-
The Journal of Biological Chemistry Jun 2024During postnatal cardiac hypertrophy, cardiomyocytes undergo mitotic exit, relying on DNA replication-independent mechanisms of histone turnover to maintain chromatin...
During postnatal cardiac hypertrophy, cardiomyocytes undergo mitotic exit, relying on DNA replication-independent mechanisms of histone turnover to maintain chromatin organization and gene transcription. In other tissues, circadian oscillations in nucleosome occupancy influence clock-controlled gene expression, suggesting a role for the circadian clock in temporal control of histone turnover and coordinated cardiomyocyte gene expression. We sought to elucidate roles for the master circadian transcription factor, Bmal1, in histone turnover, chromatin organization, and myocyte-specific gene expression and cell growth in the neonatal period. Bmal1 knockdown in neonatal rat ventricular myocytes decreased myocyte size, total cellular protein synthesis, and transcription of the fetal hypertrophic gene Nppb after treatment with serum or the α-adrenergic agonist phenylephrine. Depletion of Bmal1 decreased the expression of clock-controlled genes Per2 and Tcap, as well as Sik1, a Bmal1 target upregulated in adult versus embryonic hearts. Bmal1 knockdown impaired Per2 and Sik1 promoter accessibility as measured by micrococcal nuclease-quantitative PCR and impaired histone turnover as measured by metabolic labeling of acid-soluble chromatin fractions. Sik1 knockdown in turn decreased myocyte size, while simultaneously inhibiting natriuretic peptide B transcription and activating Per2 transcription. Linking these changes to chromatin remodeling, depletion of the replication-independent histone variant H3.3a inhibited myocyte hypertrophy and prevented phenylephrine-induced changes in clock-controlled gene transcription. Bmal1 is required for neonatal myocyte growth, replication-independent histone turnover, and chromatin organization at the Sik1 promoter. Sik1 represents a novel clock-controlled gene that coordinates myocyte growth with hypertrophic and clock-controlled gene transcription. Replication-independent histone turnover is required for transcriptional remodeling of clock-controlled genes in cardiac myocytes in response to growth stimuli.
PubMed: 38830405
DOI: 10.1016/j.jbc.2024.107434 -
Journal of Cardiology Cases Jun 2024Atrial amyloidosis is primarily caused by atrial natriuretic peptide (ANP) amyloid deposition. The main precursor protein causing cardiac amyloidosis is transthyretin...
UNLABELLED
Atrial amyloidosis is primarily caused by atrial natriuretic peptide (ANP) amyloid deposition. The main precursor protein causing cardiac amyloidosis is transthyretin (TTR), also known as TTR amyloid cardiomyopathy (ATTR-CM). A 73-year-old man, who presented with external dyspnea, was diagnosed with decompensated heart failure due to atrial fibrillation and severe mitral regurgitation. Left ventricular hypertrophy and elevated levels of high-sensitivity cardiac troponin T indicated cardiac amyloidosis. technetium pyrophosphate scintigraphy findings and cardiac magnetic resonance imaging in the absence of monoclonal proteins were consistent with those of ATTR-CM. The patient underwent mitral valve repair, a maze procedure, and left atrial appendage (LAA) excision. While the histological analysis of the sampled left ventricular tissue led to diagnosis of ATTR-CM, the histological analysis revealed the coexistence of ANP and TTR amyloid deposition in the resected LAA. We report a case of ATTR-CM in which TTR and ANP amyloid deposition coexisted in the surgically resected LAA, indicating that both TTR and ANP amyloid correlate with atrial amyloidosis development in ATTR-CM.
LEARNING OBJECTIVES
Atrial natriuretic peptide (ANP) and transthyretin (TTR) amyloids can coexist in the same atrium. Not only TTR amyloids but also ANP amyloids can be correlated with the development of atrial amyloidosis in TTR amyloid cardiomyopathy with subsequent increased risk of atrial fibrillation.
PubMed: 38826764
DOI: 10.1016/j.jccase.2024.02.008 -
Revista Espanola de Medicina Nuclear E... May 2024Myocardial uptake on bone scintigraphy has become useful for the detection of transthyretin cardiac amyloidosis (ATTR-CA). This study aimed to assess the prevalence of...
