scholarly journals Adrenomedullin-RAMP2 and -RAMP3 systems regulate cardiac homeostasis during cardiovascular stress

Endocrinology ◽  
2021 ◽  
Author(s):  
Nanqi Cui ◽  
Takayuki Sakurai ◽  
Akiko Kamiyoshi ◽  
Yuka Ichikawa-Shindo ◽  
Hisaka Kawate ◽  
...  
Keyword(s):  
Systolic Function ◽  
Lymphatic Vessels ◽  
Peptide Hormone ◽  
Base Line ◽  
Ventricular Contractility ◽  
Wild Type ◽  
Aortic Constriction ◽  
Cardiovascular Stress ◽  
Receptor Activity Modifying Proteins ◽  
And Oxidative Stress

Abstract Adrenomedullin (AM) is a peptide hormone with multiple physiological functions, which are regulated by its receptor activity-modifying proteins, RAMP2 and RAMP3. We previously reported that AM or RAMP2 knockout (AM-/-, RAMP2-/-) is embryonically lethal in mice, whereas RAMP3-/- mice are apparently normal. AM, RAMP2 and RAMP3 are all highly expressed in the heart; however, their functions there are not fully understood. Here, we analyzed the pathophysiological functions of the AM-RAMP2 and AM-RAMP3 systems in hearts subjected to cardiovascular stress.Cardiomyocyte-specific RAMP2-/- (C-RAMP2-/-) and RAMP3-/- showed no apparent heart failure at base line. After one week of transverse aortic constriction (TAC), however, C-RAMP2-/- exhibited significant cardiac hypertrophy, decreased ejection fraction and increased fibrosis as compared to wild-type mice. Both dP/dtmax and dP/dtmin were significantly reduced in C-RAMP2-/-, indicating reduced ventricular contractility and relaxation. Exposing CRAMP2/- cardiomyocytes to isoproterenol enhanced their hypertrophy and oxidative stress as compared to wild-type cells. CRAMP2/- cardiomyocytes also contained fewer viable mitochondria and showed reduced mitochondrial membrane potential and respiratory capacity. RAMP3-/- also showed reduced systolic function and enhanced fibrosis after TAC, but those only became apparent after 4 weeks. A reduction in cardiac lymphatic vessels was the characteristic feature in RAMP3-/-.These observations indicate the AM-RAMP2 system is necessary for early adaptation to cardiovascular stress through regulation of cardiac mitochondria. AM-RAMP3 is necessary for later adaptation through regulation of lymphatic vessels. The AM-RAMP2 and AM-RAMP3 systems thus play separate critical roles in the maintenance of cardiovascular homeostasis against cardiovascular stress.

Abstract 172: Lumican-null Mice Are Susceptible to Aging and Isoproterenol-induced Myocardial Fibrosis

2014 ◽  
Vol 115 (suppl_1) ◽  
Author(s):  
Pao-Hsien Chu
Keyword(s):  
Matrix Metalloproteinase ◽  
Atrial Natriuretic Peptide ◽  
Natriuretic Peptide ◽  
Myocardial Fibrosis ◽  
Cardiac Remodeling ◽  
Cardiac Fibrosis ◽  
Systolic Function ◽  
Wild Type ◽  
Matrix Metalloproteinase 1 ◽  
Membrane Type

Aims: With aging and stresses, the myocardium undergoes structural remodeling and often leading to fibrosis. Main Methods: To examine whether lumican, one of the class II small leucine-rich proteoglycans, has a role in cardiac remodeling and fibrosis, we analyzed the basic cardiac phenotypes of lumican-null (Lum-/-) mice in both youth and elder, and then used the isoproterenol-induced cardiac fibrosis model to study the roles of extra-cellular matrix and apoptosis in cardiac remodeling. Key Findings: Higher mortality resulted from significantly impaired systolic function, and an increase of atrial natriuretic peptide secreted by the ventricles in response to excessive stretching of myocytes of Lum-/- mice in comparison to wild type littermates. In addition, Lum-/- mice exhibited higher level of TGF-β, collagen I/III, and membrane-type matrix metalloproteinase-1 (MT1-MMP, or MMP-14) during cardiac remodeling. Significance: Our data implicates that the lumican protein plays an important role in the pathogenesis of cardiac fibrosis.

