Levels of Small Extracellular Vesicles Containing hERG-1 and Hsp47 as Potential Biomarkers for Cardiovascular Diseases

The diagnosis of cardiovascular disease (CVD) is still limited. Therefore, this study demonstrates the presence of human ether-a-go-go-related gene 1 (hERG1) and heat shock protein 47 (Hsp47) on the surface of small extracellular vesicles (sEVs) in human peripheral blood and their association with CVD. In this research, 20 individuals with heart failure and 26 participants subjected to cardiac stress tests were enrolled. The associations between hERG1 and/or Hsp47 in sEVs and CVD were established using Western blot, flow cytometry, electron microscopy, ELISA, and nanoparticle tracking analysis. The results show that hERG1 and Hsp47 were present in sEV membranes, extravesicularly exposing the sequences 430AFLLKETEEGPPATE445 for hERG1 and 169ALQSINEWAAQTT- DGKLPEVTKDVERTD196 for Hsp47. In addition, upon exposure to hypoxia, rat primary cardiomyocytes released sEVs into the media, and human cardiomyocytes in culture also released sEVs containing hERG1 (EV-hERG1) and/or Hsp47 (EV-Hsp47). Moreover, the levels of sEVs increased in the blood when cardiac ischemia was induced during the stress test, as well as the concentrations of EV-hERG1 and EV-Hsp47. Additionally, the plasma levels of EV-hERG1 and EV-Hsp47 decreased in patients with decompensated heart failure (DHF). Our data provide the first evidence that hERG1 and Hsp47 are present in the membranes of sEVs derived from the human cardiomyocyte cell line, and also in those isolated from human peripheral blood. Total sEVs, EV-hERG1, and EV-Hsp47 may be explored as biomarkers for heart diseases such as heart failure and cardiac ischemia.

Gender Differences in Self-reported Faculty Developmental Networks

Scholars have long recognized gender variation in social relationship dynamics. However, how gender shapes developmental networking relationships for career advancement, particularly among university faculty members, is understudied. This area of research is important since women comprise an increasing proportion of faculty and yet report receiving less mentoring and lower career satisfaction, productivity, and advancement than their male counterparts. This cross-sectional study assessed gender differences in self-reported dimensions of faculty participants' developmental networks by collecting information on relationships with developers, who are people who have taken concerted action and offered professional and personal guidance to help participants advance in their careers over the past year. The investigators used egocentric network data from an electronically administered Mentoring Network Questionnaire collected from 159 faculty involved in a mentoring intervention during the pandemic. Faculty were from multiple Southwest and Mountain West institutions. Statistical analyses were performed using the Chi-squared test, Wilcoxon rank-sum test, and unadjusted multilevel regression. Female faculty chose developers of lower gender diversity than male faculty (p=0.01). Compared to male faculty, female faculty reported receiving more psychosocial support from individual developers (p=0.03). Female faculty members' developers were more often characterized as friends and less often described as sponsors and allies than male faculty, based on relative levels of career and psychosocial support that individual developers provided (p<0.001). No gender differences were found in other network characteristics. Female faculty build developmental networks that have different factors compared to male faculty. Greater levels of psychosocial support and fewer allies and sponsors for female faculty may have long-term implications for differential career advancement for women vs. men in academic careers. Strategies to enhance networking should address gender differences and include a structured framework for assessing network gaps.

Curriculum-based Faculty Training in Networking: Knowledge and Self-efficacy Outcomes

Although the advantages of developmental networks are well-known, most faculty do not know how to participate in such networks actively. Additionally, institutions face challenges in teaching faculty the best practices of networking. This deficiency constitutes a critical gap in the literature, which may slow career advancement for faculty, particularly from underrepresented groups. The study's purpose was to examine the effectiveness of a curriculum-based faculty training in developmental networks, utilizing the Extension for Community Health Outcomes (ECHO) platform. In this pre-post study, 33 faculty members participated in the intervention utilizing eight modules involving four competencies. Each module followed a standard format, including a short didactic, two facilitated case study discussions based on real-life scenarios, and self-reading of selected literature. Outcomes included (i) change in knowledge scores obtained from two questions per module and (ii) self-efficacy scores measured on a scale of 0-100. Paired student's t-test and mixed model regression analyses were used. A significant increase in knowledge score was documented using mixed model regression for 4 of the eight modules (mean change score 0.4-0.8, p≤0.03 for all analyses). The proportion of faculty participants reporting correct knowledge items for all modules increased from 49.8% (pre) to 64.3% (post), which was statistically significant (p<0.001). Significant increases in paired self-efficacy scores were reported for each of the eight modules (mean change score 17-37, p<0.05 for all analyses). This study highlights the importance of curriculum-based training in networking. Participants showed a significant increase in pre-post networking self-efficacy and knowledge scores. Our ECHO-based curriculum, facilitator training, and manual enable easy implementation in other institutions, ensuring scalability and adaptability. Our analysis provides the evidence basis for examining the impact of a developmental network intervention in enhancing individual career networks.

