Allosteric competition and inhibition in AMPA receptors.

Excitatory neurotransmission is principally mediated by α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA)-subtype ionotropic glutamate receptors (AMPARs). Negative allosteric modulators are therapeutic candidates that inhibit AMPAR activation and can compete with positive modulators to control AMPAR function through unresolved mechanisms. Here we show that allosteric inhibition pushes AMPARs into a distinct state that prevents both activation and positive allosteric modulation. We used cryo-electron microscopy to capture AMPARs bound to glutamate, while a negative allosteric modulator, GYKI-52466, and positive allosteric modulator, cyclothiazide, compete for control of the AMPARs. GYKI-52466 binds in the ion channel collar and inhibits AMPARs by decoupling the ligand-binding domains from the ion channel. The rearrangement of the ligand-binding domains ruptures the cyclothiazide site, preventing positive modulation. Our data provide a framework for understanding allostery of AMPARs and for rational design of therapeutics targeting AMPARs in neurological diseases.

Structure of Transmembrane AMPA Receptor Regulatory Protein Subunit γ2.

Transmembrane AMPA receptor regulatory proteins (TARPs) are claudin-like proteins that tightly regulate AMPA receptors (AMPARs) and are fundamental for excitatory neurotransmission. We used cryo-electron microscopy (cryo-EM) to reconstruct the 36 kDa TARP subunit γ2 to 2.3 Šand reveal the structural diversity of TARPs. Our data reveals critical motifs that distinguish TARPs from claudins and define how sequence variations within TARPs differentiate subfamilies and their regulation of AMPARs.

Allosteric Competition and Inhibition in AMPA Receptors.

Excitatory neurotransmission is principally mediated by AMPA-subtype ionotropic glutamate receptors (AMPARs). Dysregulation of AMPARs is the cause of many neurological disorders and how therapeutic candidates such as negative allosteric modulators inhibit AMPARs is unclear. Here, we show that non-competitive inhibition desensitizes AMPARs to activation and prevents positive allosteric modulation. We dissected the noncompetitive inhibition mechanism of action by capturing AMPARs bound to glutamate and the prototypical negative allosteric modulator, GYKI-52466, with cryo-electron microscopy. Noncompetitive inhibition by GYKI-52466, which binds in the transmembrane collar region surrounding the ion channel, negatively modulates AMPARs by decoupling glutamate binding in the ligand binding domain from the ion channel. Furthermore, during allosteric competition between negative and positive modulators, negative allosteric modulation by GKYI-52466 outcompetes positive allosteric modulators to control AMPAR function. Our data provide a new framework for understanding allostery of AMPARs and foundations for rational design of therapeutics targeting AMPARs in neurological diseases.

Engineered adhesion molecules drive synapse organization.

In multicellular organisms, cell-adhesion molecules connect cells into tissues and mediate intercellular signaling between these cells. In vertebrate brains, synaptic cell-adhesion molecules (SAMs) guide the formation, specification, and plasticity of synapses. Some SAMs, when overexpressed in cultured neurons or in heterologous cells co-cultured with neurons, drive formation of synaptic specializations onto the overexpressing cells. However, genetic deletion of the same SAMs from neurons often has no effect on synapse numbers, but frequently severely impairs synaptic transmission, suggesting that most SAMs control the function and plasticity of synapses (i.e., organize synapses) instead of driving their initial establishment (i.e., make synapses). Since few SAMs were identified that mediate initial synapse formation, it is difficult to develop methods that enable experimental control of synaptic connections by targeted expression of these SAMs. To overcome this difficulty, we engineered novel SAMs from bacterial proteins with no eukaryotic homologues that drive synapse formation. We named these engineered adhesion proteins "Barnoligin" and "Starexin" because they were assembled from parts of Barnase and Neuroligin-1 or of Barstar and Neurexin3ß, respectively. Barnoligin and Starexin robustly induce the formation of synaptic specializations in a specific and directional manner in cultured neurons. Synapse formation by Barnoligin and Starexin requires both their extracellular Barnase- and Barstar-derived interaction domains and their Neuroligin- and Neurexin-derived intracellular signaling domains. Our findings support a model of synapse formation whereby trans-synaptic interactions by SAMs drive synapse organization via adhesive interactions that activate signaling cascades.

Congregational COVID-19 Conversations: Utilization of Medical-Religious Partnerships During the SARS-CoV-2 Pandemic.

