Lowering the blood glucose of diabetes mellitus mice by oral administration with transgenic human insulin-like growth factor I silkworms.
To evaluate the biological activity of the posterior silk glands of transgenic silkworms expressing human insulin-like growth factor I (hIGF-I), we bred hIGF-I-transgenic silkworms through eight generations by continuously selecting with green fluorescence and G418. The G8 transgenic silkworms were confirmed by polymerase chain reaction and dot blotting, and their posterior silk glands were removed from the fifth instar larvae to make freeze-dried powders. Enzyme-linked immunosorbent assay results showed that the expression level of hIGF-I in the posterior silk glands of G8 transgenic silkworm is approximately 493 ng/g of freeze-dried powder. When the freeze-dried powder was administrated by gavage to diabetes mellitus (DM) mice, the blood glucose in DM mice significantly decreased (P < 0.05) in a time- and dose-dependent manner compared with that of DM mice orally administrated with distilled water and normal freeze-dried powders made of untreated silk glands. These results demonstrated that hIGF-I expressed in posterior silk glands of transgenic silkworms could reduce blood glucose by oral administration.
School of Biology and Basic Medical Sciences, Soochow University, Suzhou 215123, China.
Renyu
R
Xue
Yang
Y
Wang
Guangli
G
Cao
Zhonghua
Z
Pan
Xiaojian
X
Zheng
Wenlin
W
Zhou
Chengliang
C
Gong
D000818:Animals; D030801:Animals, Genetically Modified / Q000378:metabolism*; D001786:Blood Glucose / Q000032:analysis*; D012831:Bombyx / Q000235:genetics / Q000378:metabolism*; D003921:Diabetes Mellitus, Experimental / Q000188:drug therapy*; D005088:Exocrine Glands / Q000737:chemistry / Q000378:metabolism; D005612:Freeze Drying; D015870:Gene Expression; D006801:Humans; D007334:Insulin-Like Growth Factor I / Q000008:administration & dosage* / Q000235:genetics*; D008297:Male; D051379:Mice; D008813:Mice, Inbred ICR; D011208:Powders
D001786:Blood Glucose; D011208:Powders; D007334:Insulin-Like Growth Factor I