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Draoui N, de Zeeuw P, Carmeliet P. Angiogenesis revisited from a metabolic perspective: role and therapeutic implications of endothelial cell metabolism. Open Biol 2018; 7:rsob.170219. [PMID: 29263247 PMCID: PMC5746547 DOI: 10.1098/rsob.170219] [Citation(s) in RCA: 91] [Impact Index Per Article: 15.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2017] [Accepted: 11/28/2017] [Indexed: 12/16/2022] Open
Abstract
Endothelial cell (EC) metabolism has lately emerged as a novel and promising therapeutic target to block vascular dysregulation associated with diseases like cancer and blinding eye disease. Glycolysis, fatty acid oxidation (FAO) and, more recently, glutamine/asparagine metabolism emerged as key regulators of EC metabolism, able to impact angiogenesis in health and disease. ECs are highly glycolytic as they require ATP and biomass for vessel sprouting. Notably, a regulator of the glycolytic pathway, 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase 3, controls vessel sprouting during the angiogenic switch and its inhibition in tumour ECs leads to vessel normalization, thereby reducing metastasis and ameliorating chemotherapy. Moreover, FAO promotes EC proliferation through DNA synthesis, and plays an essential role in lymphangiogenesis via epigenetic regulation of histone acetylation. Pathological angiogenesis was decreased upon blockade of carnitine palmitoyltransferase 1, a regulator of FAO in ECs. More recently, metabolism of glutamine, in conjunction with asparagine, was reported to maintain EC sprouting through TCA anaplerosis, redox homeostasis, mTOR activation and endoplasmic stress control. Inactivation or blockade of glutaminase 1, which hydrolyses glutamine into ammonia and glutamate, impairs angiogenesis in health and disease, while silencing of asparagine synthetase reduces vessel sprouting in vitro. In this review, we summarize recent insights into EC metabolism and discuss therapeutic implications of targeting EC metabolism.
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Affiliation(s)
- Nihed Draoui
- Laboratory of Angiogenesis and Vascular Metabolism, Department of Oncology, KU Leuven, Leuven 3000, Belgium.,Laboratory of Angiogenesis and Vascular Metabolism, Center for Cancer Biology, VIB, KU Leuven, Campus Gasthuisberg O&N4, Herestraat 49-912, Leuven 3000, Belgium
| | - Pauline de Zeeuw
- Laboratory of Angiogenesis and Vascular Metabolism, Department of Oncology, KU Leuven, Leuven 3000, Belgium.,Laboratory of Angiogenesis and Vascular Metabolism, Center for Cancer Biology, VIB, KU Leuven, Campus Gasthuisberg O&N4, Herestraat 49-912, Leuven 3000, Belgium
| | - Peter Carmeliet
- Laboratory of Angiogenesis and Vascular Metabolism, Department of Oncology, KU Leuven, Leuven 3000, Belgium .,Laboratory of Angiogenesis and Vascular Metabolism, Center for Cancer Biology, VIB, KU Leuven, Campus Gasthuisberg O&N4, Herestraat 49-912, Leuven 3000, Belgium
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52
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Huang Y, Fan X, Tao R, Song Q, Wang L, Zhang H, Kong H, Huang J. Effect of miR-182 on hepatic fibrosis induced by Schistosomiasis japonica by targeting FOXO1 through PI3K/AKT signaling pathway. J Cell Physiol 2018; 233:6693-6704. [PMID: 29323718 DOI: 10.1002/jcp.26469] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2017] [Accepted: 01/05/2018] [Indexed: 02/06/2023]
Abstract
The study aimed to investigate the impact of miR-182 and FOXO1 on S. japonica-induced hepatic fibrosis. Microarray analysis was performed to screen out differential expressed miRNAs and mRNAs. Rat hepatic fibrosis model and human hepatocellular cell line LX-2 were used to study the effect of miR-182 and FOXO1. qRT-PCR and Western blot were used to detect the expression of miR-182, FOXO1 or other fibrosis markers. The targeting relationship between FOXO1 and miR-182 was verified by luciferase reporter assay. Immunohistochemistry or immunofluorescence staining was conducted to detect FOXO1 or α-SMA in rat hepatic tissues. Cell viability and apoptosis were detected by MTT assay and flow cytometry. The expression of PI3K/AKT pathway-related proteins was detected by Western blot. miR-182 was highly expressed in liver fibrosis samples, and FOXO1 expression was negatively correlated with miR-182 expression. After transfection of miR-182, FOXO1 expression was down-regulated, with the results of LX-2 cells proliferation inhibition and apoptosis induction, as well as the aggravation of rat hepatic fibrosis. The expression of p-AKT/AKT and p-S6/S6 was increased, meaning that the PI3K/AKT signal pathway was activated. The results were reversed when treated with Wortmannin (PI3K inhibitor). After transfection of miR-182 inhibitor, FOXO1 expression was up-regulated, LX-2 cell proliferation was inhibited, and apoptosis rate was increased. High-expressed miR-182 and low-expressed FOXO1 promoted proliferation and inhibiting apoptosis on liver fibrosis cells, stimulating the development of S. japonica-induced hepatic fibrosis through feeding back to PI3K/AKT signaling pathway.
