scholarly journals KIAA1429 and ALKBH5 Oppositely Influence Aortic Dissection Progression via Regulating the Maturation of Pri-miR-143-3p in an m6A-Dependent Manner

2021 ◽  
Vol 9 ◽  
Author(s):  
Peng Wang ◽  
Zhiwei Wang ◽  
Min Zhang ◽  
Qi Wu ◽  
Feng Shi ◽  
...  
Keyword(s):  
Aortic Dissection ◽  
Dependent Manner ◽  
Loss Of Function ◽  
Therapeutic Approaches ◽  
Downstream Target ◽  
Downstream Target Gene ◽  
Molecular Mechanism Of Action ◽  
New Research

Despite decades of study into aortic dissection (AD), a lethal cardiovascular emergency due to a tear in the aorta intima or bleeding within the aortic wall, leading to the separation of the different layers of it, the factors that influence its progression and the deeper regulatory mechanisms remain poorly understood. Nowadays, with the maturity of N6-methyladenosine (m6A) sequence technology, m6A modification, one type of RNA epigenesis, has gradually become a new research hotspot for epigenetic molecular regulation. Especially recently, increasing evidence has revealed that m6A modification functions as a pivotal post-transcriptional modification to influence the progression of multiple diseases. Based on these findings, it is reasonable to speculate that m6A modification may affect the onset and progression of AD. To explore the validity of our conjecture and to elucidate its underlying molecular mechanism of action, we conducted the present study. In this study, we found that KIAA1429 is downregulated while ALKBH5 is upregulated in aortic tissues from AD patients. Furthermore, gain- and loss-of-function studies showed that KIAA1429 and ALKBH5 can oppositely regulate HASMC proliferation, HAEC apoptosis, and AD progression in AngII-infused mice. Mechanistically, we demonstrated that KIAA1429/ALKBH5-mediated m6A modifications can regulate the processing of pri-miR-143-3p through interacting with the microprocessor protein DGCR8, thus indirectly regulating the downstream target gene of mature miR-143-3p, DDX6, to perform their biological functions in vitro and in vivo. Our findings have revealed a novel connection between m6A modification and AD progression and may provide a novel molecular basis for subsequent researchers to search for novel therapeutic approaches to improve the health of patients struggling with AD.

Pelle kinase is activated by autophosphorylation during Toll signaling in Drosophila

Development ◽  
2002 ◽  
Vol 129 (8) ◽  
pp. 1925-1933 ◽  
Author(s):  
Baohe Shen ◽  
James L. Manley
Keyword(s):  
Dependent Manner ◽  
Loss Of Function ◽  
Concentration Dependent Manner ◽  
Downstream Target ◽  
Toll Signaling ◽  
Early Embryos ◽  
High Concentrations ◽  
L2 Cells

The Drosophila Pelle kinase plays a key role in the evolutionarily conserved Toll signaling pathway, but the mechanism responsible for its activation has been unknown. We present in vivo and in vitro evidence establishing an important role for concentration-dependent autophosphorylation in the signaling process. We first show that Pelle phosphorylation can be detected transiently in early embryos, concomitant with activation of signaling. Importantly, Pelle phosphorylation is enhanced in a gain-of-function Toll mutant (Toll10b), but decreased by loss-of-function Toll alleles. Next we found that Pelle is phosphorylated in transfected Schneider L2 cells in a concentration-dependent manner such that significant modification is observed only at high Pelle concentrations, which coincide with levels required for phosphorylation and activation of the downstream target, Dorsal. Pelle phosphorylation is also enhanced in L2 cells co-expressing Toll10b, and is dependent on Pelle kinase activity. In vitro kinase assays revealed that recombinant, autophosphorylated Pelle is far more active than unphosphorylated Pelle. Importantly, unphosphorylated Pelle becomes autophosphorylated, and activated, by incubation at high concentrations. We discuss these results in the context of Toll-like receptor mediated signaling in both flies and mammals.

