Characterization of Extracellular Zinc-mediated Inhibition of Human HRVs

As the predominant etiological agent of the “common cold,” human rhinoviruses (HRVs) have a substantial economic impact and contribute to severe respiratory complications in immune compromised and asthmatic individuals. While zinc (Zn) ions have been previously shown to have an inhibitory effect upon HRVs, clinical trials using Zn products have produced conflicting results, and the lack of a known mechanism of Zn inhibition has stymied therapeutic development. Previous research on the potential anti-rhinoviral mechanism of Zn compounds focused upon intracellular processes. My research has demonstrated that extracellular exposure of both major and minor group HRVs to Zn chloride (ZnCl) and Zn gluconate (ZnG) is sufficient to profoundly decrease the infectivity of the viral population. The infectivity of other representatives of the picornavirus family is not decreased in the presence of Zn compounds, suggesting that Zn-mediated virus inhibition is HRV specific. Other metal cations similar to Zn have not demonstrated HRV inhibition. Zn-based inhibition of HRVs is independent of pH, is effected within minutes and is dampened at lower temperatures. Furthermore, whereas EDTA can chelate Zn to prevent inhibition of HRVs, it cannot reverse the Zn-based inhibition after it has occurred. In addition, infectious center plaque assay (ICPA) and competition assay data suggest that this mechanism is not related to the virus-cellular receptor interaction, and that Zn-treated viral capsids are still able to interact with receptor binding sites. Moreover, cultivation and analysis of Zn-resistant HRV1A isolates suggests that genomic discrepancies in the VP1 capsid protein play a role in the mechanism of Zn inhibition. 3 distinct point mutations that conferred amino acid substitutions were found in multiple Zn-resistant isolates. Located in the exterior B-C loop and the interior viral-genome neighboring region of VP1, 2 out of the 3 mutations resulted in a dramatic amino-acid polarity change which likely has the chemical consequence of effectively repelling 2+ cations such as Zn. Furthermore, northern blot analysis reveals that Zn-treated HRVs exhibit an increased susceptibility to genomic RNA degradation, a phenomena that may be facilitated by a Zn-mediated cleavage of viral RNA within the viral capsid. Zn complexed to chelating compounds Hinokital (HK), Pyrithione (PT) and Pyrrolidine Dithiocarbamate (PDTC) also demonstrated extracellular HRV inhibition, with the sequence and ratio of exposure, or precipitate formation, modulating the outcome. It is not clear if these compounds augment the antiviral mechanism of Zn alone, or initiate a distinct antiviral mechanism unrelated to that performed by Zn in isolation. Based upon the data presented here, Zn mediated inhibition of HRVs can occur in a cell-independent, extracellular manner to degrade viral RNA and thereby abrogate viral infectivity. This mechanism may provide novel insight into further therapeutic development of these compounds or template the design of future small molecule therapeutics against these and similar viruses

Lipid Metabolites Enhance Secretion Acting on SNARE Microdomains and Altering the Extent and Kinetics of Single Release Events in Bovine Adrenal Chromaffin Cells

Lipid molecules such as arachidonic acid (AA) and sphingolipid metabolites have been implicated in modulation of neuronal and endocrine secretion. Here we compare the effects of these lipids on secretion from cultured bovine chromaffin cells. First, we demonstrate that exogenous sphingosine and AA interact with the secretory apparatus as confirmed by FRET experiments. Examination of plasma membrane SNARE microdomains and chromaffin granule dynamics using total internal reflection fluorescent microscopy (TIRFM) suggests that sphingosine production promotes granule tethering while arachidonic acid promotes full docking. Our analysis of single granule release kinetics by amperometry demonstrated that both sphingomyelinase and AA treatments enhanced drastically the amount of catecholamines released per individual event by either altering the onset phase of or by prolonging the off phase of single granule catecholamine release kinetics. Together these results demonstrate that the kinetics and extent of the exocytotic fusion pore formation can be modulated by specific signalling lipids through related functional mechanisms

Impaired Carbohydrate Digestion and Transport and Mucosal Dysbiosis in the Intestines of Children with Autism and Gastrointestinal Disturbances

Gastrointestinal disturbances are commonly reported in children with autism, complicate clinical management, and may contribute to behavioral impairment. Reports of deficiencies in disaccharidase enzymatic activity and of beneficial responses to probiotic and dietary therapies led us to survey gene expression and the mucoepithelial microbiota in intestinal biopsies from children with autism and gastrointestinal disease and children with gastrointestinal disease alone. Ileal transcripts encoding disaccharidases and hexose transporters were deficient in children with autism, indicating impairment of the primary pathway for carbohydrate digestion and transport in enterocytes. Deficient expression of these enzymes and transporters was associated with expression of the intestinal transcription factor, CDX2. Metagenomic analysis of intestinal bacteria revealed compositional dysbiosis manifest as decreases in Bacteroidetes, increases in the ratio of Firmicutes to Bacteroidetes, and increases in Betaproteobacteria. Expression levels of disaccharidases and transporters were associated with the abundance of affected bacterial phylotypes. These results indicate a relationship between human intestinal gene expression and bacterial community structure and may provide insights into the pathophysiology of gastrointestinal disturbances in children with autism

