Amyloid fibrils composed of hexameric peptides attenuate neuroinflammation

Energy landscapes for clusters of hexapeptides

We present the results for energy landscapes of hexapeptides obtained using interfaces to the Large-scale Atomic/Molecular Massively Parallel Simulator (LAMMPS) program. We have used basin-hopping global optimization and discrete path sampling to explore the landscapes of hexapeptide monomers, dimers, and oligomers containing 10, 100, and 200 monomers modeled using a residue-level coarse-grained potential, Mpipi, implemented in LAMMPS. We find that the dimers of peptides containing amino acid residues that are better at promoting phase separation, such as tyrosine and arginine, have melting peaks at higher temperature in their heat capacity compared to phenylalanine and lysine, respectively. This observation correlates with previous work on the same uncapped hexapeptide monomers modeled using atomistic potential. For oligomers, we compare the variation in monomer conformations with radial distance and observe trends for selected angles calculated for each monomer. The LAMMPS interfaces to the GMIN and OPTIM programs for landscape exploration offer new opportunities to investigate larger systems and provide access to the coarse-grained potentials implemented within LAMMPS.

Molecular mechanisms linking type 2 diabetes mellitus and late-onset Alzheimer's disease: A systematic review and qualitative meta-analysis

Research evidence indicating common metabolic mechanisms through which type 2 diabetes mellitus (T2DM) increases risk of late-onset Alzheimer's dementia (LOAD) has accumulated over recent decades. The aim of this systematic review is to provide a comprehensive review of common mechanisms, which have hitherto been discussed in separate perspectives, and to assemble and evaluate candidate loci and epigenetic modifications contributing to polygenic risk linkages between T2DM and LOAD. For the systematic review on pathophysiological mechanisms, both human and animal studies up to December 2023 are included. For the qualitative meta-analysis of genomic bases, human association studies were examined; for epigenetic mechanisms, data from human studies and animal models were accepted. Papers describing pathophysiological studies were identified in databases, and further literature gathered from cited work. For genomic and epigenomic studies, literature mining was conducted by formalised search codes using Boolean operators in search engines, and augmented by GeneRif citations in Entrez Gene, and other sources (WikiGenes, etc.). For the systematic review of pathophysiological mechanisms, 923 publications were evaluated, and 138 gene loci extracted for testing candidate risk linkages. 3 57 publications were evaluated for genomic association and descriptions of epigenomic modifications. Overall accumulated results highlight insulin signalling, inflammation and inflammasome pathways, proteolysis, gluconeogenesis and glycolysis, glycosylation, lipoprotein metabolism and oxidation, cell cycle regulation or survival, autophagic-lysosomal pathways, and energy. Documented findings suggest interplay between brain insulin resistance, neuroinflammation, insult compensatory mechanisms, and peripheral metabolic dysregulation in T2DM and LOAD linkage. The results allow for more streamlined longitudinal studies of T2DM-LOAD risk linkages.

Data-mining unveils structure-property-activity correlation of viral infectivity enhancing self-assembling peptides

Gene therapy via retroviral vectors holds great promise for treating a variety of serious diseases. It requires the use of additives to boost infectivity. Amyloid-like peptide nanofibers (PNFs) were shown to efficiently enhance retroviral gene transfer. However, the underlying mode of action of these peptides remains largely unknown. Data-mining is an efficient method to systematically study structure-function relationship and unveil patterns in a database. This data-mining study elucidates the multi-scale structure-property-activity relationship of transduction enhancing peptides for retroviral gene transfer. In contrast to previous reports, we find that not the amyloid fibrils themselves, but rather µm-sized β-sheet rich aggregates enhance infectivity. Specifically, microscopic aggregation of β-sheet rich amyloid structures with a hydrophobic surface pattern and positive surface charge are identified as key material properties. We validate the reliability of the amphiphilic sequence pattern and the general applicability of the key properties by rationally creating new active sequences and identifying short amyloidal peptides from various pathogenic and functional origin. Data-mining-even for small datasets-enables the development of new efficient retroviral transduction enhancers and provides important insights into the diverse bioactivity of the functional material class of amyloids.

Energy Landscapes and Heat Capacity Signatures for Monomers and Dimers of Amyloid-Forming Hexapeptides

Amyloid formation is a hallmark of various neurodegenerative disorders. In this contribution, energy landscapes are explored for various hexapeptides that are known to form amyloids. Heat capacity (CV) analysis at low temperature for these hexapeptides reveals that the low energy structures contributing to the first heat capacity feature above a threshold temperature exhibit a variety of backbone conformations for amyloid-forming monomers. The corresponding control sequences do not exhibit such structural polymorphism, as diagnosed via end-to-end distance and a dihedral angle defined for the monomer. A similar heat capacity analysis for dimer conformations obtained using basin-hopping global optimisation shows clear features in end-to-end distance versus dihedral correlation plots, where amyloid-forming sequences exhibit a preference for larger end-to-end distances and larger positive dihedrals. These results hold true for sequences taken from tau, amylin, insulin A chain, a de novo designed peptide, and various control sequences. While there is a little overall correlation between the aggregation propensity and the temperature at which the low-temperature CV feature occurs, further analysis suggests that the amyloid-forming sequences exhibit the key CV feature at a lower temperature compared to control sequences derived from the same protein.

Multiple Sclerosis: Inflammatory and Neuroglial Aspects

Multiple sclerosis (MS) represents the most common acquired demyelinating disorder of the central nervous system (CNS). Its pathogenesis, in parallel with the well-established role of mechanisms pertaining to autoimmunity, involves several key functions of immune, glial and nerve cells. The disease's natural history is complex, heterogeneous and may evolve over a relapsing-remitting (RRMS) or progressive (PPMS/SPMS) course. Acute inflammation, driven by infiltration of peripheral cells in the CNS, is thought to be the most relevant process during the earliest phases and in RRMS, while disruption in glial and neural cells of pathways pertaining to energy metabolism, survival cascades, synaptic and ionic homeostasis are thought to be mostly relevant in long-standing disease, such as in progressive forms. In this complex scenario, many mechanisms originally thought to be distinctive of neurodegenerative disorders are being increasingly recognized as crucial from the beginning of the disease. The present review aims at highlighting mechanisms in common between MS, autoimmune diseases and biology of neurodegenerative disorders. In fact, there is an unmet need to explore new targets that might be involved as master regulators of autoimmunity, inflammation and survival of nerve cells.

β-sheets in serum protein are independent risk factors for coronary lesions besides LDL-C in coronary heart disease patients

Background

Coronary heart disease (CHD) patients with standard low-density lipoprotein cholesterol (LDL-C) remain at risk of cardiovascular events, making it critical to explore new targets to reduce the residual risk. The relationship between β-sheet conformation and CHD is gaining attention. This study was designed to compare the coronary lesions in CHD patients with varying LDL-C and evaluate whether serum β-sheets are associated with coronary damage.

