Therapeutic potential of statins in multiple sclerosis: immune modulation, neuroprotection and neurorepair

Identification of small molecule modulators of class II transactivator-I using computational approaches

Major histocompatibility complex II (MHCII), a mediator of the innate and adaptive immune system, plays a central role in regulating inflammation and its progression. Class II transactivator (CIITA) is a master regulator of MHCII expression and controls antigen presentation followed by T-cell activation. Regulation of inflammation by modulation of CIITA has been suggested as a promising intervention for several disorders, including neuroinflammation, rheumatoid arthritis and other autoimmune diseases. This study aimed to (i) identify possible pharmacological agents which could bind to and inhibit isoform I of CIITA (CIITA-I) and (ii) determine their strength of interactions. The structure of CIITA-I isoform was predicted using phyre2 and refined via 3D refine. Loops were refined using ModBase, followed by quality assessment based on ERRAT value. The refined 3D structure was subjected to docking via Maestro (from Schrodinger) using glide module against small molecule databases. Molecules having the least glide score and favorable ADME properties were subjected to molecular simulation by GROMACS. We used the 3D refined structure of CIITA-I, with a score of 83.4% in ERRAT for docking studies. The ligand 4-(2-((6-oxo-4-phenyl-1,6-dihydropyrimidin-2-yl) thio) acetamido) benzamide (ZINC5154833), showed maximum glide score (-6.591) followed by N-[4-(3-oxo-3-{4-[3-(trifluoromethyl) phenyl] piperazin-1-yl} propyl)-1,3-thiazol-2-yl] benzamide (F5254-0161, glide score -6.41). Simulation studies using GROMACS showed F5254-0161 to have a more stable interaction with CIITA-I. Based on our analysis, we propose ZINC5154833 and F5254-0161 as potential modulators for CIITA-I.Communicated by Ramaswamy H. Sarma.

Evaluation of Rosuvastatin Therapy on SIRT1 Gene Expression in Patients with Multiple Sclerosis: An Uncontrolled Clinical Trial

Background

Multiple sclerosis (MS) is a chronic autoimmune disease. Current medications have some limitations such as low efficacy and high side effects. In recent years, statins have been raised as potential therapeutics for MS treatment with minimal complications. In addition, patient monitoring using suitable molecular markers is necessary for treatment response evaluation.

Objective

The aim of the present study was the evaluation of SIRT1 gene expression changes following rosuvastatin therapy in patients with MS.

Methods

This before-after uncontrolled clinical trial study was performed on 25 patients with MS. Patients were treated with 20 mg rosuvastatin daily for 3 months. The Expanded Disability Status Scale (EDSS) was measured before and after statin therapy. Blood samples were taken from patients 2 times, before and after statin therapy, and centrifuged for white blood cell isolation. Total RNA was extracted using RNX-plus reagent, and complementary DNA was synthesized using Pars Tous cDNA Synthesis Kit. Real-time polymerase chain reaction was done using SYBR blue master mix and gene-specific primers in Roche light cycler. Patients' information was recorded using a checklist. Data analysis was performed using SPSS version 23 and Graph Pad version 9 software and P < 0.05 was considered a significant level.

Results

SIRT1 was significantly upregulated in MS patients after statin therapy. Subsequently, EDSS of patients was decreased along with the increase in SIRT1 gene expression, although EDSS changes were not significant (P > 0.05). Pearson correlation test showed no significant relationship between EDSS and SIRT1 gene expression (P > 0.05). No significant relationship was observed between SIRT1 expression or EDSS levels with patients' age, sex, weight, height, and body mass index and administrated drugs (P > 0.05).

Conclusions

SIRT1 potentially is a sensitive and reliable biomarker for patients with MS monitoring during statin therapy.

