Quantitative analysis of redox proteome reveals oxidation-sensitive protein thiols acting in fundamental processes of developmental hematopoiesis

Fetal and adult hematopoietic stem and progenitor cells (HSPCs) are characterized by distinct redox homeostasis that may influence their differential cellular behavior in normal and malignant hematopoiesis. In this work, we have applied a quantitative mass spectrometry-based redox proteomic approach to comprehensively describe reversible cysteine modifications in primary mouse fetal and adult HSPCs. We defined the redox state of 4,438 cysteines in fetal and adult HSPCs and demonstrated a higher susceptibility to oxidation of protein thiols in fetal HSPCs. Our data identified ontogenic changes to oxidation state of thiols in proteins with a pronounced role in metabolism and protein homeostasis. Additional redox proteomic analysis identified oxidation changes to thiols acting in mitochondrial respiration as well as protein homeostasis to be triggered during onset of MLL-ENL leukemogenesis in fetal HSPCs. Our data has demonstrated that redox signaling contributes to the regulation of fundamental processes of developmental hematopoiesis and has pinpointed potential targetable redox-sensitive proteins in in utero-initiated MLL-rearranged leukemia.

New insights into the cytoplasmic function of PML

PML is a tumour suppressor inactivated in Acute Promyelocytic Leukaemia (APL). PML is the essential component of a subnuclear structure called the PML nuclear body (PML-NB), which is disrupted in APL. By targeting different cellular proteins to this structure, PML can either hamper or potentiate their functions. The PML transcript undergoes alternative splicing to generate both nuclear and cytoplasmic isoforms. Most of the research in this field has focused its attention on studying nuclear PML. Nevertheless, new exciting studies show that cytoplasmic PML may control essential cellular functions, thus opening new avenues for investigation.

Non-HDL cholesterol predicts coronary heart disease in primary prevention: findings from an Italian a 40-69 year-old cohort in general practice

Scopo. La frazione lipoproteica denominata “colesterolo non-HDL” viene raccomandata come un indice di rischio coronarico (RC) associata alla dislipidemia combinata ed è stata trovata un utile fattore predittivo del rischio coronarico nei pazienti diabetici. Abbiamo studiato l’associazione tra i fattori di RC noti, incluso la colesterolo non-HDL ed una “condizione di RC elevato”, cioè un “RC a 5-anni >15%” in medicina generale. Metodi. Abbiamo studiato 4085 individui di età 40-69 anni, 489 diabetici e 3596 non-diabetici, appartenenti ad una coorte opportunistica. Sono state utilizzate le statistiche descrittive, e la regressione logistica multivariata aggiustata per età e sesso per i confronti tra i 2 gruppi. Risultati. Circa il 12% dei participanti era diabetico. I confronti aggiustati per età e sesso hanno mostrato che tutte le variabili erano significativamente peggiori nei diabetici rispetto ai non-diabetici (eccetto fumo, colesterolo totale e rapporto colesterolo totale/HDL). I diabetici avevano un “RC medio a 5-anni” più alto dei non-diabetici (18.8±11.9% vs 7.5±6.9%, P15%” (55.4% vs 11.1%, P<0.01). Nei diabetici, le variabili associate ad una “condizione di RC elevato” sono: fumo, pressione arteriosa sistolica (PAS) e colesterolemia non-HDL; nei non-diabetici: fumo, PAS, colesterolemia non-HDL e HDL (inversamente). Conclusioni. Il colesterolo non-HDL – oltre a fumo e PAS – è un forte predittore di una “condizione di RC elevato” sia negli individui diabetici che non-diabetici.