Parkinson's disease (PD) is a neurodegenerative disorder characterized by degeneration of dopaminergic neurons associated with dysregulation of iron homeostasis in the brain. Ferroptosis is an iron-dependent cell death process that serves as a significant regulatory mechanism in PD. However, its underlying mechanisms are not yet fully understood. By performing RNA sequencing analysis, we found that the main iron storage protein ferritin heavy chain 1 (FTH1) is differentially expressed in the rat 6hydroyxdopamine (6-OHDA) model of PD compared with control rats. Our present work demonstrates that FTH1 is involved in iron accumulation and the ferroptosis pathway in this model. Knockdown of FTH1 in PC-12 cells significantly inhibited cell viability and caused mitochondrial dysfunction. Moreover, FTH1 was found to be involved in ferritinophagy, a selective form of autophagy involving the degradation of ferritin by ferroptosis. Overexpression of FTH1 in PC-12 cells impaired ferritinophagy and downregulated microtubule-associated protein light chain 3 and nuclear receptor coactivator 4 expression, ultimately suppressing cell death induced by ferroptosis. Consistent with these findings, the ferritinophagy inhibitors chloroquine and bafilomycin A1 inhibited ferritin degradation and ferroptosis in 6-OHDA-treated PC-12 cells. This entire process was mediated by the cyclic regulation of FTH1 and ferritinophagy. Taken together, these results suggest that FTH1 links ferritinophagy and ferroptosis in the 6-OHDA model of PD, and provide a new perspective and potential for a pharmacological target in this disease.
The use of a halogen bond donor to catalyze Friedel–Crafts reactions of indoles with a range of aldehydes and ketones to directly produce bis(indolyl)methanes, including the natural products arsindoline A, arundine, trisindoline, and vibrindole A, is reported. The bidentate catalyst used in these reactions proved to be more effective than a monondentate analogue, a thiourea commonly used as an organocatalyst, and even a trityl cation that has been used previously in the synthesis of bis(indolyl)methanes.
Objective To observe the protective effect of epigallocatechin gallate (EGCG) on dextran sulfate sodium- (DSS-) induced ulcerative colitis in rats and to explore the roles of TLR4/MyD88/NF-κB signaling pathway. Methods Rat models of ulcerative colitis were established by giving DSS. EGCG (50 mg/kg/d) was given to assess disease activity index. HE staining was applied to observe histological changes. ELISA and qPCR detected the expression of inflammatory factors. Flow cytometry was used to measure the percentage of CD4+IFN-γ+ and CD4+IL-4+ in the spleen and colon. TLR4 antagonist E5564 was given in each group. Flow cytometry was utilized to detect CD4+IFN-γ+ and CD4+IL-4+ cells. Immunohistochemistry, qPCR, and western blot assay were applied to measure the expression of TLR4, MyD88, and NF-κB. Results EGCG improved the intestinal mucosal injury in rats, inhibited production of inflammatory factors, maintained the balance of Th1/Th2, and reduced the expression of TLR4, MyD88, and NF-κB. After TLR4 antagonism, the protective effect of EGCG on intestinal mucosal injury was weakened in rats with ulcerative colitis, and the expressions of inflammatory factors were upregulated. Conclusion EGCG can inhibit the intestinal inflammatory response by reducing the severity of ulcerative colitis and maintaining the Th1/Th2 balance through the TLR4/MyD88/NF-κB signaling pathway.
Here a new, mild and versatile method for one-pot cascade synthesis of diverse N-methoxyisoquinolinediones via Rh(III)-catalyzed regioselective carbenoid insertion C-H activation/cyclization of N-methoxybenzamides with α-diazotized Meldrum's acid has been achieved. Extension of the developed Rh(III) catalysis for building new analogs of the marketed drug Edaravone has also been demonstrated.
BackgroundExposure to cold weather is associated with infaust cardiovascular responses, including myocardial infarction and arrhythmias. However, the exact mechanisms of these adverse changes in the myocardium under cold stress are unknown. This study was designed to investigate the mechanisms of cardiac injury induced by cold stress in mice.MethodsThe mice were randomly divided into three groups, normal control (no handling), 1-week cold stress and 2-week cold stress. We observed physiological changes of the mice and morphological changes of myocardium tissues, and we measured the changes of 3′-nitrotyrosine and 4-hydroxynonenal, the expression levels of superoxide dismutase-1, superoxide dismutase-2, Bax, Bad, Bcl-2, Nuclear factor erythroid-derived 2-like 2 (Nrf2) and Kelch like-ECH-associated protein 1 (Keap1) in myocardium by western blot. Besides, we detected mRNA of superoxide dismutase-1, superoxide dismutase-2, Bax, Bad, Bcl-2, Nrf2 and Keap1 by real-time PCR. One-way analysis of variance, followed by LSD-t test, was used to compare each variable for differences among the groups.ResultsEchocardiography analyses demonstrated left ventricle dysfunction in the groups receiving cold stress. Histological analyses witnessed inflammation, vacuolar and eosinophilic degeneration occurred in left ventricle tissues. Western blotting results showed increased 3′-nitrotyrosine and 4-hydroxynonenal and decreased antioxidant enzymes (superoxide dismutase-1 and superoxide dismutase-2) in the myocardium. Expression of Nrf2 and Keap1 followed a downward trend under cold exposure, as indicated by western blotting and real-time PCR. Expression of anti-apoptotic protein Bcl-2 also showed the same trend. In contrast, expression of pro-apoptotic proteins Bax and Bad followed an upward trend under cold exposure. The results of real-time PCR were consistent with those of western blotting.ConclusionsThese findings were very significant, showing that cold exposure induced cardiac injury by inhibiting the Nrf2-Keap1 signaling pathway.
