Binding of RAGE and RIPK1 induces cognitive deficits in chronic hyperglycemia-derived neuroinflammation

AIMS

Chronic hyperglycemia-induced inflammation of the hippocampus is an important cause of cognitive deficits in diabetic patients. The receptor for advanced glycation end products (RAGE), which is widely expressed in the hippocampus, is a crucial factor in this inflammation and the associated cognitive deficits. We aimed to reveal the underlying mechanism by which RAGE regulates neuroinflammation in the pathogenesis of diabetes-induced cognitive impairment.

METHODS

We used db/db mice as a model for type 2 diabetes to investigate whether receptor-interacting serine/threonine protein kinase 1 (RIPK1), which is expressed in microglia in the hippocampal region, is a key protein partner for RAGE. GST pull-down assays and AutoDock Vina simulations were performed to identify the key structural domain in RAGE that binds to RIPK1. Western blotting, co-immunoprecipitation (Co-IP), and immunofluorescence (IF) were used to detect the levels of key proteins or interaction between RAGE and RIPK1. Cognitive deficits in the mice were assessed with the Morris water maze (MWM) and new object recognition (NOR) and fear-conditioning tests.

RESULTS

RAGE binds directly to RIPK1 via the amino acid sequence (AAs) 362-367, thereby upregulating phosphorylation of RIPK1, which results in activation of the NLRP3 inflammasome in microglia and ultimately leads to cognitive impairments in db/db mice. We mutated RAGE AAs 362-367 to reverse neuroinflammation in the hippocampus and improve cognitive function, suggesting that RAGE AAs 362-367 is a key structural domain that binds directly to RIPK1. These results also indicate that hyperglycemia-induced inflammation in the hippocampus is dependent on direct binding of RAGE and RIPK1.

CONCLUSION

Direct interaction of RAGE and RIPK1 via AAs 362-367 is an important mechanism for enhanced neuroinflammation in the hyperglycemic environment and is a key node in the development of cognitive deficits in diabetes.

MKK3 K329 Mutation Attenuates Diabetes-Associated Cognitive Dysfunction by Blocking the MKK3-RAGE Interaction and Inhibiting Neuroinflammation

The receptor for advanced glycation end products (RAGE) contributes to diabetes-associated cognitive dysfunction (DACD) through the interaction of its C-terminal AAs 2-5 with mitogen-activated protein kinase kinase 3 (MKK3). However, the associated MKK3 binding site is unknown. Here, db/db mice were used as a model for type 2 diabetes. GST pull-down assays and AutoDock Vina simulations were conducted to identify the key RAGE binding site in MKK3. This binding site was mutated to investigate its effects on DACD and to elucidate the underlying mechanisms. The interaction of MKK3 and RAGE, the levels of inflammatory factors, and the activation of microglia and astrocytes were tested. Synaptic morphology and plasticity in hippocampal neurons were assessed via electrophysiological recordings and Golgi staining. Behavioral tests were used to assess cognitive function. In this study, MKK3 bound directly to RAGE via its lysine 329 (K329), leading to the activation of the nuclear factor-κB (NF-κB) signaling pathway, which in turn triggered neuroinflammation and synaptic dysfunction, and ultimately contributed to DACD. MKK3 mutation at K329 reversed synaptic dysfunction and cognitive deficits by downregulating the NF-κB signaling pathway and inhibiting neuroinflammation. These results confirm that neuroinflammation and synaptic dysfunction in the hippocampus rely on the direct binding of MKK3 and RAGE. We conclude that MKK3 K329 binding to C-terminal RAGE (ct-RAGE) is a key mechanism by which neuroinflammation and synaptic dysfunction are induced in the hippocampus. This study presents a novel mechanism for DACD and proposes a novel therapeutic avenue for neuroprotection in DACD.

Development and validation of survival nomograms for patients with differentiated thyroid cancer with distant metastases: a SEER Program-based study

BACKGROUND

We aimed to develop a nomogram model of overall survival (OS) and cancer-specific survival (CSS) in patients with differentiated thyroid cancer with distant metastases, and to evaluate and validate the nomogram. Also, its prognostic value was compared with that of the 8th edition of the American Joint Committee on Cancer tumor-node-metastasis staging system (AJCC8SS).

METHODS

Patients with distant metastatic differentiated thyroid cancer (DMDTC) from 2004 to 2015 were selected from the Surveillance, Epidemiology, and End Results (SEER) Program to extract the clinical variables used for analysis. A total of 906 patients were divided into a training set (n = 634) and validation set (n = 272). OS and CSS were selected as the primary end point and secondary end point. LASSO regression analysis and multivariate Cox regression analysis were applied to screen variables for constructing OS and CSS nomograms for survival probability at 3, 5, and 10 years. Nomograms were evaluated and validated using the consistency index (C-index), time-dependent receiver operator characteristic (ROC) curves, area under the ROC curve, calibration curves, and decision curve analysis (DCA). The predictive survival of the nomogram was compared with that of AJCC8SS. Kaplan-Meier curves and log-rank tests were used to evaluate the risk-stratification ability OS and CSS nomograms.

RESULTS

CS and CSS nomograms included six independent predictors: age, marital status, type of surgical procedure, lymphadenectomy, radiotherapy, and T stage. The C-index for the OS nomogram was 0.7474 (95% CI = 0.7199-0.775), and that for the CSS nomogram was 0.7572 (0.7281-0.7862). The nomogram showed good agreement with the "ideal" calibration curve in the training set and validation sets. DCA confirmed that the survival probability predicted by the nomogram had high clinical predictive value. The nomogram could stratify patients more accurately, and showed more robust accuracy and predictive power, than AJCC8SS.

CONCLUSIONS

We established and validated prognostic nomograms for patients with DMDTC, which had significant clinical value compared with AJCC8SS.

Efficacy and safety of cetagliptin as monotherapy in patients with type 2 diabetes: A randomized, double-blind, placebo-controlled phase 3 trial

AIM

To assess the efficacy and safety of the dipeptidyl peptidase-4 inhibitor, cetagliptin, as monotherapy in Chinese patients with type 2 diabetes (T2D) and inadequate glycaemic control.

MATERIALS AND METHODS

In total, 504 eligible patients with T2D were enrolled and randomized to cetagliptin 50 mg once daily, cetagliptin 100 mg once daily or placebo at a ratio of 2:2:1 for 24 weeks of double-blind treatment, then all patients received cetagliptin 100 mg once daily for 28 weeks of open-label treatment. The primary efficacy endpoint was the change in HbA1c level from baseline at week 24.

RESULTS

After 24 weeks, HbA1c from baseline was significantly reduced with cetagliptin 50 mg (-1.08%) and cetagliptin 100 mg (-1.07%) compared with placebo (-0.35%). The placebo-subtracted HbA1c reduction was -0.72% with cetagliptin 50 mg and 100 mg. Patients with a baseline HbA1c of 8.5% or higher had a greater HbA1c reduction with cetagliptin than those patients with a baseline HbA1c of less than 8.5%. Both doses studied led to a significantly higher proportion of patients (42.3% with 100 mg and 45.0% with 50 mg) achieving an HbA1c of less than 7.0% compared with placebo (12.9%). Cetagliptin also significantly lowered fasting plasma glucose and 2-hour postmeal plasma glucose relative to placebo. The incidence of adverse experiences was similar between cetagliptin and placebo. No drug-related hypoglycaemia was reported.

CONCLUSIONS

Cetagliptin monotherapy was effective and well tolerated in Chinese patients with T2D who had inadequate glycaemic control on exercise and diet.

