Alternative Lengthening of Telomeres (ALT) is a telomere maintenance pathway utilised in 15% of cancers. ALT cancers are strongly associated with inactivating mutations in ATRX; yet loss of ATRX ...alone is insufficient to trigger ALT, suggesting that additional cooperating factors are involved. We identify H3.3
and IDH1/2 mutations as two such factors in ATRX-mutated glioblastomas. Both mutations are capable of inactivating histone demethylases, and we identify KDM4B as the key demethylase inactivated in ALT. Mouse embryonic stem cells inactivated for ATRX, TP53, TERT and KDM4B (KDM4B knockout or H3.3
) show characteristic features of ALT. Conversely, KDM4B over-expression in ALT cancer cells abrogates ALT-associated features. In this work, we demonstrate that inactivation of KDM4B, through H3.3
or IDH1/2 mutations, acts in tandem with ATRX mutations to promote ALT in glioblastomas.
São Paulo is the most populous, developed and industrialized state of Brazil. Despite of intensive human activities, large habitat loss and fragmentation of the native vegetation cover, pumas (
Puma ...concolor
) still inhabit remnant habitat fragments in the northeastern area of the state. We investigated the occurrence of genetic structure and levels of genetic variability on pumas to aggregate basic information for conservation efforts to maintain long term viable populations of this top-predator in the region. By analyzing microsatellite loci variation, we corroborated the hypothesis of absence of genetic structure, and estimated high levels of genetic diversity (expected heterozygosity of 0.79 and mean of 10 alleles per locus). In spite of the increasing number of roadkilling and puma-human conflicts in the area, apparently pumas still maintain some level of gene flow between protected areas of the region. The observed excess of heterozygotes suggests a recent bottleneck event in this population, probably a consequence of the profound landscape transformation of the studied area during the last century; another possibility is this may be due to the observed deviation in the population sex ratio, which may be influencing the pumas’ mating system. We propose that: (1) landscape management in the study area should be focused on increasing habitat connectivity, creating protected areas and structures to allow highway crossing of pumas; (2) educational actions should be undertaken to change community perception of large carnivores, and possibly the implementation of compensatory actions to ranchers.
Prion diseases are transmissible neurodegenerative conditions characterized by the accumulation of protease-resistant forms of the prion protein (PrP), termed PrPres, in the brain. Insoluble PrPres ...tends to aggregate into amyloid fibrils. The anthracycline 4'-iodo-4'-deoxy-doxorubicin (IDX) binds to amyloid fibrils and induces amyloid resorption in patients with systemic amyloidosis. To test IDX in an experimental model of prion disease, Syrian hamsters were inoculated intracerebrally either with scrapie-infected brain homogenate or with infected homogenate coincubated with IDX. In IDX-treated hamsters, clinical signs of disease were delayed and survival time was prolonged. Neuropathological examination showed a parallel delay in the appearance of brain changes and in the accumulation of PrPres and PrP amyloid
Abstract Anandamide (AEA) has been reported to have pleiotropic effects on reproduction, but the mechanism by which it exerts these effects is unclear. The aim of this study is to characterize rat ...placental endocannabinoid system and to analyze the possible functional role of AEA in the regulation of NO levels in rat placenta during pregnancy. We found that cannabinoids receptors (CB1 and CB2), FAAH and TRPV1 were expressed in chorio-allantoic placenta. NOS activity peaked at day 13 and decreased with progression of pregnancy. Both exogenous and endogenous AEA significantly decreased NOS activity. Although pre-incubation with AM251 (CB1 antagonist) or AM630 (CB2 antagonist) had no effect, co-incubation with both antagonists induced NOS activity. Furthermore, pre-incubation with exogenous AEA and both antagonists resulted in the induction of placental NOS activity and this effect was reverted with capsazepine (selective TRPV1 antagonist). Additionally, the enhanced NO synthesis caused by capsaicin was abrogated by co-treatment with capsazepine, illustrating that NOS activity could be modulated by TRPV1. Finally, the inhibition of TRPV1 receptor by capsazepine caused a significant fall in NOS activity. These data support the concept that AEA modulates NO levels by two independent pathways: (1) diminishing the NOS activity via CBs; and (2) stimulating NO synthesis via TRPV1. We hypothesized that AEA have an important implication in the normal function of placental tissues.
