scholarly journals Loss of CREST leads to neuroinflammatory responses and ALS-like motor defects in mice

2018 ◽  
Author(s):  
Cheng Cheng ◽  
Kan Yang ◽  
Xinwei Wu ◽  
Yuefang Zhang ◽  
Shifang Shan ◽  
...  
Keyword(s):  
Motor Neurons ◽  
Microglial Activation ◽  
Molecular Mechanisms ◽  
Motor Coordination ◽  
Inflammatory Responses ◽  
Late Onset ◽  
Critical Role ◽  
Histone Deacetylation ◽  
Loss Of Function ◽  
Sporadic Als

SUMMARYAmyotrophic lateral sclerosis (ALS) is a late onset neurodegenerative disease with fast progression. Mutations of the CREST gene (also known as SS18L1) are identified in sporadic ALS patients. Whether CREST mutations may lead to ALS remained largely unclear. In this study, we showed that the ALS-related CREST-Q388X mutation exhibited loss-of-function effects. Importantly, we found that microglial activation were prevalent in CREST haploinsufficieny mice and the Q394X mice mimicking the human CREST Q388X mutation. Furthermore, we showed that both CREST haploinsufficieny and the Q394X mice displayed deficits in motor coordination. Finally, we identified the critical role of CREST-BRG1 complex in repressing the expression of immune-related cytokines including Ccl2 and Cxcl10 in neurons, via histone deacetylation, providing the molecular mechanisms underlying inflammatory responses lack of CREST. These findings indicate that elevated inflammatory responses in a subset of ALS may be caused by neuron-derived factors, suggesting potential therapeutic methods through inflammation pathways.In BriefCheng et al. discovered that neuronal loss of CREST reduces the protein level of FUS, de-represses the transcriptional inhibition of chemokine genes which in turn causes microglial activation and proinflammation, and ultimately leads to axonal degeneration of motor neurons and impairment of locomotion.

scholarly journals Histatin-1 Attenuates LPS-Induced Inflammatory Signaling in RAW264.7 Macrophages

2021 ◽  
Vol 22 (15) ◽  
pp. 7856
Author(s):  
Sang Min Lee ◽  
Kyung-No Son ◽  
Dhara Shah ◽  
Marwan Ali ◽  
Arun Balasubramaniam ◽  
...  
Keyword(s):  
Molecular Mechanisms ◽  
Cytokine Production ◽  
Inflammatory Responses ◽  
Critical Role ◽  
Mapk Signaling ◽  
Response To Treatment ◽  
No Production ◽  
Inflammatory Signaling ◽  
Raw264.7 Macrophages ◽  
Inflammatory Mediator Production

Macrophages play a critical role in the inflammatory response to environmental triggers, such as lipopolysaccharide (LPS). Inflammatory signaling through macrophages and the innate immune system are increasingly recognized as important contributors to multiple acute and chronic disease processes. Nitric oxide (NO) is a free radical that plays an important role in immune and inflammatory responses as an important intercellular messenger. In addition, NO has an important role in inflammatory responses in mucosal environments such as the ocular surface. Histatin peptides are well-established antimicrobial and wound healing agents. These peptides are important in multiple biological systems, playing roles in responses to the environment and immunomodulation. Given the importance of macrophages in responses to environmental triggers and pathogens, we investigated the effect of histatin-1 (Hst1) on LPS-induced inflammatory responses and the underlying molecular mechanisms in RAW264.7 (RAW) macrophages. LPS-induced inflammatory signaling, NO production and cytokine production in macrophages were tested in response to treatment with Hst1. Hst1 application significantly reduced LPS-induced NO production, inflammatory cytokine production, and inflammatory signaling through the JNK and NF-kB pathways in RAW cells. These results demonstrate that Hst1 can inhibit LPS-induced inflammatory mediator production and MAPK signaling pathways in macrophages.

scholarly journals Reversal of the Inflammatory Responses in Fabry Patient iPSC-Derived Cardiovascular Endothelial Cells by CRISPR/Cas9-Corrected Mutation

