Persistence of Western Diet-Associated Pathway Activity Profiles in Ventricular Tissues

Space radiation represents a significant health risk for deep-space exploration, yet its long-term effects on cardiovascular function remain poorly understood. While our previous studies have highlighted persistent transcriptional changes in left ventricular (LV) and right ventricular (RV) tissues after a single whole-body irradiation in mice, a systems-level understanding of pathway activity deregulation is lacking. To address this gap, we applied the Pathway Signal Flow (PSF) algorithm to analyze long-term pathway activity alterations in LV and RV tissues of C57Bl/6J mice exposed to gamma radiation (100 cGy 137Cs) or the simplified Galactic Cosmic Ray simulation (simGCRsim, 50 cGy 500 MeV/n) composition of ion beams. RNA sequencing data were analyzed to assess pathway activity changes, sex-specific effects, and ventricular differences 440 days post-irradiation. We observed marked sex- and ventricle-specific differences in pathway deregulation. Left ventricular tissues in females exhibited broad signaling pathway alterations after simGCRsim exposure, particularly in immune response, cytoskeletal remodeling, and survival-related pathways (e.g., NF-κB, VEGF, and MAPK). In contrast, male RV tissues demonstrated higher pathway deregulation than LV, particularly in PPAR, NF-κB, and HIF-1 pathways, implicating metabolic disruption and survival adaptations. Furthermore, simGCRsim exposure induced greater long-term pathway perturbations than gamma rays. Our findings suggest that sex-dependent and ventricle-specific signaling alterations contribute to long-term cardiovascular risks following space irradiation. Notably, VEGF and NF-κB signaling emerge as key regulators of cardiac adaptation in females. Future studies in larger cohorts, incorporating early-stage molecular responses and broader pathway analyses, are needed to refine cardiovascular risk assessments for space travel.

Background: Congenital heart disease (CHD) affects ~1% of infants. Hypoplastic left heart syndrome (HLHS), a severe form of CHD in which the left ventricle is underdeveloped, is associated by a 15% incidence of heart failure by 6 years of age. Only 6% of HLHS patients have a genetic cause identified on exome sequencing, limiting the ability of patients to receive a diagnosis and potentially benefit from targeted treatments. Hypothesis: Novel HLHS genes are differentially expressed in HLHS cardiac tissues, or in cells with differential abundance in HLHS hearts. Goals: To use single nucleus RNA sequencing of HLHS patient cardiac tissues to identify candidate HLHS genes. Methods: Single nucleus RNA sequencing (nucSeq) was performed on paired left and right ventricular tissues (LV, RV) from 9 participants with HLHS. Left ventricular cardiac tissues from children (4) and adults (12) without CHD were used for comparison. Filtering with CellBender and Solo were used to remove low-quality nuclei. Analysis was performed in R using the Seurat package. Results: HLHS LV tissues had a higher proportion of cardiomyocytes than pediatric or adult control tissues, (78.7% vs 64.1%, p=0.005; 78.7 % vs 47.0%, p=1.8E-08, respectively), and a lower proportion of mural cells (3.1% vs 9.3%, p=3.9E-05; 3.1 % vs 23.5%, p=7.3E-15, respectively). By contrast, there were similar proportions of endothelial cells in the HLHS, pediatric and adult tissues (7.1%, 8.8% and 7.9%, respectively; p=0.56). Within HLHS tissues, the LV had a higher proportion of cardiomyocytes than the RV (78.7% vs 51.2%, p=4.8E-04) while the proportion of endothelial cells were similar in the LV and RV (7.3% and 9.1%, respectively; p=0.33). LV tissues from HLHS participants 2-18 years of age had fewer capillary endothelial cells than pediatric controls (31.2% vs 57.8%, p=0.001), and gene markers of HLHS endothelial cells included PBX1 , which is required for Hox D-3 mediated angiogenesis, as well as ARHGAP26 and RORA, inhibitors of VEGF signaling. Conclusion: HLHS cardiac tissues have a higher proportion of cardiomyocytes in the LV despite a smaller chamber size. Differences in gene expression that accompany the differences in cell proportion could identify novel HLHS genes as well as potential therapeutic targets.

