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Dive into the research topics where Keren Regev is active.

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Featured researches published by Keren Regev.


Handbook of Clinical Neurology | 2014

Nonsteroidal anti-inflammatory drugs exposure and the central nervous system

Eitan Auriel; Keren Regev; Amos D. Korczyn

Nonsteroidal anti-inflammatory drugs (NSAIDs) are among the most commonly used agents in clinical practice. They are employed as anti-inflammatory, analgesic, and antipyretic agents for a wide spectrum of clinical conditions. Their anti-inflammatory properties are primarily due to inhibition of prostaglandin synthesis. In this paper we review the neurological effects associated with the use of NSAIDs. Acute CNS toxicity related to NSAID use is pervasive and varied. A prospective study looking at ibuprofen overdose noted that 30% of patients experience CNS effects ranging from drowsiness to coma. Case reports have identified numerous neurologic sequelae including ataxia, vertigo, dizziness, recurrent falls, nystagmus, headache, encephalopathy, and disorientation. Seizures have also been reported, mostly after overdose ingestions, but even therapeutic doses have occasionally been associated with seizures. One of the important neurologic side-effects attributed to the use of NSAIDs is aseptic meningitis. The clinical signs of drug-induced meningitis are similar to those of infectious meningitis and include fever, headache, photophobia, and stiff neck. The laboratory findings are also similar, including cerebrospinal fluid (CSF) pleocytosis of several hundred or thousand cells, mainly neutrophils, elevated levels of protein, normal or low glucose levels and negative cultures. Drug-induced meningitis is a transient disorder with an excellent prognosis. Most or all drugs used for the treatment of headache, including NSAIDs, may cause a condition known as medication overuse headache - a refractory chronic daily headache that tends to resolve following discontinuation of the analgesics. Reyes syndrome is a rare severe illness occurring mainly in children and adolescents and characterized by abnormal liver function, vomiting, and encephalopathy, with a mortality rate approaching 40%. The pathogenesis is currently unknown, but commonly the syndrome is preceded by a viral episode, with an intermediate latent period of 3-5 days. An association with aspirin use is strongly suggested. Aspirin, the classic and most commonly used NSAID, has a well-documented effect in inhibiting intravascular clotting, thus reducing the occurrence of ischemic strokes and other vascular events. NSAIDs, however, have a double impact on coagulation. On the one hand, most agents inhibit the synthesis of thromboxane in the platelets, thereby inhibiting coagulation. On the other hand, they also inhibit the production of prostacyclin by endothelial cells, resulting in a prothrombotic state. Selective inhibition of COX-2 by drugs such as rofecoxib (Vioxx) and valdecoxib (Bextra) results in specific inhibition of synthesis of prostaglandins participating in inflammation and was found to lead to vascular complications including an increased risk for stroke. The connection between inflammation and neuronal degeneration is well established. Most studies, including the prospective Rotterdam study, have found an inverse correlation between the use of NSAIDs and the risk for dementia. Two meta-analyses have found 40% and 25% reduction, respectively, in the risk of Alzheimers disease among NSAID users. However, some large, well designed studies failed to confirm these results, and some even found that NSAID use is associated with cognitive decline. The clinical impact of NSAIDs on Parkinsons disease (PD) remains unclear. While some studies showed that chronic NSAID use is protective against PD, other studies could not confirm the existence of a significant relationship. A recent meta-analysis indicated that the use of non-aspirin NSAID, particularly ibuprofen, reduces the risk of PD by 15% while the use of aspirin did not show any effect.


