Role of Epigenetics in Cardiac Development and Congenital Diseases.

The heart is the first organ to be functional in the fetus. Heart formation is a complex morphogenetic process regulated by both genetic and epigenetic mechanisms. Congenital heart diseases (CHD) are the most prominent congenital diseases. Genetics is not sufficient to explain these diseases or the impact of them on patients. Epigenetics is more and more emerging as a basis for cardiac malformations. This review brings the essential knowledge on cardiac biology of development. It further provides a broad background on epigenetics with a focus on three-dimensional conformation of chromatin. Then, we summarize the current knowledge of the impact of epigenetics on cardiac cell fate decision. We further provide an update on the epigenetic anomalies in the genesis of CHD.

Neuropsychiatric symptoms of dementia in those with and without a recorded history of psychological trauma: A comparative study from an Australian dementia support service.

OBJECTIVE: To compare the number and severity of neuropsychiatric symptoms (NPS) and associated caregiver distress between those with and without a noted history of psychological trauma among those referred to a specialised national dementia NPS support service. METHODS: This was a 5-year retrospective observational study of records from the Dementia Support Australia NPS support service. NPS were reported by formal or informal caregivers at service entry using the Neuropsychiatric Inventory Nursing Home version or Questionnaire version. A history of psychological trauma was recorded in the person's social or medical history and/or endorsed as a contributor to NPS by a trained dementia consultant after a comprehensive clinical review. Regression was used to examine the impact of a recorded history of psychological trauma on NPS severity and associated caregiver distress, controlling for age and sex. RESULTS: Among 41,876 eligible referrals with dementia, 6% (n = 2529) had some reference in their records to a history of psychological trauma. Referrals with a recorded history of psychological trauma were rated with a higher rate of both NPS severity (mean = 12.0) and associated caregiver distress (mean = 16.5) at service entry than those without a recorded history of psychological trauma (means = 10.7 and 14.5, respectively). A recorded history of psychological trauma was associated with higher odds of psychotic symptoms, agitation/aggression, irritability, disinhibition, affective symptoms and night-time behaviours. CONCLUSIONS: Traumatic stress symptoms may represent a neglected target for intervention to reduce the impact of NPS in people with dementia.

The effect of food and acid-reducing agents on the pharmacokinetic profile of capivasertib: Results from a randomized, crossover study.

AIMS: This two-part, adaptive study assessed the effect of food and an acid-reducing agent (rabeprazole) on the pharmacokinetics (PK) and safety of capivasertib, a potent AKT inhibitor, in clinical development for cancer treatment. METHODS: In Part 1, healthy participants (n = 24) were randomized to receive single-dose capivasertib after overnight fasting, a high-fat, high-calorie meal and with rabeprazole postovernight fasting in one of six treatment sequences. Based on Part 1 results, a new group of participants (n = 24) were randomized (Part 2) to receive capivasertib after overnight fasting, a low-fat, low-calorie meal and modified fasting (food restricted from 2 h before dosing to 1 h postdose) in one of six treatment sequences. Blood samples were collected for PK analyses. RESULTS: Following a high-fat, high-calorie meal, capivasertib exposure increased versus overnight fasting (geometric mean ratio [GMR] [90% confidence interval (CI)]: area under the concentration-time curve [AUCinf ] 1.32 [1.22, 1.43], maximum concentration [Cmax ] 1.23 [1.08, 1.41]), but was comparable to that postmodified fasting (GMR: AUCinf 1.13 [0.99, 1.29], Cmax 0.85 [0.70, 1.04]). AUCinf was similar and Cmax was lower with/without rabeprazole (GMR: AUCinf 0.94 [0.87, 1.02]), Cmax 0.73 [0.64, 0.84]). Capivasertib exposure was similar after a low-fat, low-calorie meal versus overnight fasting (GMR: AUCinf 1.14 [1.05, 1.25], Cmax 1.21 [0.99, 1.48]) or modified fasting (GMR: AUCinf 0.96 [0.88, 1.05], Cmax 0.86 [0.70, 1.06]). Safety was consistent with that in larger trials. CONCLUSIONS: This study demonstrates that administering capivasertib with food or acid-reducing agents does not lead to clinically relevant PK or safety profile changes.

