Pinocembrin Ameliorates Cognitive Impairment Induced by Vascular Dementia: Contribution of Reelin-dab1 Signaling Pathway.

BACKGROUND: As a substrate of apoER2, Reelin has been verified to exert neuroprotection by preventing memory impairment. Pinocembrin is the most abundant natural flavonoid found in propolis, and it has been used to exert neuroprotection, blood-brain barrier protection, anti-oxidation, and inflammation diminishing, both in vitro and in vivo. However, the roles and molecular mechanisms of pinocembrin in neurobehavioral outcomes and neuronal repair after vascular dementia are still under investigation. PURPOSE: To explore the role of pinocembrin in the involvement of the Reelin-dab1 signaling pathway in improving memory impairment, both in cell culture and animals experiments. MATERIAL AND METHODS: Behavioral tests were conducted on day 48 to confirm the protection of pinocembrin against cognitive impairment. Cell and molecular biology experiments demonstrated that the Reelin-dab1 pathway mediates the underlying mechanism of cognitive improvement by pinocembrin. RESULTS: It was showed that pinocembrin alleviated learning and memory deficits induced by vascular dementia, by inducing the expression of Reelin, apoER2, and p-dab1 in the hippocampus. The expression of Reelin and p-dab1 was both inhibited following Reelin RNA interference in SH-SY5Y prior to oxygen glucose deprivation (OGD) injury, suggesting that Reelin played a core role in pinocembrin's effect on OGD in vitro. CONCLUSION: Pinocembrin improves the cognition via the Reelin-dab1 signaling pathway.

Ponatinib attenuates experimental pulmonary arterial hypertension by modulating Wnt signaling and vasohibin-2/vasohibin-1.

AIMS: An abnormal ratio of vasohibin-2/vasohibin-1 may be involved in the abnormal angiogenesis and vascular remodeling during pulmonary arterial hypertension (PAH). MAIN METHODS: To evaluate the pharmacological actions of Ponatinib (AP) in experimental model of PAH, the effects of AP on TGF-ß1-mediated endothelial-mesenchymal transition (EndoMT) in human pulmonary microvascular endothelial cells (HPMEC), and the hypoxic human pulmonary artery smooth muscle cells (HPASMC) proliferation and HPMEC in vitro, and on bleomycin (BLM)-induced PAH in vivo were investigated. KEY FINDINGS: AP treatment resulted in a reduction of EndoMT in HPMECs with a decrease of vimentin, whereas an increase of VE-cadherin, reduction of fibroblast growth factor (FGF-2), vascular endothelial growth factor (VEGF) and vasohibin-2 (VASH-2), whereas an increase of vasohibin-1 (VASH-1) in the hypoxic HPMEC, a reduction of the HPASMC proliferation with decreases of wnt5a, ß-catenin and cyclin D1 expression. AP ameliorated BLM-induced PAH in rats with reductions of FGF-2, VEGF, von Willebrand factor (vWF) and VASH-2 expression, whereas an increase of VASH-1 expression. AP ameliorated BLM-induced PAH in rats with reductions of the pathological score and the collagen deposition. In addition, AP ameliorated hemodynamics and right ventricular hypertrophy. SIGNIFICANCES: Our results identified a therapeutic potential of AP in PAH therapy might be modulated VASH-2/VASH-1 and the Wnt signaling.

Cornin increases angiogenesis and improves functional recovery after stroke via the Ang1/Tie2 axis and the Wnt/ß-catenin pathway.

