A unique localization of mechanoreceptors in the periodontal tissue of guinea pig teeth

This study describes the unique distribution of Ruffini endings (RE) in the periodontal tissues of the guinea pig teeth with special references to their presence in the enamel-related aspects of the continuously growing incisors and molars. In guinea pig incisors, immunohistochemistry for PGP 9.5 and glia specific S-100 protein revealed a condensed distribution of well-developed RE in the bone-related part of the lingual periodontal ligament as has been reported in many other rodents. In most cases, some RE-like nerve elements characterized by dendritic ramification and rounded terminal Schwann cells were found to be located in the labial, enamel-related regions, where no periodontal ligament-like fiber arrangement was established. In the molar periodontal ligament, well-developed RE-like nerve elements were also distributed in the enamel-related part, but in intimate relation to thick periodontal fiber bundles inserted in the cementum pearls grown on the enamel surface. In some cases, few RE were located in the apical region of the alveolar socket, where no periodontal fiber bundles could be identified. Our data provide the first morphological evidence of the presence of RE-like nerve elements in the enamel-related, fibrous connective tissue of continuously erupting rodent incisors. These data indicate that RE in guinea pig periodontal tissues have variable spatial correlation to the surrounding fibers, implicating their diverse mechanoreceptive properties depending on the anatomical location.     

Enhanced stability and clinical absorption of a form of encapsulated vitamin A for food fortification

Food fortification is an effective strategy to address vitamin A (VitA) deficiency, which is the leading cause of childhood blindness and drastically increases mortality from severe infections. However, VitA food fortification remains challenging due to significant degradation during storage and cooking. We utilized an FDA-approved, thermostable, and pH-responsive basic methacrylate copolymer (BMC) to encapsulate and stabilize VitA in microparticles (MPs). Encapsulation of VitA in VitA-BMC MPs greatly improved stability during simulated cooking conditions and long-term storage. VitA absorption was nine times greater from cooked MPs than from cooked free VitA in rats. In a randomized controlled cross-over study in healthy premenopausal women, VitA was readily released from MPs after consumption and had a similar absorption profile to free VitA. This VitA encapsulation technology will enable global food fortification strategies toward eliminating VitA deficiency.

Vitamin A (VitA) plays an essential role in visual health, immune function, and fetal growth and development (1). VitA deficiency (VAD) arises from diets with insufficient fat-soluble micronutrients (MNs) and is currently estimated as the second most common cause of malnutrition, after iron, globally (2). VAD can lead to xerophthalmia (preventable childhood blindness) and weakened host resistance to infection, which can increase the risk of mortality from infectious diseases, such as measles and COVID-19 (3, 4). The WHO estimated that VAD affected 190 million preschool-age children (33.3% of the preschool-age population) and >19 million pregnant women (15.3% of the pregnant population) globally in the period spanning 1995–2005 (5). The most severely affected regions still reached VAD prevalence levels of 48% in sub-Saharan Africa and 44% in South Asia in children in 2013 (6). To reduce the high burden of VAD, a VitA supplementation program was implemented worldwide in 1990 that distributed high-dose VitA capsules every 4–6 mo to over 80% of the total child population in low-income countries (7). This project effectively reduced all-cause mortality caused by severe VAD by 12% (8). However, progress toward VAD elimination was limited to a rate of improvement of only ~0.3% per year from 1990 to 2007, showing that more impactful strategies are required (9, 10).To raise and maintain serum retinol levels, frequent intake of VitA at physiological doses is proven to be more effective than one or two high doses administered over 6 mo (11). However, VitA food fortification is challenging due to its poor stability, which can lead to poor bioavailability after degradation, and fat solubility, which limits the inclusion of VitA in water-based and dry food matrices (12). To prevent VitA degradation and improve miscibility, VitA has previously been encapsulated within matrices composed of polysaccharides (13), proteins (14), and/or lipids (15); however, these materials provide limited protection during storage and cooking (16 –18) and can take up to 3 h to release in the stomach (19). Poor protection and slow release of VitA prevent effective absorption. Therefore, the ideal microparticle (MP) platform for VitA fortification should meet these criteria: i) protect VitA against degradation during storage and cooking; ii) rapidly release VitA in the gastrointestinal tract with high absorption; and iii) readily mix with various food matrices at a tunable concentration to meet the dynamic needs of the target population.We hypothesized that by encapsulating VitA with a pH-responsive hydrophobic polymer, we could enhance stability during storage and cooking and ensure its rapid release in the gastrointestinal tract for subsequent absorption. A commercially available, FDA-approved basic methacrylate copolymer (BMC), also known as either Eudragit® E PO or GRAS-status Eudraguard®, was identified from our previous work (20). BMC is generally regarded as safe with an acceptable daily intake of 20 mg/kg body weight (21). VitA-encapsulated BMC MPs were prepared by emulsion at the laboratory scale and by a commercial process at the kilogram scale. Our VitA-BMC-S MPs readily mix with flour and bouillon cubes and demonstrate enhanced stability under cooking and long-term storage conditions (over 12 mo) in comparison to a leading commercial encapsulated VitA product. The bioavailability of VitA from VitA-BMC MPs was first demonstrated in a rodent model, resulting in a ninefold increase in the accumulation of VitA in the liver from cooked VitA-BMC MPs, as compared to cooked unencapsulated free VitA. In a human clinical study, the absorption of VitA from bread fortified with VitA-BMC-S MPs was investigated, with or without the codelivery of encapsulated iron sulfate (FeSO₄) and folic acid (FA), MNs that children and pregnant women globally are also often deficient in (22, 23). The results indicate that VitA is readily released and absorbed from VitA-BMC-S MPs, and the codelivery of encapsulated iron and free FA does not influence the absorption of VitA. In total, we demonstrated scalable production of MP-encapsulated VitA with enhanced stability and good bioavailability in humans, which could potentially mitigate the high burden of VAD and be codelivered with other MNs.     

