Evaluating protein cross-linking as a therapeutic strategy to stabilize SOD1 variants in a mouse model of familial ALS.

Mutations in the gene encoding Cu-Zn superoxide dismutase 1 (SOD1) cause a subset of familial amyotrophic lateral sclerosis (fALS) cases. A shared effect of these mutations is that SOD1, which is normally a stable dimer, dissociates into toxic monomers that seed toxic aggregates. Considerable research effort has been devoted to developing compounds that stabilize the dimer of fALS SOD1 variants, but unfortunately, this has not yet resulted in a treatment. We hypothesized that cyclic thiosulfinate cross-linkers, which selectively target a rare, 2 cysteine-containing motif, can stabilize fALS-causing SOD1 variants in vivo. We created a library of chemically diverse cyclic thiosulfinates and determined structure-cross-linking-activity relationships. A pre-lead compound, "S-XL6," was selected based upon its cross-linking rate and drug-like properties. Co-crystallographic structure clearly establishes the binding of S-XL6 at Cys 111 bridging the monomers and stabilizing the SOD1 dimer. Biophysical studies reveal that the degree of stabilization afforded by S-XL6 (up to 24°C) is unprecedented for fALS, and to our knowledge, for any protein target of any kinetic stabilizer. Gene silencing and protein degrading therapeutic approaches require careful dose titration to balance the benefit of diminished fALS SOD1 expression with the toxic loss-of-enzymatic function. We show that S-XL6 does not share this liability because it rescues the activity of fALS SOD1 variants. No pharmacological agent has been proven to bind to SOD1 in vivo. Here, using a fALS mouse model, we demonstrate oral bioavailability; rapid engagement of SOD1G93A by S-XL6 that increases SOD1G93A's in vivo half-life; and that S-XL6 crosses the blood-brain barrier. S-XL6 demonstrated a degree of selectivity by avoiding off-target binding to plasma proteins. Taken together, our results indicate that cyclic thiosulfinate-mediated SOD1 stabilization should receive further attention as a potential therapeutic approach for fALS.

Effectiveness of Transitional Care Program among High-Risk Discharged Patients: A Quasi-Experimental Study on Saving Costs, Post-Discharge Readmissions and Emergency Department Visits.

Transitional care programs (TCPs), where hospital care team members repeatedly follow up with discharged patients, aim to reduce post-discharge hospital or emergency department (ED) utilization and healthcare costs. We examined the effectiveness of TCPs at reducing healthcare costs, hospital readmissions, and ED visits. Centers for Medicare and Medicaid Services Bundled Payments for Care Improvement (BPCI) program adjudicated claims files and electronic health records from Greenville Memorial Hospital, Greenville, SC, were accessed. Data on post-discharge 30- and 90-day ED visits and readmissions, total costs, and episodes with costs over BPCI target prices were extracted from November 2017 to July 2020 and compared between the "TCP-Graduates" (N = 85) and "Did Not Graduate" (DNG) (N = 1310) groups. As compared to the DNG group, the TCP-Graduates group had significantly fewer 30-day (7.1% vs. 14.9%, p = 0.046) and 90-day (15.5% vs. 26.3%, p = 0.025) readmissions, episodes with total costs over target prices (25.9% vs. 36.6%, p = 0.031), and lower total cost/episode (USD 22,439 vs. USD 28,633, p = 0.018), but differences in 30-day (9.4% vs. 11.2%, p = 0.607) and 90-day (20.0% vs. 21.9%, p = 0.680) ED visits were not significant. TCP was associated with reduced post-discharge hospital readmissions, total care costs, and episodes exceeding target prices. Further studies with rigorous designs and individual-level data should test these findings.

Adult perioperative cardiac arrest: An overview of 684 cases reported to webAIRS.

