ABSTRACT
BACKGROUND: Ischemic stroke presents a significant threat to human health due to its high disability rate and mortality. Currently, the clinical treatment drug, rt-PA, has a narrow therapeutic window and carries a high risk of bleeding. There is an urgent need to find new effective therapeutic drugs for ischemic stroke. Icariin (ICA), a key ingredient in the traditional Chinese medicine Epimedium, undergoes metabolism in vivo to produce Icaritin (ICT). While ICA has been reported to inhibit neuronal apoptosis after cerebral ischemia-reperfusion (I/R), yet its underlying mechanism remains unclear. METHODS: PC-12 cells were treated with 200 µM H2O2 for 8 h to establish a vitro model of oxidative damage. After administration of ICT, cell viability was detected by Thiazolyl blue tetrazolium Bromide (MTT) assay, reactive oxygen species (ROS) and apoptosis level, mPTP status and mitochondrial membrane potential (MMP) were detected by flow cytometry and immunofluorescence. Apoptosis and mitochondrial permeability transition pore (mPTP) related proteins were assessed by Western blotting. Middle cerebral artery occlusion (MCAO) model was used to establish I/R injury in vivo. After the treatment of ICA, the neurological function was scored by ZeaLonga socres; the infarct volume was observed by 2,3,5-Triphenyltetrazolium chloride (TTC) staining; HE and Nissl staining were used to detect the pathological state of the ischemic cortex; the expression changes of mPTP and apoptosis related proteins were detected by Western blotting. RESULTS: In vitro: ICT effectively improved H2O2-induced oxidative injury through decreasing the ROS level, inhibiting mPTP opening and apoptosis. In addition, the protective effects of ICT were not enhanced when it was co-treated with mPTP inhibitor Cyclosporin A (CsA), but reversed when combined with mPTP activator Lonidamine (LND). In vivo: Rats after MCAO shown cortical infarct volume of 32-40%, severe neurological impairment, while mPTP opening and apoptosis were obviously increased. Those damage caused was improved by the administration of ICA and CsA. CONCLUSIONS: ICA improves cerebral ischemia-reperfusion injury by inhibiting mPTP opening, making it a potential candidate drug for the treatment of ischemic stroke.
Subject(s)
Apoptosis , Flavonoids , Ischemic Stroke , Membrane Potential, Mitochondrial , Mitochondrial Permeability Transition Pore , Oxidative Stress , Reactive Oxygen Species , Animals , Oxidative Stress/drug effects , Rats , Flavonoids/pharmacology , Flavonoids/therapeutic use , Mitochondrial Permeability Transition Pore/metabolism , Apoptosis/drug effects , Ischemic Stroke/drug therapy , Ischemic Stroke/metabolism , Ischemic Stroke/etiology , PC12 Cells , Reactive Oxygen Species/metabolism , Membrane Potential, Mitochondrial/drug effects , Male , Reperfusion Injury/metabolism , Reperfusion Injury/drug therapy , Disease Models, Animal , Hydrogen Peroxide/metabolism , Cell Survival/drug effects , Mitochondrial Membrane Transport Proteins/metabolism , Neuroprotective Agents/pharmacology , Neuroprotective Agents/therapeutic use , Rats, Sprague-DawleyABSTRACT
OBJECTIVE: Icariin (ICA) has a good neuroprotective effect and can upregulate neuronal basal autophagy in naturally aging rats. Mitochondrial dysfunction is associated with brain aging-related neurodegenerative diseases. Abnormal opening of the mitochondrial permeability transition pore (mPTP) is a crucial factor in mitochondrial dysfunction and is associated with excessive autophagy. This study aimed to explore that ICA protects against neuronal injury by blocking the mPTP opening and down-regulating autophagy levels in a D-galactose (D-gal)-induced cell injury model. METHODS: A cell model of neuronal injury was established in rat pheochromocytoma cells (PC12 cells) treated with 200 mmol/L D-gal for 48 h. In this cell model, PC12 cells were pre-treated with different concentrations of ICA for 24 h. MTT was used to detect cell viability. Senescence associated ß-galactosidase (SA-ß-Gal) staining was used to observe cell senescence. Western blot analysis was performed to detect the expression levels of a senescence-related protein (p21), autophagy markers (LC3B, p62, Atg7, Atg5 and Beclin 1), mitochondrial fission and fusion-related proteins (Drp1, Mfn2 and Opa1), and mitophagy markers (Pink1 and Parkin). The changes of autophagic flow were detected by using mRFP-GFP-LC3 adenovirus. The intracellular ultrastructure was observed by transmission electron microscopy. Immunofluorescence was used to detect mPTP, mitochondrial membrane potential (MMP), mitochondrial reactive oxygen species (mtROS) and ROS levels. ROS and apoptosis levels were detected by flow cytometry. RESULTS: D-gal treatment significantly decreased the viability of PC12 cells, and markedly increased the SA-ß-Gal positive cells as compared to the control group. With the D-gal stimulation, the expression of p21 was significantly up-regulated. Furthermore, D-gal stimulation resulted in an elevated LC3B II/I ratio and decreased p62 expression. Meanwhile, autophagosomes and autolysosomes were significantly increased, indicating abnormal activation of autophagy levels. In addition, in this D-gal-induced model of cell injury, the mPTP was abnormally open, the ROS generation was continuously increased, the MMP was gradually decreased, and the apoptosis was increased. ICA effectively improved mitochondrial dysfunction to protect against D-gal-induced cell injury and apoptosis. It strongly inhibited excessive autophagy by blocking the opening of the mPTP. Cotreatment with ICA and an mPTP inhibitor (cyclosporin A) did not ameliorate mitochondrial dysfunction. However, the protective effects were attenuated by cotreatment with ICA and an mPTP activator (lonidamine). CONCLUSION: ICA inhibits the activation of excessive autophagy and thus improves mitochondrial dysfunction by blocking the mPTP opening.
