scholarly journals Retinitis Pigmentosa Results in Neurodegeneration Concomitant With Neuroinflammation, Extracellular Matrix Disorganization and the Upregulation of Neuroprotective Pathways in Glial Cells and Neurons

2020 ◽  
Author(s):  
Christina B. Bielmeier ◽  
Saskia Roth ◽  
Sabrina I. Schmitt ◽  
Stefaniya K. Boneva ◽  
Anja Schlecht ◽  
...  
Keyword(s):  
Extracellular Matrix ◽  
Retinitis Pigmentosa ◽  
Retinal Degeneration ◽  
Molecular Mechanisms ◽  
Genetic Model ◽  
Immunofluorescent Staining ◽  
System Response ◽  
Photoreceptor Degeneration ◽  
The Impact

Abstract BackgroundHereditary retinal degenerations like retinitis pigmentosa (RP) are amongst the leading causes of blindness in younger patients. To enable in vivo investigation of cellular and molecular mechanisms responsible for photoreceptor cell death and to allow testing of therapeutic strategies that could prevent retinal degeneration, animal models have been created. Here, we in-depth characterized the transgenic VPP mouse model, a genetic model for autosomal dominant RP. MethodsWe examined the degree of photoreceptor degeneration and studied the impact of the VPP transgene-induced retinal degeneration on the transcriptome level of the retina using next generation RNA sequencing (RNASeq) analyses followed by weighted correlation network analysis (WGCNA). We furthermore identified cellular subpopulations responsible for some of the observed dysregulations using in situ hybridizations, immunofluorescent staining and 3D reconstruction. ResultsOne month-old VPP mice showed a significantly higher number of apoptotic photoreceptor cells that resulted in a significantly thinner ONL in three months-old VPP mice, concomitant with an increase in reactivity of microglia and Müller cells. By RNASeq analysis we identified 9,256 dysregulated genes and six significantly associated gene modules in the subsequently performed WGCNA. Gene ontology enrichment showed, amongst others, dysregulation of TGF-β regulated extracellular matrix organization, factors of the (ocular) immune system/response and apoptosis. ConclusionThe predominant effect pointed towards induction of neuroinflammation and the upregulation of neuroprotective pathways like TGF-β, G-protein activated and VEGF signaling that were significantly associated with the VPP transgene-induced photoreceptor degeneration. Thus, modulation of these processes might represent new therapeutic options to delay the degeneration of photoreceptors in diseases like RP.

scholarly journals Transcriptional Profiling Identifies Upregulation of Neuroprotective Pathways in Retinitis Pigmentosa

2021 ◽  
Vol 22 (12) ◽  
pp. 6307
Author(s):  
Christina B. Bielmeier ◽  
Saskia Roth ◽  
Sabrina I. Schmitt ◽  
Stefaniya K. Boneva ◽  
Anja Schlecht ◽  
...  
Keyword(s):  
Retinitis Pigmentosa ◽  
Signaling Pathways ◽  
Retinal Degeneration ◽  
G Protein ◽  
Molecular Mechanisms ◽  
System Response ◽  
Photoreceptor Degeneration ◽  
Vegf Signaling ◽  
The Impact

Hereditary retinal degenerations like retinitis pigmentosa (RP) are among the leading causes of blindness in younger patients. To enable in vivo investigation of cellular and molecular mechanisms responsible for photoreceptor cell death and to allow testing of therapeutic strategies that could prevent retinal degeneration, animal models have been created. In this study, we deeply characterized the transcriptional profile of mice carrying the transgene rhodopsin V20G/P23H/P27L (VPP), which is a model for autosomal dominant RP. We examined the degree of photoreceptor degeneration and studied the impact of the VPP transgene-induced retinal degeneration on the transcriptome level of the retina using next generation RNA sequencing (RNASeq) analyses followed by weighted correlation network analysis (WGCNA). We furthermore identified cellular subpopulations responsible for some of the observed dysregulations using in situ hybridizations, immunofluorescence staining, and 3D reconstruction. Using RNASeq analysis, we identified 9256 dysregulated genes and six significantly associated gene modules in the subsequently performed WGCNA. Gene ontology enrichment showed, among others, dysregulation of genes involved in TGF-β regulated extracellular matrix organization, the (ocular) immune system/response, and cellular homeostasis. Moreover, heatmaps confirmed clustering of significantly dysregulated genes coding for components of the TGF-β, G-protein activated, and VEGF signaling pathway. 3D reconstructions of immunostained/in situ hybridized sections revealed retinal neurons and Müller cells as the major cellular population expressing representative components of these signaling pathways. The predominant effect of VPP-induced photoreceptor degeneration pointed towards induction of neuroinflammation and the upregulation of neuroprotective pathways like TGF-β, G-protein activated, and VEGF signaling. Thus, modulation of these processes and signaling pathways might represent new therapeutic options to delay the degeneration of photoreceptors in diseases like RP.

