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Histone deacetylase 8 (HDAC8), a class I HDAC that modifies non-histone proteins such as p53, is highly expressed in different hematological neoplasms including a subtype of acute myeloid leukemia (AML) bearing inversion of chromosome 16 [inv(16)]. To investigate HDAC8 contribution to hematopoietic stem cell maintenance and myeloid leukemic transformation, we generated a zebrafish model with Hdac8 overexpression and observed an increase in hematopoietic stem/progenitor cells, a phenotype that could be reverted using a specific HDAC8 inhibitor, PCI-34051 (PCI). In addition, we demonstrated that AML cell lines respond differently to PCI treatment: HDAC8 inhibition elicits cytotoxic effect with cell cycle arrest followed by apoptosis in THP-1 cells, and cytostatic effect in HL60 cells that lack p53. A combination of cytarabine, a standard anti-AML chemotherapeutic, with PCI resulted in a synergistic effect in all the cell lines tested. We, then, searched for a mechanism behind cell cycle arrest caused by HDAC8 inhibition in the absence of functional p53 and demonstrated an involvement of the canonical WNT signaling in zebrafish and in cell lines. Together, we provide the evidence for the role of HDAC8 in hematopoietic stem cell differentiation in zebrafish and AML cell lines, suggesting HDAC8 inhibition as a therapeutic target in hematological malignancies. Accordingly, we demonstrated the utility of a highly specific HDAC8 inhibition as a therapeutic strategy in combination with standard chemotherapy.

Deficiency of adenosine deaminase 2 (DADA2) is an inborn error of immunity caused by loss-of-function mutations in the adenosine deaminase 2 ( ADA2 ) gene. Clinical manifestations of DADA2 include vasculopathy and immuno-hematological abnormalities, culminating in bone marrow failure. A major gap exists in our knowledge of the regulatory functions of ADA2 during inflammation and hematopoiesis, mainly due to the absence of an ADA2 orthologue in rodents. Exploring these mechanisms is essential for understanding disease pathology and developing new treatments. Zebrafish possess two ADA2 orthologues, cecr1a and cecr1b , with the latter showing functional conservation with human ADA2. We establish a cecr1b -loss-of-function zebrafish model that recapitulates the immuno-hematological and vascular manifestations observed in humans. Loss of Cecr1b disrupts hematopoietic stem cell specification, resulting in defective hematopoiesis. This defect is caused by induced inflammation in the vascular endothelium. Blocking inflammation, pharmacological modulation of the A 2 r pathway, or the administration of the recombinant human ADA2 corrects these defects, providing insights into the mechanistic link between ADA2 deficiency, inflammation and immuno-hematological abnormalities. Our findings open up potential therapeutic avenues for DADA2 patients. A DADA2 zebrafish model with cecr1b deficiency was generated. Characterization of hematopoietic processes revealed a role of Cecr1b in regulating inflammation and hematopoietic stem cell production through the A 2b r-mediated adenosine signaling.

The genes of the cohesin complex exert different functions, ranging from the adhesion of sister chromatids during the cell cycle, DNA repair, gene expression and chromatin architecture remodeling. In recent years, the improvement of DNA sequencing technologies allows the identification of cohesin mutations in different tumors such as acute myeloid leukemia (AML), acute megakaryoblastic leukemia (AMKL), and myelodysplastic syndromes (MDS). However, the role of cohesin dysfunction in cancer insurgence remains elusive. In this regard, cells harboring cohesin mutations do not show any increase in aneuploidy that might explain their oncogenic activity, nor cohesin mutations are sufficient to induce myeloid neoplasms as they have to co-occur with other causative mutations such as , , and . Several works, also using animal models for cohesin haploinsufficiency, correlate cohesin activity with dysregulated expression of genes involved in myeloid development and differentiation. These evidences support the involvement of cohesin mutations in myeloid neoplasms.

Transcriptional changes normally occur during development but also underlie differences between healthy and pathological conditions. Transcription factors or chromatin modifiers are involved in orchestrating gene activity, such as the cohesin genes and their regulator NIPBL. In our previous studies, using a zebrafish model for nipblb knockdown, we described the effect of nipblb loss-of-function in specific contexts, such as central nervous system development and hematopoiesis. However, the genome-wide transcriptional impact of nipblb loss-of-function in zebrafish embryos at diverse developmental stages remains under investigation. By RNA-seq analyses in zebrafish embryos at 24 h post-fertilization, we examined genome-wide effects of nipblb knockdown on transcriptional programs. Differential gene expression analysis revealed that nipblb loss-of-function has an impact on gene expression at 24 h post fertilization, mainly resulting in gene inactivation. A similar transcriptional effect has also been reported in other organisms, supporting the use of zebrafish as a model to understand the role of Nipbl in gene regulation during early vertebrate development. Moreover, we unraveled a connection between nipblb-dependent differential expression and gene expression patterns of hematological cell populations and AML subtypes, enforcing our previous evidence on the involvement of NIPBL-related transcriptional dysregulation in hematological malignancies.

