Ligliptin for treatment of type 2 diabetes mellitus with early renal injury: Efficacy and impact on endogenous hydrogen sulfide and endothelial function.

BACKGROUND: Diabetes is a clinically common chronic disease, and its incidence has been increasing in recent years. Diabetes is believed to accelerate the process of atherosclerosis in patients, and abnormal endothelial function is an important factor leading to diabetic kidney damage. AIM: To investigate the efficacy of ligliptin in the treatment of type 2 diabetes mellitus (T2DM) with early renal injury and its effect on serum endogenous hydrogen sulfide (H2S), endothelial cell particles, and endothelial function. METHODS: From January 2018 to April 2019, 110 patients with T2DM and early kidney injury treated at our hospital were divided into an observation group (receiving ligliptin treatment, n = 54) and a control group (receiving gliquidone therapy, n = 56). Blood glucose and renal function before and after treatment were compared between the two groups. RESULTS: The differences in fasting blood glucose, 2 h blood glucose, and glycated hemoglobin were not statistically significant between the two groups after treatment. The urinary albumin excretion rate after treatment in the ligliptin group was 70.32 ± 11.21 µg/min, which was significantly lower than that of the gliquidone group (P = 0.000). Serum endogenous H2S and endothelial cell microparticles of the ligliptin treatment group were 40.04 ± 8.82 mol/L and 133.40 ± 34.39, respectively, which were significantly lower than those of the gliquidone treatment group (P = 0.000 for both); endothelin-dependent diastolic function and nitric oxide after treatment in the ligliptin group were 7.98% ± 1.22% and 190.78 ± 30.32 mol/L, significantly higher than those of the gliquidone treatment group (P = 0.000 for both). CONCLUSION: Ligliptin treatment of T2DM with early renal injury has the same glucose-lowering effect as gliquidone treatment. Ligliptin treatment has a better effect and it can significantly improve the renal function and vascular endothelial function of patients, and reduce serum endogenous H2S and endothelial cell particle levels.

Risk factors for elevated serum colorectal cancer markers in patients with type 2 diabetes mellitus.

The study aims to examine the risk factors for increased colorectal cancer (CRC) markers in patients with type 2 diabetes mellitus (T2DM). The 229 patients retrospectively reviewed were categorized into two groups: CRC tumor marker-positive and -negative groups. Patients who tested positive for all three of the following CRC markers were included in the CRC tumor marker-positive group: serum carcinoembryonic antigen, carbohydrate antigen 19-9 and septin9 methylation. Univariate analysis revealed that most CRC marker-positive patients had higher age, a family history of CRC, history of smoking and alcohol intake, high body mass index (BMI; overweight), longer history of T2DM, worse diabetes control (with high glycated hemoglobin A1c [HbA1c]), lower level of serum vitamin D (VD), high-density lipoprotein cholesterol and higher level of total cholesterol and triglyceride (TG). Logistic regression analysis showed that BMI, VD, HbA1c and TG were independent predictors of CRC marker-positive status (OR, 95% confidence intervals and P values were 1.912 [1.346-2.716], <0.001; 0.773 [0.633-0.943], 0.011; 9.082 [3.52-23.433], <0.001; and 11.597 [3.267-41.164], <0.001, respectively). In this retrospective study, high BMI, HbA1c and TG as well as low level of VD were correlated with CRC tumor marker-positive status in T2DM patients. Patients with these risk factors may benefit from more frequent screening for CRC tumor markers.

Individual and joint association of bioavailable testosterone and aging with neutrophil-to-lymphocyte ratio in Chinese middle-aged and elderly men.

BACKGROUND AND OBJECTIVES: Accumulating evidences suggest that chronic systemic inflammation (CSI) is independently associated with large number of major non-communicable chronic diseases (NCDs) ranging from metabolic disorders to cancers, and neutrophil-to-lymphocyte ratio (NLR) has been accepted as a novel, convenient marker for CSI response. Testosterone deficiency in men is linked to high risk of NCDs. This cross-sectional study aimed to investigate the individual and joint association of bioavailable testosterone (BIOT) and aging with NLR. METHODS: A total of 132 male adults were enrolled during Jan. 2011 and Oct. 2017 in the first affiliated hospital of University of Science and Technology of China. Local weighted regression (LOESS) and multivariable generalized linear regression models were utilized to comprehensively examine the individual and joint association between BIOT and age with NLR. RESULTS: Obvious linear relationships between NLR and BIOT or age were observed with the LOESS models. NLR was negatively correlated to BIOT after adjusting for some potential confounding factors (P = 0.034). As compared to the lowest quartile of BIOT, the adjusted decrease of NLR for the 2nd, 3rd and 4th quartiles were 0.40, 0.64 and 0.72, respectively. Meanwhile, NLR was observed to be independently correlated to elevated age (P = 0.043). Furthermore, as compared to the counterparts, men over 70 years combined with plasma BIOT less than 4.7 nmol/L had the highest NLR level, which suggested that low BIOT and aging jointly correlated to the level of NLR (P = 0.005). CONCLUSION: BIOT deficiency and aging were individually and jointly correlated to CSI. Men over 70 years combined with BIOT < 4.7 nmol/L were more like to have higher grade of CSI than others.

