82 research outputs found
Glycan-independent role of calnexin in the intracellular retention of Charcot-Marie-tooth 1A Gas3/PMP22 mutants
Missense point mutations in Gas3/PMP22 are responsible for the peripheral neuropathies Charcot-Marie-Tooth 1A and Dejerine Sottas syndrome. These mutations induce protein misfolding with the consequent accumulation of the proteins in the endoplasmic reticulum and the formation of aggresomes. During folding, Gas3/PMP22 associates with the lectin chaperone calnexin. Here, we show that calnexin interacts with the misfolded transmembrane domains of Gas3/PMP22, fused to green fluorescent protein, in a glycan-independent manner. In addition, photobleaching experiments in living cells revealed that Gas3/PMP22-green fluorescent protein mutants are mobile but diffuse at almost half the diffusion coefficient of wild type protein. Our results support emerging models for a glycan-independent chaperone role for calnexin and for the mechanism of retention of misfolded membrane proteins in the endoplasmic reticulum
Ureteral or vesical involvement in Henoch-Schönlein syndrome: a systematic review of the literature
Background: Little information is available on ureteral or vesical involvement in Henoch-Schönlein syndrome. To determine the features of this condition we performed a formal analysis of peer-reviewed scientific literature on this topic. Methods: The US National Library of Medicine database was used as the data source. All articles published as full-length articles or letters were collected. Reports published in languages other than English, French, German, Italian or Spanish were not considered. Results: We analyzed 32 reports describing 35 cases (24 male and 11 female subjects aged between 3.5 and 63, median 7.0years) with ureteral (n = 30), vesical (n = 4), or both ureteral and vesical involvement (n = 1). The presentation included colicky abdominal pain, macroscopic hematuria (sometimes containing blood clots), urinary tract infection or urinary retention. The diagnosis of ureteral involvement was often fortuitous. Patients with vesical involvement were managed conservatively. However, the majority of those with ureteral involvement were managed surgically. Conclusions: Ureteral or vesical involvement is unusual and likely underappreciated in Henoch-Schönlein syndrome. Improved recognition and wider appreciation of this involvement can help to avoid associated morbidity. Management must be individualized for each patient. A multidisciplinary approach may be of value in planning medical treatment, surgical intervention, and follow-up
Early occurrence of lung adenocarcinoma and breast cancer after radiotherapy of a chest wall sarcoma in a patient with a de novo germline mutation in TP53
We report a 26-year-old female patient who was diagnosed within 4years with chest sarcoma, lung adenocarcinoma, and breast cancer. While her family history was unremarkable, DNA sequencing of TP53 revealed a germline de novo non-sense mutation in exon 6 p.Arg213X. One year later, she further developed a contralateral ductal carcinoma in situ, and 18months later a jaw osteosarcoma. This case illustrates the therapeutic pitfalls in the care of a young cancer patient with TP53 de novo germline mutations and the complications related to her first-line therapy. Suggestion is made to use the less stringent Chompret criteria for germline TP53 mutation screening. Our observation underlines the possibly negative effect of radiotherapy in generating second tumors in patients with a TP53 mutation. We also present a review of six previously reported cases, comparing their cancer phenotypes with those generally produced by TP53 mutation
Functional genomic analysis of constitutive and inducible defense responses to Fusarium verticillioides infection in maize genotypes with contrasting ear rot resistance.
Background: Fusarium verticillioides causes ear rot in maize (Zea mays L.) and accumulation of mycotoxins, that
affect human and animal health. Currently, chemical and agronomic measures to control Fusarium ear rot are not
very effective and selection of more resistant genotypes is a desirable strategy to reduce contaminations. A deeper
knowledge of molecular events and genetic basis underlying Fusarium ear rot is necessary to speed up progress in
breeding for resistance.
Results: A next-generation RNA-sequencing approach was used for the first time to study transcriptional changes
associated with F. verticillioides inoculation in resistant CO441 and susceptible CO354 maize genotypes at 72 hours
post inoculation. More than 100 million sequence reads were generated for inoculated and uninoculated control
plants and analyzed to measure gene expression levels. Comparison of expression levels between inoculated vs.
uninoculated and resistant vs. susceptible transcriptomes revealed a total number of 6,951 differentially expressed
genes. Differences in basal gene expression were observed in the uninoculated samples. CO441 genotype showed
a higher level of expression of genes distributed over all functional classes, in particular those related to secondary
metabolism category. After F. verticillioides inoculation, a similar response was observed in both genotypes, although
the magnitude of induction was much greater in the resistant genotype. This response included higher activation of
genes involved in pathogen perception, signaling and defense, including WRKY transcription factors and jasmonate/
ethylene mediated defense responses. Interestingly, strong differences in expression between the two genotypes were
observed in secondary metabolism category: pathways related to shikimate, lignin, flavonoid and terpenoid biosynthesis
were strongly represented and induced in the CO441 genotype, indicating that selection to enhance these traits is an
additional strategy for improving resistance against F. verticillioides infection.