Comparing clinico-demographics and neuropsychiatric symptoms for immigrant and non-immigrant aged care residents living with dementia: a retrospective cross-sectional study from an Australian dementia-specific support service.

BACKGROUND: Neuropsychiatric symptoms of dementia such as agitation and aggression are common in people living with dementia. The presentation of neuropsychiatric symptoms is influenced by the cultural background of people living with dementia. Further, identifying factors contributing to neuropsychiatric symptoms may be complicated if people living with dementia are immigrants or from non-English-speaking backgrounds. Most of what is known about differences in neuropsychiatric symptoms between racial and ethnic groups living with dementia come from community-based samples. This study investigated differences in clinico-demographics and neuropsychiatric symptoms between immigrants and non-immigrants living with dementia in residential aged care homes who were referred to two Dementia Support Australia programs. METHODS: This was a retrospective observational cross-sectional study from 2018 to 2022 using data extracted from the Dementia Support Australia database. Immigrant status was identified by documented country of birth. We conducted exploratory subgroup analyses for English-speaking or non-English-speaking immigrants in comparison to non-immigrants. Neuropsychiatric Inventory and PainChek® were used to assess neuropsychiatric symptoms of dementia and pain, respectively. RESULTS: Of the 23,889 referrals, 36% were immigrants living with dementia. Immigrants were 0.8 years older than non-immigrants on average. Immigrants had a slightly higher prevalence of mixed dementia (9.5%) than non-immigrants (8.2%). Overall, the groups had no difference in the severity of neuropsychiatric symptoms and associated caregiver distress. However, there was a significant difference in the total number of neuropsychiatric inventory domains (Cohen's d = -0.06 [-0.09, - 0.02], p <.001) between non-English-speaking immigrants and non-immigrants. Immigrants were more likely to present with agitation/aggression, while non-immigrants were more likely to present with hallucinations. Factors contributing to neuropsychiatric symptoms were common between the groups, with language barriers and cultural considerations frequently endorsed for immigrants. CONCLUSION: This study reveals a mixed picture of neuropsychiatric symptoms between immigrants and non-immigrants. However, due to the exploratory nature of the hypotheses, our findings need to be replicated in future studies to confirm any conclusions. There is a need for increased awareness on the impact of culture and language on neuropsychiatric symptoms for people receiving residential care. Future studies investigating neuropsychiatric symptoms in different immigrant groups will help increase our understanding of neuropsychiatric symptoms for all people.

Exercise-induced hypohydration impairs 3 km treadmill-running performance in temperate conditions.

Research assessing exercise-induced hypohydration on running performance in a temperate environment is scarce. Given the weight-bearing nature of running, the negative effects of hypohydration might be offset by the weight-loss associated with a negative fluid balance. Therefore, this study investigated the effect of exercise-induced hypohydration on running performance in temperate conditions. Seventeen intermittent games players (age 22 ± 1 y; VO2peak 52.5 ± 4.1 mL∙kg-1∙min-1) completed preliminary and familiarisation trials, and two experimental trials consisting of 12 blocks of 6 min of running (65% VO2peak; preload) with 1 min passive rest in-between, followed by a 3 km time trial (TT). During the preload, subjects consumed minimal fluid (60 mL) to induce hypohydration (HYP) or water to replace 95% sweat losses (1622 ± 343 mL; EUH). Body mass loss (EUH -0.5 ± 0.3%; HYP -2.2 ± 0.4%; P < 0.001), and other changes indicative of hypohydration, including increased serum osmolality, heart rate, thirst sensation, and decreased plasma volume (P ≤ 0.022), were apparent in HYP by the end of the preload. TT performance was ~6% slower in HYP (EUH 900 ± 87 s; HYP 955 ± 110 s; P < 0.001). Exercise-induced hypohydration of ~2% body mass impaired 3 km running TT performance in a temperate environment.

