Therapeutic effects of antibodies to tumor necrosis factor-α, interleukin-6 and cytotoxic T-lymphocyte antigen 4 immunoglobulin in mice with glucose-6-phosphate isomerase induced arthritis

Introduction  

Immunization with glucose-6-phosphate isomerase (GPI) induces severe arthritis in DBA/1 mice. The present study was designed to identify the cytokines and co-stimulatory molecules involved in the development of GPI-induced arthritis.     

The role of the activin-follistatin system in the developmental and regeneration processes of the kidney

Regeneration processes in many tissues are modulated by various factors, which are involved in their organogenesis. Activin A, a member of the TGF-β superfamily, inhibits branching tubulogenesis of the kidney in organ culture system as well as in in vitro tubulogenesis model. On the other hand, follistatin, an antagonist activin A, reverses the effect of activin A on kidney development, induces branching tubulogenesis, and also promotes tubular regeneration after ischemia/reperfusion injury by blocking the action of endogenous activin A. The activin-follistatin system is one of the important regulatory systems modulating developmental and regeneration processes of the kidneys.     

Adplot: detection and visualization of repetitive patterns in complete genomes

MOTIVATION: Repetitive DNA sequences are abundant in genomes and efficient mining of significant repeats is important as the first step of repetitive sequence research. Although many computational tools for the purpose, either automatic or visualization ones, have been developed, detection and analysis of approximate repeats are still non-trivial task. RESULTS: Auto Dot PLOT (Adplot), a dotplot-like repetitive pattern visualization program with a window filtering based on iid Bernoulli trials, is developed and applied to yeast chromosomes and human T cell receptor locus sequence. Typical examples found in yeast chromosomes 1 and 10 and a tandem repeat of periods longer than 10,000 bp in human T cell receptor locus are presented. A complex structure composed of both direct and palindromic repeats found in yeast chromosome 10 is also visualized as specific dot pattern. Computational time measured by a Pentium 3 PC for each yeast auto chromosome with a standard parameter setting is linearly scaled and below 10 s per one chromosome, indicating efficiency of the program. From the examples, it is shown that Adplot can visualize approximate local repeat structures and give us a diagnosis power for inferring a duplicational history of repeats. AVAILABILITY: Adplot can be obtained by an e-mail request.     

A quantitative analysis and chemical approach for the reduction of nonspecific binding proteins on affinity resins

Tubulin and actin often bind nonspecifically to affinity chromatography resins, complicating research toward identifying the cellular targets of small molecules. Reduction of nonspecific binding proteins is important for the success of such biochemical approaches. To develop strategies to circumvent this problem, we quantitatively investigated the binding of tubulin and actin to a series of affinity resins bearing 15 variant ligands on 3 commercially available polymer supports. Nonspecific protein binding was proportional to the hydrophobicity of the affinity resins and could be quantitatively correlated to the CLOGP values of the ligands, which are a measure of compound hydrophobicity. When compounds had CLOGP values greater than 1.5, (amount of tubulin) = 0.73 x CLOGP - 1.1 (n = 7, r = 0.97), and (amount of actin) = 0.42 x CLOGP - 0.79 (n = 7, r = 0.99). On the basis of these studies, we designed a novel hydrophilic poly(ethylene glycol) (PEG) spacer (26) for the conjugation of ligands to chromatography resins. As predicted by our binding algorithm, introduction of this spacer reduced the amount of nonspecific protein binding in proportion to the number of ethylene glycol units.     

Sphingolipids involved in the induction of multinuclear cell formation

In this review, we focus on sphingolipids as potential regulators of the induction of multinuclear cell formation through the inhibition of cytokinesis. A sphingolipid, psychosine (Psy) (galactosylsphingosine), was demonstrated to be a trigger lipid for the inhibition of cytokinesis and the induction of multinuclear giant cells associated with a sphingolipid metabolic disease, globoid cell leukodystrophy (GLD). Indeed, Psy is known to accumulate in the patients' brains. Interestingly, inhibition of sphingolipid biosynthesis also induced multinuclear cells. When cells were treated with a new immunosuppressant, ISP-1/myriocin, which inhibits serine palmitoyltransferase, the first step enzyme of sphingolipid biosynthesis, the cells underwent multinucleation and apoptosis. At present, a definitive model of the function of sphingolipids as to the induction of multinuclear cell formation is not available due to the rudimentary information but possible mechanisms are discussed.     

