Abstract 2178: Sonic Hedgehog In Adult Hypoxic Cerebellum

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.

Biology ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 767
Author(s):  
Filippo Torrisi ◽  
Cristiana Alberghina ◽  
Debora Lo Furno ◽  
Agata Zappalà ◽  
Samuel Valable ◽  
...  

Glioblastoma (GBM) represents the most common primary brain tumor within the adult population. Current therapeutic options are still limited by high rate of recurrences and signalling axes that promote GBM aggressiveness. The contribution of gap junctions (GJs) to tumor growth and progression has been proven by experimental evidence. Concomitantly, tumor microenvironment has received increasing interest as a critical process in dysregulation and homeostatic escape, finding a close link between molecular mechanisms involved in connexin 43 (CX43)-based intercellular communication and tumorigenesis. Moreover, evidence has come to suggest a crucial role of sonic hedgehog (SHH) signalling pathway in GBM proliferation, cell fate and differentiation. Herein, we used two human GBM cell lines, modulating SHH signalling and CX43-based intercellular communication in in vitro models using proliferation and migration assays. Our evidence suggests that modulation of the SHH effector smoothened (SMO), by using a known agonist (i.e., purmorphamine) and a known antagonist (i.e., cyclopamine), affects the CX43 expression levels and therefore the related functions. Moreover, SMO activation also increased cell proliferation and migration. Importantly, inhibition of CX43 channels was able to prevent SMO-induced effects. SHH pathway and CX43 interplay acts inducing tumorigenic program and supporting cell migration, likely representing druggable targets to develop new therapeutic strategies for GBM.


2020 ◽  
Author(s):  
Luca Ducoli ◽  
Saumya Agrawal ◽  
Eliane Sibler ◽  
Tsukasa Kouno ◽  
Carlotta Tacconi ◽  
...  

AbstractRecent studies have revealed the importance of long noncoding RNAs (lncRNAs) as tissue-specific regulators of gene expression. There is ample evidence that distinct types of vasculature undergo tight transcriptional control to preserve their structure, identity, and functions. We determined, for the first time, the global lineage-specific lncRNAome of human dermal blood and lymphatic endothelial cells (BECs and LECs), combining RNA-Seq and CAGE-Seq. A subsequent genome-wide antisense oligonucleotide-knockdown screen of a robust set of BEC- and LEC-specific lncRNAs identified LETR1 as a critical gatekeeper of the global LEC transcriptome. Deep RNA-DNA, RNA-protein, and phenotype rescue analyses revealed that LETR1 acts as a nuclear trans-acting lncRNA modulating, via key epigenetic factors, the expression of essential target genes, including KLF4 and SEMA3C, governing the growth and migratory ability of LECs. Together, our study provides new evidence supporting the intriguing concept that every cell type expresses precise lncRNA signatures to control lineage-specific regulatory programs.


2020 ◽  
Vol 40 (6) ◽  
Author(s):  
Xing Peng ◽  
Jinyu Gao ◽  
Chunyan Cai ◽  
Yumei Zhang

Abstract Cervical cancer (CC), an aggressive malignancy, has a high risk of relapse and death, mainly occurring in females. Accumulating investigations have confirmed the critical role of long noncoding RNAs (lncRNAs) in diverse cancers. LncRNA LINC01503 has been reported as an oncogene in several cancers. Nonetheless, its role and molecular mechanism in CC have not been explored. In the present study, we found that FXYD3 expression was considerably up-regulated in CC tissues and cells. Moreover, FXYD3 deficiency conspicuously hampered cell proliferation and migration while facilitated cell apoptosis in CC cells. Subsequently, molecular mechanism experiments implied that FXYD3 was a downstream target gene of miR-342-3p, and FXYD3 expression was reversely mediated by miR-342-3p. Moreover, we discovered that LINC01503 acted as the endogenous sponge for miR-342-3p. Besides, LINC01503 negatively regulated miR-342-3p expression and positively regulated FXYD3 expression in CC. Rescue assays revealed that LINC01503 depletion-induced repression on CC progression could be partly recovered by miR-342-3p inhibition, and then the co-transfection of sh-FXYD3#1 rescued this effect. Conclusively, LINC01503 aggravated CC progression through sponging miR-342-3p to mediate FXYD3 expression, providing promising therapeutic targets for CC patients.