Genetic evidence for the transcriptional-activating function of Homothorax during adult fly development

Development ◽  
2001 ◽  
Vol 128 (18) ◽  
pp. 3405-3413 ◽  
Author(s):  
Adi Inbal ◽  
Naomi Halachmi ◽  
Charna Dibner ◽  
Dale Frank ◽  
Adi Salzberg
Keyword(s):  
Transcriptional Activity ◽  
Target Genes ◽  
Genetic Evidence ◽  
In Vivo Studies ◽  
Loss Of Function ◽  
Native Form ◽  
Downstream Target ◽  
Activating Function

Homothorax (HTH) is a homeobox-containing protein, which plays multiple roles in the development of the embryo and the adult fly. HTH binds to the homeotic cofactor Extradenticle (EXD) and translocates it to the nucleus. Its function within the nucleus is less clear. It was shown, mainly by in vitro studies, that HTH can bind DNA as a part of ternary HTH/EXD/HOX complexes, but little is known about the transcription regulating function of HTH-containing complexes in the context of the developing fly. Here we present genetic evidence, from in vivo studies, for the transcriptional-activating function of HTH. The HTH protein was forced to act as a transcriptional repressor by fusing it to the Engrailed (EN) repression domain, or as a transcriptional activator, by fusing it to the VP16 activation domain, without perturbing its ability to translocate EXD to the nucleus. Expression of the repressing form of HTH in otherwise wild-type imaginal discs phenocopied hth loss of function. Thus, the repressing form was working as an antimorph, suggesting that normally HTH is required to activate the transcription of downstream target genes. This conclusion was further supported by the observation that the activating form of HTH caused typical hth gain-of-function phenotypes and could rescue hth loss-of-function phenotypes. Similar results were obtained with XMeis3, the Xenopus homologue of HTH, extending the known functional similarity between the two proteins. Competition experiments demonstrated that the repressing forms of HTH or XMeis3 worked as true antimorphs competing with the transcriptional activity of the native form of HTH. We also describe the phenotypic consequences of HTH antimorph activity in derivatives of the wing, labial and genital discs. Some of the described phenotypes, for example, a proboscis-to-leg transformation, were not previously associated with alterations in HTH activity. Observing the ability of HTH antimorphs to interfere with different developmental pathways may direct us to new targets of HTH. The HTH antimorph described in this work presents a new means by which the transcriptional activity of the endogenous HTH protein can be blocked in an inducible fashion in any desired cells or tissues without interfering with nuclear localization of EXD.

scholarly journals MicroRNA-346 inhibits the growth of glioma by directly targeting NFIB

2019 ◽  
Vol 19 (1) ◽  
Author(s):  
Yangyang Li ◽  
Jia Xu ◽  
Jiale Zhang ◽  
Jie Zhang ◽  
Jian Zhang ◽  
...  
Keyword(s):  
Target Gene ◽  
Glioma Cells ◽  
Downstream Target ◽  
Downstream Target Gene ◽  
Direct Target ◽  
Proliferation Assays ◽  
The Relationship ◽  
Proliferation In Vitro

Abstract Background Glioma is considered one of the most common tumors and has a poor prognosis. Recently, microRNAs (miRNAs) have been reported to be strongly linked to various human tumors including glioma. In this study, we investigated a new anticancer miRNA, miR-346, to determine the effects and mechanism of miR-346 and its downstream target gene NFIB on tumors. Methods Lentivirus transfection, real-time PCR, western blotting, immunohistochemistry, cell proliferation assays, and mouse experiments were used to examine the relationship between miR-346 and its regulation of NFIB in glioma cells. Results The expression of miR-346 was downregulated in glioma cells. Overexpression of miR-346 arrested the cell cycle of glioma cells and inhibited their proliferation in vitro and in vivo. NFIB was a direct target of miR-346, whose expression was reduced by the miRNA. Overexpression of NFIB reversed all tested functions of miR-346. Conclusion miR-346 inhibited the growth of glioma cells by targeting NFIB and may be a new prognostic and diagnostic biomarker for glioma.

GFI1 Is a Tumor Suppressor in Myeloid Progenitors

Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 2942-2942
Author(s):  
Aditya Chaubey ◽  
Shane Hormon ◽  
Chinavenmeni S. Velu ◽  
Tristan Bourdeau ◽  
Jinfang Zhu ◽  
...  
Keyword(s):  
Dna Sequences ◽  
Myeloid Leukemia ◽  
Dependent Manner ◽  
Loss Of Function ◽  
Increased Risk ◽  
Myeloid Leukemias ◽  
Dose Dependent ◽  
Anterior Posterior

