Profile of Toll-Like Receptors on Peripheral Blood Cells in Relation to Acute Graft-versus-Host Disease after Allogeneic Stem Cell Transplantation

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Endothelial-to-hematopoietic transition: Notch-ing vessels into blood

During development, hematopoietic stem cells (HSCs) are formed in a temporally and spatially restricted manner, arising from specialized endothelial cells (ECs) in the ventral wall of the dorsal aorta within the evolutionary conserved aorta-gonad-mesonephros region. Our understanding of the processes regulating the birth of HSCs from ECs has been recently advanced by comprehensive molecular analyses of developing murine hematopoietic cell populations complemented by studies in the zebrafish model, with the latter offering unique advantages for genetic studies and direct in vivo visualization of HSC emergence. Here, we provide a concise review of the current knowledge and recent advances regarding the cellular origin and molecular regulation of HSC development, with particular focus on the process of endothelial-to-hematopoietic transition and its primary regulator, the Notch signaling pathway

Zebrafish disease models in hematology: Highlights on biological and translational impact

Zebrafish (Danio rerio) has proven to be a versatile and reliable in vivo experimental model to study human hematopoiesis and hematological malignancies. As vertebrates, zebrafish has significant anatomical and biological similarities to humans, including the hematopoietic system. The powerful genome editing and genome-wide forward genetic screening tools have generated models that recapitulate human malignant hematopoietic pathologies in zebrafish and unravel cellular mechanisms involved in these diseases. Moreover, the use of zebrafish models in large-scale chemical screens has allowed the identification of new molecular targets and the design of alternative therapies. In this review we summarize the recent achievements in hematological research that highlight the power of the zebrafish model for discovery of new therapeutic molecules. We believe that the model is ready to give an immediate translational impact into the clinic

Age-dependent association of idiopathic achalasia with vasoactive intestinal peptide receptor 1 gene

Idiopathic achalasia is a rare disorder of the oesophagus of unknown aetio-pathogenesis characterized by a myenteric inflammation, aperistalsis and insufficient lower oesophageal sphincter relaxation. Vasoactive intestinal peptide (VIP), present in the myenteric plexus, is involved in smooth muscle relaxation and acts as an anti-inflammatory cytokine. The human VIP receptor 1 gene (VIPR1) is highly polymorphic and may play a role in idiopathic achalasia. One hundred and four consecutive patients and 300 random controls from the same geographic area were typed for five SNPs mapping in the VIPR1 gene. Patients with idiopathic achalasia show a significant difference in allele, genotype and phenotype distribution of SNP rs437876 mapping in intron 4. This association, however, was almost entirely due to the group of patients with late disease onset (P = 0.0005). These results strongly suggest that idiopathic achalasia is a heterogeneous disease with a different aetiology in cases with early or late disease onset

Targeting HRASV12G Expression to the Zebrafish Early Hemogenic Progenitors Induces a Myeloproliferative Disorder by Repressing the Notch Pathway.

17nonenoneAlghisi, E; Malagola, M; Santoriello, C; Distel, M; Henkel, C; Skert, C; Filì, C; Bergonzi, C; Perucca, S; Turra, A; Di Palma, A; Cancelli, V; Ribolla, R; Cattina, F; Zedda, S; Simona Bernardi, S; Russo, DAlghisi, Elisa; Malagola, Michele; Santoriello, C; Distel, M; Henkel, C; Skert, C; Filì, C; Bergonzi, C; Perucca, Simone; Turra, Alessandro; DI PALMA, Andrea; Cancelli, Valeria; Ribolla, R; Cattina, Federica; Zedda, S; Bernardi, Simona; Russo, Domenic

Peripheral Blood WT1 Expression Predicts Relapse in AML Patients Undergoing Allogeneic Stem Cell Transplantation

To evaluate if WT1 expression may predict relapse after allo-SCT, we analyzed WT1 levels on peripheral blood (PB) and bone marrow (BM) before and after allo-SCT in 24 AML patients with WT1 overexpression at diagnosis. Five copies of WT1/ABL × 104 from PB were identified as the threshold value that correlated with relapse after allo-SCT. The same correlation was not identified when WT1 expression was assessed from bone marrow (BM). Eight out of 11 (73%) patients with a pre-allo-SCT PB-WT1 ≥ 5 and 4/13 (31%) patients with a pre-allo-SCT PB-WT1 < 5 relapsed, respectively (P = 0.04). The incidence of relapse was higher in patients with PB-WT1 ≥ 5 measured after allo-SCT, at the 3rd (56% versus 38%; P = 0.43) and at the 6th month (71% versus 20%; P = 0.03). Patients with pretransplant PB-WT1 < 5 had significantly better 2-year OS and LFS than patients with a PB-WT1 ≥ 5 (81% versus 0% and 63% versus 20%) (P = 0.02). Our data suggest the usefulness of WT1 monitoring from PB to predict the relapse in allotransplanted AML patients and to modulate the intensity of conditioning and/or the posttransplant immunosuppression in an attempt to reduce the posttransplant relapse risk