Acetylation controls Notch3 stability and function in T-cell leukemia

Post-translational modifications of Notch3 and their functional role with respect to Notch3 overexpression in T-cell leukemia are still poorly understood. We identify here a specific novel property of Notch3 that is acetylated and deacetylated at lysines 1692 and 1731 by p300 and HDAC1, respectively, a balance impaired by HDAC inhibitors (HDACi) that favor hyperacetylation. By using HDACi and a non-acetylatable Notch3 mutant carrying K/R(1692-1731) mutations in the intracellular domain, we show that Notch3 acetylation primes ubiquitination and proteasomal-mediated degradation of the protein. As a consequence, Notch3 protein expression and its transcriptional activity are decreased both in vitro and in vivo in Notch3 transgenic (tg) mice, thus impairing downstream signaling upon target genes. Consistently, Notch3-induced T-cell proliferation is inhibited by HDACi, whereas it is enhanced by the non-acetylatable Notch3-K/R(1692-1731) mutant. Finally, HDACi-induced Notch3 hyperacetylation prevents in vivo growth of T-cell leukemia/lymphoma in Notch3 tg mice. Together, our findings suggest a novel level of Notch signaling control in which Notch3 acetylation/deacetylation process represents a key regulatory switch, thus representing a suitable druggable target for Notch3-sustained T-cell acute lymphoblastic leukemia therapy.

[Italian translation and validation of the Nordic IRSST standardized questionnaire for the analysis of musculoskeletal symptoms]

BACKGROUND

Data on self-reported symptoms and/or functional impairments are important in research on work-related musculoskeletal disorders (WRMSDs). In such cases the availability of international standardized questionnaires is extremely important since they permit comparison of studies performed in different Countries.

OBJECTIVES

Translation into Italian and validation of the Nordic Musculoskeletal Questionnaire (NMQ), a tool which is widely used in studies on WRMSDs in the international scientific literature.

METHODS

The extended Canadian version of the NMQ was translated into Italian. As per the current guidelines, the cross-cultural adaptation was performed by translation of the items from French, back-translation by independent mother-tongue translators and committee review. The resulting version of the questionnaire underwent pre-testing in 3 independent groups of subjects. The comprehensibility, reliability (internal consistency and reproducibility) and sensitivity were evaluated.

RESULTS

After translation/back-translation and review of the items the comprehensibility of the Italian version of the questionnaire was judged good in a group of 40 workers. The internal consistency was evaluated using the Cronbach's Alpha test in the same group and in another 98 engineering workers: the results were on the whole acceptable. The reproducibility, which was tested with Cohen's Kappa test in the 40 workers, was good/excellent. In a preliminary evaluation, performed in 30 outpatients of a of Rehabilitation Service, sensitivity was very good.

CONCLUSIONS

The results show that the Italian version of the Nordic Musculoskeletal Questionnaire is valid for self-administration and can be applied in 'field" studies on self-reported musculoskeletal symptoms and functional impairments in group of workers.

[The Italian version of Nordic Musculoskeletal Standardized Questionnaire]

We translated into Italian the Nordic musculoskelethal questionnaire, as completed by Canadian IRSST with Authors' agreement in 2001, according to OMS recommendations. This translation involved the following items: aches and troubles of neck, dorsal region, low back, shoulders, elbows, hands and wrists, hips and thighs, ankles and feet in the last 12 months. The questionnaire was then submitted to reliability and stability tests. The Italian version of the questionnaire, already used in different languages, proved to be suitable and reliable also for self administration.

[Assessment of the risk of occupational biomechanical overload: comparison of methods currently used]

Some of the most common methods for the evaluation of the ergonomic risk of Work-Related Musculo Skeletal Disorders were applied to different workplaces. The results show that an evaluation of the single components of the synthetic risk-indices given by the methods is needed to evidence the specific critical aspects.