Pressure overload of the heart leads to cardiac remodeling that may progress into heart failure, a common, morbid and mortal condition. Increased mechanistic insight into remodeling is instrumental ...for development of novel heart failure treatment. Cardiac remodeling comprises cardiomyocyte hypertrophic growth, extracellular matrix alterations including fibrosis, and inflammation. Fibromodulin is a small leucine-rich proteoglycan that regulates collagen fibrillogenesis. Fibromodulin is expressed in the cardiac extracellular matrix, however its role in the heart remains largely unknown. We investigated fibromodulin levels in myocardial biopsies from heart failure patients and mice, subjected fibromodulin knock-out (FMOD-KO) mice to pressure overload by aortic banding, and overexpressed fibromodulin in cultured cardiomyocytes and cardiac fibroblasts using adenovirus. Fibromodulin was 3-10-fold upregulated in hearts of heart failure patients and mice. Both cardiomyocytes and cardiac fibroblasts expressed fibromodulin, and its expression was increased by pro-inflammatory stimuli. Without stress, FMOD-KO mice showed no cardiac phenotype. Upon aortic banding, left ventricles of FMOD-KO mice developed mildly exacerbated hypertrophic remodeling compared to wild-type mice, with increased cardiomyocyte size and altered infiltration of leukocytes. There were no differences in mortality, left ventricle dilatation, dysfunction or expression of heart failure markers. Although collagen amount and cross-linking were comparable in FMOD-KO and wild-type, overexpression of fibromodulin in cardiac fibroblasts in vitro decreased their migratory capacity and expression of fibrosis-associated molecules, i.e. the collagen-cross linking enzyme lysyl oxidase, transglutaminase 2 and periostin. In conclusion, despite a robust fibromodulin upregulation in clinical and experimental heart failure, FMOD-KO mice showed a relatively mild hypertrophic phenotype. In cultured cardiac fibroblasts, fibromodulin has anti-fibrotic effects.
Nucleotide-binding oligomerization domain-Like Receptor with a Pyrin domain 3 (NLRP3) is considered necessary for initiating a profound sterile inflammatory response. NLRP3 forms multi-protein ...complexes with Apoptosis-associated Speck-like protein containing a Caspase recruitment domain (ASC) and Caspase-1, which activate pro-interleukin-1β (IL-1β) and pro-IL-18. The role of NLRP3 in cardiac cells is not known. Thus, we investigated the expression and function of NLRP3 during myocardial ischaemia.
Myocardial infarction (MI) was induced in adult C57BL/6 mice and Wistar rats by ligation of the coronary artery. A marked increase in NLRP3, IL-1β, and IL-18 mRNA expression was found in the left ventricle after MI, primarily located to myocardial fibroblasts. In vitro studies in cells from adult mice showed that myocardial fibroblasts released IL-1β and IL-18 when primed with lipopolysaccharide and subsequently exposed to the danger signal adenosine triphosphate, a molecule released after tissue damage during MI. When hearts were isolated from NLRP3-deficient mice, perfused and subjected to global ischaemia and reperfusion, a marked improvement of cardiac function and reduction of hypoxic damage was found compared with wild-type hearts. This was not observed in ASC-deficient hearts, potentially reflecting a protective role of other ASC-dependent inflammasomes or inflammasome-independent effects of NLRP3.
This study shows that the NLRP3 inflammasome is up-regulated in myocardial fibroblasts post-MI, and may be a significant contributor to infarct size development during ischaemia-reperfusion.
•In this cross-sectional study, we found decreased serum levels of primary bile acids and increased levels of specific secondary bile acids, resulting in increased ratios of secondary to primary bile ...acids, in patients with chronic heart failure.•The ratio of secondary to primary bile acids was associated with reduced overall survival in univariate analysis, but not in multivariate analyses.•Although the production of secondary bile acids depends on the gut microbiota, several factors affecting the production, regulation, and elimination of bile acids could contribute to these findings.•Future studies should assess the potential role of bile acid composition in patients with heart failure and investigate whether manipulation of factors influencing bile acid metabolism, including the intestinal microbial community, could alter clinical outcome.
Bile acids (BAs) are now recognized as signaling molecules and emerging evidence suggests that BAs affect cardiovascular function. The gut microbiota has recently been linked to the severity of heart failure (HF), and microbial metabolism has a major impact on BA homeostasis. We aimed to investigate the pattern of BAs, and particularly microbiota-transformed (secondary) BAs, in patients with chronic HF.
