Viral RNA exported from the coronavirus replication organelle is likely to be mediated by a crown-shaped molecular pore.
A gateway to the cytosol
Coronaviruses transform host cell membranes into ...peculiar double-membrane vesicles that have long been thought to accommodate viral genome replication. However, because these compartments appeared to be completely sealed, it has remained unknown how the newly made viral RNA could be exported to the cytosol for translation and packaging into new virions. Wolff
et al.
used cryo–electron microscopy to identify a molecular pore that spans the double membrane (see the Perspective by Unchwaniwala and Ahlquist). Six copies of a large coronavirus transmembrane protein formed the core of this structure, which may constitute a viral RNA export channel and provide a target for future antiviral interventions.
Science
, this issue p.
1395
; see also p.
1306
Coronavirus genome replication is associated with virus-induced cytosolic double-membrane vesicles, which may provide a tailored microenvironment for viral RNA synthesis in the infected cell. However, it is unclear how newly synthesized genomes and messenger RNAs can travel from these sealed replication compartments to the cytosol to ensure their translation and the assembly of progeny virions. In this study, we used cellular cryo–electron microscopy to visualize a molecular pore complex that spans both membranes of the double-membrane vesicle and would allow export of RNA to the cytosol. A hexameric assembly of a large viral transmembrane protein was found to form the core of the crown-shaped complex. This coronavirus-specific structure likely plays a key role in coronavirus replication and thus constitutes a potential drug target.
Development of novel antimicrobial agents is a top priority in the fight against multidrug-resistant (MDR) and persistent bacteria. We developed a panel of synthetic antimicrobial and antibiofilm ...peptides (SAAPs) with enhanced antimicrobial activities compared to the parent peptide, human antimicrobial peptide LL-37. Our lead peptide SAAP-148 was more efficient in killing bacteria under physiological conditions in vitro than many known preclinical- and clinical-phase antimicrobial peptides. SAAP-148 killed MDR pathogens without inducing resistance, prevented biofilm formation, and eliminated established biofilms and persister cells. A single 4-hour treatment with hypromellose ointment containing SAAP-148 completely eradicated acute and established, biofilm-associated infections with methicillin-resistant
and MDR
from wounded ex vivo human skin and murine skin in vivo. Together, these data demonstrate that SAAP-148 is a promising drug candidate in the battle against antibiotic-resistant bacteria that pose a great threat to human health.
Complement activation by antibodies bound to pathogens, tumors, and self antigens is a critical feature of natural immune defense, a number of disease processes, and immunotherapies. How antibodies ...activate the complement cascade, however, is poorly understood. We found that specific noncovalent interactions between Fc segments of immunoglobulin G (IgG) antibodies resulted in the formation of ordered antibody hexamers after antigen binding on cells. These hexamers recruited and activated C1, the first component of complement, thereby triggering the complement cascade. The interactions between neighboring Fc segments could be manipulated to block, reconstitute, and enhance complement activation and killing of target cells, using all four human IgG subclasses. We offer a general model for understanding antibody-mediated complement activation and the design of antibody therapeutics with enhanced efficacy.
The food system in Vietnam is changing whilst the middle class is growing. Agri-food smallholders have the strengths of responding to the changing needs of the middle class by offering freshness, ...proximity and convenience but they also face increasing competition from larger and international firms. At the same time, issues with food safety are prevalent and a rising concern among consumers. For this study we completed sixteen co-creation workshops between local agri-food smallholders and consumers. The goal of these workshops was to explore the value of participatory processes, non-hierarchical decision making and creativity for smallholder firms in Vietnam through co-creation workshops focused on sustainability. The outcomes show that the workshops can stimulate customer understanding and participatory processes among the smallholder businesses, but creativity in the form of novel ideas less so. The workshops did not result in directly feasible or manageable product and service concepts. The topic of sustainable food opened a dialogue: insights between the firms and customers on this topic were mutually rich. The outcomes suggest that co-creation workshops can create a sense of community and urgency for sustainability. In the future, the challenge for smallholders is to invest in participatory processes with a long-term view on sustainability as well as come to practical design outcomes on the short term.
