scholarly journals NOD-Like Receptor Signaling in Cholesteatoma

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Anke Leichtle ◽  
Christin Klenke ◽  
Joerg Ebmeyer ◽  
Markus Daerr ◽  
Karl-Ludwig Bruchhage ◽  
...  

Background. Cholesteatoma is a destructive process of the middle ear resulting in erosion of the surrounding bony structures with consequent hearing loss, vestibular dysfunction, facial paralysis, or intracranial complications. The etiopathogenesis of cholesteatoma is controversial but is associated with recurrent ear infections. The role of intracellular innate immune receptors, the NOD-like receptors, and their associated signaling networks was investigated in cholesteatoma, since mutations in NOD-like receptor-related genes have been implicated in other chronic inflammatory disorders.Results. The expression of NOD2 mRNA and protein was significantly induced in cholesteatoma compared to the external auditory canal skin, mainly located in the epithelial layer of cholesteatoma. Microarray analysis showed significant upregulation for NOD2, not for NOD1, TLR2, or TLR4 in cholesteatoma. Moreover, regulation of genes in an interaction network of the NOD-adaptor molecule RIPK2 was detected. In addition to NOD2, NLRC4, and PYCARD, the downstream molecules IRAK1 and antiapoptotic regulator CFLAR showed significant upregulation, whereas SMAD3, a proapoptotic inducer, was significantly downregulated. Finally, altered regulation of inflammatory target genes of NOD signaling was detected.Conclusions. These results indicate that the interaction of innate immune signaling mediated by NLRs and their downstream target molecules is involved in the etiopathogenesis and growth of cholesteatoma.

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Aileen Patricia Szczepanski ◽  
Lu Wang

AbstractHistone H2AK119 mono-ubiquitination (H2AK119Ub) is a relatively abundant histone modification, mainly catalyzed by the Polycomb Repressive Complex 1 (PRC1) to regulate Polycomb-mediated transcriptional repression of downstream target genes. Consequently, H2AK119Ub can also be dynamically reversed by the BAP1 complex, an evolutionarily conserved multiprotein complex that functions as a general transcriptional activator. In previous studies, it has been reported that the BAP1 complex consists of important biological roles in development, metabolism, and cancer. However, identifying the BAP1 complex’s regulatory mechanisms remains to be elucidated due to its various complex forms and its ability to target non-histone substrates. In this review, we will summarize recent findings that have contributed to the diverse functional role of the BAP1 complex and further discuss the potential in targeting BAP1 for therapeutic use.


2021 ◽  
Vol 6 (1) ◽  
Author(s):  
Xiulin Jiang ◽  
Baiyang Liu ◽  
Zhi Nie ◽  
Lincan Duan ◽  
Qiuxia Xiong ◽  
...  

AbstractN6-methyladenosine (m6A) is the most prevalent, abundant and conserved internal cotranscriptional modification in eukaryotic RNAs, especially within higher eukaryotic cells. m6A modification is modified by the m6A methyltransferases, or writers, such as METTL3/14/16, RBM15/15B, ZC3H3, VIRMA, CBLL1, WTAP, and KIAA1429, and, removed by the demethylases, or erasers, including FTO and ALKBH5. It is recognized by m6A-binding proteins YTHDF1/2/3, YTHDC1/2 IGF2BP1/2/3 and HNRNPA2B1, also known as “readers”. Recent studies have shown that m6A RNA modification plays essential role in both physiological and pathological conditions, especially in the initiation and progression of different types of human cancers. In this review, we discuss how m6A RNA methylation influences both the physiological and pathological progressions of hematopoietic, central nervous and reproductive systems. We will mainly focus on recent progress in identifying the biological functions and the underlying molecular mechanisms of m6A RNA methylation, its regulators and downstream target genes, during cancer progression in above systems. We propose that m6A RNA methylation process offer potential targets for cancer therapy in the future.


2017 ◽  
Vol 8 (10) ◽  
pp. e3078-e3078 ◽  
Author(s):  
Puja Kumari ◽  
Irene Saha ◽  
Athira Narayanan ◽  
Sathish Narayanan ◽  
Akinori Takaoka ◽  
...  

Circulation ◽  
2007 ◽  
Vol 116 (suppl_16) ◽  
Author(s):  
Giuseppe Straface ◽  
Andrea Flex ◽  
Federico Biscetti ◽  
Eleonora Gaetani ◽  
Giovanni Pecorini ◽  
...  

Background: Cerebellar hypoxia is responsible for important aspects of cognitive deterioration and motor disturbances in neurological disorders, such as stroke, vascular dementia, and neurodegeneration. In the cerebellum, VEGF is significantly upregulated after hypoxia and is able to induce angiogenesis, reduce neuronal apoptosis, and regulate neuronal differentiation, proliferation, and migration. But, VEGF is not sufficient to provide neuroprotection. A crucial role is played by growth associated protein-43 (GAP43), for which important activities have been described. The purpose of this study was to investigate the role of the developmental Sonic hedgehog (Shh) signaling pathway in postnatal hypoxic cerebellum and its relationship with VEGF and GAP43 expression. Methods: We used adult C57BL/6J mice, ptc1-lacZ mice, and GAP43−/− mice for these experiments. Ptc1-lacZ mice carry a non-disruptive insertion of the lacZ gene under the control of the ptc1 promoter. Ptc1 is a downstream-transcriptional target of Shh and its upregulation indicates activation of the Shh pathway. Mice were exposed to systemic normobaric hypoxia (6%O 2 ) for 6 hours and the expression of Shh, Ptc1, VEGF, and GAP43 were investigated. Results: After exposure to hypoxia, Shh-positive staining was detected in Purkinje cells (PCs). The same cells were also lacZ(ptc1)-positive, indicating that PCs are both Shh-producing and -responding elements. Also the cells of the internal granular layer (IGL) were lacZ(ptc1)-positive, indicating that these cells are Shh-responsive. LacZ(ptc1)-positive IGL cells were also immunopositive for VEGF and GAP-43. We also found that ptc1 expression is lost in PCs of GAP43−/− mice, indicating that Shh requires GAP43 to activate its downstream target genes in PCs. Finally, when cultures enriched in granular cells were stimulated with Shh recombinant protein, GAP43 phosphorylation was increased. This effect was inhibited by Shh-inhibitor cyclopamine. Conclusions: This is the first time that hypoxia is reported to activate the Shh pathway in the adult. Our data suggest that the Shh pathway might be important for the cerebellar response to hypoxia, through interactions with VEGF and GAP43.


