Protective effects of GuanXinNing tablet (GXNT) on diabetic encephalopathy in zucker diabetic obesity (ZDF) rats.

BACKGROUND: Diabetic encephalopathy (DE) is a complication of diabetes that leads to cognitive and behavioral decline. Utilizing safe and effective complementary and alternative medications for its management is a wise choice. Previous studies have shown that GuanXinNing Tablet (GXNT), an oral preparation primarily derived from two Chinese herbs, Salvia miltiorrhiza Bge. and Ligusticum chuanxiong Hort., exerts a beneficial neuroprotective effect. In this study, we explored the protective effects of GXNT on DE in male Zucker diabetic fatty (ZDF) rats induced by a high-fat diet, aiming to ascertain its significance and potential mechanisms. METHODS: ZDF rats were induced to develop type 2 diabetes (T2DM) with DE by a high-fat diet and treated with GXNT for 8 weeks until they were 20 weeks old. Throughout the experiment, the animals' vital parameters, such as body weight, were continuously monitored. Cognitive function was evaluated using the Y maze test. Biochemical kits were employed to analyze blood glucose, lipids, and vascular endothelial-related factors. Cerebrovascular lesions were assessed using magnetic resonance angiography (MRA) imaging. Brain lesions were evaluated using hematoxylin and eosin (H&E) staining and ultrastructure observation. IgG and albumin (ALB) leakage were detected using immunofluorescence. RESULTS: GXNT demonstrated an enhancement in the overall well-being of the animals. It notably improved cognitive and behavioral abilities, as demonstrated by extended retention time in the novel heterogeneous arm during the Y-maze test. GXNT effectively regulated glucose and lipid metabolism, reducing fasting and postprandial blood glucose, glycated hemoglobin (HbA1c), and total cholesterol (TC) levels. Additionally, it exhibited a protective effect on the vascular endothelium by reducing the serum TXB2/PGI2 ratio while elevating NO and PGI2 levels. Moreover, GXNT ameliorated stenosis and occlusion in cerebral vessel branches, increased the number of microvessels and neurons around the hippocampus, and improved microvascular occlusion in the cerebral cortex, along with addressing perivascular cell abnormalities. Immunofluorescence staining showed a decrease in the fluorescence intensity of IgG and ALB in the cerebral cortex. CONCLUSIONS: GXNT demonstrated a highly satisfactory protective effect on DE in ZDF rats. Its mechanism of action could be based on the regulation of glucolipid metabolism and its protective effect on the vascular endothelium.

Corneal Outcomes Following Cataract Surgery Using Ophthalmic Viscosurgical Devices Composed of Chondroitin Sulfate-Hyaluronic Acid: A Systematic Review and Meta-Analysis.

Background: Ophthalmic viscosurgical devices (OVDs) are commonly used during cataract surgery to protect the corneal endothelium. A systematic literature review and meta-analysis were conducted to assess the clinical evidence of OVDs composed of chondroitin sulfate-hyaluronic acid (CS-HA) versus other OVDs in maintaining endothelial cell density (ECD) and corneal thickness (CT). Methods: MEDLINE and EMBASE databases were searched from 2000 to 2020. Randomized controlled trials (RCTs, N ≥ 20 per group) comparing an OVD containing CS-HA (ie, VISCOAT®, DuoVisc® or DisCoVisc®) to any other OVD were included. The identified comparators were limited to the OVDs found in the literature, which included those composed of HA-only or hydroxypropyl methylcellulose (HPMC). Outcomes of focus included changes in ECD (baseline to 3 months) and CT (baseline to 24 hours). Meta-analyses were performed using R software, to assess mean differences (MD) in ECD and CT change between CS-HA OVDs and HA-only or HPMC OVDs. Results: A total of 966 abstracts were screened, and data were extracted from 12 RCTs. Meta-analyses using a random-effects model revealed significantly lower percent (%) decrease in ECD for CS-HA OVDs compared to both HA-only (MD: -4.10%; 95% CI: -5.81 to -2.40; p < 0.0001; 9 studies) and HPMC (MD: -6.47%; 95% CI: -10.41 to -2.52; p = 0.001; 2 studies) products. Similarly, % CT increase was significantly lower with CS-HA than with HA-only OVDs (MD: -3.22%; 95% CI: -6.24% to -0.20%; p = 0.04; 4 studies). However, there were no significant differences when comparing % CT change between CS-HA and HPMC OVDs (MD: 2.65%; 95% CI: -0.43% to 0.95%; p = 0.4; 2 studies). Conclusion: CS-HA OVDs lead to less postoperative loss of endothelial cells and may better protect corneal endothelium during cataract surgery, relative to other OVDs. Future randomized studies may be needed to solidify these findings.

