Pathophysiology Of Disease Research Articles

New insights into the pathophysiology of rheumatic valve disease based on different genetic and proteomics profiles

Abstract Introduction Rheumatic heart disease (RHD) pathogenesis is not fully understood. Purpose The protein profile in rheumatic heart disease may have a different fingerprint in the aortic and mitral valves, which results in different evolution in terms of valve damage. Methods To evaluate the genetic profile in symptomatic RHD, 4 simultaneous mitral and aortic valves were obtained during valve replacement, as well as 4 "normal" valves from cadavers (Control Group). The expression of 90 genes was evaluated using a customized RT-PCR array kit. A second experiment was carried out to evaluate proteomics. Then, 7 mitral and aortic valves, from the same patient, were also collected during valve surgery. The Control Group consisted of 6 mitral and aortic valves obtained from explanted hearts during heart transplantation due to non-valvular pathologies. Additionally, histopathological and sectoral proteomic analysis of amyloid deposits, found in some mitral and aortic valves, from the second experiment, were also reported. Results Mitral rheumatic valves exhibited higher expression of genes linked to calcification and immuno-inflammation compared to aortic rheumatic valves (Figure 1). Proteomic analysis, visualized through PCA graphs, highlighted differences in proteomic patterns. Despite having the same genetic pattern, control valves exhibited different proteomic profiles (Figure 1) Rheumatic mitral and aortic valves, even from the same individual, showed distinct proteomic fingerprint (Figure 1). A total of 49 significant proteins were identified in distinguishing healthy mitral and aortic valves from the same individual (Figure 1). The aortic valve displayed a richer extracellular matrix and higher levels of housekeeping proteins that maintain valve homeostasis compared to the mitral valve (Figure 1). The dominant proteomic pattern in valvular rheumatic disease was identified as alterations in critical mitochondrial metabolic activities related to proteostasis. (Figure 2). Particularly notable was the upregulation of pathways associated with lipid metabolism (Figure 2). Finally, amyloid deposits suggested APOA1 as a potential deposit protein in RHD (Figure 2). Conclusion The study confirms distinct constitutional differences between mitral and aortic valves affecting rheumatic disease progression. It emphasizes the role of altered proteostasis and altered proteins deposit, mitochondrial metabolic changes, and inflammatory responses in the disease's pathophysiology, highlighting the complexity of valvular rheumatic disease involvement.For the first time amyloid deposition has been reported as a likely consequence of significant disruption in valvular proteostasis and the proteins potentially comprising this deposit within a rheumatic valve.Genomic and proteomic overviewproteomic fingerprint of RHD and amyloid

Effects of empagliflozin on myocardial transcriptome in rats with aortic stenosis-induced heart failure

Abstract Introduction Aortic stenosis (AS) represents one of the most prevalent valvular heart diseases and an important cause of heart failure. Currently, no medical therapies influence the natural history of aortic stenosis. Although sodium glucose co-transporter 2 inhibitors (SGLT2i) have improved cardiovascular outcomes in heart failure patients with both reduced and preserved ejection fraction, their action mechanisms are not clear. Transcriptome analysis present great potential to identify biomarkers of disease and to gain insight into disease pathophysiology. In this study, we analyzed myocardial mRNA profile in aortic stenosis rats treated with empagliflozin. Methods Eighteen weeks after supra-aortic banding surgery, male Wistar rats were divided into 3 groups: Sham (n=15); aortic stenosis (AS, n=27); AS+empagliflozin (AS-EMP, n=27). Empagliflozin (10 mg/kg/day) was added to rat chow for 8 weeks. Transcriptome of left ventricle (LV) myocardium was studied by RNA-sequencing (sample size: 5 per group). Differential gene expression was analyzed in R environment using the DESeq2 package. Genes were considered differentially expressed (DEG) when they exhibited a log2 fold change (log2FC) higher than 1 (upregulated) or lower than -1 (downregulated), coupled with an adjusted p-value below 0.05. Functional enrichment analysis using gene ontology was performed by the online tool Enrich. Statistical analysis: ANOVA and Tukey. Results AS-EMP had lower LV diastolic diameter (Sham 8.39±0.57; AS 9.80±0.53*; AS-EMP 9.08±0.87# mm; p<0.05: * vs Sham; # vs AS), left atrium diameter (Sham 5.68±0.40; AS 9.67±1.00*; AS-EMP 8.97±1.36*# mm; p<0.05: * vs Sham; # vs AS), and LV mass (Sham 0.85±0.11; AS 2.19±0.27*; AS-EMP 1.76±0.34*# g; p<0.05: * vs Sham; # vs AS) than AS. A total of 1246 differentially expressed genes were identified, comprising 663 upregulated genes (70 genes in AS vs SHAM; 593 in AS-EMP vs AS) and 583 downregulated genes (35 genes in AS vs SHAM; 548 in AS-EMP vs AS). Most of the differentially expressed genes were enriched in processes such as extracellular matrix and structure organization, signal transduction regulation, and substrate-dependent cell migration (AS vs SHAM), as well as myocardial contraction, negative regulation of programmed cell death, and mitochondrial membrane organization (AS-EMP vs AS). The main upregulated genes were Loxl1, Mfap4, Postn, Col8a1, Pi16, and Nppa in AS vs SHAM; and Mxra8, Zfta, Pnisr, Thoc1, and Ralbp1 in AS-EMP vs AS comparison. The main downregulated genes were Mxra8, Ralbp1, and Tubgcp6 in AS vs SHAM; and Itgb5, Ltbp2, Tmem109, Plec, and Rorc in AS-EMP vs AS comparison. Conclusion We identified myocardial genes and biological processes that are potentially involved in aortic stenosis-induced heart failure. Empagliflozin attenuates cardiac remodeling and modulates myocardial genes involved with myocyte contraction, apoptosis, and mitochondrial organization in aortic stenosis rats.

