OBJECTIVE--To study whether passive smoking at work is a risk factor for coronary heart disease. DESIGN--Case-control study. SETTING--Xi'an, China. SUBJECTS--59 patients with coronary heart disease and 126 controls, all Chinese women with full time jobs, who had never smoked cigarettes. RESULTS--The crude odds ratio for passive smoking from husband was 2.12 (95% confidence interval 1.06 to 4.25) and at work was 2.45 (1.23 to 4.88). The final logistic regression model, with passive smoking from husband and at work as the base, included age, history of hypertension, type A personality, and total cholesterol and high density lipoprotein cholesterol concentrations; the adjusted odds ratios for passive smoking from husband and at work were 1.24 (0.56 to 2.72) and 1.85 (0.86 to 4.00) respectively. For passive smoking at work, statistically significant linear trends of increasing risks (for both crude and adjusted odds ratios) with increasing exposures (amount exposed daily, number of smokers, number of hours exposed daily, and cumulative exposure) were observed. When these exposure variables were analysed as continuous variables, the crude and adjusted odds ratios were also significant. CONCLUSION--Passive smoking at work is a risk factor for coronary heart disease. Urgent public health measures are needed to reduce smoking and to protect non-smokers from passive smoking in China.
FMS-like tyrosine kinase 3 (FLT3) normally functions in the survival/proliferation of hematopoietic stem/progenitor cells, but its constitutive activation by internal tandem duplication (ITD) mutations correlates with a poor prognosis in AML. The development of FLT3 tyrosine kinase inhibitors (TKI) is a promising strategy, but resistance that arises during the course of treatment caused by secondary mutations within the mutated gene itself poses a significant challenge. In an effort to predict FLT3 resistance mutations that might develop in patients, we used saturation mutagenesis of FLT3/ITD followed by selection of transfected cells in FLT3 TKI. We identified F621L, A627P, F691L and Y842C mutations in FLT3/ITD that confer varying levels of resistance to FLT3 TKI. Western blotting confirmed that some FLT3 TKI were ineffective at inhibiting FLT3 autophosphorylation and signaling through MAP kinase, STAT5 and AKT in some mutants. Balb/c mice transplanted with the FLT3/ITD Y842C mutation confirmed resistance to sorafenib in vivo but not to lestaurtinib. These results indicate a growing number of FLT3 mutations that are likely to be encountered in patients. Such knowledge, combined with known remaining sensitivity to other FLT3 TKI, will be important to establish as secondary drug treatments that can be substituted when these mutants are encountered.
acute myeloid leukemia; mutant FLT3; drug resistance; tyrosine kinase inhibitors
The unfolded protein response (UPR) is generally activated in solid tumors and results in tumor cell anti-apoptosis and drug resistance. However, tumor-specific UPR transducers are largely unknown. In the present study, we identified CD147, a cancer biomarker, as an UPR inducer in hepatocellular carcinoma (HCC). The expression of the major UPR target, Bip, was found to be positively associated with CD147 in human hepatoma tissues. By phosphorylating FAK and Src, CD147-enhanced TFII-I tyrosine phosphorylation at Tyr248. CD147 also induced p-TFII-I nuclear localization and binding to the Bip promoter where endoplasmic reticulum (ER) stress response element 1 (ERSE1) (−82/−50) is the most efficient target of the three ERSEs, thus increasing transcription of Bip. Furthermore, by inducing UPR, CD147 inhibited HCC cell apoptosis and decreased cell Adriamycin chemosensitivity, thus decreasing the survival rate of hepatoma-bearing nude mice. Together, these results reveal pivotal roles for CD147 in modulating the UPR in HCC and raise the possibility that CD147 is a target that promotes HCC cell apoptosis and increases the sensitivity of tumors to anti-cancer drugs. Therefore, CD147 inhibition provides an opportunity to enhance the efficacy of existing agents and represents a novel target for HCC treatment.
CD147; unfolded protein response (UPR); hepatocellular carcinoma (HCC); Bip; apoptosis; chemosensitivity
To evaluate the impact of risk minimisation policies on the use of rosiglitazone-containing products and on glycaemic control among patients in Denmark and the UK.
