The reactive oxygen species(ROS) generation efficiency is always limited by the extreme tumor microenvironment(TME), leading to unsatisfactory antitumor effects in photodynamic therapy(PDT). As a promising gas therapy molecule, nitric oxide(NO) is independent of oxygen and could even synergize ROS to enhance the therapeutic effect. However, the short half-life, instability, and uncontrollable release of exogenous NO limited the application of tumor synergistic therapy. Herein, we reported a novel kind of red-emissive carbon dots(CDs) that was capable of lysosome-targeted and light-controlled NO delivery. The CDs were synthesized by using metformin and methylene blue(MB) via a hydrothermal method.The obtained metformin-MB CDs(MMCDs) exhibited a higher1O2quantum yield and NO generation efficiency under light emitting diode(LED) light irradiation. Noteworthily, the1O2could further in situ oxidize NO into peroxynitrite anions(ONOO-), which own the higher cytotoxicity against cancer cells.Cell experiments indicate that MMCDs could destruct lysosome membrane integrity and kill almost 80%of Hep G2 cells under light irradiation while very low cytotoxicity in the dark. Moreover, MMCDs significantly decreased tumor volume and weight after phototherapy in hepatoma Hep G2-bearing mice. Our study provides a new strategy for light-controlled NO generation as well as precise lysosome-targeting for enhancement of PDT efficiency.
目的:探讨CD38对巨噬细胞溶酶体再生及胆固醇外流的影响。方法:以低密度脂蛋白(LDL)受体敲除(LDLr^(-/-))小鼠的骨髓源性巨噬细胞为细胞模型。采用活细胞成像系统观察烟酸腺嘌呤二核苷酸磷酸(NAADP)对巨噬细胞溶酶体数量的影响;利用ELISA检测巨噬细胞内NAADP的水平;细胞经NA处理后,利用RT-q PCR检测CD38 m RNA表达,利用Western blot检测CD38蛋白表达和转录因子EB(TFEB)磷酸化水平;利用激光共聚焦技术观察CD38/NAADP信号通路对溶酶体数量和胆固醇外流的影响。结果:NAADP可显著增加巨噬细胞中溶酶体的数量(P<0.05),这种效应可被NAADP拮抗剂NED-19、Ca^(2+)螯合剂BAPTA及钙调磷酸酶抑制剂Cs A明显抑制(P<0.05);CD38可明显促进巨噬细胞中NAADP的合成(P<0.05);NAADP合成底物NA可明显促进CD38 m RNA和蛋白表达(P<0.05);NA还可显著降低TFEB的磷酸化水平,且这一效应也可被NED-19、BAPTA和Cs A明显抑制(P<0.05);阻断CD38/NAADP信号通路可明显抑制NA诱导的溶酶体数量增加和溶酶体游离胆固醇及胞质胆固醇酯的外流(P<0.05);在LDLr/CD38双基因敲除巨噬细胞中,NA诱导的溶酶体数量增加和溶酶体游离胆固醇及胞质胆固醇酯的外流效应消失,CD38基因回补后,这一效应即可恢复(P<0.05)。结论:CD38可经TFEB介导,触发巨噬细胞溶酶体再生,进而促进巨噬细胞溶酶体游离胆固醇和胞质中胆固醇酯的外流。
Parkinson’s disease is a common neurodegenerative disease with movement disorders associated with the intracytoplasmic deposition of aggregate proteins such asα-synuclein in neurons.As one of the major intracellular degradation pathways,the autophagy-lysosome pathway plays an important role in eliminating these proteins.Accumulating evidence has shown that upregulation of the autophagy-lysosome pathway may contribute to the clearance ofα-synuclein aggregates and protect against degeneration of dopaminergic neurons in Parkinson’s disease.Moreover,multiple genes associated with the pathogenesis of Parkinson’s disease are intimately linked to alterations in the autophagy-lysosome pathway.Thus,this pathway appears to be a promising therapeutic target for treatment of Parkinson’s disease.In this review,we briefly introduce the machinery of autophagy.Then,we provide a description of the effects of Parkinson’s disease–related genes on the autophagy-lysosome pathway.Finally,we highlight the potential chemical and genetic therapeutic strategies targeting the autophagy–lysosome pathway and their applications in Parkinson’s disease.
Lysosomes are discrete organelles that act as recycling centers for extracellular and intracellular materials,playing a pivotal role in maintaining cellular homeostasis.Their acidic environment,maintained by numerous hydrolytic enzymes,facilitates substrate degradation.Dysfunction in lysosomal processes can lead to abnormal substrate degradation,significantly impacting cellular homeostasis.High energy-demanding cells,such as post-mitotic neurons,are especially vulnerable to these changes,often resulting in neurological diseases.Autophagy,a conserved catabolic process,requires extensive lysosomal utilization.It plays a key role in removing unnecessary intracellular components,ensuring cellular homeostasis,and promoting cell survival during stress conditions such as starvation,infection,or cellular damage.
Macrocycle confinement induced guest near-infrared(NIR)luminescence was research hotspot currently.Here in,we reported a cucurbit[7]uril(CB[7])confined 3,7-bis((E)-2-(pyridin-4-yl)vinyl)-10-Hphenothiazine bridged bis(4-(4-bromophenyl)pyridine)(G),which not only boosted its NIR luminescence but also realized detection of HClO/ClO^(-)in living cells and lysosome imaging.Fluorescence spectroscopy experiments were performed to calculate the detection ability of probe G to HClO/ClO^(-)up to 147 nmol/L.As compared with G,supramolecular probe G■CB[7]formed after encapsulated by CB[7],the detection ability towards HClO/ClO^(-)was improved to 24 nmol/L which was ascribe to the macrocycle CB[7]confinement increasing the fluorescence intensity to 103 folds.Accompanying the excitation wavelength changing,the fluorescence red-shifted to 820 nm when excited by 570 nm light,which was used to NIR lysosome imaging.Meanwhile,the supramolecular assembly G■CB[7]was also successfully used to highly sense to exogenous HClO/ClO^(-)in RAW 264.7 cells and live animal.
Hui-Juan WangWen-Wen XingZhen-Hai YuYong-Xue LiHeng-Yi ZhangQilin YuHongjie ZhuYao-Yao WangYu Liu