Antiprotozoal glutathione derivatives with flagellar membrane binding activity against T. brucei rhodesiense.

A new series of N-substituted S-(2,4-dinitrophenyl)glutathione dibutyl diesters were synthesized to improve in vitro anti-protozoal activity against the pathogenic parasites Trypanosoma brucei rhodesiense, Trypanosoma cruzi and Leishmania donovani. The results obtained indicate that N-substituents enhance the inhibitory properties of glutathione diesters whilst showing reduced toxicity against KB cells as in the cases of compounds 5, 9, 10, 16, 18 and 19. We suggest that the interaction of N-substituted S-(2,4-dinitrophenyl) glutathione dibutyl diesters with T. b. brucei occurs mainly by weak hydrophobic interactions such as London and van der Waals forces. A QSAR study indicated that the inhibitory activity of the peptide is associated negatively with the average number of C atoms, NC and positively to SZX, the ZX shadow a geometric descriptor related to molecular size and orientation of the compound. HPLC-UV studies in conjunction with optical microscopy indicate that the observed selectivity of inhibition of these compounds against bloodstream form T. b. brucei parasites in comparison to L. donovani under the same conditions is due to intracellular uptake via endocytosis in the flagellar pocket

Differential expression of mitogen activating protein kinases in periodontitis

Aim Following toll‐like receptor ( TLR ) engagement, lipopolysaccharide ( LPS ) can stimulate the expression of pro‐inflammatory cytokines thus activating the innate immune response. The production of inflammatory cytokines results, in part, from the activation of kinase‐induced signalling cascades and transcriptional factors. Of the four distinct classes of mitogen‐activated protein kinases ( MAPK ) described in mammals, p38, c‐Jun N‐terminal activated kinases ( JNK 1‐3) and extracellular activated kinases ( ERK 1,2) are the best studied. Previous data have established that p38 MAPK signalling is required for inflammation and bone loss in periodontal disease pre‐clinical animal models. Materials & Methods In this study, we obtained healthy and diseased periodontal tissues along with clinical parameters and microbiological parameters. Excised fixed tissues were immunostained with total and phospho‐specific antibodies against p38, JNK and ERK kinases. Results Intensity scoring from immunostained tissues was correlated with clinical periodontal parameters. Rank correlations with clinical indices were statistically significantly positive ( p ‐value < 0.05) for total p38 (correlations ranging 0.49–0.68), phospho‐p38 (range 0.44–0.56), and total ERK (range 0.52–0.59) levels, and correlations with JNK levels also supported association (range 0.42–0.59). Phospho‐ JNK and phospho‐ ERK showed no significant positive correlation with clinical parameters of disease. Conclusion These data strongly implicate p38 MAPK as a major MAPK involved in human periodontal inflammation and severity.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/98997/1/jcpe12123.pd

Tristetraprolin Regulates Interleukin-6 Expression Through p38 MAPK-Dependent Affinity Changes with mRNA 3' Untranslated Region

Tristetraprolin (TTP) is a well-characterized, zinc finger-containing, RNA-binding protein. TTP targets tumor necrosis factor alpha for degradation via the 3- untranslated region (3-UTR). Although AU-rich elements (AREs) in the 3-UTR of interleukin-6 (IL-6) mRNA dictate mRNA degradation, the role of TTP in the post-transcriptional regulation of IL-6 gene expression is unclear. Here we used TTP-deficient mice to test the hypothesis that IL-6 expression is influenced by TTP. Genetic and siRNA-mediated knockdown of TTP resulted in increased IL-6 production and overexpression of TTP had the reverse effect. IL-6 and tumor necrosis factor alpha production were elevated after injection of IL-1- in TTP-deficient mice. Further, embryonic fibroblasts from these mice (mouse embryonic fibroblasts) exhibited greater IL-6 mRNA expression and longer half-life than wild-type mouse embryonic fibroblasts. Overexpression of TTP reduced IL-6 3-UTR luciferase reporter activity in an ARE-dependent manner. Proximal and distal regions of the 3-UTR acted synergistically to produce the full repression of TTP. Mutation-based luciferase assays show that ARE2, ARE3, and ARE4 are required for TTP-mediated repression. The constitutively activated p38-MK2 pathway abrogated TTP-mediated repression of IL-6 3-UTR reporter activity. RNA immunoprecipitation assay indicated that the deficiency of p38alpha resulted in the increased affinity of TTP to IL-6 mRNA. Taken together, we propose that TTP downregulates IL-6 gene expression at the post-transcriptional level by targeting ARE elements in the 3-UTR region.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/90500/1/jir-2E2010-2E0154.pd

Buoyancy-induced time delays in Babcock-Leighton flux-transport dynamo models

The Sun is a magnetic star whose cyclic activity is thought to be linked to internal dynamo mechanisms. A combination of numerical modelling with various levels of complexity is an efficient and accurate tool to investigate such intricate dynamical processes. We investigate the role of the magnetic buoyancy process in 2D Babcock-Leighton dynamo models, by modelling more accurately the surface source term for poloidal field. Methods. To do so, we reintroduce in mean-field models the results of full 3D MHD calculations of the non-linear evolution of a rising flux tube in a convective shell. More specifically, the Babcock-Leighton source term is modified to take into account the delay introduced by the rise time of the toroidal structures from the base of the convection zone to the solar surface. We find that the time delays introduced in the equations produce large temporal modulation of the cycle amplitude even when strong and thus rapidly rising flux tubes are considered. Aperiodic modulations of the solar cycle appear after a sequence of period doubling bifurcations typical of non-linear systems. The strong effects introduced even by small delays is found to be due to the dependence of the delays on the magnetic field strength at the base of the convection zone, the modulation being much less when time delays remain constant. We do not find any significant influence on the cycle period except when the delays are made artificially strong. A possible new origin of the solar cycle variability is here revealed. This modulated activity and the resulting butterfly diagram are then more compatible with observations than what the standard Babcock-Leighton model produces.Comment: 13 pages, 10 figures, accepted for publication in A&

