scholarly journals Alcohol-induced Hsp90 acetylation is a novel driver of liver sinusoidal endothelial dysfunction and alcoholic liver disease

2020 ◽  
Author(s):  
Yilin Yang ◽  
Panjamaporn Sungwung ◽  
Yirang Jung ◽  
Reiichiro Kondo ◽  
Matthew McConnell ◽  
...  

AbstractBackgroundIt is unknown whether liver sinusoidal endothelial cells (LSECs) metabolize alcohol. Chronic alcohol consumption decreases endothelial nitric oxide synthase (eNOS)-derived NO production typical of LSEC dysfunction. Heat shock protein 90 (Hsp90) interacts with eNOS to increase its activity. Cytochrome P450 2E1 (CYP2E1) is a key enzyme in alcohol metabolism and facilitates protein acetylation via acetyl-CoA, but its expression in LSECs is unknown. This study investigates alcohol metabolism by LSECs, the mechanism of alcohol-induced LSEC dysfunction and a potential therapeutic approach for alcohol-induced liver injury.MethodsPrimary human, rat and mouse LSECs were used. Histone deacetylase 6 (HDAC6) was overexpressed specifically in liver ECs using an adeno-associated virus (AAV)-mediated gene delivery system to decrease Hsp90 acetylation in ethanol fed mice.ResultsLSECs expressed CYP2E1 and alcohol dehydrogenase 1 (ADH1) and metabolized alcohol. Ethanol induced CYP2E1 in LSECs, but not ADH1. Alcohol metabolism by CYP2E1 increased Hsp90 acetylation and decreased its interaction with eNOS along with a decrease in NO production. A non-acetylation mutant of Hsp90 increased its interaction with eNOS and NO production, whereas a hyper-acetylation mutant decreased NO production, compared with wildtype Hsp90. These results indicate that Hsp90 acetylation is responsible for decreases in its interaction with eNOS and eNOS-derived NO production. Adeno-associated virus 8 (AAV8)-driven HDAC6 overexpression specifically in liver ECs deacetylated Hsp90, restored Hsp90’s interaction with eNOS and ameliorated alcohol-induced liver injury in mice.ConclusionRestoring LSEC function is important for ameliorating alcohol-induced liver injury. To this end, blocking acetylation of Hsp90 specifically in LSECs via AAV-mediated gene delivery has the potential to be a new therapeutic strategy.

Cells ◽  
2020 ◽  
Vol 9 (2) ◽  
pp. 456 ◽  
Author(s):  
Ute A. Schwinghammer ◽  
Magda M. Melkonyan ◽  
Lilit Hunanyan ◽  
Roman Tremmel ◽  
Ralf Weiskirchen ◽  
...  

The noradrenergic system is proposed to play a prominent role in the pathogenesis of liver fibrosis. While α1- and β-adrenergic receptors (ARs) are suggested to be involved in a multitude of profibrogenic actions, little is known about α2-AR-mediated effects and their expression pattern during liver fibrosis and cirrhosis. We explored the expression of α2-AR in two models of experimental liver fibrosis. We further evaluated the capacity of the α2-AR blocker mesedin to deactivate hepatic stellate cells (HSCs) and to increase the permeability of human liver sinusoidal endothelial cells (hLSECs). The mRNA of α2a-, α2b-, and α2c-AR subtypes was uniformly upregulated in carbon tetrachloride-treated mice vs the controls, while in bile duct-ligated mice, only α2b-AR increased in response to liver injury. In murine HSCs, mesedin led to a decrease in α-smooth muscle actin, transforming growth factor-β and α2a-AR expression, which was indicated by RT-qPCR, immunocytochemistry, and Western blot analyses. In a hLSEC line, an increased expression of endothelial nitric oxide synthase was detected along with downregulated transforming growth factor-β. In conclusion, we suggest that the α2-AR blockade alleviates the activation of HSCs and may increase the permeability of liver sinusoids during liver injury.


