ABSTRACT
BACKGROUND: Inflammatory bowel disease (IBD) is an incurable disease that negatively influences the quality of life of patients. Current and emerging therapies target proinflammatory cytokines and/or receptors to downregulate proinflammatory responses, but insufficient remission requires other therapeutic agents. Herein, we report that the synthetic anti-inflammatory peptide 15 (SAP15) is capable of cell penetration and anti-inflammatory activity in human macrophages. METHODS: SAP15 was labeled with fluorescence and administered to human leukemia monocytic cells (THP-1) cells for cell penetration analysis. Using biolayer interferometry analysis, the binding affinity of SAP15 with histone deacetylase 5 (HDAC5) was measured. SAP15-treated THP-1 cells were analyzed by protein phosphorylation assay, flow cytometry, and enzyme-linked immunosorbent assay (ELISA). In addition, in vivo analysis of the therapeutic effect on IBD was observed in a dextran sulfate sodium (DSS)-induced model. Samples from SAP15-treated mice were analyzed at both the macroscopic and microscopic levels using ELISA, myeloperoxidase (MPO) assays, and histological evaluations. RESULTS: SAP15 was internalized within the cytosol and nucleus of THP-1 cells and bound to the HDAC5 protein. SAP15-treated macrophages were assessed for protein phosphorylation and showed inhibited phosphorylation of HDAC5 and other immune-related proteins, which led to increased M2-like macrophage markers and decreased M1-like macrophage markers and tumor necrosis factor-α and interleukin-6 cytokine levels. The SAP15 treatment on IBD model showed significant recovery of colon length. Further histological analysis of colon demonstrated the therapeutic effect of SAP15 on mucosal layer. Moreover, proinflammatory cytokine levels and MPO activity from the plasma show that SAP15 is effective in reduced proinflammatory responses. CONCLUSION: These findings suggest that SAP15 is a novel peptide with a novel cell-penetrating peptide with anti-inflammatory property that can be used as a therapeutic agent for IBD and other inflammatory diseases.
Subject(s)
Cell-Penetrating Peptides , Inflammatory Bowel Diseases , Humans , Animals , Mice , Cell-Penetrating Peptides/adverse effects , Quality of Life , Inflammatory Bowel Diseases/drug therapy , Inflammatory Bowel Diseases/chemically induced , Inflammatory Bowel Diseases/pathology , Cytokines/metabolism , Anti-Inflammatory Agents/pharmacology , Histone Deacetylases/adverse effectsABSTRACT
Alveolar bone is both morphologically and functionally different from other bones of the axial or peripheral skeleton. Because of its sensitive nature to external stimuli including mechanical stress, bone loss stimuli, and medication-related osteonecrosis of the jaw, alveolar bone rendering is seen as an important factor in various dental surgical processes. Although multiple studies have validated the response of long bone to various factors, how alveolar bone responds to functional stimuli still needs further clarification. To examine the characteristics of bone in vitro, we isolated cells from alveolar, femur, and tibia bone tissue. Although primary cultured mouse alveolar bone-derived cells (mABDCs) and mouse long bone-derived cells (mLBDCs) exhibited similar osteoblastic characteristics, morphology, and proliferation rates, both showed distinct expression of neural crest (NC) and epithelial-mesenchymal interaction (EMI)-related genes. Furthermore, they showed significantly different mineralization rates. RNA sequencing data demonstrated distinct transcriptome profiles of alveolar bone and long bone. Osteogenic, NC-, and EMI-related genes showed distinct expression between mABDCs and mLBDCs. When the gene expression patterns during osteogenic differentiation were analyzed, excluding several osteogenic genes, NC- and EMI-related genes showed different expression patterns. Among EMI-related proteins, BMP4 elevated the expression levels of osteogenic genes, Msx2, Dlx5, and Bmp2 the most, more noticeably in mABDCs than in mLBDCs during osteogenic differentiation. In in vivo models, the BMP4-treated mABDC group showed massive bone formation and maturation as opposed to its counterpart. Bone sialoprotein expression was also validated in calcified tissues. Overall, our data suggest that alveolar bone and long bone have different responsiveness to EMI by distinct gene regulation. In particular, BMP4 has critical bone formation effects on alveolar bone, but not on long bone. © 2020 The Authors. JBMR Plus published by Wiley Periodicals, Inc. on behalf of American Society for Bone and Mineral Research.