2021 ◽  
Vol 22 (5) ◽  
pp. 2381
Author(s):  
Hui-Yung Song ◽  
Yi-Ping Yang ◽  
Yueh Chien ◽  
Wei-Yi Lai ◽  
Yi-Ying Lin ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Inflammatory Responses ◽  
Late Onset ◽  
Critical Role ◽  
Vascular Complications ◽  
Digital Pcr ◽  
Mapk Signaling ◽  
Autophagic Flux ◽  
Fabry Patient ◽  
Genomic Editing

The late-onset type of Fabry disease (FD) with GLA IVS4 + 919G > A mutation has been shown to lead to cardiovascular dysfunctions. In order to eliminate variations in other aspects of the genetic background, we established the isogenic control of induced pluripotent stem cells (iPSCs) for the identification of the pathogenetic factors for FD phenotypes through CRISPR/Cas9 genomic editing. We adopted droplet digital PCR (ddPCR) to efficiently capture mutational events, thus enabling isolation of the corrected FD from FD-iPSCs. Both of these exhibited the characteristics of pluripotency and phenotypic plasticity, and they can be differentiated into endothelial cells (ECs). We demonstrated the phenotypic abnormalities in FD iPSC-derived ECs (FD-ECs), including intracellular Gb3 accumulation, autophagic flux impairment, and reactive oxygen species (ROS) production, and these abnormalities were rescued in isogenic control iPSC-derived ECs (corrected FD-ECs). Microarray profiling revealed that corrected FD-derived endothelial cells reversed the enrichment of genes in the pro-inflammatory pathway and validated the downregulation of NF-κB and the MAPK signaling pathway. Our findings highlighted the critical role of ECs in FD-associated vascular dysfunctions by establishing a reliable isogenic control and providing information on potential cellular targets to reduce the morbidity and mortality of FD patients with vascular complications.

scholarly journals Heterogeneity and molecular programming of progenitors for motor neurons and oligodendrocytes

2021 ◽  
Author(s):  
Lingyan Xing ◽  
Rui Chai ◽  
jiaqi wang ◽  
Jiaqi Lin ◽  
Hanyang Li ◽  
...  
Keyword(s):  
Cell Fate ◽  
Motor Neurons ◽  
Molecular Mechanisms ◽  
Critical Role ◽  
Oligodendrocyte Progenitor Cells ◽  
Zebrafish Model ◽  
Fate Determination ◽  
Molecular Programming ◽  
The Central Nervous System

The pMN domain is a restricted domain in the ventral spinal cords, defined by the expression of olig2 gene. The fate determination of pMN progenitors is highly temporally and spatially regulated, with motor neurons and oligodendrocyte progenitor cells (OPCs) developing sequentially. Insight into the heterogeneity and molecular programs of pMN progenitors is currently lacking. With the zebrafish model, we identified multiple states of neural progenitors using single-cell sequencing: proliferating progenitors, common progenitors for both motor neurons and OPCs, and restricted precursors for either motor neurons or OPCs. We found specific molecular programs for neural progenitor fate transition, and manipulations of representative genes in the motor neuron or OPC lineage confirmed their critical role in cell fate determination. The transcription factor NPAS3 is necessary for the development of the OPC lineage and can interact with many known genes associated with schizophrenia. Deciphering progenitor heterogeneity and molecular mechanisms for these transitions will elucidate the formation of complex neuron-glia networks in the central nervous system during development, and understand the basis of neurodevelopmental disorders.

scholarly journals Modeling Inflammation in Zebrafish for the Development of Anti-inflammatory Drugs

2021 ◽  
Vol 8 ◽  
Author(s):  
Yufei Xie ◽  
Annemarie H. Meijer ◽  
Marcel J. M. Schaaf
Keyword(s):  
Immune System ◽  
Inflammatory Response ◽  
Molecular Mechanisms ◽  
Inflammatory Responses ◽  
Inflammatory Diseases ◽  
Critical Role ◽  
Model Systems ◽  
Trinitrobenzene Sulfonic Acid ◽  
Inflammatory Drugs ◽  
Anti Inflammatory

