Potential Changes Research Articles

Safety of SGLT-2 inhibitors in the management of heart failure in the adult congenital heart disease patient population

BackgroundSodium glucose transporter 2 inhibitors (SGLT-2i) have shown safety and efficacy in patients with heart failure (HF). However, evidence for the use of SGLT-2i in adult congenital heart disease (ACHD) patients with HF is limited. MethodsWe performed a retrospective, single center analysis of 18 patients (>18 years of age) with ACHD and a diagnosis of HF who were initiated on an SGLT-2i. Patient characteristics, including vital signs, laboratory values, concomitant medications, clinical outcomes, and echocardiograms, were obtained as part of standardized clinical care at our ACHD program before and 2–6 months after initiation of SGLT-2i. The primary outcome was to demonstrate safety of SGLT-2i initiation via potential changes in systolic blood pressure, serum sodium, and serum creatinine. ResultsOf the 18 patients, 11 (61%) had moderate complexity congenital heart disease while 7 (39%) had great complexity congenital heart disease. Post initiation, there were no significant differences in systolic blood pressure (121.8 ± 20.8 mmHg to 114.4 ± 14.9 mmHg, p = 0.06), sodium level (138.7 ± 2.9 mMol/L to 138.0 ± 2.2 mMol/L, p = 0.75), and creatinine level (0.85 ± 0.18 mg/dL to 0.89 ± 0.18 mg/dL, p = 0.07). There was a statistically significant decline in weight (78.9 ± 22.9 kg to 76.0 ± 23.0 kg, p = 0.0039) but without a statistically significant change in NT-pro NBP (1358.2 ± 2735.0 pg/mL to 601.6 ± 786.1 pg/mL, p = 0.36). ConclusionsWe demonstrated the use of SGLT-2i in a small cohort of ACHD population, including patients with complex congenital heart disease, appears safe and well tolerated. The safety and potential efficacy of SGLT-2i in patients with ACHD will require further evaluation in prospective multicenter studies.

Canopy nitrogen addition and understory removal destabilize the microbial community in a subtropical Chinese fir plantation

Subtropical Chinese fir plantations have been experiencing increased nitrogen deposition and understory management because of human activities. Nevertheless, effect of increased nitrogen deposition and understory removal in the plantations on microbial community stability and the resulting consequences for ecosystem functioning is still unclear. We carried out a 5-year experiment of canopy nitrogen addition (2.5 g N m−2 year−1), understory removal, and their combination to assess their influences on microbial community stability and functional potentials in a subtropical Chinese fir plantation. Nitrogen addition, understory removal, and their combination reduced soil bacterial diversity (OUT richness, Inverse Simpson index, Shannon index, and phylogenetic diversity) by 11–18%, 15–24%, and 19–31%; reduced fungal diversity indexes by 3–5%, 5–6%, and 5–7%, respectively. We found that environmental filtering and interspecific interactions together determined changes in bacterial community stability, while changes in fungal community stability were mainly caused by environmental filtering. Fungi were more stable than bacteria under disturbances, possibly from having a more stable network structure. Furthermore, we found that microbial community stability was linked to changes in microbial community functional potentials. Importantly, we observed synergistic interactions between understory removal and nitrogen addition on bacterial diversity, network structure, and community stability. These findings suggest that understory plants play a significant role in promoting soil microbial community stability in subtropical Chinese fir plantations and help to mitigate the negative impacts of nitrogen addition. Hence, it is crucial to retain understory vegetation as important components of subtropical plantations.

