Interleukin 12 (IL-12) family cytokines: Role in immune pathogenesis and treatment of CNS autoimmune disease

Cytokines play crucial roles in coordinating the activities of innate and adaptive immune systems. In response to pathogen recognition, innate immune cells secrete cytokines that inform the adaptive immune system about the nature of the pathogen and instruct naïve T cells to differentiate into the appropriate T cell subtypes required to clear the infection. These include Interleukins, Interferons and other immune-regulatory cytokines that exhibit remarkable functional redundancy and pleiotropic effects. The focus of this review, however, is on the enigmatic Interleukin 12 (IL-12) family of cytokines. This family of cytokines plays crucial roles in shaping immune responses during antigen presentation and influence cell-fate decisions of differentiating naïve T cells. They also play essential roles in regulating functions of a variety of effector cells, making IL-12 family cytokines important therapeutic targets or agents in a number of inflammatory diseases, such as the CNS autoimmune diseases, uveitis and multiple sclerosis.     

Catecholamine-containing biodegradable microsphere implants as a novel approach in the treatment of CNS neurodegenerative disease

Biodegradable controlled-release microsphere systems made with the biocompatible biodegradable polyester excipient poly (dl-lactide-co-glycolide) constitute an exciting new technology for drug delivery to the central nervous system (CNS). Implantable controlled-release microspheres containing dopamine (DA) or norepinephrine (NE) provide a novel means to compare DA- or NE-induced restitution of function in unilateral 6-hydroxydopamine lesioned rats. A suspension of 3 μL of DA- or NE-containing microspheres or empty microspheres was implanted in 2 sites of the DA denervated striatum of rats previously unilaterally lesioned with 6-hydroxydopamine. Contralateral-rotational behavior induced by apomorphine was used as an index of lesion success and, following implantation of the microspheres, also as an index of functional recovery. Interestingly, both DA- and NE-microsphere-implanted rats displayed a 30–50% reduction in the number of apomorphine-induced rotations up to 8 wk postimplantation. Rats implanted with empty microspheres did not demonstrate significant changes in contralateral rotational behavior. Behavioral studies following implantation of a mixture of DA and NE microspheres revealed an 80% decrease in the number of apomorphine induced rotations up to 4 wk. On conclusion of the studies, immunocytochemical examination revealed growth of DA and tyrosine hydroxylase immunoreactive fibers in the striatum of DA and NE microsphere-implanted rats. Functional behavior appeared to correlate with the degree of fiber growth. Preliminary electron microscopic studies showed signs of axonal sprouting in the vicinity of the implanted microspheres. No growth was noted in rats implanted with empty microspheres. This report reviews the abilities of both microencapsulated NE and DA to assure functional recovery and to promote DA fiber (re)growth in parkinsonian rats. This novel means to deliver these substances to the central nervous system could be of therapeutic usefulness in Parkinson's disease.     

The commonality of protein interaction networks determined in neurodegenerative disorders (NDDs)

MOTIVATION: Neurodegenerative disorders (NDDs) are progressive and fatal disorders, which are commonly characterized by the intracellular or extracellular presence of abnormal protein aggregates. The identification and verification of proteins interacting with causative gene products are effective ways to understand their physiological and pathological functions. The objective of this research is to better understand common molecular pathogenic mechanisms in NDDs by employing protein-protein interaction networks, the domain characteristics commonly identified in NDDs and correlation among NDDs based on domain information. RESULTS: By reviewing published literatures in PubMed, we created pathway maps in Kyoto Encyclopedia of Genes and Genomes (KEGG) for the protein-protein interactions in six NDDs: Alzheimer's disease (AD), Parkinson's disease (PD), amyotrophic lateral sclerosis (ALS), Huntington's disease (HD), dentatorubral-pallidoluysian atrophy (DRPLA) and prion disease (PRION). We also collected data on 201 interacting proteins and 13 compounds with 282 interactions from the literature. We found 19 proteins common to these six NDDs. These common proteins were mainly involved in the apoptosis and MAPK signaling pathways. We expanded the interaction network by adding protein interaction data from the Human Protein Reference Database and gene expression data from the Human Gene Expression Index Database. We then carried out domain analysis on the extended network and found the characteristic domains, such as 14-3-3 protein, phosphotyrosine interaction domain and caspase domain, for the common proteins. Moreover, we found a relatively high correlation between AD, PD, HD and PRION, but not ALS or DRPLA, in terms of the protein domain distributions. AVAILABILITY: http://www.genome.jp/kegg/pathway/hsa/hsa01510.html (KEGG pathway maps for NDDs).     