scholarly journals Ferulic acid attenuates microglia-mediated neuroinflammation in retinal degeneration

2020 ◽  
Author(s):  
Xiaowei Sun ◽  
Peng Sun ◽  
Limei Liu ◽  
Pengfei Jiang ◽  
YUANBIN LI
Keyword(s):  
Ferulic Acid ◽  
Retinal Degeneration ◽  
Microglia Activation ◽  
Immunofluorescent Staining ◽  
Inflammatory Factors ◽  
Immunomodulatory Activity ◽  
Ccl2 Expression ◽  
The Impact

Abstract Background: To use a rd10 mouse model as a means of exploring the impact of Ferulic acid(FA) on microglia-mediated neuroinflammation as well as associated retinal degeneration. Methods: Rd10 mice received different concentrations of FA treatment every day from postnatal day (P)4 to P24. At P25, mice visual function were detected by electroretinogram, then retinae were collected for further investigation. Retinal microglia activation state and relevant cytokines were evaluated by qPCR, Western blot and immunofluorescent staining. The retinal structure was assessed by HE Staining. Results:50mg/Kg FA supplement exhibited optimal protection against retinal degeneration, with treated mice exhibiting more photoreceptor nuclei as well as significant wave amplitude amplification in electroretinograms. FA suppressed microglia activation both in vivo and in vitro, inhibited pro-inflammatory factors Tnfα, IL1β, Ccl2 expression in rd10 retinae. Furthermore, FA suppressed the activation of STAT1 and subsequently IRF8 expression, potentially highlighting a role for these pathways in FA-mediated immunomodulatory activity. Conclusions: Attenuating neuroinflammation by FA may be beneficial to retard retinal degeneration.

scholarly journals Ferulic acid attenuates microglia-mediated neuroinflammation in retinal degeneration

2020 ◽  
Author(s):  
Xiaowei Sun ◽  
Peng Sun ◽  
Limei Liu ◽  
Pengfei Jiang ◽  
YUANBIN LI
Keyword(s):  
Ferulic Acid ◽  
Retinal Degeneration ◽  
Microglia Activation ◽  
Immunofluorescent Staining ◽  
Inflammatory Factors ◽  
Immunomodulatory Activity ◽  
Ccl2 Expression ◽  
The Impact

Abstract Background : To explore the impact of Ferulic acid (FA) on microglia-mediated neuroinflammation as well as associated retinal degeneration by using a rd10 mouse model as a means. Methods : Rd10 mice received different concentrations of FA treatment every day from postnatal day (P)4 to P24. At P25, mice visual function were detected by electroretinogram, then retinae were collected for further investigation. Retinal microglia activation state and relevant cytokines were evaluated by qPCR, Western blot and immunofluorescent staining. The retinal structure was assessed by HE Staining. Results :50mg/kg FA supplement exhibited optimal protection against retinal degeneration, with treated mice exhibiting more photoreceptor nuclei as well as significant wave amplitude amplification in electroretinograms. FA suppressed microglia activation both in vivo and in vitro , inhibited pro-inflammatory factors Tnfα, IL1β, Ccl2 expression in rd10 retinae. Furthermore, FA suppressed the activation of STAT1 and subsequently IRF8 expression, potentially highlighting a role for these pathways in FA-mediated immunomodulatory activity. Conclusions : Attenuating neuroinflammation by FA may be beneficial to retard retinal degeneration.

scholarly journals The impact of FGF19/FGFR4 signaling inhibition in antitumor activity of multi-kinase inhibitors in hepatocellular carcinoma

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Hiroaki Kanzaki ◽  
Tetsuhiro Chiba ◽  
Junjie Ao ◽  
Keisuke Koroki ◽  
Kengo Kanayama ◽  
...  
Keyword(s):  
Hepatocellular Carcinoma ◽  
Molecular Mechanisms ◽  
Kinase Inhibitors ◽  
Progression Free Survival ◽  
Erk Signaling ◽  
Enzyme Linked Immunosorbent Assay ◽  
Antitumor Effects ◽  
The Impact