Conclusions: The work demonstrates that the global transcriptional analysis provided an exhaustive view of genes
involved in pathogen recognition and signaling, and controlling activities of different TFs, phytohormones and secondary
metabolites, that contribute to host resistance against F. verticillioides. This work provides an important source of markers
for development of disease resistance maize genotypes andmay have relevance to study other pathosystems involving
mycotoxin-producing fungi
Klebsiella pneumoniae carrying multiple alleles of antigen 43-encoding gene of Escherichia coli associated with biofilm formation
A clinical strain of Klebsiella pneumoniae typed as sequence type 307 carrying three different alleles of the flu gene encoding the Escherichia coli virulence factor antigen 43 associated with biofilm formation was detected and characterized. The flu alleles are located in the chromosome inside putative integrative conjugative elements. The strain displays the phenotypes associated with Ag43, i.e. bi-phasic colony morphology and enhanced biofilm production. Furthermore, the strain produces low amount of capsule known to affect Ag43 function. Analysis of 1431 worldwide deposited genomes revealed that 3.7% Klebsiella pneumoniae carry one or two flu alleles
Distinct colonization patterns and cDNA-AFLP transcriptome profiles in compatible and incompatible interactions between melon and different races of Fusarium oxysporum f. sp. melonis
Background: Fusarium oxysporum f. sp. melonis Snyd. & Hans. (FOM) causes Fusarium wilt, the most important infectious disease of melon (Cucumis melo L.). The four known races of this pathogen can be distinguished only by infection on appropriate cultivars. No molecular tools are available that can discriminate among the races, and the molecular basis of compatibility and disease progression are poorly understood. Resistance to races 1 and 2 is controlled by a single dominant gene, whereas only partial polygenic resistance to race 1,2 has been described. We carried out a large-scale cDNA-AFLP analysis to identify host genes potentially related to resistance and susceptibility as well as fungal genes associated with the infection process. At the same time, a systematic reisolation procedure on infected stems allowed us to monitor fungal colonization in compatible and incompatible host-pathogen combinations. Results: Melon plants (cv. Charentais Fom-2), which are susceptible to race 1,2 and resistant to race 1, were artificially infected with a race 1 strain of FOM or one of two race 1,2 w strains. Host colonization of stems was assessed at 1, 2, 4, 8, 14, 16, 18 and 21 days post inoculation (dpi), and the fungus was reisolated from infected plants. Markedly different colonization patterns were observed in compatible and incompatible host-pathogen combinations. Five time points from the symptomless early stage (2 dpi) to obvious wilting symptoms (21 dpi) were considered for cDNA-AFLP analysis. After successful sequencing of 627 transcript-derived fragments (TDFs) differentially expressed in infected plants, homology searching retrieved 305 melon transcripts, 195 FOM transcripts expressed in planta and 127 orphan TDFs. RNA samples from FOM colonies of the three strains grown in vitro were also included in the analysis to facilitate the detection of in planta-specific transcripts and to identify TDFs differentially expressed among races/strains. Conclusion: Our data suggest that resistance against FOM in melon involves only limited transcriptional changes, and that wilting symptoms could derive, at least partially, from an active plant response. We discuss the pathogen-derived transcripts expressed in planta during the infection process and potentially related to virulence functions, as well as transcripts that are differentially expressed between the two FOM races grown in vitro. These transcripts provide candidate sequences that can be further tested for their ability to distinguish between races. Sequence data from this article have been deposited in GenBank, Accession Numbers: HO867279-HO867981
Racial differences in systemic sclerosis disease presentation: a European Scleroderma Trials and Research group study
