Synthesis of a 2,4,6-trisubstituted 5-cyano-pyrimidine library and evaluation of its immunosuppressive activity in a Mixed Lymphocyte Reaction assay

Construction of Isocytosine Scaffolds via DNA-Compatible Biginelli-like Reaction

Herein we report a DNA-compatible Biginelli reaction to construct isocytosine scaffolds. This reaction utilizes a one-pot reaction of DNA-conjugated guanidines with aldehydes and methyl cyanoacetates to give isocytosine derivatives, and the method is well compatible with different types of substrates. This is the first report on the synthesis of an isocytosine backbone in the field of DNA-compatible organic synthesis. The successful development of this reaction can widen the chemical space of DELs.

A Possible Reason to Induce Acute Graft-vs.-Host Disease After Hematopoietic Stem Cell Transplantation: Lack of Sirtuin-1 in CD4+ T Cells

Sirtuin 1 (SIRT1) is a critical suppressor of T cell immunity. However, whether SIRT1 is involved in the progression of acute graft-vs.-host disease (aGVHD) has still remained unclear. PI3K/Akt/mTOR pathway is a crucial element involved in the activation and functions of T cells. Over-activation of PI3K/Akt/mTOR signaling may be related to the occurrence of aGVHD. STAT3 activation requires phosphorylation and acetylation. A recent study showed that STAT3 hyperphosphorylation in CD4⁺ T cells may be a trigger of aGVHD. The role of the STAT3 acetylation in aGVHD pathogenesis is still unclear. The present study revealed that SIRT1 deficiency as a critical factor is involved in the excessive activation of mTOR pathway and upregulation of STAT3 acetylation and phosphorylation in CD4⁺ T cells from patients with aGVHD. Exorbitant activation of IL-1β signaling is the main reason for TAK1-dependent SIRT1 insufficiency. The findings of the present study might provide a new therapeutic target for treating aGVHD.

Design and synthesis of a novel series of N,4-diphenylpyrimidin-2-amine derivatives as potent and selective PI3Kγ inhibitors

Twenty-one novelN,4-diphenylpyrimidin-2-amine derivatives have been synthesized as PI3Kγ selective inhibitors and compoundC8demonstrated the most potent inhibitory activity against PI3Kγ kinase.