Outcomes from studies of Antineutrophil Cytoplasm Antibody Associated Vasculitis: a systematic review by the European League Against Rheumatism systemic vasculitis task force.

Objectives: We undertook a systematic literature review as a background to the European League Against Rheumatism (EULAR) recommendations for conducting clinical trials in anti-neutrophil cytoplasm antibody associated vasculitis (AAV), and to assess the quality of evidence for outcome measures in AAV. Methods: Using a systematic Medline search, we categorised the identified studies according to diagnoses. Factors affecting remission, relapse, renal function and overall survival were identified. Results: A total of 44 papers were reviewed from 502 identified by our search criteria. There was considerable inconsistency in definitions of end points. Remission rates varied from 30% to 93% in Wegener granulomatosis (WG), 75% to 89% in microscopic polyangiitis (MPA) and 81% to 91% in Churg¿Strauss syndrome (CSS). The 5-year survival for WG, MPA and CSS was 74¿91%, 45¿76% and 60¿97%. Relapse (variably defined) was common in the first 2 years but the frequency varied: 18% to 60% in WG, 8% in MPA, and 35% in CSS. The rate of renal survival in WG varied from 23% at 15 months to 23% at 120 months. Methods used to assess morbidity varied between studies. Ignoring the variations in definitions of the stage of disease, factors influencing remission, relapse, renal and overall survival included immunosuppressive therapy used, type of organ involvement, presence of ANCA, older age and male ender. Conclusions: Factors influencing remission, relapse, renal and overall survival include the type of immunosuppressive therapy used, pattern of organ involvement, presence of ANCA, older age and male gender. Methodological variations between studies highlight the need for a consensus on terminology and definitions for future conduct of clinical studies in AAV.

Clinical implications in the shift of syndecan-1 expression from the cell membrane to the cytoplasm in bladder cancer

Background To determine the diagnostic and prognostic capability of urinary and tumoral syndecan-1 (SDC-1) levels in patients with cancer of the urinary bladder. Methods SDC-1 levels were quantitated by enzyme-linked immunosorbent assay (ELISA) in 308 subjects (102 cancer subjects and 206 non-cancer subjects) to assess its diagnostic capabilities in voided urine. The performance of SDC-1 was evaluated using the area under the curve of a receiver operating characteristic curve. In addition, immunohistochemical (IHC) staining assessed SDC-1 protein expression in 193 bladder specimens (185 cancer subjects and 8 non-cancer subjects). Outcomes were correlated to SDC-1 levels. Results Mean urinary levels of SDC-1 did not differ between the cancer subjects and the non-cancer subjects, however, the mean urinary levels of SDC-1 were reduced in high-grade compared to low-grade disease (p < 0.0001), and in muscle invasive bladder cancer (MIBC) compared to non-muscle invasive bladder cancer (NMIBC) (p = 0.005). Correspondingly, preliminary data note a shift from a membranous cellular localization of SDC-1 in normal tissue, low-grade tumors and NMIBC, to a distinctly cytoplasmic localization in high-grade tumors and MIBC was observed in tissue specimens. Conclusion Alone urinary SDC-1 may not be a diagnostic biomarker for bladder cancer, but its urinary levels and cellular localization were associated with the differentiation status of patients with bladder tumors. Further studies are warranted to define the potential role for SDC-1 in bladder cancer progression.

Clinical implications in the shift of syndecan-1 expression from the cell membrane to the cytoplasm in bladder cancer

Background To determine the diagnostic and prognostic capability of urinary and tumoral syndecan-1 (SDC-1) levels in patients with cancer of the urinary bladder. Methods SDC-1 levels were quantitated by enzyme-linked immunosorbent assay (ELISA) in 308 subjects (102 cancer subjects and 206 non-cancer subjects) to assess its diagnostic capabilities in voided urine. The performance of SDC-1 was evaluated using the area under the curve of a receiver operating characteristic curve. In addition, immunohistochemical (IHC) staining assessed SDC-1 protein expression in 193 bladder specimens (185 cancer subjects and 8 non-cancer subjects). Outcomes were correlated to SDC-1 levels. Results Mean urinary levels of SDC-1 did not differ between the cancer subjects and the non-cancer subjects, however, the mean urinary levels of SDC-1 were reduced in high-grade compared to low-grade disease (p < 0.0001), and in muscle invasive bladder cancer (MIBC) compared to non-muscle invasive bladder cancer (NMIBC) (p = 0.005). Correspondingly, preliminary data note a shift from a membranous cellular localization of SDC-1 in normal tissue, low-grade tumors and NMIBC, to a distinctly cytoplasmic localization in high-grade tumors and MIBC was observed in tissue specimens. Conclusion Alone urinary SDC-1 may not be a diagnostic biomarker for bladder cancer, but its urinary levels and cellular localization were associated with the differentiation status of patients with bladder tumors. Further studies are warranted to define the potential role for SDC-1 in bladder cancer progression.

