| First Author | Weitz JR | Year | 2018 |
| Journal | Diabetologia | Volume | 61 |
| Issue | 1 | Pages | 182-192 |
| PubMed ID | 28884198 | Mgi Jnum | J:256203 |
| Mgi Id | MGI:6106638 | Doi | 10.1007/s00125-017-4416-y |
| Citation | Weitz JR, et al. (2018) Mouse pancreatic islet macrophages use locally released ATP to monitor beta cell activity. Diabetologia 61(1):182-192 |
| abstractText | AIMS/HYPOTHESIS: Tissue-resident macrophages sense the microenvironment and respond by producing signals that act locally to maintain a stable tissue state. It is now known that pancreatic islets contain their own unique resident macrophages, which have been shown to promote proliferation of the insulin-secreting beta cell. However, it is unclear how beta cells communicate with islet-resident macrophages. Here we hypothesised that islet macrophages sense changes in islet activity by detecting signals derived from beta cells. METHODS: To investigate how islet-resident macrophages respond to cues from the microenvironment, we generated mice expressing a genetically encoded Ca(2+) indicator in myeloid cells. We produced living pancreatic slices from these mice and used them to monitor macrophage responses to stimulation of acinar, neural and endocrine cells. RESULTS: Islet-resident macrophages expressed functional purinergic receptors, making them exquisite sensors of interstitial ATP levels. Indeed, islet-resident macrophages responded selectively to ATP released locally from beta cells that were physiologically activated with high levels of glucose. Because ATP is co-released with insulin and is exclusively secreted by beta cells, the activation of purinergic receptors on resident macrophages facilitates their awareness of beta cell secretory activity. CONCLUSIONS/INTERPRETATION: Our results indicate that islet macrophages detect ATP as a proxy signal for the activation state of beta cells. Sensing beta cell activity may allow macrophages to adjust the secretion of factors to promote a stable islet composition and size. |