This was a prospective, observational, single-center study including 142 patients with chronic HF and 20 age- and sex-matched healthy control subjects. We measured plasma levels of primary, secondary, and total BAs, and explored their associations with clinical characteristics and survival. Plasma levels of primary BAs were lower (P < .01) and the ratios of secondary to primary BAs higher (P < .001) in patients with HF compared with control subjects. Approximately 40% of patients in the upper tertile of the ratio of secondary to primary BAs died during 5.6 years of follow-up (unadjusted Cox regression: hazard ratio 1.93, 95% confidence interval 1.01–3.68, compared with the lower tertiles). However, this association was attenuated and no longer significant in multivariate analyses.
Levels of primary BAs were reduced and specific secondary BAs increased in patients with chronic HF. This pattern was associated with reduced overall survival in univariate analysis, but not in multivariate analyses. Future studies should assess the regulation and potential role of BA metabolism in HF.
Human-induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CM) are increasingly being used for modeling heart disease and are under development for regeneration of the injured heart. However, ...incomplete structural and functional maturation of hiPSC-CM, including lack of T-tubules, immature excitation-contraction coupling, and inefficient Ca-induced Ca release remain major limitations.
Thyroid and glucocorticoid hormones are critical for heart maturation. We hypothesized that their addition to standard protocols would promote T-tubule development and mature excitation-contraction coupling of hiPSC-CM when cultured on extracellular matrix with physiological stiffness (Matrigel mattress).
hiPSC-CM were generated using a standard chemical differentiation method supplemented with T3 (triiodothyronine) and/or Dex (dexamethasone) during days 16 to 30 followed by single-cell culture for 5 days on Matrigel mattress. hiPSC-CM treated with T3+Dex, but not with either T3 or Dex alone, developed an extensive T-tubule network. Notably, Matrigel mattress was necessary for T-tubule formation. Compared with adult human ventricular cardiomyocytes, T-tubules in T3+Dex-treated hiPSC-CM were less organized and had more longitudinal elements. Confocal line scans demonstrated spatially and temporally uniform Ca release that is characteristic of excitation-contraction coupling in the heart ventricle. T3+Dex enhanced elementary Ca release measured by Ca sparks and promoted RyR2 (ryanodine receptor) structural organization. Simultaneous measurements of L-type Ca current and intracellular Ca release confirmed enhanced functional coupling between L-type Ca channels and RyR2 in T3+Dex-treated cells.
Our results suggest a permissive role of combined thyroid and glucocorticoid hormones during the cardiac differentiation process, which when coupled with further maturation on Matrigel mattress, is sufficient for T-tubule development, enhanced Ca-induced Ca release, and more ventricular-like excitation-contraction coupling. This new hormone maturation method could advance the use of hiPSC-CM for disease modeling and cell-based therapy.
Two-stage process of dark fermentation (DF) and photo fermentation (PF), using fruit and vegetable waste (FVW) and cheese whey powder (CWP), was used as an approach to enhance the hydrogen (H2) ...production. FVW and CWP at C/N ratios of 34, 39, 60, 71 and 82 were tested as substrates for DF. Dilution (1:2, 1:5, 1:10) of the DF effluents was used as a coupling strategy. DF effluents with low-butyrate and high lactate concentrations were obtained as a function of an increased C/N ratio, which results in high H2 production during the PF. Maximum overall H2 yields of 793.7 and 695.4 mLH2/gChemical Oxygen Demand (COD) were obtained using a 1:10 dilution, at a C/N ratio of 60 and 70, respectively. These H2 yields were higher than those obtained with the individual processes. The C/N ratio at the DF stage regulate not only H2 production but also the distribution and concentrations of by-products. These metabolites, in turn, control the H2 production during the PF. Predominant microbial population for both processes (DF: C/N = 34 Acetobacter lovaniensis, Clostridium butyricum; C/N = 39 C. butyricum, Enterobacter sp, Bifidobacterium; C/N = 82 Lactobacillus casei; PF: Rhodopseudomonas palustris) were in accordance with the final metabolic products.
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•Enhanced H2 production by dark-photo (DF-PF) fermentations was demonstrated.•Fruit and vegetable waste and cheese whey as substrate allows waste removal and H2 production.•Increased C/N ratio reduces H2 yield at DF, but increase the H2 production at PF.•DF effluents with high lactate concentrations promotes high H2 production at PF.•Microbial population for both DF, PF in accordance with the final metabolic products.
