Free Radical Biology and Medicine最新文献_第5页

Cellular damage photosensitized by dasatinib, radical-mediated mechanisms and photoprotection in reconstructed epidermis 达沙替尼光敏化的细胞损伤、自由基介导的机制以及重建表皮的光保护作用。

IF 7.1 2区生物学 Q1 BIOCHEMISTRY & MOLECULAR BIOLOGY

Free Radical Biology and Medicine

Pub Date : 2024-09-21 DOI: 10.1016/j.freeradbiomed.2024.09.027

Dasatinib (DAS) is an anticancer drug employed in the treatment of certain hematological malignancies. Although DAS has been mainly developed for oral administration, it has recently garnered attention for its possible topical application. The use of topical drugs can cause photosensitivity, which is not listed as an adverse reaction for DAS. Since DAS absorbs UVA, it could potentially induce photosensitivity reactions and lead to oxidative damage to cellular targets. This study aims to investigate whether DAS exhibits phototoxic reactions on primary cellular targets in both solution and artificial skin, mimicking topical drug administration. It also examines the potential generation of highly reactive intermediates like organic radicals and ROS, which could trigger photosensitivity reactions. Upon DAS irradiation in the UVA region, the first transient species detected was the diradicaloid triplet excited state (³DAS∗) with an absorption maximum of around 490 nm, which was quenched by oxygen to produce singlet oxygen. Quenching experiments with linoleic acid and 3-methylindole indicated that radical-mediated (Type I) photosensitized damage to lipids and proteins is possible. However, the lack of triplet quenching with guanosine suggests that the Type II mechanism also plays a role in the photooxidation of biomolecules. Accordingly, the neutral red uptake phototoxicity test (photoirritation factor of 5) and the comet assay, revealed that this drug is photo(geno)toxic to cells. Moreover, investigations on lipid photoperoxidation, and protein and DNA photooxidation strongly support that different cellular compartments are potential targets for DAS-induced phototoxicity.

Regarding its potential application in topical dermatological formulations, an O/W emulsion of DAS was prepared and tested in reconstructed human epidermis, and a significant phototoxicity was also demonstrated. Fortunately, this undesired side effect disappeared upon formulation of DAS along with a sunscreen. Thus, for topical treatments, the photosensitivity reactions induced by DAS can be prevented by using formulations including appropriate UVA filters.

达沙替尼（DAS）是一种用于治疗某些血液恶性肿瘤的抗癌药物。虽然达沙替尼主要用于口服，但最近因其可能的局部应用而备受关注。使用外用药物可能会引起光敏反应，但这并不属于 DAS 的不良反应。由于 DAS 可吸收 UVA，因此有可能诱发光敏反应，导致细胞靶点氧化损伤。本研究旨在模仿局部用药，调查 DAS 是否会在溶液和人造皮肤中对主要细胞靶点产生光毒性反应。研究还探讨了有机自由基和 ROS 等高活性中间产物的潜在生成，这些中间产物可能会引发光敏反应。当 DAS 在 UVA 区域照射时，检测到的第一个瞬态物种是吸收最大值约为 490 nm 的二环类三重激发态 (3DAS*)，它被氧气淬灭后产生单线态氧。用亚油酸和 3-甲基吲哚进行的淬灭实验表明，自由基介导的（I 型）对脂质和蛋白质的光敏破坏是可能的。然而，鸟苷缺乏三重淬灭表明，第二类机制也在生物大分子的光氧化过程中发挥作用。因此，中性红吸收光毒性试验（光刺激因子为 5）和彗星试验表明，这种药物对细胞具有光（基因）毒性。此外，对脂质光过氧化反应以及蛋白质和 DNA 光氧化反应的研究也有力地证明，不同的细胞区是 DAS 诱导光毒性的潜在靶点。关于 DAS 在皮肤外用制剂中的潜在应用，我们制备了一种 DAS 的水包油型乳液，并在重建的人体表皮中进行了测试，结果表明这种乳液具有显著的光毒性。幸运的是，当 DAS 与防晒霜一起配制时，这种不良副作用消失了。因此，在局部治疗中，使用含有适当 UVA 过滤器的配方可以防止 DAS 引起的光敏反应。

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引用次数: 0

Hederagenin inhibits mitochondrial damage in Parkinson’s disease via mitophagy induction Hederagenin通过诱导有丝分裂抑制帕金森病的线粒体损伤。

IF 7.1 2区生物学 Q1 BIOCHEMISTRY & MOLECULAR BIOLOGY

Free Radical Biology and Medicine

Pub Date : 2024-09-21 DOI: 10.1016/j.freeradbiomed.2024.09.030

Background

Parkinson's disease (PD) is a neurodegenerative disorder marked by the loss of dopaminergic neurons and the formation of α-synuclein aggregates. Mitochondrial dysfunction and oxidative stress are pivotal in PD pathogenesis, with impaired mitophagy contributing to the accumulation of mitochondrial damage. Hederagenin (Hed), a natural triterpenoid, has shown potential neuroprotective effects; however, its mechanisms of action in PD models are not fully understood.