[11C]Metoclopramide PET can detect a seizure-induced up-regulation of cerebral P-glycoprotein in epilepsy patients

BackgroundP-glycoprotein (P-gp) is an efflux transporter which is abundantly expressed at the blood-brain barrier (BBB) and which has been implicated in the pathophysiology of various brain diseases. The radiolabelled antiemetic drug [11C]metoclopramide is a P-gp substrate for positron emission tomography (PET) imaging of P-gp function at the BBB. To assess whether [11C]metoclopramide can detect increased P-gp function in the human brain, we employed drug-resistant temporal lobe epilepsy (TLE) as a model disease with a well characterised, regional P-gp up-regulation at the BBB.MethodsEight patients with drug-resistant (DRE) TLE, 5 seizure-free patients with drug-sensitive (DSE) focal epilepsy, and 15 healthy subjects underwent brain PET imaging with [11C]metoclopramide on a fully-integrated PET/MRI system. Concurrent with PET, arterial blood sampling was performed to generate a metabolite-corrected arterial plasma input function for kinetic modelling. The choroid plexus was outmasked on the PET images to remove signal contamination from the neighbouring hippocampus. Using a brain atlas, 10 temporal lobe sub-regions were defined and analysed with a 1-tissue-2-rate constant compartmental model to estimate the rate constants for radiotracer transfer from plasma to brain (K1) and from brain to plasma (k2), and the total volume of distribution (VT = K1/k2).ResultsDRE patients but not DSE patients showed significantly higher k2 values and a trend towards lower VT values in several temporal lobe sub-regions located ipsilateral to the epileptic focus as compared to healthy subjects (k2: hippocampus: +34%, anterior temporal lobe, medial part: +28%, superior temporal gyrus, posterior part: +21%).Conclusions[11C]Metoclopramide PET can detect a seizure-induced P-gp up-regulation in the epileptic brain. The efflux rate constant k2 seems to be the most sensitive parameter to measure increased P-gp function with [11C]metoclopramide. Our study provides evidence that disease-induced alterations in P-gp expression at the BBB can lead to changes in the distribution of a central nervous system-active drug to the human brain, which could affect the efficacy and/or safety of drugs. [11C]Metoclopramide PET may be used to assess or predict the contribution of increased P-gp function to drug resistance and disease pathophysiology in various brain diseases.Trial registrationEudraCT 2019-003137-42. Registered 28 February 2020.

Increased index of microcirculatory resistance, capillary rarefaction, elevated troponin levels, and their association with transthyretin amyloidosis cardiomyopathy

Abstract Background The pathophysiology of coronary microvascular disease (CMD) in patients with transthyretin amyloidosis cardiomyopathy (ATTR-CM) remains unclear. Objective This study aims to functionally and pathologically assess coronary microvasculature to elucidate the underlying mechanisms of myocardial injury in patients with ATTR-CM. Methods Fifty patients (median age, 74 years; men, n=46, 92%) with echocardiographic evidence of left ventricular hypertrophy (≥12 mm) who underwent endomyocardial biopsy (EMB) and invasive coronary physiological assessments following coronary angiography were enrolled between October 2021 and September 2023 and divided into ATTR-CM (n=30) and non-cardiac amyloidosis (CA) (n=20) groups according to EMB results. All patients with ATTR-CM exhibited positive heart-to-contralateral (H/CL) ratios (>1.5) on technetium 99m pyrophosphate scintigraphy. Fractional flow reserve (FFR), coronary flow reserve (CFR), and index of microcirculatory resistance (IMR) were measured using the PressureWire X guidewire in the left anterior descending artery. Capillary density (/mm2) was determined with EMB tissues by counting the number of CD31 immunopositive luminal structures, whereas the amyloid deposition burden was assessed by measuring the transthyretin immunopositive areas. Circulating cardiac troponin T (hs-cTnT) and brain natriuretic peptide (BNP) were measured. Results Compared to the non-CA group, the ATTR-CM group exhibited lower CFR (2.4±0.3 vs. 3.6±0.4, p=0.01), higher IMR (35.4±3.0 vs. 18.7±3.7, p=0.0009), lower capillary density (255.3±24.9 /mm2 vs. 408.6±29.5 /mm2 , p=0.0002), and elevated hs-cTnT levels (0.056±0.006 ng/mL vs. 0.036±0.004 ng/mL, p=0.01), with similar FFR (0.87±0.015 vs. 0.84±0.013, p=0.1) and BNP levels (229.6±38.1 pg/mL vs. 210.2±46.7 pg/mL, p=0.75). In the overall and ATTR-CM groups, capillary density had no significant correlation with IMR (r=0.16, p=0.41 and r=0.04, p=0.84, respectively) and a significant inverse correlation with hs-cTnT (r=-0.47, p=0.001, and r=-0.48, p=0.009, respectively). In the ATTR-CM group, capillary density was not significantly correlated with the H/CL ratio (r=-0.23, p=0.09); nevertheless, transthyretin immunopositive areas were positively correlated with the H/CL ratio (r=0.47, p=0.01). Conclusion Capillary rarefaction correlates with elevated hs-cTnT levels but not with elevated IMR, and H/CL ratios, suggesting that CMD is involved at the capillary level in ATTR-CM-related myocardial injury independent of the amyloid deposition burden.

