98 research outputs found
SIK1/SOS2 networks: decoding sodium signals via calcium-responsive protein kinase pathways
Changes in cellular ion levels can modulate distinct signaling networks aimed at correcting major disruptions in ion balances that might otherwise threaten cell growth and development. Salt-inducible kinase 1 (SIK1) and salt overly sensitive 2 (SOS2) are key protein kinases within such networks in mammalian and plant cells, respectively. In animals, SIK1 expression and activity are regulated in response to the salt content of the diet, and in plants SOS2 activity is controlled by the salinity of the soil. The specific ionic stress (elevated intracellular sodium) is followed by changes in intracellular calcium; the calcium signals are sensed by calcium-binding proteins and lead to activation of SIK1 or SOS2. These kinases target major plasma membrane transporters such as the Na+,K+-ATPase in mammalian cells, and Na+/H+ exchangers in the plasma membrane and membranes of intracellular vacuoles of plant cells. Activation of these networks prevents abnormal increases in intracellular sodium concentration
A polymorphic variant of the insulin-like growth factor 1 (IGF-1) receptor correlates with male longevity in the Italian population: a genetic study and evaluation of circulating IGF-1 from the "Treviso Longeva (TRELONG)" study
<p>Abstract</p> <p>Background</p> <p>An attenuation of the insulin-like growth factor 1 (IGF-1) signaling has been associated with elongation of the lifespan in simple metazoan organisms and in rodents. In humans, IGF-1 level has an age-related modulation with a lower concentration in the elderly, depending on hormonal and genetic factors affecting the IGF-1 receptor gene (<it>IGF-1R</it>).</p> <p>Methods</p> <p>In an elderly population from North-eastern Italy (<it>n </it>= 668 subjects, age range 70–106 years) we investigated the <it>IGF-1R </it>polymorphism G3174A (<it>rs2229765</it>) and the plasma concentration of free IGF-1. Frequency distributions were compared using χ<sup>2</sup>-test "Goodness of Fit" test, and means were compared by one-way analysis of variance (ANOVA); multiple regression analysis was performed using JMP7 for SAS software (SAS Institute, USA). The limit of significance for genetic and biochemical comparison was set at α = 0.05.</p> <p>Results</p> <p>Males showed an age-related increase in the A-allele of <it>rs2229765 </it>and a change in the plasma level of IGF-1, which dropped significantly after 85 years of age (85+ group). In the male 85+ group, A/A homozygous subjects had the lowest plasma IGF-1 level. We found no clear correlation between <it>rs2229765 </it>genotype and IGF-1 in the females.</p> <p>Conclusion</p> <p>These findings confirm the importance of the <it>rs2229765 </it>minor allele as a genetic predisposing factor for longevity in Italy where a sex-specific pattern for IGF-1 attenuation with ageing was found.</p
WHOLE-GENOME RE-SEQUENCING OF TWO TOMATO LANDRACES REVEALS SEQUENCE VARIATIONS UNDERPINNING KEY ECONOMICALLY IMPORTANT TRAITS
In the post-genomic era, one of the major challenges is the identification of alleles directly
responsible for phenotype variation among different genotypes within the same species. Tomato is a
model crop for understanding the development and ripening of climacteric fleshy fruits, and it is
also known to be an important source of health-promoting compounds. In addition, cultivated
tomato germplasm shows a high phenotypic variation despite its very low genetic diversity. Toward
the identification of sequence variations responsible for stress tolerance, high fruit quality and long
shelf life, we re-sequenced the genomes of two traditional landraces grown in the Campania region
(Southern Italy). Crovarese, belonging to the Corbarino type (COR), and Lucariello (LUC) are
typically grown under low water regimes and produce highly appreciated fruits, which can be stored
up to 4-8 months. We generated 65.8M and 56.4M of paired-end 30-150 bp reads with an average
insert size of 380 bp (± 52bp) and 364 bp (± 49bp) for COR and LUC, respectively. A referenceguided
assembly was performed using 'Heinz 1706' as a reference genome. We estimated a mean
coverage depth of ~15X for COR and 13X for LUC. Comparing the genomes of COR and LUC
with that of 'Heinz 1706' we found a similar distribution of SNPs (68.8% vs. 69.9%, respectively),
small deletions (8.9% vs. 8.6%) and small insertions (22.1% vs. 21.3%). Through a de novo
assembly of the unmapped reads we identified 29 and 36 new contigs in COR and LUC,
respectively. The new contigs could be assigned to the chromosomes thanks to the use of a splitread
approach. On average, the contigs inserted in COR were 654bp, whereas those inserted in LUC
were 616bp. Using custom RNA-seq data, a total of 43054 and 44576 gene loci were annotated in
COR and LUC, corresponding to 62369 and 65094 transcripts, respectively. Among the genes
showing a similar structure in COR and LUC compared to 'Heinz 1706', we identified ~2000 and
1700 SNPs causing potentially disruptive effects on the function of 1371 and 1201 genes in COR
and LUC, respectively. Interesting GO categories highly represented in genes affected by sequence
changes were identified. Major variations were present in stress-responsive genes as well as in fruit
quality and development-related genes. From a practical perspective, the identified SNPs and
InDels are candidate polymorphisms to track DNA variations associated to key traits of economic
interest
Medical treatment of renal cancer: new horizons.
