Discovery of Novel Azaindoles as Potent and Selective PI3Kδ Inhibitors for Treatment of Multiple Sclerosis.

Multiple sclerosis (MS) is a chronic autoimmune disorder of the central nervous system and the unmet need for MS treatment demands new therapeutic development. Particularly, PI3Kδ is a high-value target for autoimmune disease, while the investigation of PI3Kδ inhibitors for MS therapy is relatively scarce. Herein, we report a novel class of azaindoles as PI3Kδ inhibitors for MS treatment. Compound 31, designed via nitrogen bioisosterism, displayed excellent PI3Kδ inhibitory activity and selectivity. In vitro assay showed that 31 exhibited superior activity on T lymphocytes to inhibit the proliferation of CD4+, CD8+, and CD3+ T cells. In the experimental autoimmune encephalomyelitis (EAE) model, 31 showed a comparable therapeutical efficacy with Dexamethasone to significantly ameliorate EAE symptoms. Mechanistic studies showed that compound 31 could significantly inhibit the PI3K/AKT/mTOR signaling pathway and inhibited T-cell proliferation and differentiation. Overall, this work provides a new structural PI3Kδ inhibitor and a new vision for MS therapy.

Macrophage senescence in health and diseases.

Macrophage senescence, manifested by the special form of durable cell cycle arrest and chronic low-grade inflammation like senescence-associated secretory phenotype, has long been considered harmful. Persistent senescence of macrophages may lead to maladaptation, immune dysfunction, and finally the development of age-related diseases, infections, autoimmune diseases, and malignancies. However, it is a ubiquitous, multi-factorial, and dynamic complex phenomenon that also plays roles in remodeled processes, including wound repair and embryogenesis. In this review, we summarize some general molecular changes and several specific biomarkers during macrophage senescence, which may bring new sight to recognize senescent macrophages in different conditions. Also, we take an in-depth look at the functional changes in senescent macrophages, including metabolism, autophagy, polarization, phagocytosis, antigen presentation, and infiltration or recruitment. Furthermore, some degenerations and diseases associated with senescent macrophages as well as the mechanisms or relevant genetic regulations of senescent macrophages are integrated, not only emphasizing the possibility of regulating macrophage senescence to benefit age-associated diseases but also has an implication on the finding of potential targets or drugs clinically.

Discovery and Optimization of N-Acyl-6-sulfonamide-tetrahydroquinoline Derivatives as Novel Non-Steroidal Selective Glucocorticoid Receptor Modulators.

Selective glucocorticoid receptor modulators (SGRMs), which can dissociate the transactivation from the transrepression of the glucocorticoid receptor (GR), are regarded as very promising therapeutics for inflammatory and autoimmune diseases. We previously discovered a SGRM HP-19 based on the passive antagonistic conformation of GR and bioassays. In this study, we further analyzed the dynamic changes of the passive antagonistic state upon the binding of HP-19 and designed and synthesized 62 N-acyl-6-sulfonamide-tetrahydroquinoline derivatives by structural optimization of HP-19. Therein, compound B53 exhibits the best transrepression activity (IC50 NF-κB = 0.009 ± 0.001 µM) comparable with dexamethasone (IC50 NF-κB = 0.005 ± 0.001 µM) and no transactivation activity. B53 can efficiently reduce the expression of inflammatory factors IL-6, IL-1ß, TNF-α, and so on and makes a milder adverse effect and is highly specific to GR. Furthermore, B53 is able to significantly relieve dermatitis on a mouse model via oral drug intervention.

Discovery of new macrophage M2 polarization modulators as multiple sclerosis treatment agents that enable the inflammation microenvironment remodeling.

The M2 polarized macrophages modulation has been described as a beneficial approach to facilitate the myelin repairing and inflammation microenvironment remodeling of multiple sclerosis (MS). Whereas, the M2 polarization involves complex mechanisms, and the modulators are still limited. As a protein kinase B (Akt) inhibitor, compound 2 was found promoting M2 polarization activity in our previous research, here we report the identification of a new modulator B9 with high M2-marker Arg1 upregulation activity, M1 polarization inhibition and ablated Akt1 inhibition activities. B9 has promising pharmacokinetic profiles, and significantly ameliorates the symptom and reduces demyelination in EAE mice. Moreover, the inflammation microenvironment is remodeled after B9 administration, with promoted M2-type macrophages and inhibited M1 polarization in the CNS and periphery, and suppressed the proinflammatory Th1 and Th17 cells responses. Therefore, the new macrophage M2 polarization modulator B9 could present a candidate for fulfilling the therapeutic strategies of MS.

Resibufogenin Suppresses Triple-Negative Breast Cancer Angiogenesis by Blocking VEGFR2-Mediated Signaling Pathway.

Resibufogenin (RBF), an active compound from Bufo bufonis, has been used for the treatment of multiple malignant cancers, including pancreatic cancer, colorectal cancer, and breast cancer. However, whether RBF could exert its antitumor effect by inhibiting angiogenesis remains unknown. Here, we aimed to explore the antiangiogenic activity of RBF and its underlying mechanism on human umbilical vein endothelial cell (HUVEC), and the therapeutic efficacy with regard to antiangiogenesis in vivo using two triple-negative breast cancer (TNBC) models. Our results demonstrated that RBF can inhibit the proliferation, migration, and tube formation of HUVECs in a dose-dependent manner. Spheroid sprouts were thinner and shorter after RBF treatment in vitro 3D spheroid sprouting assay. RBF also significantly suppressed VEGF-mediated vascular network formation in vivo Matrigel plug assay. In addition, Western blot analysis was used to reveal that RBF inhibited the phosphorylation of VEGFR2 and its downstream protein kinases FAK and Src in endothelial cells (ECs). Molecular docking simulations showed that RBF affected the phosphorylation of VEGFR2 by competitively binding to the ATP-bound VEGFR2 kinase domain, thus preventing ATP from providing phosphate groups. Finally, we found that RBF exhibited promising antitumor effect through antiangiogenesis in vivo without obvious toxicity. The present study first revealed the high antiangiogenic activity and the underlying molecular basis of RBF, suggesting that RBF could be a potential antiangiogenic agent for angiogenesis-related diseases.