ERBB4 activation prevents microvascular dysfunction in a large animal model of hypertensive heart disease

Abstract Background Coronary microvascular dysfunction (CMD) participates in the pathophysiology of multiple cardiovascular diseases, but treatment options are limited. A new treatment option may include ERBB4 stimulation by neuregulin-1 (NRG1), which has anti-inflammatory, antifibrotic, and cardioprotective effects in models of heart failure. Objectives To assess the effect NRG1/ERBB4 stimulation on CMD in hypertensive heart disease. Methods Hypertensive heart disease was induced in 12 Aachener minipigs by implantation of deoxycorticosterone acetate (DOCA) pellets for 8 weeks and compared to 6 controls. The DOCA pigs were randomized to a weekly infusion of JK07, a NRG1 fusion protein with improved pharmacokinetic and pharmacodynamic properties, or vehicle. Microvascular resistance was measured using the bolus thermodilution method. Results DOCA significantly increased microvascular resistance compared to controls (from 14.5 to 19.9 mmHg.s, p = 0.028). This increase was abrogated by JK07 (11.3 mmHg.s, p = 0.018 vs DOCA). dP/dtmax increased by DOCA compared to controls (from 2415.5 to 4455.5 mmHg/s, p = 0.011), which was also abrogated by JK07 (3107.3 mmHg/s, p = 0.055 vs DOCA). Interstitial left ventricular fibrosis was significantly lower in JK07-treated pigs compared to DOCA only (2.1 vs. 5.4 %, p = 0.026), but without difference in perivascular fibrosis (p = 0.48). JK07 did not affect myocyte cross-sectional area, capillary density, pericyte coverage, or microvascular vessel thickness. Conclusions ERBB4 activation by JK07 is capable to prevent CMD in a DOCA hypertensive pig model. Functional rather than structural alterations may explain the protective effects of JK07 on microvascular resistance.Visual summaryJK07 decreases microvascular resistance

Single cell multi-omics analysis unveils a distinct mechanism of exercise-mediated cardioprotection in ischemic cardiomyopathy

Abstract Background Exercise is pivotal in heart disease prevention, with proven cardioprotective effects in clinical trials. However, its precise molecular mechanisms remain elusive. Recent advancements in single-cell omics have revealed cellular heterogeneity within heart tissues, offering a deeper understanding of the pathophysiology of cardiac diseases. Purpose To investigate the exercise-induced physiological changes in heart tissue at the single-cell level and elucidate the molecular mechanisms underlying its cardioprotective effect on ischemic cardiomyopathy. Methods Murine myocardial infarction (MI) model was established by ligating the left ascending coronary artery, and a six-week voluntary wheel running exercise regimen was implemented to investigate the effect of aerobic exercise on ischemic cardiomyopathy. Integrated multi-omics analyses of single-cell DNA methylation profiling, single-nucleus assay for transposase-accessible chromatin sequencing (snATAC-seq) and single-nucleus RNA sequencing (snRNA-seq) were conducted to clarify the molecular mechanism of exercise-mediated cardioprotection at single-cell resolution. Overexpression and short hairpin RNA-mediated knockdown of gene X were conducted for murine MI model using cardiomyocyte-specific Myo-AAV2a vector. snRNA-seq of heart tissues from heart failure patients was performed to validate the clinical significance of the expression of gene X in cardiomyocytes. Results Exercise attenuates pathological cardiac remodeling, inducing physiological hypertrophy in non-infarcted areas while suppressing pathological remodeling of cardiomyocytes in infarct border zones. Single-cell epigenetic analysis unveiled intricate molecular mechanisms underlying exercise-induced transcriptome changes, providing insights into the gene regulatory networks modulated by exercise in the heart. In addition, integrated with snRNA-seq, we identified exercise-specific cardiomyocyte clusters, highlighting the substantial role of gene X in the molecular mechanism of exercise. Functional studies confirmed the essential role of gene X in exercise-induced cardioprotection, as its overexpression suppressed the adverse remodeling after MI and knockdown abolished the beneficial effects of exercise. Furthermore, snRNA-seq of heart failure patients revealed that higher expression of gene X was associated with ventricular reverse remodeling and favorable clinical outcomes, underscoring its significance in the pathophysiology of patients with heart failure. Conclusion Our study elucidates exercise-specific gene expression regulation networks in ischemic cardiomyopathy by unraveling the cellular heterogeneity and molecular changes associated with exercise. We identified gene X as a central player in exercise-mediated cardioprotection and further confirmed its significance in clinical settings, providing a potential therapeutic target for heart failure.