The transcription factor RUNX1, a pivotal regulator of HSCs and haematopoiesis, is a frequent target of chromosomal translocations, point mutations or altered gene/protein dosage. These modifications lead or contribute to the development of myelodysplasia, leukaemia or platelet disorders. A better understanding of how regulatory elements contribute to fine‐tune the RUNX1 expression in haematopoietic tissues could improve our knowledge of the mechanisms responsible for normal haematopoiesis and malignancy insurgence. The cohesin RAD21 was reported to be a regulator of RUNX1 expression in the human myeloid HL60 cell line and during primitive haematopoiesis in zebrafish. In our study, we demonstrate that another cohesin, NIPBL, exerts positive regulation of RUNX1 in three different contexts in which RUNX1 displays important functions: in megakaryocytes derived from healthy donors, in bone marrow samples obtained from adult patients with acute myeloid leukaemia and during zebrafish haematopoiesis. In this model, we demonstrate that alterations in the zebrafish orthologue nipblb reduce runx1 expression with consequent defects in its erythroid and myeloid targets such as gata1a and spi1b in an opposite way to rad21. Thus, also in the absence of RUNX1 translocation or mutations, additional factors such as defects in the expression of NIPBL might induce haematological diseases.

Deficiency of adenosine deaminase 2 (DADA2) is an inborn error of immunity caused by loss-of-function mutations in the adenosine deaminase 2 (ADA2) gene. Clinical manifestations of DADA2 include vasculopathy and immuno-hematological abnormalities, culminating in bone marrow failure. A major gap exists in our knowledge of the regulatory functions of ADA2 during inflammation and hematopoiesis, mainly due to the absence of an ADA2 orthologue in rodents. Exploring these mechanisms is essential for understanding disease pathology and developing new treatments. Zebrafish possess two ADA2 orthologues, cecr1a and cecr1b, with the latter showing functional conservation with human ADA2. We establish a cecr1b-loss-of-function zebrafish model that recapitulates the immuno-hematological and vascular manifestations observed in humans. Loss of Cecr1b disrupts hematopoietic stem cell specification, resulting in defective hematopoiesis. This defect is caused by induced inflammation in the vascular endothelium. Blocking inflammation, pharmacological modulation of the A r pathway, or the administration of the recombinant human ADA2 corrects these defects, providing insights into the mechanistic link between ADA2 deficiency, inflammation and immuno-hematological abnormalities. Our findings open up potential therapeutic avenues for DADA2 patients.

It has been shown that growth hormone-releasing hormone (GHRH) reduces cardiomyocyte (CM) apoptosis, prevents ischemia/reperfusion injury, and improves cardiac function in ischemic rat hearts. However, it is still not known whether GHRH would be beneficial for life-threatening pathological conditions, like cardiac hypertrophy and heart failure (HF). Thus, we tested the myocardial therapeutic potential of GHRH stimulation in vitro and in vivo, using GHRH or its agonistic analog MR-409. We show that in vitro, GHRH(1-44)NH₂ attenuates phenylephrine-induced hypertrophy in H9c2 cardiac cells, adult rat ventricular myocytes, and human induced pluripotent stem cell-derived CMs, decreasing expression of hypertrophic genes and regulating hypertrophic pathways. Underlying mechanisms included blockade of Gq signaling and its downstream components phospholipase Cβ, protein kinase Cε, calcineurin, and phospholamban. The receptor-dependent effects of GHRH also involved activation of Gαs and cAMP/PKA, and inhibition of increase in exchange protein directly activated by cAMP1 (Epac1). In vivo, MR-409 mitigated cardiac hypertrophy in mice subjected to transverse aortic constriction and improved cardiac function. Moreover, CMs isolated from transverse aortic constriction mice treated with MR-409 showed improved contractility and reversal of sarcolemmal structure. Overall, these results identify GHRH as an antihypertrophic regulator, underlying its therapeutic potential for HF, and suggest possible beneficial use of its analogs for treatment of pathological cardiac hypertrophy.

