- The Effects of Uncoupling Protein 3 Overexpression on Glucose Metabolism in OLETF Rats in Vivo and Cultured Skeletal Muscle Cells in Vitro.
-
Jeong Hee Han, Hye Seon Park, Jung Min Koh, Ha Young Kim, Ho Kyung Kang, In Kyu Lee, Joong Yeol Park, Sung Kwan Hong, Jae Dam Lee, Ki Up Lee
-
Korean Diabetes J. 2001;25(6):460-468. Published online December 1, 2001
-
-
-
Abstract
PDF
- BACKGROUND
UCP3 is a mitochondrial membrane protein expressed selectively in the skeletal muscle and brown adipose tissue. Since the skeletal muscle is the main organ determining insulin sensitivity in the body, it was hypothesized that UCP3 overexpression in skeletal muscle cells would improve glucose metabolism. METHODS: An adenovirus-UCP3 was produced by a recombinant DNA method. OLETF rats were divided into 2 groups. Four rats were injected with the adenovirus- UCP3 (UCP3 group) and others were injected with the adenovirus (control group) in the skeletal muscle. The UCP3 group was provided with the same quantity of food as that consumed by the control group on the previous day. Insulin sensitivity was evaluated by the euglycemic hyperinsulinemic clamp method. In a separate experiment, glucose transport and glycogen synthesis we evaluated in C2C12 cells transfected with ether an adenovirus or the adenovirus-UCP3. RESULTS: The insulin sensitivity improved significantly and the body weight decreased in the UCP3 group. The glucose transport and glycogen synthesis were higher in the UCP3-C2C12 skeletal muscle cells at the basal state. After insulin treatment, glucose transport and glycogen synthesis were also higher in the UCP3-C2C12 cells but the increments were reduced after treatment with wortmannin, a PI3K inhibitor. CONCLUSION: Insulin sensitivity was higher in the UCP3-overexpressed OLETF rats in the in vivo study. UCP3 transfection also increased glucose transport and glycogen synthesis in the cultured skeletal muscle cells by a PI3K dependent mechanism.
- Changes of Glomerular Filtration Rate and Urinary Albumin Excretion Rate in NIDDM patients with Microalbuminuria.
-
Hyo Jung Kim, Jung Min Koh, Eun Sug Shin, Yun Ey Chung, Young Il Kim, Chul Hee Kim, Joong Yeol Park, Sung Kwan Hong, Ki Up Lee
-
Korean Diabetes J. 1997;21(4):414-424. Published online January 1, 2001
-
-
-
Abstract
PDF
- BACKGROUND
We previously suggested that micro-albuminuria in the presence of retinopathy may represent a state of real incipient diabetic nephropathy with declining glomerular filtration rate(GFR), while the meaning of microalbuminuria in the absence of retinopathy may be more heterogeneous. This study was performed to further test this hypothesis. METHODS: We prospectively followed up the changes in GFR and urinary albumin excretinn rate (UAE) in microalbuminuric NIDDM patients with or without diabetic retinopathy for 3.1 years. RESULTS: 1) Among 45 patients who completed the followup, 27 had retinopathy from the baseline(group A), while 18 patients did not have retinopathy throughout the study(group B). 2) UAE at baseline was not statistically different between the group A and group B. During follow-up, VAE remained stable in the group B patients(40.0 [20.5 ~ 158.0) to 60.0[20.2 ~ 231.0] ug/min, NS). On the other hand, UAE significantly increased in the group A patients(47.9[20.0~186.0] to 140.0[24.5~2862.0] ug/min, P <0.001). 3) Thirty percent of the group A patients(8/27) progressed to overt proteinuria, while 11%(2/18) of the group B patients developed overt proteinuria(NS). 4) GFR significantly decreased both in the group A (113.0+21.2 to 89.1+24.0 mL/min/1.73 m, P < 0,001) and in the group B patients(134.1+27.2 to 121.5+27.3 mL/min/1.73 m, P<0.01). However, the magnitude of change in GFR was significantly higher in the group A than in the group B patients(7.7+7.6 vs 3.9+4.2 mL/min/1.73 m /year, P <0.05), 5) Multiple logistic regression analysis revealed that the presence of retinopathy was a independent risk factor for faster decline in GFR. CONCLUSION: It appears that clinical course is different in NIDDM patients with microalbuminuria, according to the presence or absence of diabetic retinopathy. Microalbuminuria in the presence of retinopathy predicts aggravation of albuminuria and decline in GFR. In contrast, the renal function in microalbuminuric NIDDM patients in the absence of retinopathy may remain stable for years.
|