CO2 uptake of urban vegetation in a warming Nordic city

Many cities are committed to reducing greenhouse gas emissions, improving air quality, and reducing air temperatures through climate actions. Maintaining or increasing carbon sinks in urban green areas is relevant, as the sinks compensate a part of the emissions in addition to reducing emissions themselves. This research assesses the magnitude of carbon dioxide (CO2) net uptake (i.e. respiration and CO2 uptake by photosynthesis) and local 2-m air temperature in Helsinki, Finland, using an urban ecosystem model SUEWS (The Surface Urban Energy and Water Balance Scheme), and examines their potential future changes due to climate change. The model was run at an hourly resolution within the entire city at a spatial resolution of 250 × 250 m2. Two separate simulations were considered: the present climate by simulating years 2014–2019 and the future climate in the 2050s following the climate scenario RCP8.5. Each modelled grid was further divided into natural and built surfaces using Local Climate Zones (LCZs) to determine how vegetation in forests and various urban vegetation types contributes to cooling and carbon sequestration. According to our simulations, the urban green space in Helsinki annually sequestered 36.3 ± 7.7 kt C in 2015–2019, offsetting circa 7% of the city’s anthropogenic emissions. The mean annual temperatures varied by 2.1∘C between natural and built areas within the city. Although urban forests were the strongest sinks (0.3 kg C m−2 year−1), urban neighbourhoods contributed 47% of Helsinki’s net carbon sinks. Local temperatures were expected to increase with the RCP8.5 climate scenario on average by 1.3∘C within the simulated area and CO2 net uptake by 11%, without altering existing green spaces. Overall, this research highlights the significance of urban green as carbon sinks and how climate change may influence their role in mitigating greenhouse gas emissions and local climate conditions in urban environments.

Spatio-Temporal Changes and Habitats of Rare and Endangered Species in Yunnan Province Based on MaxEnt Model

Biodiversity is crucial for ecosystem functioning, but it is rapidly declining due to human activities and climate change. Protecting biodiversity has become a key priority for global environmental conservation actions. Rare and endangered species have a great impact on the ecosystem, yet due to their limited survival capacity, they are more prone to extinction, thus exerting a significant impact on biodiversity. However, current research reveals a lack of information concerning the potential distribution and changes of these species. This study used the maximum entropy model to predict the present and future potential habitats of rare and endangered species in Yunnan Province. After superimposing model results, four richness regions are divided by the natural breakpoint method and analyzed. Existing protected areas are compared with hotspots, and the land-use composition of hotspots is also analyzed. The results revealed that, in both current and future scenarios, rare and endangered species in Yunnan Province are primarily found in the western mountainous region, the Xishuangbanna–Wenshan high temperature area, and the Kunming–Qujing dense vegetation cover area. These species are also expanding their distribution towards the western mountainous area. However, under the low carbon emission scenario (RCP2.6), these species will spread from the high abundance regions to the low altitude hotspots by 2070. In the high carbon emissions scenario (RCP8.5), there will be fewer high abundance areas in 2070 than in 2050. The transfer matrix analysis reveals regional richness variations over time. Furthermore, the analysis revealed significant conservation gaps and found that existing hotspot areas were heavily affected by human activities. To improve conservation efficiency, it is necessary to enhance the protection of existing hotspots in Yunnan Province. Climate change plays a significant role in species migration, with precipitation levels being a key factor. The necessary actions should be taken to address the insufficient protection, resolve conflicts between human activities and land use in critical areas, and formulate effective strategies for adapting to future climate changes. Yunnan Province, with its rich species resources, has the potential to become a global innovator in biodiversity conservation by implementing improved conservation strategies.

Democratisation and Educational Inclusion during Lockdown Times: Perceptions of Portuguese Teachers

The COVID-19 pandemic had a significant impact on school education, as confirmed by numerous studies produced at the international level. One of the most profound effects was the potential change to the political mandates of schools and resulting alterations in professional teaching practices, given the proliferation of remote (online and blended) teaching. This article aims to explore the extent to which the pandemic crisis has reconfigured schools’ educational priorities, with an emphasis on democratisation and inclusion at the expense of learning outcomes and meritocratic approaches. Based on an extensive study as part of a wider international project, the results of a questionnaire survey of Portuguese teachers (n = 3983) during the initial lockdown period in 2020 are analysed. The empirical evidence suggests that the pandemic resulted in a strengthening of the democratising pole, underpinned by the principles of equal opportunities, inclusion, and social justice, even though the practices and priorities of teachers as a whole are not homogeneous. This heterogeneity reflects pre-existing professional and school cultures, which vary depending on level of education, gender, school type, and career length, among other important factors.

