Production of a recombinant hybrid molecule of cholera toxin-B-subunit and proteolipid-protein-peptide for the treatment of experimental encephalomyelitis

Mucosal administration of experimental autoimmune encephalomyelitis (EAE)-specific autoantigens can reduce the onset of disease. To examine whether cholera toxin-B-subunit (CTB)-conjugated EAE-specific T-cell epitope can reduce development of the autoimmune disease in mice, we produced a recombinant hybrid molecule of CTB fusion protein linked with proteolipid-protein (PLP)-peptide139-151(C140S) at levels up to 0.1 gram per liter culture media in Bacillus brevis as a secretion-expression system. Amino acid sequencing and GM1-receptor binding assay showed that this expression system produced a uniformed recombinant hybrid protein. EAE was induced in SJL/J mice by systemic administration with the PLP-peptide. When nasally immunized 5 times with 70 microg rCTB PLP-peptide hybrid protein, mice showed a significantly suppressed development of ongoing EAE and an inhibition of both the PLP-peptide-specific delayed-type hypersensitivity (DTH) responses and leukocyte infiltration into the spinal cord. In contrast, all mice given the PLP-peptide alone or the PLP-peptide with the free form of CTB did not suppress the development of EAE and DTH responses. These results suggest that nasal treatment with the recombinant B. brevis-derived hybrid protein of CTB and autoantigen peptide could prove useful in the control of multiple sclerosis.     

Evidence that the interaction between insulin-like growth factor (IGF)-II and IGF binding protein (IGFBP)-4 is essential for the action of the IGF-II-dependent IGFBP-4 protease

A variety of human cell types, including human osteoblasts (hOBs), produce an IGFBP-4 protease, which cleaves IGFBP-4 in the presence of IGF-II. Recently, the pregnancy-associated plasma protein (PAPP)-A has been determined to be the IGF-II-dependent IGFBP-4 protease produced by human fibroblasts. This study sought to define the mechanism by which IGF-II enhances IGFBP-4 proteolysis. Addition of PAPP-A antibody blocked the IGFBP-4 proteolytic activity in hOB conditioned medium (CM), suggesting that PAPP-A is the major IGFBP-4 protease in hOB CM. Pre-incubation of IGFBP-4 with IGF-II, followed by removal of unbound IGF-II, led to IGFBP-4 proteolysis without further requirement of the presence of IGF-II in the reaction. In contrast, prior incubation of the partially purified IGFBP-4 protease from either hOB CM or human pregnancy serum with IGF-II did not lead to IGFBP-4 proteolysis unless IGF-II was re-added to the assays. To further confirm that the interaction between IGF-II and IGFBP-4 is required for IGFBP-4 protease activity, we prepared IGFBP-4 mutants, which contained the intact cleavage site (Met135-Lys136) but lacked the IGF binding activity, by deleting the residues Leu72-His74 in the IGF binding domain or Cys183-Glu237 that contained an IGF binding enhancing motif. The IGFBP-4 protease was unable to cleave these IGFBP-4 mutants, regardless of whether or not IGF-II was present in the assay. Conversely, an IGFBP-4 mutant with His74 replaced by an Ala, which exhibited normal IGF binding activity, was effectively cleaved in the presence of IGF-II. Taken together, these findings provided strong evidence that the interaction between IGF-II and IGFBP-4, rather than the direct interaction between IGF-II and IGFBP-4 protease, is required for optimal IGFBP-4 proteolysis.     

A simplified procedure for the purification of human N-acetylglucosaminyltransferase-III from human hepatocellular carcinoma tissues

Human N-acetylglucosaminyltransferase-III (GnT-III) has not been hitherto purified from either tissue or cell line. Although rat GnT-III has been purified from rat kidney tissue, the procedure involves laborious and complex steps. We have developed a simplified procedure based on a QAE (diethyl[2-hydroxypropyl]aminoethyl)-Sepharose and an immunoaffinity chromatography technique. The immunoaffinity chromatography utilized a monoclonal antibody to human aglycosyl recombinant N-acetylglucosaminyltransferase-III. With the new procedure, human N-acetylglucosaminyltransferase-III was purified from hepatocellular carcinoma tissues with an increase in the specific enzyme activity of 378-fold.     