Understanding the chemical composition and sources of organic aerosol (OA) in the Arctic is critical given its importance for particle climate-relevant properties. This study presents a year-long analysis (May 2019–June 2020) of PM1 filter samples collected in Ny-Ålesund, Svalbard. A multi-instrumental approach is employed to characterize the comprehensive chemical composition of PM1, with a specific focus on its water-soluble organic fraction depicted combining proton nuclear magnetic resonance spectroscopy (H-NMR) and high-resolution time-of-flight aerosol mass spectrometry (HR-TOF-AMS), which provide complementary insights into the nature and structure of the organic aerosol classes characterizing the bulk OA mixture. Positive matrix factorization (PMF) source apportionment identifies consistent OA sources from the H-NMR and AMS datasets, showing a pronounced seasonality in their relative contributions to total OA mass. Winter–spring aerosol is dominated by long-range transport of Eurasian anthropogenic pollution (up to 70 %), while summer is characterized by biogenic aerosols from marine sources (up to 44 %), including sulfur compounds, amines, and fatty acids. Occasional summertime high OA loadings are associated with wildfire aerosols enriched in levoglucosan and humic-like substances (HULIS; averagely 27 %–28 %). Eventually, about 28 %–40 % of the OA mass is attributed to an unresolved mixture of extremely oxidized compounds of difficult specific source attribution. This integrated approach provides valuable insights into the seasonal dynamics of OA sources in the Arctic.

RationaleIn patients with COVID-19 pneumonia and mild hypoxaemia, the clinical benefit of high-flow nasal oxygen (HFNO) remains unclear. We aimed to examine whether HFNO compared with conventional oxygen therapy (COT) could prevent escalation of respiratory support in this patient population.MethodsIn this multicentre, randomised, parallel-group, open-label trial, patients with COVID-19 pneumonia and peripheral oxygen saturation (SpO2) ≤92% who required oxygen therapy were randomised to HFNO or COT. The primary outcome was the rate of escalation of respiratory support (ie, continuous positive airway pressure, non-invasive ventilation or invasive mechanical ventilation) within 28 days. Among secondary outcomes, clinical recovery was defined as the improvement in oxygenation (SpO2 ≥96% with fractional inspired oxygen (FiO2) ≤30% or partial pressure of arterial carbon dioxide/FiO2 ratio >300 mm Hg).ResultsAmong 364 randomised patients, 55 (30.3%) of 181 patients assigned to HFNO and 70 (38.6%) of 181 patients assigned to COT underwent escalation of respiratory support, with no significant difference between groups (absolute risk difference −8.2% (95% CI −18% to +1.4%); RR 0.79 (95% CI 0.59 to 1.05); p=0.09). There was no significant difference in clinical recovery (69.1% vs 60.8%; absolute risk difference 8.2% (95% CI −1.5% to +18.0%), RR 1.14 (95% CI 0.98 to 1.32)), intensive care unit admission (7.7% vs 11.0%, absolute risk difference −3.3% (95% CI −9.3% to +2.6%)), and in hospital length of stay (11 (IQR 8–17) vs 11 (IQR 7–20) days, absolute risk difference −1.0% (95% CI −3.1% to +1.1%)).ConclusionsAmong patients with COVID-19 pneumonia and mild hypoxaemia, the use of HFNO did not significantly reduce the likelihood of escalation of respiratory support.Trial registration number NCT04655638.

Minimally invasive surgery is the standard approach for right-sided colon cancer, but conventional laparoscopic specimen extraction (CVT) requires additional abdominal incisions, increasing the risk of postoperative complications and delayed recovery. Natural orifice specimen extraction (NOSE) minimizes abdominal incisions, potentially improving patient outcomes. This meta-analysis compares NOSE and CVT in terms of postoperative complications, operative characteristics, and long-term outcomes. A comprehensive literature search was conducted in PubMed, Scopus, the Cochrane Central Register of Clinical Trials, and Web of Science for studies available up to December 2024. A random-effects model was applied to compute ORs and mean differences (MDs) with 95% CIs. Heterogeneity was evaluated using the I² statistic. All statistical analyses were performed using R software (version 4.4.1, R Foundation for Statistical Computing). Seven propensity score-matched studies with 566 patients were included, with 240 (42.4%) undergoing NOSE and 326 (57.6%) undergoing CVT. NOSE was associated with significantly reduced postoperative pain on the 3rd day (MD -1.1; 95% CI -1.7 to -0.5; p < 0.01), lower SSI rates (OR 0.23; 95% CI 0.08-0.73; p = 0.012), and a shorter time to pass flatus (MD -0.8; 95% CI -1.2 to -0.4; p < 0.01). However, NOSE was linked to longer operative times (MD 36.4 minutes; 95% CI 3.4-69.4; p = 0.03). No significant differences were found in hospital stay (MD -0.5 days; 95% CI -2.1 to 1.1; p = 0.57), blood loss (MD -2.1; 95% CI -9.6 to 5.4; p = 0.58), or local recurrence (OR 0.44; 95% CI 0.07-3.01; p = 0.405). In conclusion, NOSE offers advantages such as reduced postoperative pain, lower SSI rates, and faster bowel recovery, with prolonged operative time as its main limitation. These findings support NOSE as a viable alternative to CVT for right-sided colon cancer without compromising safety or long-term outcomes.