Design, setting and participants
We used population-based data from the Aarhus University Prescription Database (AUPD) in northern Denmark and from the General Practice Research Database (GPRD) in the UK.
Main outcome measures
We examined the use of rosiglitazone during its entire period of availability on the European market (2000–2010) and evaluated changes in the glycated haemoglobin (HbA1c) and fasting plasma glucose (FPG) levels among patients discontinuing this drug.
During 2000–2010, 2321 patients with records in AUPD used rosiglitazone in northern Denmark and 25 428 patients with records in GPRD used it in the UK. The proportion of rosiglitazone users among all users of oral hypoglycaemic agents peaked at 4% in AUPD and at 15% in GPRD in May 2007, the month of publication of a meta-analysis showing increased cardiovascular morbidity associated with rosiglitazone use. 12 months after discontinuation of rosiglitazone-containing products, the mean change in HbA1c was −0.16% (95% CI −3.4% to 3.1%) in northern Denmark and −0.17% (95% CI −0.21% to 0.13%) in the UK. The corresponding mean changes in FPG were 0.01 mmol/L (95% CI −7.3 to 7.3 mmol/L) and 0.03 mmol/L (95% CI −0.22 to 0.28 mmol/L).
Publication of evidence concerning the potential cardiovascular risks of rosiglitazone was associated with an irreversible decline in the use of rosiglitazone-containing products in Denmark and the UK. The mean changes in HbA1c and FPG after drug discontinuation were slight.
diabetes mellitus; drug safety; glucose-lowering drugs; rosiglitazone; thiazolidinediones
To evaluate the effects of heart rate and heart rate variability on image quality, patient dose and diagnostic accuracy of 320-detector row CT.
94 patients were prospectively enrolled. Heart rate was defined as the mean value of different intervals elapsing between two consecutive R waves in an electrocardiogram (R–R intervals) and the heart rate variability was calculated as the standard deviation from the average heart rate. The image quality was evaluated by four grades, according to motion artefacts (“step artefacts” and “blurring artefacts”). The diagnostic accuracy was analysed in 43 patients who were scheduled for invasive coronary angiography (ICA). The coeffects of heart rate and heart rate variability on image quality, radiation dose and diagnostic accuracy were evaluated by multivariate regression.
The mean image quality score was 1.2±0.5 and the mean effective dose was 14.8±9.8 mSv. The results showed that heart rate (74.0±11.2 beats per minute) was the single factor influencing image quality (p<0.001) and radiation dose (p<0.001), while heart rate variability (3.7±4.6) had no significant effect on them (p=0.16 and p=0.47, respectively). For 43 patients who underwent ICA, heart rate and heart rate variability showed no influence on the accuracy (p=0.17 and p=0.12, respectively). Overall sensitivity was 97.4% (37/38), specificity was 99.4% (351/353), positive predictive value was 94.9% (37/39) and negative predictive value was 99.7% (351/352).
320-detector row CT, with improved longitudinal coverage of detector, resolves step artefact and high patient dose caused by irregular heart rate. However, it is still recommended to control heart rate to a lower level to eliminate blurring artefact and radiation dose.
The present study investigated the relationships among oxidative stress, β-amyloid and cognitive abilities in the APP/PSEN1 double-transgenic mouse model of Alzheimer’s disease. In two experiments, long-term dietary supplements were given to aged APP/PSEN1 mice containing vitamin C alone (1g/kg diet, Expt. 1) or in combination with a high (750 IU/kg diet, Expts. 1 and 2) or lower (400 IU/kg diet, Expt. 2) dose of vitamin E. Oxidative stress, measured by F4-neuroprostanes or malondialdehyde, was elevated in cortex of control-fed APP/PSEN1 mice and reduced to wild-type levels by vitamin supplementation. High dose vitamin E with C was less effective at reducing oxidative stress than vitamin C alone or the low EC diet combination. The high-dose combination also impaired water maze performance in mice of both genotypes. In Experiment 2 the lower vitamin EC treatment attenuated spatial memory deficits in APP/PSEN1 mice and improved performance in wild-type mice in the water maze. Amyloid deposition was not reduced by antioxidant supplementation in either experiment.
