änderung der audiogenen Symptomatik. Behandlungen über einen längeren Zeitraum an einer größeren Fallzahl wären daher sinnvoll. Die Ergebnisse könnten als erste sekundärpräventive Behandlung betrachtet werden, die im Einzelfall eine Hörgeräteversorgung entbehrlich machte. Sie stellen einen Beitrag zu Pfisters Empfehlung dar, mit den vorhandenen Erkenntnissen exogener Risikomechanismen, dringend neue therapeutische Präventionsstrategien für die HNO-ärztliche Tätigkeit zu entwickeln, die die neurale und molekulare Basis anstelle der Symptome der Erkrankung fokussieren.

Age related macular degeneration (AMD) is a public health concern in an aging society. The retinal pigment epithelium (RPE) layer of the eye is a principal site of pathogenesis for AMD. Morphological characteristics of the cells in the RPE layer can be used to discriminate age and disease status of individuals. In this thesis three genotypes of mice of various ages are used to study the predictive abilities of these characteristics. The disease state is represented by two mutant genotypes and the healthy state by the wild-type. Classification analysis is applied to the RPE morphology from the different spatial regions of the RPE layer. Variable reduction is accomplished by principal component analysis (PCA) and classification analysis by the k-nearest neighbor (k-NN) algorithm. In this way the differential ability of the spatial regions to predict age and disease status by cellular variables is explored.

Darbo uždaviniai: 1. Nustatyti pradinės AGDD paplitimą vidutinio amžiaus (40 – 64 metų) pacientų, sergančių IŠL grupėje bei atsitiktinėje to paties amžiaus Kauno miesto gyventojų imtyje. 2. Palyginti pacientų, sergančių tik IŠL ir IŠL bei pradinės AGDD klinikinius duomenis. 3. Nustatyti MMP-2 (-735 C/T), MMP-2 (-1306 C/T), MMP-3 (-1171 5A/6A), MMP-9 (-1562 C/T) genotipų dažnį bei genotipų derinių įtaką AGDD susiformavimui. 4. Nustatyti MMP-2 (-735 C/T), MMP-2 (-1306 C/T), MMP-3 (-1171 5A/6A), MMP-9 (-1562 C/T) genotipų dažnį esant minkštoms ir kietoms drūzoms, sergant AGDD. 5. Nustatyti MMP-2 (-735 C/T), MMP-2 (-1306 C/T), MMP-3 (-1171 5A/6A), MMP-9 (-1562 C/T) genotipų dažnį bei genotipų derinių įtaką AGDD ir IŠL drauge bei tik IŠL pasireiškimui. 6. Nustatyti funkcinio kontrastinio jautrumo tyrimo rodmenis pacientams, sergantiems pradine lengva ir pradine vidutine AGDD bei spalvų juslės pokyčius sergantiems pradine AGDD, ir oftalmologiškai sveikiems pacientams. / The goals were as follows: 1. To determine the prevalence of AMD in patients with IHD and compare with the prevalence in a random sample of Kaunas population (at 40-64 yrs old). 2. To compare the main clinical characteristics of the patients exhibiting early AMD and IHD together with the patients with IHD alone. 3. To determine the frequency of the genotypes of the matrix metalloproteinases (MMP-2 (-735 C/T), MMP-2 (-1306 C/T), MMP-3 (-1171 5A/6A), MMP-9 (-1562 C/T)), and genotype combinations that have an influence on the development of early AMD. 4. To determine the frequency of the genotypes of the matrix metallo¬proteinases (MMP-2 (-735 C/T), MMP-2 (-1306 C/T), MMP-3 (-1171 5A/6A), MMP-9 (-1562 C/T)), in early AMD patients with soft or hard drusen. 5. To determine the frequency of the genotypes of the matrix metallo¬proteinases (MMP-2 (-735 C/T), MMP-2 (-1306 C/T), MMP-3 (-1171 5A/6A), MMP-9 (-1562 C/T)), and the influence of genotype combi¬na¬tions on the development of AMD and IHD together, and only on IHD development. 6. To determine the results of functional acuity contrast sensitivity test in patients with early mild and early intermediate AMD, and color contrast sensitivity in patients with AMD, and in ophthalmologically healthy patients.

