scholarly journals Nr4a1 siRNA Expression Attenuates α-MSH Regulated Gene Expression in 3T3-L1 Adipocytes

2011 ◽  
Vol 25 (2) ◽  
pp. 291-306 ◽  
Author(s):  
S.-C. Mary Wang ◽  
Stephen A. Myers ◽  
Natalie A. Eriksson ◽  
Rebecca L. Fitzsimmons ◽  
George E. O. Muscat
Keyword(s):  
Gene Expression ◽  
Mrna Expression ◽  
Cross Talk ◽  
Energy Homeostasis ◽  
Critical Role ◽  
Nuclear Hormone Receptor ◽  
Sirna Expression ◽  
Regulated Gene Expression

Abstract Several recent investigations have underscored the growing role of melanocortin signaling in the peripheral regulation of lipid, glucose, and energy homeostasis. In addition, the melanocortins play a critical role in the central control of satiety. These observations, and the latest reports highlighting the emerging role of the nuclear hormone receptor (NR) 4A subgroup in metabolism, have prompted us to investigate the cross talk between [Nle4, d-Phe7] (NDP)-α-MSH and Nr4a signaling in adipose. We have shown that NDP-MSH strikingly and preferentially induces the expression of the NR4A subgroup (but not any other members of the NR superfamily) in differentiated 3T3-L1 adipocytes. Utilization of quantitative PCR on custom-designed metabolic TaqMan low-density arrays identified the concomitant and marked induction of the mRNAs encoding Il-6, Cox2, Pdk4, and Pck-1 after NDP-MSH treatment. Similar experiments demonstrated that the mRNA expression profile induced by cAMP and NDP-MSH treatment displayed unique but also overlapping properties and suggested that melanocortin-mediated induction of gene expression involves cAMP-dependent and -independent signaling. Nr4a1/Nur77 small interfering RNA (siRNA) expression suppressed NDP-MSH-mediated induction of Nr4a1/Nur77 and Nr4a3/Nor-1 (but not Nr4a2/Nurr1). Moreover, expression of the siRNA-attenuated NDP-MSH mediated induction of the mRNAs encoding Il-6, Cox2/Ptgs2, and Pck-1 expression. In addition, Nur77 siRNA expression attenuated NDP-MSH-mediated glucose uptake. In vivo, ip administration of NDP-MSH to C57 BL/6J (male) mice significantly induced the expression of the mRNA encoding Nur77 and increased IL-6, Cox2, Pck1, and Pdk4 mRNA expression in (inguinal) adipose tissue. We conclude that Nur77 expression is necessary for MSH-mediated induction of gene expression in differentiated adipocytes. Furthermore, this study demonstrates cross talk between MSH and Nr4a signaling in adipocytes.

scholarly journals Redundant Role of Tissue-Selective TAFII105 in B Lymphocytes

2002 ◽  
Vol 22 (18) ◽  
pp. 6564-6572 ◽  
Author(s):  
Richard N. Freiman ◽  
Shane R. Albright ◽  
Leslie E. Chu ◽  
Shuang Zheng ◽  
Hong-Erh Liang ◽  
...  
Keyword(s):  
B Cells ◽  
Rna Polymerase Ii ◽  
B Lymphocyte ◽  
Critical Role ◽  
Central Component ◽  
Related Factors ◽  
Tissue Specific ◽  
Regulated Gene Expression

ABSTRACT Regulated gene expression is a complex process achieved through the function of multiple protein factors acting in concert at a given promoter. The transcription factor TFIID is a central component of the machinery regulating mRNA synthesis by RNA polymerase II. This large multiprotein complex is composed of the TATA box binding protein (TBP) and several TBP-associated factors (TAFIIs). The recent discovery of multiple TBP-related factors and tissue-specific TAFIIs suggests the existence of specialized TFIID complexes that likely play a critical role in regulating transcription in a gene- and tissue-specific manner. The tissue-selective factor TAFII105 was originally identified as a component of TFIID derived from a human B-cell line. In this report we demonstrate the specific induction of TAFII105 in cultured B cells in response to bacterial lipopolysaccharide (LPS). To examine the in vivo role of TAFII105, we have generated TAFII105-null mice by homologous recombination. Here we show that B-lymphocyte development is largely unaffected by the absence of TAFII105. TAFII105-null B cells can proliferate in response to LPS, produce relatively normal levels of resting antibodies, and can mount an immune response by producing antigen-specific antibodies in response to immunization. Taken together, we conclude that the function of TAFII105 in B cells is likely redundant with the function of other TAFII105-related cellular proteins.

