Expression and subcellular localization of myogenic regulatory factors during the differentiation of skeletal muscle C2C12 myoblasts

It is known that the MyoD family members (MyoD, Myf5, myogenin, and MRF4) play a pivotal role in the complex mechanism of skeletal muscle cell differentiation. However, fragmentary information on transcription factor-specific regulation is available and data on their posttranscriptional and post-translational behavior are still missing. In this work, we combined mRNA and protein expression analysis with their subcellular localization. Each myogenic regulator factor (MRF) revealed a specific mRNA trend and a protein quantitative analysis not overlapping, suggesting the presence of post-transcriptional mechanisms. In addition, each MRF showed a specific behavior in situ, characterized by a differentiation stage-dependent localization suggestive of a post-translational regulation also. Consistently with their transcriptional activity, immunogold electron microscopy data revealed MRFs distribution in interchromatin domains. Our results showed a MyoD and Myf5 contrasting expression profile in proliferating myoblasts, as well as myogenin and MRF4 opposite distribution in the terminally differentiated myotubes. Interestingly, MRFs expression and subcellular localization analysis during C2C12 cell differentiation stages showed two main MRFs regulation mechanisms: (i) the protein half-life regulation to modulate the differentiation stage-dependent transcriptional activity and (ii) the cytoplasmic retention, as a translocation process, to inhibit the transcriptional activity. Therefore, our results exhibit that MRFs nucleo-cytoplasmic trafficking is involved in muscle differentiation and suggest that, besides the MRFs expression level, also MRFs subcellular localization, related to their functional activity, plays a key role as a regulatory step in transcriptional control mechanisms

Melatonin reduces early changes in intramitochondrial cardiolipin during apoptosis in U937 cell line

Cardiolipin (CL) is found exclusively in the inner mitochondrial membrane. CL deficiency leads to an alteration in the stability of mitochondrial membranes, to an increased permeability as well as a decreased respiratory rate, and therefore to mitochondria which are completely dysfunctional. It is known that reactive oxygen species (ROS) cause a decrease and a variation in CL content, concomitantly the formation of the mitochondrial permeability transition pore facilitates the release of cytochrome c (cyt c) into the cytosol. Melatonin (Mel), the secretory product of the pineal gland, is a potent and efficient endogenous radical scavenger. It has been shown to protect, various biomolecules, such as DNA, membrane lipids, and cytosolic proteins from oxidative damage. To evaluate the protective role of Mel, we have studied U937 cells treated with UV-B irradiation. In our model, the administration of 1 mM Mel before UV-B irradiation showed a significant protection from apoptotic cell death, in particular, mitochondrial structure and function were preserved through apoptotic pathways when cells were preincubated with 1 mM Mel before UV-B exposure. The cardiolipin-sensitive probe 10-nonyl acridine orange (NAO) was used to monitor changes in mitochondrial lipids. Our data suggest that the Mel treatment protects CL from ROS and this suggests a possible link with the reduction of the apoptotic phenomenon. © 2006 Elsevier Ltd. All rights reserved

Learning Wal(l)kscape

Le Mura Aureliane sono percepite come segno di sfondo del paesaggio urbano e come attore muto della vita urbana che viene messa in scena intorno a loro. La consistenza fisica e la rilevanza storica e culturale delle Mura richiamano, tuttavia, la necessità di restituire loro un ruolo all’interno di Roma, consono ad una nuova condizione contemporanea della città, dalla quale sono state separate. Trattate come pura barriera da superare, ostacolo da bucare, tagliare e sezionare, per far spazio al passaggio incessante delle macchine e del traffico urbano, le Mura devono tornare ad essere figura e devono tornare a raccontare una storia, alla città e ai cittadini

Age and dPCR can predict relapse in CML patients who discontinued imatinib: The ISAV study

Imatinib is effective for the treatment of chronic myeloid leukemia (CML). However even undetectable BCR-ABL1 by Q-RT-PCR does not equate to eradication of the disease. Digital-PCR (dPCR), able to detect 1 BCR-ABL1 positive cell out of 107, has been recently developed. The ISAV study is a multicentre trial aimed at validating dPCR to predict relapses after imatinib discontinuation in CML patients with undetectable Q-RT-PCR. CML patients under imatinib therapy since more than 2 years and with undetectable PCR for at least 18 months were eligible. Patients were monitored by standard Q-RT-PCR for 36 months. Patients losing molecular remission (two consecutive positive Q-RT-PCR with at least 1 BCR-ABL1/ABL1 value above 0.1%) resumed imatinib. The study enrolled 112 patients, with a median follow-up of 21.6 months. Fifty-two of the 108 evaluable patients (48.1%), relapsed; 73.1% relapsed in the first 9 months but 14 late relapses were observed between 10 and 22 months. Among the 56 not-relapsed patients, 40 (37.0% of total) regained Q-RT-PCR positivity but never lost MMR. dPCR results showed a significant negative predictive value ratio of 1.115 [95% CI: 1.013-1.227]. An inverse relationship between patients age and risk of relapse was evident: 95% of patients <45 years relapsed versus 42% in the class 6545 to <65 years and 33% of patients 6565 years [P(\u3c72)<0.0001]. Relapse rates ranged between 100% (<45 years, dPCR+) and 36% (>45 years, dPCR-). Imatinib can be safely discontinued in the setting of continued PCR negativity; age and dPCR results can predict relapse