ABSTRACT
BACKGROUND: Intrahepatic cholangiocarcinoma (ICC) remains a significant challenge in cancer therapy, especially due to its resistance to established treatments like Gemcitabine, necessitating novel therapeutic approaches. METHODS: This study utilized Gemcitabine-resistant cell lines, patient-derived organotypic tumor spheroids (PDOTs), and patient-derived xenografts (PDX) to evaluate the effects of Saikosaponin-a (SSA) on ICC cellular proliferation, migration, apoptosis, and its potential synergistic interaction with Gemcitabine. Techniques such as transcriptome sequencing, Luciferase reporter assays, and molecular docking were employed to unravel the molecular mechanisms. RESULTS: SSA exhibited antitumor effects in both in vitro and PDX models, indicating its considerable potential for ICC treatment. SSA markedly inhibited ICC progression by reducing cellular proliferation, enhancing apoptosis, and decreasing migration and invasion. Crucially, it augmented Gemcitabine's efficacy by targeting the p-AKT/BCL6/ABCA1 signaling pathway. This modulation led to the downregulation of p-AKT and suppression of BCL6 transcriptional activity, ultimately reducing ABCA1 expression and enhancing chemosensitivity to Gemcitabine. Additionally, ABCA1 was validated as a predictive biomarker for drug resistance, with a direct correlation between ABCA1 expression levels and the IC50 values of various small molecule drugs in ICC gene profiles. CONCLUSION: This study highlights the synergistic potential of SSA combined with Gemcitabine in enhancing therapeutic efficacy against ICC and identifies ABCA1 as a key biomarker for drug responsiveness. Furthermore, the introduction of the novel PDOTs microfluidic model provides enhanced insights into ICC research. This combination strategy may provide a novel approach to overcoming treatment challenges in ICC.
ABSTRACT
BACKGROUND: The therapeutic potential of immune checkpoint blockade (ICB) extends across various cancers; however, its effectiveness in treating hepatocellular carcinoma (HCC) is frequently curtailed by both inherent and developed resistance. OBJECTIVE: This research explored the effectiveness of integrating anlotinib (a broad-spectrum tyrosine kinase inhibitor) with programmed death-1 (PD-1) blockade and offers mechanistic insights into more effective strategies for treating HCC. METHODS: Using patient-derived organotypic tissue spheroids and orthotopic HCC mouse models, we assessed the effectiveness of anlotinib combined with PD-1 blockade. The impact on the tumour immune microenvironment and underlying mechanisms were assessed using time-of-flight mass cytometry, RNA sequencing, and proteomics across cell lines, mouse models, and HCC patient samples. RESULTS: The combination of anlotinib with an anti-PD-1 antibody enhanced the immune response against HCC in preclinical models. Anlotinib remarkably suppressed the expression of transferrin receptor (TFRC) via the VEGFR2/AKT/HIF-1α signaling axis. CD8+ T-cell infiltration into the tumour microenvironment correlated with low expression of TFRC. Anlotinib additionally increased the levels of the chemokine CXCL14, crucial for attracting CD8+ T cells. CXCL14 emerged as a downstream effector of TFRC, exhibiting elevated expression following the silencing of TFRC. Importantly, low TFRC expression was also associated with a better prognosis, enhanced sensitivity to combination therapy, and a favourable response to anti-PD-1 therapy in patients with HCC. CONCLUSIONS: Our findings highlight anlotinib's potential to augment the efficacy of anti-PD-1 immunotherapy in HCC by targeting TFRC and enhancing CXCL14-mediated CD8+ T-cell infiltration. This study contributes to developing novel therapeutic strategies for HCC, emphasizing the role of precision medicine in oncology. HIGHLIGHTS: Synergistic effects of anlotinib and anti-PD-1 immunotherapy demonstrated in HCC preclinical models. Anlotinib inhibits TFRC expression via the VEGFR2/AKT/HIF-1α pathway. CXCL14 upregulation via TFRC suppression boosts CD8+ T-cell recruitment. TFRC emerges as a potential biomarker for evaluating prognosis and predicting response to anti-PD-1-based therapies in advanced HCC patients.