Adenoviral vector expressing IGF-1 protects murine chondrogenic ATDC5 cells against hydrogen peroxide-induced mitochondrial dysfunction and apoptosis

Induction of Apoptosis, Inhibition of MCL-1, and VEGF-A Expression Are Associated with the Anti-Cancer Efficacy of Magnolol Combined with Regorafenib in Hepatocellular Carcinoma

While regorafenib was approved for the treatment of advanced HCC in 2017, with a partial response and survival benefit; other combination agents to facilitate the efficacy of regorafenib still need to be explored. Magnolol is a potential natural anti-tumor compound for many types of cancers. Combination indexes calculated on the basis of both in vitro and in vivo models have indicated a synergistic effect of the combination of regorafenib and magnolol. The overexpression of the VEGF-A protein significantly diminished regorafenib's inhibition of cell viability, while the transient knockdown of VEGF-A by siRNA effectively sensitized HCC cells to regorafenib. In addition, the inhibition of MCL-1 by siRNA combined with regorafenib allowed for a significantly greater inhibition of cell growth, compared to regorafenib alone. A lower protein expression level for VEGF-A and MCL-1 was found for the combination treatment of HCC in vitro and in vivo. A superior metastasis inhibition was also found in the combination group, as compared to the single-treatment groups, using a transwell assay, wound healing assay, and Western blotting. The caspase-dependent and -independent and DNA damage effects, as determined by flow cytometry and a comet assay, were increased by the combination therapy. Taken together, magnolol sensitized HCC to regorafenib, which was correlated with the reduction of VEGF-A and MCL-1 and the induction of apoptosis.

Diosbulbin B-Induced Mitochondria-Dependent Apoptosis in L-02 Hepatocytes is Regulated by Reactive Oxygen Species-Mediated Autophagy

Aim: Diosbulbin B (DB) is a major diterpenoid compound found in Dioscorea bulbifera L, a traditional medicinal herb in China. Clinical reports have confirmed that Dioscorea bulbifera L. can induce significant hepatotoxicity. In this study, we showed that DB can induce mitochondria-dependent apoptosis and investigated the role of autophagy in DB-induced hepatotoxicity in L-02 hepatocytes.

Methods: L-02 hepatocytes were treated with different concentrations of DB for 48 h, after which indicators of autophagy and apoptosis were measured. 3-Methyladenine (3-MA) and rapamycin (Rapa) were used as inhibitor and agonist of autophagy, respectively. Furthermore, the reactive oxygen species (ROS) scavenger N-acetyl-l-cysteine (NAC) was used in combination with DB to evaluate the relationship between ROS and autophagy.

Results: L-02 cell viability was significantly decreased after treatment with DB for 48 h. Additionally, DB induced concentration-dependent apoptosis and autophagy and increased the activities of caspase-3, caspase-9, alanine aminotransferase (ALT), and aspartate transaminase (AST), and induced excessive leakage of lactate dehydrogenase (LDH). Inhibition of autophagy by 3-MA increased DB-induced apoptosis, resulting in aggravation of hepatotoxicity. Conversely, treatment with Rapa increased malondialdehyde (MDA) content and reduced superoxide dismutase (SOD) activity. Moreover, we found that DB treatment increased the level of intracellular ROS, decreased the mitochondrial membrane potential (MMP) and adenosine triphosphate (ATP) production, and caused abnormal opening of the mitochondrial permeability transition pore (mPTP), which were finally restored by the ROS scavenger NAC.

Conclusions: Accumulation of ROS can induce mitochondria-dependent apoptosis and likely to play a key role in DB-induced hepatocellular injury. Activation of autophagy may inhibit apoptosis, but also reduces antioxidant capacity.

Proteomic analysis of ginsenoside Re attenuates hydrogen peroxide-induced oxidative stress in human umbilical vein endothelial cells

Ginsenoside Re is an active component in ginseng that has attracted much attention because of its evident therapeutic effects on the cardiovascular system. However, little basic information is available on the mechanisms and pharmacological effects of ginsenoside Re. The potential mechanisms and protective effects of Re on H2O2-induced oxidative injury in human umbilical vein endothelial cells (HUVECs) were investigated in this study. An oxidative injury model was established using H2O2. The anti-oxidative effects of Re were determined using a series of experiments, such as MTT and anti-oxidative indicator assays. The potential protective mechanisms of Re were explored at the proteomic level, and differentially expressed proteins were validated by quantitative real-time polymerase chain reaction and western blotting. Results indicated that Re could be a potential anti-oxidant to protect HUVECs against oxidative stress damage. Proteomic analysis showed that the expression of 23 protein spots was upregulated in Re and H2O2 groups to resist oxidative stress, 15 of which were identified by their mass spectrum. These upregulated proteins were involved in stress response, anti-oxidative systems, protein synthesis, regulation of transcription and post-translational modifications, and repair of mitochondrial functions. This study may provide new insights into the mechanisms of ginsenoside Re in protecting the cardiovascular system.