Methods

Two hundred and one patients diagnosed with stable CHD were recruited and divided into four groups according to LDL-C. Baseline information, coronary lesion-related indicators, and peripheral blood samples were collected. Serum β-sheet content was determined by thioflavin T fluorescence.

Results

The baseline information was comparable in CHD patients with different LDL-C. No difference was found in indicators relevant to coronary lesions among groups. The content of β-sheet was negatively correlated with LDL-C. Multiple linear regression revealed that serum β-sheet was positively correlated with coronary lesion when risk factors such as age, smoking, and LDL-C were controlled.

Conclusions

This is the first study that reports the serum β-sheet levels of CHD patients being gradually increased with decreasing LDL-C when coronary lesions were comparable. Serum β-sheet might exacerbate the coronary lesions in CHD patients independent of known risk factors such as LDL-C.

Nutrient-sensing amyloid metastasis

Amyloids are organized suprastructural polypeptide arrangements. The prevalence of amyloid-related processes of pathophysiological relevance has been linked to aging-related degenerative diseases. Besides the role of genetic polymorphisms on the relative risk of amyloid diseases, the contributions of nongenetic ontogenic cluster of factors remain elusive. In recent decades, mounting evidences have been suggesting the role of essential micronutrients, in particular transition metals, in the regulation of amyloidogenic processes, both directly (such as binding to amyloid proteins) or indirectly (such as regulating regulatory partners, processing enzymes, and membrane transporters). The features of transition metals as regulatory cofactors of amyloid proteins and the consequences of metal dyshomeostasis in triggering amyloidogenic processes, as well as the evidences showing amelioration of symptoms by dietary supplementation, suggest an exaptative role of metals in regulating amyloid pathways. The self- and cross-talk replicative nature of these amyloid processes along with their systemic distribution support the concept of their metastatic nature. The role of amyloidosis as nutrient sensors would act as intra- and transgenerational epigenetic metabolic programming factors determining health span and life span, viability, which could participate as an evolutive selective pressure.

MTADV 5-MER peptide suppresses chronic inflammations as well as autoimmune pathologies and unveils a new potential target-Serum Amyloid A

Despite the existence of potent anti-inflammatory biological drugs e.g., anti-TNF and anti IL-6 receptor antibodies, for treating chronic inflammatory and autoimmune diseases, these are costly and not specific. Cheaper oral available drugs remain an unmet need. Expression of the acute phase protein Serum Amyloid A (SAA) is dependent on release of pro-inflammatory cytokines IL-1, IL-6 and TNF-α during inflammation. Conversely, SAA induces pro-inflammatory cytokine secretion, including Th17, leading to a pathogenic vicious cycle and chronic inflammation. 5- MER peptide (5-MP) MTADV (methionine-threonine-alanine-aspartic acid-valine), also called Amilo-5MER, was originally derived from a sequence of a pro-inflammatory CD44 variant isolated from synovial fluid of a Rheumatoid Arthritis (RA) patient. This human peptide displays an efficient anti-inflammatory effects to ameliorate pathology and clinical symptoms in mouse models of RA, Inflammatory Bowel Disease (IBD) and Multiple Sclerosis (MS). Bioinformatics and qRT-PCR revealed that 5-MP, administrated to encephalomyelytic mice, up-regulates genes contributing to chronic inflammation resistance. Mass spectrometry of proteins that were pulled down from an RA synovial cell extract with biotinylated 5-MP, showed that it binds SAA. 5-MP disrupted SAA assembly, which is correlated with its pro-inflammatory activity. The peptide MTADV (but not scrambled TMVAD) significantly inhibited the release of pro-inflammatory cytokines IL-6 and IL-1β from SAA-activated human fibroblasts, THP-1 monocytes and peripheral blood mononuclear cells. 5-MP suppresses the pro-inflammatory IL-6 release from SAA-activated cells, but not from non-activated cells. 5-MP could not display therapeutic activity in rats, which are SAA deficient, but does inhibit inflammations in animal models of IBD and MS, both are SAA-dependent, as shown by others in SAA knockout mice. In conclusion, 5-MP suppresses chronic inflammation in animal models of RA, IBD and MS, which are SAA-dependent, but not in animal models, which are SAA-independent.

The role of wild-type tau in Alzheimer's disease and related tauopathies

Tau oligomers have recently emerged as the principal toxic species in Alzheimer's disease (AD) and tauopathies. Tau oligomers are spontaneously self-assembled soluble tau proteins that are formed prior to fibrils, and they have been shown to play a central role in neuronal cell death and in the induction of neurodegeneration in animal models. As the therapeutic paradigm shifts to targeting toxic tau oligomers, this suggests the focus to study tau oligomerization in species that are less susceptible to fibrillization. While truncated and mutation containing tau as well as the isolated repeat domains are particularly prone to fibrillization, the wild-type (WT) tau proteins have been shown to be resistant to fibril formation in the absence of aggregation inducers. In this review, we will summarize and discuss the toxicity of WT tau both in vitro and in vivo, as well as its involvement in tau oligomerization and cell-to-cell propagation of pathology. Understanding the role of WT tau will enable more effective biomarker development and therapeutic discovery for treatment of AD and tauopathies.

Development of a brain-permeable peptide nanofiber that prevents aggregation of Alzheimer pathogenic proteins

Alzheimer's disease (AD) is proposed to be induced by abnormal aggregation of amyloidβ in the brain. Here, we designed a brain-permeable peptide nanofiber drug from a fragment of heat shock protein to suppress aggregation of the pathogenic proteins. To facilitate delivery of the nanofiber into the brain, a protein transduction domain from Drosophila Antennapedia was incorporated into the peptide sequence. The resulting nanofiber efficiently suppressed the cytotoxicity of amyloid βby trapping amyloid β onto its hydrophobic nanofiber surface. Moreover, the intravenously or intranasally injected nanofiber was delivered into the mouse brain, and improved the cognitive function of an Alzheimer transgenic mouse model. These results demonstrate the potential therapeutic utility of nanofibers for the treatment of AD.

Amyloids in Site-Specific Autoimmune Reactions and Inflammatory Responses

Amyloid deposition is a histological hallmark of common human disorders including Alzheimer's disease (AD) and type 2 diabetes. Although some reports highlight that amyloid fibrils might activate the innate immunity system via pattern recognition receptors, here, we provide multiple lines of evidence for the protection by site-specific amyloid protein analogs and fibrils against autoimmune attacks: (1) strategies targeting clearance of the AD-related brain amyloid plaque induce high risk of deadly autoimmune destructions in subjects with cognitive dysfunction; (2) administration of amyloidogenic peptides with either full length or core hexapeptide structure consistently ameliorates signs of experimental autoimmune encephalomyelitis; (3) experimental autoimmune encephalomyelitis is exacerbated following genetic deletion of amyloid precursor proteins; (4) absence of islet amyloid coexists with T-cell-mediated insulitis in autoimmune diabetes and autoimmune polyendocrine syndrome; (5) use of islet amyloid polypeptide agonists rather than antagonists improves diabetes care; and (6) common suppressive signaling pathways by regulatory T cells are activated in both local and systemic amyloidosis. These findings indicate dual modulation activity mediated by amyloid protein monomers, oligomers, and fibrils to maintain immune homeostasis. The protection from autoimmune destruction by amyloid proteins offers a novel therapeutic approach to regenerative medicine for common degenerative diseases.

