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Mascareno E, Gupta R, Martello LA, Dhar-Mascareno M, Salciccioli L, Beckles D, Walsh MG, Machado FS, Tanowitz HB, Haseeb M. Rapidly progressive course of Trypanosoma cruzi infection in mice heterozygous for hexamethylene bis-acetamide inducible 1 (Hexim1) gene. Microbes Infect 2018; 20:25-36. [DOI: 10.1016/j.micinf.2017.09.001] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2017] [Revised: 08/30/2017] [Accepted: 09/04/2017] [Indexed: 01/02/2023]
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Dhar-Mascareno M, Rozenberg I, Iqbal J, Hussain MM, Beckles D, Mascareno E. Hexim1 heterozygosity stabilizes atherosclerotic plaque and decreased steatosis in ApoE null mice fed atherogenic diet. Int J Biochem Cell Biol 2017; 83:56-64. [PMID: 28013147 DOI: 10.1016/j.biocel.2016.12.010] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2016] [Revised: 12/14/2016] [Accepted: 12/19/2016] [Indexed: 01/13/2023]
Abstract
Hexim-1 is an inhibitor of RNA polymerase II transcription elongation. Decreased Hexim-1 expression in animal models of chronic diseases such as left ventricular hypertrophy, obesity and cancer triggered significant changes in adaptation and remodeling. The main aim of this study was to evaluate the role of Hexim1 in lipid metabolism focused in the progression of atherosclerosis and steatosis. We used the C57BL6 apolipoprotein E (ApoE null) crossed bred to C57BL6Hexim1 heterozygous mice to obtain ApoE null - Hexim1 heterozygous mice (ApoE-HT). Both ApoE null backgrounds were fed high fat diet for twelve weeks. Then, we evaluated lipid metabolism, atherosclerotic plaque formation and liver steatosis. In order to understand changes in the transcriptome of both backgrounds during the progression of steatosis, we performed Affymetrix mouse 430 2.0 microarray. After 12 weeks of HFD, ApoE null and ApoE-HT showed similar increase of cholesterol and triglycerides in plasma. Plaque composition was altered in ApoE-HT. Additionally, liver triglycerides and steatosis were decreased in ApoE-HT mice. Affymetrix analysis revealed that decreased steatosis might be due to impaired inducible SOCS3 expression in ApoE-HT mice. In conclusion, decreased Hexim-1 expression does not alter cholesterol metabolism in ApoE null background after HFD. However, it promotes stable atherosclerotic plaque and decreased steatosis by promoting the anti-inflammatory TGFβ pathway and blocking the expression of the inducible and pro-inflammatory expression of SOCS3 respectively.
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Affiliation(s)
- Manya Dhar-Mascareno
- Department of Biological Sciences, State University of New York, College at Old Westbury, Old Westbury, New York 11568, USA
| | - Inna Rozenberg
- Department of Cell Biology, State University of New York Downstate Medical Center, Brooklyn, New York, 11203 USA
| | - Jahangir Iqbal
- Department of Cell Biology, State University of New York Downstate Medical Center, Brooklyn, New York, 11203 USA
| | - M Mahmood Hussain
- Department of Cell Biology, State University of New York Downstate Medical Center, Brooklyn, New York, 11203 USA
| | - Daniel Beckles
- Department of Cell Biology, State University of New York Downstate Medical Center, Brooklyn, New York, 11203 USA; Departments of Surgery, Medicine and Cell Biology, State University of New York Downstate Medical Center, Brooklyn, New York, 11203 USA
| | - Eduardo Mascareno
- Department of Cell Biology, State University of New York Downstate Medical Center, Brooklyn, New York, 11203 USA.