AIM
Myocardial uptake on bone scintigraphy has become useful for the detection of transthyretin cardiac amyloidosis (ATTR-CA). This study aimed to assess the prevalence of myocardial uptake in patients over 18 years of age with no clinical suspicion of cardiac amyloidosis (CA) who had undergone bone scintigraphy.
METHODS AND RESULTS
This was an observational, retrospective, multicenter study across 21 Spanish hospitals (September-November 2019). Of the 9864 scans analyzed (locally and centrally), incidental cardiac uptake was observed in 71 patients (0.72%), a prevalence that increased with age. A previous diagnosis of heart failure was found in 16.9% of patients with positive uptake, with >50% in NYHA II. ATTR-CA was diagnosed in 10 patients, with a mean delay of 10.4 months (95% CI: 5.1-15.7). All were >70 years old, primarily male, and had greater left ventricular hypertrophy than patients without a confirmed diagnosis (p<0.0001). ATTR-CA patients had higher rates of orthostatic hypotension (30.0% vs. 3.8% in non-ATTR-CA; p=0.025).
CONCLUSIONS
This is the first retrospective, national, multicenter study evaluating the prevalence of incidental cardiac uptake in bone scintigraphy performed for non-cardiac reasons, showing a prevalence of 0.72% in this population. Referral of these patients may facilitate early diagnosis of CA with a resulting benefit for patients.
PubMed: 38821407
DOI: 10.1016/j.remnie.2024.500020 -
Frontiers in Endocrinology 2024X-linked hypophosphatemia (XLH) is caused by an inactivating mutation in the phosphate-regulating endopeptidase X-linked () gene whose defective product fails to control... (Observational Study)
Observational Study
INTRODUCTION
X-linked hypophosphatemia (XLH) is caused by an inactivating mutation in the phosphate-regulating endopeptidase X-linked () gene whose defective product fails to control phosphatonin fibroblast growth factor 23 (FGF23) serum levels. Although elevated FGF23 levels have been linked with detrimental cardiac effects, the cardiologic outcomes in XLH patients have been subject to debate. Our study aimed to evaluate the prevalence and severity of cardiovascular morbidity in pediatric XLH patients before, during, and after a 2-year treatment period with burosumab, a recombinant anti-FGF23 antibody.
METHODS
This prospective observational study was conducted in a tertiary medical center, and included 13 individuals with XLH (age range 0.6-16.2 years) who received burosumab every 2 weeks. Clinical assessment at treatment initiation and after .5, 1, and 2 years of uninterrupted treatment included anthropometric measurements and cardiologic evaluations (blood pressure [BP], electrocardiogram, conventional echocardiography, and myocardial strain imaging).
RESULTS
The linear growth of all patients improved significantly (mean height z-score: from -1.70 ± 0.80 to -0.96 ± 1.08, =0.03). Other favorable effects were decline in overweight/obesity rates (from 46.2% to 23.1%) and decreased rates of elevated BP (systolic BP from 38.5% to 15.4%; diastolic BP from 38.5% to 23.1%). Electrocardiograms revealed no significant abnormality throughout the study period. Cardiac dimensions and myocardial strain parameters were within the normative range for age at baseline and remained unchanged during the study period.
CONCLUSION
Cardiologic evaluations provided reassurance that 2 years of burosumab therapy did not cause cardiac morbidity. The beneficial effect of this treatment was a reduction in cardiovascular risk factors, as evidenced by the lower prevalence of both overweight/obesity and elevated BP.
Topics: Humans; Child; Adolescent; Male; Familial Hypophosphatemic Rickets; Fibroblast Growth Factor-23; Child, Preschool; Prospective Studies; Infant; Female; Antibodies, Monoclonal, Humanized; Cardiovascular Diseases; Follow-Up Studies; Fibroblast Growth Factors
PubMed: 38818505
DOI: 10.3389/fendo.2024.1400273 -
Journal of Cardiovascular Echography 2024Overlapping of left ventricular noncompaction (LVNC) and hypertrophic cardiomyopathy in the same patient is rare and is associated with a more severe clinical course and...
