In coeliac disease (CD), the upper bowel lesion is associated with a marked infiltration of the mucosa with Th1 cells secreting interferon gamma (IFNgamma) and expressing the Th1-associated ...transcription factor, T-bet. However, the molecular mechanisms which regulate T-bet and promote the Th1 cell response are unknown.
To examine whether interleukin 21 (IL21), a cytokine that regulates T cell activation, has a role in CD.
Duodenal mucosal samples were taken from CD patients and normal controls. IL21 and T-bet were examined by real-time PCR and western blotting, and IFNgamma was assessed by real-time PCR and ELISA. The effect of blockade of endogenous IL21 on the expression of T-bet was examined in an ex vivo culture of biopsies taken from untreated CD patients. Finally, the role of IL21 in controlling T-bet and IFNgamma was also evaluated in cultures of biopsies taken from treated CD patients and cultured with a peptic-tryptic digest of gliadin (PT) in the presence or absence of a neutralising IL21 antibody.
Enhanced IL21 RNA and protein expression was seen in duodenal samples from untreated CD patients. Blockade of IL21 activity in biopsies of untreated CD patients reduced T-bet and IFNgamma secretion. Stimulation of treated CD biopsies with PT enhanced IL21 expression, and neutralisation of IL21 largely prevented PT-driven T-bet and IFNgamma induction.
IL21 is overproduced in the mucosa of CD patients, where it helps sustain T-bet expression and IFNgamma production.
Alzheimer's disease (AD) and multiple sclerosis (MS) are two CNS disorders affecting millions of people, for which no cure is available. AD is usually diagnosed in individuals age 65 and older and ...manifests with accumulation of beta amyloid in the brain. MS, a demyelinating disorder, is most commonly diagnosed in its relapsing-remitting (RRMS) form in young adults (age 20-40). The lack of success in a number of recent clinical trials of immune- or amyloid-targeting therapeutics emphasizes our incomplete understanding of their etiology and pathogenesis. Evidence is accumulating that infectious agents such as viruses may contribute either directly or indirectly. With the emerging recognition that demyelination plays a role in risk and progression of AD, we propose that MS and AD are connected by sharing a common environmental factor (a viral infection such as HSV-1) and pathology (demyelination). In the viral DEmyelinating Neurodegenerative Trigger (vDENT) model of AD and MS, the initial demyelinating viral (e.g., HSV-1) infection provokes the first episode of demyelination that occurs early in life, with subsequent virus reactivations/demyelination and associated immune/inflammatory attacks resulting in RRMS. The accumulating damage and/or virus progression deeper into CNS leads to amyloid dysfunction, which, combined with the inherent age-related defects in remyelination, propensity for autoimmunity, and increased blood-brain barrier permeability, leads to the development of AD dementia later in life. Preventing or diminishing vDENT event(s) early in life, thus, may have a dual benefit of slowing down the progression of MS and reducing incidence of AD at an older age.
Most cancers are characterized by the somatic acquisition of genomic rearrangements during tumour evolution that eventually drive the oncogenesis. Here, using multiplatform sequencing technologies, ...we identify and characterize a remarkable mutational mechanism in human hepatocellular carcinoma caused by Hepatitis B virus, by which DNA molecules from the virus are inserted into the tumour genome causing dramatic changes in its configuration, including non-homologous chromosomal fusions, dicentric chromosomes and megabase-size telomeric deletions. This aberrant mutational mechanism, present in at least 8% of all HCC tumours, can provide the driver rearrangements that a cancer clone requires to survive and grow, including loss of relevant tumour suppressor genes. Most of these events are clonal and occur early during liver cancer evolution. Real-time timing estimation reveals some HBV-mediated rearrangements occur as early as two decades before cancer diagnosis. Overall, these data underscore the importance of characterising liver cancer genomes for patterns of HBV integration.
