Immun tényezők, parvalbumin és PARP aktiváció jelentősége neurodegeneratív kórképekben = The role of immune factors, parvalbumin and activation of PARP, neurodegenerative diseases

A neurodegeneratív betegségekben a károsodás közös útja az intraneuronális Ca emelkedése. Amyotrophiás laterálsclerosisban (ALS), /humán motoneuron (MN) betegség/, Parkinson kórban (PK) és állatkísérletes modelljeikben azok az idegsejtek, amelyek képesek kompenzatórikusan megemelni a Ca-kötő parvalbumin szintjüket, rezisztensek a károsodásra. A sérülékeny sejtek NMDA receptor antagonistákkal, Ca-csatorna gátlókkal és a parvalbumin gén beültetéssel megóvhatók a pusztulástól a kísérletes MN betegségben. DNS károsodás és az intraneuronális Ca emelkedés aktiválja a poly(ADP-ribose) polymerase (PARP) DNS javító enzymet ALS-ben a corticális MN-okban, PK-ban a dopaminerg sejtekben. A túlfokozott aktiváció elhasználva a sejt energia forrásait sejthalált okoz. A PARP aktiválódik a microgliában is, mely szabályozza a helyi immun-gyulladásos reakciót. A PARP gátlók adásának kedvező hatását tapasztaltuk a MN betegség immun-mediált kísérletes modelljében, s potenciálisan használhatónak tűnnek ALS-ben és PK-ban. Az autoimmun IgG intraneuronális felvételéből, a microglia aktiválódásából és antigén prezentáló dendritikus sejtekké alakulásából, T lymphocyták odavándorlásából álló immun-gyulladásos reakció figyelhető meg ALS-ből, PK-ból származó boncolási anyagban az érintett régiókban. A microglia aktiváció gátlók csökkentik a neuronokra káros anyagok elválasztását, akadályozzák a lokális antigén prezentációt és így a neuronokat károsító másodlagos autoimmun reakciót. | The rise in intraneuronal Ca is the common pathway of cell injury in neurodegenerative diseases. The neurons which are able to upregulate a calcium-buffering protein, parvalbumin are resistant to the damage in amyotrophic lateral sclerosis (ALS), in Parkinson disease (PD) and in their animal models. NMDA receptor antagonists, Ca-channel blockers and parvalbumin gene transfer were successfully used for ameliorating the MN damage in animal models. The rise in intraneuronal Ca upregulates the DNA repair enzyme poly(ADP-ribose) polymerase in the cortical MNs in ALS and in the dopaminergic neurons in PD. The overactivation of PARP exhausts the energy sources of the cells leading to death. The PARP is also upregulated in microglia, which dictates the local immune-inflammatory reaction. The beneficial effect of the use of PARP inhibitors is predicted in the treatment of the diseases and was experienced in an immune-mediated model of MN disease. An immune-inflammatory reaction consisting of autoimmune IgG uptake by the neurons, microglia activation and conversion to antigen presenting dendritic cells, and the recruitment of T lymphocytes was noted in autopsy materials from ALS, PD and from Alzheimer disease in the affected areas. The inhibitors of the activation of microglia may be useful to diminish the harmful effect of the materials secreted by it to damage neurons and can prevent the local antigen presentation and the secondary autoimmune attack targeting neurons

Passive transfer of blood sera from ALS patients with identified mutations results in elevated motoneuronal calcium level and loss of motor neurons in the spinal cord of mice