There were 684 perioperative cardiac arrests reported to webAIRS between September 2009 and March 2022. The majority involved patients older than 60 years, classified as American Society of Anesthesiologists Physical Status 3 to 5, undergoing an emergency or major procedure. The most common precipitants included airway events, cardiovascular events, massive blood loss. medication issues, and sepsis. The highest mortality rate was 54% of the 46 cases in the miscellaneous category (this included 34 cases of severe sepsis, which had a mortality of 65%). This was followed by cardiovascular precipitants (n = 424) in which there were 147 deaths (35% mortality): these precipitants included blood loss (53%), embolism (61%) and myocardial infarction (70%). Airway and breathing events accounted for 25% and anaphylaxis 8%. A specialist anaesthetist attended the majority of these cardiac arrests. As webAIRS is a voluntary database, it is not possible to determine the incidence of perioperative cardiac arrest and only descriptive information on factors associated with cardiac arrest can be obtained. Nevertheless, the large number of reports includes a wide range of cases, precipitants, demographics and outcomes, providing ample opportunity to learn from these events. The data also provide rich scope for further research into further initiatives to prevent cardiac arrest in the perioperative period, and to improve outcomes, should a cardiac arrest occur.

Oxygenation during the apnoeic phase preceding intubation in adults in prehospital, emergency department, intensive care and operating theatre environments.

BACKGROUND: Apnoeic oxygenation is the delivery of oxygen during the apnoeic phase preceding intubation. It is used to prevent respiratory complications of endotracheal intubation that have the potential to lead to significant adverse events including dysrhythmia, haemodynamic decompensation, hypoxic brain injury and death. Oxygen delivered by nasal cannulae during the apnoeic phase of intubation (apnoeic oxygenation) may serve as a non-invasive adjunct to endotracheal intubation to decrease the incidence of hypoxaemia, morbidity and mortality. OBJECTIVES: To evaluate the benefits and harms of apnoeic oxygenation before intubation in adults in the prehospital, emergency department, intensive care unit and operating theatre environments compared to no apnoeic oxygenation during intubation. SEARCH METHODS: We used standard, extensive Cochrane search methods. The latest search date was 4 November 2022. SELECTION CRITERIA: We included randomized controlled trials (RCTs) and quasi-RCTs that compared the use of any form of apnoeic oxygenation including high flow and low flow nasal cannulae versus no apnoeic oxygenation during intubation. We defined quasi-randomization as participant allocation to each arm by means that were not truly random, such as alternation, case record number or date of birth. We excluded comparative prospective cohort and comparative retrospective cohort studies, physiological modelling studies and case reports. DATA COLLECTION AND ANALYSIS: We used standard Cochrane methods. Our primary outcomes were 1. hospital stay and 2. incidence of severe hypoxaemia. Our secondary outcomes were 3. incidence of hypoxaemia, 4. lowest recorded saturation of pulse oximetry (SpO2), 5. intensive care unit (ICU) stay, 6. first pass success rate, 7. adverse events and 8. MORTALITY: We used GRADE to assess certainty of evidence. MAIN RESULTS: We included 23 RCTs (2264 participants) in our analyses. Eight studies (729 participants) investigated the use of low-flow (15 L/minute or less), and 15 studies (1535 participants) investigated the use of high-flow (greater than 15 L/minute) oxygen. Settings were varied and included the emergency department (2 studies, 327 participants), ICU (7 studies, 913 participants) and operating theatre (14 studies, 1024 participants). We considered two studies to be at low risk of bias across all domains. None of the studies reported on hospital length of stay. In predominately critically ill people, there may be little to no difference in the incidence of severe hypoxaemia (SpO2 less than 80%) when using apnoeic oxygenation at any flow rate from the start of apnoea until successful intubation (risk ratio (RR) 0.86, 95% confidence interval (CI) 0.66 to 1.11; P = 0.25, I² = 0%; 15 studies, 1802 participants; low-certainty evidence). There was insufficient evidence of any effect on the incidence of hypoxaemia (SpO2 less than 93%) (RR 0.58, 95% CI 0.23 to 1.46; P = 0.25, I² = 36%; 3 studies, 489 participants; low-certainty evidence). There may be an improvement in the lowest recorded oxygen saturation, with a mean increase of 1.9% (95% CI 0.75% to 3.05%; P < 0.001, I² = 86%; 15 studies, 1525 participants; low-certainty evidence). There may be a reduction in the duration of ICU stay with the use of apnoeic oxygenation during intubation (mean difference (MD) ‒1.13 days, 95% CI ‒1.51 to ‒0.74; P < 0.0001, I² = 46%; 5 studies, 815 participants; low-certainty evidence). There may be little to no difference in first pass success rate (RR 1.00, 95% CI 0.93 to 1.08; P = 0.79, I² = 0%; 8 studies, 826 participants; moderate-certainty evidence). There may be little to no difference in incidence of adverse events including oral trauma, arrhythmia, aspiration, hypotension, pneumonia and cardiac arrest when apnoeic oxygenation is used. There was insufficient evidence about any effect on mortality (RR 0.84, 95% CI 0.70 to 1.00; P = 0.06, I² = 0%; 6 studies, 1015 participants; low-certainty evidence). AUTHORS' CONCLUSIONS: There was some evidence that oxygenation during the apnoeic phase of intubation may improve the lowest recorded oxygen saturation. However, the differences in oxygen saturation were unlikely to be clinically significant. This did not translate into any measurable effect on the incidence of hypoxaemia or severe hypoxaemia in a group of predominately critically ill people. We were unable to assess the influence on hospital length of stay; however, there was a reduction in ICU stay in the apnoeic oxygenation group. The mechanism for this is unclear as there was little to no difference in first pass success or adverse event rates.

