Upregulation of SOCS-1 by Nutlin-3 in acute myeloid leukemia cells but not in primary normal cells

OBJECTIVE: It has been shown that SOCS-1 plays an important role in the proper control of cytokine/growth factor responses and acts as a tumor suppressor in acute myeloid leukemias. Therefore, the objective of the present study was to evaluate the in vitro effect of treatment with Nutlin-3, a small molecule inhibitor of the MDM2/p53 interaction, on the expression of the suppressor of cytokine signaling 1 in primary acute myeloid leukemia cells and in myeloid cell lines with differential p53 status. METHOD: The expression of the suppressor of cytokine signaling 1 was quantitatively analyzed by real-time PCR in myeloid p53wild-type (OCI and MOLM) and p53null HL-60, leukemic cell lines, in patient-derived acute myeloid leukemia blasts, and in primary normal cell types, such as macrophages, endothelial cells, and bone marrow mesenchymal stem cells. The p53-dependence of the suppressor of cytokine signaling 1 upregulation that is induced by Nutlin-3 was analyzed in experiments performed using siRNA for p53, while the functional upregulation of the suppressor of cytokine signaling 1 was analyzed by assessing the levels of phosphorylated STAT-3. RESULTS: Nutlin-3 significantly upregulated the transcription of the suppressor of cytokine signaling 1 in p53wild-type OCI and MOLM but not in p53deleted p53null HL60, myeloid leukemic cell lines, as well as in primary acute myeloid leukemia blasts. Conversely, and somewhat unexpectedly, Nutlin-3 did not modulate the suppressor of cytokine signaling 1 expression in primary normal macrophages, endothelial cells, and bone marrow mesenchymal stem cells. The p53-dependent upregulation of the suppressor of cytokine signaling 1 by Nutlin-3 was associated with the downregulation of phosphorylated STAT-3, a major molecular target of the suppressor of cytokine signaling 1. CONCLUSION: Overall, our data suggest a potential role for the suppressor of cytokine signaling 1 as a therapeutic target of Nutlin-3 in p53 wild-type acute myeloid leukemias

Potential role of circulating microRNAs as early markers of preeclampsia

Abstract Objective To identify microRNAs (miRNAs) differentially expressed at early stages of gestation (12–14 weeks) in the serum of pregnant women, who later developed severe preeclampsia (sPE) in the third trimester of pregnancy ( n = 24) compared to women with normal pregnancy ( n = 24). Materials and Methods Sera from 12–14-week-gestation whole blood were subjected to microarray analysis with TaqMan Low Density Array chips (human microRNA panel V3.0), and to quantitative real-time polymerase chain reaction. Results By using the TaqMan Low Density Array chip technology, 19 mature miRNAs appeared differentially expressed in the group of women who later developed sPE as compared to normal women. The expression of four miRNAs (miR-1233, miR-520, miR-210, miR-144) was validated by quantitative real-time polymerase chain reaction analysis. MiR-1233 was the most overexpressed in the serum of women who later developed sPE. Conclusion Circulating miRNAs deserve further investigation in order to explore their potential role in the pathogenesis of preeclampsia. In particular, miR-1233 might represent a potential marker of early sPE

Repositioning Of Tak-475 In Mevalonate Kinase Disease: Translating Theory Into Practice

Mevalonate Kinase Deficiency (MKD, OMIM #610377) is a rare autosomal recessive metabolic and inflammatory disease. In MKD, defective function of the enzyme mevalonate kinase (MK), due to a mutation in the MVK gene, leads to the shortage of mevalonate-derived intermediates, which results in unbalanced prenylation of proteins and altered metabolism of sterols. These defects lead to a complex multisystem inflammatory and metabolic syndrome. Although biologic therapies aimed at blocking the inflammatory cytokine interleukin-1 (IL-1) can significantly reduce inflammation, they cannot completely control the clinical symptoms that affects the nervous system. For this reason, MKD can still be considered an orphan drug disease. Cellular models for MKD can be obtained by biochemical inhibition of mevalonate-derived isoprenoids. Of note, these cells present an exaggerated response to inflammatory stimuli that can be reduced by treatment with zaragozic acid, an inhibitor of squalene synthase (SQS) able to increase the availability of isoprenoids intermediates upstream the enzymatic block. A similar action might be obtained by lapaquistat acetate (TAK-475, Takeda), a drug that underwent extensive clinical trials as a cholesterol lowering agent 10 years ago, with a good safety profile. Here we describe the preclinical evidence supporting the possible repositioning of TAK-475 from its originally intended use to the treatment of MKD and discuss its potential to modulate the mevalonate pathway in inflammatory diseases

