TY - JOUR
T1 - Noradrenergic fibers are associated with beta-cell dedifferentiation and impaired beta-cell function in humans
AU - Cinti, Francesca
AU - Mezza, Teresa
AU - Severi, I.
AU - Suleiman, M.
AU - Cefalo, Chiara Maria Assunta
AU - Sorice, G. P.
AU - Moffa, Simona
AU - Impronta, Flavia
AU - Quero, Giuseppe
AU - Alfieri, Sergio
AU - Mari, A.
AU - Pontecorvi, Alfredo
AU - Marselli, L.
AU - Cinti, S.
AU - Cinti, Saverio
AU - Marchetti, P.
AU - Giaccari, Andrea
PY - 2021
Y1 - 2021
N2 - Aims/hypothesis: Type 2 diabetes (T2D) is characterized by a progressive loss of beta-cell function, and the “disappearance” of beta-cells in T2D may also be caused by the process of beta -cell dedifferentiation. Since noradrenergic innervation inhibits insulin secretion and density of noradrenergic fibers is increased in type 2 diabetes mouse models, we aimed to study the relation between islet innervation, dedifferentiation and beta-cell function in humans. Methods: Using immunohistochemistry and electron microscopy, we analyzed pancreata from organ donors and from patients undergoing pancreatic surgery. In the latter, a pre-surgical detailed metabolic characterization by oral glucose tolerance test (OGTT) and hyperglycemic clamp was performed before surgery, thus obtaining in vivo functional parameters of beta-cell function and insulin secretion. Results: The islets of diabetic subjects were 3 times more innervated than controls (0.91 ± 0.21 vs 0.32 ± 0.10, n.fibers/islet; p = 0.01), and directly correlated with the dedifferentiation score (r = 0.39; p = 0.03). In vivo functional parameters of insulin secretion, assessed by hyperglycemic clamp, negatively correlated with the increase in fibers [beta-cell Glucose Sensitivity (r = −0.84; p = 0.01), incremental second-phase insulin secretion (r = −0.84, p = 0.03) and arginine-stimulated insulin secretion (r = −0.76, p = 0.04)]. Moreover, we observed a progressive increase in fibers, paralleling worsening glucose tolerance (from NGT through IGT to T2D). Conclusions/interpretation: Noradrenergic fibers are significantly increased in the islets of diabetic subjects and this positively correlates with beta-cell dedifferentiation score. The correlation between in vivo insulin secretion parameters and the density of pancreatic noradrenergic fibers suggests a significant involvement of these fibers in the pathogenesis of the disease, and indirectly, in the islet dedifferentiation process.
AB - Aims/hypothesis: Type 2 diabetes (T2D) is characterized by a progressive loss of beta-cell function, and the “disappearance” of beta-cells in T2D may also be caused by the process of beta -cell dedifferentiation. Since noradrenergic innervation inhibits insulin secretion and density of noradrenergic fibers is increased in type 2 diabetes mouse models, we aimed to study the relation between islet innervation, dedifferentiation and beta-cell function in humans. Methods: Using immunohistochemistry and electron microscopy, we analyzed pancreata from organ donors and from patients undergoing pancreatic surgery. In the latter, a pre-surgical detailed metabolic characterization by oral glucose tolerance test (OGTT) and hyperglycemic clamp was performed before surgery, thus obtaining in vivo functional parameters of beta-cell function and insulin secretion. Results: The islets of diabetic subjects were 3 times more innervated than controls (0.91 ± 0.21 vs 0.32 ± 0.10, n.fibers/islet; p = 0.01), and directly correlated with the dedifferentiation score (r = 0.39; p = 0.03). In vivo functional parameters of insulin secretion, assessed by hyperglycemic clamp, negatively correlated with the increase in fibers [beta-cell Glucose Sensitivity (r = −0.84; p = 0.01), incremental second-phase insulin secretion (r = −0.84, p = 0.03) and arginine-stimulated insulin secretion (r = −0.76, p = 0.04)]. Moreover, we observed a progressive increase in fibers, paralleling worsening glucose tolerance (from NGT through IGT to T2D). Conclusions/interpretation: Noradrenergic fibers are significantly increased in the islets of diabetic subjects and this positively correlates with beta-cell dedifferentiation score. The correlation between in vivo insulin secretion parameters and the density of pancreatic noradrenergic fibers suggests a significant involvement of these fibers in the pathogenesis of the disease, and indirectly, in the islet dedifferentiation process.
KW - Beta cell failure
KW - Dedifferentiation
KW - Human type 2 diabetes mellitus
KW - Innervation
KW - Personalized medicine
KW - Beta cell failure
KW - Dedifferentiation
KW - Human type 2 diabetes mellitus
KW - Innervation
KW - Personalized medicine
UR - http://hdl.handle.net/10807/169262
U2 - 10.1016/j.metabol.2020.154414
DO - 10.1016/j.metabol.2020.154414
M3 - Article
SN - 0026-0495
VL - 114
SP - 1
EP - 8
JO - METABOLISM, CLINICAL AND EXPERIMENTAL
JF - METABOLISM, CLINICAL AND EXPERIMENTAL
ER -