Comparison of endothelial differentiation capacity of adipose-derived stem cells and bone marrow mesenchymal stem cells from rats / 南方医科大学学报

<p><b>OBJECTIVE</b>To compared the differentiation capacity of rat adipose-derived stem cells (ASCs) and bone marrow mesenchymal stem cells (BMSCs) into endothelial cells.</p><p><b>METHODS</b>Rat BMSCs and ASCs were isolated, cultured and identified for cell surface markers using flow cytometry. The cell growth curves were drawn by CCK-8 assay, and the cells in active growth were induced for endothelial differentiation following standard protocols. On day 21 of induction, the cells were examined for mRNA expressions of endothelial cell specific markers CD31, KDR, and vWF using qPCR. Immunostaining was performed to observe the expression of CD31 on the cells. The induced cells were also tested for Dil-labeled acetylated low-density lipoprotein (ac-LDL) uptake ability. The tube-forming ability of the induced cells was verified on Matrigel.</p><p><b>RESULTS</b>We successfully isolated rat ASCs and BMSCs. Morphologically, ASCs were similar with BMSCs, both having long spindle-shaped and fibroblast-like morphology. Flow cytometry showed that both BMSCs and ASCs had high expressions of mesenchymal markers CD29 and CD90 and a low expression of hematopoietic cell surface markers CD45. CCK-8 assay showed that ASCs proliferated more quickly than BMSCs. The cells with induced endothelial differentiation exhibited increased levels of CD31, KDR, and vWF mRNA expressions and immunofluorescent staining identified CD31 antigen expression on the cell membrane. Fluorescence microscopy revealed red fluorescence in the induced cells suggesting uptake of Dil-Ac-LDL by the cells. The induced cells were capable of forming tube on Matrigel, confirming their identity of endothelial cells.</p><p><b>CONCLUSION</b>Both rat BMSCs and ASCs can be induced to differentiate into endothelial cells, but ASCs differentiate more quickly into endothelial cells and possess a stronger proliferation ability, suggesting its greater potential than BMSCs in future applications.</p>

Cellular memory of high glucose exposure in normoglycemia is probably mediated by reactive oxygen species in INS-1 cells / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the cellular memory of previous high glucose exposure in rat islet cell line (INS-1) and explore the possible mechanism.</p><p><b>METHODS</b>INS-1 cells were exposed to a high glucose (33.3 mmol/L) culture for 48 h followed by further culture in the presence of 11.1 mmol/L glucose in the culture medium for 3 or 5 days. The levels of bax and caspase-3 mRNA were measured by real-time PCR, the production of reactive oxygen species (ROS) was assayed using the dihydroethidium probe, and the cell viability was detected by MTT assay.</p><p><b>RESULTS</b>High glucose exposure of the cells for 48 h resulted in significantly increased ROS production and bax and caspase-3 mRNA expressions and lowered cell viability (P<0.001). In cells cultured in 11.1 mmol/L glucose following previous high glucose exposure, the ROS production and bax and caspase-3 mRNA expressions still maintained the high levels (P<0.05) while the cell viability remained significantly lower than the control cells (P<0.001).</p><p><b>CONCLUSION</b>High glucose causes persistent changes in cell viability and apoptosis-related gene expressions even after recovery of normoglycemia, the mechanism of which is probably related to increased ROS production.</p>

Adiponectin decreases insulin receptor substrate-1 phosphorylation in the liver of OLETF rats possibly through nuclear factor-κB signaling pathway / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the effect of adiponectin (APN) on the insulin pathway in the liver of OLETF rats and explore its molecular mechanism.</p><p><b>METHODS</b>Twenty male OLETF rats and 10 male LETO rats were sacrificed at 8 and 32 weeks of age to examine the fasting blood glucose, serum insulin, adiponectin and blood lipid profiles. The APN, phosphotyrosine of insulin receptor substrate-1 (IRS-1), IKKβ and nuclear-κB (NF-κB) in the liver tissue were determined using ELISA, Western blotting or immunohistochemistry.</p><p><b>RESULTS</b>The plasma adiponectin level in OLETF rats was significantly lower than that of LETO rats since 8 weeks of age (P<0.01). At 32 weeks of age, the blood lipid levels of OLETF rats increased significantly (P<0.05) with inverse correlations to plasma adiponectin (P<0.01). The liver APN, py-IRS-1, IKKβ and NF-κB levels in OLETF rats differed significantly from those of LETO rats at both 8 and 32 weeks. At 32 weeks of age, the APN level of both rats were correlated to the levels of NF-κB and py-IRS-1 (P<0.01).</p><p><b>CONCLUSION</b>APN may decrease tyrosine phosphorylation of IRS-1 via the IKK/NFκB pathway and inhibit insulin signaling pathway in the liver, which contributes to hyperlipidemia, hyperglycemia and development of type 2 diabetes.</p>