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Nguyen D, Fayol O, Buisine N, Lecorre P, Uguen P. Functional Interaction between HEXIM and Hedgehog Signaling during Drosophila Wing Development. PLoS One 2016; 11:e0155438. [PMID: 27176767 PMCID: PMC4866710 DOI: 10.1371/journal.pone.0155438] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2016] [Accepted: 04/28/2016] [Indexed: 12/13/2022] Open
Abstract
Studying the dynamic of gene regulatory networks is essential in order to understand the specific signals and factors that govern cell proliferation and differentiation during development. This also has direct implication in human health and cancer biology. The general transcriptional elongation regulator P-TEFb regulates the transcriptional status of many developmental genes. Its biological activity is controlled by an inhibitory complex composed of HEXIM and the 7SK snRNA. Here, we examine the function of HEXIM during Drosophila development. Our key finding is that HEXIM affects the Hedgehog signaling pathway. HEXIM knockdown flies display strong phenotypes and organ failures. In the wing imaginal disc, HEXIM knockdown initially induces ectopic expression of Hedgehog (Hh) and its transcriptional effector Cubitus interuptus (Ci). In turn, deregulated Hedgehog signaling provokes apoptosis, which is continuously compensated by apoptosis-induced cell proliferation. Thus, the HEXIM knockdown mutant phenotype does not result from the apoptotic ablation of imaginal disc; but rather from the failure of dividing cells to commit to a proper developmental program due to Hedgehog signaling defects. Furthermore, we show that ci is a genetic suppressor of hexim. Thus, HEXIM ensures the integrity of Hedgehog signaling in wing imaginal disc, by a yet unknown mechanism. To our knowledge, this is the first time that the physiological function of HEXIM has been addressed in such details in vivo.
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Affiliation(s)
- Duy Nguyen
- UMR-S1174, Univ. Paris-Sud, Inserm, Université Paris-Saclay, Bât. 440, 91405 Orsay, France
| | - Olivier Fayol
- UMR-S1174, Univ. Paris-Sud, Inserm, Université Paris-Saclay, Bât. 440, 91405 Orsay, France
| | | | - Pierrette Lecorre
- UMR-S1174, Univ. Paris-Sud, Inserm, Université Paris-Saclay, Bât. 440, 91405 Orsay, France
| | - Patricia Uguen
- UMR-S1174, Univ. Paris-Sud, Inserm, Université Paris-Saclay, Bât. 440, 91405 Orsay, France
- * E-mail:
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Jiang J, Zhang L, Zhang L, Xia X. Application of recombinant peroxisome proliferator-activated receptor-γ coactivator-1α mediates neovascularization in the retina. Mol Med Rep 2015; 13:1311-9. [PMID: 26676891 DOI: 10.3892/mmr.2015.4678] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2015] [Accepted: 10/26/2015] [Indexed: 11/06/2022] Open
Abstract
Peroxisome proliferator-activated receptor-γ coactivator-1α (PGC-1α) is able to induce the expression of vascular endothelial growth factor (VEGF), promoting the formation of new blood vessels in skeletal muscle. The aim of the current study was to determine whether PGC-1α is able to regulate angiogenesis in human retinal vascular endothelial cells (hRVECs) in vitro and in retinas in vivo. hRVECs treated with recombinant PGC-1α were incubated for 24 h and then placed into a normoxic (20% O2) or hypoxic (1% O2) environment for a further 16 h. Following this, VEGF mRNA and protein levels were significantly increased. Cellular proliferation was enhanced by treatment with recombinant PGC-1α in normoxic and hypoxic conditions. At 24 h following recombinant PGC-1α treatment, hRVECs were plated into Matrigel-coated plates and cultured under normoxic (20% O2) or hypoxic (1% O2) conditions for a further 24 h. Recombinant PGC-1α-treated cells were observed to form significantly greater numbers of tubes. In a C57BL/6J mouse model of ischemic retinopathy, mice received an intravitreal injection of recombinant PGC-1α, resulting in a significant increase in VEGF mRNA and protein levels in the retina. Retinal neovascular tufts and neovascular nuclei were investigated by angiographic and cross-sectional analysis and were observed to be significantly increased in the PGC-1α group compared with the control group. These results indicate that PGC-1α is able to induce angiogenesis in hRVECs and retinas, and suggests that PGC-1α is a potential anti-angiogenic target in retinal neovascularization.