Neuronal dysfunction associated with cholesterol deregulation

Cholesterol metabolism is crucial for cells and, in particular, its biosynthesis in the central nervous system occurs in situ, and its deregulation involves morphological changes that cause functional variations and trigger programmed cell death. The pathogenesis of rare diseases, such as Mevalonate Kinase Deficiency or Smith–Lemli–Opitz Syndrome, arises due to enzymatic defects in the cholesterol metabolic pathways, resulting in a shortage of downstream products. The most severe clinical manifestations of these diseases appear as neurological defects. Expanding the knowledge of this biological mechanism will be useful for identifying potential targets and preventing neuronal damage. Several studies have demonstrated that deregulation of the cholesterol pathway induces mitochondrial dysfunction as the result of respiratory chain damage. We set out to determine whether mitochondrial damage may be prevented by using protective mitochondria-targeted compounds, such as MitoQ, in a neuronal cell line treated with a statin to induce a biochemical block of the cholesterol pathway. Evidence from the literature suggests that mitochondria play a crucial role in the apoptotic mechanism secondary to blocking the cholesterol pathway. Our study shows that MitoQ, administered as a preventive agent, could counteract the cell damage induced by statins in the early stages, but its protective role fades over time

Purinergic Signaling in Controlling Macrophage and T Cell Functions During Atherosclerosis Development

Atherosclerosis is a hardening and narrowing of arteries causing a reduction of blood flow. It is a leading cause of death in industrialized countries as it causes heart attacks, strokes, and peripheral vascular disease. Pathogenesis of the atherosclerotic lesion (atheroma) relies on the accumulation of cholesterol-containing low-density lipoproteins (LDL) and on changes of artery endothelium that becomes adhesive for monocytes and lymphocytes. Immunomediated inflammatory response stimulated by lipoprotein oxidation, cytokine secretion and release of pro-inflammatory mediators, worsens the pathological context by amplifying tissue damage to the arterial lining and increasing flow-limiting stenosis. Formation of thrombi upon rupture of the endothelium and the fibrous cup may also occur, triggering thrombosis often threatening the patient’s life. Purinergic signaling, i.e., cell responses induced by stimulation of P2 and P1 membrane receptors for the extracellular nucleotides (ATP, ADP, UTP, and UDP) and nucleosides (adenosine), has been implicated in modulating the immunological response in atherosclerotic cardiovascular disease. In this review we will describe advancements in the understanding of purinergic modulation of the two main immune cells involved in atherogenesis, i.e., monocytes/macrophages and T lymphocytes, highlighting modulation of pro- and anti-atherosclerotic mediated responses of purinergic signaling in these cells and providing new insights to point out their potential clinical significance

DIFFERENTIAL REGULATION OF BCL-2 AND C-FOS GENES BY HIV-1 TAT PROTEIN IN SERUM-STARVED AND ACTIVATED LYMPHOID T CELLS

The regulatory Tat protein of HIV-1 exerts a pleyotropic activity on the survival and proliferation of different cell types both in vivo and in vitro. We investigated the effect of Tat protein on Bcl-2 and cfos gene expression and cell survival in Jurkat T cell line and primary peripheral blood mononuclear cells (PBMC). Jurkat cells stably expressing tat cDNA were cotransfected with a plasmid containing Bcl-2 promoter in front of the bacterial cloramphenicol acetyltransferase CAT (Bcl-2 Pr/CAT) or with a plasmid containing the c-fos promoter (FC3, from -711 to +42) in front of CAT. While Bcl-2/CAT was significantly activated in serum-starved Jurkat-/a; cells, c-fos/CAT required the addition of 15% PCS or 10'7M PMA plus 5 u.g/ml PHA in order to be activated by Tat. In further experiments, we found that Jurkat-/a/ showed a significant increase of endogenous Bcl-2 and c-fos mRNA and protein expression under serum-free and serum-containing cultures, respectively. The overexpression of Bcl-2 significantly correlated with the inhibition of apoptosis in serum-free culture. Moreover, picomolar concentrations (ng/ml) of recombinant Tat protein were able to upregulate Bcl-2 expression in serum-starved Jurkat cells and PBMC, suggesting that also extracellular Tat, actively released by infected cells, may play a significant role in suppressing apoptosis

