The structure of the Caenorhabditis elegans TMC-2 complex suggests roles of lipid-mediated subunit contacts in mechanosensory transduction.

Mechanotransduction is the process by which a mechanical force, such as touch, is converted into an electrical signal. Transmembrane channel-like (TMC) proteins are an evolutionarily conserved family of membrane proteins whose function has been linked to a variety of mechanosensory processes, including hearing and balance sensation in vertebrates and locomotion in Drosophila. TMC1 and TMC2 are components of ion channel complexes, but the molecular features that tune these complexes to diverse mechanical stimuli are unknown. Caenorhabditis elegans express two TMC homologs, TMC-1 and TMC-2, both of which are the likely pore-forming subunits of mechanosensitive ion channels but differ in their expression pattern and functional role in the worm. Here, we present the single-particle cryo-electron microscopy structure of the native TMC-2 complex isolated from C. elegans. The complex is composed of two copies of the pore-forming TMC-2 subunit, the calcium and integrin binding protein CALM-1 and the transmembrane inner ear protein TMIE. Comparison of the TMC-2 complex to the recently published cryo-EM structure of the C. elegans TMC-1 complex highlights conserved protein-lipid interactions, as well as a π-helical structural motif in the pore-forming helices, that together suggest a mechanism for TMC-mediated mechanosensory transduction.

Infectious pathogens and risk of esophageal, gastric and duodenal cancers and ulcers in China: A case-cohort study.

Infection by certain pathogens is associated with cancer development. We conducted a case-cohort study of ~2500 incident cases of esophageal, gastric and duodenal cancer, and gastric and duodenal ulcer and a randomly selected subcohort of ~2000 individuals within the China Kadoorie Biobank study of >0.5 million adults. We used a bead-based multiplex serology assay to measure antibodies against 19 pathogens (total 43 antigens) in baseline plasma samples. Associations between pathogens and antigen-specific antibodies with risks of site-specific cancers and ulcers were assessed using Cox regression fitted using the Prentice pseudo-partial likelihood. Seroprevalence varied for different pathogens, from 0.7% for Hepatitis C virus (HCV) to 99.8% for Epstein-Barr virus (EBV) in the subcohort. Compared to participants seronegative for the corresponding pathogen, Helicobacter pylori seropositivity was associated with a higher risk of non-cardia (adjusted hazard ratio [HR] 2.73 [95% CI: 2.09-3.58]) and cardia (1.67 [1.18-2.38]) gastric cancer and duodenal ulcer (2.71 [1.79-4.08]). HCV was associated with a higher risk of duodenal cancer (6.23 [1.52-25.62]) and Hepatitis B virus was associated with higher risk of duodenal ulcer (1.46 [1.04-2.05]). There were some associations of antibodies again some herpesviruses and human papillomaviruses with risks of gastrointestinal cancers and ulcers but these should be interpreted with caution. This first study of multiple pathogens with risk of gastrointestinal cancers and ulcers demonstrated that several pathogens are associated with risks of gastrointestinal cancers and ulcers. This will inform future investigations into the role of infection in the etiology of these diseases.

Insights into the role of the respiratory tract microbiome in defense against bacterial pneumonia.

The respiratory tract microbiome (RTM) is a microbial ecosystem inhabiting different niches throughout the airway. A critical role for the RTM in dictating lung infection outcomes is underlined by recent efforts to identify community members benefiting respiratory tract health. Obligate anaerobes common in the oropharynx and lung such as Prevotella and Veillonella are associated with improved pneumonia outcomes and activate several immune defense pathways in the lower airway. Colonizers of the nasal cavity, including Corynebacterium and Dolosigranulum, directly impact the growth and virulence of lung pathogens, aligning with robust clinical correlations between their upper airway abundance and reduced respiratory tract infection risk. Here, we highlight recent work identifying respiratory tract bacteria that promote airway health and resilience against disease, with a focus on lung infections and the underlying mechanisms driving RTM-protective benefits.

Association between dental visits during pregnancy and setting for prenatal care.