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Affiliation(s)
- Jian Jiang
- Department of Ophthalmology, Xiangya Hospital, Central South University, Changsha, Hunan 410008, P.R. China
| | - Lixin Zhang
- Department of Ophthalmology, Xiangya Hospital, Central South University, Changsha, Hunan 410008, P.R. China
| | - Lu Zhang
- Department of Ophthalmology, Xiangya Hospital, Central South University, Changsha, Hunan 410008, P.R. China
| | - Xiaobo Xia
- Department of Ophthalmology, Xiangya Hospital, Central South University, Changsha, Hunan 410008, P.R. China
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Jiang J, Zhang L, Xia XB. Small interfering RNA targeting PGC-1α inhibits VEGF expression and tube formation in human retinal vascular endothelial cells. Int J Ophthalmol 2015; 8:877-83. [PMID: 26558195 DOI: 10.3980/j.issn.2222-3959.2015.05.05] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2015] [Accepted: 05/27/2015] [Indexed: 11/02/2022] Open
Abstract
AIM To determine whether small interfering RNA (siRNA) of PGC-1α could inhibit vascular endothelial growth factor (VEGF) expression and tube formation in human retinal vascular endothelial cells (hRVECs). METHODS hRVECs transfected with peroxisome proliferator-activated receptor-γ coactivator-1α (PGC-1α) siRNA were incubated for 24h and then placed into a normoxic (20%, O2) or hypoxic (1%, O2) environment for another 16h. PGC-1α mRNA and protein levels were detected by real-time PCR and Western blot. VEGF mRNA and protein levels were detected by real-time PCR and ELISA. Cell proliferation was evaluated by BrdU incorporation assay. Forty-eight hours after siRNA transfection, hRVECs were planted into Matrigel-coated plates and cultured under normoxic (20%, O2) or hypoxic (1%, O2) conditions for another 48h. The tube formation of hRVECs was observed under an optical microscope and quantified by counting the number of branch points and calculating the total tube length. RESULTS PGC-1α mRNA and protein levels were significantly reduced by PGC-1α siRNA, and VEGF mRNA and protein levels also decreased significantly. The percentage of BrdU-labeled cells in siPGC-1α groups were significantly decreased compared with control siRNA groups under normoxia and hypoxia in cell proliferation assay. In the tube formation assay, PGC-1α siRNA treated cells formed significantly fewer tubes. CONCLUSION Blocking PGC-1α expression can inhibit VEGF expression in hRVECs and inhibit their ability to form tubes under both normoxic and hypoxic conditions.
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Affiliation(s)
- Jian Jiang
- Department of Ophthalmology, Xiangya Hospital, Central South University, Changsha 410008, Hunan Province, China
| | - Lu Zhang
- Department of Ophthalmology, Xiangya Hospital, Central South University, Changsha 410008, Hunan Province, China
| | - Xiao-Bo Xia
- Department of Ophthalmology, Xiangya Hospital, Central South University, Changsha 410008, Hunan Province, China
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Yoshikawa N, Shimizu N, Ojima H, Kobayashi H, Hosono O, Tanaka H. Down-regulation of hypoxia-inducible factor-1 alpha and vascular endothelial growth factor by HEXIM1 attenuates myocardial angiogenesis in hypoxic mice. Biochem Biophys Res Commun 2014; 453:600-5. [DOI: 10.1016/j.bbrc.2014.09.135] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2014] [Accepted: 09/30/2014] [Indexed: 11/29/2022]
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Zhang L, Jiang J, Xia X. Suppression of retinal neovascularization by small interfering RNA targeting PGC-1α. Int J Mol Med 2014; 33:1523-30. [PMID: 24682380 DOI: 10.3892/ijmm.2014.1717] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2013] [Accepted: 03/13/2014] [Indexed: 11/05/2022] Open
Abstract
Peroxisome proliferator-activated receptor-γ coactivator-1α (PGC-1α) is a key coordinator of gene programs in metabolism and energy homeostasis in mammals. The aim of this study was to determine whether PGC-1α is involved in the transcriptional regulation of retinal neovascularization in oxygen-induced retinopathy (OIR). The expression of PGC-1α in the retina of mice with OIR was detected by real-time polymerase chain reaction (PCR) and western blot analysis. Mice with OIR were administered small interfering RNA (siRNA) targeting PGC-1α by intravitreal injection, and the effects of PGC-1α siRNA were confirmed by fluorescein angiography and quantification of pre-retinal neovascular nuclei in the retinal sections. PGC-1α was upregulated at both the mRNA and protein level under hypoxic conditions. Retinal neovascularization was inhibited by PGC-1α siRNA. Furthermore, PGC-1α mRNA and protein levels were also reduced by PGC-1α siRNA, which were detected by real-time PCR and western blot analysis. The downregulation of PGC-1α expression resulted in the reduction of vascular endothelial growth factor (VEGF) expression in the mice. In conclusion, siRNA targeting PGC-1α inhibits retinal neovascularization by downregulating the expression of PGC-1α and VEGF in the murine retina. Therefore, PGC-1α represents a potential therapeutic target for ischemia-induced retinal diseases and other ocular neovascular diseases.
