Common and Distinct Clinical Features in Adult Patients with Anti-Aminoacyl-tRNA Synthetase Antibodies: Heterogeneity within the Syndrome

Objective

To identify similarities and differences in the clinical features of adult Japanese patients with individual anti-aminoacyl-tRNA synthetase antibodies (anti-ARS Abs).

Methods

This was a retrospective analysis of 166 adult Japanese patients with anti-ARS Abs detected by immunoprecipitation assays. These patients had visited Kanazawa University Hospital or collaborating medical centers from 2003 to 2009.

Results

Anti-ARS Ab specificity included anti-Jo-1 (36%), anti-EJ (23%), anti-PL-7 (18%), anti-PL-12 (11%), anti-KS (8%), and anti-OJ (5%). These anti-ARS Abs were mutually exclusive, except for one serum Ab that had both anti-PL-7 and PL-12 reactivity. Myositis was closely associated with anti-Jo-1, anti-EJ, and anti-PL-7, while interstitial lung disease (ILD) was correlated with all 6 anti-ARS Abs. Dermatomyositis (DM)-specific skin manifestations (heliotrope rash and Gottron’s sign) were frequently observed in patients with anti-Jo-1, anti-EJ, anti-PL-7, and anti-PL-12. Therefore, most clinical diagnoses were polymyositis or DM for anti-Jo-1, anti-EJ, and anti-PL-7; clinically amyopathic DM or ILD for anti-PL-12; and ILD for anti-KS and anti-OJ. Patients with anti-Jo-1, anti-EJ, and anti-PL-7 developed myositis later if they had ILD alone at the time of disease onset, and most patients with anti-ARS Abs eventually developed ILD if they did not have ILD at disease onset.

Conclusion

Patients with anti-ARS Abs are relatively homogeneous. However, the distribution and timing of myositis, ILD, and rashes differ among patients with individual anti-ARS Abs. Thus, identification of individual anti-ARS Abs is beneficial to define this rather homogeneous subset and to predict clinical outcomes within the “anti-synthetase syndrome.”     

Combined trisomy 9P and Shprintzen syndrome resulting from a paternal t(9;22)

The authors report on a female infant with partial trisomy 9 (pter-->q12) together with partial monosomy 22 (pter-->q11.23) that included DiGeorge critical region (DGCR), as a result of adjacent-2 disjunction. In addition to the clinical features characteristic of trisomy 9p syndrome, the patient had Truncus arteriosus type A2, bilateral hydronephrosis, palatal anomaly, retrognathia, and laryngeal hypotonia, which are likely to be attributed to 22q11.2 deletion. This patient appears to be the first reported case with such unbalanced translocation resulting from a paternal reciprocal translocation. For live birth, the risk for male carrier is 8.7-17.4%. It is important to consider this higher risk when counseling. Precise study concerning the presence of the DGCR can facilitate in the better understanding of the condition.     

Vanadate protects human neuroblastoma SH-SY5Y cells against peroxynitrite-induced cell death

We investigated the effect of vanadate, a tyrosine phosphatase inhibitor, on cell death induced by peroxynitrite in human neuroblastoma SH-SY5Y cells. Vanadate prevented cell death induced by 3-morpholinosydnonimine (SIN-1), a peroxynitrite donor; whereas SIN-1-induced cell death was not prevented by neither okadaic acid, an inhibitor of serine/threonine phosphatases 1 and 2A, nor cyclosporin A, an inhibitor of serine/threonine phosphatase 2B. Vanadate did not prevent cell death induced by N-ethyl-2-(1-ethyl-hydroxy-2-nitrosohydrazino)-ethanamine, a nitric oxide donor. Wortmannin, an inhibitor of phosphatidylinositol 3-kinase (PI3-kinase), did not block the protective effect of vanadate, suggesting that the protective effect of vanadate is independent on PI3-kinase. Vanadate increased tyrosine phosphorylation of several proteins including the focal adhesion protein p130 Crk-associated substrate (p130(cas)). By the treatment with SIN-1, the endogenous association of p130(cas) and Crk was disrupted, and the association was restored by vanadate treatment. These results suggest that disruption of tyrosine phosphorylation signaling may be critical for peroxynitrite-induced cell death, and that vanadate prevents cell death at least in part through the enhancement in tyrosine phosphorylation of the proteins including p130(cas).     