Fetal hemodynamic changes and mitochondrial dysfunction in myocardium and brain tissues in response to anemia: a lesson from hemoglobin Bart’s disease

ObjectiveWhether or not the effects of anemia in the early phase, while the fetuses attempts to increase cardiac output to meet oxygen requirement in peripheral organs, is detrimental to the fetal developing vital organs is little-known. The objective of this is to compare prenatal cardiovascular changes and post-abortal cellular damages in the myocardium as a pumping organ and the brain as a perfused organ between anemic fetuses (using fetal Hb Bart’s disease as a study model) in pre-hydropic phase and non-anemic fetuses.MethodsFetuses affected by Hb Bart’s disease and non-anemic fetuses at 16–22 weeks were recruited to undergo comprehensive fetal echocardiography. Cord blood analysis was used to confirm the definite diagnosis of fetal Hb Bart’s disease and normal fetuses. Fetal cardiac and brain tissues were collected shortly after pregnancy termination for the determination of oxidative stress and mitochondrial function, including mitochondrial ROS production and mitochondrial membrane changes.ResultsA total of 18 fetuses affected by Hb Bart’s disease and 13 non-anemic fetuses were recruited. The clinical characteristics of both groups were comparable. The affected fetuses showed a significant increase in cardiac dimensions, cardiac function, cardiac output and brain circulation without deteriorating cardiac contractility and preload. However, in the affected fetuses, mitochondrial dysfunction was clearly demonstrated in brain tissues and in the myocardium, as indicated by a significant increase in the membrane potential change (p-value < 0.001), and a significant increase in ROS production in brain tissues, with a trend to increase in myocardium. The findings indicated cellular damage in spite of good clinical compensation.ConclusionThe new insight is that, in response to fetal anemia, fetal heart increases in size (dilatation) and function to increase cardiac output and blood flow velocity to provide adequate tissue perfusion, especially brain circulation. However, the myocardium and brain showed a significant increase in mitochondrial dysfunction, suggesting cellular damage secondary to anemic hypoxia. The compensatory increase in circulation could not completely prevent subtle brain and heart damage.

The epidemiological impact of reduced childhood vaccination in Brazil: a desk research from 2012 to 2022

Vaccination acts as the main method of preventing potential changes to global health, which have started outbreaks, endemics, epidemics and pandemics. Epidemiological profile’s analysis allows identifying, planning, executing and evaluating possible actions to control pathologies. A preventive control intervention that contributes positively to these epidemiological actions is immunization. This study aims to analyze the epidemiological impact of the reduction in childhood vaccination between 2012 to 2022. This is a documentary and epidemiological research of a retrospective nature that was carried out in April 2023, using free data, available at the Department of Informatics of the Unified Health System. A significant curve was observed relating vaccination between the years of the research, data demonstrates the continued importance of vaccination in preventing vaccine-preventable diseases. These numbers reflect the impact of the reduction in childhood vaccination and highlight the need for awareness raising and vaccination reinforcement actions to prevent the spread of vaccine-preventable diseases.

Ripa-56 protects retinal ganglion cells in glutamate-induced retinal excitotoxic model of glaucoma

