KLF4 IS A KEY DETERMINANT IN THE DEVELOPMENT AND PROGRESSION OF CEREBRAL CAVERNOUS MALFORMATIONS

Cerebral cavernous malformations (CCMs) are capillary-venous malformations located in the central nervous system that often lead to neurological deficits and cerebral hemorrhage. Pharmacological treatment limiting disease progression is dearly needed, as available therapy is limited to surgical lesion eradication or stereotactic radiosurgery. CCM affects up to 0.5% of the human population and can occur either in a sporadic or familial form. Loss-of-function mutations in any of three genes CCM1, CCM2 and CCM3 have been associated to familial CCM. Postnatal endothelial-specific deletion of any of the three Ccm genes in mice results in the development of multiple brain vascular malformations that faithfully resemble human CCM lesions. Here we describe that CCM malformations are formed by endothelial cells (ECs) undergoing endothelial-to-mesenchymal transition (EndMT), a phenotype that recapitulates most of the previously observed functional changes that are responsible for dysplasia and fragility of CCM lesions. Ccm1 deletion leads to activation of the MEKK3-MEK5-ERK5-MEF2 signaling cascade resulting in a marked upregulation of the transcription factor Kru\u308ppel-like factor 4 (KLF4) in ECs in vivo. KLF4 promotes an endogenous production of bone morphogenetic protein 6 (BMP6) in ECs that, in turn, activates the transforming growth factor-\u3b2 (TGF-\u3b2) and bone morphogenetic protein (BMP) signalling pathway. KLF4 transcriptional activity and KLF4-dependent TGF-\u3b2/BMP pathway activation are responsible for the EndMT switch observed in the absence of Ccm1. Interestingly, using both a pharmacological treatment to inhibit TGF-\u3b2/BMP pathway or a genetic approach based on endothelial-specific Ccm1 and Klf4 double knockout mice, we strongly reduce the development and progression of CCM lesions. Importantly loss of Klf4 almost abolishes mouse mortality due to brain hemorrhage in endothelial Ccm1-ablated mice. These data indicate that KLF4, TGF- \u3b2/BMP pathway and EndMT are crucial events for CCM pathogenesis and unveil KLF4 as a key therapeutic target for CCM

Cross-Domain Transfer Learning with CoRTe: Consistent and Reliable Transfer from Black-Box to Lightweight Segmentation Model

Many practical applications require training of semantic segmentation models on unlabelled datasets and their execution on low-resource hardware. Distillation from a trained source model may represent a solution for the first but does not account for the different distribution of the training data. Unsupervised domain adaptation (UDA) techniques claim to solve the domain shift, but in most cases assume the availability of the source data or an accessible white-box source model, which in practical applications are often unavailable for commercial and/or safety reasons. In this paper, we investigate a more challenging setting in which a lightweight model has to be trained on a target unlabelled dataset for semantic segmentation, under the assumption that we have access only to black-box source model predictions. Our method, named CoRTe, consists of (i) a pseudo-labelling function that extracts reliable knowledge from the black-box source model using its relative confidence, (ii) a pseudo label refinement method to retain and enhance the novel information learned by the student model on the target data, and (iii) a consistent training of the model using the extracted pseudo labels. We benchmark CoRTe on two synthetic-to-real settings, demonstrating remarkable results when using black-box models to transfer knowledge on lightweight models for a target data distribution.Comment: 11 pages, 6 figures, ICCV2023 worksho

Candida Bezoars with Urinary Tract Obstruction in Two Women without Immunocompromising Conditions

More than half of the cases of fungal infections of the urinary tract are caused by Candida sp., but occurrence of obstructive uropathy caused by mycetomas or fungus balls (urobezoars) is extremely rare. The latter are conglomerates of fungal hyphae. Diabetes mellitus, immunosuppression, chronic disease, and malignancies are known predisposing factors. Preoperative imaging is not pathognomonic; blood clots, radiolucent urinary calculi, air bubbles, and inflammatory debris can mimic urobezoars. We report on two otherwise healthy women presenting with urinary tract obstruction caused by candidal mycetomas of the renal pelvis that mimicked matrix lithiasis

catheter and laryngeal mask endotracheal surfactant therapy the calmest approach as a novel mist technique