Role of phosphatidylglycerol in the function and assembly of Photosystem II reaction center, studied in a cdsA-inactivated PAL mutant strain of Synechocystis sp. PCC6803 that lacks phycobilisomes

To analyze the role of phosphatidylglycerol (PG) in photosynthetic membranes of cyanobacteria we used two mutants of Synechocystis sp. PCC6803: the PAL mutant which has no phycobilisomes and shows a high PSII/PSI ratio, and a mutant derived from it by inactivating its cdsA gene encoding cytidine 5'-diphosphate diacylglycerol synthase, a key enzyme in PG synthesis. In a medium supplemented with PG the PAL/ΔcdsA mutant cells grew photoautotrophically. Depletion of PG in the medium resulted (a) in an arrest of cell growth and division, (b) in a slowdown of electron transfer from the acceptor Q_A to Q_B in PSII and (c) in a modification of chlorophyll fluorescence curve. The depletion of PG affected neither the redox levels of Q_A nor the S₂ state of the oxygen-evolving manganese complex, as indicated by thermoluminescence studies. Two-dimensional PAGE showed that in the absence of PG (a) the PSII dimer was decomposed into monomers, and (b) the CP43 protein was detached from a major part of the PSII core complex. [³⁵S]-methionine labeling confirmed that PG depletion did not block de novo synthesis of the PSII proteins. We conclude that PG is required for the binding of CP43 within the PSII core complex.     

Hemextin AB complex, a unique anticoagulant protein complex from Hemachatus haemachatus (African Ringhals cobra) venom that inhibits clot initiation and factor VIIa activity

During injury or trauma, blood coagulation is initiated by the interaction of factor VIIa (FVIIa) in the blood with freshly exposed tissue factor (TF) to form the TF.FVIIa complex. However, unwanted clot formation can lead to death and debilitation due to vascular occlusion, and hence, anticoagulants are important for the treatment of thromboembolic disorders. Here, we report the isolation and characterization of two synergistically acting anticoagulant proteins, hemextins A and B, from the venom of Hemachatus haemachatus (African Ringhals cobra). N-terminal sequences and CD spectra of the native proteins indicate that these proteins belong to the three-finger toxin family. Hemextin A (but not hemextin B) exhibits mild anticoagulant activity. However, hemextin B forms a complex (hemextin AB complex) with hemextin A and synergistically enhances its anticoagulant potency. Prothrombin time assay showed that these two proteins form a 1:1 complex. Complex formation was supported by size-exclusion chromatography. Using a "dissection approach," we determined that hemextin A and the hemextin AB complex prolong clotting by inhibiting TF.FVIIa activity. The site of anticoagulant effects was supported by their inhibitory effect on the reconstituted TF.FVIIa complex. Furthermore, we demonstrated their specificity of inhibition by studying their effects on 12 serine proteases; the hemextin AB complex potently inhibited the amidolytic activity of FVIIa in the presence and absence of soluble TF. Kinetic studies showed that the hemextin AB complex is a noncompetitive inhibitor of soluble TF.FVIIa amidolytic activity, with a Ki of 50 nm. Isothermal titration calorimetric studies showed that the hemextin AB complex binds directly to FVIIa with a binding constant of 1.62 x 10(5) m(-1). The hemextin AB complex is the first reported natural inhibitor of FVIIa that does not require a scaffold to mediate its inhibitory activity. Molecular interactions of the hemextin AB complex with FVIIa/TF.FVIIa will provide a new paradigm in the search for anticoagulants that inhibit the initiation of blood coagulation.     

Structure and function relationship of staphylocoagulase

The bacterial protein staphylocoagulase binds stoichiometrically to human prothrombin, resulting in a coagulant complex, staphylothrombin. The enzymatic properties of staphylothrombin differ from those of -thrombin in their substrate specificities toward natural and synthetic substrates, in addition to their interaction with protease inhibitors. In order to obtain information about the region of staphylocoagulase that interacts with human prothrombin, staphylocoagulase was cleaved by -chymotrypsin. Limited -chymotryptic cleavage of staphylocoagulase yielded three large fragments, of 43, 30, and 20 kD. The 43-kD fragment exhibited a high affinity for human prothrombin (K_d=1.7 nM), which is comparable to the affinity observed using intact staphylocoagulase (K_d=0.46 nM). A complex of the 43-kD fragment and prothrombin possessed both clotting and amidase activity essentially identical to that observed in a complex of intact staphylocoagulase and prothrombin. The 30-kD fragment exhibited weaker affinity for prothrombin (K_d=120 nM.) While clotting activity was not observed with a complex of this fragment and prothrombin, it nonetheless possessed a weak amidase activity. The 20-kD fragment was found only to bind to prothrombin. The NH₂-terminal sequence analyses of these fragments revealed that the 43-kD fragment constitutes the NH₂-terminal portion of staphylocoagulase, and contains the 30-kD and 20-kD fragments. It is therefore concluded that the functional region of staphylocoagulase for binding and activation of prothrombin is localized in the NH₂-terminal region of the intact protein. The 43-kD fragment contained 324 amino acids with a molecular weight of 38,098. The 43-kD fragment had an unusual amino acid composition based on a sequence in which the sum of Asp (28 residues), Asn (22), Glu (35), Gln (9), and Lys (52) residues accounted for more than 45% of the total. A comparison of the amino acid sequence of the 43-kD fragment with that of streptokinase did not reveal any obvious sequence homology. There was also no sequence homology with that of trypsin, -chymotrypsin, and elastase.This article was presented during the proceedings of the International Conference on Macromolecular Structure and Function, held at the National Defence Medical College, Tokorozawa, Japan, December 1985.     