Over the last 12-months during the pandemic caused by the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), the Centers for Disease Control and Prevention (CDC) have issued public health instructions with the hope of mitigating the spread of the virus. Through existing relationships established by an academic hospital, we established weekly community conference calls to disseminate such critical information on the pandemic and allow community leaders to discuss struggles and successes. From these calls, we were able to collaborate in a more intimate manner with faith-based organizations, whereby we emphasized and planned the role they could undertake during the pandemic. Such emphasis was made between our medical institution and various faith-based organizations through meetings titled "Congregational COVID-19 Conversations." Over the past 12-months, we held virtual meetings with 38 faith-based organizations: 15 Christian congregations, 21 Jewish synagogues, and 2 Islamic masjids. We describe in detail in this report a narrative summary of the meetings. From these meetings, we discussed several COVID-19-related themes that included how to have their place of worship disseminate public health messaging, aid in preparing buildings for public worship, and insight into preparing their regions for aid in both COVID-19 testing and for potential SARS-CoV-2 vaccine sites. This medical-religious partnership has proven feasible and valuable during the pandemic and warrants emphasis in that it has the potential to serve a vital role in mitigating COVID-19-related disparities in certain communities, as well as potentially ending the COVID-19 pandemic completely.

Community Testing and SARS-CoV-2 Rates for Latinxs in Baltimore.

INTRODUCTION: Latinxs have been disproportionately impacted by COVID-19. Latinx immigrants, in particular, face significant barriers to SARS-CoV-2 testing, including lack of insurance, language barriers, stigma, work conflicts, and limited transportation. METHODS: In response to a disproportionately high SARS-CoV-2 positivity rate among Latinxs at the Johns Hopkins Health System, investigators implemented free community-based testing by partnering with religious leaders and leveraging the skill of trusted community health workers. Data were extracted from the electronic health record and a Research Electronic Data Capture database. SARS-CoV-2 positivity was evaluated per event stratified by race/ethnicity. Total rates of SARS-CoV-2 positivity and categorical patient characteristics were compared between groups using chi-square tests. RESULTS: Between June 25, 2020 and October 15, 2020, a total of 1,786 patients (57.5% Latinx, 31.2% non-Hispanic White, 5.9% non-Hispanic Black, and 5.3% non-Hispanic other) were tested for SARS-CoV-2 in 18 testing events. Among them, 355 (19.9%) tested positive. The positivity rate was 31.5% for Latinxs, 7.6% for non-Hispanic Blacks, 3.4% for non-Hispanic Whites, and 5.3% for patients of other races/ethnicities. Compared with Latinxs who tested negative, Latinxs who tested positive were more likely to report Spanish as their preferred language (91.6% vs 81.7%, p<0.001), be younger (30.4 vs 33.4 years, p<0.008), and have a larger household size (4.8 vs 4.3 members, p<0.002). CONCLUSIONS: Community-based testing identified high levels of ongoing SARS-CoV-2 transmission among primarily Latinxs with limited English proficiency. During this period, the overall positivity rate at this community testing site was almost 10 times higher among Latinxs than among non-Hispanic Whites.

Community Calls: Lessons and Insights Gained from a Medical-Religious Community Engagement During the COVID-19 Pandemic.

During the pandemic caused by the severe acute respiratory syndrome coronavirus-2, public health instructions were issued with the hope of curbing the virus' spread. In an effort to assure accordance with these instructions, equitable strategies for at-risk and vulnerable populations and communities are warranted. One such strategy was our community conference calls, implemented to disseminate information on the pandemic and allow community leaders to discuss struggles and successes. Over the first 6 weeks, we held 12 calls, averaging 125 (standard deviation 41) participants. Participants were primarily from congregations and faith-based organizations that had an established relationship with the hospital, but also included school leaders, elected officials, and representatives of housing associations. Issues discussed included reasons for quarantining, mental health, social isolation, health disparities, and ethical concerns regarding hospital resources. Concerns identified by the community leaders as barriers to effective quarantining and adherence to precautions included food access, housing density, and access to screening and testing. Through the calls, ways to solve such challenges were addressed, with novel strategies and resources reaching the community. This medical-religious resource has proven feasible and valuable during the pandemic and warrants discussions on reproducing it for other communities during this and future infectious disease outbreaks.

Community Intervention for Syrian Refugees in Baltimore City: The Lay Health Educator Program at a Local Mosque.