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Affiliation(s)
- Yu Huang
- Department and Institute of Infectious Disease, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China.,Department of Nephrology, The First People's Hospital of Yichang, The People's Hospital of China Three Gorges University, Yichang, Hubei, China
| | - Xiangxue Fan
- Department and Institute of Infectious Disease, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China.,Department and Institute of Infectious Disease, Liaocheng People's Hospital, Liaocheng, Shandong, China
| | - Ran Tao
- Department and Institute of Infectious Disease, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Qiqin Song
- Department and Institute of Infectious Disease, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Likui Wang
- Savaid Medical School, University of Chinese Academy of Sciences Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
| | - Hongyue Zhang
- Department and Institute of Infectious Disease, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Hongyan Kong
- Department and Institute of Infectious Disease, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Jiaquan Huang
- Department and Institute of Infectious Disease, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
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53
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Tight regulation of FOXO1 is essential for maintenance of B-cell precursor acute lymphoblastic leukemia. Blood 2018; 131:2929-2942. [PMID: 29622548 DOI: 10.1182/blood-2017-10-813576] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2017] [Accepted: 03/26/2018] [Indexed: 12/30/2022] Open
Abstract
The FOXO1 transcription factor plays an essential role in the regulation of proliferation and survival programs at early stages of B-cell differentiation. Here, we show that tightly regulated FOXO1 activity is essential for maintenance of B-cell precursor acute lymphoblastic leukemia (BCP-ALL). Genetic and pharmacological inactivation of FOXO1 in BCP-ALL cell lines produced a strong antileukemic effect associated with CCND3 downregulation. Moreover, we demonstrated that CCND3 expression is critical for BCP-ALL survival and that overexpression of CCND3 protected BCP-ALL cell lines from growth arrest and apoptosis induced by FOXO1 inactivation. Most importantly, pharmacological inhibition of FOXO1 showed antileukemia activity on several primary, patient-derived, pediatric ALL xenografts with effective leukemia reduction in the hematopoietic, lymphoid, and central nervous system organ compartments, ultimately leading to prolonged survival without leukemia reoccurrence in a preclinical in vivo model of BCP-ALL. These results suggest that repression of FOXO1 might be a feasible approach for the treatment of BCP-ALL.
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Zhang S, Li P, Yuan Z, Tan J. Effects of platelet-rich plasma on the activity of human menstrual blood-derived stromal cells in vitro. Stem Cell Res Ther 2018; 9:48. [PMID: 29482651 PMCID: PMC6389087 DOI: 10.1186/s13287-018-0795-3] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2017] [Revised: 12/04/2017] [Accepted: 02/01/2018] [Indexed: 01/15/2023] Open
Abstract
Background Human menstrual blood-derived stromal cells (MenSCs) are highly proliferative and show multiple differentiation capacity. The convenience and non-invasiveness make MenSC a novel cell source for regenerative medicine applications. Platelet-rich plasma (PRP) contains abundant growth factors which are beneficial to wound healing. However, the influence of PRP on MenSCs remains elusive. Here, we evaluated the role of PRP in MenSCs proliferation and assessed the effects of PRP on endometrial receptivity regulation in vitro. Methods MenSCs cultured with 10% activated PRP were compared with those cultured with 10% fetal bovine serum (FBS). Differences in cell proliferation, differentiation, and endometrial receptivity-related gene expression were evaluated. Results Notably, 10% activated PRP significantly promoted MenSCs proliferation and adipogenic/osteogenic differentiation while suppressing apoptosis. Expression of the mesenchymal stem cells (MSCs) marker CD105 and the perivascular markers SUSD2 and CD146 were elevated after PRP treatment. Moreover, short-term PRP stimulation activated the phosphorylation of Akt and signal transducer and activator of transcription 3 (STAT3) pathways, upregulated expression of FoxO1, LIF, and IL1-β, and downregulated IL-6. Conclusions In summary, PRP could promote MenSC proliferation, markedly accelerate cell stemness, and evaluate MenSC functions by enhancing the expression of angiogenesis and endometrial receptivity markers, suggesting its potential use as a promising supplement for MenSCs in endometrial regenerative medicine. Our results provide a theoretical basis for the clinical application of co-transplantation of PRP combined with MenSCs. Electronic supplementary material The online version of this article (10.1186/s13287-018-0795-3) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Siwen Zhang
- Reproductive medicine Center, Obstetrics and Gynecology Department, Shengjing Hospital affiliated to China Medical University, No. 39 Huaxiang Road, Tiexi District, Shenyang, 110022, China
| | - Pingping Li
- Reproductive medicine Center, Obstetrics and Gynecology Department, Shengjing Hospital affiliated to China Medical University, No. 39 Huaxiang Road, Tiexi District, Shenyang, 110022, China
| | - Zhengwei Yuan
- Key Laboratory of Health Ministry for Congenital Malformation, Shengjing Hospital affiliated to China Medical University, No. 7, Economic Development Zone, Benxi, 117004, China
| | - Jichun Tan
- Reproductive medicine Center, Obstetrics and Gynecology Department, Shengjing Hospital affiliated to China Medical University, No. 39 Huaxiang Road, Tiexi District, Shenyang, 110022, China.
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55
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Fine-tuning of FOXO3A in cHL as a survival mechanism and a hallmark of abortive plasma cell differentiation. Blood 2018; 131:1556-1567. [PMID: 29439954 DOI: 10.1182/blood-2017-07-795278] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2017] [Accepted: 02/12/2018] [Indexed: 12/22/2022] Open
Abstract
We recently found that FOXO1 repression contributes to the oncogenic program of classical Hodgkin lymphoma (cHL). Interestingly, FOXO3A, another member of the FOXO family, was reported to be expressed in the malignant Hodgkin and Reed-Sternberg cells of cHL at higher levels than in non-Hodgkin lymphoma subtypes. We thus aimed to investigate mechanisms responsible for the maintenance of FOXO3A as well as the potential role of FOXO3A in cHL. Here, we show that high FOXO3A levels in cHL reflect a B-cell-differentiation-specific pattern. In B cells, FOXO3A expression increases during the process of centroblast to plasma cell (PC) differentiation. FOXO3A levels in cHL were found higher than in germinal center B cells, but lower than in terminally differentiated PCs. This intermediate FOXO3A expression in cHL might manifest the "abortive PC differentiation" phenotype. This assumption was further corroborated by the finding that overexpression of FOXO3A in cHL cell lines induced activation of the master PC transcription factor PRDM1α. As factors attenuating FOXO3A expression in cHL, we identified MIR155 and constitutive activation of extracellular signal-regulated kinase. Finally, we demonstrate the importance of FOXO3A expression in cHL using an RNA interference approach. We conclude that tightly regulated expression of FOXO3A contributes to the oncogenic program and to the specific phenotype of cHL.