2020 ◽  
Vol 40 (10) ◽  
Author(s):  
Hui Chen ◽  
Mudunov Ali ◽  
Azizyan Ruben ◽  
Dimitry Stelmakh ◽  
Maksim Pak

ABSTRACT Recently, abundant evidence has clarified that long noncoding RNAs (lncRNAs) play an oncogenic or anticancer role in the tumorigenesis and development of diverse human cancers. Described as a crucial regulator in some cancers, MIR22HG has not yet been studied in laryngocarcinoma and therefore the underlying regulatory role of MIR22HG in laryngocarcinoma is worth detecting. In this study, MIR22HG expression in laryngocarcinoma cells was confirmed to be downregulated, and upregulated MIR22HG expression led to suppressive effects on laryngocarcinoma cell proliferation and migration. Molecular mechanism assays revealed that MIR22HG sponges miR-5000-3p in laryngocarcinoma cells. Besides, decreased expression of miR-5000-3p suppressed laryngocarcinoma cell proliferation and migration. Moreover, the FBXW7 gene was reported to be a downstream target gene of miR-5000-3p in laryngocarcinoma cells. More importantly, rescue assays verified that FBXW7 depletion or miR-5000-3p upregulation countervailed the repressive effects of MIR22HG overexpression on laryngocarcinoma progression. In addition, E2F6 was proved to be capable of inhibiting MIR22HG transcription in laryngocarcinoma cells. To sum up, E2F6-induced downregulation of MIR22HG promotes laryngocarcinoma progression through the miR-5000-3p/FBXW7 axis.


2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Dan Rao ◽  
Songmei Guan ◽  
Junwei Huang ◽  
Qing Chang ◽  
Shigang Duan

Hepatocellular carcinoma (HCC) is one of the most common and dangerous malignant tumors in China, which causes a large number of deaths every year. MicroRNAs (miRNAs) dysfunction contributes to the malignant progression of tumors. The aim of our study was to investigate the relationship between the biological role of miR-425-5p and malignant progression of HCC. Our results showed that miR-425-5p expression was significantly upregulated in HCC tissues and closely related to the poor prognosis of HCC patients. The knockdown of miR-425-5p inhibited cell proliferation and migration. Further, we identified RNF11 as the downstream target gene of miR-425-5p. In addition, the rescue experiments showed that the upregulation of RNF11 could rescue the inhibitory effect of miR-425-5p on HCC. In general, miR-425-5p as an oncogene promotes the malignant development of HCC via RNF11 and serves as a molecular target for predicting the prognosis of HCC patients.


2017 ◽  
Author(s):  
Serena Martinelli ◽  
Vanessa D'Antongiovanni ◽  
Susan Richter ◽  
Letizia Canu ◽  
Tonino Ercolino ◽  
...  

2019 ◽  
Vol 18 (1) ◽  
pp. 78-87 ◽  
Author(s):  
Jian-kai Yang ◽  
Hong-jiang Liu ◽  
Yuanyu Wang ◽  
Chen Li ◽  
Ji-peng Yang ◽  
...  

Background and Objective: Exosomes communicate inter-cellularly and miRNAs play critical roles in this scenario. MiR-214-5p was implicated in multiple tumors with diverse functions uncovered. However, whether miR-214-5p is mechanistically involved in glioblastoma, especially via exosomal pathway, is still elusive. Here we sought to comprehensively address the critical role of exosomal miR-214-5p in glioblastoma (GBM) microenvironment.Methods:The relative expression of miR-214-5p was determined by real-time PCR. Cell viability and migration were measured by MTT and transwell chamber assays, respectively. The secretory cytokines were measured with ELISA kits. The regulatory effect of miR-214-5p on CXCR5 expression was interrogated by luciferase reporter assay. Protein level was analyzed by Western blot.Results:We demonstrated that miR-214-5p was aberrantly overexpressed in GBM and associated with poorer clinical prognosis. High level of miR-214-5p significantly contributed to cell proliferation and migration. GBM-derived exosomal miR-214-5p promoted inflammatory response in primary microglia upon lipopolysaccharide challenge. We further identified CXCR5 as the direct target of miR-214- 5p in this setting.Conclusion:Overexpression of miR-214-5p in GBM modulated the inflammatory response in microglia via exosomal transfer.


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.


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