Human Glucocorticoid Receptor β Regulates Gluconeogenesis and Inflammation in Mouse Liver

Whilein vitrostudies have demonstrated that a glucocorticoid receptor (GR) splice isoform, β-isoform of human GR (hGRβ), acts as a dominant-negative inhibitor of the classic hGRα and confers glucocorticoid resistance, thein vivofunction of hGRβ is poorly understood. To this end, we created an adeno-associated virus (AAV) to express hGRβ in the mouse liver under the control of the hepatocyte-specific promoter. Genome-wide expression analysis of mouse livers showed that hGRβ significantly increased the expression of numerous genes, many of which are involved in endocrine system disorders and the inflammatory response. Physiologically, hGRβ antagonized GRα's function and attenuated hepatic gluconeogenesis through downregulation of phosphoenolpyruvate carboxykinase (PEPCK) in wild-type (WT) mouse liver. Interestingly, however, hGRβ did not repress PEPCK in GR liver knockout (GRLKO) mice. In contrast, hGRβ regulates the expression of STAT1 in the livers of both WT and GRLKO mice. Chromatin immunoprecipitation (ChIP) and luciferase reporter assays demonstrated that hGRβ binds to the intergenic glucocorticoid response element (GRE) of the STAT1 gene. Furthermore, treatment with RU486 inhibited the upregulation of STAT1 mediated by hGRβ. Finally, our array data demonstrate that hGRβ regulates unique components of liver gene expressionin vivoby both GRα-dependent and GRα-independent mechanisms.

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Interaction of interleukin-6 and the BMP pathway in pulmonary smooth muscle

AJP Lung Cellular and Molecular Physiology ◽

10.1152/ajplung.00197.2006 ◽

2007 ◽

Vol 292 (6) ◽

pp. L1473-L1479 ◽

Cited By ~ 104

Author(s):

Moira Hagen ◽

Karen Fagan ◽

Wolfgang Steudel ◽

Michelle Carr ◽

Kirk Lane ◽

...

Keyword(s):

Smooth Muscle ◽

Transgenic Mice ◽

Bmp Signaling ◽

Dominant Negative ◽

Luciferase Reporter ◽

Second Hit ◽

Protein Receptor ◽

Bmp Pathway

The majority of familial pulmonary arterial hypertension (PAH) cases are caused by mutations in the type 2 bone morphogenetic protein receptor (BMPR2). However, less than one-half of BMPR2 mutation carriers develop PAH, suggesting that the most important function of BMPR2 mutation is to cause susceptibility to a “second hit.” There is substantial evidence from the literature implicating dysregulated inflammation, in particular the cytokine IL-6, in the development of PAH. We thus hypothesized that the BMP pathway regulates IL-6 in pulmonary tissues and conversely that IL-6 regulates the BMP pathway. We tested this in vivo using transgenic mice expressing an inducible dominant negative BMPR2 in smooth muscle, using mice injected with an IL-6-expressing virus, and in vitro using small interfering RNA (siRNA) to BMPR2 in human pulmonary artery smooth muscle cells (PA SMC). Consistent with our hypothesis, we found upregulation of IL-6 in both the transgenic mice and in cultured PA SMC with siRNA to BMPR2; this could be abolished with p38MAPK inhibitors. We also found that IL-6 in vivo caused a twofold increase in expression of the BMP signaling target Id1 and caused increased BMP activity in a luciferase-reporter assay in PA SMC. Thus we have shown both in vitro and in vivo a complete negative feedback loop between IL-6 and BMP, suggesting that an important consequence of BMPR2 mutations may be poor regulation of cytokines and thus vulnerability to an inflammatory second hit.

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Fosl1 is vital to heart regeneration upon apex resection in adult Xenopus tropicalis

npj Regenerative Medicine ◽

10.1038/s41536-021-00146-y ◽

2021 ◽

Vol 6 (1) ◽

Author(s):

Hai-Yan Wu ◽

Yi-Min Zhou ◽

Zhu-Qin Liao ◽

Jia-Wen Zhong ◽

You-Bin Liu ◽

...