Rangelands in a fragmented grass-dominated landscape are vulnerable to tree invasion from roadsides

Roadsides can be vectors for tree invasion within rangelands by bisecting landscapes and facilitating propagule spread to interior habitat. Current invasive tree management in North America’s Great Plains focuses on reducing on-site (i.e., interior habitat) vulnerability through on-site prevention and eradication, but invasive tree management of surrounding areas known to serve as invasion vectors, such as roadsides and public rights-of-ways, is sporadic. We surveyed roadsides for invasive tree propagule sources in a central Great Plains grassland landscape to determine how much of the surrounding landscape is potentially vulnerable to roadside invasion, and by which species, and thereby provide insights into the locations and forms of future landcover change. Invasive tree species were widespread in roadsides. Given modest seed dispersal distances of 100–200 m, our results show that roadsides have potential to serve as major sources of rangeland exposure to tree invasion, compromising up to 44% of rangelands in the study area. Under these dispersal distances, funds spent removing trees on rangeland properties may have little impact on the landscape’s overall vulnerability, due to exposure driven by roadside propagule sources. A key implication from this study is that roadsides, while often neglected from management, represent an important component of integrated management strategies for reducing rangeland vulnerability to tree invasion.

Excessive release of inorganic phosphate by ALS/FTD astrocytes causes non-cell-autonomous toxicity to motoneurons

Non-cell-autonomous mechanisms contribute to neurodegenerative diseases such as amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD), in which astrocytes release unidentified factors that are toxic to motoneurons (MNs). We report here that mouse and patient iPSC-derived astrocytes with diverse ALS/FTD-linked mutations (SOD1, TARDBP, and C9ORF72) display elevated levels of intracellular inorganic polyphosphate (polyP), a ubiquitous, negatively charged biopolymer. PolyP levels are also increased in astrocyte-conditioned media (ACM) from ALS/FTD astrocytes. ACM-mediated MN death is prevented by degrading or neutralizing polyP in ALS/FTD astrocytes or ACM. Studies further reveal that postmortem familial and sporadic ALS spinal cord sections display enriched polyP staining signals and that ALS cerebrospinal fluid (CSF) exhibits increased polyP concentrations. Our in vitro results establish excessive astrocyte-derived polyP as a critical factor in non-cell-autonomous MN degeneration and a potential therapeutic target for ALS/FTD. The CSF data indicate that polyP might serve as a new biomarker for ALS/FTD.

Developmental Networks Among Mentors and Mentees Involved in a Mentoring Intervention

The growing application of social network-based theories and methods (Burt et al., 2013) in scholarship on mentoring illustrates that mentoring goes beyond dyadic relationships comprising a senior mentor and a junior protégé (Higgins & Kram, 2001). However, limited data exist on the state of developmental networks of university faculty. This study examines developmental network characteristics among mentors and mentees participating in an ongoing intervention that aims to enhance career success through improved mentoring. Cross-sectional data come from 81 faculty mentors and mentees at three universities in the Southwestern United States. Using the online Modified Mentoring Network Questionnaire (MNQ), participants provided information on relationships with developers, who are people that have taken concerted action, and provided professional and/or personal guidance to help participants advance in their careers. An individual's developmental network comprises relationships with developers. We conducted exploratory analyses examining key characteristics of mentors' and mentees' developmental networks. Participants received psychosocial and career support from an average of 4.9 developers (4.8 and 5.1 for mentors and mentees respectively) from 2.3 arenas (2.2 and 2.4 arenas for mentors and mentees, respectively). While the most common arena was the respondents' current job/position (62%, 64% and 59% for all participants, mentors, and mentees respectively), developers were from graduate school (11%, 6% and 17%); prior jobs/positions (13%, 16% and 9%) and family (8%, 5% and 11%). Our preliminary findings suggest that developers are important for university faculty and that methods and insights from social network analysis can be applied to examine their support networks. As our study is part of an ongoing longitudinal intervention, these findings will inform future analyses that will examine changes in developmental network characteristics and its impact on participants' careers.