Nipbl Haploinsufficiency Leads to Delayed Outflow Tract Septation and Aortic Valve Thickening.

Cornelia de Lange Syndrome (CdLS) patients, who frequently carry a mutation in NIPBL, present an increased incidence of outflow tract (OFT)-related congenital heart defects (CHDs). Nipbl+/- mice recapitulate a number of phenotypic traits of CdLS patients, including a small body size and cardiac defects, but no study has specifically focused on the valves. Here, we show that adult Nipbl+/- mice present aortic valve thickening, a condition that has been associated with stenosis. During development, we observed that OFT septation and neural crest cell condensation was delayed in Nipbl+/- embryos. However, we did not observe defects in the deployment of the main lineages contributing to the semilunar valves. Indeed, endocardial endothelial-to-mesenchymal transition (EndMT), analysed via outflow tract explants, and neural crest migration, analysed via genetic lineage tracing, did not significantly differ in Nipbl+/- mice and their wild-type littermates. Our study provides the first direct evidence for valve formation defects in Nipbl+/- mice and points to specific developmental defects as an origin for valve disease in patients.

Reactivation of the Epicardium at the Origin of Myocardial Fibro-Fatty Infiltration During the Atrial Cardiomyopathy.

RATIONALE: Fibro-fatty infiltration of subepicardial layers of the atrial wall has been shown to contribute to the substrate of atrial fibrillation. OBJECTIVE: Here, we examined if the epicardium that contains multipotent cells is involved in this remodeling process. METHODS AND RESULTS: One hundred nine human surgical right atrial specimens were evaluated. There was a relatively greater extent of epicardial thickening and dense fibro-fatty infiltrates in atrial tissue sections from patients aged over 70 years who had mitral valve disease or atrial fibrillation when compared with patients aged less than 70 years with ischemic cardiomyopathy as indicated using logistic regression adjusted for age and gender. Cells coexpressing markers of epicardial progenitors and fibroblasts were detected in fibro-fatty infiltrates. Such epicardial remodeling was reproduced in an experimental model of atrial cardiomyopathy in rat and in Wilms tumor 1 (WT1)CreERT2/+;ROSA-tdT+/- mice. In the latter, genetic lineage tracing demonstrated the epicardial origin of fibroblasts within fibro-fatty infiltrates. A subpopulation of human adult epicardial-derived cells expressing PDGFR (platelet-derived growth factor receptor)-α were isolated and differentiated into myofibroblasts in the presence of Ang II (angiotensin II). Furthermore, single-cell RNA-sequencing analysis identified several clusters of adult epicardial-derived cells and revealed their specification from adipogenic to fibrogenic cells in the rat model of atrial cardiomyopathy. CONCLUSIONS: Epicardium is reactivated during the formation of the atrial cardiomyopathy. Subsets of adult epicardial-derived cells, preprogrammed towards a specific cell fate, contribute to fibro-fatty infiltration of subepicardium of diseased atria. Our study reveals the biological basis for chronic atrial myocardial remodeling that paves the way of atrial fibrillation.

Clinico-demographics of people with younger-onset dementia and neuropsychiatric symptoms referred to an Australian dementia support service: A comparison study with older-onset dementia.