Vitamin C; Vitamin E; oxidative stress; Alzheimer’s disease; cognition
Hepatic oval cells (HOCs) are recognized as facultative liver progenitor cells that
play a role in liver regeneration after acute liver injury. Here, we investigated the
in vitro proliferation and differentiation characteristics of
HOCs in order to explore their potential capacity for intrahepatic transplantation.
Clusters or scattered HOCs were detected in the portal area and interlobular bile
duct in the liver of rats subjected to the modified 2-acetylaminofluorene and partial
hepatectomy method. Isolated HOCs were positive for c-kit and CD90 staining (99.8%
and 88.8%, respectively), and negative for CD34 staining (3.6%) as shown by
immunostaining and flow cytometric analysis. In addition, HOCs could be
differentiated into hepatocytes and bile duct epithelial cells after leukemia
inhibitory factor deprivation. A two-cuff technique was used for orthotopic liver
transplantation, and HOCs were subsequently transplanted into recipients. Biochemical
indicators of liver function were assessed 4 weeks after transplantation. HOC
transplantation significantly prolonged the median survival time and improved the
liver function of rats receiving HOCs compared to controls (P=0.003, Student
t-test). Administration of HOCs to rats also receiving liver
transplantation significantly reduced acute allograft rejection compared to control
liver transplant rats 3 weeks following transplantation (rejection activity index
score: control=6.3±0.9; HOC=3.5±1.5; P=0.005). These results indicate that HOCs may
be useful in therapeutic liver regeneration after orthotopic liver
Hepatic oval cells; Proliferation; Differentiation; Liver transplantation
Several Bmp genes are expressed in the developing mouse tooth germ from the initiation to the late-differentiation stages, and play pivotal roles in multiple steps of tooth development. In this study, we investigated the requirement of BMP activity in early tooth development by transgenic overexpression of the extracellular BMP antagonist Noggin. We show that overexpression of Noggin in the dental epithelium at the tooth initiation stage arrests tooth development at the lamina/early-bud stage. This phenotype is coupled with a significantly reduced level of cell proliferation rate and a down-regulation of Cyclin-D1 expression, specifically in the dental epithelium. Despite unaltered expression of genes known to be implicated in early tooth development in the dental mesenchyme and dental epithelium of transgenic embryos, the expression of Pitx2, a molecular marker for the dental epithelium, became down-regulated, suggesting the loss of odontogenic fate in the transgenic dental epithelium. Our results reveal a novel role for BMP signaling in the progression of tooth development from the lamina stage to the bud stage by regulating cell proliferation and by maintaining odontogenic fate of the dental epithelium.
BMP signaling; BMP antagonist; Noggin overexpression; tooth progression; Cyclin-D; transgenic mice
Background and Objectives
The macrophage is an important early cellular marker related to risk of future rupture of atherosclerotic plaques. Two-channel two-photon luminescence (TPL) microscopy combined with optical coherence tomography (OCT) was used to detect, and further characterize the distribution of aorta-based macrophages using plasmonic gold nanorose as an imaging contrast agent.
Study Design/Materials and Methods
Nanorose uptake by macrophages was identified by TPL microscopy in macrophage cell culture. Ex vivo aorta segments (8 × 8 × 2 mm3) rich in macrophages from a rabbit model of aorta inflammation were imaged by TPL microscopy in combination with OCT. Aorta histological sections (5 µm in thickness) were also imaged by TPL microscopy.
Merged two-channel TPL images showed the lateral and depth distribution of nanorose-loaded macrophages (confirmed by RAM-11 stain) and other aorta components (e.g., elastin fiber and lipid droplet), suggesting that nanorose-loaded macrophages are diffusively distributed and mostly detected superficially within 20 µm from the luminal surface of the aorta. Moreover, OCT images depicted detailed surface structure of the diseased aorta.
