作者: François, Florence ; Malfroy-Camine, Bernard ; Affortit, Corentin ; Venail, Frederic ; Menardo, Julien ; Puel, Jean-Luc ; Wang, Jing ; Benkafadar, Nesrine ; Ceccato, Jean-Charles ; Casas, François

In our aging society, age-related hearing loss (ARHL) has become a major socioeconomic issue. Reactive oxygen species (ROS) may be one of the main causal factors of age-related cochlear cell degeneration. We examined whether ROS-induced DNA damage response drives cochlear cell senescence and contributes to ARHL from the cellular up to the system level. Our results revealed that sublethal concentrations of hydrogen peroxide (H₂O₂) exposure initiated a DNA damage response illustrated by increased γH2AX and 53BP1 expression and foci formation mainly in sensory hair cells, together with increased levels of p-Chk2 and p53. Interestingly, postmitotic cochlear cells exposed to H₂O₂ displayed key hallmarks of senescent cells, including dramatically increased levels of p21, p38, and p-p38 expression, concomitant with decreased p19 and BubR1 expression and positive senescence-associated β-galactosidase labeling. Importantly, the synthetic superoxide dismutase/catalase mimetic EUK-207 attenuated H₂O₂-induced DNA damage and senescence phenotypes in cochlear cells in vitro. Furthermore, systemic administration of EUK-207 reduced age-related loss of hearing and hair cell degeneration in senescence-accelerated mouse-prone 8 (SAMP8) mice. Altogether, these findings highlight that ROS-induced DNA damage responses drive cochlear cell senescence and contribute to accelerated ARHL. EUK-207 and likely other antioxidants with similar mechanisms of action could potentially postpone cochlear aging and prevent ARHL in humans.

2018-11-01·Journal of the American Society of Echocardiography2区 · 医学

Assessment of Novel Antioxidant Therapy in Atherosclerosis by Contrast Ultrasound Molecular Imaging

2区 · 医学

Article

作者: Jose Lopez ; Aris Xie ; Yue Qi ; Jonathan R. Lindner ; William Packwood ; Tamara Atkinson ; Zaverio Ruggeri ; Brian P. Davidson ; Sherry Liang

BACKGROUNDUltrasound molecular imaging was used to evaluate the therapeutic effects of antioxidant therapy with EUK-207, which has superoxide dismutase and catalase activities, on suppressing high-risk atherosclerotic features.METHODSMice with age-dependent atherosclerosis produced by deletion of the low-density lipoprotein receptor and Apobec-1 were studied at 20 and 40 weeks of age. EUK-207 or vehicle was administered for the preceding 8 weeks. Therapy for 28 weeks was also studied for 40-week-old mice. Ultrasound molecular imaging of the thoracic aorta was performed with contrast agents targeted to endothelial P-selectin, von Willebrand factor A1-domain, and platelet glycoprotein Ibα or control agent. Aortic plaque area and macrophage content were assessed by histology.RESULTSIn 20-week-old double-knockout mice, EUK-207 compared with sham therapy produced only nonsignificant trends for reduction in molecular imaging signal for endothelial P-selectin, von Willebrand factor A1-domain, and platelet adhesion. At 40 weeks, EUK-207 given for 8 or 28 weeks significantly (P < .05) reduced signal for all three endothelial-associated events essentially to background levels, with the exception of glycoprotein Ibα signal after 8 weeks (P = .06). On aortic histology, EUK-207 therapy for 8 weeks did not affect plaque area or macrophage content at either age. However, EUK-207 for 28 weeks almost completely suppressed plaque development (350 ± 258 vs 4 ± 6 × 10³ μm², P = .014) and macrophage content (136 ± 103 vs 3 ± 2 × 10³ μm², P = .002) compared with control mice at 40 weeks.CONCLUSIONSMolecular imaging can be used to assess vascular responses to antioxidants and has demonstrated that certain antioxidants reduce vascular endothelial activation and platelet adhesion, but reductions in plaque size and macrophage content occurs only with long-duration therapy that is started early.

2015-10-27·Current Aging Science

Mitochondrial Pharmaceutics: A New Therapeutic Strategy to Ameliorate Oxidative Stress in Alzheimer’s Disease

Review

作者: Ajith, Thekkuttuparambil A. ; Padmajanair, Gangadharan

Association between amyloid-β (Aβ) toxicity, mitochondrial dysfunction, oxidative stress and neuronal damage has been demonstrated in the pathophysiology of Alzheimer's disease (AD). In the early stages of the disease, the defect in energy metabolism was found to be severe. This may probably due to the Aβ and ROS-induced declined activity of complexes in electron transport chain (ETC) as well as damages to mitochondrial DNA. Though clinically inconclusive, supplementation with antioxidants is reported to be beneficial especially in the early stages of the disease. A mild to moderate improvement in dementia is possible with therapy using antioxidants viz coenzyme Q10 (ubiquinone), α -lipoic acid, selenium, omega-3 fatty acids and vitamin E, emphasize their possible role as an adjuvant with the existing conventional treatment. Since mitochondrial dysfunction has been observed, a new therapeutic strategy called as 'Mitochondrial Medicine' which is aimed to maintain the energy production as well as to ameliorate the enhanced apoptosis of nerve cells, has been developed. Mitochondrial CoQ10, Szeto-Schiller peptide-31 and superoxide dismutase/ catalase mimetic, EUK-207 were the mitochondrial targeted agents demonstrated in experimental studies. This article discusses the mitochondrial impairment and the possible mitochondria targeted therapeutic intervention in AD.

100 项与 EUK 207 相关的药物交易

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