Quinazolinone derivative BNUA-3 ameliorated [NDEA+2-AAF]-induced liver carcinogenesis in SD rats by modulating AhR-CYP1B1-Nrf2-Keap1 pathway.

Cytochrome P450 1B1, considered as one of the novel chemotherapeutic targets involved in cancer prevention and therapy is also associated with the conversion of procarcinogens into their active metabolites. The aryl hydrocarbon receptor (AhR) is responsible for mediating different biological responses to a wide variety of environmental pollutants and also causes transcriptional activation of cytochrome P450 enzymes including CYP1B1 and thus plays a pivotal role for initiating cancer and its progression. On the other hand, active carcinogenic metabolites and reactive oxygen species-mediated stress alter different molecular signalling pathways and gene expressions. Quinazoline derivatives are recognized for their diversified biological activities including anticancer properties. The current study was designed for evaluation of chemotherapeutic efficacy of a synthetic quinazolinone derivative BNUA-3 against hepatocellular cancer in Sprague-Dawley (SD) rats. A detailed in vivo analysis was performed by administrating BNUA-3 (15, 30 mg/kg b.w. for 28 days, i.p.) in N-Nitrosodiethylamine + 2-Acetylaminofluorene induced partially hepatectomized liver cancer in SD rats. This was followed by morphological evaluations, biochemical estimations and analysis of different mRNA and protein expressions. The results demonstrated the potency of BNUA-3 in efficient restoration of the altered morphology of liver, its protective effect against lipid peroxidation, enzymic and non-enzymic antioxidants levels in liver tissue which was disrupted after cancer induction. The study also demonstrated downregulation of AhR, CYP1B1 and Keap1 expressions with subsequent augmentation of protective Nrf2, HO-1, NQO1 and GSTA1 expressions thus, revealing the chemotherapeutic potency of BNUA-3 in inhibiting liver carcinogenesis through AhR/CYP1B1/Nrf2/Keap1 pathway.

Structure Based Multitargeted Molecular Docking Analysis of Selected Furanocoumarins against Breast Cancer.

Breast cancer is one of the biggest global dilemmas and its current therapy is to target the hormone receptors by the use of partial agonists/antagonists. Potent drugs for breast cancer treatment are Tamoxifen, Trastuzumab, Paclitaxel, etc. which show adverse effects and resistance in patients. The aim of the study has been on certain phytochemicals which has potent actions on ERα, PR, EGFR and mTOR inhibition. The current study is performed by the use of molecular docking as protein-ligand interactions play a vital role in drug design. The 3D structures of ERα, PR, EGFR and mTOR were obtained from the protein data bank and docked with 23 3D PubChem structures of furanocoumarin compounds using FlexX. Drug-likeness property was checked by applying the Lipinski's rule of five on the furanocoumarins to evaluate anti-breast cancer activity. Antagonist and inhibition assay of ERα, EGFR and mTOR respectively has been performed using appropriate in-vitro techniques. The results confirm that Xanthotoxol has the best docking score for breast cancer followed by Bergapten, Angelicin, Psoralen and Isoimperatorin. Further, the in-vitro results also validate the molecular docking analysis. This study suggests that the selected furanocoumarins can be further investigated and evaluated for breast cancer treatment and management strategies.

Bergapten inhibits liver carcinogenesis by modulating LXR/PI3K/Akt and IDOL/LDLR pathways.