Method

We investigated the effects of Hed on 6-hydroxydopamine (6-OHDA)-induced cytotoxicity in SH-SY5Y cells by assessing cell viability, mitochondrial function, and oxidative stress markers. Mitophagy induction was evaluated using autophagy and mitophagy inhibitors and fluorescent staining techniques. Additionally, transgenic Caenorhabditis elegans (C. elegans) models of PD were used to validate the neuroprotective effects of Hed in vivo by focusing on α-synuclein aggregation, mobility, and dopaminergic neuron integrity.

Results

Hed significantly enhanced cell viability in 6-OHDA-treated SH-SY5Y cells by inhibiting cell death and reducing oxidative stress. It ameliorated mitochondrial damage, evidenced by decreased mitochondrial superoxide production, restored membrane potential, and improved mitochondrial morphology. Hed also induced mitophagy, as shown by increased autophagosome formation and reduced oxidative stress; these effects were diminished by autophagy and mitophagy inhibitors. In C. elegans models, Hed activated mitophagy and reduced α-synuclein aggregation, improved mobility, and mitigated the loss of dopaminergic neurons. RNA interference targeting the mitophagy-related genes pdr-1 and pink-1 partially reversed these benefits, underscoring the role of mitophagy in Hed's neuroprotective actions.

Conclusion

Hed exhibits significant neuroprotective effects in both in vitro and in vivo PD models by enhancing mitophagy, reducing oxidative stress, and mitigating mitochondrial dysfunction. These findings suggest that Hed holds promise as a therapeutic agent for PD, offering new avenues for future research and potential drug development.

背景：帕金森病（PD）是一种以多巴胺能神经元丧失和α-突触核蛋白聚集体形成为特征的神经退行性疾病。线粒体功能障碍和氧化应激在帕金森病的发病机制中起着关键作用，有丝分裂吞噬功能受损会导致线粒体损伤累积。Hederagenin（Hed）是一种天然三萜类化合物，具有潜在的神经保护作用，但其在帕金森病模型中的作用机制尚未完全明了：我们通过评估细胞活力、线粒体功能和氧化应激标记物，研究了Hed对6-羟基多巴胺（6-OHDA）诱导的SH-SY5Y细胞细胞毒性的影响。利用自噬和有丝分裂抑制剂以及荧光染色技术评估了有丝分裂的诱导作用。此外，研究人员还利用转基因秀丽隐杆线虫（C. elegans）模型，通过关注α-突触核蛋白的聚集、流动性和多巴胺能神经元的完整性，验证了赫德在体内的神经保护作用：结果：通过抑制细胞死亡和减少氧化应激，Hed能明显提高经6-OHDA处理的SH-SY5Y细胞的存活率。线粒体超氧化物生成的减少、膜电位的恢复和线粒体形态的改善表明，Hed 能改善线粒体损伤。Hed 还能诱导有丝分裂，表现为自噬体形成增加和氧化应激减少；自噬和有丝分裂抑制剂会减弱这些作用。在C.elegans模型中，Hed激活了有丝分裂，减少了α-突触核蛋白的聚集，提高了移动性，并减轻了多巴胺能神经元的损失。针对有丝分裂相关基因 pdr-1 和 pink-1 的 RNA 干扰部分逆转了这些益处，突出了有丝分裂在 Hed 神经保护作用中的作用：结论：通过增强有丝分裂、减少氧化应激和减轻线粒体功能障碍，Hed在体外和体内帕金森病模型中都表现出了明显的神经保护作用。这些研究结果表明，Hed有望成为一种治疗帕金森病的药物，为未来的研究和潜在药物开发提供了新的途径。

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引用次数: 0

Gaudichaudione H ameliorates liver fibrosis and inflammation by targeting NRF2 signaling pathway 高地茶醌 H 通过靶向 NRF2 信号通路改善肝纤维化和炎症。