Sodium-glucose cotransporter 2 inhibitors alter cardiac glucose transporter expression in patients with heart failure

The effects of short-term hypertensive left ventricular hypertrophy on intracellular pH and intracellular electrolytes in rats

Myocardial biopsies have been obtained from patients with hypertrophic or congestive cardiomyopathies. Marker enzymes for the principal subcellular organelles of the myocardium were estimated using highly sensitive assay procedures. The results were compared with those obtained in tissue from patients with valvular heart disease with good or poor left ventricular function. Left ventricular myocardial tissue from patients with hypertrophic cardiomyopathy showed essentially normal levels of enzymic activities. In congestive cardiomyopathy, right ventricular tissue showed reduced levels of mitochondrial enzymes with increased levels of lactate dehydrogenase. Left ventricular tissue from patients with congestive cardiomyopathy showed reduced levels of mitochondrial and myofibril enzymes but high levels of lactate dehydrogenase. The reduced levels of myofibril Ca++-activated ATP in congestive cardiomyopathy is similar to that found in patients with impaired left ventricular function secondary to valvular disease. It is suggested that defective mitochondrial function is a characteristic feature of congestive cardiomyopathy and that the increased levels of lactate dehydrogenase reflect a compensatory response.

The question of whether the coronary vasospasm induced by intravenous administration of vasopressin produces any remodeling of the capillary network in the left ventricle was investigated. To this end, cardiac tissues obtained from vasopressin-injected rats were stained to allow capillary counting and for basic fibroblast growth factor (bFGF). Nine male Donryu rats were divided into three groups that received, respectively, 0.25 ml of saline containing 0, 0.5, or 1.0 U/kg vasopressin injected into the tail vein once daily for 4 days. Rats were killed 30 days after the last injection. Two additional rats each received a single intravenous injection of 1.0 U/kg vasopressin and were killed 24 hours later. The left ventricles were removed and 16- or 10-micron frozen sections were cut for differential staining and distribution of bFGF, respectively. Differential staining was used to classify the capillary portions, and bFGF was identified by immunohistological staining. Compared with the control group, total capillary density was increased in both vasopressin-treated groups, capillary to myocyte ratio was increased, and the capillary domain areas decreased in the three capillary portions. Arteriolar and intermediate capillary portions increased, while the venular capillary portion decreased. In rats killed 24 hours after vasopressin injection, a considerable amount of bFGF could be demonstrated immunohistochemically in the ventricular tissues, and the punctate distribution of bFGF was still found in rats killed 30 days after treatment. A remodeling of capillary network which would increase the oxygen transport capacity to cardiac tissues was produced in left ventricular tissues by intravenous injection of vasopressin. bFGF located around capillaries and in the interstitial space may have been involved in the capillary remodeling.

Cardiac collagen remodeling in the cardiomyopathic Syrian hamster and the effect of losartan.

Association of neonatal hypoxia with lasting changes in left ventricular gene expression: An animal model

The effects of long-standing hypertensive left ventricular hypertrophy on intracellular pH and intracellular electrolytes in rats

Individuals with type 2 diabetes mellitus (T2DM) are at an increased risk for heart failure, yet preventive cardiac care is suboptimal in this population. Pyridoxamine (PM), a vitamin B6 analog, has been shown to exert protective effects in metabolic and cardiovascular diseases. In this study, we aimed to investigate whether PM limits adverse cardiac remodeling and dysfunction in rats who develop T2DM. Male rats received a standard chow diet or Western diet (WD) for 18 weeks to induce prediabetes. One WD group received additional PM (1 g/L) via drinking water. Glucose tolerance was assessed with a 1 h oral glucose tolerance test. Cardiac function was evaluated using echocardiography and hemodynamic measurements. Histology on left ventricular (LV) tissue was performed. Treatment with PM prevented the increase in fasting plasma glucose levels compared to WD-fed rats (p < 0.05). LV cardiac dilation tended to be prevented using PM supplementation. In LV tissue, PM limited an increase in interstitial collagen deposition (p < 0.05) seen in WD-fed rats. PM tended to decrease 3-nitrotyrosine and significantly lowered 4-hydroxynonenal content compared to WD-fed rats. We conclude that PM alleviates interstitial fibrosis and oxidative stress in the hearts of WD-induced prediabetic rats.

Trimethylamine N-oxide (TMAO), a gut microbiota-dependent metabolite, has been shown to aggravate cardiovascular disease. However, the mechanisms of TMAO in the setting of cardiovascular disease progress remain unclear. Here, we aim to investigate the effects of TMAO on atherosclerosis (AS) development and the underlying mechanisms. Apoe –/– mice received choline or TMAO supplementation in a normal diet and a western diet for 12 weeks. Choline or TMAO supplementation in both normal diet and western diet significantly promoted plaque progression in Apoe–/– mice. Besides, serum lipids levels and inflammation response in the aortic root were enhanced by choline or TMAO supplementation. In particular, choline or TMAO supplementation in the western diet changed intestinal microbiota composition and bile acid metabolism. Therefore, choline or TMAO supplementation may promote AS by modulating gut microbiota in mice fed with a western diet and by other mechanisms in mice given a normal diet, even choline or TMAO supplementation in a normal diet can promote AS.