Keyword(s):

Early Stage ◽

Dominant Negative ◽

Luciferase Reporter ◽

Heart Regeneration ◽

Cell Cycle Regulators ◽

Cardiomyocyte Proliferation ◽

Neonatal Mice ◽

Heart Injury

AbstractCardiovascular disease is the leading cause of death in the world due to losing regenerative capacity in the adult heart. Frogs possess remarkable capacities to regenerate multiple organs, including spinal cord, tail, and limb, but the response to heart injury and the underlying molecular mechanism remains largely unclear. Here we demonstrated that cardiomyocyte proliferation greatly contributes to heart regeneration in adult X. tropicalis upon apex resection. Using RNA-seq and qPCR, we found that the expression of Fos-like antigen 1 (Fosl1) was dramatically upregulated in early stage of heart injury. To study Fosl1 function in heart regeneration, its expression was modulated in vitro and in vivo. Overexpression of X. tropicalis Fosl1 significantly promoted the proliferation of cardiomyocyte cell line H9c2. Consistently, endogenous Fosl1 knockdown suppressed the proliferation of H9c2 cells and primary cardiomyocytes isolated from neonatal mice. Taking use of a cardiomyocyte-specific dominant-negative approach, we show that blocking Fosl1 function leads to defects in cardiomyocyte proliferation during X. tropicalis heart regeneration. We further show that knockdown of Fosl1 can suppress the capacity of heart regeneration in neonatal mice, but overexpression of Fosl1 can improve the cardiac function in adult mouse upon myocardium infarction. Co-immunoprecipitation, luciferase reporter, and ChIP analysis reveal that Fosl1 interacts with JunB and promotes the expression of Cyclin-T1 (Ccnt1) during heart regeneration. In conclusion, we demonstrated that Fosl1 plays an essential role in cardiomyocyte proliferation and heart regeneration in vertebrates, at least in part, through interaction with JunB, thereby promoting expression of cell cycle regulators including Ccnt1.

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Period 2 Regulates CYP2B10 Expression and Activity in Mouse Liver

Frontiers in Pharmacology ◽

10.3389/fphar.2021.764124 ◽

2021 ◽

Vol 12 ◽

Author(s):

MengLin Chen ◽

Min Chen ◽

Danyi Lu ◽

Yi Wang ◽

Li Zhang ◽

...

Keyword(s):

Mouse Liver ◽

Luciferase Reporter ◽

Specific Substrate ◽

Dependent Manner ◽

Hepatic Expression ◽

Period 2 ◽

Reporter Assays ◽

Expression And Activity

CYP2B10 is responsible for metabolism and detoxification of many clinical drugs. Here, we aimed to investigate a potential role of Period 2 (PER2) in regulating expression of hepatic CYP2B10. Regulatory effects of PER2 on hepatic expression of CYP2B10 and other enzymes were determined using Per2-deficient mice with exons 4-6 deleted (named Per2Del4-6 mice). In vitro and in vivo metabolic activities of CYP2B10 were probed using cyclophosphamide (CPA) as a specific substrate. Regulatory mechanism was investigated using luciferase reporter assays. Genotyping and Western blotting demonstrated loss of wild-type Per2 transcript and markedly reduced PER2 protein in Per2Del4-6 mice. Hepatic expression of a plenty of drug-metabolizing genes (including Cyp2a4/2a5, Cyp2b10, Ugt1a1, Ugt1a9, Ugt2b36, Sult1a1 and Sult1e1) were altered (and majority were down-regulated) in Per2Del4-6 mice. Of note, Cyp2b10, Ugt1a9 and Sult1a1 were three genes considerably affected with reduced expression. Decreased expression of CYP2B10 was translated to reduced metabolism and altered pharmacokinetics of CPA as well as attenuated CPA hepatotoxicity in Per2Del4-6 mice. Positive regulation of CYP2B10 by PER2 was further confirmed in both Hepa-1c1c7 and AML-12 cells. Based on luciferase reporter assays, it was shown that PER2 regulated Cyp2b10 transcription in a REV-ERBα-dependent manner. REV-ERBα was negatively regulated by PER2 (increased REV-ERBα expression in Per2Del4-6 mice) and itself was also a repressor of CYP2B10. In conclusion, PER2 positively regulates CYP2B10 expression and activity in mouse liver through inhibiting its repressor REV-ERBα.