IF 7.1 2区生物学 Q1 BIOCHEMISTRY & MOLECULAR BIOLOGY

Free Radical Biology and Medicine

Pub Date : 2024-09-21 DOI: 10.1016/j.freeradbiomed.2024.09.020

Gaudichaudione H (GH) is a natural small molecular compound isolated from Garcinia oligantha Merr. (Clusiaceae). Being an uncommon rare caged polyprenylated xanthone, the potential pharmacological functions of GH remain to be fully elucidated currently. In this study, we primarily focused on identifying potential bioavailable targets and elucidating related therapeutic actions. Herein, the network pharmacology analysis, metabolomics analysis and genome-wide mRNA transcription assay were performed firstly to predict the major pharmacological action and potential targets of GH. To confirm the hypothesis, gene knockout model was created using CRISPR/Cas9 method. The pharmacological action of GH was evaluated in vitro and in vivo. Firstly, our results of network pharmacology analysis and omics assay indicated that GH significantly activated NRF2 signaling pathway, and the function could be associated with liver disease treatment. Then, the pharmacological action of GH was evaluated in vitro and in vivo. The treatment with GH significantly increased the protein levels of NRF2 and promoted the transcription of NRF2 downstream genes. Further analysis suggested that GH regulated NRF2 through an autophagy-mediated non-canonical mechanism. Additionally, the administration of GH effectively protected the liver from carbon tetrachloride (CCl₄)-induced liver fibrosis and inflammation, which depended on the activation of NRF2 in hepatic stellate cells and inflammatory cells respectively. Collectively, our findings underscore the potential therapeutic effect of GH on alleviating hepatic fibrosis and inflammation through the augmentation of NRF2 signaling pathway, providing a promising avenue for the treatment of liver fibrosis and inflammation in clinical settings.

Gaudichaudione H（GH）是从Garcinia oligantha Merr.（Clusiaceae）中分离出来的一种天然小分子化合物。作为一种不常见的稀有笼状多烯基黄酮，GH 的潜在药理功能目前仍有待全面阐明。在本研究中，我们主要侧重于确定潜在的生物利用靶点并阐明相关的治疗作用。在本研究中，我们首先进行了网络药理学分析、代谢组学分析和全基因组 mRNA 转录分析，以预测 GH 的主要药理作用和潜在靶点。为了证实这一假设，研究人员利用CRISPR/Cas9方法创建了基因敲除模型。对 GH 的药理作用进行了体外和体内评估。首先，网络药理学分析和omics检测结果表明，GH能显著激活NRF2信号通路，其功能可能与肝病治疗有关。随后，我们对 GH 的药理作用进行了体外和体内评估。经 GH 治疗后，NRF2 蛋白水平明显升高，并促进了 NRF2 下游基因的转录。进一步分析表明，GH通过自噬介导的非经典机制调控NRF2。此外，服用 GH 能有效保护肝脏免受四氯化碳（CCl4）诱导的肝纤维化和炎症的影响，而这分别依赖于肝星状细胞和炎症细胞中 NRF2 的激活。总之，我们的研究结果强调了 GH 通过增强 NRF2 信号通路缓解肝纤维化和炎症的潜在治疗效果，为临床上治疗肝纤维化和炎症提供了一个前景广阔的途径。

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引用次数: 0

The effect of tau K677 lactylation on ferritinophagy and ferroptosis in Alzheimer's disease Tau K677乳化对阿尔茨海默病中噬铁蛋白和铁蛋白沉积的影响

IF 7.1 2区生物学 Q1 BIOCHEMISTRY & MOLECULAR BIOLOGY

Free Radical Biology and Medicine

Pub Date : 2024-09-21 DOI: 10.1016/j.freeradbiomed.2024.09.021

Alzheimer's disease (AD) is characterized by cognitive decline and the accumulation of amyloid-beta plaques and hyperphosphorylated tau protein. The role of tau lactylation at the K677 site in AD progression is not well understood. This study explores how tau K677 lactylation affects ferritinophagy, ferroptosis, and their functions in an AD mouse model. Results show that mutating the K677 site to R reduces tau lactylation and inhibits ferroptosis by regulating iron metabolism factors like NCOA4 and FTH1.Tau-mutant mice showed improved memory and learning skills compared to wild-type mice. The mutation also reduced neuronal damage and was associated with decreased tau lactylation at the K677 site, regardless of phosphorylated tau levels. Gene set enrichment analysis showed that lactylation at this site was linked to the MAPK pathway, which was important for ferritinophagy in AD mice. In summary, our research indicates that the K677 mutation in tau protein may protect against AD by influencing ferritinophagy and ferroptosis through MAPK signaling pathways. Understanding these modifications in tau could lead to new treatments for AD.