scholarly journals Endogenous Hydrogen Sulfide Is an Important Factor in Maintaining Arterial Oxygen Saturation

2021 ◽  
Vol 12 ◽  
Author(s):  
Yan Huang ◽  
Gang Wang ◽  
Zhan Zhou ◽  
Zhengshan Tang ◽  
Ningning Zhang ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Lung Injury ◽  
Arterial Oxygen Saturation ◽  
Arterial Oxygen ◽  
Wall Thickening ◽  
Alveolar Wall ◽  
Leukocyte Infiltration ◽  
Wild Type ◽  
Interstitial Edema ◽  
And Oxidative Stress

The gasotransmitter H2S is involved in various physiological and pathophysiological processes. The aim of this study was to investigate the physiological functions of H2S in the lungs. In the model of mouse with genetic deficiency in a H2S natural synthesis enzyme cystathionine-γ-lyase (CSE), we found that arterial oxygen saturation (SaO2) was decreased compared with wild type mice. Hypoxyprobe test showed that mild hypoxia occurred in the tissues of heart, lungs and kidneys in Cse-/- mice. H2S donor GYY4137 treatment increased SaO2 and ameliorated hypoxia state in cardiac and renal tissues. Further, we revealed that lung blood perfusion and airway responsiveness were not linked to reduced SaO2 level. Lung injury was found in Cse-/- mice as evidenced by alveolar wall thickening, diffuse interstitial edema and leukocyte infiltration in pulmonary tissues. IL-8, IL-1β, and TNF-α levels were markedly increased and oxidative stress levels were also significantly higher with increased levels of the pro-oxidative biomarker, MDA, decreased levels of the anti-oxidative biomarkers, T-AOC and GSH/GSSG, and reduced superoxide dismutase (SOD) activity in lung tissues of Cse-/- mice compared with those of wild type mice. GYY4137 treatment ameliorated lung injury and suppressed inflammatory state and oxidative stress in lung tissues of Cse-/- mice. A decrease in SaO2 was found in normal mice under hypoxia. These mice displayed lung injury as evidenced by alveolar wall thickening, interstitial edema and leukocyte infiltration. Increased levels of inflammatory cytokines and oxidative stress were also found in lung tissues of the mice with hypoxia insult. GYY4137 treatment increased SaO2 and ameliorated lung injury, inflammation and oxidative stress. Our data indicate that endogenous H2S is an important factor in maintaining normal SaO2 by preventing oxidative stress and inflammation in the lungs.

Abstract 338: Cardiac Overexpression of Creatine Kinase Improves Cardiomycytes Function in Heart Failure and During Increased Redox Stress

2015 ◽  
Vol 117 (suppl_1) ◽  
Author(s):  
Carlo G Tocchetti ◽  
Michelle Leppo ◽  
Djahida Bedja ◽  
Yibin Wang ◽  
Robert G Weiss ◽  
...  
Keyword(s):  
Heart Failure ◽  
Myocardial Dysfunction ◽  
Similar Response ◽  
Wild Type ◽  
Aortic Constriction ◽  
Redox Stress ◽  
Adult Cardiomyocytes ◽  
Metabolic Role ◽  
Myocyte Function ◽  
Fractional Shortening

