EGFR L858R/T790M/C797S inhibitors(China Pharmaceutical University)

Clostridioides difficile ( C. difficile ) is a Gram‐positive anaerobic bacillus that causes intestinal disorders. Toll‐like receptor 4 (TLR4) plays a key role in innate immunity. This study examines the role of TLR4 in the response to C. difficile toxins, which induce cell death and inflammatory responses in enteric glial cells (EGCs). Male C57BL/6 mice were infected with C. difficile , and cecum samples were analysed 3 days post‐infection for TLR4 expression. In vitro, EGCs were exposed to C. difficile toxins with or without C34, a TLR4 antagonist, or pre‐exposed to TLR4‐specific 21‐nt small interfering RNAs (siRNA). TLR4 expression was assessed by immunocytochemistry, immunofluorescence, qPCR, and Western blotting. NFκB p65, TNF‐α, IL‐6, cleaved caspase‐3, and phosphatidylserine binding to annexin‐V were evaluated. TLR4 expression increased in infected intestinal tissue and toxin‐exposed EGCs. TLR4 antagonist or TLR4 knockdown reduced NFκB p65 nuclear translocation and TNF‐α expression but did not affect IL‐6 upregulation. Additionally, TLR4 antagonist or TLR4 knockdown mitigated toxin‐induced cell death, as shown by decreased cleaved caspase‐3 and phosphatidylserine binding. These findings suggest that TLR4 contributes to C. difficile pathogenesis and that its inhibition reduces inflammation and prevents cell death in EGCs.

Since the membrane fusion step is the last chance to block the virus extracellularly, membrane fusion is an important target for anti‐human immunodeficiency virus (HIV) agents. Previously, the dimeric derivatives of C34, which are contained in the HIV‐1 envelope protein gp41 are found, linked by a disulfide bridge or a pegylated linker at its C ‐terminus have more potent anti‐HIV activity than the C34 peptide monomer, and that bivalent inhibitors crosslinking two peptidomimetic small compounds have more potent anti‐HIV activity than the parent small compounds. In the present study, the hybrids of small compounds ( 7 – 9 ) and peptides (SC34 ( 2 ) and SC22EK ( 3 )) are designed as heterodimeric molecules ( 10 – 15 ) to compensate for the drawbacks of the above homodimeric molecules. Some hybrid molecules of small compounds ( 7 – 9 ) and peptide SC22EK ( 3 ) have remarkably higher anti‐HIV activity than peptide SC22EK ( 3 ). Crosslinking small compounds and peptides ( 3 ) is found to be critical for an increase in anti‐HIV activity. Hybrid molecules with small compounds and peptides are useful HIV‐1 fusion inhibitors.