阿尔茨海默病（AD）的特征是认知能力下降、淀粉样蛋白-β斑块和高磷酸化 tau 蛋白堆积。目前还不太清楚 K677 位点的 tau 乳化在阿尔茨海默病进展中的作用。本研究探讨了在一个AD小鼠模型中，tau K677乳化如何影响铁蛋白吞噬、铁突变及其功能。结果表明，将K677位点突变为R可减少tau乳化，并通过调节铁代谢因子（如NCOA4和FTH1）抑制铁嗜噬。与野生型小鼠相比，Tau突变小鼠的记忆力和学习能力有所提高。突变还减少了神经元损伤，并与K677位点的tau乳化减少有关，与磷酸化tau水平无关。基因组富集分析表明，该位点的乳化与MAPK通路有关，而MAPK通路对AD小鼠的噬铁蛋白作用非常重要。总之，我们的研究表明，tau蛋白中的K677突变可能会通过MAPK信号通路影响铁蛋白吞噬和铁变态反应，从而预防AD。了解tau蛋白的这些改变可能会为AD带来新的治疗方法。

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引用次数: 0

Effects of intermittent exposure to hypobaric hypoxia and cold on skeletal muscle regeneration: Mitochondrial dynamics, protein oxidation and turnover 间歇性暴露于低压缺氧和低温对骨骼肌再生的影响：线粒体动力学、蛋白质氧化和周转。

IF 7.1 2区生物学 Q1 BIOCHEMISTRY & MOLECULAR BIOLOGY

Free Radical Biology and Medicine

Pub Date : 2024-09-21 DOI: 10.1016/j.freeradbiomed.2024.09.032

Muscle injuries and the subsequent regeneration events compromise muscle homeostasis at morphological, functional and molecular levels. Among the molecular alterations, those derived from the mitochondrial function are especially relevant. We analysed the mitochondrial dynamics, the redox balance, the protein oxidation and the main protein repairing mechanisms after 9 days of injury in the rat gastrocnemius muscle. During the recovery rats were exposed to intermittent cold exposure (ICE), intermittent hypobaric hypoxia (IHH), and both simultaneous combined stimuli. Non-injured contralateral legs were also analysed to evaluate the specific effects of the three environmental exposures. Our results showed that ICE enhanced mitochondrial adaptation by improving the electron transport chain efficiency during muscle recovery, decreased the expression of regulatory subunit of proteasome and accumulated oxidized proteins. Exposure to IHH did not show mitochondrial compensation or increased protein turnover mechanisms; however, no accumulation of oxidized proteins was observed. Both ICE and IHH, when applied separately, elicited an increased expression of eNOS, which could have played an important role in accelerating muscle recovery. The combined effect of ICE and IHH led to a complex response that could potentially impede optimal mitochondrial function and enhanced the accumulation of protein oxidation. These findings underscore the nuanced role of environmental stressors in the muscle healing process and their implications for optimizing recovery strategies.

肌肉损伤和随后的再生事件在形态、功能和分子水平上损害了肌肉的稳态。在分子变化中，线粒体功能的变化尤为重要。我们分析了大鼠腓肠肌损伤 9 天后的线粒体动态、氧化还原平衡、蛋白质氧化和主要蛋白质修复机制。在恢复期间，大鼠暴露于间歇性冷暴露（ICE）、间歇性低压缺氧（IHH）和两种同时存在的综合刺激下。还对未受伤的对侧腿部进行了分析，以评估三种环境暴露的具体影响。我们的结果表明，在肌肉恢复过程中，ICE 通过提高电子传递链的效率增强了线粒体的适应性，降低了蛋白酶体调节亚基的表达，并积累了氧化蛋白质。暴露于 IHH 并未显示出线粒体补偿或蛋白质周转机制的增加；然而，也未观察到氧化蛋白质的积累。单独使用 ICE 和 IHH 时，都会引起 eNOS 的表达增加，这可能在加速肌肉恢复方面发挥了重要作用。ICE 和 IHH 的联合作用导致了一种复杂的反应，可能会阻碍线粒体功能的优化并增加蛋白质氧化的积累。这些发现强调了环境应激源在肌肉愈合过程中的微妙作用及其对优化恢复策略的影响。

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引用次数: 0

Ubiquitination of ATAD3A by TRIM25 exacerbates cerebral ischemia-reperfusion injury via regulating PINK1/Parkin signaling pathway-mediated mitophagy TRIM25对ATAD3A的泛素化会通过调节PINK1/Parkin信号通路介导的有丝分裂而加重脑缺血再灌注损伤。

IF 7.1 2区生物学 Q1 BIOCHEMISTRY & MOLECULAR BIOLOGY

Free Radical Biology and Medicine

Pub Date : 2024-09-20 DOI: 10.1016/j.freeradbiomed.2024.09.029

Background

Cerebral ischemia-reperfusion injury (CI/RI) is a complex process leading to neuronal damage and death, with mitophagy implicated in its pathogenesis. However, the significance of mitophagy in CI/RI remains debated.

