Publications by authors named "Stephen L Archer"

Article Synopsis
  • - Drp1, a protein involved in mitochondrial fission, contributes to the increase in pulmonary artery smooth muscle cells in pulmonary arterial hypertension (PAH), and researchers developed a new inhibitor called Drpitor1a to test its effectiveness.
  • - Experiments showed that Drpitor1a successfully inhibited Drp1 activity, reduced cell proliferation and increased apoptosis in PAH cells, while not affecting normal cells or causing toxicity.
  • - The findings suggest that Drpitor1a could be a viable treatment for PAH by targeting Drp1, with notable differences in effectiveness observed between male and female subjects.
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Individuals with clonal hematopoiesis of indeterminate potential (CHIP) are at increased risk of aging related health conditions and all-cause mortality, but whether CHIP affects risk of infection is much less clear. Using UK Biobank data, we revealed a positive association between CHIP and incident pneumonia in 438,421 individuals. We show that inflammation enhanced pneumonia risk, as CHIP carriers with a hypomorphic IL6 receptor polymorphism were protected.

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Background: Mutations are found in 10-20% of idiopathic PAH (IPAH) patients, but none are consistently identified in connective tissue disease-associated PAH (APAH), which accounts for ∼45% of PAH cases. mutations, a cause of clonal hematopoiesis of indeterminant potential (CHIP), predispose to an inflammatory type of PAH. We now examine mutations in another CHIP gene, , in PAH.

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Rationale: Dynamin-related protein 1 (Drp1), a large GTPase, mediates mitochondrial fission. Increased Drp1-mediated fission permits accelerated mitosis, contributing to hyperproliferation of pulmonary artery smooth muscle cells (PASMC), which characterizes pulmonary arterial hypertension (PAH). We developed a Drp1 inhibitor, Drpitor1a, and tested its ability to regress PAH.

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Article Synopsis
  • - Pulmonary hypertension is a condition with elevated pressures in the pulmonary arteries, classified into five main groups, including pulmonary arterial hypertension (rare) and pulmonary hypertension linked to left-sided heart disease (very common), among others.
  • - It affects at least 1% of the global population, with a more significant impact in low and middle-income countries, and can lead to serious complications such as right ventricle failure if not managed properly.
  • - Current treatments focus on the underlying causes, especially for pulmonary arterial hypertension and chronic thromboembolic pulmonary hypertension, but more research is needed to improve understanding and treatment options for other forms.
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Article Synopsis
  • Drp1 is a GTPase protein that promotes mitochondrial fission and increases reactive oxygen species (ROS) in heart cells, making it a potential target for reducing damage from ischemia/reperfusion (IR) injury.
  • Using both cardiomyocyte-specific Drp1 knockout (KO) mice and a new, specific Drp1 inhibitor (Drpitor1a), researchers found that short-term Drp1 inhibition improves heart function and mitochondrial performance after IR injury.
  • However, prolonged ablation of Drp1 led to cardiomyopathy, indicating that while short-term Drp1 inhibition can be beneficial, extended absence may disrupt normal heart function.
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After entry into cells, herpes simplex virus (HSV) nucleocapsids dock at nuclear pore complexes (NPCs) through which viral genomes are released into the nucleoplasm where viral gene expression, genome replication, and early steps in virion assembly take place. After their assembly, nucleocapsids are translocated to the cytoplasm for final virion maturation. Nascent cytoplasmic nucleocapsids are prevented from binding to NPCs and delivering their genomes to the nucleus from which they emerged, but how this is accomplished is not understood.

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DNA methylation is an epigenetic mechanism that regulates gene expression without altering gene sequences in health and disease. DNA methyltransferases (DNMTs) are enzymes responsible for DNA methylation, and their dysregulation is both a pathogenic mechanism of disease and a therapeutic target. DNMTs change gene expression by methylating CpG islands within exonic and intergenic DNA regions, which typically reduces gene transcription.

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Background: Right ventricular failure (RVF) is a leading cause of morbidity and mortality in multiple cardiovascular diseases, but there are no treatments for RVF as therapeutic targets are not clearly defined. Contemporary transcriptomic/proteomic evaluations of RVF are predominately conducted in small animal studies, and data from large animal models are sparse. Moreover, a comparison of the molecular mediators of RVF across species is lacking.

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Mitochondria, which generate ATP through aerobic respiration, also have important noncanonical functions. Mitochondria are dynamic organelles, that engage in fission (division), fusion (joining) and translocation. They also regulate intracellular calcium homeostasis, serve as oxygen-sensors, regulate inflammation, participate in cellular and organellar quality control and regulate the cell cycle.