Targeting mPGES-2 to protect against acute kidney injury via inhibition of ferroptosis dependent on p53

Acute kidney injury (AKI) is a clinical syndrome with high morbidity and mortality but no specific therapy. Microsomal prostaglandin E synthase-2 (mPGES-2) is a PGE2 synthase but can metabolize PGH2 to malondialdehyde by forming a complex with heme. However, the role and mechanism of action of mPGES-2 in AKI remain unclear. To examine the role of mPGES-2, both global and tubule-specific mPGES-2-deficient mice were treated with cisplatin to induce AKI. mPGES-2 knockdown or overexpressing HK-2 cells were exposed to cisplatin to cause acute renal tubular cell injury. The mPGES-2 inhibitor SZ0232 was used to test the translational potential of targeting mPGES-2 in treating AKI. Additionally, mice were subjected to unilateral renal ischemia/reperfusion to further validate the effect of mPGES-2 on AKI. Interestingly, both genetic and pharmacological blockage of mPGES-2 led to decreased renal dysfunction and morphological damage induced by cisplatin and unilateral renal ischemia/reperfusion. Mechanistic exploration indicated that mPGES-2 deficiency inhibited ferroptosis via the heme-dependent regulation of the p53/SLC7A11/GPX4 axis. The present study indicates that mPGES-2 blockage may be a promising therapeutic strategy for AKI.

Exploring the molecular targets for Type 2 diabetes-induced Alzheimer's disease through bioinformatics analysis

Aim: The purpose of this study was to elucidate the potential mechanisms of Alzheimer's disease (AD) induced by Type 2 diabetes mellitus (T2DM) through bioinformatics analysis, to provide new treatment targets for this disease. Methods: We used weighted gene coexpression network analysis and differentially expressed genes analysis to identify significantly differentially expressed genes shared by T2DM and AD. Molecular docking was used to predict possible protein targets for T2DM-induced AD. Results: The direct interaction of CD44 and STAT3 may play a significant role in the development of T2DM-induced AD. Conclusion: A new approach to treating T2DM-associated AD may be provided by these hub genes and their predicted molecular targets.

Targeting mTOR/YY1 signaling pathway by quercetin through CYP7A1-mediated cholesterol-to-bile acids conversion alleviated type 2 diabetes mellitus induced hepatic lipid accumulation

BACKGROUND

Hepatic lipid accumulation was a major promoter for the further development of non-alcoholic fatty liver disease (NAFLD) in type 2 diabetes (T2DM). mTOR/YY1 signaling pathway regulated many metabolic processes in different organs, and played an important role in hepatic lipid metabolism. Thus, targeting mTOR/YY1 signaling pathway might be a novel therapeutic strategy of T2DM-associated NALFD.

PURPOSE

To investigate the effects and the mechanism of quercetin against T2DM-associated NAFLD.

STUDY DESIGN AND METHODS

The combine abilities of 24 flavonoid compounds with mTOR were detected by computer virtual screening (VS) and molecular modeling. mTOR/YY1 signaling pathway was examined in the liver of db/db mice, and high glucose (HG) and free fatty acid (FFA) co-cultured HepG2 cells. YY1 overexpression lentivirus vector and mTOR specific inhibitor rapamycin were used to further identify the indispensable role of mTOR/YY1 signaling pathway in quercetin's amelioration effect of hepatic lipid accumulation in vitro. Clinical studies, luciferase assay and chromatin immunoprecipitation (ChIP) assay were all carried out to investigate the potential mechanisms by which quercetin exerted its amelioration effect of hepatic lipid accumulation.

RESULTS

Quercetin had the strongest ability to combine with mTOR and could competitively occupy its binding pocked. Along with the alleviated hepatic injury by quercetin, mTOR/YY1 signaling pathway was down-regulated in vivo and in vitro. However, the alleviation effect of quercetin against hepatic lipid accumulation was inhibited by YY1 overexpression in vitro. Mechanistically, the down-regulated nuclear YY1 induced by quercetin directly bound to CYP7A1 promoter and activated its transcription, resulting in the restoration of cholesterol homeostasis via the conversion of cholesterol-to-bile acids (BAs).

CONCLUSION

The hepatoprotective effect of quercetin on T2DM-associated NAFLD was linked to the restoration of cholesterol homeostasis by the conversion of cholesterol-to-BAs via down-regulating mTOR/YY1 signaling pathway, leading to the increased CYP7A1 activity.

Treadmill exercise training alleviates diabetes-induced depressive-like behavior and cognitive impairment by improving hippocampal CA1 neurons injury in db/db mice

Patients with diabetes mellitus (DM) have an increased risk of diabetic encephalopathy symptoms such as depressive-like behaviour and cognitive impairment. Exercise is an effective strategy for preventing and treating DM and diabetic complications. The aim of this study is to investigate the effects and potential mechanisms of treadmill exercise training on diabetes-induced depressive-like behavior and cognitive impairment in db/db mice. In this study, the mice were divided into three groups (n=10 per group) as follows: healthy-sedentary (db/m), diabetes-sedentary (db/db), and diabetes-treadmill exercise training (db/db-TET). The db/db-TET mice were performed five days per week at a speed of 8m/min for 60min/day for 8 weeks, following which body weight, fasting blood glucose, insulin resistance, behavioral, synaptic ultrastructure, oxidative stress, apoptotic signaling, and inflammatory responses were evaluated. As a result, treadmill exercise training significantly decreased body weight and fasting blood glucose levels, increased insulin sensitivity, protected synaptic ultrastructure, reduced depression-like behavior, and improved learning and memory deficits in db/db mice. In addition, treadmill exercise training significantly suppressed NOX2-mediated oxidative stress, resulting in a decrease in NOX2-dependent ROS generation in the db/db mouse hippocampus CA1 region. Reduced ROS generation prevented the apoptotic signaling pathway and NLRP3 inflammasome activation, thereby ameliorating hippocampus neuronal damage. In summary, the results indicated that treadmill exercise training significantly ameliorates hippocampus injury by suppressing oxidative stress-induced apoptosis and NLRP3 inflammasome activation, consequently ameliorating diabetes-induced depressive-like behavior and cognitive impairment in db/db mice.

Aerobic exercise training alleviates renal injury in db/db mice through inhibiting Nox4-mediated NLRP3 inflammasome activation

Diabetic kidney disease (DKD) is the leading cause of end-stage renal disease, with few therapeutic options available to slow its progression. Aerobic exercise training is an effective strategy for diabetes mellitus and its complications' prevention and treatment. The purpose of this study was to determine the effects of aerobic exercise training on diabetic kidney injury in db/db mice and to characterize the mechanism underlying the renal protective effects. The db/db mice were exercised 5 days a week for 60 min each day for 8 weeks at a speed of 5.6 m/min, after which renal function, morphology, oxidative stress, inflammation, fibrosis, and the expression of the Nox4/ROS/NF-κB/NLRP3 signaling pathway-related protein were assessed. Our results showed that aerobic exercise training significantly reduced body weight and microalbuminuria, improved renal function, and attenuated renal pathological changes in db/db mice independent of hyperglycemic state. Aerobic exercise training was also found to significantly improve oxidative stress and inflammation in the kidneys of db/db mice by decreasing the activity of complex I, the levels of MDA, 8-OHdG, Nox4, ROS, TNF-α, MCP-1, IL-6, and IL-18, increasing the activities of SOD and GSH-Px, the expression of klotho and NPHS2, and decreasing the phosphorylation of NF-κB p65 and IκBα, as well as the expression of NLRP3, ASC, caspase-1 p20, and IL-1β. Additionally, aerobic exercise training decreased TGF-β, collagen I, collagen IV, and α-SMA expression, thereby slowing the progression of kidney fibrosis in db/db mice. In conclusion, aerobic exercise training effectively reduces oxidative stress, inflammation, and renal fibrosis by modulating the Nox4/ROS/NF-κB/NLRP3 signaling pathway, implying that aerobic exercise training has significant potential to protect diabetic kidney injury and should be given more emphasis in DKD treatment.

Preoperative platelet distribution width-to-platelet ratio combined with serum thyroglobulin may be objective and popularizable indicators in predicting papillary thyroid carcinoma

Objectives

The incidence of papillary thyroid carcinoma (PTC) has increased more rapidly than that of any other cancer type in China. Early indicators with high sensitivity and specificity during diagnosis are required. To date, there has been a paucity of studies investigating the relationship between preoperative platelet distribution width‐to‐platelet count ratio (PPR) and PTC. This study thus aimed to assess the diagnostic value of PPR combined with serum thyroglobulin (Tg) in patients with PTC.