Results suggest that TPL microscopy combined with OCT can simultaneously reveal macrophage distribution with respect to aorta surface structure, which has the potential to detect vulnerable plaques and monitor plaque-based macrophages overtime during cardiovascular interventions.
atherosclerosis; macrophage; nanorose; two-photon luminescence microscopy; optical coherence tomography; photothermal wave imaging
We are interested in investigating whether cancer therapy may alter the mitochondrial redox state in cancer cells to inhibit their growth and survival. The redox state can be imaged by the redox scanner that collects the fluorescence signals from both the oxidized-flavoproteins (Fp) and the reduced form of nicotinamide adenine dinucleotide (NADH) in snap-frozen tissues and has been previously employed to study tumor aggressiveness and treatment responses. Here, with the redox scanner we investigated the effects of chemotherapy on mouse xenografts of a human diffuse large B-cell lymphoma cell line (DLCL2). The mice were treated with CHOP therapy, i.e., cyclophosphamide (C) + hydroxydoxorubicin (H) + Oncovin (O) + prednisone (P) with CHO administration on day 1 and prednisone administration on days 1–5. The Fp content of the treated group was significantly decreased (p = 0.033) on day 5, and the mitochondrial redox state of the treated group was slightly more reduced than that of the control group (p = 0.048). The decrease of the Fp heterogeneity (measured by the mean standard deviation) had a border-line statistical significance (p = 0.071). The result suggests that the mitochondrial metabolism of lymphoma cells was slightly suppressed and the lymphomas became less aggressive after the CHOP therapy.
NADH; flavoprotein; DLCL2; therapeutic effect; tumor metabolism
The associations between plasma letrozole concentrations and CYP2A6 and CYP3A5 genetic variants were tested in the Exemestane and Letrozole Pharmacogenomics (ELPH) trial. ELPH is a multicenter, open-label prospective clinical trial in women randomly assigned (n ≈ 250 in each arm) to receive 2 years of treatment with either oral letrozole (2.5 mg/day) or oral exemestane (25 mg/day). CYP2A6 and CYP3A showed effects on letrozole metabolism in vitro. DNA samples were genotyped for variants in the CYP2A6 and CYP3A5 genes. plasma letrozole concentrations showed high interpatient variability (>10-fold) and were associated significantly with CYP2A6 genotypes (P < 0.0001), body mass index (BMI) (P < 0.0001), and age (P = 0.0035). However, CYP3A5 genotypes showed no association with plasma letrozole concentrations. These data suggest that CYP2A6 is the principal clearance mechanism for letrozole in vivo. CYP2A6 metabolic status, along with BMI and age, may serve as a biomarker of the efficacy of letrozole treatment or a predictor of adverse effects.
The aim of this article was to prospectively evaluate the accuracy and radiation dose of 320-detector row dynamic volume CT (DVCT) for the detection of coronary artery disease (CAD) in a high-risk population.
60 patients with a high risk of CAD underwent DVCT without preceding heart rate control and also underwent invasive coronary angiography (ICA), which served as the standard reference.
On a per segment analysis, overall sensitivity was 95.3%, specificity was 97.6%, positive predictive value was 90.6%, negative predictive value was 98.8% and Youden index was 0.93. In both heart rate subgroups, diagnostic accuracy for the assessment of coronary artery stenosis was similar. The accuracy of the subgroup with an Agatston score ≥100 was lower than that for patients with an Agatston score <100. However, the difference between DVCT and ICA results was not significant (p=0.08). The mean estimated effective dose of CT was 12.5±9.4 mSv. In those patients with heart rates less than 70 beats per minute (bpm), the mean radiation exposure of DVCT was 5.2±0.9 mSv. The effective radiation dose was significantly lower than that of ICA (14.1±5.9 mSv) (p<0.001). When the heart rate was >70 bpm, a significantly higher dose was delivered to patients with DVCT (22.6±5.2 mSv, p<0.001) than with ICA (15.0±5.3 mSv, p<0.001).
DVCT reliably provides high diagnostic accuracy without heart rate/rhythm control. However, from a dosimetric point of view, it is recommended that heart rate should be controlled to <70 bpm to decrease radiation dose.