An approach to quantify ortho-phthalaldehyde contamination on work surfaces.

Ortho-phthalaldehyde (OPA) is used as a high-level disinfectant for reusable medical devices in healthcare settings. The ACGIH recently adopted a Threshold Limit Value-Surface Limit (TLV-SL; 25 µg/100 cm2) for OPA surface contamination to prevent induction of dermal and respiratory sensitization following dermal exposure. However, there is no current validated method to measure OPA surface contamination. This study aimed to develop a standardized approach for sample collection and quantitative determination of OPA from work surfaces for use in risk assessment practices. The reported method utilises readily available commercial wipes to collect surface samples coupled with direct detection of OPA via liquid chromatography time of flight mass spectrometry (LC-ToF-MS). This approach avoided complex derivatization steps commonly required for the analysis of aldehydes. Method evaluation was conducted in accordance with the Occupational Safety and Health Administration (OSHA) surface sampling guidelines. Overall recoveries of 25 µg/100 cm2 of OPA from stainless steel and glass surfaces were 70% and 72%, respectively. The reported LOD for this method was 1.1 µg/sample and the LOQ was 3.7 µg/sample. OPA remained stable on the sampling medium for up to 10 days, when stored at 4 °C. The method was demonstrated in a workplace surface assessment at a local hospital sterilising unit, successfully detecting OPA on work surfaces. This method is intended to supplement airborne exposure assessment and provide a quantitative assessment tool for potential dermal exposure. When used in conjunction with a thorough occupational hygiene program that includes hazard communication, engineering controls, and personal protective equipment, skin exposure and consequent sensitization risks in the workplace can be minimized.

Gene network based analysis identifies a coexpression module involved in regulating plasma lipids with high-fat diet response.

Plasma lipids are modulated by gene variants and many environmental factors, including diet-associated weight gain. However, understanding how these factors jointly interact to influence molecular networks that regulate plasma lipid levels is limited. Here, we took advantage of the BXD recombinant inbred family of mice to query weight gain as an environmental stressor on plasma lipids. Coexpression networks were examined in both nonobese and obese livers, and a network was identified that specifically responded to the obesogenic diet. This obesity-associated module was significantly associated with plasma lipid levels and enriched with genes known to have functions related to inflammation and lipid homeostasis. We identified key drivers of the module, including Cidec, Cidea, Pparg, Cd36, and Apoa4. The Pparg emerged as a potential master regulator of the module as it can directly target 19 of the top 30 hub genes. Importantly, activation of this module is causally linked to lipid metabolism in humans, as illustrated by correlation analysis and inverse-variance weighed Mendelian randomization. Our findings provide novel insights into gene-by-environment interactions for plasma lipid metabolism that may ultimately contribute to new biomarkers, better diagnostics, and improved approaches to prevent or treat dyslipidemia in patients.

PI(4,5)P2 regulates the gating of NaV1.4 channels.