Lipin1 prevents ischemic heart disease by regulating lipid homeostasis

Abstract Background Lipid metabolism plays a crucial role in the pathophysiology of cardiovascular diseases. Lipin1 plays a pivotal role in lipid metabolism regulation. In the nucleus, Lipin1 acts as a transcriptional co-stimulatory molecule, interacting with peroxisome proliferator–activated receptor–gamma coactivator 1 alpha (PGC1α) and peroxisome proliferator–activated receptor alpha (PPARα). In the cytoplasm, Lipin1 functions as a phosphatidate phosphatase, converting phosphatidic acid to diacylglycerol to regulate lipid metabolism. Low expression of Lipin1 has been implicated in the severity of cardiac dysfunction in mice. Purpose This study aimed to investigate the role of Lipin1 in the cardiac remodeling after myocardial infarction (MI), revealing its impact on lipid metabolism and molecular pathway associated with cardiac dysfunction. Methods Two types of transgenic mice, cardiomyocyte-specific Lipin1 knockout (cKO) and overexpression (cOE) mice were used in this study. Eight to ten-week-old male mice were subjected to MI by coronary artery ligation. Cardiac lipid droplets were quantified, and triacylglycerol and free fatty acid levels were measured one week after MI surgery. Four weeks after MI, cardiac morphology and function were evaluated using echocardiography, alongside measurements of body weight (BW) and heart weight (HW). Additionally, gene expression analysis and histological evaluation were conducted to assess fatty acid metabolism, cardiac fibrosis, inflammation, and oxidative damage. Results Before MI surgery, there were no differences in HW/BW ratio, left ventricular end-diastolic diameter (LVDd) or LV fractional area change (LVFAC) among cKO/ cOE mice and their littermate controls. After MI, cKO mice exhibited significant cardiac dysfunction with larger LVDd, lower LVFAC and increased HW/BW ratio compared to littermate controls. This was accompanied by exacerbated cardiac fibrosis, increased inflammation, and augmented reactive oxygen species accumulation compared with their controls. Conversely, cOE mice displayed improved LVFAC, reduced cardiac fibrosis, inflammation, and reactive oxygen species accumulation compared to their littermate controls. Notably, the transgene of Lipin1 induced changes in the number of cardiac lipid droplets (LDs). cKO mice hearts showed a reduction in cardiac LDs with decreased levels of triacylglycerol and free fatty acids compared to the littermate controls. In contrast, cOE mice displayed increased cardiac LDs and upregulated expression of fatty acid metabolism–related genes after MI. Conclusion These results suggested that Lipin1 has a protective role against ischemic injury through controlling lipid metabolism in ischemic cardiomyocytes. Thus, Lipin1 emerges as a potential therapeutic target for myocardial infarction.

M/EEG source localization for both subcortical and cortical sources using a convolutional neural network with a realistic head conductivity model

While electroencephalography (EEG) and magnetoencephalography (MEG) are well-established noninvasive methods in neuroscience and clinical medicine, they suffer from low spatial resolution. Electrophysiological source imaging (ESI) addresses this by noninvasively exploring the neuronal origins of M/EEG signals. Although subcortical structures are crucial to many brain functions and neuronal diseases, accurately localizing subcortical sources of M/EEG remains particularly challenging, and the feasibility is still a subject of debate. Traditional ESIs, which depend on explicitly defined regularization priors, have struggled to set optimal priors and accurately localize brain sources. To overcome this, we introduced a data-driven, deep learning-based ESI approach without the need for these priors. We proposed a four-layered convolutional neural network (4LCNN) designed to locate both subcortical and cortical sources underlying M/EEG signals. We also employed a sophisticated realistic head conductivity model using the state-of-the-art segmentation method of ten different head tissues from individual MRI data to generate realistic training data. This is the first attempt at deep learning-based ESI targeting subcortical regions. Our method showed excellent accuracy in source localization, particularly in subcortical areas compared to other methods. This was validated through M/EEG simulations, evoked responses, and invasive recordings. The potential for accurate source localization of the 4LCNNs demonstrated in this study suggests future contributions to various research endeavors such as the clinical diagnosis, understanding of the pathophysiology of various neuronal diseases, and basic brain functions.

Comparison of Methodologies for Absolute Binding Free Energy Calculations of Ligands to Intrinsically Disordered Proteins.

Modulating the function of Intrinsically Disordered Proteins (IDPs) with small molecules is of considerable importance given the crucial roles of IDPs in the pathophysiology of numerous diseases. Reported binding affinities for ligands to diverse IDPs vary broadly, and little is known about the detailed molecular mechanisms that underpin ligand efficacy. Molecular simulations of IDP ligand binding mechanisms can help us understand the mode of action of small molecule inhibitors of IDP function, but it is still unclear how binding energies can be modeled rigorously for such a flexible class of proteins. Here, we compare alchemical absolute binding free energy calculations (ABFE) and Markov-State Modeling (MSM) protocols to model the binding of the small molecule 10058-F4 to a disordered peptide extracted from a segment of the oncoprotein c-Myc. The ABFE results produce binding energy estimates that are sensitive to the choice of reference structure. In contrast, the MSM results produce more reproducible binding energy estimates consistent with weak mM binding affinities and transient intermolecular contacts reported in the literature.