This study focused on a partnership with a mosque in Baltimore, MD, and its impact on the local Syrian refugee population through a peer-to-peer healthcare training program. We implemented the Lay Health Educator Program over a 6-week period in an effort to teach members of the mosque about healthcare-related topics that they could then disseminate to the Syrian refugee population that attends the mosque. Physicians and nurses instructed community members on health, healthcare resources, and healthcare information during 2-h long sessions once a week. A total of 18 community members took part in the program, and their participation highlighted that the most significant health issues for the Syrian refugees are "access to healthcare," "mental health," and insight into certain noncommunicable disease. Finally, the community program graduates implemented several health-related campaigns over 2 years in an effort to disseminate information taught to them. In doing so, they significantly impacted the ability of the refugees to assimilate to the US healthcare system.

Sociodemographic Factors Associated with Types of Projects Implemented by Volunteer Lay Health Educators in Their Congregations.

This study focused on the association between type of community health interventions and lay health educator variables. Lay health educators are volunteers from local faith communities who complete a healthcare training program, taught by physicians in-training. Lay health educators are instructed to implement health-related initiatives in their respective communities after graduation. Of the 72 graduates since 2011, we surveyed 55 lay health educators to gain insight into their involvement with their congregation and the type of health projects they have implemented. We dichotomized the health projects into "raising awareness" and "teaching new health skills." Using adjusted logistic regression models, variables associated with implementing health projects aimed at teaching health skills included length of time as a member of their congregation, current employment, and age. These results may help future programs prepare lay health community educators for the type of health interventions they intend to implement in their respective communities.

Autism-associated neuroligin-4 mutation selectively impairs glycinergic synaptic transmission in mouse brainstem synapses.

In human patients, loss-of-function mutations of the postsynaptic cell-adhesion molecule neuroligin-4 were repeatedly identified as monogenetic causes of autism. In mice, neuroligin-4 deletions caused autism-related behavioral impairments and subtle changes in synaptic transmission, and neuroligin-4 was found, at least in part, at glycinergic synapses. However, low expression levels precluded a comprehensive analysis of neuroligin-4 localization, and overexpression of neuroligin-4 puzzlingly impaired excitatory but not inhibitory synaptic function. As a result, the function of neuroligin-4 remains unclear, as does its relation to other neuroligins. To clarify these issues, we systematically examined the function of neuroligin-4, focusing on excitatory and inhibitory inputs to defined projection neurons of the mouse brainstem as central model synapses. We show that loss of neuroligin-4 causes a profound impairment of glycinergic but not glutamatergic synaptic transmission and a decrease in glycinergic synapse numbers. Thus, neuroligin-4 is essential for the organization and/or maintenance of glycinergic synapses.

EXPLORING NON-TRADITIONAL PARTICIPATION AS AN APPROACH TO MAKE WATER QUALITY TRADING MARKETS MORE EFFECTIVE.

Water quality trading (WQT) has potential to be a low-cost means for achieving water quality goals. WQT allows regulated wastewater treatment plants (WWTPs) facing discharge limits the flexibility to either reduce their own discharge or purchase pollution control from other WWTPs or nonpoint sources (NPSs) such as agricultural producers. Under this limited scope, programs with NPSs have been largely unsuccessful at meeting water quality goals. The decision to participate in trading depends on many factors including the pollution control costs, uncertainty in pollution control, and discharge limits. Current research that focuses on making WQT work tends to identify how to increase participation by traditional traders such as WWTPs and agricultural producers. As an alternative, but complementary approach, we consider whether augmenting WQT markets with non-traditional participants would help increase the number of trades. Determining the economic incentives for these potential participants requires the development of novel benefit functions requiring not only economic considerations, but also accounting for ecological and engineering processes. Existing literature on non-traditional participants in environmental markets tends to center on air quality and only increasing citizen participation as buyers. Here, we consider the issues for broadening participation (both buyers and sellers) in WQT and outline a multidisciplinary approach to begin evaluating feasibility.

Unique versus Redundant Functions of Neuroligin Genes in Shaping Excitatory and Inhibitory Synapse Properties.