Enhancement of Secretion and Extracellular Stability of Staphylokinase in Bacillus subtilis by wprA Gene Disruption

Staphylokinase (SAK), a polypeptide secreted by Staphylococcus aureus, is a plasminogen activator with a therapeutic potential in thrombosis diseases. A Bacillus subtilis strain which is multiply deficient in exoproteases was transformed by an expression plasmid carrying a promoter and a signal sequence of subtilisin fused in frame with the sak open reading frame. However, the amount of SAK secretion was marginal (45 mg/liter). In contrast, disruption of the wprA gene, which encodes a subtilisin-type protease, strongly promoted the production of SAK in the stationary phase (181 mg/liter). In addition, the extracellular stability of mature SAK was dramatically enhanced. These data indicate a significant role of the wprA gene product in degrading foreign proteins, both during secretion and in the extracellular milieu.     

Rice LIM protein OsPLIM2a is involved in rice seed and tiller development

Yield of major monocotyledonous crops including wheat, rice, barley, and sorghum is greatly influenced by tillering. However, deciphering the underlying mechanisms of the tillering has long been hindered because many changeable factors are involved in the process. Plant two LIM-domain-containing proteins bind to and stabilize actin filaments that are major constituents in the formation of higher-order actin cytoskeleton. Here, we report that rice LIM-domain protein, OsPLIM2a, is involved in rice tillering likely through actin cytoskeleton organization. OsPLIM2 genes (OsPLIM2a, OsPLIM2b, and OsPLIM2c) expressed in reproductive organs including anthers, but not in other tissues. Analysis of both OsPLIM2a and OsPLIM2c promoter fused to GUS reporter revealed that both promoters directed strong and specific GUS expression in pollens. Transient expression of OsPLIM2a-GFP and OsPLIM2c-GFP in tobacco leaves showed that OsPLIM2a and OsPLIM2c could bind to actin filaments, which is consistent with other plant LIM proteins with actin-binding property. To examine further physiological roles of rice OsPLIM2a and OsPLIM2c, transgenic rice plants with 35S:OsPLIM2a or 35S:OsPLIM2c were examined for any phenotypic changes. Transgenic plants overexpressing OsPLIM2a produced bigger seeds than wild type, whereas they exhibited reduction in tiller numbers. These results suggest that OsPLIM2a may participate positively in seed development but negatively in tiller differentiation. Protein interaction assays using OsPLIM2c proteins revealed that OsPLIM2c interacted with at least three proteins including rice Fimbrin, of which homologs in Arabidopsis play crucial roles in pollen tube growth, implying that rice OsPLIM2c and Fimbrin may exert roles together in pollen tube growth.     

From cell senescence to age-related diseases: differential mechanisms of action of senescence-associated secretory phenotypes

Cellular senescence is a process by which cells enter a state of permanent cell cycle arrest. It is commonly believed to underlie organismal aging and age-associated diseases. However, the mechanism by which cellular senescence contributes to aging and age-associated pathologies remains unclear. Recent studies showed that senescent cells exert detrimental effects on the tissue microenvironment, generating pathological facilitators or aggravators. The most significant environmental effector resulting from senescent cells is the senescence-associated secretory phenotype (SASP), which is constituted by a strikingly increased expression and secretion of diverse pro-inflammatory cytokines. Careful investigation into the components of SASPs and their mechanism of action, may improve our understanding of the pathological backgrounds of age-associated diseases. In this review, we focus on the differential expression of SASP-related genes, in addition to SASP components, during the progress of senescence. We also provide a perspective on the possible action mechanisms of SASP components, and potential contributions of SASP-expressing senescent cells, to age-associated pathologies. [BMB Reports 2015; 48(10): 549-558]     

Clinical Value of Core Length in Contemporary Multicore Prostate Biopsy

Objectives

There is little data about the clinical value of core length for prostate biopsy (PBx). We investigated the clinical values of various clinicopathological biopsy-related parameters, including core length, in the contemporary multi-core PBx.

Patients and Methods

Medical records of 5,243 consecutive patients who received PBx at our institution were reviewed. Among them, 3,479 patients with prostate-specific antigen (PSA) ≤10ng/ml level who received transrectal ultrasound (TRUS)-guided multi (≥12)-core PBx at our institution were analyzed for prostate cancer (PCa). Gleason score upgrading (GSU) was analyzed in 339 patients who were diagnosed with low-risk PCa and received radical prostatectomy. Multivariate logistic regression analyses for PCa detection and prediction of GSU were performed.

