Aim. Based on the previously established method, we developed a better and stable animal model of type 2 diabetes mellitus by high‐fat diet combined with multiple low‐dose STZ injections. Meanwhile, this new model was used to evaluate the antidiabetic effect of berberine.Method. Wistar male rats fed with regular chow for 4 weeks received vehicle (control groups), rats fed with high‐fat diet for 4 weeks received different amounts of STZ once or twice by intraperitoneal injection (diabetic model groups), and diabetic rats were treated with berberine (100 mg/kg, berberine treatment group). Intraperitoneal glucose tolerance test and insulin tolerance test were carried out. Moreover, fasting blood glucose, fasting insulin, total cholesterol, and triglyceride were measured to evaluate the dynamic blood sugar and lipid metabolism.Result. The highest successful rate (100%) was observed in rats treated with a single injection of 45 mg/kg STZ, but the plasma insulin level of this particular group was significantly decreased, and ISI has no difference compared to control group. The successful rate of 30 mg/kg STZ twice injection group was significantly high (85%) and the rats in this group presented a typical characteristic of T2DM as insulin resistance, hyperglycemia, and blood lipid disorder. All these symptoms observed in the 30 mg/kg STZ twice injection group were recovered by the treatment of berberine.Conclusion. Together, these results indicated that high‐fat diet combined with multiple low doses of STZ (30 mg/kg at weekly intervals for 2 weeks) proved to be a better way for developing a stable animal model of type 2 diabetes, and this new model may be suitable for pharmaceutical screening.
The mechanism by which adipocyte-derived endocrine factors promote insulin resistance in skeletal muscle are not fully understood. MiR-27a is highly expressed in sera of obese individuals with prediabetes and T2DM, and mainly derived by adipose tissues. Thus, miR-27a secreted into circulation by adipose tissue may regulate insulin resistance in skeletal muscle.
This report describes an integrated study on identification of potential markers for gastric cancer in patients’ cancer tissues and sera based on: (i) genome-scale transcriptomic analyses of 80 paired gastric cancer/reference tissues and (ii) computational prediction of blood-secretory proteins supported by experimental validation. Our findings show that: (i) 715 and 150 genes exhibit significantly differential expressions in all cancers and early-stage cancers versus reference tissues, respectively; and a substantial percentage of the alteration is found to be influenced by age and/or by gender; (ii) 21 co-expressed gene clusters have been identified, some of which are specific to certain subtypes or stages of the cancer; (iii) the top-ranked gene signatures give better than 94% classification accuracy between cancer and the reference tissues, some of which are gender-specific; and (iv) 136 of the differentially expressed genes were predicted to have their proteins secreted into blood, 81 of which were detected experimentally in the sera of 13 validation samples and 29 found to have differential abundances in the sera of cancer patients versus controls. Overall, the novel information obtained in this study has led to identification of promising diagnostic markers for gastric cancer and can benefit further analyses of the key (early) abnormalities during its development.
Mesenchymal stem cells (MSCs) hold great potential for tissue engineering and regeneration medicine. However, for clinical use, MSCs may be detrimental due to their uncertain fate during the transplantation. It is therefore highly desirable to develop biocompatible nanomaterials to integrate cell fate regulation with monitoring for MSC-based therapy. Herein, we employ recently developed citric acid-based carbon dots (CDs) and their derivatives (Et-IPCA) for labeling and tracking of rat bone marrow mesenchymal stem cells (rBMSCs). We further investigate their biocompatibility and effects on the osteogenic differentiation of rBMSCs. These highly fluorescent probes provide labeling of rBMSCs by internalization without affecting cell viability or inducing apoptosis when the concentration is lower than 50 μg mL−1. Importantly, the presence of the CDs and Et-IPCA facilitates high-efficiency osteogenic differentiation of rBMSCs by promoting osteogenic transcription and enhancing matrix mineralization. Compared to Et-IPCA, CDs considerably provide long-term tracking and promote the differentiation of rBMSCs toward osteoblasts through the ROS-mediated MAPK pathway. Taken together, our results consistently demonstrate that carbon dots are capable of both tracking and enhancing the osteogenic differentiation of MSCs. This study sheds new light on the potential of carbon dots as a bifunctional tool in the thriving field of MSC-based therapy.