Objective To explore the effect of microRNA-132 of heart failure and provide theoretical guidance for clinical treatment of heart failure (HF). Methods Peripheral blood was collected from HF patients. RT-qPCR was used to determine microRNA-132 expression. Mouse models of heart failure were established. Color Doppler ultrasound was utilized to measure the changes of cardiac function. HE and Masson staining were applied to observe pathological changes of the myocardium. After H9C2 cells were transfected with microRNA-132, MTT assay was employed to detect the stability of H9C2 cells. ELISA was used to measure the levels of oxidative stress factors. Western blot assay and RT-qPCR were utilized to determine the expression of Bax, Bcl-2, TGF-β1, and smad3. Results MicroRNA-132 expression was downregulated in HF patients' blood. After establishing mouse models of HF, cardiac function obviously decreased. HE staining revealed the obvious edema and hypertrophy of cardiomyocytes. Masson staining demonstrated that cardiomyocytes were markedly fibrotic. After microRNA-132 transfection and H9C2 cell apoptosis induced by H2O2, antioxidant stress and antiapoptotic ability of the H9C2 cells obviously increased. TGF-β1 and smad3 expression remarkably diminished. Conclusion Overexpression of microRNA-132 dramatically increased the antioxidant stress and antiapoptotic ability of H9C2 cells and decreased the expression of TGF-β1 and smad3.
Myocardial ischemia, hypoxia and reperfusion injury are induced by aortic occlusion, cardiac arrest and resuscitation during cardiopulmonary bypass (CPB), which can severely affect cardiac function. The aim of the present study was to investigate the effects of hydrogen-rich solution (HRS) and aquaporin (AQP) on cardiopulmonary bypass (CPB)-induced myocardial injury, and determine the mechanism of the phosphatidylinositol 3-kinase (PI3K)/protein kinase B (Akt) signaling pathway. Sprague Dawley rats were divided into a sham operation group, a CPB surgery group and a HRS group. A CPB model was established, and the hemodynamic parameters were determined at the termination of CPB. The myocardial tissues were observed by hematoxylin and eosin, and Masson staining. The levels of myocardial injury markers [adult cardiac troponin I (cTnI), lactate dehydrogenase (LDH), creatine kinase MB (CK-MB) and brain natriuretic peptide (BNP)], inflammatory factors [interleukin (IL)-1β, IL-6 and tumor necrosis factor-α (TNF-α)] and oxidative stress indicators [superoxide dismutase (SOD), malondialdehyde (MDA) and myeloperoxidase (MPO)] were determined by ELISA. Furthermore, H9C2 cells were treated with HRS following hypoxia/reoxygenation. Cell viability and cell apoptosis were investigated. The expression of apoptosis regulator Bcl-2 (Bcl-2), apoptosis regulator Bax (Bax), caspase 3, AQP-1, AQP-4, phosphorylated (p)-Akt, heme oxygenase 1 (HO-1) and nuclear factor erythroid 2-related factor 2 (Nrf2) were investigated using western blotting and quantitative-polymerase chain reaction of tissues and cells. Following CPB, myocardial cell arrangement was disordered, myocardial injury markers (cTnI, LDH, CK-MB and BNP), inflammatory cytokines (IL-1β, IL-6 and TNF-α) and MDA levels were significantly increased compared with the sham group; whereas the SOD levels were significantly downregulated following CPB compared with the sham group. HRS attenuated myocardial injury, reduced the expression levels of cTnI, LDH, CK-MB, BNP, IL-1β, IL-6, TNF-α, MDA and MPO, and increased SOD release. Levels of Bcl-2, AQP-1, AQP-4, p-Akt, HO-1 and Nrf2 were significantly increased following HRS; whereas Bax and caspase-3 expression levels were significantly reduced following CPB. HRS treatment significantly increased the viability of myocardial cells, reduced the rate of myocardial cell apoptosis and the release of MDA and LDH compared with the CPB group. A PI3K inhibitor (LY294002) was revealed to reverse the protective effect of HRS treatment. HRS was demonstrated to attenuate CPB-induced myocardial injury, suppress AQP-1 and AQP-4 expression following CPB treatment and protect myocardial cells via the PI3K/Akt signaling pathway.
Parkinson's disease (PD) is a neurodegenerative disease characterized by the selective loss of dopaminergic neurons in the substantia nigra (SN). In a previous study, the authors demonstrated that ferritin heavy chain 1 (FTH1) inhibited ferroptosis in a model of 6-hydroxydopamine (6-OHDA)-induced PD. However, whether and how microRNAs (miRNAs/miRs) modulate FTH1 in PD ferroptosis is not yet well understood. In the present study, in vivo and in vitro models of PD induced by 6-OHDA were established. The results in vivo and in vitro revealed that the levels of the ferroptosis marker protein, glutathione peroxidase 4 (GPX4), and the PD marker protein, tyrosine hydroxylase (TH), were decreased in the model group, associated with a decreased FTH1 expression and the upregulation of miR-335. In both the in vivo and in vitro models, miR-335 mimic led to a lower FTH1 expression, exacerbated ferroptosis and an enhanced PD pathology. The luciferase 3′-untranslated region reporter results identified FTH1 as the direct target of miR-335. The silencing of FTH1 in 6-OHDA-stimulated cells enhanced the effects of miR-335 on ferroptosis and promoted PD pathology. Mechanistically, miR-335 enhanced ferroptosis through the degradation of FTH1 to increase iron release, lipid peroxidation and reactive oxygen species (ROS) accumulation, and to decrease mitochondrial membrane potential (MMP). On the whole, the findings of the present study reveal that miR-335 promotes ferroptosis by targeting FTH1 in in vitro and in vivo models of PD, providing a potential therapeutic target for the treatment of PD.
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