Associations between Vitamin D and ß-Cell Function and Colorectal Cancer-Associated Tumor Markers in Chinese Type 2 Diabetic Patients with Albuminuria.

BACKGROUND: This study is to investigate the protective effects of vitamin D in T2DM, as well as the associations between serum calcifediol level and ß-cell function, and risk of CRC, in Chinese type 2 diabetes mellitus (T2DM) patients with albuminuria. METHODS: Serum calcifediol levels were analyzed and compared among healthy individuals and T2DM patients stratified by albumin/creatinine ratio (ACR). Relative correlation analyses were performed with ß-cell function (BCF) and risk of CRC. RESULTS: Patients' ACR was positively associated with fasting plasma glucose and insulin, homeostasis model assessment (HOMA) of insulin resistance (IR), alpha-fetoprotein (AFP), carcinoembryonic antigen (CEA), carbohydrate antigen (CA)199, CA125, and Septin9 methylation, but inversely associated with HOMA-BCF and insulin secretion. Serum calcifediol level in the healthy controls was significantly higher than T2DM patients. In T2DM patients, calcifediol level was inversely associated with ACR, HOMA-IR, AFP, CEA, and Septin9 methylation, but positively associated with HOMA-BCF and insulin secretion. Multivariate stepwise principal component regression analysis indicated that calcifediol, hemoglobin A1c, and serum creatinine were independent risk factors for elevated CEA in T2DM. CONCLUSIONS: Higher serum calcifediol level is correlated with better ß-cell function, lower insulin resistance, and decreased risk of CRC. Vitamin D may have suppressive effects on T2DM-associated complications and therefore represents a potential prophylactic treatment against ß-cell dysfunction and cancer development in T2DM patients with albuminuria.

Cyclic Cushing's syndrome caused by neuroendocrine tumor: a case report.

Cushing's syndrome (CS) is a clinical syndrome characterized by hypercortisolemia. Cyclic Cushing's syndrome (CCS), which exhibits a periodic or irregular increasing pattern in cortisol, is a rare type of Cushing's syndrome. A 37-year-old man came to our hospital because of repeated dizzy spells, weakness and hypercortisolemia lasting two weeks. Endocrinological examinations indicated CCS with periodic and intermittent increases in cortisol. Enhanced computed tomography (CT) revealed space occupying lesions on the upper lobe of left lung, and biopsy eventually proved that these were pulmonary carcinoid tumors with ectopic ACTH secretion, which was subsequently manifested a Cushing's syndrome. PET-CT, ultrasound and biopsy of the thyroid gland indicated bilateral thyroid papillary carcinoma. CT scan showed bilateral nodular hyperplasia of the adrenal gland. Enhanced magnetic resonance imaging (MRI) confirmed that the high signal disappeared on the posterior lobe of the pituitary gland and that the pituitary stalk shifted left, which was suspected to be non-functional pituitary microadenoma. The patient underwent surgery involving resection of the left upper pulmonary lobe and the mediastinal lymph node around the hilus pulmonis, which resulted in complete remission of CCS. The patient then chose elective surgery for the thyroid papillary carcinoma. An analysis of the patient's genomic DNA identified a novel mutation in PDE11A: c.2032 (exon 12) G > A, which is associated with primary pigmented nodular adrenocortical disease (PPNAD). This is a novel mutation which has been no previous public clinical report on this mutation as it relates to this disease.

Hydroxysafflor yellow A attenuates high glucose-induced pancreatic ß-cells oxidative damage via inhibiting JNK/c-jun signaling pathway.