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Affiliation(s)
- Lixin Zhang
- Department of Ophthalmology, Xiangya Hospital, Central South University, Changsha, Hunan 410008, P.R. China
| | - Jian Jiang
- Department of Ophthalmology, Xiangya Hospital, Central South University, Changsha, Hunan 410008, P.R. China
| | - Xiaobo Xia
- Department of Ophthalmology, Xiangya Hospital, Central South University, Changsha, Hunan 410008, P.R. China
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Yoshikawa N, Shimizu N, Maruyama T, Sano M, Matsuhashi T, Fukuda K, Kataoka M, Satoh T, Ojima H, Sawai T, Morimoto C, Kuribara A, Hosono O, Tanaka H. Cardiomyocyte-specific overexpression of HEXIM1 prevents right ventricular hypertrophy in hypoxia-induced pulmonary hypertension in mice. PLoS One 2012; 7:e52522. [PMID: 23300697 PMCID: PMC3534105 DOI: 10.1371/journal.pone.0052522] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2012] [Accepted: 11/14/2012] [Indexed: 01/19/2023] Open
Abstract
Right ventricular hypertrophy (RVH) and right ventricular (RV) contractile dysfunction are major determinants of prognosis in pulmonary arterial hypertension (PAH) and PAH remains a severe disease. Recently, direct interruption of left ventricular hypertrophy has been suggested to decrease the risk of left-sided heart failure. Hexamethylene bis-acetamide inducible protein 1 (HEXIM1) is a negative regulator of positive transcription elongation factor b (P-TEFb), which activates RNA polymerase II (RNAPII)-dependent transcription and whose activation is strongly associated with left ventricular hypertrophy. We hypothesized that during the progression of PAH, increased P-TEFb activity might also play a role in RVH, and that HEXIM1 might have a preventive role against such process. We revealed that, in the mouse heart, HEXIM1 is highly expressed in the early postnatal period and its expression is gradually decreased, and that prostaglandin I(2), a therapeutic drug for PAH, increases HEXIM1 levels in cardiomyocytes. These results suggest that HEXIM1 might possess negative effect on cardiomyocyte growth and take part in cardiomyocyte regulation in RV. Using adenovirus-mediated gene delivery to cultured rat cardiomyocytes, we revealed that overexpression of HEXIM1 prevents endothelin-1-induced phosphorylation of RNAPII, cardiomyocyte hypertrophy, and mRNA expression of hypertrophic genes, whereas a HEXIM1 mutant lacking central basic region, which diminishes P-TEFb-suppressing activity, could not. Moreover, we created cardiomyocyte-specific HEXIM1 transgenic mice and revealed that HEXIM1 ameliorates RVH and prevents RV dilatation in hypoxia-induced PAH model. Taken together, these findings indicate that cardiomyocyte-specific overexpression of HEXIM1 inhibits progression to RVH under chronic hypoxia, most possibly via inhibition of P-TEFb-mediated enlargement of cardiomyocytes. We conclude that P-TEFb/HEXIM1-dependent transcriptional regulation may play a pathophysiological role in RVH and be a novel therapeutic target for mitigating RVH in PAH.