Kinase inhibitors for the treatment of inflammatory and autoimmune disorders

Drugs targeting inhibition of kinases for the treatment of inflammation and autoimmune disorders have become a major focus in the pharmaceutical and biotech industry. Multiple kinases from different pathways have been the targets of interest in this endeavor. This review describes some of the recent developments in the search for inhibitors of IKK2, Syk, Lck, and JAK3 kinases. It is anticipated that some of these compounds or newer inhibitors of these kinases will be approved for the treatment of rheumatoid arthritis, psoriasis, organ transplantation, and other autoimmune diseases.     

Neuroprotective and neurotoxic roles of levodopa (L-DOPA) in neurodegenerative disorders relating to Parkinson's disease

Summary.  Despite its being the most efficacious drug for symptom reversal in Parkinson's disease (PD), there is concern that chronic levodopa (L-DOPA) treatment may be detrimental. In this paper we review the potential for L-DOPA to 1) autoxidize from a catechol to a quinone, and 2) generate other reactive oxygen species (ROS). Overt toxicity and neuroprotective effects of L-DOPA, both in vivo and in vitro, are described in the context of whether L-DOPA may accelerate or delay progression of human Parkinson's disease. Received June 29, 2001 Accepted August 6, 2001 Published online June 3, 2002     

Cutting edge: oral type I IFN-tau promotes a Th2 bias and enhances suppression of autoimmune encephalomyelitis by oral glatiramer acetate

IFN-tau, a novel type I IFN that possesses immunomodulatory properties, lacks toxicity normally associated with other type I IFNs. We examined the effects of oral IFN-tau alone and in combination with oral glatiramer acetate in experimental allergic encephalomyelitis (EAE). By comparison of oral administration of IFN-alpha, -beta, and -tau to myelin basic protein-specific TCR-transgenic mice, we demonstrate these type I IFNs promote secretion of the Th2 cytokine IL-10 with similar efficiency. Whereas IFN-alpha and -beta induced IFN-gamma secretion, a Th1 cytokine, IFN-tau did not. Oral IFN-tau alone suppressed EAE. When suboptimal doses were administered orally in combination to wild-type mice, IFN-tau and glatiramer acetate had a synergistic beneficial effect in suppression of EAE. This combination was associated with TGF-beta secretion and enhanced IL-10 production. Thus, IFN-tau is a potential candidate for use as a single agent or in combination therapy for multiple sclerosis.     

Adeno-associated virus-mediated gene delivery approaches for the treatment of CNS disorders

Over the last few years, a large number of preclinical and clinical studies have demonstrated the potential of gene therapy applications using adeno-associated viral (AAV) vectors. Gene transfer via AAV vectors has been particularly successful for the treatment or adjunct therapy of several CNS disorders. The present review summarizes the progress on AAV gene delivery models for three different CNS disorders. In particular, we discuss advances in AAV-mediated gene transfer strategies in animal models of Parkinson's disease, Alzheimer's disease and spinal cord trauma and summarize the results from the first clinical studies using AAV systems.     