Didėjant vyresnių žmonių populiacijai amžinė geltonosios dėmės degeneracija (AGDD) yra vis dažnesnė vyresnio nei 50 metų amžiaus žmonių negrįžtamo regos netekimo priežastis. AGDD prevencinės priemonės bei gydymo galimybės ribotos, nes ligos etiopatogenezė iki šiol nėra visiškai aiški. Disertacinio darbo metu įvertintos AGDD ir išeminės širdies ligos (IŠL) sąsajos, atsižvelgiant į vainikinių arterijų aterosklerozinius pažeidimus. Pirmą kartą analizuota SCARB1 rs5888 C/T genotipų įtaka AGDD ir IŠL pasireiškimui. Tyrimo rezultatai parodė, kad AGDD ir IŠL, kai vainikinėse arterijose yra aterosklerozinių pažeidimų (IŠLath+), sieja bendri, šių ligų pasireiškimo galimybę didinantys, klinikiniai veiksniai ir oksidacinis stresas. Nustatytas „apsauginis“ SCARB1 rs5888 T/T genotipas, mažinantis AGDD ir IŠLath+, bei „rizikingas“ SCARB1 rs5888 C/T genotipas, didinantis AGDD+IŠLath+ galimybę. Pritaikius matematinės morfologijos metodus, nustatyta, jog sergantiems vėlyvąja AGDD SCARB1 rs5888 „rizikingas“ genetinis variantas susijęs su didesniu centrinės tinklainės dalies pažeidimo plotu. Bendrų AGDD ir IŠL patogenezinių grandžių tyrimas suteikia naujos informacijos apie AGDD etiologiją, patogenezę ir galbūt pasitarnaus efektyvaus gydymo bei prevencijos krypčių kūrimui. Tyrimo metu taikyti morfometriniai geltonosios dėmės pažaidos ploto matavimai gali būti naudojami gydytojų-oftalmologų klinikinėje praktikoje, siekiant tiksliau įvertinti centrinės tinklainės dalies pokyčius dinamikoje... [toliau žr. visą tekstą] / Age-related macular degeneration (ARMD) is the commonest cause of blindness among persons over the age of 50 and its prevalence is likely to increase as a consequence of population ageing. ARMD is a disorder of unknown cause and pathogenesis, therefore current options for ARMD prevention and treatment are limited. In the recent study the associations between ARMD and CAD, according the angiographic findings of atherosclerosis in the coronary arteries, were analyzed. The oxidative stress impact and clinical factors determining susceptibility to ARMD and CADath+, separately and common susceptibility factors for both diseases prediction were ascertained. Analysis of novel genetic biomarker, the rs5888 variant of SCARB1 gene, identified the „protective“ SCARB1 rs5888 TT genotype, associated with the lower risk of ARMD and CADath+, and a „risk-determining“ CT genotype, determining higher ARMD+CADath+ risk. The evaluation of macular lesion area by using the methods of mathematical morphology revealed that in late stage ARMD subjects carriers of SCARB1 rs5888 CT genotype the area of macular lesion was larger than in TT genotype carriers. New information about ARMD and CAD discovered additional knowledge about ARMD etiopathogenesis and might be helpfull in search of new treatments or strategies for ARMD prevention. Evaluation of macular lesion area by mathematical morphology methods used in this study may be useful in ophthalmological practice to monitor the dynamics of ARMD.

Aging research on item- and associative-recognition memory has demonstrated that older adults are deficient in forming associations between two unrelated stimuli. Although older adult performance on tests of item-recognition is similar to younger adult performance, older adults perform worse than younger adults on tests of associative memory (Naveh-Benjamin, Hussain, Guez, & Bar-On, 2003). In addition to the idea that younger adult performance on associative-recognition tests is superior to that of older adults, research has shown that reward cues can enhance motivated learning and item memory performance of younger adults. In an fMRI study that examined the influence of reward anticipation on episodic memory formation, Adcock and colleagues (2006) examined memory performance in response to reward cues that preceded single stimuli and found that young adult participants remembered more stimuli associated with high value reward cues than those associated with low value reward cues. The aim of the current study was to examine whether reward cues that precede a stimulus pair might enhance an association between two stimuli and influence younger and older adult performance on tests of item- and associative-recognition. Our study confirms the idea that while older adult memory for individual items is intact, older adult memory for associations is impaired (Naveh-Benjamin et al., 2003). The results supported the idea that younger and older adult item-recognition is better for high versus low reward cues, but the reward cues had no influence on the associative-recognition of either age group. Therefore, the age-related associative deficit was not improved by reward cues that preceded each stimulus pair.

