Search

Highlights: [•] We indicate the importance of the hypoxic condition for embryonic kidney development. [•] HIF-1α enhances the expression of GDNF and FGF10 in kidney development. [•] HIF-1α promotes ureteric bud branching. [•] Hypoxia inhibits ureteric bud cell apoptosis. [•] Wnt11 is increased by hypoxia and enhances the ureteric bud branching. [Copyright &y& Elsevier]

Highlights: [•] DPP-4 inhibitor decreased urinary albumin excretion in a rat of type 1 diabetes. [•] DPP-4 inhibitor ameliorated histlogical changes of diabetic nephropathy. [•] DPP-4 inhibitor has reno-protective effects through anti-inflammatory action. [•] DPP-4 inhibitor is beneficial on diabetic nephropathy besides lowering blood glucose. [ABSTRACT FROM AUTHOR]

Abstract: MAPKs are involved in acetaminophen (APAP)-hepatotoxicity, but the regulatory mechanism remains unknown. Here, we explored the role of Spred-2 that negatively regulates Ras/ERK pathway in APAP-hepatotoxicity. Spred-2 knockout (KO) mice demonstrated exacerbated liver injury, an event that was associated with increased numbers of CD4+ T, CD8+ T and NK cells in the liver compared to the control. Levels of CXCL9/CXCL10 that attract and activate these cells were increased in Spred-2 KO-liver. Kupffer cells isolated from Spred-2 KO mice after APAP challenge expressed higher levels of CXCL9/CXCL10 than those from the control. Upon stimulation with APAP or IFNγ, naïve Kupffer cells from Spred-2 KO mice expressed higher levels of CXCL9/CXCL10. NK cell-depletion attenuated APAP-hepatotoxicity with lowered hepatic IFNγ and decreased numbers of not only NK cells but also CD4+ T and CD8+ T cells in the liver. These results suggest that Spred-2 negatively regulates APAP-hepatotoxicity under the control of Kupffer cells and NK cells. [Copyright &y& Elsevier]

Abstract: Objectives: TNF-like weak inducer of apoptosis (TWEAK), a member of the TNF superfamily, has been shown to increase cytokine production by rheumatoid arthritis (RA) fibroblast-like synoviocytes (FLS). In this study, we determined the effect of interaction between TWEAK and its receptor fibroblast growth factor-inducible-14 (Fn14) on cytokine expression in RAFLS. Methods: RAFLS were obtained from surgical synovial specimens and used at passage 5–10. Cytokine protein and mRNA expression were measured with ELISA and real time-PCR, respectively. Apoptotic cells were detected by TUNEL assay. RelB activation was detected by Western blot analysis. Results: TWEAK inhibited IL-6 production from total synovial cells from RA. TWEAK weakly induced FLS IL-6 and IL-8, but in contrast TWEAK dose-dependently inhibited IL-6 and IL-8 production by TNFα-activated FLS. TWEAK did not induce apoptosis in FLS but inhibited proliferation of TNFα-activated FLS. TWEAK induced RelB activation and suppressed IL-6 mRNA expression in TNFα-activated FLS and both of these phenomenon were abolished by inhibition of new protein synthesis with cycloheximide. Conclusions: TWEAK has a previously unsuspected inhibitory effect on cytokine production by TNFα-activated RAFLS. This observation suggests that the effects of TWEAK on cytokine expression varies with the pro-inflammatory context, and that in TNFα-activated states such as RA TWEAK may have a net inhibitory effect. [Copyright &y& Elsevier]

Abstract: Aberrant O-glycosylation of serum and tonsillar IgA1 is one of the main pathogeneses of IgA nephropathy (IgAN). However, the synthesis of underglycosylated IgA1 in tonsils has not yet been characterized. This study examined tonsillar B lymphocytes of IgAN (n =34) using tonsils derived from patients with chronic tonsillitis (n =24) and sleep apnea syndrome (n =14) as a control. Gene expression of β1,3-galactosyltransferase (β3GalT), and the core 1 β3GalT-specific molecular chaperone, Cosmc, UDP-N-acetyl-α-D-galactosamine: polypeptide N-acetylgalactosaminyl-transferase 2, were significantly decreased in tonsillar CD19-positive B lymphocytes from IgAN patients compared to control tonsillar tissues as determined by real-time RT-PCR. Tonsillar B cell β3GalT gene expression significantly correlated with estimated GFR and negatively correlated with proteinuria and histological injury score. Western blotting showed the protein expression of β3GalT in the tonsils to significantly decrease in IgAN in comparison to the controls. These data suggest the downregulation of β3GalT in tonsillar B lymphocytes to be closely associated with the clinical characteristics of IgAN. [ABSTRACT FROM AUTHOR]

Abstract: Sphingosine 1-phosphate (S1P) is an important vascular barrier regulatory agonist which enhances the junctional integrity of human lung endothelial cell monolayers. We have now demonstrated that S1P induced cortical actin ring formation and redistribution of focal adhesion kinase (FAK) and paxillin to the cell periphery suggesting the critical role of cell–cell adhesion in endothelial barrier enhancement. Co-immunoprecipitation studies revealed increased association of VE-cadherin with FAK and paxillin in S1P-challenged human pulmonary artery endothelial cell (HPAEC) monolayers. Furthermore, S1P-induced enhancement of VE-cadherin interaction with α-catenin and β-catenin was associated with the increased formation of FAK–β-catenin protein complexes. Depletion of β-catenin (siRNA) resulted in loss of S1P-mediated VE-cadherin association with FAK and paxillin rearrangement. Furthermore, transendothelial electrical resistance (an index of barrier function) demonstrated that β-catenin siRNA significantly attenuated S1P-induced barrier enhancement. These results demonstrate a mechanism of S1P-induced endothelial barrier enhancement via β-catenin-linked adherens junction and focal adhesion interaction. [Copyright &y& Elsevier]

