Application of zwitterionic detergent to the solubilization of Klebsiella pneumoniae outer membrane proteins for two-dimensional gel electrophoresis

Klebsiella pneumoniae is a frequent cause of nosocomial respiratory, urinary and gastrointestinal tract infections and septicemia with the multidrug-resistant K. pneumoniae being a major public health concern. Outer membrane proteins (OMPs) are important virulence factors responsible for the appropriate adaptation to the host environment. They constitute of the antigens being the first in contact with infected organism. However, K. pneumoniae strains are heavily capsulated and it is important to establish the OMPs isolation procedure prior to proteomics extensive studies. In this study we used Zwittergent Z 3-14® as a detergent to isolate the OMPs from K. pneumoniae cells and resolve them using two-dimensional electrophoresis (2-DE). As a result we identified 134 protein spots. The OMPs identified in this study are possible candidates for the development of a protein-based vaccine against K. pneumoniae infections.

Immunophenotypic characterization of canine malignant lymphoma: a retrospective study of cases diagnosed in Poland Lower Silesia, over the period 2011-2013

Lymphoma is the most frequently diagnosed cancer of the canine haematopoietic system. In this study, the flow cytometry and polymerase chain reaction (PCR) analysis were used to characterize a series of canine lymphomas in detail. The aim of this study was to determine the incidence of B- and T-cell high-grade lymphomas and their immunophenotypic characterization in Lower Silesia, Poland. The results show that the frequency of each type of lymphoma is 71% for B-cell and 17% for T-cell lymphomas. In two cases the PCR techniques confirmed the presence of simultaneous double gene rearrangements of the BCR and TCR receptors.

Type of desmin expression in cardiomyocytes - a good marker of heart failure development in idiopathic dilated cardiomyopathy

AIM

The aim of this study was to determine whether remodelling of the desmin (DES) cytoskeleton affects myocardial function and whether it could be a useful marker of disease progression in patients with idiopathic dilated cardiomyopathy (IDCM).

MATERIAL AND METHODS

Endomyocardial biopsy was performed in 195 IDCM patients, and five to six specimens were collected from the left ventricle. DES expression was evaluated using tissue immunostaining and Western blotting. The study population was assigned to four groups according to DES expression type: I, normal DES staining at Z-lines giving a regular pattern of cross-striation (n = 57); IIA, increased DES staining with a regular pattern of cross-striation (n = 40); IIB, increased DES staining with an irregular pattern of cross-striation and/or the presence of aggregates (n = 56); and III, decreased/lack of DES staining (n = 42). Fibrosis, cardiomyocyte hypertrophy and ultrastructure were assessed for the four types of DES expression.

RESULTS

The pathological types of DES expression (IIB or III) were associated with pathological changes in mitochondria and the contractile apparatus. Cardiomyocyte diameter and level of fibrosis were both significantly affected. DES expression type correlated with NYHA class, left ventricular end-diastolic diameter, left ventricular ejection fraction and the level of N-terminal pro-brain natriuretic protein.

CONCLUSION

The type of immunohistochemical DES expression correlated with the level of myocardial injury at the cellular and organ levels. This correlation was similar to that observed between DES expression and the well-established biochemical, echocardiographic and clinical parameters of heart failure (HF). DES expression type could be used as an important diagnostic feature of HF development.

Upregulation of nuclear factor-related kappa B suggests a disorder of transcriptional regulation in minimal change nephrotic syndrome

Immune mechanisms underlying the pathophysiology of idiopathic nephrotic syndrome, the most frequent glomerular disease in children, are believed to involve a systemic disorder of T cell function and cell mediated immunity. How these perturbations take place remains unclear. We report here that NFRKB, a member of the chromatin remodeling complex, is upregulated in MCNS relapse, mainly in CD4+T cells and B cells and undergo post-translational modifications including sumoylation. We showed that NFRKB was highly expressed in nuclear compartment during the relapse, while it was restricted to cytoplasm in remission. NFRKB induced the activation of AP1 signaling pathway by upregulating the expression of c-jun. We showed that NFRKB promotes hypomethylation of genomic DNA, suggesting its implication in regulation of gene expression by enhancing the binding of transcription factors through chromatin remodeling. These results suggest for the first time that NFRKB may be involved in the disorders of transcriptional regulation commonly observed in MCNS relapse.

