Anticoagulation of cancer patients with nonâ valvular atrial fibrillation receiving chemotherapy: Guidance from the SSC of the ISTH

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/150593/1/jth14478.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/150593/2/jth14478_am.pd

Fibroblast growth factor 1 induced during myogenesis by a transcription–translation coupling mechanism

Fibroblast growth factor 1 (FGF1) is involved in muscle development and regeneration. The FGF1 gene contains four tissue-specific promoters allowing synthesis of four transcripts with distinct leader regions. Two of these transcripts contain internal ribosome entry sites (IRESs), which are RNA elements allowing mRNA translation to occur in conditions of blockade of the classical cap-dependent mechanism. Here, we investigated the function and the regulation of FGF1 during muscle differentiation and regeneration. Our data show that FGF1 protein expression is induced in differentiating myoblasts and regenerating mouse muscle, whereas siRNA knock-down demonstrated FGF1 requirement for myoblast differentiation. FGF1 induction occurred at both transcriptional and translational levels, involving specific activation of both promoter A and IRES A, whereas global cap-dependent translation was inhibited. Furthermore, we identified, in the FGF1 promoter A distal region, a cis-acting element able to activate the IRES A-driven translation. These data revealed a mechanism of molecular coupling of mRNA transcription and translation, involving a unique process of IRES activation by a promoter element. The crucial role of FGF1 in myoblast differentiation provides physiological relevance to this novel mechanism. This finding also provides a new insight into the molecular mechanisms linking different levels of gene expression regulation

Long term expression of bicistronic vector driven by the FGF-1 IRES in mouse muscle

<p>Abstract</p> <p>Background</p> <p>Electrotransfer of plasmid DNA into skeletal muscle is a promising strategy for the delivery of therapeutic molecules targeting various muscular diseases, cancer and lower-limb ischemia. Internal Ribosome Entry Sites (IRESs) allow co-expression of proteins of interest from a single transcriptional unit. IRESs are RNA elements that have been found in viral RNAs as well as a variety of cellular mRNAs with long 5' untranslated regions. While the encephalomyocarditis virus (EMCV) IRES is often used in expression vectors, we have shown that the FGF-1 IRES is equally active to drive short term transgene expression in mouse muscle. To compare the ability of the FGF-1 IRES to drive long term expression against the EMCV and FGF-2 IRESs, we performed analyses of expression kinetics using bicistronic vectors that express the bioluminescent <it>renilla </it>and firefly luciferase reporter genes. Long term expression of bicistronic vectors was also compared to that of monocistronic vectors. Bioluminescence was quantified <it>ex vivo </it>using a luminometer and <it>in vivo </it>using a CCD camera that monitors luminescence within live animals.</p> <p>Results</p> <p>Our data demonstrate that the efficiency of the FGF-1 IRES is comparable to that of the EMCV IRES for long term expression of bicistronic transgenes in mouse muscle, whereas the FGF-2 IRES has a very poor activity. Interestingly, we show that despite the global decrease of vector expression over time, the ratio of firefly to <it>renilla </it>luciferase remains stable with bicistronic vectors containing the FGF-1 or FGF-2 IRES and is slightly affected with the EMCV IRES, whereas it is clearly unstable for mixed monocistronic vectors. In addition, long term expression more drastically decreases with monocistronic vectors, and is different for single or mixed vector injection.</p> <p>Conclusion</p> <p>These data validate the use of bicistronic vectors rather than mixed monocistronic vectors for long term expression, and support the use of the FGF-1 IRES. The use of a cellular IRES over one of viral origin is of particular interest in the goal of eliminating viral sequences from transgenic vectors. In addition, the FGF-1 IRES, compared to the EMCV IRES, has a more stable activity, is shorter in length and more flexible in terms of downstream cloning of second cistrons. Finally, the FGF-1 IRES is very attractive to develop multicistronic expression cassettes for gene transfer in mouse muscle.</p

Rivaroxaban for the treatment of noncirrhotic splanchnic vein thrombosis: an interventional prospective cohort study.

Heparins and vitamin K antagonists are the mainstay of treatment of splanchnic vein thrombosis (SVT). Rivaroxaban is a potential alternative, but data to support its use are limited. We aimed to evaluate the safety and efficacy of rivaroxaban for the treatment of acute SVT. In an international, single-arm clinical trial, adult patients with a first episode of noncirrhotic, symptomatic, objectively diagnosed SVT received rivaroxaban 15 mg twice daily for 3 weeks, followed by 20 mg daily for an intended duration of 3 months. Patients with Budd-Chiari syndrome and those receiving full-dose anticoagulation for &gt;7 days prior to enrollment were excluded. Primary outcome was major bleeding; secondary outcomes included death, recurrent SVT, and complete vein recanalization within 3 months. Patients were followed for a total of 6 months. A total of 103 patients were enrolled; 100 were eligible for the analysis. Mean age was 54.4 years; 64% were men. SVT risk factors included abdominal inflammation/infection (28%), solid cancer (9%), myeloproliferative neoplasms (9%), and hormonal therapy (9%); 43% of cases were unprovoked. JAK2 V617F mutation was detected in 26% of 50 tested patients. At 3 months, 2 patients (2.1%; 95% confidence interval, 0.6-7.2) had major bleeding events (both gastrointestinal). One (1.0%) patient died due to a non-SVT-related cause, 2 had recurrent SVT (2.1%). Complete recanalization was documented in 47.3% of patients. One additional major bleeding event and 1 recurrent SVT occurred at 6 months. Rivaroxaban appears as a potential alternative to standard anticoagulation for the treatment of SVT in non-cirrhotic patients. This trial was registered at www.clinicaltrials.gov as #NCT02627053 and at eudract.ema.europa.eu as #2014-005162-29-36

Calmodulin-dependent nuclear import of HMG-box family nuclear factors: importance of the role of SRY in sex reversal

The HMG (high-mobility group)-box-containing chromatin-remodelling factor SRY (sex-determining region on the Y chromosome) plays a key role in sex determination. Its role in the nucleus is critically dependent on two NLSs (nuclear localization signals) that flank its HMG domain: the C-terminally located ‘β-NLS’ that mediates nuclear transport through Impβ1 (importin β1) and the N-terminally located ‘CaM-NLS’ which is known to recognize the calcium-binding protein CaM (calmodulin). In the present study, we examined a number of missense mutations in the SRY CaM-NLS from human XY sex-reversed females for the first time, showing that they result in significantly reduced nuclear localization of GFP (green fluorescent protein)–SRY fusion proteins in transfected cells compared with wild-type. The CaM antagonist CDZ (calmidazolium chloride) was found to significantly reduce wild-type SRY nuclear accumulation, indicating dependence of SRY nuclear import on CaM. Intriguingly, the CaM-NLS mutants were all resistant to CDZ's effects, implying a loss of interaction with CaM, which was confirmed by direct binding experiments. CaM-binding/resultant nuclear accumulation was the only property of SRY found to be impaired by two of the CaM-NLS mutations, implying that inhibition of CaM-dependent nuclear import is the basis of sex reversal in these cases. Importantly, the CaM-NLS is conserved in other HMG-box-domain-containing proteins such as SOX-2, -9, -10 and HMGN1, all of which were found for the first time to rely on CaM for optimal nuclear localization. CaM-dependent nuclear translocation is thus a common mechanism for this family of important transcription factors