Rapeseed cytoplasm gives advantage in wild relatives and complicates genetically modified crop biocontainment

Biocontainment methods for genetically modified crops closest to commercial reality (chloroplast transformation, male sterility) would be compromised (in absolute terms) by seed-mediated gene flow leading to chloroplast capture. Even in these circumstances, however, it can be argued that biocontainment still represses transgene movement, with the efficacy depending on the relative frequency of seed-and pollen-mediated gene flow. In this study, we screened for crop-specific chloroplast markers from rapeseed (Brassica napus) amongst sympatric and allopatric populations of wild B. oleracea in natural cliff-top populations and B. rapa in riverside and weedy populations. We found only modest crop chloroplast presence in wild B. oleracea and in weedy B. rapa, but a surprisingly high incidence in sympatric (but not in allopatric) riverside B. rapa populations. Chloroplast inheritance models indicate that elevated crop chloroplast acquisition is best explained if crop cytoplasm confers selective advantage in riverside B. rapa populations. Our results therefore imply that chloroplast transformation may slow transgene recruitment in two settings, but actually accelerate transgene spread in a third. This finding suggests that the appropriateness of chloroplast transformation for biocontainment policy depends on both context and geographical location.

From cytoplasm to environment: The inorganic ingredients for the origin of life

Early in its history, Earth's surface developed from an uninhabitable magma ocean to a place where life could emerge. The first organisms, lacking ion transporters, fixed the composition of their cradle environment in their intracellular fluid. Later, though life adapted and spread, it preserved some qualities of its initial environment within. Modern prokaryotes could thus provide insights into the conditions of early Earth and the requirements for the emergence of life. In this work, we constrain Earth's life-forming environment through detailed analysis of prokaryotic intracellular fluid. Rigorous assessment of the constraints placed on the early Earth environment by intracellular liquid will provide insight into the conditions of abiogenesis, with implications not only for our understanding of early Earth but also the formation of life elsewhere in the Universe. Copyright © 2013, Mary Ann Liebert, Inc. 2013.

Hepatitis C Virus NS2 Protein Inhibits DNA Damage Pathway by Sequestering p53 to the Cytoplasm

Chronic hepatitis C virus (HCV) infection is an important cause of morbidity and mortality globally, and often leads to end-stage liver disease. The DNA damage checkpoint pathway induces cell cycle arrest for repairing DNA in response to DNA damage. HCV infection has been involved in this pathway. In this study, we assess the effects of HCV NS2 on DNA damage checkpoint pathway. We have observed that HCV NS2 induces ataxia-telangiectasia mutated checkpoint pathway by inducing Chk2, however, fails to activate the subsequent downstream pathway. Further study suggested that p53 is retained in the cytoplasm of HCV NS2 expressing cells, and p21 expression is not enhanced. We further observed that HCV NS2 expressing cells induce cyclin E expression and promote cell growth. Together these results suggested that HCV NS2 inhibits DNA damage response by altering the localization of p53, and may play a role in the pathogenesis of HCV infection. © 2013 Bitter et al.

Klf4 transcription factor is expressed in the cytoplasm of prostate cancer cells

BACKGROUND: Cancer initiation and progression might be driven by small populations of cells endowed with stem cell-like properties. Here we comparatively addressed the expression of genes encoding putative stemness regulators including c-Myc, Klf4, Nanog, Oct4A and Sox2 genes in benign prostatic hyperplasia (BPH) and prostate cancer (PCA). METHODS: Fifty-eight PCA and thirty-nine BPH tissues samples were used for gene expression analysis, as evaluated by quantitative real-time polymerase chain reaction (qRT-PCR). The expression of specific Klf4 isoforms was tested by conventional PCR. Klf4 specific antibodies were used for protein detection in a tissue microarray including 404 prostate samples. RESULTS: Nanog, Oct4A and Sox2 genes were comparably expressed in BPH and PCA samples, whereas c-Myc and Klf4 genes were expressed to significantly higher extents in PCA than in BPH specimens. Immunohistochemical studies revealed that Klf4 protein is detectable in a large majority of epithelial prostatic cells, irrespective of malignant transformation. However, in PCA, a predominantly cytoplasmic location was observed, consistent with the expression of a differentially spliced Klf4α isoform. CONCLUSION: Klf4 is highly expressed at gene and protein level in BPH and PCA tissues but a cytoplasmic location of the specific gene product is predominantly detectable in malignant cells. Klf4 location might be of critical relevance to steer its functions during oncogenesis.