Objectives. Racial factors play a significant role in SSc. We evaluated differences in SSc presentations between white patients (WP), Asian patients (AP) and black patients (BP) and analysed the effects of geographical locations.Methods. SSc characteristics of patients from the EUSTAR cohort were cross-sectionally compared across racial groups using survival and multiple logistic regression analyses.Results. The study included 9162 WP, 341 AP and 181 BP. AP developed the first non-RP feature faster than WP but slower than BP. AP were less frequently anti-centromere (ACA; odds ratio (OR) = 0.4, P < 0.001) and more frequently anti-topoisomerase-I autoantibodies (ATA) positive (OR = 1.2, P = 0.068), while BP were less likely to be ACA and ATA positive than were WP [OR(ACA) = 0.3, P < 0.001; OR(ATA) = 0.5, P = 0.020]. AP had less often (OR = 0.7, P = 0.06) and BP more often (OR = 2.7, P < 0.001) diffuse skin involvement than had WP.AP and BP were more likely to have pulmonary hypertension [OR(AP) = 2.6, P < 0.001; OR(BP) = 2.7, P = 0.03 vs WP] and a reduced forced vital capacity [OR(AP) = 2.5, P < 0.001; OR(BP) = 2.4, P < 0.004] than were WP. AP more often had an impaired diffusing capacity of the lung than had BP and WP [OR(AP vs BP) = 1.9, P = 0.038; OR(AP vs WP) = 2.4, P < 0.001]. After RP onset, AP and BP had a higher hazard to die than had WP [hazard ratio (HR) (AP) = 1.6, P = 0.011; HR(BP) = 2.1, P < 0.001].Conclusion. Compared with WP, and mostly independent of geographical location, AP have a faster and earlier disease onset with high prevalences of ATA, pulmonary hypertension and forced vital capacity impairment and higher mortality. BP had the fastest disease onset, a high prevalence of diffuse skin involvement and nominally the highest mortality
Chromosomal contacts connect loci associated with autism, BMI and head circumference phenotypes
Copy number variants (CNVs) are major contributors to genomic imbalance disorders. Phenotyping of 137 unrelated deletion and reciprocal duplication carriers of the distal 16p11.2 220 kb BP2-BP3 interval showed that these rearrangements are associated with autism spectrum disorders and mirror phenotypes of obesity/underweight and macrocephaly/microcephaly. Such phenotypes were previously associated with rearrangements of the non-overlapping proximal 16p11.2 600 kb BP4-BP5 interval. These two CNV-prone regions at 16p11.2 are reciprocally engaged in complex chromatin looping, as successfully confirmed by 4C-seq, fluorescence in situ hybridization and Hi-C, as well as coordinated expression and regulation of encompassed genes. We observed that genes differentially expressed in 16p11.2 BP4-BP5 CNV carriers are concomitantly modified in their chromatin interactions, suggesting that disruption of chromatin interplays could participate in the observed phenotypes. We also identified cis- and trans-acting chromatin contacts to other genomic regions previously associated with analogous phenotypes. For example, we uncovered that individuals with reciprocal rearrangements of the trans-contacted 2p15 locus similarly display mirror phenotypes on head circumference and weight. Our results indicate that chromosomal contacts’ maps could uncover functionally and clinically related genes.Molecular Psychiatry advance online publication, 31 May 2016; doi:10.1038/mp.2016.84
Heterozygous Variants in KMT2E Cause a Spectrum of Neurodevelopmental Disorders and Epilepsy.
We delineate a KMT2E-related neurodevelopmental disorder on the basis of 38 individuals in 36 families. This study includes 31 distinct heterozygous variants in KMT2E (28 ascertained from Matchmaker Exchange and three previously reported), and four individuals with chromosome 7q22.2-22.23 microdeletions encompassing KMT2E (one previously reported). Almost all variants occurred de novo, and most were truncating. Most affected individuals with protein-truncating variants presented with mild intellectual disability. One-quarter of individuals met criteria for autism. Additional common features include macrocephaly, hypotonia, functional gastrointestinal abnormalities, and a subtle facial gestalt. Epilepsy was present in about one-fifth of individuals with truncating variants and was responsive to treatment with anti-epileptic medications in almost all. More than 70% of the individuals were male, and expressivity was variable by sex; epilepsy was more common in females and autism more common in males. The four individuals with microdeletions encompassing KMT2E generally presented similarly to those with truncating variants, but the degree of developmental delay was greater. The group of four individuals with missense variants in KMT2E presented with the most severe developmental delays. Epilepsy was present in all individuals with missense variants, often manifesting as treatment-resistant infantile epileptic encephalopathy. Microcephaly was also common in this group. Haploinsufficiency versus gain-of-function or dominant-negative effects specific to these missense variants in KMT2E might explain this divergence in phenotype, but requires independent validation. Disruptive variants in KMT2E are an under-recognized cause of neurodevelopmental abnormalities
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