AbstractFGF19/FGFR4 autocrine signaling is one of the main targets for multi-kinase inhibitors (MKIs). However, the molecular mechanisms underlying FGF19/FGFR4 signaling in the antitumor effects to MKIs in hepatocellular carcinoma (HCC) remain unclear. In this study, the impact of FGFR4/ERK signaling inhibition on HCC following MKI treatment was analyzed in vitro and in vivo assays. Serum FGF19 in HCC patients treated using MKIs, such as sorafenib (n = 173) and lenvatinib (n = 40), was measured by enzyme-linked immunosorbent assay. Lenvatinib strongly inhibited the phosphorylation of FRS2 and ERK, the downstream signaling molecules of FGFR4, compared with sorafenib and regorafenib. Additional use of a selective FGFR4 inhibitor with sorafenib further suppressed FGFR4/ERK signaling and synergistically inhibited HCC cell growth in culture and xenograft subcutaneous tumors. Although serum FGF19high (n = 68) patients treated using sorafenib exhibited a significantly shorter progression-free survival and overall survival than FGF19low (n = 105) patients, there were no significant differences between FGF19high (n = 21) and FGF19low (n = 19) patients treated using lenvatinib. In conclusion, robust inhibition of FGF19/FGFR4 is of importance for the exertion of antitumor effects of MKIs. Serum FGF19 levels may function as a predictive marker for drug response and survival in HCC patients treated using sorafenib.

scholarly journals Caenorhabditis elegans as an in vivo Model to Assess Amphetamine Tolerance

2021 ◽  
pp. 1-9
Author(s):  
Dayana Torres Valladares ◽  
Sirisha Kudumala ◽  
Murad Hossain ◽  
Lucia Carvelli
Keyword(s):  
Caenorhabditis Elegans ◽  
Molecular Mechanisms ◽  
Drugs Of Abuse ◽  
Genetic Model ◽  
In Vivo Model ◽  
C Elegans ◽  
Hyperactivity Disorder ◽  
In Vitro Data

Amphetamine is a potent psychostimulant also used to treat attention deficit/hyperactivity disorder and narcolepsy. In vivo and in vitro data have demonstrated that amphetamine increases the amount of extra synaptic dopamine by both inhibiting reuptake and promoting efflux of dopamine through the dopamine transporter. Previous studies have shown that chronic use of amphetamine causes tolerance to the drug. Thus, since the molecular mechanisms underlying tolerance to amphetamine are still unknown, an animal model to identify the neurochemical mechanisms associated with drug tolerance is greatly needed. Here we took advantage of a unique behavior caused by amphetamine in <i>Caenorhabditis elegans</i> to investigate whether this simple, but powerful, genetic model develops tolerance following repeated exposure to amphetamine. We found that at least 3 treatments with 0.5 mM amphetamine were necessary to see a reduction in the amphetamine-induced behavior and, thus, to promote tolerance. Moreover, we found that, after intervals of 60/90 minutes between treatments, animals were more likely to exhibit tolerance than animals that underwent 10-minute intervals between treatments. Taken together, our results show that <i>C. elegans</i> is a suitable system to study tolerance to drugs of abuse such as amphetamines.

Emodin reduces tumor burden by diminishing M2-like macrophages in colorectal cancer

2022 ◽  
Author(s):  
Alexander T Sougiannis ◽  
Brandon N. VanderVeen ◽  
Ioulia Chatzistamou ◽  
Jason L Kubinak ◽  
Mitzi Nagarkatti ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
Genetic Model ◽  
Tumor Burden ◽  
M1 Macrophages ◽  
Chemically Induced ◽  
Poor Understanding ◽  
Exposed Bone ◽  
The Impact ◽  
Nos2 Expression

Emodin, a natural anthraquinone, has been shown to have anti-tumorigenic properties and may be an effective therapy for colorectal cancer (CRC). However, its clinical development has been hampered by a poor understanding of its mechanism of action. The purpose of this study was to 1) evaluate the efficacy of emodin in mouse models of intestinal/colorectal cancer and 2) to examine the impact of emodin on macrophage behavior in the context of CRC. We utilized a genetic model of intestinal cancer (ApcMin/+) and a chemically induced model of CRC (AOM/DSS). Emodin was administered orally (40 mg/kg or 80 mg/kg in AOM/DSS and 80mg/kg in ApcMin/+) 3x/week to observe its preventative effects. Emodin reduced polyp count and size in both rodent models (p<0.05). We further analyzed the colon microenvironment of AOM/DSS mice and found that mice treated with emodin exhibited lower pro-tumorigenic M2-like macrophages and a reduced ratio of M2/M1 macrophages within the colon (p<0.05). Despite this, we did not detect any significant changes in M2-associated cytokines (IL10, IL4, and Tgfb1) nor M1-associated cytokines (IL6, TNFα, IL1β, and IFNγ) within excised polyps. However, there was a significant increase in NOS2 expression (M1 marker) in mice treated with 80 mg/kg emodin (p<0.05). To confirm emodin's effects on macrophages, we exposed bone marrow-derived macrophages (BMDMs) to C26 colon cancer cell conditioned media. Supporting our in vivo data, emodin reduced M2-like macrophages. Overall, these data support the development of emodin as a natural compound for prevention of CRC given its ability to target pro-tumor macrophages.