Stimulating a Canadian narrative for climate

ABSTRACT: This perspective documents current thinking around climate actions in Canada by synthesizing scholarly proposals made by Sustainable Canada Dialogues (SCD), an informal network of scholars from all 10 provinces, and by reviewing responses from civil society representatives to the scholars' proposals. Motivated by Canada's recent history of repeatedly missing its emissions reduction targets and failing to produce a coherent plan to address climate change, SCD mobilized more than 60 scholars to identify possible pathways towards a low-carbon economy and sustainable society and invited civil society to comment on the proposed solutions. This perspective illustrates a range of Canadian ideas coming from many sectors of society and a wealth of existing inspiring initiatives. Solutions discussed include climate change governance, low-carbon transition, energy production, and consumption. This process of knowledge synthesis/creation is novel and important because it provides a working model for making connections across academic fields as well as between academia and civil society. The process produces a holistic set of insights and recommendations for climate change actions and a unique model of engagement. The different voices reported here enrich the scope of possible solutions, showing that Canada is brimming with ideas, possibilities, and the will to act

Specialized mechanoreceptor systems in rodent glabrous skin

Rodents use their forepaws to actively interact with their tactile environment. Studies on the physiology and anatomy of glabrous skin that makes up the majority of the forepaw are almost non-existent in themouse.Here we developed a preparation to record from single sensory fibres of the forepaw and compared anatomical and physiological receptor properties to those of the hindpaw glabrous and hairy skin. We found that the mouse forepaw skin is equipped with a very high density of mechanoreceptors; >3 times more than hindpaw glabrous skin. In addition, rapidly adapting mechanoreceptors that innervate Meissner’s corpuscles of the forepaw were severalfold more sensitive to slowly moving mechanical stimuli compared to their counterparts in the hindpaw glabrous skin. All other mechanoreceptor types as well as myelinated nociceptors had physiological properties that were invariant regardless of which skin area they occupied. We discovered a novel D-hair receptor innervating a small group of hairs in the middle of the hindpaw glabrous skin in mice. These glabrous skin D-hair receptors were direction sensitive albeit with an orientation sensitivity opposite to that described for hairy skin D-hair receptors. Glabrous skin hairs do not occur in all rodents, but are present in North American and African rodent species that diverged more than 65 million years ago. The function of these specialized hairs is unknown, but they are nevertheless evolutionarily very ancient. Our study reveals novel physiological specializations of mechanoreceptors in the glabrous skin that likely evolved to facilitate tactile exploration.Supplementary Video 1. A series of confocal microscopy images (multiple z‐stacks) of one entire footpad showing NF200‐positive fibres innervating Meissner's corpuscles.Supplementary Video 2. The experimental set‐up for recording directional sensitivity of glabrous D‐hair receptors. The single hairs were moved within a glass capillary and the corresponding single‐unit firing behaviour is shown in response to four axes of movement.Supplementary Video 3. Maximum intensity projection of tdTomato labelled endings around a single glabrous hair follicle.Grants from the Deutsche Forschungsgemeinschaft (SFB 665 Project B6 to G.R.L.) and a European Research Council advanced grant (ERC 294678).https://physoc.onlinelibrary.wiley.com/journal/14697793am2019Zoology and Entomolog

Assessment of Polymicrobial Infections in Ticks in New York State

Ixodes scapularis ticks are clinically important hematophagous vectors. A single tick bite can lead to a polymicrobial infection. We determined the prevalence of polymicrobial infection with Borrelia burgdorferi, Anaplasma phagocytophilum, Babesia microti, Borrelia miyamotoi, and Powassan virus in 286 adult ticks from the two counties in New York State where Lyme disease is endemic, utilizing a MassTag multiplex polymerase chain reaction assay. Seventy-one percent of the ticks harbored at least one organism; 30% had a polymicrobial infection. Infections with three microbes were detected in 5% of the ticks. One tick was infected with four organisms. Our results show that coinfection is a frequent occurrence in ticks in the two counties surveyed

Stimulating a Canadian narrative for climate

This perspective documents current thinking around climate actions in Canada by synthesizing scholarly proposals made by Sustainable Canada Dialogues (SCD), an informal network of scholars from all 10 provinces, and by reviewing responses from civil society representatives to the scholars’ proposals. Motivated by Canada’s recent history of repeatedly missing its emissions reduction targets and failing to produce a coherent plan to address climate change, SCD mobilized more than 60 scholars to identify possible pathways towards a low-carbon economy and sustainable society and invited civil society to comment on the proposed solutions. This perspective illustrates a range of Canadian ideas coming from many sectors of society and a wealth of existing inspiring initiatives. Solutions discussed include climate change governance, low-carbon transition, energy production, and consumption. This process of knowledge synthesis/creation is novel and important because it provides a working model for making connections across academic fields as well as between academia and civil society. The process produces a holistic set of insights and recommendations for climate change actions and a unique model of engagement. The different voices reported here enrich the scope of possible solutions, showing that Canada is brimming with ideas, possibilities, and the will to act