Cardiology ◽  
2015 ◽  
Vol 132 (4) ◽  
pp. 252-260 ◽  
Author(s):  
Wen-Qi Han ◽  
Feng-Jun Chang ◽  
Qun-Rang Wang ◽  
Jun-Qiang Pan

Objectives: Endothelial dysfunction is involved in the development of the acute coronary syndrome (ACS). Plasma microparticles (MPs) from other diseases have been demonstrated to initiate coagulation and endothelial dysfunction. However, whether MPs from ACS patients impair vasodilatation and endothelial function remains unclear. Methods: Patients (n = 62) with ACS and healthy controls (n = 30) were recruited for MP isolation. Rat thoracic aortas were incubated with MPs from ACS patients or healthy controls to determine the effects of MPs on endothelial-dependent vasodilatation, the phosphorylation of Akt and endothelial nitric oxide synthase (eNOS), the interaction of eNOS with heat shock protein 90 (Hsp90), and nitric oxide (NO) and superoxide anion (O2-) production. The origin of MPs was assessed by flow cytometry. Results: MP concentrations were increased in patients with ACS compared with healthy controls. They were positively correlated with the degree of coronary artery stenosis. MPs from ACS patients impair endothelial-dependent vasodilatation, decrease both Akt and eNOS phosphorylation, decrease the interaction between eNOS and Hsp90, and decrease NO production but increase O2- generation in rat thoracic aortas. Endothelial-derived MPs and platelet-derived MPs made up nearly 75% of MPs. Conclusions: Our data indicate that MPs from ACS patients negatively affect endothelial-dependent vasodilatation via Akt/eNOS-Hsp90 pathways.


2009 ◽  
Vol 296 (1) ◽  
pp. C182-C192 ◽  
Author(s):  
Sumathy Mohan ◽  
Ryszard Konopinski ◽  
Bo Yan ◽  
Victoria E. Centonze ◽  
Mohan Natarajan

A decline in the bioavailability of nitric oxide (NO) that causes endothelial dysfunction is a hallmark of diabetes. The availability of NO to the vasculature is regulated by endothelial nitric oxide synthase (eNOS) activity and the involvement of heat shock protein-90 (Hsp-90) in the regulation of eNOS activity has been demonstrated. Hsp-90 has been shown to interact with upstream kinases [inhibitor κB kinases (IKK)α, β, and γ] in nonvascular cells. In this study, we have investigated the interaction of Hsp-90-IKKβ in endothelial cells under conditions of high glucose (HG) as a possible mechanism that diminishes Hsp-90-eNOS interaction, which could contribute to reduced bioavailability of NO. We report for the first time that IKKβ interacts with Hsp-90, and this interaction is augmented by HG in vascular endothelial cells. HG also augments transcriptional (3.5 ± 0.65-fold) and translational (1.97 ± 0.17-fold) expression as well as the catalytic activity of IKKβ (2.45 ± 0.4-fold). Both IKKβ and eNOS could be coimmunoprecipitated with Hsp-90. Inhibition of Hsp-90 with geldanamycin (2 μM) or Radicicol (20 μM) mitigated (0.45 ± 0.04-fold and 0.93 ± 0.16-fold, respectively) HG induced-IKKβ activity (2.5 ± 0.42-fold). Blocking of IKKβ expression by IKK inhibitor II (15 μM wedelolactone) or small interferring RNA (siRNA) improved Hsp-90-eNOS interaction and NO production under conditions of HG. These results illuminate a possible mechanism for the declining eNOS activity reported under conditions of HG.


2002 ◽  
Vol 23 (5) ◽  
pp. 665-686 ◽  
Author(s):  
Ken L. Chambliss ◽  
Philip W. Shaul

Abstract Over the past decade, clinical and basic research has demonstrated that estrogen has a dramatic impact on the response to vascular injury and the development of atherosclerosis. Further work has indicated that this is at least partially mediated by an enhancement in nitric oxide (NO) production by the endothelial isoform of NO synthase (eNOS) due to increases in both eNOS expression and level of activation. The effects on eNOS abundance are primarily mediated at the level of gene transcription, and they are dependent on estrogen receptors (ERs), which classically serve as transcription factors, but they are independent of estrogen response element action. Estrogen also has potent nongenomic effects on eNOS activity mediated by a subpopulation of ERα localized to caveolae in endothelial cells, where they are coupled to eNOS in a functional signaling module. These observations, which emphasize dependence on cell surface-associated receptors, provide evidence for the existence of a steroid receptor fast-action complex, or SRFC, in caveolae. Estrogen binding to ERα on the SRFC in caveolae leads to Gαi activation, which mediates downstream events. The downstream signaling includes activation of tyrosine kinase-MAPK and Akt/protein kinase B signaling, stimulation of heat shock protein 90 binding to eNOS, and perturbation of the local calcium environment, leading to eNOS phosphorylation and calmodulin-mediated eNOS stimulation. These unique genomic and nongenomic processes are critical to the vasoprotective and atheroprotective characteristics of estrogen. In addition, they serve as excellent paradigms for further elucidation of novel mechanisms of steroid hormone action.