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56
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Ruiz S, Chandakkar P, Zhao H, Papoin J, Chatterjee PK, Christen E, Metz CN, Blanc L, Campagne F, Marambaud P. Tacrolimus rescues the signaling and gene expression signature of endothelial ALK1 loss-of-function and improves HHT vascular pathology. Hum Mol Genet 2017; 26:4786-4798. [PMID: 28973643 PMCID: PMC5886173 DOI: 10.1093/hmg/ddx358] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2017] [Revised: 08/09/2017] [Accepted: 09/11/2017] [Indexed: 01/02/2023] Open
Abstract
Hereditary hemorrhagic telangiectasia (HHT) is a highly debilitating and life-threatening genetic vascular disorder arising from endothelial cell (EC) proliferation and hypervascularization, for which no cure exists. Because HHT is caused by loss-of-function mutations in bone morphogenetic protein 9 (BMP9)-ALK1-Smad1/5/8 signaling, interventions aimed at activating this pathway are of therapeutic value. We interrogated the whole-transcriptome in human umbilical vein ECs (HUVECs) and found that ALK1 signaling inhibition was associated with a specific pro-angiogenic gene expression signature, which included a significant elevation of DLL4 expression. By screening the NIH clinical collections of FDA-approved drugs, we identified tacrolimus (FK-506) as the most potent activator of ALK1 signaling in BMP9-challenged C2C12 reporter cells. In HUVECs, tacrolimus activated Smad1/5/8 and opposed the pro-angiogenic gene expression signature associated with ALK1 loss-of-function, by notably reducing Dll4 expression. In these cells, tacrolimus also inhibited Akt and p38 stimulation by vascular endothelial growth factor, a major driver of angiogenesis. In the BMP9/10-immunodepleted postnatal retina-a mouse model of HHT vascular pathology-tacrolimus activated endothelial Smad1/5/8 and prevented the Dll4 overexpression and hypervascularization associated with this model. Finally, tacrolimus stimulated Smad1/5/8 signaling in C2C12 cells expressing BMP9-unresponsive ALK1 HHT mutants and in HHT patient blood outgrowth ECs. Tacrolimus repurposing has therefore therapeutic potential in HHT.
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Affiliation(s)
- Santiago Ruiz
- Litwin-Zucker Research Center for the Study of Alzheimer's Disease
| | | | - Haitian Zhao
- Litwin-Zucker Research Center for the Study of Alzheimer's Disease
| | | | - Prodyot K Chatterjee
- Center for Biomedical Science, The Feinstein Institute for Medical Research, Manhasset, NY 11030, USA
| | - Erica Christen
- Litwin-Zucker Research Center for the Study of Alzheimer's Disease
| | - Christine N Metz
- Center for Biomedical Science, The Feinstein Institute for Medical Research, Manhasset, NY 11030, USA
- Hofstra Northwell School of Medicine, Hempstead, NY 11549, USA
| | - Lionel Blanc
- Center for Autoimmune and Musculoskeletal Disorders
- Hofstra Northwell School of Medicine, Hempstead, NY 11549, USA
| | - Fabien Campagne
- The HRH Prince Alwaleed Bin Talal Bin Abdulaziz Alsaud Institute for Computational Biomedicine
- Department of Physiology and Biophysics, The Weill Cornell Medical College, New York, NY 10021, USA
| | - Philippe Marambaud
- Litwin-Zucker Research Center for the Study of Alzheimer's Disease
- Hofstra Northwell School of Medicine, Hempstead, NY 11549, USA
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57
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Ushmorov A, Wirth T. FOXO in B-cell lymphopoiesis and B cell neoplasia. Semin Cancer Biol 2017; 50:132-141. [PMID: 28774833 DOI: 10.1016/j.semcancer.2017.07.008] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2017] [Revised: 07/17/2017] [Accepted: 07/30/2017] [Indexed: 12/31/2022]
Abstract
FOX O family transcription factors are important for differentiation and function of multiple cell types. In B lymphocytes they play a critical role. The activity of FOXOs is directly regulated both by signaling from B cell receptor (BCR) and cytokine receptors. FOXO1 action controls the transition between differentiation stages of B cell development. In comparison to other FOXO family members, FOXO1 plays a superior role in the regulation of early stages of B-cell differentiation. Although being known as a negative regulator of cell proliferation and therefore potential tumor suppressor, FOXO1 is downregulated only in Hodgkin lymphoma (HL) subtypes. In non-Hodgkin lymphoma (NHL) entities its expression is maintained at significant levels, raising the question on the role of FOXO-transcription factors in the proliferation and survival programs in the process of B cell differentiation as well as their contribution to the oncogenic programs of B-cell lymphomas. In particular, we discuss molecular mechanisms that might determine the switch between pro-apoptotic and pro-survival effects of FOXO1 and their interplay with specific differentiation programs.
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Affiliation(s)
- Alexey Ushmorov
- Institute of Physiological Chemistry, University of Ulm, Ulm, Germany
| | - Thomas Wirth
- Institute of Physiological Chemistry, University of Ulm, Ulm, Germany.
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58
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10-Gingerol as an inducer of apoptosis through HTR1A in cumulus cells: In-vitro and in-silico studies. J Taibah Univ Med Sci 2017; 12:397-406. [PMID: 31435270 PMCID: PMC6695051 DOI: 10.1016/j.jtumed.2017.05.012] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2016] [Revised: 05/17/2017] [Accepted: 05/21/2017] [Indexed: 12/20/2022] Open
Abstract
Objectives Cumulus cells play a crucial role as essential mediators in the maturation of ova. Ginger contains 10-gingerol, which induces apoptosis in colon cancer cells. Based on this hypothesis, this study aimed to determine whether 10-gingerol is able to induce apoptosis in normal cells, namely, cumulus cells. Methods This study used an in vitro analysis by culturing Cumulus cells in M199 containing 10-gingerol in various concentrations (12, 16, and 20 μM) and later detected early apoptotic activity using an Annexin V-FITC detection kit. Result The in vitro data revealed that the number of apoptosis cells increased along with the period of incubation as follows: 12 μM (63.71% ± 2.192%); 16 μM (74.51% ± 4.596%); and 20 μM (78.795% ± 1.435%). The substance 10-gingerol induces apoptosis in cumulus cells by inhibiting HTR1A functions and inactivating GSK3B and AKT-1. Conclusions These findings indicate that further examination is warranted for 10-gingerol as a contraception agent.