Renal cell carcinoma (RCC) makes up 2-3% of adult cancers. The introduction of tyrosine kinase inhibitors (TKIs) and mammalian target of rapamycin inhibitors in the mid-2000s radically changed the management of RCC. These targeted treatments superseded immunotherapy with interleukin-2 and interferon. The pendulum now appears to be shifting back towards immunotherapy, with the evidence of prolonged overall survival of patients with metastatic RCC on treatment with the anti-programmed cell death 1 ligand monoclonal antibody, nivolumab. Clinical prognostic criteria aid prediction of relapse risk for resected localised disease. Unfortunately, for patients at high risk of relapse, no adjuvant treatment has yet shown benefit, although further trials are yet to report. Clinical prognostic models also have a role in the management of advanced disease; now there is a pressing need for predictive biomarkers to direct therapy. Treatment selection for metastatic disease is currently based on histology, prognostic group and patient preference based on side effect profile. In this article, we review the current medical and surgical management of localised, oligometastatic and advanced RCC, including side effect management and the evidence base for management of poor-risk and non-clear cell disease. We discuss recent results from clinical trials and how these are likely to shape future practice and a renaissance of immunotherapy for renal cell cancer
Salinity and aba seed responses in pepper: Expression and interaction of ABA core signaling components
Abscisic acid (ABA) plays an important role in various aspects of plant growth and development, including adaptation to stresses, fruit development and ripening. In seeds, ABA participates through its core signaling components in dormancy instauration, longevity determination, and inhibition of germination in unfavorable environmental conditions such as high soil salinity. Here, we show that seed germination in pepper was delayed but only marginally reduced by ABA or NaCl with respect to control treatments. Through a similarity search, pepper orthologs of ABA core signaling components PYL (PYRABACTIN RESISTANCE1-LIKE), PP2C (PROTEIN PHOSPHATASE2C), and SnRK2 (SUCROSE NONFERMENTING1 (SNF1)-RELATED PROTEIN KINASE2) genes were identified. Gene expression analyses of selected members showed a low abundance of PYL and SnRK2 transcripts in dry seeds compared to other tissues, and an up-regulation at high concentrations of ABA and/or NaCl for both positive and negative regulators of ABA signaling. As expected, in hydroponically-grown seedlings exposed to NaCl, only PP2C encoding genes were up-regulated. Yeast two hybrid assays performed among putative pepper core components and with Arabidopsis thaliana orthologs confirmed the ability of the identified proteins to function in ABA signaling cascade, with the exception of a CaABI isoform cloned from seeds. BiFC assay in planta confirmed some of the interactions obtained in yeast. Altogether, our results indicate that a low expression of perception and signaling components in pepper seeds might contribute to explain the observed high percentages of seed germination in the presence of ABA. These results might have direct implications on the improvement of seed longevity and vigor, a bottleneck in pepper breeding
DJ-1 modulates a-synuclein aggregation state in a cellular model of oxidative stress: Relevance for Parkinson\u2019s disease and involvement of HSP-70.
BACKGROUND:
Parkinson's disease (PD) is a neurodegenerative pathology whose molecular etiopathogenesis is not known. Novel contributions have come from familial forms of PD caused by alterations in genes with apparently unrelated physiological functions. The gene coding for alpha-synuclein (alpha-syn) (PARK1) has been investigated as alpha-syn is located in Lewy bodies (LB), intraneuronal inclusions in the substantia nigra (SN) of PD patients. A-syn has neuroprotective chaperone-like and antioxidant functions and is involved in dopamine storage and release. DJ-1 (PARK7), another family-PD-linked gene causing an autosomal recessive form of the pathology, shows antioxidant and chaperone-like activities too.
METHODOLOGY/PRINCIPAL FINDINGS:
The present study addressed the question whether alpha-syn and DJ-1 interact functionally, with a view to finding some mechanism linking DJ-1 inactivation and alpha-syn aggregation and toxicity. We developed an in vitro model of alpha-syn toxicity in the human neuroblastoma cell line SK-N-BE, influencing DJ-1 and alpha-syn intracellular concentrations by exogenous addition of the fusion proteins TAT-alpha-syn and TAT-DJ-1; DJ-1 was inactivated by the siRNA method. On a micromolar scale TAT-alpha-syn aggregated and triggered neurotoxicity, while on the nanomolar scale it was neuroprotective against oxidative stress (induced by H(2)O(2) or 6-hydroxydopamine). TAT-DJ-1 increased the expression of HSP70, while DJ-1 silencing made SK-N-BE cells more susceptible to oxidative challenge, rendering TAT-alpha-syn neurotoxic at nanomolar scale, with the appearance of TAT-alpha-syn aggregates.
CONCLUSION/SIGNIFICANCE:
DJ-1 inactivation may thus promote alpha-syn aggregation and the related toxicity, and in this model HSP70 is involved in the antioxidant response and in the regulation of alpha-syn fibril formation
The urokinase-type plasminogen activator polymorphism PLAU_1 is a risk factor for APOE-epsilon4 non-carriers in the Italian Alzheimer's disease population and does not affect the plasma Abeta(1-42) level
Sporadic Alzheimer's disease (AD) is the most frequent form of dementia in the elderly. A non-conservative polymorphism in the urokinase-type plasminogen activator gene (PLAU_1=RS2227564) has been analyzed, but data are conflicting on whether it is a risk factor for AD. To clarify whether this genetic variant modifies AD risk in the Italian population, we ran a case-control association study on 192 AD and 126 age-matched controls. We did not find any association between PLAU_1 genotype and AD in the whole AD population, but when we stratified our sample by APOE-epsilon4 status, we found a significant association between PLAU_1 genotype (C/T+T/T) and APOE-epsilon4 negative AD subjects (p=0.02, chi(2)-test). The PLAU_1 genotype did not appear to affect the plasma Abeta42 concentration. Our data support a role for PLAU_1 as an independent genetic risk factor for AD in the Italian population for those subjects who do not have the APOE-epsilon4 allele
- …