Phosphoinositide 3-kinase (PI3K) activity is crucial for leukocyte function, but the roles of the four receptor-activated isoforms are unclear. Mice lacking heterotrimeric guanine nucleotide-binding protein (G protein)–coupled PI3Kγ were viable and had fully differentiated neutrophils and macrophages. Chemoattractant-stimulated PI3Kγ ^−/− neutrophils did not produce phosphatidylinositol 3,4,5-trisphosphate, did not activate protein kinase B, and displayed impaired respiratory burst and motility. Peritoneal PI3Kγ-null macrophages showed a reduced migration toward a wide range of chemotactic stimuli and a severely defective accumulation in a septic peritonitis model. These results demonstrate that PI3Kγ is a crucial signaling molecule required for macrophage accumulation in inflammation.

Natural products represent an inexhaustible source of novel therapeutic agents. Their complex and constrained three-dimensional structures endow these molecules with exceptional biological properties, thereby giving them a major role in drug discovery programs. However, the search for new bioactive metabolites is hampered by the chemical complexity of the biological matrices in which they are found. The purification of single constituents from such matrices requires such a significant amount of work that it should be ideally performed only on molecules of high potential value (i.e., chemical novelty and biological activity). Recent bioinformatics approaches based on mass spectrometry metabolite profiling methods are beginning to address the complex task of compound identification within complex mixtures. However, in parallel to these developments, methods providing information on the bioactivity potential of natural products prior to their isolation are still lacking and are of key interest to target the isolation of valuable natural products only. In the present investigation, we propose an integrated analysis strategy for bioactive natural products prioritization. Our approach uses massive molecular networks embedding various informational layers (bioactivity and taxonomical data) to highlight potentially bioactive scaffolds within the chemical diversity of crude extracts collections. We exemplify this workflow by targeting the isolation of predicted active and nonactive metabolites from two botanical sources (Bocquillonia nervosa and Neoguillauminia cleopatra) against two biological targets (Wnt signaling pathway and chikungunya virus replication). Eventually, the detection and isolation processes of a daphnane diterpene orthoester and four 12-deoxyphorbols inhibiting the Wnt signaling pathway and exhibiting potent antiviral activities against the CHIKV virus are detailed. Combined with efficient metabolite annotation tools, this bioactive natural products prioritization pipeline proves to be efficient. Implementation of this approach in drug discovery programs based on natural extract screening should speed up and rationalize the isolation of bioactive natural products.

The Wnt/β-catenin signaling pathway is crucial in animal development from sponges to humans. Its activity in the adulthood is less general, with exceptions having huge medical importance. Namely, improper activation of this pathway is carcinogenic in many tissues, most notably in the colon, liver and the breast. On the other hand, the Wnt/β-catenin signaling must be re-activated in cases of tissue damage, and insufficient activation results in regeneration failure and degeneration. These both medically important implications are unified by the emerging importance of this signaling pathway in the control of proliferation of various types of stem cells, crucial for tissue regeneration and, in case of cancer stem cells – cancer progression and relapse. This article aims at briefly reviewing the current state of knowledge in the field of Wnt signaling, followed by a detailed discussion of current medical developments targeting distinct branches of the Wnt pathway for anti-cancer and pro-regeneration therapies.

Treatment multiple tumors by immune therapy can be achieved by mobilizing both innate and adaptive immunity. The programmed death ligand 1 (PD-L1; or CD274, B7-H1) is a critical "don't find me" signal to the adaptive immune system. Equally CD47 is a critical "don't eat me" signal to the innate immune system and a regulator of the adaptive immune response. Both of CD47 and PD-L1 are overexpressed on the surface of cancer cells to enable to escape immune-surveillance. We designed EpCAM (epithelial cell adhesion molecule)-targeted cationic liposome (LPP-P4-Ep) containing si-CD47 and si-PD-L1 could target high-EpCAM cancer cells and knockdown both CD47 and PD-L1 proteins. Efficient silencing of CD47 and PD-L1 versus single gene silencing in vivo by systemic administration of LPP-P4-Ep could significantly inhibited the growth of solid tumors in subcutaneous and reduced lung metastasis in lung metastasis model. Target delivery of the complexes LPP-P4-Ep increased anti-tumor T cell and NK cell response, and release various cytokines including IFN-γ and IL-6 in vivo and in vitro. This multi-nanoparticles showed significantly high-EpCAM tumor targeting and lower toxicity, and enhanced immune therapeutic efficacy. Our data indicated that dual-blockade tumor cell-specific innate and adaptive checkpoints represents an improved strategy for tumor immunotherapy. FUND: This research supported by the Ministry of Science and Technology of the People's Republic of China (grant number 2015CB931804); the National Natural Science Foundation of China (NSFC, grant numbers 81703555, U1505225 and 81773063), and the China Postdoctoral Science Foundation (grant number 2017 M620268).