Mouse 3T3-L1 cells acquire resistance against oxidative stress as the adipocytes differentiate via the transcription factor FoxO

Repression of excessive increase and enlargement of adipocytes that is closely associated with obesity is effective in the prevention and treatment of metabolic syndrome. Generally, apoptosis is induced in cells via a wide variety of intracellular or extracellular substances, and recently, it has been suggested that the FoxO subfamily is involved in the induction of apoptosis. We aimed to elucidate the mechanism of FoxO-mediated apoptosis-induction in the adipocytes under the reactive oxygen species (ROS) stimulus. The treatment of differentiated and undifferentiated 3T3-L1 cells with glucose oxidase (GOD), an enzyme that generates H2O2, induced apoptosis and led to the accumulation of 8-OHdG. Apoptosis analysis revealed that GOD treatment induced apoptosis in differentiated 3T3-L1 cells less efficiently than in undifferentiated preadipocytes. GOD remarkably increased the levels of Bad, Bax, and Bim—the genes that are actively involved in cell apoptosis. GOD treatment also increased the expression of FoxO3a mRNA and protein. The introduction of FoxO3a-siRNA into 3T3-L1 cells suppressed the oxidative stress-induced expression of Bim mRNA, as well as the GOD-induced apoptosis. Furthermore, the expression of MnSOD, Cu/ZnSOD, and catalase, as well as of FoxO, increased significantly along with the progression of adipocyte differentiation. These results indicated that ROS-induced apoptosis in undifferentiated 3T3-L1 cells via the expression of FoxO3a, whereas FoxO expression suppressed the ROS-induced apoptosis in differentiated 3T3-L1 cells via the expression of ROS-scavenging enzymes

Generalized Lévy walks and the role of chemokines in migration of effector CD8+ T cells.

Chemokines have a central role in regulating processes essential to the immune function of T cells, such as their migration within lymphoid tissues and targeting of pathogens in sites of inflammation. Here we track T cells using multi-photon microscopy to demonstrate that the chemokine CXCL10 enhances the ability of CD8+ T cells to control the pathogen Toxoplasma gondii in the brains of chronically infected mice. This chemokine boosts T-cell function in two different ways: it maintains the effector T-cell population in the brain and speeds up the average migration speed without changing the nature of the walk statistics. Notably, these statistics are not Brownian; rather, CD8+ T-cell motility in the brain is well described by a generalized Lévy walk. According to our model, this unexpected feature enables T cells to find rare targets with more than an order of magnitude more efficiency than Brownian random walkers. Thus, CD8+ T-cell behaviour is similar to Lévy strategies reported in organisms ranging from mussels to marine predators and monkeys, and CXCL10 aids T cells in shortening the average time taken to find rare targets

Toxoplasma Infection Induces Sustained Up-Regulation of Complement Factor B and C5a Receptor in the Mouse Brain via Microglial Activation: Implication for the Alternative Complement Pathway Activation and Anaphylatoxin Signaling in Cerebral Toxoplasmosis

Toxoplasma gondii is a neurotropic protozoan parasite, which is linked to neurological manifestations in immunocompromised individuals as well as severe neurodevelopmental sequelae in congenital toxoplasmosis. While the complement system is the first line of host defense that plays a significant role in the prevention of parasite dissemination, Toxoplasma artfully evades complement-mediated clearance via recruiting complement regulatory proteins to their surface. On the other hand, the details of Toxoplasma and the complement system interaction in the brain parenchyma remain elusive. In this study, infection-induced changes in the mRNA levels of complement components were analyzed by quantitative PCR using a murine Toxoplasma infection model in vivo and primary glial cells in vitro. In addition to the core components C3 and C1q, anaphylatoxin C3a and C5a receptors (C3aR and C5aR1), as well as alternative complement pathway components properdin (CFP) and factor B (CFB), were significantly upregulated 2 weeks after inoculation. Two months post-infection, CFB, C3, C3aR, and C5aR1 expression remained higher than in controls, while CFP upregulation was transient. Furthermore, Toxoplasma infection induced significant increase in CFP, CFB, C3, and C5aR1 in mixed glial culture, which was abrogated when microglial activation was inhibited by pre-treatment with minocycline. This study sheds new light on the roles for the complement system in the brain parenchyma during Toxoplasma infection, which may lead to the development of novel therapeutic approaches to Toxoplasma infection-induced neurological disorders

Clinicopathological study on pIgR expression and tumor progression in advanced colorectal cancer

This study is aimed at investigating the relationship between the polymeric immunoglobulin receptor （pIgR） expression and clinicopathological factors in advanced colorectal cancer （CRC） patients. The study involved 47 advanced CRC patients who were surgically resected and underwent KRAS gene test. The pIgR expression was analyzed by immunohistochemistry, and the patients were classified into high and low （pIgR-H and pIgR-L, respectively） groups based on the staining intensity and range. A total of 13 cases was classified under the pIgR-H group, and the remaining 34 were classified under the pIgR-L group. Results suggest no significant differences in most clinicopathological factors between the pIgR-H and pIgR-L groups, although the pIgR-L group had a significantly higher frequency of venous invasion than the pIgR-H group, whereas the frequency of KRAS gene mutation was significantly higher in the pIgR-H group than that in the pIgR-L group. The findings in this study showed little significant correlation between the pIgR expression and clinicopathological factors in advanced CRC patients. Further research on the biological behavior of pIgR as a drug treatment option for KRAS-mutated advanced CRCs is also warranted