Glaucoma is a prevalent cause of blindness globally, characterized by the progressive degeneration of retinal ganglion cells (RGCs). Among various factors, glutamate excitotoxicity stands out as a significant contributor of RGCs loss in glaucoma. Our study focused on Ripa-56 and its protective effect against NMDA-induced retinal damage in mice, aiming to delve into the potential underlying mechanism. The R28 cells were categorized into four groups: glutamate (Glu), Glu + Ripa-56, Ripa-56 and Control group. After 24 h of treatment, cell death was assessed by PI / Hoechst staining. Mitochondrial membrane potential changes, apoptosis and reactive oxygen species (ROS) production were analyzed using flow cytometry. The alterations in the expression of RIP-1, p-MLKL, Bcl-2, BAX, Caspase-3, Gpx4 and SLC7A11 were examined using western blot analysis. C57BL/6j mice were randomly divided into NMDA, NMDA + Ripa-56, Ripa-56 and control groups. Histological changes in the retina were evaluated using hematoxylin and eosin (H&E) staining. RGCs survival and the protein expression changes of RIP-1, Caspase-3, Bcl-2, Gpx4 and SLC7A11 were observed using immunofluorescence. Ripa-56 exhibited a significant reduction in the levels of RIP-1, p-MLKL, Caspase-3, and BAX induced by glutamate, while promoting the expression of Bcl-2, Gpx-4, and SLC7A1 in the Ripa-56-treated group. In our study, using an NMDA-induced normal tension glaucoma mice model, we employed immunofluorescence and H&E staining to observe that Ripa-56 treatment effectively ameliorated retinal ganglion cell loss, mitigating the decrease in retinal ganglion cell layer and bipolar cell layer thickness caused by NMDA. In this study, we have observed that Ripa-56 possesses remarkable anti- necroptotic, anti-apoptotic and anti-ferroptosis properties. It demonstrates the ability to combat not only glutamate-induced excitotoxicity in R28 cells, but also NMDA-induced retinal excitotoxicity in mice. Therefore, Ripa-56 could be used as a potential retinal protective agent.

Epidemiology of reported cases of leptospirosis in the EU/EEA, 2010 to 2021.

BackgroundLeptospirosis is a zoonotic disease caused by bacteria of the genus Leptospira. Humans are infected by exposure to animal urine or urine-contaminated environments. Although disease incidence is lower in Europe compared with tropical regions, there have been reports of an increase in leptospirosis cases since the 2000s in some European countries.AimWe aimed to describe the epidemiology of reported cases of leptospirosis in the European Union/European Economic Area (EU/EEA) during 2010-2021 and to identify potential changes in epidemiological patterns.MethodsWe ran a descriptive analysis of leptospirosis cases reported by EU/EEA countries to the European Centre for Disease Prevention and Control with disease during 2010-2021. We also analysed trends at EU/EEA and national level.ResultsDuring 2010-2021, 23 countries reported 12,180 confirmed leptospirosis cases corresponding to a mean annual notification rate of 0.24 cases per 100,000 population. Five countries (France, Germany, the Netherlands, Portugal and Romania) accounted for 79% of all reported cases. The highest notification rate was observed in Slovenia with 0.82 cases per 100,000 population. Overall, the notification rate increased by 5.0% per year from 2010 to 2021 (95% CI: 1.2-8.8%), although trends differed across countries.ConclusionThe notification rate of leptospirosis at EU/EEA level increased during 2010-2021 despite including the first 2 years of the COVID-19 pandemic and associated changes in population behaviours. Studies at (sub)national level would help broaden the understanding of differences at country-level and specificities in terms of exposure to Leptospira, as well as biases in diagnosis and reporting.

Plagiarism in Academic Writing in Higher Education Institutions: A Bibliometric Analysis

Higher education institutions (HEI) are increasingly challenged by plagiarism, which threatens their academic standards and integrity. This is due to the fact that students have access to an overwhelming amount of information online, making it easier for them to copy and paste without giving proper credit or attribution. Additionally, the prevalence of technology has made it easier to copy and paste without detection. The study aimed to analyze the trends in plagiarism in academic writing by using bibliometric analysis, which is a technique that can measure and analyze the use of published documents. This analysis was used to identify any potential changes in the prevalence of plagiarism in academic writing over time and to identify potential factors that could be influencing it. The data is extracted from Scopus database with Boolean and proximity search strategy and found 579 related journal articles. There are tabulations of results ranging from descriptive analysis, citation analysis, co-citation analysis, and co-word analysis. The descriptive findings revealed that 'academic integrity', despite not being included in the search string, was the most commonly occurring word with 284 indicating a significant relationship between plagiarism in academic writing in HEIs. In addition, citation analysis for the top ten documents was presented. The findings of co-citation analysis highlight factors, new trends of academic integrity, and mitigation plans against plagiarism, while co-word analysis are thematically presented in three prominent clusters which is academic misconduct study, ethics and academic integrity. In most prominent articles cited by many authors, contract cheating is the new trend of plagiarism. As a result, it sheds light on the fact that academic integrity issues go beyond a new phenomenon that needs to be taken seriously. This study has both theoretical and practical implications for minimizing future plagiarism risks as well as identifying and recommending potential solutions to the problem.

