MmuPV1 E7's interaction with PTPN14 delays Epithelial differentiation and contributes to virus-induced skin disease.

Human papillomaviruses (HPVs) contribute to approximately 5% of all human cancers. Species-specific barriers limit the ability to study HPV pathogenesis in animal models. Murine papillomavirus (MmuPV1) provides a powerful tool to study the roles of papillomavirus genes in pathogenesis arising from a natural infection. We previously identified Protein Tyrosine Phosphatase Non-Receptor Type 14 (PTPN14), a tumor suppressor targeted by HPV E7 proteins, as a putative cellular target of MmuPV1 E7. Here, we confirmed the MmuPV1 E7-PTPN14 interaction. Based on the published structure of the HPV18 E7/PTPN14 complex, we generated a MmuPV1 E7 mutant, E7K81S, that was defective for binding PTPN14. Wild-type (WT) and E7K81S mutant viral genomes replicated as extrachromosomal circular DNAs to comparable levels in mouse keratinocytes. E7K81S mutant virus (E7K81S MmuPV1) was generated and used to infect FoxN/Nude mice. E7K81S MmuPV1 caused neoplastic lesions at a frequency similar to that of WT MmuPV1, but the lesions arose later and were smaller than WT-induced lesions. The E7K81S MmuPV1-induced lesions also had a trend towards a less severe grade of neoplastic disease. In the lesions, E7K81S MmuPV1 supported the late (productive) stage of the viral life cycle and promoted E2F activity and cellular DNA synthesis in suprabasal epithelial cells to similar degrees as WT MmuPV1. There was a similar frequency of lateral spread of infections among mice infected with E7K81S or WT MmuPV1. Compared to WT MmuPV1-induced lesions, E7K81S MmuPV1-induced lesions had a significant expansion of cells expressing differentiation markers, Keratin 10 and Involucrin. We conclude that an intact PTPN14 binding site is necessary for MmuPV1 E7's ability to contribute to papillomavirus-induced pathogenesis and this correlates with MmuPV1 E7 causing a delay in epithelial differentiation, which is a hallmark of papillomavirus-induced neoplasia.

Frequency and Geographic Distribution of Borrelia miyamotoi, Borrelia burgdorferi, and Babesia microti Infections in New England Residents.

BACKGROUND: Borrelia miyamotoi is a relapsing fever spirochete that relatively recently has been reported to infect humans. It causes an acute undifferentiated febrile illness that can include meningoencephalitis and relapsing fever. Like Borrelia burgdorferi, it is transmitted by Ixodes scapularis ticks in the northeastern United States and by Ixodes pacificus ticks in the western United States. Despite reports of clinical cases from North America, Europe, and Asia, the prevalence, geographic range, and pattern of expansion of human B. miyamotoi infection are uncertain. To better understand these characteristics of B. miyamotoi in relation to other tickborne infections, we carried out a cross-sectional seroprevalence study across New England that surveyed B. miyamotoi, B. burgdorferi, and Babesia microti infections. METHODS: We measured specific antibodies against B. miyamotoi, B. burgdorferi, and B. microti among individuals living in 5 New England states in 2018. RESULTS: Analysis of 1153 serum samples collected at 11 catchment sites showed that the average seroprevalence for B. miyamotoi was 2.8% (range, 0.6%-5.2%), which was less than that of B. burgdorferi (11.0%; range, 6.8%-15.6%) and B. microti (10.0%; range, 6.5%-13.6%). Antibody screening within county residence in New England showed varying levels of seroprevalence for these pathogens but did not reveal a vectoral geographical pattern of distribution. CONCLUSIONS: Human infections caused by B. miyamotoi, B. burgdorferi, and B. microti are widespread with varying prevalence throughout New England.

Human-Biting Ixodes scapularis Submissions to a Crowd-Funded Tick Testing Program Correlate with the Incidence of Rare Tick-Borne Disease: A Seven-Year Retrospective Study of Anaplasmosis and Babesiosis in Massachusetts.

Tick-borne zoonoses pose a serious burden to global public health. To understand the distribution and determinants of these diseases, the many entangled environment-vector-host interactions which influence risk must be considered. Previous studies have evaluated how passive tick testing surveillance measures connect with the incidence of human Lyme disease. The present study sought to extend this to babesiosis and anaplasmosis, two rare tick-borne diseases. Human cases reported to the Massachusetts Department of Health and submissions to TickReport tick testing services between 2015 and 2021 were retrospectively analyzed. Moderate-to-strong town-level correlations using Spearman's Rho (ρ) were established between Ixodes scapularis submissions (total, infected, adult, and nymphal) and human disease. Aggregated ρ values ranged from 0.708 to 0.830 for anaplasmosis and 0.552 to 0.684 for babesiosis. Point observations maintained similar patterns but were slightly weaker, with mild year-to-year variation. The seasonality of tick submissions and demographics of bite victims also correlated well with reported disease. Future studies should assess how this information may best complement human disease reporting and entomological surveys as proxies for Lyme disease incidence in intervention studies, and how it may be used to better understand the dynamics of human-tick encounters.