AbstractPurpose: Neonatal respiratory distress syndrome (RDS) is a major cause of mortality and morbidity among preterm infants. Although the INSURE (INtubation, SURfactant administration, Estubation) technique for surfactant replacement therapy is so far the gold standard method, over the last years new approaches have been studied, i.e. less invasive surfactant administration (LISA) or minimally invasive surfactant therapy (MIST). Here we propose an originally modified MIST, called CALMEST (Catheter And Laryngeal Mask Endotracheal Surfactant Therapy), using a particular laryngeal mask as a guide for a thin catheter to deliver surfactant directly in the trachea.Materials and methods: We performed a preliminary study on a mannequin and a subsequent in vivo pilot trial.Results and conclusions: This novel procedure is quick, effective and well tolerated and might represent an improvement in reducing neonatal stress. Ultimately, CALMEST offers an alternative approach that could be extremely useful for medica..

HIF factors cooperate with PML-RARα to promote acute promyelocytic leukemia progression and relapse

Acute promyelocytic leukemia (APL) is epitomized by the chromosomal translocation t(15;17) and the resulting oncogenic fusion protein PML-RARα. Although acting primarily as a transcriptional repressor, PML-RARα can also exert functions of transcriptional co-activation. Here, we find that PML-RARα stimulates transcription driven by HIF factors, which are critical regulators of adaptive responses to hypoxia and stem cell maintenance. Consistently, HIF-related gene signatures are upregulated in leukemic promyelocytes from APL patients compared to normal promyelocytes. Through in vitro and in vivo studies, we find that PML-RARα exploits a number of HIF-1α-regulated pro-leukemogenic functions that include cell migration, bone marrow (BM) neo-angiogenesis and self-renewal of APL blasts. Furthermore, HIF-1α levels increase upon treatment of APL cells with all-trans retinoic acid (ATRA). As a consequence, inhibiting HIF-1α in APL mouse models delays leukemia progression and exquisitely synergizes with ATRA to eliminate leukemia-initiating cells (LICs)

Extracellular vesicle microRNAs contribute to Notch signaling pathway in T-cell acute lymphoblastic leukemia

T-cell acute lymphoblastic leukemia (T-ALL) is an aggressive T-cell malignancy characterized by genotypically-defined and phenotypically divergent cell populations, governed by adaptive landscapes. Clonal expansions are associated to genetic and epigenetic events, and modulation of external stimuli that affect the hierarchical structure of subclones and support the dynamics of leukemic subsets. Recently, small extracellular vesicles (sEV) such as exosomes were also shown to play a role in leukemia. Here, by coupling miRNome, bulk and single cell transcriptome profiling, we found that T-ALL-secreted sEV contain NOTCH1-dependent microRNAs (EV-miRs), which control oncogenic pathways acting as autocrine stimuli and ultimately promoting the expansion/survival of highly proliferative cell subsets of human T-cell leukemias. Of interest, we found that NOTCH1-dependent EV-miRs mostly comprised members of miR-17-92a cluster and paralogues, which rescued in vitro the proliferation of T-ALL cells blocked by γ-secretase inhibitors (GSI) an regulated a network of genes characterizing patients with relapsed/refractory early T-cell progenitor (ETP) ALLs. All these findings suggest that NOTCH1 dependent EV-miRs may sustain the growth/survival of immunophenotypically defined cell populations, altering the cell heterogeneity and the dynamics of T-cell leukemias in response to conventional therapies

Non-coding RNAs as prognostic biomarkers: A miRNA signature specific for aggressive early-stage lung adenocarcinomas

Lung cancer burden can be reduced by adopting primary and secondary prevention strategies such as anti-smoking campaigns and low-dose CT screening for high risk subjects (aged >50 and smokers >30 packs/year). Recent CT screening trials demonstrated a stage-shift towards earlier stage lung cancer and reduction of mortality (~20%). However, a sizable fraction of patients (30–50%) with early stage disease still experience relapse and an adverse prognosis. Thus, the identification of effective prognostic biomarkers in stage I lung cancer is nowadays paramount. Here, we applied a multi-tiered approach relying on coupled RNA-seq and miRNA-seq data analysis of a large cohort of lung cancer patients (TCGA-LUAD, n = 510), which enabled us to identify prognostic miRNA signatures in stage I lung adenocarcinoma. Such signatures showed high accuracy (AUC ranging between 0.79 and 0.85) in scoring aggressive disease. Importantly, using a network-based approach we rewired miRNA-mRNA regulatory networks, identifying a minimal signature of 7 miRNAs, which was validated in a cohort of FFPE lung adenocarcinoma samples (CSS, n = 44) and controls a variety of genes overlapping with cancer relevant pathways. Our results further demonstrate the reliability of miRNA-based biomarkers for lung cancer prognostication and make a step forward to the application of miRNA biomarkers in the clinical routine