Modelling the cost effectiveness of interferon beta and glatiramer acetate in the management of multiple sclerosis

ObjectiveTo evaluate the cost effectiveness of four disease modifying treatments (interferon betas and glatiramer acetate) for relapsing remitting and secondary progressive multiple sclerosis in the United Kingdom.DesignModelling cost effectiveness.SettingUK NHS.ParticipantsPatients with relapsing remitting multiple sclerosis and secondary progressive multiple sclerosis.ResultsThe base case cost per quality adjusted life year gained by using any of the four treatments ranged from £42 000 ($66 469; €61 630) to £98 000 based on efficacy information in the public domain. Uncertainty analysis suggests that the probability of any of these treatments having a cost effectiveness better than £20 000 at 20 years is below 20%. The key determinants of cost effectiveness were the time horizon, the progression of patients after stopping treatment, differential discount rates, and the price of the treatments.ConclusionsCost effectiveness varied markedly between the interventions. Uncertainty around point estimates was substantial. This uncertainty could be reduced by conducting research on the true magnitude of the effect of these drugs, the progression of patients after stopping treatment, the costs of care, and the quality of life of the patients. Price was the key modifiable determinant of the cost effectiveness of these treatments.

What is already known on this topic

Interferon beta and glatiramer acetate are the only disease modifying therapies used to treat multiple sclerosisEconomic evaluations of these drugs have had flaws in the specification of the course of the disease, efficacy, duration of treatment, mortality, and the analysis of uncertaintyNone of the existing estimates of cost effectiveness can be viewed as robust

What this study adds

The cost per quality adjusted life year gained is unlikely to be less than £40 000 for interferon beta or glatiramer acetateExperience after stopping treatment is a key determinant of the cost effectiveness of these therapiesKey factors affecting point estimates of cost effectiveness are the cost of interferon beta and glatiramer acetate, the effect of these therapies on disease progression, and the time horizon evaluated     

1-(Benzo[d]thiazol-2-yl)-3-phenylureas as dual inhibitors of casein kinase 1 and ABAD enzymes for treatment of neurodegenerative disorders

Several neurodegenerative disorders including Alzheimer’s disease (AD) have been connected with deregulation of casein kinase 1 (CK1) activity. Inhibition of CK1 therefore presents a potential therapeutic strategy against such pathologies. Recently, novel class of CK1-specific inhibitors with N-(benzo[d]thiazol-2-yl)-2-phenylacetamide structural scaffold has been discovered. 1-(benzo[d]thiazol-2-yl)-3-phenylureas, on the other hand, are known inhibitors amyloid-beta binding alcohol dehydrogenase (ABAD), an enzyme also involved in pathophysiology of AD. Based on their tight structural similarity, we decided to evaluate series of previously published benzothiazolylphenylureas, originally designed as ABAD inhibitors, for their inhibitory activity towards CK1. Several compounds were found to be submicromolar CK1 inhibitors. Moreover, two compounds were found to inhibit both, ABAD and CK1. Such dual-activity could be of advantage for AD treatment, as it would simultaneously target two distinct pathological processes involved in disease’s progression. Based on PAMPA testing both compounds were suggested to permeate the blood-brain barrier, which makes them, together with their unique dual activity, interesting lead compounds for further development.     

Neuroprotective effect of combination therapy of glatiramer acetate and epigallocatechin-3-gallate in neuroinflammation

Multiple sclerosis (MS) is an inflammatory autoimmune disease of the central nervous system. However, studies of MS and the animal model, experimental autoimmune encephalomyelitis (EAE), indicate that neuronal pathology is the principle cause of clinical disability. Thus, there is need to develop new therapeutic strategies that not only address immunomodulation but also neuroprotection. Here we show that the combination therapy of Glatiramer acetate (GA), an immunomodulatory MS therapeutic, and the neuroprotectant epigallocatechin-3-gallate (EGCG), the main phenol in green tea, have synergistic protective effects in vitro and in the EAE model. EGCG and GA together led to increased protection from glutamate- and TRAIL-induced neuronal cell death in vitro. EGCG combined with GA induced regeneration of hippocampal axons in an outgrowth assay. The combined application of EGCG and GA did not result in unexpected adverse events in vivo. Neuroprotective and neuroregenerative effects could be translated in the in vivo model, where combination treatment with EGCG and GA significantly delayed disease onset, strongly reduced clinical severity, even after onset of symptoms and reduced inflammatory infiltrates. These results illustrate the promise of combining neuroprotective and anti-inflammatory treatments and strengthen the prospects of EGCG as an adjunct therapy for neuroinflammatory and neurodegenerative diseases.     