Pancreatic ß-cells apoptosis and dysfunction induced by glucose toxicity were attributed to the formation of excess oxidative damage. Some studies have found that hydroxysafflor yellow A has strong effects to scavenge oxidative stress and inhibit apoptosis. In order to explore the influence of HSYA on oxidative stress induced by high glucose and the potential mechanisms, we set up a high glucose damage model and induced oxidative stress in INS-1 rat insulinoma cells. N-acetylcysteine was added as a group of oxidative stress scavenger. After 72 h of cultivation, the related indexes of oxidative stress (reactive oxygen species, catalase, glutathione peroxidase, lipid peroxidation, and superoxide dismutase), apoptosis (caspase3, parp) and the function of glucose stimulated insulin secretion were determined. In addition, the signaling pathway proteins of C-Jun NH2 -terminal kinases (JNK), phosphorylated JNK, C-jun, phosphorylated C-jun were evaluated. Fluorescence microscopy, qRT-PCR, western blotting were the main methods used in the experiment. Our results showed that hydroxysafflor yellow A reduced pancreatic ß-cells apoptosis by attenuating oxidative damage, and JNK/c-Jun signaling pathway was involved. It indicated a significant mechanism for the positive impacts of HSYA on oxidative stress induced by high glucose, and provide important basis for using HSYA in diabetic prevention and therapy.

The role of Keap1-Nrf2-ARE signal pathway in diabetic retinopathy oxidative stress and related mechanisms.

OBJECTIVE: Diabetic retinopathy (DR) is one severe complication of diabetes, and involves reactive oxygen species (ROS) produced under oxidative stress (OS) conditions. Keap1-Nrf2-ARE is one important endogenous anti-OS signal pathway. This study generated a type 2 DR rat model, on which expression of Nrf2/ARE pathway related proteins were measured to investigate functional role and mechanism of Keap1-Nrf2-ARE signal pathway in DR. PATIENTS AND METHODS: Using DR model rats, blood samples were collected for measuring FBG, TC, TG, HDL-C, and LDL-C for evaluating blood glucose and lipid. Retinas were collected for measuring ROS content using DCFH-DA staining, and caspase-3 activity was measured by colorimetry. Cell apoptosis was measured by flow cytometry. Keap1 and Nrf2 proteins were quantified by Western blot. Aqueous humor was collected for measuring MDA, SOD, GSH-Px, and T-AOC. RESULTS: Model rats had significantly elevated blood FBG, TG, TC, and LDL-C, plus decreased HDL-C. Model rats also had higher retinal ROS content, enhanced caspase-3 activity, and potentiated apoptosis. Compared to the control group, model rats had elevated MDA and lower activity of SOD, GSH-Px, and T-AOC in aqueous humor, plus lower Keap1 and higher Nrf2 expression in retina. CONCLUSION: DR rats showed significantly elevated retinal apoptosis, with prominent OS. Under diabetic conditions, activation of Keap1-Nrf2-ARE pathway may play a role in alleviating OS damage and protecting retina.

A 3-year follow-up study of ß-cell function in patients with early-onset type 2 diabetes.

Insulin resistance and reduced ß-cell glucose sensitivity are present in patients with type 2 diabetes. In the present study, we investigated the changes in ß-cell function in patients with type 2 diabetes during a 3-year follow-up study. A total of 48 patients with early-onset type 2 diabetes (EOD) and 55 patients with late-onset type 2 diabetes (LOD) were enrolled. Weight, height, waist circumference, hip circumference, blood pressure and plasma levels of lipids, glucose, fasting serum C-peptide (CPR0) and serum C-peptide 6 min after glucagon stimulation (CPR6) were measured. In addition, islet ß-cell secretory activity was detected. Subjects with EOD had lower Systolic blood pressure (SBP), diastolic blood pressure (DBP), body mass index (BMI), fasting CPR0, CPR6 and greater glycated hemoglobin A1c (HbA1c), triglyceride (TG) compared with subjects with LOD. CPR0, CPR6 and TG were decreased in both EOD and LOD groups 3 years later. The ratio of ß-cell function failure was 29.17 and 10.91% in the EOD and LOD groups, respectively, and there was significant difference between the two groups. A positive correlation was identified between the CPR0 and waist-hip ratio, HbA1c in the EOD group. A similar positive correlation was observed between CPR0 and BMI in the LOD group. Collectively, islet ß-cell function has declined in patients with EOD, and this change may be more evident when compared with those with LOD.

Epidemiological characteristics of thyroid nodules and risk factors for malignant nodules: a retrospective study from 6,304 surgical cases.