Dysregulation of the inflammatory response in humans can lead to various inflammatory diseases, like asthma and rheumatoid arthritis. The innate branch of the immune system, including macrophage and neutrophil functions, plays a critical role in all inflammatory diseases. This part of the immune system is well-conserved between humans and the zebrafish, which has emerged as a powerful animal model for inflammation, because it offers the possibility to image and study inflammatory responses in vivo at the early life stages. This review focuses on different inflammation models established in zebrafish, and how they are being used for the development of novel anti-inflammatory drugs. The most commonly used model is the tail fin amputation model, in which part of the tail fin of a zebrafish larva is clipped. This model has been used to study fundamental aspects of the inflammatory response, like the role of specific signaling pathways, the migration of leukocytes, and the interaction between different immune cells, and has also been used to screen libraries of natural compounds, approved drugs, and well-characterized pathway inhibitors. In other models the inflammation is induced by chemical treatment, such as lipopolysaccharide (LPS), leukotriene B4 (LTB4), and copper, and some chemical-induced models, such as treatment with trinitrobenzene sulfonic acid (TNBS), specifically model inflammation in the gastro-intestinal tract. Two mutant zebrafish lines, carrying a mutation in the hepatocyte growth factor activator inhibitor 1a gene (hai1a) and the cdp-diacylglycerolinositol 3-phosphatidyltransferase (cdipt) gene, show an inflammatory phenotype, and they provide interesting model systems for studying inflammation. These zebrafish inflammation models are often used to study the anti-inflammatory effects of glucocorticoids, to increase our understanding of the mechanism of action of this class of drugs and to develop novel glucocorticoid drugs. In this review, an overview is provided of the available inflammation models in zebrafish, and how they are used to unravel molecular mechanisms underlying the inflammatory response and to screen for novel anti-inflammatory drugs.

scholarly journals Nuclear depletion of RNA binding protein ELAVL3 (HuC) in sporadic and familial amyotrophic lateral sclerosis

2021 ◽  
Author(s):  
Sandra Diaz-Garcia ◽  
Vivian I. Ko ◽  
Sonia Vazquez-Sanchez ◽  
Ruth Chia ◽  
Olubankole Aladesuyi Arogundade ◽  
...  
Keyword(s):  
Amyotrophic Lateral Sclerosis ◽  
Motor Neurons ◽  
Rna Binding ◽  
Binding Protein ◽  
Rna Binding Protein ◽  
Loss Of Function ◽  
Cryptic Exon ◽  
Protein Levels ◽  
Sporadic Als ◽  
Lateral Sclerosis

Amyotrophic lateral sclerosis is a progressive fatal neurodegenerative disease caused by loss of motor neurons and characterized neuropathologically in almost all cases by nuclear depletion and cytoplasmic aggregation of TDP-43, a nuclear RNA binding protein (RBP). We identified ELAVL3 as one of the most downregulated genes in our transcriptome profiles of laser captured microdissection of motor neurons from sporadic ALS nervous systems and the top dysregulated RBPs. Neuropathological characterizations showed ELAVL3 nuclear depletion in a great percentage of remnant motor neurons, sometimes accompanied by cytoplasmic accumulations. These abnormalities were common in sporadic cases with and without intermediate expansions in ATXN2 and familial cases carrying mutations in C9orf72 and SOD1. Depletion of ELAVL3 occurred at both the RNA and protein levels and a short protein isoform was identified but it is not related to a TDP-43-dependent cryptic exon in intron 3. Strikingly, ELAVL3 abnormalities were more frequent than TDP-43 abnormalities and occurred in motor neurons still with normal nuclear TDP-43 present, but all neurons with abnormal TDP-43 also had abnormal ELAVL3. In a neuron-like cell culture model using SH-SY5Y cells, ELAVL3 mislocalization occurred weeks before TDP-43 abnormalities were seen. We interrogated genetic databases but did not identify association of ELAVL3 genetic structure associated with ALS. Taken together, these findings suggest that ELAVL3 is an important RBP in ALS pathogenesis acquired early and the neuropathological data suggest it is involved by loss of function rather than cytoplasmic toxicity.