OBJECTIVE: Younger-onset dementia accounts for about 5-10% of all dementias in Australia. Little data is available on neuropsychiatric symptoms in people with younger-onset dementia compared to those with older-onset dementia. This study aims to compare the types of neuropsychiatric symptoms and their clinico-demographic characteristics of people with younger-onset dementia and older-onset dementia who are referred to a specific dementia support service. METHODS: A 2-year retrospective observational cross-sectional analysis was undertaken on referrals with neuropsychiatric symptoms from Dementia Support Australia programmes. Neuropsychiatric symptoms were measured using the Neuropsychiatric Inventory total severity scores and distress scores. Contributing factors to neuropsychiatric symptoms for dementia groups were examined. Logistic regression was used to examine the relationship between individual neuropsychiatric symptoms and having older-onset dementia vs younger-onset dementia. RESULTS: Of the 15,952 referrals, about 5% (n = 729, mean age: 60.7 years, standard deviation = 5.4) were individuals with younger-onset dementia. Referrals with older-onset dementia were more likely to be female (56%), whereas referrals with younger-onset dementia were more likely to be male (54%). There was a four times greater rate of frontotemporal dementia for those with younger-onset dementia (16.0%, n = 117) compared to those with older-onset dementia (2.8%, n = 427), χ2 (1) = 366.2, p < 0.001. Referrals with younger-onset dementia were more likely to be referred from community settings and those with older-onset dementia were more likely to be from residential aged care. Overall, there was no difference in the severity and distress of neuropsychiatric symptoms between the two groups. Contributing factors to neuropsychiatric symptoms were different between the groups, with pain being more frequently endorsed for individuals with older-onset dementia whereas communication difficulties were more commonly identified for those with younger-onset dementia. CONCLUSION: Clinico-demographics of referrals with younger-onset dementia differ from those with older-onset dementia. There were some differences in the characteristics of neuropsychiatric symptoms between younger-onset dementia and older-onset dementia. Our findings have implications for service provision and support for people with dementia at different ages.

Basilar decompression via a far lateral transcondylar approach: technical note.

BACKGROUND: Treatments for symptomatic or unstable basilar invagination (BI) include posterior decompression, distraction/fusion, trans-nasal or trans-oral anterior decompression, and combined techniques, with the need for occipitocervical fusion based on the degree of craniocervical instability. Variations of the far lateral transcondylar approach are described in limited case series for BI, but have not been widely applied. METHODS: A single-institution, retrospective review of consecutive patients undergoing a far lateral transcondylar approach for odontoidectomy (± resection of the inferior clivus) followed by occipitocervical fusion over a 6-year period (1/1/2016 to 12/31/2021) is performed. Detailed technical notes are combined with images from cadaveric dissections and patient surgeries to illustrate our technique using a lateral retroauricular incision. RESULTS: Nine patients were identified (3 males, 6 females; mean age 40.2 ± 19.6 years). All patients had congenital or acquired BI causing neurologic deficits. There were no major neurologic or wound-healing complications. 9/9 patients (100%) experienced improvement in preoperative symptoms. CONCLUSIONS: The far lateral transcondylar approach provides a direct corridor for ventral brainstem decompression in patients with symptomatic BI. A comprehensive knowledge of craniovertebral junction anatomy is critical to the safe performance of this surgery, especially when using a lateral retroauricular incision.

Examining barriers to participation in further and continuing education in Germany: Why a regional perspective is (still) important.

Further and continuing education is not only important for individual employability, but also for regional development. Therefore, improving participation in further and continuing education and removing barriers to participation are key concerns of regional education governance. The present study was conducted in a peripheral region of Rhineland-Palatinate in western Germany, where the annual participation rate in continuing education is relatively low compared to other geographic areas in Germany. This quantitative study was designed to understand: (1) To what extent do adult learners engage in continuing education within their habitual lifelong learning process? (2) Which circumstantial factors influence their participation in continuing education? And (3) What are the barriers hindering their participation? The authors found that for two-thirds of adult learners, a precondition for their enrolment in a continuing education course was the satisfaction of both work-related and private life-related factors. The authors' findings point towards the need for flexible study programmes which learners can fit to the demands of their work and life.

