Embodiment
Below in conjunction with specific embodiment, further set forth the present invention.These embodiment only are used to the present invention is described and are not used in and limit the scope of the invention.The experimental technique of unreceipted actual conditions in the following example, usually according to normal condition, for example the Sambrook equimolecular is cloned: laboratory manual (New York:Cold SpringHarbor Laboratory Press, 1989) condition described in, or the condition of advising according to manufacturer.
Embodiment
Reagent: tetraoxypyrimidine Alloxan monohydrate (the HPLC pure reagent is available from U.S. sigma company, production code member A7413);
Glucose assays test kit---glucose oxidase-peroxidase method (available from Shanghai Rongsheng Bioisystech Co., Ltd, production code member 361510, lot number 20030101);
Laboratory animal: healthy male ♂ Kunming mouse in six ages in week is provided by Shanghai Si Laike experimental animal responsibility company limited that (credit number SCXK (Shanghai)-2007-0005) experimentizes after cultivating a week by adaptability in 20 ℃ of light and shade alternate environments is pre-.
Experimentation comprises the steps:
Step 1, the siRNA design is synthetic
The siRNA of design mouse glucagon receptor (GCGR), refseq sequence NM_008101 according to GCGR, use the siRNA design software of masschusetts, u.s.a Whitehead biomedical research institute, format is the siRNA of AA19NTT, and it is as follows to select three results:
GCGR
SiRNA_1 target sequence AAAGCTCTTCAGGAGGAAAGGTT (1451-1473),
Positive-sense strand 5 '-AGCUCUUCAGGAGGAAAGGUU
Antisense strand 3 '-UUUCGAGAAGUCCUCCUUUCC;
SiRNA_2 target sequence AAAGTGCAGCACCGCCTAGTGTT (455-477),
Positive-sense strand 5 '-AGUGCAGCACCGCCUAGUGUU,
Antisense strand 3 '-UUUCACGUCGUGGCGGAUCAC;
SiRNA_3 target sequence AACTACATCCATGGGAACCTGTT (707-729),
Positive-sense strand 5 '-CUACAUCCAUGGGAACCUGUU
Antisense strand 3 '-UUGAUGUAGGUACCCUUGGAC.
The non-target siRNA of control group
Positive-sense strand 5 '-UUCUCCGAACGUGUCACGUTT,
Antisense strand 3 '-TTAAGAGGCUUGCACAGUGCA.
The synthetic of siRNA finished by Shanghai JiMa pharmacy Technology Co., Ltd.
Step 2, the foundation of diabetic mice model and model stability property testing
20 of Kunming mouses, body weight and blood glucose value after adapting to one week of feeding environment and surveying normal mouse empty stomach 4h; After water 12h is can't help in the mouse fasting, prepare fresh tetraoxypyrimidine inductor solution, administering mode is disposable mouse peritoneal injection (ip), and dosage is 200mgKg-1The mouse body weight.Be that mouse is replenished drinking-water and food after injection finishes, and change bedding and padding.Behind the injection inductor 72h, measure later mouse body weight and the blood sugar of 4h on an empty stomach, detection is modeled as power and divides into groups.In 16 days, detect mouse body weight situation after the modeling to understand the model state of health.
Step 3, the blood sugar test standard method is set up
The mouse fasting be can't help water on an empty stomach after the 4h, keeps mouse mood calmness as far as possible, gets about blood 100ul (3 bleed to 4) in the mouse eyeground with glass capillary rapidly, places the 0.5ml centrifuge tube.Blood sample in 4 ℃ of refrigerator and cooled hide be placed to the centrifuge tube bottom and coagulation of blood occurs after, centrifugal (3000rpm 5min) gets upper serum and makes glucose content and detect in 4 ℃ immediately.
