Pharmacological Inhibition of Acid Sphingomyelinase Ameliorates Experimental Autoimmune Encephalomyelitis.

BACKGROUND/AIMS: Multiple sclerosis (MS) is one of the most common autoimmune disorders of the central nervous system (CNS) and the leading cause of neurological disability among young adults in the Western world. We have previously shown that the acid sphingomyelinase plays an important role in the pathogenesis of experimental autoimmune encephalomyelitis (EAE), an animal model for multiple sclerosis. METHODS: We induced adoptively transferred EAE in wildtype and acid sphingomyelinase-deficient mice. In addition, we immunized mice with MOGaa35-55 to induce active EAE and treated the mice with amitriptyline, a functional inhibitor of the acid sphingomyelinase. We investigated symptoms of EAE, blood-brain barrier integrity and neuroinflammation. RESULTS: In the model of adoptively transferred EAE we demonstrate that expression of acid sphingomyelinase in the recipients rather than on transferred encephalitogenic T cells contributes to the clinical development of EAE symptoms. To test if pharmacological targeting of acid sphingomyelinase can be explored for the development of novel therapies for MS, we inhibited acid sphingomyelinase with amitriptyline in mice in which EAE was induced by active immunization. We demonstrate that pharmacological inhibition of acid sphingomyelinase using amitriptyline protects against the development of EAE and markedly attenuates the characteristic detrimental neuroinflammatory response. CONCLUSION: The studies identify the acid sphingomyelinase as a novel therapeutic target for treating MS patients.

Blockade of Experimental Multiple Sclerosis by Inhibition of the Acid Sphingomyelinase/Ceramide System.

BACKGROUND: Multiple sclerosis (MS) is a severe and common autoimmune disorder of the central nervous system. Despite the availability of several novel treatment options, the disease is still poorly controlled, since the pathophysiological mechanisms are not fully understood. METHODS: We tested the role of the acid sphingomyelinase/ceramide system in a model of MS, i.e. experimental autoimmune encephalomyelitis (EAE). Mice were immunized with myelin-oligodendrocyte glycoprotein and the development of the disease was analyzed by histology, immunological tests and clinical assessment in wildtype and acid sphingomyelinase (Asm)-deficient mice. RESULTS: Genetic deficiency of acid sphingomyelinase (Asm) protected against clinical symptoms in EAE and markedly attenuated the characteristic detrimental neuroinflammatory response. T lymphocyte adhesion, integrity of tight junctions, blood-brain barrier disruption and subsequent intracerebral infiltration of inflammatory cells were blocked in Asm-deficient mice after immunization. This resulted in an almost complete block of the development of disease symptoms in these mice, while wildtype mice showed severe neurological symptoms typical for EAE. CONCLUSION: Activation of the Asm/ceramide system is a central step for the development of EAE. Our findings may serve to identify novel therapeutic strategies for MS patients.

Acid sphingomyelinase deficiency enhances myelin repair after acute and chronic demyelination.

The cuprizone animal model, also known as the toxic demyelination model, is a well-reproducible model of demyelination- and remyelination in mice, and has been useful in studying important aspect of human demyelinating diseases, including multiple sclerosis. In this study, we investigated the role of acid sphingomyelinase in demyelination and myelin repair by inducing acute and chronic demyelination with 5- or 12-week cuprizone treatment, followed by a 2-week cuprizone withdrawal phase to allow myelin repair. Sphingolipids, in particular ceramide and the enzyme acid sphingomyelinase, which generates ceramide from sphingomyelin, seem to be involved in astrocyte activation and neuronal damage in multiple sclerosis. We used immunohistochemistry to study glial reaction and oligodendrocyte distribution in acid sphingomyelinase deficient mice and wild-type C57BL/6J littermates at various time intervals after demyelination and remyelination. Axonal injury was quantified using amyloid precursor protein and synaptophysin, and gene expression and protein levels were measured using gene analysis and Western blotting, respectively. Our results show that mice lacking acid sphingomyelinase had a significant increase in myelin recovery and a significantly higher oligodendrocyte cell count after 2 weeks remyelination compared to wild-type littermates. Detrimental astroglial distribution was also significantly reduced in acid sphingomyelinase deficient animals. We obtained similar results in experiments using amitriptyline to inhibit acid sphingomyelinase. These findings suggest that acid sphingomyelinase plays a significant role in myelin repair, and its inhibition by amitriptyline may constitute a novel therapeutic approach for multiple sclerosis patients.

Comparison of Antiepileptic Approaches in Treatment of Benzodiazepine Nonresponsive Status Epilepticus.

