scholarly journals Overexpression of E3 ubiquitin ligase Cbl attenuates endothelial dysfunction in diabetes mellitus by inhibiting the JAK2/STAT4 signaling and Runx3-mediated H3K4me3

2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Qingsong Jin ◽  
Liangyan Lin ◽  
Tiantian Zhao ◽  
Xiaoyan Yao ◽  
Yaqin Teng ◽  
...  

Abstract Background Diabetes mellitus (DM), a most common chronic disease, is featured with impaired endothelial function and bioavailability of nitric oxide (NO), while E3 ubiquitin ligase appears to alleviate endothelial dysfunction as a promising option for DM treatment. Herein, we aimed to determine whether E3 ubiquitin ligase casitas B-lineage lymphoma (Cbl) alleviates endothelial dysfunction in DM rats by JAK2/STAT4 pathway. Methods A rat model of DM was developed through intraperitoneal injection of streptozotocin, followed by collection of aortic tissues to determine the expression of Cbl, JAK2, runt-related transcription factor 3 (Runx3) and STAT4. Human umbilical vein endothelial cells (HUVECs) were cultured in high glucose (HG) condition to induce DM as an in vitro model. With gain- and loss-function method, we assessed the aberrantly expressed Cb1 on endothelial dysfunction, NO production and apoptosis of HUVECs. Results Cbl was reduced in DM rat tissues and HG-induced HUVECs, where JAK2, Runx3 and STAT4 were elevated. It was found that overexpression of Cbl alleviated endothelial dysfunction by increasing NO production and restoring vasodilation and suppressing apoptosis of HUVECs. Mechanistically, Cb1 enhanced JAK2 ubiquitination and decreased JAK2 and STAT4 expression, where STAT4 improved Runx3 expression by regulating histone H3 lysine 4 trimethylation level. Overexpression of JAK2 and STAT4, or Runx3 increased apoptosis of HUVECs, abrogating the effect of Cb1 on endothelial function. Conclusion In conclusion, Cbl alleviates endothelial dysfunction by inactivation of the JAK2/STAT4 pathway and inhibition of Runx3 expression in DM. These evidence might underlie novel Cbl-based treatment against DM in the future.

2002 ◽  
Vol 175 (1) ◽  
pp. 217-223 ◽  
Author(s):  
K Matsumoto ◽  
R Morishita ◽  
N Tomita ◽  
A Moriguchi ◽  
K Yamasaki ◽  
...  

We have previously reported that a decrease in hepatocyte growth factor (HGF), which has many protective functions against endothelial damage by high d-glucose, might be a trigger of endothelial injury. However, the regulation of vascular HGF in diabetes mellitus (DM) has not been clarified in vivo, although vascular disease is frequently observed in DM patients. In addition, our previous report revealed that a prostaglandin I(2) (PGI(2)) analogue prevented endothelial cell death through the induction of vascular HGF production in cultured human epithelial cells. Thus, in this study, we examined the effects of a PGI(2) analogue in the regulation of the local HGF system using DM rats. A PGI(2) analogue (beraprost sodium; 300 and 600 micro g/kg per day) or vehicle was administered to 16-week-old DM rats induced by administration of streptozotocin for 28 days. Endothelial function was evaluated by the vasodilator response to acetylcholine, and the expression of vascular HGF mRNA was measured by Northern blotting. Of importance, expression of HGF mRNA was significantly decreased in the blood vessels of DM rats as compared with non-DM (P<0.01). In addition, the in vitro vasodilator response of the abdominal aorta to acetylcholine was markedly impaired in DM rats. Importantly, the vasodilator response was restored by PGI(2) treatment in a dose-dependent manner (P<0.01), whereas N(omega)-nitro-l-arginine methyl ester inhibited the restoration of endothelial function. Of particular interest, vascular HGF mRNA and protein were significantly increased in the blood vessels of DM rats treated with PGI(2) as compared with vehicle. Similarly, an increase in HGF protein was also confirmed by immunohistochemical analysis. In addition, the specific HGF receptor, c-met, was also increased by PGI(2) treatment. Overall, this study demonstrated that treatment with a PGI(2) analogue restored endothelial dysfunction in DM rats, accompanied by the induction of vascular HGF and c-met expression. Increased local vascular HGF production by a PGI(2) analogue may prevent endothelial injury, potentially resulting in the improvement of endothelial dysfunction.