2019 ◽  
Vol 81 (1) ◽  
pp. 453-482 ◽  
Author(s):  
Diane M. Ward ◽  
Suzanne M. Cloonan

Mitochondria are an iconic distinguishing feature of eukaryotic cells. Mitochondria encompass an active organellar network that fuses, divides, and directs a myriad of vital biological functions, including energy metabolism, cell death regulation, and innate immune signaling in different tissues. Another crucial and often underappreciated function of these dynamic organelles is their central role in the metabolism of the most abundant and biologically versatile transition metals in mammalian cells, iron. In recent years, cellular and animal models of mitochondrial iron dysfunction have provided vital information in identifying new proteins that have elucidated the pathways involved in mitochondrial homeostasis and iron metabolism. Specific signatures of mitochondrial iron dysregulation that are associated with disease pathogenesis and/or progression are becoming increasingly important. Understanding the molecular mechanisms regulating mitochondrial iron pathways will help better define the role of this important metal in mitochondrial function and in human health and disease.


2020 ◽  
Vol 21 (24) ◽  
pp. 9614
Author(s):  
Iain A. Murray ◽  
Gary H. Perdew

Increasingly, the aryl hydrocarbon receptor (AHR) is being recognized as a sensor for endogenous and pseudo-endogenous metabolites, and in particular microbiota and host generated tryptophan metabolites. One proposed explanation for this is the role of the AHR in innate immune signaling within barrier tissues in response to the presence of microorganisms. A number of cytokine/chemokine genes exhibit a combinatorial increase in transcription upon toll-like receptors and AHR activation, supporting this concept. The AHR also plays a role in the enhanced differentiation of intestinal and dermal epithelium leading to improved barrier function. Importantly, from an evolutionary perspective many of these tryptophan metabolites exhibit greater activation potential for the human AHR when compared to the rodent AHR. These observations underscore the importance of the AHR in barrier tissues and may lead to pharmacologic therapeutic intervention.


2017 ◽  
Vol 10 (2) ◽  
pp. 85-93 ◽  
Author(s):  
Keaton M. Crosse ◽  
Ebony A. Monson ◽  
Michael R. Beard ◽  
Karla J. Helbig

The ability of a host to curb a viral infection is heavily reliant on the effectiveness of an initial antiviral innate immune response, resulting in the upregulation of interferon (IFN) and, subsequently, IFN-stimulated genes (ISGs). ISGs serve to mount an antiviral state within a host cell, and although the specific antiviral function of a number of ISGs has been characterized, the function of many of these ISGs remains to be determined. Recent research has uncovered a novel role for a handful of ISGs, some of them directly induced by IFN regulatory factor 3 in the absence of IFN itself. These ISGs, most with potent antiviral activity, are also able to augment varying arms of the innate immune response to viral infection, thereby strengthening this response. This new understanding of the role of ISGs may, in turn, help the recent advancement of novel therapeutics aiming to augment innate signaling pathways in an attempt to control viral infection and pathogenesis.


2016 ◽  
Vol 96 (3) ◽  
pp. 347-354 ◽  
Author(s):  
X.W. Dou ◽  
W. Park ◽  
S. Lee ◽  
Q.Z. Zhang ◽  
L.R. Carrasco ◽  
...  

Mandibular torus (MT) is a common intraoral osseous outgrowth located on the lingual surface of the mandible. Histologic features include hyperplastic bone consisting of mature cortical and trabecular bone. Some theories on the etiology of MT have been postulated, such as genetic factors, masticatory hyperfunction, trauma, and continued growth, but the underlying mechanism remains largely unknown. In this study, we investigated the potential role of mesenchymal stem cells (MSCs) derived from human MT in the pathogenesis of bone outgrowth. We demonstrated that MT harbored a distinct subpopulation of MSCs, with enhanced osteogenic and decreased adipogenic differentiation capacities, as compared with their counterparts from normal jaw bone. The increased osteogenic differentiation of mandibular torus MSCs was associated with the suppression of Notch3 signaling and its downstream target genes, Jag1 and Hey1, and a reciprocal increase in the transcriptional activation of ATF4 and NFATc1 genes. Targeted knockdown of Notch3 expression by transient siRNA transfection promoted the expression of osteogenic transcription factors in normal jaw bone MSCs. Our data suggest that the loss of Notch3 signaling may contribute partly to bone outgrowth in MT, as mediated by enhanced MSC-driven osteogenic differentiation in the jaw bone.


2015 ◽  
Vol 38 (1) ◽  
pp. 29-43 ◽  
Author(s):  
Yuliya Skabytska ◽  
Susanne Kaesler ◽  
Thomas Volz ◽  
Tilo Biedermann

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