Vaccination targeting senescence-associated transmembrane protein alleviated cardiovascular pathology in the mice

Abstract Introduction Accumulation of senescent cells is observed in various organs including vasculature, heart and white adipose tissue with age, and known to become a substrate of pathophysiology of various cardiovascular-metabolic diseases. We have previously developed a vaccine to eliminate senescent cells, so-called "senolytic vaccine" by targeting Glycoprotein Nonmetastatic Melanoma Protein B (GPNMB) as a cellular-senescence-associated cell surface protein. We have demonstrated that GPNMB senolytic vaccine could remove senescent cells and alleviate the pathology cardiovascular-metabolic diseases. Senescence-associated adhesion molecule 1 (SAAM-1) is also known as a cell-surface membrane to increase its expression during cellular senescence in endothelial cells as well as the development of cardiovascular diseases. Here, we identified SAAM-1 as another senescence antigen and created a vaccine to eliminate senescent cells by targeting SAAM-1. Purpose This study was purposed to evaluate the efficacy of SAAM-1 vaccine for the treatment of cardiovascular diseases in mice models. Methods As a pressure overload-induced heart failure (HF) model, C57BL/6N wild type (WT) mice were underwent transverse aortic constriction (TAC) or sham opretaion at 13 weeks of age. SAAM-1 or control vaccination were given at 8 and 10 weeks of age before operation. Echocardiography examination was conducted two weeks after TAC operation, followed by tissue sampling 3 weeks after the examination. As an atherosclerosis model, ApoE KO mice were subjected to a high-fat diet (HFD) starting at 4 weeks of age. Vaccination of ApoE KO mice was administered at 8 weeks of age with SAAM-1-vaccine or control-vaccine, followed by sacrifice 4 weeks later for further analysis. ApoE-KO mice were also crossed with p16-mediated Luciferase expressing mice (p16-Luc mice) and subjected to generation of atherosclerosis model. Results SAAM-1 expression was significantly increased in left ventricle (LV) in TAC mice but its increase was suppressed by SAAM-1 vaccination. Interestingly, both worsening systolic function and dilatation of LV by pressure overload were significantly alleviated by SAAM-1 vaccination. Furthermore, expression level of senescent markers including p16 and p21, as well as several inflammation markers were increased in failing heart along with development of cardiac fibrosis, but SAAM-1 vaccine could significantly attenuate this pathological change. In ApoE KO mice, SAAM-1 vaccine decreased expression level of several inflammation markers in the mice, along with a decreasing p16 signal in the aorta. Conclusions Targeting SAAM-1 for vaccination would be a novel and promising approach to alleviating age-related cardiovascular disease.

Association of left atrial strain and exercise capacity among patients with hypertension: a single center study

Abstract Introduction Hypertension has been identified as one of the leading risk factors for developing cardiovascular disease in the Philippines. 1 The long term increase in afterload causes the progressive decline in both the systolic and diastolic function of hypertensive patients. There has been an increasing recognition in the role of left atrial function in the pathophysiology of several cardiac diseases, including hypertension. Purpose For patients with hypertension, exercise capacity is reduced by 30%.2 As exercise capacity is a known prognostic marker for adverse cardiovascular outcomes, identifying patients with hypertension with impaired left atrial reservoir strain may also improve cardiovascular risk stratification. With the use of two-dimensional (2D) speckle tracking echocardiography, left atrial strain can now be utilized in the evaluation of left atrial reservoir, conduit, and contractile function. Left atrial strain (LA strain) can now serve as a biomarker of adverse cardiovascular outcomes, including the exercise capacity of patients. Another goal of the study is to identify other clinical and echocardiographic factors that may affect exercise capacity Methods A single center, retrospective cross sectional study was conducted in a tertiary hospital to validate the association of left atrial strain with exercise capacity in terms of metabolic equivalent (METs) achieved during treadmill exercise echocardiography of patients diagnosed with hypertension. The primary objective of this study is to determine the left atrial strain cutoff that reliably discriminates poor, fair, average, good, or high exercise capacity. Data was obtained by conducting a chart and echocardiography review of adult patients from January 2023 to April 2023. The independent association of LA strain with METs was studied with regression analysis. Results were considered significant at p≤0.05 at 95% confidence interval. Receiver-operating characteristic curve analysis was utilized to determine the strength of the LA strain to discriminate between the different exercise capacities. Results A total of 136 patients were included in the study. LA strain, particularly the reservoir, can discriminate exercise capacity, specifically to discriminate good to high capacity from fair to average as their AUC is 0.678 (95% CI 0.58 to 0.77, p=.0001). The best cut-off is 30.2 which resulted to 80% sensitivity (95% CI 66.3 to 90) while specificity is only 51.16% (95% CI 40.1 to 62.1). Spearman rank correlation analysis showed that LA reservoir is significantly correlated with E/A and E/e’. The relationships are linear and positive. Among the other 2D echo parameters, only EDV, E/a and E/e’ were found to have a linear relationship or correlation with METS. Conclusion The study revealed that there is moderate correlation of LA reservoir strain in terms of METS achieved during treadmill stress echocardiography (rs=0.3196, p=0.0001).LA reservoir strain AUCLA strain and other echo parameters

Plasma levels of human growth differentiation factor 15 (GDF-15) and their effect of alirocumab on major adverse cardiovascular events and all-cause death after acute coronary syndrome

