Background: Previous studies provide considerable evidence that excitation-contraction coupling may be disturbed at the level of the sarcoplasmic reticulum (SR) in the failing human heart. Disturbed SR function may result from altered expression of calcium-handling proteins.
Methods And Results: Levels of SR proteins involved in calcium release (ryanodine receptor), calcium binding (calsequestrin, calreticulin), and calcium uptake (calcium ATPase, phospholamban) were measured by Western blot analysis in nonfailing human myocardium (n = 7) and in end-stage failing myocardium due to dilated cardiomyopathy (n = 14). The levels of the ryanodine receptor, calsequestrin, and calreticulin were not significantly different in nonfailing and failing human myocardium. Phospholamban protein levels (pentameric form) normalized per total protein were decreased by 18% in the failing myocardium (P < .05). However, phospholamban protein levels were not significantly different in failing and nonfailing myocardium when normalization was performed per calsequestrin. Protein levels of SR calcium ATPase, normalized per total protein or per calsequestrin, were decreased by 41% (P < .001) or 33% (P < .05), respectively, in the failing myocardium. Furthermore, SR calcium ATPase was decreased relative to ryanodine receptor by 37% (P < .05) and relative to phospholamban by 28% (P < .05).
Conclusions: Levels of SR proteins involved in calcium binding and release are unchanged in failing dilated cardiomyopathy. In contrast, protein levels of calcium ATPase involved in SR calcium uptake are reduced in the failing myocardium. Moreover, SR calcium ATPase is decreased relative to its inhibitory protein, phospholamban.(ABSTRACT TRUNCATED AT 250 WORDS)
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1161/01.cir.92.4.778 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Exploring the Internal Environmental Changes of Muscle Cells and Apoptotic Phase of Mitochondria in Dry-Cured Loin Using Electrical Stimulation: Promoting the Precise Regulation of Loin Ham Quality.
J Agric Food Chem
January 2025
Guizhou Key Laboratory of New Quality Processing and Storage of Ecological Specialty Food; School of Liquor and Food Engineering, Guizhou University, Guiyang 550025, China.
Traditional dry-curing methods have a long cycle time and low efficiency, resulting in the inconsistent quality of dry-cured ham. By applying electrical stimulation (ES) technology in the dry-curing process, it was found that ES affected mitochondrial apoptosis by modulating the intracellular environment of muscle cells, which, in turn, enhanced the quality of dry-cured pork loin. Specifically, ES accelerated glycogen and ATP depletion, which led to a rapid decline in pH.
View Article and Find Full Text PDFChemigenetic Ca2+ indicators report elevated Ca2+ levels in endothelial Weibel-Palade bodies.
PLoS One
January 2025
Institute of Medical Biochemistry, Center for Molecular Biology of Inflammation, University of Muenster, Muenster, Germany.
Weibel-Palade bodies (WPB) are secretory organelles exclusively found in endothelial cells and among other cargo proteins, contain the hemostatic von-Willebrand factor (VWF). Stimulation of endothelial cells results in exocytosis of WPB and release of their cargo into the vascular lumen, where VWF unfurls into long strings of up to 1000 µm and recruits platelets to sites of vascular injury, thereby mediating a crucial step in the hemostatic response. The function of VWF is strongly correlated to its structure; in order to fulfill its task in the vascular lumen, VWF has to undergo a complex packing/processing after translation into the ER.
View Article and Find Full Text PDFSagittaria sagittifolia polysaccharide extract regulates Nrf2 to improve endoplasmic reticulum stress-mediated apoptosis in rat cataracts and HLEB3 cells.
Int J Biol Macromol
January 2025
School of Traditional Chinese Medicine, Beijing University of Chinese Medicine, Beijing 102446, China. Electronic address:
Age-related cataract (ARC) remains the leading cause of blindness worldwide. Sagittaria sagittifolia polysaccharide (SSP) extract, a key component of Sagittaria sagittifolia L., exhibits anti-oxidant and anti-apoptotic effects with potential applications in ARC.
View Article and Find Full Text PDFThe Protective Effect of Nimodipine in Schwann Cells Is Related to the Upregulation of LMO4 and SERCA3 Accompanied by the Fine-Tuning of Intracellular Calcium Levels.
Int J Mol Sci
January 2025
Department of Neurosurgery, Medical Faculty, Martin Luther University Halle-Wittenberg, Ernst-Grube-Straße 40, 06120 Halle (Saale), Germany.
Nimodipine is the current gold standard in the treatment of subarachnoid hemorrhage, as it is the only known calcium channel blocker that has been proven to improve neurological outcomes. In addition, nimodipine exhibits neuroprotective properties in vitro under various stress conditions. Furthermore, clinical studies have demonstrated a neuroprotective effect of nimodipine after vestibular schwannoma surgery.
View Article and Find Full Text PDFMechanistic Insights into Melatonin's Antiarrhythmic Effects in Acute Ischemia-Reperfusion-Injured Rabbit Hearts Undergoing Therapeutic Hypothermia.
Int J Mol Sci
January 2025
Division of Cardiology, Department of Internal Medicine, Chang Gung Memorial Hospital, Taoyuan Branch, Taoyuan 33304, Taiwan.
The electrophysiological mechanisms underlying melatonin's actions and the electrophysiological consequences of superimposed therapeutic hypothermia (TH) in preventing cardiac ischemia-reperfusion (IR) injury-induced arrhythmias remain largely unknown. This study aimed to unveil these issues using acute IR-injured hearts. Rabbits were divided into heart failure (HF), HF+melatonin, control, and control+melatonin groups.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!