scholarly journals Early Changes in Exo- and Endocytosis in the EAE Mouse Model of Multiple Sclerosis Correlate with Decreased Synaptic Ribbon Size and Reduced Ribbon-Associated Vesicle Pools in Rod Photoreceptor Synapses

2021 ◽  
Vol 22 (19) ◽  
pp. 10789
Author(s):  
Ajay Kesharwani ◽  
Karin Schwarz ◽  
Ekta Dembla ◽  
Mayur Dembla ◽  
Frank Schmitz

Multiple sclerosis (MS) is an inflammatory disease of the central nervous system that finally leads to demyelination. Demyelinating optic neuritis is a frequent symptom in MS. Recent studies also revealed synapse dysfunctions in MS patients and MS mouse models. We previously reported alterations of photoreceptor ribbon synapses in the experimental auto-immune encephalomyelitis (EAE) mouse model of MS. In the present study, we found that the previously observed decreased imunosignals of photoreceptor ribbons in early EAE resulted from a decrease in synaptic ribbon size, whereas the number/density of ribbons in photoreceptor synapses remained unchanged. Smaller photoreceptor ribbons are associated with fewer docked and ribbon-associated vesicles. At a functional level, depolarization-evoked exocytosis as monitored by optical recording was diminished even as early as on day 7 after EAE induction. Moreover compensatory, post-depolarization endocytosis was decreased. Decreased post-depolarization endocytosis in early EAE correlated with diminished synaptic enrichment of dynamin3. In contrast, basal endocytosis in photoreceptor synapses of resting non-depolarized retinal slices was increased in early EAE. Increased basal endocytosis correlated with increased de-phosphorylation of dynamin1. Thus, multiple endocytic pathways in photoreceptor synapse are differentially affected in early EAE and likely contribute to the observed synapse pathology in early EAE.

2021 ◽  
Author(s):  
Weikan Wang ◽  
Rachel Thomas ◽  
Jiyoung Oh ◽  
Dong-Ming Su

Although typically associated with onset in young adults, multiple sclerosis (MS) also attacks aged people, which is termed late-onset MS. The disease can be recapitulated and studied in the aged mouse model of experimental autoimmune encephalomyelitis (EAE). The onset of induced EAE is delayed in aged mice, but the disease severity is increased relative to standard EAE in young mice. Given that CD4+FoxP3+ regulatory T (Treg) cells play an ameliorative role in MS/EAE severity and the aged immune system accumulates Treg cells, failure of these cells to prevent or ameliorate EAE disease is enigmatic. When analyzing the distribution of Treg cells in EAE mice, the aged mice exhibited a higher proportion of polyclonal(pan) Treg cells and a lower proportion of antigen-specific-Treg cells in their periphery, but lower proportions of pan- and antigen-specific-Treg cells in the central nervous system (CNS). Furthermore, in the aged CNS, Treg cells exhibited a higher plasticity and T effector (Teff) cells exhibited a greater clonal expansion, which disrupted the Treg/Teff balance. Transiently inhibiting FoxP3 expression in peripheral Treg cells partially ameliorated the disease and corrected Treg distribution in the aged mice. These results provide evidence that accumulated aged Treg cells play a detrimental role in neuronal inflammation of aged MS.


Author(s):  
Л.И. Герасимова-Мейгал ◽  
И.М. Сиренев

Цель исследования - изучение особенностей восприимчивости пациентов с рассеянным склерозом (РС) к холодовому воздействию с помощью функциональных тестов, характеризующих функцию терморегуляции. Как известно, РС - хроническое прогрессирующее аутоиммунное заболевание центральной нервной системы мультифакториальной природы, более часто встречающееся в регионах с холодным и влажным климатом. Нарушения терморегуляции вследствие автономной дисфункции являются характерным признаком РС, вместе с тем участию холодового фактора в развитии заболевания не придается существенного значения. Методика. Обследовано 32 пациента (17 мужчин и 15 женщин, средний возраст 29,6 ± 4,2 года) с установленным диагнозом: РС ремиттирующе-рецидивирующая форма течения (средняя продолжительность заболевания - 4,2 ± 2,7 года) и 18 практически здоровых лиц группы сравнения. Восприятие холода оценивали с помощью визуально-аналоговой шкалы. Продолжительность холод-индуцированной вазоконстрикции после локального холодового теста изучали по данным инфракрасной термометрии. Вегетативную регуляцию вазомоторных реакций оценивали по результатам анализа вызванных кожных вегетативных потенциалов (ВКВП). Результаты. На основе анализа самооценки восприятия холода у пациентов с РС показана низкая переносимость холодового фактора. При проведении локального холодового теста отмечено замедление восстановления температуры кожи кисти, что характерно для усиления холод-индуцированной вазоконстрикции. В группе пациентов с РС выявлено снижение параметров ВКВП ладоней и стоп, свидетельствующее о дефиците нейрогенного контроля терморегуляционных сосудистых реакций. Заключение. У пациентов с РС выявлены нарушения механизмов терморегуляции при действии холода, что обусловливает высокую индивидуальную восприимчивость к холоду у данной категории лиц. Сопоставление результатов анализа механизмов индивидуальной холод-индуцированной реактивности у пациентов с РС с данными эпидемиологических исследований приводит к заключению о потенциальном модулирующем влиянии холодового фактора на течение РС. The purpose of the present study was focused on the evaluation of the sensitivity to cold in multiple sclerosis (MS) patients by means of functional thermoregulatory based tests. MS is known to be a chronic autoimmune progressive disease of the central nervous system of multifactor origin that is very common in regions with cold and humid climate. Disorder of thermoregulation caused by autonomic dysfunction is a typical feature of MS, however the role of the cold in the disease development is still underestimated. Methods. Thirty two MS patients (17 males, 15 females, mean age 29,6 ± 4,2 years) with the remittent form of the disease (mean disease duration 4,2 ± 2,7 years) and 18 age-matched healthy controls volunteered to participate in this study. Susceptibility to cold was analyzed with the use of visual-analogous scale. The duration of cold-induced vasoconstriction after local cold test was estimated using by infrared thermometry. Autonomic regulation of vasomotor reactions was investigated with the help of the skin sympathetic response (SSR) analysis. Results. The analysis of self-reported perception of the cold in MS patients showed their low tolerance to cold. Slow recovery of the skin temperature of the hand in the local cold test observed in MS patients was considered as the aggravated cold-induced vasoconstriction. The decreased SSR in the hands and feet in MS patients was found that indicates the deficit of the neurogenic control of thermoregulatory vasomotor reactions. Conclusion. The results obtained demonstrate the impairment of thermoregulation under cold in MS patients that leads to higher individual susceptibility to cold of this group. Comparing of the data found in this study on the mechanisms of the individual cold-induced reactivity in MS patients with epidemiological surveys enable to conclude that cold environment has potential modulating effect of on the course of MS.