Abstract 3594: Nogo-B is Essential for Macrophage Dependent Inflammatory Arteriogenesis and Angiogenesis

Circulation ◽  
2008 ◽  
Vol 118 (suppl_18) ◽  
Author(s):  
Jun Yu ◽  
Carlos Fernandez-Hernando ◽  
Yajaira Suarez ◽  
Yajaira Suarez ◽  
Michael Schleicher ◽  
...  
Keyword(s):  
Blood Flow ◽  
Smooth Muscle ◽  
Blood Vessel ◽  
Plaque Rupture ◽  
Critical Role ◽  
Hindlimb Ischemia ◽  
Littermate Control ◽  
Regulated Gene Expression

Nogo-B, a member of the reticulon 4 family of proteins, is the dominant isoform expressed in endothelial, vascular smooth muscle and inflammatory cells. We previously have shown Nogo-B plays a critical role in vascular remodeling after injury in vivo . In mice and rabbits, neointimal expansion of injured blood vessels is associated with a marked reduction in Nogo-B, and, in humans, the loss of Nogo-B correlates with stenotic lesions and plaque rupture. However, the role of Nogo-B in regulating arteriogenesis or angiogenesis is not known. In the present study, we investigated the role of Nogo-B in arteriogenesis/angiogenesis using a mouse hindlimb ischemia model in Nogo-A/B KO (NgKO) and wild-type (WT) littermate control mice. Nogo-B mRNA and protein levels increased in the ischemic leg relative to the contralateral leg in WT. Hindlimb ischemia reduces tissue perfusion by 80% followed by a complete recovery of flow to pre-surgical values in WT after 4 weeks. In NgKO, there was a marked decrease in blood flow recovery post-ischemia, which was accompanied by a reduction in capillary density (assessed by isolectin staining), a decrease in smooth muscle/pericyte recruitment and an impaired collateral artery remodeling (assessed by quantitative angiography) compared to WT. Blood vessel formation and remodeling during ischemia requires coordination of the inflammatory response with regulated gene expression that promotes blood vessel assembly. Thus, we assessed the presence of tissue macrophages (F4/80 immunochemistry) 3 days after ischemia and found a 76% reduction of F4/80 positive cells in ischemic tissue in NgKO compared to WT. Mechanistically, the impaired recruitment of tissue macrophages was associated with reduced spreading, impairment of chemotaxis in response to monocyte chemokines compared to WT cells (76±4 vs. 113±8 cells/field in NgKO vs. WT), but not adhesion, of isolated bone marrow derived monocytes from NgKO compared to controls. Moreover, NgKO macrophage demonstrated impaired Rac activation, translocation and cytoskeletal organization upon stimulation of with chemokines. In conclusion, our data suggests that endogenous Nogo coordinates macrophage mediated inflammation with angiogenesis, arteriogenesis and blood flow control.

scholarly journals RUNX1 mutations promote leukemogenesis of myeloid malignancies in ASXL1-mutated leukemia

2019 ◽  
Vol 12 (1) ◽  
Author(s):  
Rabindranath Bera ◽  
Ming-Chun Chiu ◽  
Ying-Jung Huang ◽  
Tung-Huei Lin ◽  
Ming-Chung Kuo ◽  
...  
Keyword(s):  
Gene Expression ◽  
Bone Marrow ◽  
Bone Marrow Cells ◽  
Critical Role ◽  
Mouse Bone Marrow ◽  
Myeloid Malignancies ◽  
Inhibitor Of Dna Binding