Four-way DNA intermediates, also known as Holliday junctions, are formed during homologous recombination and DNA repair, and their resolution is necessary for proper chromosome segregation. Here we ...identify nucleases from Saccharomyces cerevisiae and human cells that promote Holliday junction resolution, in a manner analogous to that shown by the Escherichia coli Holliday junction resolvase RuvC. The human Holliday junction resolvase, GEN1, and its yeast orthologue, Yen1, were independently identified using two distinct experimental approaches: GEN1 was identified by mass spectrometry following extensive fractionation of HeLa cell-free extracts, whereas Yen1 was detected by screening a yeast gene fusion library for nucleases capable of Holliday junction resolution. The eukaryotic Holliday junction resolvases represent a new subclass of the Rad2/XPG family of nucleases. Recombinant GEN1 and Yen1 resolve Holliday junctions by the introduction of symmetrically related cuts across the junction point, to produce nicked duplex products in which the nicks can be readily ligated.
DNA repair by homologous recombination is under stringent cell cycle control. This includes the last step of the reaction, disentanglement of DNA joint molecules (JMs). Previous work has established ...that JM resolving nucleases are activated specifically at the onset of mitosis. In case of budding yeast Mus81‐Mms4, this cell cycle stage‐specific activation is known to depend on phosphorylation by CDK and Cdc5 kinases. Here, we show that a third cell cycle kinase, Cdc7‐Dbf4 (DDK), targets Mus81‐Mms4 in conjunction with Cdc5—both kinases bind to as well as phosphorylate Mus81‐Mms4 in an interdependent manner. Moreover, DDK‐mediated phosphorylation of Mms4 is strictly required for Mus81 activation in mitosis, establishing DDK as a novel regulator of homologous recombination. The scaffold protein Rtt107, which binds the Mus81‐Mms4 complex, interacts with Cdc7 and thereby targets DDK and Cdc5 to the complex enabling full Mus81 activation. Therefore, Mus81 activation in mitosis involves at least three cell cycle kinases, CDK, Cdc5 and DDK. Furthermore, tethering of the kinases in a stable complex with Mus81 is critical for efficient JM resolution.
Synopsis
DNA joint molecule resolution by the Mus81‐Mms4 nucleases is tightly controlled during mitosis. Dbf4‐dependent kinase (DDK), best known for its replication roles, now joins previously implicated cell cycle kinases CDK and Cdc5/Plk in this regulation.
The budding yeast Cdc7‐Dbf4 kinase regulates the Mus81‐Mms4 resolvase in mitosis.
DDK and Cdc5 form a complex that targets Mms4 and leads to mitotic Mus81 activation.
Scaffold protein Rtt107 promotes DDK and Cdc5 activity towards Mus81‐Mms4 and is required for full Mus81 activation.
DDK, Cdc5 and Rtt107 target Mms4 interdependently, suggesting that they form a signal amplification loop.
Cdc7‐Dbf4 kinase joins CDK and Cdc5/Plk cell cycle kinases to exquisitely time resolution of DNA joint molecules before cell division.
Abstract
This work aimed to study the effect of using anaerobically digested gelatin industry wastewater as a culture medium for the cultivation of Chlorella vulgaris microalgae in bubble column ...photobioreactors (PBRs). Batch experiments were carried out to determine the growth kinetics by inoculating microalgae in wastewater prepared with different dilutions and supplemented with Bold's Basal Medium (BBM). From the values of the saturation constants (KS = 50.25 mgN-NH4+·L−1) and substrate inhibition (KI = 28.12 mgN-NH4+·L−1) obtained in the adjustment to the Andrews kinetic model (R2 = 0.817), the PBRs achieved specific maximum growth rates (μmax) of 0.343 d−1, biomass productivity of 0.141 g·L−1·d−1, lipid content of 12.45%, lipid productivity of 17.63 mg·L−1·d−1 and instantaneous ammoniacal nitrogen consumption rates of 20.06 and 14.22 mg·L−1·d−1. The addition of wastewater to the culture medium provided an increase in biomass productivity of 57.45% in relation to the negative control. The results obtained demonstrate the high efficiency of C. vulgaris in the removal of nitrogenous compounds and the potential of using anaerobically digested gelatin industry wastewater in the production of microalgae biomass.
•Non-target GC×GC−ToF MS was used to characterise samples affected by a tire fire.•Aromatic classes present in soils and ash after the tire fire were identified.•Variations of the abundances of ...pollutants with time and distance were evaluated.•PBDE, DP and OPFR levels in these kind of samples were reported for the first time.
