Evaluation of iNSiGHT VET DXA (Dual-Energy X-ray Absorptiometry) for assessing body composition in obese rats fed with high fat diet: a follow-up study of diet induced obesity model for 8 weeks

Aerobic exercise attenuates high-fat diet-induced renal injury through kidney metabolite modulation in mice

PURPOSE

To investigate the preventive effect of aerobic exercise on renal damage caused by obesity.

METHODS

The mice in the Control (Con) and Control + Exercise (Con + Ex) groups received a standard chow diet for the 21-week duration of the study, while the High-fat diet (HFD) group and High-fat diet + Exercise (HFD + Ex) group were fed an HFD. Mice were acclimated to the laboratory for 1 week, given 12 weeks of being on their respective diets, and then the Con + Ex and HFD + Ex groups were subjected to moderate intensity aerobic treadmill running 45 min/day, 5 days/week for 8 weeks.

RESULTS

We found that HFD-induced obesity mainly impacts kidney glycerin phospholipids, glycerides, and fatty acyls, and aerobic exercise mainly impacts kidney glycerides, amino acids and organic acids as well as their derivatives. We identified 18 metabolites with significantly altered levels that appear to be involved in aerobic exercise mediated prevention of HFD-induced obesity and renal damage, half of which were amino acids and organic acids and their derivatives.

CONCLUSION

Aerobic exercise rewires kidney metabolites to reduce high-fat diet-induced obesity and renal injury.

Chronic Administration of Exogenous Lactate Increases Energy Expenditure during Exercise through Activation of Skeletal Muscle Energy Utilization Capacity in Mice

We compared the effects of chronic exogenous lactate and exercise training, which influence energy substrate utilization and body composition improvements at rest and during exercise, and investigated the availability of lactate as a metabolic regulator. The mice were divided into four groups: CON (sedentary + saline), LAC (sedentary + lactate), EXE (exercise + saline), and EXLA (exercise + lactate). The total experimental period was set at 4 weeks, the training intensity was set at 60-70% VO2max, and each exercise group was administered a solution immediately after exercise. Changes in the energy substrate utilization at rest and during exercise, the protein levels related to energy substrate utilization in skeletal muscles, and the body composition were measured. Lactate intake and exercise increased carbohydrate oxidation as a substrate during exercise, leading to an increased energy expenditure and increased protein levels of citrate synthase and malate dehydrogenase 2, key factors in the TCA(tricarboxylic acid) cycle of skeletal muscle. Exercise, but not lactate intake, induced the upregulation of the skeletal muscle glucose transport factor 4 and a reduction in body fat. Hence, chronic lactate administration, as a metabolic regulator, influenced energy substrate utilization by the skeletal muscle and increased energy expenditure during exercise through the activation of carbohydrate metabolism-related factors. Therefore, exogenous lactate holds potential as a metabolic regulator.

Combined Treatment of Mori folium and Mori Cortex Radicis Ameliorate Obesity in Mice via UCP-1 in Brown Adipocytes

Mori Folium (Morus alba leaf, MF) and Mori Cortex Radicis (Morus alba root cortex, MR) have been studied for their anti-obesity effects by enhancing the browning process and inhibiting adipogenesis. However, important aspects of their protective mechanisms have not been thoroughly investigated, which could aid in developing functional food. Thus, this study aims to determine the synergistic effects of MF and MR against obesity and its associated mechanisms. In an in vitro cell culture model of brown adipocytes, a 1:1 mixture of MF and MR showed a synergistic effect on the expression of brown adipocyte-specific genes, including Ucp-1, Ppargc1a, Cbp/p300-interacting transactivator (Cited), Prdm16, Tbx1, and Fgf21 compared with either MF- or MR-treated conditions. Moreover, they demonstrated the involvement of cAMP and Ca2+ in induction of brown adipocyte-specific genes. In an in vivo model using HFD-fed mice, MF/MR significantly inhibited weight gain, plasma cholesterol, LDL, TG content, fat mass, and adipocyte size. Furthermore, MF/MR inhibited morphological alteration and the expressions of fatty acid synthesis genes such as Srebp1 and Fasn in the white adipose tissue. Thermogenesis genes were recovered in the brown adipose tissue with MF/MR supplementation, indicating that MF/MR regulated adipocytic dysmetabolism where AMPK signaling is involved. In conclusion, these results suggested that MF/MR regulates brown and beige adipocyte processes, providing one of the preventive functional food/herbal medicines against obesity and its associated metabolic diseases.

