Cardiac and vascular changes in elderly atherosclerotic mice: the influence of gender

<p>Abstract</p> <p>Background</p> <p>Although advanced age is considered a risk factor for several diseases, the impact of gender on age-associated cardiovascular diseases, such as atherosclerotic processes and valvular diseases, remains not completely clarified. The present study was designed to assess aortic valve morphology and function and vascular damage in elderly using the apolipoprotein E knockout (ApoE KO) mouse. Our hypothesis was that advanced age-related cardiovascular changes are aggravated in atherosclerotic male mice.</p> <p>Methods</p> <p>The grade (0 to 4) of aortic regurgitation was evaluated through angiography. In addition, vascular lipid deposition and senescence were evaluated through histochemical analyses in aged male and female ApoE KO mice, and the results were compared to wild-type C57BL/6J (C57) mice.</p> <p>Results</p> <p>Aortic regurgitation was observed in 92% of the male ApoE KO mice and 100% of the male C57 mice. Comparatively, in age-matched female ApoE KO and C57 mice, aortic regurgitation was observed in a proportion of 58% and 53%, respectively. Histological analysis of the aorta showed an outward (positive) remodeling in ApoE KO mice (female: 1.86 ± 0.15; male: 1.89 ± 0.68) using C57 groups as reference values. Histochemical evaluation of the aorta showed lipid deposition and vascular senescence only in the ApoE KO group, which were more pronounced in male mice.</p> <p>Conclusion</p> <p>The data show that male gender contributes to the progression of aortic regurgitation and that hypercholesterolemia and male gender additively contribute to the occurrence of lipid deposition and vascular senescence in elderly mice.</p

Circulating clonotypic B cells in multiple myeloma and monoclonal gammopathy of undetermined significance

This is an open-access paper.The B-cell compartment in which multiple myeloma stem cells reside remains unclear. We investigated the potential presence of mature, surface-membrane immunoglobulin-positive B lymphocytes clonally related to the tumor bone marrow plasma cells among different subsets of peripheral blood B cells from ten patients (7 with multiple myeloma and 3 with monoclonal gammopathies of undetermined significance). The presence of clonotypic immunoglobulin heavy chain gene rearrangements was determined in multiple highly-purified fractions of peripheral blood B-lymphocytes including surface-membrane IgM+ CD27- naïve B-lymphocytes, plus surface-membrane IgG+, IgA+ and IgM+ memory CD27+ B cells, and normal circulating plasma cells, in addition to (mono)clonal plasma cells, by a highly-specific and sensitive allele-specific oligonucleotide polymerase chain reaction directed to the CDR3 sequence of the rearranged IGH gene of tumor plasma cells from individual patients. Our results showed systematic absence of clonotypic rearrangements in all the different B-cell subsets analyzed, including M-compo-nent isotype-matched memory B-lymphocytes, at frequencies <0.03 cells/mL (range: 0.0003-0.08 cells/mL); the only exception were the myeloma plasma cells detected and purified from the peripheral blood of four of the seven myeloma patients. These results indicate that circulating B cells from patients with multiple myeloma and monoclonal gammopathies of undetermined significance are usually devoid of clonotypic B cells while the presence of immunophenotypically aberrant myeloma plasma cells in peripheral blood of myeloma patients is a relatively frequent finding.This work was supported by grants from European Union FP6 STREP MSCNet (N. E06005FF), Cooperative Research Thematic Network on Cancer (RTICs; RTICC RD06/0020/0035-FEDER, RD06/0020/0006, RD12/0036/0048, RD12/0036/0069 and G03/136), Instituto de Salud Carlos III/Subdirección General de Investigación Sanitaria Ministerio de Sanidad y Consumo (FIS: PI060339; 02/0905; 01/0089/01-02;PS09/01897, and PI06/0824-FEDER), Asociacion Española Contra el Cancer AECC (GCB120981SAN) and Gerencia Regional de Salud de Castilla y León; Ayuda de Excelencia de Castilla y León, Consejería de Educación (EDU/894/2009, GR37) Junta de Castilla y León, Valladolid, Spain. LST received a CAPES/Ministério da Educação scholarship from the Brazilian Government.Peer Reviewe