AIMS: Status epilepticus and seizure clusters are common neurological emergencies. The purpose of this monocentric, retrospective cohort study was to comparatively assess different antiepileptic approaches in the treatment of status epilepticus and seizure clusters, which were nonresponsive to benzodiazepines. METHODS: We reviewed medical records of 66 patients, who were treated for status epilepticus or seizure clusters in the Department of Neurology at the University of the Saarland between January 2007 and July 2012, and failed to respond to benzodiazepines with the equivalent dosage of at least 20 mg of diazepam. As endpoints, we analyzed both the effectiveness of lacosamide, levetiracetam, valproic acid, and phenytoin used as second- and third-line therapy, and the Glasgow Outcome Scale at day 7. RESULTS: Sixty-one (92.4%) of the patients had status epilepticus, and 5 (7.6%) had seizure clusters. The compared drugs were equally effective in terminating seizures. There was also no significant difference in the Glasgow Outcome Scale (P = 0.60) after 7 days. CONCLUSION: Our data support the use of the modern antiepileptic treatment strategies, such as levetiracetam, valproic acid, and lacosamide in the treatment of status epilepticus and seizure clusters.

'Stroke Room': Diagnosis and Treatment at a Single Location for Rapid Intraarterial Stroke Treatment.

BACKGROUND: For patients with acute ischemic stroke, intra-arterial treatment (IAT) is considered to be an effective strategy for removing the obstructing clot. Because outcome crucially depends on time to treatment ('time-is-brain' concept), we assessed the effects of an intervention based on performing all the time-sensitive diagnostic and therapeutic procedures at a single location on the delay before intra-arterial stroke treatment. METHODS: Consecutive acute stroke patients with large vessel occlusion who obtained IAT were evaluated before and after implementation (April 26, 2010) of an intervention focused on performing all the diagnostic and therapeutic measures at a single site ('stroke room'). RESULT: After implementation of the intervention, the median intervals between admission and first angiography series were significantly shorter for 174 intervention patients (102 min, interquartile range (IQR) 85-120 min) than for 81 control patients (117 min, IQR 89-150 min; p < 0.05), as were the intervals between admission and clot removal or end of angiography (152 min, IQR 123-185 min vs. 190 min, IQR 163-227 min; p < 0.001). However, no significant differences in clinical outcome were observed. CONCLUSION: This study shows for the, to our knowledge, first time that for patients with acute ischemic stroke, stroke diagnosis and treatment at a single location ('stroke room') saves crucial time until IAT.

The Innate Immune Receptor CD14 Mediates Lymphocyte Migration in EAE.

BACKGROUND: Multiple sclerosis is the most common autoimmune disease of the central nervous system in young adults and histopathologically characterized by inflammation, demyelination and gliosis. It is considered as a CD4+ T cell-mediated disease, but also a disease-promoting role of the innate immune system has been proposed, based e.g. on the observation that innate immune receptors modulate disease severity of experimental autoimmune encephalomyelitis. Recent studies of our group provided first evidence for a key role of the innate immune LPS receptor (CD14) in pathophysiology of experimental autoimmune encephalomyelitis. CD14-deficient experimental autoimmune encephalomyelitis mice showed increased clinical symptoms and enhanced infiltration of monocytes and neutrophils in brain and spinal cord. METHODS: In the current study, we further investigated the causes of the disease aggravation by CD14-deficiency and examined T cell activation, also focusing on the costimulatory molecules CTLA-4 and CD28, and T cell migration capacity over the blood brain barrier by FACS analysis, in vitro adhesion and transmigration assays. RESULTS: In the results, we observed a significantly increased migration of CD14-deficient lymphocytes across an endothelial monolayer. In contrast, we did not see any differences in expression levels of TCR/CTLA-4 or TCR/CD28 and lymphocyte adhesion to endothelial cells from CD14-deficient compared to wildtype mice. CONCLUSION: The results demonstrate an important role of CD14 in migration of lymphocytes, and strengthen the importance of innate immune receptors in adaptive immune disorders, such as multiple sclerosis.

A central role for the acid sphingomyelinase/ceramide system in neurogenesis and major depression.

Major depressive disorder is a severe and chronic illness with high lifetime prevalence and a high incidence of suicide as the cause of death for patients with this diagnosis. Major depressive disorder is often treated with anti-depressants. Although these drugs have been used for many years, their exact mode of action is still unknown. It has been suggested that many anti-depressants act by increasing the concentrations of serotonergic transmitters in the synaptic space. However, recent studies have examined the effects of anti-depressants on neurogenesis in the hippocampus, the restoration of hippocampal neuronal networks that may be affected by major depression, and the regulation of the hypothalamic-pituitary-adrenal axis by immature neurons in the hippocampus. Here, we present and discuss a novel hypothesis suggesting that these events are regulated by the concentrations of sphingolipids, in particular ceramide, in the hippocampus. These concepts suggest that the acid sphingomyelinase/ceramide system plays a central role in the pathogenesis of major depression and may be a novel target for anti-depressants.

