Docosahexaenoic acid [DHA, 22:6(n-3)], a major component of membrane phospholipids in brain and retina, is profoundly susceptible to oxidative stress in vitro. The extent of this peroxidation in organs when DHA is ingested in mammals, however, is not well elucidated. We investigated the effect of dietary DHA-containing oils (DHA 7.0-7.1 mol/100 mol total fatty acids), in the form of triacylglycerols (TG), ethyl esters (EE) and phospholipids (PL), on tissue lipid metabolism and lipid peroxidation in rats. Groups of Sprague-Dawley rats were fed semipurified diets containing 15 g/100 g test oils and were compared with those fed 80% palm oil and 20% soybean oil as the control (unsupplemented group) for 3 wk. The DHA oil diets markedly increased (P: < 0.05) the levels of DHA in the plasma, liver and kidney, 1.5-1.9, 2.5-3.8 and 2.2-2.5 times the control values, respectively, whereas there was a concomitant reduction (P: < 0.05) in arachidonic acid. All forms of DHA oil caused lower TG concentrations in plasma (P: < 0.05) and liver (P: < 0.05), but had no effect in kidney. The DHA oil-fed rats had greater phospholipid hydroperoxide accumulations in plasma (191-192% of control rats), liver (170-230%) and kidney (250-340%), whereas the alpha-tocopherol level was reduced concomitantly (21-73% of control rats). Consistent with these results, rats fed DHA-containing oils had more thiobarbituric reactive substances in these organs than the controls. Thus, high incorporation of (n-3) fatty acids (mainly DHA) into plasma and tissue lipids due to DHA-containing oil ingestion may undesirably affect tissues by enhancing susceptibility of membranes to lipid peroxidation and by disrupting the antioxidant system.

Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) is capable of inducing apoptosis in non-small cell lung carcinoma (NSCLC). However, many of the human NSCLC cell lines are resistant to TRAIL, and TRAIL treatment of the resistant cells leads to the activation of nuclear factor-KB (NF-KB) and extracellular signal-regulated kinase 1/2 (ERK1/2). TRAIL can induce apoptosis in TRAIL-sensitive NSCLC cells through the induction of death-inducing signaling complex (DISC) assembly in lipid rafts of plasma membrane. In the DISC, caspase-8 is cleaved and initiates TRAIL-induced apoptosis. In contrast, TRAIL-DISC assembly in the nonraft phase of the plasma membrane leads to the inhibition of caspase-8 cleavage and NF-KB and ERK1/2 activation in TRAILresistant NSCLC cells. Receptor-interacting protein (RIP) and cellular Fas-associated death domain-like interleukin-1B-converting enzyme-inhibitory protein (c-FLIP) mediates the DISC assembly in nonrafts and selective knockdown of either RIP or c-FLIP with interfering RNA redistributes the DISC from nonrafts to lipid rafts, thereby switching the DISC signals from NF-KB and ERK1/2 activation to caspase-8-initiated apoptosis. Chemotherapeutic agents inhibit c-FLIP expression, thereby enhancing the DISC assembly in lipid rafts for caspase-8-initiated apoptosis. These studies indicate that RIP and c-FLIP-mediated assembly of the DISC in nonrafts is a critical upstream event in TRAIL resistance and thus targeting of either RIP or c-FLIP may lead to the development of novel therapeutic strategies that can overcome TRAIL resistance in human NSCLC. [Cancer Res 2007;67(14):6946-55]