This research was designed to address important issues for the effective prescription of, and training in the use of, magnifiers for reading patients with visual impairment. The emphasis was on the development of simple methods of assessment and training that could be easily implemented, at no great cost, by low vision practitioners in clinical practice. To ensure that the results would be widely applicable, the research focused on subjects with age-related macular degeneration (AMD) using stand magnifiers (being the most common cause of low vision and the most commonly prescribed magnifiers respectively). From this research, modifications to the current methods of reading rehabilitation are suggested to more effectively improve low vision reading for the millions of people with low vision around the world. The magnification and reading performance achieved with the magnifier determined by the fixed acuity reserve method was as valid as that achieved with the magnifier determined by the individual acuity reserve method. The fixed acuity reserve is a simpler method to calculate the required magnification, as it requires only near visual acuity and the patient's goal reading task. This method was primarily used to select the appropriate illuminated stand magnifiers for the subjects participating in the subsequent studies and is recommended for use as the starting point in clinical low vision practice. The main study of this thesis was a longitudinal investigation of the benefit of large print reading practice on reading performance with stand magnifiers. Instead of the intensive training programs on magnifier use which have been suggested by previous studies, this study aimed to investigate the effect of simple large print reading practice, under either full or restricted field of view (the latter simulated by a practice stand), on reading rate with stand magnifiers for subjects with AMD. The experimental hypothesis was that reading practice prior to the prescription of stand magnifiers would improve reading performance with the stand magnifiers for subjects with AMD. As previous studies have shown, reading rate reduced when a stand magnifier was first introduced. One week of reading practice on large print, with or without a reduced field of view, gave an improvement in reading rate with the stand magnifier for passages of text (such that the reading rates with and without magnifiers were not significantly different). There was a suggestion that this practice may give a more rapid improvement in reading rate than that achieved by the control subjects who did not do any large print reading practice, but this did not reach statistical significance. Even very brief reading with the stand magnifiers by the control subjects gave some improvement in reading rate. Therefore, home or in-office reading practice on large print or with magnifiers is recommended for patients with AMD before magnifiers are prescribed. Subjects who had neither reading practice nor exposure to the magnifier prior to its prescription required two weeks practice using their stand magnifiers to achieve their maximum reading rate. This suggests that home practice in using stand magnifiers is beneficial and a follow up visit is recommended two weeks after the provision of a magnifier to assess any change in reading rate. If no improvement in the magnifier reading rate is found or the rate is less than the reading rate on large print without a magnifier, further investigations of the patients' vision and/or their magnifier manipulation strategy are necessary. In the last study, a simple method aimed at alleviating difficulties with magnifier manipulation and navigation, the attachment of a line guide to the base of the stand magnifier, was investigated using both objective methods (recording magnifier movements and reading rate measures) and subjective methods (simple questionnaire). Although there was no improvement in the objective measures of reading or navigation performance with the line guide, more than half of the subjects with low vision preferred to have the line guide on their stand magnifiers. This suggests that the objective measures might not be sensitive enough to predict the subjective response, or that other factors that were not measured in this study influenced subjects' preferences in selecting the line guide (e.g., psychological support provided by the line guide in reading orientation). Clinically, the subjective response of patients to the use of low vision aids as well as their motivation are important criteria for success in low vision rehabilitation. There was a tendency for less experienced users to prefer the line guide to assist their use of the stand magnifier for reading. Therefore, a line guide could be offered as a preliminary training aid when stand magnifiers are first prescribed for AMD patients. Possible improvements to the design of the line guide were identified. Further research is required to assess the benefits of this or similar devices for new magnifier users and to understand the difficulties that people with visual impairment have with page navigation in order to determine improved methods of training navigation strategies. The unique contribution of this study to the field of low vision rehabilitation is that the benefit of short-term reading practice, on large print or with magnifiers, as simple, cheap methods of enhancing reading performance with stand magnifiers was demonstrated. The results of this study have led to the development of recommendations for assessing and training AMD patients who are prescribed stand magnifiers.

