Role of Nrf2 signaling in regulation of antioxidants and phase 2 enzymes in cardiac fibroblasts: Protection against reactive oxygen and nitrogen species-induced cell injury

AbstractUnderstanding the molecular pathway(s) of antioxidant gene regulation is of crucial importance for developing antioxidant-inducing agents for the intervention of oxidative cardiac disorders. Accordingly, this study was undertaken to determine the role of Nrf2 signaling in the basal expression as well as the chemical inducibility of endogenous antioxidants and phase 2 enzymes in cardiac fibroblasts. The basal expression of a scope of key cellular antioxidants and phase 2 enzymes was significantly lower in cardiac fibroblasts derived from Nrf2−/− mice than those from wild type control. These include catalase, reduced glutathione (GSH), glutathione reductase (GR), GSH S-transferase (GST), and NAD(P)H:quinone oxidoreductase-1 (NQO1). Incubation of Nrf2+/+ cardiac fibroblasts with 3H-1,2-dithiole-3-thione (D3T) led to a significant induction of superoxide dismutase (SOD), catalase, GSH, GR, glutathione peroxidase (GPx), GST, and NQO1. The inducibility of SOD, catalase, GSH, GR, GST, and NQO1, but not GPx by D3T was completely abolished in Nrf2−/− cells. The Nrf2−/− cardiac fibroblasts were much more sensitive to reactive oxygen and nitrogen species-mediated cytotoxicity. Upregulation of antioxidants and phase 2 enzymes by D3T in Nrf2+/+ cardiac fibroblasts resulted in a dramatically increased resistance to the above species-induced cytotoxicity. In contrast, D3T-treatment of the Nrf2−/− cells only provided a slight cytoprotection. Taken together, this study demonstrates for the first time that Nrf2 is critically involved in the regulation of the basal expression and chemical induction of a number of antioxidants and phase 2 enzymes in cardiac fibroblasts, and is an important factor in controlling cardiac cellular susceptibility to reactive oxygen and nitrogen species-induced cytotoxicity

The HHID syndrome of hypertrichosis, hyperkeratosis, abnormal corpus callosum, intellectual disability, and minor anomalies is caused by mutations in ARID1B

Non peer reviewe

Mowat-Wilson syndrome

Mowat-Wilson syndrome (MWS) is a multiple congenital anomaly syndrome characterized by a distinct facial phenotype (high forehead, frontal bossing, large eyebrows, medially flaring and sparse in the middle part, hypertelorism, deep set but large eyes, large and uplifted ear lobes, with a central depression, saddle nose with prominent rounded nasal tip, prominent columella, open mouth, with M-shaped upper lip, frequent smiling, and a prominent but narrow and triangular pointed chin), moderate-to-severe intellectual deficiency, epilepsy and variable congenital malformations including Hirschsprung disease (HSCR), genitourinary anomalies (in particular hypospadias in males), congenital heart defects, agenesis of the corpus callosum and eye anomalies. The prevalence of MWS is currently unknown, but 171 patients have been reported so far. It seems probable that MWS is under-diagnosed, particularly in patients without HSCR. MWS is caused by heterozygous mutations or deletions in the Zinc finger E-box-binding homeobox 2 gene, ZEB2, previously called ZFHX1B (SIP1). To date, over 100 deletions/mutations have been reported in patients with a typical phenotype; they are frequently whole gene deletions or truncating mutations, suggesting that haploinsufficiency is the main pathological mechanism. Studies of genotype-phenotype analysis show that facial gestalt and delayed psychomotor development are constant clinical features, while the frequent and severe congenital malformations are variable. In a small number of patients, unusual mutations can lead to an atypical phenotype. The facial phenotype is particularly important for the initial clinical diagnosis and provides the hallmark warranting ZEB2 mutational analysis, even in the absence of HSCR. The majority of MWS cases reported so far were sporadic, therefore the recurrence risk is low. Nevertheless, rare cases of sibling recurrence have been observed. Congenital malformations and seizures require precocious clinical investigation with intervention of several specialists (including neonatologists and pediatricians). Psychomotor development is delayed in all patients, therefore rehabilitation (physical therapy, psychomotor and speech therapy) should be started as soon as possible

Transcriptional repressor ZEB2 promotes terminal differentiation of CD8⁺ effector and memory T cell populations during infection

