SRPK1 maintains acute myeloid leukemia through effects on isoform usage of epigenetic regulators including BRD4.

We recently identified the splicing kinase gene SRPK1 as a genetic vulnerability of acute myeloid leukemia (AML). Here, we show that genetic or pharmacological inhibition of SRPK1 leads to cell cycle arrest, leukemic cell differentiation and prolonged survival of mice transplanted with MLL-rearranged AML. RNA-seq analysis demonstrates that SRPK1 inhibition leads to altered isoform levels of many genes including several with established roles in leukemogenesis such as MYB, BRD4 and MED24. We focus on BRD4 as its main isoforms have distinct molecular properties and find that SRPK1 inhibition produces a significant switch from the short to the long isoform at the mRNA and protein levels. This was associated with BRD4 eviction from genomic loci involved in leukemogenesis including BCL2 and MYC. We go on to show that this switch mediates at least part of the anti-leukemic effects of SRPK1 inhibition. Our findings reveal that SRPK1 represents a plausible new therapeutic target against AML

Micro- and macrovascular treatment targets in scleroderma heart disease

Cardiac involvement in systemic sclerosis (SSc) is a frequent visceral complication that considerably affects the prognosis of the disease. The pathophysiologic hallmark is myocardial fibrosis which can progress leading to arrhythmia, right and/or left heart dysfunction and failure. Symptoms range from unusual to prominent and from mild to dramatic, but clinically overt disease is a poor prognostic factor. Primary myocardial involvement is related to focal ischemia due to transient coronary spasm, and the available data support that microvascular functional and structural abnormalities rather than macrovascular coronary involvement represent the main underlying mechanism of the disease. However, the existence and prevalence of atherosclerotic coronary artery disease in SSc remain to be determined, as several studies have generated conflicting reports. Despite the lack of effective targeted therapy for SSc itself, sensitive and quantitative techniques have demonstrated the ability of vasodilators to improve myocardial function and perfusion and to prevent the evolution of subclinical heart involvement to decompensated heart failure. Further research will provide a better understanding of the disease by detecting the potent contribution of coronary artery involvement, explaining differences in accelerated atherosclerosis between SSc and other autoimmune disorders, and opening directions for the development of novel treatment strategies for this life-threatening complication of SSc. © 2014 Bentham Science Publishers

Molecular and Cellular Pathways as Treatment Targets for Biologic Therapies in Systemic Sclerosis

Recent advances have shed light on the complex pathogenic processes that underlie the development and progression of Systemic Sclerosis (SSc) but management of the disease remains problematic and curative treatment is not available. Better understanding of the underlying pathology has enabled novel therapeutic approaches to be investigated, as therapies in rheumatology are becoming increasingly disease/organ-specific, targeting unique biological networks and signalling pathways. The pathophysiologic and clinical pleiomorphism of SSc however, represents a major barrier to conducting large well-controlled studies for the evaluation of non-selective immunosuppressive and novel highly selective agents. Therapeutic biologic strategies targeting inflammatory or profibrotic cytokines and lymphocyte activation proved to be efficacious in other systemic rheumatic diseases but have demonstrated contradictory results in SSc. Blocking of tumour necrosis factor alpha and interleukin-6 may improve SSc-associated arthritis, while depletion of B-cells may have benefits for skin and lung fibrosis, but randomized studies are needed. In this review we critically appraise available data for the treatment of SSc focusing on immunologic and antifibrotic strategies. Attenuation of the fibrotic process remains an unmet goal but the potential to prevent damage by promoting tissue repair has been shown in preclinical studies. Translation of these findings into clinical practice will hopefully establish new therapeutic options and improve prognosis of these patients, for which our therapeutic armamentarium remains poor

Association Between Uric Acid and Worsening Peripheral Microangiopathy in Systemic Sclerosis

Objective: The key element in the pathogenesis of systemic sclerosis (SSc) is microcirculatory changes in several vascular beds. Uric acid is associated with endothelial dysfunction and therefore, microvascular damage. The aim of this study was to examine the association between uric acid (UA) and peripheral microvascular involvement in patients with SSc.Methods: We included consecutive, consenting patients with SSc. Serum UA, urea and creatinine were measured, and glomerular filtration rate (GFR) was calculated with CKD-EPI. All participants underwent nailfold video-capillaroscopy (NVC) to evaluate the microcirculation.Results: A total of 64 patients (95.3% women) were included in the study. UA levels were significantly associated with the number of avascular areas (r = 0.290; p = 0.020), whereas no correlation was shown for the GFR (r = −0.065; p = 0.609). A significant trend of UA in the three capillaroscopic patterns was shown (3.90 ± 1.52 vs. 4.15 ± 0.98 vs. 5.38 ± 2.26; for early, active, and late patterns respectively, p = 0.028). Multivariate analysis showed that male gender (β = 3.049; 95% CI = 0.997–5.101) and UA (β = 0.352; 95% CI = 0.117–0.588) were independently associated with the number of avascular areas.Conclusion: These data suggest that UA levels are significantly associated with the capillaroscopic patterns, reflecting a progressive microvasculopathy.</jats:p

Arterial stiffness correlates with progressive nailfold capillary microscopic changes in systemic sclerosis: results from a cross-sectional study

Abstract Background While microangiopathy is well-documented in systemic sclerosis (SSc), a potential link between SSc and macrovascular disease is highly debated and remains to be established. The aim of the present study is to investigate the association between micro- and macrovascular involvement in the setting of SSc. Methods Consecutive, consenting SSc patients were assessed by nailfold video-capillaroscopy (NVC) to evaluate the microcirculation. The number of capillaries per mm2 and the capillaroscopic skin ulcer risk index (CSURI) were measured, and findings were also classified into three scleroderma patterns (i.e., early, active, and late). Carotid intima-media thickness (IMT), aortic augmentation index corrected for a heart rate of 75 beats per minute (AIx-75), carotid-femoral pulse wave velocity (PWV), and central systolic and diastolic blood pressure were also determined to assess macrovascular function. Results A total of 37 patients were studied. A significant correlation was observed between AIx and the average number of capillaries per mm2 (r = − 0.34, p = 0.047) and between AIx and CSURI (r = 0.35, p = 0.044). Patients with the “early” scleroderma pattern had lower AIx values compared with “active” (20.5 ± 11.4 vs 34.1 ± 11.5%, p = 0.02) and “late” (20.5 ± 11.4 vs 33.4 ± 8.8%, p = 0.05) patterns. No other significant correlations were found between macrovascular biomarkers (PWV, carotid IMT, systolic and diastolic central blood pressure) and the capillaroscopic measurements. Conclusions These data suggest that arterial stiffness (as assessed by AIx-75) correlates with microvascular damage in patients with SSc. </jats:sec