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Spall, S.

Publications and source records attributed to Spall, S..

2 recordsLinked to original sources

Megakaryocytic proteomic signatures define myeloproliferative neoplasms

The classical Philadelphia-negative myeloproliferative neoplasms (MPNs) are clonal stem cell disorders of the bone marrow with significant niche dysregulation driven in part by abnormal megakaryocytes. The three classical MPNs: polycythemia vera (PV), essential thrombocythemia (ET) and primary myelofibrosis (PMF), display established megakaryocytic morphological differences which aid in their diagnostic classification. The paucity of megakaryocytes in the bone marrow aspirate has previously limited a proteomic analysis of megakaryocytes in clinical samples. We aimed to undertake an unbiased proteomic analysis of in situ megakaryocytes from the bone marrow of patients with PV, ET, and PMF. Using a novel, deep visual proteomics strategy, we dissected and analyzed megakaryocytes from 60 MPN patients and 20 controls (patients with limited stage non-Hodgkin lymphoma who had uninvolved bone marrow). We reveal that megakaryocyte proteomics from MPN patients are distinct to those from control patients, and further, that the megakaryocytes from the three MPNs have unique, disease-specific signatures. The disease-specific megakaryocyte proteome highlights novel pathways of disease.

cancer biology↗

Missense mutations in the MLKL brace region lead to lethal neonatal inflammation in mice and are present in high frequency in humans.

We have isolated a mouse strain with a single missense mutation in the gene encoding MLKL, the essential effector of necroptotic cell death. The resulting substitution lies within the two-helix brace and confers constitutive, RIPK3 independent, killing activity to MLKL. Mice homozygous for MlklD139V develop lethal inflammation within days of birth, implicating the salivary glands and pericardium as hotspots for necroptosis and inflammatory infiltration. The normal development of MlklD139V homozygotes until birth, and the absence of any overt phenotype in heterozygotes provides important in vivo precedent for the capacity of cells to clear activated MLKL. These observations offer an important insight into the potential disease-modulating roles of three common human MLKL polymorphisms that encode amino acid substitutions within or adjacent to the brace region. Compound heterozygosity of these variants is found at up to 12-fold the expected frequency in patients that suffer from a pediatric autoinflammatory disease, CRMO.

cell biology↗