OBJECTIVES: Federally Qualified Health Centers (FQHCs) may be well positioned to facilitate dental visits during pregnancy for low-income women. We sought to compare receipt of dental visits during pregnancy for women who received prenatal care at an FQHC versus a non-FQHC setting. METHODS: We analyzed Michigan Medicaid administrative data for all live birth deliveries between April 2018 and December 2020. We used billing data to categorize the predominant setting for prenatal care as occurring at a FQHC or a non-FQHC and claims data to identify dental visits during pregnancy (in the 9 months prior to delivery). We employed bivariate and multivariate analyses to explore the relationship between setting for prenatal care and dental visits during pregnancy. RESULTS: Women who received prenatal care at an FQHC versus non-FQHC had a higher proportion of dental visits during pregnancy (31.85% vs. 19.37%, p < 0.0001). In multivariate analyses, the strongest predictors of having a dental visit during pregnancy were FQHC prenatal care setting, having a dental emergency visit, having ≥3 prenatal visits, and having Medicaid coverage throughout pregnancy. Hispanic or Black race/ethnicity and 2020 delivery year were predictors of a lower likelihood of a dental visit. These predictors were consistent for the overall population and for the subset who had no dental visits pre-pregnancy. CONCLUSION: Medicaid-enrolled women who receive prenatal care at an FQHC are more likely to have a dental visit during pregnancy than their counterparts who receive prenatal care in a non-FQHC setting.

Is repeated mistake-making an effective treatment strategy for perfectionism? Findings from a randomized controlled trial.

BACKGROUND AND OBJECTIVES: Perfectionism has been linked to self-criticism, procrastination, and psychological disorders. In a previous study, an exposure-based treatment for perfectionism (ETP), which included exposures targeted at concern over mistakes, showed positive outcomes when compared to waitlist. The aim of this study was to further investigate ETP by comparing it to a stress-management condition and assessing durability of treatment effects by conducting a one-month follow-up assessment. METHODS: Eighty-five individuals with elevated perfectionism were randomly assigned to receive ETP (n = 43) or a stress management treatment (n = 42). ETP involved repeatedly practicing mistake-making by completing computerized tasks engineered to cause individuals to make mistakes. The stress management condition included listening to videos and answering questions about healthy habits, such as diet, exercise, and sleep, as well as viewing calming videos. Participants completed eight treatment sessions as well as baseline, post-test, and one month follow-up self-report questionnaires. RESULTS: Contrary to predictions, compared to ETP, stress management led to significantly lower overall perfectionism, depression, generalized anxiety, and social anxiety at post and significantly lower depression, generalized anxiety, and social anxiety at follow-up. Further, individuals who completed ETP did not habituate to the exposure tasks, but distress increased from the first to the last treatment session. LIMITATIONS: The duration of treatment was relatively brief. CONCLUSIONS: This study highlights the importance of using active psychological control conditions in treatment outcome studies and the need to test various components of treatments for perfectionism to observe what may be effective or even potentially iatrogenic.

Evaluation of Ten Alternative Treatments for the Management of Harlequin Bug (Murgantia histrionica) on Brassica Crops.

Harlequin bug (Murgantia histrionica) poses a significant threat to cruciferous vegetable crops, leading to economic losses and challenges in sustainable agriculture. This 2-year field study evaluated the efficacy of exclusion netting and selected biopesticides in controlling harlequin bug populations in a field-grown broccoli crop. Treatments included an untreated control, industry standards Azera and Entrust, and ProtekNet mesh netting. Additionally, three commercial essential oil treatments including Essentria IC-3, Nature-Cide, and Zero Tolerance were tested along with two bokashi fermented composting products BrewKashi and Oriental Herbal Nutrient (OHN). During both the first and second year of the study, none of the commercially produced essential oil products or bokashi products were effective in controlling harlequin bug or preventing leaf scars. Conversely, ProtekNet consistently provided the highest level of protection against harlequin bugs of all stages as well as leaf damage scars; it also provided the largest broccoli head width and highest yield. Entrust showed similar results compared to ProtekNet, both with the control of harlequin bug life stages and with leaf scars. These findings indicate that both ProtekNet and Entrust are effective organic alternatives for managing harlequin bug on broccoli, while the selected essential oil and bokashi products do not appear to be effective.

Benefits of a health advocacy intervention intended to improve self-efficacy for self-care in residents of a homeless shelter.