Abstract Background Additional sex combs-like 1 (ASXL1) mutations have been described in all forms of myeloid neoplasms including chronic myelomonocytic leukemia (CMML) and associated with inferior outcomes, yet the molecular pathogenesis of ASXL1 mutations (ASXL1-MT) remains poorly understood. Transformation of CMML to secondary AML (sAML) is one of the leading causes of death in CMML patients. Previously, we observed that transcription factor RUNX1 mutations (RUNX1-MT) coexisted with ASXL1-MT in CMML and at myeloid blast phase of chronic myeloid leukemia. The contribution of RUNX1 mutations in the pathogenesis of myeloid transformation in ASXL1-mutated leukemia, however, remains unclear. Methods To evaluate the leukemogenic role of RUNX1-MT in ASXL1-mutated cells, we co-expressed RUNX1-MT (R135T) and ASXL1-MT (R693X) in different cell lines and performed immunoblot, co-immunoprecipitation, gene expression microarray, quantitative RT-PCR, cell proliferation, differentiation, and clonogenic assays for in vitro functional analyses. The in vivo effect was investigated using the C57BL/6 mouse bone marrow transplantation (BMT) model. Results Co-expression of two mutant genes increased myeloid stem cells in animal model, suggesting that cooperation of RUNX1 and ASXL1 mutations played a critical role in leukemia transformation. The expression of RUNX1 mutant in ASXL1-mutated myeloid cells augmented proliferation, blocked differentiation, and increased self-renewal activity. At 9 months post-BMT, mice harboring combined RUNX1 and ASXL1 mutations developed disease characterized by marked splenomegaly, hepatomegaly, and leukocytosis with a shorter latency. Mice transduced with both ASXL1 and RUNX1 mutations enhanced inhibitor of DNA binding 1 (ID1) expression in the spleen, liver, and bone marrow cells. Bone marrow samples from CMML showed that ID1 overexpressed in coexisted mutations of RUNX1 and ASXL1 compared to normal control and either RUNX1-MT or ASXL1-MT samples. Moreover, the RUNX1 mutant protein was more stable than WT and increased HIF1-α and its target ID1 gene expression in ASXL1 mutant cells. Conclusion The present study demonstrated the biological and functional evidence for the critical role of RUNX1-MT in ASXL1-mutated leukemia in the pathogenesis of myeloid malignancies.

scholarly journals Transcriptional Regulatory Role of NELL2 in Preproenkephalin Gene Expression

2021 ◽  
Author(s):  
Han Rae Kim ◽  
Dong Hee Kim ◽  
Chang Man Ha ◽  
Jungil Choi ◽  
Jeong Woo Park ◽  
...  
Keyword(s):  
Gene Expression ◽  
Mrna Level ◽  
Critical Role ◽  
Expression Vectors ◽  
Endogenous Opioid ◽  
Activation Effect ◽  
Nih3t3 Cells ◽  
The Brain

Preproenkephalin (PPE) is a precursor molecule for multiple endogenous opioid peptides Leu-enkephalin (ENK) and Met-ENK, which are involved in a wide variety of modulatory functions in the nervous system. Despite the functional importance of ENK in the brain, the effect of brain-derived factor(s) on PPE expression is unknown. We report the dual effect of neural epidermal growth factor (EGF)-like-like 2 (NELL2) on PPE gene expression. In cultured NIH3T3 cells, transfection of NELL2 expression vectors induced an inhibition of PPE transcription intracellularly, in parallel with downregulation of protein kinase C signaling pathways and extracellular signal-regulated kinase. Interestingly, these phenomena were reversed when synthetic NELL2 was administered extracellularly. The in vivo disruption of NELL2 synthesis resulted in an increase in PPE mRNA level in the rat brain, suggesting that the inhibitory action of intracellular NELL2 predominates the activation effect of extracellular NELL2 on PPE gene expression in the brain. Biochemical and molecular studies with mutant NELL2 structures further demonstrated the critical role of EGF-like repeat domains in NELL2 for regulation of PPE transcription. These are the first results to reveal the spatio-specific role of NELL2 in the homeostatic regulation of PPE gene expression.

scholarly journals ESM-1 Overexpression is Involved in Increased Tumorigenesis of Radiotherapy-Resistant Breast Cancer Cells

Cancers ◽  
2020 ◽  
Vol 12 (6) ◽  
pp. 1363 ◽  
Author(s):  
Hana Jin ◽  
Trojan Rugira ◽  
Young Shin Ko ◽  
Sang Won Park ◽  
Seung Pil Yun ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Gene Expression ◽  
Cancer Cells ◽  
Breast Cancer Cells ◽  
Critical Role ◽  
Migration And Invasion ◽  
Expression Array ◽  
4T1 Cells