Analyse des obstacles à la participation à la formation continue en Allemagne : Pourquoi une perspective régionale est (encore) importante ­ L'éducation complémentaire et continue est importante non seulement pour l'employabilité des individus, mais aussi pour le développement régional. Par conséquent, l'amélioration de la participation à la formation continue et l'élimination des obstacles à la participation sont des préoccupations essentielles de la gouvernance régionale de l'éducation. La présente étude a été menée dans une région périphérique de la Rhénanie-Palatinat, dans l'ouest de l'Allemagne, où le taux de participation annuel à la formation continue est relativement faible par rapport à d'autres zones géographiques en Allemagne. Cette étude quantitative a été conçue pour comprendre : (1) Dans quelle mesure est-ce que les apprenants adultes s'engagent dans la formation continue dans le cadre de leur processus habituel d'apprentissage tout au long de la vie ? (2) Quels sont les facteurs circonstanciels qui influencent leur participation à la formation continue ? et (3) Quels sont les obstacles qui entravent leur participation ? Les auteurs ont constaté que pour deux tiers des apprenants adultes, une condition préalable à leur inscription à un cours de formation continue était la satisfaction de facteurs liés à la fois à leur vie professionnelle et à leur vie privée. Les conclusions des auteurs soulignent la nécessité de programmes d'études flexibles que les apprenants peuvent adapter aux exigences de leur travail et de leur vie personnelle.

Xpert Xpress Flu/RSV: Validation and impact evaluation at a large UK hospital trust.

Despite vaccination programs and antivirals, influenza remains a prominent cause of morbidity and mortality. The Xpert Xpress Flu/respiratory syncytial virus (RSV) test is a leading influenza point-of-care test, but its evaluation has been limited to nasopharyngeal samples. In addition, the clinical impacts of Xpress Flu/RSV have not yet been quantified. We evaluated the performance of Xpress Flu/RSV at three locations in a UK Hospital Trust against an existing laboratory assay. Multiple upper respiratory tract sample types were included. In addition, we calculated time saved by Xpert, and the associations between Xpert use and rates of early patient isolation and antiviral prescription as recorded at the time of the laboratory result being telephoned out. A total of 642 patients were included in the diagnostic performance analysis. There were 177 laboratory-confirmed cases of influenza A, 7 influenza B and 86 RSV. For influenza A, sensitivity and specificity were 96.6% (95% confidence interval [CI]: 92.8%-98.8%) and 98.1% (CI: 96.4%-99.1%), respectively. This was sustained across all locations and sample types. The negative predictive value was 98.7% (CI: 97.2%-99.4%). The median amount of time saved was 27.1 h. Xpert use was associated with sixfold higher rates of isolation and threefold higher rates of antiviral prescribing by the time the laboratory result was available. Sensitivity for RSV was lower at 86.0% (95% CI: 76.9%-92.6%). Xpert Xpress Flu/RSV reliably detects influenza A infection and has significant clinical impacts. Cartridge optimization is required to enable accurate multiplexing, including from a range of sample types.

Effect of COVID-19 on BPSD severity and caregiver distress: Trend data from national dementia-specific behavior support programs in Australia.

BACKGROUND: Globally, Coronavirus disease 2019 (COVID-19) caused a significant disruption to the physical and mental well-being of all individuals, including those living with dementia. Social restrictions and lockdown measures due to COVID-19 have worsened the feelings of loneliness and behaviours and psychological symptoms of dementia (BPSD). National BPSD support programs in Australia are offered by Dementia Support Australia (DSA) through the Dementia Behavior Management Advisory Service (DBMAS) and the Severe Behavior Response Teams (SBRT). This study aims to investigate the impact of COVID-19 on BPSD severity and related caregiver distress among referrals to DSA programs. METHODS: A retrospective comparative analysis was conducted on the intake data of referrals to DSA between two periods: Pre-COVID-19 Period (January 2018-Decmeber 2019) and COVID-19 Period (January 2020-July 2021). Referrals were compared on demographic characteristics (e.g., age), and BPSD severity (i.e., neuropsychiatric symptoms such as agitation) and caregiver distress as measured by the Neuropsychiatric Inventory (NPI). NPI scores were compared on a month-to-month basis between the specified periods. RESULTS: Across the two periods, there were a total of 23,180 referrals eligible for the analysis. While no differences were noted in age, sex, or dementia subtype, there were elevated levels of NPI severity and caregiver distress scores during COVID-19 Period compared to the Pre-COVID-19 Period. The month-to-month trends of these differences (Figure 1, Figure 2) reflect the timing of outbreaks across Australia. Specifically, there were no significant differences at the start of 2020 prior to the declaration of the pandemic, with an initial rise in NPI severity and distress through April after initial measures were implemented nationally in March 2020. These levels of severity and distress continued to rise through the remainder of 2020, alongside outbreaks in specific regions within Australia, such as Victoria (June-October), and New South Wales (December/January). NPI severity and caregiver distress then began to return to Pre-COVID levels from February-May before elevating again with the outbreak of the Delta variant in Australia. CONCLUSIONS: COVID-19 has a significant impact on the severity levels of BPSD and related caregiver distress.

