Mercury (Hg) is a well-known toxic element, diffused in the environment, especially in the Mediterranean Sea which is rich in cinnabar deposits. Mercury bioaccumulation in fish is of great concern, especially for top-level aquatic predators (e.g., shark, tuna, swordfish) and above all for species of large human consumption and high nutritional value. This work aimed to determine Hg concentrations in farmed and wild Atlantic Bluefin tuna (Thunnus thynnus) caught in the Mediterranean area in order to evaluate the level of Hg bioaccumulation. selenium (Se) content was also determined, since this element is an antagonist of mercury toxicity. Mercury and Se were analysed by atomic absorption spectrometry after microwave digestion of the samples. Hg content in farmed tuna was below the legal limit (1 mg/kg, wet weight, w.w.) for all specimens (0.6 ± 0.2 mg/kg), whereas the wild ones had a content over the limit (1.7 ± 0.6 mg/kg); Se concentration was higher in farmed specimens (1.1 ± 0.9 mg/kg) compared to wild ones (0.6 ± 0.3 mg/kg). A safe seafood could show a Se/Hg ratio >1 and a health benefit value (HBVSe) > 0: farmed tuna had higher values than the wild specimens (Se/Hg 5.48 vs. 1.32; HBVSe 11.16 vs. 0.29). These results demonstrate that for Hg, there is a better risk/benefit ratio in farmed T. thynnus. making it safer than wild tuna.
The present study was conducted to examine, for the first time in Nothobranchius furzeri , the effects of mating in different aged breeders with particular emphasis on reproductive fitness and the effects of parental aging on offspring gametogenesis. In N. furzeri , the increase of maternal and paternal age is often a predictable indicator of the upcoming deterioration on their natural habitat (i.e., ephemeral puddles) during African dry season. We previously revealed that elderly parents respond to their physiological decline state by decelerating offspring's development and growth rate. In the present study, we focused on the effects of different age parents at the onset of female offspring's sexual maturity since interaction between growth and reproduction traits generally occurs in vertebrates and could represent a life strategy. For this purpose, four different age breeder groups were set up. The age-specific breeder differences in reproductive performance were examined by analyzing the reproductive age-related fitness, the gametogenesis process in F1 females by histology, the offspring oocytes quality analyzing the gene expression of age-related molecular markers, like sirt1 and foxo3a , and the biochemical composition of vitellogenic oocytes using a spectroscopic approach. Results suggest that both maternal and paternal age affect reproductive performance and could influence the onset of sexual maturity in female offspring. In conclusion, these findings highlighted the effects of parental aging on life history traits in the short-lived model N. furzeri . Our results suggested that the advanced sexual maturity in offspring from young parents could be related to an adaptive response to the temporary habitat conditions.
Shwachman–Diamond syndrome (SDS) is a rare inherited bone marrow failure syndrome, resulting in neutropenia and a risk of myeloid neoplasia. A mutation in a ribosome maturation factor accounts for almost all of the cases. Lymphoid involvement in SDS has not been well characterized. We recently reported that lymphocyte subpopulations are reduced in SDS patients. We have also shown that the mTOR-STAT3 pathway is hyper-activated in SDS myeloid cell populations. Here we show that mTOR-STAT3 signaling is markedly upregulated in the lymphoid compartment of SDS patients. Furthermore, our data reveal elevated IL-6 levels in cellular supernatants obtained from lymphoblasts, bone marrow mononuclear and mesenchymal stromal cells, and plasma samples obtained from a cohort of 10 patients. Of note, everolimus-mediated inhibition of mTOR signaling is associated with basal state of phosphorylated STAT3. Finally, inhibition of mTOR-STAT3 pathway activation leads to normalization of IL-6 expression in SDS cells. Altogether, our data strengthen the hypothesis that SDS affects both lymphoid and myeloid blood compartment and suggest everolimus as a potential therapeutic agent to reduce excessive mTOR-STAT3 activation in SDS.