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Background As partial pressure of oxygen (pO) rises with the first breath, the ductus arteriosus (DA) constricts, diverting blood flow to the pulmonary circulation. The DA's O sensor resides within smooth muscle cells. The DA smooth muscle cells' mitochondrial electron transport chain (ETC) produces reactive oxygen species (ROS) in proportion to oxygen tension, causing vasoconstriction by regulating redox-sensitive ion channels and enzymes.

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The ductus arteriosus (DA) connects the aorta to the pulmonary artery (PA), directing placentally oxygenated blood away from the developing lungs. High pulmonary vascular resistance and low systemic vascular resistance facilitate shunting of blood in utero from the pulmonary to the systemic circulation through the widely patent DA, thereby optimizing fetal oxygen (O) delivery. With the transition from fetal (hypoxia) to neonatal (normoxia) oxygen conditions, the DA constricts while the PA dilates.

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Background Digoxin acutely increases cardiac output in patients with pulmonary arterial hypertension (PAH) and right ventricular failure; however, the effects of chronic digoxin use in PAH are unclear. Methods and Results Data from the Minnesota Pulmonary Hypertension Repository were used. The primary analysis used likelihood of digoxin prescription.

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Pulmonary arterial hypertension (PAH) is an orphan disease of the cardiopulmonary unit that reflects an obstructive pulmonary vasculopathy and presents with hypertrophy, inflammation, fibrosis, and ultimately failure of the right ventricle (RVF). Despite treatment using pulmonary hypertension (PH)-targeted therapies, persistent functional impairment reduces the quality of life for people with PAH and death from RVF occurs in approximately 40% of patients within 5 years of diagnosis. PH-targeted therapeutics are primarily vasodilators and none, alone or in combination, are curative.

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Right ventricular failure (RVF) is a leading cause of morbidity and mortality in multiple cardiovascular diseases, but there are no approved treatments for RVF as therapeutic targets are not clearly defined. Contemporary transcriptomic/proteomic evaluations of RVF are predominately conducted in small animal studies, and data from large animal models are sparse. Moreover, a comparison of the molecular mediators of RVF across species is lacking.

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Pulmonary arterial hypertension (PAH) is an obstructive pulmonary vasculopathy that results in death from right ventricular failure (RVF). There is limited understanding of the molecular mechanisms of RVF in PAH. In a PAH-RVF model induced by injection of adult male rats with monocrotaline (MCT; 60 mg/kg), we performed mass spectrometry to identify proteins that change in the RV as a consequence of PAH induced RVF.

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Article Synopsis
  • SARS-CoV-2, the virus responsible for COVID-19, may harm lung cells by damaging mitochondria, leading to cell death and impaired oxygen regulation in the body.
  • The study investigated how SARS-CoV-2 and its proteins affect cell processes like apoptosis (cell death), mitochondrial function, and hypoxic pulmonary vasoconstriction (the body’s way to control blood flow in response to low oxygen).
  • Findings showed that SARS-CoV-2 disrupts mitochondrial functions and activates pathways that promote cell death, affecting energy production and overall lung health very shortly after infection.
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Pulmonary arterial hypertension (PAH) often results in death from right ventricular failure (RVF). NLRP3 (nucleotide-binding domain, leucine-rich-containing family, pyrin domain-containing-3)-macrophage activation may promote RVF in PAH. Evaluating the contribution of the NLRP3 inflammasome in RV macrophages to PAH RVF.

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Real-world identification of pulmonary hypertension (PH) is largely based on the use of administrative databases identified by ICD codes. This approach has not been validated. The aim of this study was to validate a diagnosis of PH and its comorbidities using ICD 9/10 codes.

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Article Synopsis
  • Metastatic breast cancer cells thrive in soft microenvironments, which influence their response to cancer treatments, particularly their resilience against oxidative stress.
  • Research reveals that a soft extracellular matrix enhances mitochondrial activity and increases the production of reactive oxygen species, leading to a stronger antioxidant response in cancer cells.
  • In mouse models, disrupting specific mitochondrial dynamics and antioxidant pathways can restore sensitivity to chemotherapy drugs like cisplatin, suggesting new strategies to prevent cancer recurrence.
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The Ductus Arteriosus (DA) is a fetal vessel that connects the aorta to the pulmonary artery ensuring that placental oxygenated blood is diverted from the lungs to the systemic circulation. Following exposure to oxygen (O), in the first few days of life, the DA responds with a functional closure that is followed by anatomical closure. Here, we study human DA smooth muscle cells (DASMC) taken from 10 term infants during congenital heart surgery.

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