Molecular phylogeny of Asian termites (Isoptera) of the families Termitidae and Rhinotermitidae based on mitochondrial COII sequences

The families Termitidae and Rhinotermitidae are the most evolved and diverse groups of the social insects, termites (Order Isoptera), showing elaborated morphology and complex behavior. Molecular phylogeny of termites with the emphasis on these families was examined by Bayesian and maximum-likelihood analyses based on DNA sequence of mitochondrial cytochrome oxidase II (COII) gene of 31 genera sampled in Asia (mainly Thailand and Japan) along with those reported previously. Termitidae was monophyletic and originated from within polyphyletic Rhinotermitidae. Among the four subfamilies of Termitidae, Macrotermitinae was monophyletic suggesting a single common origin of fungus-growing habit characteristic for this subfamily, and was placed in the basal position in the family. A group consisting of other subfamilies Termitinae and Nasutitermitinae, though some important groups were still untouched, was the most apical but neither Termitinae nor Nasutitermitinae formed a monophyletic lineage. It was implied that, as defense systems of the soldier castes, the appearance of snapping mandibles has occurred at a single event, but the development of nasus for chemical secretion has probably not. Our tree provides some evidence concerning contradictions in the previously proposed phylogeny of termites.     

Chiral recognition ability of curdlan triacetate: solvent and temperature effects

The chiral recognition ability of the chiral stationary phase (CSP) consisting of curdlan (beta-1,3-glucan) triacetate coated on silica gel was clearly changed by the contacting solvents and heat treatment. The chiral recognition ability significantly decreased, particularly at temperatures above 45 degrees C, depending on the racemates. The molecular weight of the curdlan triacetate slightly influenced its ability. The recognition abilities of curdlan tricetate that was lost by heat treatment were partially recovered by contact with methanol. However, when it was contacted with ethanol a different selectivity was observed. The labile chiral recognition ability of curdlan triacetate is in striking contrast to the very stable chiral recognition of cellulose (beta-1,4-glucan) triacetate (Chiralcel OA). This difference may be ascribed to the conformational stability of the acetates consisting of curdlan (beta-1,3-glucan) and cellulose (beta-1,4-glucan) with different sugar linkages.     

Inhibition of cytokinesis by a lipid metabolite, psychosine

Although a number of cellular components of cytokinesis have been identified, little is known about the detailed mechanisms underlying this process. Here, we report that the lipid metabolite psychosine (galactosylsphingosine), derived from galactosylceramide, induced formation of multinuclear cells from a variety of nonadherent and adherent cells due to inhibition of cytokinesis. When psychosine was added to the human myelomonocyte cell line U937, which was the most sensitive among the cell lines tested, cleavage furrow formed either incompletely or almost completely. However, abnormal contractile movement was detected in which the cellular contents of one of the hemispheres of the contracting cell were transferred into its counterpart. Finally, the cleavage furrow disappeared and cytokinesis was reversed. Psychosine treatment also induced giant clots of actin filaments in the cells that probably consisted of small vacuoles with filamentous structures, suggesting that psychosine affected actin reorganization. These observations could account for the formation of multinuclear globoid cells in the brains of patients with globoid cell leukodystrophy, a neurological disorder characterized by the accumulation of psychosine due to galactosylceramidase deficiency.     

Interruption of CryAB-amyloid oligomer formation by HSP22

An R120G missense mutation in alpha-B-crystallin (CryAB), a small heat-shock protein (HSP), causes a desmin-related cardiomyopathy (DRM) that is characterized by the formation of aggregates containing CryAB and desmin. The mutant CryAB protein leads to the formation of inclusion bodies, which contain amyloid oligomer intermediates (amyloid oligomer) in the cardiomyocytes. To further address the underlying mechanism(s) of amyloid oligomer formation in DRM linked to the CryAB R120G, a recombinant CryAB R120G protein was generated. The purified CryAB R120G protein can form a toxic amyloid oligomer, whereas little immunoreactivity was observed in the wild-type CryAB protein. A native PAGE showed that the oligomerized form was present in the CryAB R120G protein, whereas only a high molecular mass was detected in the wildtype CryAB. The oligomerized CryAB R120G of around 240-480 kDa showed strong positive immunoreactivity against an anti-oligomer antibody. The CryAB R120G amyloid oligomer was unstable and easily lost its conformation by beta-mercaptoethanol and SDS. Recombinant HSP25 or HSP22 proteins can directly interrupt oligomer formation by the CryAB R120G protein, whereas the amyloid oligomer is still present in the mixture of the wild-type CryAB and CryAB R120G proteins. This interruption by HSP25 and HSP22 was confirmed in a cardiomyocyte-based study using an adenoviral transfection system. Blockade of amyloid oligomer formation by HSP25 and HSP22 recovered the ubiquitin proteosomal activity and cellular viability. Blockade of oligomer formation by small HSP may be a new therapeutic strategy for treating DRM as well as other types of amyloid-based degenerative diseases.