ProPane: Image Warping with Fire

In this paper we introduce the software package ProPane, written for the R data analysis language. ProPane combines the full range of wcslib projections with the C++ image manipulation routines provided by the CImg library. ProPane offers routines for image warping and combining (including stacking), and various related tasks such as image alignment tweaking and pixel masking. It can stack an effectively unlimited number of target frames using multiple parallel cores, and offers threading for many lower level routines. It has been used for a number of current and upcoming large surveys, and we present a range of its capabilities and features. ProPane is already available under a permissive open-source LGPL-3 license at github.com/asgr/ProPane (DOI: 10.5281/zenodo.10057053).Comment: 19 pages, 17 figures, 5 tables, accepted to MNRA

Detection of Brain-Derived Cell-Free DNA in Plasma

Background: Neuronal loss is a major pathological feature of neurodegenerative diseases. The analysis of plasma cell-free DNA (cfDNA) is an emerging approach to track cell death events in a minimally invasive way and from inaccessible areas of the body, such as the brain. Previous studies showed that DNA methylation (DNAm) profiles can be used to map the tissue of origin of cfDNA and to identify molecules released from the brain upon cell death. The aim of the present study is to contribute to this research field, presenting the development and validation of an assay for the detection of brain-derived cfDNA (bcfDNA). Methods: To identify CpG sites with brain-specific DNAm, we compared brain and non-brain tissues for their chromatin state profiles and genome-wide DNAm data, available in public datasets. The selected target genomic regions were experimentally validated by bisulfite sequencing on DNA extracted from 44 different autoptic tissues, including multiple brain regions. Sequencing data were analysed to identify brain-specific epihaplotypes. The developed assay was tested in plasma cfDNA from patients with immune effector cell-associated neurotoxicity syndrome (ICANS) following chimeric antigen receptor T (CAR-T) therapy. Results: We validated five genomic regions with brain-specific DNAm (four hypomethylated and one hypermethylated in the brain). DNAm analysis of the selected genomic regions in plasma samples from CAR-T patients revealed higher levels of bcfDNA in participants with ongoing neurotoxicity syndrome. Conclusions: We developed an assay for the analysis of bcfDNA in plasma. The assay is a promising tool for the early detection of neuronal loss in neurodegenerative diseases

Bisphosphonates Inhibit Expression of p63 by Oral Keratinocytes

Osteonecrosis of the jaw (ONJ), a side-effect of bisphosphonate therapy, is characterized by exposed bone that fails to heal within eight weeks. Healing time of oral epithelial wounds is decreased in the presence of amino-bisphosphonates; however, the mechanism remains unknown. We examined human tissue from individuals with ONJ and non-bisphosphonate-treated controlindividuals to identify changes in oral epithelium and connective tissue. Oral and intravenous bisphosphonate-treated ONJ sites had reduced numbers of basal epithelial progenitor cells, as demonstrated by a 13.8 ± 1.1% and 31.9 ± 5.8% reduction of p63 expression, respectively. No significant differences in proliferation rates, vessel density, or macrophage number were noted. In vitro treatment of clonal and primary oral keratinocytes with zoledronic acid (ZA) inhibited p63, and expression was rescued by the addition of mevalonate pathway intermediates. In addition, both ZA treatment and p63 shRNA knock-down impaired formation of 3D Ex Vivo Produced Oral Mucosa Equivalents (EVPOME) and closure of an in vitro scratch assay. Analysis of our data suggests that bisphosphonate treatment may delay oral epithelial healing by interfering with p63-positive progenitor cells in the basal layer of the oral epithelium in a mevalonate-pathway-dependent manner. This delay in healing may increase the likelihood of osteonecrosis developing in already-compromised bone

Novel germline variants identified in the inner mitochondrial membrane transporter TIMM44 and their role in predisposition to oncocytic thyroid carcinomas

Familial Non-Medullary Thyroid Carcinoma (fNMTC) represents 3–7% of all thyroid tumours and is associated with some of the highest familial risks among all cancers, with an inheritance pattern compatible with an autosomal dominant model with reduced penetrance. We previously mapped a predisposing locus, TCO (Thyroid tumour with Cell Oxyphilia) on chromosome 19p13.2, for a particular form of thyroid tumour characterised by cells with an abnormal proliferation of mitochondria (oxyphilic or oncocytic cells). In the present work, we report the systematic screening of 14 candidate genes mapping to the region of linkage in affected TCO members, that led us to identify two novel variants respectively in exon 9 and exon 13 of TIMM44, a mitochondrial inner membrane translocase for the import in the mitochondria of nuclear-encoded proteins. These variants were co-segregating with the TCO phenotype, were not present in a large group of controls and were predicted to negatively affect the protein (exon 9 change) or the transcript (exon 13 change). Functional analysis was performed in vitro for both changes and although no dramatic loss of function effects were identified for the mutant alleles, subtler effects might still be present that could alter Timm44 function and thus promote oncocytic tumour development. Thus we suggest that TIMM44 should be considered for further studies in independent samples of affected individuals with TCO