Primitive Neuroectodermal Tumor (PNET) of the kidney: a case report

BACKGROUND: A case of Primitive Neuroectodermal Tumor (PNET) of the kidney in a 27-year-old woman is presented. Few cases are reported in the literature with a variable, nonspecific presentation and an aggressive behaviour. In our case, a radical nephrectomy with lymphadenectomy was performed and there was no residual or recurrent tumour at 24-month follow-up. METHODS: The surgical specimens were formalin-fixed and paraffin embedded. The sections were stained with routinary H&E. Immunohistochemistry was performed. RESULTS: The immunohistochemical evaluation revealed a diffuse CD99 positivity in the cytoplasm of the neoplastic cells. Pankeratin, cytokeratin AE1/AE3, vimentin, desmin, S100, cromogranin were negative. The clinical presentation and the macroscopic aspect, together with the histological pattern, the cytological characteristic and the cellular immunophenotype addressed the diagnosis towards primary PNET of kidney. CONCLUSIONS: Since sometimes it is difficult to discriminate between PNET and Ewing's tumour, we reviewed the difficulties in differential diagnosis. These tumors have a common precursor but the stage of differentiation in which it is blocked is probably different. This could also explain their different biological behaviour and prognosis

MicroRNA expression profile in primary lung cancer cells lines obtained by endobronchial ultrasound transbronchial needle aspiration

Background: Novel cancer biomarkers like microRNA (miRNA) are promising tools to gain a better understanding of lung cancer pathology and yield important information to guide therapy. In recent years, new less invasive methods for the diagnosis and staging of NSCLC have become key tools in thoracic oncology and the worldwide spread of endobronchial ultrasound transbronchial needle aspiration (EBUS-TBNA). However, appropriate specimen handling is mandatory to achieve adequate results and reproducibility. The aim of this single centre prospective study was to evaluate the feasibility of a complete miRNA expression profile in fresh NSCLC cell lines obtained by EBUS-TBNA. Methods: Patients with proven NSCLC underwent EBUS-TBNA for the diagnosis of suspect lymph node metastasis, and cytological specimens were collected for epithelial cell culture and miRNA expression analysis. To validate the miRNA expression profile, we compared the results from EBUS-TBNA NSCLC specimens with those obtained from formalin-fixed paraffin-embedded (FFPE) mediastinoscopy specimens. Results: Analysis of the miRNA expression profiles of three independent EBUS-TBNA-derived primary cell lines allowed the screening of 377 different human miRNAs. One hundred and fifty miRNAs were detected in all cell lines. Analysis of the miRNA expression profile in mediastinoscopy specimens showed a strong similarity in the clusters analysed. Conclusions: The miRNA expression profile is feasible and reliable in EBUS-TBNA specimens. Validation of this protocol in fresh cytological specimens represents an effective and reproducible method to correlate translational and clinical research

KLF4 is a key determinant in the development and progression of cerebral cavernous malformations

Cerebral cavernous malformations (CCMs) are vascular malformations located within the central nervous system often resulting in cerebral hemorrhage. Pharmacological treatment is needed, since current therapy is limited to neurosurgery. Familial CCM is caused by loss-of-function mutations in any of Ccm1, Ccm2, and Ccm3 genes. CCM cavernomas are lined by endothelial cells (ECs) undergoing endothelial-to-mesenchymal transition (EndMT). This switch in phenotype is due to the activation of the transforming growth factor beta/bone morphogenetic protein (TGF\u3b2/BMP) signaling. However, the mechanism linking Ccm gene inactivation and TGF\u3b2/BMP-dependent EndMT remains undefined. Here, we report that Ccm1 ablation leads to the activation of a MEKK3-MEK5-ERK5-MEF2 signaling axis that induces a strong increase in Kruppel-like factor 4 (KLF4) in ECs in\ua0vivo. KLF4 transcriptional activity is responsible for the EndMT occurring in CCM1-null ECs. KLF4 promotes TGF\u3b2/BMP signaling through the production of BMP6. Importantly, in endothelial-specific Ccm1 and Klf4 double knockout mice, we observe a strong reduction in the development of CCM and mouse mortality. Our data unveil KLF4 as a therapeutic target for CCM