Oxidative Stress and Neurodegeneration: Interconnected Processes in PolyQ Diseases

Neurodegenerative polyglutamine (polyQ) disorders are caused by trinucleotide repeat expansions within the coding region of disease-causing genes. PolyQ-expanded proteins undergo conformational changes leading to the formation of protein inclusions which are associated with selective neuronal degeneration. Several lines of evidence indicate that these mutant proteins are associated with oxidative stress, proteasome impairment and microglia activation. These events may correlate with the induction of inflammation in the nervous system and disease progression. Here, we review the effect of polyQ-induced oxidative stress in cellular and animal models of polyQ diseases. Furthermore, we discuss the interplay between oxidative stress, neurodegeneration and neuroinflammation using as an example the well-known neuroinflammatory disease, Multiple Sclerosis. Finally, we review some of the pharmaceutical interventions which may delay the onset and progression of polyQ disorders by targeting disease-associated mechanisms.

Anti-inflammatory Effects of Statins in Lung Vascular Pathology: From Basic Science to Clinical Trials

HMG-CoA reductase inhibitors (or statins) are cholesterol-lowering drugs and are among the most widely prescribed medications in the United States. Statins exhibit pleiotropic effects that extend beyond cholesterol reduction including anti-atherosclerotic, antiproliferative, anti-inflammatory, and antithrombotic effects. Over the last 20 years, statins have been studied and examined in pulmonary vascular disorders, including both chronic pulmonary vascular disease such as pulmonary hypertension, and acute pulmonary vascular endothelial injury such as acute lung injury. In both research and clinical settings, statins have demonstrated promising vascular protection through modulation of the endothelium, attenuation of vascular leak, and promotion of endothelial repair following lung inflammation. This chapter provides a summary of the rapidly changing literature, summarizes the anti-inflammatory mechanism of statins on pulmonary vascular disorders, and explores clinical evidence for statins as a potential therapeutic approach to modulation of the endothelium as well as a means to broaden our understanding of pulmonary vasculopathy pathophysiology.

Statins, metformin, proprotein-convertase-subtilisin-kexin type-9 (PCSK9) inhibitors and sex hormones: Immunomodulatory properties?

The immune system is closely intertwined with the endocrine system. Many effects of medications used for various clinical endocrine conditions such as the metabolic syndrome, hypercholesterolemia, diabetes mellitus, hypertension, Graves' disease and others also have an impact on the immune system. Some drugs including statins, metformin, angiotensin converting enzyme and proprotein-convertase-subtilisin-kexin type-9 (PCSK9) inhibitors and sex hormones are known to have immunomodulatory properties. We here review the literature on this topic and provide some clinical examples including the use of statins in Graves' orbitopathy, rheumatoid arthritis, multiple sclerosis, and adult-onset Still's disease. In that context, we introduce a special immunodiagnostics method developed at the Institute of  Diabetes "Gerhardt Katsch" in Karlsburg, Germany, to not only measure but also monitor immune disease activity.

Impact of trial design and patient heterogeneity on the identification of clinically effective therapies for progressive MS

Clinically effective immunomodulatory therapies have been developed for relapsing-remitting multiple sclerosis (RRMS), but they have generally not translated to a corresponding slowing of disability accumulation in progressive forms of multiple sclerosis (MS). Since disability is multifaceted, progressive patients are heterogeneous, and the drivers of disease progression are still unclear, it has been difficult to identify the most informative outcome measures for progressive trials. Historically, secondary outcome measures have focused on inflammatory measures, which contributed to the recent identification of immunomodulatory therapies benefiting younger patients with more inflammatory progressive MS. Meanwhile, agents capable of treating late-stage disease have remained elusive. Consequently, measures of neurodegeneration are becoming common. Here, we review completed clinical trials testing immunomodulatory therapies in primary progressive multiple sclerosis (PPMS) or secondary progressive multiple sclerosis (SPMS) and discuss the features contributing to trial design variability in relation to trial outcomes, and how efforts toward better patient stratification and inclusion of reliable progression markers could improve outcomes.