Methods

A total of 1001 participants were included in our study. 876 patients who underwent surgery for nodular goiter were divided into the PTC group or benign thyroid nodule (BTN) group according to pathology reports, and 125 healthy controls (HCs) were included. Preoperative hemogram parameters and serum Tg levels were compared among three groups. Receiver operating characteristic (ROC) curve was used to evaluate the value of PPR combined with serum Tg for diagnosing PTC.

Results

Platelet distribution width (PDW) and PPR levels were higher in the PTC group than in the BTN and HC groups (both p < 0.05) but did not significantly differ between the BTN and HC groups. PDW and PPR levels significantly differed in the presence/absence of lymph node metastasis, the presence/absence of capsule invasion (p = 0.005), and TNM stages (p < 0.001). Multivariable analyses indicated that high serum Tg levels [adjusted odds ratio (OR), 1.007; 95% confidence interval (CI), 1.004–1.009; p < 0.001], high neutrophil‐to‐lymphocyte ratio (NLR,adjusted OR, 1.928; 95% CI, 1.619–2.295; p < 0.001), and high PPR (adjusted OR, 1.378; 95% CI, 1.268–1.497; p < 0.001) were independent risk factors for PTC. In ROC analysis, the areas under the curves (AUCs) of serum Tg, PDW, PPR, and NLR for predicting PTC were 0.603, 0.610, 0.706, and 0.685, respectively. PPR combined with serum Tg (PPR + Tg) had a higher diagnostic value (AUC, 0.738; sensitivity, 60%; specificity, 74.7%) compared with PDW + Tg (AUC, 0.656; sensitivity, 64.4%; specificity, 59.9%) and NLR + Tg (AUC, 0.714; sensitivity, 61.6%; specificity, 71.1%).

Conclusions

Preoperative PPR combined with serum Tg may be objective and popularizable indicators for effective predicting PTC.

The Scope of HbA1c Variability and Risk of Vascular Complications Among Patients with Type 2 Diabetes: A Systematic Review and Meta-Analysis of Prospective Studies

Glycated hemoglobin (HbA1c) variability is emerging as an indicator of long-term glycemic control, which may play a significant role during vascular complications. We conducted a systematic review and meta-analysis to assess the association between the scope of HbA1c variability and vascular complications in patients with type 2 diabetes mellitus. PubMed and Embase were searched for studies that evaluated the association of HbA1c variability with vascular complications in patients with type 2 diabetes. Two reviewers independently completed data extraction. Random-effects meta-analysis was conducted with stratification according to the type of vascular complications. Nine studies were eligible for inclusion in our systematic review and meta-analysis. Six studies evaluated the impact of the standard deviation of HbA1c (HbA1c-SD) on cardiovascular events and showed an association of HbA1c-SD with cardiovascular events (HR: 1.25, 95% CI 1.18-1.32, 5 studies). Six studies evaluated renal disease associated with HbA1c-SD and showed that HbA1c-SD was correlated with an increased risk of renal disease (HR: 1.19, 95% CI 1.13-1.24). Two studies evaluated HbA1c-SD and the risk of retinopathy and showed that no significant association was found between retinopathy and HbA1c-SD (HR 1.08, 95% CI 0.92-125). For HbA1c-SD ranging from 0.6 to 0.8%, HbA1c-SD was associated with an increased risk of cardiovascular events (HR: 1.25, 95% CI 1.15-1.35) and renal disease (HR: 1.16, 95% CI 1.11-1.22). For individuals with index HbA1c variability greater than or equal to 0.6%, HbA1c variability was significantly associated with vascular complications in patients with type 2 diabetes mellitus.

Activation of the NLRP3 inflammasome by RAC1 mediates a new mechanism in diabetic nephropathy

OBJECTIVE

Inflammation is central to the development and progression of diabetic nephropathy (DN). Although the exact mechanisms of inflammation in the kidney have not been well elucidated, pyrin domain containing 3 (NLRP3) inflammasome activation is involved in the onset and progression of DN. Here, we investigated the underlying regulatory mechanisms of hyperglycaemia-induced NLRP3 inflammasome activation in the kidney.

METHODS

HEK293T cells received high glucose, and the cell proliferation and apoptosis were detected. Biochemical indicators in db/db mice were tested by kits, and the morphological changes in the kidney were observed using staining methods and transmission electron microscopy. The interaction of Ras-related C3 botulinum toxin substrate 1 (RAC1) and NLRP3 inflammasome in cells and in mice was assessed by co-immunoprecipitation (Co-IP) and immunofluorescence. Expression of all proteins was examined by western blotting and immunohistochemistry. In additional, the directly combination of RAC1 and NLRP3 was evaluated by GST Pulldown.

RESULTS

High-glucose and hyperglycaemia conditions resulted in Ras-related C3 botulinum toxin substrate 1 (RAC1) and NLRP3 inflammasome interactions in cells and in mice. Additionally, RAC1 promoted NLRP3 inflammasome activation and then induced cell damage, and morphological and functional abnormalities in the kidney. We also observed that RAC1 activates the NLRP3 inflammasome by directly binding to NLRP3.

CONCLUSION

In the present study, we confirmed that RAC1 binding to NLRP3 is sufficient to activate the NLRP3 inflammasome in the kidney and accelerate DN pathological processes. These results elucidate the upstream cellular and molecular mechanisms of NLRP3 inflammasome activation and provide new therapeutic strategies for the treatment of DN.

MR Imaging Differences in the Circle of Willis between Healthy Children and Adults

BACKGROUND AND PURPOSE

Asymmetries in the circle of Willis have been associated with several conditions, including migraines and stroke, but they may also be age-dependent. This study examined the impact of age and age-dependent changes in cerebral perfusion on circle of Willis anatomy in healthy children and adults.

MATERIALS AND METHODS

We performed an observational, cross-sectional study of bright and black-blood imaging of the proximal cerebral vasculature using TOF-MRA and T2 sampling perfection with application-optimized contrasts by using different flip angle evolution (T2-SPACE) imaging at the level of the circle of Willis in 23 healthy children and 43 healthy adults (4-74 years of age). We compared arterial diameters measured manually and cerebral perfusion via pseudocontinuous arterial spin-labeling between children and adults.

RESULTS

We found that the summed cross-sectional area of the circle of Willis is larger in children than in adults, though the effect size was smaller with T2-SPACE-based measurements than with TOF-MRA. The circle of Willis is also more symmetric in children, and nonvisualized segments occur more frequently in adults than in children. Moreover, the size and symmetry of the circle of Willis correlate with cerebral perfusion.

CONCLUSIONS

Our results demonstrate that the circle of Willis is different in size and symmetry in healthy children compared with adults, likely associated with developmental changes in cerebral perfusion. Further work is needed to understand why asymmetric vasculature develops in some but not all adults.

Age Moderates the Impact of TRAbs on Thyroid Hormones and Hepatic Function in Patients with Graves' Disease

Thyrotropin receptor antibodies (TRAbs) play a significant role in the course of hepatic dysfunction (HDF) in patients with Graves' disease (GD). However, few studies have considered the factors that influence the relationships among TRAbs, thyroid hormone levels, and hepatic function in subjects with newly diagnosed GD. Here we investigated the associations of TRAbs with thyroid hormones and hepatic function and assessed potential factors that can influence these associations among patients with GD. A total of 368 patients newly diagnosed with GD were collected in this cross-sectional study. Patients who had received antithyroid drugs, radioactive iodine, or surgery were excluded. Levels of TRAbs and thyroid hormones and hepatic function were recorded. Linear and binary logistic regression analysis models were applied to investigate associations among these variables after adjusting for confounding characteristics. There was a significant difference in TRAbs indices between the HDF and normal hepatic function groups (p <0.05). After adjusting for confounders, the relationship between TRAbs and thyroid hormones was nonlinear, showing a curve with an initial positive slope and a subsequent flattening (p <0.05). Higher TRAbs were associated with HDF [odds ratio (OR) 1.036, 95% confidence interval (CI) 1.018-1.053 per 1-IU/l increase]. These associations were modified by age, but not by gender, smoking status, Graves' orbitopathy, thyroid-peroxidase antibody levels, or thyroglobulin antibody levels. In younger patients, increasing TRAbs were correlated with higher thyroid hormones and HDF (OR 1.034, 95% CI 1.017-1.052) per1-IU/l increase). In older patients, TRAbs were not correlated with thyroid hormones or HDF (OR 1.024, 95% CI 0.993-1.056) per 1-IU/l increase. Age can affect the impact of TRAbs on thyroid hormone levels and hepatic function in GD. TRAb measurement can have good predictive value in younger patients.

