vivit-peptide and Disease-Models--Animal

To observe the effect of 11R-VIVIT on lipopolysaccharide (LPS)-induced expression of urokinase-type plasminogen activator receptor (uPAR) in podocytes.. A LPS-induced proteinuria mouse model and in vitro cultured podocytes treated with LPS were both divided into control group, LPS group and LPS+11 R-VIVIT group. The mRNA and protein expressions of uPAR in mouse kidney tissues and the podocytes were measured by real-time qPCR, laser scanning confocal microscopy and Western blotting.. Compared with LPS group, LPS+11 R-VIVIT group showed a significantly lowered urine albumin/creatinine ratio (P<0.001) and markedly reduced mRNA and protein expressions of uPAR (PuPAR mRNA<0.001; PuPAR=0.001).. 11R-VIVIT can ameliorate proteinuria probably by decreasing the expression of uPAR in podocytes.

Topics: Animals; Disease Models, Animal; Lipopolysaccharides; Male; Mice; Mice, Inbred C57BL; Oligopeptides; Podocytes; Proteinuria; Receptors, Urokinase Plasminogen Activator

Nuclear factor of activated T cells (NFAT) is an important transcription factor for the production of interleukin (IL)-2 upon T-cell receptor (TcR) signaling. Therefore, inhibition of the NFAT-carcineurin pathway is an important target for inflammatory disease inhibition and graft rejection. A novel cell permeable peptide (CPP), Sim-2, has been identified from a human transcription factor, and Sim-2-CPP conjugated to β-galactosidase or EGFP protein was efficiently delivered into cells in vitro and in vivo. A cell permeable form of the NFAT inhibitory peptide VIVIT (Sim-2-VIVIT) was synthesized and showed inhibitory effects on human CD4 or CD8 T-cell activation through NFAT transcriptional activity suppression and IL-2 inhibition. Intranasal administration of the Sim-2-VIVIT peptide in an ovalbumin (OVA)-induced murine asthma model alleviated peribronchial and perivascular infiltration of inflammatory cells in the lung and caused airway remodeling and airway hyper-responsiveness. These results suggest that cell permeable Sim-2-VIVIT peptide has clinical potential as an immunosuppressive agent for inflammatory diseases.

Topics: Administration, Intranasal; Amino Acid Sequence; Animals; Asthma; Disease Models, Animal; Female; Humans; Immunosuppressive Agents; Interleukin-2; Lymphocyte Activation; Mice; Mice, Inbred BALB C; Molecular Sequence Data; NFATC Transcription Factors; Oligopeptides; T-Lymphocytes

Amyloid β (Aβ) peptides, the main pathological species associated with Alzheimer's disease (AD), disturb intracellular calcium homeostasis, which in turn activates the calcium-dependent phosphatase calcineurin (CaN). CaN activation induced by Aβ leads to pathological morphological changes in neurons, and overexpression of constitutively active calcineurin is sufficient to generate a similar phenotype, even without Aβ. Here, we tested the hypothesis that calcineurin mediates neurodegenerative effects via activation of the nuclear transcription factor of activated T-cells (NFAT). We found that both spine loss and dendritic branching simplification induced by Aβ exposure were mimicked by constitutively active NFAT, and abolished when NFAT activation was blocked using the genetically encoded inhibitor VIVIT. When VIVIT was specifically addressed to the nucleus, identical beneficial effects were observed, thus enforcing the role of NFAT transcriptional activity in Aβ-related neurotoxicity. In vivo, when VIVIT or its nuclear counterpart were overexpressed in a transgenic model of Alzheimer's disease via a gene therapy approach, the spine loss and neuritic abnormalities observed in the vicinity of amyloid plaques were blocked. Overall, these results suggest that NFAT/calcineurin transcriptional cascades contribute to Aβ synaptotoxicity, and may provide a new specific set of pathways for neuroprotective strategies.

Topics: Alzheimer Disease; Amyloid beta-Peptides; Animals; Dendrites; Disease Models, Animal; HEK293 Cells; Humans; Mice; Mice, Transgenic; Neural Inhibition; NFATC Transcription Factors; Oligopeptides; Signal Transduction