Abstract In severe congenital neutropenia (SCN) patients and mice with Growth factor independent-1 (Gfi1) loss of function, arrested progenitors are suspended in a hyperproliferative state while terminal granulpoiesis is blocked. SCN patients are at increased risk for the development of acute myeloid leukemia. We demonstrate that Gfi1 directly targets HoxA9, Pbx1 and Meis1 during normal myelopoiesis. Gfi1−/− progenitors exhibit elevated levels of HoxA9, Pbx1 and Meis1, exaggerated HoxA9-Pbx1-Meis1 activity, and increased persistence in vivo and in vitro. Limiting HoxA9 alleles corrects, in a dose dependent manner, in vivo and in vitro phenotypes observed with loss of Gfi1. Moreover, in a manner conserved in Drosophila anterior/posterior patterning, we demonstrate that these factors can compete for occupancy of DNA sequences encoding composite Gfi1-HoxA9-Pbx1-Meis1 binding sites. Finally, the expression of Gfi1 and HoxA9 are inverse and stratify human myeloid leukemias, suggesting a role for HoxA9- Gfi1 antagonism in human AML. In agreement with this, a myeloproliferative disorder progresses into a rapid, lethal and transplantable myeloid leukemia in a Gfi1−/− setting. We conclude that the lifespan and oncogenic transformation of hematopoietic progenitor cells is regulated through a conserved competition between Gfi1 and HoxA9-Pbx1-Meis1.

scholarly journals The cerebral cavernous malformation proteins CCM2L and CCM2 prevent the activation of the MAP kinase MEKK3

2015 ◽  
Vol 112 (46) ◽  
pp. 14284-14289 ◽  
Author(s):  
Xavier Cullere ◽  
Eva Plovie ◽  
Paul M. Bennett ◽  
Calum A. MacRae ◽  
Tanya N. Mayadas
Keyword(s):  
Endothelial Cells ◽  
Cavernous Malformation ◽  
Body Axis ◽  
Cerebral Cavernous Malformations ◽  
Loss Of Function ◽  
Cavernous Malformations ◽  
Downstream Target ◽  
Density Flow

Three genes, CCM1, CCM2, and CCM3, interact genetically and biochemically and are mutated in cerebral cavernous malformations (CCM). A recently described member of this CCM family of proteins, CCM2-like (CCM2L), has high homology to CCM2. Here we show that its relative expression in different tissues differs from that of CCM2 and, unlike CCM2, the expression of CCM2L in endothelial cells is regulated by density, flow, and statins. In vitro, both CCM2L and CCM2 bind MEKK3 in a complex with CCM1. Both CCM2L and CCM2 interfere with MEKK3 activation and its ability to phosphorylate MEK5, a downstream target. The in vivo relevance of this regulation was investigated in zebrafish. A knockdown of ccm2l and ccm2 in zebrafish leads to a more severe “big heart” and circulation defects compared with loss of function of ccm2 alone, and also leads to substantial body axis abnormalities. Silencing of mekk3 rescues the big heart and body axis phenotype, suggesting cross-talk between the CCM proteins and MEKK3 in vivo. In endothelial cells, CCM2 deletion leads to activation of ERK5 and a transcriptional program that are downstream of MEKK3. These findings suggest that CCM2L and CCM2 cooperate to regulate the activity of MEKK3.

scholarly journals Capsule carbohydrate structure determines virulence in Acinetobacter baumannii

2021 ◽  
Vol 17 (2) ◽  
pp. e1009291
Author(s):  
Yuli Talyansky ◽  
Travis B. Nielsen ◽  
Jun Yan ◽  
Ulrike Carlino-Macdonald ◽  
Gisela Di Venanzio ◽  
...  
Keyword(s):  
Acinetobacter Baumannii ◽  
Bacterial Pathogen ◽  
Specific Gene ◽  
Dependent Manner ◽  
Bacterial Burden ◽  
Carbohydrate Structure ◽  
Loss Of Function ◽  
Capsule Assembly

Acinetobacter baumannii is a highly antibiotic-resistant bacterial pathogen for which novel therapeutic approaches are needed. Unfortunately, the drivers of virulence in A. baumannii remain uncertain. By comparing genomes among a panel of A. baumannii strains we identified a specific gene variation in the capsule locus that correlated with altered virulence. While less virulent strains possessed the intact gene gtr6, a hypervirulent clinical isolate contained a spontaneous transposon insertion in the same gene, resulting in the loss of a branchpoint in capsular carbohydrate structure. By constructing isogenic gtr6 mutants, we confirmed that gtr6-disrupted strains were protected from phagocytosis in vitro and displayed higher bacterial burden and lethality in vivo. Gtr6+ strains were phagocytized more readily and caused lower bacterial burden and no clinical illness in vivo. We found that the CR3 receptor mediated phagocytosis of gtr6+, but not gtr6-, strains in a complement-dependent manner. Furthermore, hypovirulent gtr6+ strains demonstrated increased virulence in vivo when CR3 function was abrogated. In summary, loss-of-function in a single capsule assembly gene dramatically altered virulence by inhibiting complement deposition and recognition by phagocytes across multiple A. baumannii strains. Thus, capsular structure can determine virulence among A. baumannii strains by altering bacterial interactions with host complement-mediated opsonophagocytosis.