Abstract: The cellular mechanism by which TNF-α inhibits osteoblastic differentiation induced by BMPs was investigated using mouse myoblast C2C12 cells expressing functional BMP receptors and Smad signaling molecules except ALK-6. Osteoblast transformation in response to BMP-2 was morphologically suppressed by TNF-α. Expression of biological markers for osteoblasts including Runx2 and osteocalcin, alkaline phosphatase activity, and parathyroid hormone (PTH) responsiveness shown by PTH-induced cAMP production were readily activated by BMP-2, -4, -6, and -7. The BMP-induced osteoblastic phenotype was dose-dependently inhibited by TNF-α. BMP-induced Smad1,5,8 phosphorylation of C2C12 cells was suppressed by TNF-α signaling. In addition, cDNA array analysis showed an increased expression of inhibitory Smad6 by TNF-α. MAP kinase analysis showed that ERK1/ERK2 and SAPK/JNK phosphorylation were selectively activated by TNF-α regardless of the presence of BMP ligands. BMPs had no effect on expression levels of TNF type 1 and 2 receptors. Notably, inhibition of SAPK/JNK restored TNF-α effects on BMP-induced osteoblast differentiation demonstrated by Id-1-promoter activity as well as Runx2 and osteocalcin mRNA levels. Collectively, TNF-α elicits BMP-induced osteogenic inhibition by suppressing BMP-Smad signaling pathway, at least in part, through SAPK/JNK activation and Smad6 upregulation. [Copyright &y& Elsevier]

Abstract: To establish new treatment for cardiovascular disease, the development of safe and highly efficient vectors is necessary. Especially, non-viral vectors are considered to be ideal for human gene therapy, since recent adverse events with retroviral or adenoviral vectors have highlighted the issue of safety. Although we previously reported safety and high efficiency of HVJ-liposome method, we have modified the envelope of HVJ (Sendai virus). In this novel non-viral vector, the envelope of HVJ alone was utilized as a carrier to deliver proteins, genes and oligodeoxynucleotides (ODN). Thus, we optimized the transfection efficiency of HVJ-envelope vector into neonatal cardiac myocytes in this study, since cardiac myocytes is one of the most difficult cells to be transfected. HVJ-envelope, obtained after complete destruction of HVJ genome, containing FITC-labeled ODN or luciferase plasmid was incubated with cardiac myocytes. In addition, the concentration of protamine sulfate was modified (0–700 μg/ml) to increase transfection efficacy. Without HVJ-envelope vector, few cells showed fluorescence, whereas most cells demonstrated fluorescence with HVJ-envelope vector. Consistent with the high transfection efficiency of ODN, high luciferase activity was also detected using HVJ-envelope vector. Moreover, the transfection efficiency varied according to the concentration of protamine sulfate. No obvious cytotoxicity was observed in cells transfected with HVJ-envelope vector. The present study demonstrated the development of a highly efficient novel non-viral vector for cardiac myocytes, suggesting that further development may provide a new useful tool for research and clinical gene therapy in the field of cardiovascular disease. [Copyright &y& Elsevier]

Since restenosis after angioplasty still remains a major clinical problems, inhibition of neointimal formation is an important subject. In this study, we focused on the transcription factor, E2F, that plays a pivotal role in the transactivation of cell-cycle regulatory genes, and also we developed a newly delivery system of decoy oligodeoxynucleotides (ODN). We transfected E2F decoy ODN mixed with an echo-contrast microbubble agent (Optison) into rat carotid artery balloon-injured model by using therapeutic ultrasound (US) to inhibit neointimal formation. Two weeks after transfection, the intimal to medial area ratio in E2F decoy + Optison + US group was significantly decreased (P<0.01). Inhibition of cell growth was also confirmed by PCNA staining. No apparent toxicity such as inflammation could be detected in blood vessels transfected with E2F decoy ODN with Optison and ultrasound. Overall, the present studies demonstrated a novel non-viral ODN transfer method into blood vessels. A novel therapeutic strategy using E2F decoy ODN with Optison using ultrasound may be useful to inhibit restenosis in clinical practice without a viral vector. [Copyright &y& Elsevier]

Roles of activin/bone morphogenetic protein (BMP) system in the pathogenesis of human pituitary adenoma remain unknown although these factors stimulate follicle-stimulating hormone (FSH) secretion in the normal pituitary. Here we demonstrated that type-I and -II subunit mRNAs of activin/BMP receptors are expressed in Pit-1-negative FSH-producing (FSH-oma) and nonfunctioning pituitary adenomas (NF-oma). Basal levels of serum FSH standardized by luteinizing hormone (LH) were markedly high in FSH-omas in contrast to NF-omas. However, gonadotropin-releasing hormone (GnRH)-induced increment of FSH standardized by that of LH was not changed in FSH-omas, suggesting that imbalanced FSH secretion by FSH-oma is not attributable to GnRH regardless of the expression of GnRH receptor. Although activin βA subunit was detected in neither adenoma, the βB subunit was expressed highly in FSH-omas and, to lesser extent, in NF-omas. As for BMPs, BMP-6 and -7 were detected in NF-omas while BMP-4 and -15 were not detected in either type of adenoma. In the presence of pituitary activin/BMP system, the levels of co-expressing follistatin mRNA in the tumors were reduced in FSH-oma compared with NF-oma, suggesting that endogenous follistatin is involved in FSH overproduction through inhibition of activin/BMP system independently of GnRH. [Copyright &y& Elsevier]