JAMA Neurology | 2014

Central Nervous System Manifestation of IgG4-Related Disease

Keren Regev; Tami Nussbaum; Emanuela Cagnano; Nir Giladi; Arnon Karni

IMPORTANCE IgG4-related disease (IgG4-RD) is characterized by an inflammatory reaction rich in IgG4-positive plasma cells. Head and brain involvement is rare in IgG4-RD, and brain parenchyma involvement has never been reported. OBSERVATION A man in his mid-50s with multiorgan IgG4-RD developed progressive spastic hemiparesis and dementia. Magnetic resonance imaging of the brain revealed several cortical and subcortical lesions. Pathologic findings in the brain were consistent with IgG4-related central nervous system involvement. The patient was treated with high-dose corticosteroids followed by rituximab, and his cognitive and motor functions improved significantly. CONCLUSIONS AND RELEVANCE IgG4-RD should be considered in patients with unusual neurologic manifestations suggestive of autoimmune disease.


Journal of Molecular Neuroscience | 2002

A quantitative bioassay for nerve growth factor, using PC12 clones expressing different levels of trkA receptors

Itzhak Katzir; Jashovam Shani; Keren Regev; Dalia Shabashov; Philip Lazarovici

Nerve growth factor (NGF) is a neurotrophin required for differentiation, development, and survival of the sympathetic nervous system, with many of its biological effects being mediated via trkA receptors. There is a need for a standard quantitative bioassay for NGF, to be used in basic research and in pharmaceutical studies. The objective of the present research was to develop a selective, quantitative, and reliable bioassay for NGF, using a morphological criterion: neurite cell outgrowth. In addition, we aimed to apply the aforementioned bioassay to measure NGF administered to mice. Pheochromocytoma PC12 cell variants including wild-type cultures, and a trkA-overexpressing stable transfectant PC12-6.24-I, PC12nnr5, and PC12EN lacking trkA receptors, were used. Dose-response curves were generated with NGF β-subunit (2.5S) purified from mouse submaxillary glands. Our results demonstrated that the bioassay was sensitive to 0.3–20 ng/mL, and selective, as neurite outgrowth was not seen by any other growth factor other than NGF. In addition, variant clones PC12nnr5 and PC12EN, lacking trkA receptors, did not respond to NGF. The bioassay detected NGF in serum of mice injected with NGF. This novel developed bioassay can serve as a model system for various neuroscience purposes.


Neuroimmunology and Neuroinflammation | 2016

Serum lipid antibodies are associated with cerebral tissue damage in multiple sclerosis

Rohit Bakshi; Ada Yeste; Bonny Patel; Shahamat Tauhid; Subhash Tummala; Roya Rahbari; Renxin Chu; Keren Regev; Pia Kivisäkk; Howard L. Weiner; Francisco J. Quintana

Objective: To determine whether peripheral immune responses as measured by serum antigen arrays are linked to cerebral MRI measures of disease severity in multiple sclerosis (MS). Methods: In this cross-sectional study, serum samples were obtained from patients with relapsing-remitting MS (n = 21) and assayed using antigen arrays that contained 420 antigens including CNS-related autoantigens, lipids, and heat shock proteins. Normalized compartment-specific global brain volumes were obtained from 3-tesla MRI as surrogates of atrophy, including gray matter fraction (GMF), white matter fraction (WMF), and total brain parenchymal fraction (BPF). Total brain T2 hyperintense lesion volume (T2LV) was quantified from fluid-attenuated inversion recovery images. Results: We found serum antibody patterns uniquely correlated with BPF, GMF, WMF, and T2LV. Furthermore, we identified immune signatures linked to MRI markers of neurodegeneration (BPF, GMF, WMF) that differentiated those linked to T2LV. Each MRI measure was correlated with a specific set of antibodies. Strikingly, immunoglobulin G (IgG) antibodies to lipids were linked to brain MRI measures. Based on the association between IgG antibody reactivity and each unique MRI measure, we developed a lipid index. This comprised the reactivity directed against all of the lipids associated with each specific MRI measure. We validated these findings in an additional independent set of patients with MS (n = 14) and detected a similar trend for the correlations between BPF, GMF, and T2LV vs their respective lipid indexes. Conclusions: We propose serum antibody repertoires that are associated with MRI measures of cerebral MS involvement. Such antibodies may serve as biomarkers for monitoring disease pathology and progression.


