Browning of white adipose tissue (WAT) has shown to be highly beneficial for obesity and diabetes. Adipose stromal stem cells (ASCs) can be converted to beige adipocytes. However, the current strategies in browning of WAT have many limitations and problems. Our laboratory has developed trans-resveratrol (RES) encapsulated nanoparticles (NPs) carrying ASC-targeting peptides (ASC-targeted RES-NPs), which can enhance targeted delivery of RES to ASCs after intravenous administration, resulting in browning of WAT and subsequently dramatic body weight and fat loss. However, the liver still has strong NP signals after intravenous administration, which must be reduced. To bypass the liver and other tissues, we propose to subcutaneously administer ASC-targeted RES-NPs to inguinal WAT in mice in this project. We expect browning of WAT will be enhanced when these NPs are administrated locally. Successful completion of this approach should lay the foundation for an approach of eventually inducing browning of subcutaneous WAT in humans under controlled conditions and therapeutic dosage. Although some studies are investigating the effects of brown adipose tissue on type 2 diabetes, it is still an unexplored area in studying whether and how WAT browning affects type 2 diabetes. In this regard, the objective of this proposal is to determine the effects of browning WAT via subcutaneous delivery of ASC-targeted RES-NPs on type 2 diabetes in db/db mice, a commonly studied mouse model of type 2 diabetes. We hypothesize that browning WAT can reduce body weight and fat mass and improve insulin sensitivity and glucose homeostasis by enhancing energy expenditure, increasing glucose uptake and clearance, and decreasing inflammation and lipotoxicity. The novelty of this research lies at the use of ASC-targeted RES-NPs for conveniently inducing browning of WAT and treating diabetes. The project addresses the following specific aims: 1) to determine ASC- targeted RES-NPs characteristics in vitro, their target capacity in human adipose stromal cells collected from subjects with different adiposity, ages, genders, and health status (diabetic or non-diabetic), and their biodistribution and target capacity in db/db mice; 2) to determine the efficacy by which ASC-targeted RES-NPs induces browning and improves insulin signaling in primary mouse stromal cells; and 3) to determine anti-diabetic effects and safety of the ASC-targeted RES-NPs in db/db mice. Browning of WAT using nanotechnology and local and targeted delivery approaches represents an innovative strategy for the treatment of obesity and type 2 diabetes with enhanced efficacy and minimized side effects and toxicity. This project will strengthen research at Texas Tech University, and provide a strong opportunity for training of undergraduate and graduate students in the biomedical field.
Browning of subcutaneous white adipose tissue can simultaneously combat obesity and type 2 diabetes. We will use biocompatible and biodegradable resveratrol-encapsulated nanoparticles for inducing white adipose tissue browning, with the goal of enhancing body weight and fat loss and decreasing blood glucose levels. The outcome of this project is expected to improve the quality of life and produce dramatic savings in the cost of medical care. 1
