The Antioxidative Effect of Heat‐Shock Protein 70 in Dendritic Cells

Reactive oxygen species (ROS) are produced by dendritic cells (DCs) during antigen presentation in contact hypersensitivity (CHS). ROS cause a number of non‐enzymatic protein modifications, such as carbonylation. Carbonylated proteins in DCs in response to hapten have not been fully identified yet. To identify the proteins carbonylated by ROS, murine epidermis‐derived DC line XS106 was challenged with a hapten, 2,4,6‐trinitrobenzene sulphonic acid (TNBS). MALDI‐TOF analysis revealed that heat‐shock protein 70 (HSP70) was one of the carbonylated proteins induced by TNBS. To verify the role of HSP70 in TNBS‐treated XS106 cell, we fused protein transduction domain (PTD) with HSP70 to facilitate protein delivery into the cell. The transfected fusion protein HSP70 within the cell caused transient increase of the cellular level of HSP70. Transient increase of HSP70 level in XS‐106 DCs resulted in inhibition of ROS production, carbonylation of HSP70, p38 MAPK activation and subsequently IL‐12 secretion. To investigate the effects of PTD–HSP70 in vivo, ear‐swelling experiments with 2,4,6‐trinitro‐1‐chlorobenzene (TNCB) were performed in BALB/c mice. Pretreatment of PTD–HSP70 reduced the CHS response to TNCB in vivo. We report here that carbonylation of HSP70 by ROS is associated with the pathogenesis of CHS, suggesting possibility of HSP70‐targeting therapy in CHS.     

Geometric control of capillary architecture via cell-matrix mechanical interactions

Capillary morphogenesis is a multistage, multicellular activity that plays a pivotal role in various developmental and pathological situations. In-depth understanding of the regulatory mechanism along with the capability of controlling the morphogenic process will have direct implications on tissue engineering and therapeutic angiogenesis. Extensive research has been devoted to elucidate the biochemical factors that regulate capillary morphogenesis. The roles of geometric confinement and cell-matrix mechanical interactions on the capillary architecture, nevertheless, remain largely unknown. Here, we show geometric control of endothelial network topology by creating physical confinements with microfabricated fences and wells. Decreasing the thickness of the matrix also results in comparable modulation of the network architecture, supporting the boundary effect is mediated mechanically. The regulatory role of cell-matrix mechanical interaction on the network topology is further supported by alternating the matrix stiffness by a cell-inert PEG-dextran hydrogel. Furthermore, reducing the cell traction force with a Rho-associated protein kinase inhibitor diminishes the boundary effect. Computational biomechanical analysis delineates the relationship between geometric confinement and cell-matrix mechanical interaction. Collectively, these results reveal a mechanoregulation scheme of endothelial cells to regulate the capillary network architecture via cell-matrix mechanical interactions.     

In vitro antioxidation activity and genoprotective effect of selected Chinese medicinal herbs

Some traditional Chinese medicinal seeds and fruits are well known for their antioxidant properties. This research aims to investigate whether Fructus Lycii, Fructus Schisandrae Chinensis, Fructus Ligustri Lucidi and Semen Cuscutae protect DNA from oxidant challenge by hydrogen peroxide (H(2)O(2)). The standard comet assay was used to assess the genoprotective effect of these medicinal herbs. Blood was taken from three healthy adults, aged from 36 to 42. Lymphocytes were isolated and treated with different concentrations of aqueous herbal extracts, while controls were treated with phosphate buffered saline. The lymphocytes were stressed with 50 μM H(2)O(2). Treated cells were embedded in agarose and layered on slides. These sandwiched lymphocytes were lysed and afterwards subjected to an electric field in an alkaline environment. Damaged DNA was pulled out from the nucleus towards the positive electrode as a comet tail; its density was related to the degree of DNA damage. Finally, the slides were stained with fluorescence dye and tails were visually scored for 100 cells. The experiment was repeated three times and DNA damage in treated cells was compared to the controls. There was no statistical difference in DNA damage among the herb treated cells and untreated cells in the comet assay. Our data demonstrated that the selected medicinal herbs did not show in vitro DNA protection in the comet assay against oxidant challenge.     

Normal cerebral asymmetry in familial and non-familial schizophrenic probands and their unaffected relatives

Loss of normal fronto-occipital cerebral asymmetry has been reported in patients with schizophrenia and also in their well relatives from multiply affected families, suggesting a relationship with susceptibility genes. We sought to confirm this relationship in a family study of patients with schizophrenia and their unaffected relatives of presumed differing genetic risk. MRI scans were carried out on 25 probands from families multiply affected with the disorder, and 36 of their unaffected relatives, 34 probands from families with no other affected members, 42 of their unaffected relatives, and 76 controls. Volumetric measurements of prefrontal, premotor, sensorimotor and occipitoparietal regions were obtained from which a measure of fronto-occipital torque was derived. There were no significant differences in measurements of fronto-occipital torque between the subject groups. Both schizophrenic probands and their relatives displayed the normal pattern of cerebral asymmetry, with larger right than left frontal regions and a larger left than right occipitoparietal region. Our findings failed to confirm an association between loss of fronto-occipital torque and genetic liability for schizophrenia and also failed to replicate the previously reported association between loss/reversal of fronto-occipital asymmetry and schizophrenia.     