Atorvastatin Inhibits the HIF1α-PPAR Axis, Which Is Essential for Maintaining the Function of Human Induced Pluripotent Stem Cells

We herein report a novel mechanism of action of statin preparations using a new drug discovery method. Milk fat globule-EGF factor 8 protein (MFG-E8) was identified from the secretory component of mouse embryonic fibroblast (MEF) as a cell adhesion-promoting factor effective for screening active cellular agents of human induced pluripotent stem cells (hiPSCs) in vitro using electrochemical impedance. Our analyses showed that atorvastatin did not cause death in myocardial cells differentiated from hiPSCs but reduced the pluripotent cell survival in vitro when using serum- and albumin-free media, and inhibited the ability to form teratomas in mice. This result could have been already the cytopathic effect of atorvastatin, and complete elimination of hiPSCs was confirmed in the xenotransplantation assay. The administration of atorvastatin to hiPSCs caused the expression of hypoxia inducible factor (HIF)1α mRNA to be unchanged at 6 hr and downregulated at 24 hr. In addition, the inhibition of the survival of hiPSCs was confirmed by HIF1α-peroxisome proliferator-activated receptor (PPAR) axis inhibition. These results suggest that the addition of atorvastatin to hiPSC cultures reduces the survival of pluripotent cells by suppressing the HIF1α-PPAR axis. In summary, the HIF1α-PPAR axis has an important role in maintaining the survival of pluripotent hiPSCs.

Effect of Atorvastatin on the Disease Activity and Severity of Rheumatoid Arthritis: Double-Blind Randomized Controlled Trial

INTRODUCTION

HMG-CoA (3-hydroxy-3- methylglutary lcoenzyme A) reductase inhibitors (statins) have anti-inflammatory properties which may be particularly useful in rheumatoid arthritis to suppress disease activity and inflammatory factors.

AIM

The purpose of this clinical trial was to determine anti-inflammatory properties of statins in rheumatoid arthritis.

MATERIALS AND METHODS

Eighty Iranian patients with rheumatoid arthritis, aged between 19 to 75 years were recruited to take part in this randomized, double-blind placebo-controlled trial. Subjects were randomly allocated to two groups to take atorvastatin or placebo 40 mg daily as an adjunct to current disease-modifying anti-rheumatic drugs (DMARDs) treatment. Disease Activity Score-28 (DAS28), C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), swollen joint count (SJC) & tender joint count (TJC) were assessed before and after three months intervention.

RESULTS

Analysis was based on intention to treat. DAS28 significantly declined in the atorvastatin group in comparison with placebo (p< 0.001). SJC, TJC, CRP and ESR also were significantly dropped in the atorvastatin group in comparison with placebo.

CONCLUSION

It can be concluded that atorvastatin can suppress RA activity and inflmmatory factors in RA patients for high to moderate grade of inflmmation.

Atorvastatin added to interferon beta for relapsing multiple sclerosis: 12-month treatment extension of the randomized multicenter SWABIMS trial

Background

Statins have anti-inflammatory and immunomodulatory properties in addition to lipid-lowering effects.

Objectives

To report the 12-month extension of a phase II trial evaluating the efficacy, safety and tolerability of atorvastatin 40 mg/d added to interferon beta-1b (IFNB-1b) in relapsing-remitting multiple sclerosis (RRMS).

Methods

In the randomized, multicenter, parallel-group, rater-blinded core study, 77 RRMS patients started IFNB-1b. At month three they were randomized 1∶1 to receive atorvastatin 40 mg/d or not in addition to IFNB-1b until month 15. In the subsequent extension study, patients continued with unchanged medication for another 12 months. Data at study end were compared to data at month three of the core study.

Results

27 of 72 patients that finished the core study entered the extension study. 45 patients were lost mainly due to a safety analysis during the core study including a recruitment stop for the extension study. The primary end point, the proportion of patients with new lesions on T2-weighted images was equal in both groups (odds ratio 1.926; 95% CI 0.265–14.0007; p = 0.51). All secondary endpoints including number of new lesions and total lesion volume on T2-weighted images, total number of Gd-enhancing lesions on T1-weighted images, volume of grey and white matter, EDSS, MSFC, relapse rate, number of relapse-free patients and neutralizing antibodies did not show significant differences either. The combination therapy was well tolerated.