Introduction: Previously, we demonstrated the degeneration of axon terminals in mice after repeated injections of blood sera from amyotrophic lateral sclerosis (ALS) patients with identified mutations. However, whether a similar treatment affects the cell body of motor neurons (MNs) remained unresolved. Methods: Sera from healthy individuals or ALS patients with a mutation in different ALS-related genes were intraperitoneally injected into ten-week-old male Balb/c mice (n = 3/serum) for two days. Afterward, the perikaryal calcium level was measured using electron microscopy. Furthermore, the optical disector method was used to evaluate the number of lumbar MNs. Results: The cytoplasmic calcium level of the lumbar MNs of the ALS-serum-treated mice, compared to untreated and healthy-serum-treated controls, was significantly elevated. While injections of the healthy serum did not reduce the number of MNs compared to the untreated control group, ALS sera induced a remarkable loss of MNs. Discussion: Similarly to the distant motor axon terminals, the injection of blood sera of ALS patients has a rapid degenerative effect on MNs. Analogously, the magnitude of the evoked changes was specific to the type of mutation; furthermore, the degeneration was most pronounced in the group treated with sera from ALS patients with a mutation in the chromosome 9 open reading frame 72 gene

Passive transfer of sera from als patients with identified mutations evokes an increased synaptic vesicle number and elevation of calcium levels in motor axon terminals, similar to sera from sporadic patients

Previously, we demonstrated increased calcium levels and synaptic vesicle densities in the motor axon terminals (MATs) of sporadic amyotrophic lateral sclerosis (ALS) patients. Such alterations could be conferred to mice with an intraperitoneal injection of sera from these patients or with purified immunoglobulin G. Later, we confirmed the presence of similar alterations in the superoxide dismutase 1 G93A transgenic mouse strain model of familial ALS. These consistent observations suggested that calcium plays a central role in the pathomechanism of ALS. This may be further reinforced by completing a similar analytical study of the MATs of ALS patients with identified mutations. However, due to the low yield of muscle biopsy samples containing MATs, and the low incidence of ALS patients with the identified mutations, these examinations are not technically feasible. Alternatively, a passive transfer of sera from ALS patients with known mutations was used, and the MATs of the inoculated mice were tested for alterations in their calcium homeostasis and synaptic activity. Patients with 11 different ALS-related mutations participated in the study. Intraperitoneal injection of sera from these patients on two consecutive days resulted in elevated intracellular calcium levels and increased vesicle densities in the MATs of mice, which is comparable to the effect of the passive transfer from sporadic patients. Our results support the idea that the pathomechanism underlying the identical manifestation of the disease with or without identified mutations is based on a common final pathway, in which increasing calcium levels play a central role

Experimental Motor Neuron Disease Induced in Mice with Long-Term Repeated Intraperitoneal Injections of Serum from ALS Patients

In an earlier study, signs of commencing degeneration of spinal motor neurons were induced in mice with short-term intraperitoneal injections of immunoglobulin G (IgG) taken from patients with amyotrophic lateral sclerosis (ALS). Since in that study, neither weakness nor loss of motor neurons was noted, to test whether the ALS IgG in this paradigm has the potential to evoke relentless degeneration of motor neurons, treatment with repeated injections over a longer period was carried out. Mice were systematically injected intraperitoneally with serum taken from ALS patients over a 75-day period. At selected time points, the isometric force of the limbs, number of spinal motor neurons and their intracellular calcium levels were determined. Furthermore, markers of glial activation and the motoneuronal uptake of human IgG were monitored. During this period, gliosis and progressive motoneuronal degeneration developed, which led to gradual loss of spinal motor neurons, more than 40% at day 21, along with decreasing muscle strength in the limbs. The inclusion-like accumulation of IgG appeared in the perikarya with the increase of intracellular calcium in the cell bodies and motor nerve terminals. Our results demonstrate that ALS serum can transfer motor neuron disease to mice

Treatment possibilities for psychosis in Parkinson's disease with an emphasis on the newly approved drug: Pimavanserin