Serum lipid peroxide levels of albino rats administered naphthalene

When naphthalene was administered at a daily dose of 1 g/kg body weight to Wistar strain rats, their serum lipid peroxide levels were increased on the 4th day after the first administration and reached a maximum on the 7th day. This seems to be due to lipid peroxidation in the liver, in which lipid peroxide levels were increased in a similar pattern as those in the serum. The content of reduced glutathione in lenses of naphthalene-administered rats decreased on the 4th day. These results suggest that in naphthalene-induced cataract in albino rats increased lipid peroxides in the bloodstream may play a role in cataractogenesis.     

The repair of UV-irradiated plasmids transfected into cultured fish cells

UV-irradiated plasmids (pNPV B and pBSCATSV) were transfected into RBCF-1 cells derived from a goldfish (Carassius auratus) and into a xeroderma pigmentosum (group A) cell line, XP20SSV. The frequency of stable neor transformation by pNPV B decreased in a dose-dependent manner. However, in spite of large differences in UV sensitivity detected in the colony formation assay, the dose-response curves of RBCF-1 cells and XP20SSV cells were almost the same. The photorecovery (PR) of transforming activity of UV-irradiated plasmids was confirmed in RBCF-1 cells but its extent was much smaller than that observed in the survival assay. The expression of the transfected cat (chloramphenicol acetyltransferase; CAT) gene after 24-h incubation in the dark was much more sensitive to UV irradiation when compared with the stable transformation assay. The extent of PR of cat gene expression in RBCF-1 cells was high and comparable with that of the survival assay. The CAT value of RBCF-1 cells transfected with UV-irradiated plasmids relative to that of unirradiated controls increased as incubation time in the dark after transfection became longer. This suggests that the UV lesions on the plasmids transfected in the RBCF-1 cells were repaired in the dark. The cat gene expression of UV-irradiated plasmids in XP20SSV was very low and independent of incubation time after transfection.     

Biosynthesis of polymyxin E by a cell-free enzyme system. IV. Acylation of enzyme-bound L-2,4-diaminobutyric acid

An enzyme fraction, which catalyzes the ATP-PPi exchange reaction dependent on the three constituent amino acids of polymyxin E, was partially purified from crude extracts of Aerobacillus polyaerogenes. The approximate molecular weight was estimated to be 640,000 by Sepharose 4B gel filtration. Incubation of the enzyme with octanoyl coenzyme A and diaminobutyric acid in the presence of ATP and an ammonium sulfate fraction yielded octanoyldiaminobutyric acid thioesterified to the enzyme protein. On mild alkali treatment, octanoyldiaminobutyric acid, identified by paper chromatography, was released from the enzyme protein. From its acid hydrolyzate, diaminobutyric acid and octanoic acid were recovered in a molar ratio of 1 to 0.7. An ammonium sulfate fraction was required as the source of an acyltransferase for acylation of the enzyme-bound diaminobutyric acid. When [14C]-threonine was incubated with L-2,4-diaminobutyric acid in the presence of octanoyl coenzyme A, octanoyldiaminobutyrylthreonine bound to the enzyme protein was formed. These results suggest that acyldiaminobutyric acid bound to the enzyme protein is a possible initiation complex in the biosynthesis of polymyxin E.     

Optimal coordination of maximal-effort horizontal and vertical jump motions – a computer simulation study

Background  

The purpose of this study was to investigate the coordination strategy of maximal-effort horizontal jumping in comparison with vertical jumping, using the methodology of computer simulation.