Regulatory role of miR-142-3p on the functional hepatic cancer stem cell marker CD133

Tumor relapse after therapy typifies hepatocellular carcinoma (HCC) and is believed to be attributable to residual cancer stem cells (CSCs) that survive treatment. We have previously identified a CSC population derived from HCC that is characterized by CD133. Despite our growing knowledge of the importance of this subset of cells in driving HCC, the regulatory mechanism of CD133 is not known. Epigenetic changes are believed to be essential in the control of cancer and stem cells. Here, we report the epigenetic regulation of CD133 by miR-142-3p. The interaction between CD133 and miR-142-3p was identified by in silico prediction and substantiated by luciferase reporter analysis. Expression of CD133 was found to be inversely correlated with miR-142-3p in HCC clinical samples as well as in cell lines. Importantly, lower miR-142-3p expression in HCC was significantly associated with worst survival. Functional studies with miR-142-3p stably transduced in HCC cells demonstrated a diminished ability to self-renew, initiate tumor growth, invade, migrate, induce angiogenesis and resist chemotherapy. Rescue experiments whereby CD133 and miR-142-3p is simultaneously overexpressed compensated the deregulated ability of the cells to confer these features. Thus, miR-142-3p directly targets CD133 to regulate its ability to confer cancer and stem cell-like features in HCC.     

CLUMPHAP: a simple tool for performing haplotype-based association analysis

The completion of the HapMap Project and the development of high-throughput single nucleotide polymorphism genotyping technologies have greatly enhanced the prospects of identifying and characterizing the genetic variants that influence complex traits. In principle, association analysis of haplotypes rather than single nucleotide polymorphisms may better capture an underlying causal variant, but the multiple haplotypes can lead to reduced statistical power due to the testing of (and need to correct for) a large number of haplotypes. This paper presents a novel method based on clustering similar haplotypes to address this issue. The method, implemented in the CLUMPHAP program, is an extension of the CLUMP program designed for the analysis of multi-allelic markers (Sham and Curtis [1995] Ann. Hum. Genet. 59(Pt1):97-105). CLUMPHAP performs a hierarchical clustering of the haplotypes and then computes the chi(2) statistic between each haplotype cluster and disease; the statistical significance of the largest of the chi(2) statistics is obtained by permutation testing. A significant result suggests that the presence of a disease-causing variant in the haplotype cluster is over-represented in cases. Using simulation studies, we have compared CLUMPHAP and more widely used approaches in terms of their statistical power to identify an untyped susceptibility locus. Our results show that CLUMPHAP tends to have greater power than the omnibus haplotype test and is comparable in power to multiple regression locus-coding approaches.     

Hepatic FDG Uptake is not Associated with Hepatic Steatosis but with Visceral Fat Volume in Cancer Screening

Purpose

We aimed to evaluate the relation between visceral fat volume and fluorodeoxyglucose (FDG) uptake of the liver measured by maximum or mean standardized uptake value.

Methods

We retrospectively analyzed 96 consecutive records of positron emission tomography/computed tomography (PET/CT) performed for cancer screening between May 2011 and December 2011. Subjects were divided into 2 groups according to Hounsfield unit (HU) of the liver comparing with that of the spleen. The control group (20 women, 56 men) demonstrating HU of the liver equal or greater than that of the spleen included 76 patients, while the fatty liver group (2 women, 18 men) showing HU of the liver less than that of the spleen included 20 patients. We compared FDG uptake of the liver and visceral fat volume between two groups. We evaluated correlation of hepatic FDG uptake measured by maximum or mean standardized uptake value (SUV) with visceral fat volume and attenuation.

Results

The fatty liver disease group showed higher aspartate aminotransferase (AST)of (24.42 ± 7.22, p = 0.012), alanine aminotransferase (ALT) of (25.16 ± 11.68, p = 0.001), body mass index (BMI) of (24.58 ± 3.29, p = 0.021), and visceral fat volume (3063.53 ± 1561.43, p = 0.011) than the control group. There were no statistically significant differences of mean standardized uptake value of the liver (liver SUV_mean) (2.73 ± 0.19, p = 0.723), maximum standardized uptake value of the liver (liver SUV_max) (3.39 ± 0.53, p = 0.8248) and liver SUV_mean/spleen SUV_mean (1.13 ± 0.10, p = 0.081) between the two groups. Strong correlations were shown between liver SUV_mean and BMI (r = 0.609, p < 0.001) and between liver SUV_mean and visceral fat volume (r = 0.457, p < 0.001). Liver SUV_max was also strongly correlated with BMI (r = 0.622, p = 0.001) and visceral fat volume (r = 0.547, p < 0.001). There was no significant association of mean attenuation value of the liver (liver HU_mean) with liver SUV_mean (r = -0.003, p = 0.979) or liver SUV_max (r = -0.120, p = 0.244).

Conclusion

Hepatic FDG uptake quantified as SUV_mean or SUV_max is not correlated with hepatic steatosis but with visceral fat volume in cancer screening.