Despite a great need for healthcare, unhoused individuals encounter significant barriers to utilizing public healthcare systems. Given the inequities in access to healthcare, accompanied by disabilities and health risks associated with homelessness, self-efficacy for self-care is particularly critical. As a primary purpose of this article, we describe a self-care intervention (Health Advocacy Behavioral Activation), which was implemented within a long-standing participatory community action research project for homeless shelters, and report evidence of the intervention's effectiveness in enhancing self-efficacy for self-care. Participants included 62 residents of the St. Vincent de Paul Gateway Shelter for Men (Dayton, Ohio). Shelter residents with disabilities and those without disability benefited approximately equally from the intervention and both showed statistically significant pre- to post-intervention improvements in self-efficacy for self-care. Recommendations for future research examining the effectiveness of the intervention are provided. As a secondary (supplementary) purpose, we report preliminary evidence of psychometric validation for a new instrument (Scale of Self-Efficacy for Self-Care), which was developed in service of our primary purpose (i.e., to examine the effects of intervention on self-efficacy for self-care) because a literature search did not identify an appropriate measure. Because this new instrument fills a void in the literature, we anticipate that it will be useful in practice and research, and so we delineate research recommendations for additional psychometric validation of this measure. Because of the barriers that unhoused people encounter with regard to access to healthcare in the community, self-care interventions provided (and evaluated) on-site (e.g., in homeless shelters) are necessary.

Structural basis of bulk lipid transfer by bridge-like lipid transfer protein LPD-3.

Bridge-like lipid transport proteins (BLTPs) are an evolutionarily conserved family of proteins that localize to membrane contact sites and are thought to mediate the bulk transfer of lipids from a donor membrane, typically the endoplasmic reticulum (ER), to an acceptor membrane, such as a that of the cell or an organelle 1 . Despite the fundamental importance of BLTPs for cellular function, the architecture, composition, and lipid transfer mechanisms remain poorly characterized. Here, we present the subunit composition and the cryo-electron microscopy structure of the native LPD-3 BLTP complex isolated from transgenic C. elegans . LPD-3 folds into an elongated, rod-shaped tunnel whose interior is filled with ordered lipid molecules that are coordinated by a track of ionizable residues that line one side of the tunnel. LPD-3 forms a complex with two previously uncharacterized proteins, here named "Intake" and "Spigot", both of which interact with the N-terminal end of LPD-3 where lipids enter the tunnel. Intake has three transmembrane helices, one of which borders the entrance to the tunnel; Spigot has one transmembrane helix and extends 80 Å along the cytosolic surface of LPD-3. Experiments in multiple model systems indicate that Spigot plays a conserved role in ER-PM contact site formation. Our LPD-3 complex structural data, together with molecular dynamics simulations of the transmembrane region in a lipid bilayer, reveal protein-lipid interactions that suggest a model for how the native LPD-3-complex mediates bulk lipid transport and provide a foundation for mechanistic studies of BLTPs.

Heme sequestration by hemophilin from Haemophilus haemolyticus reduces respiratory tract colonization and infection with non-typeable Haemophilus influenzae.

Iron acquisition is a key feature dictating the success of pathogen colonization and infection. Pathogens scavenging iron from the host must contend with other members of the microbiome similarly competing for the limited pool of bioavailable iron, often in the form of heme. In this study, we identify a beneficial role for the heme-binding protein hemophilin (Hpl) produced by the non-pathogenic bacterium Haemophilus haemolyticus against its close relative, the opportunistic respiratory tract pathogen non-typeable Haemophilus influenzae (NTHi). Using a mouse model, we found that pre-exposure to H. haemolyticus significantly reduced NTHi colonization of the upper airway and impaired NTHi infection of the lungs in an Hpl-dependent manner. Further, treatment with recombinant Hpl was sufficient to decrease airway burdens of NTHi without exacerbating lung immunopathology or systemic inflammation. Instead, mucosal production of the neutrophil chemokine CXCL2, lung myeloperoxidase, and serum pro-inflammatory cytokines IL-6 and TNFα were lower in Hpl-treated mice. Mechanistically, H. haemolyticus suppressed NTHi growth and adherence to human respiratory tract epithelial cells through the expression of Hpl, and recombinant Hpl could recapitulate these effects. Together, these findings indicate that heme sequestration by non-pathogenic, Hpl-producing H. haemolyticus is protective against NTHi colonization and infection. IMPORTANCE: The microbiome provides a critical layer of protection against infection with bacterial pathogens. This protection is accomplished through a variety of mechanisms, including interference with pathogen growth and adherence to host cells. In terms of immune defense, another way to prevent pathogens from establishing infections is by limiting the availability of nutrients, referred to as nutritional immunity. Restricting pathogen access to iron is a central component of this approach. Here, we uncovered an example where these two strategies intersect to impede infection with the respiratory tract bacterial pathogen Haemophilus influenzae. Specifically, we find that a non-pathogenic (commensal) bacterium closely related to H. influenzae called Haemophilus haemolyticus improves protection against H. influenzae by limiting the ability of this pathogen to access iron. These findings suggest that beneficial members of the microbiome improve protection against pathogen infection by effectively contributing to host nutritional immunity.