Discarded vehicle tires have become an increasing concern worldwide due to the enormous amount of wastes generated and the increasing evidence of health problems associated to their disposal and accidental combustion. Previous studies conducted involving either simulated or open uncontrolled tire fires have identified aromatics belonging to two main classes, volatile organic compounds and polycyclic aromatic compounds (PAHs), as the most relevant chemicals generated in these burning processes. As a consequence, and due to their recognized toxicity, most studies reported up to now have mainly focused on these two categories of compounds being information concerning the possible occurrence of other aromatic classes rather limited.
In this study, the enhanced separation power and structural confirmation capabilities provided by comprehensive two-dimensional gas chromatography–time-of-flight mass spectrometry (GC×GC–ToF MS) has been used, for the first time, for the non-targeted analysis of soils impacted by a tire fire and an ash collected at the scene of the fire. In total, 118 volatile and semi-volatile aromatic compounds have been differentiated. Among them, 104 compounds have been either positively or tentatively identified. PAHs with 3–5 rings and their alkyl-derivatives were the most numerous and relevant classes in the investigated samples. A significant number of sulfur, oxygen- and nitrogen-containing PAHs were also detected in the samples. The application of a script function to the raw GC×GC–ToF MS data allowed the fast filtering and automatic recognition of compounds containing halogens in their structure. This part of the study evidenced that only a limited number of regulated persistent organic pollutants were present in the investigated samples. However, it also revealed the presence of emerging organophosphorous flame retardants, whose levels in tire fire impacted soils are reported for the first time.
Three point turn: A metallosupramolecular helicate with trigonal‐antiprismatic geometry fits perfectly into the central hydrophobic cavity of a three‐way DNA junction allowing a new mode of DNA ...recognition.
Background
Children with relapsed acute lymphoblastic leukemia (ALL) in low‐income and middle‐income countries rarely survive. The Pediatric Hematology‐Oncology Association of Central America ...(AHOPCA) developed the AHOPCA‐ALL REC 2014 protocol to improve outcomes in resource‐constrained settings without access to stem cell transplantation.
Methods
The AHOPCA‐ALL REC 2014 protocol was based on a modified frontline induction phase 1A, a consolidation therapy with six modified R‐blocks derived from the ALL–Berlin‐Frankfurt‐Munster REZ 2002 protocol and intermittent maintenance therapy. Children with B‐lineage ALL were eligible after a late medullary relapse, an early or late combined relapse, or any extramedullary relapses. Those with T‐lineage ALL were eligible after early and late extramedullary relapses, as were those with both B‐lineage and T‐lineage relapses occurring at least 3 months after therapy abandonment.
Results
The study population included 190 patients with T‐lineage (n = 3) and B‐lineage (n = 187) ALL. Of those with B‐lineage ALL, 25 patients had a very early extramedullary relapse, 40 had an early relapse (32 extramedullary and 8 combined), and 125 had a late relapse (34 extramedullary, 19 combined, and 72 medullary). The main cause of treatment failure was second relapse (52.1%). The 3‐year event‐free survival rate (± standard error) was 25.9% ± 3.5%, and the 3‐year overall survival rate was 36.7% ± 3.8%. The 3‐year event‐free survival rate was 47.2% ± 4.7% for late relapses. The most frequently reported toxicity was grade 3 or 4 infection. Mortality during treatment occurred in 17 patients (8.9%), in most cases because of infectious complications.
Conclusions
Selected children with relapsed ALL in Central America can be cured with second‐line regimens even without access to consolidation with stem cell transplantation. Children in low‐income and middle‐income countries who have lower risk relapses of ALL should be treated with curative intent.
In the context of a Central American setting, the authors describe the Pediatric Hematology‐Oncology Association of Central America acute lymphocytic leukemia (ALL) REC 2014 protocol for ALL relapse at favorable risk and its results—the first report of a second‐line protocol for ALL in low‐income and middle‐income countries. This experience suggests that, in settings like those of Central America, second‐line regimens currently used for childhood ALL relapses may be of benefit only for patients who have B‐lineage late medullary or extramedullary first relapses.
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