High-resolution imaging atlas reveals context-dependent role of pancreatic sympathetic innervation in diabetic mice

Abstract

Gaining a better understanding of how sympathetic nerves impact pancreatic function is helpful for understanding diabetes. However, there is still uncertainty and controversy surrounding the roles of sympathetic nerves within the pancreas. To address this, we utilize high-resolution imaging and advanced three-dimensional (3D) reconstruction techniques to study the patterns of sympathetic innervation and morphology in islets of adult WT and diabetic mice. Our data shows that more than [~]30% /{beta}-cells are innervated by sympathetic nerves in both WT and diabetic mice. Also, sympathetic innervated /{beta}-cells are reduced in DIO mice, whereas sympathetic innervated {beta}-cells are increased in db/db mice. Besides, in situ chemical pancreatic sympathetic denervation (cPSD) improves glucose tolerance in WT and db/db mice, but decreases in DIO mice. In situ cPSD also enhances insulin sensitivity in diabetic mice without affecting WT mice. Overall, our findings advance our comprehension of diabetes by highlighting the distinctive impact of pancreatic sympathetic innervation on glucose regulation. HighlightsPancreatic sympathetic innervation plays an important role in glucose homeostasis. In our study, we systematically investigate sympathetic innervation in the islets of WT and diabetic mice. O_LI45.9% -cells and 31.8% {beta}-cells are innervated by sympathetic nerves in 10-week-old WT mice. C_LIO_LISympathetic innervated /{beta}-cells are reduced in DIO mice, whereas sympathetic innervated {beta}-cells are increased in db/db mice. C_LIO_LIUnlike the core-mantle structure observed in WT and DIO mice, -cells and {beta}-cells are intermixed in db/db mice. C_LIO_LIPancreatic sympathetic denervation elicits varied responses across diabetic models, where it improves glucose tolerance and insulin sensitivity in db/db mice, yet it increases insulin sensitivity but reduces glucose tolerance in DIO mice. C_LI Graphical abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=136 SRC="FIGDIR/small/623708v2_ufig1.gif" ALT="Figure 1"> View larger version (41K): org.highwire.dtl.DTLVardef@183be78org.highwire.dtl.DTLVardef@4dc76borg.highwire.dtl.DTLVardef@5f5ca0org.highwire.dtl.DTLVardef@ba3cc7_HPS_FORMAT_FIGEXP M_FIG Summary of morphological and physiological phenotypes in diabetic mice. All data are normalized to that of WT-10 mice. The numbers of "+" refer to their relative numbers. {uparrow} or {downarrow} refers to increase or decrease, ns refers to "not significant". "-" refers to the experiment has not been carried out. C_FIG