Bai-Feng L, Yong-Feng L, Ying C. Silencing inducible nitric oxide synthase protects rat pancreatic islet.
Diabetes Res Clin Pract 2010;
89:268-75. [PMID:
20541824 DOI:
10.1016/j.diabres.2010.05.013]
[Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/23/2010] [Revised: 05/13/2010] [Accepted: 05/17/2010] [Indexed: 12/20/2022]
Abstract
OBJECTIVE
To investigate the effect of inducible nitric oxide synthase (iNOS) RNA interference on cytokine-induced injury of pancreatic islet in rats.
MATERIALS AND METHODS
Islets from Wistar rats were cultured in vitro and then randomly divided into five groups: group A, islets were cultured exclusively; group B, islets were transfected with negative control siRNA; group C, islets were transfected with iNOS siRNA; group D, islets were transfected with iNOS siRNA and then treated with TNF-alpha+IL-1beta; group E, islets were treated with TNF-alpha+IL-1beta. The expression of iNOS, Bax and Fas was determined by RT-PCR and Western blot. The viability of islet was examined by AO/EB staining and function was examined by glucose-stimulated insulin secretion (GSIS) assay.
RESULTS
The expression of iNOS and the promoting apoptosis gene Bax and Fas were significantly up-regulated by the induction of IL-1beta and TNF-alpha. Thus they led to apoptosis increase and the insulin secretion index decrease (1.87+/-0.31 vs 3.83+/-1.40, P<0.01). Silencing iNOS by RNAi prevented the up-regulation of Bax and Fas induced by cytokine, thus reduced apoptosis of islets and recovered the insulin secretion index (3.43+/-0.24 vs 1.87+/-0.31, P<0.01).
CONCLUSION
The apoptosis from cytokines to islets mediated by iNOS could be suppressed by RNA interference, which favors the survival and function of islets.
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