Oxysterol receptors LXRs (α and ß) are recently reported to be one of the novel and potential therapeutic targets in reducing cell proliferation and tumor growth in different system model. Activation of LXRs is correlated with modification of PI3K/Akt pathway. LXRs are also found to play a critical role in maintaining lipid homeostatais by regulating ABCA1, IDOL, SREBP1, LDLR and also certain lipogenic genes such as FASN and SCD1. In the present study a potential furanocoumarin, Bergapten (BeG) has been evaluated for its anticancer property on Hepatocellular Carcinoma (HCC) on LXR axis. The molecular docking analysis was carried out for BeG on LXR (α & ß) using Maestro tool and compared with reference ligands. This was followed by in vitro (HepG2 cell lines) and in vivo (on NDEA induced HCC in Wistar albino rats) anticancer evaluation of BeG. The docking results revealed polar and hydrophobic interactions of BeG with LXR (α,ß). The in vitro studies revealed the potential of BeG in lowering the accumulation of lipid droplets in HepG2 cells which was correlated with increase in LXR (α,ß) protein expressions. Furthermore, the in vivo studies demonstrated the potential of BeG in ameliorating the cancer induced alterations in body weight, liver weight and significant restoration of the changes in mRNA and protein expressions of LXR(α,ß), ABCA1, IDOL, SREBP1 and LDLR. BeG also modulated the expressions of PI3K, Akt and certain lipogenic genes like FASN and SCD1 and reduced the lipid droplets level in liver cancer cells. These results provide evidence and validates the critical role of BeG in maintaining the lipid homeostasis and justifies its anticancer potential against NDEA-induced HCC.

Perivascular macrophages in health and disease.

Macrophages are a heterogeneous group of cells that are capable of carrying out distinct functions in different tissues, as well as in different locations within a given tissue. Some of these tissue macrophages lie on, or close to, the outer (abluminal) surface of blood vessels and perform several crucial activities at this interface between the tissue and the blood. In steady-state tissues, these perivascular macrophages maintain tight junctions between endothelial cells and limit vessel permeability, phagocytose potential pathogens before they enter tissues from the blood and restrict inappropriate inflammation. They also have a multifaceted role in diseases such as cancer, Alzheimer disease, multiple sclerosis and type 1 diabetes. Here, we examine the important functions of perivascular macrophages in various adult tissues and describe how these functions are perturbed in a broad array of pathological conditions.

Taxifolin binds with LXR (α & ß) to attenuate DMBA-induced mammary carcinogenesis through mTOR/Maf-1/PTEN pathway.

AIM: 7,12-dimethylbenz(a)anthracene(DMBA), a PAH derivative initializes cascades of signaling events that alters a variety of enzymes responsible for lipid and glucose homeostasis resulting in enhanced availability and consumption of energy producing molecules for the development of carcinogenesis. 3-hydroxy-3-methylglutaryl-coenzyme A reductase (HMG-CoAR) is a key enzyme regulating the pathway of synthesis of cholesterol whereas liver-X-receptor (LXR) regulates lipid, carbohydrate metabolism in various malignancies including mammary carcinogenesis (MC). In this study Taxifolin (TAX), a potential flavanoid has been subjected to evaluate its anti-cancer potential on (MC). METHODS: We designed to screen the molecular docking analysis of TAX on LXRα, LXRß, HMG-CoAR, mTOR and PTEN using MAESTRO tool comparing with their reference ligands. MC was developed by the administration of DMBA in the air pouch (under the mammary fat pad) of the female Sprague-Dawley rats (55 days old). After 90 days of cancer induction, the chemotherapeutic potential of TAX was evaluated by administering TAX at different doses (10, 20 and 40 mg/kg b.w./day). Then western blot and RT-qPCR analysis were performed for determination of the protein and mRNA expressions respectively. RESULTS: The docking analysis revealed significant interaction with LXR (α&ß), HMG-CoAR, mTOR and PTEN. The docking results were validated with the enzyme inhibition assay using HMG-CoAR (EC 1.1.1.34). TAX inhibited the HMG-CoAR activity with an IC50 value of 97.54 ±â€¯2.5 nM whereas the reference molecule pavastatin revealed an IC50 value of 84.35 ±â€¯1.2 nM. Moreover, TAX modulated the energy regulation on DMBA-induced MC in SD-rats by significantly restoring the cancer-induced alterations in body weight, tumor growth and lipid, lipoproteins, lipid metabolizing enzymes and glycolytic enzymes. TAX interacted with LXRs, HMG-CoAR, metabolic enzymes and restored the altered metabolism that accelerates uncontrolled cell proliferation in MC. Moreover, TAX also altered the mRNA and protein expressions of HMG-CoAR, LXR (α,ß), Maf1, PTEN, phosphoinositide 3-kinase (PI3K), Akt, mTOR, fatty acid synthase (FASN) and acetyl-CoA carboxylase 1 (ACC1) in a dose dependent manner. CONCLUSION: These results validate the anti-cancer potential of TAX in DMBA-induced MC through LXR-mTOR/Maf1/PTEN axis.