Regional and cellular organization of the autism-associated protein UBE3A/E6AP and its antisense transcript in the brain of the developing rhesus monkey.

Angelman syndrome (AS) is a neurogenetic disorder caused by mutations or deletions in the maternally-inherited UBE3A allele, leading to a loss of UBE3A protein expression in neurons. The paternally-inherited UBE3A allele is epigenetically silenced in neurons during development by a noncoding transcript (UBE3A-ATS). The absence of neuronal UBE3A results in severe neurological symptoms, including speech and language impairments, intellectual disability, and seizures. While no cure exists, therapies aiming to restore UBE3A function-either by gene addition or by targeting UBE3A-ATS-are under development. Progress in developing these treatments relies heavily on inferences drawn from mouse studies about the function of UBE3A in the human brain. To aid translational efforts and to gain an understanding of UBE3A and UBE3A-ATS biology with greater relevance to human neurodevelopmental contexts, we investigated UBE3A and UBE3A-ATS expression in the developing brain of the rhesus macaque, a species that exhibits complex social behaviors, resembling aspects of human behavior to a greater degree than mice. Combining immunohistochemistry and in situ hybridization, we mapped UBE3A and UBE3A-ATS regional and cellular expression in normal prenatal, neonatal, and adolescent rhesus macaque brains. We show that key hallmarks of UBE3A biology, well-known in rodents, are also present in macaques, and suggest paternal UBE3A silencing in neurons-but not glial cells-in the macaque brain, with onset between gestational day 48 and 100. These findings support proposals that early-life, perhaps even prenatal, intervention is optimal for overcoming the maternal allele loss of UBE3A linked to AS.

White matter and latency of visual evoked potentials during maturation: a miniature pig model of adolescent development.

BACKGROUND: Continuous myelination of cerebral white matter (WM) during adolescence overlaps with the formation of higher cognitive skills and the onset of many neuropsychiatric disorders. We developed a miniature-pig model of adolescent brain development for neuroimaging and neurophysiological assessment during this critical period. Minipigs have gyroencephalic brains with a large cerebral WM compartment and a well-defined adolescence period. METHODS: Eight SinclairTM minipigs (Sus scrofa domestica) were evaluated four times during weeks 14-28 (40, 28 and 28 days apart) of adolescence using monocular visual stimulation (1Hz)-evoked potentials and diffusion MRI (dMRI) of WM. The latency for the pre-positive 30 ms (PP30), positive 30 ms (P30) and negative 50 ms (N50) components of the flash visual evoked potentials (fVEPs) and their interhemispheric latency (IL) were recorded in the frontal, central and occipital areas during ten 60-second stimulations for each eye. The dMRI imaging protocol consisted of fifteen b-shells (b = 0-3500s/mm2) with 32 directions/shell, providing measurements that included fractional anisotropy (FA), radial kurtosis, kurtosis anisotropy (KA), axonal water fraction (AWF), and the permeability-diffusivity index (PDI). RESULTS: Significant reductions (p < 0.05) in the latency and IL of fVEP measurements paralleled significant rises in FA, KA, AWF and PDI over the same period. The longitudinal latency changes in fVEPs were primarily associated with whole-brain changes in diffusion parameters, while fVEP IL changes were related to maturation of the corpus callosum. CONCLUSIONS: Good agreement between reduction in the latency of fVEPs and maturation of cerebral WM was interpreted as evidence for ongoing myelination and confirmation of the minipig as a viable research platform. Adolescent development in minipigs can be studied using human neuroimaging and neurophysiological protocols and followed up with more invasive assays to investigate key neurodevelopmental hypotheses in psychiatry.