Although the genus Prevotella is part of the general human flora, species of this anaerobic gram-negative bacteria have been described as cause of persisting nonpuerperal breast abscesses. Collecting ...punctate samples and testing these samples for anaerobic bacteria, is not part of the common diagnostic workflow in atypical breast abscesses. The causative anaerobic micro-organism can remain unclear and patients can be treated with multiple inadequate antibiotics and/or extensive surgical procedures. The aim of this cohort study of Prevotella induced breast abscesses is to gain more insights into the diagnostic procedures and treatment.
Medical charts of patients with a Prevotella induced breast abscess between 2015 and 2021, were retrospectively reviewed on patient characteristics, diagnostic procedures, treatment and outcome.
Twenty-one patients were included. Six subspecies of Prevotella were determined by culturing. High susceptibility was observed for amoxicillin/clavulanic acid (100%, n = 12). Nine patients (43%) were treated with antibiotics, eight patients (38%) with antibiotics and incision and drainage, and four patients (19%) with only incision and drainage. Recurrence was observed in nine patients (43%), of whom five patients were treated with antibiotics and three patients had surgery. The mean duration of antibiotic administration in patients with recurrence was significantly shorter compared to those without recurrence (5.6 days vs. 19.5 days, p = 0.039).
Specific anaerobic culturing should be common practice in atypical breast abscesses to confirm Prevotella species. The high recurrence rate emphasizes the need of further research for optimal treatment. Prolonged duration of antibiotics could be considered and amoxicillin/clavulanic acid seems to be the first choice.
Synthetic antimicrobial and antibiofilm peptide (SAAP-148) commits significant antimicrobial activities against antimicrobial resistant (AMR) planktonic bacteria and biofilms. However, SAAP-148 is ...limited by its low selectivity index, i.e., ratio between cytotoxicity and antimicrobial activity, as well as its bioavailability at infection sites. We hypothesized that formulation of SAAP-148 in PLGA nanoparticles (SAAP-148 NPs) improves the selectivity index due to the sustained local release of the peptide. The aim of this study was to investigate the physical and functional characteristics of SAAP-148 NPs and to compare the selectivity index of the formulated peptide with that of the peptide in solution. SAAP-148 NPs displayed favorable physiochemical properties size = 94.1 ± 23 nm, polydispersity index (PDI) = 0.08 ± 0.1, surface charge = 1.65 ± 0.1 mV, and encapsulation efficiency (EE) = 86.7 ± 0.3% and sustained release of peptide for up to 21 days in PBS at 37 °C. The antibacterial and cytotoxicity studies showed that the selectivity index for SAAP-148 NPs was drastically increased, by 10-fold, regarding AMR
and 20-fold regarding AMR
after 4 h. Interestingly, the antibiofilm activity of SAAP-148 NPs against AMR
and
gradually increased overtime, suggesting a dose-effect relationship based on the peptide's in vitro release profile. Using 3D human skin equivalents (HSEs), dual drug SAAP-148 NPs and the novel antibiotic halicin NPs provided a stronger antibacterial response against planktonic and cell-associated bacteria than SAAP-148 NPs but not halicin NPs after 24 h. Confocal laser scanning microscopy revealed the presence of SAAP-148 NPs on the top layers of the skin models in close proximity to AMR
at 24 h. Overall, SAAP-148 NPs present a promising yet challenging approach for further development as treatment against bacterial infections.
Frontotemporal dementia (FTD) is the second most common type of presenile dementia and can be distinguished into various clinical variants. The identification of MAPT and GRN defects and the ...discovery of the TDP-43 protein in FTD have led to the classification of pathologic and genetic subtypes. In addition to these genetic subtypes, there exist familial forms of FTD with unknown genetic defects.
We investigated the frequency, demographic, and clinical data of patients with FTD with a positive family history in our prospective cohort of 364 patients. Genetic analysis of genes associated with FTD was performed on all patients with a positive family history. Immunohistochemical studies were carried out with a panel of antibodies (tau, ubiquitin, TDP-43) in brains collected at autopsy.
In the total cohort of 364 patients, 27% had a positive family history suggestive for an autosomal mode of inheritance, including MAPT (11%) and GRN (6%) mutations. We identified a new Gln300X GRN mutation in a patient with a sporadic FTD. The mean age at onset in GRN patients (61.8 +/- 9.9 years) was higher than MAPT patients (52.4 +/- 5.9 years). In the remaining 10% of patients with suggestive autosomal dominant inheritance, the genetic defect has yet to be identified. Neuropathologically, this group can be distinguished into familial FTLD+MND and familial FTLD-U with hippocampal sclerosis.
