Rewiring the Three-Carbon Metabolism Abrogates Multiple MAPK-Induced Cellular Dysfunctions During Metabolic Disorder

Loss of membrane raft integrity, metabolic dysregulation and inflammation are hallmarks of chronic diseases and aging. It is not well understood how the stress response itself may contribute to the manifestation of these common traits. To explore this question, we screened the model organism S. cerevisiae, for the secretion of glycosylphosphatidylinositol-anchored proteins (GPI-APs) as a proxy for membrane raft instability. It is shown here that the multiple cellular dysfunctions previously described for a defect in the methylation pathway for phosphatidyl choline (PC) synthesis (opi3Δ) are linked with GPI-APs secretion. They collectively result from the sustained activation of the mitogen-activated protein kinase (MAPK) Hog1p. Through modifying the dihydroxyacetone phosphate / glycerol-3-phosphate ratio, activated MAPK promotes phospholipid gene de-repression and interferes with GPI anchor synthesis. Rewiring the three carbon metabolism, namely by deleting the mitochondrial glycerol phosphate dehydrogenase, abrogated the opi3Δ mutant pleiotropic phenotypes identifying key targets to counteract MAPK-induced cellular dysfunctions.

Study on the Mechanism of Liuwei Dihuang Pill s Formula in Treating Parkinson's Disease Based on Network Pharmacology

Background: Parkinson's Disease (PD) is a common neurodegenerative disease in middle-aged and elderly people. Liuwei Dihuang Pill (LWDH Pills) has good effect on Parkinson's disease but the mechanism of action is not clear. Network pharmacology is the result of integrating the basic theories and research methods of medicine, biology, computer science, bioinformatics and other disciplines, which can systematically and comprehensively reflect the mechanism of drug intervention in disease network.Methods: Obtained the main components and targets of herbs in LWDH Pills through Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform (TCMSP) database, and screen the active components of traditional Chinese medicine according to ADME; The PD-related targets were obtained from Gencards, OMIM, TTD, DRUGBANK databases. Used Jvenn to take the intersection of targets of LWDH Pills and PD-related targets, use the String platform to analyze protein interactions, construct a PPI network and explore potential protein functional modules in the network. The Metascape platform was used to performe KEGG pathway and GO Function enrichment analysis. Finally, the Cytoscape software was used to construct the drug-components-target network.Results: After screening and de-weighting, 210 effective active ingredients of LWDH Pills, 204 drug targets, 4333 diabetic nephropathy disease targets, and 162 drug-disease targets were obtained by the intersection of Jvenn. GO and KEGG enrichment analysis showed that these targets are involved in neuron death, G protein-coupled amine receptor activity, reactive oxygen species metabolic process, membrane raft, MAPK signaling pathway, cellular senescence and other biological processes. Drug-components-target shows that the hub components of Liuwei Dihuang Pills were quercetin, Stigmasterol, kaempferol, and beta-sitosterolConclusion: LWDH Pill has the characteristics of multi-component, multi-target and multi-pathway for the treatment of PD. The hub components may be quercetin, Stigmasterol, kaempferol, and beta-sitosterol, and may be through pairing hub targets such as AKT1, VEGFA, IL6, etc. to regulate Neuron death, G protein-coupled amine receptor activity, reactive oxygen species metabolic process, membrane raft, MAPK signaling pathway, cellular senescence to play a role in the treatment of PD

Growth cone repulsion to Netrin-1 depends on lipid raft microdomains enriched in UNC5 receptors

During brain development, Uncoordinated locomotion 5 (UNC5) receptors control axonal extension through their sensing of the guidance molecule Netrin-1. The correct positioning of receptors into cholesterol-enriched membrane raft microdomains is crucial for the efficient transduction of the recognized signals. However, whether such microdomains are required for the appropriate axonal guidance mediated by UNC5 receptors remains unknown. Here, we combine the use of confocal microscopy, live-cell FRAP analysis and single-particle tracking PALM to characterize the distribution of UNC5 receptors into raft microdomains, revealing differences in their membrane mobility properties. Using pharmacological and genetic approaches in primary neuronal cultures and brain cerebellar explants we further demonstrate that disrupting raft microdomains inhibits the chemorepulsive response of growth cones and axons against Netrin-1. Together, our findings indicate that the distribution of all UNC5 receptors into cholesterol-enriched raft microdomains is heterogeneous and that the specific localization has functional consequences for the axonal chemorepulsion against Netrin-1.

10-Gingerol Targets Lipid Rafts Associated PI3K/Akt Signaling in Radio-Resistant Triple Negative Breast Cancer Cells

10-Gingerol is a major phenolic lipid found in the rhizomes of ginger (Zingiber officinale). Being amphiphilic in nature, phenolic lipids have the ability to incorporate into cell membranes and modulate membrane properties. The purpose of the present study was to evaluate the effects of 10-gingerol on lipid raft/membrane raft modulation in radio-resistant triple negative breast cancer (MDA-MB-231/IR) cells. The effects of 10-gingerol on MDA-MB-231/IR cells’ proliferation, clonogenic growth, migration, and invasion were assayed using MTT, colony formation, cell migration, and invasion assays, respectively. Sucrose density gradient centrifugation was used to extract lipid rafts. Western blotting and immunofluorescence were employed to assess the effects of 10-gingerol on lipid raft/membrane raft modulation and lipid rafts-associated PI3K/Akt signaling. Cholesterol measurements were carried out using a commercially available kit. 10-gingerol suppressed the proliferation, migration, invasion, and induced apoptosis through targeting the PI3K/Akt signaling pathway in MDA-MB-231/IR cells. Moreover, 10-gingerol was found to modulate the lipid rafts of MDA-MB-231/IR cells and attenuate the key PI3K/Akt signaling components in lipid rafts. The cholesterol content of the lipid rafts and rafts-resident Akt signaling were also affected by exposure to 10-gingerol. The results of the present study highlight rafts-associated PI3K/Akt signaling as a new target of 10-gingerol in MDA-MB-231/IR cells, thus rationalizing a new rafts-mediated treatment approach for radio-resistant triple negative breast cancer cells.

Prospects of Gene Knockouts in the Functional Study of MAMP-Triggered Immunity: A Review

Plants depend on both preformed and inducible defence responses to defend themselves against biotic stresses stemming from pathogen attacks. In this regard, plants perceive pathogenic threats from the environment through pattern recognition receptors (PRRs) that recognise microbe-associated molecular patterns (MAMPs), and so induce plant defence responses against invading pathogens. Close to thirty PRR proteins have been identified in plants, however, the molecular mechanisms underlying MAMP perception by these receptors/receptor complexes are not fully understood. As such, knockout (KO) of genes that code for PRRs and co-receptors/defence-associated proteins is a valuable tool to study plant immunity. The loss of gene activity often causes changes in the phenotype of the model plant, allowing in vivo studies of gene function and associated biological mechanisms. Here, we review the functions of selected PRRs, brassinosteroid insensitive 1 (BRI1) associated receptor kinase 1 (BAK1) and other associated defence proteins that have been identified in plants, and also outline KO lines generated by T-DNA insertional mutagenesis as well as the effect on MAMP perception—and triggered immunity (MTI). In addition, we further review the role of membrane raft domains in flg22-induced MTI in Arabidopsis, due to the vital role in the activation of several proteins that are part of the membrane raft domain theory in this regard.