Genomic Analyses, Gene Expression and Antigenic Profile of the Trans-Sialidase Superfamily of Trypanosoma cruzi Reveal an Undetected Level of Complexity

The protozoan parasite Trypanosoma cruzi is the etiologic agent of Chagas disease, a highly debilitating human pathology that affects millions of people in the Americas. The sequencing of this parasite's genome reveals that trans-sialidase/trans-sialidase-like (TcS), a polymorphic protein family known to be involved in several aspects of T. cruzi biology, is the largest T. cruzi gene family, encoding more than 1,400 genes. Despite the fact that four TcS groups are well characterized and only one of the groups contains active trans-sialidases, all members of the family are annotated in the T. cruzi genome database as trans-sialidase. After performing sequence clustering analysis with all TcS complete genes, we identified four additional groups, demonstrating that the TcS family is even more heterogeneous than previously thought. Interestingly, members of distinct TcS groups show distinctive patterns of chromosome localization. Members of the TcSgroupII, which harbor proteins involved in host cell attachment/invasion, are preferentially located in subtelomeric regions, whereas members of the largest and new TcSgroupV have internal chromosomal locations. Real-time RT-PCR confirms the expression of genes derived from new groups and shows that the pattern of expression is not similar within and between groups. We also performed B-cell epitope prediction on the family and constructed a TcS specific peptide array, which was screened with sera from T. cruzi-infected mice. We demonstrated that all seven groups represented in the array are antigenic. A highly reactive peptide occurs in sixty TcS proteins including members of two new groups and may contribute to the known cross-reactivity of T. cruzi epitopes during infection. Taken together, our results contribute to a better understanding of the real complexity of the TcS family and open new avenues for investigating novel roles of this family during T. cruzi infection

ClpP protease activation results from the reorganization of the electrostatic interaction networks at the entrance pores

Bacterial ClpP is a highly conserved, cylindrical, self-compartmentalizing serine protease required for maintaining cellular proteostasis. Small molecule acyldepsipeptides (ADEPs) and activators of self-compartmentalized proteases 1 (ACP1s) cause dysregulation and activation of ClpP, leading to bacterial cell death, highlighting their potential use as novel antibiotics. Structural changes in Neisseria meningitidis and Escherichia co ClpP upon binding to novel ACP1 and ADEP analogs were probed by X-ray crystallography, methyl-TROSY NMR, and small angle X-ray scattering. ACP1 and ADEP induce distinct conformational changes in the ClpP structure. However, reorganization of electrostatic interaction networks at the ClpP entrance pores is necessary and sufficient for activation. Further activation is achieved by formation of ordered N-terminal axial loops and reduction in the structural heterogeneity of the ClpP cylinder. Activating mutations recapitulate the structural effects of small molecule activator binding. Our data, together with previous findings, provide a structural basis for a unified mechanism of compound-based ClpP activation2CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQCOORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIOR - CAPESFUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESP306943/2015-8; 420567/2016-099999.004913/2015-092015/15822-1; 2012/01953-9; 2016/05019-0; 2012/50161-8Precision Medicine Initiative (PRiME) at the University of Toronto internal fellowship [PMRF2019-007]; Canadian Institutes of Health Research (CIHR) postdoctoral fellowshipCanadian Institutes of Health Research (CIHR); CNPq-Brazil fellowship [202192/2015-6]; Saskatchewan Health Research Foundation postdoctoral fellowship; Ontario Graduate Scholarship (OGS)Ontario Graduate Scholarship; Department of Biochemistry at the University of Toronto; Centre for Pharmaceutical Oncology (University of Toronto); CIHR Training Program in Protein Folding and Interaction Dynamics: Principles and Diseases fellowshipCanadian Institutes of Health Research (CIHR) [TGF-53910]; University of Toronto Fellowship from the Department of Biochemistry; OGS fellowship; NSERC PGS-D2 fellowship; CIHR Emerging Team Grants from the Institute of Infection and ImmunityCanadian Institutes of Health Research (CIHR) [XNE-86945]; CIHR Project grantCanadian Institutes of Health Research (CIHR) [PJT-148564]; Global Affairs Canada (Canada); CAPES (Brazil)CAPES [99999.004913/2015-09]; NSERCNatural Sciences and Engineering Research Council of Canada [RGPIN-2015-04877, DG-20234]; Canada Research Chairs ProgramCanada Research Chairs; CIHR new investigator programCanadian Institutes of Health Research (CIHR); FAPESPFundacao de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP) [2015/15822-1, 2012/01953-9, 2016/05019-0, 2012/50161-8]; CNPqNational Council for Scientific and Technological Development (CNPq) [306943/2015-8, 420567/2016-0]; AbbVie [1097737]; BayerBayer AG [1097737]; Boehringer IngelheimBoehringer Ingelheim [1097737]; Genome Canada through Ontario Genomics Institute GrantGenome Canada [1097737, OGI-055]; GlaxoSmithKlineGlaxoSmithKline [1097737]; JanssenJohnson & Johnson USAJanssen Biotech Inc [1097737]; Lilly CanadaEli Lilly [1097737]; MerckMerck & Company [1097737]; Novartis Research Foundation [1097737]; Ontario Ministry of Economic Development and Innovation [1097737]; PfizerPfizer [1097737]; TakedaTakeda Pharmaceutical Company Ltd [1097737]; Wellcome Trust GrantWellcome Trust [1097737, 092809/Z/10/Z]; Canada Foundation for InnovationCanada Foundation for Innovation; NSERCNatural Sciences and Engineering Research Council of Canada; University of Saskatchewan; Government of Saskatchewan; Western Economic Diversification Canada; National Research Council Canada; CIHRCanadian Institutes of Health Research (CIHR