Parkinson's disease (PD) is a progressive neurodegenerative disorder with prominent motor and non-motor symptoms. Psychosis develops in over 40% of PD patients and it is one of the most distressing symptoms for patients and caregivers alike. Until recently, atypical antipsychotics, clozapine and quetiapine were used to treat psychotic symptoms, but treatment was associated with substantial concerns for side-effects of clozapine and unfounded efficacy for quetiapine. Extensive research has shown that the antipsychotic effect of these drugs could be attributed to serotonin 2a receptor (5-HT2A) triggered mechanisms. A selective 5-HT2A inverse agonist, pimavanserin, has been developed, investigated and has gained approval in April 2016 in the US for the treatment of hallucinations and delusions in PD. In this review we primarily focus on psychosis in PD, the current treatment possibilities and the new, emerging therapy, pimavanserin, a selective 5-HT2A inverse agonist. All articles were reviewed in this topic and indexed in PubMed with keywords: Parkinson's disease psychosis, serotonin 2a receptor inverse agonist, clozapine, quetiapine, pimavanserin

Intraperitoneally administered IgG from patients with amyotrophic lateral sclerosis or from an immune-mediated goat model increase the levels of TNF-α, IL-6, and IL-10 in the spinal cord and serum of mice

Background: Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease that involves the selective loss of the upper and lower motor neurons (MNs). Neuroinflammation has been implicated in the pathogenesis of the sporadic form of the disease. We earlier developed immune-mediated animal models of ALS and demonstrated humoral and cellular immune reactions in the nervous system and in the sera of patients and animals. The accumulation of immunoglobulin G (IgG), an elevated intracellular level of calcium, ultrastructural alterations in the MNs, and activation of the microglia were noted in the spinal cord of ALS patients. Similar alterations developed in mice inoculated intraperitoneally with IgG from ALS patients or from an immune-mediated goat model. Methods: We have now examined whether the intraperitoneal injection of mice with IgG from sporadic ALS patients or from immunized goats with the homogenate of the anterior horn of the bovine spinal cord is associated with changes in the pro-inflammatory (TNF-α and IL-6) and anti-inflammatory (IL-10) cytokines in the spinal cord and serum of the mice. The levels of cytokines were measured by ELISA. Results: Intraperitoneally administered IgG from the ALS patients induced subclinical signs of MN disease, while the injection of IgG from immunized goats resulted in a severe respiratory dysfunction and limb paralysis 24 h after the injections. Significantly increased levels of TNF-α and IL-10 were detected in the spinal cord of the mice injected with the human ALS IgG. The level of IL-6 increased primarily in the serum. The IgG from the immunized goats induced highly significant increases in the levels of all three cytokines in the serum and the spinal cord of mice. Conclusions: Our earlier experiments had proved that when ALS IgG or IgG from immune-mediated animal models was inoculated into mice, it was taken up in the MNs and had the ability to initiate damage in them. The pathological process was paralleled by microglia recruitment and activation in the spinal cord. The present experiment revealed that these forms of IgG cause significant increases in certain cytokine levels locally in the spinal cord and in the serum of the inoculated mice. These results suggest that IgG directed to the MNs may be an initial element in the damage to the MNs both in human ALS and in its immune-mediated animal models. © 2016 The Author(s)

Paraneoplastic neuromyelitis optica spectrum disorder: a case report and review of the literature

Neuromyelitis optica spectrum disorders (NMOSD) are demyelinating, autoimmune diseases affecting the central nervous system. Typically, recurrent optic neuritis and longitudinal extensive transverse myelitis dominates the clinical picture. In most cases NMOSD are associated with autoantibodies targeting the water channel aquaporin-4 (AQP-4). NMOSD usually present in young adults. Clinical findings suggestive of NMOSD in elderly patients should raise the suspicion of a paraneoplastic etiology. To our knowledge, we report the first case of a 66 year-old female patient with paraneoplastic NMOSD that is associated with squamous cell lung carcinoma. Anti-AQP-4 was present in both the serum and cerebrospinal fluid of the patient. However, immunhistological staining of the malignant tissue did not show presence of AQP-4 on the surface of tumour cells. © 2017 Elsevier Ltd