Recent advances in infectious disease research using cryo-electron tomography.

With the increasing spread of infectious diseases worldwide, there is an urgent need for novel strategies to combat them. Cryogenic sample electron microscopy (cryo-EM) techniques, particularly electron tomography (cryo-ET), have revolutionized the field of infectious disease research by enabling multiscale observation of biological structures in a near-native state. This review highlights the recent advances in infectious disease research using cryo-ET and discusses the potential of this structural biology technique to help discover mechanisms of infection in native environments and guiding in the right direction for future drug discovery.

Vesicular zinc regulates the Ca2+ sensitivity of a subpopulation of presynaptic vesicles at hippocampal mossy fiber terminals.

Synaptic vesicles segregate into functionally diverse subpopulations within presynaptic terminals, yet there is no information about how this may occur. Here we demonstrate that a distinct subgroup of vesicles within individual glutamatergic, mossy fiber terminals contain vesicular zinc that is critical for the rapid release of a subgroup of synaptic vesicles during increased activity in mice. In particular, vesicular zinc dictates the Ca(2+) sensitivity of release during high-frequency firing. Intense synaptic activity alters the subcellular distribution of zinc in presynaptic terminals and decreases the number of zinc-containing vesicles. Zinc staining also appears in endosomes, an observation that is consistent with the preferential replenishment of zinc-enriched vesicles by bulk endocytosis. We propose that functionally diverse vesicle pools with unique membrane protein composition support different modes of transmission and are generated via distinct recycling pathways.

Disubstituted 1,8-diamidonaphthalene ligands as a flexible, responsive, and reactive framework for tantalum complexes.

Deprotonated N,N'-disubstituted 1,8-diaminonaphthalenes (R(2)DAN(2-); R = (CH(3))(2)CH, C(6)H(5), 3,5-Me(2)C(6)H(3)) were incorporated into Ta(V) complexes employing two methods. The direct proton transfer reaction of the parent amine, 1,8-(RNH)(2)C(10)H(6), with TaMe(3)Cl(2) led to elimination of methane and formation of TaCl(3)[1,8-(RN)(2)C(10)H(6)] (1, 2). Reaction of the dilithiated amido species, Li(2)R(2)DAN, with TaMe(3)Cl(2) or [Ta(NEt(2))(2)Cl(3) ] yielded TaMe(3)[1,8-(RN)(2)C(10)H(6)] (3, 4) and TaCl(NEt(2))(2)[1,8-(RN)(2)C(10)H(6)] (5, 6), respectively. X-ray structural studies of these complexes revealed the flexible coordination behavior of R(2)DAN(2-) by demonstrating that the ligand bonded to Ta with a coordination array dependent on the identity of the other ligands bonded to tantalum. Computational analysis of these complexes confirmed that the energetic components for binding of R(2)DAN(2-) to these TaX(3)(2+) fragments were dominated by the electronic features of the metal fragment. Chemical transformations of the bound ligand were evaluated by reaction of compounds 5 and 6 with LiNMe(2) and MeLi. Simple metathesis products Ta(NEt(2))(2)NMe(2)[1,8-((i)PrN)(2)C(10)H(6)] (R = (i)Pr 7, R = 3,5-Me(2)(C(6)H(3)) 8) were obtained from reactions with LiNMe(2). In contrast, when the R group of the DAN ligand was (i)Pr, reaction with MeLi ultimately led to activation of the isopropyl group and formation of the metallaziridine [kappa(3)-(Me(2)CN)((i)PrN)C(10)H(6)]Ta(NEt(2))(2) (9) species via the elimination of methane.

ß cell responses to inflammation.

BACKGROUND: The extended and clinically silent progression of Type 1 diabetes (T1D) creates a challenge for clinical interventions and for understanding the mechanisms that underlie its pathogenesis. Over the course of the development of Type 1 diabetes, studies in animal models and of human tissues have identified adaptive changes in ß cells that may affect their immunogenicity and susceptibility to killing. Loss of ß cells has traditionally been identified by impairment in function but environmental factors may affect these measurements. SCOPE OF REVIEW: In this review we will highlight features of ß cell responses to cell death, particularly in the setting of inflammation, and focus on methods of detecting ß cell death in vivo. MAJOR CONCLUSIONS: We developed an assay to measure ß cell death in vivo by detecting cell free DNA with epigenetic modifications of the INS gene that are found in ß cells. This assay has robust technical performance and identifies killing in individuals at very high risk for disease, but its ability to identify ß cell killing in at-risk relatives is limited by the short half-life of the cell free DNA and the need for repeated sampling over an extended course. We present results from the Diabetes Prevention Trial-1 using this assay. In addition, recent studies have identified cellular adaptations in some ß cells that may avoid killing but impair metabolic function. Cells with these characteristics may aggravate the autoimmune response but also may represent a potentially recoverable source of functional ß cells.

Exercise training attenuated the PKB and GSK-3 dephosphorylation in the myocardium of ZDF rats.