Dothideales

The type specimens or representative specimens of the potentially dothidealean genera Bagnisiella, Botryochora, Coccostromella, Columnosphaeria, Delphinella, Dictyodothis, Discosphaerina, Dothidea, Dothiora, Endodothiora, Jaffuela, Mycoporis, Omphalospora, Pachysacca, Plowrightia, Saccothecium, Stylodothis, Sydowia and Yoshinagaia were examined while, fresh specimens of Aureobasidium pullulans, Dothidea insculpta, Plowrightia ribesia and Saccothecium sepincola were made from Italy and Thailand. An introduction and the history of these genera, their family placement, morphology, and molecular phylogeny are provided. Morphology plus GenBank data are used to provide a systematic treatment of Dothideales. Phylogenetic analysis of LSU, SSU and ITS gene regions was carried out and in the resulting phylogenetic tree the taxa cluster in two clades with high bootstrap support. Clade A comprises Dothideaceae, the family type of Dothideales. The family Dothioraceae is not recognized as a distinct family and is synonymized under Dothideaceae. Neocylindroseptoria is introduced to accommodate Cylindroseptoria pistaciae as it forms a well-supported distinct clade in Dothideaceae. Clade B comprises Aureobasidium, Kabatiella, Pseudoseptoria, Saccothecium and Selenophoma species and Columnosphaeria fagi, for which we propose a new family, Aureobasidiaceae. The recently introduced Sydowia eucalypti also clustered within Clade B and therefore based on morphology and molecular phylogeny a new genus Pseudosydowia is introduced for Sydowia eucalypti. Celosporium laricicola is separated in a distinct clade, and therefore it is placed in Dothideales, genera, incertae sedis. The genera Bagnisiella, Botryochora, Coccostromella, Jaffuela, Lucidascocarpa, Mycoporis, Omphalospora, Pachysacca and Yoshinagaia are excluded from Dothideales and their placements are discussed.     

N-Linked Glycosylation on Anthrax Toxin Receptor 1 Is Essential for Seneca Valley Virus Infection

Seneca Valley virus (SVV) is a picornavirus with potency in selectively infecting and lysing cancerous cells. The cellular receptor for SVV mediating the selective tropism for tumors is anthrax toxin receptor 1 (ANTXR1), a type I transmembrane protein expressed in tumors. Similar to other mammalian receptors, ANTXR1 has been shown to harbor N-linked glycosylation sites in its extracellular vWA domain. However, the exact role of ANTXR1 glycosylation on SVV attachment and cellular entry was unknown. Here we show that N-linked glycosylation in the ANTXR1 vWA domain is necessary for SVV attachment and entry. In our study, tandem mass spectrometry analysis of recombinant ANTXR1-Fc revealed the presence of complex glycans at N166, N184 in the vWA domain, and N81 in the Fc domain. Symmetry-expanded cryo-EM reconstruction of SVV-ANTXR1-Fc further validated the presence of N166 and N184 in the vWA domain. Cell blocking, co-immunoprecipitation, and plaque formation assays confirmed that deglycosylation of ANTXR1 prevents SVV attachment and subsequent entry. Overall, our results identified N-glycosylation in ANTXR1 as a necessary post-translational modification for establishing stable interactions with SVV. We anticipate our findings will aid in selecting patients for future cancer therapeutics, where screening for both ANTXR1 and its glycosylation could lead to an improved outcome from SVV therapy.     

Cryo-EM Structure of a Possum Enterovirus

Enteroviruses (EVs) represent a substantial concern to global health. Here, we present the cryo-EM structure of a non-human enterovirus, EV-F4, isolated from the Australian brushtail possum to assess the structural diversity of these picornaviruses. The capsid structure, determined to ~3 Å resolution by single particle analysis, exhibits a largely smooth surface, similar to EV-F3 (formerly BEV-2). Although the cellular receptor is not known, the absence of charged residues on the outer surface of the canyon suggest a different receptor type than for EV-F3. Density for the pocket factor is clear, with the entrance to the pocket being smaller than for other enteroviruses.