New Required Characteristics for Entrepreneurs Trans-COVID-19 Vis-a-Vis Pre-COVID-19

This qualitative systematic study analyzes the entrepreneur concept and its transformation during the COVID-19 pandemic. The study reports the results of a metasearch of keywords such as entrepreneurial traits, entrepreneur’s characteristics, business adaptations due to COVID-19, COVID-19 protocols, management responses to COVID-19, and entrepreneurship during COVID-19, among others. It has fulfilled the objective of confirming the presence of an adaptation and transformation process of the skill set and traits of a successful entrepreneur Trans-COVID-19 vis-a-vis Pre-COVID-19. Prevalent characteristics during the COVID-19 pandemic include adaptability, technological knowledge, creativity, innovation, ability to network, and creating new relationships. These characteristics suggest avenues for further investigation. Research opportunity lies in examining potential shifts in strategic orientations that may arise from the post-traumatic effects on organizations due to the profound changes brought about by the COVID-19 pandemic. Furthermore, the recognition of these new traits and shifts in managerial paradigms during the Trans-COVID-19 period raises significant questions about potential changes in academic processes aimed at developing future entrepreneurs.

Suicide rates before and during the COVID-19 pandemic: a systematic review and meta-analysis.

The effects of the COVID-19 pandemic on mental health issues such as depression and anxiety are well-documented in the literature, but its influence on suicidal patterns shows divergent results. We aim to comprehensively synthesize evidence on potential changes or stability of suicide rates during the COVID-19 pandemic worldwide. A comprehensive search of studies reporting suicide rates before and during the COVID-19 pandemic was conducted. Eligible studies reported incidences of confirmed suicides (suspected in special cases) for two time periods, before (until February 2020) and during (from March 2020 to June 2021) the COVID-19 pandemic. A meta-analysis of proportions using a random-effect model was performed to estimate the pre- and during-pandemic incidence rates of suicide with 95% confidence intervals. Differences in pre- and during-pandemic rates were formally tested using a heterogeneity test. A total of 34 studies were included in the review capturing suicide data from over 40 countries and regions. The meta-analysis outputs did not indicate a significant change in suicide rates during the COVID-19 pandemic. The pooled suicide rate in the studied period before the pandemic was 11.38 per 100,000 (95% CI 9.35-13.42) and in the period during the pandemic was 10.65 per 100,000 (95% CI 8.61-12.68). No significant change in suicide rates was observed during the COVID pandemic from a global perspective for the periods examined. A longer follow-up can provide additional insights into such suicide trends globally. Improvements in data reporting, specifically with implementation of real-time surveillance, is imperative to provide adequate suicide prevention and support.

Rapid antibiotic screening based on E. coli apoptosis using a potentiometric sensor array

Phenotypic antimicrobial susceptibility testing enables reliable antibiotic screening but requires multiple strategies to identify each phenotypic change induced by different bactericidal mechanisms. Bacteria apoptosis with typical phenotypic features has never been explored for antibiotic screening. Herein, we developed an antibiotic screening method based on the measurement of antibiotic-induced phosphatidylserine (PS) exposure of apoptotic bacteria. Phosphatidylserine externalization of E. coli that can be widely used as an apoptosis marker for antibiotics with different antibacterial mechanisms was explored. A positively charged PS-binding peptide was immobilized on magnetic beads (MBs) to recognize and capture apoptotic E. coli with PS externalization. Apoptotic E. coli binding led to the charge or charge density change of MBs-peptide, resulting in a potential change on a magneto-controlled polymeric membrane potentiometric sensor. Based on the detection of apoptotic E. coli killed by antibiotics, antibiotic screening for different classes of antibiotics and silver nanoparticles was achieved within 1.5 h using a potentiometric sensor array. This approach enables sensitive, general, and time-saving antibiotic screening, and may open up a new path for antibiotic susceptibility testing.

