Blood glucose monitor

8 week-old male db/db mice, their db/m littermates, and male BALB/c mice were purchased from the GemPharmatech Co., Ltd., (Nanjing China). Animals were maintained in a controlled environment (12 h light/dark cycle at 23°C) with free access to food and water. The experiments were performed following the National Institutes of Health guidelines and with approval from the Animal Care and Use Committee of Wenzhou Medical University, China.
For the DN model, db/db mice were intraperitoneally (i.p.) injected with FGF1^ΔHBS at 0.5 mg/kg body weight every other day for 8 weeks while db/m and db/db mice were received 0.9% normal saline as controls. Blood glucose levels were measured using a blood glucose monitor (Roche).
For the adriamycin-induced nephropathy (AN) model, mice were injected with a single dose of ADR (11 mg/kg) through the tail vein. FGF1^ΔHBS (0.5 mg/kg body weight) or normal saline was administered i.p. every other day starting one week before ADR injection and lasting for 5 weeks. Metabolic cages (TSE Systems, MO) were chosen to collect mice urine for 24 h.

Cellular ATP concentrations were determined with an ATP Detection Assay Kit (Beyotime) according to the manufacturer’s instructions (catalogue number S0026). Glucose concentrations were analyzed using a blood glucose monitor (Roche). The activity of PDH was determined by micro PDH assay Kit from Solarbio, catalogue number BC0385. To determine the concentrations of other metabolites, kits were purchased from Nanjing Jiancheng Bioengineering Research Institute as follows and used according to the manufacturer’s instructions: NAD^+/NADH, catalogue number A114; free fatty acids, catalogue number A042-2; PGE2, catalogue number H099; and lactate, catalogue number A019-2. The absorbance was measured by using a Multiskan™ FC Microplate Photometer (ThermoFisher) immediately after sample preparation. Background absorbance was subtracted.