Abstract Finding the genetic causes leading to phenotypes of mitochondrial diseases is challenging because of heterogeneity of the disorders and variety of the underlying biochemical defects. In adults, many of the manifestations of mitochondrial diseases cannot be distinguished from the neurodegenerative processes associated with old age. A single mutation or mutations within the same gene can result in a broad range of disorders. Conversely, clinically similar, monogenic disorders may be caused by genes which are governing entirely different cellular pathways. This study investigated the genetic etiology underlying certain symptoms which are characteristic for mitochondrial syndromes, or mimics of the mitochondrial ones. In the first project, we presented the contribution of genetic variation in the Wolfram Syndrome 1 gene to the risk of diabetes mellitus and sensorineural hearing impairment. We also estimated the frequency of a rare pathogenic variation in WFS1. The second project detected a link between the complex phenotype of age-related hearing impairment and the WFS1 gene. Monogenic forms of ARHI are extremely rare and we succeeded in recognizing one Mendelian form of the trait. The third project confirmed the Mitofusin 2 gene causality in the outlier phenotype of Charcot-Marie-Tooth disease. The fourth project described a Finnish family with two affected siblings with adult-onset ataxia, diabetes mellitus, and hypergonadotropic hypogonadism. The found novel mutation in mtDNA, m.8561C>G, was located in the overlapping region of two mitochondrial genes and resulted in an impaired assembly and dysfunctional energy production of mitochondrial ATP synthase. This thesis expands our knowledge about complex neurological phenotypes and identifies not only some causative genes but also outlier phenotypes, which should be noted in clinical practice. / Tiivistelmä Perintötekijät mitokondriaalisten ja niiden kaltaisten tautien taustalla ovat vaikeasti tunnistettavissa. Tautien kirjo on valtava, ja niihin johtavat biokemialliset syyt ovat moninaisia. Aikuisten mitokondriotaudit voivat jäädä diagnosoimatta, koska oireet voivat peittyä vanhenemiseen liittyviin neurodegeneratiivisiin prosesseihin. Sama mutaatio tai eri mutaatiot samassa geenissä voivat johtaa kliinisesti täysin erilaisiin ilmiasuihin. Toisaalta, kliinisesti samankaltaiset taudit voivat olla geneettisesti ja solubiologiallisesti kirjavia. Tässä tutkimuksessa selvitetään geneettistä etiologiaa tiettyjen mitokondriaalisille ja niiden kaltaisille taudeille tyypillisten oireiden taustalla. Ensimmäisessä osajulkaisussa tunnistetaan geneettisiä riskivariantteja Wolfram Syndrome 1 -geenissä diabeteksen ja kuulonaleneman taustalta. Lisäksi tutkimuksessa estimoidaan harvinaisen tautia aiheuttavan variaation määrää kyseisessä geenissä. Toinen projekti esittelee suomalaisen perheen, jossa myöhään alkaneen kuulonaleneman, ikäkuulon, geneettinen syy paljastuu WFS1-geenistä, jota ei aiemmin ole liitetty kyseiseen ilmiasuun. Yhden geenin aiheuttamat ikäkuulotapaukset ovat todella harvinaisia, koska ikäkuulo on monimutkainen kokonaisuus, johon ympäristötekijöillä on suuri vaikutus. Kolmas osajulkaisu kuvaa potilastapauksia, joiden ilmiasu on epätyypillinen Charcot-Marie-Toothin neuropatia. Tautigeeni on tunnettu Mitofusin 2, mutta sen aiheuttaman taudinkuvat ovat yleensä vakavampia ja varhain alkaneita. Viimeinen osajulkaisu kuvaa suomalaisen perheen, jonka kahden oireisen sisaruksen taustalta löytyy mitokondriaalisen DNA:n uusi mutaatio, joka sijaitsee kahden geenin alueella muuttaen niiden molempien lopputuotetta. Mutaation, m.8561C>G, osoitetaan vaikuttavan mitokondriaalisen ATP-syntaasin rakentumiseen ja energiatuotantoon. Tämä väitöskirja laajentaa geneettistä tietoisuutta neurologisten tautien taustalla ja esittelee uusia geneettisiä syitä ja ilmiasuja, jotka tulisi huomioida kliinisessä työssä terveydenhuollossa.