Overlapping of left ventricular noncompaction (LVNC) and hypertrophic cardiomyopathy in the same patient is rare and is associated with a more severe clinical course and unfavorable prognosis. The present report describes the case of a severely regurgitant bicuspid aortic valve in a 68-year-old man with overlapping LVNC and asymmetrical septal hypertrophy. Aortic valve replacement controlled the left ventricular dilatation that occurred secondary to the volume overload induced by the valvular disease. However, even 3 years postoperatively, severe systolic dysfunction persisted due to the preexisting myocardial disease, requiring close and lifelong follow-up with special attention to life-threatening arrhythmias and thromboembolism.
PubMed: 38818313
DOI: 10.4103/jcecho.jcecho_4_24 -
Annals of Pediatric Cardiology 2023Childhood obesity has become a global concern, with its prevalence steadily increasing over the past decade. This condition negatively impacts the cardiovascular system,...
BACKGROUND
Childhood obesity has become a global concern, with its prevalence steadily increasing over the past decade. This condition negatively impacts the cardiovascular system, increasing the risk of morbidity and mortality in adulthood. This study aimed to identify cardiac function abnormalities and related risk factors among overweight and obese Thai children.
MATERIALS AND METHODS
A cross-sectional observational study of 70 children with body mass index (BMI) >1 standard deviation above the mean for Thai children was conducted at Naresuan University Hospital. Body fat percentage (%Fat) was measured, and standard transthoracic echocardiography was performed. Metabolic profiles were collected from medical records.
RESULTS
The thickness and diameter of the Left ventricle (LV) wall, including the LV posterior wall, LV internal diameter, and interventricular septum (IVS), were significantly increased in both systolic and diastolic phases in obese children. LV concentric hypertrophy and an abnormal E/E' ratio were found in 27% and 34.3% of participants, respectively. Right ventricular systolic dysfunction indicated by abnormal tricuspid annular plane systolic excursion values was found in 55.7% of all participants. In addition, 27.1% of all obese children had pulmonary hypertension. Significant differences in BMI and %Fat were detected between children with abnormal and normal IVS diastolic (IVSd) ( = 0.016). Our univariate and multivariate correlation analyses revealed a significant positive association between abnormal IVSd and %Fat, with an odd ratio (OR) of 1.13 (95% confidence interval [CI]: 1.01-1.27; = 0.047) and an adjusted OR of 1.17 (95% CI: 1.01-1.36; = 0.04).
CONCLUSIONS
Cardiac function abnormalities in childhood obesity exhibit a significant positive correlation with BMI and various cardiac dimensions, including ventricular wall thickness. One important related risk factor for increased IVS thickness is %Fat. Therefore, multidisciplinary management of obesity should be initiated as early as possible to prevent future cardiovascular morbidity and mortality.
PubMed: 38817261
DOI: 10.4103/apc.apc_134_23 -
Scientific Reports May 2024Pulmonary arterial hypertension (PAH) is a fatal disease featured by high morbidity and mortality. Although Cordycepin is known for its anti-inflammatory, antioxidant...
Pulmonary arterial hypertension (PAH) is a fatal disease featured by high morbidity and mortality. Although Cordycepin is known for its anti-inflammatory, antioxidant and immune-enhancing effects, its role in PAH treatment and the underlying mechanisms remain unclear. The therapeutic effects of Cordycepin on rats with PAH were investigated using a monocrotaline (MCT)-induced rat model. The metabolic effects of Cordycepin were assessed based on the plasma metabolome. The potential mechanisms of Cordycepin in PAH treatment were investigated through transcriptome sequencing and validated in pulmonary artery smooth muscle cells (PASMC). Evaluations included hematoxylin and eosin staining for pulmonary vascular remodeling, CCK-8 assay, EDU, and TUNEL kits for cell viability, proliferation, and apoptosis, respectively, and western blot for protein expression. Cordycepin significantly reduced right ventricular systolic pressure (RVSP) and right ventricular hypertrophy index (RVHI) in PAH rats, and mitigated pulmonary vascular remodeling. Plasma metabolomics showed that Cordycepin could reverse the metabolic disorders in the lungs of MCT-induced PAH rats, particularly impacting linoleic acid and alpha-linolenic acid metabolism pathways. Transcriptomics revealed that the P53 pathway might be the primary pathway involved, and western blot results showed that Cordycepin significantly increased P53 and P21 protein levels in lung tissues. Integrated analysis of transcriptomics and metabolomics suggested that these pathways were mainly enriched in linoleic acid metabolism and alpha-linolenic acid metabolism pathway. In vitro experiments demonstrated that Cordycepin significantly inhibited the PDGFBB (PD)-induced abnormal proliferation and migration of PASMC and promoted PD-induced apoptosis. Meanwhile, Cordycepin enhanced the expression levels of P53 and P21 proteins in PD-insulted PASMC. However, inhibitors of P53 and P21 eliminated these effects of Cordycepin. Cordycepin may activate the P53-P21 pathway to inhibit abnormal proliferation and migration of PASMC and promote apoptosis, offering a potential approach for PAH treatment.