Journal of the Neurological Sciences | 2010

Dysregulated neurotrophin mRNA production by immune cells of patients with relapsing remitting multiple sclerosis

Nataly Urshansky; Karin Mausner-Fainberg; Eitan Auriel; Keren Regev; Firas Farhum; Arnon Karni

Recent studies have suggested a neuroprotective activity of the lesion-infiltrating immune cells in multiple sclerosis (MS) by secretion of neurotrophins. We had earlier reported that immune cells from relapsing remitting MS (RR-MS) patients secrete low levels of brain-derived neurotrophic factor (BDNF), and that its secretion is dysregulated after CD40 stimulation. Here, we measured mRNA levels for BDNF, NT3 and NGF-beta mRNA in unstimulated PBMCs and found levels lower in untreated RR-MS patients than in healthy controls (HC). T-cell stimulation with anti-CD3/CD28 mAb up-regulated neurotrophin mRNA expression in untreated RR-MS patients and not in HC, whereas stimulation of PBMCs with anti-CD40 mAb up-regulated neurotrophin mRNA expression in HC and not in RR-MS patients. Further cellular analyses of the production of the neurotrophin mRNA in individual cells revealed that T cells were the main producers of the neurotrophin mRNA in RR-MS patients, and that monocytes were the main producers of NT3 and NGF-beta mRNA in HC. BDNF mRNA was similarly produced in monocytes and T cells in the HC group. The cytokines TNF-alpha and IL-17 up-regulated the expression of neurotrophin mRNA in HC but not in RR-MS patients. The neuroprotective activity of PBMCs appeared to be dysregulated in untreated patients with RR-MS, while the differences between the IFN-beta-treated RR-MS patients and the HC were smaller.


Neuroimmunology and Neuroinflammation | 2016

Comprehensive evaluation of serum microRNAs as biomarkers in multiple sclerosis

Keren Regev; Anu Paul; Brian C. Healy; Felipe von Glenn; Camilo Diaz-Cruz; Taha Gholipour; Maria Antonietta Mazzola; Radhika Raheja; Parham Nejad; Bonnie I. Glanz; Pia Kivisäkk; Tanuja Chitnis; Howard L. Weiner; Roopali Gandhi

Objective: To identify circulating microRNAs (miRNAs) linked to disease stage and disability in multiple sclerosis (MS). Methods: Sera from 296 participants including patients with MS, other neurologic diseases (Alzheimer disease and amyotrophic lateral sclerosis), and inflammatory diseases (rheumatoid arthritis and asthma) and healthy controls (HCs) were tested. miRNA profiles were determined using LNA (locked nucleic acid)-based quantitative PCR. Patients with MS were categorized according to disease stage and disability. In the discovery phase, 652 miRNAs were measured in sera from 26 patients with MS and 20 HCs. Following this, significant miRNAs (p < 0.05) from the discovery set were validated using quantitative PCR in 58 patients with MS, 30 HCs, and in 74 samples from other disease controls (Alzheimer disease, amyotrophic lateral sclerosis, asthma, and rheumatoid arthritis). Results: We validated 7 miRNAs that differentiate patients with MS from HCs (p < 0.05 in both the discovery and validation phase); miR-320a upregulation was the most significantly changing serum miRNA in patients with MS. We also identified 2 miRNAs linked to disease progression, with miR-27a-3p being the most significant. Ten miRNAs correlated with the Expanded Disability Status Scale of which miR.199a.5p had the strongest correlation with disability. Of the 15 unique miRNAs we identified in the different group comparisons, 12 have previously been reported to be associated with MS but not in serum. Conclusions: Our findings identify circulating serum miRNAs as potential biomarkers to diagnose and monitor disease status in MS. Classification of evidence: This study provides Class III evidence that circulating serum miRNAs can be used as biomarker for MS.