Hypothesis

We hypothesized that TRIM25 reduces ATAD3A expression by ubiquitinating ATAD3A, promoting mitophagy via the PINK1/Parkin pathway, and aggravating CI/RI.

Study design

Rat middle cerebral artery occlusion (MCAO) followed by reperfusion and oxygen-glucose deprivation and reoxygenation (OGD/R) in PC12 cells were used as animal and cell models, respectively.

Methods

To evaluate the success of the CI/R modeling, TTC and HE staining were employed. The determination of serum biochemical indexes was carried out using relative assay kits. The Western Blot analysis was employed to assess the expression of ATAD3A, TRIM25, as well as mitophagy-related proteins (PINK1, Parkin, P62, and LC3II/LC3I). The mRNA levels were detected using QRT-PCR. Mitochondrial membrane potential was assessed through JC-1 staining. Mitosox Red Assay Kit was utilized to measure mitochondrial reactive oxygen species levels in PC12 cells. Additionally, characterization of the mitophagy structure was performed using transmission electron microscopy (TEM).

Results

Our findings showed down-regulation of ATAD3A and up-regulation of TRIM25 in both in vivo and in vitro CI/RI models. Various experimental techniques such as Western Blot, JC-1 staining, Mitosox assay, Immunofluorescence assay, and TEM observation supported the occurrence of PINK1/Parkin signaling pathway-mediated mitophagy in both models. ATAD3A suppressed mitophagy, while TRIM25 promoted it during CI/RI injury. Additionally, the results indicated that TRIM25 interacted with and ubiquitinated ATAD3A via the proteasome pathway, affecting ATAD3A protein stability and expression.

Conclusion

TRIM25 promoted Pink1/Parkin-dependent excessive mitophagy by destabilizing ATAD3A, exacerbating CI/RI. Targeting TRIM25 and ATAD3A may offer therapeutic strategies for mitigating CI/RI and associated neurological damage.

背景：脑缺血再灌注损伤（CI/RI）是一个导致神经元损伤和死亡的复杂过程，其发病机制与有丝分裂有关。然而，有丝分裂在 CI/RI 中的意义仍存在争议：我们假设TRIM25通过泛素化ATAD3A减少ATAD3A的表达，通过PINK1/Parkin途径促进线粒体自噬，并加重CI/RI.研究设计：研究设计：分别以大鼠大脑中动脉闭塞（MCAO）后再灌注和PC12细胞氧-葡萄糖剥夺和再氧合（OGD/R）为动物模型和细胞模型：为了评估 CI/R 模型的成功与否，采用了 TTC 和 HE 染色法。使用相对测定试剂盒测定血清生化指标。采用 Western 印迹分析评估 ATAD3A、TRIM25 以及有丝分裂相关蛋白（PINK1、Parkin、P62 和 LC3II/LC3I）的表达。采用 QRT-PCR 技术检测 mRNA 水平。线粒体膜电位通过 JC-1 染色进行评估。Mitosox Red 检测试剂盒用于测量 PC12 细胞线粒体活性氧水平。此外，还利用透射电子显微镜（TEM）对线粒体吞噬结构进行了表征：结果：我们的研究结果表明，在体内和体外 CI/RI 模型中，ATAD3A 下调，TRIM25 上调。Western印迹、JC-1染色、Mitosox检测、免疫荧光检测和TEM观察等多种实验技术都支持在这两种模型中发生由PINK1/Parkin信号通路介导的有丝分裂。在 CI/RI 损伤过程中，ATAD3A 抑制了有丝分裂，而 TRIM25 则促进了有丝分裂。此外，研究结果表明，TRIM25通过蛋白酶体途径与ATAD3A相互作用并泛素化，影响了ATAD3A蛋白的稳定性和表达：结论：TRIM25通过破坏ATAD3A的稳定性，促进了Pink1/Parkin依赖性的过度有丝分裂，从而加剧了CI/RI。靶向 TRIM25 和 ATAD3A 可为减轻 CI/RI 及相关神经损伤提供治疗策略。

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引用次数: 0

Detection of lipid radicals generated via cerebral ischemia/reperfusion injury using a radiolabeled nitroxide probe 使用放射性标记的亚硝基探针检测脑缺血/再灌注损伤产生的脂质自由基。

