Peizhen Jiang, Daxiang Sun, Yaoyin Zhang, Dexiu Wang, Jiaqi He, Xudong Tang
This study proposes a novel microenvironment-targeted paradigm for QHP. The presence of MDS tumour cells has been demonstrated to induce a significant state of senescence and metabolic fragility in BMMSCs, accompanied by inflammatory secretion. The active components of QHP have been demonstrated to alleviate BMMSC senescence and partially ameliorate metabolic abnormalities. These microenvironmental remodelling effects may involve the selective curtailment of abnormal glycolysis and may be involved in or associated with the regulation of the AMPK/EZH2 signalling axis.,highlighting the immense potential of targeting stromal metabolic vulnerabilities with TCM in haematological malignancies.
ETHNOPHARMACOLOGICAL RELEVANCE: Myelodysplastic syndromes (MDS) are haematological malignancies for which traditional Chinese medicine (TCM) has been shown to provide distinctive clinical value. Qinghuang powder (QHP), a traditional Chinese medicinal preparation, has been shown to possess significant therapeutic potential in the treatment of myelodysplastic syndrome (MDS). The composition of QHP includes Indigo naturalis, which is known to produce indirubin, and Realgar, a substance that contains As2S2.Notably, QHP has been observed to alleviate MDS symptoms and delay disease progression.However, the precise pharmacological mechanisms by which QHP exerts its effects, particularly with regard to the protection and remodelling of the senescent and metabolically impaired bone marrow stromal niche (e.g., bone marrow mesenchymal stem cells, BMMSCs), remain to be fully elucidated.
AIM OF THE STUDY: The present study uniquely shifts the therapeutic focus from hematopoietic malignant clones to the stromal microenvironment, with the aim of exploring the potential mechanisms by which QHP's core components (As2S2 and indirubin) mitigate MDS-associated BMMSC senescence and ameliorate metabolic imbalance.
MATERIALS AND METHODS: An in vitro co-culture system was established, comprising patient-derived BMMSCs and the MDS cell line SKM-1. The system was treated with As2S2 and indirubin, the core active components of Qinghuang powder (QHP). Subsequent evaluations of cellular senescence, SASP, and metabolic profiles were systematically conducted using SA-β-Gal staining, Seahorse metabolic assays, ELISA, flow cytometry, qPCR, and Western blotting.
RESULTS: In comparison with healthy controls, MDS-BMMSCs demonstrated impaired proliferation, significantly elevated SA-β-Gal positivity (P<0.001), and increased expression of senescence-associated proteins, including p16, p21, and p53 (P < 0.05). This resulted in a senescence phenotype, characterised by cell cycle arrest without significant pro-inflammatory secretion (P > 0.05). It is noteworthy that co-culture with SKM-1 cells significantly exacerbated this senescent state, resulting in substantial secretion of pro-inflammatory SASP factors (e.g., IL-6, P < 0.05; IL-8, P < 0.001) and the triggering of severe metabolic dysregulation, characterised by NAD+ depletion (P < 0.0001), mitochondrial impairment, and abnormal glycolytic compensation. Following QHP intervention, SA-β-Gal positivity (P < 0.001) and the secretion of pro-inflammatory cytokines (IL-6, P < 0.05; IL-8, P < 0.001) were significantly downregulated. In addition, QHP exhibited a partial amelioration of the cellular energy status, as evidenced by a significantly increased NAD+/NADH ratio (P < 0.001) and the upregulation of SIRT1 expression (P < 0.05). Concurrently, QHP effectively suppressed the abnormally elevated glycolytic reserve capacity (P < 0.05), leading to decreased absolute ATP levels and an elevated ADP/ATP ratio (P < 0.05). Mechanistic analyses indicated that the QHP-induced downregulation of the key senescence protein p16 (P < 0.01) is closely associated with the activation of the energy sensor AMPK (P < 0.05) and the modulation of the epigenetic regulator EZH2, characterised by a significant upregulation of EZH2 mRNA (P < 0.01) alongside a concurrent downregulation of EZH2 protein (P < 0.05).
CONCLUSION: This study proposes a novel microenvironment-targeted paradigm for QHP. The presence of MDS tumour cells has been demonstrated to induce a significant state of senescence and metabolic fragility in BMMSCs, accompanied by inflammatory secretion. The active components of QHP have been demonstrated to alleviate BMMSC senescence and partially ameliorate metabolic abnormalities. These microenvironmental remodelling effects may involve the selective curtailment of abnormal glycolysis and may be involved in or associated with the regulation of the AMPK/EZH2 signalling axis.,highlighting the immense potential of targeting stromal metabolic vulnerabilities with TCM in haematological malignancies.