Endothelin-1 is a potent stimulator of alpha1beta1 integrin-mediated collagen matrix remodeling by rat mesangial cells

Endothelin-1 (ET) is known to stimulate mesangial cell (MC) proliferation, extracellular matrix (ECM) synthesis, and thereby contribute to the progression of glomerulonephritis (GN). To clarify the molecular and cellular mechanisms of how ET is involved in the development of glomerular sclerosis, we investigated the influence of ET on the MC-alpha1beta1 integrin-mediated collagen matrix reorganization using a collagen gel contraction assay. ET enhanced MC-alpha1beta1 integrin-mediated gel contraction in a dose-dependent manner. Addition of the endothelin A (ETA) receptor antagonist, BQ123, into collagen gels abolished ET-induced gel contraction by MC. Cell behavior involved in ET-induced gel contraction was investigated in combination with function-blocking anti-alpha1-integrin antibody. Migration and adhesion assays revealed that ET stimulated alpha1beta1 integrin-mediated MC migration but did not influence cell adhesion to type I collagen (collagen I). Integrin-function blocking studies using anti-alpha1 integrin antibody indicated that MC-alpha1beta1 integrin is required not only for collagen-dependent migration, but also for gel contraction. Zymography showed that ET increased MC matrix metalloproteinase-2 (MMP-2) activity in a dose-dependent manner during MC-induced gel contraction process. Finally, flow cytometry analysis indicated that ET did not affect the cell surface expression of the MC-alpha1beta1 integrin within the collagen gel. These data suggested that ET promotes collagen matrix reorganization through the enhancement of MC-alpha1beta1 integrin-dependent migration and MMP-2 activity. We therefore conclude that ET is a potential molecule inducing pathological collagen matrix remodeling observed in progressive GN.     

Determination of polycyclic aromatic hydrocarbons in milk samples by high-performance liquid chromatography with fluorescence detection

This paper describes a high-performance liquid chromatographic (HPLC) method for the determination of polycyclic aromatic hydrocarbons (PAHs) in milk samples. The method involves a liquid-liquid extraction procedure after saponification of milk samples with sodium hydroxide. Reproducible determination with highly sensitive detection was attained by HPLC with fluorescence detection using 1,2-bis(9-anthryl)ethane as an internal standard. The detection limits of 12 kinds of PAHs ranged from 1.3 to 76 ng/kg milk at a signal/noise ratio of 3. By the proposed method, the presence of 12 and 11 kinds of PAHs could be confirmed in commercial milk and human milk samples, respectively. The average concentrations of total PAHs (mean+/-SD, micro g/kg) were found to be 0.99+/-0.37 for commercial milk (n=14), 2.01+/-0.30 for infant formula (n=3) and 0.75+/-0.47 for human milk (n=51). High correlation coefficients between the concentrations of total PAHs and triglyceride were observed for commercial milk (r=0.659) and human milk (r=0.645).     

Interaction between leukemic-cell VLA-4 and stromal fibronectin is a decisive factor for minimal residual disease of acute myelogenous leukemia

Bone-marrow minimal residual disease (MRD) causes relapse after chemotherapy in patients with acute myelogenous leukemia (AML). We postulate that the drug resistance is induced by the attachment of very late antigen (VLA)-4 on leukemic cells to fibronectin on bone-marrow stromal cells. We found that VLA-4-positive cells acquired resistance to anoikis (loss of anchorage) or drug-induced apoptosis through the phosphatidylinositol-3-kinase (PI-3K)/AKT/Bcl-2 signaling pathway, which is activated by the interaction of VLA-4 and fibronectin. This resistance was negated by VLA-4-specific antibodies. In a mouse model of MRD, we achieved a 100% survival rate by combining VLA-4-specific antibodies and cytosine arabinoside (AraC), whereas AraC alone prolonged survival only slightly. In addition, overall survival at 5 years was 100% for 10 VLA-4-negative patients and 44.4% for 15 VLA-4-positive patients. Thus, the interaction between VLA-4 on leukemic cells and fibronectin on stromal cells may be crucial in bone marrow MRD and AML prognosis.     

The PAR-1-activating peptide facilitates pepsinogen secretion in rats

Protease-activated receptor-2 (PAR-2) is abundantly expressed in gastric mucosal chief cells, facilitating pepsinogen secretion. In the present study, we investigated whether PAR-1, a thrombin receptor, could modulate pepsinogen secretion in rats. The PAR-1-activating peptide TFLLR-NH(2) as well as the PAR-2-activating peptide SLIGRL-NH(2), administered i.v. repeatedly at 1-h intervals, significantly increased gastric pepsinogen secretion over 2-4 h (after two to four doses). In contrast, the control peptide FTLLR-NH(2), given in the same manner, had no such effect. Thus, PAR-1, like PAR-2, might function to facilitate pepsinogen secretion, suggesting a novel role of the thrombin-PAR-1-pathway in the stomach.     

