Objective To observe the month age distribution of peroxisome proliferators activated receptor gamma (PPARγ) expression in rat kedney. Methods Wistar rats aged 3 months,12 months and 24 months were made as models who represented young, middle-aged and old group respectively. Western blotting, immunohistochemical (IHC) and in-situ hybridization (ISH) were used to detect the expression and location of protein and mRNA of PPARγ in rat kidney. Results Western blotting results showed that the expression of PPARγ protein was higher in 3 months group than in 24 months group (0.94±0.05 vs. 0.78±0.02, P＜0.01) and 12 months group (0.87±0.04, P＞0.05), and it reduced in 24 months group than in 12 months group (P＞0.05). By IHC,the PPARγ protein was localized predominantly in the nuclear of tubular epithelia and collecting duct cells in each group. In old age group, PPARγ protein was also detected little in the mesangial and Bowman's capsule epithelial cells. Meanwhile, the distribution of PPARγ mRNA with ISH was consistent with above findings. Additional, semi-quantitative analysis of ISH results verified that the level of PPARγ mRNA decreased with ageing. Conclusions As a nuclear transcription factor,PPARγ participates in the regulation of rat kidney aging.

Objective To investigate the effect of rosiglitazone (RGTZ) on anti-oxidation in aging rat kidney. Methods Twenty-four-month-old male Sprague-Dawley rats were randomly divided into three groups (n=10): control group (CON), rosiglitazone group (RGTZ) and caloric restriction group (CR). The CON rats were allowed ad libitum access to feed and tap water.The RGTZ rats received intragastric administration of RGTZ (4 mg·kg-1·d-1),and the CR rats were provided with a vitamin and mineral fortified version of the same diet at a level of 40% less food (by weight) than the CON rats. After 12 weeks all the animals were sacrificed by decapitation, and both the body weight and the percentage of kidney and heart in each group were measured.Western blot was performed to analyze the expression of PPARγ protein. The content of MDA and the activity of SOD and GSH-PX in kidney tissue were detected. Besides, frozen sections of kidney tissue were stained for senescence-associated-13 galactosidase (SA-β-Gal). Results The body weight of CR rats decreased obviously, in contrast, which did not change in CON and RGTZ group. Percentage of kidney and heart to body weight was normal in CR or RGTZ group after intervention. Western blot result showed that PPARγ protein expression in rat kidney was significantly higher in RGTZ and CR group as compared to CON group (P<0.05). Compared with RGTZ and CR rats, obviously lower activities of SOD and GSH-Px were noted in CON rats, however, the content of MDA was higher in CON rats. Additionally, the positive staining area of [3-Gal in CR and RGTZ group was significantly smaller than that in CON rats (P<0.05, P<0.01 ). Conclusion RGTZ can defer the kidney aging in senescence SD rat, and the mechanism may be related to amelioration of oxidative damage and enhancement of antioxidation.

Objective:To investigate the intravoxel incoherent motion (IVIM) diffusion-weighted imaging (DWI) in the differential diagnosis of diabetic nephropathy (DN) and non-diabetic renal disease (NDRD) among patients with type 2 diabetes mellitus (T2DM).Methods:A diagnostic test. In this prospective study, patients with T2DM who underwent both IVIM-DWI and renal biopsy at the First Medical Center of Chinese PLA General Hospital between October 2017 and September 2021 were consecutively enrolled. IVIM-DWI parameters including perfusion fraction (f), pure diffusion coefficient (D), and pseudo-diffusion coefficient (D*) were measured in the renal cortex, medulla, and parenchyma. Patients were divided into the DN group and NDRD group based on the renal biopsy results. IVIM-DWI parameters, clinical information, and diabetes-related biochemical indicators between the two groups were compared using Student′s t-test or Mann-Whitney U test. The correlation of IVIM-DWI parameters with diabetic nephropathy histological scores were analyzed using Spearman′s correlation analyzes. The diagnostic efficiency of IVIM-DWI parameters for distinguishing between DN and NDRD were assessed using the receiver operating characteristic (ROC) curves. Results:A total of 27 DN patients and 23 NDRD patients were included in this study. The DN group comprised 19 male and 8 female patients, with an average age of 52±9 years. The NDRD group comprised 16 male and 7 female patients, with an average age of 49±10 years. The DN group had a higher D* value in the renal cortex and a lower f value in the renal medulla than the NDRD group (9.84×10 -3 mm 2/s vs. 7.35×10 -3 mm 2/s, Z=-3.65; 41.01% vs. 46.74%, Z=-2.29; all P<0.05). The renal medulla D* value was negatively correlated with DN grades, interstitial lesion score, and interstitial fibrosis and tubular atrophy (IFTA) score ( r=-0.571, -0.409, -0.409; all P<0.05) while the renal cortex f value was positively correlated with vascular sclerosis score ( r=0.413, P=0.032). The renal cortex D* value had the highest area under the curve (AUC) for discriminating between the DN and NDRD groups (AUC=0.802, sensitivity 91.3%, specificity 55.6%). Conclusion:IVIM-derived renal cortex D* value can be used non-invasively to differentiate DN from NDRD in patients with T2DM that can potentially facilitate individualized treatment planning for diabetic patients.