Progressive retinal degeneration and glial activation in the Cln6nclf mouse model of neuronal ceroid lipofuscinosis : a beneficial effect of DHA and Curcumin supplementation

Neuronal ceroid lipofuscinosis (NCL) is a group of neurodegenerative lysosomal storage disorders characterized by vision loss, mental and motor deficits, and spontaneous seizures. Neuropathological analyses of autopsy material from NCL patients and animal models revealed brain atrophy closely associated with glial activity. Earlier reports also noticed loss of retinal cells and reactive gliosis in some forms of NCL. To study this phenomenon in detail, we analyzed the ocular phenotype of CLN6nclf mice, an established mouse model for variant-late infantile NCL. Retinal morphometry, immunohistochemistry, optokinetic tracking, electroretinography, and mRNA expression were used to characterize retinal morphology and function as well as the responses of Müller cells and microglia. Our histological data showed a severe and progressive degeneration in the CLN6nclf retina co-inciding with reactive Müller glia. Furthermore, a prominent phenotypic transformation of ramified microglia to phagocytic, bloated, and mislocalized microglial cells was identified in CLN6nclf retinas. These events overlapped with a rapid loss of visual perception and retinal function. Based on the strong microglia reactivity we hypothesized that dietary supplementation with immuno-regulatory compounds, curcumin and docosahexaenoic acid (DHA), could ameliorate microgliosis and reduce retinal degeneration. Our analyses showed that treatment of three-week-old CLN6nclf mice with either 5% DHA or 0.6% curcumin for 30 weeks resulted in a reduced number of amoeboid reactive microglia and partially improved retinal function. DHA-treatment also improved the morphology of CLN6nclf retinas with a preserved thickness of the photoreceptor layer in most regions of the retina. Our results suggest that microglial reactivity closely accompanies disease progression in the CLN6nclf retina and both processes can be attenuated with dietary supplemented immuno-modulating compounds

Neue Modelle mit Akteuren entwickeln

Klimaangepasste Agrarentwicklung erfordert die Einbindung ökologischer Nachhaltigkeit. Daraus ergeben sich methodische Herausforderungen. Zur Entwicklung neuer integraler Strategien wird ein dynamisches Modell mit Stakeholderanalysen kombiniert

Nachhaltigkeit im Klimawandel

Einführung in das Schwerpunktthem

Luteolin triggers global changes in the microglial transcriptome leading to a unique anti-inflammatory and neuroprotective phenotype

<p>Abstract</p> <p>Background</p> <p>Luteolin, a plant derived flavonoid, exerts a variety of pharmacological activities and anti-oxidant properties associated with its capacity to scavenge oxygen and nitrogen species. Luteolin also shows potent anti-inflammatory activities by inhibiting nuclear factor kappa B (NFkB) signaling in immune cells. To better understand the immuno-modulatory effects of this important flavonoid, we performed a genome-wide expression analysis in pro-inflammatory challenged microglia treated with luteolin and conducted a phenotypic and functional characterization.</p> <p>Methods</p> <p>Resting and LPS-activated BV-2 microglia were treated with luteolin in various concentrations and mRNA levels of pro-inflammatory markers were determined. DNA microarray experiments and bioinformatic data mining were performed to capture global transcriptomic changes following luteolin stimulation of microglia. Extensive qRT-PCR analyses were carried out for an independent confirmation of newly identified luteolin-regulated transcripts. The activation state of luteolin-treated microglia was assessed by morphological characterization. Microglia-mediated neurotoxicity was assessed by quantifying secreted nitric oxide levels and apoptosis of 661W photoreceptors cultured in microglia-conditioned medium.</p> <p>Results</p> <p>Luteolin dose-dependently suppressed pro-inflammatory marker expression in LPS-activated microglia and triggered global changes in the microglial transcriptome with more than 50 differentially expressed transcripts. Pro-inflammatory and pro-apoptotic gene expression was effectively blocked by luteolin. In contrast, mRNA levels of genes related to anti-oxidant metabolism, phagocytic uptake, ramification, and chemotaxis were significantly induced. Luteolin treatment had a major effect on microglial morphology leading to ramification of formerly amoeboid cells associated with the formation of long filopodia. When co-incubated with luteolin, LPS-activated microglia showed strongly reduced NO secretion and significantly decreased neurotoxicity on 661W photoreceptor cultures.</p> <p>Conclusions</p> <p>Our findings confirm the inhibitory effects of luteolin on pro-inflammatory cytokine expression in microglia. Moreover, our transcriptomic data suggest that this flavonoid is a potent modulator of microglial activation and affects several signaling pathways leading to a unique phenotype with anti-inflammatory, anti-oxidative, and neuroprotective characteristics. With the identification of several novel luteolin-regulated genes, our findings provide a molecular basis to understand the versatile effects of luteolin on microglial homeostasis. The data also suggest that luteolin could be a promising candidate to develop immuno-modulatory and neuroprotective therapies for the treatment of neurodegenerative disorders.</p

A Circulating MicroRNA Profile in a Laser-Induced Mouse Model of Choroidal Neovascularization

Funding: This research was funded by the Deutsche Forschungsgemeinschaft (GR5065/1-1). Author Contributions: Conceptualization, F.G. and B.H.F.W.; Data curation, T.S.; Formal analysis, P.B., M.K., A.A., and T.S.; Funding acquisition, C.K. and F.G.; Investigation, M.K. and B.H.F.W.; Methodology, C.K. and A.A.;Project administration, B.H.F.W.; Resources, M.K., A.A., T.L., and F.G.; Software, C.K. and T.S.; Supervision, T.L., F.G., and B.H.F.W.; Validation, P.B.; Visualization, C.K.; Writing—original draft, C.K. and P.B.; Writing—review & editing, B.H.F.W. All authors have read and agreed to the published version of the manuscript.Peer reviewedPublisher PD