We investigated whether cornin, an iridoid glycoside isolated from fruits of Verbena officinalis L., regulated angiogenesis and thereby improved functional outcomes after stroke and discovered a potential mechanism. The effects of cornin on proliferation of rat artery smooth muscle cell (RASMC) and signalling was investigated in vitro. Adult male rats were subjected to 1 h of middle cerebral artery occlusion (MCAO) and reperfusion and treated with or without 25 mg/kg of cornin, starting 24 h after ischemia and reperfusion, by continuous intravenous injection daily for 14 days. Neurological functional tests were performed and cerebral Evans blue extravasation was measured. Angiogenesis and angiogenic factor expressions were measured by immunohistochemistry and Western blotting, respectively. Cornin increased the proliferation of RASMC and enhanced the expression of Wnt5a, ß-catenin, cyclin D1 and angiopoietin-1 (Ang1). Cornin treatment promoted angiogenesis in the ischemic brain core and improved functional outcomes after stroke. Cornin-treated MCAO rats showed significant increase in vascularization and expression of vascular endothelial growth factor and Ang1 and phosphorylation of Tie2 and Akt compared with vehicle-treated MCAO rats. The Ang1/Tie2 axis and Wnt/ß-catenin pathways appear to mediate cornin-induced angiogenesis.

Ponatinib ameliorates pulmonary fibrosis by suppressing TGF-ß1/Smad3 pathway.

TGF-ß1/Smad3 pathway plays a key role in the pathogenesis of idiopathic pulmonary fibrosis, including lung fibroblasts proliferation and epithelial cell aberrant activation. Ponatinib is a multi-targeted tyrosine-kinase inhibitor. However, whether Ponatinib has anti-fibrotic functions is unknown. In this study, the effects of Ponatinib on TGF-ß1-mediated epithelial-mesenchymal transition (EMT) in A549 cells, on the proliferation of human lung fibroblasts (HLF-1), on the apoptosis of human type I alveolar epithelial cells (AT I) in vitro, and on bleomycin (BLM)-induced pulmonary fibrosis was investigated in vivo. Treatment with Ponatinib resulted in a reduction of EMT in A549 cells with a decrease in vimentin and p-Smad3, whereas an increase in E-cadherin. Apoptosis of AT I was attenuated with an increase in the Bcl-2/Bax ratio. HLF-1 proliferation was reduced with a decrease in PDGF-BB and FGF-2 expressions. Treatment with Ponatinib resulted in an amelioration of the BLM-induced pulmonary fibrosis in rats with reductions of the pathological score, collagen deposition, p-Smad3, α-SMA, PDGF-BB and FGF-2 expression. In summary, Ponatinib reversed the EMT, inhibited the apoptosis of AT I, as well as HLF-1 proliferation and prevented pulmonary fibrosis by suppressing the TGF-ß1/Smad3 pathway.

Protocatechuic aldehyde ameliorates experimental pulmonary fibrosis by modulating HMGB1/RAGE pathway.

An abnormal high mobility group box 1 (HMGB1) activation and a decrease in receptor for advanced glycation end-product (RAGE) play a key role in the pathogenesis of pulmonary fibrosis. Protocatechuic aldehyde (PA) is a naturally occurring compound, which is extracted from the degradation of phenolic acids. However, whether PA has anti-fibrotic functions is unknown. In this study, the effects of PA on the transforming growth factor-ß1 (TGF-ß1)-mediated epithelial-mesenchymal transition (EMT) in A549 cells, on the apoptosis of human type I alveolar epithelial cells (AT I), on the proliferation of human lung fibroblasts (HLF-1) in vitro, and on bleomycin (BLM)-induced pulmonary fibrosis in vivo were investigated. PA treatment resulted in a reduction of EMT in A549 cells with a decrease in vimentin and HMGB, an increase of E-cadherin and RAGE, a reduction of HLF-1 proliferation with a decrease of fibroblast growth factor 2 (FGF-2) and platelet-derived growth factor (PDGF). Apoptosis of AT I was attenuated with an increase of RAGE. PA ameliorated BLM-induced pulmonary fibrosis in rats with a reduction of histopathological scores and collagen deposition, and a lower FGF-2, PDGF, α-smooth muscle actin (α-SMA) and HMGB1 expression, whereas higher RAGE was found in BLM-instilled lungs. Through the decrease of HGMB1 and the regulation of RAGE, PA reversed the EMT, inhibited HLF-1 proliferation as well as reduced apoptosis in AT I, and prevented pulmonary fibrosis in vivo. Collectively, our results demonstrate that PA prevents experimental pulmonary fibrosis by modulating HMGB1/RAGE pathway.