Antiobesity Effects of Lactobacillus paracasei Subsp. paracasei, L. casei 431 on High-Fat Diet-Induced Obese Rats

Obesity is currently regarded as a global concern, and the key objectives of the global health strategy include its prevention and control. Probiotic supplementation can help achieve these objectives. This study aimed to assess whether a probiotic strain Lactobacillus paracasei ssp. paracasei, Lactobacillus casei 431 (henceforth, L. casei 431) possesses antiobesogenic properties. High-fat diet-induced obese Sprague-Dawley rats were treated with L. casei 431 for 10 weeks, and the outcomes were compared with those of rats treated with the antiobesity medication orlistat. Body weights, epididymal fat, and tissues from mice were assessed. Furthermore, serological and histological analyses were performed. Epididymal fat accumulation was significantly reduced in groups administered L. casei 431 and orlistat. Furthermore, L. casei 431 and orlistat treatments lowered serum alanine transaminase, aspartate aminotransferase, and triglyceride (TG) levels. Hematoxylin and eosin staining of the liver and epididymal adipose tissues showed that the L. casei 431-treated groups exhibited reduced lipid buildup and adipocyte size. Furthermore, sterol regulatory element-binding protein 1c, adipose TG lipase, and lipoprotein lipase messenger RNA (mRNA) levels were upregulated, leading to lipid oxidation and degradation, in L. casei 431-supplemented groups. Furthermore, carnitine palmitoyltransferase 1, a major factor in lipolysis, was consistently upregulated at the protein level after L. casei 431 administration. Collectively, these results demonstrate the potential of L. casei 431 in alleviating obesity in rats through optimizing lipid metabolism and some related biomarkers.

Noninvasive monitoring of muscle atrophy and bone metabolic disorders using dual-energy X-ray absorptiometry in diabetic mice

Tracking metabolic changes in skeletal muscle and bone using animal models of diabetes mellitus (DM) provides important insights for the management of DM complications. In this study, we aimed to establish a method for monitoring changes in body composition characteristics, such as fat mass, skeletal muscle mass (lean mass), bone mineral density, and bone mineral content, during DM progression using a dual-energy X-ray absorptiometry (DXA) system in a mouse model of streptozotocin (STZ)-induced type 1 DM. In the DM model, STZ administration resulted in increased blood glucose levels, increased water and food intake, and decreased body weight. Serum insulin levels were significantly decreased on day 30 of STZ administration. The DXA analysis revealed significant and persistent decreases in fat mass, lower limb skeletal muscle mass, and bone mineral content in DM mice. We measured tibialis anterior (TA) muscle weight and performed a quantitative analysis of tibial microstructure by micro-computed tomography imaging in DM mice. The TA muscle weight of DM mice was significantly lower than that of control mice. In addition, the trabecular bone volume fraction, trabecular thickness, trabecular number, and cortical thickness were significantly decreased in DM mice. Pearson's product-moment correlation coefficient analysis showed a high correlation between the DXA-measured and actual body composition. In conclusion, longitudinal measurement of body composition changes using a DXA system may be useful for monitoring abnormalities in muscle and bone metabolism in animal models of metabolic diseases such as DM mice.

Gegen Qinlian Decoction ameliorates type 2 diabetes osteoporosis via IGFBP3/MAPK/NFATc1 signaling pathway based on cytokine antibody array

BACKGROUND

Osteoporosis affects more than half the patients with type 2 diabetes mellitus (T2DM). Up to data, there is no effective clinical practice in managing type 2 diabetes osteoporosis (T2DOP) because of its complex pathogenesis. Gegen Qinlian Decoction (GQD) has been used for the long-term management of T2DM. However, the underlying mechanism of GQD in the treatment of T2DOP remains unknown.

PURPOSE

To reveal the role of GQD in T2DOP and its potential therapeutic targets in the management of T2DOP.

STUDY DESIGN

The effect of GQD on T2DOP was observed in db/db mice in four groups: model group, GQD low-dose group (GQD-L), GQD high-dose group (GQD-H), and metformin (positive control) group. C57BL/6J mice were used as the negative control group.

METHODS

Quantitative phytochemical analysis of GQD was performed using high-performance liquid chromatography (HPLC). Micro-CT and hematoxylin-eosin (H&E) staining were used to evaluate bone histomorphometry. To screen for candidate targets of GQD, a cytokine antibody array was used, followed by bioinformatics analysis. Quantitative real-time PCR (qRT-PCR) and western blotting (WB) were used to determine expression levels.

RESULTS

The major active components of GQD were confirmed by HPLC. Micro-CT and H&E staining showed that bone mass was significantly increased in the GQD-H group compared with the model group. Antibody arrays revealed that the expression of insulin-like growth factor binding protein 3 (IGFBP3) was elevated in the GQD-H group. The MAPK pathway was identified using bioinformatics analysis. Additionally, the levels of osteoclastogenesis-related genes, including cathepsin K (Ctsk), acid phosphatase 5 (Acp5), matrix metallopeptidase 9 (Mmp9), and ATPase H+ transporting V0 subunit D2 (Atp6v0d2) were significantly decreased in the GQD-H group. Compared with the model group, high-dosage GQD inhibited phosphorylation of extracellular signal-regulated kinases (ERKs) and P38 mitogen-activated protein kinase (MAPK) and the expression of c-Fos and nuclear factor of activated T cells 1 (NFATc1).

