Sejt-autonóm és nem sejt-autonóm tényezők tanulmányozása a motoros idegsejtek degenerációja során = Study of the role of cell-autonomous and non cell-autonomous processes in the degeneration of motor neurons

Kísérleteink során a mozgató idegsejtek kalcium-kötő fehérje tartalmával jellemzett "sejt-autonóm" tulajdonsága és a környéki mikrogliális reakció mértékével jelzett "nem sejt-autonóm" sajátságok akut és krónikus stressz helyzetben kimutatható összefüggéseit vizsgáltuk. Akut sérülést előidéző modellen igazoltuk, hogy a természetesen különböző kalcium-kötő fehérje tartalmú mozgató idegsejtek kalcium-kötő fehérje tartalma és ellenálló képessége között korreláció áll fenn. Továbblépve, az idegsejtek egyfajta kalcium-kötő fehérje tartalmát (parvalbumin) génsebészeti módszerrel megemelve kimutattuk, hogy ezzel a beavatkozással a sejtek korlátozottan megnövelt ellenálló képességgel ruházhatók fel. Génsebészeti úton előidézett krónikus stressz alkalmazásával igazoltuk, hogy az ilyen jellegű ellenálló képesség növelés hatékonysága, kapacitása véges. Ezen kísérletek során derült fény arra, hogy az idegsejtek károsodásához, és pusztulásához a mozgató idegsejtek környéki mikroglia sejtjei aktívan hozzájárulnak, s igazoltuk, hogy a (mozgató) idegsejtek sérüléssel szembeni hatékony védelmének kidolgozásához a mikroglia sejteket is "kezelni" kell. Ezt, az állatkísérletekkel megfelelően alátámasztott stratégiát klinikai gyakorlatban is (csontvelő átültetéssel) kipróbáltuk. Bár az eljárásnak szignifikáns terápiás hatása nem volt, megmutattuk, hogy ezzel a beavatkozással a donor eredetű sejtek a sérülés helyére vándorolnak, melyek így felhasználhatók trofikus faktorok célzott bejuttatásához. | In our study, the interaction between the cell-autonomous properties (characterized by intracellular calcium buffering capacity) and non cell-autonomous properties (characterized by local microglial activation) of motor neurons has been examined experimentally in acute and chronic stress conditions. During acute lesion, evoked by nerve transection, the correlation between the naturally occurring elevated calcium binding protein capacity and increased resistance of motor neurons against injury has been demonstrated. Next, using transgenic technology, it has been proved that by this way though limited, but increased resistance could be transferred to motor neurons, by increasing their parvalbumin content. During these experiments it became also evident that, in certain stress conditions, the neighboring microglial cells could actively contribute to the destruction of motor neurons, thus, to develop an efficient protection against their injury, microglial cells has to be "treated", as well. This strategy, supported by firm experimental data from animal studies, has been tested clinically through bone marrow transplantation in (voluntary) patients with motor neuron disease. Although this intervention did not yield significant therapeutic benefit, it could be demonstrated that a certain population of cells of donor origin migrate to the site of injury, thus might be used as vehicles for targeted delivery of trophic factors to the lesion

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

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

Males and Females Contribute Unequally to Offspring Genetic Diversity in the Polygynandrous Mating System of Wild Boar

The maintenance of genetic diversity across generations depends on both the number of reproducing males and females. Variance in reproductive success, multiple paternity and litter size can all affect the relative contributions of male and female parents to genetic variation of progeny. The mating system of the wild boar (Sus scrofa) has been described as polygynous, although evidence of multiple paternity in litters has been found. Using 14 microsatellite markers, we evaluated the contribution of males and females to genetic variation in the next generation in independent wild boar populations from the Iberian Peninsula and Hungary. Genetic contributions of males and females were obtained by distinguishing the paternal and maternal genetic component inherited by the progeny. We found that the paternally inherited genetic component of progeny was more diverse than the maternally inherited component. Simulations showed that this finding might be due to a sampling bias. However, after controlling for the bias by fitting both the genetic diversity in the adult population and the number of reproductive individuals in the models, paternally inherited genotypes remained more diverse than those inherited maternally. Our results suggest new insights into how promiscuous mating systems can help maintain genetic variation

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)

Calcium in the pathomechanism of amyotrophic lateral sclerosis - Taking center stage?

Amyotrophic lateral sclerosis is an incurable, relentlessly progressive disease primarily affecting motor neurons. The cause of the disease, except for the mutations identified in a small fraction of patients, is unknown. The major mechanisms contributing to the degeneration of motor neurons have already been disclosed and characterized, including excitotoxicity, oxidative stress, mitochondrial dysfunction, and immune/inflammatory processes. During the progression of the disease these toxic processes are not discrete, but each facilitates the deleterious effect of the other. However, due to their common reciprocal calcium dependence, calcium ions may act as a common denominator and through a positive feedback loop may combine the individual pathological processes into a unified escalating mechanism of neuronal destruction. This mini-review provides an overview of the mutual calcium dependence of the major toxic mechanisms associated with amyotrophic lateral sclerosis

Calcium in the pathomechanism of amyotrophic lateral sclerosis - Taking center stage?

Amyotrophic lateral sclerosis is an incurable, relentlessly progressive disease primarily affecting motor neurons. The cause of the disease, except for the mutations identified in a small fraction of patients, is unknown. The major mechanisms contributing to the degeneration of motor neurons have already been disclosed and characterized, including excitotoxicity, oxidative stress, mitochondrial dysfunction, and immune/inflammatory processes. During the progression of the disease these toxic processes are not discrete, but each facilitates the deleterious effect of the other. However, due to their common reciprocal calcium dependence, calcium ions may act as a common denominator and through a positive feedback loop may combine the individual pathological processes into a unified escalating mechanism of neuronal destruction. This mini-review provides an overview of the mutual calcium dependence of the major toxic mechanisms associated with amyotrophic lateral sclerosis