Astilbin protects diabetic rat heart against ischemia-reperfusion injury via blockade of HMGB1-dependent NF-κB signaling pathway.

Astilbin, a flavonoid compound was isolated from the rhizome of Smilax china L. In this study, we investigated the anti-myocardial ischemia and reperfusion (I/R) injury effect of Astilbin on diabetic rats in vivo and elucidated the potential mechanism in vitro. The results showed that Astilbin significantly attenuated hypoxia-induced cell injury in a concentration-dependent manner. Treatment of H9c2 cells with Astilbin at 15 µM blocked nuclear factor kappaB (NF-κB) phosphorylation by blocking High-mobility group box protein 1 (HMGB1) expression. Treatment of diabetic rats with Astilbin by intravenous injection (i.v.) at a single dose of 50 mg/kg protected the rats from myocardial I/R injury as indicated by decreasing infarct volume, improving hemodynamics and reducing myocardial damage, and also lowered serum levels of pro-inflammatory factors, reduced HMGB1 and phosphorylated NF-κB expression in ischemic myocardial tissue from diabetic rats. Additionally, treatment of diabetic rats with Astilbin at dose of 50 mg/kg by i.v. for continuous 14 days attenuated cardiac remodeling in the model myocardial I/R injury. These protective effects suggested that Astilbin might be due to block of the myocardial inflammatory cascade via the HMGB1-dependent NF-κB signaling pathway.

Protocatechuic acid induces angiogenesis through PI3K-Akt-eNOS-VEGF signalling pathway.

In this study, we sought to elucidate whether protocatechuic acid contributes to induce angiogenesis as well as its mechanisms. To this end, we examined the role of protocatechuic acid on human brain microvascular endothelial cell line (HBMEC) proliferation, invasion and tube formation in in vitro. For the study of mechanisms involved, the phosphoinositide 3 kinase (PI3K)-Akt inhibitor LY294002, the endothelial nitric oxide synthase (eNOS) inhibitor L-NAME, vascular endothelial growth factor (VEGF), antagonist sFlt-1 and VEGF receptor blocker SU-1498 were used. Proliferation of HBMEC was tested by MTT. Scratch adhesion test was used to assess the ability of invasion. A Matrigel tube formation assay was performed to test capillary tube formation ability. PI3K-Akt-eNOS-VEGF pathway activation in HBMEC was tested by Western blot. Our data suggested that protocatechuic acid induces angiogenesis in vitro by increasing proliferation, invasion and tube formation. VEGF expression was increasing by protocatechuic acid and counteracted by VEGF antagonist sFlt-1, LY294002 and L-NAME in HBMEC. Tube formation was increased by protocatechuic acid and counteracted by VEGF receptor blocker-SU1498, LY294002 and L-NAME. These data suggest that protocatechuic acid may be a candidate therapy for stroke recovery by promoting angiogenesis via a programmed PI3K/Akt/eNOS/VEGF signalling axis.

Cornin induces angiogenesis through PI3K-Akt-eNOS-VEGF signaling pathway.

In the present study, we sought to elucidate whether Cornin contributes to induce angiogenesis and its mechanisms. To this end, we examined the role of Cornin on human brain microvascular endothelial cell line (HBMEC) proliferation, invasion, and tube formation in in vitro. For study of mechanism, the phosphoinositide 3 kinase (PI3K)-Akt inhibitor LY294002, endothelial nitric oxide synthase (eNOS) inhibitor L-NAME, vascular endothelial growth factor (VEGF) antagonist sFlt-1 and VEGF receptor blocker SU-1498 were used. HMBEC proliferation was tested by MTT. Scratch adhesion test was used to assess the ability of invasion. A matrigel tube formation assay was performed to test capillary tube formation ability. PI3K-Akt-eNOS-VEGF pathway activation in HMBEC was tested by Western blot. Our data suggested that Cornin induces angiogenesis in vitro by increasing proliferation, invasion and tube formation. VEGF expression was increasing by Cornin and counteracted by VEGF antagonist sFlt-1, LY294002 and L-NAME in HMBEC. Tube formation was increased by Cornin and counteracted by VEGF receptor blocker-SU1498, LY294002 and L-NAME. It may be suggested that Cornin induces angiogenesis in vitro via a programmed PI3K/Akt/eNOS/VEGF signaling axis.