Abstract Background Human growth differentiation factor 15 (GDF-15) is a stress response cytokine of the transforming growth factor-β superfamily with roles in health and disease, cell survival and inflammation, and whose elevated plasma levels impair muscle metabolism and cause cachexia. GDF-15 also may play multiple roles in the pathophysiology of cardiovascular disease. Methods The ODYSSEY OUTCOMES trial compared the PCSK9 inhibitor alirocumab to placebo added to high-intensity or maximum-tolerated statin in patients post-acute coronary syndrome (ACS). We assessed in >11,000 patients for whom biobank samples were available, the relation between GDF-15 levels (Roche Diagnostics) at baseline and at 4 months with risk of major adverse cardiovascular events (MACE; primary endpoint, comprising coronary heart disease death, non-fatal myocardial infarction, fatal/non-fatal ischaemic stroke, unstable angina requiring hospitalization) and all-cause death, with adjustment for age and sex. Results Median GDF-15 (quartile [Q]1, Q3) at baseline was 1022 (755, 1465) pg/mL and was reduced by a placebo-adjusted median of 22 pg/mL with alirocumab (p=0.0009) at month 4. This lowering of GDF-15 by alirocumab may represent the first such report via pharmacotherapy. In the placebo group, baseline GDF-15 was significantly associated with risks of MACE (Figure Panel A) and death (Panel B). Relative risk reduction with alirocumab did not vary according to baseline GDF-15 levels for MACE (Panel C) and death (Panel D). Four-year MACE absolute risk reduction [ARR (95% CI)] with alirocumab at Q1 and Q3 of baseline GDF-15 was 2.0% (0.1%, 3.9%) and 2.6% (0.2%, 5.0%), respectively. Reduction of GDF-15 with alirocumab at month 4 was not associated with subsequent MACE (p=0.46) but was associated with death (p=0.0009), with greater reductions translating to lower risk. Conclusion In patients with recent ACS, GDF-15 is a strong predictor of both MACE and death. Reduction of GDF-15 with alirocumab at month 4 was not associated with subsequent MACE but was associated with death (p=0.0009), with greater ARR reductions translating to lower risk. Figure. Splines for baseline GDF-15 vs risk of MACE (Panel A; spline p<0.0001) or all-cause death (Panel B; spline p<00001) through 4 years in the placebo group; treatment hazard ratio for MACE (Panel C; spline p=0.52) and all-cause death (Panel D; spline p=0.78). All splines reflect adjustment for age and sexFigure

Sex-related outcomes in patients receiving shortened or longer dual antiplatelet treatment after percutaneous coronary intervention: a systematic review and meta-analysis

Abstract Background There are known gender disparities in the pathophysiology, clinical presentation, and prognosis of coronary artery disease between male and female patients. Although antiplatelet therapy cessation is more frequent among women, female gender is an independent factor for major bleeding after percutaneous coronary interventions. Considering that the ischemic and bleeding risk of women undergoing PCI differ from men, it follows that the safety and efficacy of shortened, one or 3 months, DAPT (S-DAPT) compared to longer DAPT (L-DAPT) after PCI might differ between the sexes. Purpose Our systematic review and meta-analysis aims to explore the safety and efficacy of S-DAPT versus L-DAPT in men and women having undergone PCI. Methods Three major databases (MEDLINE, Cochrane Central Register of Controlled Trials, and Scopus) were screened for eligible randomized – controlled trials, or subgroup or post – hoc analyses of them. The studies should compare S-DAPT with L-DAPT in male and female patients undergoing PCI, providing separate data. The endpoints were Net Adverse Clinical Events (NACE), Major Adverse Cardiac Events (MACE), all-cause mortality, myocardial infarction and major bleeding. All endpoints were used as per trial defined and should be evaluated in 12-months. The effect of different DAPT regimens was assessed by calculating the risk ratio (RR) with 95% confidence intervals (CIs), using a random-effects model (Mantel-Haenzel). Results A total of eight studies and 46,476 patients were included; women were underrepresented being only the 26% (N=12,063) of the total participants. MACE did not differ significantly in the two arms in the total sample (RR: 0.94, 95%CI: 0.86-1.04); however, they were significantly reduced in women treated with S-DAPT (RR: 0.82, 95%CI: 0.70-0.97) (p-interaction: 0.049). (Figure 1) S-DAPT was associated with a significant reduction in both NACE (RR: 0.91, 95% CI: 0.85-0.99) (Figure 2A) and major bleeding (RR: 0.73, 95% CI: 0.57-0.95) (Figure 2C) in the total sample, without significant differences between male and female patients (p-interaction: 0.14 and 0.053, respectively). All-cause mortality (RR: 0.86, 95%CI: 0.73-1.01) (Figure 2B) and myocardial infarction rates (RR: 1.03, 95%CI: 0.86-1.24) (Figure 2D) were similar in both S-DAPT and L-DAPT in the total sample, without any significant subgroup differences (p-interaction: 0.13 and 0.051, respectively). Conclusions Shortened duration of DAPT significantly decreased MACE in women, in contrast with male patients, showing that women may benefit from abbreviated duration of DAPT. Further studies specifically investigating the optimal duration of DAPT in women are warranted and a sex-based approach could be considered in the management of antiplatelet treatment after PCI.A. NACE B. Mortality C. Bleedings D. MI

Kiss1 receptor knockout exacerbates airway hyperresponsiveness and remodeling in a mouse model of allergic asthma