BACKGROUND: The prevalence of thyroid nodules (TN) is increasing rapidly. This study analyzed the epidemiological and clinical characteristics of TN in surgically treated patients and identified the risk factors for malignant nodules (MN) to provide more understanding of the differential diagnosis of TN. METHODS: A total of 6 304 TN cases who underwent thyroid surgery were included in this retrospective study. The clinical data were collected to evaluate the clinical and epidemiological characteristics and related risk factors for MN. The nature of TN (benign nodules (BN) or MN), medical records, laboratory data, and imaging data were analyzed. The risk factors for MN were screened using Spearman's rank correlation analysis and nonconditional binary Logistic regression analysis. RESULTS: The number of surgically treated TN cases increased yearly. A total of 34.33% of cases were MN and 65.67% were BN. Up to 56.74% of these cases underwent unnecessary surgery. Among the MN cases, papillary thyroid carcinoma accounted for 94%, in which 46.71% coexisted with benign thyroid disease and 32.28% with multiple foci. Single-related factor analysis showed that age, employment, disease duration, history of breast nodules and/or hypertension, the levels of serum thyroid-stimulating hormone (TSH), thyroglobulin antibody (TgAb), and thyroid peroxidase antibody (TPoAb), and ultrasound features of TN were related to MN. Stepwise nonconditional binary Logistic regression analysis showed that 13 factors may be the independent risk factors for MN, including <40 years old, previous history of breast nodules and/or hypertension, disease duration <1 month, employment, hypoechoic nodule, irregular nodules, nodule calcification, solid echo nodule, fuzzy boundary, rich blood flow within nodules, abnormal lymph nodes around the neck, nodule diameter <1 cm, and abnormally high TgAb. CONCLUSIONS: Our results demonstrate a rapid increase in surgically treated TN cases and ratio of MN and indicate unnecessary surgeries in some cases. This study also suggest that age, duration of thyroid disease, history of breast disease and/or hypertension, the levels of serum TSH, TgAb, and TPoAb, and ultrasound features of TN are related to MN, and some of these factors may be the risk factors for MN.

Basal insulin therapy strategy is superior to premixed insulin therapy in the perioperative period blood glucose management.

BACKGROUND: The probability and risk of operations increase in patients with type 2 diabetes mellitus. For diabetic patients, blood glucose control is a key factor to improving the prognosis of surgery. During perioperative period, insulin therapy is usually advised to be used for surgical patients with type 2 diabetes. However, the insulin regimen which one is better remains controversial. In this study, we estimated the efficacy, safety and advantage of different insulin therapy strategy during perioperative period. METHODS: A total of 1086 cases of surgical patients with type 2 diabetes mellitus enrolled in the present study. According to the glucose level at admission, all patients were divided into relatively high glucose group (group A, fasting blood glucose (FBG) ≤13.9 mmol/L) and higher glucose group (group B, FBG >13.9 mmol/L). Patients in group A randomly accepted premixed insulin twice a day, or basal insulin plus oral medications, and were divided into group A1 and A2 respectively. Patients in group B randomly received premixed insulin twice daily, basal insulin plus oral hypoglycemic agents, or basal insulin plus preprandial insulin, and were divided into group B1, B2 and B3 respectively. The data of the preoperative preparation time, the daily doses of insulin used in different periods, postoperative incision healed installments, hypoglycemic events, the total hospitalization time, postoperative complications were all collected and statistically analyzed. RESULTS: Compared the main outcome measures in groups treated by premixed insulin therapy, both in preoperative preparation and postoperative period, the daily insulin dosage and the frequency of hypoglycemic events were decreased in groups treated by basal insulin therapy (P < 0.05). The preoperative preparation time and the total hospitalization time in groups with basal insulin therapy were shorter than that in groups with premixed insulin therapy (P < 0.05). The incision healing rate of stage I, II and III among different therapy protocols were significantly different (P < 0.05). CONCLUSIONS: Basal insulin therapy could be used in diabetic patients undergoing elective major and medium surgery during whole perioperative period. Basal insulin therapy strategy, including a single injection of basal insulin and basal insulin plus preprandial insulin injection subcutaneously, is superior to premixed insulin therapy in the perioperative blood glucose management, and it could be viewed as the best choice in glucose control during perioperative period.

Effects of glucose and insulin on the H9c2 (2-1) cell proliferation may be mediated through regulating glucose transporter 4 expression.