IF 7.1 2区生物学 Q1 BIOCHEMISTRY & MOLECULAR BIOLOGY

Free Radical Biology and Medicine

Pub Date : 2024-09-19 DOI: 10.1016/j.freeradbiomed.2024.09.025

Reactive oxygen species generated via reperfusion cause lipid damage and induce lipid peroxidation, leading to cerebral ischemia/reperfusion injury and exacerbation of cerebral infarction. Lipid radicals are key molecules generated during lipid peroxidation. Therefore, understanding the spatiotemporal behavior of lipid radicals is important to improve the therapeutic outcomes of cerebral infarction. However, the behaviors of lipid radicals in the brain remain unclear. In this study, we aimed to evaluate the distribution of radioactivity in a transient middle cerebral artery occlusion (tMCAO) model using lipid radical detection probe [¹²⁵I]1 to assess the behaviors of lipid radicals after cerebral ischemia/reperfusion. The tMCAO model administered [¹²⁵I]1 exhibited significant differences in the timing and location of radioactivity accumulation between the ischemic and non-ischemic regions. Liquid chromatography/mass spectrometry analysis identified the lipid radical adducts formed by the reaction of 1 with the lipid radicals generated after reperfusion. More adducts were detected in the ischemic region samples than in the non-ischemic region samples. Therefore, 1 successfully detected the lipid radicals generated after cerebral ischemia/reperfusion. Overall, this study demonstrates the potential of nuclear medical imaging using radiolabeled 1 to detect the lipid radicals generated after cerebral ischemia/reperfusion. Our approach can aid in the development of new therapeutic agents scavenging lipid radicals after cerebral reperfusion by facilitating the determination of therapeutic efficacy and optimal administration period.

再灌注产生的活性氧会造成脂质损伤，诱发脂质过氧化，从而导致脑缺血/再灌注损伤，加重脑梗塞。脂质自由基是脂质过氧化过程中产生的关键分子。因此，了解脂质自由基的时空行为对改善脑梗塞的治疗效果非常重要。然而，脂质自由基在大脑中的行为仍不清楚。本研究旨在使用脂质自由基检测探针[125I]1评估一过性大脑中动脉闭塞（tMCAO）模型中的放射性分布，以评估脑缺血/再灌注后脂质自由基的行为。在给药[125I]1的tMCAO模型中，缺血区域和非缺血区域的放射性积累时间和位置存在显著差异。液相色谱/质谱分析确定了 1 与再灌注后产生的脂质自由基反应形成的脂质自由基加合物。与非缺血区样本相比，缺血区样本中检测到的加合物更多。因此，1 成功地检测到了脑缺血/再灌注后产生的脂质自由基。总之，这项研究证明了利用放射性标记的 1 进行核医学成像检测脑缺血/再灌注后产生的脂质自由基的潜力。我们的方法有助于确定疗效和最佳用药期，从而帮助开发清除脑再灌注后脂质自由基的新治疗药物。

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引用次数: 0

SIRT-1/RHOT-1/PGC-1α loop modulates mitochondrial biogenesis and transfer to offer resilience following endovascular stem cell therapy in ischemic stroke SIRT-1/RHOT-1/PGC-1α环路调节线粒体生物生成和转移，为缺血性中风的血管内干细胞治疗提供恢复力。

IF 7.1 2区生物学 Q1 BIOCHEMISTRY & MOLECULAR BIOLOGY

Free Radical Biology and Medicine

Pub Date : 2024-09-19 DOI: 10.1016/j.freeradbiomed.2024.09.022

Current clinical interventions for stroke majorly involve thrombolysis or thrombectomy, however, cessation of the progressive deleterious cellular cascades post-stroke and long-term neuroprotection are yet to be explored. Mitochondria are highly vulnerable organelles and their dysfunction is one of the detrimental consequences following stroke. Mitochondria dysregulation activate unfavourable cellular events over a period of time that leads to the collapse of neuronal machinery in the brain. Hence, strategies to protect and replenish mitochondria in injured neurons may be useful and needs to be explored. Stem cell therapy in ischemic stroke holds a great promise. Past studies have shown beneficial outcomes of endovascularly delivered stem cells in both pre-clinical and clinical settings. Intra-arterial (IA) administration can provide more cells to the stroke foci and affected brain regions than intravenous administration. Supplying new mitochondria to the stroke-compromised neurons either in the core or penumbra by infused stem cells can help increase their survival and longevity. Previously, our lab has demonstrated that IA 1∗10⁵ mesenchymal stem cells (MSCs) in rats were safe, efficacious and rendered neuroprotection by regulating neuronal calcineurin, modulating sirtuin1(SIRT-1) mediated inflammasome signaling, ameliorating endoplasmic reticulum-stress, alleviation of post-stroke edema and reducing cellular apoptosis. To explore further, our present study aims to investigate the potential of IA MSCs in protecting and replenishing mitochondria in the injured neurons post-stroke and the involvement of SIRT-1/RHOT-1/PGC-1α loop towards mitochondria transfer, biogenesis, and neuroprotection. This study will open new avenues for using stem cells for ischemic stroke in clinics as one of the future adjunctive therapies.