A10 PROLINE METABOLISM AFFECTS CANCER STEM CELLS IN ESOPHAGEAL SQUAMOUS CELL CARCINOMA

Abstract Background Esophageal squamous cell carcinoma (ESCC) is highly deadly with a 5-year survival rate of only 16%, partly due to treatment resistance. Resistance is associated, among others, with the presence of cancer stem cells (CSC). Previous work in the laboratory has shown that prolonged exposure to anticancer treatments such as radiation and/or 5-FU leads to increased number of CSCs. Interestingly, disruption of amino acid metabolism, especially decreased proline levels, has been observed in treated cells. Proline is a non-essential amino acid that can either be uptake from the environment or synthesized from glutamate or ornithine. However, its role in cancer cells remains poorly understood and controversial. Aims Therefore, my project aims at determining the role of proline metabolism in CSC abundance and tumoral properties in ESCC. Methods Using ESCC cell lines, TE11 and TE15, we stimulated proline metabolism by adding proline to the media or inhibited its catabolism using L-THFA. L-THFA forces proline accumulation in the cell. We then conducted flow cytometry to quantify CSC proportion, proliferation assay, spheroid formation assay and spheroids included in collagen for migration and invasion assay. Results First, the stimulation of proline metabolism decreased the proportion of CSCs in flow cytometry. These results align with our initial observations, where CSC-enriched cells exhibited reduced proline levels. Second, the inhibition of proline catabolism by L-THFA had the opposite effect, namely an increase in the proportion of CSC. Interestingly, these changes in the proportion of CSCs induced by proline or L-THFA translated into changes in clonogenic potential, a capacity typically associated with stem cells. Indeed, limiting dilution spheroids formation assays showed that proline decreased while L-THFA increased the number of formed spheroids. Since spheroids formation is linked to the presence of CSC, this provides new evidence of the impact of proline metabolism on CSC characteristics. Finally, L-THFA treatments drastically increased migratory and invasive abilities in 3D spheroid models compared to untreated or proline-treated conditions. Conclusions In conclusion, our results suggest that proline metabolism is implicated in the enrichment of cancer stem cells as well as in their functions. Funding Agencies CAG, CIHRinnovation.ca ; Centre de recherche CHUS ; FMSS ; Canada Research Chairs

Artificial Intelligence and Public Health Context: What We Should Know?

The rapid technological advancement nowadays has a wide-ranging impact on almost all industries. Artificial intelligence (AI) is one of the technologies that has received much attention and has been used widely, including in the public health sector. In this light, medical practitioners and the public are anticipating the changes brought by AI technology in the public health sector. This study is focused on thoroughly discussing the relationship of AI in the context of public health. The discussion shows that AI is giving a lot of positive potential to the public health sector. However, despite the abundant potential and promise, AI is also not running away from today's challenges. The overall discussion of this study will provide a clear picture on the link between AI, public health link and related parties, including official medical-related agencies. In other words, this paper summarises the relationship between AI and public health, specifically the challenges and potential changes AI will bring forward.

LEADING THROUGH DISASTERS AND DEPARTURES: HOW TO PREPARE FOR &amp; SUCCEED WITH UNCERTAINITY AND CHANGE

AbstractThe author, who is both a Chief Executive Officer/CEO and an attorney, writes about disaster planning and succession planning to “achieve the goals and aspirations for your organization without stumbling along the way or falling victim to a complete collapse when disasters and difficulties strike and impact your operations or personnel.” This means dealing effectively with uncertainty and change, critical/strategic decision categories, and “Committing to a regularized process for examining how to manage uncertainty and potential changes.” He presents results from surveys he has conducted with a variety of leaders, each with the results to questions about the following, in his words 1. Do You Have Processes in Place for Assessing, Deciding on, Planning, and Implementing Change? 2. What Has Been Your Most Difficult Organizational Phase? 3. What will be your most challenging future issues? 4. How do you plan for managing disasters? He discusses his process/framework of assessing, deciding, planning, and implementing. Each of these has its own figure, visualizing the steps involved. As he notes in the conclusion, “The COVID‐19 pandemic probably taught you that you cannot predict everything you and your organization will face.”