TSPO: kaleidoscopic 18-kDa amid biochemical pharmacology, control and targeting of mitochondria

The 18-kDa translocator protein (TSPO) localizes in the outer mitochondrial membrane (OMM) of cells and is readily up-regulated under various pathological conditions such as cancer, inflammation, mechanical lesions and neurological diseases. Able to bind with high affinity synthetic and endogenous ligands, its core biochemical function resides in the translocation of cholesterol into the mitochondria influencing the subsequent steps of (neuro-)steroid synthesis and systemic endocrine regulation. Over the years, however, TSPO has also been linked to core cellular processes such as apoptosis and autophagy. It interacts and forms complexes with other mitochondrial proteins such as the voltage-dependent anion channel (VDAC) via which signalling and regulatory transduction of these core cellular events may be influenced. Despite nearly 40 years of study, the precise functional role of TSPO beyond cholesterol trafficking remains elusive even though the recent breakthroughs on its high-resolution crystal structure and contribution to quality-control signalling of mitochondria. All this along with a captivating pharmacological profile provides novel opportunities to investigate and understand the significance of this highly conserved protein as well as contribute the development of specific therapeutics as presented and discussed in the present review

Age-related macular degeneration associated polymorphism rs10490924 in ARMS2 results in deficiency of a complement activator

Acknowledgements: The authors thank all German AMD patients for their participation. We also thank Maria Pötsch (Leibniz Institute for Natural Product Reseach and Infection Biology, Jena) for MS analyses. Funding: This research was supported by the German Council “Deutsche Forschungs-Gemeinschaft” SK46, Zi432, LA1206, the “Pro Retina” foundation and the Thuringian Ministry of Science and Education, Germany. HN is a member of the DFG-funded excellence cluster ImmunoSensation (EXC 1023). YL is a doctoral researcher at the International Leibniz Research School (ILRS), part of the Jena school of Microbial Communication (JSMC). Availability of data and materials: Materials are available at [email protected] reviewedPublisher PD

Isolated and Syndromic Retinal Dystrophy Caused by Biallelic Mutations in RCBTB1, a Gene Implicated in Ubiquitination.

Inherited retinal dystrophies (iRDs) are a group of genetically and clinically heterogeneous conditions resulting from mutations in over 250 genes. Here, homozygosity mapping and whole-exome sequencing (WES) in a consanguineous family revealed a homozygous missense mutation, c.973C&gt;T (p.His325Tyr), in RCBTB1. In affected individuals, it was found to segregate with retinitis pigmentosa (RP), goiter, primary ovarian insufficiency, and mild intellectual disability. Subsequent analysis of WES data in different cohorts uncovered four additional homozygous missense mutations in five unrelated families in whom iRD segregates with or without syndromic features. Ocular phenotypes ranged from typical RP starting in the second decade to chorioretinal dystrophy with a later age of onset. The five missense mutations affect highly conserved residues either in the sixth repeat of the RCC1 domain or in the BTB1 domain. A founder haplotype was identified for mutation c.919G&gt;A (p.Val307Met), occurring in two families of Mediterranean origin. We showed ubiquitous mRNA expression of RCBTB1 and demonstrated predominant RCBTB1 localization in human inner retina. RCBTB1 was very recently shown to be involved in ubiquitination, more specifically as a CUL3 substrate adaptor. Therefore, the effect on different components of the CUL3 and NFE2L2 (NRF2) pathway was assessed in affected individuals' lymphocytes, revealing decreased mRNA expression of NFE2L2 and several NFE2L2 target genes. In conclusion, our study puts forward mutations in RCBTB1 as a cause of autosomal-recessive non-syndromic and syndromic iRD. Finally, our data support a role for impaired ubiquitination in the pathogenetic mechanism of RCBTB1 mutations

Systems pathology analysis identifies neurodegenerative nature of age-related vitreoretinal interface diseases

Aging is a phenomenon that is associated with profound medical implications. Idiopathic epiretinal membrane (iEMR) and macular hole (MH) are the major vision-threatening vitreoretinal diseases affecting millions of aging people globally, making these conditions an important public health issue. iERM is characterized by fibrous tissue developing on the surface of the macula, which leads to biomechanical and biochemical macular damage. MH is a small breakage in the macula and is associated with many ocular conditions. Although several individual factors and pathways are suggested, a systems pathology level understanding of the molecular mechanisms underlying these disorders is lacking. Therefore, we performed mass spectrometry-based label-free quantitative proteomics analysis of the vitreous proteomes from patients with iERM and MH to identify the key proteins, as well as the multiple interconnected biochemical pathways, contributing to the development of these diseases. We identified a total of 1,014 unique proteins, many of which are linked to inflammation and the complement cascade, revealing the inflammation processes in retinal diseases. Additionally, we detected a profound difference in the proteomes of iEMR and MH compared to those of diabetic retinopathy with macular edema and rhegmatogenous retinal detachment. A large number of neuronal proteins were present at higher levels in the iERM and MH vitreous, including neuronal adhesion molecules, nervous system development proteins, and signaling molecules, pointing toward the important role of neurodegenerative component in the pathogenesis of age-related vitreoretinal diseases. Despite them having marked similarities, several unique vitreous proteins were identified in both iERM and MH, from which candidate targets for new diagnostic and therapeutic approaches can be provided.Peer reviewe