目前针对中风的临床干预措施主要包括溶栓或血栓切除术，然而，停止中风后逐渐恶化的细胞级联和长期神经保护仍有待探索。线粒体是非常脆弱的细胞器，其功能障碍是中风后的有害后果之一。线粒体失调会在一段时间内激活不利的细胞事件，导致大脑神经元机制崩溃。因此，保护和补充损伤神经元线粒体的策略可能是有用的，需要进行探索。干细胞疗法在缺血性中风中大有可为。过去的研究表明，在临床前和临床环境中，血管内输送干细胞都能产生有益的结果。与静脉给药相比，动脉内给药能为中风灶和受影响的脑区提供更多细胞。通过注入干细胞为中风受损的核心或半影神经元提供新的线粒体，有助于提高它们的存活率和寿命。在此之前，我们的实验室已经证实，在大鼠体内注入1*105间充质干细胞（MSCs）是安全、有效的，并能通过调节神经元钙调蛋白、调节sirtuin1（SIRT-1）介导的炎性体信号转导、改善内质网应激、减轻中风后水肿和减少细胞凋亡来提供神经保护。本研究旨在进一步探讨 IA 间充质干细胞在中风后保护和补充损伤神经元线粒体方面的潜力，以及 SIRT-1/RHOT-1/PGC-1α 环路在线粒体转移、生物生成和神经保护方面的参与。这项研究将为临床利用干细胞治疗缺血性中风开辟新的途径，成为未来的辅助疗法之一。

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引用次数: 0

Mapping of oxidative modifications on the alpha-keto glutarate dehydrogenase complex induced by singlet oxygen: Effects on structure and activity 绘制单线态氧诱导的α-酮谷氨酸脱氢酶复合物氧化修饰图：对结构和活性的影响。

IF 7.1 2区生物学 Q1 BIOCHEMISTRY & MOLECULAR BIOLOGY

Free Radical Biology and Medicine

Pub Date : 2024-09-18 DOI: 10.1016/j.freeradbiomed.2024.09.024

The large multi-subunit mitochondrial alpha-keto glutarate dehydrogenase (KGDH) complex plays a key, rate-determining, role in the tricarboxylic acid (Krebs) cycle, catalyzing the conversion of alpha-keto glutarate to succinyl-CoA. This complex is both a source and target of oxidants, but the sites of modification and association with structural changes and activity loss are poorly understood. We report here oxidative modifications induced by Rose Bengal (RB) in the presence of O₂, a source of singlet oxygen (¹O₂). A rapid loss of activity was detected, with this being dependent on light exposure, illumination time, and the presence of RB and O₂. Activity loss was enhanced by D₂O (consistent with ¹O₂ involvement), but diminished by both pre- and (to a lesser extent) post-illumination addition of lipoic acid and lipoamide. Aggregates containing all three KGDH subunits were detected on photooxidation. LC-MS experiments provided evidence for oxidation at 45 sites, including specific Met, His, Trp, Tyr residues and the lipoyllysine active-site cofactor. Products include mono- and di-oxygenated species, and kynurenine from Trp. Mapping of the modifications to the 3-D structure showed that these are localized to both the inner channel and the external surface, consistent with reactions of free ¹O₂, however the sites and extent of modification do not correlate with their solvent accessibility. These products are generated concurrently with loss of activity, indicative of strong links between these events. These data provide evidence for the impairment of KGDH activity by ¹O₂ via the oxidation of specific residues on the protein subunits of the complex.