Feasibility and evaluation of the Dementia Engagement Modelling Program (DEMP): a novel model of aged care during COVID-19.

BACKGROUND: The COVID-19 pandemic has a significant impact on the quality of life of aged care residents living with dementia (RLWD). Lockdown measures necessary to protect RLWD and caring staff from COVID-19 have resulted in increased social isolation, loneliness, and behaviors and psychological symptoms of dementia (BPSD). In response, the Australian Government funded a pilot program, the Dementia Engagement Modelling Program (DEMP) as part of the Aged Care COVID-19 Grief and Trauma support package for RLWD, their families and aged care staff. Operated by the Dementia Centre of HammondCare, the DEMP provides first-line multimodal external support for RLWD at a greater risk of developing BPSD due to COVID-19 restrictions. This study aims to describe the DEMP and evaluate its feasibility and outcomes for Australian RLWD. METHODS: A team of 10 trained DEMP consultants was involved in delivering a consultancy service that modelled best practice and person-centred activities of engagement to support staff in providing residents with meaningful purpose, comfort, and reassurance. Consultants also provided coaching and development opportunities for staff to enhance their knowledge regarding communication and engagement. Outcome measures included the regular administration of the Engagement in Preferred ActivitieS Scale (EPASS; ≥4-9 moderate-to-high engagement). A phone evaluation survey for supported residential aged care homes (RACHs) was conducted to determine the feasibility of DEMP. RESULTS: A total of 60 residents (86.0 ± 7.8 y; 68% female) across 10 RACHs from three Australian states (VIC, NSW, QLD) was supported by DEMP between May and July 2021. More than half of the residents had Alzheimer's disease (n = 24, 40%) and vascular dementia (n = 7, 12%). Completed EPASS assessments (n = 389) demonstrated that the vast majority (64%-72%) of residents scored moderate-to-high engagement. All supported RACHs highly recommended the DEMP to other colleagues and rated the program highly for implementation feasibility including the recommended engagement activities/brokered items. CONCLUSIONS: The DEMP is a novel, feasible and effective dementia-specific engagement modelling program for Australian RLWD in the era of COVID-19 pandemic.

A genomics approach to male infertility.

PURPOSE: Male infertility remains poorly understood at the molecular level. We aimed in this study to investigate the yield of a "genomics first" approach to male infertility. METHODS: Patients with severe oligospermia and nonobstructive azoospermia were investigated using exome sequencing (ES) in parallel with the standard practice of chromosomal analysis. RESULTS: In 285 patients, 10.5% (n = 30) had evidence of chromosomal aberrations while nearly a quarter (n = 69; 24.2%) had a potential monogenic form of male infertility. The latter ranged from variants in genes previously reported to cause male infertility with or without other phenotypes in humans (24 patients; 8.4%) to those in novel candidate genes reported in this study (37 patients; 12.9%). The 33 candidate genes have biological links to male germ cell development including compatible mouse knockouts, and a few (TERB1 [CCDC79], PIWIL2, MAGEE2, and ZSWIM7) were found to be independently mutated in unrelated patients in our cohort. We also found that male infertility can be the sole or major phenotypic expression of a number of genes that are known to cause multisystemic manifestations in humans (n = 9 patients; 3.1%). CONCLUSION: The standard approach to male infertility overlooks the significant contribution of monogenic causes to this important clinical entity.

Infarct Fibroblasts Do Not Derive From Bone Marrow Lineages.