Journal of Headache and Pain | 2008

Not only headache : higher degree of sexual pain symptoms among migraine sufferers

Gal Ifergane; Itzhak Z. Ben-Zion; Ygal Plakht; Keren Regev; Itzhak Wirguin

Chronic illness and chronic pain can have profound negative effects on relationship and sexual satisfaction, yet the influence of migraine on sexuality has not been previously evaluated. To assess sexual functions in subjects with migraine compared to those with no migraine. We evaluated female university students using the Israeli sexual behavior inventory (ISBI). Migraine was diagnosed according to self-reported symptoms according to the IHS criteria. Several dimensions of female sexuality—desire, orgasm, sexual avoidance, interpersonal sexual relationship, health influence, satisfaction and pain were evaluated using a structured questionnaire. Thirty-three (23.9%) of the participants met the IHS criteria for episodic migraine with and without aura. Sexual activity, desire, orgasm and satisfaction from sexual life did not differ significantly between migraine sufferers and non-sufferers. Migraine patients reported lower ISBI scores, higher health influence on sexual life, higher levels of sexual pain and lower sexual satisfaction. Migraine negatively affected the sexual life of sufferers. Sexual pain disorder is more common among migraine sufferers compared to non-migraineurs.


Journal of Neuroinflammation | 2015

Identification of a novel mechanism of action of fingolimod (FTY720) on human effector T cell function through TCF-1 upregulation

Maria Antonietta Mazzola; Radhika Raheja; Gopal Murugaiyan; Hasan Rajabi; Deepak Kumar; Thomas Pertel; Keren Regev; Russell Griffin; Lilian Aly; Pia Kivisäkk; Parham Nejad; Bonny Patel; Nguendab Gwanyalla; Hillary Hei; Bonnie I. Glanz; Tanuja Chitnis; Howard L. Weiner; Roopali Gandhi

BackgroundFingolimod (FTY720), the first oral treatment for multiple sclerosis (MS), blocks immune cell trafficking and prevents disease relapses by downregulation of sphingosine-1-phosphate receptor. We determined the effect of FTY720 on human T cell activation and effector function.MethodsT cells from MS patients and healthy controls were isolated to measure gene expression profiles in the presence or absence of FTY720 using nanostring and quantitative real-time polymerase chain reaction (qPCR). Cytokine protein expression was measured using luminex assay and flow cytometry analysis. Lentivirus vector carrying short hairpin RNA (shRNA) was used to knock down the expression of specific genes in CD4+ T cells. Chromatin immunoprecipitation was performed to assess T cell factor 1 (TCF-1) binding to promoter regions. Luciferase assays were performed to test the direct regulation of interferon gamma (IFN-γ) and granzyme B (GZMB) by TCF-1. Western blot analysis was used to assess the phosphorylation status of Akt and GSK3β.ResultsWe showed that FTY720 treatment not only affects T cell trafficking but also T cell activation. Patients treated with FTY720 showed a significant reduction in circulating CD4 T cells. Activation of T cells in presence of FTY720 showed a less inflammatory phenotype with reduced production of IFN-γ and GZMB. This decreased effector phenotype of FTY720-treated T cells was dependent on the upregulation of TCF-1. FTY720-induced TCF-1 downregulated the pathogenic cytokines IFN-γ and GZMB by binding to their promoter/enhancer regions and mediating epigenetic modifications. Furthermore, we observed that TCF-1 expression was lower in T cells from multiple sclerosis patients than in those from healthy individuals, and FTY720 treatment increased TCF-1 expression in multiple sclerosis patients.ConclusionsThese results reveal a previously unknown mechanism of the effect of FTY720 on human CD4+ T cell modulation in multiple sclerosis and demonstrate the role of TCF-1 in human T cell activation and effector function.