Ras-Related C3 Botulinum Toxin Substrate 1 Combining With the Mixed Lineage Kinase 3- Mitogen-Activated Protein Kinase 7- c-Jun N-Terminal Kinase Signaling Module Accelerates Diabetic Nephropathy

Ras-related C3 botulinum toxin substrate 1 (RAC1) activation plays a vital role in diabetic nephropathy (DN), but the exact mechanism remains unclear. In this study, we attempted to elucidate the precise mechanism of how RAC1 aggravates DN through cellular and animal experiments. In this study, DN was induced in mice by intraperitoneal injection of streptozotocin (STZ, 150mg/kg), and the RAC1 inhibitor NSC23766 was administered by tail vein injection. Biochemical indicators, cell proliferation and apoptosis, and morphological changes in the kidney were detected. The expression of phosphorylated c-Jun N-terminal kinase (p-JNK), nuclear factor-κB (NF-κB), and cleaved caspase-3 and the interaction between RAC1 and the mixed lineage kinase 3 (MLK3)-mitogen-activated protein kinase 7 (MKK7)-JNK signaling module were determined. Furthermore, the colocalization and direct co-interaction of RAC1 and MLK3 were confirmed. Our results showed that RAC1 accelerates renal damage and increases the expression of p-JNK, NF-κB, and cleaved caspase-3. However, inhibition of RAC1 ameliorated DN by downregulating p-JNK, NF-κB, and cleaved caspase-3. Also, RAC1 promoted the assembly of MLK3-MKK7-JNK, and NSC23766 blocked the interaction between RAC1 and MLK3-MKK7-JNK and inhibited the assembly of the MLK3-MKK7-JNK signaling module. Furthermore, RAC1 was combined with MLK3 directly, but the RAC1 Y40C mutant inhibited the interaction between RAC1 and MLK3. We demonstrated that RAC1 combining with MLK3 activates the MLK3-MKK7-JNK signaling module, accelerating DN occurrence and development, and RAC1 Y40 is an important site for binding of RAC1 to MLK3. This study illustrates the cellular and molecular mechanisms of how RAC1 accelerates DN and provides evidence of DN-targeted therapy.

Glycemic variability indices determined by self-monitoring of blood glucose are associated with β-cell function in Chinese patients with type 2 diabetes

INTRODUCTION

Glycemic control plays an important role in diabetes management, and self-monitoring of blood glucose (SMBG) is critical to achieving good glycemic control. However, there are few studies about the relationship between SMBG-estimated glycemic indices and β-cell function. Here we investigated the association between glucose variation indices estimated by SMBG and β-cell function among Chinese patients with type 2 diabetes mellitus (T2DM).

METHODS

In this cross‑sectional study, 397 patients with T2DM were recruited from February 2015 to October 2016. β-cell function was monitored using the Homeostasis Model Assessment 2 (HOMA2)-%β index. The parameters evaluated by SMBG were the mean blood glucose (MBG), standard deviation of MBG (SDBG), largest amplitude of glycemic excursions (LAGE), and postprandial glucose excursion (PPGE).

RESULTS

HOMA2-%β was negatively correlated with SDBG, LAGE, PPGE, and MBG (r = -0.350, -0.346, -0.178, and -0.631, respectively; all p < 0.01). After adjusting for confounding characteristics (diabetic duration, triglyceride, total cholesterol, fasting C-peptide, HOMA2-insulin resistance index, hypoglycemia, and diabetic treatments) and glycated hemoglobin A1c on a continuous scale, odds ratios of SDBG, LAGE, PPGE, and MBG between the patients in the lowest and highest HOMA2-%β quartiles were 2.02 (1.14-3.57), 1.24 (1.04-1.49), 1.13 (0.86-1.51), and 2.26 (1.70-3.00). HOMA2-%β was independently associated with SDBG, LAGE, and MBG.

CONCLUSIONS

Increased SDBG and LAGE assessed by SMBG are associated with β-cell dysfunction in Chinese patients with T2DM.

Glucose fluctuation increased mesangial cell apoptosis related to AKT signal pathway

INTRODUCTION

Blood glucose fluctuation is an important factor for the development of diabetic complications. Glucose fluctuation aggravated the renal injury in diabetic nephropathy. In the present study, our aim was to investigate the effects of blood glucose fluctuation on the glomerular mesangal cells and its related mechanism.

MATERIAL AND METHODS

Mesangial cells were divided into four groups: the normal glucose group (NG) cells were incubated in normal glucose conditions (5.6 mmol/l); the high glucose group (HG) cells were treated with 25 mmol/l; the glucose fluctuation (FG) group received 5.6 mmol/l and 25 mmol/l glucose repeated 3 times; the mannitol group (MG) received 5.6 mmol/l glucose plus 24.4 mmol/l mannitol as a control. Cell viability and apoptosis were detected, reactive oxygen species (ROS) level, superoxide dismutase (SOD) activity and malonaldehyde (MDA) levels were measured. Phosphorylated ser/thr protein kinase (P-AKT, phosphor-Ser473), phosphorylated glycogen synthase kinase-3β (P-GSK-3β, phosphor-Ser9) and cleaved cysteinyl aspartate-specific proteinase-3 (cleaved caspase-3) levels were assessed using western blot.

RESULTS

Data suggested that mesangial cells in the FG group show higher cell viability in 12 h, and lower cell viability from 48 h. The FG group showed cell apoptosis accompanied by a significant MDA level increase and SOD activity decrease in 48 h. More importantly, glucose fluctuation could aggravate oxidative stress in glomerular mesangial cells. Furthermore, the P-AKT level was lower, and increased P-GSK-3β and cleaved caspase-3 levels were higher in the FG group than in the HG group.

CONCLUSIONS

Glucose fluctuation aggravates mesangial cell apoptosis, which may be partly induced by activating oxidative stress and inhibiting the AKT signaling pathway.

Fasting plasma glucose variability levels and risk of adverse outcomes among patients with type 2 diabetes: A systematic review and meta-analysis

AIM

This systematic review and meta-analysis assessed the association between fasting plasma glucose (FPG) variability levels and the risk of retinopathy and all-cause mortality in patients with type 2 diabetes.

METHODS

PubMed and EMBASE were searched to identify studies that evaluated the association between FPG variability and retinopathy and all-cause mortality in patients with type 2 diabetes mellitus. The hazard ratios (HRs) and 95% confidence intervals (CIs) were pooled with the random-effects model.

RESULTS

Eight studies were included in our meta-analysis. Five studies evaluated the impact of FPG variability on all-cause mortality and showed that high FPG variability was associated with the risk of all-cause mortality (HR 1.28, 95% CI 1.12-1.46; three studies). For median or mean FPG variability levels under 20%, the relationship between all-cause mortality and FPG variability was not significant. Three studies evaluated FPG variability and the risk of diabetic retinopathy and showed that high FPG variability was strongly associated with the risk of retinopathy (odds ratio (OR) = 3.68; 95% CI 1.01-13.4).

CONCLUSION

High FPG variability levels were positively associated with the risk of retinopathy and all-cause mortality in patients with type 2 diabetes.

