Oral P. gingivalis impairs gut permeability and mediates immune responses associated with neurodegeneration in LRRK2 R1441G mice.

BACKGROUND: The R1441G mutation in the leucine-rich repeat kinase 2 (LRRK2) gene results in late-onset Parkinson's disease (PD). Peripheral inflammation and gut microbiota are closely associated with the pathogenesis of PD. Chronic periodontitis is a common type of peripheral inflammation, which is associated with PD. Porphyromonas gingivalis (Pg), the most common bacterium causing chronic periodontitis, can cause alteration of gut microbiota. It is not known whether Pg-induced dysbiosis plays a role in the pathophysiology of PD. METHODS: In this study, live Pg were orally administrated to animals, three times a week for 1 month. Pg-derived lipopolysaccharide (LPS) was used to stimulate mononuclear cells in vitro. The effects of oral Pg administration on the gut and brain were evaluated through behaviors, morphology, and cytokine expression. RESULTS: Dopaminergic neurons in the substantia nigra were reduced, and activated microglial cells were increased in R1441G mice given oral Pg. In addition, an increase in mRNA expression of tumor necrosis factor (TNF-α) and interleukin-1ß (IL-1ß) as well as protein level of α-synuclein together with a decrease in zonula occludens-1 (Zo-1) was detected in the colon in Pg-treated R1441G mice. Furthermore, serum interleukin-17A (IL-17A) and brain IL-17 receptor A (IL-17RA) were increased in Pg-treated R1441G mice. CONCLUSIONS: These findings suggest that oral Pg-induced inflammation may play an important role in the pathophysiology of LRRK2-associated PD.

Lack of evidence for Nocardia asteroides in brain specimens from Lewy body-containing disorders.

Previous studies have suggested that Nocardia asteroides may play a role in the pathogenesis of Parkinson's disease (PD), including the production of Lewy bodies, the inclusion bodies present in this disorder. This study explored the possible connection between Nocardia and two Lewy body-containing disorders, PD and dementia with Lewy bodies (DLB). Substantia nigra specimens from individuals with PD, DLB, other neurodegenerative disorders, and normal subjects were evaluated for nocardial infection by in situ hybridization, PCR, and Gram staining. Brain specimens from a cynomolgus monkey experimentally infected with N. asteroides for 48 h served as the controls for in situ hybridization and Gram staining, and a nocardial pellet was the PCR control. The organism was detected by in situ hybridization and Gram stain in the experimentally infected monkey brain, and by PCR from the nocardial pellet. However, in situ hybridization reactivity was detected in only three of the 125 human brain specimens (2.4%; one case each of PD, DLB, and Alzheimer's disease), and none of the specimens was positive for Nocardia by PCR or Gram staining. These findings do not support an association of Nocardia with Lewy body-containing disorders.

Nocardia otitidiscaviarum (GAM-5) induces parkinsonian-like alterations in mouse.

Parkinson's disease, a major neurodegenerative disorder in humans whose etiology is unknown, may be associated with some environmental factors. Nocardia otitidiscaviarum (GAM-5) isolated from a patient with an actinomycetoma produced signs similar to Parkinson's disease following iv injection into NMRI mice. NMRI mice were infected intravenously with a non-lethal dose of 5 x 10(6) colony forming units of N. otitidiscaviarum (GAM-5). Fourteen days after bacterial infection, most of the 60 mice injected exhibited parkinsonian features characterized by vertical head tremor, akinesia/bradykinesia, flexed posture and postural instability. There was a peak of nocardial growth in the brain during the first 24 h followed by a decrease, so that by 14 days nocardiae could no longer be cultured. At 24 h after infection, Gram staining showed nocardiae in neurons in the substantia nigra and occasionally in the brain parenchyma in the frontal and parietal cortex. At 21 days post-infection, tyrosine hydroxylase immunolabeling showed a 58% reduction of tyrosine hydroxylase in the substantia nigra, and a 35% reduction of tyrosine hydroxylase in the ventral tegmental region. Dopamine levels were reduced from 110 +/- 32.5 to 58 +/- 16.5 ng/mg protein (47.2% reduction) in brain from infected mice exhibiting impaired movements, whereas serotonin levels were unchanged (191 +/- 44 protein in control and 175 +/- 39 ng/mg protein in injected mice). At later times, intraneuronal inclusion bodies were observed in the substantia nigra. Our observations emphasize the need for further studies of the potential association between Parkinson's disease or parkinsonism-like disease and exposure to various nocardial species.

Neuroinvasive Nocardia asteroides GUH-2 induces apoptosis in the substantia nigra in vivo and dopaminergic cells in vitro.