Voltage-gated sodium (NaV) channels are densely expressed in most excitable cells and activate in response to depolarization, causing a rapid influx of Na+ ions that initiates the action potential. The voltage-dependent activation of NaV channels is followed almost instantaneously by fast inactivation, setting the refractory period of excitable tissues. The gating cycle of NaV channels is subject to tight regulation, with perturbations leading to a range of pathophysiological states. The gating properties of most ion channels are regulated by the membrane phospholipid, phosphatidylinositol (4,5) bisphosphate (PI(4,5)P2). However, it is not known whether PI(4,5)P2 modulates the activity of NaV channels. Here, we utilize optogenetics to activate specific, membrane-associated phosphoinositide (PI)-phosphatases that dephosphorylate PI(4,5)P2 while simultaneously recording NaV1.4 channel currents. We show that dephosphorylating PI(4,5)P2 left-shifts the voltage-dependent gating of NaV1.4 to more hyperpolarized membrane potentials, augments the late current that persists after fast inactivation, and speeds the rate at which channels recover from fast inactivation. These effects are opposed by exogenous diC8PI(4,5)P2. We provide evidence that PI(4,5)P2 is a negative regulator that tunes the gating behavior of NaV1.4 channels.

Imaging Membrane Proteins Using Total Internal Reflection Fluorescence Microscopy (TIRFM) in Mammalian Cells.

The cell surfaceome is of vital importance across physiology, developmental biology, and disease states alike. The precise identification of proteins and their regulatory mechanisms at the cell membrane has been challenging and is typically determined using confocal microscopy, two-photon microscopy, or total internal reflection fluorescence microscopy (TIRFM). Of these, TIRFM is the most precise, as it harnesses the generation of a spatially delimited evanescent wave at the interface of two surfaces with distinct refractive indices. The limited penetration of the evanescent wave illuminates a narrow specimen field, which facilitates the localization of fluorescently tagged proteins at the cell membrane but not inside of the cell. In addition to constraining the depth of the image, TIRFM also significantly enhances the signal-to-noise ratio, which is particularly valuable in the study of live cells. Here, we detail a protocol for micromirror TIRFM analysis of optogenetically activated protein kinase C-ε in HEK293-T cells, as well as data analysis to demonstrate the translocation of this construct to the cell-surface following optogenetic activation. Graphic abstract.

SUMOylation of NaV1.2 channels regulates the velocity of backpropagating action potentials in cortical pyramidal neurons.

Voltage-gated sodium channels located in axon initial segments (AIS) trigger action potentials (AP) and play pivotal roles in the excitability of cortical pyramidal neurons. The differential electrophysiological properties and distributions of NaV1.2 and NaV1.6 channels lead to distinct contributions to AP initiation and propagation. While NaV1.6 at the distal AIS promotes AP initiation and forward propagation, NaV1.2 at the proximal AIS promotes the backpropagation of APs to the soma. Here, we show the small ubiquitin-like modifier (SUMO) pathway modulates Na+ channels at the AIS to increase neuronal gain and the speed of backpropagation. Since SUMO does not affect NaV1.6, these effects were attributed to SUMOylation of NaV1.2. Moreover, SUMO effects were absent in a mouse engineered to express NaV1.2-Lys38Gln channels that lack the site for SUMO linkage. Thus, SUMOylation of NaV1.2 exclusively controls INaP generation and AP backpropagation, thereby playing a prominent role in synaptic integration and plasticity.

Optogenetic dephosphorylation of phosphatidylinositol 4,5 bisphosphate in Xenopus laevis oocytes.

Here, we present a protocol for optogenetic dephosphorylation of the phosphoinositide PI(4,5)P2 at the plasma membrane of Xenopus laevis oocytes. We first describe the co-injection of oocytes with cRNAs encoding (1) a light-activated PI(4,5)P2 5-phosphatase fusion protein, (2) its dimerization partner fused to the plasma membrane, and (3) the potassium channel reporter for PI(4,5)P2 dephosphorylation. We then detail blue light illumination to induce PI(4,5)P2 dephosphorylation, combined with simultaneous two-electrode voltage clamp electrophysiological recording to assess potassium channel current responses. For complete details on the use and execution of this protocol, please refer to Xu et al. (2022).1.