BACKGROUND: The change of glucose transporter 4 (GLUT4) expression could influence glucose uptake in the myocardial cells and then effect myocardial metabolism, which maybe one of the factor for the diabetes cardiovascular disease. This study aimed to explore the influence of glucose and insulin at different concentrations on H9c2 (2-1) cell proliferation and its GLUT4 expression in vitro, and evaluate the correlation between myocardial cells proliferation and GLUT4 expression. This might be helpful for understanding the relationship between glucose metabolism and cardiovascular disease. METHODS: According to glucose concentrations in culture medium, cultured H9c2 rat myocardial cells were divided into five groups: control group (NC, glucose concentration 5.0 mmol/L), low glucose group (LG, glucose concentration 0.1 mmol/L), high glucose group 1 (HG1, glucose concentration 10 mmol/L), high glucose group 2 (HG2, glucose concentration 15 mmol/L), high glucose group 3 (HG3, glucose concentration 20 mmol/L). Then according to different insulin concentrations in culture medium, each group was further divided into two subgroups: normal insulin subgroup (INSc, insulin concentration 3.8 mU/L), high insulin subgroup (INSh, insulin concentration 7.6 mU/L). H9c2 (2-1) cells were cultured for 1, 2, 3 days, the proliferation of cells were assayed by cell counting Kit-8 assay, the expressions of GLUT4 mRNA and protein were detected with RT-PCR and Western Blotting technique, and the relation between myocardial cells proliferation and GLUT4 expression was evaluated. RESULTS: Compared with NC group, cell proliferation (OD value) was lower in LG, HG2, HG3 group but higher in HG1 group on the second and the third day (P < 0.05). There was a negative correlation between OD value and the glucose level in HG1, HG2, HG3 groups (P < 0.05). OD value in INSc subgroups was lower than that in INSh subgroups (P < 0.05). GLUT4 mRNA was lower in LG, HG2, HG3 groups than that in NC group (P < 0.05). Compared with NC group, GLUT4 mRNA level in HG1 group was higher on the first day but lower on the second and third day (P < 0.05). In HG1, HG2 and HG3 groups, GLUT4 mRNA level had a negative correlation with the level of glucose (P < 0.05). GLUT4 mRNA in INSc subgroups was lower than that in INSh subgroups (P < 0.05). The expression of GLUT4 protein was similar to that of GLUT4 mRNA. There was a positive correlation between H9c2 cell proliferation and GLUT4 expression (P < 0.02). CONCLUSIONS: Glucose levels could regulate glucose uptake in myocardial cells through influencing GLUT4 expression, and thus affected the cell proliferation and cell function. Insulin levels could affect the myocardial cell function by regulating GLUT4 expression. Effects of glucose and insulin on the myocardial cells proliferation might be mediated through regulating GLUT4 expression. There may be a mechanism of hyperglycemia pre-accommodation (HGPA) in myocardial cells mediated through regulation of GLUT4 expression.

Chemerin and apelin are positively correlated with inflammation in obese type 2 diabetic patients.

BACKGROUND: As two novel adipocytokines, chemerin and apelin play a key role in the pathological process of insulin resistance (IR), glucose metabolism and obesity, researchers have found that the levels of chemerin and apelin changed significantly in type 2 diabetic patients with obesity, however, the underlying mechanism involved remains unclear. The aim of this study was to investigate whether chemerin and apelin play an important role in the pathophysiologic proceeding of diabetes. METHODS: This study enrolled 81 newly diagnosed obese type 2 diabetes mellitus (T2DM) patients (T2DM group, n = 81). All the patients were randomly assigned to DM1 group treated with metformin (n = 41) and DM2 group treated with pioglitazone (n = 40). After hypoglycemic agents treatment, patients under better blood glucose control were chosen to be given antioxidant treatment. Another 79 subjects without T2DM were recruited as normal control group (NC group), including 40 subjects (NC1 group) with normal body mass index (BMI) and 39 obese subjects (NC2 group). Levels of chemerin, apelin, BMI, tumor necrosis factor-α (TNF-α), homeostasis model assessment of IR (HOMA-IR) and 8-isoprotaglandim F2α (8-iso-PGF2α) were examined at baseline and post-treatment. The relationship between chemerin, apelin and BMI, TNF-α, HOMA-IR, 8-iso-PGF2α was analyzed. RESULTS: The baseline levels of chemerin, apelin, TNF-α, HOMA-IR and 8-iso-PGF2α in T2DM group were significantly higher than normal control group (P < 0.001). All indices mentioned above were significantly decreased after treatment (P < 0.05). In T2DM patients treated with pioglitazone, indices mentioned above except for HOMA-IR, were decreased significantly compared with patients treated with metformin (P < 0.05). After antioxidant treatment using lipoic acid, levels of chemerin, apelin, TNF-α and 8-iso-PGF2α were further significantly decreased (P < 0.05). Correlation analysis showed that the levels of chemerin and apelin correlated positively with BMI, TNF-α, HOMA-IR and 8-iso-PGF2α before and after treatment with hypoglycemic agents (P < 0.01). The levels of chemerin and apelin also had positive correlation with TNF-α and 8-iso-PGF2α after antioxidant treatment (P < 0.05). CONCLUSIONS: The levels of chemerin and apelin in obese T2DM patients are closely related to IR. The increased levels may be a result of compensatory response to IR, and also may be the causative factor of IR. The levels of chemerin and apelin correlate closely with oxidative stress and inflammation. The two adipokines may be inflammatory factors playing important roles in the initiation and development of obese T2DM. Chemerin and apelin are related to the pathophysiology of IR, oxidative stress and inflammation.