Abstract In women, the association between chronic marijuana smoking and early miscarriage has long been known. Anandamide, a major endocannabinoid, mimics some of the psychotropic, hypnotic and ...analgesic effects of Δ9 -tetrahydrocannabinol, the psychoactive component of marijuana. The uterus contains the highest concentrations of anandamide yet discovered in mammalian tissues and this suggests that it might play a role in reproduction. The production of small amounts of nitric oxide (NO) regulates various physiological events including implantation and myometrial relaxation, but in an inflammatory setting such as sepsis, NO has toxic effects as it is a free radical. The results presented in this study indicate that anandamide modulates NO production induced by lipopolysaccharide (LPS) in an in-vitro murine model. It was shown that LPS-induced NO synthesis and tissue damage were mediated by anandamide, as a cannabinoid receptor type 1 antagonist could block the effect of LPS ( P < 0.001). This endotoxin inhibited anandamide uterine degradation ( P < 0.05) and increased the expression of one of its synthesizing enzymes ( P < 0.05). Contrary to the known anti-inflammatory and protective effects, in this model anandamide seems to act as a pro-inflammatory molecule modulating the production of NO induced by LPS. This pro-inflammatory effect of anandamide may be implicated in pathological reproductive events such as septic abortion.
Understanding hepatitis C virus (HCV) replication has been limited by access to serial samples of liver, the primary site of viral replication. Our understanding of how HCV replicates and develops ...drug‐resistant variants in the liver is limited. We studied 15 patients chronically infected with genotype 1 HCV treated with telaprevir (TVR)/pegylated‐interferon alpha/ribavirin. Hepatic fine needle aspiration was performed before treatment and at hour 10, days 4 and 15, and week 8 after initiation of antiviral therapy. We measured viral kinetics, resistance patterns, TVR concentrations, and host transcription profiles. All patients completed all protocol‐defined procedures that were generally well tolerated. First‐phase HCV decline (baseline/treatment day 4) was significantly slower in liver than in plasma (slope plasma: −0.29; liver, −0.009; P < 0.001), whereas second‐phase decline (posttreatment days 4‐15) did not differ between the two body compartments (−0.11 and −0.15, respectively; P = 0.1). TVR‐resistant variants were detected in plasma, but not in liver (where only wild‐type virus was detected). Based upon nonstructural protein 3 sequence analysis, no compartmentalization of viral populations was observed between plasma and liver compartments. Gene expression profiling revealed strong tissue‐specific expression signatures. Human intrahepatic TVR concentration, measured for the first time, was lower, compared to plasma, on a gram per milliliter basis. We found moderate heterogeneity between HCV RNA levels from different intrahepatic sites, indicating differences in hepatic microenvironments. Conclusion: These data support an integrated model for HCV replication wherein the host hepatic milieu and innate immunity control the level of viral replication, and the early antiviral response observed in the plasma is predominantly driven by inhibition of hepatic high‐level HCV replication sites. (Hepatology 2014;60:1825–1836)
PNU-151774E (S)-(+)-2-(4-(3-fluorobenzyloxy)benzylamino)propanamide methanesulfonate, a new anticonvulsant that displays a wide therapeutic window, has a potency comparable or superior to that of ...most classic anticonvulsants. PNU-151774E is chemically unrelated to current antiepileptics. In animal seizure models it possesses a broad spectrum of action. In the present study, the action mechanism of PNU-151774E has been investigated using electrophysiological and biochemical assays. Binding studies performed with rat brain membranes show that PNU-151774E has high affinity for binding site 2 of the sodium channel receptor, which is greater than that of phenytoin or lamotrigine (IC50, 8 microM versus 47 and 185 microM, respectively). PNU-151774E reduces sustained repetitive firing in a use-dependent manner without modifying the first action potential in hippocampal cultured neurons. In the same preparation PNU-151774E inhibits tetrodotoxin-sensitive fast sodium currents and high voltage-activated calcium currents under voltage-clamp conditions. These electrophysiological activities of PNU-151774E correlate with its ability to inhibit veratrine and KCl-induced glutamate release in rat hippocampal slices (IC50, 56.4 and 185.5 microM, respectively) and calcium inward currents in mouse cortical neurons. On the other hand, PNU-151774E does not affect whole-cell gamma-aminobutryic acid- and glutamate-induced currents in cultured mouse cortical neurons. These results suggest that PNU-151774E exerts its anticonvulsant activity, at least in part, through inhibition of sodium and calcium channels, stabilizing neuronal membrane excitability and inhibiting transmitter release. The possible relevance of these pharmacological properties to its antiepileptic potential is discussed.