scholarly journals Microglia dynamics in retinitis pigmentosa model: formation of fundus whitening and autofluorescence as an indicator of activity of retinal degeneration

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Kenichi Makabe ◽  
Sunao Sugita ◽  
Michiko Mandai ◽  
Yoko Futatsugi ◽  
Masayo Takahashi
Keyword(s):  
Retinitis Pigmentosa ◽  
Retinal Degeneration ◽  
Outer Nuclear Layer ◽  
Fundus Autofluorescence ◽  
Fundus Photography ◽  
Photoreceptor Outer Segments ◽  
Diagnostic Interpretation ◽  
Model Formation ◽  
Thinning Rate

Abstract In patients with retinitis pigmentosa (RP), color fundus photography and fundus autofluorescence (FAF) have been used to estimate the disease progression. To understand the origin and the diagnostic interpretation of the fundus color and FAF, we performed in vivo imaging of fundus color and FAF together with histological analyses of the retinal degeneration process using the RP model mice, rd10. FAF partly represented the accumulation of microglia in the photoreceptor outer segments. Fundus whitening suggested the presence of apoptotic cells, which spatiotemporally preceded increase in FAF. We observed two patterns of FAF localization, arcuate and diffuse, each indicating different pattern of apoptosis, wavy and diffuse, respectively. Diffuse pattern of apoptosis was suppressed in dark-raised rd10 mice, in which outer nuclear layer (ONL) loss was significantly suppressed. The occupancy of FAF correlated with the thinning rate of the ONL. Fractalkine, a microglia chemotactic factor, was detected in apoptotic photoreceptors, suggesting chemokine-induced recruitment of microglia into the ONL, which paralleled with accelerated ONL loss and increased FAF occupancy. Thus, we propose that the degree of photoreceptor apoptosis and the rate of ONL thinning in RP patients might be read from the fundus color and the FAF.

scholarly journals Alternative Splicing of FN (Fibronectin) Regulates the Composition of the Arterial Wall Under Low Flow

2020 ◽  
Author(s):  
Patrick A. Murphy ◽  
Noor Jailkhani ◽  
Sarah-Anne Nicholas ◽  
Amanda M. Del Rosario ◽  
Jeremy L. Balsbaugh ◽  
...  
Keyword(s):  
Extracellular Matrix ◽  
Alternative Splicing ◽  
Low Flow ◽  
Matrix Composition ◽  
Splice Isoforms ◽  
Vitro Assay ◽  
Disturbed Flow ◽  
The Impact

Objective: Exposure of the arterial endothelium to low and disturbed flow is a risk factor for the erosion and rupture of atherosclerotic plaques and aneurysms. Circulating and locally produced proteins are known to contribute to an altered composition of the extracellular matrix at the site of lesions, and to contribute to inflammatory processes within the lesions. We have previously shown that alternative splicing of FN (fibronectin) protects against flow-induced hemorrhage. However, the impact of alternative splicing of FN on extracellular matrix composition remains unknown. Approach and Results: Here, we perform quantitative proteomic analysis of the matrisome of murine carotid arteries in mice deficient in the production of FN splice isoforms containing alternative exons EIIIA and EIIIB (FN-EIIIAB null) after exposure to low and disturbed flow in vivo. We also examine serum-derived and endothelial-cell contributions to the matrisome in a simplified in vitro system. We found flow-induced differences in the carotid artery matrisome that were impaired in FN-EIIIAB null mice. One of the most interesting differences was reduced recruitment of FBLN1 (fibulin-1), abundant in blood and not locally produced in the intima. This defect was validated in our in vitro assay, where FBLN1 recruitment from serum was impaired by the absence of these alternatively spliced segments. Conclusions: Our results reveal the extent of the dynamic alterations in the matrisome in the acute response to low and disturbed flow and show how changes in the splicing of FN, a common response in vascular inflammation and remodeling, can affect matrix composition.

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