Background: Breast cancer demonstrates heterogeneity in biological features, and the therapeutic strategy depends on tumor subtype. African-Ancestry (AA) patients experience a disproportionally high rate of triple negative breast cancer (TNBC) and worse outcomes than European-Ancestry (EA) patients. However, the biological drivers causing this disparity between ancestral populations are not deeply understood. To address the issue, we performed genomic and transcriptomic sequencing of breast tumors for comparison between AA and EA patients according to breast cancer molecular subtypes. Materials and Methods: The study included 221 AA and 341 EA patients. Collected samples underwent the Tempus xT next-generation sequencing panel. Following DNA-panel and whole-transcriptome RNA-sequencing, we compared gene mutation rates, homologous recombination deficiency (HRD) scores, degree of immune infiltration and tumor mutational burden (TMB) between ethnicities and molecular subtypes. Additionally, differences between the activity of relevant signaling pathways were evaluated from RNA-sequencing data. Results: Relative to EA TNBC, AA TNBC tumors exhibited higher mutation rates in TP53 (94% vs 86%), KMT2C (17% vs 9%), APOB (19% vs 10%), BRCA2 (11% vs 5%), EP300 (8% vs 2%), NOTCH1 (12% vs 4%), and EGFR (11% vs 4%). Conversely, AA TNBC tumors had relatively lower rates of PIK3CA (10% vs 18%), RB1 (8% vs 15%), and NF1 (5% vs 11%) mutations. Among patients with HR+/HER2- breast cancer, AA tumors had higher mutation rates in CCND1 (23% vs 10%) and FGF3 (16% vs 10%) than EA tumors, but lower rates in TP53 (32% vs 39%). HRD scores were higher in TNBC and HR-/HER2+ tumors compared with the other subtypes (P&amp;lt;0.001). However, there was no significant difference between the HRD scores of AA and EA tumors within TNBC or HR-/HER2+ populations. The highest percentage of immune infiltration was observed in HR-/HER2+ tumors (P=0.036), with no difference between AA or EA groups. TMB did not differ across ancestries or subtypes. Although immune pathways were generally more active in TNBC compared to the other subtypes, there was no difference in pathway-specific immune activation between ethnicities. The G2M and E2F pathways were significantly more active in TNBC (P&amp;lt;2e-16 for both), in particular more active in AA than EA tumors (G2M, P=0.035; E2F, P=0.037). On the other hand, PI3K, ROS, and xenobiotic metabolism (XM) pathways were significantly less active in TNBC compared to the other subtypes (PI3K, P=2.4e-5; ROS, P=0.014; and XM, P&amp;lt;2e-16). Furthermore, these pathways were significantly less active in AA than EA tumors across all subtypes (PI3K, P=0.026; ROS, P=0.00035; and XM, P=0.00041) and within TNBC (PI3K P=0.012, ROS P=0.014, and XM P=0.00018). Conclusion: These data demonstrate significant differences in breast tumor heterogeneity and mutation spectrum in TNBC and HR+/HER2- breast cancers between AA and EA patients. Ancestral differences were also observed in the activity of relevant signaling pathways for TNBC. Overall, the results identify previously unexplored pathways and molecular phenotypes of aggressive disease, providing opportunities for development of more effective biomarker informed treatment of breast cancer in diverse populations. Citation Format: Minoru Miyashita, Joshua SK Bell, Yonglan Zheng, Toshio Yoshimatsu, Padma Sheila Rajagopal, Anna Woodard, Jean Baptiste Reynier, Elisabeth Sveen, Galina Khramtsova, Fang Liu, Abiola Ibraheem, Gini Fleming, Nora Jaskowiak, Rita Nanda, Benjamin Leibowitz, Nike Beaubier, Kevin White, Dezheng Huo, Olufunmilayo I Olopade. Comprehensive genomic and transcriptomic profiling of molecular subtypes reveal ancestral differences in the activity of signaling pathways between patients with African and European ancestry [abstract]. In: Proceedings of the 2020 San Antonio Breast Cancer Virtual Symposium; 2020 Dec 8-11; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2021;81(4 Suppl):Abstract nr SS1-04.