Neuroligins are evolutionarily conserved postsynaptic cell adhesion molecules that interact with presynaptic neurexins. Neurons express multiple neuroligin isoforms that are targeted to specific synapses, but their synaptic functions and mechanistic redundancy are not completely understood. Overexpression or RNAi-mediated knockdown of neuroligins, respectively, causes a dramatic increase or decrease in synapse density, whereas genetic deletions of neuroligins impair synapse function with only minor effects on synapse numbers, raising fundamental questions about the overall physiological role of neuroligins. Here, we have systematically analyzed the effects of conditional genetic deletions of all major neuroligin isoforms (i.e., NL1, NL2, and NL3), either individually or in combinations, in cultured mouse hippocampal and cortical neurons. We found that conditional genetic deletions of neuroligins caused no change or only a small change in synapses numbers, but strongly impaired synapse function. This impairment was isoform specific, suggesting that neuroligins are not functionally redundant. Sparse neuroligin deletions produced phenotypes comparable to those of global deletions, indicating that neuroligins function in a cell-autonomous manner. Mechanistically, neuroligin deletions decreased the synaptic levels of neurotransmitter receptors and had no effect on presynaptic release probabilities. Overexpression of neuroligin-1 in control or neuroligin-deficient neurons increased synaptic transmission and synapse density but not spine numbers, suggesting that these effects reflect a gain-of-function mechanism; whereas overexpression of neuroligin-3, which, like neuroligin-1 is also targeted to excitatory synapses, had no comparable effect. Our data demonstrate that neuroligins are required for the physiological organization of neurotransmitter receptors in postsynaptic specializations and suggest that they do not play a major role in synapse formation.SIGNIFICANCE STATEMENT Human neuroligin genes have been associated with autism, but the cellular functions of different neuroligins and their molecular mechanisms remain incompletely understood. Here, we performed comparative analyses in cultured mouse neurons of all major neuroligin isoforms, either individually or in combinations, using conditional knockouts. We found that neuroligin deletions did not affect synapse numbers but differentially impaired excitatory or inhibitory synaptic functions in an isoform-specific manner. These impairments were due, at least in part, to a decrease in synaptic distribution of neurotransmitter receptors upon deletion of neuroligins. Conversely, the overexpression of neuroligin-1 increased synapse numbers but not spine numbers. Our results suggest that various neuroligin isoforms perform unique postsynaptic functions in organizing synapses but are not essential for synapse formation or maintenance.

Policy and advocacy for informal caregivers: How state policy influenced a community initiative.

With a growing proportion of elderly in the global population, the role of 'informal caregivers' gains importance. Informal caregivers are unpaid family members or friends who provide assistance to home-dwelling adults with health-related needs or limitations. Internationally, informal caregivers provide important medical support to those with a variety of diseases. While informal caregivers will remain vital to the growing aging population's pursuit of healthy aging, they often suffer from 'caregiver burnout,' a state of physical, emotional, and mental exhaustion caused by their caregiving work. Policy and legislation are needed to diminish the burden on caregivers and to help assure that resources are allocated for these caregivers. We describe an initiative aimed at providing appropriate social support for caregivers by partnering among local organizations, hospitals, and health authorities.

The role of stress reactivity in the long-term persistence of adolescent social anxiety symptoms.

Social Anxiety Disorder (SAD) symptoms demonstrate a marked persistence over time, but little is known empirically about short-term processes that may account for this long-term persistence. In this study, we examined how self-reported and physiological stress reactivity were associated with persistence of SAD symptoms from early to late adolescence. A community sample of 327 adolescents (56% boys, Mage=13.01 at T1) reported their SAD symptoms for 6 successive years and participated in a public speaking task, during which self-reported (i.e., perceived nervousness and heart rate) and physiological (i.e., cortisol and heart rate) measures of stress were taken. Overall, our results point to a developmental process in which adolescents with a developmental history of higher SAD symptoms show both heightened perceived stress reactivity and heart rate reactivity, which, in turn, predict higher SAD symptoms into late adolescence.

Caring for the Caregiver: Identifying the Needs of Those Called to Care Through Partnerships with Congregations.

As the older adult population continues to grow, the prevalence of chronic diseases is also increasing, leading to the need for novel ways of managing this large population of patients. One solution is to focus on informal caregivers. These informal caregivers already make a substantial contribution to our nation's healthcare finances and patient health outcomes. Caregivers also derive benefits from caring for their family member or friend; however, it is not uncommon for these individuals to experience negative health consequences, or what is often called "burden of care." Those called to care are not without their own burdens, and they must frequently make significant lifestyle adjustments that impact their own health. Therefore, for caregivers to be effective, caring for the caregivers must be a focus of medicine in the twenty-first century.