Whereas heart failure with reduced ejection fraction (HFrEF) is associated with ventricular dilation and markedly reduced systolic function, heart failure with preserved ejection fraction (HFpEF) ...patients exhibit concentric hypertrophy and diastolic dysfunction. Impaired cardiomyocyte Ca2+ homeostasis in HFrEF has been linked to disruption of membrane invaginations called t-tubules, but it is unknown if such changes occur in HFpEF.
This study examined whether distinct cardiomyocyte phenotypes underlie the heart failure entities of HFrEF and HFpEF.
T-tubule structure was investigated in left ventricular biopsies obtained from HFrEF and HFpEF patients, whereas cardiomyocyte Ca2+ homeostasis was studied in rat models of these conditions.
HFpEF patients exhibited increased t-tubule density in comparison with control subjects. Super-resolution imaging revealed that higher t-tubule density resulted from both tubule dilation and proliferation. In contrast, t-tubule density was reduced in patients with HFrEF. Augmented collagen deposition within t-tubules was observed in HFrEF but not HFpEF hearts. A causative link between mechanical stress and t-tubule disruption was supported by markedly elevated ventricular wall stress in HFrEF patients. In HFrEF rats, t-tubule loss was linked to impaired systolic Ca2+ homeostasis, although diastolic Ca2+ removal was also reduced. In contrast, Ca2+ transient magnitude and release kinetics were largely maintained in HFpEF rats. However, diastolic Ca2+ impairments, including reduced sarco/endoplasmic reticulum Ca2+-ATPase activity, were specifically observed in diabetic HFpEF but not in ischemic or hypertensive models.
Although t-tubule disruption and impaired cardiomyocyte Ca2+ release are hallmarks of HFrEF, such changes are not prominent in HFpEF. Impaired diastolic Ca2+ homeostasis occurs in both conditions, but in HFpEF, this mechanism for diastolic dysfunction is etiology-dependent.
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Fibrosis accompanies most heart diseases and is associated with adverse patient outcomes. Transforming growth factor (TGF)β drives extracellular matrix remodelling and fibrosis in the failing heart. ...Some members of the ADAMTSL (a disintegrin-like and metalloproteinase domain with thrombospondin type 1 motifs-like) family of secreted glycoproteins bind to matrix microfibrils, and although their function in the heart remains largely unknown, they are suggested to regulate TGFβ activity. The aims of this study were to determine ADAMTSL2 levels in failing hearts, and to elucidate the role of ADAMTSL2 in fibrosis using cultured human cardiac fibroblasts (CFBs). Cardiac ADAMTSL2 mRNA was robustly increased in human and experimental heart failure, and mainly expressed by fibroblasts. Over-expression and treatment with extracellular ADAMTSL2 in human CFBs led to reduced TGFβ production and signalling. Increased ADAMTSL2 attenuated myofibroblast differentiation, with reduced expression of the signature molecules α-smooth muscle actin and osteopontin. Finally, ADAMTSL2 mitigated the pro-fibrotic CFB phenotypes, proliferation, migration and contractility. In conclusion, the extracellular matrix-localized glycoprotein ADAMTSL2 was upregulated in fibrotic and failing hearts of patients and mice. We identified ADAMTSL2 as a negative regulator of TGFβ in human cardiac fibroblasts, inhibiting myofibroblast differentiation and pro-fibrotic properties.
BackgroundEvidence on disease burden and the impact of interventions are instrumental in vaccine related investment decisions. It is imperative to understand what the facilitators and barriers of ...evidence use are to ensure the most effective vaccine investment decisions for public health at global and national level are made. AimsOverall, this research aims to understand if, and how, mathematical models are used to inform resource allocation decisions for vaccine-preventable diseases in low-and middle-income countries. Here we focus on exploring the role of trust in the potential use of evidence from mathematical models.MethodsTwelve semi-structured interviews were conducted with mathematical modelers (evidence producers) and employees at international organizations, who are involved in decision-making processes (evidence consumers) at a global level. Information was collected on stakeholders’ experiences and perceptions of the use of mathematical models at global and at national level. All mathematical modelers were purposively sampled by their extensive vaccine modelling experience at a global and/or national level. Data from interviews were coded and mapped to a theoretical framework, which identified the spectrum of evidence use by policy and decision makers.Expected resultsThis presentation will describe how mathematical models are being used in global level resource allocation decisions, and more specifically, how trust is understood by both model consumers and producers. Preliminary findings suggest trust is both an integral facilitator and barrier for evidence use and heavily influenced by model producer’s research environments and length of relationships with model consumers. Amongst consumers the concept of trust is most notable in the context of methodologies, data transparency and stakeholder relationships.ConclusionThis research suggests that the use of evidence and perceptions of evidence differ among stakeholders. Trust among evidence producers and consumers is an integral component in evidence informed decision-making that can be a barrier or facilitator.