scholarly journals TMED3/RPS15A Axis promotes the development and progression of osteosarcoma

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Wei Xu ◽  
Yifan Li ◽  
Xiaojian Ye ◽  
Yunhan Ji ◽  
Yu Chen ◽  
...  
Keyword(s):  
Biological Function ◽  
Profile Analysis ◽  
Tumor Model ◽  
Underlying Mechanism ◽  
Molecular Therapy ◽  
Loss Of Function ◽  
Osteosarcoma Cells ◽  
Downstream Target

Abstract Background Osteosarcoma is a primary malignant tumor that mainly affects children and young adults. Transmembrane emp24 trafficking protein 3 (TMED3) may be involved in the regulation of malignant cancer behaviors. However, the role of TMED3 in osteosarcoma remains mysterious. In this study, the potential biological function and underlying mechanism of TMED3 in progression of osteosarcoma was elaborated. Methods The expression of TMED3 in osteosarcoma was analyzed by immunohistochemical staining. The biological function of TMED3 in osteosarcoma was determined through loss-of-function assays in vitro. The effect of TMED3 downregulation on osteosarcoma was further explored by xenograft tumor model. The molecular mechanism of the regulation of TMED3 on osteosarcoma was determined by gene expression profile analysis. Results The expression of TMED3 in osteosarcoma tissues was significantly greater than that in matched adjacent normal tissues. Knockdown of TMED3 inhibited the progression of osteosarcoma by suppressing proliferation, impeding migration and enhancing apoptosis in vitro. We further validated that knockdown of TMED3 inhibited osteosarcoma generation in vivo. Additionally, ribosomal protein S15A (RPS15A) was determined as a potential downstream target for TMED3 involved in the progression of osteosarcoma. Further investigations elucidated that the simultaneous knockdown of RPS15A and TMED3 intensified the inhibitory effects on osteosarcoma cells. Importantly, knockdown of RPS15A alleviated the promotion effects of TMED3 overexpression in osteosarcoma cells. Conclusions In summary, these findings emphasized the importance of TMED3/RPS15A axis in promoting tumor progression, which may be a promising candidate for molecular therapy of osteosarcoma.

scholarly journals Novel Long Noncoding RNA 005620 Induces Epirubicin Resistance in Triple-Negative Breast Cancer by Regulating ITGB1 Expression

2021 ◽  
Vol 11 ◽  
Author(s):  
Fengliang Wang ◽  
Sujin Yang ◽  
Mingming Lv ◽  
Fei Chen ◽  
Hong Yin ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Triple Negative Breast Cancer ◽  
Noncoding Rna ◽  
Triple Negative ◽  
Sequencing Analysis ◽  
Loss Of Function ◽  
Integrin Β1 ◽  
Downstream Target

Triple-negative breast cancer (TNBC) is often treated with anthracyclines (e.g., epirubicin or doxorubicin), but very little is known about anthracycline resistance, especially epirubicin resistance in TNBC. To identify novel long noncoding RNAs (lncRNAs) involved in epirubicin resistance in TNBC, we established a new TNBC MDA-MB-231 cell line that was resistant to epirubicin (Epi-R). A total of 12 differentially expressed lncRNAs were identified using RNA sequencing analysis of Epi-R cells. Among these lncRNAs, we found a novel intronic lncRNA, lnc005620, was highly expressed in Epi-R cells and human TNBC tissues. Further gain- and loss-of-function studies demonstrated that lnc005620 played an oncogenic role and partially abrogated the effects of epirubicin on TNBC cells. Using iTRAQ proteomics analysis, we found that three members of the integrin family, integrin β4, integrin β1 and integrin α6, were all upregulated in Epi-R MDA-MB-231 cells. Integrin β1, encoded by the ITGB1 gene, was validated to be a downstream target of lnc005620 in Epi-R MDA-MB-231 cells. Our study demonstrates that novel lnc005620 promotes TNBC progression and chemoresistance to epirubicin via integrin β1 both in vitro and in vivo and provides a promising therapeutic target for TNBC patients in terms of enhancing the benefits of epirubicin treatment.