Aims: Several studies suggest that abnormal energy metabolism contributes to heart failure or that the failing heart is energy starved. Here we aim at testing whether an increase in intracellular CK improves myocellular contractility in experimental myocardial dysfunction and protects from increased oxidative conditions. Methods-Results: We tested the response to the β-agonist isoproterenol (2.5 nM, ISO) in field-stimulated (.5 Hz, RT) adult cardiomyocytes isolated from wild-type (WT) mice and mice overexpressing cardiac myofibrillar or mitochondrial CK (CK-M or CK-mito) from sham and failing (8 wk transverse aortic constriction (TAC)) hearts, to dissect whether overexpressing CK alters myocyte function at baseline and during increased energetic demand. There were no differences in sarcomere fractional shortening (FS) or Ca2+ transients at baseline and with ISO among sham WT, CK-M or CK-mito myocytes. However, ISO effects were significantly reduced in WT TAC myocytes, consistent with prior reports. Conversely, in CK-M or CK-mito TAC myocytes, ISO-induced inotropy was fully preserved. Interestingly, incubation with the AMPK-stimulator AICAR (1mM for at least 90’) did not have any effect on WT TAC, but increased FS in TAC CK-M (+82%) and CK-mito (+42%) myocytes significantly, supporting the important metabolic role played by enhancing CK in failing hearts. To test whether overexpressing CK-M or CK-mito confer protection against acute oxidative stress, sham myocytes were exposed to H2O2 (50μM, 10’) and the interval (seconds) between the beginning of H2O2 superfusion and the appearance of irreversible arrhythmias was measured. WT and CK-M myocytes had a similar response (416±91s vs 411±68s), whereas in CK-mito this interval was significantly prolonged (600±64s). Similarly, upon acute infusion of the anticancer TKI sunitinib (2μM), whose cardiotoxic properties have been linked also to an increase in ROS, irreversible arrhythmias appeared after 657±43s in CK-mito (p<.5 vs 561±66 for WT and 467±88 for CK-M). Conclusions: Overexpressing CK-M and CK-mito under failing-TAC conditions improves myocyte function likely through better preserved Ca2+ handling, whereas only the up-regulation of CK-mito is more effective in buffering ROS effects.

The kinetics of the B cyclin p56cdc13 and the phosphatase p80cdc25 during the cell cycle of the fission yeast Schizosaccharomyces pombe

1996 ◽  
Vol 109 (6) ◽  
pp. 1647-1653 ◽  
Author(s):  
J. Creanor ◽  
J.M. Mitchison
Keyword(s):  
Schizosaccharomyces Pombe ◽  
Mammalian Cells ◽  
Size Control ◽  
Base Line ◽  
Wild Type ◽  
Main Band ◽  
The Times ◽  
G1 Cells ◽  
Mutant Cells ◽  
Kinetics Of

The levels of the B cyclin p56cdc13 and the phosphatase p80cdc25 have been followed in selection-synchronised cultures of Schizosaccharomyces pombe wild-type and wee1 mutant cells. p56cdc13 has also been followed in induction-synchronised cells of the mutant cdc2-33. The main conclusions are: (1) cdc13 levels in wild-type cells start to rise from base line at about mid-G2, reach a peak before mitosis and then fall slowly through G1. Cells exit mitosis with appreciable levels of cdc13. (2) cdc13 levels in wee1 cells fall to zero in interphase. They also start to rise at the beginning of G2, which may be related to the absence of a mitotic size control. (3) cdc25 starts to rise later and reaches a peak after mitosis. This is not what would be expected from a simple mitotic inducer and suggests that cdc25 has an important function at the end of mitosis. (4) An upper (heavier) band of cdc25 peaks at the same time as the main band but rises and falls more rapidly. If this is a hyperphosphorylated form, its timing shows that it is most unlikely to function in the ways shown for such a form in eggs and mammalian cells. (5) Experiments with the mutant cdc10-129 and with hydroxyurea show that the initial signal to begin synthesis of cdc13 originates at Start. (6) In induction synchrony, where G2 spans across cell division, there is evidence that some events in one cycle cannot start in the previous one. (7) Revised timings are given for the times of mitosis in these cultures.