大型多亚基线粒体α-酮戊二酸脱氢酶（KGDH）复合物在三羧酸（克雷布斯）循环中发挥着决定速率的关键作用，催化α-酮戊二酸向琥珀酰-CoA的转化。该复合物既是氧化剂的来源，也是氧化剂的目标，但人们对其修饰部位以及与结构变化和活性丧失的关系知之甚少。我们在此报告了玫瑰红（RB）在单线态氧（1O2）来源 O2 的存在下诱导的氧化修饰。我们检测到活性迅速丧失，这与光照、光照时间以及 RB 和 O2 的存在有关。D2O 会增强活性损失（与 1O2 的参与相一致），但在光照前和光照后添加硫辛酸和脂酰胺（在较小程度上）会降低活性损失。在光氧化作用下，检测到含有所有三种 KGDH 亚基的聚集体。LC-MS 实验提供了 45 个位点氧化的证据，包括特定的 Met、His、Trp、Tyr 残基和脂酰赖氨酸活性位点辅助因子。产物包括单氧和双氧物种，以及来自 Trp 的犬尿氨酸。根据三维结构绘制的修饰图显示，这些修饰位于内通道和外表面，与游离 1O2 的反应一致，但修饰的位点和程度与其溶剂可及性并不相关。这些产物与活性丧失同时产生，表明这些事件之间存在密切联系。这些数据为 1O2 通过氧化复合物蛋白质亚基上的特定残基来损害 KGDH 的活性提供了证据。

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引用次数: 0

Lipid radicals and oxidized cholesteryl esters in low- and high-density lipoproteins in patients with β-thalassemia: Effects of iron overload and iron chelation therapy β地中海贫血患者低密度和高密度脂蛋白中的脂质自由基和氧化胆固醇酯：铁超载和铁螯合疗法的影响

IF 7.1 2区生物学 Q1 BIOCHEMISTRY & MOLECULAR BIOLOGY

Free Radical Biology and Medicine

Pub Date : 2024-09-18 DOI: 10.1016/j.freeradbiomed.2024.09.026

Iron overload results in lipid peroxidation (LPO) and the oxidative modification of circulating lipoproteins, which contributes to cardiovascular complications in patients with β-thalassemia. Investigating LPO may provide opportunities for the development of novel therapeutic strategies; however, the chemical pathways underlying iron overload-induced LPO in β-thalassemia lipoproteins remain unclear. In this study, we identified various species of lipid radicals (L^•), the key mediators of LPO, and oxidized cholesteryl esters (oxCE) derived from the in vitro oxidation of major core lipids, cholesteryl linoleate (CE18:2) and cholesteryl arachidonate (CE20:4); the levels of these radical products in low-density lipoproteins (LDL) and high-density lipoproteins (HDL) were measured and compared between β-thalassemia patients and healthy subjects by using a specific fluorescent probe for L^• with a liquid chromatography-tandem mass spectrometric method. Our results demonstrated that iron overload substantially decreased the levels of CE18:2 and CE20:4 substrates and α-tocopherol, resulting in higher levels of full-length and short-chain truncated L^• and oxCE products. In particular, CE epoxyallyl radicals (^•CE-O) were observed in the lipoproteins of β-thalassemia, revealing the pathological roles of iron overload in the progression of LPO. In addition, we found that intermission for two weeks of iron chelators can increase the production of these oxidized products; therefore, suggesting the beneficial effects of iron chelators in preventing LPO progression. In conclusion, our findings partly revealed the primary chemical pathway by which the LPO of circulating lipoproteins is influenced by iron overload and affected by iron chelation therapy. Moreover, we found that ^•CE + O shows potential as a sensitive biomarker for monitoring LPO in individuals with β-thalassemia.

铁超载会导致脂质过氧化（LPO）和循环脂蛋白的氧化修饰，从而引发β地中海贫血患者的心血管并发症。研究 LPO 可为开发新型治疗策略提供机会；然而，β-地中海贫血脂蛋白中铁超载诱导 LPO 的化学途径仍不清楚。在这项研究中，我们鉴定了脂质自由基（L-）（LPO 的关键介质）的各种类型，以及主要核心脂质胆固醇亚油酸酯（CE18:2）和胆固醇花生四烯酸酯（CE20:4）体外氧化产生的氧化胆固醇酯（oxCE）：4）；使用 L- 的特异性荧光探针和液相色谱-串联质谱法，测量低密度脂蛋白（LDL）和高密度脂蛋白（HDL）中这些自由基产物的水平，并对β-地中海贫血患者和健康人进行比较。我们的结果表明，铁超载大大降低了 CE18:2 和 CE20:4 底物以及 α-生育酚的水平，导致全长和短链截短的 L- 和 oxCE 产物水平升高。特别是在β地中海贫血症患者的脂蛋白中观察到了CE环氧烯丙基自由基（-CE-O），揭示了铁超载在LPO进展中的病理作用。此外，我们还发现，停用铁螯合剂两周可增加这些氧化产物的产生；因此，这表明铁螯合剂在防止 LPO 进展方面具有有益作用。总之，我们的研究结果部分揭示了循环脂蛋白的 LPO 受铁超载影响和铁螯合疗法影响的主要化学途径。此外，我们还发现-CE + O有望成为监测β地中海贫血患者LPO的灵敏生物标志物。

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引用次数: 0