RationaleThe SARS-CoV-2/COVID-19 pandemic has highlighted the serious unmet need for effective therapies that reduce ARDS mortality. We explored whether extracellular nicotinamide phosphoribosyltransferase (eNAMPT), a ligand for Toll-like receptor 4 and a master regulator of innate immunity and inflammation, is a potential ARDS therapeutic target.MethodsWild type C57BL/6J or endothelial cell (EC)-cNAMPT−/− knockout mice (targeted EC NAMPT deletion) were exposed to either a lipopolysaccharide (LPS)-induced (“one-hit”) or a combined LPS/ventilator (“two-hit”)-induced acute inflammatory lung injury model. A NAMPT-specific mAb imaging probe (99mTc-ProNamptorTM) was used to detect NAMPT expression in lung tissues. Either an eNAMPT-neutralising goat polyclonal antibody (pAb) or a humanised monoclonal antibody (ALT-100 mAb) were utilised in vitro and in vivo.ResultsImmunohistochemical, biochemical, and imaging studies validated time-dependent increases in NAMPT lung tissue expression in both preclinical ARDS models. Intravenous delivery of either eNAMPT-neutralising pAb/mAb significantly attenuated inflammatory lung injury (H & E staining, BAL protein, BAL PMNs, plasma IL-6) in both preclinical models. In vitro human lung EC studies demonstrated eNAMPT-neutralising antibodies (pAb, mAb) to strongly abrogate eNAMPT-induced TLR4 pathway activation and EC barrier disruption. In vivo studies in wild type and EC-cNAMPT−/− mice confirmed a highly significant contribution of EC-derived NAMPT to the severity of inflammatory lung injury in both preclinical ARDS models.ConclusionsThese findings highlight both the role of EC-derived eNAMPT and the potential for biologic targeting of the eNAMPT/TLR4 inflammatory pathway. In combination with predictive eNAMPT biomarker and NAMPT genotyping assays, this offers the opportunity to identify high-risk ARDS subjects for delivery of personalised medicine.

The serine/threonine Pim kinases are upregulated in specific hematologic neoplasms, and play an important role in key signal transduction pathways, including those regulated by MYC, MYCN, FLT3-ITD, BCR-ABL, HOXA9, and EWS fusions. We demonstrate that SMI-4a, a novel benzylidene-thiazolidine-2, 4-dione small molecule inhibitor of the Pim kinases, kills a wide range of both myeloid and lymphoid cell lines with precursor T-cell lymphoblastic leukemia/lymphoma (pre-T-LBL/T-ALL) being highly sensitive. Incubation of pre-T-LBL cells with SMI-4a induced G1 phase cell-cycle arrest secondary to a dose-dependent induction of p27 Kip1 , apoptosis through the mitochondrial pathway, and inhibition of the mammalian target of rapamycin C1 (mTORC1) pathway based on decreases in phosphop70 S6K and phospho-4E-BP1, 2 substrates of this enzyme. In addition, treatment of these cells with SMI-4a was found to induce phosphorylation of extracellular signal-related kinase1/2 (ERK1/2), and the combination of SMI-4a and a mitogenactivated protein kinase kinase 1/2 (MEK1/2) inhibitor was highly synergistic in killing pre-T-LBL cells. In immunodeficient mice carrying subcutaneous pre-T-LBL tumors, treatment twice daily with SMI-4a caused a significant delay in the tumor growth without any change in the weight, blood counts, or chemistries. Our data suggest that inhibition of the Pim protein kinases may be developed as a therapeutic strategy for the treatment of pre-T-LBL. (Blood. 2010;115:824-833) IntroductionThe serine/threonine Pim protein kinase is overexpressed in multiple hematopoietic tumors, with an approximately 3-fold increase in chronic lymphocytic leukemia, non-Hodgkin lymphoma, 1,2 and many primary human myeloid leukemic samples. 3 The level of Pim mRNA correlated with the doubling time of the chronic lymphocytic leukemia. Likewise, in mantle cell lymphoma the level of Pim protein kinase expression predicted poor patient outcome. 4 Pim protein kinase is targeted by aberrant hypermutation in 50% of the cases 5 of diffuse large B-cell lymphomas and mutations are detected in primary central nervous system lymphomas 6 and AIDS-associated non-Hodgkin lymphoma. 6 Murine models point to a role for Pim protein kinases in enhancing the transforming activity of several transcription factors known to be drivers of hematopoietic malignancies. For example, the Pim1 and Pim2 genes were originally cloned as a proviral insertion in murine lymphomas 7 that markedly enhanced both the incidence and speed of Myc-driven lymphomagenesis. 8 When the E-Pim1 transgene alone is overexpressed in mice, they exhibit a low-level (10%) occurrence of T-cell lymphoblastic lymphoma/ leukemia. 9 Conversely, E-N-myc or E-L-myc transgenic mice develop T-cell or B-cell lymphomas, respectively, and the rate of development of these tumors is greatly enhanced by breeding with E-Pim1 transgenic mice. 10 Using a retroviral tagging model in mice transgenic for the E2A-PBX1 fusion oncogenes, the Pim1 locus was targeted in 48% of the T-cell lymphomas and the occurrence of ...