Abstract 79: Sarcospan Has a Protective Effect During Development of Cardiac Disease

2016 ◽  
Vol 119 (suppl_1) ◽  
Author(s):  
Michelle S Parvatiyar ◽  
Reginald T Nguyen ◽  
Maria C Jordan ◽  
Kenneth P Roos ◽  
Rachelle H Crosbie-Watson
Keyword(s):  
Cell Adhesion ◽  
Cardiac Tissue ◽  
Physiological Function ◽  
Wall Stress ◽  
Muscle Dysfunction ◽  
Wild Type ◽  
Aortic Constriction ◽  
Muscle Histology ◽  
Cardiomyocyte Survival ◽  
Laminin Binding

Sarcospan (SSPN) has an important role in stabilizing sarcolemmal dystrophin- and utrophin-glycoprotein adhesion complexes at the cell membrane. Loss of cell adhesion leads to contraction-induced muscle damage, causing muscle dysfunction and cell death. Recently we have shown a specific role for SSPN in modulating cardiac cell adhesion and physiological function. After transthoracic aortic constriction (TAC), SSPN-null mice transitioned toward failure faster than wild-type (WT) mice. Muscle histology revealed large focal areas of collagen deposition in SSPN-null hearts after TAC compared to WT hearts, suggesting that increased membrane fragility affected cardiomyocyte survival. Our laboratory has shown that SSPN loss reduces sarcolemmal dystrophin levels and associated adhesion complexes in the heart. Whereas, the complete loss of dystrophin leads to development of Duchenne muscular dystrophy (DMD), causing cardiac dysfunction and early mortality. Overexpression of SSPN in DMD mice increased cell adhesion and laminin binding in hearts, leading to improvements in tissue histopathology and increased expression of utrophin, a functional homologue of dystrophin. Examining the restorative potential of SSPN in dystrophic cardiac tissue, led us to query whether compensatory upregulation of SSPN occurs in failing hearts of TAC-treated WT mice. In failing non-DMD hearts, we found that SSPN expression is increased. We have evidence of a chaperone role for SSPN, and its increased expression in the failing heart may contribute to the increased localization of dystrophin and associated glycoprotein complexes at the sarcolemma, which we observed in failing WT hearts compared to untreated controls. The upregulation of cell-stabilizing cell adhesion complexes may compensate for increased wall stress and counter pathological processes that culminate in cardiomyocyte demise, and we are exploring whether naturally increased expression or transgenic overexpression of SSPN in the heart may protect against damage. In summary, we have found that SSPN promotes cardiac function by maintaining cell adhesion and promoting cell survival during disease conditions.

scholarly journals LCZ696, an Angiotensin Receptor-Neprilysin Inhibitor, Improves Cardiac Hypertrophy and Fibrosis and Cardiac Lymphatic Remodeling in Transverse Aortic Constriction Model Mice

2020 ◽  
Vol 2020 ◽  
pp. 1-10 ◽  
Author(s):  
Qing Ge ◽  
Li Zhao ◽  
Chen Liu ◽  
Xiaoming Ren ◽  
Yi-hui Yu ◽  
...  
Keyword(s):  
Cardiac Hypertrophy ◽  
Protein Expression ◽  
Lymphatic System ◽  
Lymphatic Vessels ◽  
Mouse Heart ◽  
Transverse Aortic Constriction ◽  
Aortic Constriction ◽  
Expression Levels ◽  
Factor C ◽  
Proinflammatory Factors