Neurodegenerative diseases such as Parkinson's disease are increasingly prevalent in the aging population worldwide. The causes of these disorders are unknown, but many studies have suggested that the etiology is likely multifactorial and may involve exposure to something in the environment combined with the normal aging process. Nocardia asteroides are bacteria commonly found in the soil, and neuroinvasive strains of nocardiae have been described. N. asteroides strain GUH-2 invades the brains of experimentally infected animals and selectively affects dopaminergic neurons of the substantia nigra (SN), causing an L-DOPA-responsive movement disorder resembling parkinsonism. Furthermore, dopaminergic neurons undergo morphological changes characteristic of apoptosis following nocardial infection. Apoptosis has been implicated in dopaminergic neuronal dropout in Parkinson's patients as well as other parkinsonian models. Thus, in this study, in vivo and in vitro models were utilized to measure the ability of GUH-2 to induce the apoptotic death of dopaminergic cells. Following infection with GUH-2, dopaminergic apoptotic cells were identified in the SN of animals by in situ end labeling, which detects DNA fragmentation, combined with fluorescent immunolabeling of tyrosine hydroxylase-positive cells. In addition, apoptosis was observed in PC12 cell cultures incubated with GUH-2 by both in situ end labeling and the annexin V assay, which detects externalization of phosphatidylserine of the plasma membrane, indicating apoptotic death. Based on the results of these studies, it appears that experimental infection with N. asteroides provides a general model for studying apoptosis in parkinsonian disorders.

[Helicobacter pylori--does it only cause gastroduodenal disease?]. / Helicobacter pylori w chorobach górnego odcinka przewodu pokarmowego--czy tylko?

Helicobacter pylori is a human pathogen that can be found all over the world. It is responsible for the following diseases of gastrointestinal tube: gastritis, gastric ulcer, duodenal ulcer, gastric cancer, gastric lymphomas, Menetier disease. Some research has been done recently trying to identify the connection between H. pylori infection and idiopathic Parkinson's Disease morbidity. Some of them show that people with this neurological disease are more likely to have ulcers and also seropositivity in the direction of H. pylori. The direct influence of H. pylori infection on Parkinson Disease is not known but the following relations are suggested: H. pylori may produce toxins that damage substantia nigra in brain; possible cross reaction of h. pylori antibodies with dopaminergic neurons; indirect influence of antacids containing aluminium used to alleviate the symptoms of ulcers. Investigations of the reasons for idiopathic parkinson disease draw attention to the influence of food factors. Some researches show that there is a relation between the frequency of eating certain foods and the parkinson disease morbidity. We have numerous techniques that allow us to diagnose h. pylori infection. Those techniques have different sensitivity, accuracy, invasiveness and costs, which determines their usefulness in clinical diagnostics. Approach to eradication of bacteria is still discussed because H. pylori infection doesn't always lead to health problems. Polish Working Group on Helicobacter pylori, called by the National Consultant's Team on Gastroenterology explained clearly when eradication is advisable and when it can be waived.

Accumulation of acid-fast lipochrome bodies in glial cells of the midbrain nigral lesion in Parkinson's disease.

To confirm or refute the proposed link between nocardiae and Parkinson's disease (PD), we investigated the presence of acid-fast spherical structures similar to filterable nocardiae at the midbrain nigral lesions of three patients with PD. Many clusters of acid-fast lipochrome bodies were dense around blood vessels in the two patients with Hoehn and Yahr stage II and III PD. These clusters were present in the vicinity of melanin-pigmented neurons in the three PD patients studied. Examination of adjacent hematoxylin-and-eosin-stained sections indicated that they consisted of yellow-green granules, bodies, and aggregates in ballooned glial cells. On the other hand, no clusters of acid-fast lipochrome bodies were observed at the compacta region of three control patients. Our results suggest that the immunological and genetic relationship between the acid-fast lipochrome bodies and filterable nocardiae should be investigated.

[Neuroborreliosis in a patient with progressive supranuclear paralysis. An association or the cause?]. / Neuroborreliosis en un paciente con parálisis supranuclear progresiva: asociación o causa?

INTRODUCTION: Many different neurological conditions may be seen in the later stages of Lyme's Disease, such as blindness, epileptic crises, CVA, extrapyramidal disorders, amyotrophic lateral sclerosis, and dementia may be yet another form of presentation of chronic infection due to Borrelia burgdorferi (Bb). Progressive Supranuclear Paralysis (PSP), a disorder of unknown aetiology, considered to be the commonest cause of Parkinsonism-plus, one of the symptoms of which is dementia, has never been mentioned in this type of differential diagnosis. CLINICAL CASE: We present the case of a 78 year old man with sub-acute mental deterioration, Bb positive serology in both plasma and CSF, and with clinical and epidemiological features compatible with Lyme's Disease. Complementary tests were negative. The syndrome corresponded to Lyme's Disease and improved after treatment with ceftriaxona. CONCLUSIONS: We consider aspects of the aetiology of PSP which are still not clear. In our patient, the aetiology seemed to be Bb infection, according to the criteria of the original description of the disease and in view of the neuropathological findings which have shown Bb in the substancia nigra of the mid-brain and the existence of an animal model in which Bb shows a particular tendency to colonize infratentorial structures.