Small Heat Shock Proteins, Amyloid Fibrils, and Nicotine Stimulate a Common Immune Suppressive Pathway with Implications for Future Therapies

The α7 nicotinic acetylcholine receptor (α7nAChR) is central to the anti-inflammatory function of the vagus nerve in a physiological mechanism termed the inflammatory reflex. Studies on the inflammatory reflex have been instrumental for the current development of the field of bioelectronic medicine. An independent investigation of the biological role of αB-crystallin (HspB5), the most abundant gene transcript present in active multiple sclerosis lesions in human brains, also led to α7nAChR. Induction of experimental autoimmune encephalomyelitis (EAE) in HspB5^-/- mice results in greater paralytic signs, increased levels of proinflammatory cytokines, and T-lymphocyte activation relative to wild-type animals. Administration of HspB5 was therapeutic in animal models of multiple sclerosis, retinal and cardiac ischemia, and stroke. Structure-activity studies established that residues 73-92 were as potent as the parent protein, but only when it formed amyloid fibrils. Amyloid fibrils and small heat shock proteins (sHsps) selectively bound α7nAChR on peritoneal macrophages (MΦs) and B lymphocytes, converting the MΦs to an immune suppressive phenotype and mobilizing the migration of both cell types from the peritoneum to secondary lymph organs. Here, we review multiple aspects of this work, which may be of interest for developing future therapeutic approaches for multiple sclerosis and other disorders.

Sex-specific Tau methylation patterns and synaptic transcriptional alterations are associated with neural vulnerability during chronic neuroinflammation

The molecular events underlying the transition from initial inflammatory flares to the progressive phase of multiple sclerosis (MS) remain poorly understood. Here, we report that the microtubule-associated protein (MAP) Tau exerts a gender-specific protective function on disease progression in the MS model experimental autoimmune encephalomyelitis (EAE). A detailed investigation of the autoimmune response in Tau-deficient mice excluded a strong immunoregulatory role for Tau, suggesting that its beneficial effects are presumably exerted within the central nervous system (CNS). Spinal cord transcriptomic data show increased synaptic dysfunctions and alterations in the NF-kB activation pathway upon EAE in Tau-deficient mice as compared to wildtype animals. We also performed the first comprehensive characterization of Tau post-translational modifications (PTMs) in the nervous system upon EAE. We report that the methylation levels of the conserved lysine residue K306 are significantly decreased in the chronic phase of the disease. By combining biochemical assays and molecular dynamics (MD) simulations, we demonstrate that methylation at K306 decreases the affinity of Tau for the microtubule network. Thus, the down-regulation of this PTM might represent a homeostatic response to enhance axonal stability against an autoimmune CNS insult. The results, altogether, position Tau as key mediator between the inflammatory processes and neurodegeneration that seems to unify many CNS diseases.

Systematic Review of Basic Research on Alzheimer's Disease with Shen Zhi Ling Oral Liquid

OBJECTIVE

The present report systematically reviewed the basic research of Shen Zhi Ling oral liquid (Tiao Xin preparation) treatment on Alzheimer's disease (AD).

METHODS

CNKI, Wanfang, and VIP were searched, and the literature was selected according to inclusion and exclusion criteria. Data were extracted, and descriptive analysis was used.

RESULTS

Twenty-four articles were included, all of which were published as "Tiao Xin preparation." There were seven types of AD models involved. The mechanism of action of Shen Zhi Ling oral liquid in the treatment of AD primarily included suppression of Aβ deposition and tau hyperphosphorylation, regulation of multiple neurotransmitters, improvement in energy metabolism, and promotion of the expression of autophagy-related and learning-memory-associated proteins.

CONCLUSIONS

AD is a complex disease caused by multiple factors. Shen Zhi Ling oral liquid exhibited multiple and multitarget effects and great potential for treating AD. The continuous development of molecular biology and related disciplines will further elucidate the mechanism of Shen Zhi Ling oral liquid intervention in AD.

Human amylin induces CD4+Foxp3+ regulatory T cells in the protection from autoimmune diabetes

Autoimmune diabetes is a disorder of immune homeostasis that leads to targeted insulin-secreting islet β cell destruction characterized by insulitis. Human amylin (hA) is an important neuroendocrine hormone co-secreted with insulin by pancreatic β cells. Here, we report hA immune-modulatory action through inducing regulatory T cells. We ex vivo-treated human peripheral blood mononuclear cells (hPBMCs) with hA for 24 h and counted CD4+Foxp3+ regulatory T cells (Treg) using flow cytometry. Diabetic status was monitored and splenic Treg were measured in non-obese diabetic (NOD) male mice. NOD mice were intraperitoneally injected once daily with hA (n = 25) or solvent for control (n = 25) for 7 months continuously. Spleen tissues were collected at the end of intervention and processed for flow cytometry and Western blot. We found a 2.9-fold (p < 0.05) increase of CD4+Foxp3+ Treg in hPBMCs treated with 10 nmol/L hA compared with negative control. Incidence of diabetes in hA-treated NOD mice decreased 44% (p = 0.045) in the 6th month and 57% (p = 0.0002) in the 7th month. Meanwhile, the hA treatment induced a 1.5-fold increase of CD4+Foxp3+ Treg from mouse splenocytes (p = 0.0013). Expression of transforming growth factor-β (TGF-β) and toll-like receptor-4 (TLR-4) were upregulated in hA-treated mice. Human amylin might protect against autoimmune diabetes via the induction of CD4+Foxp3+ Treg, which suggests a novel approach to improve autoimmune conditions.

Recombination and identification of human alpha B-crystallin

AIM

To recombine the human alpha B-crystallin (αB-crystallin) using gene cloning technology and prokaryotic expression vector and confirm the biological activity of recombinant human αB-crystallin.

METHODS

Cloning the human αB-crystallin cDNA according to the nucleotide sequence of the human αB-crystallin, constructing the pET-28/CRYAB prokaryotic expression plasmid by restriction enzyme digestion method, and stably expressing transformed into the Escherichia coli (E. coli) DH5 alpha. The recombinant human αB-crystallin was purified by Q sepharose. By enzyme digestion analysis, Western blotting and sequencing, the recombinant human αB-crystallin was identified and the activity of its molecular protein was detected.