Discrepancies Between Perceptions of the Parent-Adolescent Relationship and Early Adolescent Depressive Symptoms: An Illustration of Polynomial Regression Analysis.

Adolescence is a critical period for the development of depressive symptoms. Lower quality of the parent-adolescent relationship has been consistently associated with higher adolescent depressive symptoms, but discrepancies in perceptions of parents and adolescents regarding the quality of their relationship may be particularly important to consider. In the present study, we therefore examined how discrepancies in parents' and adolescents' perceptions of the parent-adolescent relationship were associated with early adolescent depressive symptoms, both concurrently and longitudinally over a 1-year period. Our sample consisted of 497 Dutch adolescents (57 % boys, M age = 13.03 years), residing in the western and central regions of the Netherlands, and their mothers and fathers, who all completed several questionnaires on two occasions with a 1-year interval. Adolescents reported on depressive symptoms and all informants reported on levels of negative interaction in the parent-adolescent relationship. Results from polynomial regression analyses including interaction terms between informants' perceptions, which have recently been proposed as more valid tests of hypotheses involving informant discrepancies than difference scores, suggested the highest adolescent depressive symptoms when both the mother and the adolescent reported high negative interaction, and when the adolescent reported high but the father reported low negative interaction. This pattern of findings underscores the need for a more sophisticated methodology such as polynomial regression analysis including tests of moderation, rather than the use of difference scores, which can adequately address both congruence and discrepancies in perceptions of adolescents and mothers/fathers of the parent-adolescent relationship in detail. Such an analysis can contribute to a more comprehensive understanding of risk factors for early adolescent depressive symptoms.

Health Promotion in the Community: Impact of Faith-Based Lay Health Educators in Urban Neighborhoods.

Promoting wellness and providing reliable health information in the community present serious challenges. Lay health educators, also known as community health workers, may offer a cost-effective solution to such challenges. This is a retrospective observational study of graduates from the Lay Health Educator Program (LHEP) at Johns Hopkins Bayview Medical Center from 2013 to 2014. Students were enrolled from the surrounding community congregations and from the hospital's accredited clinical pastoral education program. There were 50 events implemented by the lay health educators during the 2014-2015 time period, reaching a total of 2004 individuals. The mean time from date of graduation from the LHEP to implementation of their first health promotional event was 196 ± 76 days. A significant number of lay health educators implemented events within the first year after completing their training. Ongoing monitoring of their community activity and the clinical impact of their efforts should be a priority for future studies.

A Brief Historical Review of Specific Religious Denominations: How History Influences Current Medical-Religious Partnerships.

Improving health care in the twenty-first century will require new and creative approaches, with special attention given to health literacy and patient engagement since these two variables play a significant role in chronic health issues and their management. In order to better improve these key variables, strong partnerships between patients, their communities, and medical institutions must be developed. One way of facilitating these relationships is through medical-religious partnerships. Religious leaders are in regular contact with people who need education about and support with health issues. However, identifying the most effective way to approach specific congregations can pose a challenge to healthcare providers and institutions. In this paper, we provide a brief historical review of certain religious traditions and how their history plays a role in current medical-religious partnerships.

Promoting Health and Wellness in Congregations Through Lay Health Educators: A Case Study of Two Churches.

Religious institutions are in regular contact with people who need education about and support with health issues. Creating lay health educators to serve in these communities can promote health initiatives centered on education and accessing resources. This paper is a prospective observational report of the impact of trained lay health community congregation members in two faith communities based on an urban setting. We describe health efforts made in an African-American Methodist church and in a Latino Spanish-speaking Catholic church. We review the intricacies in establishing trust with the community, the training of lay health educators, and the implementation strategies and outcomes of health initiatives for these communities.

The Lay Health Educator Program: Evaluating the Impact of this Community Health Initiative on the Medical Education of Resident Physicians.

Resident physicians receive little training designed to help them develop an understanding of the health literacy and health concerns of laypersons. The purpose of this study was to assess whether residents improve their understanding of health concerns of community members after participating in the Lay Health Educator Program, a health education program provided through a medical-religious community partnership. The impact was evaluated via pre-post surveys and open-ended responses. There was a statistically significant change in the residents' (n = 15) understanding of what the public values as important with respect to specific healthcare topics. Findings suggest participation in a brief, formal community engagement activity improved medical residents' confidence with community health education.