Viral infection and dissemination through the olfactory pathway and the limbic system by Theiler's virus.

Theiler's murine encephalomyelitis virus (TMEV) infection of mice can produce a biphasic disease of the central nervous system (CNS). Most susceptible strains of mice survive the acute infection and develop a chronic demyelinating disease. In this report, we analyzed the routes of spread of TMEV within the CNS of nude mice and target sites eventually infected in the CNS. Compared to the immunocompetent mouse, in which an antiviral immune response is mounted but virus persists, the nude mouse develops a severe encephalomyelitis due to the lack of functional T lymphocytes and provides a useful model for the study of viral dissemination. We demonstrated, by immunohistochemistry, the presence of viral antigen in defined regions of the CNS, corresponding to various structures of the limbic system. In addition, we found a different time course for viral spread using two different sites of intracerebral inoculation, ie, via the olfactory bulb or the cortex. Limbic structures were rapidly infected following olfactory bulb infection and then showed a decrease in viral load, presumably due to loss of target neurons. Using either route of infection, the virus was able to disseminate to similar regions. These results indicate that limbic structures and their connections are very important for the spread of TMEV in the brain. In the spinal cord, not only neuronal but hematogenous pathways were suspected to be involved in the dissemination of Theiler's virus.

Site-specific growth of Nocardia asteroides in the murine brain.

The growth of Nocardia asteroides GUH-2 and two mutants (NG-49 and I-38-syn) in regions of the brains of BALB/c mice was determined by microdissection and viable counting. GUH-2 grew throughout the murine brain but at different growth rates that depended on the specific location. The rate of increase in total CFU per brain during GUH-2 infection was unaffected by the inoculum size; however, in five of eight brain regions, an alteration in the inoculum size resulted in altered nocardial growth rates. Mutant NG-49 showed a significantly slower rate of increase in total CFU per brain than did the parental strain, GUH-2, and significantly decreased growth rates in seven brain regions. Mutant I-38-syn showed a rate of increase in total CFU per brain similar to that of the parental strain; however, this mutant grew significantly faster in the cerebellum and pons-medulla. Growth appeared to be a necessary precursor to the cellular damage that resulted in the variety of neurological disorders observed in mice infected with N. asteroides GUH-2, because mutant NG-49 exhibited a decreased ability to grow in specific regions of the brain and did not induce signs of neurological damage. In contrast, mutant I-38-syn induced neurological signs in a larger percentage of the infected animals than did parental strain GUH-2 and grew better in certain regions of the brain than did the parental strain. Furthermore, there appeared to be a relationship between the growth of N. asteroides in the substantia nigra and the induction of an L-dopa-responsive head shake that was observed in some of the mice following a sublethal intravenous injection of N. asteroides GUH-2.

Potential role of viruses in neurodegeneration.

Viruses have the capacity to induce alterations and degenerations of neurons by different direct and indirect mechanisms. In the review, we have focused on some examples that may provide new avenues for treatment or altering the course of infections, i.e., antibodies to fusogenic virus membrane proteins, drugs that interfere with lipid metabolism, calcium channel blockers, immunoregulatory molecules, and, and inhibitors of excitotoxic amino acids. Owing to their selectivity in attack on regions of nervous tissue, governed by viral factors and by routes of invasion, viral receptors or metabolic machineries of infected cells, certain viral infections show similarities in distribution of their resulting lesions in the nervous system to that of the common human neurodegenerative diseases (namely, motor neurons disease, Parkinson's disease, and Alzheimer's disease). However, it should be emphasized that no infectious agent has as yet provided a complete animal model for any of these diseases, nor has any infectious agent been linked to them from observations on clinical or postmortem materials.

Cryopreservation of human brain tissue.

Tissues from products of conception were examined to determine the feasibility of obtaining viable neural tissue after suction abortion at 9-12 weeks of gestation. The ventral mesencephalon, a prototype region whose maturation can be monitored and which is a potential tissue for transplantation, was identified in 32 of 120 cases. The tissue was then screened for the presence of infectious agents, while being held at -196 degrees C in cryopreservative solutions. Three of 32 specimens were found to be contaminated by normal vaginal bacteria; all other viral, fungal, and mycoplasma testing was negative. Thawed brain fragments retained high viability after storage in liquid nitrogen and when grown in vitro exhibited neuronal morphology, tyrosine hydroxylase immunoreactivity, and dopamine production. We have demonstrated that human fetal brain tissue can be cryopreserved in a manner which not only retains viability but allows normal phenotypic differentiation after thawing.

