CircuLex Human Progranulin ELISA Kit

Progranulin (PGRN) also called granulin/epithelin, proepithelin, prostate cancer cell-derived growth factor, acrogranin, or paragranulin, is a 593aa cysteine-rich protein that is typically secreted in a highly glycosylated 88kDa form (1, 2). PGRN is a growth factor involved in the regulation of multiple processes including cell proliferation, tumorigenesis, wound healing, development and inflammation. PGRN is widely expressed in epithelia, bone marrow, immune cells, solid organs, and the nervous system both during development and in adulthood (3-7). In 2006, mutations in PGRN were discovered to be a cause of frontotemporal lobar degeneration (FTLD) with ubiquitinated TDP-43-positive inclusions (6, 8-10, 12, 13). More than 70 mutations in PGRN, almost all of which result in null alleles, have been identified in FTLD patients. A few causative missense mutations also result in reduced levels of PGRN (10). PGRN can be found in adipose tissue, epithelial tissue, gastrointestinal tract, reproductive organs, and so forth (11). Previous studies have demonstrated that increased gene expression of PGRN stimulates cancer cell division, invasion, and against anoikis, promoting tumor formation (2). It has been shown that PGRN could restrain rheumatoid arthritis by binding directly to tumor necrosis factor receptors (TNFR) and play an anti-inflammatory role in the processes (14). In addition, it was reported that circulating PGRN levels are elevated in patients with type 2 diabetes (15). Moreover, increased plasma PGRN levels are associated with impaired glucose tolerance rather than impaired fasting glucose (16). Although type 2 diabetes is often accompanied by obesity, the respective role of elevation of circulating PGRN levels in obesity and type 2 diabetes remains to be elucidated.