Antioxidants ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 1306
Author(s):  
Tatsuya Maruhashi ◽  
Yukihito Higashi

Endothelial dysfunction plays a critical role in atherosclerosis progression, leading to cardiovascular complications. There are significant associations between diabetes mellitus, oxidative stress, and endothelial dysfunction. Oxidative stress is increased by chronic hyperglycemia and acute glucose fluctuations induced by postprandial hyperglycemia in patients with diabetes mellitus. In addition, selective insulin resistance in the phosphoinositide 3-kinase/Akt/endothelial nitric oxide (NO) synthase pathway in endothelial cells is involved in decreased NO production and increased endothelin-1 production from the endothelium, resulting in endothelial dysfunction. In a clinical setting, selecting an appropriate therapeutic intervention that improves or augments endothelial function is important for preventing diabetic vascular complications. Hypoglycemic drugs that reduce glucose fluctuations by decreasing the postprandial rise in blood glucose levels, such as glinides, α-glucosidase inhibitors and dipeptidyl peptidase 4 inhibitors, and hypoglycemic drugs that ameliorate insulin sensitivity, such as thiazolidinediones and metformin, are expected to improve or augment endothelial function in patients with diabetes. Glucagon-like peptide 1 receptor agonists, metformin, and sodium-glucose cotransporter 2 inhibitors may improve endothelial function through multiple mechanisms, some of which are independent of glucose control or insulin signaling. Oral administration of antioxidants is not recommended in patients with diabetes due to the lack of evidence for the efficacy against diabetic complications.


2021 ◽  
Vol 12 ◽  
Author(s):  
Qian Xu ◽  
Kunping Zhuo ◽  
Ruiping Cai ◽  
Xiaomin Su ◽  
Lu Zhang ◽  
...  

Yes-associated protein (YAP) and its associated coactivator of PDZ-binding motif (TAZ) are co-transcriptional regulators and down effectors of the Hippo signaling pathway. Recent studies have shown that the Hippo/YAP signaling pathway may play a role in mediating vascular homeostasis. This study investigated the role of YAP/TAZ in endothelial dysfunction and vascular inflammation in angiotensin (Ang)II hypertensive mice. The infusion of AngII (1.1 mg/kg/day by mini-pump) for 3 weeks induced the activation of YAP/TAZ, manifested by decreased cytosolic phosphor-YAP and phosphor-TAZ, and increased YAP/TAZ nuclear translocation, which were prevented by YAP/TAZ inhibitor verteporfin. AngII significantly increased systolic blood pressure (SBP), macrophage infiltration, and expressions of proinflammatory cytokines, and impaired endothelial function in the aorta of the mice. Treatment with verteporfin improved endothelial function and reduced vascular inflammation with a mild reduction in SBP. AngII also induced YAP/TAZ activation in human umbilical vein endothelial cells in vitro, which were prevented by LB-100, an inhibitor of protein phosphatase 2A (PP2A, a major dephosphorylase). Treatment with LB-100 reversed AngII-induced proinflammatory cytokine expression and impairment of phosphor-eNOS expression in vitro. Our results suggest that AngII induces YAP/TAZ activation via PP2A-dependent dephosphorylation, which may contribute to the impairment of endothelial function and the induction of vascular inflammation in hypertension. YAP/TAZ may be a new target for hypertensive vascular injury.


2021 ◽  
Vol 22 (11) ◽  
pp. 5712
Author(s):  
Michał Tracz ◽  
Ireneusz Górniak ◽  
Andrzej Szczepaniak ◽  
Wojciech Białek

The SPL2 protein is an E3 ubiquitin ligase of unknown function. It is one of only three types of E3 ligases found in the outer membrane of plant chloroplasts. In this study, we show that the cytosolic fragment of SPL2 binds lanthanide ions, as evidenced by fluorescence measurements and circular dichroism spectroscopy. We also report that SPL2 undergoes conformational changes upon binding of both Ca2+ and La3+, as evidenced by its partial unfolding. However, these structural rearrangements do not interfere with SPL2 enzymatic activity, as the protein retains its ability to auto-ubiquitinate in vitro. The possible applications of lanthanide-based probes to identify protein interactions in vivo are also discussed. Taken together, the results of this study reveal that the SPL2 protein contains a lanthanide-binding site, showing for the first time that at least some E3 ubiquitin ligases are also capable of binding lanthanide ions.


Author(s):  
Susan Gallogly ◽  
Takeshi Fujisawa ◽  
John D. Hung ◽  
Mairi Brittan ◽  
Elizabeth M. Skinner ◽  
...  