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The dominant negative β isoform of the glucocorticoid receptor is uniquely expressed in erythroid cells expanded from polycythemia vera patients

Blood ◽

10.1182/blood-2010-07-296921 ◽

2011 ◽

Vol 118 (2) ◽

pp. 425-436 ◽

Cited By ~ 27

Author(s):

Lilian Varricchio ◽

Elena Masselli ◽

Elena Alfani ◽

Angela Battistini ◽

Giovanni Migliaccio ◽

...

Keyword(s):

Glucocorticoid Receptor ◽

Polycythemia Vera ◽

Mononuclear Cells ◽

Therapeutic Agents ◽

Dominant Negative ◽

Erythropoietin Treatment ◽

Low Levels ◽

Stimulation Of

Abstract Glucocorticoid receptor (GR) agonists increase erythropoiesis in vivo and in vitro. To clarify the effect of the dominant negative GRβ isoform (unable to bind STAT-5) on erythropoiesis, erythroblast (EB) expansion cultures of mononuclear cells from 18 healthy (nondiseased) donors (NDs) and 16 patients with polycythemia vera (PV) were studied. GRβ was expressed in all PV EBs but only in EBs from 1 ND. The A3669G polymorphism, which stabilizes GRβ mRNA, had greater frequency in PV (55%; n = 22; P = .0028) and myelofibrosis (35%; n = 20) patients than in NDs (9%; n = 22) or patients with essential thrombocythemia (6%; n = 15). Dexamethasone stimulation of ND cultures increased the number of immature EBs characterized by low GATA1 and β-globin expression, but PV cultures generated great numbers of immature EBs with low levels of GATA1 and β-globin irrespective of dexamethasone stimulation. In ND EBs, STAT-5 was not phosphorylated after dexamethasone and erythropoietin treatment and did not form transcriptionally active complexes with GRα, whereas in PV EBs, STAT-5 was constitutively phosphorylated, but the formation of GR/STAT-5 complexes was prevented by expression of GRβ. These data indicate that GRβ expression and the presence of A3669G likely contribute to development of erythrocytosis in PV and provide a potential target for identification of novel therapeutic agents.

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Familial Glucocorticoid Resistance Caused by a Novel Frameshift Glucocorticoid Receptor Mutation

Endocrine Reviews ◽

10.1210/edrv.31.5.9989 ◽

2010 ◽

Vol 31 (5) ◽

pp. 777-777

Author(s):

P. Trebble ◽

L. Matthews ◽

J. Blaikley ◽

A. W. O. Wayte ◽

G. C. M. Black ◽

...

Keyword(s):

Glucocorticoid Receptor ◽

Nuclear Translocation ◽

Dominant Negative ◽

Glucocorticoid Resistance ◽

Causative Mutation ◽

Wild Type ◽

Mild Phenotype ◽

Dominant Negative Activity

ABSTRACT Context Familial glucocorticoid resistance is a rare condition with a typical presentation of women with hirsutism and hypertension, with or without hypokalemia. Objective The aim was to determine the cause of apparent glucocorticoid resistance in a young woman. Patients and Methods We studied a family with a novel glucocorticoid receptor (GR) mutation and a surprisingly mild phenotype. Their discovery resulted from serendipitous measurement of serum cortisol with little biochemical or clinical evidence for either hyperandrogenism or mineralocorticoid excess. Results The causative mutation was identified as a frameshift mutation in exon 6. Transformed peripheral blood lymphocytes were generated to analyze GR expression in vitro. Carriers of the mutation had less full-length GR, but the predicted mutant GR protein was not detected. However, this does not exclude expression in vivo, and so the mutant GR (D612GR) was expressed in vitro. Simple reporter gene assays suggested that Δ612GR has dominant negative activity. Δ612GR was not subject to ligand-dependent Ser211 phosphorylation or to ligand-dependent degradation. A fluorophore-tagged construct showed that Δ612GR did not translocate to the nucleus in response to ligand and retarded translocation of the wild-type GR. These data suggest that Δ612GR is not capable of binding ligand and exerts dominant negative activity through heterodimerization with wild-type GR. Conclusion Therefore, we describe a novel, naturally occurring GR mutation that results in familial glucocorticoid resistance. The mutant GR protein, if expressed in vivo, is predicted to exert dominant negative activity by impairing wild-type GR nuclear translocation.