Zeaxanthin improved diabetes-induced anxiety and depression through inhibiting inflammation in hippocampus

It is generally accepted that inflammation plays a key role in anxiety and depression induced by diabetes. However, the underlying mechanism and effective treatment method of these diabetes-associated behavior disorders remain to be determined. In the present study, we attempted to illuminate the implication of zeaxanthin in anxiety, depression and neuroinflammation caused by hyperglycemia, and further elaborate the relevant mechanism under these neuropsychiatric disorders. In the current work, diabetic rats were induced by high glucose and fat diet followed by a single intraperitoneal injection of streptozocin, and zeaxanthin was orally administration every day (From 6th to 19th week). Diabetes-associated anxiety and depression were assessed using open field test (OFT) and Forced swimming test (FST) respectively. Moreover, the levels of interleukin-6 (IL-6), interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF-α) in hippocampus were tested using ELISA and WB. Data showed that long-term zeaxanthin treatment improve diabetic symptoms and alleviate anxiety and depression in diabetic rats. Furthermore, excessive production of IL-6, IL-1β and TNF-α could be reduced with zeaxanthin treatment. In conclusion, we suggested that zeaxanthin can ameliorate diabetes-associated anxiety and depression, inhibit inflammation in diabetic rats. Our results could provide a potential therapeutic approach for the treatment of abnormal behavior induced by hyperglycemia.

Inhibition of NF-κB activity by aminoguanidine alleviates neuroinflammation induced by hyperglycemia

Neuroinflammation is a key feature of cerebral complication which is associated with diabetes mellitus (DM). Inducible nitric oxide synthase (iNOS) is implicated in the pathogenesis of neuroinflammation. However, how iNOS facilitates the development of inflammation in brain is still unidentified. The aim of the present study was to investigate the association of iNOS and neuroinflammation in diabetic mice, and elucidate the potential mechanisms underlying aminoguanidine (AG), the selective inhibitor of iNOS, protected neurons against inflammation in diabetic mice. In present experiment, diabetic mice model were established by a single intraperitoneal injection of streptozotocin (STZ). AG was administered to diabetic mice for ten weeks after this disease induction. Then we measured iNOS activity in the serum and brain, detected the glial fibrillary acidic protein (GFAP) and ionised calcium binding adaptor molecule-1 (Iba-1) expressions in the brain. Moreover, nuclear factor-kappa B (NF-κB) in cytoplasm and nucleus were tested by IP and WB. Results revealed that high expression of iNOS in serum and brain could be reversed by AG treatment. Furthermore, AG could also inhibit GFAP and Iba-1 expressions, and NF-κB nuclear translocation by inhibiting it from binding to iNOS in cytoplasm. Our findings indicated that iNOS can combine with NF-κB in cytoplasm and promote its nuclear transfer in diabetic mice. Furthermore, AG decreased neuroinflammation through inhibiting iNOS activity and reducing NF-κB nuclear translocation by promoting its dissociation with iNOS in cytoplasm.

Glucose variability aggravates cardiac fibrosis by altering AKT signalling path

OBJECTIVE

To study the effect of blood glucose variability on cardiac fibrosis and its mechanism in a model of diabetic cardiomyopathy.

METHODS

A total of 45 Sprague Dawley rats were randomly divided into three groups: control, control diabetes mellitus and fluctuated blood glucose groups. Fluctuated blood glucose was induced by daily subcutaneous insulin and intraperitoneal glucose injections at different time points. Blood lipids and glycosylated haemoglobin A1c were assessed. Super oxide dismutase activity and malondialdehyde level in rat heart homogenates were determined by assay kit. Structural cardiac tissue changes were observed by haematoxylin and eosin staining and Masson's trichrome staining. Collagen type 3, fibronectin, phosphorylated Ser/Thr protein kinase, phosphorylated glycogen synthase kinase-3 beta, glycogen synthase kinase-3 beta, nuclear factor kappa-light-chain-enhancer of activated B cells, cleaved-cysteinyl aspartate-specific proteinase-3 (caspase-3) and tumour necrosis factor-α levels were determined by western blot.

RESULTS

Compared with the control group, cardiac fibrosis and oxidative stress in heart tissue were aggravated in diabetic rats, which were more pronounced in glucose variability rats. However, the expression levels of AKT and glycogen synthase kinase-3 beta were not significantly different in three groups, but the expression levels of phosphorylated Ser/Thr protein kinase and phosphorylated glycogen synthase kinase-3 beta were significantly decreased in the control diabetes mellitus and fluctuated blood glucose groups compared to control group, and levels in the fluctuated blood glucose group were significantly less than in the control diabetes mellitus group. In addition, the expression levels of nuclear factor kappa B and caspase-3 in both the control diabetes mellitus and fluctuated blood glucose groups were higher than in the control group, with the highest levels measured in the fluctuated blood glucose group.

CONCLUSION

Blood glucose variability can aggravate heart tissue fibrosis, possibly involving oxidative stress by inhibiting AKT signalling path.

Zeaxanthin ameliorates high glucose-induced mesangial cell apoptosis through inhibiting oxidative stress via activating AKT signalling-pathway

Oxidative stress is a critical factor in the pathophysiology of diabetic kidney disease. Previous study shows that hyperglycaemia aggravates renal injury through oxidative stress in diabetic model, and antioxidants have beneficial effect on diabetic kidney disease. However, the role of antioxidants in the progression of diabetic kidney disease is poorly understood. The aim of this study was to clarify whether zeaxanthin, an antioxidant, could ameliorate mesangial cell injury and if so, identify the related mechanism underlying this protective effect. To that end, superoxide dismutase (SOD) activity and methane dicarboxylic aldehyde (MDA) levels were measured by an assay kit, and mesangial cell apoptosis and ROS levels were assessed using flow cytometry analysis. Furthermore, The levels of a phosphorylated ser/thr protein kinase (p-AKT), phosphorylated glycogen synthase kinase-3 beta (p-GSK-3β), Bcl-2 associated X protein (Bax) and cleaved cysteinyl aspartate-specific proteinase-3 (caspase-3) were detected by western blot. We found that zeaxanthin decreases MDA levels and increased SOD activity, as well as inhibits apoptosis and decreases ROS levels in mesangial cells in a high sugar environment. Furthermore, zeaxanthin increased p-AKT levels while decreased the levels of p-GSK-3β, Bax and cleaved-caspase-3. In addition, LY294002 reversed the protective effect of zeaxanthin on mesangial cells. In conclusion, zeaxanthin ameliorated mesangial cell apoptosis may be involved in inhibiting oxidative stress through activating of the AKT signalling pathway.

Bamboo leaf extract ameliorates diabetic nephropathy through activating the AKT signaling pathway in rats

Diabetic nephropathy (DN) is one of the most severe diabetic complication and it is becoming become a worldwide epidemic, accounting for approximately one-third of all case of end-stage renal disease. However, the underlying mechanism and strategy to alleviate renal injury remain unclear. In the present study, we assessed the protective effect of bamboo leaf extract on the DN, and investigated the underlying mechanism by which bamboo leaf extract ameliorating DN. Diabetic rats were induced by 4 weeks high sugar and high fat diet, and then injected a single dose of STZ (35mg/kg) into abdominal cavity. Different dose of bamboo extract (50mg/kg, 100mg/kg and 200mg/kg) were orally administered every day for a period of 12 weeks. Body weight, blood glucose, glycosylated hemoglobin A1c (HbAlc), blood urea nitrogen (BUN), serum creatinine (Scr), and 24-hour urinary protein (24 h-UP) were assessed. Total superoxide dismutase (T-SOD) activity and MDA (methane dicarboxylic aldehyde, MDA) level were tested by assay kit. Microstructural changes were observed by hematoxylin-eosin (HE) staining and electron microscopy. Expression of phosphorylated ser/thr protein kinase (P-AKT), phosphorylated glycogen synthase kinase-3 beta (P-GSK-3β), B cell lymphoma/leukemia 2-associated X protein (BAX) and cleaved-cysteinyl aspartate-specific proteinase-3 (Cleaved Caspase-3) were measured by Western-Blotting (WB). Results showed that diabetic rats had weight loss, high blood glucose, HbAlc, BUN, Scr and 24-UP and T-SOD activity were increased and MDA level was decreased in diabetic rats. Moreover, hyperglycemia could injury renal tissue ultrastructure, inhibit P-AKT level and increase P-GSK-3β, BAX and Cleaved Caspase-3 levels in rats. However, bamboo leaf extract treatment could reduce body weight loss, BUN, Scr, 24 h-UP and MDA level, improve T-SOD activity and alleviate renal injury in diabetic rats. Furthermore, bamboo leaf extract increased P-AKT level, decreased P-GSK-3β, BAX and Cleaved Caspase-3 levels in STZ-diabetic rats. In conclusion, our study suggested that bamboo leaf extract ameliorated DN in diabetic rats, and this protective effect is possibly related to suppressing oxidative stress through activating AKT signaling pathway. Bamboo leaf extract treatment may be a potential promising therapy for DN.

