Prostaglandin E1 reduces the keratinocyte toxicity of sorafenib by maintaining signal transducer and activator of transcription 3 (STAT3) activity and enhancing the cAMP response element binding protein (CREB) activity

PGE1 triggers Nrf2/HO-1 signal pathway to resist hemin-induced toxicity in mouse cortical neurons

Background

Prostaglandin E1 (PGE1) exerts various pharmacological effects such as membrane stabilization, anti-inflammatory functions, vasodilation, and platelet aggregation inhibition. We have previously demonstrated that PGE1 has a beneficial impact on patients suffering from intracerebral hemorrhage (ICH). The related mechanism underlying PGE1’s beneficial effect on ICH treatment needs further exploration.

Methods

The present study elucidates the mechanism of PGE1 on ICH treatment using a neuronal apoptosis model in vitro. The mouse primary cortical neurons were pretreated with different concentrations of PGE1, followed by the treatment with hemin, the main catabolite in whole blood, to mimic the clinical ICH.

Results

Comparing with the vehicle-treated group, PGE1 prevented cultured cortical neurons from the accumulation of inhibited intracellular levels of reactive oxygen species (ROS), amelioration of mitochondrial membrane potential, and hemin-induced apoptosis. The reduction of ROS and apoptosis were associated with the up-regulation of Heme oxygenase-1 (HO-1) expression. Knockdown of nuclear transcription factor erythroid 2-related factor (Nrf2) by siRNA attenuated the upregulation of HO-1 as well as the protective effect of PGE1.

Conclusions

Our work suggests that the Nrf2/HO-1 molecular pathway may play a crucial role in treating ICH patients with PGE1 and may represent novel molecular targets, resulting in discovering new drugs for ICH treatment.

Multikinase inhibitor sorafenib induces skin toxicities in tumor-bearing mice

OBJECTIVES

To investigate the pathologic changes and pathogenesis of multikinase inhibitor (MKI)-induced skin lesions in an animal model.

METHODS

Tumor-bearing nude mice and BDF1 mice were treated with different doses (30-240 mg/kg, Bid) of sorafenib. The pathology and severity of the skin lesions was assessed and evaluated. The concentration of sorafenib in the skin was also determined.

RESULTS

Sorafenib transiently induced skin rash at high doses (120-240 mg/kg). The induced skin lesions had pathological manifestations resembling the observations in human patients. The skin of mice treated with sorafenib had significantly increased pathological scores and thickness of the stratum spinosum compared with the control, and induced more severe cutaneous lesions in nude mice than in BDF1 mice. The severity of skin lesions was correlated with the local concentration of sorafenib in the skin, which was significantly higher in nude mice than in BDF1 mice. Sorafenib treatment significantly increased the expression of F4-80, Ly6G, tumor growth factor (TGF)-1β, Smad2/3, α-smooth-muscle actin, and proliferating cell nuclear antigen.

CONCLUSIONS

The severity of skin lesions was positively correlated with the concentration of sorafenib in the skin. Our results suggested the involvement of the TGF-β1/Smads signaling pathway in the skin reaction induced by MKIs.