Transforming growth factor-β-regulated expression of genes in macrophages implicated in the control of cholesterol homoeostasis

2006 ◽  
Vol 34 (6) ◽  
pp. 1141-1144 ◽  
Author(s):  
D.P. Ramji ◽  
N.N. Singh ◽  
P. Foka ◽  
S.A. Irvine ◽  
K. Arnaoutakis
Keyword(s):  
Growth Factor ◽  
Molecular Mechanisms ◽  
Transforming Growth Factor ◽  
Inflammatory Responses ◽  
Critical Role ◽  
Transforming Growth Factor Β ◽  
Crucial Importance ◽  
Expression Of Genes ◽  
Regulated Expression ◽  
Key Genes

The regulation of macrophage cholesterol homoeostasis is of crucial importance in the pathogenesis of atherosclerosis, an underlying cause of heart attack and stroke. Several recent studies have revealed a critical role for the cytokine TGF-β (transforming growth factor-β), a key regulator of the immune and inflammatory responses, in atherogenesis. We discuss here the TGF-β signalling pathway and its role in this disease along with the outcome of our recent studies on the action of the cytokine on the expression of key genes implicated in the uptake or efflux of cholesterol by macrophages and the molecular mechanisms underlying such regulation.

scholarly journals Molecular Mechanisms and Therapeutics for SBMA/Kennedy’s Disease

2019 ◽  
Vol 16 (4) ◽  
pp. 928-947 ◽  
Author(s):  
Frederick J. Arnold ◽  
Diane E. Merry
Keyword(s):  
Motor Neurons ◽  
Molecular Mechanisms ◽  
Muscular Atrophy ◽  
Structure And Function ◽  
Loss Of Function ◽  
Mechanisms Of Toxicity ◽  
Current Review ◽  
And Function ◽  
Positive Results ◽  
Polyq Expansion

Abstract Spinal and bulbar muscular atrophy (SBMA) is a neuromuscular disease caused by a polyglutamine (polyQ) expansion in the androgen receptor (AR). Despite the fact that the monogenic cause of SBMA has been known for nearly 3 decades, there is no effective treatment for this disease, underscoring the complexity of the pathogenic mechanisms that lead to a loss of motor neurons and muscle in SBMA patients. In the current review, we provide an overview of the system-wide clinical features of SBMA, summarize the structure and function of the AR, discuss both gain-of-function and loss-of-function mechanisms of toxicity caused by polyQ-expanded AR, and describe the cell and animal models utilized in the study of SBMA. Additionally, we summarize previously conducted clinical trials which, despite being based on positive results from preclinical studies, proved to be largely ineffective in the treatment of SBMA; nonetheless, these studies provide important insights as researchers develop the next generation of therapies.

scholarly journals Late Onset Death of Motor Neurons in Mice Overexpressing Wild-Type Peripherin

1999 ◽  
Vol 147 (3) ◽  
pp. 531-544 ◽  
Author(s):  
Jean-Martin Beaulieu ◽  
Minh Dang Nguyen ◽  
Jean-Pierre Julien
Keyword(s):  
Motor Neurons ◽  
Late Onset ◽  
Protein A ◽  
Sporadic Amyotrophic Lateral Sclerosis ◽  
Mutant Form ◽  
Wild Type ◽  
Neurofilament Light ◽  
Spinal Motor Neurons ◽  
Sporadic Als ◽  
Selective Death

