scholarly journals Inhibitory Effect of a Glutamine Antagonist on Proliferation and Migration of VSMCs via Simultaneous Attenuation of Glycolysis and Oxidative Phosphorylation

2021 ◽  
Vol 22 (11) ◽  
pp. 5602
Author(s):  
Hyeon Young Park ◽  
Mi-Jin Kim ◽  
Seunghyeong Lee ◽  
Jonghwa Jin ◽  
Sungwoo Lee ◽  
...  

Excessive proliferation and migration of vascular smooth muscle cells (VSMCs) contribute to the development of atherosclerosis and restenosis. Glycolysis and glutaminolysis are increased in rapidly proliferating VSMCs to support their increased energy requirements and biomass production. Thus, it is essential to develop new pharmacological tools that regulate metabolic reprogramming in VSMCs for treatment of atherosclerosis. The effects of 6-diazo-5-oxo-L-norleucine (DON), a glutamine antagonist, have been broadly investigated in highly proliferative cells; however, it is unclear whether DON inhibits proliferation of VSMCs and neointima formation. Here, we investigated the effects of DON on neointima formation in vivo as well as proliferation and migration of VSMCs in vitro. DON simultaneously inhibited FBS- or PDGF-stimulated glycolysis and glutaminolysis as well as mammalian target of rapamycin complex I activity in growth factor-stimulated VSMCs, and thereby suppressed their proliferation and migration. Furthermore, a DON-derived prodrug, named JHU-083, significantly attenuated carotid artery ligation-induced neointima formation in mice. Our results suggest that treatment with a glutamine antagonist is a promising approach to prevent progression of atherosclerosis and restenosis.

2019 ◽  
Vol 316 (1) ◽  
pp. H61-H69 ◽  
Author(s):  
Wenbo Yang ◽  
Zhijun Wu ◽  
Ke Yang ◽  
Yanxin Han ◽  
Yanjia Chen ◽  
...  

Cardiac fibrosis has been known to play an important role in the etiology of heart failure after myocardial infarction (MI). B lymphoma Mo-MLV insertion region 1 homolog (BMI1), a transcriptional repressor, is important for fibrogenesis in the kidneys. However, the effect of BMI1 on ischemia-induced cardiac fibrosis remains unclear. BMI1 was strongly expressed in the infarct region 1 wk post-MI in mice and was detected by Western blot and histological analyses. Lentivirus-mediated overexpression of BMI1 significantly promoted cardiac fibrosis, worsened cardiac function 4 wk after the intervention in vivo, and enhanced the proliferation and migration capabilities of fibroblasts in vitro , whereas downregulation of BMI1 decreased cardiac fibrosis and prevented cardiac dysfunction in mice 4 wk post-MI in vivo. Furthermore, upregulated BMI1 inhibited phosphatase and tensin homolog (PTEN) expression, enhanced phosphatidylinositol 3-kinase (PI3K) expression, and increased the phosphorylation level of Akt and mammalian target of rapamycin (mTOR) in mice 4 wk after lentiviral infection, which was in accordance with the changes seen in their infarcted myocardial tissues. At the same time, the effects of BMI1 on cardiac fibroblasts were reversed in vitro when these cells were exposed to NVP-BEZ235, a dual-kinase (PI3K/mTOR) inhibitor. In conclusion, BMI1 is associated with cardiac fibrosis and dysfunction after MI by regulating cardiac fibroblast proliferation and migration, and these effects could be partially explained by the regulation of the PTEN-PI3K/Akt-mTOR pathway. NEW & NOTEWORTHY Ischemia-induced B lymphoma Mo-MLV insertion region 1 homolog (BMI1) significantly promoted cardiac fibrosis and worsened cardiac function in vivo, whereas downregulation of BMI1 decreased cardiac fibrosis and prevented cardiac dysfunction in myocardial infarcted mice. BMI1 also enhanced proliferation and migration capabilities of fibroblasts in vitro; these effects were reversed by NVP-BEZ235. Effects of BMI1 on cardiac fibrosis could be partially explained by regulation of the phosphatase and tensin homolog-phosphatidylinositol 3-kinase/Akt-mammalian target of rapamycin pathway.


2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
J Dutzmann ◽  
L.M Bode ◽  
L Korte ◽  
K Kalies ◽  
S Koch ◽  
...  