A novel spontaneous mutation in the TAP2 gene unravels its role in macrophage survival.

We report a new mouse strain with a single point mutation in the type 2 transporter associated with antigen processing (TAP2). This strain randomly arose in one of our C57BL/6J mouse colonies and was initially discovered because of the lack of CD8+ T cells in the periphery. Following our observation, we subsequently revealed a lack of cell surface MHC-I expression, derived from TAP2 protein deficiency. Our strain, named eightless, has a C to T substitution in exon 5 resulting in a glutamine to stop codon substitution at position 285 in the TAP2 protein. Interestingly, in addition to the expected lack of CD8+ T cell phenotype, eightless mice have a diminished number of macrophages in their peritoneum. Moreover, following peritoneal inflammation, elicited eightless macrophages showed impaired survival both in vivo and ex vivo. Our study describes the first ever TAP2 complete knockout mouse strain and provides a possible explanation for why patients with TAP2 deficiency syndrome present clinical manifestations that would suggest a phagocyte defect rather than a lack of CD8+ T cells.

Schlafen2 mutation unravels a role for chronic ER stress in the loss of T cell quiescence.

Immunologically naïve lymphocytes are kept in a quiescent state until antigen engagement. These quiescent immune cells are characterized by small cell size, lack of spontaneous proliferation and low metabolic rate. Lymphocyte quiescence is actively enforced condition which ensures the preservation of proper differentiation and proliferation capabilities of naïve and memory lymphocytes. Previously we described a chemically induced mutation in Schlafen2 (Slfn2), termed elektra, which breaks quiescence and compromises immunity. However, the mechanism by which Slfn2 maintains quiescence remains unknown. Here we demonstrate that elektra T cells display chronic ER stress under steady state conditions. Modulation of ER stress response by depletion of either UPR mediators XBP1 or CHOP, improved viability and partially corrected the developmental abnormalities and proliferation capabilities of elektra T cells. Altogether, our results demonstrate a functional connection between Slfn2 induced quiescence in T cells and ER homeostasis, clarifying a novel mechanism by which immune cell quiescence is maintained.

Cellular signalling pathways in immune aging and regeneration.

The thymus is one of the cornerstones of an effective immune system. It produces new T-cells for the naïve T-cell pool, thus refreshing the peripheral repertoire. As we age, the thymus atrophies and there is a decrease in the area of active T-cell production. A decline in the output of the thymus eventually leads to changes in the peripheral T-cell pool which includes increases in the number of cells at or near their replicative limit and contraction of the repertoire. Debate about the age-associated changes in the thymus leading to functional decline centres on whether this is due to problems with the environment provided by the thymus or with defects in the progenitor cell compartment. In mice, the evidence points towards problems in the epithelial component of the thymus and the production of IL-7 (interleukin 7). But there are discussions about how appropriate mouse models are for human aging. We have developed a simple system that utilizes both human keratinocyte and fibroblast cell lines arrayed on a synthetic tantalum-coated matrix to provide a permissive environment for the maturation of human CD34+ haemopoietic progenitor cells into mature CD4+ or CD8+ T-lymphocytes. We have characterized the requirements for differentiation within these cultures and used this system to compare the ability of CD34+ cells derived from different sources to produce mature thymocytes. The TREC (T-cell receptor excision circle) assay was used as a means of identifying newly produced thymocytes.