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Key Words
- 10-Gingerol
- ARG, arginine
- Apoptosis
- Cumulus cells
- FOXO, forkhead box
- GLU, glutamine
- GLY, glycine
- GSK3B, glycogen synthase kinase-3β
- HTR1A
- HTR1A, 5-hydroxytryptamine receptor 1 A
- ILE, ileusine
- ILK, integrin-linked kinase
- In silico
- In vitro
- LYS, lysine
- MDM2, murine double minute clone 2
- MET, methionine
- NO, nitric oxide
- NOS3, nitric oxide synthase 3
- PTEN, phosphatase and tensin homologue delete on chromosome ten
- RICTOR, rapamycin-insensitive companion of mTOR
- TYR, tyrosine
- eNOS, endothelial nitric oxide synthase
- mTOR, mammalian target of rapamycin
- mTORC1, mTOR complex 1
- mTORC2, mTOR complex 2
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Park DY, Lee J, Kim J, Kim K, Hong S, Han S, Kubota Y, Augustin HG, Ding L, Kim JW, Kim H, He Y, Adams RH, Koh GY. Plastic roles of pericytes in the blood-retinal barrier. Nat Commun 2017; 8:15296. [PMID: 28508859 PMCID: PMC5440855 DOI: 10.1038/ncomms15296] [Citation(s) in RCA: 189] [Impact Index Per Article: 27.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2016] [Accepted: 03/17/2017] [Indexed: 01/18/2023] Open
Abstract
The blood-retinal barrier (BRB) consists of tightly interconnected capillary endothelial cells covered with pericytes and glia, but the role of the pericytes in BRB regulation is not fully understood. Here, we show that platelet-derived growth factor (PDGF)-B/PDGF receptor beta (PDGFRβ) signalling is critical in formation and maturation of BRB through active recruitment of pericytes onto growing retinal vessels. Impaired pericyte recruitment to the vessels shows multiple vascular hallmarks of diabetic retinopathy (DR) due to BRB disruption. However, PDGF-B/PDGFRβ signalling is expendable for maintaining BRB integrity in adult mice. Although selective pericyte loss in stable adult retinal vessels surprisingly does not cause BRB disintegration, it sensitizes retinal vascular endothelial cells (ECs) to VEGF-A, leading to upregulation of angiopoietin-2 (Ang2) in ECs through FOXO1 activation and triggering a positive feedback that resembles the pathogenesis of DR. Accordingly, either blocking Ang2 or activating Tie2 greatly attenuates BRB breakdown, suggesting potential therapeutic approaches to reduce retinal damages upon DR progression.
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Affiliation(s)
- Do Young Park
- Graduate School of Medical Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Korea
| | - Junyeop Lee
- Graduate School of Medical Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Korea
| | - Jaeryung Kim
- Graduate School of Medical Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Korea
| | - Kangsan Kim
- Center for Vascular Research, Institute of Basic Science (IBS), Daejeon 34141, Korea
| | - Seonpyo Hong
- Graduate School of Medical Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Korea
| | - Sangyeul Han
- Center for Vascular Research, Institute of Basic Science (IBS), Daejeon 34141, Korea
| | - Yoshiaki Kubota
- The Laboratory of Vascular Biology, Keio University, Tokyo 160-8582, Japan
| | - Hellmut G Augustin
- Division of Vascular Oncology and Metastasis, German Cancer Research Center, DKFZ-ZMBH Alliance, 69120 Heidelberg, Germany
| | - Lei Ding
- Columbia Stem Cell Initiative, Department of Rehabilitation and Regenerative Medicine, Department of Microbiology and Immunology, Columbia University Medical Center, New York, New York 10032, USA
| | - Jin Woo Kim
- Department of Biological Sciences, KAIST, Daejeon 34141, Korea
| | - Hail Kim
- Graduate School of Medical Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Korea
| | - Yulong He
- Cyrus Tang Hematology Center, Collaborative Innovation Center of Hematology, Soochow University, Suzhou 215123, China
| | - Ralf H Adams
- Department of Tissue Morphogenesis, Max-Planck-Institute for Molecular Biomedicine, and Faculty of Medicine, University of Münster, D-48149 Münster, Germany
| | - Gou Young Koh
- Graduate School of Medical Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Korea.,Center for Vascular Research, Institute of Basic Science (IBS), Daejeon 34141, Korea
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Swiatkowski P, Nikolaeva I, Kumar G, Zucco A, Akum BF, Patel MV, D'Arcangelo G, Firestein BL. Role of Akt-independent mTORC1 and GSK3β signaling in sublethal NMDA-induced injury and the recovery of neuronal electrophysiology and survival. Sci Rep 2017; 7:1539. [PMID: 28484273 PMCID: PMC5431483 DOI: 10.1038/s41598-017-01826-w] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2016] [Accepted: 04/03/2017] [Indexed: 01/02/2023] Open
Abstract
Glutamate-induced excitotoxicity, mediated by overstimulation of N-methyl-D-aspartate (NMDA) receptors, is a mechanism that causes secondary damage to neurons. The early phase of injury causes loss of dendritic spines and changes to synaptic activity. The phosphatidylinositol-4,5-bisphosphate 3-kinase/Akt/ mammalian target of rapamycin (PI3K/Akt/mTOR) pathway has been implicated in the modulation and regulation of synaptic strength, activity, maturation, and axonal regeneration. The present study focuses on the physiology and survival of neurons following manipulation of Akt and several downstream targets, such as GSK3β, FOXO1, and mTORC1, prior to NMDA-induced injury. Our analysis reveals that exposure to sublethal levels of NMDA does not alter phosphorylation of Akt, S6, and GSK3β at two and twenty four hours following injury. Electrophysiological recordings show that NMDA-induced injury causes a significant decrease in spontaneous excitatory postsynaptic currents at both two and twenty four hours, and this phenotype can be prevented by inhibiting mTORC1 or GSK3β, but not Akt. Additionally, inhibition of mTORC1 or GSK3β promotes neuronal survival following NMDA-induced injury. Thus, NMDA-induced excitotoxicity involves a mechanism that requires the permissive activity of mTORC1 and GSK3β, demonstrating the importance of these kinases in the neuronal response to injury.
