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Metabolic crosstalk between fatty pancreas and fatty liver: Effects on local inflammation and insulin secretion.
Diabetologia 60, 2240-2251 (2017)
Aims/hypothesis Obesity-linked ectopic fat accumulation is associated with the development of type 2 diabetes. Whether pancreatic and liver steatosis impairs insulin secretion is controversial. We examined the crosstalk of human pancreatic fat cells with islets and the role of diabetogenic factors, i.e. palmitate and fetuin-A, a hepatokine released from fatty liver. Methods Human pancreatic resections were immunohistochemically stained for insulin, glucagon, somatostatin and the macrophage/monocyte marker CD68. Pancreatic adipocytes were identified by Oil Red O and adiponectin staining. Primary pancreatic pre-adipocytes and differentiated adipocytes were co-cultured with human islets isolated from organ donors and the metabolic crosstalk between fatty liver and fatty pancreas was mimicked by the addition of palmitate and fetuin-A. Insulin secretion was evaluated by ELISA and RIA. Cytokine expression and secretion were assessed by RTPCR and multiplex assay, respectively. Subcellular distribution of proteins was examined by confocal microscopy and protein phosphorylation by western blotting. Results In human pancreatic parenchyma, highly differentiated adipocytes were detected in the proximity of islets with normal architecture and hormone distribution. Infiltration of adipocytes was associated with an increased number of CD68-positive cells within islets. In isolated primary pancreatic preadipocytes and differentiated adipocytes, palmitate and fetuin-A induced IL6, CXCL8 and CCL2 mRNA expression. Cytokine production was toll-like receptor 4 (TLR4)-dependent and further accentuated in pre-adipocytes when co-cultured with islets. In islets, IL6 and CXCL8 mRNA levels were also increased by fetuin-A and palmitate. Only in macrophages within the isolated islets, palmitate and fetuin-A stimulated the production of the cytotoxic cytokine IL-1 beta. Palmitate, but not fetuin-A, exerted pro-apoptotic effects in islet cells. Instead, fetuin-A impaired glucose-induced insulin secretion in a TLR4-independent, but c-Jun N-terminal kinase- and Ca2+-dependent, manner. Conclusions/interpretation These results provide the first evidence that fetuin-A-mediated metabolic crosstalk of fatty liver with islets may contribute to obesity-linked glucose blindness of beta cells, while fatty pancreas may exacerbate local inflammation.
Impact Factor
Scopus SNIP
Web of Science
Times Cited
Times Cited
Scopus
Cited By
Cited By
Altmetric
6.080
1.732
48
53
Anmerkungen
Besondere Publikation
Auf Hompepage verbergern
Publikationstyp
Artikel: Journalartikel
Dokumenttyp
Wissenschaftlicher Artikel
Schlagwörter
Adipocytes ; Beta Cells ; Fetuin-a ; Inflammation ; Islets ; Palmitate ; Tlr4; Beta-cell Function; Fetuin-a; Islet Inflammation; Adipose-tissue; Macrophages; Resistance; Humans; Inhibition; Alpha; Contributes
Sprache
Veröffentlichungsjahr
2017
HGF-Berichtsjahr
2017
ISSN (print) / ISBN
0012-186X
e-ISSN
1432-0428
Zeitschrift
Diabetologia
Quellenangaben
Band: 60,
Heft: 11,
Seiten: 2240-2251
Verlag
Springer
Verlagsort
Berlin ; Heidelberg [u.a.]
Begutachtungsstatus
Peer reviewed
POF Topic(s)
90000 - German Center for Diabetes Research
Forschungsfeld(er)
Helmholtz Diabetes Center
PSP-Element(e)
G-502400-002
G-502400-001
G-502400-001
PubMed ID
28791439
WOS ID
WOS:000412414700015
Scopus ID
85027027335
Erfassungsdatum
2017-11-13