A computational model of the glucagon/insulin-driven liver glucohomeostasis function, focusing on the buffering of glucose into glycogen, has been developed. The model exemplifies an ‘engineering’ approach to modelling in systems biology, and was produced by linking together seven component models of separate aspects of the physiology. The component models use a variety of modelling paradigms and degrees of simplification. Model parameters were determined by an iterative hybrid of fitting to high-scale physiological data, and determination from small-scale in vitro experiments or molecular biological techniques. The component models were not originally designed for inclusion within such a composite model, but were integrated, with modification, using our published modelling software and computational frameworks. This approach facilitates the development of large and complex composite models, although, inevitably, some compromises must be made when composing the individual models. Composite models of this form have not previously been demonstrated.
computational modelling; glucose homeostasis; liver; systems biology
Using a composite model of the glucose homeostasis system, consisting of seven interconnected submodels, we enumerate the possible behaviours of the model in response to variation of liver insulin sensitivity and dietary glucose variability. The model can reproduce published experimental manipulations of the glucose homeostasis system and clearly illustrates several important properties of glucose homeostasis—boundedness in model parameters of the region of efficient homeostasis, existence of an insulin sensitivity that allows effective homeostatic control and the importance of transient and oscillatory behaviour in characterizing homeostatic failure. Bifurcation analysis shows that the appearance of a stable limit cycle can be identified.
computational modelling; glucose homeostasis; liver; bifurcation analysis
BMP signaling plays crucial roles in the development of many organs, including the tooth. Equally important is BMP signaling homeostasis, as demonstrated by multiple organ defects in mice lacking the extracellular BMP antagonist Noggin. Here, we show that Noggin is initially expressed in the maxillary mesenchyme adjunct to the upper incisor at the initiation stage, and then in the developing teeth, including incisors and molars, from the bud stage. Noggin mutants develop normal molars and mandibular incisors, but form a single, medially located upper incisor that is arrested at the late bud stage. Histological and molecular marker analyses demonstrated that two distinct upper incisor placodes initiate independently at E11.5, but begin to fuse at E12.5, coupling with elevated cell proliferation rates in the developing tooth germs. We further found that Chordin and Gremlin, two other BMP antagonists, are co-expressed with Noggin in the developing lower incisor and molar teeth. These observations indicate the importance of BMP signaling homeostasis, and suggest a functional redundancy between BMP antagonists during tooth development.
BMP antagonist; BMP homeostasis; Chordin; Gremlin; tooth development; tooth fusion
To evaluate the efficacy and treatment-related toxicity of accelerated hyperfractionation field-involved re-irradiation combined with concurrent capecitabine chemotherapy for locally recurrent and irresectable rectal cancer (LRIRC).
72 patients with LRIRC who underwent the treatment were studied. Three-dimensional conformal accelerated hyperfractionation radiotherapy (3D-CAHRT) was performed and the dose was delivered with a schedule of 1.2 Gy twice daily, with an interval of at least 6 h between fractions, 5 days a week. Concurrent capecitabine chemotherapy was administered twice daily. After 36 Gy in 30 fractions over 3 weeks, patients were evaluated to define the resectability of the disease. If resection was not feasible irradiation was resumed until the total dose administered to the tumour reached 51.6–56.4 Gy.
Two patients temporarily interrupted concurrent chemoradiation because of Grade IV diarrhoea. The remaining 70 patients completed the planned concurrent chemoradiation. In all patients, the complete response rate was 8.3% and the partial response rate was 51.4%. The overall response rate was 59.7% and clinical benefit rate was 93.1%. Symptomatic responses proved to be obvious and tumour resection was performed in 18 patients. The overall median survival time and median progression-free survival time were 32 and 17 months, respectively. 3 year overall survival and progression-free survival were 45.12% and 31.19%, respectively. Severely acute toxicities included Grade III–IV diarrhoea and granulocytopenia with 9.7% and 8.3% incidence respectively. Small bowel obstruction was severely late toxicity, and the incidence was 1.4%.
Three-dimensional conformal accelerated hyperfractionation field-involved re-irradiation combined with concurrent capecitabine chemotherapy might be an effective and well-tolerated regimen for patients with LRIRC.
Obesity-associated carcinogenesis is postulated to be mediated through the proliferative actions of insulin and the insulin-like growth factor (IGF) family. The aim of this study was to determine whether the insulin/IGF-1 pathway is involved in the sequential progression from metaplastic Barrett's esophagus (BE) to dysplasia to esophageal adenocarcinoma (EAC).
