Flavonoid genistein protects bone marrow sinusoidal blood vessels from damage by methotrexate therapy in rats.

Cancer chemotherapy can cause significant damage to the bone marrow (BM) microvascular (sinusoidal) system. Investigations must now address whether and how BM sinusoidal endothelial cells (SECs) can be protected during chemotherapy. Herein we examined the potential protective effects of genistein, a soy-derived flavonoid, against BM sinusoidal damage caused by treatment with methotrexate (MTX). The groups of young adult rats were gavaged daily with genistein (20 mg/kg) or placebo. After 1 week, rats also received daily injections of MTX (0.75 mg/kg) or saline for 5 days and were killed after a further 4 days. Histological analyses showed that BM sinusoids were markedly dilated ( p < 0.001) in the MTX-alone group but were unaffected or less dilated in the genistein+MTX group. In control rats, genistein significantly enhanced expression of vascular endothelial growth factor (VEGF; p < 0.01), particularly in osteoblasts, and angiogenesis marker CD31 ( p < 0.001) in bone. In MTX-treated rats, genistein suppressed MTX-induced apoptosis of BM SECs ( p < 0.001 vs MTX alone group) and tended to increase expression of CD31 and VEGF ( p < 0.05). Our in vitro studies showed that genistein in certain concentrations protected cultured SECs from MTX cytotoxic effects. Genistein enhanced tube formation of cultured SECs, which is associated with its ability to induce expression of endothelial nitric oxide synthase and production of nitric oxide. These data suggest that genistein can protect BM sinusoids during MTX therapy, which is associated, at least partially, with its indirect effect of promoting VEGF expression in osteoblasts and its direct effect of enhancing nitric oxide production in SECs.

Body mass index and C-peptide are important for the promptly differential diagnosis of maturity-onset diabetes from familial type 2 diabetes in outpatient clinic.

Type 2 diabetic patients are becoming younger and having a tendency to family aggregation, they are easily suspected as maturity-onset diabetes of young (MODY) in the outpatient clinic and send to genetic testing. 9 diabetic families were compared in our outpatient clinic who met the primary diagnosis criteria of MODY. Detailed clinical features and laboratory data including gene sequence were collected and analyzed. The patients met the primary clinical diagnostic criteria of MODY for genetic testing at the first look. However, members of families A1 to A3 had normal Body mass index (BMI) and a lower C-peptide level which indicated impaired pancreatic islet function. In contrast, the members with diabetes of families B1 to B6 had normal or increased C-peptide level which indicated insulin resistance and were overweight with BMI. Genetic testing showed that the mutations in HNF1A, INS, KCNJ11 and so on in families A were consistent with the diagnosis of MODY. No pathogenic mutation was found in the members of families B which were diagnosed with familial T2D. Before the clinical laboratory testing and the further gene test, BMI and the concentration of C-peptide are important for the promptly differential diagnosis of MODY from familial type 2 diabetes and medication instruction in the outpatient clinic which could help to alleviate the burden of genetic testing for them.

Association of Sex Hormones and Fat Distribution in Men with Different Obese and Metabolic Statuses.

PURPOSE: Although several studies have explored the association of sex hormones with glucose metabolism, the association between sex hormones and body fat distribution, which is closely related to insulin resistance, has not been fully elucidated. We have tried to explore the relationship of testosterone (T) and estradiol (E2) with visceral adipose tissue (VAT) and subcutaneous adipose tissue (SAT) mass in Chinese men with different obese and metabolic statuses. PATIENTS AND METHODS: A total of 128 men from the Health Management Center of the Second Xiangya Hospital, Central South University were collected and grouped in accordance with their obese and metabolic syndrome (MS) statuses: metabolically healthy non-overweight/obese men (MHNO), metabolically healthy overweight/obese men (MHO) and metabolically unhealthy overweight/obese men (MUO). Multiple regression analyses were performed to estimate contributions of sex hormones levels to the variations of body fat distribution and the contributions of body fat distribution to the variations of sex hormone levels. RESULTS: With fat mass parameters as independent variables, SAT had a strong negative association with T in MHNO (ß = -2.772, P = 0.034), VAT was positively correlated with E2 in MHO (ß = 22.269, P = 0.009), and SAT was negatively associated with T in MUO (ß = -3.315, P = 0.010). With sex hormones as independent variables, E2 positively correlated with VAT (ß = -176.259, P = 0.048), while T negatively correlated with VAT in MHO (ß = 183.150, P = 0.029). In MUO, an inverse association of T with SAT was observed (ß = -213.689, P = 0.021). CONCLUSION: E2 and VAT had a mutual influence, thus resulting in a vicious circle, and the negative correlation between T and VAT may be related to the decrease of the MS occurrence in the MHO group. There were bi-directional relationships between sex hormones and fat distribution in men with different obese and metabolic statuses. TRIAL REGISTRATION: Chinese Clinical Trial Registry, ChiCTR-EOC-16010194. Retrospectively registered.

