Ergosterol promotes neurite outgrowth, inhibits amyloid-beta synthesis, and extends longevity: In vitro neuroblastoma and in vivo Caenorhabditis elegans evidence.

AIMS: Alzheimer's disease (AD), the most common neurodegenerative disorder associated with aging, is characterized by amyloid-ß (Aß) plaques in the hippocampus. Ergosterol, a mushroom sterol, exhibits neuroprotective activities; however, the underlying mechanisms of ergosterol in promoting neurite outgrowth and preventing Aß-associated aging have never been investigated. We aim to determine the beneficial activities of ergosterol in neuronal cells and Caenorhabditis elegans (C. elegans). MATERIALS AND METHODS: The neuritogenesis and molecular mechanisms of ergosterol were investigated in wild-type and Aß precursor protein (APP)-overexpressing Neuro2a cells. The anti-amyloidosis properties of ergosterol were determined by evaluating in vitro Aß production and the potential inhibition of Aß-producing enzymes. Additionally, AD-associated transgenic C. elegans was utilized to investigate the in vivo attenuating effects of ergosterol. KEY FINDINGS: Ergosterol promoted neurite outgrowth in Neuro2a cells through the upregulation of the transmembrane protein Teneurin-4 (Ten-4) mRNA and protein expressions, phosphorylation of the extracellular signal-regulated kinases (ERKs), activity of cAMP response element (CRE), and growth-associated protein-43 (GAP-43). Furthermore, ergosterol enhanced neurite outgrowth in transgenic Neuro2A cells overexpressing either the wild-type APP (Neuro2a-APPwt) or the Swedish mutant APP (Neuro2a-APPswe) through the Ten-4/ERK/CREB/GAP-43 signaling pathway. Interestingly, ergosterol inhibited Aß synthesis in Neuro2a-APPwt cells. In silico analysis indicated that ergosterol can interact with the catalytic sites of ß- and γ-secretases. In Aß-overexpressing C. elegans, ergosterol decreased Aß accumulation, increased chemotaxis behavior, and prolonged lifespan. SIGNIFICANCE: Ergosterol is a potential candidate compound that might benefit AD patients by promoting neurite outgrowth, inhibiting Aß synthesis, and enhancing longevity.

Study of siRNA Delivery via Polymeric Nanoparticles in Combination with Angiogenesis Inhibitor for The Treatment of AFP-Related Liver Cancer.

Angiogenesis inhibitor drugs have been explored as important pharmacological agents for cancer therapy, including hepatocellular carcinoma. These agents have several drawbacks, such as drug resistance, nonspecific toxicity, and systemic side effects. Therefore, combination therapy of the drug and small interfering RNA could be a promising option to achieve high therapeutic efficacy while allowing a lower systemic dose. Therefore, we studied adding an alpha-fetoprotein siRNA (AFP-siRNA) incorporated on polymeric nanoparticles (NPs) along with angiogenesis inhibitor drugs. The AFP siRNA-loaded NPs were successfully synthesized at an average size of 242.00 ± 2.54 nm. Combination treatment of AFP-siRNA NPs and a low dose of sunitinib produced a synergistic effect in decreasing cell viability in an in vitro hepatocellular carcinoma (HCC) model. AFP-siRNA NPs together with sorafenib or sunitinib greatly inhibited cell proliferation, showing only 39.29 ± 2.72 and 44.04 ± 3.05% cell viability, respectively. Moreover, quantitative reverse transcription PCR (qRT-PCR) demonstrated that AFP-siRNA incorporated with NPs could significantly silence AFP-mRNA expression compared to unloaded NPs. Interestingly, the expression level of AFP-mRNA was further decreased to 28.53 ± 5.10% when sunitinib was added. Therefore, this finding was considered a new promising candidate for HCC treatment in reducing cell proliferation and enhancing therapeutic outcomes.

PLGA nanoparticles containing α-fetoprotein siRNA induce apoptosis and enhance the cytotoxic effects of doxorubicin in human liver cancer cell line.

Hepatocellular carcinoma (HCC) is one of the most common cancers and is a leading cause of death. Delivery of therapeutic molecules, e.g., siRNA, to HCC cells could potentially be an alternative treatment for HCC. In this study, the siRNA targeting α-fetoprotein (AFP) mRNA was found to specifically induce apoptosis and significant cell death in HepG2 cells. It also enhanced the cytotoxic effects of doxorubicin by about two-fold, making it the candidate therapeutic molecule for HCC treatment. To deliver the siRNAs into HCC cells, the AFP siRNAs were loaded into the nanoparticles based on poly (lactic-co-glycolic) acid (PLGA). These nanoparticles induced apoptosis in HepG2 cells and synergistically increased the cytotoxicity of doxorubicin. In summary, the delivery of the AFP siRNA-loaded PLGA nanoparticles in combination with doxorubicin could be a very promising approach for the treatment of HCC.