Mechanism of PKCε regulation of cardiac GIRK channel gating.

G-protein-gated inwardly rectifying potassium (GIRK) channel activity is regulated by the membrane phospholipid, phosphatidylinositol-4,5-bisphosphate (PI 4,5P2). Constitutive activity of cardiac GIRK channels in atrial myocytes, that is implicated in atrial fibrillation (AF), is mediated via a protein kinase C-ε (PKCε)-dependent mechanism. The novel PKC isoform, PKCε, is reported to enhance the activity of cardiac GIRK channels. Here, we report that PKCε stimulation leads to activation of GIRK channels in mouse atria and in human stem cell-derived atrial cardiomyocytes (iPSCs). We identified residue GIRK4(S418) which when mutated to Ala abolished, or to Glu, mimicked the effects of PKCε on GIRK currents. PKCε strengthened the interactions of the cardiac GIRK isoforms, GIRK4 and GIRK1/4 with PIP2, an effect that was reversed in the GIRK4(S418A) mutant. This mechanistic insight into the PKCε-mediated increase in channel activity because of GIRK4(S418) phosphorylation, provides a precise druggable target to reverse AF-related pathologies due to GIRK overactivity.

Perioperative corneal abrasions: A report of 42 cases from the webAIRS database.

Corneal abrasions are an uncommon complication of anaesthesia. The aim of this study was to identify potential risk factors, treatment and outcomes associated with corneal abrasions reported to the web-based anaesthesia incident reporting system (webAIRS), a voluntary de-identified anaesthesia incident reporting system in Australia and New Zealand, from 2009 to 2021. There were 43 such cases of corneal abrasions reported to webAIRS over this period. The most common postoperative finding was a painful eye. Common features included older patients, individuals with pre-existing eye conditions, general anaesthesia and procedures longer than 60 minutes. Most cases were treated with a combination of lubricating eye drops or aqueous antibiotic eye drops. The findings indicate that patients who sustain a perioperative corneal abrasion can be reassured that in many cases it will heal within 48 hours, but they should seek earlier review if symptoms persist or deteriorate. None of the cases in this series resulted in permanent harm. Well established eye protective measures are important to utilise throughout the perioperative period, including the time until the patient has recovered in the post-anaesthesia care unit.

Hypoxia inhibits the cardiac I K1 current through SUMO targeting Kir2.1 activation by PIP2.

Cardiovascular diseases remain the leading cause of death worldwide. Most deaths are sudden and occur secondary to the occlusion of coronary arteries resulting in a rapid decrease in cellular oxygen levels. Acute hypoxia is proarrhythmic, leading to disordered electrical signals, conduction block, and uncoordinated beating of the myocardium. Although acute hypoxia is recognized to perturb the electrophysiology of heart muscle, the mechanistic basis for the effect has remained elusive, hampering the development of targeted therapeutic interventions. Here, we show that acute hypoxia activates the redox-sensitive SUMO pathway in cardiomyocytes, causing rapid inhibition of the inward-rectifying K+ channel, Kir2.1. We find that SUMOylation decreases the activation of Kir2.1 channels by the membrane phospholipid phosphatidylinositol 4,5-bisphosphate (PIP2). These data provide a mechanistic basis for the proarrhythmic effects of acute hypoxia and offer a framework for understanding the central role of PIP2 in mediating the sequelae of hypoxia and SUMOylation in cardiovascular disease.

Preferential Gs protein coupling of the galanin Gal1 receptor in the µ-opioid-Gal1 receptor heterotetramer.

Recent studies have proposed that heteromers of µ-opioid receptors (MORs) and galanin Gal1 receptors (Gal1Rs) localized in the mesencephalon mediate the dopaminergic effects of opioids. The present study reports converging evidence, using a peptide-interfering approach combined with biophysical and biochemical techniques, including total internal reflection fluorescence microscopy, for a predominant homodimeric structure of MOR and Gal1R when expressed individually, and for their preference to form functional heterotetramers when co-expressed. Results show that a heteromerization-dependent change in the Gal1R homodimeric interface leads to a switch in G-protein coupling from inhibitory Gi to stimulatory Gs proteins. The MOR-Gal1R heterotetramer, which is thus bound to Gs via the Gal1R homodimer and Gi via the MOR homodimer, provides the framework for a canonical Gs-Gi antagonist interaction at the adenylyl cyclase level. These novel results shed light on the intense debate about the oligomeric quaternary structure of G protein-coupled receptors, their predilection for heteromer formation, and the resulting functional significance.