[A genetic and clinical study in a family with familial hypercholesterolemia].

OBJECTIVE: To investigate the low density lipoprotein receptor (LDLR) gene and apolipoprotein (Apo) B gene mutation in a Chinese family with familial hypercholesterolemia (FH) and give the kindreds clinical check-ups. METHODS: After physical examination, the kindreds underwent ECG and ultrasound checks. Blood samples were tested for lipid profiles. The promoter and all eighteen exons of LDLR gene were investigated by using PCR and agarose gel electrophoresis in combination with DNA sequence analysis. The results were compared with the normal sequences in GenBank and FH database (www.ucl.ac.uk/fh) to find mutations. In addition, the apolipoprotein B100 gene for known mutations (R3500Q, R3531C, R3501W and R3480W) that cause familial defective ApoB100 (FDB) was also tested using the same method. RESULTS: A novel homozygous G > A mutation at the 1581 bp of exon 10 was detected in the proband and his siblings. It caused a substitution of amino acid Glu to Gly at codon 496. A novel heterozygous G > A mutation at the 1581 bp of exon 10 was detected in his parents. No mutations of R3500Q, R3531C, R3501W and R3480W of ApoB100 were observed. ECGs were normal. Atherosclerosis were found in all family members by ultrasound checks. CONCLUSIONS: The homozygous G > A mutation at the 1581 bp of exon 10 was first determined in our country. The change of amino acid Glu to Gly is responsible for FH of the family. The type of the gene mutation was not found in the FH database (www. ucl.ac.uk/fh). It's a new type of LDLR mutation.

Dynamic expression of glucose transporters 1 and 3 in the brain of diabetic rats with cerebral ischemia reperfusion.

BACKGROUND: Blood glucose control improves the outcome of diabetic patients with stroke, but the target range of blood glucose control remains controversial. The functional recruitment of ischemia penumbra is extremely important to the recovery after stroke. The present study aimed to explore the expression of brain-type glucose transporters (GLUT1 and GLUT3) in cerebral ischemic penumbra at different blood glucose levels and different ischemic-reperfusion time in diabetic hypoxia-ischemia rats. The results might provide an experimental basis for clinical treatment of diabetic patients with stroke. METHODS: The Wistar rats included in this study were randomly assigned to 4 groups (50 rats each): normal control group (NC), uncontrolled diabetic group (DM1), poorly-controlled diabetic group (DM2), and well-controlled diabetic group (DM3). Diabetic rats were induced by single intraperitoneal injection of streptozotocin, and the focal ischemic rat model of middle artery occlusion (MCAO) was made by insertion of fishing thread in 6 weeks after the establishment of the diabetic model. Each group was divided into 5 subgroups (10 rats each): four focal ischemic subgroups at different ischemic-reperfusion time (at 3,12, 24 and 72 hours after reperfusion, respectively) and one sham-operated subgroup. The mRNA and protein expression of GLUT1 and GLUT3 was assessed by RT-PCR and Western blotting, respectively. RESULTS: There was significant difference in the mRNA expression of GLUT1 and GLUT3 between the four focal ischemic subgroups and the sham-operated subgroup at different reperfusion time in each group. The mRNA expression of GLUT1 and GLUT3 in the 4 ischemic groups began to increase at 3 hours, peaked at 24 hours after reperfusion and maintained at a higher level even at 72 hours compared with that of the sham-operated subgroup. The mRNA expression of GLUT1 increased more significantly than that of GLUT3. The mRNA expression of GLUT1 and GLUT3 was significantly different between the diabetic groups and normal control group. The mRNA expression of GLUT1 and GLUT3 was increased more significantly in the diabetic groups than that in the normal control group. There was a significant difference in the mRNA expression in the groups with different blood glucose levels. The mRNA expression tended to decrease with increased blood glucose levels. The expression trend of GLUT1 and GLUT3 protein was similar to that of GLUT1 and GLUT3 mRNA. CONCLUSIONS: GLUT1 and GLUT3 expression was notably up-regulated in the penumbra region after cerebral ischemia in this study. But the up-regulated amplitude of GLUT1 and GLUT3 in the diabetic rats with cerebral ischemic injury became smaller than that of the normal controls. In the treatment of diabetic patients with cerebral embolism, blood glucose control should not be too strict, otherwise the up-regulation of GLUT1 and GLUT3 induced by cerebral ischemic injury might not be able to meet the needs of energy metabolism in cells.

