Secreted Frizzled-Related Protein 5 is Downregulated in Obesity and Promotes -Cell Proliferation [10 days]

Obesity is associated with an increase in -cell mass in response tothe rising demand for insulin. -cell plasticity is essential to maintaining glucose homeostasis, however,the cellular and molecular mechanisms by which -cell mass is regulated remain poorly understood.Recently, we described the existence of a crosstalk between the peripancreatic adipose tissue and -cells as a novel mechanism that participates in the regulation of -cell plasticity. Here, we identify the secreted frizzled-related protein (Sfrp) 5 as down-regulated in the pancreatic islets of obese rats as well as in the pancreatic islets of human obese patients. Our results demonstrate that the silencing of Sfrp5 induces an increase in -cell proliferation, which we correlate with the activation of Wnt signaling and of the MAPK and PI3 kinase pathways. Together, these findings expand our understanding of the mechanisms underlying -cell proliferation under conditions of obesity. Furthermore, this study opens new insights into the specific targeting of Sfrp5 as a novel therapeutic strategy for balancing -cell mass.

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Rebuffat SA, Oliveira JM, Altirriba J, Palau N, Garcia A, Esteban Y, Nadal B, Gomis R