DIO-B6-M Mice

Catalog Number: C001549

Genetic Background: C57BL/6NCya

Strain Description

Obesity is a chronic, recurrent disorder characterized by excessive body weight and fat accumulation. Beyond its impact on physical appearance, obesity poses significant risks for developing a spectrum of complications, including cardiovascular diseases (CVD), gastrointestinal disorders, type 2 diabetes (T2D), musculoskeletal conditions, respiratory disorders, and other related pathologies. Diet-induced animal models, such as the Diet-Induced Obesity (DIO) mouse model, are designed to mimic human obesity through excessive fat accumulation driven by a high-fat diet. These models are indispensable for preclinical studies assessing the efficacy of therapeutic interventions targeting obesity and its associated complications.

The C57BL/6 inbred mouse strain is extensively utilized in the construction of DIO models. Comparative studies indicate that C57BL/6J mice harbor spontaneous deletions in exons 7-11 of the Nnt gene, a mutation associated with abnormal mitochondrial metabolism in pancreatic β-cells and impaired insulin secretion. Consequently, C57BL/6J mice demonstrate glucose intolerance and reduced insulin secretion ^[1-3], rendering them less suitable for research in metabolic diseases. The Nnt gene is implicated in NAD binding activity, NAD(P)+ transhydrogenase activity, and NADP binding activity. Deficiencies in Nnt may impact studies involving NADPH-dependent mechanisms. Thus, the use of C57BL/6N mice, which retain functional Nnt, offers scientific advantages and validity for constructing DIO models.

The DIO-B6-M model represents a Diet-Induced Obesity (DIO) mouse model, generated by subjecting male C57BL/6NCya mice to a 60% high-fat diet (HFD). These mice exhibit significant weight gain, elevated random blood glucose levels, increased populations of NK cells and macrophages, and elevated blood lipids and liver function markers. This model is highly valuable for investigating metabolic diseases, such as obesity, diabetes, and inflammation, and for evaluating the efficacy of potential therapeutic agents in preclinical studies. The effectiveness of diet-induced obesity (DIO) modeling can be influenced by various factors including diet, strain, condition, and husbandry practices. Some variability between model batches may occur; please contact us for further information.

Application

• Research on diet-induced obesity, diabetes, inflammation, fatty liver, and other metabolic disorders;
• Preclinical evaluation of anti-obesity drugs.

Validation Data

1. Body Weight Changes and Blood Glucose Assay in Mice Fed a 60% High-Fat Diet (HFD)

Figure 1. Weight changes and blood glucose measurements in DIO-B6-M mice (n_ND=10, n_HFD=20). Male C57BL/6NCya mice, aged 4 weeks, were fed a 60% high-fat diet after a 1-week adaptation period. Body weight was periodically monitored, and random blood glucose levels were measured after 25 weeks of high-fat feeding. The results reveal that compared to the normal diet group (ND), the 60% high-fat diet group (HFD) displayed significant weight gain, with an average body weight of approximately 50g after 25 weeks of high-fat feeding. Additionally, random blood glucose levels were significantly higher in the HFD group compared to the ND group at 25 weeks (Data presented as Mean±SD; ***p<0.001).

2. Immune Cell Profiling in Peripheral Blood

Figure 2. Flow cytometry analysis of immune cells (T cells, B cells, NK cells, and macrophages) in peripheral blood of normal diet (ND) and 60% high-fat diet (HFD) fed mice after 25 weeks (n=10). The results indicate that DIO-B6-M mice exhibit a significant increase in NK cells and macrophages after 25 weeks of high-fat feeding, suggesting an enhanced inflammatory response (Mouse weight range for analysis: 50-55g; Data presented as Mean±SD; *p<0.05, **p<0.01).

3. Blood Biochemistry

Figure 3. Blood lipid and liver function indicators in normal diet (ND) and 60% high-fat diet (HFD) fed mice after 25 weeks of dietary induction* (n_ND=10, n_HFD=20). The results show that After 25 weeks, DIO-B6-M mice exhibited significant elevations in T-CHO, HDL-C, LDL-C, AST, and ALT levels compared to the ND group (Data presented as Mean±SD; **p<0.01, **p<0.001).

*TG: Triglycerides; T-CHO: Total cholesterol; HDL-C: High-density lipoprotein cholesterol; LDL-C: Low-density lipoprotein cholesterol; AST: Aspartate aminotransferase; ALT: Alanine aminotransferase.