Mesenchymal stem cell therapy for diabetes through paracrine mechanisms.

Type 1 diabetes is a chronic disorder characterized by the destruction of pancreatic islet beta-cells through autoimmune assault. Insulin replacement is the current main therapeutic approach. In recent years, several studies have showed that mesenchymal stem cells (MSCs) transplantation can improve the metabolic profiles of diabetic animal models. However the exact mechanisms of reversing hyperglycemia remain to be elusive. Trans-differentiation of MSCs into insulin-producing cells (IPCs) has ever been regarded as the main mechanism. But other reports have contradicted these findings and it is difficult to explain the timing and extent of improvement by only the effect through trans-differentiation. Researches have found that MSCs naturally produce a variety of cytokines and growth factors, promoting the survival of surrounding cells, called as paracrine mechanisms. Paracrine effects have been proved to play an important role in tissue regeneration and repair in recent researches. Therefore we speculate that MSCs transplantation into diabetic animals may prevent apoptosis of injured pancreatic beta cells and enhance regeneration of endogenous progenitor cells through paracrine actions such as angiogenic, cytoprotective, anti-inflammatory, mitogenic and anti-apoptotic effects. This hypothesis, if proved to be valid, may represent an important breakthrough in developing effective molecular or genetic therapeutics for diabetes.

[Clinical evaluation of efficacy and safety of nateglinide in the treatment of type 2 diabetes].

OBJECTIVE: To evaluate the efficacy and safety of nateglinide, a new antidiabetic agent, in the treatment of type 2 diabetes. METHODS: A total of 219 treatment-naïve patients with type 2 diabetes from 6 centers were enrolled in this study and blindly divided into nateglinide group (n = 105) and repaglinide group (n = 114). In all patients, the disease was confirmed for at least three months. The whole observation lasted for 12 weeks. The efficacy indicators measured include glycohemoglobin A1c (HbA1c), fasting blood glucose, and 2 hours postprandial blood glucose, and the safety parameters measured included renal and hepatic function, serum lipids, and blood and urea profiles. RESULTS: Similar decreases in fasting blood glucose, 2 hours postprandial blood glucose, and HbA1 c were found in both nateglinide group and repaglinide group without significant differences. No severe adverse events were noted. The hypoglycemia event reports were not significantly different between these two groups. CONCLUSION: Nateglinide is an effective and safe drug in treating type 2 diabetes.

Influence of blood glucose on the expression of glucose trans-porter proteins 1 and 3 in the brain of diabetic rats.

BACKGROUND: The delivery of glucose from the blood to the brain involves its passage across the endothelial cells of the blood-brain barrier (BBB), which is mediated by the facilitative glucose transporter protein 1 (GLUT(1)), and then across the neural cell membranes, which is mediated by GLUT(3). This study aimed to evaluate the dynamic influence of hyperglycemia on the expression of these GLUTs by measuring their expression in the brain at different blood glucose levels in a rat model of diabetes. This might help to determine the proper blood glucose threshold level in the treatment of diabetic apoplexy. METHODS: Diabetes mellitus was induced with streptozotocin (STZ) in 30 rats. The rats were randomly divided into 3 groups: diabetic group without blood glucose control (group DM1), diabetic rats treated with low dose insulin (group DM2), and diabetic rats treated with high dose insulin (group DM3). The mRNA and protein levels of GLUT(1) and GLUT(3) were assayed by reverse transcriptase-polymerase chain reaction (RT-PCR) and immunohistochemistry, respectively. RESULTS: Compared with normal control rats, the GLUT(1) mRNA was reduced by 46.08%, 29.80%, 19.22% (P < 0.01) in DM1, DM2, and DM3 group, respectively; and the GLUT(3) mRNA was reduced by 75.00%, 46.75%, and 17.89% (P < 0.01) in DM1, DM2, and DM3 group, respectively. The abundance of GLUT(1) and GLUT(3) proteins had negative correlation with the blood glucose level (P < 0.01). The density of microvessels in the brain of diabetic rats did not change significantly compared with normal rats. CONCLUSIONS: Chronic hyperglycemia downregulates GLUT(1) and GLUT(3) expression at both mRNA and protein levels in the rat brain, which is not due to the decrease of the density of microvessels. The downregulation of GLUT(1) and GLUT(3) expression might be the adaptive reaction of the body to prevent excessive glucose entering the cell that may lead to cell damage.

Adipocytokines and breast cancer risk.