Fasting serum levels of insulin, glucose, IGF-1, insulin growth factor binding protein-1 (IGFBP1), and IGFBP3 were measured in 44 non-dysplastic, 9 low-grade dysplasia (LGD), 12 high-grade dysplasia (HGD), and 10 EAC subjects. Immunohistochemistry was performed on paraffin-embedded tissue derived from BE cases using rabbit monoclonal antibodies to p-mammalian target of rapamycin (mTOR) and p-AKT, mouse monoclonal antibody to Ki-67, and rabbit polyclonal antibody to p-insulin receptor substrate 1 (IRS1).
Nineteen of 44 (43.2%) BE, 5/9 (55%) LGD, 8/12 (66.7%) HGD and EAC 7/10 (70%) cases showed strong staining for p-IRS1. A significantly higher proportion of HGD/EAC subjects showed p-IRS1 staining when compared with BE/LGD subjects, 63.6% vs. 41.5%, P<0.05. p-IRS1 immunostaining was moderately correlated with strong immunostaining of the downstream mediators p-AKT and p-mTOR (Spearman correlation coefficient=0.167 and 0.27 for p-IRS1/p-AKT and for p-IRS1/p-mTOR, respectively) and the proliferation marker Ki-67 (Spearman correlation coefficient=0.20, P=0.09). However, systemic levels of insulin, IGF-1, or IGF-2 were not associated with tissue immunostaining of p-IRS1.
Activation of the insulin/IGF-1 pathway in BE may be associated with cellular proliferation and appears to have a role in the progression from metaplasia to cancer. The activation of the insulin/IGF-1 pathway at the tissue level is likely complex and does not have a simple association with systemic measures of insulin or IGF-1.
Computational mechanics has been advanced in every area of orthopedic biomechanics. The objective of this paper is to provide a general review of the computational models used in the analysis of the mechanical function of the knee joint in different loading and pathological conditions. Major review articles published in related areas are summarized first. The constitutive models for soft tissues of the knee are briefly discussed to facilitate understanding the joint modeling. A detailed review of the tibiofemoral joint models is presented thereafter. The geometry reconstruction procedures as well as some critical issues in finite element modeling are also discussed. Computational modeling can be a reliable and effective method for the study of mechanical behavior of the knee joint, if the model is constructed correctly. Single-phase material models have been used to predict the instantaneous load response for the healthy knees and repaired joints, such as total and partial meniscectomies, ACL and PCL reconstructions, and joint replacements. Recently, poromechanical models accounting for fluid pressurization in soft tissues have been proposed to study the viscoelastic response of the healthy and impaired knee joints. While the constitutive modeling has been considerably advanced at the tissue level, many challenges still exist in applying a good material model to three-dimensional joint simulations. A complete model validation at the joint level seems impossible presently, because only simple data can be obtained experimentally. Therefore, model validation may be concentrated on the constitutive laws using multiple mechanical tests of the tissues. Extensive model verifications at the joint level are still crucial for the accuracy of the modeling.
Background Variation in the complement factor H gene (CFH) is associated with risk of late age-related macular degeneration (AMD). Previous studies have been case–control studies in populations of European ancestry with little differentiation in AMD subtype, and insufficient power to confirm or refute effect modification by smoking.
Methods To precisely quantify the association of the single nucleotide polymorphism (SNP rs1061170, ‘Y402H’) with risk of AMD among studies with differing study designs, participant ancestry and AMD grade and to investigate effect modification by smoking, we report two unpublished genetic association studies (n = 2759) combined with data from 24 published studies (26 studies, 26 494 individuals, including 14 174 cases of AMD) of European ancestry, 10 of which provided individual-level data used to test gene–smoking interaction; and 16 published studies from non-European ancestry.
Results In individuals of European ancestry, there was a significant association between Y402H and late-AMD with a per-allele odds ratio (OR) of 2.27 [95% confidence interval (CI) 2.10–2.45; P = 1.1 x 10−161]. There was no evidence of effect modification by smoking (P = 0.75). The frequency of Y402H varied by ancestral origin and the association with AMD in non-Europeans was less clear, limited by paucity of studies.
Conclusion The Y402H variant confers a 2-fold higher risk of late-AMD per copy in individuals of European descent. This was stable to stratification by study design and AMD classification and not modified by smoking. The lack of association in non-Europeans requires further verification. These findings are of direct relevance for disease prediction. New research is needed to ascertain if differences in circulating levels, expression or activity of factor H protein explain the genetic association.