Optogenetic confirmation of transverse-tubular membrane excitability in intact cardiac myocytes.

T-tubules (TT) form a complex network of sarcolemmal membrane invaginations, essential for well-co-ordinated excitation-contraction coupling (ECC) and thus homogeneous mechanical activation of cardiomyocytes. ECC is initiated by rapid depolarization of the sarcolemmal membrane. Whether TT membrane depolarization is active (local generation of action potentials; AP) or passive (following depolarization of the outer cell surface sarcolemma; SS) has not been experimentally validated in cardiomyocytes. Based on the assessment of ion flux pathways needed for AP generation, we hypothesize that TT are excitable. We therefore explored TT excitability experimentally, using an all-optical approach to stimulate and record trans-membrane potential changes in TT that were structurally disconnected, and hence electrically insulated, from the SS membrane by transient osmotic shock. Our results establish that cardiomyocyte TT can generate AP. These AP show electrical features that differ substantially from those observed in SS, consistent with differences in the density of ion channels and transporters in the two different membrane domains. We propose that TT-generated AP represent a safety mechanism for TT AP propagation and ECC, which may be particularly relevant in pathophysiological settings where morpho-functional changes reduce the electrical connectivity between SS and TT membranes. KEY POINTS: Cardiomyocytes are characterized by a complex network of membrane invaginations (the T-tubular system) that propagate action potentials to the core of the cell, causing uniform excitation-contraction coupling across the cell. In the present study, we investigated whether the T-tubular system is able to generate action potentials autonomously, rather than following depolarization of the outer cell surface sarcolemma. For this purpose, we developed a fully optical platform to probe and manipulate the electrical dynamics of subcellular membrane domains. Our findings demonstrate that T-tubules are intrinsically excitable, revealing distinct characteristics of self-generated T-tubular action potentials. This active electrical capability would protect cells from voltage drops potentially occurring within the T-tubular network.

Local Electric Potential-Driven Nanofluidic Ion Transport for Ultrasensitive Biochemical Sensing.

Nanofluidic biosensors have been widely used for detection of analytes based on the change of system resistance before and after target-probe interactions. However, their sensitivity is limited when system resistance barely changes toward low-concentration targets. Here, we proposed a strategy to address this issue by means of target-induced change of local membrane potential under relatively unchanged system resistance. The local membrane potential originated from the directional diffusion of photogenerated carriers across nanofluidic biosensors and gated photoinduced ionic current signal before and after target-probe interactions. The sensitivity of such biosensors for the detection of biomolecules such as circulating tumor DNA (ctDNA) and lysozyme exceeds that of applying a traditional strategy by more than 3 orders of magnitude under unchanged system resistance. Such biosensors can specifically detect the small molecule biomarker in the blood sample between prostate cancer patients and healthy humans. The key advantages of such nanofluidic biosensors are therefore complementary to traditional nanofluidic biosensors, with potential applications in a point-of-care analytical tool.

Hesperetin Inhibits Bladder Cancer Cell Proliferation and Promotes Apoptosis and Cycle Arrest by PI3K/AKT/FoxO3a and ER Stress-mitochondria Pathways.