Hypoadiponectinemia leads to insulin resistance in OLETF rats: a preliminary study / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the association between plasma adiponectin and insulin resistance in OLETF rats.</p><p><b>METHODS</b>Twenty male Otsuka Long-Evans Tokushima Fatty (OLETF) rats and 10 male Long-evans Tokushima Otsuka (LETO) rats underwent oral glucose tolerance test (OGTT) at 13 and 40 weeks of age. At 8, 32 and 40 weeks of age, the rats were sacrificed to measure the blood glucose, plasma insulin and adiponectin levels, and serum levels of TG, CHOL and FFA.</p><p><b>RESULTS</b>The plasma adiponectin level was significantly decreased in 8-week-old OLETF rats compared with that of LETO rats (P<0.05). The plasma insulin level, TG, CHOL, and FFA were significantly higher in OLETF rats than in LETO rats at 32 and 40 weeks of age.</p><p><b>CONCLUSION</b>A decreased plasma level of adiponectin preludes insulin resistance and is inversely correlated to insulin sensitivity. Hypoadiponectinemia may be an important reason leading to insulin resistance.</p>

Relationship between visceral fat depot and adiponectin mRNA level in the adipose tissue of OLETF rats / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the relationship between visceral fat depot and adiponectin level in OLETF rats.</p><p><b>METHODS</b>Twenty male OLETF rats and 10 male Long-Evans Tokushima Otsuka (LETO) rats were subjected to regular oral glucose tolerance test (OGTT). The rats were sacrificed at the ages of 8, 32 and 40 weeks for measurements of the body weight, blood glucose, blood lipid level, blood insulin, and weight of the visceral fat.</p><p><b>RESULTS</b>Compared with LETO rats, OLETF rats had significantly higher body weight and visceral fat with impaired glucose tolerance (P<0.05). OLETF rats also had higher blood insulin, TG, FFA and CHOL levels (P<0.05). The plasma adiponectin level was significantly lower in OLETF rats than in LETO rats at different ages (P<0.05). The adiponectin mRNA level in the adipose tissue of OLETF rats was comparable with that in LETO rats, but significantly decreased at 32 and 40 weeks of age (P<0.01).</p><p><b>CONCLUSION</b>Plasma adiponectin level is significantly correlated to insulin sensitivity and visceral fat depots in OLETF rats, but a lowered APN mRNA expression level is not the main reason for a decreased plasma adiponectin level in the early stage.</p>

Epidemiological investigation of diabetes and prediabetes in community residents in the suburbs of Guangzhou / 南方医科大学学报

<p><b>OBJECTIVE</b>To identify the prevalence and risk factors of diabetes and prediabetes in the community residents above 18 years old in the suburbs of Guangzhou.</p><p><b>METHODS</b>Between April and May in 2008, the residents above 18 years living in 6 communities of Guangzhou for 5 or more years were sampled with multistage clustering sampling. The sampled residents were surveyed by questionnaires, and physical examination and glucose determination were carried out.</p><p><b>RESULTS</b>A total of 1532 residents were sampled. The incidence of diabetes mellitus in these community residents was 8.46%, and that of impaired glucose regulation was 6.59%. Age, body mass index, family history of diabetes mellitus, case history of hypertension, hyperlipidemia, hypertension and smoking were all the independent risk factors for impaired glucose regulation and diabetes mellitus.</p><p><b>CONCLUSION</b>Diabetes and prediabetes are prevalent in the community residents in Guangzhou. Controlling the risk factors such as obesity, hypertension, lipid metabolism disorder among the residents above 40 years with a family history of diabetes mellitus and hypertension is key to prevention of impaired glucose regulation and diabetes mellitus.</p>

Relationship between expressions of serum amyloid A and insulin resistance in 3T3-L1 adipocytes / 南方医科大学学报

<p><b>OBJECTIVE</b>To study the relationship between the expression of serum amyloid A (SAA) and insulin resistance in 3T3-L1 adipocytes.</p><p><b>METHODS</b>3T3-L1 adipocytes were incubated with different concentrations of dexamethasone (10, 100, and 1000 nmol/L) for 48 h to establish cell models of insulin resistance at different resistant levels (models 1, 2, and 3, respectively). The degree of insulin resistance of 3T3-L1 adipocytes was assayed by 2-deoxy-[(3)H]-D-glucose uptake. Semi- quantitative RT-PCR was performed for quantification of SAA mRNA expression. SAA concentrations in the culture medium were determined by ELISA.</p><p><b>RESULT</b>Dexamethasone did not affect the basal glucose transport (P>0.05). Insulin-stimulated glucose uptake was significantly decreased by 15% (P<0.05), 40% (P<0.01), and 55% (P<0.01) in models 1, 2, and 3 in comparison with the untreated group, respectively; the expressions of SAA mRNA were upregulated by 2.5 (P<0.01), 3.33 (P<0.01), and 4.08 folds (P<0.01) and SAA concentrations increased by 2.05, 3.13, and 4.23 folds, respectively. The expressions of SAA mRNA were positively correlated to the degree of insulin resistance (r=0.773, P<0.01) and SAA concentration (r=0.832, P<0.01).</p><p><b>CONCLUSION</b>A cell model of insulin resistance has been established in 3T3-L1 adipocytes by dexamethasone exposure. SAA is closely associated with insulin resistance and may serve as a marker of insulin resistance.</p>

