Publications by authors named "Ryan O'Kelly"

Age-related macular degeneration (AMD) is a major cause of vision loss in older adults. AMD is caused by degeneration in the macula of the retina. The retina is the highest oxygen consuming tissue in our body and is prone to oxidative damage.

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Cellular senescence is a key driver of the aging process and contributes to tissue dysfunction and age-related pathologies. Senolytics have emerged as a promising therapeutic intervention to extend healthspan and treat age-related diseases. Through a senescent cell-based phenotypic drug screen, we identified a class of conjugated polyunsaturated fatty acids, specifically α-eleostearic acid and its methyl ester derivative, as novel senolytics that effectively killed a broad range of senescent cells, reduced tissue senescence, and extended healthspan in mice.

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Age is the greatest risk factor for the development of type 2 diabetes mellitus (T2DM). Age-related decline in organ function is attributed to the accumulation of stochastic damage, including damage to the nuclear genome. Islets of T2DM patients display increased levels of DNA damage.

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Article Synopsis
  • Cardiomyopathy is a progressive heart disease linked to impaired function, with genotoxic cancer therapies recognized as key risk factors, though natural causes remain uncertain.
  • In a study, researchers engineered mice to lack a DNA repair gene (Ercc1) in heart muscle, resulting in severe heart issues like ventricular dilation and systolic dysfunction by 7 months of age.
  • The findings suggest that internal DNA damage leads to cardiac problems through the activation of the p53 protein and increased oxidative stress, ultimately causing heart cell death and related diseases.
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Constitutive NF-κB activation is associated with cellular senescence and stem cell dysfunction and rare variants in NF-κB family members are enriched in centenarians. We recently identified a novel small molecule (SR12343) that inhibits IKK/NF-κB activation by disrupting the association between IKKβ and NEMO. Here we investigated the therapeutic effects of SR12343 on senescence and aging in three different mouse models.

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The COVID-19 pandemic has revealed the pronounced vulnerability of the elderly and chronically ill to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-induced morbidity and mortality. Cellular senescence contributes to inflammation, multiple chronic diseases, and age-related dysfunction, but effects on responses to viral infection are unclear. Here, we demonstrate that senescent cells (SnCs) become hyper-inflammatory in response to pathogen-associated molecular patterns (PAMPs), including SARS-CoV-2 spike protein-1, increasing expression of viral entry proteins and reducing antiviral gene expression in non-SnCs through a paracrine mechanism.

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Ageing of the immune system, or immunosenescence, contributes to the morbidity and mortality of the elderly. To define the contribution of immune system ageing to organism ageing, here we selectively deleted Ercc1, which encodes a crucial DNA repair protein, in mouse haematopoietic cells to increase the burden of endogenous DNA damage and thereby senescence in the immune system only. We show that Vav-iCre;Ercc1 mice were healthy into adulthood, then displayed premature onset of immunosenescence characterized by attrition and senescence of specific immune cell populations and impaired immune function, similar to changes that occur during ageing in wild-type mice.

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NF-κB is a transcription factor activated in response to inflammatory, genotoxic and oxidative stress and important for driving senescence and aging. Ataxia-telangiectasia mutated (ATM) kinase, a core component of DNA damage response signaling, activates NF-κB in response to genotoxic and oxidative stress via post-translational modifications. Here we demonstrate that ATM is activated in senescent cells in culture and murine tissues from -deficient mouse models of accelerated aging, as well as naturally aged mice.

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Acute kidney injury, defined by a rapid deterioration of renal function, is a common complication in hospitalized patients. Among the recent therapeutic options, the use of extracellular vesicles (EVs) is considered a promising strategy. Here we propose a possible therapeutic use of renal-derived EVs isolated from normal urine (urine-derived EVs [uEVs]) in a murine model of acute injury generated by glycerol injection.

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Hemolysis is a potential limitation of percutaneously delivered left-sided mechanical circulatory support pumps, including trans valvular micro-axial flow pumps (TVP). Hemolytic biomarkers among durable left ventricular assist devices include lactate dehydrogenase (LDH) >2.5 times the upper limit of normal (ULN) and plasma-free hemoglobin (pf-Hb) >20 mg/dL.

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Background: Prognosis is poor for patients with decompensated advanced heart failure (HF) refractory to medical therapy. Evaluating candidacy for durable mechanical circulatory support (MCS), cardiac transplantation, or palliative care is complex, and time is often needed to stabilize the patient hemodynamically. The Impella 5.

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Background: Biventricular failure is associated with high in-hospital mortality. Limited data regarding the efficacy of biventricular Impella axial flow catheters (BiPella) support for biventricular failure exist. The aim of this study was to explore the clinical utility of percutaneously delivered BiPella as a novel acute mechanical support strategy for patients with cardiogenic shock complicated by biventricular failure.

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Article Synopsis
  • The study investigates the effectiveness of intra-aortic balloon counterpulsation pumps (IABPs) in improving hemodynamic status in patients with advanced heart failure (HF) before LVAD surgery.
  • It compares 10 patients with advanced HF receiving IABP therapy to 5 control patients with preserved left ventricular function, examining changes in various cardiac metrics.
  • Results show that IABP therapy significantly increased cardiac index and improved the myocardial oxygen supply:demand ratio while reducing left ventricular stroke work, particularly benefiting those classified as CI-responders.
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