4. Semaglutide Efficacy Validation

Figure 4. The efficacy of Semaglutide in reducing body weight and blood glucose in DIO-B6-M mice, as well as improving glucose tolerance.

A: After 12 weeks of a 60% high-fat diet, DIO-B6-M mice received subcutaneous injections of 30 nmol/kg Semaglutide twice weekly (30-90 minutes before the dark cycle). Control groups (B6N+ND and B6N+HFD) received equivalent doses of a control solvent. Weight, food intake, and blood glucose levels were monitored regularly.

B~E: Semaglutide treatment significantly reduced body weight, blood glucose, and food intake in DIO-B6-M mice (n=6).

F~G: Semaglutide significantly improved glucose tolerance in DIO-B6-M mice, with the area under the IPGTT curve (AUC) comparable to the B6N+ND group and substantially lower than the B6N+HFD group (n=6).

H: At the experimental endpoint, DIO-B6-M mice treated with Semaglutide had a leaner body type compared to the B6N+HFD group, with minimal differences compared to the B6N+ND group.

*Semaglutide is an anti-obesity drug with a relatively long half-life ^[4].

Husbandry

Temperature: 20-26 °C

Humidity: 40-70 %

Diet: 60% high-fat diet

Modeling Period: Begin high-fat feeding at 4-5 weeks of age, following a 1-week adaptation period (see Table 1). Transition to a complete 60% high-fat diet.

Table 1. High-Fat Diet Adaptation Conditions

Feed Storage: Store the high-fat diet at -20°C and replace the feed in cages twice a week to prevent spoilage.

Handling Guidelines: Handle mice with care, minimizing noise, vibration, and disturbances to reduce stress, which can help DIO mice maintain appropriate weight.

Bedding Choice: Avoid corn cob bedding, which may cause mice to feel satiated without consuming calories, potentially hindering weight gain. Use wood shavings and nesting paper, changing them weekly in sync with weighing to minimize disturbance.

Assist Dental Health: Due to the softer texture of high-fat diet pellets, provide wooden blocks or similar items in cages to help mice maintain dental health.

Greasy Fur Issue: Late-stage obesity in high-fat-fed mice may lead to slightly greasy fur. Providing nesting material can alleviate this. Some hair loss may occur but typically does not affect weight gain.

Reference

[1] Simon MM, Greenaway S, White JK, Fuchs H, Gailus-Durner V, Wells S, Sorg T, Wong K, Bedu E, Cartwright EJ, Dacquin R, Djebali S, Estabel J, Graw J, Ingham NJ, Jackson IJ, Lengeling A, Mandillo S, Marvel J, Meziane H, Preitner F, Puk O, Roux M, Adams DJ, Atkins S, Ayadi A, Becker L, Blake A, Brooker D, Cater H, Champy MF, Combe R, Danecek P, di Fenza A, Gates H, Gerdin AK, Golini E, Hancock JM, Hans W, Hölter SM, Hough T, Jurdic P, Keane TM, Morgan H, Müller W, Neff F, Nicholson G, Pasche B, Roberson LA, Rozman J, Sanderson M, Santos L, Selloum M, Shannon C, Southwell A, Tocchini-Valentini GP, Vancollie VE, Westerberg H, Wurst W, Zi M, Yalcin B, Ramirez-Solis R, Steel KP, Mallon AM, de Angelis MH, Herault Y, Brown SD. A comparative phenotypic and genomic analysis of C57BL/6J and C57BL/6N mouse strains. Genome Biol. 2013 Jul 31;14(7):R82.
[2] Freeman H, Shimomura K, Horner E, Cox RD, Ashcroft FM. Nicotinamide nucleotide transhydrogenase: a key role in insulin secretion. Cell Metab. 2006 Jan;3(1):35-45.
[3] Hull RL, Willard JR, Struck MD, Barrow BM, Brar GS, Andrikopoulos S, Zraika S. High fat feeding unmasks variable insulin responses in male C57BL/6 mouse substrains. J Endocrinol. 2017 Apr;233(1):53-64.
[4] Christou GA, Katsiki N, Blundell J, Fruhbeck G, Kiortsis DN. Semaglutide as a promising antiobesity drug. Obes Rev. 2019 Jun;20(6):805-815.