ZEB2 is a multi-zinc-finger transcription factor known to play a significant role in early neurogenesis and in epithelial-mesenchymal transition-dependent tumor metastasis. Although the function of ZEB2 in T lymphocytes is unknown, activity of the closely related family member ZEB1 has been implicated in lymphocyte development. Here, we find that ZEB2 expression is up-regulated by activated T cells, specifically in the KLRG1(hi) effector CD8(+) T cell subset. Loss of ZEB2 expression results in a significant loss of antigen-specific CD8(+) T cells after primary and secondary infection with a severe impairment in the generation of the KLRG1(hi) effector memory cell population. We show that ZEB2, which can bind DNA at tandem, consensus E-box sites, regulates gene expression of several E-protein targets and may directly repress Il7r and Il2 in CD8(+) T cells responding to infection. Furthermore, we find that T-bet binds to highly conserved T-box sites in the Zeb2 gene and that T-bet and ZEB2 regulate similar gene expression programs in effector T cells, suggesting that T-bet acts upstream and through regulation of ZEB2. Collectively, we place ZEB2 in a larger transcriptional network that is responsible for the balance between terminal differentiation and formation of memory CD8(+) T cells

Parkes Weber Syndrome: Contribution of the Genotype to the Diagnosis

Objectives: Parkes Weber syndrome (PWS) is a rare disorder that combines overgrowth, capillary malformations, and arteriovenous malformations (AVM)/arteriovenous fistulas, for which underlying activating mutations in the ras/mitogen-activated protein kinase/extracellular-signal-regulated kinase signaling pathway have been described. The clinical overlap with Klippel-Trenauny syndrome, associated with mutations in PIK3CA, is significant. This case series aimed to elaborate on the phenotypic description of PWS, to underline its clinical overlap with Klippel-Trenauny syndrome and nonsyndromic AVM, and to evaluate the contribution of genotypic characterization to the diagnosis. Methods: All patients diagnosed with PWS upon enrollment in the Bernese VAScular COngenital Malformations (VASCOM) cohort were included. The diagnostic criteria of PWS were retrospectively reviewed. A next-generation sequencing (NGS) gene panel (TSO500, Illumina) was used on tissue biopsy samples. Results: Overall, 10/559 patients of the VAScular COngenital Malformations cohort were initially diagnosed with PWS. Three patients were reclassified as nonsyndromic AVM (Kristen Rat Sarcoma Viral oncogene homolog [KRAS], KRAS+tumor protein p53, and protein tyrosine phosphatase non-receptor type 11). Finally, 7 patients fulfilled all clinical diagnostic criteria of PWS. Genetic testing was available in 5 PWS patients. Only 1 patient had the classic RASA1 mutation; another patient had mutations in G protein subunit alpha q (GNAQ) and phosphatase and tensin homolog. In a third case, a PIK3CA mutation was detected. In 2 patients, no mutations were identified. Conclusion: Overgrowth syndromes with vascular malformations are rare and their clinical overlap hampers the classification of individual phenotypes under specific syndrome labels, sometimes even despite genetic testing. To provide optimal patient care, an accurate phenotypic description combined with the identification of molecular targets for precision medicine may be more meaningful than the syndrome classification itself

Cardiomyocyte-restricted overexpression of extracellular superoxide dismutase increases nitric oxide bioavailability and reduces infarct size after ischemia/reperfusion

published_or_final_versio

Clinical spectrum of females with HCCS mutation: from no clinical signs to a neonatal lethal form of the microphthalmia with linear skin defects (MLS) syndrome

Background: Segmental Xp22.2 monosomy or a heterozygous HCCS mutation is associated with the microphthalmia with linear skin defects (MLS) or MIDAS (microphthalmia, dermal aplasia, and sclerocornea) syndrome, an X-linked disorder with male lethality. HCCS encodes the holocytochrome c-type synthase involved in mitochondrial oxidative phosphorylation (OXPHOS) and programmed cell death. Methods: We characterized the X-chromosomal abnormality encompassing HCCS or an intragenic mutation in this gene in six new female patients with an MLS phenotype by cytogenetic analysis, fluorescence in situ hybridization, sequencing, and quantitative real-time PCR. The X chromosome inactivation (XCI) pattern was determined and clinical data of the patients were reviewed. Results: Two terminal Xp deletions of ≥11.2 Mb, two submicroscopic copy number losses, one of ~850 kb and one of ≥3 Mb, all covering HCCS, 1 nonsense, and one mosaic 2-bp deletion in HCCS are reported. All females had a completely (>98:2) or slightly skewed (82:18) XCI pattern. The most consistent clinical features were microphthalmia/anophthalmia and sclerocornea/corneal opacity in all patients and congenital linear skin defects in 4/6. Additional manifestations included various ocular anomalies, cardiac defects, brain imaging abnormalities, microcephaly, postnatal growth retardation, and facial dysmorphism. However, no obvious clinical sign was observed in three female carriers who were relatives of one patient. Conclusion: Our findings showed a wide phenotypic spectrum ranging from asymptomatic females with an HCCS mutation to patients with a neonatal lethal MLS form. Somatic mosaicism and the different ability of embryonic cells to cope with an OXPHOS defect and/or enhanced cell death upon HCCS deficiency likely underlie the great variability in phenotypes

