Aims: Sodium-glucose-cotransporter-2 inhibitors showed favourable cardiovascular outcomes, but the underlying mechanisms are still elusive. This study investigated the mechanisms of empagliflozin in human and murine heart failure with preserved ejection fraction (HFpEF).
Methods And Results: The acute mechanisms of empagliflozin were investigated in human myocardium from patients with HFpEF and murine ZDF obese rats, which were treated in vivo. As shown with immunoblots and ELISA, empagliflozin significantly suppressed increased levels of ICAM-1, VCAM-1, TNF-α, and IL-6 in human and murine HFpEF myocardium and attenuated pathological oxidative parameters (H2O2, 3-nitrotyrosine, GSH, lipid peroxide) in both cardiomyocyte cytosol and mitochondria in addition to improved endothelial vasorelaxation. In HFpEF, we found higher oxidative stress-dependent activation of eNOS leading to PKGIα oxidation. Interestingly, immunofluorescence imaging and electron microscopy revealed that oxidized PKG1α in HFpEF appeared as dimers/polymers localized to the outer-membrane of the cardiomyocyte. Empagliflozin reduced oxidative stress/eNOS-dependent PKGIα oxidation and polymerization resulting in a higher fraction of PKGIα monomers, which translocated back to the cytosol. Consequently, diminished NO levels, sGC activity, cGMP concentration, and PKGIα activity in HFpEF increased upon empagliflozin leading to improved phosphorylation of myofilament proteins. In skinned HFpEF cardiomyocytes, empagliflozin improved cardiomyocyte stiffness in an anti-oxidative/PKGIα-dependent manner. Monovariate linear regression analysis confirmed the correlation of oxidative stress and PKGIα polymerization with increased cardiomyocyte stiffness and diastolic dysfunction of the HFpEF patients.
Conclusion: Empagliflozin reduces inflammatory and oxidative stress in HFpEF and thereby improves the NO-sGC-cGMP-cascade and PKGIα activity via reduced PKGIα oxidation and polymerization leading to less pathological cardiomyocyte stiffness.
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http://dx.doi.org/10.1093/cvr/cvaa123 | DOI Listing |
Plant Physiol Biochem
January 2025
Laboratory of Microbial Genetics, Department of Botany, Institute of Science, Banaras Hindu University, Varanasi, 221005, India. Electronic address:
Nitric oxide synthases (NOSs) are heme-based monooxygenases that catalyze the NADPH-dependent oxidation of L-arginine to produce NO and L-citrulline. Over the past five years, the identification and characterization of NOS homologs in cyanobacteria have significantly advanced our understanding of these enzymes. However, the precise mechanisms through which NOS-derived NO influences nitrogen metabolism remain incompletely elucidated.
View Article and Find Full Text PDFNanotechnology
January 2025
Centre for Analysis and Synthesis, NanoLund, Lund University, Box 124, Lund, 221 00, SWEDEN.
Developing a reliable procedure for the growth of III-V nanowires (NW) on silicon (Si) substrates remains a significant challenge, as current methods rely on trial-and-error approaches with varying interpretations of critical process steps such as sample preparation, Au-Si alloy formation in the growth reactor, and nanowire alignment. Addressing these challenges is essential for enabling high-performance electronic and optoelectronic devices that combine the superior properties of III-V NW semiconductors with the well-established Si-based technology. Combining conventional scalable growth methods, such as Metalorganic Chemical Vapor Deposition (MOCVD) with in situ characterization using Environmental Transmission Electron Microscopy (ETEM-MOCVD) enables a deeper understanding of the growth dynamics, if that knowledge is transferable to the scalable processes.
View Article and Find Full Text PDFJ Org Chem
January 2025
Antibiotics Research and Re-evaluation Key Laboratory of Sichuan Province, Sichuan Industrial Institute of Antibiotics, School of Pharmacy, Chengdu University, 2025 Chengluo Avenue, Chengdu 610016, P.R. China.
Herein, we report the first example that P(O)-H species including -phosphonates and -phosphine oxides could participate in a highly regioselective 1,4-addition to in situ generated 1-benzopyrylium ion from C3-substituted 2-chromene hemiketals, which provides a brand-new and effective approach for the synthesis of C4-phosphorylated 4-chromenes with diverse C3-functionality (ketone, ester, sulfonyl, aryl, and alkyl groups). In total, the reaction features the use of inexpensive Zn(ClO)·6HO as a catalyst, low catalyst loading (only 5 mol %), mild reaction conditions (60 °C, 10 min to 24 h), and broad substrate scope (46 examples) as well as good to high yields (>90% yield on average). More importantly, mechanistic experiments demonstrated the essential role of the C3-substituent on 2-chromene hemiketals in stabilizing the in situ generated 1-benzopyrylium ion and the regioselective 1,4-addition control.
View Article and Find Full Text PDFMedicine (Baltimore)
January 2025
Department of Biochemistry, Republic of Turkey Ministry of Health Taksim Training and Research Hospital, İstanbul, Turkey.
This prospective observational study aimed to compare abdominal hysterectomy (AH), vaginal hysterectomy (VH), and total laparoscopic hysterectomy (TLH) in terms of oxidative stress (OS) by measuring serum levels of total antioxidant status (TAS), total oxidant status (TOS), and oxidative stress index (OSI). Of the 3 groups, namely, AH, VH, and TLH, 22 patients were enrolled in each to investigate the aim of the study mentioned above. Patient demographics, clinical and surgical characteristics, and preoperative and postoperative (0th and 24th hours) serum TAS, TOS, and OSI levels were investigated.
View Article and Find Full Text PDFJ Neurosurg
January 2025
4Department of Neurosurgery, Royal Melbourne Hospital, Melbourne, Victoria, Australia.
Objective: The pathophysiology of delayed cerebral ischemia (DCI) is not fully elucidated. The lack of accurate diagnostic tools increases the probability of delayed diagnosis and timely treatment. The authors assessed the relationship of 8-iso-prostaglandin F2α (F2-IsoP) and oxidative stress biomarkers, nitric oxide synthase 3 (NOS3) and nicotinamide adenine dinucleotide phosphate (NADPH), with DCI after aneurysmal subarachnoid hemorrhage (aSAH).
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!