Abstract Purpose Endothelial dysfunction is central to the pathogenesis of acute coronary syndrome. The study of diseased endothelium is very challenging due to inherent difficulties in isolating endothelial cells from the coronary vascular bed. We sought to isolate and characterise coronary endothelial cells from patients undergoing thrombectomy for myocardial infarction to develop a patient-specific in vitro model of endothelial dysfunction. Methods In a prospective cohort study, 49 patients underwent percutaneous coronary intervention with thrombus aspiration. Specimens were cultured, and coronary endothelial outgrowth (CEO) cells were isolated. CEO cells, endothelial cells isolated from peripheral blood, explanted coronary arteries, and umbilical veins were phenotyped and assessed functionally in vitro and in vivo. Results CEO cells were obtained from 27/37 (73%) atherothrombotic specimens and gave rise to cells with cobblestone morphology expressing CD146 (94 ± 6%), CD31 (87 ± 14%), and von Willebrand factor (100 ± 1%). Proliferation of CEO cells was impaired compared to both coronary artery and umbilical vein endothelial cells (population doubling time, 2.5 ± 1.0 versus 1.6 ± 0.3 and 1.2 ± 0.3 days, respectively). Cell migration was also reduced compared to umbilical vein endothelial cells (29 ± 20% versus 85±19%). Importantly, unlike control endothelial cells, dysfunctional CEO cells did not incorporate into new vessels or promote angiogenesis in vivo. Conclusions CEO cells can be reliably isolated and cultured from thrombectomy specimens in patients with acute coronary syndrome. Compared to controls, patient-derived coronary endothelial cells had impaired capacity to proliferate, migrate, and contribute to angiogenesis. CEO cells could be used to identify novel therapeutic targets to enhance endothelial function and prevent acute coronary syndromes.


2014 ◽  
Vol 1842 (9) ◽  
pp. 1527-1538 ◽  
Author(s):  
Katharina Flach ◽  
Ellen Ramminger ◽  
Isabel Hilbrich ◽  
Annika Arsalan-Werner ◽  
Franziska Albrecht ◽  
...  

2012 ◽  
Vol 123 (3) ◽  
pp. 147-159 ◽  
Author(s):  
Ting-Hsing Chao ◽  
Shih-Ya Tseng ◽  
Yi-Heng Li ◽  
Ping-Yen Liu ◽  
Chung-Lung Cho ◽  
...  

Cilostazol is an anti-platelet agent with vasodilatory activity that acts by increasing intracellular concentrations of cAMP. Recent reports have suggested that cilostazol may promote angiogenesis. In the present study, we have investigated the effect of cilostazol in promoting angiogenesis and vasculogenesis in a hindlimb ischaemia model and have also examined its potential mechanism of action in vitro and in vivo. We found that cilostazol treatment significantly increased colony formation by human early EPCs (endothelial progenitor cells) through a mechanism involving the activation of cAMP/PKA (protein kinase A), PI3K (phosphoinositide 3-kinase)/Akt/eNOS (endothelial NO synthase) and ERK (extracellular-signal-regulated kinase)/p38 MAPK (mitogen-activated protein kinase) signalling pathways. Cilostazol also enhanced proliferation, chemotaxis, NO production and vascular tube formation in HUVECs (human umbilical vein endothelial cells) through activation of multiple signalling pathways downstream of PI3K/Akt/eNOS. Cilostazol up-regulated VEGF (vascular endothelial growth factor)-A165 expression and secretion of VEGF-A in HUVECs through activation of the PI3K/Akt/eNOS pathway. In a mouse hindlimb ischaemia model, recovery of blood flow ratio (ipsilateral/contralateral) 14 days after surgery was significantly improved in cilostazol-treated mice (10 mg/kg of body weight) compared with vehicle-treated controls (0.63±0.07 and 0.43±0.05 respectively, P<0.05). Circulating CD34+ cells were also increased in cilostazol-treated mice (3614±670 compared with 2151±608 cells/ml, P<0.05). Expression of VEGF and phosphorylation of PI3K/Akt/eNOS and ERK/p38 MAPK in ischaemic muscles were significantly enhanced by cilostazol. Our data suggest that cilostazol produces a vasculo-angiogenic effect by up-regulating a broad signalling network that includes the ERK/p38 MAPK, VEGF-A165, PI3K/Akt/eNOS and cAMP/PKA pathways.


2007 ◽  
Vol 179 (5) ◽  
pp. 935-950 ◽  
Author(s):  
K.G. Suresh Kumar ◽  
Hervé Barriere ◽  
Christopher J. Carbone ◽  
Jianghuai Liu ◽  
Gayathri Swaminathan ◽  
...  

Ligand-induced endocytosis and lysosomal degradation of cognate receptors regulate the extent of cell signaling. Along with linear endocytic motifs that recruit the adaptin protein complex 2 (AP2)–clathrin molecules, monoubiquitination of receptors has emerged as a major endocytic signal. By investigating ubiquitin-dependent lysosomal degradation of the interferon (IFN)-α/β receptor 1 (IFNAR1) subunit of the type I IFN receptor, we reveal that IFNAR1 is polyubiquitinated via both Lys48- and Lys63-linked chains. The SCFβTrcp (Skp1–Cullin1–F-box complex) E3 ubiquitin ligase that mediates IFNAR1 ubiquitination and degradation in cells can conjugate both types of chains in vitro. Although either polyubiquitin linkage suffices for postinternalization sorting, both types of chains are necessary but not sufficient for robust IFNAR1 turnover and internalization. These processes also depend on the proximity of ubiquitin-acceptor lysines to a linear endocytic motif and on its integrity. Furthermore, ubiquitination of IFNAR1 promotes its interaction with the AP2 adaptin complex that is required for the robust internalization of IFNAR1, implicating cooperation between site-specific ubiquitination and the linear endocytic motif in regulating this process.