BackgroundIn asthma, sex-steroids signaling is recognized as a critical regulator of disease pathophysiology. However, the paradoxical role of sex-steroids, especially estrogen, suggests that an upstream mechanism or even independent of estrogen plays an important role in regulating asthma pathophysiology. In this context, in our previous studies, we explored kisspeptin (Kp) and its receptor Kiss1R’s signaling in regulating human airway smooth muscle cell remodeling in vitro and airway hyperresponsiveness (AHR) in vivo in a mouse (wild-type, WT) model of asthma. In this study, we evaluated the effect of endogenous Kp in regulating AHR and remodeling using Kiss1R knockout (Kiss1R−/−) mice.MethodsC57BL/6J WT (Kiss1R+/+) and Kiss1R−/− mice, both male and female, were intranasally challenged with mixed-allergen (MA) and/or phosphate-buffered saline (PBS). We used flexiVent analysis to assess airway resistance (Rrs), elastance (Ers), and compliance (Crs). Following this, broncho-alveolar lavage (BAL) was performed for differential leukocyte count (DLC) and cytokine analysis. Histology staining was performed using hematoxylin and eosin (H&E) for morphological analysis and Masson’s Trichrome (MT) for collagen deposition. Additionally, lung sections were processed for immunofluorescence (IF) of Ki-67, α-smooth muscle actin (α-SMA), and tenascin-c.ResultsInterestingly, the loss of Kiss1R exacerbated lung function and airway contractility in mice challenged with MA, with more profound effects in Kiss1R−/− female mice. MA-challenged Kiss1R−/− mice showed a significant increase in immune cell infiltration and proinflammatory cytokine levels. Importantly, the loss of Kiss1R aggravated Th2/Th17 biased cytokines in MA-challenged mice. Furthermore, histology of lung sections from Kiss1R−/− mice showed increased collagen deposition on airway walls and mucin production in airway cells compared to Kiss1R+/+ mice. In addition, immunofluorescence analysis showed loss of Kiss1R significantly aggravated airway remodeling and subsequently AHR.ConclusionsThese findings demonstrate the importance of inherent Kiss1R signaling in regulating airway inflammation, AHR, and remodeling in the pathophysiology of asthma.

A potential role of gut microbiota in stroke: mechanisms, therapeutic strategies and future prospective.

Neurological conditions like Stroke and Alzheimer's disease (AD) often include inflammatory responses in the nervous system. Stroke, linked to high disability and mortality rates, poses challenges related to organ-related complications. Recent focus on understanding the pathophysiology of ischemic stroke includes aspects like cellular excitotoxicity, oxidative stress, cell death mechanisms, and neuroinflammation. The objective of this paper is to summarize and explore the pathophysiology of ischemic stroke, elucidates the gut-brain axis mechanism, and discusses recent clinical trials, shedding light on novel treatments and future possibilities. Changes in gut architecture and microbiota contribute to dementia by enhancing intestinal permeability, activating the immune system, elevating proinflammatory mediators, altering blood-brain barrier (BBB) permeability, and ultimately leading to neurodegenerative diseases (NDDs). The gut-brain axis's potential role in disease pathophysiology offers new avenues for cell-based regenerative medicine in treating neurological conditions. In conclusion, the gut microbiome significantly impacts stroke prognosis by highlighting the role of the gut-brain axis in ischemic stroke mechanisms. This insight suggests potential therapeutic strategies for improving outcomes.

Development of a Desorption Electrospray Ionization-Multiple-Reaction-Monitoring Mass Spectrometry (DESI-MRM) Workflow for Spatially Mapping Oxylipins in Pulmonary Tissue.

Oxylipins are a class of low-abundance lipids formed via oxygenation of fatty acids. These compounds include potent signaling molecules (e.g., octadecanoids, eicosanoids) that can exert essential functions in the pathophysiology of inflammatory diseases including asthma. While some oxylipin signaling cascades have been unraveled using LC-MS/MS-based methods, measurements in homogenate samples do not represent the spatial heterogeneity of lipid metabolism. Mass spectrometry imaging (MSI) directly detects analytes from a surface, which enables spatial mapping of oxylipin biosynthesis and migration within the tissue. MSI has lacked the sensitivity to routinely detect low-abundance oxylipins; however, new multiple-reaction-monitoring (MRM)-based MSI technologies show increased sensitivity. In this study, we developed a workflow to apply desorption electrospray ionization coupled to a triple quadrupole mass spectrometer (DESI-MRM) to spatially map oxylipins in pulmonary tissue. The targeted MSI workflow screened guinea pig lung extracts using LC-MS/MS to filter oxylipin targets based on their detectability by DESI-MRM. A panel of 5 oxylipins was then selected for DESI-MRM imaging derived from arachidonic acid (TXB2, 11-HETE, 12-HETE), linoleic acid (12,13-DiHOME), and α-linolenic acid (16-HOTrE). To parse this new data type, a custom-built R package (quantMSImageR) was developed with functionality to label regions of interest as well as quantify and analyze lipid distributions. The spatial distributions quantified by DESI-MRM were supported by LC-MS/MS analysis, with both indicating that 16-HOTrE and 12-HETE were associated with airways, while 12,13-DiHOME and arachidonic acid were mapped to parenchyma. This study realizes the potential of targeted MSI to routinely map low-abundance oxylipins with high specificity at scale.

New mechanisms in diisocyanate-mediated allergy/toxicity: are microRNAs in play?