Conclusions

Atorvastatin 40 mg/day in addition to IFNB-1b did not have any beneficial effects on RRMS compared to IFNB-1b monotherapy over a period of 24 months.

Trial Registration

ClinicalTrials.gov NCT01111656

Stimulation of osteoclast formation by RANKL requires interferon regulatory factor-4 and is inhibited by simvastatin in a mouse model of bone loss

Diseases of bone loss are a major public health problem. Here, we report the novel therapeutic action of simvastatin in osteoclastogenesis and osteoprotection, demonstrated by the ability of simvastatin to suppress osteoclast formation in vitro and in vivo. We found that in vitro, IRF4 expression is upregulated during osteoclast differentiation induced by RANKL (receptor activator of nuclear factor-κB ligand), while simvastatin blocks RANKL-induced osteoclastogenesis and decreases expression of NFATc1 (nuclear factor of activated T-cells, cytoplasmic, calcineurin-dependent 1), IRF4 and osteoclast markers. We also show that IRF4 acts in cooperation with NFATc2 and NF-κB on the promoter region of NFATc1 to accelerate its initial transcription during the early stage of osteoclastogenesis. Moreover, our study using IRF4 siRNA knockdown directly demonstrates the requirement for IRF4 in NFATc1 mRNA transcription and its necessity in RANKL-induced osteoclast differentiation. Our results suggest that the reduction in osteoclastogenesis is partly due to the inhibition of IRF4 production in RANKL-induced osteoclast differentiation. To investigate the in vivo effects of simvastatin in RANKL-treated mice, we examined the bone mineral density (BMD) of a mouse model of bone loss, and found that simvastatin significantly reduced bone loss by suppressing osteoclast numbers in vivo, even in the presence of high concentrations of RANKL. These results suggest that the depletion of osteoclasts is not due to the reduction in RANKL produced by osteoblasts in vivo. The results are consistent with the hypothesis that simvastatin blocks RANKL-induced IRF4 expression in osteoclastogenesis. We propose that the expression of IRF4 by osteoclasts could be a promising new therapeutic target in bone-loss diseases.

Simvastatin ameliorates cauda equina compression injury in a rat model of lumbar spinal stenosis

Lumbar spinal stenosis (LSS) is the leading cause of morbidity and mortality worldwide. LSS pathology is associated with secondary injury caused by inflammation, oxidative damage and cell death. Apart from laminectomy, pharmacological therapy targeting secondary injury is limited. Statins are FDA-approved cholesterol-lowering drug. They also show pleiotropic anti-inflammatory, antioxidant and neuroprotective effects. To investigate the therapeutic efficacy of simvastatin in restoring normal locomotor function after cauda equina compression (CEC) in a rat model of LSS, CEC injury was induced in rats by implanting silicone gels into the epidural spaces of L4 and L6. Experimental group was treated with simvastatin (5 mg/kg body weight), while the injured (vehicle) and sham operated (sham) groups received vehicle solution. Locomotor function in terms of latency on rotarod was measured for 49 days and the threshold of pain was determined for 14 days. Rats were sacrificed on day 3 and 14 and the spinal cord and cauda equina fibers were extracted and studied by histology, immunofluorescence, electron microscopy (EM) and TUNEL assay. Simvastatin aided locomotor functional recovery and enhanced the threshold of pain after the CEC. Cellular Infiltration and demyelination decreased in the spinal cord from the simvastatin group. EM revealed enhanced myelination of cauda equina in the simvastatin group. TUNEL assay showed significantly decreased number of apoptotic neurons in spinal cord from the simvastatin group compared to the vehicle group. Simvastatin hastens the locomotor functional recovery and reduces pain after CEC. These outcomes are mediated through the neuroprotective and anti-inflammatory properties of simvastatin. The data indicate that simvastatin may be a promising drug candidate for LSS treatment in humans.