Schistosoma mansoni : use of a fluorescent indicator to detect nitric oxide and related species in living parasites

Author Posting. © The Authors, 2005. This is the author's version of the work. It is posted here by permission of Elsevier B.V. for personal use, not for redistribution. The definitive version was published in Experimental Parasitology 113 (2006): 130-133, doi:10.1016/j.exppara.2005.12.013.Nitric oxide (NO) is synthesized enzymatically by nitric oxide synthase (NOS). Several groups have previously presented evidence for NOS activity and immunoreactivity in several parasitic platyhelminths, including schistosomes. Here, we use 4,5-diaminofluorescein-2 diacetate (DAF-2 DA), a fluorescent indicator of NO, to detect NO in living schistosomes. In adult worms, DAF-2 fluorescence is found selectively in epithelial-like cells. Fluorescence increases when worms are incubated in L-arginine, the precursor of NO synthesis, and decreases dramatically in the presence of the NOS inhibitor NG-nitro-L-arginine methyl ester (L-NAME), indicating that predicted NO release may be NOS-dependent, and that enzymatic NO signaling pathways may play an important role in schistosome physiology.This work was supported by NIH grant NS 39103 and NSF grants 0304569 (LLM), and NIH grant AI 40522 and the Neal Cornell Research Fund at the Marine Biological Laboratory (RMG)

Thiram inhibits angiogenesis and slows the development of experimental tumours in mice

Thiram-tetramethylthiuram disulphide – a chelator of heavy metals, inhibited DNA synthesis and induced apoptosis in cultured bovine capillary endothelial cells. Bovine capillary endothelial cells were 10–60-fold more sensitive to thiram than other cell types. These effects were prevented by addition of antioxidants, indicating involvement of reactive oxygen species. Exogenously added Cu2+ impeded specifically and almost completely the inhibitory effect of thiram for bovine capillary endothelial cells. Moreover, thiram had markedly inhibited human recombinant Cu/Zn superoxide dismutase enzymatic activity (85%) in vitro. Moreover, PC12-SOD cells with elevated Cu/Zn superoxide dismutase were less sensitive to thiram treatment than control cells. These data indicate that the effects of thiram are mediated by inhibition of Cu/Zn superoxide dismutase activity. Oral administration of thiram (13–30 μg mouse−1), inhibited angiogenesis in CD1 nude mice. Tumour development is known to largely depend on angiogenesis. We found that oral administration of thiram (30 μg) to mice caused significant inhibition of C6 glioma tumour development (60%) and marked reduction (by 3–5-fold) in metastatic growth of Lewis lung carcinoma. The data establish thiram as a potential inhibitor of angiogenesis and raise the possibility for its use as therapy in pathologies in which neovascularisation is involved, including neoplasia

Phenotype and genotype of 87 patients with Mowat-Wilson syndrome and recommendations for care

Mowat-Wilson syndrome (MWS) is a rare intellectual disability/multiple congenital anomalies syndrome caused by heterozygous mutation of the ZEB2 gene. It is generally underestimated because its rarity and phenotypic variability sometimes make it difficult to recognize. Here, we aimed to better delineate the phenotype, natural history, and genotype-phenotype correlations of MWS.MethodsIn a collaborative study, we analyzed clinical data for 87 patients with molecularly confirmed diagnosis. We described the prevalence of all clinical aspects, including attainment of neurodevelopmental milestones, and compared the data with the various types of underlying ZEB2 pathogenic variations.ResultsAll anthropometric, somatic, and behavioral features reported here outline a variable but highly consistent phenotype. By presenting the most comprehensive evaluation of MWS to date, we define its clinical evolution occurring with age and derive suggestions for patient management. Furthermore, we observe that its severity correlates with the kind of ZEB2 variation involved, ranging from ZEB2 locus deletions, associated with severe phenotypes, to rare nonmissense intragenic mutations predicted to preserve some ZEB2 protein functionality, accompanying milder clinical presentations.ConclusionKnowledge of the phenotypic spectrum of MWS and its correlation with the genotype will improve its detection rate and the prediction of its features, thus improving patient care.GENETICS in MEDICINE advance online publication, 4 January 2018; doi:10.1038/gim.2017.221