Atypical juvenile hereditary hemochromatosis onset with positive pancreatic islet autoantibodies diabetes caused by novel mutations in HAMP and overall clinical management.

BACKGROUND: Atypical clinical symptoms of juvenile hereditary hemochromatosis (JHH) often leads to misdiagnosis and underdiagnosis bringing ominous outcomes, even death. METHODS: The whole exome was sequenced and interpreted. A literature review assisted to analyze and verify the phenotype-genotype relationships. We revealed the entire process of diagnosis, treatments, and outcome of two diabetic onset of JHH families to provide new insights for genotype-phenotype relation with novel compound heterozygous mutations in the hepcidin antimicrobial peptide (HAMP, OMIM: 606464). RESULTS: Two probands were diagnosed and treated as type 1 diabetes initially because of specific symptoms and positive islet autoantibodies. Poor control of hyperglycemia and progressive symptoms occurred. Sequencing informed that the compound heterozygous and homozygous mutations c.166C>G and c.223C>T in HAMP caused type 1 diabetic-onset JHH. The two patients accessed irregular phlebotomy treatments, and then, experienced poor prognosis. We summarized the process of overall clinical management of reported 26 cases comparing to our novel atypical diabetic onsets Juvenile Hereditary Hemochromatosis cases. CONCLUSION: It was first reported that positive pancreatic islet autoantibodies diabetes onset of JHH resulted from loss-of-function mutations of HAMP, of which the atypical JHH should be differentially diagnosed with type 1 diabetes at the onset. Early administration of phlebotomy and vital organs protection and surveillance might be important for the treatment of atypical JHH.

[Evaluation of insulin resistance in type 1 diabetes with euglycemic-hyperinsulinemic clamp].

OBJECTIVE: To investigate insulin resistance in type 1 diabetes (T1DM) with euglycemic-hyperinsulinemic clamp. METHODS: Eight cases of newly diagnosed T1DM and 8 cases of newly diagnosed type 2 diabetes (T2DM) were selected. Their insulin sensitivity index (ISI) was evaluated with euglycemic-hyperinsulinemic clamp after 2 week insulin intensive treatment and compared with that of 10 healthy volunteers (normal control group, NC group). RESULTS: Age, BMI, fasting insulin (FIns), fasting C-peptide in the T1DM group were significantly lower than those in the NC group, while waist-to-hip ratio (WHR), systolic blood pressure (SBP), diastolic blood pressure (DBP), TC, TG, LDL-C, HDL-C were not significantly different between the T1DM and NC groups. Age, BMI, WHR, FIns, fasting C-peptide, SBP, TC, TG in the T1DM group were significantly lower than those in the T2DM group. The ISI of the NC, T1DM and T2DM groups were 12. 83 +/- 1.09, 9.95 +/-0.50, 3.80 +/- 0.20, respectively. There was significant difference among the three groups (P < 0.05). CONCLUSION: The ISI in T1DM was significantly lower than that in NC group, but higher than that in T2DM.

NADPH Oxidase Isoforms Are Involved in Glucocorticoid-Induced Preosteoblast Apoptosis.