Abstract Background Empagliflozin, an inhibitor of the sodium glucose co-transporter 2 (SGLT2), developed as an anti-diabetic agent exerts additional beneficial effects on heart failure outcomes in patients with type 2 diabetes mellitus at high cardiovascular risk. However, the effect of empagliflozin on vascular cell function and vascular remodeling processes remain largely elusive. Methods/Results Immunocytochemistry and immunoblotting revealed SGLT2 to be expressed in human diabetic and non-diabetic smooth muscle (SMC) and endothelial cells (EC) as well as in murine femoral arteries. In vitro, empagliflozin significantly reduced serum-induced proliferation and migration of human diabetic and non-diabetic SMCs in a dose-dependent manner without any toxic or apoptotic effects. In contrast, empagliflozin significantly increased the cell count and migrational capacity of human diabetic ECs, but not of human non-diabetic ECs. In vivo, therapeutic application of empagliflozin (225 mg/kg medicated diet) resulted in a significantly reduced number of Ki-67+ proliferating neointimal cells in response to femoral artery wire-injury in C57BL/6J mice. Empagliflozin furthermore prevented subsequent neointima formation (luminal stenosis 91.2% vs. 80.6% at 21 days; P<0.05). Comparable effects of empagliflozin were observed in a streptozocin-induced diabetic model of apolipoprotein E−/− mice. Conclusive to the in vitro-results, re-endothelialization was not significantly affected in C57BL/6 mice (non-reendothelialized distance 2.57 mm vs. 2.3 mm; P=0.07), but even significantly improved in diabetic mice after treatment with empagliflozin (3.1 mm vs. 2.58 mm; P<0.001) assessed by Evan's Blue staining 3 days after electric denudation of the murine carotid artery. Microarray analysis of human SMCs identified the vasoactive peptide apelin to be decisively regulated in response to empagliflozin treatment. Further pathway analysis exhibited apelin to prevent SMC proliferation by de-phosphorylation of Akt and to augment EC proliferation by phosphorylation of p38 MAPK. Conclusion These data document the functional impact of empagliflozin on vascular SMCs and ECs for the first time. Empagliflozin significantly reduces serum-induced proliferation and migration of SMCs in vitro and prevented neointima formation in vivo, while augmenting EC proliferation in vitro and re-endothelialization in vivo after vascular injury. Thus, empagliflozin holds promise to exert favorable effects on vascular healing, and to prevent neointima formation following vascular injury in diabetic and non-diabetic patients. Funding Acknowledgement Type of funding source: Public Institution(s). Main funding source(s): Hannover Medical School, Martin-Luther-University Halle-Wittenberg


2017 ◽  
Vol 113 (13) ◽  
pp. 1653-1663 ◽  
Author(s):  
Jochen Dutzmann ◽  
Alexander Koch ◽  
Simona Weisheit ◽  
Kristina Sonnenschein ◽  
Laura Korte ◽  
...  

Abstract Aims Adventitial cells have been suggested to contribute to neointima formation, but the functional relevance and the responsible signalling pathways are largely unknown. Sonic hedgehog (Shh) is a regulator of vasculogenesis and promotes angiogenesis in the adult. Methods and results Here we show that proliferation of vascular smooth muscle cells (SMC) after wire-induced injury in C57BL/6 mice is preceded by proliferation of adventitial fibroblasts. Simultaneously, the expression of Shh and its downstream signalling protein smoothened (SMO) were robustly increased within injured arteries. In vitro, combined stimulation with Shh and platelet-derived growth factor (PDGF)-BB strongly induced proliferation and migration of human adventitial fibroblasts. The supernatant of these activated fibroblasts contained high levels of interleukin-6 and -8 and strongly induced proliferation and migration of SMC. Inhibition of SMO selectively prevented fibroblast proliferation, cytokine release, and paracrine SMC activation. Mechanistically, we found that PDGF-BB activates protein kinase A in fibroblasts and thereby induces trafficking of SMO to the plasma membrane, where it can be activated by Shh. In vivo, SMO-inhibition significantly prevented the proliferation of adventitial fibroblasts and neointima formation following wire-induced injury. Conclusions The initial activation of adventitial fibroblasts is essential for the subsequent proliferation of SMC and neointima formation. We identified SMO-dependent Shh signalling as a specific process for the activation of adventitial fibroblasts.


2018 ◽  
Vol 115 (37) ◽  
pp. E8660-E8667 ◽  
Author(s):  
Abu Shufian Ishtiaq Ahmed ◽  
Kunzhe Dong ◽  
Jinhua Liu ◽  
Tong Wen ◽  
Luyi Yu ◽  
...  