Future genetic studies need to identify genetic defects in at least two distinct familial forms of frontotemporal dementia (FTD) with unknown genetic defects: frontotemporal lobe degeneration with ubiquitin-positive inclusions with hippocampal sclerosis and frontotemporal lobe degeneration with motor neuron disease.
While type 2 diabetes is well-known to be associated with poorer cognitive performance, few studies have reported on the association of metabolic syndrome (MetS) and contributing factors, such as ...insulin-resistance -IR), low adiponectin-, and high C-reactive protein (CRP)-levels. We studied whether these factors are related to cognitive function and which of the MetS components are independently associated. The study was embedded in an ongoing family-based cohort study in a Dutch population. All participants underwent physical examinations, biomedical measurements, and neuropsychological testing. Linear regression models were used to determine the association between MetS, HOMA-IR, adiponectin levels, CRP, and cognitive test scores. Cross-sectional analyses were performed in 1,898 subjects (mean age 48 years, 43% men). People with MetS had significantly higher HOMA-IR scores, lower adiponectin levels, and higher CRP levels. MetS and high -IR were associated with poorer executive function in women (P = 0.03 and P = 0.009). MetS and HOMA-IR are associated with poorer executive function in women.
Chronic wound infections colonized by bacteria are becoming more difficult to treat with current antibiotics due to the development of antimicrobial resistance (AMR) as well as biofilm and persister ...cell formation. Synthetic antibacterial and antibiofilm peptide (SAAP)-148 is an excellent alternative for treatment of such infections but suffers from limitations related to its cationic peptidic nature and thus instability and possible cytotoxicity, resulting in a narrow therapeutic window. Here, we evaluated SAAP-148 encapsulation in nanogels composed of octenyl succinic anhydride (OSA)-modified hyaluronic acid (HA) to circumvent these limitations. SAAP-148 was efficiently (>98%) encapsulated with high drug loading (23%), resulting in monodispersed anionic OSA-HA nanogels with sizes ranging 204-253 nm. Nanogel lyophilization in presence of polyvinyl alcohol maintained their sizes and morphology. SAAP-148 was sustainedly released from lyophilized nanogels (37-41% in 72 h) upon reconstitution. Lyophilized SAAP-148-loaded nanogels showed similar antimicrobial activity as SAAP-148 against planktonic and biofilm-residing AMR
and
. Importantly, formulated SAAP-148 showed reduced cytotoxicity against human erythrocytes, primary human skin fibroblasts and human keratinocytes. Additionally, lyophilized SAAP-148-loaded nanogels eradicated AMR
and
colonizing a 3D human epidermal model, without inducing any cytotoxicity in contrast to SAAP-148. These findings indicate that OSA-HA nanogels increase SAAP-148's therapeutic potential for treatment of skin wound infections.
The Netherlands Climate Change Agreement aims to reduce CO
2
emissions and seismic events by halting natural gas usage by 2050. This will require widespread societal acceptance by 90% of households. ...The study investigates the social acceptance of a district heating network (DHN) among social housing tenants in Haarlem, Netherlands. The findings of a survey administered to ninety-five tenants revealed a substantial level of support for the DHN project. A significant portion of respondents, 75%, expressed their approval for the DHN, surpassing the legally required threshold of 70% for implementing building retrofits. Findings imply that although the participants possess an adequate comprehension of the rationale for energy transition, their familiarity with the precise particulars and practical information pertaining to the proposed transition to DHN is inadequate. The level of trust in housing corporations, energy providers, and the municipality is uniformly low, indicating a lack of institutional trust. Generally, the interpersonal trust among tenants tends to be lower than their trust in the broader public, which in turn restricts their capacity for self-organization and exercising influence over energy institutions. Although DHNs are typically regarded as environmentally friendly and secure, there are several challenges that need to be addressed, including the uncertainty about who will cover the costs of transitioning and the doubts surrounding DHN feasibility (warmth and reliability). We suggest implementing interventions to improve tenants' comprehension of the DHN project's particulars (capability), provide practical information regarding costs and feasibility (motivation), and foster trust at both interpersonal and institutional levels (opportunity).
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