[A cross-sectional survey on current status of type 2 diabetes mellitus with overweight or obesity in Guangdong province].

OBJECTIVE: To explore the glycemic control status and related risk factors of overweight or obesity patients with type 2 diabetes mellitus (T2DM) in Guangdong province. METHODS: The medical records of overweight or obesity patients with T2DM from 60 tertiary and secondary hospitals in Guangdong Province were collected by questionnaire and physical examination. And the clinical data were analyzed to explore the influencing factors of glycemic control. The HbA1c level was used to assess glycemic control. HbA1c < 7.0% indicated that glycemic control was up to standard. RESULTS: From August 2011 to March 2012, 5241 T2DM patients were recruited. The scope of current analysis was restricted to 4768 subjects with true data and deficiency no more than 5%. There were 2252 males and 2516 females. The age range was from 16 to 90 years, a median age 59.0 (50.0 - 69.0) years, onset age of diabetes 52.0 (44.0 - 60.0) years; a range of disease duration from 1 day to 42 years and a median of 5.0 (2.0 - 11.0) years. The median body mass index was 26.33(24.88 - 28.34) kg/m(2) and median waist circumference 93.0 (88.0 - 100.0) cm. Median HbA1c was 8.1% (6.9% - 10.1%) and only 26.2% patients reached the target level of HbA1c < 7.0%. Influencing factors of poor glycemic control were central obesity, high levels of resting heart rate, concurrent fatty liver and high intensity of treatment. And influencing factors of good glycemic control were regular exercises, smoking cessation, regular glycemic monitoring and good control of total cholesterol/triglyceride. CONCLUSION: A majority of Guangdong type 2 diabetics fail to achieve target values for glycemic control. There is an urgent need for comprehensive management for improving glycemic control.

[Transcription and promoter hypermethylation of thyroid stimulating hormone receptor gene in human papillary thyroid carcinoma].

OBJECTIVE: To study the mRNA expression of the tumor suppressor gene thyroid stimulating hormone receptor (TSHR) gene in papillary thyroid carcinoma (PTC) and the correlation between aberrant promoter methylation of TSHR gene and the tumorigenesis of PTC. METHODS: RT-PCR was used to detect the mRNA expression of TSHR gene in 50 PTC cases, 20 cases of nodular goiter and 12 cases of thyroid adenoma tissue. The status of TSHR gene promoter methylation was determined using methylation-specific PCR technique. RESULTS: Of the 50 PTC patients, 34 (68%) were found to have hypermethylation of TSHR gene promoter region, as compared to 7 out of the 32 control patients (21.9%) positive for TSHR gene promoter hypermethylation, suggesting a significantly higher rate of TSHR promoter methylation of in PTC patients than in the control patients (chi(2) = 16.61, P<0.05). Of the 34 PTC patients with TSHR promoter methylation, 14 (41.2%) showed the absence of TSHR mRNA expression; in the 16 PTC patients without TSHR promoter methylation, only 2 (12.5%) were negative for TSHR mRNA expression, showing a significant difference in the rate of negative TSHR mRNA expression with regard to TSHR promoter methylation. The PTC patients had a significantly lower TSHR mRNA expression than the control patients (chi(2) = 4.02, P<0.05). CONCLUSION: Methylation of TSHR gene in the promoter region is a common molecular event, which might be associated with the tumorigenesis and progression of human PTC.

[Protective effect of losartan on insulin secretion function of RIN-m cells against angiotensin II-induced injury and the mechanism].

OBJECTIVE: To investigate the protective effect of losartan against angiotensin II (AngII)-induced beta cell (RIN-m) impairment and explore its mechanism. METHODS: In vitro cultured RIN-m cells were divided into control group, 100 nmol/L AngII group and losartan pretreatment group. After cell incubation with the corresponding agents for 24 h, the amount of basal (3.3 mmol/L) and glucose-stimulated (16.7 mmol/L) insulin secretion (GSIS) was detected by radioimmunoassay, and the cellular reactive oxygen species (ROS) was assayed by flow cytometry with DCFH-DA staining; the mRNA and protein expressions of uncoupling protein 2 (UCP2) were determined by RT-PCR and Western blotting, respectively. RESULTS: The basal insulin secretion showed no significant differences between the 3 groups (P>0.05). The GSIS in 100 nmol/L AngII group was significantly lower than that of the control group (P<0.001), but losartan pretreatment markedly restored the insulin secretion function to a level comparable to that of the control group (P<0.05). Compared with the control group, 100 nmol/L AngII significantly increased the cellular ROS level and the mRNA and protein expressions of UCP2 (P<0.05), and these changes were eliminated by losartan pretreatment. CONCLUSIONS: Losartan pretreatment offers protective effect against AngII-induced impairment of the GSIS of beta cells possibly by antagonizing the effects of AngII that causes increased ROS level and UCP2 expressions in beta-cells.

