ABSTRACT
The development of antimalarial drug resistance is an ongoing problem threatening progress towards the elimination of malaria, and antimalarial treatments are urgently needed for drug-resistant malaria infections. Host-directed therapies (HDT) represent an attractive strategy for the development of new antimalarials with untapped targets and low propensity for resistance. In addition, drug repurposing in the context of HDT can lead to a substantial decrease in the time and resources required to develop novel antimalarials. Host BCL-xL is a target in anti-cancer therapy and is essential for the development of numerous intracellular pathogens. We hypothesised that red blood cell (RBC) BCL-xL is essential for Plasmodium development and tested this hypothesis using six BCL-xL inhibitors, including one FDA-approved compound. All BCL-xL inhibitors tested impaired proliferation of Plasmodium falciparum 3D7 parasites in vitro at low micromolar or sub-micromolar concentrations. Western blot analysis of infected cell fractions and immunofluorescence microscopy assays revealed that host BCL-xL is relocated from the RBC cytoplasm to the vicinity of the parasite upon infection. Further, immunoprecipitation of BCL-xL coupled with mass spectrometry analysis identified that BCL-xL forms unique molecular complexes with human µ-calpain in uninfected RBCs, and with human SHOC2 in infected RBCs. These results provide interesting perspectives for the development of host-directed antimalarial therapies and drug repurposing efforts.
ABSTRACT
BACKGROUND: As one of traditional Chinese medicine, mulberry leaf is abundant in diverse active ingredients and widely used for the treatment of metabolic disease and its complications. However, there are a few of reports on its application in the prevention and treatment of obesity. And the molecular mechanism on the anti-obesity of mulberry leaf are unknown till now. PURPOSE: The present study aimed to evaluate the potential ingredients and targets of mulberry leaf and uncover the anti-obesity mechanisms by using the network pharmacology tactics and verify its effect by biological experiments. STUDY DESIGN: Active ingredients and key targets of mulberry leaf, genes related to obesity were screened through public database. Based on the results of network pharmacology, the flavonoids-enriched fraction of mulberry leaf (MLF) was extracted and composition of this fraction was identified. After that, HepG2 cells model of lipid accumulation was established for verifying the effect of MLF and related mechanisms. RESULTS: A total of 37 active ingredients in mulberry leaf, 192 predicted biological targets and 8813 obesity-related targets were determined, of which 180 overlapping targets might have obvious curative effects on obesity. The networks showed that mulberry leaf might play a role through key targets, such as AKT, MAPK and IL-6, and regulated PI3K-Akt signaling pathway. Based on HPLC-ESI-QQQ-MS analysis, 13 constituents of MLF were identified, including 9 flavonoids. Furthermore, HepG2 cells model of lipid accumulation was established. The results indicated that MLF treatment could down-regulate the secretion of inflammatory cytokines, as well as clearly inhibited lipid droplets formation and alleviated TC, TG, HDL-C and LDL-C levels. Positive effect was observed on hypolipidemic efficacy due to the regulation of PI3K/Akt/Bcl-xl pathway, as indicated by the amelioration of PI3K, Akt and Bcl-xl gene and protein expression. CONCLUSION: This study firstly systematically disclose the multi-ingredients, multi-targets mechanisms of mulberry leaf on obesity by using network pharmacology approach, and validate in HepG2 cells that the protective effect of MLF against obesity involved both inflammation response and lipid metabolism involving PI3K/Akt/Bcl-xl signaling pathway. It provides indications for further mechanistic research of mulberry leaf and also for the development as a potential candidate for the therapy for obese patients.
Subject(s)
Morus , Humans , Molecular Biology , Obesity/drug therapy , Phosphatidylinositol 3-Kinases , Plant LeavesABSTRACT
Bcl-xL represents a family of proteins responsible for the regulation of the intrinsic apoptosis pathway. Due to its anti-apoptotic activity, Bcl-xL co-determines the viability of various virally infected cells. Their survival may determine the effectiveness of viral replication and spread, dynamics of systemic infection, and viral pathogenesis. In this paper, we have reviewed the role of Bcl-xL in the context of host infection by eight different RNA and DNA viruses: hepatitis B virus (HBV), hepatitis C virus (HCV), human immunodeficiency virus (HIV), influenza A virus (IAV), Epstein-Barr virus (EBV), human T-lymphotropic virus type-1 (HTLV-1), Maraba virus (MRBV), Schmallenberg virus (SBV) and coronavirus (CoV). We have described an influence of viral infection on the intracellular level of Bcl-xL and discussed the impact of Bcl-xL-dependent cell survival control on infection-accompanying pathogenic events such as tissue damage or oncogenesis. We have also presented anti-viral treatment strategies based on the pharmacological regulation of Bcl-xL expression or activity.