RESULTS

Compared with the gene bank (GeneBank), the cloned human sequence of human αB-crystallin cDNA has the same open reading frame. Identification and sequencing of the cloned human αB-crystallin cDNA in prokaryotic expression vector confirmed the full length sequence, and the vector was constructed successfully. The E. coli containing plasmid pET-28/CRYAB induced by isopropyl-β-D-thiogalactoside successfully expressed the human αB-crystallin. Insulin confirmed that the recombinant human αB-crystallin has a molecular chaperone activity.

CONCLUSION

The prokaryotic expression vector pET-28/CRYAB of recombinant human αB-crystallin is successfully constructed, and the recombinant human αB-crystallin with molecular chaperone activity is obtained, which lay a foundation for the research and application of the recombinant human αB-crystallin and its chaperone activity.

Glatiramer acetate persists at the injection site and draining lymph nodes via electrostatically-induced aggregation

Glatiramer acetate (GA) is widely prescribed for the treatment of relapsing-remitting multiple sclerosis, however, the mechanism of action is still not fully understood. We investigated the structural properties of GA and examined alterations to the drug upon injection into the subcutaneous space. First, a variety of biophysical characterization techniques were employed to characterize GA in solution. GA was found to exist as alpha helices in solution with a hydrodynamic radius of ~3 nm in size. To simulate GA behavior at the site of injection, GA was injected into a solution of 1.5 MDa hyaluronic acid (HA). Visible aggregates were observed immediately upon injection and subsequent testing indicated aggregation was driven by electrostatic interactions between the positively-charged GA and negatively-charged HA. In vivo testing confirmed GA formed spherical particles in the nano- to micrometer size range, suggesting this mechanism contributes to persistence at the injection site and in draining lymph nodes. The aggregates were found to associate with glycosaminoglycans, suggesting an electrostatic mechanism of induced aggregation like the simulated injection. These novel observations may help explain the complex immunomodulatory mechanisms of GA and adverse injection site reactions seen in patients.

An amyloidogenic hexapeptide derived from amylin attenuates inflammation and acute lung injury in murine sepsis

Although the accumulation of amyloidogenic proteins in neuroinflammatory conditions is generally considered pathologic, in a murine model of multiple sclerosis, amyloid-forming fibrils, comprised of hexapeptides, are anti-inflammatory. Whether these molecules modulate systemic inflammatory conditions remains unknown. We hypothesized that an amylin hexapeptide that forms fibrils can attenuate the systemic inflammatory response in a murine model of sepsis. To test this hypothesis, mice were pre-treated with either vehicle or amylin hexapeptide (20 μg) at 12 hours and 6 hours prior to intraperitoneal (i.p.) lipopolysaccharide (LPS, 20 mg/kg) administration. Illness severity and survival were monitored every 6 hours for 3 days. Levels of pro- (IL-6, TNF-α, IFN-γ) and anti-inflammatory (IL-10) cytokines were measured via ELISA at 1, 3, 6, 12, and 24 hours after LPS (i.p.). As a metric of lung injury, pulmonary artery endothelial cell (PAEC) barrier function was tested 24 hours after LPS administration by comparing lung wet-to-dry ratios, Evan’s blue dye (EBD) extravasation, lung histology and caspase-3 activity. Compared to controls, pretreatment with amylin hexapeptide significantly reduced mortality (p<0.05 at 72 h), illness severity (p<0.05), and pro-inflammatory cytokine levels, while IL-10 levels were elevated (p<0.05). Amylin pretreatment attenuated LPS-induced lung injury, as demonstrated by decreased lung water and caspase-3 activity (p<0.05, versus PBS). Hence, in a murine model of systemic inflammation, pretreatment with amylin hexapeptide reduced mortality, disease severity, and preserved lung barrier function. Amylin hexapeptide may represent a novel therapeutic tool to mitigate sepsis severity and lung injury.

Identification of a common immune regulatory pathway induced by small heat shock proteins, amyloid fibrils, and nicotine

Although certain dogma portrays amyloid fibrils as drivers of neurodegenerative disease and neuroinflammation, we have found, paradoxically, that amyloid fibrils and small heat shock proteins (sHsps) are therapeutic in experimental autoimmune encephalomyelitis (EAE). They reduce clinical paralysis and induce immunosuppressive pathways, diminishing inflammation. A key question was the identification of the target for these molecules. When sHsps and amyloid fibrils were chemically cross-linked to immune cells, a limited number of proteins were precipitated, including the α7 nicotinic acetylcholine receptor (α7 NAChR). The α7 NAChR is noteworthy among the over 20 known receptors for amyloid fibrils, because it plays a central role in a well-defined immune-suppressive pathway. Competitive binding between amyloid fibrils and α-bungarotoxin to peritoneal macrophages (MΦs) confirmed the involvement of α7 NAChR. The mechanism of immune suppression was explored, and, similar to nicotine, amyloid fibrils inhibited LPS induction of a common set of inflammatory cytokines while inducing Stat3 signaling and autophagy. Consistent with this, previous studies have established that nicotine, sHsps, and amyloid fibrils all were effective therapeutics in EAE. Interestingly, B lymphocytes were needed for the therapeutic effect. These results suggest that agonists of α7 NAChR might have therapeutic benefit for a variety of inflammatory diseases.

Identification of brain antigens recognized by autoantibodies in experimental autoimmune encephalomyelitis-induced animals treated with etomoxir or interferon-β

Multiple sclerosis (MS) is a neurodegenerative autoimmune disease, where chronic inflammation plays an essential role in its pathology. A feature of MS is the production of autoantibodies stimulated by an altered-peptide-ligand response and epitope spreading, resulting in loss of tolerance for self-proteins. The involvement of autoantibodies in MS pathogenesis has been suggested to initiate and drive progression of inflammation; however, the etiology of MS remains unknown. The effect of etomoxir and interferon-β (IFN-β) was examined in an experimental-autoimmune-encephalomyelitis (EAE) model of MS. Moreover, the impact of etomoxir and IFN-β on recognition of brain proteins in serum from EAE rats was examined with the purpose of identifying the autoantibody reactivities involved in MS. Animals treated with etomoxir on day 1 exhibited a statistically significantly lower disease score than animals treated with IFN-β (on day 1 or 5) or placebo. Etomoxir treatment on day 5 resulted in a significantly lower disease score than IFN-β treatment on day 1. After disease induction antibodies was induced to a broad pallet of antigens in the brain. Surprisingly, by blocking CPT1 and therewith lipid metabolism several alterations in the antibody response was observed suggesting that autoantibodies play a role in the EAE animal model.

Science is 1% inspiration and 99% biomarkers

Neurodegeneration plays a key role in multiple sclerosis (MS) contributing to long-term disability in patients. The prognosis is, however, unpredictable coloured by complex disease mechanisms which can only be clearly appreciated using biomarkers specific to pathobiology of the underlying process. Here, we describe six promising neurodegenerative biomarkers in MS (neurofilament proteins, neurofilament antibodies, tau, N-acetylaspartate, chitinase and chitinase-like proteins and osteopontin), critically evaluating the evidence using a modified Bradford Hill criteria.