Blood glucose fluctuation accelerates renal injury involved to inhibit the AKT signaling pathway in diabetic rats

Blood glucose fluctuation is associated with diabetic nephropathy. However, the mechanism by which blood glucose fluctuation accelerates renal injury is not fully understood. The aim of the present study was to assess the effects of blood glucose fluctuation on diabetic nephropathy in rats and investigate its underlying mechanism. Diabetes in the rats was induced by a high sugar, high-fat diet, and a single dose of STZ (35 mg/kg)-injected intraperitoneally. Unstable blood sugar models were induced by subcutaneous insulin injection and intravenous glucose injection alternately. Body weight, glycosylated hemoglobin A1c (HbAlc), blood urea nitrogen (BUN), serum creatinine (Scr), and Creatinine clearance (Ccr) were assessed. T-SOD activity and MDA level were measured by assay kit. Change in renal tissue ultrastructure was observed by light microscopy and electron microscopy. Phosphorylated ser/thr protein kinase (p-AKT) (phosphor-Ser473), phosphorylated glycogen synthase kinase-3 beta (p-GSK-3β) (phosphor-Ser9), Bcl-2-associated X protein (BAX), B cell lymphoma/leukemia 2 (BCL-2), and cleaved-cysteinyl aspartate-specific proteinase-3 (caspase-3) levels were detected by immunohistochemistry and Western blot. We observed that BUN and Scr were increased in diabetic rats, and Ccr was decreased. Furthermore, blood glucose fluctuations could exacerbate the Ccr changes. Renal tissue ultrastructure was also seriously injured by glucose variability in diabetic rats. In addition, glucose fluctuation increased the oxidative stress of renal tissue. Moreover, fluctuating blood glucose decreased p-AKT level and BCL-2, and increased p-GSK-3β, BAX, cleaved-caspase-3 levels, and ratio of BAX/BCL-2 in the kidneys of diabetic rats. In conclusion, these results suggest that blood glucose fluctuation accelerated renal injury is due, at least in part to its oxidative stress promoting and inhibiting the AKT signaling pathway in diabetic rats.

Enhanced antitumor effect of combining TRAIL and MnSOD mediated by CEA-controlled oncolytic adenovirus in lung cancer

Lung cancer, especially adenocarcinoma, is one of the leading causes of death in the world. Carcinoembryonic antigen (CEA), a superb non-small-cell lung cancer marker candidate, showed a beneficial effect in cancer therapy with oncolytic adenovirus in recent studies. Cancer-targeting dual gene-virotherapy delivers two therapeutic genes, linked by a connexon, in the replication-deficient vector instead of one gene so that they can work in common. In this study, we constructed a tumor-specific oncolytic adenovirus, CD55-TRAIL-IETD-MnSOD. The virus has the fusion protein complementary DNAs for tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) and for manganese superoxide dismutase (MnSOD) complementary DNA linked through a 4-amino acid caspase-8 cleavage site (IETD), and uses a CEA promoter to control virus E1A express. This is the first work to use a CEA promoter-regulated oncolytic adenovirus carrying two therapeutic genes for cancer research. Its targeting and anticancer capacity was evaluated by in vitro and in vivo experiments. The results indicated that CD55-TRAIL-IETD-MnSOD caused more cell apoptosis than CD55-TRAIL or CD55-MnSOD alone, or their combination in vitro, with low cytotoxicity of normal cells. In the A549 tumor xenograft model in nude mice, data showed that CD55-TRAIL-IETD-MnSOD could effectively suppress tumor growth than single gene groups, with no histological damage in liver, spleen or kidney tissues. Thus, the CEA-regulated dual-gene oncolytic virus CD55-TRAIL-IETD-MnSOD may be a novel potential therapy for lung cancer.

Deficiency of antithrombin and protein C gene in 202 Chinese venous thromboembolism patients

INTRODUCTION

Antithrombin and protein C gene deficiencies are commonly inherited risk factors for VTE patients. We aim to investigate the deficiency of these two gene in 202 Chinese patients with venous thromboembolism (VTE).

METHODS

Antithrombin activity (AT: A) and protein C activity (PC: A) were measured in 202 VTE patients, and for those with unexplainable low results, PCR and direct sequencing of the related genes were carried out.

RESULTS

Deficiency levels of antithrombin and protein C gene were found to be 2% and 8%, respectively. AT or PC hereditary deficiency can be found in 10% patients with VTE.

CONCLUSION

Protein C gene deficiency might be more prevalent than AT gene deficiency in Chinese VTE patients. Functional assay combined with genetic analysis is useful in the diagnosis of inherited defects in VTE patients.

Reduction of osteopontin in vivo inhibits tubular epithelial to mesenchymal transition in rats with chronic allograft nephropathy

OBJECTIVE

Chronic allograft nephropathy (CAN) is an important etiological factor causing graft loss. However, the mechanism of CAN is unclear. Osteopontin (OPN), a proinflammatory and profibrosis molecule, plays a key role in late stages of renal diseases. We investigated the potential role of OPN in the pathogenesis of CAN.

METHODS

Using a F344 to Lewis rat CAN model, we injected short hairpin RNA (shRNA) constructs targeting OPN or negative control plasmids through the renal vein following electroporation. At 12 weeks after the transplantation, we determined interstitial fibrosis (IF) and tubular atrophy (TA) of the tubular epithelial cells (TECs). OPN expression was examined using Western blots and immunohistochemistry (IHC). Molecules involved in epithelial to mesenchymal transition (EMT) of TECs were examined using IHC and Western blots.

RESULTS

OPN expression in kidney grafts was decreased by the RNA interference (RNAi) group. Histology observations showed IF and TA to be mild with stable renal function in the RNAi-treated group. EMT of TECs was significantly lessened after reducing OPN.

CONCLUSION

Reduction of OPN in vivo inhibited progression of CAN. OPN may be of therapeutic value in transplantation settings.

Comparison of risk factors associated with hypertension subtypes by classification tree method in Tongshan County of Jiangsu Province, China

BACKGROUND

There are only a very limited number of studies relating to risk factors for hypertension in rural populations in China. There are even fewer studies comparing various hypertension subtypes.

METHODS

A cross-sectional investigation was carried out in a representative sample of 20,390 subjects drawn from among 1,180,000 adult residents of Tongshan County of Jiangsu Province, China. The impact of risk factors including demographic, socioeconomic, dietary, and behavioral, on three hypertension subtypes, namely, isolated systolic hypertension (ISH), isolated diastolic hypertension (IDH), and systolic-diastolic hypertension (SDH), was analyzed by applying statistical tests and a classification tree.

RESULTS

ISH was the predominant untreated hypertension subtype (13.68 +/- 0.24%) in the adults of Tongshan County, followed by SDH (11.70 +/- 0.23%) and IDH (6.24 +/- 0.17%). Age, number of cigarettes smoked daily, and the types of vitamins taken varied among the ISH, IDH, and SDH classification trees. Low socioeconomic status was associated with an increased risk for ISH and SDH. Light alcohol intake was associated with higher risk for ISH, but with lower risks for IDH and SDH. Light cigarette smoking was associated with higher ISH risk but lower SDH risk. The intake of appropriate amounts of fish, shrimp, or meat lowered the risks for ISH and IDH. The intake of appropriate amounts of seafood, eggs, milk, or fruit lowered the risks for all hypertension subtypes. Interestingly, an excessive preference for sweet or salty foods was associated with a higher risk for all the subtypes.