Hesperetin (HSE) is a natural flavonoid derived from the hydrolysis of Hesperidin, which is mainly found in traditional natural Chinese herbs, such as Chenpi and Hovenia caryophyllus. HSE displays anti-inflammatory and antioxidant activities. However, its potential mechanism of action on bladder cancer (BLCA) remains unknown. The aim of this study was to investigate the potential mechanism of action of HSE on BLCA cells. Network pharmacology analysis was used to construct a composite target network, combined with Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis to identify HSE-induced cell death patterns and signaling pathway alterations. Cytotoxicity evaluation was determined by CCK-8 assay. A clone formation assay was performed to assess cell proliferative capacity. Scratch and Transwell assays were performed to evaluate cell migration and invasion ability. Hoechst 33342 staining was visualized to observe morphological features of apoptosis. Apoptosis, cycle distribution, reactive oxygen species (ROS) generation, and mitochondrial membrane potential (MMP) changes were examined by flow cytometry. Western blot analysis was performed to analyze the expression of key proteins associated with cell proliferation, apoptosis, cycle block, PI3K/AKT/FoxO3a and endoplasmic reticulum (ER) stress-mitochondrial pathways. Network pharmacology analysis was performed to identify 155 potential candidate targets of HSE-BLCA, and further topological analysis was performed to obtain 34 hub-gene. Enrichment analysis yielded patterns of death and key pathways, revealing that the anti-BLCA effect of HSE may be related to the positive regulation of PI3K/AKT/FoxO3a and ER stress-mitochondrial pathways. in vitro results showed that HSE blocked cell proliferation, migration, and invasion in a concentration-dependent manner and triggered apoptosis, G0/G1 phase blockade, ROS production, and MMP depolarization. In addition, Western blot results showed that HSE downregulated phosphorylated (p)-3-phosphoinositide-dependent kinase-1 (PI3K), phosphorylated (p)-AKT serine/threonine kinase 1 (AKT), phosphorylated (p)-Forkhead box O 3a (FoxO3a), anti-apoptotic proteins, proliferation-associated proteins, and cell cycle promoters, whereas the levels of proteins related to the expression of cell cycle regulators, pro-apoptotic proteins, and ER stress-mitochondrial pathway were up-regulated in BLCA cells by the intervention of HSE. PI3K agonist (YS-49) and ER stress inhibitor (4-PBA) partially or completely reversed HSE-mediated proliferation, apoptosis, and cycle blockade in BLCA cells. The anticancer effects of HSE in BLCA may be attributed to its coordination of actions, inhibiting cell proliferation, migration, and invasion, inducing apoptosis, G0/G1 phase arrest, generating reactive oxygen species, causing MMP loss, and engaging the caspase protein family. These actions are likely mediated through the PI3K/AKT/FoxO3a and ER stress-mitochondrial pathways. Thus, our findings suggest that HSE is a promising novel therapeutic candidate for the prevention and treatment of BLCA.

Dexamethasone upregulates macrophage PIEZO1 via SGK1, suppressing inflammation and increasing ROS and apoptosis

The side effects of high-dose dexamethasone in anti-infection include increased ROS production and immune cell apoptosis. Dexamethasone effectively activates serum/glucocorticoid-regulated kinase 1 (SGK1), which upregulates various ion channels by activating store-operated calcium entry (SOCE), leading to Ca2+ oscillations. PIEZO1 plays a crucial role in macrophages' immune activity and function, but whether dexamethasone can regulate PIEZO1 by enhancing SOCE via SGK1 activation remains unclear. The effects of dexamethasone were assessed in a mouse model of sepsis, and primary BMDMs and the RAW264.7 were treated with overexpression plasmids, siRNAs, or specific activators or inhibitors to examine the relationships between SGK1, SOCE, and PIEZO1. The functional and phenotypic changes of mouse and macrophage models were detected. The results indicate that high-dose dexamethasone upregulated SGK1 by activating the macrophage glucocorticoid receptor, which enhanced SOCE and subsequently activated PIEZO1. Activation of PIEZO1 resulted in Ca2+ influx and cytoskeletal remodelling. The increase in intracellular Ca2+ mediated by PIEZO1 further increased the activation of SGK1 and ORAI1/STIM1, leading to intracellular Ca2+ peaks. In the context of inflammation, activation of PIEZO1 suppressed the activation of TLR4/NFκB p65 in macrophages. In RAW264.7 cells, PIEZO1 continuous activation inhibited the change in mitochondrial membrane potential, accelerated ROS accumulation, and induced autophagic damage and cell apoptosis in the late stage. CaMK2α was identified as a downstream mediator of TLR4 and PIEZO1, facilitating high-dose dexamethasone-induced macrophage immunosuppression and apoptosis. PIEZO1 is a new glucocorticoid target to regulate macrophage function and activity. This study provides a theoretical basis for the rational use of dexamethasone.