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Affiliation(s)
- Przemyslaw Swiatkowski
- Department of Cell Biology and Neuroscience, Rutgers University, 604 Allison Road, Piscataway, New Jersey, 08854-8082, USA.,Graduate Program in Molecular Biosciences, Rutgers University, 604 Allison Road, Piscataway, New Jersey, 08854-8082, USA
| | - Ina Nikolaeva
- Department of Cell Biology and Neuroscience, Rutgers University, 604 Allison Road, Piscataway, New Jersey, 08854-8082, USA.,Graduate Program in Molecular Biosciences, Rutgers University, 604 Allison Road, Piscataway, New Jersey, 08854-8082, USA
| | - Gaurav Kumar
- Department of Cell Biology and Neuroscience, Rutgers University, 604 Allison Road, Piscataway, New Jersey, 08854-8082, USA
| | - Avery Zucco
- Department of Cell Biology and Neuroscience, Rutgers University, 604 Allison Road, Piscataway, New Jersey, 08854-8082, USA.,Graduate Program in Neurosciences, Rutgers University, 604 Allison Road, Piscataway, New Jersey, 08854-8082, USA
| | - Barbara F Akum
- Department of Cell Biology and Neuroscience, Rutgers University, 604 Allison Road, Piscataway, New Jersey, 08854-8082, USA
| | - Mihir V Patel
- Department of Cell Biology and Neuroscience, Rutgers University, 604 Allison Road, Piscataway, New Jersey, 08854-8082, USA.,Graduate Program in Neurosciences, Rutgers University, 604 Allison Road, Piscataway, New Jersey, 08854-8082, USA
| | - Gabriella D'Arcangelo
- Department of Cell Biology and Neuroscience, Rutgers University, 604 Allison Road, Piscataway, New Jersey, 08854-8082, USA
| | - Bonnie L Firestein
- Department of Cell Biology and Neuroscience, Rutgers University, 604 Allison Road, Piscataway, New Jersey, 08854-8082, USA.
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61
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Shafique E, Torina A, Reichert K, Colantuono B, Nur N, Zeeshan K, Ravichandran V, Liu Y, Feng J, Zeeshan K, Benjamin LE, Irani K, Harrington EO, Sellke FW, Abid MR. Mitochondrial redox plays a critical role in the paradoxical effects of NAPDH oxidase-derived ROS on coronary endothelium. Cardiovasc Res 2017; 113:234-246. [PMID: 28088753 DOI: 10.1093/cvr/cvw249] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/06/2016] [Revised: 12/25/2016] [Accepted: 12/07/2016] [Indexed: 12/31/2022] Open
Abstract
AIMS There are conflicting reports on the role of reactive oxygen species (ROS) i.e. beneficial vs. harmful, in vascular endothelium. Here, we aim to examine whether duration of exposure to ROS and/or subcellular ROS levels are responsible for the apparently paradoxical effects of oxidants on endothelium. METHODS AND RESULTS We have recently generated binary (Tet-ON/OFF) conditional transgenic mice (Tet-Nox2:VE-Cad-tTA) that can induce 1.8 ± 0.42-fold increase in NADPH oxidase (NOX)-derived ROS specifically in vascular endothelium upon withdrawal of tetracycline from the drinking water. Animals were divided in two groups: one exposed to high endogenous ROS levels for 8 weeks (short-term) and the other for 20 weeks (long-term). Using endothelial cells (EC) isolated from mouse hearts (MHEC), we demonstrate that both short-term and long-term increase in NOX-ROS induced AMPK-mediated activation of eNOS. Interestingly, although endothelium-dependent nitric oxide (NO)-mediated coronary vasodilation was significantly increased after short-term increase in NOX-ROS, coronary vasodilation was drastically reduced after long-term increase in ROS. We also show that short-term ROS increase induced proliferation in EC and angiogenic sprouting in the aorta. In contrast, long-term increase in cytosolic ROS resulted in nitrotyrosine-mediated inactivation of mitochondrial (mito) antioxidant MnSOD, increase in mito-ROS, loss of mitochondrial membrane potential (Δψm), decreased EC proliferation and angiogenesis. CONCLUSION The findings suggest that NOX-derived ROS results in increased mito-ROS. Whereas short-term increase in mito-ROS was counteracted by MnSOD, long-term increase in ROS resulted in nitrotyrosine-mediated inactivation of MnSOD, leading to unchecked increase in mito-ROS and loss of Δψm followed by inhibition of endothelial function and proliferation.