Amylin and its G-protein-coupled receptor: A probable pathological process and drug target for Alzheimer's disease

G-protein-coupled receptors (GPCRs) are shown to be involved in Alzheimer's disease (AD) pathogenesis. However, because GPCRs include a large family of membrane receptors, it is unclear which specific GPCR or pathway with rational ligands can become effective therapeutic targets for AD. Amylin receptor (AmR) is a GPCR that mediates several activities, such as improving glucose metabolism, relaxing cerebrovascular structure, modulating inflammatory reactions and potentially enhancing neural regeneration. Recent studies show that peripheral treatments with amylin or its clinical analog, pramlintide, reduced several components of AD pathology, including amyloid plaques, tauopathy, neuroinflammation and other components in the brain, corresponding with improved learning and memory in AD mouse models. Because amylin shares a similar secondary structure with amyloid-β peptide (Aβ), I propose that the AmR/GPCR pathway is disturbed by a large amount of Aβ in the AD brain, leading to tau phosphorylation, neuroinflammation and neuronal death in the pathological cascade. Amylin-type peptides, readily crossing the blood-brain barrier (BBB), are the rational ligands to enhance this GPCR pathway and may exhibit utility as novel therapeutic agents for treating AD.

Amylin receptor ligands reduce the pathological cascade of Alzheimer's disease

Amylin is an important gut-brain axis hormone. Since amylin and amyloid-β peptide (Aβ) share similar β sheet secondary structure despite not having the same primary sequences, we hypothesized that the accumulation of Aβ in the brains of subjects with Alzheimer's disease (AD) might compete with amylin for binding to the amylin receptor (AmR). If true, adding exogenous amylin type peptides would compete with Aβ and reduce the AD pathological cascade, improving cognition. Here we report that a 10-week course of peripheral treatment with human amylin significantly reduced multiple different markers associated with AD pathology, including reducing levels of phospho-tau, insoluble tau, two inflammatory markers (Iba1 and CD68), as well as cerebral Aβ. Amylin treatment also led to improvements in learning and memory in two AD mouse models. Mechanistic studies showed that an amylin receptor antagonist successfully antagonized some protective effects of amylin in vivo, suggesting that the protective effects of amylin require interaction with its cognate receptor. Comparison of signaling cascades emanating from AmR suggest that amylin electively suppresses activation of the CDK5 pathway by Aβ. Treatment with amylin significantly reduced CDK5 signaling in a receptor dependent manner, dramatically decreasing the levels of p25, the active form of CDK5 with a corresponding reduction in tau phosphorylation. This is the first report documenting the ability of amylin treatment to reduce tauopathy and inflammation in animal models of AD. The data suggest that the clinical analog of amylin, pramlintide, might exhibit utility as a therapeutic agent for AD and other neurodegenerative diseases.

An amylin analog used as a challenge test for Alzheimer's disease

INTRODUCTION

Preclinical studies demonstrate the potential of amylin in the diagnosis of Alzheimer's disease (AD). We aimed to lay the foundation for repurposing the amylin analog and a diabetes drug, pramlintide, for AD in humans.

METHODS

We administered a single subcutaneous injection of 60 μg of pramlintide to nondiabetic subjects under fasting conditions.

RESULTS

None of the participants developed hypoglycemia after the injection of pramlintide. The pramlintide challenge induced a significant surge of amyloid-β peptide and a decrease in total tau in the plasma of AD subjects but not in control participants. The pramlintide injection provoked an increase in interleukin 1 receptor antagonist and a decrease in retinol-binding protein 4, which separates AD subjects from control subjects.

DISCUSSION

Pramlintide use appeared to be safe in the absence of diabetes. The biomarker changes as a result of the pramlintide challenge, which distinguished AD from control subjects and mild cognitive impairment.

Genetic background modulates outcome of therapeutic amyloid peptides in treatment of neuroinflammation

Amyloid hexapeptide molecules are effective in the treatment of the murine model of neuroinflammation, known as experimental autoimmune encephalomyelitis (EAE). Efficacy however differs between two inbred mouse strains, C57BL/6J (B6) and C57BL/10SnJ (B10). Amyloid hexapeptide treatments improved the clinical outcomes of B6, but not B10 mice, indicating that genetic background influences therapeutic efficacy. Moreover, although previous studies indicated that prion protein deficiency results in more severe EAE in B6 mice, we observed no such effect in B10 mice. In addition, we found that amyloid hexapeptide treatments of B10 and B6 mice elicited differential IL4 responses. Thus, the modulatory potential of prion protein and related treatments with other amyloid hexapeptides in EAE depends on mouse strain.

Further understanding of the immunopathology of multiple sclerosis: impact on future treatments

INTRODUCTION

The understanding of the immunopathogenesis of multiple sclerosis (MS) has expanded with more research into T-cell subtypes, cytokine contributors, B-cell participation, mitochondrial dysfunction, and more. Treatment options have rapidly expanded with three relatively recent oral therapy alternatives entering the arena.

AREAS COVERED

In the following review, we discuss current mechanisms of immune dysregulation in MS, how they relate to current treatments, and the impact these findings will have on the future of therapy. Expert commentary: The efficacy of these medications and understanding their mechanisms of actions validates the immunopathogenic mechanisms thought to underlie MS. Further research has exposed new targets, while new promising therapies have shed light on new aspects into the pathophysiology of MS.

A Journey in Science: The Privilege of Exploring the Brain and the Immune System

Real innovations in medicine and science are historic and singular; the stories behind each occurrence are precious. At Molecular Medicine we have established the Anthony Cerami Award in Translational Medicine to document and preserve these histories. The monographs recount the seminal events as told in the voice of the original investigators who provided the crucial early insight. These essays capture the essence of discovery, chronicling the birth of ideas that created new fields of research; and launched trajectories that persisted and ultimately influenced how disease is prevented, diagnosed, and treated. In this volume, the Cerami Award Monograph is by Lawrence Steinman, MD, of Stanford University in California. A visionary in the field of neurology, this is the story of Dr. Steinman's scientific journey.

Amyloid Proteins and Their Role in Multiple Sclerosis. Considerations in the Use of Amyloid-PET Imaging

Thioflavin T derivatives are used in positron-emission tomography (PET) studies to detect amyloid protein deposits in patients with Alzheimer disease. These tracers bind extensively to white matter, which suggests that they may be useful in studies of multiple sclerosis (MS), and that proteins resulting from proteolytic processing of the amyloid precursor protein (APP) may contribute to MS. This article reviews data from both clinical and preclinical studies addressing the role of these proteins, whether they are detected in CSF studies or using PET imaging. APP is widely expressed in demyelinated axons and may have a protective effect in MS and in experimental allergic encephalomyelitis in animals. Several mechanisms associated with this increased expression may affect the degree of remyelination in MS. Amyloid-PET imaging may help determine the degree of demyelination and provide information on the molecular changes linked to APP proteolytic processing experienced by patients with MS.