Endothelial protection in lung grafts through heparanase inhibition during ex vivo lung perfusion in rats.

BACKGROUND: We hypothesized that enhancing glycocalyx preservation would reduce endothelial damage in lung grafts during ex-vivo lung perfusion (EVLP) leading to better transplant outcomes. In this study, we characterized the effects of inhibiting heparanase (HPSE), an enzyme responsible for glycocalyx shedding, on lung quality during EVLP. METHODS: Human clinical EVLP perfusate from lung graft patients was utilized to identify a potential association between glycocalyx integrity in grafted lung tissue and clinical data. In addition, we performed pre-clinical studies in which rat lungs underwent normothermic EVLP for 4 hours with/without HPSE inhibitors, heparin (1,000-U/h) or heparastatin (SF4; 1-µM), added to the perfusate. After 4-hours EVLP, left lungs were transplanted into syngeneic rats then evaluated for graft quality 2-hours after reperfusion. RESULTS: Clinically, increased degradation of syndecan-1 was identified in dysfunctional grafts during EVLP. Levels of heparan sulfate in perfusate after EVLP were associated with incidence of graft dysfunction after transplantation. In the pre-clinical rat study, SF4 effectively inhibited HPSE activity, and significantly attenuated dissociated glycocalyx levels, endothelial dysfunction, edema, and inflammation in lungs during EVLP compared to both controls and heparin groups. High-doses of heparin demonstrated markedly increased perfusate syndecan-1 concentrations and deteriorated lung quality during EVLP compared with controls. Post-transplant graft function and inflammation were significantly improved in SF4-treated group compared to those in both control and heparin-treated groups. CONCLUSIONS: This study demonstrated that HPSE activity inhibition by SF4 can improve graft preservation during EVLP by protecting the glycocalyx and endothelial function, leading to better lung function following transplantation.

Statin-based endothelial prophylaxis and outcome after allogeneic stem cell transplantation.

BACKGROUND: Allogeneic haematopoietic stem cell transplantation (alloSCT) often remains the only curative therapy for hematologic malignancies. Although the management of transplant-associated adverse events considerably improved over the last decades, nonrelapse mortality (NRM) remains a challenge, and endothelial dysfunction was identified as a major contributor to NRM. METHODS: Statin-based endothelial prophylaxis (SEP) has been implemented in the standard of care in our transplant centre to reduce NRM caused by endothelial injury. Here, we retrospectively analysed the impact of SEP on clinical outcome in a cohort of 347 alloSCT patients. RESULTS: SEP (n = 209) was associated with significantly reduced NRM (hazard ratio 0.61, 95% CI 0.38-0.96) and better overall survival (OS) after acute graft-versus-host disease (HR 0.59, 95% CI 0.37-0.93). Subgroup analyses showed that the NRM benefit was mainly found in patients with an intermediate endothelial activation and stress index (EASIX), while relapse risk was not affected. On day 100 post-alloSCT, patients receiving SEP had significantly higher levels of the rate-limiting enzyme of tryptophan metabolism, indoleamine 2,3-dioxygenase (IDO), higher kynurenine to tryptophan ratios as a proxy of IDO activity and tended to have lower levels of the endothelial injury marker ST2 (p = .055). No significant differences in interferon-gamma or IL18 levels were observed. These biomarker signatures suggest that the beneficial effects of SEP might be mediated by both endothelial protection and immunomodulation. CONCLUSIONS: Together, these data suggest that SEP improves NRM and OS post-alloSCT in particular in patients with intermediate endothelial risk and provide first mechanistic clues about its potential mode of action.