In response to vascular injury, vascular smooth muscle cells (VSMCs) may switch from a contractile to a proliferative phenotype thereby contributing to neointima formation. Previous studies showed that the long noncoding RNA (lncRNA) NEAT1 is critical for paraspeckle formation and tumorigenesis by promoting cell proliferation and migration. However, the role of NEAT1 in VSMC phenotypic modulation is unknown. Herein we showed that NEAT1 expression was induced in VSMCs during phenotypic switching in vivo and in vitro. Silencing NEAT1 in VSMCs resulted in enhanced expression of SM-specific genes while attenuating VSMC proliferation and migration. Conversely, overexpression of NEAT1 in VSMCs had opposite effects. These in vitro findings were further supported by in vivo studies in which NEAT1 knockout mice exhibited significantly decreased neointima formation following vascular injury, due to attenuated VSMC proliferation. Mechanistic studies demonstrated that NEAT1 sequesters the key chromatin modifier WDR5 (WD Repeat Domain 5) from SM-specific gene loci, thereby initiating an epigenetic “off” state, resulting in down-regulation of SM-specific gene expression. Taken together, we demonstrated an unexpected role of the lncRNA NEAT1 in regulating phenotypic switching by repressing SM-contractile gene expression through an epigenetic regulatory mechanism. Our data suggest that NEAT1 is a therapeutic target for treating occlusive vascular diseases.


2021 ◽  
Vol 12 (4) ◽  
Author(s):  
Jianye Xu ◽  
Jian Zhang ◽  
Zongpu Zhang ◽  
Zijie Gao ◽  
Yanhua Qi ◽  
...  

AbstractExosomes participate in intercellular communication and glioma microenvironment modulation, but the exact mechanisms by which glioma-derived exosomes (GDEs) promote the generation of the immunosuppressive microenvironment are still unclear. Here, we investigated the effects of GDEs on autophagy, the polarization of tumor-associated macrophages (TAMs), and glioma progression. Compared with normoxic glioma-derived exosomes (N-GDEs), hypoxic glioma-derived exosomes (H-GDEs) markedly facilitated autophagy and M2-like macrophage polarization, which subsequently promoted glioma proliferation and migration in vitro and in vivo. Western blot and qRT-PCR analyses indicated that interleukin 6 (IL-6) and miR-155-3p were highly expressed in H-GDEs. Further experiments showed that IL-6 and miR-155-3p induced M2-like macrophage polarization via the IL-6-pSTAT3-miR-155-3p-autophagy-pSTAT3 positive feedback loop, which promotes glioma progression. Our study clarifies a mechanism by which hypoxia and glioma influence autophagy and M2-like macrophage polarization via exosomes, which could advance the formation of the immunosuppressive microenvironment. Our findings suggest that IL-6 and miR-155-3p may be novel biomarkers for diagnosing glioma and that treatments targeting autophagy and the STAT3 pathway may contribute to antitumor immunotherapy.


2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Zhenghui Cheng ◽  
Yawen Zhang ◽  
Yinchao Tian ◽  
Yuhan Chen ◽  
Fei Ding ◽  
...  

Abstract Background Schwann cells (SCs) play a crucial role in the repair of peripheral nerves. This is due to their ability to proliferate, migrate, and provide trophic support to axon regrowth. During peripheral nerve injury, SCs de-differentiate and reprogram to gain the ability to repair nerves. Cysteine-rich 61 (Cyr61/CCN1) is a member of the CCN family of matrix cell proteins and have been reported to be abundant in the secretome of repair mediating SCs. In this study we investigate the function of Cyr61 in SCs. Results We observed Cyr61 was expressed both in vivo and in vitro. The promoting effect of Cyr61 on SC proliferation and migration was through autocrine and paracrine mechanisms. SCs expressed αvβ3 integrin and the effect of Cyr61 on SC proliferation and migration could be blocked via αvβ3 integrin. Cyr61 could influence c-Jun protein expression in cultured SCs. Conclusions In this study, we found that Cyr61 promotes SC proliferation and migration via αvβ3 integrin and regulates c-Jun expression. Our study contributes to the understanding of cellular and molecular mechanisms underlying SC’s function during nerve injury, and thus, may facilitate the regeneration of peripheral nerves after injury.


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