PNU-151774E (S)-(+)-2-(4-(3-fluorobenzyloxy) benzylamino) propanamide, methanesulfonate is a structurally novel anticonvulsant having Na+ channel-blocking and glutamate release-inhibiting properties, ...as well as being a MAOB inhibitor. Its anticonvulsant activity was evaluated in the maximal electroshock (MES) test and in chemically induced seizures (bicuculline, BIC; picrotoxin, PIC; 3-mercaptopropionic acid, 3-MPA; pentylenetetrazole, PTZ; strychnine, STRYC). Behavioral toxicity was evaluated in the rotorod test with measurements of spontaneous locomotor activity and passive avoidance responding. The anti-MES activity of PNU-151774E in both mice and rats, respectively, produced ED50 values of 4.1 mg/kg and 6.9 mg/kg after i.p. administration or 8.0 mg/kg and 11.8 mg/kg after p.o. administration. Oral anti-MES activity in rats peaked between 1 and 2 h after administration and was evident up to 4 h. This activity was related to brain levels of unchanged drug which peaked at 37 mM within 1 h. Oral ED50 values (mg/kg) effective in blocking tonic extension seizures by chemical convulsants in mice were: BIC (26.9), PIC (60.6), 3-MPA (21.5), STRYC (104.1) and PTZ (26.8). This potency was associated with high therapeutic indices relative to: MES (78.2), BIC (23.3), PIC (10.3), 3-MPA (29.1) and STRYC (6.0). No evidence of tolerance to anti-MES activity after repeated dosing was observed. PNU-151774E did not show anti-absence seizure activity as assessed by i.v. infusion of PTZ. PNU-151774E impaired spontaneous activity in rats only at the oral rotorod ED50 dose of 700 mg/kg p.o. PNU-151774E did not impair passive avoidance responding at doses up to 40 times the oral MES ED50 dose in rats. These results indicate that PNU-151774E is an anticonvulsant effective in various seizure models with a wide therapeutic window, and with a low potential to induce tolerance and locomotor or cognitive side effects.
Summary
What is already known about this subject
Circulating immune cells such as monocytes and T cells infiltrate adipose tissue in the context of obesity.
Plasma leptin and free fatty acid levels ...are usually elevated in obesity.
Apart from the involvement of the innate immune response in obesity, the role of adaptive immunity is now beginning to be unravelled.
What this study adds
Circulating monocytes and T cells are committed to a pro‐inflammatory state regardless of their entry into the adipose tissue of obese children.
Leptin and linoleic acid effects on monocytes contribute to the promotion of inflammation in obesity.
An increased Th1 and cytotoxic commitment and a higher leptin‐mediated up‐regulation of interferon gamma in CD4+ and CD8+ T cells are observed in obese children.
Background
Adipose tissue is the main source of the cytokines and adipokines that are increased in the context of obesity. The production of reactive oxygen species (ROS) and cytokines by circulating immune cells can be regulated by these pro‐inflammatory factors even before infiltration into adipose tissue.
Objective
To investigate the alterations that can occur in circulating monocytes and lymphocytes in paediatric obesity.
Methods
In this study, 54 paediatric obese patients and 30 age‐matched metabolically healthy individuals were enrolled. Intracellular cytokines were analyzed after phorbol myristate acetate (PMA) or leptin plus PMA stimulation of lymphocytes and monocytes by flow cytometry. ROS generation was measured using dichlorofluorescein‐diacetate. Both a ‘stimulation index’ and a ‘fold of increase’ were calculated for statistical purposes.
Results
Both interferon gamma (IFN‐γ) production by circulating CD4+ and CD8+ lymphocytes and ROS production by monocytes following PMA stimulation were increased in obese patients. Leptin induced an increased production of IFN‐γ in both subsets of T cells and tumour necrosis factor alpha in monocytes, and linoleic acid induced a higher ROS production in monocytes.
Conclusions
The distinct functional responses of circulating cells suggest that alterations in both innate and adaptive immune cells are involved in the maintenance of low‐grade inflammation in paediatric obesity.
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