Oroxylin-A and its phosphonate derivative potentiate eNOS/NO-mediated relaxation and attenuate vasoconstrictor-induced contraction in the mouse aorta.

Oroxylin-A (OroA), a flavonoid isolated from Scutellariae baicalensis, alleviates cardiovascular dysfunction. Several procedures for synthesizing OroA have been developed but show low production yield and regioselectivity. We synthesized OroA from baicalin using a one-pot reaction to increase its overall yield. We also determined the chemical properties and mechanism of action of the synthesized OroA and OroA phosphate diethyl ester (OroA-OET) in vascular function. The induction of vascular reactivity by OroA and OroA-OET was evaluated using blood vessel myography and biochemical analysis to assess nitric oxide synthase-mediated nitric oxide production in mouse aortic arteries. OroA and OroA-OET (0.1-30 µM) induced sustained vasorelaxation, which was partly mediated by the endothelium in isolated normal arteries pre-contracted with phenylephrine. OroA and OroA-OET significantly attenuated vasoconstrictors-induced contractile responses. Dilation effects were blocked by the non-selective nitric oxide synthase inhibitor N (omega)-nitro-l-arginine methyl ester but not by tetraethylammonium or 1H-(1,2,4)oxadiazolo [4,3-a]quinoxalin-1-one. Notably, preincubation with OroA and OroA-OET potentiated acetylcholine-induced relaxation and endothelial nitric oxide production in the arteries with the endothelium. OroA and OroA-OET protected against cardiovascular dysfunction. The synthesis and lead compounds used not only improved the yield of OroA from natural sources but also potentially regulated vascular tone.

Synergistic protection of quercetin and lycopene against oxidative stress via SIRT1-Nox4-ROS axis in HUVEC cells.

Oxidative stress is a potential factor in the promotion of endothelial dysfunction. In this research, flavonoids (quercetin, luteolin) combined with carotenoids (lycopene, lutein), especially quercetin-lycopene combination (molar ratio 5:1), prevented the oxidative stress in HUVEC cells by reducing the reactive oxygen species (ROS) and suppressing the expression of NADPH oxidase 4 (Nox4), a major source of ROS production. RNA-seq analysis indicated quercetin-lycopene combination downregulated inflammatory genes induced by H2O2, such as IL-17 and NF-κB. The expression of NF-κB p65 was activated by H2O2 but inhibited by the quercetin-lycopene combination. Moreover, the quercetin and lycopene combination promoted the thermostability of Sirtuin 1 (SIRT1) and activated SIRT1 deacetyl activity. SIRT1 inhibitor EX-527 attenuated the inhibitory effects of quercetin, lycopene, and their combination on the expression of p65, Nox4 enzyme, and ROS. Quercetin-lycopene combination could interact with SIRT1 to inhibit Nox4 and prevent endothelial oxidative stress, potentially contributing to the prevention of cardiovascular disease.

Is the Endothelium the Missing Link in the Pathophysiology and Treatment of COVID-19 Complications?