CONCLUSIONS

In Tongshan County, there was a considerable prevalence of hypertension of various subtypes, each associated with distinctive and complex risk factors. This suggests that there is a need for testing more diverse prevention measures, tailored to specific subtypes.

Growth inhibition of human endothelial cells by the phyto-oestrogen biochanin A, a metabolite of genistein

This study examined the growth regulatory effects of a phyto-oestrogen, biochanin A, on a transformed human endothelial cell line ECV304in vitro. Biochanin A was found to inhibit cell proliferation in a dose-dependent fashion and this effect was influenced by the concentration of serum present in the culture medium. In the absence of serum, the calculated IC50of biochanin A was 0.18 ± 0.1 μM COMPARED TO AN IC50OF 35±5 Μm at 10 % serum. At low cell density, the growth inhibitory effects of biochanin A were more evident than at high cell density. Co-administration of a synthetic oestrogen diethylstilboestrol with biochanin A did not suppress the growth regulatory effects of biochanin A treatment. We conclude that biochanin A inhibits the cell proliferation of human endothelial cells at concentrations that are physiologically achievablein vivoand that this effect may play an important role in the cancer-preventing activity of the phyto-oestrogens.

CDX2 has tumorigenic potential in the human colon cancer cell lines LOVO and SW48

CDX2 is a Drosophila caudal-related homeobox transcription factor that is important for the establishment and maintenance of intestinal epithelial cells. CDX2 is a marker of colon cancer, with strong staining in up to 90% of colonic adenocarcinomas. CDX2 heterozygous-null mice develop colonic neoplasms, which have suggested that CDX2 is a tumor suppressor. However, CDX2 has not been reported to affect xenograft growth. Furthermore, CDX2 is rarely mutated in colon cancer, which has led to suggestions that it may play only a minor role as a tumor suppressor in colon cancer. To understand the functional contributions of CDX2 to colon cancer, we disrupted CDX2 in LOVO and SW48 human colon cancer cell lines by targeted homologous recombination. Consistent with the literature, disruption of CDX2 enhanced anchorage-dependent cell proliferation. However, homozygous loss of CDX2 led to significant inhibition of anchorage-independent growth in LOVO cells, and cell lethality in SW48 cells. Further analyses revealed that disruption of CDX2 led to anchorage-independent G1 to S growth arrest and anoikis. In vivo xenograft studies confirmed that disruption of CDX2 inhibited LOVO tumor growth. These data demonstrate that CDX2 mediates anchorage-independent growth and survival. Thus, CDX2 has tumorigenic potential in the human colon cancer cell lines LOVO and SW48.

Antiviral potential of a new generation of acyclic nucleoside phosphonates, the 6-[2-(phosphonomethoxy)alkoxy]-2,4-diaminopyrimidines

Three acyclic nucleoside phosphonates (ANPs) have been formally approved for clinical use in the treatment of 1) cytomegalovirus retinitis in AIDS patients (cidofovir, by the intravenous route), 2) chronic hepatitis B virus (HBV) infections (adefovir dipivoxil, by the oral route), and 3) human immunodeficiency virus (HIV) infections (tenofovir disoproxil fumarate, by the oral route). The activity spectrum of cidofovir {(S)- 1-[3-hydroxy-2-(phosphonomethoxy)propyl]cytosine [(S)-HPMPC)]}, like that of (S)-HPMPA [(S)-9-[3-hydroxy-2-(phosphonomethoxy)propyl]adenine) and (S)-HPMPDAP [(S)-9-[3-hydroxy-2-(phosphonomethoxy)propyl]-2, 6-diaminopurine), encompasses a broad spectrum of DNA viruses, including polyoma-, papilloma-, adeno-, herpes-, and poxviruses. Adefovir {9-[2-(phosphonomethoxy)ethyl]adenine (PMEA)} and tenofovir [(R)-9-[2-(phosphonomethoxy) propyl]adenine [(R)-PMPA)]} are particularly active against retroviruses (ie., HIV) and hepadnaviruses (ie., HBV); additionally, PMEA also shows activity against herpes- and poxviruses. We have recently identified a new class of ANPs, namely 6-[2-(phosphonomethoxy)alkoxy]-2,4-diaminopyrimidines, named, in analogy with their alkylpurine counterparts, HPMPO-DAPy, PMEO-DAPy, and (R)-PMPO-DAPy. These compounds exhibit an antiviral activity spectrum and potency that is similar to that of (S)-HPMPDAP, PMEA, and (R)-PMPA, respectively. Thus, PMEO-DAPy and (R)-PMPO-DAPy, akin to PMEA and (R)-PMPA, proved particularly active against HIV- 1, HIV-2, and the murine retrovirus Moloney sarcoma virus (MSV). PMEO-DAPy and (R)-PMPO-DAPy also showed potent activity against both wild-type and lamivudine-resistant strains of HBV. HPMPO-DAPy was found to inhibit different poxviruses (ie., vaccinia, cowpox, and orf) at a similar potency as cidofovir. HPMPO-DAPy also proved active against adenoviruses. In vivo, HPMPO-DAPy proved equipotent to cidofovir in suppressing vaccinia virus infection (tail lesion formation) in immunocompetent mice and promoting healing of disseminated vaccinia lesions in athymic-nude mice. The 6-[2-(phosphonomethoxy)alkoxy]-2,4-diaminopyrimidines offer substantial potential for the treatment of a broad range of retro-, hepadna-, herpes-, adeno-, and poxvirus infections.

Novel acyclic nucleoside phosphonate analogues with potent anti-hepatitis B virus activities

Novel acyclic nucleoside phosphonates with a pyrimidine base preferentially containing an amino group at C-2 and C-4 and a 2-(phosphonomethoxy)ethoxy or (R)-2-(phosphonomethoxy)propoxy group at C-6 selectively inhibit the replication of wild-type and lamivudine-resistant hepatitis B viruses. The activity of the most potent compounds was comparable to that of adefovir.

Effects of the dietary phytoestrogen biochanin A on cell growth in the mammary carcinoma cell line MCF-7

Studies of the dietary phytoestrogen biochanin A on cell proliferation of the cultured estrogen responsive cells human breast carcinoma MCF-7 showed that biochanin A exhibits biphasic regulation on MCF-7 cells. At concentrations of less than 10 microg/mL, cells respond to biochanin A by increasing cell growth and de novo DNA synthesis. The addition of biochanin A at concentrations of greater than 30 microg/mL significantly inhibited cell growth and DNA synthesis in a dose-dependent fashion, resulting in an IC(50) value of 40 microg/mL. The reversibility of these inhibitory effects by biochanin A appears also to be concentration dependent. Cells previously treated with high concentrations (>60 microg/mL) of biochanin A did not regain normal growth after treatment ceased. Biochanin A was cytostatic at low concentrations (<40 microg/mL) and cytotoxic at higher concentrations. Upon exposure to 100 microg/mL of biochanin A, cell morphology was severely altered, cell volume decreased, and condensation of cell components was clearly noticeable. In addition, biochanin A damaged cell membranes by increasing membrane permeability. These results suggest possible molecular and cellular mechanisms of the action of dietary phytoestrogens on estrogen target cells.