Peripherin, a type III intermediate filament (IF) protein, upregulated by injury and inflammatory cytokines, is a component of IF inclusion bodies associated with degenerating motor neurons in sporadic amyotrophic lateral sclerosis (ALS). We report here that sustained overexpression of wild-type peripherin in mice provokes massive and selective degeneration of motor axons during aging. Remarkably, the onset of peripherin-mediated disease was precipitated by a deficiency of neurofilament light (NF-L) protein, a phenomenon associated with sporadic ALS. In NF-L null mice, the overexpression of peripherin led to early- onset formation of IF inclusions and to the selective death of spinal motor neurons at 6 mo of age. We also report the formation of similar peripherin inclusions in presymptomatic transgenic mice expressing a mutant form of superoxide dismutase linked to ALS. Taken together, these results suggest that IF inclusions containing peripherin may play a contributory role in motor neuron disease.

scholarly journals Oligodendrocyte-encoded Kir4.1 function is required for axonal integrity

eLife ◽  
2018 ◽  
Vol 7 ◽  
Author(s):  
Lucas Schirmer ◽  
Wiebke Möbius ◽  
Chao Zhao ◽  
Andrés Cruz-Herranz ◽  
Lucile Ben Haim ◽  
...  
Keyword(s):  
Late Onset ◽  
Critical Role ◽  
Neuronal Loss ◽  
Conditional Knockout ◽  
Motor Deficits ◽  
Loss Of Function ◽  
Axonal Dysfunction ◽  
Retinal Thinning

Glial support is critical for normal axon function and can become dysregulated in white matter (WM) disease. In humans, loss-of-function mutations of KCNJ10, which encodes the inward-rectifying potassium channel KIR4.1, causes seizures and progressive neurological decline. We investigated Kir4.1 functions in oligodendrocytes (OLs) during development, adulthood and after WM injury. We observed that Kir4.1 channels localized to perinodal areas and the inner myelin tongue, suggesting roles in juxta-axonal K+ removal. Conditional knockout (cKO) of OL-Kcnj10 resulted in late onset mitochondrial damage and axonal degeneration. This was accompanied by neuronal loss and neuro-axonal dysfunction in adult OL-Kcnj10 cKO mice as shown by delayed visual evoked potentials, inner retinal thinning and progressive motor deficits. Axon pathologies in OL-Kcnj10 cKO were exacerbated after WM injury in the spinal cord. Our findings point towards a critical role of OL-Kir4.1 for long-term maintenance of axonal function and integrity during adulthood and after WM injury.

scholarly journals A specific RIP3+ subpopulation of microglia promotes retinopathy through a hypoxia-triggered necroptotic mechanism

2021 ◽  
Vol 118 (11) ◽  
pp. e2023290118
Author(s):  
Chang He ◽  
Yan Liu ◽  
Zijing Huang ◽  
Ziqi Yang ◽  
Tian Zhou ◽  
...  
Keyword(s):  
Microglial Activation ◽  
Visual Loss ◽  
Molecular Mechanisms ◽  
Retinal Neovascularization ◽  
Loss Of Function ◽  
Severe Visual Loss ◽  
Single Cell Rna Sequencing ◽  
Retinal Angiogenesis ◽  
Signaling Components ◽  
Specific Deletion

Retinal neovascularization is a leading cause of severe visual loss in humans, and molecular mechanisms of microglial activation-driven angiogenesis remain unknown. Using single-cell RNA sequencing, we identified a subpopulation of microglia named sMG2, which highly expressed necroptosis-related genes Rip3 and Mlkl. Genetic and pharmacological loss of function demonstrated that hypoxia-induced microglial activation committed to necroptosis through the RIP1/RIP3-mediated pathway. Specific deletion of Rip3 gene in microglia markedly decreased retinal neovascularization. Furthermore, hypoxia induced explosive release of abundant FGF2 in microglia through RIP3-mediated necroptosis. Importantly, blocking signaling components of the microglia necropotosis–FGF2 axis largely ablated retinal angiogenesis and combination therapy with simultaneously blocking VEGF produced synergistic antiangiogenic effects. Together, our data demonstrate that targeting the microglia necroptosis axis is an antiangiogenesis therapy for retinal neovascular diseases.

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