Patients with COVID-19 present a wide spectrum of disease severity, from asymptomatic cases in the majority to serious disease leading to critical care and even death. Clinically, four different scenarios occur within the typical disease timeline: first, an incubation and asymptomatic period; second, a stage with mild symptoms due mainly to the virus itself; third, in up to 20% of the patients, a stage with severe symptoms where a hyperinflammatory response with a cytokine storm driven by host immunity induces acute respiratory distress syndrome; and finally, a post-acute sequelae (PASC) phase, which present symptoms that can range from mild or annoying to actually quite incapacitating. Although the most common manifestation is acute respiratory failure of the lungs, other organs are also frequently involved. The clinical manifestations of the COVID-19 infection support a key role for endothelial dysfunction in the pathobiology of this condition. The virus enters into the organism via its interaction with angiotensin-converting enzyme 2-receptor that is present prominently in the alveoli, but also in endothelial cells, which can be directly infected by the virus. Cytokine release syndrome can also drive endothelial damage independently. Consequently, a distinctive feature of SARS-CoV-2 infection is vascular harm, with severe endothelial injury, widespread thrombosis, microangiopathy, and neo-angiogenesis in response to endothelial damage. Therefore, endothelial dysfunction seems to be the pathophysiological substrate for severe COVID-19 complications. Biomarkers of endothelial injury could constitute strong indicators of disease progression and severity. In addition, the endothelium could represent a very attractive target to both prevent and treat these complications. To establish an adequate therapy, the underlying pathophysiology and corresponding clinical stage should be clearly identified. In this review, the clinical features of COVID-19, the central role of the endothelium in COVID-19 and in other pathologies, and the potential of specific therapies aimed at protecting the endothelium in COVID-19 patients are addressed.

Ischemia-Reperfusion Injury in Lung Transplantation.

Lung transplantation has been established worldwide as the last treatment for end-stage respiratory failure. However, ischemia-reperfusion injury (IRI) inevitably occurs after lung transplantation. The most severe form of IRI leads to primary graft failure, which is an important cause of morbidity and mortality after lung transplantation. IRI may also induce rejection, which is the main cause of mortality in recipients. Despite advances in donor management and graft preservation, most donor grafts are still unsuitable for transplantation. Although the pulmonary endothelium is the primary target site of IRI, the pathophysiology of lung IRI remains incompletely understood. It is essential to understand the mechanism of pulmonary IRI to improve the outcomes of lung transplantation. Therefore, we reviewed the state-of-the-art in the management of pulmonary IRI after lung transplantation. Recently, the ex vivo lung perfusion (EVLP) system has been clinically introduced worldwide. Various promising therapeutic strategies for the protection of the endothelium against IRI, including EVLP, inhalation therapy with therapeutic gases and substances, fibrinolytic treatment, and mesenchymal stromal cell therapy, are awaiting clinical application. We herein review the latest advances in the field of pulmonary IRI in lung transplantation.

PRE-084 as a tool to uncover potential therapeutic applications for selective sigma-1 receptor activation.

The discovery of a highly selective putative sigma-1 (σ1) receptor agonist, PRE-084, has revealed the numerous potential uses of this receptor subtype as a therapeutic target. While much work has been devoted to determining the role of σ1 receptors in normal and pathophysiological states in the nervous system, recent work suggests that σ1 receptors may be important for modulating functions of other tissues. These discoveries have provided novel insights into σ1 receptor structure, function, and importance in multiple intracellular signaling mechanisms. These discoveries were made possible by σ1 receptor-selective agonists such as PRE-084. The chemical properties and pharmacological actions of PRE-084 will be reviewed here, along with the expanding list of potential therapeutic applications for selective activation of σ1 receptors.

Carnosol as a Nrf2 Activator Improves Endothelial Barrier Function Through Antioxidative Mechanisms.

Oxidative stress is the main pathogenesis of diabetic microangiopathy, which can cause microvascular endothelial cell damage and destroy vascular barrier. In this study, it is found that carnosol protects human microvascular endothelial cells (HMVEC) through antioxidative mechanisms. First, we measured the antioxidant activity of carnosol. We showed that carnosol pretreatment suppressed tert-butyl hydroperoxide (t-BHP)-induced cell viability, affected the production of lactate dehydrogenase (LDH) as well as reactive oxygen species (ROS), and increased the produce of nitric oxide (NO). Additionally, carnosol promotes the protein expression of vascular endothelial cadherin (VE-cadherin) to keep the integrity of intercellular junctions, which indicated that it protected microvascular barrier in oxidative stress. Meanwhile, we investigated that carnosol can interrupt Nrf2-Keap1 protein-protein interaction and stimulated antioxidant-responsive element (ARE)-driven luciferase activity in vitro. Mechanistically, we showed that carnosol promotes the expression of heme oxygenase 1(HO-1) and nuclear factor-erythroid 2 related factor 2(Nrf2). It can also promote the expression of endothelial nitric oxide synthase (eNOS). Collectively, our data support the notion that carnosol is a protective agent in HMVECs and has the potential for therapeutic use in the treatments of microvascular endothelial cell injury.