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Affiliation(s)
- Ehtesham Shafique
- Cardiovascular Research Center, Division of Cardiothoracic Surgery, Department of Surgery, Rhode Island Hospital, 1 Hoppin St, Providence, RI 02903, USA
| | - Anali Torina
- Cardiovascular Research Center, Division of Cardiothoracic Surgery, Department of Surgery, Rhode Island Hospital, 1 Hoppin St, Providence, RI 02903, USA
| | - Karla Reichert
- Cardiovascular Research Center, Division of Cardiothoracic Surgery, Department of Surgery, Rhode Island Hospital, 1 Hoppin St, Providence, RI 02903, USA
| | - Bonnie Colantuono
- Cardiovascular Research Center, Division of Cardiothoracic Surgery, Department of Surgery, Rhode Island Hospital, 1 Hoppin St, Providence, RI 02903, USA
| | - Nasifa Nur
- Cardiovascular Research Center, Division of Cardiothoracic Surgery, Department of Surgery, Rhode Island Hospital, 1 Hoppin St, Providence, RI 02903, USA
| | - Khawaja Zeeshan
- Cardiovascular Research Center, Division of Cardiothoracic Surgery, Department of Surgery, Rhode Island Hospital, 1 Hoppin St, Providence, RI 02903, USA
| | - Vani Ravichandran
- Cardiovascular Research Center, Division of Cardiothoracic Surgery, Department of Surgery, Rhode Island Hospital, 1 Hoppin St, Providence, RI 02903, USA
| | - Yuhong Liu
- Cardiovascular Research Center, Division of Cardiothoracic Surgery, Department of Surgery, Rhode Island Hospital, 1 Hoppin St, Providence, RI 02903, USA.,Warren Alpert Medical School of Brown University, 593 Eddy St, Providence, RI 02903, USA
| | - Jun Feng
- Cardiovascular Research Center, Division of Cardiothoracic Surgery, Department of Surgery, Rhode Island Hospital, 1 Hoppin St, Providence, RI 02903, USA.,Warren Alpert Medical School of Brown University, 593 Eddy St, Providence, RI 02903, USA
| | - Khawaja Zeeshan
- Cardiovascular Research Center, Division of Cardiothoracic Surgery, Department of Surgery, Rhode Island Hospital, 1 Hoppin St, Providence, RI 02903, USA
| | | | - Kaikobad Irani
- University of Iowa Carver School of Medicine, Iowa, IA, USA
| | - Elizabeth O Harrington
- Providence VA Medical Center, Providence, RI, USA.,Brown University, Providence, RI, USA
| | - Frank W Sellke
- Cardiovascular Research Center, Division of Cardiothoracic Surgery, Department of Surgery, Rhode Island Hospital, 1 Hoppin St, Providence, RI 02903, USA.,Warren Alpert Medical School of Brown University, 593 Eddy St, Providence, RI 02903, USA
| | - Md Ruhul Abid
- Cardiovascular Research Center, Division of Cardiothoracic Surgery, Department of Surgery, Rhode Island Hospital, 1 Hoppin St, Providence, RI 02903, USA; .,Warren Alpert Medical School of Brown University, 593 Eddy St, Providence, RI 02903, USA.,Brown University, Providence, RI, USA
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Potz BA, Sabe AA, Elmadhun NY, Clements RT, Abid MR, Sodha NR, Sellke FW. Calpain inhibition modulates glycogen synthase kinase 3β pathways in ischemic myocardium: A proteomic and mechanistic analysis. J Thorac Cardiovasc Surg 2016; 153:342-357. [PMID: 27986275 DOI: 10.1016/j.jtcvs.2016.09.087] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/17/2016] [Revised: 09/15/2016] [Accepted: 09/26/2016] [Indexed: 12/20/2022]
Abstract
BACKGROUND Calpain inhibition has an enhancing effect on myocardial perfusion and improves myocardial density by inhibiting glycogen synthase kinase 3β (GSK-3β) and up-regulating downstream signaling pathways, including the insulin/PI3K and WNT/β-catenin pathways, in a pig model of chronic myocardial ischemia in the setting of metabolic syndrome. METHODS Pigs were fed a high-fat diet for 4 weeks, then underwent placement of an ameroid constrictor to the left circumflex artery. Three weeks later, the animals received no drug (high-cholesterol controls [HCC]), a high-dose calpain inhibitor (HCI), a low-dose calpain inhibitor (LCI), or a GSK-3β inhibitor (GSK-3βI). The diets and drug regimens were continued for 5 weeks and the myocardial tissue was harvested. RESULTS Calpain and GSK-3β inhibition caused an increase in myocardial perfusion ratios at rest and during pacing compared with controls. Pigs in the LCI and HCI groups had increased vessel density in the ischemic myocardium, and pigs in the GSK-3βI group had increased vessel density in the ischemic and nonischemic myocardium compared with the HCC group. Calpain inhibition modulates proteins involved in the insulin/PI3K and WNT/β-catenin pathways. Quantitative proteomics revealed that calpain and GSK-3β inhibition significantly modulated the expression of proteins enriched in cytoskeletal regulation, metabolism, respiration, and calcium-binding pathways. CONCLUSIONS In the setting of metabolic syndrome, calpain or GSK-3β inhibition increases vessel density in both ischemic and nonischemic myocardial tissue. Calpain inhibition may exert these effects through the inhibition of GSK-3β and up-regulation of downstream signaling pathways, including the insulin/PI3K and WNT/β-catenin pathways.
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Affiliation(s)
- Brittany A Potz
- Division of Cardiothoracic Surgery, Department of Surgery, Cardiovascular Research Center, Rhode Island Hospital, Alpert Medical School of Brown University, Providence, RI
| | - Ashraf A Sabe
- Division of Cardiothoracic Surgery, Department of Surgery, Cardiovascular Research Center, Rhode Island Hospital, Alpert Medical School of Brown University, Providence, RI
| | - Nassrene Y Elmadhun
- Division of Cardiothoracic Surgery, Department of Surgery, Cardiovascular Research Center, Rhode Island Hospital, Alpert Medical School of Brown University, Providence, RI
| | - Richard T Clements
- Division of Cardiothoracic Surgery, Department of Surgery, Cardiovascular Research Center, Rhode Island Hospital, Alpert Medical School of Brown University, Providence, RI
| | - M Ruhul Abid
- Division of Cardiothoracic Surgery, Department of Surgery, Cardiovascular Research Center, Rhode Island Hospital, Alpert Medical School of Brown University, Providence, RI
| | - Neel R Sodha
- Division of Cardiothoracic Surgery, Department of Surgery, Cardiovascular Research Center, Rhode Island Hospital, Alpert Medical School of Brown University, Providence, RI
| | - Frank W Sellke
- Division of Cardiothoracic Surgery, Department of Surgery, Cardiovascular Research Center, Rhode Island Hospital, Alpert Medical School of Brown University, Providence, RI.