Cardioprotection with 8-O-acetyl shanzhiside methylester on experimental myocardial ischemia injury.

8-O-acetyl shanzhiside methylester (ND01) was isolated from the leaves of Lamiophlomis rotata (Benth.) Kudo. In this study, we investigated the anti-myocardial ischemia and reperfusion (I/R) injury effects of ND01 in vivo and elucidated the potential mechanism in vitro. The results indicated that ND01 significantly attenuated hypoxia-induced cytotoxicity in a concentration-dependent manner in H9c2 cells. Treatment of H9c2 cells with ND01 9 µM blocked TNF-α-induced nuclear factor kappaB (NF-κB) phosphorylation by blocking High-mobility group box1 (HMGB1) expression. Treatment of rats with ND01 10mg/kg, (i.v.) protected the animals from myocardial I/R injury as indicated by a decrease in infarct volume, improvement in hemodynamics and reduction of myocardial damage severity. Treatment with ND01 also lowered serum levels of pro-inflammatory factors and reduced High mobility group box-1 protein (HMGB1) and phosphorylated NF-κB expression in ischemic myocardial tissue. Additionally, continuous i.v. of ND01 14 days attenuated cardiac remodeling. These protective effects suggested that ND01 might be due to block of myocardial inflammatory cascades through an HMGB1-dependent NF-κB signaling pathway.

Effects of L-carnitine against oxidative stress in human hepatocytes: involvement of peroxisome proliferator-activated receptor alpha.

BACKGROUND: Excessive oxidative stress and lipid peroxidation have been demonstrated to play important roles in the production of liver damage. L-carnitine is a natural substance and acts as a carrier for fatty acids across the inner mitochondrial membrane for subsequent beta-oxidation. It is also an antioxidant that reduces metabolic stress in the cells. Recent years L-carnitine has been proposed for treatment of various kinds of disease, including liver injury. This study was conducted to evaluate the protective effect of L-carnitine against hydrogen peroxide (H2O2)-induced cytotoxicity in a normal human hepatocyte cell line, HL7702. METHODS: We analyzed cytotoxicity using MTT assay and lactate dehydrogenase (LDH) release. Antioxidant activity and lipid peroxidation were estimated by reactive oxygen species (ROS) levels, activities and protein expressions of superoxide dismutase (SOD) and catalase (CAT), and malondialdehyde (MDA) formation. Expressions of peroxisome proliferator-activated receptor (PPAR)-alpha and its target genes were evaluated by RT-PCR or western blotting. The role of PPAR-alpha in L-carnitine-enhanced expression of SOD and CAT was also explored. Statistical analysis was performed by a one-way analysis of variance, and its significance was assessed by Dennett's post-hoc test. RESULTS: The results showed that L-carnitine protected HL7702 cells against cytotoxity induced by H2O2. This protection was related to the scavenging of ROS, the promotion of SOD and CAT activity and expression, and the prevention of lipid peroxidation in cultured HL7702 cells. The decreased expressions of PPAR-alpha, carnitine palmitoyl transferase 1 (CPT1) and acyl-CoA oxidase (ACOX) induced by H2O2 can be attenuated by L-carnitine. Besides, we also found that the promotion of SOD and CAT protein expression induced by L-carnitine was blocked by PPAR-alpha inhibitor MK886. CONCLUSIONS: Taken together, our findings suggest that L-carnitine could protect HL7702 cells against oxidative stress through the antioxidative effect and the regulation of PPAR-alpha also play an important part in the protective effect.