RATIONALE: Myocardial infarction is a major cause of adult mortality worldwide. The origin(s) of cardiac fibroblasts that constitute the postinfarct scar remain controversial, in particular the potential contribution of bone marrow lineages to activated fibroblasts within the scar. OBJECTIVE: The aim of this study was to establish the origin(s) of infarct fibroblasts using lineage tracing and bone marrow transplants and a robust marker for cardiac fibroblasts, the Collagen1a1-green fluorescent protein reporter. METHODS AND RESULTS: Using genetic lineage tracing or bone marrow transplant, we found no evidence for collagen-producing fibroblasts derived from hematopoietic or bone marrow lineages in hearts subjected to permanent left anterior descending coronary artery ligation. In fact, fibroblasts within the infarcted area were largely of epicardial origin. Intriguingly, collagen-producing fibrocytes from hematopoietic lineages were observed attached to the epicardial surface of infarcted and sham-operated hearts in which a suture was placed around the left anterior descending coronary artery. CONCLUSIONS: In this controversial field, our study demonstrated that the vast majority of infarct fibroblasts were of epicardial origin and not derived from bone marrow lineages, endothelial-to-mesenchymal transition, or blood. We also noted the presence of collagen-producing fibrocytes on the epicardial surface that resulted at least in part from the surgical procedure.

Atrial natriuretic peptide regulates adipose tissue accumulation in adult atria.

The abundance of epicardial adipose tissue (EAT) is associated with atrial fibrillation (AF), the most frequent cardiac arrhythmia. However, both the origin and the factors involved in EAT expansion are unknown. Here, we found that adult human atrial epicardial cells were highly adipogenic through an epithelial-mesenchymal transition both in vitro and in vivo. In a genetic lineage tracing the WT1CreERT2+/-RosatdT+/- mouse model subjected to a high-fat diet, adipocytes of atrial EAT derived from a subset of epicardial progenitors. Atrial myocardium secretome induces the adipogenic differentiation of adult mesenchymal epicardium-derived cells by modulating the balance between mesenchymal Wingless-type Mouse Mammary Tumor Virus integration site family, member 10B (Wnt10b)/ß-catenin and adipogenic ERK/MAPK signaling pathways. The adipogenic property of the atrial secretome was enhanced in AF patients. The atrial natriuretic peptide secreted by atrial myocytes is a major adipogenic factor operating at a low concentration by binding to its natriuretic peptide receptor A (NPRA) receptor and, in turn, by activating a cGMP-dependent pathway. Hence, our data indicate cross-talk between EAT expansion and mechanical function of the atrial myocardium.

Sphingosine 1-phosphate activation of ERM contributes to vascular calcification.

Vascular calcification is the deposition of mineral in the artery wall by vascular smooth muscle cells (VSMCs) in response to pathological stimuli. The process is similar to bone formation and is an independent risk factor for cardiovascular disease. Given that ceramide and sphingosine 1-phosphate (S1P) are involved in cardiovascular pathophysiology and biomineralization, their role in VSMC matrix mineralization was investigated. During phosphate-induced VSMC mineralization, endogenous S1P levels increased accompanied by increased sphingosine kinase (SK) activity and increased mRNA expression of SK1 and SK2. Consistent with this, mineralization was increased by exogenous S1P, but decreased by C2-ceramide. Mechanistically, exogenous S1P stimulated ezrin-radixin-moesin (ERM) phosphorylation in VSMCs and ERM phosphorylation was increased concomitantly with endogenous S1P during mineralization. Moreover, inhibition of acid sphingomyelinase and ceramidase with desipramine prevented increased S1P levels, ERM activation, and mineralization. Finally, pharmacological inhibition of ERM phosphorylation with NSC663894 decreased mineralization induced by phosphate and exogenous S1P. Although further studies will be needed to verify these findings in vivo, this study defines a novel role for the SK-S1P-ERM pathways in phosphate-induced VSMC matrix mineralization and shows that blocking these pathways with pharmacological inhibitors reduces mineralization. These results may inform new therapeutic approaches to inhibit or delay vascular calcification.