Reduced NK-Cell Activity in Patients with Metastatic Colon Cancer

Natural killer cells (NK-cells) are believed to play an essential role in the immune surveillance against tumors and infectious diseases. The role of NK-cells in colon cancer remains obscure, since increased as well as decreased percentages and/or activity of NK-cells in comparison to control patients have been reported. Percentage and cytolytic activity of NKcells in the peripheral blood were analyzed in 42 patients with colon cancer before surgery and one year thereafter in comparison to control patients with non-malignant diseases. Patients without distant metastasis at the time of diagnosis displayed a significantly increased percentage of NK-cells as well as sustained NK-cell activity in the peripheral blood prior to surgery when compared to control patients. In contrast, patients with metastatic disease at the time of diagnosis displayed significantly decreased NK-cell activity in the peripheral blood when compared to control patients. One year after surgery, patients who remained free of metastasis still displayed sustained NK-cell activity, whereas patients who developed metastasis presented with profoundly decreased levels of NK-cell activity. Further analysis of these patients revealed that patients who developed metastasis within the first year after surgery already displayed reduced NK-cell activity prior to curative colorectal surgery. These observations indicate that metastatic spread of colorectal cancer is associated with decreased NK-cell activity. It remains speculative whether decreased NK-cell activity precedes the development of metastasis and thus may help to identify patients with a high risk of rapid tumor progression following curative colorectal surgery

TNF inhibits malaria hepatic stages in vitro via synthesis of IL-6

We examined the capacity of murine recombinant tumor necrosis factor (rmTNF) to induce an inhibitory effect at the hepatic stage on malaria induced by Plasmodium yoelll sporozoitea. When injected three times, 1.0 μg of rmTNF was found to protect 78% of mice against a sporozoite challenge. In contrast, whatever the dose and the schedule of administration, no inhibition was observed when purified hepatocyte cultures were infected with P. yoelii. The addition of non-parenchymal hepatic cells to hepatocyte cultures restored the capacity of TNF to modulate hepatic stage development, leading to up to 44% inhibition. Antibodies to interleukin 6 reversed the anti-parasite activity in the co-culture syste

TGF-β1 As Possible Link between Loss of Bone Mineral Density and Chronic Inflammation

and their possible role in bone homeostasis in primary human osteoblasts. application.

Monocytes Do Not Transdifferentiate into Proper Osteoblasts

Recent publications suggested that monocytes might be an attractive cell type to transdifferentiate into various cellular phenotypes. Aim was, therefore, to evaluate the potential of blood monocytes to transdifferentiate into osteoblasts. Monocytes isolated from peripheral blood were subjected to two previously published treatments to obtain unique, multipotent cell fractions, named programmable cells of monocytic origin (PCMOs) and monocyte-derived mesenchymal progenitor cells (MOMPs). Subsequently, MOMPs and PCMOs were treated with osteogenic differentiation medium (including either vitamin D or dexamethasone) for 14 days. Regarding a variety of surface markers, no differences between MOMPs, PCMOs, and primary monocytes could be detected. The treatment with osteogenic medium neither resulted in loss of hematopoietic markers nor in adoption of mesenchymal phenotype in all cell types. No significant effect was observed regarding the expression of osteogenic transcription factors, bone-related genes, or production of mineralized matrix. Osteogenic medium resulted in activation of monocytes and appearance of osteoclasts. In conclusion, none of the investigated monocyte cell types showed any transdifferentiation characteristics under the tested circumstances. Based on our data, we rather see an activation and maturation of monocytes towards macrophages and osteoclasts

Differential effects of clinically used derivatives and metabolites of artemisinin in the activation of constitutive androstane receptor isoforms

