Vitamin B5 and succinyl-CoA improve ineffective erythropoiesis in SF3B1-mutated myelodysplasia

Patients with myelodysplastic syndrome and ring sideroblasts (MDS-RS) present with symptomatic anemia due to ineffective erythropoiesis that impedes their quality of life and increases morbidity. More than 80% of patients with MDS-RS harbor splicing factor 3B subunit 1 (SF3B1) mutations, the founder aberration driving MDS-RS disease. Here, we report how mis-splicing of coenzyme A synthase (COASY), induced by mutations in SF3B1, affects heme biosynthesis and erythropoiesis. Our data revealed that COASY was up-regulated during normal erythroid differentiation, and its silencing prevented the formation of erythroid colonies, impeded erythroid differentiation, and precluded heme accumulation. In patients with MDS-RS, loss of protein due to COASY mis-splicing led to depletion of both CoA and succinyl-CoA. Supplementation with COASY substrate (vitamin B5) rescued CoA and succinyl-CoA concentrations in SF3B1mut cells and mended erythropoiesis differentiation defects in MDS-RS primary patient cells. Our findings reveal a key role of the COASY pathway in erythroid maturation and identify upstream and downstream metabolites of COASY as a potential treatment for anemia in patients with MDS-RS.

Characteristics of young women presenting with acute myocardial infarction: the prospective, multicentre, observational WAMIF study

Background

Cardiovascular diseases are the leading cause of death in women, killing sevenfold more women than breast cancer. Rates of hospital death for myocardial infarction in women, although decreasing, remains significantly higher than in men (more than double), especially among women under the age of 50. The occurrence of myocardial infarction in non-menopausal women is not unusual, and the incidence continues to rise. While women under the age of 60 accounted for less than 12% of patients with myocardial infarction admitted in 1995, they accounted for more than 25% in 2015. In addition to the traditional cardiovascular risk factors, women present specific ones linked to hormonal modifications, inflammatory high-risk profiles, and thrombophilia.

Purpose

We comprehensively and systematically collected all clinical and biological data and the results of morphological explorations in all women admitted for myocardial infarction under the age of 50 in high-volume French centres. To date, no systematic descriptive analysis has been carried out incorporating not only clinical, morphological, and extraordinary characteristics, but biological characteristics, in particular hormonal and immunological parameters.

Methods

This prospective, observational study included all women admitted for myocardial infarction under the age of 50 years at 30 centres in France from May 2017 to June 2019.

Results

The population comprised 314 women (mean age 44.9 years): 192 presented with ST-segment elevation myocardial infarction and 122 with non-ST-segment elevation myocardial infarction, 75% were current smokers, 35 had a family history of cardiovascular disease, 33% had a complication of pregnancy, and 55% reported recent emotional stress. Ten had a normal coronary angiogram. Independent predictors of premature MI, <35 yo, were cannabis use and oral contraceptive therapy. No deaths, but 3 strokes, 3 recurrent myocardial infarctions, and 1 serious bleed occurred during hospitalization. At 12 months, 2 deaths occurred but linked to progressive cancer, 25 patients had recurrent PCI, 4 symptoms driven. Otherwise, 90.4% were event free and 72% completely symptoms free.

Conclusion

The WAMIF study showed that most young women with acute myocardial infarction reported typical symptoms of chest pain, and modifiable cardiovascular risk factors, most commonly tobacco use. Gynaecological status, history of pregnancy complications, and non-compliance with non-indication of combined contraception were overrepresented, emphasizing the urge for a better cardiological and gynaecological network. The overall prognosis for these women was better than previously reported despite the high rate of emergency consultations in the year following the index myocardial infarction, highlighting the need for more comprehensive follow-up following the myocardial infarction.

Funding Acknowledgement

Type of funding sources: Other. Main funding source(s): French Society of CardiologyGrants from Indusctries Biosensors Europe SA, AstraZeneca, Boston Scientific Corporation, Abbott Medical Devices, Terumo Corporation, Daiichi Sankyo, Inc., Hexacath, France, Biotronik SE & Co. KG.

Identification of altered cell signaling pathways using proteomic profiling in stable and progressive chronic lymphocytic leukemia

Chronic lymphocytic leukemia (CLL) is characterized by significant biologic and clinical heterogeneity. This study was designed to explore CLL B-cells' proteomic profile in order to identify biologic processes affected at an early stage and during disease evolution as stable or progressive. Purified B cells from 11 untreated CLL patients were tested at two time points by liquid chromatography-tandem mass spectrometry. Patients included in the study evolved to either progressive (n = 6) or stable disease (n = 5). First, at an early stage of the disease (Binet stage A), based on the relative abundance levels of 389 differentially expressed proteins (DEPs), samples were separated into stable and progressive clusters with the main differentiating factor being the RNA splicing pathway. Next, in order to test how the DEPs affect RNA splicing, a RNA-Seq study was conducted showing 4217 differentially spliced genes between the two clusters. Distinct longitudinal evolutions were observed with predominantly proteomic modifications in the stable CLL group and spliced genes in the progressive CLL group. Splicing events were shown to be six times more frequent in the progressive CLL group. The main aberrant biologic processes controlled by DEPs and spliced genes in the progressive group were cytoskeletal organization, Wnt/β-catenin signaling, and mitochondrial and inositol phosphate metabolism with a downstream impact on CLL B-cell survival and migration. This study suggests that proteomic profiles at the early stage of CLL can discriminate progressive from stable disease and that RNA splicing dysregulation underlies CLL evolution, which opens new perspectives in terms of biomarkers and therapy.