BACKGROUND: Many researches suggested that obesity increased the risk of breast cancer, but the mechanism was currently unknown. Adipocytokines might mediate the relationship. Our study was aimed to investigate the relationship between serum levels of resistin, adiponectin and leptin and the onset, invasion and metastasis of breast cancer. METHODS: Blood samples were collected from 80 newly diagnosed, histologically confirmed breast cancer patients and 50 age-matched healthy controls. Serum levels of resistin, adiponectin and leptin were determined by enzyme-linked immunosorbent assays (ELISA); fasting blood glucose (FBG), lipids, body mass index (BMI), and waist circumference (WC) were assayed simultaneously. RESULTS: Serum levels of adiponectin ((8.60 +/- 2.92) mg/L vs (10.37 +/- 2.81) mg/L, P = 0.001) and HDL-c were significantly decreased in breast cancer patients in comparison to controls. Serum levels of resistin ((26.35 +/- 5.36) microg/L vs (23.32 +/- 4.75) microg/L, P = 0.000), leptin ((1.35 +/- 0.42) microg/L vs (1.06 +/- 0.39) microg/L, P = 0.003), FBG and triglyceride (TG) in breast cancer patients were increased in contrast to controls, respectively. However, we did not find the significant difference of the serum levels of resistin, adiponectin and leptin between premenopausal breast cancer patients and healthy controls (P = 0.091, 0.109 and 0.084, respectively). The serum levels of resistin, adiponectin and leptin were significantly different between patients with lymph node metastasis (LNM) and those without LNM (P = 0.001, 0.000 and 0.006, respectively). The stepwise regression analysis indicated that the tumor size had the close correlation with leptin (R(2) = 0.414, P = 0.000) and FBG (R(2) = 0.602, P = 0.000). Logistic regression analysis showed that reduced serum levels of adiponectin (OR: 0.805; 95% CI: 0.704 - 0.921; P = 0.001), HDL (OR: 0.087; 95% CI: 0.011 - 0.691, P = 0.021), elevated leptin (OR: 2.235; 95% CI: 1.898 - 4.526; P = 0.004) and resistin (OR: 1.335; 95% CI: 1.114 - 2.354; P = 0.012) increased the risk for breast cancer; Reduced serum levels of adiponectin (OR: 0.742; 95% CI: 0.504 - 0.921; P = 0.003) and elevated leptin (OR: 2.134; 95% CI: 1.725 - 3.921; P = 0.001) were associated with lymph node metastasis of breast cancer. CONCLUSIONS: The decreased serum adiponectin levels and increased serum resistin and leptin levels are risk factors of breast cancer. The low serum adiponectin levels and high serum leptin levels are independent risk factors for metastasis of cancer. The association between obesity and breast cancer risk might be explained by adipocytokines.

Differentiation of bone marrow-derived mesenchymal stem cells from diabetic patients into insulin-producing cells in vitro.

BACKGROUND: Stem cells, which have the ability to differentiate into insulin-producing cells (IPCs), would provide a potentially unlimited source of islet cells for transplantation and alleviate the major limitations of availability and allogeneic rejection. Therefore, the utilization of stem cells is becoming the most promising therapy for diabetes mellitus (DM). Here, we studied the differentiation capacity of the diabetic patient's bone marrow-derived mesenchymal stem cells (MSCs) and tested the feasibility of using MSCs for beta-cell replacement. METHODS: Bone marrow-derived MSCs were obtained from 10 DM patients (5 type 1 DM and 5 type 2 DM) and induced to IPCs under a three-stage protocol. Representative cell surface antigen expression profiles of MSCs were analysed by flow cytometric analysis. Reverse transcription-polymerase chain reaction (RT-PCR) was performed to detect multiple genes related to pancreatic beta-cell development and function. The identity of the IPCs was illustrated by the analysis of morphology, ditizone staining and immunocytochemistry. Release of insulin by these cells was confirmed by immunoradioassay. RESULTS: Flow cytometric analysis of MSCs at passage 3 showed that these cells expressed high levels of CD29 (98.28%), CD44 (99.56%) and CD106 (98.34%). Typical islet-like cell clusters were observed at the end of the protocol (18 days). Ditizone staining and immunohistochemistry for insulin were both positive. These differentiated cells at stage 2 (10 days) expressed nestin, pancreatic duodenal homeobox-1 (PDX-1), Neurogenin3, Pax4, insulin, glucagon, but at stage 3 (18 days) we observed the high expression of PDX-1, insulin, glucagon. Insulin was secreted by these cells in response to different concentrations of glucose stimulation in a regulated manner (P<0.05). CONCLUSIONS: Bone marrow-derived MSCs from DM patients can differentiate into functional IPCs under certain conditions in vitro. Using diabetic patient's own bone marrow-derived MSCs as a source of autologous IPCs for beta-cell replacement would be feasible.