To describe recent findings of diisocyanate-mediated mechanisms in allergy and toxicology by addressing the role of microRNA (miR) in immune responses that may contribute to the development of occupational asthma (OA). Studies of diisocyanate asthma have traditionally focused on the immune and inflammatory patterns associated with diisocyanate exposures; however, recognized knowledge gaps exist regarding the detailed molecular mechanism(s) of pathogenesis. Recent studies demonstrate the critical role endogenous microRNAs play as gene regulators in maintaining homeostasis of the human body, and in the pathophysiology of many diseases including asthma. Given that diisocyanate-OA shares many pathophysiological characteristics with asthma, it is likely that miR-mediated mechanisms are involved in the pathophysiology of diisocyanate-OA. Recent reports have shown that changes in expression of endogenous miRs are associated with exposure to the occupationally relevant diisocyanates, toluene diisocyanate (TDI) and methylene diphenyl diisocyanate (MDI). Continued mechanistic study of these relevant miRs may lead to the development of novel biomarkers of occupational exposure and/or provide efficacious targets for therapeutic strategies in diisocyanate asthma. The molecular mechanisms underlying diisocyanate-OA pathophysiology are heterogeneous and complicated. In this review, we highlight recent research into the roles and potential regulation of miRs in diisocyanate-OA.

Genetics in nephrology - any news?

While genetic kidney diseases were long regarded as a rare cause of kidney failure, it has been shown in recent years that they account for a relevant proportion of cases. In cohorts of kidney transplant recipients, a monogenic cause is found in up to 30% of cases. Identifying the genetic cause of kidney disease has become much easier thanks to technological advances in DNA sequencing. The focus has now shifted to understanding the significance of the findings and identifying diagnostic gaps. It is still not possible to clarify all CKD cases of unclear aetiology. Besides very effective generic treatments for monogenic kidney disease (e.g., ACE-inhibitor use in Alport Syndrome), increasing knowledge of the pathophysiology of genetic kidney diseases has led to a growing number of targeted therapies. These include the treatment of ADPKD with Tolvaptan, which has now been in use for 10 years. Recently, exciting, and completely new approaches have been added, such as the first siRNA therapies in nephrology for primary hyperoxaluria type 1, the targeted treatment of hyperphagia in Bardet-Biedl syndrome, the therapy of APOL1-associated kidney disease or the use of the HIF-2 antagonist Belzutifan for renal cell carcinoma associated with Von-Hippel-Lindau syndrome. The new possibilities in the treatment of patients with genetic kidney diseases have also clearly revealed deficits in current patient care. Centers of excellence with extensive experience in this area therefore play an important role in improving care. This also applies to the further training of colleagues in the field. In Germany, the National Action Alliance for People with Rare Diseases (NAMSE) and the nationwide establishment of - to date - 36 centers for rare diseases play an important role in this regard.

Emerging Concepts in Bronchiectasis: Diagnosis, Pathophysiology, and Relevance in Lung Disease

This symposium took place during the 2024 European Respiratory Society (ERS) Congress held in Vienna, Austria. The main objective was to discuss the clinical aspects, diagnosis, and pathophysiology of bronchiectasis, a chronic, abnormal dilation of the bronchi, and its association with other lung diseases. The current understanding of the characteristics and prevalence of bronchiectasis in patients with chronic obstructive pulmonary disease (COPD) and alpha 1 antitrypsin (AAT) deficiency was discussed, as well as the relationship between the extent of traction bronchiectasis and exacerbations in idiopathic pulmonary fibrosis (IPF). The overarching message from the symposium was that advances are being made in elucidating the pathophysiology of bronchiectasis, and this is helping clinicians to understand why it occurs in patients with COPD and AAT deficiency. Increased characterisation of bronchiectasis is needed, including the understanding of its aetiology, disease development and progression, and the role of biomarkers in clinical management. This may help to identify treatable traits leading to personalised therapy with anti-inflammatory and antimicrobial drugs in the future.

UBL3 Interacts with PolyQ-Expanded Huntingtin Fragments and Modifies Their Intracellular Sorting.

UBL3 (Ubiquitin-like 3) is a protein that plays a crucial role in post-translational modifications, particularly in regulating protein transport within small extracellular vesicles. While previous research has predominantly focused on its interactions with α-synuclein, this study investigates UBL3's role in Huntington's disease (HD). HD is characterized by movement disorders and cognitive impairments, with its pathogenesis linked to toxic, polyglutamine (polyQ)-expanded mutant huntingtin fragments (mHTT). However, the mechanisms underlying the interaction between UBL3 and mHTT remain poorly understood. To elucidate this relationship, we performed hematoxylin and eosin (HE) staining and immunohistochemistry (IHC) on postmortem brain tissue from HD patients. Gaussia princeps-based split-luciferase complementation assay and co-immunoprecipitation were employed to confirm the interaction between UBL3 and mHTT. Additionally, we conducted a HiBiT lytic detection assay to assess the influence of UBL3 on the intracellular sorting of mHTT. Finally, immunocytochemical staining was utilized to validate the colocalization and distribution of these proteins. Our findings revealed UBL3-positive inclusions in the cytoplasm and nuclei of neurons throughout the striatum of HD patients. We discovered that UBL3 colocalizes and interacts with mHTT and modulates its intracellular sorting. These results suggest that UBL3 may play a significant role in the interaction and sorting of mHTT, contributing to the understanding of its potential implications in the pathophysiology of Huntington's disease.