Atorvastatin added to interferon β for relapsing multiple sclerosis: a randomized controlled trial

Statins have anti-inflammatory and immunomodulatory properties in addition to lipid-lowering effects. The present study evaluated the effect of atorvastatin added to interferon beta-1b in multiple sclerosis (MS) in a multicenter, randomized, parallel-group, rater-blinded study performed in eight Swiss hospitals. Seventy-seven patients with relapsing-remitting MS started interferon beta-1b every other day. After 3 months, they were randomized 1:1 to receive atorvastatin 40 mg/day or not in addition to interferon beta-1b until month 15. The primary endpoint was the proportion of patients with new lesions on T2-weighted images at month 15 compared to baseline at month three. At study end, the proportion of patients with new lesions on T2-weighted images was equal in both groups (odds ratio 1.14; 95 % CI 0.36-3.56; p = 0.81). All predefined secondary endpoints including number of new lesions and total lesion volume on T2-weighted images, total number of new Gd-enhancing lesions on T1-weighted images, total brain volume, volume of grey matter, volume of white matter, EDSS, MSFC, relapse rate, time to first relapse, number of relapse-free patients and neutralizing antibodies did not show any significant differences (all p values >0.1). Transient elevations of liver enzymes were more frequent with atorvastatin (p = 0.02). In conclusion, atorvastatin 40 mg/day in addition to interferon beta-1b did not have a beneficial effect on relapsing-remitting MS compared to interferon beta-1b monotherapy over a 12-month period.

Simvastatin inhibits IFN regulatory factor 4 expression and Th17 cell differentiation in CD4+ T cells derived from patients with multiple sclerosis

Subsequent to the clinical trial of simvastatin in patients with relapsing remitting multiple sclerosis (RR MS), which demonstrated the ability of simvastatin to inhibit new inflammatory CNS lesion formation, the current in vitro study has characterized the mechanisms through which simvastatin inhibits Th17 cell differentiation. The anti-inflammatory effects of statins are mediated by the inhibition of isoprenylation, which ensures proper membrane insertion and function of proteins. Small GTPases, involved in multiple signal transduction pathways, are the key targets for isoprenylation. We report that simvastatin, one of the most hydrophobic statins with good CNS penetration, inhibited Th17 cell differentiation and IL-17A, IL-17F, IL-21, and IL-22 secretion in in vitro-differentiated naive CD4(+) T cells from RR MS patients. Simvastatin exerted a less prominent effect on the cells from healthy controls, as it inhibited only IL-17F secretion. The inhibition of Th17 cell differentiation was mediated via inhibition of IFN regulatory factor 4 (IRF4) expression, which was identified as a key transcription factor for human Th17 cell differentiation using both IRF4 gene knockdown and overexpression experiments. In studies addressing which isoprenylation pathway--geranylgeranylation or farnesylation--is inhibited by simvastatin, we demonstrated that the geranylgeranyl transferase inhibitor replicated the effect of simvastatin. Selective inhibition of geranylgeranylated RhoA-associated kinase replicated the effect of simvastatin on the inhibition of IRF4 expression and IL-17A, IL-17F, IL-21, and IL-22 secretion, presenting a promising new therapeutic approach for this disabling disease.

Pleiotropic effects of the HMG-CoA reductase inhibitors

The HMG-CoA reductase inhibitors (statins) are used extensively in the treatment of hyperlipidemia. They have also demonstrated a benefit in a variety of other disease processes. These secondary actions are known as pleiotropic effects. Our paper serves as a focused and updated discussion on the pleiotropy of statins and emphasizes the importance of randomized placebo-controlled trials to further elucidate this interesting phenomenon.