2020 ◽  
Vol 16 (1) ◽  
pp. 28-36
Author(s):  
Maryam Bahrami ◽  
Ghasem Mosayebi ◽  
Ali Ghazavi ◽  
Ali Ganji

Multiple sclerosis is a chronic inflammatory and demyelinating disorder of the central nervous system (CNS) that can cause cognition, mobility, and sensory impairments. Studies have shown that the immune system through inflammation and autoreactive T cells are involved in the progression of MS. The present article aimed to review the potent anti-inflammatory, antioxidant, and immunomodulatory agents that could modulate the immune response in MS. In herbal medicine, various medicinal plants including Olive, Silybum marianum, Grape, Pomegranate peel extract, Nigella sativa, Turmeric, Green tea, Aloysia citrodora, Boswellia papyrifera, Boswellia serrata, Ruta graveolens, and Andrographis paniculata are known with therapeutic benefits in MS patients through immunoregulation and reduction of major symptoms.


2020 ◽  
Vol 16 (5) ◽  
pp. 632-637
Author(s):  
Masih Falahatian

It is an assumption that different kinds of nutrition, diet, and functional foods might have different positive or negative effects on multiple sclerosis (MS), a neuroinflammatory disease of the central nervous system (CNS). This brief paper involved a study on various kinds of nutrition including salt, fat, dairy, fruit, and vegetables. At the end of this study, appropriate diets were evaluated for MS patients. Based on previous studies both on animal models and on MS patients, excessive dietary salt intake and animal fat had worsening effects on MS patients but fruit and vegetable intake helped the remission of MS and decreased the risk of developing it. There were, of course, conflicting results in different studies over the role of some nutrition in MS and future studies on larger numbers of cases were required to collect reliable results. As a result, at the end of this study and based on literature, it is suggested that a diet should be programmed by nutritionists containing fewer salt, fat, and dairy intake and more fruits and vegetables for MS patients in order to better management of the disease.


Molecules ◽  
2021 ◽  
Vol 26 (5) ◽  
pp. 1372
Author(s):  
Tengrui Shi ◽  
Jianxi Song ◽  
Guanying You ◽  
Yujie Yang ◽  
Qiong Liu ◽  
...  

MsrB1 used to be named selenoprotein R, for it was first identified as a selenocysteine containing protein by searching for the selenocysteine insert sequence (SECIS) in the human genome. Later, it was found that MsrB1 is homologous to PilB in Neisseria gonorrhoeae, which is a methionine sulfoxide reductase (Msr), specifically reducing L-methionine sulfoxide (L-Met-O) in proteins. In humans and mice, four members constitute the Msr family, which are MsrA, MsrB1, MsrB2, and MsrB3. MsrA can reduce free or protein-containing L-Met-O (S), whereas MsrBs can only function on the L-Met-O (R) epimer in proteins. Though there are isomerases existent that could transfer L-Met-O (S) to L-Met-O (R) and vice-versa, the loss of Msr individually results in different phenotypes in mice models. These observations indicate that the function of one Msr cannot be totally complemented by another. Among the mammalian Msrs, MsrB1 is the only selenocysteine-containing protein, and we recently found that loss of MsrB1 perturbs the synaptic plasticity in mice, along with the astrogliosis in their brains. In this review, we summarized the effects resulting from Msr deficiency and the bioactivity of selenium in the central nervous system, especially those that we learned from the MsrB1 knockout mouse model. We hope it will be helpful in better understanding how the trace element selenium participates in the reduction of L-Met-O and becomes involved in neurobiology.


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