Cardiac hypertrophy and ventricular remodeling following heart failure are important causes of high mortality in heart disease patients. The cardiac lymphatic system has been associated with limited research, but it plays an important role in the improvement of myocardial edema and the promotion of fluid balance. LCZ696 is a novel combination of angiotensin and neprilysin inhibitors. Here, we studied the role played by LCZ696 during transverse aortic constriction (TAC) induced cardiac hypertrophy and changes in the lymphatic system. Mice undergoing aortic coarctation were constructed to represent a cardiac hypertrophy model and then divided into random groups that either received treatment with LCZ696 (60 mg/kg/d) or no treatment. Cardiac ultrasonography was used to detect cardiac function, and hematoxylin and eosin (H&E) and Masson staining were used to detect myocardial hypertrophy and fibrosis. The proinflammatory factors interleukin-6 (IL-6), IL-1β, and tumor necrosis factor-α (TNF-α) were detected in the blood and heart tissues of mice. The protein expression levels of lymphatic-specific markers, such as vascular endothelial growth factor C (VEGF-C), VEGF receptor 3 (VEGFR3), and lymphatic vessel endothelial hyaluronan receptor 1 (LYVE-1) were detected in mouse heart tissues. We also examined the colocalization of lymphatic vessels and macrophages by immunofluorescence. The results showed that LCZ696 significantly improved heart dysfunction, cardiac hypertrophy, and fibrosis and inhibited the expression of proinflammatory factors IL-6, IL-1β, and TNF-α in the circulating blood and heart tissues of mice. LCZ696 also decreased the protein expression levels of VEGF-C, VEGFR3, and LYVE-1 in mouse heart tissues, ameliorated the transport load of lymphatic vessels to macrophages, and improved the remodeling of the lymphatic system in the hypertrophic cardiomyopathy model induced by TAC.

scholarly journals Digenic Inheritance of LAMA4 and MYH7 Mutations in Patient with Infantile Dilated Cardiomyopathy

Medicina ◽  
2019 ◽  
Vol 55 (1) ◽  
pp. 17 ◽  
Author(s):  
Atiyeh M Abdallah ◽  
S. Justin Carlus ◽  
Abdulhadi H Al-Mazroea ◽  
Mohammad Alluqmani ◽  
Yousef Almohammadi ◽  
...  
Keyword(s):  
Dilated Cardiomyopathy ◽  
Systolic Function ◽  
Left Ventricular ◽  
Dose Effect ◽  
Family Management ◽  
Ventricular Contractility ◽  
Targeted Next Generation Sequencing ◽  
Digenic Inheritance ◽  
Novel Variant ◽  
Next Generation Sequencing Ngs

Background and objectives: Dilated cardiomyopathy (DCM) is a rare cardiac disease characterised by left ventricular enlargement, reduced left ventricular contractility, and impaired systolic function. Childhood DCM is clinically and genetically heterogenous and associated with mutations in over 100 genes. The aim of this study was to identify novel variations associated with infantile DCM. Materials and Methods: Targeted next generation sequencing (NGS) of 181 cardiomyopathy-related genes was performed in three unrelated consanguineous families from Saudi Arabia. Variants were confirmed and their frequency established in 50 known DCM cases and 80 clinically annotated healthy controls. Results: The three index cases presented between 7 and 10 months of age with severe DCM. In Family A, there was digenic inheritance of two heterozygous variants: a novel variant in LAMA4 (c.3925G > A, p.Asp1309Asn) and a known DCM mutation in MYH7 (c.2770G > A; p.Glu924Lys). The LAMA4 p.Asp1309Asn variant was predicted to be likely pathogenic according to international guidelines. The other two families had no identifiable potentially deleterious variants. Conclusions: Inheritance of two genetic variants may have a synergistic or dose effect to cause severe DCM. We report of a novel p.Asp1309Asn variation associated with DCM. Targeted NGS is useful in the molecular diagnosis of DCM and to guide whole-family management and counselling.

scholarly journals phgABC, a Three-Gene Operon Required for Growth of Streptococcus pneumoniae in Hyperosmotic Medium and In Vivo

