Human Periostin ELISA

Features

• RUO
• calibration range 78-5000 pg/ml
• limit of detection 15 pg/ml

Research topic

Bone and cartilage metabolism, Cardiovascular disease, Cytokines and chemokines and related molecules, Extracellular matrix, Oncology

Summary

Periostin, also termed osteoblast-specific factor 2 (OSF-2), is a 90-kDa secreted protein that shares a homology with the insect axon guidance protein fasciclin I (1). Periostin is one of four known mammalian genes that contain fasciclin domains with stabilin 1 and 2, as well asTGFβ- Induced Gene-Human clone 3 (BIGH3 )(2). Periostin protein is composed of a signal sequence, four-coiled fasciclin-like repeats, an amino-terminal cysteine-rich region (EMI domain), and heparin-binding domains present in the carboxyl tail. Periostin contains gamma- carboxyglutamate residues that are formed by vitamin K dependent carboxylation (3). These residues are essential for the binding of calcium. Periostin is thought to be involved in osteoblast recruitment, attachment and spreading. It is a component of the extracellular matrix. The N-terminus part of periostin (up to exon 16) is conserved, while the C-terminal region (comprising exon 17–23) gives rise to different splice isoforms upon alternative splicing. The isoforms have a molecular weight range from 83 kDa to 93 kDa (4). Six different periostin splice isoforms have been reported, but only four of them were sequenced and annotated. Periostin is expressed during ontogenesis and down regulated in adult except in bones, in collagen-rich fibrous connective tissues subjected to constant mechanical stress, such as periodontal ligament (PDL), heart valves, skin and tendons. Periostin expression is also observed in niches in direct contact with tissue-specific stem cells in mammary gland, bone, and intestine. Periostin has been found to be overexpressed in various type of human tumors including neuroblastoma, head and neck cancer, nasopharyngeal carcinoma, non-small cell lung carcinoma, breast cancer, colon cancer, pancratic ductal adenocarcinoma and ovarian cancer (5). Isoforms of periostin are over-expressed by stromal cells in several human ovary, breast, colon, and brain tumors. Abnormal expression of periostin is also linked to angiogenesis and metastasis in epithelial tumors. Periostin is expressed by fibroblasts in the normal tissue and in the stroma of the primary tumour. Infiltrating tumour cells need to induce stromal Periostin expression in the secondary target organ to initiate colonization. Periostin is crucial for cancer stem cell maintenance (6). Periostin up-regulation in cancers usually correlates with aggressiveness and/or poor survival.