c-mip impairs podocyte proximal signaling and induces heavy proteinuria

Idiopathic nephrotic syndrome comprises several podocyte diseases of unknown origin that affect the glomerular podocyte, which controls the permeability of the filtration barrier in the kidney to proteins. It is characterized by the daily loss of more than 3 g of protein in urine and the lack of inflammatory lesions or cell infiltration. We found that the abundance of c-mip (c-maf inducing protein) was increased in the podocytes of patients with various acquired idiopathic nephrotic syndromes in which the podocyte is the main target of injury. Mice engineered to have excessive c-mip in podocytes developed proteinuria without morphological alterations, inflammatory lesions, or cell infiltration. Excessive c-mip blocked podocyte signaling by preventing the interaction of the slit diaphragm transmembrane protein nephrin with the tyrosine kinase Fyn, thereby decreasing phosphorylation of nephrin in vitro and in vivo. Moreover, c-mip inhibited interactions between Fyn and the cytoskeletal regulator N-WASP (neural Wiskott-Aldrich syndrome protein) and between the adaptor protein Nck and nephrin, potentially accounting for cytoskeletal disorganization and the effacement of foot processes seen in idiopathic nephrotic syndromes. The intravenous injection of small interfering RNA targeting c-mip prevented lipopolysaccharide-induced proteinuria in mice. Together, these results identify c-mip as a key component in the molecular pathogenesis of acquired podocyte diseases.

Identification of transcripts by macroarrays, RT–PCR and in situ hybridization in human ejaculate spermatozoa

Round spermatids contain high levels of extremely varied mRNAs that are synthesized either throughout early spermatogenesis or during spermiogenesis from the haploid genome. Concomitantly, with major changes in the chromatin organization, arrest of transcription occurs at midspermiogenesis. However, previous investigations using RT-PCR have revealed the persistence of numerous and different transcripts in ejaculated spermatozoa. In the present study, a step-by-step analysis by means of macroarray hybridization, RT-PCR and in situ hybridization was performed to identify more accurately the different mRNA species found in the human ejaculated spermatozoa. The data showed an extended pattern of various transcripts encoding a diverse range of proteins involved in signal transduction and cell proliferation. For the first time, they demonstrated that mRNAs coding for the transcription factors NFkappaB, HOX2A, ICSBP, protein kinase JNK2, growth factor HBEGF and receptors RXRbeta and ErbB3 accumulate within the sperm nucleus. The origin and fate of the sperm transcripts remain subject to discussion.

Abnormal RNA processing and altered expression of serin-rich proteins in minimal-change nephrotic syndrome

Mechanisms underlying the pathophysiology of minimal-change nephrotic syndrome (MCNS), the most frequent glomerular disease in children, remain elusive, but recent findings argue for a T cell dysfunction. Starting from a differential cDNA library from T cells of a patient under relapse and remission, we identified 16 transcripts specific for MCNS. All of these transcripts that were selectively up-regulated during the relapse phase of the disease were generated by alternative splicing of known genes. This abnormal RNA expression was associated with a down-regulation of serin-rich protein 75 and serin-rich protein 40, two proteins involved in mRNA splicing. Taken together, these data suggest that T cell dysfunction in MCNS is associated with abnormal mRNA splicing.

NF-κB p65 Antagonizes IL-4 Induction by c-mafin Minimal Change Nephrotic Syndrome

Mechanisms underlying the pathophysiology of minimal change nephrotic syndrome (MCNS), the most frequent of glomerular diseases in children, remain elusive, although recent arguments suggest that T cell dysfunction may be involved in the pathogenesis of this disease. Recently, we reported that activated T cells of these patients display a down-regulation of IL-12R beta2 chain, suggesting an early commitment toward Th2 phenotype. In this study, we show that the short form of the proto-oncogene c-maf, a known activator of the IL-4 gene, is highly induced in MCNS T cells during relapse, where it translocates to the nuclear compartment and binds to the DNA responsive element. Unexpectedly, the nuclear localization of c-maf did not promote the IL-4 gene transcription in relapse. Using several approaches, we show in this study that RelA blunts IL-4 induction in T cells during the relapse in these patients. We demonstrate that the ex vivo inhibition of proteasome activity in T cells from relapse, which blocks NF-kappaB activity, strongly increases the IL-4 mRNA levels. Overexpression of c-maf in T cells induces a high level of IL-4 promoter-driven luciferase activity. In contrast, coexpression of c-maf with NF-kappaB RelA/p50, or RelA, but not p50, inhibits the c-maf-dependent IL-4 promoter activity. Finally, we demonstrated that, in T cell overexpressing RelA and c-maf, RelA expelled c-maf from its DNA binding site on IL-4 gene promoter, which results in active inhibition of IL-4 gene transcription. Altogether, these results suggest that the involvement of c-maf in Th2 commitment in MCNS operates through IL-4-independent mechanisms.