Association of serum interleukin-6 and high-sensitivity C-reactive protein levels with insulin resistance in gestational diabetes mellitus / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the association of serum concentration of interleukin-6 (IL-6) and high-sensitivity C-reactive protein (hs-CRP) with insulin resistance in women with gestational diabetes mellitus (GDM).</p><p><b>METHODS</b>Forty normal pregnant women (NGT group) and 23 women with GDM (GDM group) were enrolled in this study with another 25 women of child-bearing age as the control group. Radio immunoassay (RIA) was used to measure the fasting serum IL-6 levels, and immunoturbidimetry performed to evaluate serum hs-CRP levels. The homeostasis model assessment-insulin resistance (HOMA-IR) and the homeostasis model assessment-B (HOMA-B) were calculated.</p><p><b>RESULTS</b>Compared with NGT group and control group, GDM group had significantly elevated serum IL-6 and hs-CRP (P<0.01), but the levels were comparable between the former two groups (P>0.05). HOMA-IR was the highest in GDM group (P<0.001), and NGT group had significantly higher HOMA-IR than the control group (P<0.05), whereas the reverse was true for HOMA-B (P<0.01). Pearson correlation analysis showed that fasting blood glucose (FBG), fasting insulin (FINS), IL-6 and hs-CRP had significant association with HOMA-IR (P<0.01). Multiple regression analysis identified FINS, FBG, IL-6, and hs-CRP as the factors significantly affecting HOMA-IR (regression coefficient of 0.563, 0.992, 0.325, and 0.231, respectively, P<0.01).</p><p><b>CONCLUSIONS</b>Serum levels of IL-6 and hs-CRP are elevated in women with GDM, which are the most significant factors affecting HOMA-IR. IL-6 and CRP may aggravate insulin resistance through various mechanisms and participate in the pathogenesis of GDM.</p>

Liuweidihuang pills reduces visceral fat deposition in Otsuka Long-Evans Tokushima Fatty rats / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the effects of Liuweidihuang pills (LP) on visceral fat deposition in Otsuka Long-Evans Tokushima Fatty (OLETF) rats.</p><p><b>METHODS</b>Forty male OLETF rats were randomly divided into LP group and control group (n=20 per group), and 10 male Long-evans Tokushima Otsuka (LETO) rats were used as normal controls. The rats in LP group were given LP(2.4 mg/kg) daily by intragastric administration since the age of 8 weeks, and those in the other two groups were given water of the same volume by intragastric administration. Blood glucose of all the rats was determined by oral glucose tolerance test (OGTT) and visceral fat deposition examined after the rats were sacrificed.</p><p><b>RESULTS</b>OLETF rats had obviously greater amount of visceral fat than LETO rats (P<0.05) and administration of LP ameliorated the increment of visceral fat deposition in this type 2 diabetic model, producing significant effect at the age of 40 weeks (P<0.01).</p><p><b>CONCLUSION</b>LP may effectively decrease visceral fat deposition in OLETF rats.</p>

Advanced oxidation protein products in diabetic nephropathy patients and its relation with superoxide dismutase, glutathione peroxidase, neopterin / 中南大学学报(医学版)

OBJECTIVE@#To determine the changes of advanced oxidation protein products (AOPP) in diabetic nephropathy (DN) patients, as well as its relationship with superoxide dismutase (SOD), glutathione peroxidase (GPx) and neopterin (NPT).@*METHODS@#By the concentration of urinary albumin excretion rate (UAER) and creatinine (Cr), 85 diabetes mellitus (DM) patients were divided into 4 groups as non-DN group (DM), early-staged DN group (DN3), significant DN group (DN4) and end-staged DN group (DN5). The concentration of the serum AOPP was measured by ameliorated method introduced by Wikto-Sarsat, while SOD by Xanthine oxidase test, GPx by [5,5'Dithio-bis (2-Nitrobenzoic aicd) ] (DTNB) reaction test and NPT by ELISA.@*RESULTS@#AOPP in Group DN5 [(117.8 +/- 64.8) [micromol/L] and Group DN4 [ (80.0 +/- 23.0) micromol/L] were significantly higher than those in Group DM [(58.2 +/- 17.7) micromol/L]. There was no significant difference of AOPP between Group DN3 [(72.7 +/-17.2) micromol/L] and Group DM. Serum AOPP negatively correlated with SOD and GPx (r = -0.217 and -0.374 respectively, P < 0.05), while positively correlated with NPT (r = 0.499, P < 0.01).@*CONCLUSION@#DN patient has enhanced protein oxidation than DM patient, which is related to oxidative stress and chronic inflammation in DN.