An interdisciplinary approach to perception of water quality for human consumption in a Mapuche community of arid Patagonia, Argentina

Vital for human consumption, water is a scarce resource, particularly in the arid environments of Patagonia. In this study we analysed local perspectives and the use of different water sources, based on two case studies in rural communities of Mapuche and Creole ancestry inhabiting extra-Andean Patagonia in Chubut, Argentina. Water quality was evaluated using an ethnolimnological, interdisciplinary approach, taking into account local perspectives and scientific contributions. In addition, we analysed appropriation strategies, management and local organoleptic characteristics. The work was based on semi-structured interviews, tours guided by informants, and physicochemical and microbiological analysis of water sources. It was found that 92% of local inhabitants mainly used superficial and subterranean sources of water for consumption, among which stood out: river, streams, springs, wells, and boreholes. Differences were observed between local and scientific perspectives in terms of water quality (chemical and microbiological). Most water sources used by inhabitants presented water of deficient quality for human consumption (61%), whereas locals considered the water to be fresh, delicious, and transparent. Nevertheless, some points of agreement were found in terms of organoleptic characteristics (e.g., odour, colour) and physicochemical parameters in certain water sources. In general, locals do not recognise the deterioration of their water supply, but the importance of organoleptic characteristics in local perception should be highlighted. These aspects speak of a need to promote opportunities for dialogue, and implement effective health measures, taking local perspectives into account.

KCTD5, a novel TRPM4-regulatory protein required for cell migration as a new predictor for breast cancer prognosis

Transient receptor potential melastatin 4 (TRPM4) is a Ca²⁺ -activated nonselective cationic channel that regulates cell migration and contractility. Increased TRPM4 expression has been related to pathologies, in which cytoskeletal rearrangement and cell migration are altered, such as metastatic cancer. Here, we identify the K⁺ channel tetramerization domain 5 (KCTD5) protein, a putative adaptor of cullin3 E3 ubiquitin ligase, as a novel TRPM4-interacting protein. We demonstrate that KCTD5 is a positive regulator of TRPM4 activity by enhancing its Ca²⁺ sensitivity. We show that through its effects on TRPM4 that KCTD5 promotes cell migration and contractility. Finally, we observed that both TRPM4 and KCTD5 expression are increased in distinct patterns in different classes of breast cancer tumor samples. Together, these data support that TRPM4 activity can be regulated through expression levels of either TRPM4 or KCTD5, not only contributing to increased understanding of the molecular mechanisms involved on the regulation of these important ion channels, but also providing information that could inform treatments based on targeting these distinct molecules that define TRPM4 activity.

Calcium-dependent inactivation controls cardiac L-type Ca2+ currents under β-adrenergic stimulation

During a cardiac action potential, the activity of L-type Ca²⁺ channels (LTCCs) is modulated by voltage- and calcium-dependent inactivation processes. Morales et al. show that, in the context of β-adrenergic stimulation, calcium-dependent inactivation directs the regulation of LTCC activity, limiting calcium influx during the action potential.

The activity of L-type calcium channels is associated with the duration of the plateau phase of the cardiac action potential (AP) and it is controlled by voltage- and calcium-dependent inactivation (VDI and CDI, respectively). During β-adrenergic stimulation, an increase in the L-type current and parallel changes in VDI and CDI are observed during square pulses stimulation; however, how these modifications impact calcium currents during an AP remains controversial. Here, we examined the role of both inactivation processes on the L-type calcium current activity in newborn rat cardiomyocytes in control conditions and after stimulation with the β-adrenergic agonist isoproterenol. Our approach combines a self-AP clamp (sAP-Clamp) with the independent inhibition of VDI or CDI (by overexpressing Ca_Vβ_2a or calmodulin mutants, respectively) to directly record the L-type calcium current during the cardiac AP. We find that at room temperature (20–23°C) and in the absence of β-adrenergic stimulation, the L-type current recapitulates the AP kinetics. Furthermore, under our experimental setting, the activity of the sodium–calcium exchanger (NCX) does not affect the shape of the AP. We find that hindering either VDI or CDI prolongs the L-type current and the AP in parallel, suggesting that both inactivation processes modulate the L-type current during the AP. In the presence of isoproterenol, wild-type and VDI-inhibited cardiomyocytes display mismatched L-type calcium current with respect to their AP. In contrast, CDI-impaired cells maintain L-type current with kinetics similar to its AP, demonstrating that calcium-dependent inactivation governs L-type current kinetics during β-adrenergic stimulation.

FR58P1a; a new uncoupler of OXPHOS that inhibits migration in triple-negative breast cancer cells via Sirt1/AMPK/β1-integrin pathway