Rarity of monodominance in hyperdiverse Amazonian forests.

Tropical forests are known for their high diversity. Yet, forest patches do occur in the tropics where a single tree species is dominant. Such "monodominant" forests are known from all of the main tropical regions. For Amazonia, we sampled the occurrence of monodominance in a massive, basin-wide database of forest-inventory plots from the Amazon Tree Diversity Network (ATDN). Utilizing a simple defining metric of at least half of the trees ≥ 10 cm diameter belonging to one species, we found only a few occurrences of monodominance in Amazonia, and the phenomenon was not significantly linked to previously hypothesized life history traits such wood density, seed mass, ectomycorrhizal associations, or Rhizobium nodulation. In our analysis, coppicing (the formation of sprouts at the base of the tree or on roots) was the only trait significantly linked to monodominance. While at specific locales coppicing or ectomycorrhizal associations may confer a considerable advantage to a tree species and lead to its monodominance, very few species have these traits. Mining of the ATDN dataset suggests that monodominance is quite rare in Amazonia, and may be linked primarily to edaphic factors

On the roles of AA15 lytic polysaccharide monooxygenases derived from the termite Coptotermes gestroi

Lytic polysaccharide monooxygenases (LPMOs) are copper-dependent enzymes which catalyze the oxidative cleavage of polysaccharides. LPMOs belonging to family 15 in the Auxiliary Activity (AA) class from the Carbohydrate-Active Enzyme database are found widespread across the Tree of Life, including viruses, algae, oomycetes and animals. Recently, two AA15s from the firebrat Thermobia domestica were reported to have oxidative activity, one towards cellulose or chitin and the other towards chitin, signalling that AA15 LPMOs from insects potentially have different biochemical functions. Herein, we report the identification and characterization of two family AA15 members from the lower termite Coptotermes gestroi. Addition of Cu(II) to CgAA15a or CgAA15b had a thermostabilizing effect on both. Using ascorbate and O2 as co-substrates, CgAA15a and CgAA15b were able to oxidize chitin, but showed no activity on celluloses, xylan, xyloglucan and starch. Structural models indicate that the LPMOs from C. gestroi (CgAA15a/CgAA15b) have a similar fold but exhibit key differences in the catalytic site residues when compared to the cellulose/chitin-active LPMO from T. domestica (TdAA15a), especially the presence of a non-coordinating phenylalanine nearby the Cu ion in CgAA15a/b, which appears as a tyrosine in the active site of TdAA15a. Despite the overall similarity in protein folds, however, mutation of the active site phenylalanine in CgAA15a to a tyrosine did not expanded the enzymatic specificity from chitin to cellulose. Our data show that CgAA15a/b enzymes are likely not involved in lignocellulose digestion but might play a role in termite developmental processes as well as on chitin and nitrogen metabolisms