Fish sauce, a traditional Asian condiment, is derived from the prolonged hydrolysis of salted small fishes, resulting in a mixture of amino acids and proteins. While fermented products are generally ...considered safe for consumption, ensuring the safety of public consumers remains paramount. Despite this concern, limited research exists in the Philippines on the protein content and microbial quality of fish sauce. Therefore, this study aims to assess the protein content, total halophilic count, and the presence of Salmonella spp. and Staphylococcus aureus in fish sauce produced by unregistered manufacturers in specific provinces of the Philippines. The Kjehldal method was employed to determine the crude protein content, and the organoleptic characteristics, including color, odor, flavor, and aftertaste liking, were evaluated by a panel of 10 sensory experts using a descriptive sensory score sheet. Furthermore, the acceptability of the samples was assessed through a 9-point hedonic scale. The results indicated that the protein content of the five fish sauce samples ranged from 1.00% to 2.06%. According to the required minimum standard set by the Department of Health (DOH) (4.5-2.5%), all fish sauce samples were classified as "fish sauce below standard." Regarding microbiological quality, the Philippines currently lacks standardized limits for fish sauce products. The halophilic count in the samples ranged from 308 to 930 cfu·g-1, while all samples yielded a Staphylococcal count of <10 MPN·g-1 and were negative for Salmonella spp. Furthermore, based on the 9-point hedonic scale, the acceptance score of the five fish sauces was found to be 5.0. This research sheds light on the protein content, microbial safety, and consumer perception of fish sauce produced by unregistered manufacturers in select provinces of the Philippines, emphasizing the need for establishing quality standards to safeguard public health.
During progression to heart failure (HF), myocardial extracellular matrix (ECM) alterations and tissue inflammation are central. Lumican is an ECM‐localized proteoglycan associated with inflammatory ...conditions and known to bind collagens. We hypothesized that lumican plays a role in the dynamic alterations in cardiac ECM during development of HF. Thus, we examined left ventricular cardiac lumican in a mouse model of pressure overload and in HF patients, and investigated expression, regulation and effects of increased lumican in cardiac fibroblasts. After 4 weeks of aortic banding, mice were divided into groups of hypertrophy (AB) and HF (ABHF) based on lung weight and left atrial diameter. Sham‐operated mice were used as controls. Accordingly, cardiac lumican mRNA and protein levels were increased in mice with ABHF. Similarly, cardiac biopsies from patients with end‐stage HF revealed increased lumican mRNA and protein levels compared with control hearts. In vitro, mechanical stretch and the proinflammatory cytokine interleukin‐1β increased lumican mRNA as well as secreted lumican protein from cardiac fibroblasts. Stimulation with recombinant glycosylated lumican increased collagen type I alpha 2, lysyl oxidase and transforming growth factor‐β1 mRNA, which was attenuated by costimulation with an inhibitor of the proinflammatory transcription factor NFκB. Furthermore, lumican increased the levels of the dimeric form of collagen type I, decreased the activity of the collagen‐degrading enzyme matrix metalloproteinase‐9 and increased the phosphorylation of fibrosis‐inducing SMAD3. In conclusion, cardiac lumican is increased in experimental and clinical HF. Inflammation and mechanical stimuli induce lumican production by cardiac fibroblasts and increased lumican altered molecules important for cardiac remodeling and fibrosis in cardiac fibroblasts, indicating a role in HF development.
Lumican was increased in the failing heart of mice and men. In vitro cyclic mechanical stretch and inflammation induced lumican expression and protein secretion from cardiac fibroblasts. Moreover, increased lumican in cardiac fibroblasts induced expression of molecules important for cardiac remodeling and fibrosis, suggesting a role for lumican in heart failure development.
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