αB-crystallin is essential for the TGF-β2-mediated epithelial to mesenchymal transition of lens epithelial cells

Transforming growth factor (TGF)-β2-mediated pathways play a major role in the epithelial to mesenchymal transition (EMT) of lens epithelial cells (LECs) during secondary cataract formation, which is also known as posterior capsule opacification (PCO). Although αB-crystallin is a major protein in LEC, its role in the EMT remains unknown. In a human LEC line (FHL124), TGF-β2 treatment resulted in changes in the EMT-associated proteins at the mRNA and protein levels. This was associated with nuclear localization of αB-crystallin, phosphorylated Smad2 (pSmad2) (S245/250/255), pSmad3 (S423/425), Smad4 and Snail and the binding of αB-crystallin to these transcription factors, all of which were reduced by the down-regulation of αB-crystallin. Expression of the functionally defective R120G mutant of αB-crystallin reduced TGF-β2-induced EMT in LECs of αB-crystallin knockout (KO) mice. Treatment of bovine lens epithelial explants and mouse LEC with TGF-β2 resulted in changes in the EMT-associated proteins at the mRNA and protein levels. This was accompanied by increase in phosphorylation of p44/42 mitogen-activated protein kinases (MAPK) (T202/Y204), p38 MAPK (T180/Y182), protein kinase B (Akt) (S473) and Smad2 when compared with untreated cells. These changes were significantly reduced in αB-crystallin depleted or knocked out LEC. The removal of the fibre cell mass from the lens of wild-type (WT) mice resulted in the up-regulation of EMT-associated genes in the capsule-adherent epithelial cells, which was reduced in the αB-crystallin KO mice. Together, our data show that αB-crystallin plays a central role in the TGF-β2-induced EMT of LEC. αB-Crystallin could be targeted to prevent PCO and pathological fibrosis in other tissues.

Advances in the immunopathogenesis of multiple sclerosis

PURPOSE OF REVIEW

Recent studies indicate a role for immune dysregulation in the pathogenesis of multiple sclerosis, an inflammatory demyelinating and degenerative disease of the central nervous system. This review addresses the current mechanisms of immune dysregulation in the development of multiple sclerosis, including the impact of environmental risk factors on immunity in both multiple sclerosis and its animal models.

RECENT FINDINGS

CD4 T-helper (Th) cells have long been implicated as the main drivers of pathogenesis of multiple sclerosis. However, current studies indicate that multiple sclerosis is largely a heterogeneous disease process, which involves both innate and adaptive immune-mediated inflammatory mechanisms that ultimately contribute to demyelination and neurodegeneration. Therefore, B cells, CD8 T cells, and microglia/macrophages can also play an important role in the immunopathogenesis of multiple sclerosis apart from proinflammatory CD4 Th1/Th17 cell subsets. Furthermore, increasing evidence indicates that environmental risk factors, such as Vitamin D deficiency, Epstein-Barr virus, smoking, Western diet, and the commensal microbiota, influence the development of multiple sclerosis through interactions with genetic variants of multiple sclerosis, thus leading to the dysregulation of immune responses.

SUMMARY

A better understanding of immune-mediated mechanisms in the pathogenesis of multiple sclerosis and the contribution of environmental risk factors toward the development of multiple sclerosis will help further improve therapeutic approaches to prevent disease progression.

Amyloid fibrils activate B-1a lymphocytes to ameliorate inflammatory brain disease

Amyloid fibrils composed of peptides as short as six amino acids are therapeutic in experimental autoimmune encephalomyelitis (EAE), reducing paralysis and inflammation, while inducing several pathways of immune suppression. Intraperitoneal injection of fibrils selectively activates B-1a lymphocytes and two populations of resident macrophages (MΦs), increasing IL-10 production, and triggering their exodus from the peritoneum. The importance of IL-10-producing B-1a cells in this effective therapy was established in loss-of-function experiments where neither B-cell-deficient (μMT) nor IL10(-/-) mice with EAE responded to the fibrils. In gain-of-function experiments, B-1a cells, adoptively transferred to μMT mice with EAE, restored their therapeutic efficacy when Amylin 28-33 was administered. Stimulation of adoptively transferred bioluminescent MΦs and B-1a cells by amyloid fibrils resulted in rapid (within 60 min of injection) trafficking of both cell types to draining lymph nodes. Analysis of gene expression indicated that the fibrils activated the CD40/B-cell receptor pathway in B-1a cells and induced a set of immune-suppressive cell-surface proteins, including BTLA, IRF4, and Siglec G. Collectively, these data indicate that the fibrils activate B-1a cells and F4/80(+) MΦs, resulting in their migration to the lymph nodes, where IL-10 and cell-surface receptors associated with immune-suppression limit antigen presentation and T-cell activation. These mechanisms culminate in reduction of paralytic signs of EAE.

Neural Plasticity in Multiple Sclerosis: The Functional and Molecular Background

Multiple sclerosis is an autoimmune neurodegenerative disorder resulting in motor dysfunction and cognitive decline. The inflammatory and neurodegenerative changes seen in the brains of MS patients lead to progressive disability and increasing brain atrophy. The most common type of MS is characterized by episodes of clinical exacerbations and remissions. This suggests the presence of compensating mechanisms for accumulating damage. Apart from the widely known repair mechanisms like remyelination, another important phenomenon is neuronal plasticity. Initially, neuroplasticity was connected with the developmental stages of life; however, there is now growing evidence confirming that structural and functional reorganization occurs throughout our lifetime. Several functional studies, utilizing such techniques as fMRI, TBS, or MRS, have provided valuable data about the presence of neuronal plasticity in MS patients. CNS ability to compensate for neuronal damage is most evident in RR-MS; however it has been shown that brain plasticity is also preserved in patients with substantial brain damage. Regardless of the numerous studies, the molecular background of neuronal plasticity in MS is still not well understood. Several factors, like IL-1β, BDNF, PDGF, or CB1Rs, have been implicated in functional recovery from the acute phase of MS and are thus considered as potential therapeutic targets.

Arginine deprivation and immune suppression in a mouse model of Alzheimer's disease

The pathogenesis of Alzheimer's disease (AD) is a critical unsolved question; and although recent studies have demonstrated a strong association between altered brain immune responses and disease progression, the mechanistic cause of neuronal dysfunction and death is unknown. We have previously described the unique CVN-AD mouse model of AD, in which immune-mediated nitric oxide is lowered to mimic human levels, resulting in a mouse model that demonstrates the cardinal features of AD, including amyloid deposition, hyperphosphorylated and aggregated tau, behavioral changes, and age-dependent hippocampal neuronal loss. Using this mouse model, we studied longitudinal changes in brain immunity in relation to neuronal loss and, contrary to the predominant view that AD pathology is driven by proinflammatory factors, we find that the pathology in CVN-AD mice is driven by local immune suppression. Areas of hippocampal neuronal death are associated with the presence of immunosuppressive CD11c(+) microglia and extracellular arginase, resulting in arginine catabolism and reduced levels of total brain arginine. Pharmacologic disruption of the arginine utilization pathway by an inhibitor of arginase and ornithine decarboxylase protected the mice from AD-like pathology and significantly decreased CD11c expression. Our findings strongly implicate local immune-mediated amino acid catabolism as a novel and potentially critical mechanism mediating the age-dependent and regional loss of neurons in humans with AD.