Selective inhibition of Tumor necrosis factor receptor-1 (TNFR1) for the treatment of autoimmune diseases

Anti-TNF biologics have achieved great success in the treatment of autoimmune diseases and have been the most selling biologics on market. However, the anti-TNF biologics have shown some disadvantages such as poor efficacy to some patients and high risk of infection and malignancies during clinical application. Current anti-TNF biologics are antibodies or antibody fragments that bind to TNF-α and subsequently block both TNF-TNFR1 and TNF-TNFR2 signaling. Transgenic animal studies indicate that TNFR1 signaling is responsible for chronic inflammation and cell apoptosis whereas TNFR2 signaling regulates tissue regeneration and inflammation. Recent studies propose to selectively inhibit TNFR1 to enhance efficacy and avoid side effects. In this review, we introduce the biology of TNF-TNFR1 and TNF-TNFR2 signaling, the advantages of selective inhibition of TNF-TNFR1 signaling and research updates on the development of selective inhibitors for TNF-TNFR1 signaling. Antibodies, small molecules and aptamers that selectively inhibit TNFR1 have showed therapeutic potential and less side effects in preclinical studies. Development of selective inhibitors for TNFR1 is a good strategy to enhance the efficacy and reduce the side effects of anti-TNF inhibitors and will be a trend for next-generation of anti-TNF inhibitors.     

Relevance of protein nitration in brain injury: a key pathophysiological mechanism in neurodegenerative, autoimmune, or inflammatory CNS diseases and stroke

Summary. This review has focused on the evidence for the involvement of nitrative oxidation in certain neurodegenerative disorders (Parkinsons Disease, Alzheimers Disease, Amyotrophic Lateral Sclerosis), stroke, and inflammatory and autoimmune disorders (with particular attention devoted to multiple sclerosis).The relationship between protein peroxidation and pathological changes observed in the above disorders has been reported. Whereas many of the findings are from studies with animal models and autoptic specimens from human patients, few data are available from cerebrospinal fluid and blood samples of the patients at different times and disease stages.The participation of nitrative oxidation to the direct and indirect injury of neurons and other cells of the brain (i.e., oligodendrocytes, for multiple sclerosis) is clear; less evident is their relevance for the development and progression of these disorders.Further studies should be aimed to establish the clinical and prognostic value of peroxidative markers for the CNS diseases considered. This is fundamental for the development of therapeutic interventions antagonizing nitric oxide-related species damage.     

S-Nitrosylation and uncompetitive/fast off-rate (UFO) drug therapy in neurodegenerative disorders of protein misfolding

Although activation of glutamate receptors is essential for normal brain function, excessive activity leads to a form of neurotoxicity known as excitotoxicity. Key mediators of excitotoxic damage include overactivation of N-methyl-D-aspartate (NMDA) receptors, resulting in excessive Ca(2+) influx with production of free radicals and other injurious pathways. Overproduction of free radical nitric oxide (NO) contributes to acute and chronic neurodegenerative disorders. NO can react with cysteine thiol groups to form S-nitrosothiols and thus change protein function. S-nitrosylation can result in neuroprotective or neurodestructive consequences depending on the protein involved. Many neurodegenerative diseases manifest conformational changes in proteins that result in misfolding and aggregation. Our recent studies have linked nitrosative stress to protein misfolding and neuronal cell death. Molecular chaperones - such as protein-disulfide isomerase, glucose-regulated protein 78, and heat-shock proteins - can provide neuroprotection by facilitating proper protein folding. Here, we review the effect of S-nitrosylation on protein function under excitotoxic conditions, and present evidence that NO contributes to degenerative conditions by S-nitrosylating-specific chaperones that would otherwise prevent accumulation of misfolded proteins and neuronal cell death. In contrast, we also review therapeutics that can abrogate excitotoxic damage by preventing excessive NMDA receptor activity, in part via S-nitrosylation of this receptor to curtail excessive activity.     