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Periovulatory Expression of Hyaluronan and Proteoglycan Link Protein 1 (Hapln1) in the Rat Ovary: Hormonal Regulation and Potential Function

Endocrine Reviews ◽

10.1210/edrv.31.2.9997 ◽

2010 ◽

Vol 31 (2) ◽

pp. 262-263

Author(s):

Jing Liu ◽

Eun-Sil Park ◽

Thomas E. Curry ◽

Misung Jo

Keyword(s):

Granulosa Cells ◽

Hormonal Regulation ◽

Dominant Negative ◽

Luciferase Reporter ◽

Growth Factor Signaling ◽

Link Protein ◽

Epidermal Growth Factor Signaling ◽

Serum Gonadotropin

ABSTRACT Periovulatory follicular matrix plays an important role in cumulus-oocyte complex (COC) expansion, ovulation, and luteal formation. Hyaluronan and proteoglycan link protein 1 (HAPLN1), a component of follicular matrix, was shown to enhance COC expansion in vitro. However, the regulatory mechanisms of periovulatory expression of Hapln1 and its role in periovulatory granulosa cells have not been elucidated. We first determined the periovulatory expression pattern of Hapln1 using pregnant mare serum gonadotropin/human chorionic gonadotropin (hCG)-primed immature rat ovaries. Hapln1 expression was transiently induced both in intact ovaries and granulosa cells at 8 h and 12 h after hCG injection. This in vivo expression of Hapln1 was recapitulated by culturing preovulatory granulosa cells with hCG. The stimulatory effect of hCG was blocked by inhibition of protein kinase A, phosphatidylinositol dependent kinase, p38 MAPK, epidermal growth factor signaling, and prostaglandin synthesis, revealing key mediators involved in LH-induced Hapln1 expression. In addition, knockdown of Runx1 and Runx2 expression by small interfering RNA or inhibition of RUNX activities by dominant-negative RUNX decreased hCG or agonist-induced Hapln1 expression. Chromatin immunoprecipitation assays verified the in vivo binding of RUNX1 and RUNX2 to the Hapln1 promoter in periovulatory granulosa cells. Luciferase reporter assays revealed that mutation of the RUNX binding sites completely obliterated the agonist-induced activity of the Hapln1 promoter. These data conclusively identified RUNX proteins as the crucial transcription regulators for LH-induced Hapln1 expression. Functionally, treatment with HAPLN1 increased the viability of cultured granulosa cells and decreased the number of the cells undergoing apoptosis, whereas knockdown of Hapln1 expression decreased granulosa cells viability. This novel finding indicates that HAPLN1 may promote periovulatory granulosa cell survival, which would facilitate their differentiation into luteal cells.

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Functional role of alternatively spliced deoxycytidine kinase in sensitivity to cytarabine of acute myeloid leukemic cells

Blood ◽

10.1182/blood.v99.4.1373 ◽

2002 ◽

Vol 99 (4) ◽

pp. 1373-1380 ◽

Cited By ~ 27

Author(s):

Marjan J. T. Veuger ◽

Mirjam H. M. Heemskerk ◽

M. Willy Honders ◽

Roel Willemze ◽

Renée M. Y. Barge

Keyword(s):