Immunomodulatory drug treatment in multiple sclerosis

The fundamental role of inflammatory immune processes in the pathology of multiple sclerosis (MS) provides the rationale for immunomodulatory therapies that attempt to shift the immune system from pro-inflammatory to anti-inflammatory pathways and induce regulatory mechanisms. Growing understanding of immune cellular and molecular mechanisms together with modern biotechnology engendered promising immunomodulatory treatment strategies, with novel mechanisms of actions and different levels of specificity. These include inhibitory molecules, monoclonal antibodies, cell therapies and agents that are administered orally or by infrequent infusions. Several of these treatments have demonstrated impressive efficacy in Phase II and III clinical trials by reducing disease activity and accumulation of disability. However, with the advent of potent therapies, rare but severe adverse effects, such as CNS infections and malignancies, have occurred. This article describes current and upcoming immunomodulatory strategies for MS therapy. The potential of immunomodulatory treatments to counteract the inflammatory characteristics of MS and support neuroprotective processes is discussed.

Comparative neuroprotective profile of statins in quinolinic acid induced neurotoxicity in rats

A possible neuroprotective role has been recently suggested for 3H3MGCoA reductase inhibitors (statins). Here, we sought to determine neuroprotective effect of statins in quinolinic acid induced neurotoxicity in rats. Rats were surgically administered quinolinic acid and treated with Atorvastatin (10, 20 mg/kg), simvastatin (15, 30 mg/kg) and fluvastatin (5, 10 mg/kg) once daily up to 3 weeks. Atorvastatin (10, 20 mg/kg), simvastatin (30 mg/kg) and fluvastatin (10 mg/kg) treatment significantly attenuated the quinolinic acid induced behavioral (locomotor activity, rotarod performance and beam walk test), biochemical (lipid peroxidation, nitrite concentration, SOD and catalase), mitochondrial enzyme complex alterations in rats suggesting their free radical scavenging potential. Additionally, atorvastatin (10, 20 mg/kg), simvastatin (30 mg/kg) and fluvastatin (10 mg/kg) significantly decrease the TNF-α level and striatal lesion volume in quinolinic acid treated animals indicating their anti-inflammatory effects. In comparing the protective effect of different statins, atorvastatin is effective at both the doses while simvastatin and fluvastatins at respective lower doses were not able to produce the protective effect in quinolinic acid treated animals. These modulations can account, at least partly, for the beneficial effect of statins in our rodent model of striatal degeneration. Our findings show that statins could be explored as possible neuroprotective agents for neurodegenerative disorders such as HD.

SWiss Atorvastatin and interferon Beta-1b trial In Multiple Sclerosis (SWABIMS)--rationale, design and methodology

Background

Statins have anti-inflammatory and immunomodulatory properties in addition to their lipid-lowering effects. Currently, the effects of statins on multiple sclerosis are still controversial. Therefore, randomized clinical trials are needed to provide better evidence on the therapeutic potential of statins in multiple sclerosis. The SWiss Atorvastatin and Interferon Beta-1b trial in Multiple Sclerosis (SWABIMS) evaluates the efficacy, safety and tolerability of atorvastatin 40 mg per os daily and subcutaneous interferon beta-1b every other day compared to monotherapy with subcutaneous interferon beta-1b every other day in patients with relapsing-remitting multiple sclerosis.

Methods/Design

SWABIMS is a multi-centre, randomized, parallel-group, rater-blinded, Phase IIb-study conducted in eight hospitals in Switzerland. 80 treatment naïve patients with relapsing-remitting forms of multiple sclerosis will receive subcutaneous interferon beta-1b for three months. Afterwards, they are randomized into two equal-sized parallel arms, receiving atorvastatin 40 mg/d or not in addition to interferon beta-1b for another 12 months. Disease activity measured by the proportion of patients with new T2 lesions is the primary endpoint.

Discussion

SWABIMS is designed to give further information about the therapeutic effect of atorvastatin 40 mg per os daily as add-on therapy to interferon beta-1b in patients with relapsing-remitting multiple sclerosis. Furthermore important safety and tolerability data will be generated.

Trial Registration

http://www.clinicaltrials.gov. Identifier: NCT00942591; Swissmedic reference number: 2005DR2119