Journal of Neuroimmunology | 2011

Reduced production of noggin by immune cells of patients with relapsing-remitting multiple sclerosis

Nataly Urshansky; Karin Mausner-Fainberg; Eitan Auriel; Keren Regev; Natan M. Bornstein; Arnon Karni

Multiple sclerosis (MS) plaques are characterized by neurodegeneration, astrogliolis, the presence of immature oligodendrocytes and infiltrating immune cells. Recent studies revealed a putative role for noggin in both neurogenesis and oligodenrocytes development. In order to study the potential of peripheral immune cells to contribute to neurogenesis in MS, we studied the mRNA expression, protein secretion and regulation profile of noggin in peripheral blood mononuclear cells (PBMCs) of untreated patients with relapsing-remitting MS (RR-MS), interferon-β (IFN-β) treated RR-MS patients compared to matched healthy controls (HC). Basal levels of noggin mRNA expression, determined by quantitative real-time PCR were lower in untreated patients than in HC. No differences were found between untreated patients and IFN-β treated patients. Similarly, the secreted levels of noggin, detected in 24h PBMCs supernatants by ELISA, were decreased in untreated RR-MS patients than in HC. Again no significant differences were found between untreated patients and IFN-β treated patients. Stimulation with anti-CD3/CD28 mAbs increased noggin mRNA expression in untreated patients but not in HC. However, noggin mRNA levels in untreated patients PBMCs stimulated with anti-CD3/CD28 did not reach noggin levels in unstimulated PBMCs of HC. Purification of monocytes (CD14+) and T cells (CD3+ cells) by magnet-activated cell separation has demonstrated that noggin mRNA is predominantly expressed in CD3(+) cells in both HC and in RR-MS patients. This pattern also appeared in protein level of noggin, tested by Western blot. The incubation of the PBMCs with TNF-α increased the expression of noggin only in HC group. In conclusion, T cells possess the potential to participate in the induction of neurogeneration by the production of noggin. This potential seems to be defective in immune cells of RR-MS patients as there is reduced mRNA expression and protein secretion levels of noggin, insufficient stimulatory effect of CD3/CD28 stimulation and unresponsiveness to TNF-α in these patients PBMCs.


Journal of the Neurological Sciences | 2014

Multiple sclerosis is associated with psoriasis. A case–control study

Avi Fellner; Marina Dano; Keren Regev; Amnon Mosek; Arnon Karni

BACKGROUND MS and psoriasis are both autoimmune diseases putatively mediated mainly by T cells. OBJECTIVE We conducted a case control study to investigate whether patients with MS have a high rate of comorbid psoriasis. METHODS The cohort consisted of 214 consecutive MS patients and a control group of 192 consecutive patients with headache. RESULTS There was a higher than expected frequency of psoriasis among the MS patients. There was no gender effect and none of the 9 affected MS patients were among the 22 MS patients with primary progressive disease. Six of those 9 patients started interferon-β treatment after being diagnosed with MS, and 4 of them experienced exacerbation of psoriasis during exposure to interferon-β. There was no exacerbation in the co-morbid patients during treatment with other disease-modifying drugs. CONCLUSIONS Our observation confirms other reports on an association of MS with autoimmune diseases and supports the hypothesis of autoimmune pathogenesis for MS. The current findings should raise the level of awareness of psoriasis among patients with MS, and of the need to consider a potential exacerbation of psoriasis by interferon-β therapy.

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Arnon Karni

Tel Aviv Sourasky Medical Center

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Howard L. Weiner

Brigham and Women's Hospital

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Pia Kivisäkk

Brigham and Women's Hospital

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Roopali Gandhi

Brigham and Women's Hospital

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Anu Paul

Brigham and Women's Hospital

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Karin Mausner-Fainberg

Tel Aviv Sourasky Medical Center

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Brian C. Healy

Brigham and Women's Hospital

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Radhika Raheja

Brigham and Women's Hospital

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