Dose response kinetics of CD8 lymphocytes from young animals transfused into old animals and challenged with influenza.

Transfusion of autologous leukocytes after prolonged storage has been proposed as a means of rejuvenating the immune system of older individuals. The rationale for this approach is that age related immune decline is associated with a diminished pool of naïve T cells following atrophy of the thymus and reduction in thymic output. The presence of high levels of naïve T cells within the blood of young individuals could provide a boost to the immune system of an older "self" through a rejuvenation of the naïve T cell pool. However what remains unresolved is whether the cells could be incorporated effectively into the T cell pool of the host and whether effectors could be generated. Using CD45 congenic mice in our experiments we show that the transfusion of young donor cells into older congenic host animals leads to their successful incorporation into the peripheral T cell pool. When the recipients were challenged with influenza virus, specific effector CD8 cells were generated which were of both host and donor origin. We found no relationship between the number of responder cells of donor origin at the time of assay and the number of cells injected.

A simple model system enabling human CD34(+) cells to undertake differentiation towards T cells.

BACKGROUND: Channelling the development of haematopoietic progenitor cells into T lymphocytes is dependent upon a series of extrinsic prompts whose temporal and spatial sequence is critical for a productive outcome. Simple models of human progenitor cells development depend in the main on the use of xenogeneic systems which may provide some limitations to development. METHODS AND FINDINGS: Here we provide evidence that a simple model system which utilises both human keratinocyte and fibroblast cell lines arrayed on a synthetic tantalum coated matrix provides a permissive environment for the development of human CD34⁺ haematopoietic cells into mature CD4⁺ or CD8⁺ T lymphocytes in the presence of Interleukin 7 (IL-7), Interleukin 15 (IL-15) and the Fms-like tyrosine kinase 3 ligand (Flt-3L). This system was used to compare the ability of CD34(+) cells to produce mature thymocytes and showed that whilst these cells derived from cord blood were able to productively differentiate into thymocytes the system was not permissive for the development of CD34(+) cells from adult peripheral blood. CONCLUSIONS/SIGNIFICANCE: Our study provides direct evidence for the capacity of human cord blood CD34(+) cells to differentiate along the T lineage in a simple human model system. Productive commitment of the CD34⁺ cells to generate T cells was found to be dependent on a three-dimensional matrix which induced the up-regulation of the Notch delta-like ligand 4 (Dll-4) by epithelial cells.

Pulmonary delivery of interleukin-7 provides efficient and safe delivery to the aging immune system.

Age-associated atrophy of the thymus with coincident reduction in thymopoeisis, decline in thymic output, and subsequent immune dysfunction has been reversed by the use of interleukin-7 (IL-7). In the earlier studies and in clinical trials, delivery of IL-7 has been by multiple injections over several days to maintain effective activity levels in the tissues. This is unlikely to meet with high compliance rates in future clinical use, and so we tested alternate routes of delivery using a technique involving tagging IL-7 with fluorescent dye that emits in the near-infrared region and whose fluorescence can be visualized within the tissues of live animals. We have shown that intratracheal instillation, enabling transfer through the lungs, provides an effective route for delivering IL-7 into the bloodstream and from there into the tissues in older animals. Delivery is rapid and widespread tissue distribution is seen. Comparison of administration either subcutaneously or by instillation reveals that IL-7 delivery by the pulmonary route provides significantly greater transmission to lymphoid tissues when compared with injection. In functional assessment studies, pulmonary administration led to significantly improved intrathymic T cell development in older animals when compared with IL-7 delivered by injection. Furthermore, in these older animals, delivery of IL-7 by intratracheal instillation was not accompanied by any apparent adverse events when compared with controls receiving saline vehicle by instillation or animals receiving IL-7 by subcutaneous injection.