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Background: 20(S)-ginsenoside Rh2(GRh2), an effective natural histone deacetylase inhibitor, can inhibit acute myeloid leukemia (AML) cell proliferation. Lactate regulated histone lactylation, which has different temporal dynamics from acetylation. However, whether the high level of lactylation modification that we first detected in acute promyelocytic leukemia (APL) is associated with all-trans retinoic acid (ATRA) resistance has not been reported. Furthermore, Whether GRh2 can regulate lactylation modification in ATRA-resistant APL remains unknown. Methods: Lactylation and METTL3 expression levels in ATRA-sensitive and ATRA-resistant APL cells were detected by Western blot analysis, qRT-PCR and CO-IP. Flow cytometry (FCM) and APL xenograft mouse models were used to determine the effect of METTL3 and GRh2 on ATRA-resistance. Results: Histone lactylation and METTL3 expression levels were considerably upregulated in ATRA-resistant APL cells. METTL3 was regulated by histone lactylation and direct lactylation modification. Overexpression of METTL3 promoted ATRA-resistance. GRh2 ameliorated ATRA-resistance by downregulated lactylation level and directly inhibiting METTL3. Conclusions: This study suggests that lactylation-modified METTL3 could provide a promising strategy for ameliorating ATRA-resistance in APL, and GRh2 could act as a potential lactylation-modified METTL3 inhibitor to ameliorate ATRA-resistance in APL.
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BACKGROUND: Various studies have highlighted the significance of miR-125b-5p in tumour chemotherapy resistance; However, whether miR-125b-5p is associated with all-trans retinoic acid (ATRA) resistance in acute promyelocytic leukemia (APL) has not been reported. METHODS: Drug-resistance-related factors in APL were predicted using the DRESIS database. The expression levels of miR-125b-5p in ATRA-sensitive and ATRA-resistant APL cells were determined using quantitative reverse transcription polymerase chain reaction (qRT-PCR). A nitrotetrazolium blue (NBT) reduction assay and flow cytometry (FCM) were used to detect the effect of miR-125b-5p on ATRA resistance in APL cells. An APL xenograft tumour mouse model was established to determine the effect of miR-125b-5p on ATRA resistance. A dual-luciferase gene reporter assay, qRT-PCR, and western blotting verified the regulation by miR-125b-5p of its target gene, MAPK1, and the MAPK1 downstream factor, C/EBPα. An NBT reduction assay and FCM were used to detect the effect of C/EBPα on ATRA resistance in APL cells. Western blotting and qRT-PCR were used to assess the regulation of miR-125b-5p and MAPK1 by C/EBPα. RESULTS: miR-125b-5p expression levels were dramatically increased in ATRA-resistant APL cells. Both in vitro and in vivo experiments revealed that miR-125b-5p overexpression enhanced ATRA resistance in APL. miR-125b-5p promoted ATRA resistance by sponging MAPK1. C/EBPα was negatively regulated by miR-125b-5p, which in addition, regulated ATRA resistance in APL cells. C/EBPα also regulated the miR-125b-5p-MAPK1 axis. CONCLUSION: The findings of this study indicate that the miR-125b-5p-MAPK1-C/EBPα feedback loop regulated ATRA resistance in APL. Thus, miR-125b-5p may be a promising target for treating ATRA resistance in APL.
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Aristolochic acid I (AAI) can cause nephrotoxicity and is characterized by interstitial fibrosis. The C3a/C3aR axis of macrophages and matrix metalloproteinase-9 (MMP-9) play important roles in fibrosis, but whether they are involved in AAI-induced renal interstitial fibrosis and are related remains to be elucidated. In this study, we investigated whether C3a/C3aR axis of macrophages promotes renal interstitial fibrosis by regulating MMP-9 in aristolochic acid nephropathy (AAN). Intraperitoneal injection of AAI for 28 days successfully induced AAN in C57bl/6 mice. The content of C3a in the kidney of AAN mice was increased, and there was a significant distribution of macrophages in the renal tubules. The same results were observed in the in vitro experiment. We also explored the role and mechanism of macrophages after AAI administration in the epithelial-mesenchymal transformation (EMT) of renal tubular epithelial cells (RTECs) and found that AAI could activate the C3a/C3aR axis of macrophages to upregulate p65 expression in macrophages. p65 upregulated MMP-9 expression in macrophages not only directly but also by promoting the secretion if interleukin-6 by macrophages and then activating STAT3 in RTECs. The upregulation of MMP-9 expression could promote the EMT of RTECs. Taken together, our study demonstrated that the AAI-activated the C3a/C3aR axis of macrophages, which induced MMP-9 production, was one of the causes of renal interstitial fibrosis. Therefore, targeting the C3a/C3aR axis of macrophages is an effective therapeutic strategy for the prevention and treatment of renal interstitial fibrosis in AAN.