Crystallins and neuroinflammation: The glial side of the story

BACKGROUND

There is an abundance of evidence to support the association of damaging neuroinflammation and neurodegeneration across a multitude of diseases. One of the links between these pathological phenomena is the role of chaperone proteins as both neuroprotective and immune-regulatory agents.

SCOPE OF REVIEW

Chaperone proteins are highly expressed at sites of neuroinflammation both in glial cells and in the injured neurons that initiate the immune response. For this reason, the use of chaperones as treatment for various diseases associated with neuroinflammation is a highly active area of investigation. This review explores the various ways that the small heat shock protein chaperones, α-crystallins, can affect glial cell function with a specific focus on their implication in the inflammatory response associated with neurodegenerative disorders, and their potential as therapeutic treatment.

MAJOR CONCLUSIONS

Although the mechanisms are still under investigation, a clear link has now been established between alpha-crystallins and neuroinflammation, especially through their roles in microglial and macroglial cells. Interestingly, similar to inflammation in itself, crystallins can have a beneficial or detrimental impact on the CNS based on the context and duration of the condition.

GENERAL SIGNIFICANCE

Overall this review points out the novel roles that chaperones such as alpha-crystallins can play outside of the classical protein folding pathways, and their potential in the development of new therapies for the treatment of neuroinflammatory/neurodegenerative diseases. This article is part of a Special Issue entitled Crystallin Biochemistry in Health and Disease.

No quiet surrender: molecular guardians in multiple sclerosis brain

The brain under immunological attack does not surrender quietly. Investigation of brain lesions in multiple sclerosis (MS) reveals a coordinated molecular response involving various proteins and small molecules ranging from heat shock proteins to small lipids, neurotransmitters, and even gases, which provide protection and foster repair. Reduction of inflammation serves as a necessary prerequisite for effective recovery and regeneration. Remarkably, many lesion-resident molecules activate pathways leading to both suppression of inflammation and promotion of repair mechanisms. These guardian molecules and their corresponding physiologic pathways could potentially be exploited to silence inflammation and repair the injured and degenerating brain and spinal cord in both relapsing-remitting and progressive forms of MS and may be beneficial in other neurologic and psychiatric conditions.

Therapeutic potential of α-crystallin

BACKGROUND

The findings that α-crystallins are multi-functional proteins with diverse biological functions have generated considerable interest in understanding their role in health and disease. Recent studies have shown that chaperone peptides of α-crystallin could be delivered into cultured cells and in experimental animals with beneficial effects against protein aggregation, oxidation, inflammation and apoptosis.

SCOPE OF REVIEW

In this review, we will summarize the latest developments on the therapeutic potential of α-crystallins and their functional peptides.

MAJOR CONCLUSIONS

α-Crystallins and their functional peptides have shown significant favorable effects against several diseases. Their targeted delivery to tissues would be of great therapeutic benefit. However, α-crystallins can also function as disease-causing proteins. These seemingly contradictory functions must be carefully considered prior to their therapeutic use.

GENERAL SIGNIFICANCE

αA and αB-Crystallin are members of the small heat shock protein family. These proteins exhibit molecular chaperone and anti-apoptotic activities. The core crystallin domain within these proteins is largely responsible for these prosperities. Recent studies have identified peptides within the crystallin domain of both α- and αB-crystallins with remarkable chaperone and anti-apoptotic activities. Administration of α-crystallin or their functional peptides has shown substantial inhibition of pathologies in several diseases. However, α-crystallins have been shown to promote disease-causing pathways. These two sides of the proteins are discussed in this review. This article is part of a Special Issue entitled Crystallin Biochemistry in Health and Disease.

Positive or negative involvement of heat shock proteins in multiple sclerosis pathogenesis: an overview

Multiple sclerosis (MS) is the most diffuse chronic inflammatory disease of the central nervous system. Both immune-mediated and neurodegenerative processes apparently play roles in the pathogenesis of this disease. Heat shock proteins (HSPs) are a family of highly evolutionarily conserved proteins; their expression in the nervous system is induced in a variety of pathologic states, including cerebral ischemia, neurodegenerative diseases, epilepsy, and trauma. To date, investigators have observed protective effects of HSPs in a variety of brain disease models (e.g. of Alzheimer disease and Parkinson disease). In contrast, unequivocal data have been obtained for their roles in MS that depend on the HSP family and particularly on their localization (i.e. intracellular or extracellular). This article reviews our current understanding of the involvement of the principal HSP families in MS.

Development of therapies for autoimmune disease at Stanford: a tale of multiple shots and one goal

The title of this contribution on Immunology at Stanford is purposely ambiguous. One goal is the development of safe and effective therapy for autoimmune diseases. Another definition of goal is to score, and this would ultimately mean the development of an approved drug. Indeed, the efforts in my four decades at Stanford, have included the discovery and subsequent development of a monoclonal antibody to block homing to the inflamed brain, leading to natalizumab, an approved therapeutic for two autoimmune diseases: relapsing-remitting MS and for inflammatory bowel disease. Multiple attempts to develop new therapies for autoimmune disease are described here: The trimolecular complex and the immune synapse serve as one major set of targets, with attempts to inhibit particular major histocompatibility molecules, the variable regions of the T cell receptor, and CD4. Other approaches focusing on antigen-specific tolerance include ongoing attempts with tolerizing DNA vaccines in type 1 diabetes. Finally, the repurposing of popular drugs approved for other indications, including statins and inhibitors of angiotensin converting enzyme is under development and showing promise in the clinic, particularly for secondary progressive multiple sclerosis. The milieu within Stanford Immunology has helped to nurture these efforts to translate discoveries in immunology and to take them from bench to bedside.

Role of amyloid from a multiple sclerosis perspective: a literature review

The traditional concept of multiple sclerosis (MS), that it is primarily a white matter inflammatory disease, has changed a great deal. Thanks to the recent development witnessed in MS research, a whole new idea has emerged that MS is a neurodegenerative disease, and neurodegeneration occurs rather earlier in the pathological process. This has also led to the foundation of the hypothesis that two fundamentally different diseases, Alzheimer's disease (AD) and MS, may share a common mechanism of neurodegeneration. Conventionally, amyloid is thought to be a consequence of protein misfolding and aggregation and is most notorious for its association with debilitating and chronic human diseases. Amyloid is implicated to be related with the deterioration and progression of AD. The finding of amyloid precursor protein expression in axons around the plaque in MS, as well as the correlation of amyloid-β (Aβ) with different stages of MS, has clearly indicated that amyloid plays some kind of key role in MS disease pathogenesis. Excitingly, a paradoxical phenomenon of Aβ has also been observed in several studies recently. It has been shown that amyloid might actually be helping in ameliorating the inflammatory effect in diseases like AD and MS. Amyloid imaging allows earlier diagnosis of MS by taking advantage of the relation of amyloid with MS. This will have a big impact on patient diagnosis and management. In this review I have included the findings of research studies dating from several years back to the most recent ones. Through this review I have tried to show the critical role of amyloid in MS and the importance of investigating through PET imaging.