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Kim MS, Krawczyk SA, Doridot L, Fowler AJ, Wang JX, Trauger SA, Noh HL, Kang HJ, Meissen JK, Blatnik M, Kim JK, Lai M, Herman MA. ChREBP regulates fructose-induced glucose production independently of insulin signaling. J Clin Invest 2016; 126:4372-4386. [PMID: 27669460 DOI: 10.1172/jci81993] [Citation(s) in RCA: 139] [Impact Index Per Article: 17.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2015] [Accepted: 08/18/2016] [Indexed: 12/15/2022] Open
Abstract
Obese, insulin-resistant states are characterized by a paradoxical pathogenic condition in which the liver appears to be selectively insulin resistant. Specifically, insulin fails to suppress glucose production, yet successfully stimulates de novo lipogenesis. The mechanisms underlying this dysregulation remain controversial. Here, we hypothesized that carbohydrate-responsive element-binding protein (ChREBP), a transcriptional activator of glycolytic and lipogenic genes, plays a central role in this paradox. Administration of fructose increased hepatic hexose-phosphate levels, activated ChREBP, and caused glucose intolerance, hyperinsulinemia, hypertriglyceridemia, and hepatic steatosis in mice. Activation of ChREBP was required for the increased expression of glycolytic and lipogenic genes as well as glucose-6-phosphatase (G6pc) that was associated with the effects of fructose administration. We found that fructose-induced G6PC activity is a major determinant of hepatic glucose production and reduces hepatic glucose-6-phosphate levels to complete a homeostatic loop. Moreover, fructose activated ChREBP and induced G6pc in the absence of Foxo1a, indicating that carbohydrate-induced activation of ChREBP and G6PC dominates over the suppressive effects of insulin to enhance glucose production. This ChREBP/G6PC signaling axis is conserved in humans. Together, these findings support a carbohydrate-mediated, ChREBP-driven mechanism that contributes to hepatic insulin resistance.
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Knockdown of GSK3β increases basal autophagy and AMPK signalling in nutrient-laden human aortic endothelial cells. Biosci Rep 2016; 36:BSR20160174. [PMID: 27534430 PMCID: PMC5025810 DOI: 10.1042/bsr20160174] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2016] [Accepted: 08/14/2016] [Indexed: 12/28/2022] Open
Abstract
Suppression of the enzyme glycogen synthase kinase 3β (GSK3β) increases both the turnover of damaged cellular material and the activity of the enzyme AMP-activated protein kinase (AMPK) to potentially attenuate the damage inflicted by excess sugar and fat on blood vessels. High concentrations of glucose and palmitate increase endothelial cell inflammation and apoptosis, events that often precede atherogenesis. They may do so by decreasing basal autophagy and AMP-activated protein kinase (AMPK) activity, although the mechanisms by which this occurs are not clear. Decreased function of the lysosome, an organelle required for autophagy and AMPK, have been associated with hyperactivity of glycogen synthase kinase 3β (GSK3β). To determine whether GSK3β affects nutrient-induced changes in autophagy and AMPK activity, we used a primary human aortic endothelial cell (HAEC) model of type 2 diabetes that we had previously characterized with impaired AMPK activity and autophagy [Weikel et al. (2015) Am. J. Phys. Cell Physiol. 308, C249–C263]. Presently, we found that incubation of HAECs with excess nutrients (25 mM glucose and 0.4 mM palmitate) increased GSK3β activity and impaired lysosome acidification. Suppression of GSK3β in these cells by treatment with a chemical inhibitor or overexpression of kinase-dead GSK3β attenuated these lysosomal changes. Under control and excess nutrient conditions, knockdown of GSK3β increased autophagosome formation, forkhead box protein O1 (FOXO1) activity and AMPK signalling and decreased Akt signalling. Similar changes in autophagy, AMPK and Akt signalling were observed in aortas from mice treated with the GSK3β inhibitor CHIR 99021. Thus, increasing basal autophagy and AMPK activity by inhibiting GSK3β may be an effective strategy in the setting of hyperglycaemia and dyslipidaemia for restoring endothelial cell health and reducing atherogenesis.
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Dillon CP, Tummers B, Baran K, Green DR. Developmental checkpoints guarded by regulated necrosis. Cell Mol Life Sci 2016; 73:2125-36. [PMID: 27056574 PMCID: PMC11108279 DOI: 10.1007/s00018-016-2188-z] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2016] [Accepted: 03/18/2016] [Indexed: 10/22/2022]
Abstract
The process of embryonic development is highly regulated through the symbiotic control of differentiation and programmed cell death pathways, which together sculpt tissues and organs. The importance of programmed necrotic (RIPK-dependent necroptosis) cell death during development has recently been recognized as important and has largely been characterized using genetically engineered animals. Suppression of necroptosis appears to be essential for murine development and occurs at three distinct checkpoints, E10.5, E16.5, and P1. These distinct time points have helped delineate the molecular pathways and regulation of necroptosis. The embryonic lethality at E10.5 seen in knockouts of caspase-8, FADD, or FLIP (cflar), components of the extrinsic apoptosis pathway, resulted in pallid embryos that did not exhibit the expected cellular expansions. This was the first suggestion that these factors play an important role in the inhibition of necroptotic cell death. The embryonic lethality at E16.5 highlighted the importance of TNF engaging necroptosis in vivo, since elimination of TNFR1 from casp8 (-/-), fadd (-/-), or cflar (-/-), ripk3 (-/-) embryos delayed embryonic lethality from E10.5 until E16.5. The P1 checkpoint demonstrates the dual role of RIPK1 in both the induction and inhibition of necroptosis, depending on the upstream signal. This review summarizes the role of necroptosis in development and the genetic evidence that helped detail the molecular mechanisms of this novel pathway of programmed cell death.
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Affiliation(s)
- Christopher P Dillon
- Department of Immunology, St. Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, TN, 38105, USA
| | - Bart Tummers
- Department of Immunology, St. Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, TN, 38105, USA
| | - Katherine Baran
- Department of Immunology, St. Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, TN, 38105, USA
| | - Douglas R Green
- Department of Immunology, St. Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, TN, 38105, USA.