Age-related macular degeneration (AMD); Complement factor H gene; meta-ananlysis
Inflammation can influence multipotency and self-renewal of mesenchymal stem cells (MSCs), resulting in their awakened bone-regeneration ability. Human periodontal ligament tissue-derived MSCs (PDLSCs) have been isolated, and their differentiation potential was found to be defective due to β-catenin signaling indirectly regulated by inflammatory microenvironments. Nuclear factor-κB (NF-κB) is well studied in inflammation by many different groups. The role of NF-κB needs to be studied in PDLSCs, although genetic evidences have recently shown that NF-κB inhibits osteoblastic bone formation in mice. However, the mechanism as to how inflammation leads to the modulation of β-catenin and NF-κB signaling remains unclear. In this study, we investigated β-catenin and NF-κB signaling through regulation of glycogen synthase kinase 3β activity (GSK-3β, which modulates β-catenin and NF-κB signaling) using a specific inhibitor LiCl and a phosphatidylinositol 3-kinase (PI3K) inhibitor LY 294002. We identified that NF-κB signaling might be more important for the regulation of osteogenesis in PDLSCs from periodontitis compared with β-catenin. BAY 11-7082 (an inhibitor of NF-κB) could inhibit phosphorylation of p65 and partly rescue the differentiation potential of PDLSCs in inflammation. Our data indicate that NF-κB has a central role in regulating osteogenic differentiation of PDLSCs in inflammatory microenvironments. Given the molecular mechanisms of NF-κB in osteogenic differentiation governed by inflammation, it can be said that NF-κB helps in improving stem cell-mediated inflammatory bone disease therapy.
periodontal ligament stem cell; NF-κB; GSK-3β; osteogenic differentiation; inflammation
The progression of osteoarthritis can be accompanied by depth-dependent changes in the properties of articular cartilage. The objective of the present study was to determine the subsequent alteration in the fluid pressurization in the human knee using a three-dimensional computer model. Only a small compression in the femur-tibia direction was applied to avoid numerical difficulties. The material model for articular cartilages and menisci included fluid, fibrillar and nonfibrillar matrices as distinct constituents. The knee model consisted of distal femur, femoral cartilage, menisci, tibial cartilage, and proximal tibia. Cartilage degeneration was modeled in the high load-bearing region of the medial condyle of the femur with reduced fibrillar and nonfibrillar elastic properties and increased hydraulic permeability. Three case studies were implemented to simulate (1) the onset of cartilage degeneration from the superficial zone, (2) the progression of cartilage degeneration to the middle zone, and (3) the progression of cartilage degeneration to the deep zone. As compared with a normal knee of the same compression, reduced fluid pressurization was observed in the degenerated knee. Furthermore, faster reduction in fluid pressure was observed with the onset of cartilage degeneration in the superficial zone and progression to the middle zone, as compared to progression to the deep zone. On the other hand, cartilage degeneration in any zone would reduce the fluid pressure in all three zones. The shear strains at the cartilage-bone interface were increased when cartilage degeneration was eventually advanced to the deep zone. The present study revealed, at the joint level, altered fluid pressurization and strains with the depth-wise cartilage degeneration. The results also indicated redistribution of stresses within the tissue and relocation of the loading between the tissue matrix and fluid pressure. These results may only be qualitatively interesting due to the small compression considered.
Sixty treatment-seeking individuals with methamphetamine (MA) dependence entered a randomized, placebo-controlled, double-blind clinical trial of oral dextroamphetamine (d-AMP) as a replacement therapy for MA dependence. The subjects took 60 mg sustained-release d-AMP for 8 weeks, during which time they received eight 50-min sessions of individual psychotherapy. Adverse events and urine toxicology for MA were assessed two times a week. There were no serious adverse events. Urine samples containing <1,000 ng/ml of MA were classified as negative for MA. The MA-negative scores in the d-AMP group (3.1 ± SD 4.6) were no higher than those in the placebo group (3.3 ± SD 5.3; P > 0.05). However, withdrawal and craving scores were significantly lower in the d-AMP group (P < 0.05 for both). Although subjects taking d-AMP did not reduce their use of MA, the significant reductions observed in withdrawal and craving scores in this group support the need for further exploration of d-AMP as a pharmacologic intervention for MA dependence, possibly at higher doses.