Sulphated and sulphonated polymers inhibit the initial interaction of hepatitis B virus with hepatocytes

The initial step during hepatitis B virus (HBV) infection is the specific attachment of the virus to the hepatocyte. Here we studied whether the binding of HBV to hepatocytes can, as is the case with most other enveloped viruses, be blocked by polyanionic compounds. Viral particles produced by HepAD38 cells were used as inoculum and HBV-negative HepG2 cells, as well as primary human hepatocytes, as target cells. Three sulphated polymers, that is, PAVAS (a co-polymer of acrylic acid with vinyl alcohol sulphate), heparin and dextran sulphate (DS) (MW 5000), and the sulphonated polymer PAMPS [poly(2-acryl-amido-2-methyl-1-propanesulfonic acid] (MW approximately 7000-12000), proved strong inhibitors of the binding of HBV to HepG2 cells and primary hepatocytes. The 50% effective concentration (EC50) for inhibition of HBV binding to HepG2 cells by PAVAS, heparin, DS and PAMPS was 1.3 microg/ml, 1.6 microg/ml, 1.8 microg/ml and 3.3 microg/ml, respectively, and to primary hepatocytes 1.6 microg/ml (PAVAS), 1.6 microg/ml (heparin), 2.6 microg/ml (DS) and 4.1 microg/ml (PAMPS). These values are in the same range as the concentrations required for these compounds to prevent such viruses as herpesviruses and HIV from binding to cells. These findings may be helpful in elucidating the mechanism of the initial interaction of HBV with hepatocytes.

Carrier-mediated delivery improves the efficacy of 9-(2-phosphonylmethoxyethyl)adenine against hepatitis B virus

We recently synthesized a lipophilic prodrug of 9-(2-phosphonyl-methoxyethyl)adenine (PMEA), designated PMEA-LO, and incorporated it into reconstituted lactosylated high-density lipoprotein (LacNeoHDL). In a rat model, LacNeoHDL-associated PMEA-LO was internalized by the asialoglycoprotein receptor on parenchymal liver cells and converted into its active diphosphorylated metabolite. To further evaluate the therapeutic potential of the carrier-associated prodrug, we examined in this study the processing of (125)I-labeled PMEA-LO--loaded LacNeoHDL by HepG2 cells. Upon incubation with HepG2 cells, PMEA-LO--loaded LacNeoHDL became rapidly cell-associated. The association was saturable and of high-affinity (k(d) = 3.8 +/- 0.4 nM). Asialofetuin, an established ligand for the asialoglycoprotein receptor, inhibited the association by >75%, which confirms the role of the asialoglycoprotein receptor. Association of the prodrug-loaded particles to HepG2 cells was coupled to degradation. Radiolabeled degradation products appeared in the culture medium with a lag phase of 2 h. Asialofetuin and chloroquine inhibited secretion of degradation products by 75 to 80%, indicating that PMEA-LO--loaded LacNeoHDL is internalized via the asialoglycoprotein receptor and lysosomally processed. The therapeutic potential of LacNeoHDL-associated PMEA-LO was studied by measuring its effects on hepatitis B virus (HBV) replication in Hep AD38 cells (HBV-transfected HepG2 cells). LacNeoHDL-associated PMEA-LO effectively inhibited HBV DNA synthesis. The EC(50) value of carrier-associated PMEA-LO was 35 times lower than that of free PMEA (3.4 +/- 0.4 and 120 +/- 18 ng of PMEA/ml, respectively). We conclude that the present results, combined with our earlier in vivo disposition data, underscore the therapeutic potential and utility of PMEA-LO--loaded LacNeoHDL for treatment of chronic hepatitis B.

Case-controlled study on relevant factors of adolescent sexual coercion in China

This was a case-controlled study to determine factors related to sexual coercion among adolescent abortion seekers in China. We considered the abortion-seeking women who had experienced sexual coercion as the case group and the abortion-seeking women who had never experienced sexual coercion as the control group. The results of the study indicated that the factors more likely to be related to sexual coercion include lower educational level [odds ratio (OR) = 1.55], not living with parents (OR) = 1.57, floating population (OR = 1.63), beaten by her partner (OR = 2.87), abused by her partner (OR = 1.84), multiple partners (OR = 2.10), sex after excessive drinking (OR = 5.02), younger age at first intercourse (OR = 1.68), and large difference in age between men and women (OR = 2.02). The relevant factors most likely to be associated with sexual coercion are poorly educated, not living with parents, floating population, multiple partners, younger age at first sex, and inequality between men and women.

Acyclic/carbocyclic guanosine analogues as anti-herpesvirus agents

Several guanosine analogues, i.e. acyclovir (and its oral prodrug valaciclovir), penciclovir (in its oral prodrug form, famciclovir) and ganciclovir, are widely used for the treatment of herpesvirus [i.e. herpes simplex virus type 1 (HSV-1), and type 2 (HSV-2), varicella-zoster virus (VZV) and/or human cytomegalovirus (HCMV)] infections. In recent years, several new guanosine analogues have been developed, including the 3-membered cyclopropylmethyl and -methenyl derivatives (A-5021 and synguanol) and the 6-membered D- and L-cyclohexenyl derivatives. The activity of the acyclic/carbocyclic guanosine analogues has been determined against a wide spectrum of viruses, including the HSV-1, HSV-2, VZV, HCMV, and also human herpesviruses type 6 (HHV-6), type 7 (HHV-7) and type 8 (HHV-8), and hepatitis B virus (HBV). The new guanosine analogues (i.e. A-5021 and D- and L-cyclohexenyl G) were found to be particularly active against those viruses (HSV-1, HSV-2, VZV) that encode for a specific thymidine kinase (TK), suggesting that their antiviral activity (at least partially) depends on phosphorylation by the virus-induced TK. Marked antiviral activity was also noted with A-5021 against HHV-6 and with D- and L-cyclohexenyl G against HCMV and HBV. The antiviral activity of the acyclic/carbocyclic nucleoside analogues could be markedly potentiated by mycophenolic acid, a potent inhibitor of inosine 5'-monophosphate (IMP) dehydrogenase. The new carbocyclic guanosine analogues (i.e. A-5021 and D- and L-cyclohexenyl G) hold great promise, not only as antiviral agents for the treatment of herpesvirus infections, but also an antitumor agents for the combined gene therapy/chemotherapy of cancer, provided that (part of) the tumor cells have been transduced by the viral (HSV-1, VZV) TK gene.

Expression of transthyretin gene in Pichia pastoris

Plasmid pSK-TTR was digested by BamHI and the DNA fragment containing Transthyretin gene was cloned into the BamHI site of vector pHIL-SI. The recombinant plasmid pHIL-SI-TTR was digested by BglII; the larger fragment was transformed into yeast Pichia pastoris. SDS-PAGE analysis showed that the yeast transformant can express and secrete TTR as a fusion protein, TTRF. To purify TTRF,the DEAE-Sepherose F.F. chromatography and Sephacryl S-200 chromatography were used. The in vitro test showed that TTRF could inhibit the growth of human hepatoma cells.

Anti-herpesvirus activity of (1'S,2'R)-9-[[1',2'-bis(hydroxymethyl)-cycloprop-1'-yl]methyl] x guanine (A-5021) in vitro and in vivo

The novel nucleoside analog (1S',2R')-9-[[1',2'-bis(hydroxymethyl)cycloprop-1-yl]methyl]guanine (A-5021) was previously shown to be a potent inhibitor of the replication of herpes simplex virus type 1 and 2 (HSV-1 and HSV-2) and varicella zoster virus (VZV), both in vitro and in vivo (J. Med. Chem. 41, 1284-1298; Antimicrob. Agents Chemother. 42, 1666-1670). Here we demonstrate that A-5021 is also a potent inhibitor of Epstein-Barr virus (EBV) and human herpes virus 6 (HHV-6A and HHV-6B), but that the compound lacks activity against HHV-8. A-5021, in comparison to acyclovir, was also assessed for protective activity against HSV-1-induced mortality in SCID mice. The compounds were administered at 50 mg/kg per day by subcutaneous injection for four consecutive days and treatment was initiated at either 2 h, 1 or 2 days post infection (p.i.). When administered from day 0 to 4 p.i., A-5021 conferred complete protection against the infection (as assessed at 22 days p.i.), whereas acyclovir delayed virus induced mortality by only 5 days. When treatment was begun on day 1 or 2, A-5021 still afforded marked protection against the infection, whereas acyclovir was virtually devoid of any activity under these conditions. Our data underline that A-5021 may offer great promise for the treatment of herpesvirus infections.