2004 ◽  
Vol 72 (8) ◽  
pp. 4579-4588 ◽  
Author(s):  
Jeremy S. Brown ◽  
Sarah M. Gilliland ◽  
Shilpa Basavanna ◽  
David W. Holden
Keyword(s):  
Streptococcus Pneumoniae ◽  
Mutant Strain ◽  
Compatible Solutes ◽  
Wild Type ◽  
Gram Positive Bacteria ◽  
Mutant Strains ◽  
Increased Sensitivity ◽  
Related Proteins ◽  
And Oxidative Stress

ABSTRACT To cause disease, bacterial pathogens need to be able to adapt to the physiological conditions found within the host, including an osmolality of approximately 290 mosmol kg−1. While investigating Streptococcus pneumoniae genes contained within pneumococcal pathogenicity island 1, we identified a three-gene operon of unknown function termed phgABC. PhgC has a domain with similarity to diacylglycerol kinases of eukaryotes and is the first described member of a family of related proteins found in many gram-positive bacteria. phgA and phgC mutant strains were constructed by insertional duplication mutagenesis and found to have impaired growth under conditions of high osmotic and oxidative stress. The compatible solutes proline and glycine betaine improved growth of the wild-type and the phgA mutant strains in hyperosmolar medium, and when analyzed by electron microscopy, the cellular morphology of the phgA mutant strain was unaffected by osmotic stress. The phgA and phgC mutant strains were reduced in virulence in models of both systemic and pulmonary infection. As the virulence of the phgA mutant strain was not restored in gp91phox−/− mice and the phgA and phgC mutant strains had reduced growth in both blood and serum, the reduced virulence of these strains is unlikely to be due to increased sensitivity to the respiratory burst of phagocytes but is, instead, due to impaired growth at physiological osmolality.

scholarly journals The Cell-Specific Pattern of Cholecystokinin Peptides in Endocrine Cells Versus Neurons Is Governed by the Expression of Prohormone Convertases 1/3, 2, and 5/6

Endocrinology ◽  
2007 ◽  
Vol 149 (4) ◽  
pp. 1600-1608 ◽  
Author(s):  
Jens F. Rehfeld ◽  
Jens R. Bundgaard ◽  
Jens Hannibal ◽  
Xiaorong Zhu ◽  
Christina Norrbom ◽  
...  
Keyword(s):  
Endocrine Cells ◽  
Peptide Hormone ◽  
Specific Pattern ◽  
Molecular Forms ◽  
Wild Type ◽  
Prohormone Convertases ◽  
Cerebral Neurons ◽  
Neuronal Processing ◽  
The Brain ◽  
Translational Product

Most peptide hormone genes are, in addition to endocrine cells, also expressed in neurons. The peptide hormone cholecystokinin (CCK) is expressed in different molecular forms in cerebral neurons and intestinal endocrine cells. To understand this difference, we examined the roles of the neuroendocrine prohormone convertases (PC) 1/3, PC2, and PC5/6 by measurement of proCCK, processing intermediates and bioactive, α-amidated, and O-sulfated CCK peptides in cerebral and jejunal extracts of null mice, controls, and in the PC5/6-expressing SK-N-MC cell-line. In PC1/3 null mice, the synthesis of bioactive CCK peptide in the gut was reduced to 3% of the translational product, all of which was in the form of α-amidated and tyrosine O-sulfated CCK-22, whereas the neuronal synthesis in the brain was largely unaffected. This is opposite to the PC2 null mice in which only the cerebral synthesis was affected. SK-N-MC cells, which express neither PC1/3 nor PC2, synthesized alone the processing intermediate, glycine-extended CCK-22. Immunocytochemistry confirmed that intestinal endocrine CCK cells in wild-type mice express PC1/3 but not PC2. In contrast, cerebral CCK neurons contain PC2 and only little, if any, PC1/3. Taken together, the data indicate that PC1/3 governs the endocrine and PC2 the neuronal processing of proCCK, whereas PC5/6 contributes only to a modest endocrine synthesis of CCK-22. The results suggest that the different peptide patterns in the brain and the gut are due to different expression of PCs.

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