[Insulin prevents injury and enhances survival of rat hepatocytes via its anti-inflammatory effects].
OBJECTIVE
To investigate whether insulin exerts protective effects against hepatocytes injury indirectly induced by LPS and if so, the mechanism involved.


METHODS
Kupffer cells and hepatocytes were isolated from male Sprague-Dawley rats by pronasecollagenase perfusion and cultured. Kupffer cells were stimulated by lipopolysaccharide (LPS) or LPS+insulin for 4 h, the supernatant of different groups were collected to detect TNF-alpha and IL-10 by ELISA and to stimulate the primary cultured rat hepatocytes with or without anti-TNF-alpha antibody. After the hepatocytes were stimulated for 12 h, cell survival rate and injury indexes were detected.


RESULTS
(1) The supernatant of LPS-activated Kupffer cells caused significant hepatocytes injury. Treatment with insulin produced a potent protective effect as evidenced by decreased ALT and AST levels (P<0.01, n=8) and improved hepatocytes survival rate (P<0.01, n=8). (2) Compared with the LPS group, insulin significantly decreased TNF-alpha secretion (P<0.01, n=8) and increased IL-10 secretion (P<0.05, n=8) from Kupffer cell stimulated by LPS. (3) Incubating hepatocytes with anti-TNF-alpha antibody attenuated hepatocytes injury induced by the supernatant of LPS-activated Kupffer cells. But treatment with anti-TNF-alpha antibody and insulin did not exert additive effect compared with treatment with insulin alone.


CONCLUSIONS
Insulin has protective effects on rat hepatocytes injury indirectly induced by LPS, which is associated with suppression of the pro-inflammatory cytokine TNF-alpha and increment of the anti-inflammatory cytokine IL-10 both from Kupffer cells.
Nan
Ying
Y
Department of Physiology, Xijing Hsopital, Fourth Military Medical University, Xi'an 710032, China. nanying2002419@163.com
Li
Jia
J
Zhang
Kun-ru
KR
Hu
Yong-wu
YW
Wang
Sheng-chun
SC
Liu
Jie
J
Gao
Feng
F
D000818:Animals; D004347:Drug Interactions; D022781:Hepatocytes / Q000187:drug effects* / Q000378:metabolism / Q000502:physiology; D007328:Insulin / Q000494:pharmacology*; D016753:Interleukin-10 / Q000378:metabolism; D007728:Kupffer Cells / Q000187:drug effects / Q000378:metabolism / Q000473:pathology*; D008070:Lipopolysaccharides / Q000633:toxicity*; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism
D007328:Insulin; D008070:Lipopolysaccharides; D014409:Tumor Necrosis Factor-alpha; D016753:Interleukin-10