Cardiac dysfunction is a severe secondary effect of Type 2 diabetes. Recruitment of the protein kinase B/glycogen synthase kinase-3 pathway represents an integral event in glucose homeostasis, albeit its regulation in the diabetic heart remains undefined. Thus the following study tested the hypothesis that the regulation of protein kinase B/glycogen synthase kinase-3 was altered in the myocardium of the Zucker diabetic fatty rat. Second, exercise has been shown to improve glucose homeostasis, and, in this regard, the effect of swimming training on the regulation of protein kinase B/glycogen synthase kinase-3 in the diabetic rat heart was examined. In the sedentary Zucker diabetic fatty rats, glucose levels were elevated, and cardiac glycogen content increased, compared with wild type. A 13-wk swimming regimen significantly reduced plasma glucose levels and cardiac glycogen content and partially normalized protein kinase B-serine473, protein kinase B-threonine308, and glycogen synthase kinase-3alpha phosphorylation in Zucker diabetic fatty rats. In conclusion, hyperglycemia and increased cardiac glycogen content in the Zucker diabetic fatty rats were associated with dysregulation of protein kinase B/glycogen synthase kinase-3 phosphorylation. These anomalies in the Zucker diabetic fatty rat were partially normalized with swimming. These data support the premise that exercise training may protect the heart against the deleterious consequences of diabetes.

Preserved LTP and water maze learning in hyperglycaemic-hyperinsulinemic ZDF rats.

Previous investigations have demonstrated that cognitive deficits as well as hippocampal dysfunctions are generated in animals presenting manifestations of Type 1 diabetes (T1D) mellitus. The present study examined whether such deficits can also be reproduced in the Zucker Diabetic Fatty (ZDF) rats after they developed symptoms of Type 2 diabetes (T2D). Learning and memory assessments were performed using the Morris water maze 5 weeks after the animals presented symptoms of Type 1 diabetes for Experiment 1 (Exp 1) and after 8 weeks for Experiment 2 (Exp 2). Testing in the water maze revealed that ZDF rats learned the task normally, although control rats were found to swim significantly faster after 5 or 8 weeks of untreated diabetes. From an electrophysiological perspective, we observed that the integrity of synaptic function was also preserved in ZDF rats as no alterations in long-term potentiation (LTP) were observed in the area CA1 of hippocampal slices. It is concluded that hyperglycaemia is not the only factor influencing water maze learning and LTP in this animal model of Type 2 diabetes (T2D). The experiments suggest that the resistance of ZDF rats to cognitive and electrophysiological dysfunctions might be related to the protective action of hyperinsulinemia. Indeed, measurements of the plasma insulin level at the end of testing were significantly superior in ZDF rats in comparison to control rats.

Extracellular chelation of zinc does not affect hippocampal excitability and seizure-induced cell death in rats.

In the nervous system, zinc can influence synaptic responses and at extreme concentrations contributes to epileptic and ischaemic neuronal injury. Zinc can originate from synaptic vesicles, the extracellular space and from intracellular stores. In this study, we aimed to determine which of these zinc pools is responsible for the increased hippocampal excitability observed in zinc-depleted animals or following zinc chelation. Also, we investigated the source of intracellularly accumulating zinc in vulnerable neurons. Our data show that membrane-permeable and membrane-impermeable zinc chelators had little or no effect on seizure activity in the CA3 region. Furthermore, extracellular zinc chelation could not prevent the accumulation of lethal concentrations of zinc in dying neurons following epileptic seizures. At the electron microscopic level, zinc staining significantly increased at the presynaptic membrane of mossy fibre terminals in kainic acid-treated animals. These data indicate that intracellular but not extracellular zinc chelators could influence neuronal excitability and seizure-induced zinc accumulation observed in the cytosol of vulnerable neurons.

The rapid onset of hyperglycaemia in ZDF rats was associated with a widespread alteration of metabolic proteins implicated in glucose metabolism in the heart.

The present study tested the hypothesis that the phosphorylation and regulation of metabolic proteins implicated in glucose homeostasis were impaired in the heart of the type 2 diabetic Zucker-diabetic-fatty (ZDF) rat model. The onset of hyperglycaemia in ZDF rats was not uniform, instead it either progressed rapidly (3-4 weeks) or was delayed (6-8 weeks). In both the early and late onset hyperglycaemic ZDF rats, AMPKalpha Thr172 phosphorylation in the heart was significantly decreased. In the early onset hyperglycaemic ZDF rats, PKB Ser473 phosphorylation was reduced, whereas Thr308 phosphorylation was significantly increased. In the late onset hyperglycaemic ZDF rats, PKB Ser473 phosphorylation was unchanged, but Thr308 phosphorylation remained elevated. Cardiac GLUT4 protein and mRNA expression were significantly reduced in the early onset hyperglycaemic ZDF rats, whereas increased protein expression was observed in the late onset hyperglycaemic ZDF rats. In conclusion, the present study has demonstrated that following a more rapid onset of hyperglycaemia, the type 2 diabetic heart is more prone to alterations in the signaling proteins implicated in glucose metabolism.