A novel small-molecule selective activator of homomeric GIRK4 channels.

G protein-sensitive inwardly rectifying potassium (GIRK) channels are important pharmaceutical targets for neuronal, cardiac, and endocrine diseases. Although a number of GIRK channel modulators have been discovered in recent years, most lack selectivity. GIRK channels function as either homomeric (i.e., GIRK2 and GIRK4) or heteromeric (e.g., GIRK1/2, GIRK1/4, and GIRK2/3) tetramers. Activators, such as ML297, ivermectin, and GAT1508, have been shown to activate heteromeric GIRK1/2 channels better than GIRK1/4 channels with varying degrees of selectivity but not homomeric GIRK2 and GIRK4 channels. In addition, VU0529331 was discovered as the first homomeric GIRK channel activator, but it shows weak selectivity for GIRK2 over GIRK4 (or G4) homomeric channels. Here, we report the first highly selective small-molecule activator targeting GIRK4 homomeric channels, 3hi2one-G4 (3-[2-(3,4-dimethoxyphenyl)-2-oxoethyl]-3-hydroxy-1-(1-naphthylmethyl)-1,3-dihydro-2H-indol-2-one). We show that 3hi2one-G4 does not activate GIRK2, GIRK1/2, or GIRK1/4 channels. Using molecular modeling, mutagenesis, and electrophysiology, we analyzed the binding site of 3hi2one-G4 formed by the transmembrane 1, transmembrane 2, and slide helix regions of the GIRK4 channel, near the phosphatidylinositol-4,5-bisphosphate binding site, and show that it causes channel activation by strengthening channel-phosphatidylinositol-4,5-bisphosphate interactions. We also identify slide helix residue L77 in GIRK4, corresponding to residue I82 in GIRK2, as a major determinant of isoform-specific selectivity. We propose that 3hi2one-G4 could serve as a useful pharmaceutical probe in studying GIRK4 channel function and may also be pursued in drug optimization studies to tackle GIRK4-related diseases such as primary aldosteronism and late-onset obesity.

PGDIS position statement on the transfer of mosaic embryos 2021.

Chromosome testing strategies, such as preimplantation genetic testing for aneuploidy (PGT-A), improve initial IVF outcomes by avoiding unwitting transfer of aneuploid embryos in morphology-based selection practices. Newer technologies have revealed that some embryos may appear to have intermediate whole chromosome (or parts of a chromosome termed segmental) copy number results suggesting trophectoderm mosaicism. An embryo with a trophectoderm mosaic-range result may be the only option for transfer for some patients. Recent data suggest that such mosaic embryos can be transferred without added risk of abnormal birth outcomes but may be associated with increased implantation failure and miscarriage rates, with higher values of mosaicism appearing to be less favourable for producing good outcomes. In this Position Statement, we provide guidance to laboratories, clinics, clinicians and counsellors to assist in discussions on the utility and transfer of mosaic embryos.

An optogenetic tool to recruit individual PKC isozymes to the cell surface and promote specific phosphorylation of membrane proteins.

The PKC family consists of several closely related kinases. These enzymes regulate the function of proteins through the phosphorylation of hydroxyl groups on serines and/or threonines. The selective activation of individual PKC isozymes has proven challenging because of a lack of specific activator molecules. Here, we developed an optogenetic blue light-activated PKC isozyme that harnesses a plant-based dimerization system between the photosensitive cryptochrome-2 (CRY2) and the N terminus of the transcription factor calcium and integrin-binding protein 1 (CIB1) (N-terminal region of the CRY2-binding domain of CIB1). We show that tagging CRY2 with the catalytic domain of PKC isozymes can efficiently promote its translocation to the cell surface upon blue light exposure. We demonstrate this system using PKCε and show that this leads to robust activation of a K+ channel (G protein-gated inwardly rectifying K+ channels 1 and 4), previously shown to be activated by PKCε. We anticipate that this approach can be utilized for other PKC isoforms to provide a reliable and direct stimulus for targeted membrane protein phosphorylation by the relevant PKCs.