Total flavonoids from Astragalus alleviate endothelial dysfunction by activating the Akt/eNOS pathway.

Objective To investigate the vasodilative and endothelial-protective effects and the underlying mechanisms of total flavonoids from Astragalus (TFA). Methods The vasodilative activities of TFA were measured with a myograph ex vivo using rat superior mesenteric arterial rings. The primary human umbilical vein endothelial cell (HUVEC) viabilities were assayed using the cell counting kit-8 after hypoxia or normoxia treatment with or without TFA. Akt, P-Akt, eNOS, P-eNOS, Erk, P-Erk, Bcl-2 and Bax expression were analyzed using western blotting. Results TFA showed concentration-dependent vasodilative effects on rat superior mesenteric arterial rings, but had no effects on normal or potassium chloride precontracted arterial rings. TFA did not affect HUVEC viabilities in normoxia, but dramatically promoted cell proliferation in the concentration range of 1 to 30 µg/mL under hypoxia. Moreover, TFA significantly increased the ratios of P-Akt/Akt and P-eNOS/eNOS in vascular endothelial cells under hypoxic conditions, but did not change the P-Erk/Erk or Bcl-2/Bax ratios. Conclusions TFA might exhibit vasorelaxant and endothelial-protective effects via the Akt/eNOS signaling pathway.

DPPH-HPLC-MS assisted rapid identification of endothelial protective substances from Xiao-Ke-An.

ETHNOPHARMACOLOGICAL RELEVANCE: Xiao-Ke-An formula (XKA) is a Chinese medicine widely used for treating diabetes and associated complications. Endothelial protection is thought to be one of its therapeutic mechanisms. However, the protective effect of XKA on endothelial cells remains unclear, especially in oxidative injury induced endothelial dysfunction. MATERIALS AND METHODS: A novel strategy to rapidly screen and identify potential endothelial protective substances from XKA was established by combining the 2,2'-diphenyl-1-picrylhydrazyl high performance liquid chromatography coupled with mass spectrometry (DPPH-HPLC-MS) approach with cell-based verification. Firstly, the DPPH-HPLC-MS approach was employed to identify the antioxidants in XKA. Then, the potent endothelial protective effect of XKA, and the potential active substances and mechanism of action were revealed in EA.hy926 cells injured by tert-butyl hydroperoxide (t-BHP). RESULTS: XKA exhibited potent antioxidant activity and endothelial protective effect. Phenolic acids derived from Salvia miltiorrhiza Bunge, root and rhizome, xanthones from Anemarrhena asphodeloides Bunge, rhizome, and acteoside from Rehmannia glutinosa (Gaertn.) DC., root, were identified as the major endothelial protective components in XKA. CONCLUSIONS: An efficient method for rapid identifying endothelial protective substances from complex mixtures was developed and used to identify the major endothelial protective components in XKA. This method would help reveal the material base of herbal medicine with endothelial protective effect, and could also be applied to discover novel natural-origin endothelial protective substances.

Vascular protective effects of aqueous extracts of Tribulus terrestris on hypertensive endothelial injury.