scholarly journals TCF4 and HuR Mediated-METTL14 Suppresses Dissemination of Colorectal Cancer via N6-Methyladenosine-Dependent Silencing of ARRDC4

2021 ◽  
Author(s):  
Hao Wang ◽  
Wei Wei ◽  
Zhong-Yuan Zhang ◽  
Yao Liu ◽  
Bin Shi ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
Chromatin Immunoprecipitation ◽  
Dependent Manner ◽  
Dot Blot ◽  
Downstream Target ◽  
In Vivo Assays ◽  
Rna Immunoprecipitation ◽  
Underlying Mechanisms

Abstract Background: Metastasis remains the major obstacle to improved survival for colorectal cancer (CRC) patients. Dysregulation of N6-methyladenosine (m6A) is causally associated with the development of metastasis through poorly understood mechanisms. Methods: The expression of METTL14 and its correlation with clinicopathological features were evaluated by western blot and immunohistochemistry. The roles of METTL14 in CRC metastasis were determined through in vitro and in vivo assays. The underlying mechanisms of METTL14 regulation were explored using transcriptome-sequencing, m6A-seguencing, methylated RNA immunoprecipitation (MeRIP), m6A dot blot, RNA immunoprecipitation (RIP) and chromatin immunoprecipitation (ChIP) assay.Results: METTL14 is functionally related to the inhibition of ARRDC4/ZEB1 signaling and to the consequent suppression of CRC metastasis. We unveil METTL14-mediated m6A modification profile and identify ARRDC4 as a direct downstream target of METTL14. Knockdown of METTL14 significantly enhances ARRDC4 mRNA stability relying on the “reader” protein YHTDF2 dependent manner. Moreover, TCF4 can induce METTL14 protein expression, and HuR suppresses METTL14 expression by directly binding to its promoter. Clinically, decreased METTL14 is correlated with poor prognosis and acts as an independent predictor of CRC survival. Conclusion: Our data suggest that TCF4 and HuR mediated-METTL14 can trigger the metastasis of CRC during cancer development via YHTDF2/ARRDC4/ZEB1 axis, which imposes great challenge that inhibition of METTL14 is a potential approach for cancer treatment.

scholarly journals Trib1 promotes acute myeloid leukemia progression by modulating the transcriptional programs of Hoxa9

Blood ◽  
2020 ◽  
Author(s):  
Seiko Yoshino ◽  
Takashi Yokoyama ◽  
Yoshitaka Sunami ◽  
Tomoko Takahara ◽  
Aya Nakamura ◽  
...  
Keyword(s):  
Acute Myeloid Leukemia ◽  
Myeloid Leukemia ◽  
Genetic Effect ◽  
Dependent Manner ◽  
Enhancer Activity ◽  
Downstream Target ◽  
Erk Phosphorylation ◽  
Acute Myeloid

The pseudokinase Trib1 functions as a myeloid oncogene that recruits the E3 ubiquitin ligase COP1 to C/EBPa and interacts with MEK1 to enhance ERK phosphorylation. Close genetic effect of Trib1 on Hoxa9 has been observed in myeloid leukemogenesis where Trib1 overexpression significantly accelerates Hoxa9-induced leukemia onset. However, the mechanism underlying how Trib1 functionally modulates Hoxa9 transcription activity is unclear. Herein, we provide evidence that Trib1 modulates Hoxa9-associated super-enhancers. ChIP-seq analysis identified increased histone H3K27Ac signals at super-enhancers of the Erg, Spns2, Rgl1, and Pik3cd loci, as well as increased mRNA expression of these genes. Modification of super-enhancer activity was mostly achieved via the degradation of C/EBPa p42 by Trib1, with a slight contribution from the MEK/ERK pathway. Silencing of Erg abrogated the growth advantage acquired by Trib1 overexpression, indicating that Erg is a critical downstream target of the Trib1/Hoxa9 axis. Moreover, treatment of acute myeloid leukemia (AML) cells with the BRD4 inhibitor JQ1 showed growth inhibition in a Trib1/Erg-dependent manner both in vitro and in vivo. Upregulation of ERG by TRIB1 was also observed in human AML cell lines, suggesting that Trib1 is a potential therapeutic target of Hoxa9-associated AML. Taken together, our study demonstrates a novel mechanism by which Trib1 modulates chromatin and Hoxa9-driven transcription in myeloid leukemogenesis.

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