Structural basis for VLDLR recognition by eastern equine encephalitis virus.

Eastern equine encephalitis virus (EEEV) is the most virulent alphavirus that infects humans, and many survivors develop neurological sequelae, including paralysis and intellectual disability. Alphavirus spike proteins comprise trimers of heterodimers of glycoproteins E2 and E1 that mediate binding to cellular receptors and fusion of virus and host cell membranes during entry. We recently identified very-low density lipoprotein receptor (VLDLR) and apolipoprotein E receptor 2 (ApoER2) as cellular receptors for EEEV and a distantly related alphavirus, Semliki Forest virus (SFV). Here, we use single-particle cryo-electron microscopy (cryo-EM) to determine structures of the EEEV and SFV spike glycoproteins bound to the VLDLR ligand-binding domain and found that EEEV and SFV interact with the same cellular receptor through divergent binding modes. Our studies suggest that the ability of LDLR-related proteins to interact with viral spike proteins through very small footprints with flexible binding modes results in a low evolutionary barrier to the acquisition of LDLR-related proteins as cellular receptors for diverse sets of viruses.

Single molecule studies of the native hair cell mechanosensory transduction complex.

Hearing and balance rely on the conversion of a mechanical stimulus into an electrical signal, a process known as mechanosensory transduction (MT). In vertebrates, this process is accomplished by an MT complex that is located in hair cells of the inner ear. While the past three decades of research have identified many subunits that are important for MT and revealed interactions between these subunits, the composition and organization of a functional complex remains unknown. The major challenge associated with studying the MT complex is its extremely low abundance in hair cells; current estimates of MT complex quantity range from 3-60 attomoles per cochlea or utricle, well below the detection limit of most biochemical assays that are used to characterize macromolecular complexes. Here we describe the optimization of two single molecule assays, single molecule pull-down (SiMPull) and single molecule array (SiMoA), to study the composition and quantity of native mouse MT complexes. We demonstrate that these assays are capable of detecting and quantifying low attomoles of the native MT subunits protocadherin-15 (PCDH15) and lipoma HMGIC fusion partner-like protein 5 (LHFPL5). Our results illuminate the stoichiometry of PCDH15- and LHFPL5-containing complexes and establish SiMPull and SiMoA as productive methods for probing the abundance, composition, and arrangement of subunits in the native MT complex.

Peer-Led Focus Groups Identify Barriers to Healthy Lifestyle in African American Adolescents from Baltimore City.

Objectives: Black youth are disproportionately affected by the US obesity epidemic. Early-age obesity often continues into adulthood and is associated with a higher risk of diabetes, cardiovascular disease, and premature death. Few studies have incorporated community-based participatory research (CBPR) facilitated by youth to provide frank discussions among teens living in inner cities about challenges and facilitators in maintaining a healthy weight and to design teen-identified interventions. Design: Black youth (n=10) were recruited from a Baltimore City high school during the 2019 to 2020 academic year and were trained by seasoned investigators and mentored by graduate and undergraduate students on qualitative methods using CBPR. These youth then implemented focus groups with their peers aged 15 to 18 years (10 focus groups of 10 teens each). Topics included healthy lifestyle knowledge, behaviors, attitudes, and suggested interventions. Content analyses were conducted using dual-rater techniques. Results: Focus group themes yielded strengths and challenges of weight maintenance for Black youth at various levels, including in their personal lives, families, school, and community. Themes also suggested several technology-based possibilities using social media to reach Black youth about healthy living practices. Conclusions: Engagement of Black youth in CBPR projects can yield valuable data to design more culturally responsive and developmentally appropriate interventions. Youth are competent collectors of information to identify needed changes in their schools/communities and about the use of technology/social media to facilitate improved health practices among their peers and should be involved early in the process of developing targeted obesity prevention interventions and/or programs.