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Drug Repurposing Screen Identifies Foxo1-Dependent Angiopoietin-2 Regulation in Sepsis. Crit Care Med 2015; 43:e230-40. [PMID: 25855898 DOI: 10.1097/ccm.0000000000000993] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
OBJECTIVE The recent withdrawal of a targeted sepsis therapy has diminished pharmaceutical enthusiasm for developing novel drugs for the treatment of sepsis. Angiopoietin-2 is an endothelial-derived protein that potentiates vascular inflammation and leakage and may be involved in sepsis pathogenesis. We screened approved compounds for putative inhibitors of angiopoietin-2 production and investigated underlying molecular mechanisms. DESIGN Laboratory and animal research plus prospective placebo-controlled randomized controlled trial (NCT00529139) and retrospective analysis (NCT00676897). SETTING Research laboratories of Hannover Medical School and Harvard Medical School. PATIENTS Septic patients/C57Bl/6 mice and human endothelial cells. INTERVENTIONS Food and Drug Administration-approved library screening. MEASUREMENTS AND MAIN RESULTS In a cell-based screen of more than 650 Food and Drug Administration-approved compounds, we identified multiple members of the 3-hydroxy-3-methyl-glutaryl-CoA reductase inhibitor drug class (referred to as statins) that suppressed angiopoietin-2. Simvastatin inhibited 3-hydroxy-3-methyl-glutaryl-CoA reductase, which in turn activated PI3K-kinase. Downstream of this signaling, PI3K-dependent phosphorylation of the transcription factor Foxo1 at key amino acids inhibited its ability to shuttle to the nucleus and bind cis-elements in the angiopoietin-2 promoter. In septic mice, transient inhibition of angiopoietin-2 expression by liposomal siRNA in vivo improved absolute survival by 50%. Simvastatin had a similar effect, but the combination of angiopoietin-2 siRNA and simvastatin showed no additive benefit. To verify the link between statins and angiopoietin-2 in humans, we performed a pilot matched case-control study and a small randomized placebo-controlled trial demonstrating beneficial effects on angiopoietin-2. CONCLUSIONS 3-hydroxy-3-methyl-glutaryl-CoA reductase inhibitors may operate through a novel Foxo1-angiopoietin-2 mechanism to suppress de novo production of angiopoietin-2 and thereby ameliorate manifestations of sepsis. Given angiopoietin-2's dual role as a biomarker and candidate disease mediator, early serum angiopoietin-2 measurement may serve as a stratification tool for future trials of drugs targeting vascular leakage.
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Karki S, Farb MG, Ngo DTM, Myers S, Puri V, Hamburg NM, Carmine B, Hess DT, Gokce N. Forkhead box O-1 modulation improves endothelial insulin resistance in human obesity. Arterioscler Thromb Vasc Biol 2015; 35:1498-506. [PMID: 25908760 DOI: 10.1161/atvbaha.114.305139] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2014] [Accepted: 04/14/2015] [Indexed: 01/13/2023]
Abstract
OBJECTIVE Increased visceral adiposity has been closely linked to insulin resistance, endothelial dysfunction, and cardiometabolic disease in obesity, but pathophysiological mechanisms are poorly understood. We sought to investigate mechanisms of vascular insulin resistance by characterizing depot-specific insulin responses and gain evidence that altered functionality of transcription factor forkhead box O-1 (FOXO-1) may play an important role in obesity-related endothelial dysfunction. APPROACH AND RESULTS We intraoperatively collected paired subcutaneous and visceral adipose tissue samples from 56 severely obese (body mass index, 43 ± 7 kg/m(2)) and 14 nonobese subjects during planned surgical operations, and characterized depot-specific insulin-mediated responses using Western blot and quantitative immunofluorescence techniques. Insulin signaling via phosphorylation of FOXO-1 and consequent endothelial nitric oxide synthase stimulation was selectively impaired in the visceral compared with subcutaneous adipose tissue and endothelial cells of obese subjects. In contrast, tissue actions of insulin were preserved in nonobese individuals. Pharmacological antagonism with AS1842856 and biological silencing using small interfering RNA-mediated FOXO-1 knockdown reversed insulin resistance and restored endothelial nitric oxide synthase activation in the obese. CONCLUSIONS We observed profound endothelial insulin resistance in the visceral adipose tissue of obese humans which improved with FOXO-1 inhibition. FOXO-1 modulation may represent a novel therapeutic target to diminish vascular insulin resistance. In addition, characterization of endothelial insulin resistance in the adipose microenvironment may provide clues to mechanisms of systemic disease in human obesity.
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Affiliation(s)
- Shakun Karki
- From the Evans Department of Medicine and Whitaker Cardiovascular Institute (S.K., M.G.F., D.T.M.N., S.M., V.P., N.M.H., N.G.) and Department of General Surgery (B.C., D.T.H.), Boston University School of Medicine, MA
| | - Melissa G Farb
- From the Evans Department of Medicine and Whitaker Cardiovascular Institute (S.K., M.G.F., D.T.M.N., S.M., V.P., N.M.H., N.G.) and Department of General Surgery (B.C., D.T.H.), Boston University School of Medicine, MA
| | - Doan T M Ngo
- From the Evans Department of Medicine and Whitaker Cardiovascular Institute (S.K., M.G.F., D.T.M.N., S.M., V.P., N.M.H., N.G.) and Department of General Surgery (B.C., D.T.H.), Boston University School of Medicine, MA
| | - Samantha Myers
- From the Evans Department of Medicine and Whitaker Cardiovascular Institute (S.K., M.G.F., D.T.M.N., S.M., V.P., N.M.H., N.G.) and Department of General Surgery (B.C., D.T.H.), Boston University School of Medicine, MA
| | - Vishwajeet Puri
- From the Evans Department of Medicine and Whitaker Cardiovascular Institute (S.K., M.G.F., D.T.M.N., S.M., V.P., N.M.H., N.G.) and Department of General Surgery (B.C., D.T.H.), Boston University School of Medicine, MA
| | - Naomi M Hamburg
- From the Evans Department of Medicine and Whitaker Cardiovascular Institute (S.K., M.G.F., D.T.M.N., S.M., V.P., N.M.H., N.G.) and Department of General Surgery (B.C., D.T.H.), Boston University School of Medicine, MA
| | - Brian Carmine
- From the Evans Department of Medicine and Whitaker Cardiovascular Institute (S.K., M.G.F., D.T.M.N., S.M., V.P., N.M.H., N.G.) and Department of General Surgery (B.C., D.T.H.), Boston University School of Medicine, MA
| | - Donald T Hess
- From the Evans Department of Medicine and Whitaker Cardiovascular Institute (S.K., M.G.F., D.T.M.N., S.M., V.P., N.M.H., N.G.) and Department of General Surgery (B.C., D.T.H.), Boston University School of Medicine, MA
| | - Noyan Gokce
- From the Evans Department of Medicine and Whitaker Cardiovascular Institute (S.K., M.G.F., D.T.M.N., S.M., V.P., N.M.H., N.G.) and Department of General Surgery (B.C., D.T.H.), Boston University School of Medicine, MA.
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