Neuroprotective Effect of Catalpol via Anti-Oxidative, Anti-Inflammatory, and Anti-Apoptotic Mechanisms
FRONTIERS IN PHARMACOLOGY
Authors: Yang, Chunjing; Shi, Zhengyuan; You, Longtai; Du, Yuanyuan; Ni, Jian; Yan, Dan
Abstract
Neuroinflammation and neuro-oxidative damage are now considered to be key factors in the neurological diseases. Therefore, it is important to study anti-inflammatory and neuroprotective agents. The present study investigated the anti-inflammatory and neuroprotective effects of catalpol (CAT), and the potential molecular mechanisms involved. The findings revealed that CAT markedly downregulated pro-inflammatory mediator nitric oxide (NO) and cytokines, including interleukin (IL)-6 and tumor necrosis factor (TNF)-a in lipopolysaccharide (LPS)-treated BV2 microglial cells. Moreover, CAT significantly decreased the levels of intracellular reactive oxygen species (ROS) and malondialdehyde (MDA), increased superoxide dismutase (SOD) activity and glutathione (GSH) level, reversed apoptosis, and restored mitochondrial membrane potential (MMP) in primary cortical neurons stimulated with hydrogen peroxide (H2O2). Furthermore, mechanistic studies showed that CAT inhibited nuclear factor-kappa B (NF-kappa B) pathway and p53-mediated Bcl-2/Bax/casaspe-3 apoptotic pathway. Moreover, it targeted the Kelch-like ECH-associated protein 1(Keap1)/Nuclear factor E2-related factor 2 (Nrf2) pathway. In summary, CAT may exert neuroprotective potential by attenuating microglial-mediated neuroinflammatory response through inhibition of the NF-kappa B signaling pathway. It blocked cortical neuronal oxidative damage by inhibiting p53-mediated Bcl-2/Bax/casaspe-3 apoptosis pathway and regulating Keap1/Nrf2 pathway. These results collectively indicate the potential of CAT as a highly effective therapeutic agent for neuroinflammatory and neuro-oxidative disorders.
Regulation of Canonical Oncogenic Signaling Pathways in Cancer via DNA Methylation
CANCERS
Authors: Lu, Jennifer; Wilfred, Premila; Korbie, Darren; Trau, Matt
Abstract
Simple Summary Aberrant epigenetic modifications in oncogenic pathways can lead to the onset of different cancers. This study aims to explore the role of differential DNA methylation in the regulation of oncogenic signaling pathways by integrating data from multiple sources including methylome, transcriptome and clinical presentation to uncover the effect of methylation changes acting on the four most common cancers. We utilized a differential methylation-parsing pipeline, which extracted differentially methylated biomarkers based on feature selection. Extracted biomarkers were integrated with the matching RNA-Seq and clinical data to determine if these differentially methylated CpGs could serve as potential diagnostic candidates for the four most common cancers. Our results suggested differential methylation of the genes within the NRF2-PI3K pathway may lead to the presentation of various cancer and serve as potential epigenetic biomodifiers. Disruption of signaling pathways that plays a role in the normal development and cellular homeostasis may lead to the dysregulation of cellular signaling and bring about the onset of different diseases, including cancer. In addition to genetic aberrations, DNA methylation also acts as an epigenetic modifier to drive the onset and progression of cancer by mediating the reversible transcription of related genes. Although the role of DNA methylation as an alternative driver of carcinogenesis has been well-established, the global effects of DNA methylation on oncogenic signaling pathways and the presentation of cancer is only emerging. In this article, we introduced a differential methylation parsing pipeline (MethylMine) which mined for epigenetic biomarkers based on feature selection. This pipeline was used to mine for biomarkers, which presented a substantial difference in methylation between the tumor and the matching normal tissue samples. Combined with the Data Integration Analysis for Biomarker discovery (DIABLO) framework for machine learning and multi-omic analysis, we revisited the TCGA DNA methylation and RNA-Seq datasets for breast, colorectal, lung, and prostate cancer, and identified differentially methylated genes within the NRF2-KEAP1/PI3K oncogenic pathway, which regulates the expression of cytoprotective genes, that serve as potential therapeutic targets to treat different cancers.