A synthetic histone pre-mRNA-U7 small nuclear RNA chimera undergoing cis cleavage in the cytoplasm of Xenopus oocytes.

The 3' processing of histone pre-mRNAs is a nuclear event in which the U7 small nuclear ribonucleoprotein (snRNP) participates as an essential trans-acting factor. We have constructed a chimeric histone-U7 RNA that when injected into the cytoplasm of Xenopus laevis oocytes assembles into a snRNP-like particle and becomes cleaved at the correct site(s). RNP assembly is a prerequisite for cleavage, but, since neither the RNA nor the RNP appreciably enter the nucleus, cleavage occurs mostly, if not exclusively, in the cytoplasm. Consistent with this, cleavage also occurs in enucleated oocytes or in oocytes which have been depleted of U7 snRNPs. Thus all necessary components for cleavage must be present in the oocyte cytoplasm. The novel cleavage occurs in cis, involving only a single molecule of chimeric RNA with its associated proteins. This reaction is equally dependent upon base pairing interactions between histone spacer sequences and the 5'-end of the U7 moiety as the natural in trans reaction. These results imply that U7 is the only snRNP required for histone RNA processing. Moreover, the chimeric RNA is expected to be useful for further studies of the cleavage and assembly mechanisms of U7 snRNP.

Inhibition of myogenesis by transforming growth factor β is density-dependent and related to the translocation of transcription factor MEF2 to the cytoplasm

Transforming growth factor β (TGF-β) was found to inhibit differentiation of myogenic cells only when they were grown to high density. Inhibition also occurred when myogenic cells were cocultured with other types of mesenchymal cells but not when they were cocultured with epithelial cells. It is therefore possible that some density-dependent signaling mediates the intracellular response to TGF-β. Within 30 min of treatment, TGF-β induced translocation of MEF2, but not MyoD, myogenin, or p21, to the cytoplasm of myogenic cells grown to high density. Translocation was reversible on withdrawal of TGF-β. By using immune electron microscopy and Western blot analysis on subcellular fractions, MEF2 was shown to be tightly associated with cytoskeleton membrane components. To test whether MEF2 export from the nucleus was causally related to the inhibitory action of TGF-β, we transfected C2C12 myoblasts with MEF2C containing the nuclear localization signal of simian virus 40 large T antigen (nlsSV40). Myogenic cells expressing the chimerical MEF2C/nlsSV40, but not wild-type MEF2C, retained this transcription factor in the nucleus and were resistant to the inhibitory action of TGF-β. We propose a mechanism in which the inhibition of myogenesis by TGF-β is mediated through MEF2 localization to the cytoplasm, thus preventing it from participating in an active transcriptional complex.

mRNA binding protein mrnp 41 localizes to both nucleus and cytoplasm

We have identified and molecularly characterized a human protein with a Mr of 40,880 Da. After UV irradiation of HeLa cells, this protein was cross-linked to poly(A)-containing mRNA and was therefore designated mrnp 41 (for mRNA binding protein of 41 kDa). Cell fractionation and immunoblotting showed mrnp 41 in both the cytoplasm and the nucleus and particularly in the nuclear envelope. Immunofluorescence microscopy localized mrnp 41 to distinct foci in the nucleoplasm, to the nuclear rim, and to meshwork-like structures throughout the cytoplasm. The cytoplasmic meshwork staining was disrupted by prior treatment of cells with the actin filament- or microtubule-disrupting drugs cytochalasin or nocodazole, respectively, suggesting association of mrnp 41 with the cytoskeleton. Double immunofluorescence with antibodies against mrnp 41 and the cytoplasmic poly(A) binding protein showed colocalization to the cytoplasmic meshwork. Immunogold electronmicroscopy confirmed mrnp 41’s cytoplasmic and nucleoplasmic localization and revealed a striking labeling of nuclear pore complexes. Together these data suggest that mrnp 41 may function in nuclear export of mRNPs and/or in cytoplasmic transport on, or attachment to, the cytoskeleton. Consistent with a role of mrnp 41 in nuclear export are previous reports that mutations in homologs of mrnp 41 in Schizosaccharomyces pombe, designated Rae1p, or in Saccharomyces cerevisiae, designated Gle2p, result in mRNA accumulation in the nucleus although it is presently not known whether these homologs are mRNA binding proteins as well.