Angiotensin II (Ang II) is involved in endothelium injury during the development of hypertension. Tribulus terrestris (TT) is used to treat hypertension, arteriosclerosis, and post-stroke syndrome in China. The present study aimed to determine the effects of aqueous TT extracts on endothelial injury in spontaneously hypertensive rats (SHRs) and its protective effects against Ang II-induced injury in human umbilical vein endothelial cells (HUVECs). SHRs were administered intragastrically with TT (17.2 or 8.6 g·kg-1·d-1) for 6 weeks, using valsartan (13.5 mg·kg-1·d-1) as positive control. Blood pressure, heart rate, endothelial morphology of the thoracic aorta, serum levels of Ang II, endothelin-1 (ET-1), superoxide dismutase (SOD) and malonaldehyde (MDA) were measured. The endothelial injury of HUVECs was induced by 2 × 10-6 mol·L-1 Ang II. Cell Apoptosisapoptosis, intracellular reactive oxygen species (ROS) was assessed. Endothelial nitric oxide synthase (eNOS), ET-1, SOD, and MDA in the cell culture supernatant and cell migration were assayed. The expression of hypertension-linked genes and proteins were analyzed. TT decreased systolic pressure, diastolic pressure, mean arterial pressure and heart rate, improved endothelial integrity of thoracic aorta, and decreased serum leptin, Ang II, ET-1, NPY, and Hcy, while increased NO in SHRs. TT suppressed Ang II-induced HUVEC proliferation and apoptosis and prolonged the survival, and increased cell migration. TT regulated the ROS, and decreased mRNA expression of Akt1, JAK2, PI3Kα, Erk2, FAK, and NF-κB p65 and protein expression of Erk2, FAK, and NF-κB p65. In conclusion, TT demonstrated anti-hypertensive and endothelial protective effects by regulating Erk2, FAK and NF-κB p65.

Vascular protective effects of aqueous extracts of Tribulus terrestris on hypertensive endothelial injury / 中国天然药物

Angiotensin II (Ang II) is involved in endothelium injury during the development of hypertension. Tribulus terrestris (TT) is used to treat hypertension, arteriosclerosis, and post-stroke syndrome in China. The present study aimed to determine the effects of aqueous TT extracts on endothelial injury in spontaneously hypertensive rats (SHRs) and its protective effects against Ang II-induced injury in human umbilical vein endothelial cells (HUVECs). SHRs were administered intragastrically with TT (17.2 or 8.6 g·kg·d) for 6 weeks, using valsartan (13.5 mg·kg·d) as positive control. Blood pressure, heart rate, endothelial morphology of the thoracic aorta, serum levels of Ang II, endothelin-1 (ET-1), superoxide dismutase (SOD) and malonaldehyde (MDA) were measured. The endothelial injury of HUVECs was induced by 2 × 10 mol·L Ang II. Cell Apoptosisapoptosis, intracellular reactive oxygen species (ROS) was assessed. Endothelial nitric oxide synthase (eNOS), ET-1, SOD, and MDA in the cell culture supernatant and cell migration were assayed. The expression of hypertension-linked genes and proteins were analyzed. TT decreased systolic pressure, diastolic pressure, mean arterial pressure and heart rate, improved endothelial integrity of thoracic aorta, and decreased serum leptin, Ang II, ET-1, NPY, and Hcy, while increased NO in SHRs. TT suppressed Ang II-induced HUVEC proliferation and apoptosis and prolonged the survival, and increased cell migration. TT regulated the ROS, and decreased mRNA expression of Akt1, JAK2, PI3Kα, Erk2, FAK, and NF-κB p65 and protein expression of Erk2, FAK, and NF-κB p65. In conclusion, TT demonstrated anti-hypertensive and endothelial protective effects by regulating Erk2, FAK and NF-κB p65.

Ischemia reperfusion-facilitated sinusoidal endothelial cell injury in liver transplantation and the resulting impact of extravasated platelet aggregation.