Gimema Registry of Conception/Pregnancy in Adult Patients Diagnosed with Chronic Myeloid Leukemia (CML) Treated with Tyrosine Kinase Inhibitors (TKIs)

The management of patients with chronic myeloid leukemia (CML) during pregnancy is a matter of continuous debate. The introduction of the tyrosin kinase inhibitors (TKIs) in clinical practice has dramatically changed the prognosis of CML patients. Patients diagnosed in chronic phase can expect an excellent disease control and a normal lifespan. Issues relating to fertility and pregnancy must be introduced at diagnosis. Different reports were published in patients conceving/getting pregnant during Imatinib treatment, while there are only sporadic data about other TKIs. The GIMEMA CML working party has started a retrospective and prospective study to describe all female pregnancies/male conception outcome in the CML population from January 2013 until 2015. Inclusion criteria were age>18, CML in any phase of the disease, conception/pregnancy while diagnosed with CML, treatment with TKIs (before, during or after pregnancy), and signed written informed consent IRB approved. Sixty-three patients have been enrolled so far in the study. Male to female ratio was 43/20, mother age at pregnancy (female patients or female partners of male patients) varies from 22 to 37 years. CML was diagnosed when patients were aged between 17 and 55 years old, all patients were in chronic phase at time of conception, but one. This patient was a male patient with accelerated phase aged 31 treated with Nilotinib whose conception outcome was unremarkable. Data on 71 pregnancies have been harvested. The majority of pregnancies were spontaneous, with 3 PMA (pregnancy medically assisted). All pregnancies were carried on, 2 are ongoing, and 6 ended up in an abortion within the 3rdmonth, 2 of which non induced (miscarriages). At pregnancy/conception 8 patients were treated with Nilotinib, 4 with Dasatinib, 3 with Bosutinib, the remaining patients were treated with Imatinib or were at onset with no treatment. All carried pregnancies were unremarkable, except two placental detachment, one at 5 months and one at 12 weeks pregnancy, 1 abortion threat requiring rest, 1 gestational diabetes with intra-uterine growth retard, 1 oligohydramnios, 1 congenital hip dysplasia, and 1 speech retard in a 36 months old baby girl. Data on female patients population, regarding the status of CML at pregnancy, the CML therapy since conception and throughout pregnancy, particularly regarding the organogenesis period (between 5-12 weeks), the status of the illness during pregnancy (any MR4.5, MR4 and major molecular response, complete cytogenetic response, hematologic response losses, and progressions), the outcome of pregnancy, breast feeding, baby growth and development (walk, speech, behaviour), will be detailed. The same will be for female partners of male patients treated with TKIs other than Imatinib. Acquiring detailed information about how a pregnancy/conception is managed will increase our knowledge in order to establish a consensus on patients with CML receiving TKIs who wants to father a child or become/are pregnant

Search for intermediate-mass black hole binaries in the third observing run of Advanced LIGO and Advanced Virgo

International audienceIntermediate-mass black holes (IMBHs) span the approximate mass range 100−105 M⊙, between black holes (BHs) that formed by stellar collapse and the supermassive BHs at the centers of galaxies. Mergers of IMBH binaries are the most energetic gravitational-wave sources accessible by the terrestrial detector network. Searches of the first two observing runs of Advanced LIGO and Advanced Virgo did not yield any significant IMBH binary signals. In the third observing run (O3), the increased network sensitivity enabled the detection of GW190521, a signal consistent with a binary merger of mass ∼150 M⊙ providing direct evidence of IMBH formation. Here, we report on a dedicated search of O3 data for further IMBH binary mergers, combining both modeled (matched filter) and model-independent search methods. We find some marginal candidates, but none are sufficiently significant to indicate detection of further IMBH mergers. We quantify the sensitivity of the individual search methods and of the combined search using a suite of IMBH binary signals obtained via numerical relativity, including the effects of spins misaligned with the binary orbital axis, and present the resulting upper limits on astrophysical merger rates. Our most stringent limit is for equal mass and aligned spin BH binary of total mass 200 M⊙ and effective aligned spin 0.8 at 0.056 Gpc−3 yr−1 (90% confidence), a factor of 3.5 more constraining than previous LIGO-Virgo limits. We also update the estimated rate of mergers similar to GW190521 to 0.08 Gpc−3 yr−1.Key words: gravitational waves / stars: black holes / black hole physicsCorresponding author: W. Del Pozzo, e-mail: [email protected]† Deceased, August 2020