Dominant Negative ◽

Leukemic Cells ◽

Deoxycytidine Kinase ◽

Development Of Resistance ◽

Dominant Negative Inhibitor ◽

Alternatively Spliced ◽

Acute Myeloid

Development of resistance to cytarabine (AraC) is a major problem in the treatment of patients with acute myeloid leukemia (AML). Inactivation of deoxycytidine kinase (dCK) plays an important role in AraC resistance in vitro. We have identified inactive, alternatively spliced dCK forms in leukemic blasts from patients with resistant AML. Because these dCK-spliced variants were only detectable in resistant AML, it was hypothesized that they might play a role in AraC resistance in vivo. In the current study, the biologic role of the alternatively spliced dCK forms in AraC resistance was further investigated by retroviral transductions in rat leukemic cells. Introduction of inactive, alternatively spliced dCK forms into AraC-resistant K7 cells, with no endogenous wild-type (wt) dCK activity, could not restore AraC sensitivity, whereas wt dCK fully restored the AraC-sensitive phenotype. Transfection of alternatively spliced dCK forms into AraC-sensitive KA cells, as well as in human leukemic U937 cells and in phytohemagglutinin-stimulated T cells, did not significantly change sensitivity toward AraC. In addition, cotransduction of wt dCK with alternatively spliced dCK in K7 cells did not result in altered sensitivity to AraC compared with K7 cells only transduced with wt dCK. These data indicate that the alternatively spliced dCK forms cannot act as a dominant-negative inhibitor on dCK wt activity when they are coexpressed in a single cell. However, a cell expressing alternatively spliced dCK forms that has lost wt dCK expression is resistant to the cytotoxic effects of AraC.

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In vitro and in vivo assessment of the protective effect of sufentanil in acute lung injury

Journal of International Medical Research ◽

10.1177/0300060520986351 ◽

2021 ◽

Vol 49 (2) ◽

pp. 030006052098635

Author(s):

Qi Gao ◽

Ningqing Chang ◽

Donglian Liu

Keyword(s):

Acute Lung Injury ◽

Lung Injury ◽

Protective Effect ◽

High Mobility ◽

Terminal Deoxynucleotidyl Transferase ◽

Inflammatory Factors ◽

Luciferase Reporter ◽

Hmgb1 Protein

Objectives To investigate the mechanisms underlying the protective effect of sufentanil against acute lung injury (ALI). Material and Methods Rats were administered lipopolysaccharide (LPS) by endotracheal instillation to establish a model of ALI. LPS was used to stimulate BEAS-2B cells. The targets and promoter activities of IκB were assessed using a luciferase reporter assay. Apoptosis of BEAS-2B cells was evaluated by terminal deoxynucleotidyl transferase dUTP nick end labeling. Results Sufentanil treatment markedly reduced pathological changes in lung tissue, pulmonary edema and secretion of inflammatory factors associated with ALI in vivo and in vitro. In addition, sufentanil suppressed apoptosis induced by LPS and activated NF-κB both in vivo and in vitro. Furthermore, upregulation of high mobility group box protein 1 (HMGB1) protein levels and downregulation of miR-129-5p levels were observed in vivo and in vitro following sufentanil treatment. miR-129-5p targeted the 3ʹ untranslated region and its inhibition decreased promoter activities of IκB-α. miR-129-5p inhibition significantly weakened the protective effect of sufentanil on LPS-treated BEAS-2B cells. Conclusion Sufentanil regulated the miR-129-5p/HMGB1 axis to enhance IκB-α expression, suggesting that sufentanil represents a candidate drug for ALI protection and providing avenues for clinical treatment.

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Long noncoding RNA SNHG14 promotes hepatocellular carcinoma progression by regulating miR-876-5p/SSR2 axis

Journal of Experimental & Clinical Cancer Research ◽

10.1186/s13046-021-01838-5 ◽

2021 ◽

Vol 40 (1) ◽

Author(s):

Zhibin Liao ◽

Hongwei Zhang ◽

Chen Su ◽

Furong Liu ◽

Yachong Liu ◽

...