La Dégénérescence Maculaire Liée à l'Age (DMLA) constitue dans les pays industrialisés la 1ère cause de cécité chez les personnes de plus de 50 ans, et représente un enjeu majeur de santé publique d'autant plus important que le vieillissement de la population ne fait que s'accroître. La forme atrophique de cette maladie, pour laquelle il n'existe actuellement aucun traitement, est notamment caractérisée par une inflammation sous-rétinienne associée une dégénérescence des photorécepteurs, et conduit à une perte progressive de la vision centrale pouvant aller jusqu'à la cécité. Nos résultats montrent qu'au stade précoce de la maladie (MLA) on peut déjà observer de nombreux phagocytes mononucléaires (PM) dans l'espace sous-rétinien, en contact avec les drusen. Ces PM expriment de l'apolipoprotéine E (APOE), protéine impliquée dans l'homéostasie lipidique et la régulation de réponses inflammatoires, qui est retrouvée dans les drusen des patients atteints de DMLA, et dont le variant génétique APOε2 est associé à un risque élevé de développer une DMLA. Grâce à l'utilisation de souris Cx3cr1GFP/GFP déficientes en CX3CR1, un récepteur de chimiokine, et de souris humanisées APOε2, les travaux présentés ici démontrent que l'APOE exerce un rôle pro-inflammatoire conduisant de manière dose-dépendante à une altération du privilège immun sous-rétinien. Cet environnement immunosuppresseur est dépendant du FasL exprimé par l'épithélium pigmentaire rétinien (EPR), et empêche en condition physiologique la présence de cellules inflammatoires dans la rétine externe. Nos résultats montrent que l’APOE stimule de manière autocrine la sécrétion d’IL-6 par les PM, possiblement par un mécanisme impliquant une activation des Toll-like receptors (TLR) et de leur corécepteur CD36. Nous montrons que l’IL-6 inhibe l’expression de FasL sur l’EPR et altère sa capacité de clairance sous-rétinienne, ce qui facilite la survie des PM infiltrants au contact des photorécepteurs. La persistance de cette inflammation pathologique dans la rétine externe conduit au cours du vieillissement à une dégénérescence des photorécepteurs, phénomène qui peut est inhibé chez des souris déficientes en APOE. Ensemble, ces résultats permettent d’apporter une explication inédite au risque élevé de développer une DMLA pour les porteurs de l’allèle APOε2, et pourrait ouvrir la voie vers de nouvelles perspectives thérapeutiques. / Age-related Macular Degeneration (AMD) is the first cause of blindness in people over 50 year old in industrialized countries, and represents a major public health concern as the population of elderly is more and more increasing. The atrophic form of the disease, for which there is currently no treatment available, is characterized by subretinal inflammation associated with photoreceptor degeneration and leads to a progressive loss of central vision that can lead to blindness. Our results show many mononuclear phagocytes (MP) are already present at the early stage of the disease (MLA), in the subretinal space and in apposition with drusen. These PM express apolipoprotein E (APOE), a protein involved in lipid homeostasis and the regulation of inflammatory responses, which is found in drusen in patients with AMD, and whose genetic APOε2 variant is associated with a high risk of developing AMD. Using Cx3cr1GFP/GFP mice (deficient in CX3CR1, a chemokine receptor) and humanized APOε2 mice, the work presented herein demonstrates that APOE exerts a pro-inflammatory role leading to a dose-dependent alteration of the subretinal immune privilege. This immunosuppressive environment is dependent upon FasL expression by the retinal pigment epithelium (RPE), and prevents in physiological condition the presence of inflammatory cells in the outer retina. Our results show that APOE stimulates in an autocrine fashion the secretion of IL -6 by PM, possibly through a mechanism involving activation of Toll- like receptors (TLR) and their coreceptor CD36. We show that IL-6 inhibits the expression of FasL on the RPE and impairs its subretinal clearance capacity, which facilitates the survival of infiltrating PM in contact with photoreceptors. The persistence of a pathological inflammation in the outer retina leads to age-dependent photoreceptor degeneration, which can be inhibited in APOE-deficient mice. Taken together, these results provide novel rationale for the higher risk of developing AMD for APOε2allele carriers, and could allow the emergence of new therapeutic perspectives.

Background: Olfactory dysfunction is a common symptom of many neurodegenerative diseases, and age-related macular degeneration (AMD) is a late-onset neurodegenerative disease. Objective: Thus, the aim of this study was to investigate olfactory functions in patients with AMD. Methods: A total of 69 subjects with AMD and 69 age- and sex-matched healthy controls were enrolled. After a complete ophthalmic evaluation, the AMD patients were subclassified as earlyand late-stage AMD. Psychophysical testing of olfactory function was performed using the validated Sniffin’ Sticks test. Results: This study was carried out in 138 subjects, with a mean age of 74.3 ± 8.9 years (range 51–89). The current investigation showed the following two major findings: (1) patients with AMD had decreased olfactory abilities, especially in odor discrimination and odor identification, even at early stages compared to controls, whereas patients had decreased olfactory abilities in all subtasks of olfactory testings in advanced stages of AMD disease, and (2) as the visual acuity of AMD patients decreased, the olfactory abilities of these patients worsened. Conclusion: This study demonstrated that AMD had significant negative effects on all orthonasal olfactory tasks, particularly in advanced stages. Similar to other neurodegenerative diseases, odor discrimination and identification seemed to be more affected than odor detection threshold tasks.