Nanoparticles targeting OPN loaded with BY1 inhibits vascular restenosis by inducing FTH1-dependent ferroptosis in vascular smooth muscle cells.

Vascular restenosis following angioplasty continues to pose a significant challenge. The heterocyclic trioxirane compound [1, 3, 5-tris((oxiran-2-yl)methyl)-1, 3, 5-triazinane-2, 4, 6-trione (TGIC)], known for its anticancer activity, was utilized as the parent ring to conjugate with a non-steroidal anti-inflammatory drug, resulting in the creation of the spliced conjugated compound BY1. We found that BY1 induced ferroptosis in VSMCs as well as in neointima hyperplasia. Furthermore, ferroptosis inducers amplified BY1-induced cell death, while inhibitors mitigated it, indicating the contribution of ferroptosis to BY1-induced cell death. Additionally, we established that ferritin heavy chain1 (FTH1) played a pivotal role in BY1-induced ferroptosis, as evidenced by the fact that FTH1 overexpression abrogated BY1-induced ferroptosis, while FTH1 knockdown exacerbated it. Further study found that BY1 induced ferroptosis by enhancing the NCOA4-FTH1 interaction and increasing the amount of intracellular ferrous. We compared the effectiveness of various administration routes for BY1, including BY1-coated balloons, hydrogel-based BY1 delivery, and nanoparticles targeting OPN loaded with BY1 (TOP@MPDA@BY1) for targeting proliferated VSMCs, for prevention and treatment of the restenosis. Our results indicated that TOP@MPDA@BY1 was the most effective among the three administration routes, positioning BY1 as a highly promising candidate for the development of drug-eluting stents or treatments for restenosis.

Renal sympathetic denervation attenuates left ventricle hypertrophy in spontaneously hypertensive rats by suppressing the Raf/MEK/ERK signaling pathway.

OBJECTIVE: To explore the effect of renal sympathetic denervation (RSD) on left ventricle hypertrophy and the Raf/MEK/ERK signaling pathway in spontaneously hypertensive rats (SHRs). METHODS: SHRs were divided into SHR, SHR + Sham, SHR + RSD and SHR + U0126 groups, with WKY rats as the baseline controls. The blood pressure of rats was observed, while myocardial fibrosis was evaluated through Masson staining. Thereafter, real-time quantitative polymerase chain reaction (qRT-PCR) was carried out to determine the levels of myocardial-hypertrophy-related markers, and Western blotting was used to measure the activity of the Raf/MEK/ERK signaling pathway. RESULTS: In comparison with the WKY group, significant increases were observed in the systolic pressure and diastolic pressure of rats from the other four groups at different time points after surgery. In addition, rats in these groups had obvious increases in LVMI, renal NE and IVSd and decreases in LVEDd, LVEF and LVFS. In addition, the CVF of myocardial tissues was increased, with the upregulation of ANP, BNP and ß-MHC and the downregulation of α-MHC. For the activity of the Raf/MEK/ERK signaling pathway, the levels of p-Raf/Raf, p-MEK/MEK and p-ERK1/2/ERK1/2 were all remarkably elevated (all P < .05). Further comparison with the SHR group showed that the above indexes in the rats were significantly improved in the RSD group and SHR + U0126 group (all P < .05). CONCLUSION: RSD may decrease blood pressure, mitigate hypertension-induced left ventricle hypertrophy and improve cardiac function efficiently in SHRs via the suppression of the Raf/MEK/ERK signaling pathway.

Apurinic/apyrimidinic endonuclease/redox factor 1 (APE1) alleviates myocardial hypoxia-reoxygenation injury by inhibiting oxidative stress and ameliorating mitochondrial dysfunction.

Oxidative stress and mitochondrial dysfunction are considered to be activators of apoptosis and serve a pivotal role in the pathogenesis of myocardial ischemia-reperfusion (MI/R) injury. Apurinic/apyrimidinic endonuclease/redox factor 1 (APE1) is a multifunctional protein that processes the cellular response to DNA damage and oxidative stress. Little is known about the role of APE1 in the pathogenesis of MI/R injury. The aim of the present study was to investigate the effects of APE1 on hypoxia-reoxygenation (H/R)-induced H9c2 cardiomyocyte injury and the underlying mechanism responsible. It was demonstrated that H/R decreased cell viability and increased lactic dehydrogenase (LDH) release, as well as reducing APE1 expression in H9c2 cells. However, APE1 overexpression induced by transfection with APE1-expressing lentivirus significantly increased H9c2 cell viability, decreased LDH release, decreased apoptosis and reduced caspase-3 activity in H/R-treated H9c2 cells. APE1 overexpression ameliorated the H/R-induced increases in reactive oxygen species and NAPDH oxidase expression, as well as the decreases in superoxide dismutase activity and glutathione expression. Furthermore, APE1 overexpression increased mitochondrial membrane potential and ATP production, stabilized electron transport chain activity (as illustrated by increased NADH-ubiquinone oxidoreductase, succinate dehydrogenase, coenzyme Q-cytochrome c oxidoreductase and cytochrome c oxidase activities) and decreased the ratio of B-cell lymphoma 2-associated X protein/B-cell lymphoma 2 in H/R, improving mitochondrial dysfunction. In conclusion, the results of the present study suggest that APE1 alleviates H/R-induced injury in H9c2 cells by attenuating oxidative stress and ameliorating mitochondrial dysfunction. APE1 may therefore be used as an effective treatment for MI/R injury.

[Effects of rabbit limbs ischemia/ reperfusion on myocardial necrosis and apoptosis].

OBJECTIVE: To investigate the effects of rabbit limbs ischemia/reperfusion on myocardial necrosis and apoptosis in vivo. METHODS: Thirty-six healthy new zealand rabbits were randomly divided into 3 groups: (1) Sham group; (2) I/R(Ischemia/reperfusion) group; (3) RPostC (remote postconditioning) group. The activity of blood serum creatine kinase (CK) and lactate dehydrogenase (LDH) were measured at baseline, the end of ischemia after 60 min and 120 min of reperfusion respectively. The extent of myocardial ischemia and the scope of myocardial infarction were assessed by evans blue and Triphenyl tetrazolium chloride (TTC). The myocardial cell's apoptosis at the area of myocardial ischemia was estimated by Tunel. Protein expression of caspase-3, Bcl-2 and Bax in myocardial ischemic area were analyzed with the method of immunohistochemistry. RESULTS: Compared with I/R group, the myocardial infarct size and the CK activity were significantly reduced in RPostC group. The Tunel positive index of RPostC group in ischemic myocardium was significantly lower than that in I/R group (21.79% +/- 1.07% vs 35.81% +/- 1.10%, P < 0.05). Caspase-3 positive cells index was calculated with randomly selected five regions in each slide and then the positive cells in per hundred cells were calculated. The RPostC group of caspase-3 positive cells was significantly lower than that in I/ R group(25.03% +/- 1.16% as 39% +/- 2.43%, P < 0.05). Compared with the sham group, the Bax protein expression index and the Bcl-2 protein expression index of I/R group and RPostC group were increased. The Bax/Bcl-2 ratio of RPostC group decreased, while it was increased in I/R. Compared with the I/R group, the Bax protein expression and Bax/Bcl-2 ratio of RPostC group significantly reduced, but the expression index of Bcl-2 ratio was significantly increased, the differences were statistically significant. CONCLUSION: Limbs ischemia/postconditioning could significantly reduce necrosis and apoptosis of ischemia/reperfusion myocardium. The mechanism of reducing the myocardial cell apoptosis may have relation to inhibiting the activation of pro-apoptotic gene caspase-3 and increased expression of Bcl-2.