Studies on parental aging are a very attractive field, although it is poorly understood how parental age affects embryonic development and adult traits of the offspring. In this study, we used the turquoise killifish Nothobranchius furzeri, as is the vertebrate with shortest captive lifespan and an interesting model. The embryos of N. furzeri can follow two distinct developmental pathways either entering diapause or proceeding through direct development. Thus, this embryonic plasticity allows this model to be used to study different factors that could affect their embryonic development, including parental age. The first goal of the present study was to investigate whether parental aging could affect the embryo development. To do this, we collected F1 embryos from two breeder groups (old parents and young parents). We monitored the duration of embryonic development and analyzed genes involved in dorsalization process. The second goal was to investigate if embryonic developmental plasticity could be modulated by an epigenetic process. To this end, the expression of DNMTs genes was examined. Our data support the hypothesis that diapause, occurring more frequently in embryos from old parents, is associated with increased expression of DNMT3A and DNMT3B suggesting an epigenetic control. Finally, we analyzed whether parental age could affect metabolism and growth during adult life. Morphometric results and qPCR analysis of genes from IGF system showed a slower growth in adults from old breeders. Moreover, a gender-specificity effect on growth emerged. In conclusion, these results may contribute to the better understanding of the complex mechanism of aging.
A previously established gas chromatography-mass spectrometry method was applied for the determination of the fatty acid composition in the muscles of Atlantic bluefin tuna (Thunnus thynnus L). The fish were collected in the Mediterranean Sea and cultivated for several months. The goal of the study was to demonstrate the feasibility of these measurements and to improve knowledge about the influence of size and gender on the fatty acid composition. Although no significant differences were found with respect to gender, males and females showed different correlations of fatty acid composition with weight. In the males, a statistically significant linear correlation was found for 14:0, 16:0, 18:1n9, 20:1n9, 22:1n9 (positive correlation), and for 20:4n6, 20:5n3 22:6n3 (negative correlation). In the females, a statistically significant polynomial correlation for specific fatty acids was highlighted: specimens with medium size showed the lowest content of 20:1n9 and 22:1n9 and the highest content of 20:4n6, 20:5n3, and 22:6n3. Therefore, males smaller than 150 kg and females from 150 to 250 kg appeared to have the highest greater nutritional value. This study demonstrated the practicality of the analytical methodology and enhanced the knowledge of the influence of size on the fatty acid composition of Atlantic bluefin tuna muscle, reporting a newly established gender difference and representing a starting point to produce the best nutritional characteristics for farmed tuna.
Inherited bone marrow failure syndromes (IBMFS) are a group of cancer-prone genetic diseases characterized by hypocellular bone marrow with impairment in one or more hematopoietic lineages. The pathogenesis of IBMFS involves mutations in several genes which encode for proteins involved in DNA repair, telomere biology and ribosome biogenesis. The classical IBMFS include Shwachman–Diamond syndrome (SDS), Diamond–Blackfan anemia (DBA), Fanconi anemia (FA), dyskeratosis congenita (DC), and severe congenital neutropenia (SCN). IBMFS are associated with high risk of myelodysplastic syndrome (MDS), acute myeloid leukemia (AML), and solid tumors. Unfortunately, no specific pharmacological therapies have been highly effective for IBMFS. Hematopoietic stem cell transplantation provides a cure for aplastic or myeloid neoplastic complications. However, it does not affect the risk of solid tumors. Since approximately 28% of FA, 24% of SCN, 21% of DBA, 20% of SDS, and 17% of DC patients harbor nonsense mutations in the respective IBMFS-related genes, we discuss the use of the nonsense suppression therapy in these diseases. We recently described the beneficial effect of ataluren, a nonsense suppressor drug, in SDS bone marrow hematopoietic cells ex vivo. A similar approach could be therefore designed for treating other IBMFS. In this review we explain in detail the new generation of nonsense suppressor molecules and their mechanistic roles. Furthermore, we will discuss strengths and limitations of these molecules which are emerging from preclinical and clinical studies. Finally we discuss the state-of-the-art of preclinical and clinical therapeutic studies carried out for IBMFS.