Efficient folding of proteins with multiple disulfide bonds in the Escherichia coli cytoplasm

Under physiological conditions, the Escherichia coli cytoplasm is maintained in a reduced state that strongly disfavors the formation of stable disulfide bonds in proteins. However, mutants in which the reduction of both thioredoxins and glutathione is impaired (trxB gor mutants) accumulate oxidized, enzymatically active alkaline phosphatase in the cytoplasm. These mutants grow very poorly in the absence of an exogenous reductant and accumulate extragenic suppressors at a high frequency. One such suppressor strain, FA113, grows almost as rapidly as the wild type in the absence of reductant, exhibits slightly faster kinetics of disulfide bond formation, and has fully induced activity of the transcriptional activator, OxyR. FA113 gave substantially higher yields of properly oxidized proteins compared with wild-type or trxB mutant strains. For polypeptides with very complex patterns of disulfide bonds, such as vtPA and the full-length tPA, the amount of active protein was further enhanced up to 15-fold by co-expression of TrxA (thioredoxin 1) mutants with different redox potentials, or 20-fold by the protein disulfide isomerase, DsbC. Remarkably, higher yields of oxidized, biologically active proteins were obtained by expression in the cytoplasm of E. coli FA113 compared with what could be achieved via secretion into the periplasm of a wild-type strain, even under optimized conditions. These results demonstrate that the cytoplasm can be rendered sufficiently oxidizing to allow efficient formation of native disulfide bonds without compromising cell viability.

Apg7p/Cvt2p Is Required for the Cytoplasm-to-Vacuole Targeting, Macroautophagy, and Peroxisome Degradation Pathways

Proper functioning of organelles necessitates efficient protein targeting to the appropriate subcellular locations. For example, degradation in the fungal vacuole relies on an array of targeting mechanisms for both resident hydrolases and their substrates. The particular processes that are used vary depending on the available nutrients. Under starvation conditions, macroautophagy is the primary method by which bulk cytosol is sequestered into autophagic vesicles (autophagosomes) destined for this organelle. Molecular genetic, morphological, and biochemical evidence indicates that macroautophagy shares much of the same cellular machinery as a biosynthetic pathway for the delivery of the vacuolar hydrolase, aminopeptidase I, via the cytoplasm-to-vacuole targeting (Cvt) pathway. The machinery required in both pathways includes a novel protein modification system involving the conjugation of two autophagy proteins, Apg12p and Apg5p. The conjugation reaction was demonstrated to be dependent on Apg7p, which shares homology with the E1 family of ubiquitin-activating enzymes. In this study, we demonstrate that Apg7p functions at the sequestration step in the formation of Cvt vesicles and autophagosomes. The subcellular localization of Apg7p fused to green fluorescent protein (GFP) indicates that a subpopulation of Apg7pGFP becomes membrane associated in an Apg12p-dependent manner. Subcellular fractionation experiments also indicate that a portion of the Apg7p pool is pelletable under starvation conditions. Finally, we demonstrate that the Pichia pastoris homologue Gsa7p that is required for peroxisome degradation is functionally similar to Apg7p, indicating that this novel conjugation system may represent a general nonclassical targeting mechanism that is conserved across species.

Folding of Active β-Lactamase in the Yeast Cytoplasm before Translocation into the Endoplasmic Reticulum

Polypeptides targeted to the yeast endoplasmic reticulum (ER) posttranslationally are thought to be kept in the cytoplasm in an unfolded state by Hsp70 chaperones before translocation. We show here that Escherichia coli β-lactamase associated with Hsp70, but adopted a native-like conformation before translocation in living Saccharomyces cerevisiae cells. β-Lactamase is a globular trypsin-resistant molecule in authentic form. For these studies, it was linked to the C terminus of a yeast polypeptide Hsp150Δ, which conferred posttranslational translocation and provided sites for O-glycosylation. We devised conditions to retard translocation of Hsp150Δ-β-lactamase. This enabled us to show by protease protection assays that an unglycosylated precursor was associated with the cytoplasmic surface of isolated microsomes, whereas a glycosylated form resided inside the vesicles. Both proteins were trypsin resistant and had similar β-lactamase activity and Km values for nitrocefin. The enzymatically active cytoplasmic intermediate could be chased into the ER, followed by secretion of the activity to the medium. Productive folding in the cytoplasm occurred in the absence of disulfide formation, whereas in the ER lumen, proper folding required oxidation of the sulfhydryls. This suggests that the polypeptide was refolded in the ER and consequently, at least partially unfolded for translocation.