ABSTRACT
Extracellular vesicles (EV), key players in cell-to-cell communication, may contribute to disease propagation in several neurodegenerative diseases, including Alzheimer's disease (AD), by favoring the dissemination of neurotoxic proteins within the brain. Interestingly, growing evidence supports the role of herpes simplex virus type 1 (HSV-1) infection in the pathogenesis of AD. Here, we investigated whether HSV-1 infection could promote the spread of phosphorylated tau (ptau) among neurons via EV. We analyzed the ptau species that were secreted via EV following HSV-1 infection in neuroblastoma cells and primary neurons, focusing particularly on T205, T181, and T217, the phosphorylation sites mainly associated with AD. Moreover, by overexpressing human tau tagged with GFP (htauGFP), we found that recipient tau knockout (KO) neurons uptook EV that are loaded with HSV-1-induced phtauGFP. Finally, we exploited an in vivo model of acute infection and assessed that cerebral HSV-1 infection promotes the release of ptau via EV in the brain of infected mice. Overall, our data suggest that, following HSV-1 infection, EV play a role in tau spreading within the brain, thus contributing to neurodegeneration.IMPORTANCEHerpes simplex virus type 1 (HSV-1) infection that reaches the brain has been repeatedly linked with the appearance of the pathognomonic markers of Alzheimer's disease (AD), including accumulation of amyloid beta and hyperphosphorylated tau proteins, and cognitive deficits. AD is a multifactorial neurodegenerative disease representing the most common form of dementia in the elderly, and no cure is currently available, thus prompting additional investigation on potential risk factors and pathological mechanisms. Here, we demonstrate that the virus exploits the extracellular vesicles (EV) to disseminate phosphorylated tau (ptau) among brain cells. Importantly, we provide evidence that the HSV-1-induced EV-bearing ptau can be undertaken by recipient neurons, thus likely contributing to misfolding and aggregation of native tau, as reported for other AD models. Hence, our data highlight a novel mechanism exploited by HSV-1 to propagate tau-related damage in the brain.
ABSTRACT
AIM: Insulin sensitivity is ~40% lower in women with polycystic ovary syndrome (PCOS) than in controls. We tested the hypothesis that 5 weeks of electroacupuncture treatment improves glucose regulation and androgen levels in overweight/obese women with PCOS. MATERIAL AND METHODS: Seventeen women with PCOS, aged 18 to 38 years, with a body mass index (BMI) ≥25 kg/m2 and diagnosed with PCOS were included in this experimental and feasibility study and subjected to five weeks of electroacupuncture treatments three times/week. The primary outcome was changes in whole-body glucose homeostasis measured by euglycemic hyperinsulinemic clamp before and after the intervention. Secondary outcome were changes in HbA1c, circulating catecholamines, adipocyte size and adipose tissue expression of sex steroids and nerve growth factor (NGF). RESULTS: No significant change in glucose homeostasis was observed, but HbA1c decreased by 9.5% (p = 0.004), circulating testosterone decreased by 22% (p = 0.0007) and dihydrotestosterone decreased by 12% (p = 0.007). The two vagal activity markers of plasma serotonin levels and the dopamine metabolite homovanillic acid decreased by 21% (p = 0.027) and 20% (p = 0.011), respectively. Adipose tissue concentrations of testosterone decreased by 18% (p = 0.049), and androstenedione decreased by 13% (p = 0.035), and mature NGF/proNGF ratio, a marker of sympathetic activity, increased (p = 0.04). These changes occurred without changes in anthropometrics. CONCLUSION: Five weeks of electroacupuncture treatment improves HbA1c and circulating and adipose tissue androgens in women with PCOS. This effect is mediated, at least in part, via modulation of vagal activity and adipose tissue sympathetic activity. Based on these findings, we have recently initiated a randomized controlled study (NTC02647827).
ABSTRACT
Surveys aimed at evaluating the incidence and severity of a new disease that developed in greenhouses cultivated with tomato (Solanum lycopersicum L.) were performed during 2009 and 2010 in greenhouses of the cultivars Elpida (Enza Zaden) and Colibrí (Clause) in an area of tomato production known as the Cinturón Hortícola de La Plata (the "horticultural belt of La Plata"). The disease had a 100% prevalence and 90% incidence within the ten 250 m2 greenhouses that were monitored in 2009, 2010, and 2011. In two consecutive assays, severity was 40%. The wide distribution of the disease suggests that the tomato hybrids under use lack resistance genes. The upper surface of diseased leaves had pale green to yellowish, 1- to 1.5-cm spots with undefined margins that progressed to a yellowish brown color, while on the lower side they had pale brown to brown sporulation of fungal conidiophores and conidia. Monosporic fungal cultures were obtained by needle transfer of conidia from sporulating areas of leaves (n = 20) to water agar medium. On 2% potato dextrose agar (PDA) the colonies of the relatively low growing fungus were strongly pigmented, greenish grey, and black on the reverse of the plate. The fungus developed one-celled, pale olive-green, ovoid conidia on long, branched chains, which arose from pigmented conidiophores, corresponding to the description of Cladosporium fulvum made by Joosten and de Wit (1). The identity of two isolates was confirmed by amplifying the 580-bp ITS sequences by means of primers ITS4 (5'-TCCTCCGCTTATTGATATGC-3') and ITS5 (5'-GAATTCGGAAGTAAAAGTCGTAACAAGG-3') (ITS sequence Race 0 JQ768324.1 and Race 2 JQ768325.1). Both were 100% homologous to the ITS sequences of C. fulvum strains ATCC44962 (AF393700) and ATCC44960 (AF303701). Monosporic cultures of four isolates, each obtained from leaves collected from different plants growing in different greenhouses, were inoculated on a set of differential genotypes of tomato: cvs. Moneymaker, Cf-0, Cf-2, Cf-4, Cf-5, and Cf-9 (kindly provided by the Laboratory of Phytopathology of Wageningen University). Three plants of each tomato genotype at the 5 to 6 true leaf stage were inoculated by spraying a 105 conidia/ml conidial suspension of C. fulvum on the leaflets of the 3rd and 4th leaf. Inoculation tests of each isolate were repeated at least twice. After inoculation, plants were grown in the greenhouse at 13 to 29°C and 99% relative humidity. However, for the first 20 h after inoculation, plants were kept in the dark. They were regularly monitored and were scored as resistant or susceptible at 20 days after inoculation. Susceptible genotypes developed pale green to yellow spots on the abaxial leaf surface and pale brown to olivaceous brown sporulation on the adaxial side. Plants lacking disease symptoms were considered resistant. Inoculated fungi were reisolated from infected tissue and the identity of the fungal cultures confirmed based on morphology and the ITS sequence. Based on the reactions of the tomato genotypes, two races were identified, three isolates (race 2) developed symptoms only in cv. MM Cf-2, while the remaining isolate (race 0) provoked symptoms only in cv. MM Cf-0. Reference: (1) M. Joosten and P. de Wit. Annu Rev Phytopathol. 37:335, 1999.