Oxidative stress induced by long-term glucocorticoid (GC) use weakens the repair capacity of bone tissue. Nicotinamide adenine dinucleotide phosphate, reduced form (NADPH) oxidase (NOX) is a superoxide-generating enzyme that plays an important role in regulating bone metabolism. To clarify the role of nonphagocytic NOX isoforms in osteoblast reactive oxygen species (ROS) generation and apoptosis, dexamethasone was used to establish a high-dose GC environment in vitro. A dose-dependent increase in intracellular ROS generation was demonstrated, which was accompanied by increased osteoblastic MC3T3-E1 cell apoptosis. Addition of the ROS inhibitor NAC (N-acetyl-L-cysteine) or NOX inhibitor DPI (diphenyleneiodonium) reversed this effect, indicating that NOX-derived ROS can induce osteoblast apoptosis under high-dose dexamethasone stimulation. NOX1, NOX2, and NOX4 are NOX homologs recently identified in bone tissue. To clarify the NOX isoforms that play a role in osteoblast ROS generation, Nox1, Nox2, and Nox4 mRNA expression and NOX2 and NOX4 protein expression were analyzed. Nox1 and Nox4 mRNA expression was elevated in a dose-dependent manner after culture in 100 nM, 250 nM, 500 nM, or 1000 nM dexamethasone, and the increased expression of NOX1 mRNA was more significant compared with NOX4 mRNA. Small interfering RNAs (siRNAs) were used to confirm the role of NOX1 and NOX4 in ROS generation. To clarify the signaling pathway in ROS-induced osteoblast apoptosis, mitogen-activated protein kinase (MAPK) signaling molecules were analyzed. Phosphorylated ASK1 and p38 levels were significantly higher in the 1000 nM dexamethasone group, which NAC or DPI markedly attenuated. However, the total mRNA and protein levels of ASK1 and p38 between the dexamethasone group and control were not significantly different. This is related to ROS regulating the posttranslational modification of ASK1 and p38 in MC3T3-E1 cell apoptosis. Altogether, NOX1- and NOX4-derived ROS plays a pivotal role in high-dose dexamethasone-induced preosteoblast apoptosis by increasing phosphorylated ASK1 and p38 and may be an important mechanism in steroid-induced avascular necrosis of the femoral head (SANFH).

[Evaluation of insulin secretion and insulin resistance by hyperglycemic clamp in Graves disease patients with impaired glucose tolerance].

OBJECTIVE: To investigate the state of insulin secretion and insulin resistance in patients of Graves disease (GD) with impaired glucose tolerance (IGT) by hyperglycemic clamp. METHODS: Six cases of Graves disease with IGT were selected as GD + IGT group and ten healthy volunteers as normal control group (NC group). All the subjects were required to fast for 12 hours and then underwent hyperglycemic clamp to assay insulin secretion and insulin sensitivity. Glutamic acid decarboxylase antibody (GAD-A) was tested in all the subjects. RESULTS: Insulin secretion in GD + IGT group was significantly higher than that in NC group. The 1st phase insulin secretion (1PH) was (636.31 +/- 105.54) mIU/L vs (233.56 +/- 21.33) mIU/L, P = 0.001. The 2nd phase insulin secretion (2PH) was (146.68 +/- 25.00) mIU/L vs (67.06 +/- 6.23) mIU/L, P = 0.03. The maximal insulin secretion during 120 - 150 minutes (Ins(120 - 150)) was (195.05 +/- 32.94) mIU/L vs (87.64 +/- 9.78) mIU/L, P = 0.04. The hyperglycemic clamp insulin sensitivity index (average glucose metabolic rate during 120 - 150 minutes/Ins(120 - 150)) was significantly lower in GD + IGT group than that in NC group (11.52 +/- 1.90 vs 21.72 +/- 3.25, P = 0.04). GAD-A was negative in all subjects. CONCLUSION: Cases of GD with IGT show significant insulin resistance with compensated elevated insulin secretion.

[Evaluation of first phase insulin secretion by a nateglinide-intravenous glucose insulin release test in newly diagnosed type 2 diabetics].

OBJECTIVE: To evaluate the function of the first phase of insulin secretion of pancreatic B cells in newly diagnosed type 2 diabetics using nateglinide-intravenous glucose insulin release test (NG-IVGIRT). METHODS: NG-IVGIRT and intravenous glucose insulin release test (IVGIRT) were done in 8 patients with newly diagnosed type 2 diabetes mellitus and NG-IVGIRT was done in 8 normal people. Insulin and glucose of blood were determined at - 15, 0, 2, 4, 6, 8 and 10 min in NG-IVGIRT or IVGIRT. RESULTS: The response of 0 - 10 min insulin to NG-IVGIRT was significantly higher than that to IVGIRT in the diabetics. The response of insulin to NG-IVGIRT in the normal controls was much higher than that in the diabetics. The area under curve (AUC) of insulin to NG-IVGIRT was apparently elevated and the AUC of glucose to NG-IVGIRT reduced in the normal controls as compared with those in the diabetics. CONCLUSION: The results indicated that the reserve of first phase insulin secretion in newly diagnosed type 2 diabetics could be provoked in some degree by NG-IVGIRT and there was a big difference in the reserve of the first phase of insulin secretion provoked by NG-IVGIRT between newly diagnosed type 2 diabetics and normal people.