A molecular switch controls the impact of cholesterol on a Kir channel.

SignificanceCholesterol is one of the main components found in plasma membranes and is involved in lipid-dependent signaling enabled by integral membrane proteins such as inwardly rectifying potassium (Kir) channels. Similar to other ion channels, most of the Kir channels are down-regulated by cholesterol. One of the very few notable exceptions is Kir3.4, which is up-regulated by this important lipid. Here, we discovered and characterized a molecular switch that controls the impact (up-regulation vs. down-regulation) of cholesterol on Kir3.4. Our results provide a detailed molecular mechanism of tunable cholesterol regulation of a potassium channel.

The Molecular Mechanism of Human Voltage-Dependent Anion Channel 1 Blockade by the Metallofullerenol Gd@C82(OH)22: An In Silico Study.

The endohedral metallofullerenol Gd@C82(OH)22 has been identified as a possible antineoplastic agent that can inhibit both the growth and metastasis of cancer cells. Despite these potentially important effects, our understanding of the interactions between Gd@C82(OH)22 and biomacromolecules remains incomplete. Here, we study the interaction between Gd@C82(OH)22 and the human voltage-dependent anion channel 1 (hVDAC1), the most abundant porin embedded in the mitochondrial outer membrane (MOM), and a potential druggable target for novel anticancer therapeutics. Using in silico approaches, we observe that Gd@C82(OH)22 molecules can permeate and form stable interactions with the pore of hVDAC1. Further, this penetration can occur from either side of the MOM to elicit blockage of the pore. The binding between Gd@C82(OH)22 and hVDAC1 is largely driven by long-range electrostatic interactions. Analysis of the binding free energies indicates that it is thermodynamically more favorable for Gd@C82(OH)22 to bind to the hVDAC1 pore when it enters the channel from inside the membrane rather than from the cytoplasmic side of the protein. Multiple factors contribute to the preferential penetration, including the surface electrostatic landscape of hVDAC1 and the unique physicochemical properties of Gd@C82(OH)22. Our findings provide insights into the potential molecular interactions of macromolecular biological systems with the Gd@C82(OH)22 nanodrug.

Adding a Seat at the Table: A Case Study of the Provider's Perspective on Integrating Community Health Workers at Provider Practices in California.

Blue Shield of California's Community Health Advocate Program was created to support whole person-health needs by helping individuals of all socio-economic statuses navigate and access community resources, social services, and medical systems. Blue Shield's Health Reimagined team is partnering with medical providers, community resources centers, and community partners to provide intensive person-centered and technology-enabled care to patients, ensuring social needs are met while promoting health equity. A key aspect of the Health Reimagined initiative embeds Community Health Advocates (CHAs) within physician practices serving patients using a payor-agnostic approach, by which Blue Shield aims to increase access to social services and community resources, improve health outcomes, reduce medical costs, and improve overall patient experience. The purpose of this case study is to understand the provider's perspective of embedding a CHA into the care team and the resulting impact on the practice and patients. Blue Shield also sought to identify best practices and barriers of a CHA program within primary and specialty care practices. As part of an ongoing two-year mixed-methods impact evaluation (2019-2021), 10 semi-structured interviews were conducted with a total of 18 providers and office staff at five primary care and specialty practices where CHAs have been embedded. We also conducted two focus groups with the same five CHAs at different points in time. Several themes emerged from the provider, office staff, and CHA interviews. Provider practices found great value in adding a CHA to their care team as the CHA brings flexibility and continuity to patient care. They also found that having access to a CHA with shared life experiences of the communities they served is a key component to the program's success. Providers and staff reported a new understanding of the social determinants of health that impacts a patient's wellbeing with the embedding of a CHA in the care team. Overall, practitioners expressed high satisfaction with the CHA program. During the COVID-19 pandemic, CHAs have been critically important in care, as social needs have increased, and resources have shifted. The CHA program is constantly adapting to address challenges faced by all stakeholders and applying new knowledge to ensure best practices are implemented within the CHA program.