R1 in the glucose detection test kit (Shanghai Rongsheng Bioisystech Co., Ltd, article No. 361510) is mixed as the glucose test fluid with the R2 equal proportion.Get test sample book 4ul and add in the test fluid of 1ml, fully mixing places 37 ℃ of water-bath 15min, makes it colour developing.At ultraviolet wavelength 505nm place,, read the absorbance A of sample tube with the zeroing of skip test liquid adding distil water.Simultaneously,preparation 5~30mmolL-1The glucose reference liquid of gradient concentration, thus the production standard curve reads the glucose concn of sample, typical curve R2>0.99.
Step 4 is administered systemically in the mouse model siRNA body
With becoming the mouse of mould to be divided into 4 groups according to the blood sugar test situation, be respectively siRNA_1, siRNA_2, siRNA_3 group and control group, administering mode adopts the quick push injection of tail vein high pressure.Synthetic siRNA is dissolved among the PBS that DEPC handled, carries out administration according to 0.1nmol/g mouse body weight: the liquor capacity that every mouse model is injected fast is 8% of a mouse body weight, is about the PBS-siRNA solution about 3ml.Close observation mouse after administration finishes is in time replenished drinking-water and feed.
Step 5, carbohydrate tolerance test
Carbohydrate tolerance test: 2d after administration, fasting 4h get blood (when being zero), and abdominal injection glucose (2g/kg) is measured and given 0.5,1,1.5,2 hours the blood glucose value in sugar back and calculate area under the blood glucose curve then.
Step 6, mouse model change of blood sugar curve
Respectively at 1d after the administration, 2d, 4d, 8d measures each mouse blood sugar value in 4 groups according to the blood sugar test standard method in the step 3.Obtain the mouse model blood sugar-time curve in 8 days after the administration.
Test-results and analysis
(1) foundation of diabetic mice model
MBG 7.1 ± 3.0mmolL before 20 mouse are induced-1, induce dead two of back, blood sugar is greater than 15mmolL-1Mouse is 12 (MBG 34.6 ± 3.9mmolL-1); Inducing and being modeled as power is 60%.
(2) sugar tolerance test after the siRNA administration
Calculate four groups (1) siRNA-1 as shown in Figure 1, (2) siRNA-2, (3) siRNA-3, area (AUC) is respectively under (4) non-target contrast siRNA blood sugar-time curve: 964.5; 3216.1; 2606.9 and 4173.9minmmolL-1AUC has reflected the utilize degree of animal to glucose, and the area of AUC is more little, proves that it can effectively utilize glucose more, wherein (1), (2), the AUC area of (3) group is respectively 23.11%, 77.1% and 62.5% of contrast (4) group.
(3) blood sugar-time changing curve after the siRNA administration
8 days model mice blood sugar-time curves after the administration as shown in Figure 2: induce successfully the diabetic mice model to be divided into 4 groups for 12:
1. blood sugar 38.4 ± 3.3mmolL before the siRNA-1 slice groups, administration-1, first day blood sugar 5.4 ± 1.5mmolL after the administration-1, before administration, reduced by 86.0%; After this blood-sugar content gos up to some extent in several days, but the 8th day blood-sugar content still is lower than the preceding blood sugar of administration, is 11.7 ± 3.5mmolL-1, before administration, reduced by 69.4%;
2. blood sugar 29.2 ± 4.6mmolL before the siRNA-2 slice groups, administration-1, first day blood sugar 17.1 ± 1.4mmolL after the administration-1, blood sugar has reduced by 41.4% before administration, and several days blood sugar after this go up;
3. blood sugar 34.8 ± 3.8mmolL before the siRNA-3 slice groups, administration-1, first day blood sugar 27.1 ± 7.8mmolL after the administration-1, blood sugar has reduced by 22.2% before administration; After this several days blood sugar go up;
4. blood sugar 36.1 ± 2.1mmolL before the non-target siRNA sequence control group, administration-1, first day blood sugar 37.8 ± 4.2mmolL after the administration-1, blood sugar has raise 4.7% before administration; After this several days blood sugar raise gradually, and model blood sugar has raise 32% in the time of the 8th day before administration.