Restraint Induces Sickness Responses Independent of Injection with Epstein-Barr Virus (EBV)-Encoded dUTPase

Most adult humans have been infected by Epstein-Barr virus (EBV), a putative cause of chronic fatigue syndrome, and carry latent EBV. The EBV-encoded dUTPase can induce sickness responses in mice and chronic stress exacerbates this response. Because individuals often adapt to chronic stress, we tested the hypothesis that acute restraint stress would potentiate these sickness responses elicited by EBV-encoded dUTPase. Male CD-1 mice were injected daily for one or three days with either saline or EBV-encoded dUTPase. Additionally, mice from each condition were either restrained for three hours daily or left undisturbed during the light phase when mice are inactive. Restraint decreased weight gain during the one- and three-day experiments. Restraint in saline injected mice increased anxiety-like behavior in the open field during the three-day experiment. There were no behavioral differences during the one-day experiment. Restraint stress had no effect when experienced acutely on one day, but did produce a sickness response after three days of exposure regardless of saline or dUTPase injection. In contrast to the effects of chronic stress and EBV-encoded dUTPase on the sickness response, acute stress did not affect sickness responses in association with EBV-encoded dUTPase. Thus, dUTPase does not appear to provoke the same sickness responses after acute stress as compared to chronic stress.

Alpha-synuclein overexpression in the olfactory bulb initiates prodromal symptoms and pathology of Parkinson’s disease

Background:Parkinson’s disease(PD)is a neurodegenerative disease characterized by intraneuronal Lewy Body(LB)aggregates composed of misfolded alpha-synuclein(α-syn).The spread of misfoldedα-syn follows a typical pattern:starting in the olfactory bulb(OB)and the gut,this pathology is followed by the progressive invasion of misfoldedα-syn to the posterior part of the brain.It is unknown whether the administration of human mutant alpha-synuclein(hm-α-syn,a human mutation which occurs in familial PD)into the OB of rats would trigger similarα-syn propagation and subsequently cause pathological changes in broader brain fields associated to PD and establish an animal model of prodromal PD.Methods:hm-α-syn was overexpressed in the OB of rats with an AAV injection.Then motor and non-motor symptoms of the SD rats were tested in different behavioral tasks following the AAV injection.In follow-up studies,pathological mechanisms ofα-syn spread were explored at the histological,biochemical and micro-structure levels.Results:The experimental results indicated that hm-α-syn was overexpressed in the OB 3 weeks after the AAV injection.1)overexpression of the Hm-α-syn in the OB by the AAV injection could transfer to wider adjacent fields beyond the monosynaptic scope.2)The number of tyrosine hydroxylase positive cells body and fibers was decreased in the substantia nigra(SN)12 weeks after AAV injection.This was consistent with decreased levels of the DA neurotransmitter.Importantly,behavioral dysfunctions were found that included olfactory impairment after 3 weeks,motor ability impairment and decreased muscular coordination on a rotarod 6 weeks after the AAV injection.3)The morphological level studies found that the Golgi staining revealed the number of neuronal branches and synapses in the OB,prefrontal cortex(PFC),hippocampus(Hip)and striatum caudate putamen(CPU)were decreased.4)phosphorylatedα-syn,at Ser-129(pSer129),was found to be increased in hm-α-syn injected animals in comparison to controls that overexpressed GFP alone,which was also found in the most of LB stained by the thioflavine S(ThS)in the SN field.5)A marker of autophagy(LC3B)was increased in serval fields,which was colacolizated with a marker of apoptosis in the SN field.Conclusions:These results demonstrate that expression of exogenous mutantα-syn in the OB induces pathological changes in the sensitive brain fields by transferring pathogenicα-syn to adjacent fields.This method may be useful for establishing an animal model of prodromal PD.

Retraction Note: Alpha-synuclein overexpression in the olfactory bulb initiates prodromal symptoms and pathology of Parkinson’s disease

Retraction Note:Translational Neurodegeneration(2018)7:25 https://doi.org/10.1186/s40035-018-0128-6 The Editor-in-Chief has retracted this article.After pub-lication,concerns were raised regarding image overlap across various panels in Fig.8.The authors have stated that incorrect images were used,but have been unable to provide the full raw data.Additionally,the authors could not justify the anesthetic protocol used for rat stereotaxic surgery.The Editor-in-Chief therefore no longer has con-fidence in the presented data and ethics of this article.Author Haichen Niu has stated on behalf of all co-authors that they agree to this retraction.