Molecular mechanism of the chaperone function of mini-α-crystallin, a 19-residue peptide of human α-crystallin

α-Crystallin is the archetypical chaperone of the small heat-shock protein family, all members of which contain the so-called “α-crystallin domain” (ACD). This domain and the N- and C-terminal extensions are considered the main functional units in its chaperone function. Previous studies have shown that a 19-residue fragment of the ACD of human αA-crystallin called mini-αA-crystallin (MAC) shows chaperone properties similar to those of the parent protein. Subsequent studies have confirmed the function of this peptide, but no studies have addressed the mechanistic basis for the chaperone function of MAC. Using human γD-crystallin (HGD), a key substrate protein for parent α-crystallin in the ocular lens, we show here that MAC not only protects HGD from aggregation during thermal and chemical unfolding but also binds weakly and reversibly to HGD (K_d ≈ 200–700 μM) even when HGD is in the native state. However, at temperatures favoring the unfolding of HGD, MAC forms a stable complex with HGD similar to parent α-crystallin. Using nuclear magnetic resonance spectroscopy, we identify the residues in HGD that are involved in these two modes of binding and show that MAC protects HGD from aggregation by binding to Phe 56 and Val 132 at the domain interface of the target protein, and residues Val 164 to Leu 167 in the core of the C-terminal domain. Furthermore, we suggest that the low-affinity, reversible binding of MAC on the surface of HGD in the native state is involved in facilitating its binding to both the domain interface and core regions during the early stages of the unfolding of HGD. This work highlights some structural features of MAC and MAC-like peptides that affect their chaperone activity and can potentially be manipulated for translational studies.

From defining antigens to new therapies in multiple sclerosis: honoring the contributions of Ruth Arnon and Michael Sela

Ruth Arnon and Michael Sela profoundly influenced the development of a model system to test new therapies in multiple sclerosis (MS). Their application of the animal model, known as experimental autoimmune encephalomyelitis (EAE), for the discovery of Copaxone, opened a new path for testing of drug candidates in MS. By measuring clinical, pathologic, and immunologic outcomes, the biological implications of new drugs could be elucidated. Using EAE they established the efficacy of Copaxone as a therapy for preventing and reducing paralysis and inflammation in the central nervous system without massive immune suppression. This had a huge impact on the field of drug discovery for MS. Much like the use of parabiosis to discover soluble factors associated with obesity, or the replica plating system to probe antibiotic resistance in bacteria, the pioneering research on Copaxone using the EAE model, paved the way for the discovery of other therapeutics in MS, including Natalizumab and Fingolimod. Future applications of this approach may well elucidate novel therapies for the neurodegenerative phase of multiple sclerosis associated with disease progression.

Biochemical assessment of precuneus and posterior cingulate gyrus in the context of brain aging and Alzheimer's disease

Defining the biochemical alterations that occur in the brain during “normal” aging is an important part of understanding the pathophysiology of neurodegenerative diseases and of distinguishing pathological conditions from aging-associated changes. Three groups were selected based on age and on having no evidence of neurological or significant neurodegenerative disease: 1) young adult individuals, average age 26 years (n = 9); 2) middle-aged subjects, average age 59 years (n = 5); 3) oldest-old individuals, average age 93 years (n = 6). Using ELISA and Western blotting methods, we quantified and compared the levels of several key molecules associated with neurodegenerative disease in the precuneus and posterior cingulate gyrus, two brain regions known to exhibit early imaging alterations during the course of Alzheimer’s disease. Our experiments revealed that the bioindicators of emerging brain pathology remained steady or decreased with advancing age. One exception was S100B, which significantly increased with age. Along the process of aging, neurofibrillary tangle deposition increased, even in the absence of amyloid deposition, suggesting the presence of amyloid plaques is not obligatory for their development and that limited tangle density is a part of normal aging. Our study complements a previous assessment of neuropathology in oldest-old subjects, and within the limitations of the small number of individuals involved in the present investigation, it adds valuable information to the molecular and structural heterogeneity observed along the course of aging and dementia. This work underscores the need to examine through direct observation how the processes of amyloid deposition unfold or change prior to the earliest phases of dementia emergence.

Mechanisms of action of therapeutic amyloidogenic hexapeptides in amelioration of inflammatory brain disease

Amyloid fibrils composed of peptides as short as six amino acids are effective therapeutics for experimental autoimmune encephalomyelitis (EAE). Immunosuppression arises from at least two pathways: (1) expression of type 1 IFN by pDCs, which were induced by neutrophil extracellular traps arising from the endocytosis of the fibrils; and (2) the reduced expression of IFN-γ, TNF, and IL-6. The two independent pathways stimulated by the fibrils can act in concert to be immunosuppressive in Th1 indications, or in opposition, resulting in inflammation when Th17 T lymphocytes are predominant. The generation of type 1 IFN can be minimized by using polar, nonionizable, amyloidogenic peptides, which are effective in both Th1 and Th17 polarized EAE.

Janus faces of amyloid proteins in neuroinflammation

Amyloid forming molecules are generally considered harmful. In Alzheimer's Disease two amyloid molecules Aβ A4 and tau vie for consideration as the main pathogenic culprit. But molecules obey the laws of chemistry and defy the way we categorize them as humans with our well-known proclivities to bias in our reasoning. We have been exploring the brains of multiple sclerosis patients to identify molecules that are associated with protection from inflammation and degeneration. In 2001 we noted that aB crystallin (cryab) was the most abundant transcript found in MS lesions, but not in healthy brains. Cryab can reverse paralysis and attenuate inflammation in several models of inflammation including experimental autoimmune encephalomyelitis (EAE), and various models of ischemia. Cryab is an amyloid forming molecule. We have identified a core structure common to many amyloids including amyloid protein Aβ A4, tau, amylin, prion protein, serum amyloid protein P, and cryab. The core hexapeptide structure is highly immune suppressive and can reverse paralysis in EAE when administered systemically. Administration of this amyloid forming hexapeptide quickly lowers inflammatory cytokines in plasma like IL-6 and IL-2. The hexapeptide bind a set of proinflammatory mediators in plasma, including acute phase reactants and complement components. The beneficial properties of amyloid forming hexapeptides provide a potential new therapeutic direction. These experiments indicate that amyloid forming molecules have Janus faces, providing unexpected benefit for neuroinflammatory conditions.