Acetylcholine (ACh) has a crucial role in the peripheral and central nervous systems. The enzyme choline acetyltransferase (ChAT) is responsible for synthesizing ACh from acetyl-CoA and choline in the cytoplasm and the vesicular acetylcholine transporter (VAChT) uptakes the neurotransmitter into synaptic vesicles. Following depolarization, ACh undergoes exocytosis reaching the synaptic cleft, where it can bind its receptors, including muscarinic and nicotinic receptors. ACh present at the synaptic cleft is promptly hydrolyzed by the enzyme acetylcholinesterase (AChE), forming acetate and choline, which is recycled into the presynaptic nerve terminal by the high-affinity choline transporter (CHT1). Cholinergic neurons located in the basal forebrain, including the neurons that form the nucleus basalis of Meynert, are severely lost in Alzheimer’s disease (AD). AD is the most ordinary cause of dementia affecting 25 million people worldwide. The hallmarks of the disease are the accumulation of neurofibrillary tangles and amyloid plaques. However, there is no real correlation between levels of cortical plaques and AD-related cognitive impairment. Nevertheless, synaptic loss is the principal correlate of disease progression and loss of cholinergic neurons contributes to memory and attention deficits. Thus, drugs that act on the cholinergic system represent a promising option to treat AD patients.

Zika virus (ZIKV) infection is a global health emergency that causes significant neurodegeneration. Neurodegenerative processes may be exacerbated by N-methyl-d-aspartate receptor (NMDAR)-dependent neuronal excitoxicity. Here, we have exploited the hypothesis that ZIKV-induced neurodegeneration can be rescued by blocking NMDA overstimulation with memantine. Our results show that ZIKV actively replicates in primary neurons and that virus replication is directly associated with massive neuronal cell death. Interestingly, treatment with memantine or other NMDAR blockers, including dizocilpine (MK-801), agmatine sulfate, or ifenprodil, prevents neuronal death without interfering with the ability of ZIKV to replicate in these cells. Moreover, in vivo experiments demonstrate that therapeutic memantine treatment prevents the increase of intraocular pressure (IOP) induced by infection and massively reduces neurodegeneration and microgliosis in the brain of infected mice. Our results indicate that the blockade of NMDARs by memantine provides potent neuroprotective effects against ZIKV-induced neuronal damage, suggesting it could be a viable treatment for patients at risk for ZIKV infection-induced neurodegeneration.

Rotating and permanent night shiftwork schedules typically result in acute and sometimes chronic sleep deprivation plus acute and sometimes chronic disruption of the circadian time structure. Immune system processes and functionalities are organized as circadian rhythms, and they are also strongly influenced by sleep status. Sleep is a vital behavioral state of living beings and a modulator of immune function and responsiveness. Shiftworkers show increased risk for developing viral infections due to possible compromise of both innate and acquired immunity responses. Short sleep and sleep loss, common consequences of shiftwork, are associated with altered integrity of the immune system. We discuss the possible excess risk for COVID-19 infection in the context of the common conditions among shiftworkers, including nurses, doctors, and first responders, among others of high exposure to the contagion, of sleep imbalance and circadian disruption.

We observed a marked reduction in GAGs with altered patterns of distribution in the non-inflamed colon of patients with CD. The increase in the synthesis of GAGs observed in the inflamed colon may be a compensatory mechanism for the restoration of the integrity of the intestinal mucosa.

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BackgroundThere are inconsistencies in the literature on reproductive and genital health determinants of human papillomavirus (HPV) infection, the primary cause of cervical cancer. We examined these factors in the Ludwig-McGill Cohort Study, a longitudinal, repeated-measurements investigation on the natural history of HPV infection.MethodsWe analyzed a cohort subset of 1867 women with one complete year of follow-up. We calculated odds ratios (OR) and 95 % confidence intervals (CI) for reproductive and genital health characteristics from questionnaire and laboratory data in relation to 1-year period prevalence of HPV infection. Two outcomes were measured; the first based on phylogenetic grouping of HPV types based on tissue tropism and oncogenicity (Alphapapillomavirus Subgenus 1: species 1, 8, 10 and 13; Subgenus 2: species 5, 6, 7, 9, 11; Subgenus 3: species 3, 4 and 14) and the second based on transient or persistent HPV infections.ResultsLifetime (Subgenus 3 OR = 2.00, CI: 1.23–3.24) and current (Subgenus 3 OR = 2.00, CI: 1.15–3.47) condom use and use of contraceptive injections (Subgenus 1 OR = 1.96, CI: 1.22–3.16, Subgenus 2 OR = 1.34, CI: 1.00–1.79) were associated with increased risk of HPV infection. Intrauterine device use was protective (Subgenus 1 OR = 0.48, CI: 0.30–0.75, Subgenus 2 OR = 0.78, CI: 0.62–0.98). These factors were not associated with persistence of HPV infection. Tampon use, previous gynecologic infections and cervical inflammation were associated with an overall increased risk of HPV infection.ConclusionsCervical HPV infection was associated with reproductive and genital health factors. Further studies are necessary to confirm the low to moderate associations observed.Electronic supplementary materialThe online version of this article (doi:10.1186/s12879-016-1446-x) contains supplementary material, which is available to authorized users.

Huntington's Disease (HD) is an autosomal-dominant neurodegenerative disorder, characterized by involuntary body movements, cognitive impairment, and psychiatric disorder. The metabotropic glutamate receptor 5 (mGluR5) plays an important role in HD and we have recently demonstrated that mGluR5-positive allosteric modulators (PAMs) can ameliorate pathology and the phenotypic signs of a mouse model of HD. In this study, we investigated the molecular mechanisms involved in mGluR5 PAMs effect on memory. Our results demonstrate that subchronic treatment with the mGluR5 PAM VU0409551 was effective in reversing the memory deficits exhibited by BACHD mice, a mouse model for HD. Moreover, VU0409551 treatment stabilized mGluR5 at the cellular plasma membrane of BACHD mice, increasing the expression of several genes important for synaptic plasticity, including c-Fos, brain-derived neurotrophic factor, Arc/Arg3.1, syntaxin 1A, and post-synaptic density-95. In addition, VU0409551 treatment also increased dendritic spine density and maturation and augmented the number of pre-synaptic sites. In conclusion, our results demonstrate that VU0409551 triggered the activation of cell signaling pathways important for synaptic plasticity, enhancing the level of dendritic spine maturation and rescuing BACHD memory impairment. OPEN PRACTICES: Open Science: This manuscript was awarded with the Open Materials Badge. For more information see: https://cos.io/our-services/open-science-badges/.

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