2012 ◽  
Vol 111 (suppl_1) ◽  
Author(s):  
Shirin Doroudgar ◽  
Mirko Völkers ◽  
Donna J Thuerauf ◽  
Ashley Bumbar ◽  
Mohsin Khan ◽  
...  

The endoplasmic reticulum (ER) is essential for protein homeostasis, or proteostasis, which governs the balance of the proteome. In addition to secreted and membrane proteins, proteins bound for many other cellular locations are also made on ER-bound ribosomes, emphasizing the importance of protein quality and quantity control in the ER. Unlike cytosolic E3 ubiquitin ligases studied in the heart, synoviolin/Hrd1, which has not been studied in the heart, is an ER transmembrane E3 ubiquitin ligase, which we found to be upregulated upon protein misfolding in cardiac myocytes. Given the strategic location of synoviolin in the ER membrane, we addressed the hypothesis that synoviolin is critical for regulating the balance of the proteome, and accordingly, myocyte size. We showed that in vitro, adenovirus-mediated overexpression of synoviolin decreased cardiac myocyte size and protein synthesis, but unlike atrophy-related ubiquitin ligases, synoviolin did not increase global protein degradation. Furthermore, targeted gene therapy using adeno-associated virus 9 (AAV9) showed that overexpression of synoviolin in the left ventricle attenuated maladaptive cardiac hypertrophy and preserved cardiac function in mice subjected to trans-aortic constriction (AAV9-control TAC = 22.5 ± 6.2% decrease in EF vs. AAV9-synoviolin TAC at 6 weeks post TAC; P<0.001), and decreased mTOR activity. Since calcium is a major regulator of cardiac myocyte size, we examined the effects of synoviolin gain- or loss-of-function, using AAV9-synoviolin, or an miRNA designed to knock down synoviolin, respectively. While synoviolin gain-of-function did not affect calcium handling in isolated adult myocytes, synoviolin loss-of-function increased calcium transient amplitude (P<0.01), prolonged spark duration (P<0.001), and increased spark width (P<0.001). Spark frequency and amplitude were unaltered upon synoviolin gain- or loss-of-function. Whereas SR calcium load was unaltered by synoviolin loss-of-function, SERCA-mediated calcium removal was reduced (P<0.05). In conclusion, our studies suggest that in the heart, synoviolin is 1) a critical component of proteostasis, 2) a novel determinant of cardiac myocyte size, and 3) necessary for proper calcium handling.


2021 ◽  
Vol 12 ◽  
Author(s):  
Solvey Pollmann ◽  
David Scharnetzki ◽  
Dominique Manikowski ◽  
Malte Lenders ◽  
Eva Brand

Fabry disease (FD) is an X-linked multisystemic lysosomal storage disease due to a deficiency of α-galactosidase A (GLA/AGAL). Progressive cellular accumulation of the AGAL substrate globotriaosylceramide (Gb3) leads to endothelial dysfunction. Here, we analyzed endothelial function in vivo and in vitro in an AGAL-deficient genetic background to identify the processes underlying this small vessel disease. Arterial stiffness and endothelial function was prospectively measured in five males carrying GLA variants (control) and 22 FD patients under therapy. AGAL-deficient endothelial cells (EA.hy926) and monocytes (THP1) were used to analyze endothelial glycocalyx structure, function, and underlying inflammatory signals. Glycocalyx thickness and small vessel function improved significantly over time (p&lt;0.05) in patients treated with enzyme replacement therapy (ERT, n=16) and chaperones (n=6). AGAL-deficient endothelial cells showed reduced glycocalyx and increased monocyte adhesion (p&lt;0.05). In addition, increased expression of angiopoietin-2, heparanase and NF-κB was detected (all p&lt;0.05). Incubation of wild-type endothelial cells with pathological globotriaosylsphingosine concentrations resulted in comparable findings. Treatment of AGAL-deficient cells with recombinant AGAL (p&lt;0.01), heparin (p&lt;0.01), anti-inflammatory (p&lt;0.001) and antioxidant drugs (p&lt;0.05), and a specific inhibitor (razuprotafib) of angiopoietin-1 receptor (Tie2) (p&lt;0.05) improved glycocalyx structure and endothelial function in vitro. We conclude that chronic inflammation, including the release of heparanases, appears to be responsible for the degradation of the endothelial glycocalyx and may explain the endothelial dysfunction in FD. This process is partially reversible by FD-specific and anti-inflammatory treatment, such as targeted protective Tie2 treatment.


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