Abstract
Human islet transplantation has great potential as an effective means of treating insulin-dependent diabetes mellitus. Upregulation of inducible nitric oxide synthase (iNOS) and subsequent product of radical nitric oxide (NO) impair islet β-cell function. Therefore, we hypothesize that iNOS gene silencing will prevent β-cell death and improve the survival and function of islets. Small interfering RNA duplex (siRNA) inhibited rat iNOS gene expression and NO production in rat β-cell lines (INS-1E) in a dose- and sequence-dependent manner. iNOS gene silencing also protected these β-cells from inflammatory cytokine-induced apoptosis and increased their capacity to secret insulin. Three siRNA sequences against human iNOS were then designed and transfected into human islets. Although there was dose- and sequence-dependent iNOS gene silencing and NO production in human islets, the effect of iNOS gene silencing on apoptosis of islets was only moderate, as evidenced by 25-30% reduction in caspase 3 activity and in the percentage of apoptotic cells. Since an islet is a cluster of 200-1000 cells, the transfection efficiency of lipid/siRNA complexes into human islets was only 21-28%, compared to effective transfection efficiency (>90%) in β-cell lines. Nevertheless, these results suggest that siRNA may penetrate beyond the periphery into a larger percentage of an islet mass than previously thought.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 407-417 |
| Number of pages | 11 |
| Journal | Molecular Pharmaceutics |
| Volume | 5 |
| Issue number | 3 |
| DOIs | |
| State | Published - May 1 2008 |
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Keywords
- Apoptosis
- Islet transplantation
- iNOS
- siRNA
- β cells
ASJC Scopus subject areas
- Molecular Medicine
- Pharmaceutical Science
- Drug Discovery
Cite this
iNOS gene silencing prevents inflammatory cytokine-induced β-cell apoptosis. / Li, Feng; Mahato, Ram I.
In: Molecular Pharmaceutics, Vol. 5, No. 3, 01.05.2008, p. 407-417.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - iNOS gene silencing prevents inflammatory cytokine-induced β-cell apoptosis
AU - Li, Feng
AU - Mahato, Ram I.
PY - 2008/5/1
Y1 - 2008/5/1
N2 - Human islet transplantation has great potential as an effective means of treating insulin-dependent diabetes mellitus. Upregulation of inducible nitric oxide synthase (iNOS) and subsequent product of radical nitric oxide (NO) impair islet β-cell function. Therefore, we hypothesize that iNOS gene silencing will prevent β-cell death and improve the survival and function of islets. Small interfering RNA duplex (siRNA) inhibited rat iNOS gene expression and NO production in rat β-cell lines (INS-1E) in a dose- and sequence-dependent manner. iNOS gene silencing also protected these β-cells from inflammatory cytokine-induced apoptosis and increased their capacity to secret insulin. Three siRNA sequences against human iNOS were then designed and transfected into human islets. Although there was dose- and sequence-dependent iNOS gene silencing and NO production in human islets, the effect of iNOS gene silencing on apoptosis of islets was only moderate, as evidenced by 25-30% reduction in caspase 3 activity and in the percentage of apoptotic cells. Since an islet is a cluster of 200-1000 cells, the transfection efficiency of lipid/siRNA complexes into human islets was only 21-28%, compared to effective transfection efficiency (>90%) in β-cell lines. Nevertheless, these results suggest that siRNA may penetrate beyond the periphery into a larger percentage of an islet mass than previously thought.
AB - Human islet transplantation has great potential as an effective means of treating insulin-dependent diabetes mellitus. Upregulation of inducible nitric oxide synthase (iNOS) and subsequent product of radical nitric oxide (NO) impair islet β-cell function. Therefore, we hypothesize that iNOS gene silencing will prevent β-cell death and improve the survival and function of islets. Small interfering RNA duplex (siRNA) inhibited rat iNOS gene expression and NO production in rat β-cell lines (INS-1E) in a dose- and sequence-dependent manner. iNOS gene silencing also protected these β-cells from inflammatory cytokine-induced apoptosis and increased their capacity to secret insulin. Three siRNA sequences against human iNOS were then designed and transfected into human islets. Although there was dose- and sequence-dependent iNOS gene silencing and NO production in human islets, the effect of iNOS gene silencing on apoptosis of islets was only moderate, as evidenced by 25-30% reduction in caspase 3 activity and in the percentage of apoptotic cells. Since an islet is a cluster of 200-1000 cells, the transfection efficiency of lipid/siRNA complexes into human islets was only 21-28%, compared to effective transfection efficiency (>90%) in β-cell lines. Nevertheless, these results suggest that siRNA may penetrate beyond the periphery into a larger percentage of an islet mass than previously thought.
KW - Apoptosis
KW - Islet transplantation
KW - iNOS
KW - siRNA
KW - β cells
UR - http://www.scopus.com/inward/record.url?scp=46449092492&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=46449092492&partnerID=8YFLogxK
U2 - 10.1021/mp700145f
DO - 10.1021/mp700145f
M3 - Article
C2 - 18217711
AN - SCOPUS:46449092492
VL - 5
SP - 407
EP - 417
JO - Molecular Pharmaceutics
JF - Molecular Pharmaceutics
SN - 1543-8384
IS - 3
ER -