[Effects of small interfering RNA targeting connective tissue growth factor on high glucose-induced human tubular epithelial hypertrophy].

OBJECTIVE: To observe the effect of transfection with small interfering RNA (siRNA) targeting connective tissue growth factor (CTGF) on human tubular epithelial hypertrophy induced by high glucose. METHODS: HK-2 cells were cultured in DMEM/F12 medium containing 1 g/L glucose (normal control group), 4.5 g/L glucose (high glucose group), or 1 g/L glucose+3.5 g/L mannitol (iso-osmolar control group). The cells were transfected with pGenesil-1, pGenesil/neg, or pGenesil/siRNA-CTGF and then cultured in DMEM/F12 medium containing 4.5 g/L glucose as the high glucose+blank control group, high glucose+negative control group and high glucose+interference group, respectively. After cell culture for 24, 48 and 96 h, the cells were collected to detect the mRNA and protein levels of CTGF by real-time PCR and Western blotting, respectively. The proliferative activities of the cells were evaluated with MTT assay, and the total cellular protein contents were determined with Bradford method. Flow cytometry was employed to analyzed the cell cycle changes. RESULTS: High-glucose significantly up-regulated the CTGF mRNA and protein levels in HK-2 cells. The cell proliferation was inhibited after high-glucose exposure with increased cell percentage in G1 phase and total cellular protein content suggesting cellular hypertrophy. Transfection with siRNA targeting CTGF significantly inhibited high glucose-induced up-regulation of CTGF mRNA and protein and promoted the cell proliferation, resulting also increased cells in S phase and lowered total cellular protein contents. CONCLUSION: CTGF is an important mediator of high glucose-induced tubular epithelial hypertrophy, and transfection with siRNA targeting CTGF can alleviate the hypertrophy, suggesting the potential value of CTGF-targeted treatment in the management of diabetic nephropathy.

[Effect of high glucose exposure on connective tissue growth factor expression in cultured human renal tubular epithelial cells and the role of p38MAPK pathway].

OBJECTIVE: To observe the effect of high glucose exposure on connective tissue growth factor (CTGF) expression in cultured human renal tubular epithelial cells and investigate the role of p38MAPK pathway in this process. METHODS: Human renal tubular epithelial cells (HKC) with and without SB203580 pretreatment were cultured in the presence of high glucose levels for 24, 48, 72, 96 h and 20 days. RT-PCR, immunohistochemical staining, indirect fluorescence staining and Western blotting were used to detect the changes in CTGF mRNA and protein expressions in the cells after the treatment. RESULTS: Low levels of CTGF mRNA and protein were detected in cultured HKC cells, and after high glucose treatment, the mRNA expression increased gradually and reached the peak level at 48 h, then followed by gradual decrease till recovering the baseline level at 96 h. Prolonged high glucose treatment for 20 days resulted in persisted high CTGF mRNA expression twice the level in the control group. The expression level of CTGF protein also increased progressively as the treatment time then prolonged, and long-term (20 days) treatment increased the expression by 4 folds in comparison with the expression in the control cells. SB203580 significantly inhibited the increase in the expressions of CTGF mRNA and protein stimulated by high glucose treatment. CONCLUSION: High glucose treatment can increase CTGF mRNA and protein expressions in cultured human renal tubular epithelial cells, suggesting that increased CTGF levels is a key event in the pathogenesis of renal tubulo-interstitial fibrosis in patients with diabetic nephropathy. p38MAPK pathway may also participate in this process.

Effect of estrogen and progesterone on the expression of 1, 25-dihydroxyvitamin D receptors mRNA in the liver of ovariectomized rats.

OBJECTIVE: To study the effect of estrogen and progesterone on the expression of dihydroxyvitamin D receptor (VDR) mRNA in the liver of ovariectomized rats. METHODS: Twenty-five adult female SD rats were randomly divided, with equal numbers, into sham-operated group (sham), ovariectomized group (OVX), ovariectomized group with estrogen treatment (OVX+E), ovariectomized group with progesterone treatment (OVX+P) and ovariectomized group with both estrogen and progesterone treatment (OVX+E+P). After 3 months and a half of feeding, all animals were killed to assess VDR mRNA by way of reverse transcriptase-PCR (RT-PCR). RESULTS: RT-PCR revealed marked increase in the band intensity corresponding to VDR mRNA product in Sham, OVX+E, and OVX+E+P groups. CONCLUSION: Estrogen may increase the transcription level of VDR gene in the liver of ovariectomized rats.