Topics: Animals; Deoxyadenosines; Rats; Male; Apoptosis; Pulmonary Arterial Hypertension; Cell Proliferation; Transcriptome; Metabolomics; Myocytes, Smooth Muscle; Monocrotaline; Pulmonary Artery; Rats, Sprague-Dawley; Disease Models, Animal; Vascular Remodeling; Tumor Suppressor Protein p53; Linoleic Acid; Hypertrophy, Right Ventricular; Gene Expression Profiling
PubMed: 38816406
DOI: 10.1038/s41598-024-62163-3 -
Arteriosclerosis, Thrombosis, and... Jul 2024Pulmonary hypertension (PH) represents an important phenotype in heart failure with preserved ejection fraction (HFpEF). However, management of PH-HFpEF is challenging...
BACKGROUND
Pulmonary hypertension (PH) represents an important phenotype in heart failure with preserved ejection fraction (HFpEF). However, management of PH-HFpEF is challenging because mechanisms involved in the regulation of PH-HFpEF remain unclear.
METHODS
We used a mass spectrometry-based comparative plasma proteomics approach as a sensitive and comprehensive hypothesis-generating discovery technique to profile proteins in patients with PH-HFpEF and control subjects. We then validated and investigated the role of one of the identified proteins using in vitro cell cultures, in vivo animal models, and independent cohort of human samples.
RESULTS
Plasma proteomics identified high protein abundance levels of B2M (β2-microglobulin) in patients with PH-HFpEF. Interestingly, both circulating and skeletal muscle levels of B2M were increased in mice with skeletal muscle SIRT3 (sirtuin-3) deficiency or high-fat diet-induced PH-HFpEF. Plasma and muscle biopsies from a validation cohort of PH-HFpEF patients were found to have increased B2M levels, which positively correlated with disease severity, especially pulmonary capillary wedge pressure and right atrial pressure at rest. Not only did the administration of exogenous B2M promote migration/proliferation in pulmonary arterial vascular endothelial cells but it also increased PCNA (proliferating cell nuclear antigen) expression and cell proliferation in pulmonary arterial vascular smooth muscle cells. Finally, deletion improved glucose intolerance, reduced pulmonary vascular remodeling, lowered PH, and attenuated RV hypertrophy in mice with high-fat diet-induced PH-HFpEF.
CONCLUSIONS
Patients with PH-HFpEF display higher circulating and skeletal muscle expression levels of B2M, the magnitude of which correlates with disease severity. Our findings also reveal a previously unknown pathogenic role of B2M in the regulation of pulmonary vascular proliferative remodeling and PH-HFpEF. These data suggest that circulating and skeletal muscle B2M can be promising targets for the management of PH-HFpEF.
Topics: Adult; Aged; Animals; Humans; Male; Mice; Middle Aged; beta 2-Microglobulin; Biomarkers; Case-Control Studies; Cell Movement; Cell Proliferation; Cells, Cultured; Disease Models, Animal; Endothelial Cells; Heart Failure; Hypertension, Pulmonary; Mice, Inbred C57BL; Mice, Knockout; Muscle, Skeletal; Proteomics; Pulmonary Artery; Sirtuin 3; Stroke Volume; Vascular Remodeling; Ventricular Function, Left
PubMed: 38813697
DOI: 10.1161/ATVBAHA.123.320270 -
Cureus May 2024A 37-year-old male with type two diabetes presented to the hospital with new-onset heart failure and renal dysfunction. His left ventricular (LV) ejection fraction was...
