Tu-Xian Decoction ameliorates diabetic cognitive impairment by inhibiting DAPK-1 / 中国天然药物

Tu-Xian decoction (TXD), a traditional Chinese medicine (TCM) formula, has been frequently administered to manage diabetic cognitive impairment (DCI). Despite its widespread use, the mechanisms underlying TXD's protective effects on DCI have yet to be fully elucidated. As a significant regulator in neurodegenerative conditions, death-associated protein kinase-1 (DAPK-1) serves as a focus for understanding the action of TXD. This study was designed to whether TXD mediates its beneficial outcomes by inhibiting DAPK-1. To this end, a diabetic model was established using Sprague-Dawley (SD) rats through a high-fat, high-sugar (HFHS) diet regimen, followed by streptozotocin (STZ) injection. The experimental cohort was stratified into six groups: Control, Diabetic, TC-DAPK6, high-dose TXD, medium-dose TXD, and low-dose TXD groups. Following a 12-week treatment period, various assessments-including blood glucose levels, body weight measurements, Morris water maze (MWM) testing for cognitive function, brain magnetic resonance imaging (MRI), and histological analyses using hematoxylin-eosin (H&E), and Nissl staining-were conducted. Protein expression in the hippocampus was quantified through Western blotting analysis. The results revealed that TXD significantly improved spatial learning and memory abilities, and preserved hippocampal structure in diabetic rats. Importantly, TXD administration led to a down-regulation of proteins indicative of neurological damage and suppressed DAPK-1 activity within the hippocampal region. These results underscore TXD's potential in mitigating DCIvia DAPK-1 inhibition, positioning it as a viable therapeutic candidate for addressing this condition. Further investigation into TXD's molecular mechanisms may elucidate new pathways for the treatment of DCI.

Inactivation of DAPK1 gene by methylated oligonucleotides and its effect on the proliferation of leukemia cell line K562 / 白血病·淋巴瘤

Objective To inactivate Death-associated protein kinase 1 gene (DAPK1) by transfecting complementary methylated oligonucleotides and studies its effect on the proliferation of myelogenous leukemia cell line K562. Methods Methylated oligonucleotides complementary to DAPK1 gene promoter were transfected into K562 cells by Iipo2000. Methylation specific PCR (MSP) and Reverse transcription PCR (RT-PCR) were applied to detect DAPK1 gene promoter methylation status and its mRNA expressions respectively. MTT was used to detect the proliferation of K562 cells pre- and post- oligonucleotides transfection. Results DAPK1 gene promoter in non-treated and control groups were unmethylated with detectable mRNA expressions, but it became methylated with inhibited mRNA expressions after methylated oligonucleotide transfection. Proliferation in methylated oligonucleotide treatment group was significantly higher than that in non-treated and control groups. Conclusion Complementary methylated oligonucleotides could inactivate DAPK1 gene and inhibit its expression in K562 cells, which could promote its proliferation.