Highly malignant triple-negative breast cancer (TNBC) cells rely mostly on glycolysis to maintain cellular homeostasis; however, mitochondria are still required for migration and metastasis. Taking advantage of the metabolic flexibility of TNBC MDA-MB-231 cells to generate subpopulations with glycolytic or oxidative phenotypes, we screened phenolic compounds containing an ortho-carbonyl group with mitochondrial activity and identified a bromoalkyl-ester of hydroquinone named FR58P1a, as a mitochondrial metabolism-affecting compound that uncouples OXPHOS through a protonophoric mechanism. In contrast to well-known protonophore uncoupler FCCP, FR58P1a does not depolarize the plasma membrane and its effect on the mitochondrial membrane potential and bioenergetics is moderate suggesting a mild uncoupling of OXPHOS. FR58P1a activates AMPK in a Sirt1-dependent fashion. Although the activation of Sirt1/AMPK axis by FR58P1a has a cyto-protective role, selectively inhibits fibronectin-dependent adhesion and migration in TNBC cells but not in non-tumoral MCF10A cells by decreasing β1-integrin at the cell surface. Prolonged exposure to FR58P1a triggers a metabolic reprograming in TNBC cells characterized by down-regulation of OXPHOS-related genes that promote cell survival but comprise their ability to migrate. Taken together, our results show that TNBC cell migration is susceptible to mitochondrial alterations induced by small molecules as FR58P1a, which may have therapeutic implications.

Favorable Waitlist and Posttransplant Outcomes in Children and Adolescent Patients Supported With Durable Continuous-Flow Ventricular Assist Devices

Pediatric centers are implanting durable adult continuous-flow ventricular assist devices (CFVADs) in children who are smaller than the industry-recommended size. Waitlist and posttransplant outcomes data in pediatric patients supported with CFVADs as a bridge to transplant are limited. We analyzed the United Network of Organ Sharing and Organ Procurement and Transplantation Network registry to identify patients aged ≤18 years with a CFVAD at the time of listing or transplantation. Patients were stratified by body surface area (BSA; >1.5 vs. ≤1.5 m(2) ) at time of listing. We identified 138 patients with a durable CFVAD during the listing period (100 with BSA >1.5 m(2) , 38 with BSA ≤1.5 m(2) ). Patients with BSA ≤1.5 m(2) were more likely to have a noncardiomyopathy diagnosis (18% vs. 4%, p = 0.007) and to be implanted with a centrifugal-flow rather than an axial-flow device (74% vs. 30%, p = 0.001). There was no difference in failure-free waitlist survival between BSA groups (p = 0.99) among patients with a CFVAD at listing. Posttransplantation survival was 100% and 88% at 1 and 5 years, respectively, for the entire cohort and did not differ by BSA group (p = 0.99). Consequently, waitlist and posttransplant outcomes are favorable for pediatric CFVAD recipients. Small patients (≤1.5 m(2) ) had pre- and posttransplant outcomes similar to those of larger patients that met the industry-recommended size for implantation.

Cavβ2 transcription start site variants modulate calcium handling in newborn rat cardiomyocytes

In the heart, the main pathway for calcium influx is mediated by L-type calcium channels, a multi-subunit complex composed of the pore-forming subunit CaV1.2 and the auxiliary subunits CaVα2δ1 and CaVβ2. To date, five distinct CaVβ2 transcriptional start site (TSS) variants (CaVβ2a-e) varying only in the composition and length of the N-terminal domain have been described, each of them granting distinct biophysical properties to the L-type current. However, the physiological role of these variants in Ca(2+) handling in the native tissue has not been explored. Our results show that four of these variants are present in neonatal rat cardiomyocytes. The contribution of those CaVβ2 TSS variants on endogenous L-type current and Ca(2+) handling was explored by adenoviral-mediated overexpression of each CaVβ2 variant in cultured newborn rat cardiomyocytes. As expected, all CaVβ2 TSS variants increased L-type current density and produced distinctive changes on L-type calcium channel (LTCC) current activation and inactivation kinetics. The characteristics of the induced calcium transients were dependent on the TSS variant overexpressed. Moreover, the amplitude of the calcium transients varied depending on the subunit involved, being higher in cardiomyocytes transduced with CaVβ2a and smaller in CaVβ2d. Interestingly, the contribution of Ca(2+) influx and Ca(2+) release on total calcium transients, as well as the sarcoplasmic calcium content, was found to be TSS-variant-dependent. Remarkably, determination of atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP) messenger RNA (mRNA) abundance and cell size change indicates that CaVβ2 TSS variants modulate the cardiomyocyte hypertrophic state. In summary, we demonstrate that expression of individual CaVβ2 TSS variants regulates calcium handling in cardiomyocytes and, consequently, has significant repercussion in the development of hypertrophy.

Small area estimation under Fay–Herriot models with non-parametric estimation of heteroscedasticity

Fay–Herriot models relate direct estimators of small area means to vectors of area-level auxiliary covariates. Estimation of error variances in these models is a problem because of the lack of data within areas. A non-parametric approach is proposed for estimating these variances. Estimators of the remaining model parameters are derived and their asymptotic properties are studied. Moreover, small area estimators that incorporate the estimated error variances are obtained and several simple estimators of the mean squared error of these estimators are proposed. Simulation experiments study the small sample performance of the new small area estimators and compare the different estimators of the mean squared errors. Finally, the results are applied to the estimation of unemployment proportions in Spanish domains.