Abstract. Rolipram, a phosphodiesterase-4 inhibitor, can activate the cyclic adenosine monophosphate (cAMP)/cAMP-responsive element binding protein (CREB) pathway to facilitate functional recovery following ischemic stroke. However, to date, the effects of rolipram on angiogenesis and cerebral ischemia-induced neuronal apoptosis are yet to be fully elucidated. In this study, the aim was to reveal the effect of rolipram on the angiogenesis and neuronal apoptosis following brain cerebral ischemia. Rat models of ischemic stroke were established following transient middle cerebral artery occlusion and rolipram was administered for three, seven and 14 days. The results were examined using behavioral tests, triphenyl tetrazolium chloride staining, immunostaining and terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) to evaluate the effects of rolipram therapy on functional outcome, angiogenesis and apoptosis. Western blot analysis was used to show the phosphorylated-(p-)CREB protein level in the ischemic hemisphere. The rolipram treatment group exhibited a marked reduction in infarct size and modified neurological severity score compared with the vehicle group, and rolipram treatment significantly promoted the microvessel density in the ischemic boundary region and increased p-CREB protein levels in the ischemic hemisphere. Furthermore, a significant reduction in the number of TUNEL-positive cells was observed in the rolipram group compared with the vehicle group. These findings suggest that rolipram has the ability to attenuate cerebral ischemic injury, stimulate angiogenesis and reduce neuronal apoptosis though the cAMP/CREB pathway.

Hydroxy-safflower yellow A (HSYA) is the major active component of safflower, a traditional Asia herbal medicine well known for its cardiovascular protective activities. The purpose of this study was to investigate the effect of HSYA on TNF-α-induced inflammatory responses in arterial endothelial cells (AECs) and to explore the mechanisms involved. The results showed that HSYA suppressed the up-regulation of ICAM-1 expression in TNF-α-stimulated AECs in a dose-dependent manner. High concentration (120 μM) HSYA significantly inhibited the TNF-α-induced adhesion of RAW264.7 cells to AECs. HSYA blocked the TNFR1-mediated phosphorylation and degradation of IκBα and also prevented the nuclear translocation of NF-κB p65. Moreover, HSYA reduced the cell surface level of TNFR1 and increased the content of sTNFR1 in the culture media. TNF-α processing inhibitor-0 (TAPI-0) prevented the HSYA inhibition of TNFR1-induced IκBα degradation, implying the occurrence of TNFR1 shedding. Furthermore, HSYA induced phosphorylation of TNF-α converting enzyme (TACE) at threonine 735, which is thought to be required for its activation. Conclusively, HSYA suppressed TNF-α-induced inflammatory responses in AECs, at least in part by inhibiting the TNFR1-mediated classical NF-κB pathway. TACE-mediated TNFR1 shedding can be involved in this effect. Our study provides new evidence for the antiinflammatory and anti-atherosclerotic effects of HSYA. Copyright © 2016 John Wiley & Sons, Ltd.

Ginkgolide B exerts a cardioprotective function against ischemia-caused apoptosis in myocardial infarction. Here we sought out to address a functional mechanism associated with microRNA-29 (miR-29). Rat cardiomyocytes (H9c2 cells) were cultured in ginkgolide B-conditioned medium prior to hypoxic induction. To construct miR-29-overexpressed cells, miR-29 mimic was transfected into H9c2 cells. The cells were harvested for assaying survivability and apoptosis by CCK-8 and FITC-Annexin V staining methods. Western blot was applied to identify apoptotic hallmarks and signaling transducers. RT-PCR was carried out for investigating miR-29 expression. Cardiomyocytes were sensitive to hypoxic apoptosis, while ginkgolide B intensified the abilities of cardiomyocytes to resist hypoxia by increasing survivability and repressing apoptosis. Specifically, ginkgolide B repressed Bax and cleaved caspase 3 while enhanced Bcl-2. Ginkgolide B buffered the expression of miR-29 induced by hypoxia. However, ginkgolide B showed a slight role in survivability and apoptosis in the cells overexpressing miR-29. Meanwhile, ginkgolide B triggered the phosphorylation of PI3 K and AKT, as well as induced Sp1, while this beneficial role was abrogated in the cells treated by miR-29 mimic. Our results confirmed that ginkgolide B might have therapeutic significance by repressing hypoxic apoptosis. Ginkgolide B-elicited miR-29 inhibition might be the basis of this beneficial role.

Background Yangxin granules (YXC), a Chinese herbal medicine, have been confirmed to have clinical benefits in the treatment of heart failure. This study examined the effects and molecular mechanisms of YXC in the treatment of doxorubicin-induced cardiotoxicity in vitro. Methods H9c2 cardiomyocytes were pretreated with YXC (5, 10, or 20 mg/mL) or the AKT inhibitor MK-2206 (50 nM) before doxorubicin treatment (1 µM). Cell apoptosis, viability, inflammatory factor expression (TNF-α, IL-1β, and IL-6), and oxidative stress mediator levels including superoxide dismutase, reactive oxygen species, and malondialdehyde were detected. Results YXC increased the viability of H9c2 cells. In addition, doxorubicin inhibited AKT/GSK3β/β-catenin signaling, whereas YXC increased the expression of phosphorylated AKT and GSK3β, and β-catenin in doxorubicin-treated H9c2 cells. Moreover, T-cell factor/lymphoid enhancer factor signaling downstream of β-catenin was also activated by YXC. YXC pretreatment also inhibited doxorubicin-induced inflammation, oxidative stress, and apoptosis. However, MK-2206 reversed the effects of YXC in doxorubicin-treated H9c2 cells. Conclusions YXC alleviates doxorubicin-induced inflammation, oxidative stress, and apoptosis in H9c2 cells. These effects might be mediated by the AKT/GSK3β/β-catenin signaling pathway. YXC might have preventive effects against doxorubicin-induced heart failure.

Astragaloside III (AS-III) is a triterpenoid saponin contained in Astragali Radix and has potent anti-inflammatory effects on vascular endothelial cells; however, underlying mechanisms are unclear. In this study, we provided the first piece of evidence that AS-III induced phosphorylation of TNF-α converting enzyme (TACE) at Thr735 and enhanced its sheddase activity. As a result, AS-III reduced surface TNFR1 level and increased content of sTNFR1 in the culture media, leading to the inhibition of NF-κB signaling pathway and attenuation of downstream cytokine gene expression. Furthermore, AS-III induced TACE-dependent epidermal growth factor receptor (EGFR) transactivation and activation of downstream ERK1/2 and AKT pathways. Finally, AS-III induced activation of p38. Both TACE activation and EGFR transactivation induced by AS-III were significantly inhibited by p38 inhibitor SB203580. Taken together, we concluded that AS-III activates TACE-dependent anti-inflammatory and growth factor signaling in vascular endothelial cells in a p38-dependent fashion, which may contribute to its cardiovascular protective effect. K E Y W O R D SAstragaloside III, epidermal growth factor receptor, p38, TNFR1, TNF-α converting enzyme, vascular endothelial cells