Truncation of C-mip (Tc-mip), a new proximal signaling protein, induces c-maf Th2 transcription factor and cytoskeleton reorganization

Several arguments suggest that minimal change nephrotic syndrome (MCNS) results from yet unknown systemic disorder of T cell function. By screening a cDNA library from T cell relapse, we identified a new pleckstrin homology (PH) domain-containing protein encoded by a gene located on chromosome 16q24. Two alternative transcripts were identified. The first species (c-mip) was expressed in fetal liver, kidney, and peripheral blood mononuclear cells (PBMCs), but weakly detected in PBMCs from MCNS patients. The second form (Tc-mip, standing for truncated c-maf inducing protein), corresponds to subtracted transcript and lacks the NH2-terminal PH domain. The expression of Tc-mip was restricted to fetal liver, thymus, and MCNS PBMCs where it was specifically recruited in CD4+ T cells subset. Overexpression of Tc-mip in T cell Jurkat induced c-maf, transactivated the interleukin 4 gene and down-regulated the interferon gamma expression, characteristic of a Th2 commitment. Moreover, the overexpression of Tc-mip induced Src phosphorylation, T cell clustering, and a cellular redistribution of the cytoskeleton-associated L-plastin, by a PI3 kinase independent pathway. Tc-mip represents therefore the first identified protein, which links proximal signaling to c-maf induction.

A novel approach to investigation of the pathogenesis of active minimal-change nephrotic syndrome using subtracted cDNA library screening

Clinical and experimental observations suggest that minimal-change nephrotic syndrome (MCNS) results from T cell dysfunction, via unknown mechanisms. For the identification of genes that are potentially involved in MCNS, a subtractive cDNA library was constructed from cDNA from T cell-enriched peripheral blood mononuclear cells obtained from the same patient during relapse versus remission ("relapse minus remission"). This library was screened by differential hybridization with forward ("relapse minus remission") and reverse ("remission minus relapse") subtractive cDNAs probes, as well as unsubtracted probes from relapse and remission, and irrelevant nephrotic syndrome (membranous nephropathy). A total of 84 transcripts were isolated, of which 12 matched proteins of unknown function and 30 were unknown clones. Among the 42 known transcripts, at least 18 are closely involved in the T cell receptor-mediated complex signaling cascade, including genes encoding components of the T cell receptor and proteins associated with the cytoskeletal scaffold, as well as transcription factors. In particular, it was demonstrated that the expression levels of Fyb/Slap, L-plastin, and grancalcin were increased during relapse, suggesting that the integration of proximal signaling after T cell engagement involves the preferential recruitment of these cytoskeleton-associated proteins in MCNS. Because very low levels of interleukin-12 receptor beta2 mRNA were detected in relapse samples, the interleukin-12 signaling pathway might be defective, suggesting that, in MCNS, T cell activation evolves toward a T helper 2 phenotype. Therefore, the combination of subtractive cloning and differential screening constitutes an efficient approach to the identification of genes that are likely to be involved in the pathophysiologic processes of MCNS.

Meiotic human sperm cells express a leucine-rich homologue of Caenorhabditis elegans early embryogenesis gene, Zyg-11

We cloned a human protein (Hzyg) homologue to Caenorhabditis elegans Zyg-11, an essential protein for cell division at the initial developmental stages of this species, and to a Drosophila melanogaster gene product (Mei-1) which is likely to be involved in meiosis. Hzyg mRNA encodes a protein of 766 amino acids (88 kDa), 14% of which are leucine residues, with some being arranged in four leucine rich repeat motives usually involved in protein-protein interactions. Hzyg is encoded by a single gene, located on chromosome 9q32-q34.1, and transcribed as two mRNA: a 5 kb transcript strongly expressed in testis and skeletal muscle and barely detectable in other human tissues, and an abundant 3.1 kb mRNA detected only in the testis. By using in-situ hybridization and immunohistochemistry, we clearly established the presence of Hzyg expression in pachytene spermatocytes (stage V) and spermatids (stage I and/or II) around the time of meiosis. The cell specific expression of Hzyg transcripts in testis, and the conservation of this gene among distant species, suggest that this protein may have an important role during meiosis.

Probing the spatial dependence of the emission spectrum of single human retinal lipofuscin granules using near-field scanning optical microscopy

The emission spectra of single lipofuscin granules are examined using spectrally resolved confocal microscopy and near-field scanning optical microscopy (NSOM). The emission spectrum varies among the granules examined revealing that individual granules are characterized by different distributions of fluorophores. The range of spectra observed is consistent with in vivo spectra of human retinal pigment epithelium cells. NSOM measurements reveal that the shape of the spectrum does not vary with position within the emissive regions of single lipofuscin granules. These results suggest that the relative distribution of fluorophores within the emissive regions of an individual granule is homogeneous on the spatial scale approximately 150 nm.