There is a growing interest in non-dairy alternatives fueled by concerns about personal health and the health of the planet. Sales of non-dairy frozen desserts have increased along with other non-dairy alternatives such as plant-based beverages, cheeses, yogurts and creamers. The aim of this study was to conduct a cross-sectional survey of plant-based frozen desserts to determine their nutritional content. A total of 358 plant-based frozen desserts were analyzed from the nutrition label listed on the commercial container. The various products were based upon coconut (n = 126), oat milk (n = 63), almonds (n = 42), cashews (n = 25), soy (n = 11), macadamia milk (n = 9), olive oil (n = 8), faba bean (n = 8), canola oil (n = 8), rice milk (n = 6), sunflower milk (n = 6), avocado (n = 5), pea protein (n = 5) and various fruits, nuts and mixed blends (n = 36). While 90% of the frozen desserts had high sugar levels, 73% had high levels of saturated fat (due to the presence of coconut oil) and only one in four had high levels of fat. None of the products were fortified with calcium, vitamin D or B12, but one in six products had iron levels/serving of at least 10% of Daily Value (DV) and 1 in 6 had protein levels/serving similar to regular dairy ice cream. Food manufacturers need to produce new non-dairy frozen desserts that are more nutritious, since few brands (such as those based upon avocado, apple and hemp protein, or fava bean) presently provide consumers choices with lower saturated fat and sugar levels and/or higher protein levels.

P3476High-resolution respirometry reveals enhanced myocardial mitochondrial ketone oxidation after fasting and ventricular unloading

PV112 / #584Poster Topic:AS12 - Genetics, Epigenetics, TranscriptomicsBackground/PurposeSLE is a chronic autoimmune disease with complex involvement of organs and systems. A body of evidence confirmed the central role of environmental factors in lupus pathogenesis with special place assigned to the dietary components. Although a genetic predisposition is required for the onset of SLE, epigenetic factors also play a central role in this process. Having in mind that methyl-containing nutrients are key participants in the DNA methylation processes, and that lupus patients’ DNA shows alterations in this major epigenetic modification, it is intriguing to study the therapeutic effect of these components on SLE progression and clinical manifestations. In the present study we report that the methyl-supplemented diet ameliorates the development of SLE in NSG/Rag2-γc-mice humanized with lupus patients’ PBMCs.MethodsТwo types of rodent diet were used: normal (standard) rodent diet and supplemented diet containing the following ingredients for 8 g of daily portion per mouse (Table 1).Table 1.Amounts of the components (mg/8g diet) in the normal diet and in the high-dose methyl diet. PBMCs from each SLE patient were isolated from peripheral blood. After PBMCs separation, 10 weeks old mice were injectedi.p. with 1 billion cells/mouse (2 mice per patient). Two groups of female NSG/Rag2-γc-mice were engrafted with PBMCs from SLE patients. One group was put on a normal rodent diet, the other – on methyl-supplemented diet. Two groups of control non-humanized mice were also put on either of the diets. The animals were monitored for 8 weeks with blood and urine samples being collected once a week. At the end of the dietary course the mice were sacrificed, and kidneys were examined for glomerular pathology. Assays for appearance of anti-dsDNA antibodies and proteinuria were performed.ResultsThe results showed a decrease in anti-dsDNA antibody and proteinuria levels in the mice put on the supplemented diet, compared to the mice put on normal diet. In addition, histopathological changes in the structure of the glomeruli were observed in the kidney of mice fed with the normal diet but not the supplemented group. The results showed statistically insignificant decrease in the percent atrophic glomeruli of humanized mice put on normal diet (ND group) and of humanized mice put on supplemented diet (SD group). However, the percentages of glomeruli with mesangial proliferation were significantly decreased in mice humanized with PBMCs from patients and put on supplemented diet compared to the humanized mice fed with control diet. Kidney analysis of mice engrafted with lupus patients’ PBMCs and put on normal diet showed moderate mesangial proliferation. On the contrary, mice put on supplemented diet displayed only mild cellular proliferation in the glomeruli. Kidney preparations from non-humanized mice put on normal diet or on supplemented diet did not significantly differ.ConclusionsThe observed beneficial effect of the methyl-rich diet may be related to the potential modulation of DNA methylation levels and subsequent changes in gene expression. These results point to the importance of DNA methylation as one of the major epigenetic factors responsible for the progression of SLE.