CONCLUSION

GQD plays a protective role in T2DOP by upregulating IGFBP3 expression and downregulating the IGFBP3/MAPK/NFATc1 signaling pathway. IGFBP3 in serum may also be a novel biomarker in the treatment of T2DOP. Our current findings not only expand the application of GQD, but also provide a theoretical basis and guidance for T2DOP.

Sanhuang Jiangtang tablet protects type 2 diabetes osteoporosis via AKT-GSK3β-NFATc1 signaling pathway by integrating bioinformatics analysis and experimental validation

ETHNOPHARMACOLOGICAL RELEVANCE

Sanhuang Jiangtang tablet (SHJTT), has been widely used to treat type 2 diabetes mellitus (T2DM). However, the potential and mechanism of SHJTT in treating type 2 diabetes osteoporosis (T2DOP) has not been reported.

AIM OF THE STUDY

The aim of this work was to investigate the role and the underlying molecular mechanism of SHJTT in managing type 2 diabetes osteoporosis.

MATERIALS AND METHODS

The target genes of each component consisting of SHJTT were obtained by searching the ETCM database. The target genes of osteoporosis and diabetes were individually acquired by analyzing the DisGeNET and OMIM disease databases. Then the potential therapeutic genes were obtained from the intersection of the herbal medicine targets and the disease targets which were imported into the R and STRING platform for the analysis of GO terms, KEGG pathways and PPI network. The key modules of PPI network were constructed by Cytoscape software. Finally, leptin receptor deficiency (db/db) mice were confirmed as an animal model of type 2 diabetic osteoporosis (T2DOP) through phenotype assessment and the key genes of SHJTT against T2DOP were validated by quantitative real-time PCR (qRT-PCR).

RESULTS

A total of 786 target genes of SHJTT were obtained from ETCM. Simultaneously, a total of 3906 osteoporosis and type 2 diabetes associated targets were acquired from DisGeNET and OMIM databases. Then, 97 common targets were found by overlapping them. On the basis of the GO and KEGG enrichment analysis and PPI network, we found that the related pathway of SHJTT in type 2 diabetes osteoporosis was AKT-GSK3β-NFATc1 pathway which is tightly associated with osteoclast differentiation. The expression of key genes including Akt1, Mapk3, Gsk3β, Mmp9, Nfkb1 were significantly down-regulated by SHJTT in T2DOP mice (p < 0.05).

CONCLUSIONS

SHJTT had a protective effect on T2DOP via regulating AKT-GSK3β-NFATc1 signaling pathway. This study might provide a theoretical basis for the application of SHJTT for the treatment of type 2 diabetic osteoporosis.

Hypoxic Exposure Increases Energy Expenditure by Increasing Carbohydrate Oxidation in Mice

Aims. Hypoxic exposure improves glucose metabolism. We investigated to validate the hypothesis that carbohydrate (CHO) oxidation could increase in mice exposed to severe hypoxic conditions.Methods. Seven-week-old male ICR mice (n=16) were randomly divided into two groups: the control group (CON) was kept in normoxic condition (fraction of inspiredO2=21%) and the hypoxia group (HYP) was exposed to hypoxic condition (fraction of inspiredO2=12%, ≈altitude of 4,300 m). The CON group was pair-fed with the HYP group. After 3 weeks of hypoxic exposure, we measured respiratory metabolism (energy expenditure and substrate utilization) at normoxic conditions for 24 hours using an open-circuit calorimetry system. In addition, we investigated changes in carbohydrate mechanism-related protein expression, including hexokinase 2 (HK2), pyruvate dehydrogenase (PDH), pyruvate dehydrogenase kinase 4 (PDK4), and regulator of the genes involved in energy metabolism (peroxisome proliferator-activated receptor gamma coactivator 1-alpha, PGC1α) in soleus muscle.Results. Energy expenditure (EE) and CHO oxidation over 24 hours were higher in the HYP group by approximately 15% and 34% (p<0.001), respectively. Fat oxidation was approximately 29% lower in the HYP group than the CON group (p<0.01). Body weight gains were significantly lower in the HYP group than in the CON group (CON vs. HYP;1.9±0.9vs.−0.3±0.9;p<0.001). Hypoxic exposure for 3 weeks significantly reduced body fat by approximately 42% (p<0.001). PDH and PGC1αprotein levels were significantly higher in the HYP group (p<0.05). Additionally, HK2 was approximately 21% higher in the HYP group.Conclusions. Hypoxic exposure might significantly enhance CHO oxidation by increasing the expression of PDH and HK2. This investigation can be useful for patients with impaired glucose metabolism, such as those with type 2 diabetes.