BACKGROUND: The exact sequence of events leading to ultimate hepatocellular damage following ischemia/reperfusion (I/R) is incompletely understood. In this article, we review a mechanism of organ dysfunction after hepatic I/R or immunosuppressive treatment, in addition to the potential of liver sinusoidal endothelial cell (LSEC) protection and antiplatelet treatment for the suppression of hepatocellular damage. METHODS: A review of the literature, utilizing PubMed-NCBI, was used to provide information on the components necessary for the development of hepatocellular damage following I/R. RESULTS: It is well-established that LSECs damage following hepatic I/R or immunosuppressive treatment followed by extravasated platelet aggregation (EPA) is the root cause of organ dysfunction in liver transplantation. We have classified three phases, from LSECs damage to organ dysfunction, utilizing the predicted pathogenic mechanism of sinusoidal obstruction syndrome. The first phase is detachment of LSECs and sinusoidal wall destruction after LSECs injury by hepatic I/R or immunosuppressive treatment. The second phase is EPA, accomplished by sinusoidal wall destruction. The various growth factors, including thromboxane A2, serotonin, transforming growth factor-beta and plasminogen activator inhibitor-1, released by EPA in the Disse's space of zone three, induce portal hypertension and the progression of hepatic fibrosis. The third phase is organ dysfunction following portal hypertension, hepatic fibrosis, and suppressed liver regeneration through various growth factors secreted by EPA. CONCLUSION: We suggest that EPA in the space of Disse, initiated by LSECs damage due to hepatic I/R or immunosuppressive treatment, and activated platelets may primarily contribute to liver damage in liver transplantation. Endothelial protective therapy or antiplatelet treatment may be useful in the treatment of hepatic I/R following EPA.

Identification of schisandrin as a vascular endothelium protective component in YiQiFuMai Powder Injection using HUVECs binding and HPLC-DAD-Q-TOF-MS/MS analysis.

YiQiFuMai Powder Injection (YQFM) is a re-developed preparation based on the well-known traditional Chinese medicine formula Sheng-mai-san. It has been widely used for the treatment of cardiovascular disease with definite clinical efficacy in China, but its bioactive molecules remain obscure. In this study, an effective method has been employed as a tool for screening active components in YQFM, using human umbilical vein endothelial cells (HUVECs) extraction and liquid chromatography coupled with electrospray ionization quadrupole time-of-flight tandem mass spectrometry (Q-TOF MS/MS). Nine compounds, which could interact with HUVECs, were identified as ginsenosides Rb1, Rc, Rb2, Rd, 20(S)-Rg3, 20(R)-Rg3, Rk1/Rg5 and schisandrin by comparing with reference substances or literature. In vitro assays showed that schisandrin at concentrations of 10-100 µM protected HUVECs from hypoxia/reoxygenation (H/R) injury, increased cell viability, nitric oxide (NO) content and decreased lactate dehydrogenase (LDH) leakage, malonaldehyde (MDA) content and ROS generation. Moreover, schisandrin pretreatment inhibited cell apoptosis, as evidenced by inhibiting activation of caspase-3 and increasing the Bcl-2/Bax ratio. These data indicate that HUVECs biospecific extraction coupled with HPLC-ESI-Q-TOF-MS/MS analysis is a reliable method for screening potential bioactive components from traditional Chinese medicines. Meanwhile, the vascular endothelium protective property of schisandrin might be beneficial for the treatment of cardiovascular disease.

Endothelial protective genes induced by statin are mimicked by ERK5 activation as triggered by a drug combination of FTI-277 and GGTI-298.

BACKGROUND: Statins are potent inhibitors of cholesterol biosynthesis and are clinically beneficial in preventing cardiovascular diseases, however, the therapeutic utility of these drugs is limited by myotoxicity. Here, we explored the mechanism of statin-mediated activation of ERK5 in the human endothelium with the goal of identifying compounds that confer endothelial protection but are nontoxic to muscle. METHODS: An ERK5-one hybrid luciferase reporter transfected into COS-7 cells with pharmacological and molecular manipulations dissected the signaling pathway leading to statin activation of ERK5. qRT-PCR of HUVEC cells documented the transcriptional activation of endothelial-protective genes. Lastly, morphological and cellular ATP analysis, and induction of atrogin-1 in C2C12 myotubes were used to assess statin-induced myopathy. RESULTS: Statin activation of ERK5 is dependent on the cellular reduction of GGPPs. Furthermore, we found that the combination of FTI-277 (inhibitor of farnesyl transferase) and GGTI-298 (inhibitor of geranylgeranyl transferase I) mimicked the statin-mediated activation of ERK5. FTI-277 and GGTI-298 together recapitulated the beneficial effects of statins by transcriptionally upregulating anti-inflammatory mediators such as eNOS, THBD, and KLF2. Finally, C2C12 skeletal myotubes treated with both FTI-277 and GGTI-298 evoked less morphological and cellular changes recognized as biomarkers of statin-associated myopathy. CONCLUSIONS: Statin-induced endothelial protection and myopathy are mediated by distinct metabolic intermediates and co-inhibition of farnesyl transferase and geranylgeranyl transferase I confer endothelial protection without myopathy. GENERAL SIGNIFICANCE: The combinatorial FTI-277 and GGTI-298 drug regimen provides a promising alternative avenue for endothelial protection without myopathy.