Axonal transport of rabies virus in the central nervous system of the rat.

Stereotaxic inoculation of rabies virus into specific nuclei in the central nervous system has been used for the investigation of the central neural transport mechanisms of viral information. The infection was monitored by specific fluorescence and peroxidase studies and the titration of viral infectivity in dissected brain areas. Twenty-four hours after inoculation into the striatum, cortex, or substantia nigra, infected neurons were detected only in cells from areas and nuclei which were related to the site of inoculation. The distribution of infected neurons showed that retrograde axoplasmic flow plays a determining role in the transport of rabies virus 24 hours after delivery of virus to specific target nuclei. Local destruction of neurons by kainic acid at the site of viral inoculation did not prevent the uptake and subsequent retrograde axonal transport of virus. There was an overall correlation between the major neural connections of the inoculated areas (e.g. the striatum) and the infected areas 24 hours later (e.g. the substantia nigra).

Changes in tyrosine hydroxylase, glutamic acid decarboxylase and choline acetyltransferase after local microinoculation of scrapie agent into the nigrostriatal system of the golden hamster.

A microinjection of a homogenate of scrapie agent-infected brain (strain 263 K) into the nigrostriatal system in the golden hamster is followed by the progressive development of the disease which terminates by the death of animals around the 4th month postinoculation. These intracerebral inoculations induce more rapid changes in neuronal activity which can be revealed by the assessment of the specific synthesizing enzymes of neurotransmitter systems. The microinoculation of a homogenate of an infected brain unilaterally into the substantia nigra (SN) provokes a decrease in tyrosine hydroxylase (TH), the synthesizing enzyme for dopamine in the dopaminergic neurones, in the striatum ipsilateral to the injected SN. This biochemical response, specifically induced by the active pathogen, is detectable as soon as the 5th day postinoculation and is detectable towards the 80th day. A return of TH levels to control values is detected after this period. At the end of the incubation period and towards the death of the animals, TH is not different from control TH measured from intact animals. The decrease in TH is concomitant with an increase in striatal glutamic acid decarboxylase (GAD), the synthesizing enzyme for gamma-aminobutyric acid (GABA), measured 20 days postinoculation with no change in choline acetyltransferase (ChAT), the synthesizing enzyme for acetylcholine. Studies of the biochemical responses associated locally to the scrapie agent inoculation have been performed at the striatal level. The intrastriatal administration of the infective agent induces 20 days postinoculation an increase in GAD with no change in TH and ChAT. Ninety days postinoculation, a decrease in GAD was detected associated with an increase in TH with no change in ChAT.(ABSTRACT TRUNCATED AT 250 WORDS)

Infection of the basal ganglia by a murine coronavirus.

The coronavirus, mouse hepatitis virus strain A59 (MHV-A59), causes mild encephalitis and chronic demyelination. Immunohistochemical techniques showed that MHV-A59-infected C57BL/6 mice contained dense deposits of viral antigen in the subthalamic nucleus and substantia nigra, with fewer signs of infection in other regions of the brain. The animals showed extra- and intracellular vacuolation, neuronal loss, and gliosis in the subthalamic-nigral region. Such localization is unprecedented among known viral encephalitides of humans and other species. This infection by a member of a viral class capable of causing both encephalitis and persistent infection in several species may be related to postencephalitic parkinsonism.

Intraaxonal transport of Herpes simplex virus in the rat central nervous system.

Light and electron microscopic observation 3--4 days after microinjection of Herpes simplex virus (HSV) into the left neostriatum of rat demonstrated the following results. (1) Virus labeled nerve cells were found in the ipsilateral substantia nigra; a large number of infected neurons were in the zona compacta and some were in the zona reticulata. No virus infection was evident in the contralateral side. (2) Virus labeled neurons were found in the cortex, a greater number ipsilaterally than contralaterally, and in the dorsal raphé nuclei. Cortical microinjection of HSV led to infection of some cortical cells but no neostriatal cells. We conclude, therefore, that spread of the virus to the cortex, the substantia nigra and the dorsal raphé following neostriatal injection was by retrograde axonal transport. (3) The left neostriatum, where HSV was injected, showed a surprisingly small number of virus infected neurons. The infected neurons were mostly the large neurons; the majority of medium sized neurons were well preserved. There was massive degeneration of nerve terminals throughout the neuropil. Most of these degenerating nerve terminals are considered to be afferent fibers.