As applications of nanoparticles in medical imaging and biomedicine rapidly expand, the interactions of nanoparticles with living cells have become an area of active interest. For example, intracellular trafficking of nanoparticles – an important part of cell-nanoparticle interaction, has been well studied using plasmonic nanoparticles and optical or optics-based techniques due to the change in optical properties of the nanoparticle aggregates. However, magnetic nanoparticles, despite their wide range of clinical applications, do not exhibit plasmonic-resonant properties and therefore their intracellular aggregation cannot be detected by optics-based imaging techniques. In this study, we investigated the feasibility of a novel imaging technique – pulsed magneto-motive ultrasound (pMMUS), to identify intracellular trafficking of endocytosed magnetic nanoparticles. In pulsed magneto-motive ultrasound imaging a focused, high intensity, pulsed magnetic field is used to excite the cells labeled with magnetic nanoparticles, and ultrasound imaging is then used to monitor the mechanical response of the tissue. We demonstrated previously that clusters of magnetic nanoparticles amplify the pMMUS signal in comparison to signal from individual nanoparticles. Here we further demonstrate that pMMUS imaging can identify interaction between magnetic nanoparticles and living cells, i.e. intracellular aggregation of nanoparticles within the cells. The results of our study suggest that pMMUS imaging can not only detect the presence of magnetic nanoparticles but also provides information about their intracellular trafficking non-invasively and in real-time.
Pulsed magneto-motive ultrasound imaging; superparamagnetic iron-oxide nanoparticles; macrophage; endocytosis; intracellular trafficking
Mutations in GLIS3, which encodes a Krüppel-like zinc finger transcription factor, were found to underlie sporadic neonatal diabetes. Inactivation of Glis3 by gene targeting in mice was previously shown to lead to neonatal diabetes, but the underlying mechanism remains largely unknown. We aimed to elucidate the mechanism of action of GLIS family zinc finger 3 (GLIS3) in Glis3−/− mice and to further decipher its action in in-vitro systems.
We created Glis3−/− mice and monitored the morphological and biochemical phenotype of their pancreatic islets at different stages of embryonic development. We combined these observations with experiments on Glis3 expressed in cultured cells, as well as in in vitro systems in the presence of other reconstituted components.
In vivo and in vitro analyses placed Glis3 upstream of Neurog3, the endocrine pancreas lineage-defining transcription factor. We found that GLIS3 binds to specific GLIS3-response elements in the Neurog3 promoter, activating Neurog3 gene transcription both directly, and synergistically with hepatic nuclear factor 6 and forkhead box A2.
These results indicate that GLIS3 controls fetal islet differentiation via direct transactivation of Neurog3, a perturbation that causes neonatal diabetes in mice.
GLIS3; Neonatal diabetes; Neurog3; Pancreatic islet differentiation
Methylmalonic acidemia (MMA), an inherited metabolic disorder caused by deficient activity of methylmalonyl-CoA mutase (MUT), carries a poor prognosis for long-term survival. While administration of a recombinant adeno-associated virus serotype 8 vector (rAAV8) can rescue Mut-/- mice from neonatal lethality and provide sustained phenotypic correction, translation of gene therapy to human subjects will likely require multiple rounds of systemic administration and ideally, the use of a vector that transduces the kidney. To examine the effectiveness of alternative rAAVs in the treatment of MMA, a serotype 9 rAAV expressing the Mut cDNA was constructed and delivered to newborn Mut-/- mice (n=11). rAAV9 gene therapy directed hepatic transgene expression within 24 hours and effectively rescued the Mut-/- mice from lethality, conferred long-term survival, markedly improved metabolism and resulted in striking preservation of renal function and histology. Systemic re-administration of the vector at a dose similar to that used in human clinical trials (2.5×109 GC rAAV9 per gram) to older, treated Mut-/- mice (n=5) lowered circulating metabolites, increased in vivo propionate oxidative capacity and produced transgene expression in the kidney and liver. Our data support the use of an rAAV9 vector in the acute and chronic treatment of MMA, and highlight the renotropism afforded by this novel serotype.