Review of sarcomatoid renal cell carcinoma with focus on clinical and pathobiological aspects

In sarcomatoid renal cell carcinoma (RCC), it is generally accepted that the sarcomatoid portion is derived from metaplastic transformation of carcinoma. Sarcomatoid RCCs account for about 1-8% of all renal tumors. Macroscopically, tumors generally form encapsulated masses and show invasive growth. Sarcomatoid RCCs originate from all subtypes of RCCs, including conventional, papillary, chromophobe, and collecting duct carcinomas. With regard to the growth pattern of the sarcomatoid component, malignant fibrous histiocytomatous, fibrosarcomatous and unclassified sarcomatous patterns are frequently seen. Immunohistochemically, sarcomatoid RCCs are generally positive for AE1/AE3, epithelial membrane antigen (EMA) and vimentin and negative for desmin, actin and S-100. Little is know about genetic alterations in sarcomatoid RCCs. Further studies are therefore needed to identify the key gene involved in sarcomatoid transformation of RCCs.     

Characterization of factors involved in the production of 2(E)-nonenal during mashing

To characterize the factors involved in the production of volatile aldehydes during mashing, a model mashing experiment was done. After we inactivated the endogenous lipoxygenase (LOX) activity in the mash by mashing at 70 degrees C for 30 min, further incubation with recombinant barley LOX-1 stimulated the accumulation of 2(E)-nonenal; however, this effect was significantly reduced by boiling the mash sample. The result suggests that both LOX-1 and a heat-stable enzymatic factor are involved in the production of 2(E)-nonenal during mashing. Malt contained fatty acid hydroperoxide lyase-like activity (HPL-like activity) that transformed 9-hydroperoxy-10(E), 12(Z)-octadecadienoic and 13-hydroperoxy-9(Z), 11(E)-octadecadienoic acid into 2(E)-nonenal and hexanal, respectively. Proteinase K sensitivity tests showed that they are distinct factors. 9-HPL-like activity survived through the mashing at 70 degrees C for 30 min but was inactivated by boiling, suggesting it will be the heat-stable enzymatic factor found in the model mashing experiment.     

Chemoenzymatic synthesis and application of glycopolymers containing multivalent sialyloligosaccharides with a poly(L-glutamic acid) backbone for inhibition of infection by influenza viruses

Highly water-soluble glycopolymers with poly(alpha-L-glutamic acid) (PGA) backbones carrying multivalent sialyl oligosaccharides units were chemoenzymatically synthesized as polymeric inhibitors of infection by human influenza viruses. p-Aminophenyl disaccharide glycosides were coupled with gamma-carboxyl groups of PGA side chains and enzymatically converted to Neu5Acalpha2-3Galbeta1-4GlcNAcbeta-, Neu5Acalpha2-6Galbeta1-4GlcNAcbeta-, Neu5Acalpha2-3Galbeta1-3GalNAcalpha-, and Neu5Acalpha2-3Galbeta1-3GalNAcbeta- units, respectively, by alpha2,3- or alpha2,6-sialytransferases. The glycopolymers synthesized were used for neutralization of human influenza A and B virus infection as assessed by measurement of the degree of cytopathic inhibitory effect in virus-infected MDCK cells. Among the glycopolymers tested, alpha2,6-sialo-PGA with a high molecular weight (260 kDa) most significantly inhibited infection by an influenza A virus, strain A/Memphis/1/71 (H3N2), which predominantly binds to alpha2-6 Neu5Ac residue. The alpha2,6-sialo-PGA also inhibited infection by an influenza B virus, B/Lee/40. The binding preference of viruses to terminal sialic acids was affected by core determinants of the sugar chain, Galbeta1-4GlcNAcbeta- or Galbeta1-3GalNAcalpha/beta- units. Inhibition of infection by viruses was remarkably enhanced by increasing the molecular weight and sialic acid content of glycopolymers.     

Phenolics with PPAR-gamma ligand-binding activity obtained from licorice (Glycyrrhiza uralensis roots) and ameliorative effects of glycyrin on genetically diabetic KK-A(y) mice

The EtOAc extract of licorice (Glycyrrhiza uralensis roots) exhibited considerable PPAR-gamma ligand-binding activity. Bioassay-guided fractionation of the extract using a GAL-4-PPAR-gamma chimera assay method resulted in the isolation of two isoflavenes, one of which is a new compound named dehydroglyasperin D, an isoflavan, two 3-arylcoumarins, and an isoflavanone as the PPAR-gamma ligand-binding active ingredients of licorice. The isoprenyl group at C-6 and the C-2' hydroxyl group in the aromatic ring-C part in the isoflavan, isoflavene, or arylcoumarin skeleton were found to be the structural requirements for PPAR-gamma ligand-binding activity. Glycyrin, one of the main PPAR-gamma ligands of licorice, significantly decreased the blood glucose levels of genetically diabetic KK-A(y) mice.