Sphingolipids: important players in multiple sclerosis.

Multiple Sclerosis (MS) is the most common cause for permanent disability in young adults. Current pathophysiological understanding has identified an autoaggressive immune reaction with infiltration of immune cells into the central nervous system and local inflammatory and demyelinating reactions. The current therapy focuses on a modulation or suppression of immune functions. Sphingolipids, main components of nervous tissue, have been linked to MS already 60 years ago with the description of an unusual myelin lipid distribution in diseased patients. There is tremendous information developing on the role of different sphingolipids in MS. Antibodies against sphingomyelin, sulfatide or galacosylceramide have been detected in serum or CSF of MS patients, although up to now, this knowledge did not find its way into clinical use. Ceramide and the enzymes linked to its production have been described to play a pivotal role in oligendrocyte damage and demyelination. Nowadays, especially sphingosine-1-phosphate (S1P) is in the focus of pathophysiological research and therapy development. A S1P analogue, FTY720, is a widely distributed therapy against relapsing-remitting MS, attenuating the emigration of activated, autoreactive lymphocytes from lymph nodes, thereby preventing new inflammatory infiltration into the central nervous system. Beside, there is more and more evidence, that especially S1P receptors on oligodendrocytes and astrocytes are involved in demyelination processes and subsequent axonal degeneration, important features of chonic progressive MS disease course. Further information and research on the manifold role of sphingolipids are needed to prepare the ground for further clinical trials. This review focuses on the current knowledge of the role of sphingolipids in MS and describes the current therapeutical implications.

Prescription frequency and predictors for the use of novel direct oral anticoagulants for secondary stroke prevention in the first year after their marketing in Europe--a multicentric evaluation.

BACKGROUND: Direct oral anticoagulants (DOAC) are alternatives to the use of vitamin K antagonists (VKA) as oral anticoagulant therapies to prevent stroke in patients with atrial fibrillation. AIMS: We assembled a representative secondary prevention cohort from four tertiary care stroke centers to identify factors that independently influence therapeutic decision making 1) not to anticoagulate with either VKA or DOAC and 2) to use DOAC if the patient appears suitable for oral anticoagulant therapy. METHODS: We identified all patients discharged with the diagnoses 'ischemic stroke' (ICD-10 code I63) or 'transient ischemic attack' (G45) in combination with 'atrial fibrillation' (I48) during 1 year. We performed binary logistic regression analyses to identify factors independently influencing the aforementioned decisions. RESULTS: Our cohort comprised 758 patients. At discharge from the stroke service, 374 patients (49·3%) received oral anticoagulant therapy. Older age, severe stroke, poor recovery in the acute phase, and higher serum creatinine were independent factors to withhold oral anticoagulant therapy, whereas prior oral anticoagulant therapy favored the decision to anticoagulate. Among patients who were anticoagulated, prescription was balanced for VKA (50·3%) and DOAC (49·7%). Renal function and prior oral anticoagulant therapies were the most important factors in this decision. CONCLUSIONS: Shortly after their marketing, DOAC are used as frequently as VKA for secondary stroke prevention in patients with atrial fibrillation. The decision between VKA and DOAC is mainly determined by the patient's renal function and the absence or presence of prior oral anticoagulant therapy.

Is reduced myocardial sympathetic innervation associated with clinical symptoms of autonomic impairment in idiopathic Parkinson's disease?

Patients with idiopathic Parkinson's disease (IPD) have a reduced myocardial MIBG uptake in MIBG scintigraphy, indicating myocardial sympathetic denervation. We were interested whether this myocardial sympathetic denervation coincides with clinical symptoms of autonomic impairment in IPD patients. We performed MIBG scintigraphy, the SCOPA-AUT scale, a standardized medical history (developed in our clinic) and autonomic nervous system testing in 47 IPD patients (21 female, 26 male patients). We correlated myocardial MIBG uptake with the results of the SCOPA-AUT scale, the standardized medical history and the autonomic nervous system testing through the use of Spearman's correlation. Myocardial MIBG uptake correlated significantly (p < 0.05) with several items of the SCOPA-AUT scale (in female patients: perspiration during the night, in male patients: sum score, saliva dribbling of the mouth, difficulty swallowing, fainting, constipation), of the standardized medical history (in male patients: swollen ankles) and of the autonomic nervous system testing (all patients: sum score, Ewing orthostasis test). Remarkably, we found more significant correlations in male than in female patients. Reduced myocardial sympathetic innervation-as revealed by MIBG scintigraphy-is associated with clinical symptoms of autonomic impairment. This association is more pronounced in male than in female patients. The cause for this gender-specific phenomenon is unclear.