Involvement of Adrenomedullin Expression in Tumor Cells and Stroma in the Development of Diabetes in Pancreatic Cancer Patients

Some studies have reported that adrenomedullin （AM） is involved in diabetes mellitus （DM） associated with pancreatic cancer. Therefore, in this study we investigated the relationship between diabetes and AM expression in patients with pancreatic cancer. We examined 48 biopsies and 26 surgical resections from 74 patients with histologically diagnosed pancreatic cancer. Patients were classified into either DM or non-DM groups. The immunohistochemical expression of AM and various clinicopathological factors were compared between the two groups. Among the biopsy cases, 21 were classified as DM and 27 as non-DM. AM expression in pancreatic cancer cells was significantly lower in the DM group （p＝0.03）. No significant differences were noted in age, body mass index, tumor diameter or location, serum CA19-9, amylase, or C-reactive protein levels, pancreatic ductal dilatation, portal vein invasion, clinical stage, or histological differentiation between the DM and non-DM groups. The proportion of men was significantly lower in the DM group （p＝0.04）, as was the frequency of liver metastasis at diagnosis （p＝0.03）. Among the resection cases, 13 were classified as DM and 13 as non-DM. There were no significant differences in AM expression in pancreatic cancer cells between the two groups. However, marked AM expression was observed in the inflammatory cells and fibroblasts of the tumor stroma in all cases. In addition, the inflammatory response in the tumor stroma tended to be stronger in the DM group. Although the present study failed to find a positive correlation between diabetes and AM expression in pancreatic cancer cells, the results indicate that AM expression in stromal cells may be more closely related to the development of DM in pancreatic cancer patients

C-arm Cone-beam CT-guided Needle Biopsies through the Erector Spinal Muscle for Posterior Thoracic Pulmonary Lesions

This study investigated retrospectively the diagnostic yield and complication rate of transthoracic needle biopsies for posterior thoracic pulmonary lesions using C-arm cone-beam computed tomography （CBCT）. The risk factors for pulmonary hemorrhage were evaluated. Our study included 113 patients with 113 posterior pulmonary lesions （mean longest diameter: 30.6mm, and mean depth: 4.7mm） through the erector spinal muscles using a 19/20-gauge coaxial system. The diagnostic performances of procedures for malignant lesions and the incidence of complications after biopsies were also assessed. The patient-related and procedure-related variables were investigated. Risk factors for pulmonary hemorrhage were analyzed with a multivariate logistic regression analysis. Findings revealed 99 malignant, 13 benign, and one intermediate lesion. Sensitivity, specificity, and diagnostic accuracy rates were 100％ （99/99）, 92.3％ （12/13）, and 99.1％ （111/112）, respectively. Air embolization, hemothorax, hemoptysis, pneumothorax, and pulmonary hemorrhage, occurred in 0, 2, 12, 48, and 70 procedures. The averaged spinous process-pleura depth and the traversed lung parenchyma depth achieved by the introducer needles were 54.2mm and 27.4mm, respectively. The needle position at the pleural puncture site within the intercostal space was in middle （31％） and inferior （69％） areas. The incidence of pulmonary hemorrhage was significantly higher in smaller lesions （p＝0.001）. Manual evacuation was performed in five procedures for patients with pneumothorax. The chest tube placement （trocar＞8 Fr） was performed in two procedures in patients with hemothorax and pneumothorax. In conclusion, the biopsy method with a posterior intercostal approach for posterior thoracic pulmonary lesions yielded high diagnostic accuracy and few major complications

Losartan Slows Pancreatic Tumor Progression and Extends Survival of SPARC-Null Mice by Abrogating Aberrant TGFβ Activation

Pancreatic adenocarcinoma, a desmoplastic disease, is the fourth leading cause of cancer-related death in the Western world due, in large part, to locally invasive primary tumor growth and ensuing metastasis. SPARC is a matricellular protein that governs extracellular matrix (ECM) deposition and maturation during tissue remodeling, particularly, during wound healing and tumorigenesis. In the present study, we sought to determine the mechanism by which lack of host SPARC alters the tumor microenvironment and enhances invasion and metastasis of an orthotopic model of pancreatic cancer. We identified that levels of active TGFβ1 were increased significantly in tumors grown in SPARC-null mice. TGFβ1 contributes to many aspects of tumor development including metastasis, endothelial cell permeability, inflammation and fibrosis, all of which are altered in the absence of stromal-derived SPARC. Given these results, we performed a survival study to assess the contribution of increased TGFβ1 activity to tumor progression in SPARC-null mice using losartan, an angiotensin II type 1 receptor antagonist that diminishes TGFβ1 expression and activation in vivo. Tumors grown in SPARC-null mice progressed more quickly than those grown in wild-type littermates leading to a significant reduction in median survival. However, median survival of SPARC-null animals treated with losartan was extended to that of losartan-treated wild-type controls. In addition, losartan abrogated TGFβ induced gene expression, reduced local invasion and metastasis, decreased vascular permeability and altered the immune profile of tumors grown in SPARC-null mice. These data support the concept that aberrant TGFβ1-activation in the absence of host SPARC contributes significantly to tumor progression and suggests that SPARC, by controlling ECM deposition and maturation, can regulate TGFβ availability and activation