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Affiliation(s)
- Noritada Yoshikawa
- Department of Rheumatology and Allergy, IMSUT Hospital, Institute of Medical Science, The University of Tokyo, Tokyo, Japan
| | - Noriaki Shimizu
- Department of Rheumatology and Allergy, IMSUT Hospital, Institute of Medical Science, The University of Tokyo, Tokyo, Japan
| | - Takako Maruyama
- Department of Rheumatology and Allergy, IMSUT Hospital, Institute of Medical Science, The University of Tokyo, Tokyo, Japan
| | - Motoaki Sano
- Department of Cardiology, Keio University School of Medicine, Tokyo, Japan
| | | | - Keiichi Fukuda
- Department of Cardiology, Keio University School of Medicine, Tokyo, Japan
| | - Masaharu Kataoka
- Department of Cardiology, Keio University School of Medicine, Tokyo, Japan
- Department of Cardiology, Kyorin University School of Medicine, Mitaka, Tokyo, Japan
| | - Toru Satoh
- Department of Cardiology, Kyorin University School of Medicine, Mitaka, Tokyo, Japan
| | - Hidenori Ojima
- Pathology Division, National Cancer Center Research Institute, Tokyo, Japan
| | - Takashi Sawai
- Department of Pathology, Iwate Medical University School of Medicine, Shiwa-gun, Iwate, Japan
| | - Chikao Morimoto
- Department of Therapy Development and Innovation for Immune Disorders, Juntendo University, Tokyo, Japan, Cancers, Graduate School of Medicine, Juntendo University, Tokyo, Japan
| | - Akiko Kuribara
- Department of Rheumatology and Allergy, IMSUT Hospital, Institute of Medical Science, The University of Tokyo, Tokyo, Japan
| | - Osamu Hosono
- Department of Rheumatology and Allergy, IMSUT Hospital, Institute of Medical Science, The University of Tokyo, Tokyo, Japan
| | - Hirotoshi Tanaka
- Department of Rheumatology and Allergy, IMSUT Hospital, Institute of Medical Science, The University of Tokyo, Tokyo, Japan
- * E-mail:
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Manukyan I, Galatioto J, Mascareno E, Bhaduri S, Siddiqui MAQ. Cross-talk between calcineurin/NFAT and Jak/STAT signalling induces cardioprotective alphaB-crystallin gene expression in response to hypertrophic stimuli. J Cell Mol Med 2009; 14:1707-16. [PMID: 19538478 PMCID: PMC3829032 DOI: 10.1111/j.1582-4934.2009.00804.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
Among the stress proteins that are up-regulated in the heart due to imposed biomechanical stress, αB-crystallin (CryAB) is the most abundant and pivotal in rendering protection against stress-induced cell damage. Cardiomyocyte-specific expression of the CryAB gene was shown to be dependent upon an intact αBE4 cis-element located in the CryAB enhancer. To date, there is no evidence on the identity of regulatory proteins and associated signalling molecules that control CryAB expression in cardiomyocytes. In this study, we define a mechanism by which the calcineurin/NFAT and Jak/STAT pathways regulate CryAB gene expression in response to a hypertrophic agonist endothelin-1 (En-1), in hypertrophic hearts of mice with pressure overload (TAC) and in heart-targeted calcineurin over-expressing mice (MHC-CnA). We observed that in response to various hypertrophic stimuli the transcription factors NFAT, Nished and STAT3 form a dynamic ternary complex and interact with the αBE4 promoter element of the CryAB gene. Both dominant negative NFAT and AG490, an inhibitor of the Jak2 phosphorylation, inhibited CryAB gene transcription in transient transfection assays. AG490 was also effective in blocking the nuclear translocation of NFAT and STAT3 in cardiomyocytes treated with En-1. We observed a marked increase in CryAB gene expression in MHC-CnA mouse hearts accompanied with increased phosphorylation of STAT3. We conclude that hypertrophy-dependent CryAB gene expression can be attributed to a functional linkage between the Jak/STAT and calcineurin/NFAT signalling pathways, each of which are otherwise known to be involved independently in the deleterious outcome in cardiac hypertrophy.
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Affiliation(s)
- Irena Manukyan
- Department of Anatomy and Cell Biology, Center for Cardiovascular and Muscle Research, State University of New York Downstate Medical Center, Brooklyn, New York 11203, USA
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