Ecto-F1-ATPase/P2Y pathways in metabolic and vascular functions of high density lipoproteins.

The atheroprotective property of High Density Lipoprotein (HDL) is supported by many epidemiological studies and cellular and in vivo approaches on animal models. While the anti-atherogenic effects of HDL are thought to derive primarily from its role in reverse cholesterol transport, together with anti-inflammatory, anti-oxidant, anti-thrombotic and cytoprotective properties, the mechanisms that support these effects are still not completely understood. However, many advances in identifying the cellular partners involved in HDL functions have been made over the last two decades. This review highlights the diverse roles of the HDL receptor ecto-F1-ATPase coupled to purinergic P2Y receptors in the modulation of important metabolic and vascular functions of HDL. On hepatocytes, the ecto-F1-ATPase is coupled to P2Y13 receptor and contributes to HDL holoparticle endocytosis. On endothelial cells, ecto-F1-ATPase/P2Ys pathway is involved in HDL-mediated endothelial protection and HDL transcytosis. The clinical relevance of this F1-ATPase/P2Ys axis in humans has recently been supported by the identification of serum F1-ATPase inhibitor (IF1) as an independent determinant of HDL-Cholesterol (HDL-C) and coronary heart disease risk. Therapeutic strategies targeting F1-ATPase/P2Y pathways for the treatment of atherosclerosis are currently being explored.

Corneal Endothelial Protection of Ascorbic Acid against Free Radicals during Phacoemulsification

PURPOSE: To evaluate corneal endothelial protection effect of ascorbic acid (AA) at the most appropriate concentration, and determine the synergistic effect of glutathione in irrigation solution during phacoemulsification. METHODS: Phacoemulsification was performed in the anterior chamber of 30 rabbit eyes for 5 minutes without damage to other ocular structures. Thirty rabbit eyes were divided into 6 groups, of 5 eyes each, according to the following irrigation solutions in phacoemulsification.: BSS(R) in group 1, BSS(R) with 1 mM AA in group 2, BSS Plus(R) in group 3, BSS Plus(R) with 0.1 mM AA in group 4, BSS Plus(R) with 1 mM AA in group 5 and BSS Plus(R) with 10 mM AA in group 6. Corneal endothelial loss was measured with specular microscopic photographies taken before and 1 week after surgery. RESULTS: Postoperatively endothelial counts were reduced by 592.0 +/- 100.0, 275.9 +/- 51.9, 658.2 +/- 107.1, 466.3 +/- 88.6, 259.3 +/- 61.6 and 451.6 +/- 63.7 (mean cells/mm2 +/- SD) in groups 1-6, respectively. Endothelial cells in group 2 were less reduced than in group 1 (P=0.009), but there was no difference between groups 2 and 5. Though the reduction of endothelial cells in groups 4, 5, and 6 were less than in group 3 (P<0.05), group 5 showed more significant endothelial protection effect than groups 4 and 6 (P=0.009, 0.009). CONCLUSIONS: AA in irrigation solution showed endothelial protection effect against free radicals during phacoemulsification, and 1 mM was the most effective concentration. Combination of glutathione with AA did not show any synergistic endothelial protection effect.