The key barrier to the effectiveness of radiotherapy remains the radioresistance of breast cancer cells, resulting in increased tumor recurrence and metastasis. Thus, in this study, we aimed to clarify the difference between radiotherapy-resistant (RT-R) breast cancer (BC) and BC, and accordingly, analyzed gene expression levels between radiotherapy-resistant (RT-R) MDA-MB-231 cells and MDA-MB-231 cells. Gene expression array showed that ESM-1 was the most upregulated in RT-R-MDA-MB-231 cells compared to MDA-MB-231 cells. Then, we aimed to investigate the role of ESM-1 in the increased tumorigenesis of RT-R-BC cells. RT-R-MDA-MB-231, which showed an increased expression level of ESM1, exhibited significantly enhanced proliferation, colony forming ability, migration, and invasion compared to MDA-MB-231 cells, and ESM-1 knockdown effectively reversed these effects. In addition, compared to MDA-MB-231 cells, RT-R-MDA-MB-231 cells displayed improved adhesion to endothelial cells (ECs) due to the induction of adhesion molecules and increased MMP-9 activity and VEGF-A production, which were decreased by ESM-1 knockdown. Moreover, the expression of HIF-1α and activation of NF-κB and STAT-3 were increased in RT-R-MDA-MB-231 cells compared to MDA-MB-231 cells, and these effects were abolished by the knockdown of ESM-1. Finally, we confirmed the role of ESM-1 in tumorigenesis in an in vivo mouse model. Tumor volume, lung metastasis, and tumorigenic molecules (VEGF-A, HIF-1α, MMP-9, ICAM-1, VCAM-1, and phospho-NF-κB and phospho-STAT-3) were significantly induced in mice injected with ESM-1-overexpressing 4T1 cells and greatly enhanced in those injected with ESM-1-overexpressing RT-R-4T1 cells. Taken together, these results suggest for the first time that ESM-1 plays a critical role in tumorigenesis of breast cancer cells, especially RT-R-breast cancer cells, through the induction of cell proliferation and invasion.

scholarly journals Transcriptome analysis of the role of autophagy in plant response to heat stress

PLoS ONE ◽  
2021 ◽  
Vol 16 (2) ◽  
pp. e0247783
Author(s):  
Yan Zhang ◽  
Haoxuan Min ◽  
Chengchen Shi ◽  
Gengshou Xia ◽  
Zhibing Lai
Keyword(s):  
Gene Expression ◽  
Heat Stress ◽  
Heat Tolerance ◽  
Stress Responses ◽  
Critical Role ◽  
Plant Response ◽  
Wild Type ◽  
Altered Expression ◽  
Regulated Gene Expression

Autophagy plays a critical role in plant heat tolerance in part by targeting heat-induced nonnative proteins for degradation. Autophagy also regulates metabolism, signaling and other processes and it is less understood how the broad function of autophagy affects plant heat stress responses. To address this issue, we performed transcriptome profiling of Arabidopsis wild-type and autophagy-deficient atg5 mutant in response to heat stress. A large number of differentially expressed genes (DEGs) were identified between wild-type and atg5 mutant even under normal conditions. These DEGs are involved not only in metabolism, hormone signaling, stress responses but also in regulation of nucleotide processing and DNA repair. Intriguingly, we found that heat treatment resulted in more robust changes in gene expression in wild-type than in the atg5 mutant plants. The dampening effect of autophagy deficiency on heat-regulated gene expression was associated with already altered expression of many heat-regulated DEGs prior to heat stress in the atg5 mutant. Altered expression of a large number of genes involved in metabolism and signaling in the autophagy mutant prior to heat stress may affect plant response to heat stress. Furthermore, autophagy played a positive role in the expression of defense- and stress-related genes during the early stage of heat stress responses but had little effect on heat-induced expression of heat shock genes. Taken together, these results indicate that the broad role of autophagy in metabolism, cellular homeostasis and other processes can also potentially affect plant heat stress responses and heat tolerance.

scholarly journals The role of the PZP domain of AF10 in acute leukemia driven by AF10 translocations

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Brianna J. Klein ◽  
Anagha Deshpande ◽  
Khan L. Cox ◽  
Fan Xuan ◽  
Mohamad Zandian ◽  
...  
Keyword(s):  
Critical Role ◽  
Cellular Transformation ◽  
Acute Leukemias ◽  
Hematopoietic Stem ◽  
Nucleosome Core ◽  
Stem And Progenitor Cells ◽  
Transforming Activity