Results

The mean age and PSA of the entire cohort were 63.5 years and 5.4ng/ml, respectively. The overall cancer detection rate was 28.5%. There was no statistical difference in core length between patients diagnosed with PCa and those without PCa (16.1 ± 1.8 vs 16.1 ± 1.9mm, P = 0.945). The core length was also not significantly different (16.4 ± 1.7 vs 16.4 ± 1.6mm, P = 0.889) between the GSU group and non-GSU group. Multivariate logistic regression analyses demonstrated that the core length of PBx did not affect PCa detection in TRUS-guided multi-core PBx (P = 0.923) and was not prognostic for GSU in patients with low-risk PCa (P = 0.356).

Conclusions

In patients undergoing contemporary multi-core PBx, core length may not have significant impact on PCa detection and also GSU following radical prostatectomy among low-risk PCa group.     

Blockade of Retinol Metabolism Protects T Cell-Induced Hepatitis by Increasing Migration of Regulatory T Cells

Retinols are metabolized into retinoic acids by alcohol dehydrogenase (ADH) and retinaldehyde dehydrogenase (Raldh). However, their roles have yet to be clarified in hepatitis despite enriched retinols in hepatic stellate cells (HSCs). Therefore, we investigated the effects of retinols on Concanavalin A (Con A)-mediated hepatitis.Con A was injected into wild type (WT), Raldh1 knock-out (Raldh1^−/−), CCL2^−/− and CCR2^−/− mice. For migration study of regulatory T cells (Tregs), we used in vivo and ex vivo adoptive transfer systems. Blockade of retinol metabolism in mice given 4-methylpyrazole, an inhibitor of ADH, and ablated Raldh1 gene manifested increased migration of Tregs, eventually protected against Con A-mediated hepatitis by decreasing interferon-γ in T cells. Moreover, interferon-γ treatment increased the expression of ADH3 and Raldh1, but it suppressed that of CCL2 and IL-6 in HSCs. However, the expression of CCL2 and IL-6 was inversely increased upon the pharmacologic or genetic ablation of ADH3 and Raldh1 in HSCs. Indeed, IL-6 treatment increased CCR2 expression of Tregs. In migration assay, ablated CCR2 in Tregs showed reduced migration to HSCs. In adoptive transfer of Tregs in vivo and ex vivo, Raldh1-deficient mice showed more increased migration of Tregs than WT mice. Furthermore, inhibited retinol metabolism increased survival rate (75%) compared with that of the controls (25%) in Con A-induced hepatitis.These results suggest that blockade of retinol metabolism protects against acute liver injury by increased Treg migration, and it may represent a novel therapeutic strategy to control T cell-mediated acute hepatitis.     

Screening and Characterization of a Novel RNA Aptamer That Specifically Binds to Human Prostatic Acid Phosphatase and Human Prostate Cancer Cells

Prostatic acid phosphatase (PAP) expression increases proportionally with prostate cancer progression, making it useful in prognosticating intermediate to high-risk prostate cancers. A novel ligand that can specifically bind to PAP would be very helpful for guiding prostate cancer therapy. RNA aptamers bind to target molecules with high specificity and have key advantages such as low immunogenicity and easy synthesis. Here, human PAP-specific aptamers were screened from a 2′-fluoropyrimidine (FY)-modified RNA library by SELEX. The candidate aptamer families were identified within six rounds followed by analysis of their sequences and PAP-specific binding. A gel shift assay was used to identify PAP binding aptamers and the 6N aptamer specifically bound to PAP with a Kd value of 118 nM. RT-PCR and fluorescence labeling analyses revealed that the 6N aptamer bound to PAP-positive mammalian cells, such as PC-3 and LNCaP. IMR-90 negative control cells did not bind the 6N aptamer. Systematic minimization analyses revealed that 50 nucleotide sequences and their two hairpin structures in the 6N 2′-FY RNA aptamer were equally important for PAP binding. Renewed interest in PAP combined with the versatility of RNA aptamers, including conjugation of anti-cancer drugs and nano-imaging probes, could open up a new route for early theragnosis of prostate cancer.