BACKGROUND AND PURPOSE Widespread resistance to antimalarial drugs requires combination therapies with increasing risk of pharmacokinetic drugdrug interactions. Here, we explore the capacity of antimalarial drugs to induce drug metabolism via activation of constitutive androstane receptors (CAR) by ligand binding. EXPERIMENTAL APPROACH A total of 21 selected antimalarials and 11 major metabolites were screened for binding to CAR isoforms using cellular and in vitro CAR-coactivator interaction assays, combined with in silico molecular docking. Identified ligands were further characterized by cell-based assays and primary human hepatocytes were used to elucidate induction of gene expression. KEY RESULTS Only two artemisinin derivatives arteether and artemether, the metabolite deoxyartemisinin and artemisinin itself demonstrated agonist binding to the major isoforms CAR1 and CAR3, while arteether and artemether were also inverse agonists of CAR2. Dihydroartemisinin and artesunate acted as weak inverse agonists of CAR1. While arteether showed the highest activities in vitro, it was less active than artemisinin in inducing hepatic CYP3A4 gene expression in hepatocytes. CONCLUSIONS AND IMPLICATIONS Artemisinin derivatives and metabolites differentially affect the activities of CAR isoforms and of the pregnane X receptor (PXR). This negates a common effect of these drugs on CAR/PXR-dependent induction of drug metabolism and further provides an explanation for artemisinin consistently inducing cytochrome P450 genes in vivo, whereas arteether and artemether do not. All these drugs are metabolized very rapidly, but only artemisinin is converted to an enzyme-inducing metabolite. For better understanding of pharmacokinetic drugdrug interaction possibilities, the inducing properties of artemisinin metabolites should be considered.German Federal Ministry of Education and Research (BMBF) HepatosSys network [0313081B, 0313080F, 0313080I]; Deutsche Forschungsgemeinschaft (Germany) [KE 1629/1-1]; Robert Bosch Foundation, Stuttgart, Germanyinfo:eu-repo/semantics/publishedVersio

3D Cultivation Techniques for Primary Human Hepatocytes

One of the main challenges in drug development is the prediction of in vivo toxicity based on in vitro data. The standard cultivation system for primary human hepatocytes is based on monolayer cultures, even if it is known that these conditions result in a loss of hepatocyte morphology and of liver-specific functions, such as drug-metabolizing enzymes and transporters. As it has been demonstrated that hepatocytes embedded between two sheets of collagen maintain their function, various hydrogels and scaffolds for the 3D cultivation of hepatocytes have been developed. To further improve or maintain hepatic functions, 3D cultivation has been combined with perfusion. In this manuscript, we discuss the benefits and drawbacks of different 3D microfluidic devices. For most systems that are currently available, the main issues are the requirement of large cell numbers, the low throughput, and expensive equipment, which render these devices unattractive for research and the drug-developing industry. A higher acceptance of these devices could be achieved by their simplification and their compatibility with high-throughput, as both aspects are of major importance for a user-friendly device

Age-dependent changes of the antioxidant system in rat livers are accompanied by altered MAPK activation and a decline in motor signaling

Aging is characterized by a progressive decrease of cellular functions, because cells gradually lose their capacity to respond to injury. Increased oxidative stress is considered to be one of the major contributors to age-related changes in all organs including the liver. Our study has focused on elucidating whether important antioxidative enzymes, the mTOR pathway, and MAPKs exhibit age-dependent changes in the liver of rats during aging. We found an age-dependent increase of GSH in the cytosol and mitochondria. The aged liver showed an increased SOD enzyme activity, while the CAT enzyme activity decreased. HO-1 and NOS-2 gene expression was lower in adult rats, but up-regulated in aged rats. Western blot analysis revealed that SOD1, SOD2, GPx, GR, γ-GCL, and GSS were age-dependent up-regulated, while CAT remained constant. We also demonstrated that the phosphorylation of Akt, JNK, p38, and TSC2Ser1254 decreased while ERK1/2 and TSC2Thr1462 increased agedependently. Furthermore, our data show that the mTOR pathway seems to be activated in livers of aged rats, and hence stimulating cell proliferation/regeneration, as confirmed by an age-dependent increase of PCNA and p-eIF4ESer209 protein expression. Our data may help to explain the fact that liver cells only proliferate in cases of necessity, like injury and damage. In summary, we have demonstrated that, age-dependent changes of the antioxidant system and stress-related signaling pathways occur in the livers of rats, which may help to better understand organ aging