AbstractChromosomal translocations of the AF10 (or MLLT10) gene are frequently found in acute leukemias. Here, we show that the PZP domain of AF10 (AF10PZP), which is consistently impaired or deleted in leukemogenic AF10 translocations, plays a critical role in blocking malignant transformation. Incorporation of functional AF10PZP into the leukemogenic CALM-AF10 fusion prevents the transforming activity of the fusion in bone marrow-derived hematopoietic stem and progenitor cells in vitro and in vivo and abrogates CALM-AF10-mediated leukemogenesis in vivo. Crystallographic, biochemical and mutagenesis studies reveal that AF10PZP binds to the nucleosome core particle through multivalent contacts with the histone H3 tail and DNA and associates with chromatin in cells, colocalizing with active methylation marks and discriminating against the repressive H3K27me3 mark. AF10PZP promotes nuclear localization of CALM-AF10 and is required for association with chromatin. Our data indicate that the disruption of AF10PZP function in the CALM-AF10 fusion directly leads to transformation, whereas the inclusion of AF10PZP downregulates Hoxa genes and reverses cellular transformation. Our findings highlight the molecular mechanism by which AF10 targets chromatin and suggest a model for the AF10PZP-dependent CALM-AF10-mediated leukemogenesis.

scholarly journals Essential role of IPS-1 in innate immune responses against RNA viruses

2006 ◽  
Vol 203 (7) ◽  
pp. 1795-1803 ◽  
Author(s):  
Himanshu Kumar ◽  
Taro Kawai ◽  
Hiroki Kato ◽  
Shintaro Sato ◽  
Ken Takahashi ◽  
...  
Keyword(s):  
Rna Viruses ◽  
Rna Virus ◽  
Critical Role ◽  
Nuclear Factor Κb ◽  
Type I ◽  
Innate Immune Responses ◽  
Antiviral Responses ◽  
Deficient Mice

IFN-β promoter stimulator (IPS)-1 was recently identified as an adapter for retinoic acid–inducible gene I (RIG-I) and melanoma differentiation-associated gene 5 (Mda5), which recognize distinct RNA viruses. Here we show the critical role of IPS-1 in antiviral responses in vivo. IPS-1–deficient mice showed severe defects in both RIG-I– and Mda5-mediated induction of type I interferon and inflammatory cytokines and were susceptible to RNA virus infection. RNA virus–induced interferon regulatory factor-3 and nuclear factor κB activation was also impaired in IPS-1–deficient cells. IPS-1, however, was not essential for the responses to either DNA virus or double-stranded B-DNA. Thus, IPS-1 is the sole adapter in both RIG-I and Mda5 signaling that mediates effective responses against a variety of RNA viruses.

scholarly journals Brain-Specific SNAP-25 Deletion Leads to Elevated Extracellular Glutamate Level and Schizophrenia-Like Behavior in Mice

2017 ◽  
Vol 2017 ◽  
pp. 1-11 ◽  
Author(s):  
Hua Yang ◽  
Mengjie Zhang ◽  
Jiahao Shi ◽  
Yunhe Zhou ◽  
Zhipeng Wan ◽  
...  
Keyword(s):  
Cerebral Cortex ◽  
Mouse Model ◽  
Glutamate Release ◽  
Critical Role ◽  
Conditional Knockout ◽  
Snare Complex ◽  
Extracellular Glutamate ◽  
Glutamate Level

Several studies have associated reduced expression of synaptosomal-associated protein of 25 kDa (SNAP-25) with schizophrenia, yet little is known about its role in the illness. In this paper, a forebrain glutamatergic neuron-specific SNAP-25 knockout mouse model was constructed and studied to explore the possible pathogenetic role of SNAP-25 in schizophrenia. We showed that SNAP-25 conditional knockout (cKO) mice exhibited typical schizophrenia-like phenotype. A significantly elevated extracellular glutamate level was detected in the cerebral cortex of the mouse model. Compared with Ctrls, SNAP-25 was dramatically reduced by about 60% both in cytoplasm and in membrane fractions of cerebral cortex of cKOs, while the other two core members of SNARE complex: Syntaxin-1 (increased ~80%) and Vamp2 (increased ~96%) were significantly increased in cell membrane part. Riluzole, a glutamate release inhibitor, significantly attenuated the locomotor hyperactivity deficits in cKO mice. Our findings provide in vivo functional evidence showing a critical role of SNAP-25 dysfunction on synaptic transmission, which contributes to the developmental of schizophrenia. It is suggested that a SNAP-25 cKO mouse, a valuable model for schizophrenia, could address questions regarding presynaptic alterations that contribute to the etiopathophysiology of SZ and help to consummate the pre- and postsynaptic glutamatergic pathogenesis of the illness.

Sign in / Sign up

Export Citation Format

Share Document