Differential regulation of bcl-2 and c-fos genes by HIV-1 tat protein in serum-starved and activated lymphoid T cells

The regulatory Tat protein of HIV-1 exerts a pleyotropic activity on the survival and proliferation of different cell types both in vivo and in vitro. We investigated the effect of Tat protein on Bcl-2 and cfos gene expression and cell survival in Jurkat T cell line and primary peripheral blood mononuclear cells (PBMC). Jurkat cells stably expressing tat cDNA were cotransfected with a plasmid containing Bcl-2 promoter in front of the bacterial cloramphenicol acetyltransferase CAT (Bcl-2 Pr/CAT) or with a plasmid containing the c-fos promoter (FC3, from -711 to +42) in front of CAT. While Bcl-2/CAT was significantly activated in serum-starved Jurkat-/a; cells, c-fos/CAT required the addition of 15% PCS or 10'7M PMA plus 5 u.g/ml PHA in order to be activated by Tat. In further experiments, we found that Jurkat-/a/ showed a significant increase of endogenous Bcl-2 and c-fos mRNA and protein expression under serum-free and serum-containing cultures, respectively. The overexpression of Bcl-2 significantly correlated with the inhibition of apoptosis in serum-free culture. Moreover, picomolar concentrations (ng/ml) of recombinant Tat protein were able to upregulate Bcl-2 expression in serum-starved Jurkat cells and PBMC, suggesting that also extracellular Tat, actively released by infected cells, may play a significant role in suppressing apoptosis

Levels of circulating TNF\u2011related apoptosis\u2011inducing ligand in celiac disease

It has previously been demonstrated that the circulating levels of TNF\u2011related apoptosis\u2011inducing ligand (TRAIL) are significantly lower in patients with type 1 diabetes (T1D) than in normal age- and gender\u2011matched controls. Since celiac disease (CD) is often associated with T1D, a retrospective study was performed to analyze the sera of a cohort of pediatric subjects: i) patients with CD at onset (n=100); ii) patients with potential CD (n=45); iii) patients with CD associated with other auto\u2011immune diseases (n=17); and iv) patients with eosinophilic esophagitis (n=15). Among the patients with CD, 49 were also analyzed after six months on a gluten\u2011free diet, while data were also available for 13 patients after one year on a gluten\u2011free diet. No significant differences were found in the circulating levels of TRAIL between the patients with CD and the patients with either eosinophilic esophagitis or potential CD. Patients with CD associated with other auto\u2011immune diseases showed significantly lower levels of TRAIL when compared with patients with CD alone. The gluten\u2011free diet did not significantly modify the levels of circulating TRAIL at 6 or 12 months. Thus, although T1D and CD share common immunological features, the circulating levels of TRAIL show a significant difference between the two pathologies, and do not appear to be modulated in CD

Association of Serum Tumor Necrosis Factor-Related Apoptosis Inducing Ligand with Body Fat Distribution as Assessed by Dual X-Rays Absorptiometry

A low chronic inflammation mediated by cytokine release is considered a major pathogenic mechanism accounting for the higher risk of cardiovascular disease in the overweight/obese population. In this context, although the existence of a possible interaction between soluble tumor necrosis factor- (TNF-) related apoptosis inducing ligand (TRAIL) and quantity and localization, of adiposity in the body has been hypothesized, no studies have yet investigated this link by radiologic techniques able to assess directly fat mass (FM) in different body regions. To address this issue, we assessed body fat distribution by dual X-rays absorptiometry (DXA) in a sample of 103 women and investigated the possible association between the derived adiposity measures and serum TRAIL concentration. The level of TRAIL showed a positive and independent correlation with arms FM (P < 0.05), trunk FM (P < 0.001) and trunk FM% (P < 0.05), total FM and total FM% (P < 0.001 for both), and an inverse association with legs FM% (P < 0.05). Only trunk FM retained a significant correlation (P < 0.05) with TRAIL after adjusting for all the other indices of regional adiposity. In conclusion, from our study it emerged a significant and independent association of serum TRAIL levels with overall, and, mainly, central adiposity. Further studies are needed to longitudinally investigate the cause-effect relationship between change in body fat distribution and TRAIL