Expansion of human neural precursor cells in large-scale bioreactors for the treatment of neurodegenerative disorders

The transplantation of in vitro expanded human neural precursor cells (hNPCs) represents a potential new treatment alternative for individuals suffering from incurable neurodegenerative disorders such as Parkinson's disease (PD) and Huntington's disease (HD). However, in order for cell restorative therapy to have widespread therapeutic significance, it will be necessary to generate unlimited quantities of clinical grade hNPCs in a standardized method. We report here that we have developed a serum-free medium and scale-up protocols that allow for the generation of clinical quantities of human telencephalon-derived hNPCs in 500-mL computer-controlled suspension bioreactors. The average hNPC aggregate diameter in the bioreactors was maintained below a target value of 500 microm by controlling the liquid shear field. The human cells, which were inoculated at 10(5) cells/mL, exhibited a doubling time of 84 h, underwent a 36-fold expansion over the course of 18 days, and maintained an average viability of over 90%. The bioreactor-derived hNPCs retained their nestin expression following expansion and were able to differentiate into glial and neuronal phenotypes under defined conditions. It has also been demonstrated that these hNPCs differentiated to a GABAergic phenotype that has recently been shown to be able to restore functional behavior in rat models of HD and neuropathic pain (Mukhida, K. et al. Stem Cells 2007; DOI 10.1634/stemcells.2007-0326). This study demonstrates that clinical quantities of hNPCs can be successfully and reproducibly generated under standardized conditions in computer-controlled suspension bioreactors.     

Mutant ubiquitin (UBB+1) associated with neurodegenerative disorders is hydrolyzed by ubiquitin C-terminal hydrolase L3 (UCH-L3)

Mutant ubiquitin (UBB⁺¹) accumulates in the hallmarks of tauopathies and polyglutamine diseases. We show that the deubiquitinating enzyme YUH1 of Saccharomyces cerevisiae and its mouse and human ortholog UCH-L3 are able to hydrolyze the C-terminal extension of UBB⁺¹. This yields another dysfunctional ubiquitin molecule (UB^G76Y) with biochemical properties similar to full length UBB⁺¹. UBB⁺¹ may be detected in post-mortem tissue due to impaired C-terminal truncation of UBB⁺¹. Although the level of UCH-L3 protein in several neurodegenerative diseases is unchanged, we show that in vitro oxidation of recombinant UCH-L3 impairs its deubiquitinating activity. We postulate that impaired UCH-L3 function may contribute to the accumulation of full length UBB⁺¹ in various pathologies.     

Involvement and interplay of Parkin, PINK1, and DJ1 in neurodegenerative and neuroinflammatory disorders

The involvement of parkin, PINK1, and DJ1 in mitochondrial dysfunction, oxidative injury, and impaired functioning of the ubiquitin-proteasome system (UPS) has been intensively investigated in light of Parkinson's disease (PD) pathogenesis. However, these pathological mechanisms are not restricted to PD, but are common denominators of various neurodegenerative and neuroinflammatory disorders. It is therefore conceivable that parkin, PINK1, and DJ1 are also linked to the pathogenesis of other neurological diseases, including Alzheimer's disease (AD) and multiple sclerosis (MS). The importance of these proteins in mechanisms underlying neurodegeneration is reflected by the neuroprotective properties of parkin, DJ1, and PINK1 in counteracting oxidative stress and improvement of mitochondrial and UPS functioning. This review provides a concise overview on the cellular functions of the E3 ubiquitin ligase parkin, the mitochondrial kinase PINK1, and the cytoprotective protein DJ1 and their involvement and interplay in processes underlying neurodegeneration in common neurological disorders.     

Roles of the complement system in human neurodegenerative disorders

Complement is an important component of the innate immune response with the capacity to recognize and clear infectious challenges that invade the CNS through a damaged blood brain barrier. For instance, the membrane attack complex is involved in cytotoxic and cytolytic activities while other smaller fragments lead to cell activation (chemotaxis) and phagocytosis of the intruders. It is noteworthy that there is a growing body of evidence that uncontrolled complement biosynthesis and activation in the CNS can contribute to exacerbate the neuronal loss in several neurodegenerative disorders. We provide here an insightful review of the double-edged sword activities of the local innate complement system in the CNS and discuss further the potential therapeutic avenues of delivering complement inhibitors to control brain inflammation.