2020 ◽  
Vol 20 ◽  
Author(s):  
L. Hajba ◽  
A. Guttman

: Adeno-associated virus (AAV) is one of the most promising viral gene delivery vectors with long-term gene expression and disease correction featuring high efficiency and excellent safety in human clinical trials. During the production of AAV vectors,there are several quality control (QC)parameters that should be rigorously monitored to comply with clini-cal safety and efficacy. This review gives a short summary of the most frequently used AVV production and purification methods,focusing on the analytical techniques applied to determine the full/empty capsid ratio and the integrity of the encapsidated therapeutic DNA of the products.


Nanomaterials ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 935
Author(s):  
Manas R. Biswal ◽  
Sofia Bhatia

Ocular gene therapy offers significant potential for preventing retinal dystrophy in patients with inherited retinal dystrophies (IRD). Adeno-associated virus (AAV) based gene transfer is the most common and successful gene delivery approach to the eye. These days, many studies are using non-viral nanoparticles (NPs) as an alternative therapeutic option because of their unique properties and biocompatibility. Here, we discuss the potential of carbon dots (CDs), a new type of nanocarrier for gene delivery to the retinal cells. The unique physicochemical properties of CDs (such as optical, electronic, and catalytic) make them suitable for biosensing, imaging, drug, and gene delivery applications. Efficient gene delivery to the retinal cells using CDs depends on various factors, such as photoluminescence, quantum yield, biocompatibility, size, and shape. In this review, we focused on different approaches used to synthesize CDs, classify CDs, various pathways for the intake of gene-loaded carbon nanoparticles inside the cell, and multiple studies that worked on transferring nucleic acid in the eye using CDs.


2004 ◽  
Vol 287 (1) ◽  
pp. H135-H148 ◽  
Author(s):  
Tsuneo Kobayashi ◽  
Takayuki Matsumoto ◽  
Kazuyuki Ooishi ◽  
Katsuo Kamata

The aim of the present study was to compare vascular dysfunction between the early (12 wk old) and later (36 wk old) stages of spontaneous diabetes in Goto-Kakizaki (GK) rats. We also evaluated the aortic expression of the α2D-adrenoceptor and endothelial nitric oxide synthase (eNOS). Vascular reactivity was assessed in thoracic aortas from age-matched control rats and 12- and 36-wk GK rats. Using RT-PCR and immunoblots, we also examined the changes in expression of the α2D-adrenoceptor and eNOS. In aortas from GK rats (vs. those from age-matched control rats): 1) the relaxation response to ACh was enhanced at 12 wk but decreased at 36 wk; 2) the relaxation response to sodium nitroprusside was decreased at both 12 and 36 wk, 3) norepinephrine (NE)-induced contractility was decreased at 12 wk but not at 36 wk, 4) the expressions of α1B- and α1D-adrenoceptors were unaffected, whereas those of α2D-adrenoceptor and eNOS mRNAs were increased at both 12 and 36 wk; and 5) NE- and ACh-stimulated NOx (nitrite and nitrate) levels were increased at 12 wk, although at 36 wk ACh-stimulated NOx was lower, whereas NE-stimulated NOx showed no change. These results clearly demonstrate that enhanced ACh-induced relaxation and impaired NE-induced contraction, due to NO overproduction via eNOS and increased α2D-adrenoceptor expression, occur in early-stage GK rats and that the impaired ACh-induced relaxation in later-stage GK rats is due to reductions in both NO production and NO responsiveness (but not in eNOS expression).


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