A 37-year-old male with type two diabetes presented to the hospital with new-onset heart failure and renal dysfunction. His left ventricular (LV) ejection fraction was less than 10%. Transthoracic echocardiography and cardiovascular magnetic resonance (CMR) imaging also revealed severe bicuspid aortic valve stenosis, dilated cardiomyopathy with LV hypertrophy, prominent LV trabeculations, and features suggestive of mild myocarditis with active inflammation. While myocarditis was suspected on CMR imaging, his mild degree of myocardial involvement did not explain the entirety of his clinical presentation, degree of LV dysfunction, or other structural abnormalities. An extensive work-up for his LV dysfunction was unremarkable for ischemic, metabolic, infiltrative, infectious, toxic, oncologic, connective tissue, and autoimmune etiologies. Genetic testing was positive for a () variant, which was deemed likely to be a unifying etiology underlying his presentation. The sarcomere gene allows beta-myosin expression in heart ventricles, with variants associated with hypertrophic and dilated cardiomyopathies, congenital heart diseases, myocarditis, and excessive trabeculation (formerly known as left ventricular noncompaction). This case highlights the diverse array of cardiac pathologies that can present with gene variants and reviews an extensive work-up for this unusual presentation of heart failure in a young patient.
PubMed: 38813076
DOI: 10.7759/cureus.61252 -
Growth Hormone & IGF Research :... Jun 2024Acromegaly is a disorder associated with excessive levels of growth hormone (GH) and insulin-like growth factor-1 (IGF-1). In general, GH/IGF-1 excess leads to... (Review)
Review
OBJECTIVE
Acromegaly is a disorder associated with excessive levels of growth hormone (GH) and insulin-like growth factor-1 (IGF-1). In general, GH/IGF-1 excess leads to morphologic craniofacial and acral changes as well as cardiometabolic complications, but the phenotypic changes and clinical presentation of acromegaly differ across species. Here, we review the pathophysiology, clinical presentation and management of acromegaly in humans and cats, and we provide a systematic comparison between this disease across these different species.
DESIGN
A comprehensive literature review of pathophysiology, clinical features, diagnosis and management of acromegaly in humans and in cats was performed.
RESULTS
Acromegaly is associated with prominent craniofacial changes in both species: frontal bossing, enlarged nose, ears and lips, and protuberant cheekbones are typically encountered in humans, whereas increased width of the head and skull enlargement are commonly found in cats. Malocclusion, prognathism, dental diastema and upper airway obstruction by soft tissue enlargement are reported in both species, as well as continuous growth and widening of extremities resulting in osteoarticular compromise. Increase of articular joint cartilage thickness, vertebral fractures and spine malalignment is more evident in humans, while arthropathy and spondylosis deformans may also occur in cats. Generalized organomegaly is equally observed in both species. Other similarities between humans and cats with acromegaly include heart failure, ventricular hypertrophy, diabetes mellitus, and an overall increased cardiometabolic risk. In GH-secreting pituitary tumours, local compressive effects and behavioral changes are mostly observed in humans, but also present in cats. Cutis verticis gyrata and skin tags are exclusively found in humans, while palmigrade/plantigrade stance may occur in some acromegalic cats. Serum IGF-1 is used for acromegaly diagnosis in both species, but an oral glucose tolerance test with GH measurement is only useful in humans, as glucose load does not inhibit GH secretion in cats. Imaging studies are regularly performed in both species after biochemical diagnosis of acromegaly. Hypophysectomy is the first line treatment for humans and cats, although not always available in veterinary medicine.
CONCLUSION
Acromegaly in humans and cats has substantial similarities, as a result of common pathophysiological mechanisms, however species-specific features may be found.
Topics: Acromegaly; Cats; Humans; Animals; Insulin-Like Growth Factor I; Cat Diseases
PubMed: 38810595
DOI: 10.1016/j.ghir.2024.101595