Keyword(s):

Noncoding Rna ◽

Animal Experiments ◽

Luciferase Reporter ◽

Western Blot Assay ◽

Downstream Target ◽

Protein Levels ◽

Elevated Expression ◽

Rna Immunoprecipitation

Abstract Background Aberrant expressions of long noncoding RNAs (lncRNAs) have been demonstrated to be related to the progress of HCC. The mechanisms that SNHG14 has participated in the development of HCC are obscure. Methods Quantitative real-time PCR (qRT-PCR) was used to measure the lncRNA, microRNA and mRNA expression level. Cell migration, invasion and proliferation ability were evaluated by transwell and CCK8 assays. The ceRNA regulatory mechanism of SNHG14 was evaluated by RNA immunoprecipitation (RIP) and dual luciferase reporter assay. Tumorigenesis mouse model was used to explore the roles of miR-876-5p in vivo. The protein levels of SSR2 were measured by western blot assay. Results In this study, we demonstrated that SNHG14 was highly expressed in HCC tissues, meanwhile, the elevated expression of SNHG14 predicted poor prognosis in patients with HCC. SNHG14 promoted proliferation and metastasis of HCC cells. We further revealed that SNHG14 functioned as a competing endogenous RNA (ceRNA) for miR-876-5p and that SSR2 was a downstream target of miR-876-5p in HCC. Transwell, CCK8 and animal experiments exhibited miR-876-5p inhibited HCC progression in vitro and in vivo. By conducting rescue experiments, we found the overexpression of SSR2 or knocking down the level of miR-876-5p could reverse the suppressive roles of SNHG14 depletion in HCC. Conclusion SNHG14 promotes HCC progress by acting as a sponge of miR-876-5p to regulate the expression of SSR2 in HCC.

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Honeysuckle Aqueous Extracts Induced let-7a Suppress EV71 Replication and Pathogenesis In Vitro and In Vivo and Is Predicted to Inhibit SARS-CoV-2

Viruses ◽

10.3390/v13020308 ◽

2021 ◽

Vol 13 (2) ◽

pp. 308

Author(s):

Ying-Ray Lee ◽

Chia-Ming Chang ◽

Yuan-Chieh Yeh ◽

Chi-Ying F. Huang ◽

Feng-Mao Lin ◽

...

Keyword(s):

Protein Expression ◽

Western Blotting ◽

Expression Profiles ◽

Plaque Assay ◽

Virus Titer ◽

Enterovirus 71 ◽

Luciferase Reporter ◽

Pathogen Invasion

Honeysuckle (Lonicera japonica Thunb) is a traditional Chinese medicine (TCM) with an antipathogenic activity. MicroRNAs (miRNAs) are small non-coding RNA molecules that are ubiquitously expressed in cells. Endogenous miRNA may function as an innate response to block pathogen invasion. The miRNA expression profiles of both mice and humans after the ingestion of honeysuckle were obtained. Fifteen overexpressed miRNAs overlapped and were predicted to be capable of targeting three viruses: dengue virus (DENV), enterovirus 71 (EV71) and SARS-CoV-2. Among them, let-7a was examined to be capable of targeting the EV71 RNA genome by reporter assay and Western blotting. Moreover, honeysuckle-induced let-7a suppression of EV71 RNA and protein expression as well as viral replication were investigated both in vitro and in vivo. We demonstrated that let-7a targeted EV71 at the predicted sequences using luciferase reporter plasmids as well as two infectious replicons (pMP4-y-5 and pTOPO-4643). The suppression of EV71 replication and viral load was demonstrated in two cell lines by luciferase activity, RT-PCR, real-time PCR, Western blotting and plaque assay. Furthermore, EV71-infected suckling mice fed honeysuckle extract or inoculated with let-7a showed decreased clinical scores and a prolonged survival time accompanied with decreased viral RNA, protein expression and virus titer. The ingestion of honeysuckle attenuates EV71 replication and related pathogenesis partially through the upregulation of let-7a expression both in vitro and in vivo. Our previous report and the current findings imply that both honeysuckle and upregulated let-7a can execute a suppressive function against the replication of DENV and EV71. Taken together, this evidence indicates that honeysuckle can induce the expression of let-7a and that this miRNA as well as 11 other miRNAs have great potential to prevent and suppress EV71 replication.

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