The E592K variant of SF3B1 creates unique RNA missplicing and associates with high-risk MDS without ring sideroblasts.

Among the most common genetic alterations in the myelodysplastic syndromes (MDS) are mutations in the spliceosome gene SF3B1. Such mutations induce specific RNA missplicing events, directly promote ring sideroblast (RS) formation, and generally associate with more favorable prognosis. However, not all SF3B1 mutations are the same, and little is known about how distinct hotspots influence disease. Here we report that the E592K variant of SF3B1 associates with high-risk disease features in MDS, including a lack of RS, increased myeloblasts, a distinct co-mutation pattern, and a lack of the favorable survival seen with other SF3B1 mutations. Moreover, compared to other hotspot SF3B1 mutations, E592K induces a unique RNA missplicing pattern, retains an interaction with the splicing factor SUGP1, and preserves normal RNA splicing of the sideroblastic anemia genes TMEM14C and ABCB7. These data have implications for our understanding of the functional diversity of spliceosome mutations, as well as the pathobiology, classification, prognosis, and management of SF3B1-mutant MDS.

In Vitro and In Vivo Evaluation of Bioactive Compounds from Berries for Wound Healing.

Managing chronic wounds can be challenging and have a major impact on the quality of life, due to the significant financial and psychosocial burden on the affected individuals and their families. The need for safe, effective, and cost-efficient wound healing remedies has led to the identification of naturally occurring bioactive compounds with positive effects on tissue regeneration. Berry fruits are a promising source of such compounds and may therefore prove distinctively beneficial. Here, we present a qualitative review of the available evidence specifically investigating the effects of berry extracts on in vitro and in vivo models of wound healing. The evidence shows that a variety of berry extracts significantly promote wound healing through their antibacterial, antioxidant, and anti-inflammatory properties as well as their ability to stimulate collagen synthesis, re-epithelization, granulation, and vascularization pathways. However, data are still insufficient to pinpoint the differential effect that individual berries may have based on their nutrient and bioactive profile, the type and frequency of application, and the dosage required. Future research is needed in view of translating the available evidence into practice for clinical wound treatment.

Essential role of obscurin kinase-1 in cardiomyocyte coupling via N-cadherin phosphorylation.

Obscurins are giant cytoskeletal proteins with structural and regulatory roles. Obscurin-B (~870 kDa), the largest known isoform, contains 2 enzymatically active Ser/Thr kinase (kin) domains, kin1 and kin2, which belong to the myosin light chain kinase family. Kin1 binds to and phosphorylates N-cadherin, a major component of the intercalated disc, the unique sarcolemmal microdomain that mediates the mechanochemical coupling of adjacent cardiomyocytes. Obscurin-B containing kin1 and N-cadherin colocalize at cell junctions in embryonic rat ventricular myocytes (ERVMs), and their codistribution is regulated by Ca2+. Phosphoproteomics analysis revealed that obscurin-kin1 phosphorylates N-cadherin at Ser-788 located within the juxtamembrane region of its cytoplasmic domain, with an apparent Kcat of approximately 5.05 min-1. Overexpression of obscurin-kin1 or phosphomimic-Ser-788-Glu N-cadherin in ERVMs markedly increases cell adhesion and chemical coupling. Importantly, phosphomimic Ser-788-Glu N-cadherin exhibits significantly reduced binding to p120-catenin, while overexpression of phosphoablated Ser-788-Ala N-cadherin increases RhoA activity. Consistent with an essential role of the obscurin-kin1/N-cadherin axis in cardiomyocyte coupling, it is deregulated in end-stage human heart failure. Given the nearly ubiquitous expression of obscurin and N-cadherin, our findings may have broad applicability in deciphering the obscurin-kin1/N-cadherin axis that likely mediates cell coupling in diverse tissues and organs.

Understanding the Continuum between High-Risk Myelodysplastic Syndrome and Acute Myeloid Leukemia.

Myelodysplastic syndrome (MDS) is a clonal hematopoietic neoplasm characterized by bone marrow dysplasia, failure of hematopoiesis and variable risk of progression to acute myeloid leukemia (AML). Recent large-scale studies have demonstrated that distinct molecular abnormalities detected at earlier stages of MDS alter disease biology and predict progression to AML. Consistently, various studies analyzing these diseases at the single-cell level have identified specific patterns of progression strongly associated with genomic alterations. These pre-clinical results have solidified the conclusion that high-risk MDS and AML arising from MDS or AML with MDS-related changes (AML-MRC) represent a continuum of the same disease. AML-MRC is distinguished from de novo AML by the presence of certain chromosomal abnormalities, such as deletion of 5q, 7/7q, 20q and complex karyotype and somatic mutations, which are also present in MDS and carry crucial prognostic implications. Recent changes in the classification and prognostication of MDS and AML by the International Consensus Classification (ICC) and the World Health Organization (WHO) reflect these advances. Finally, a better understanding of the biology of high-risk MDS and the mechanisms of disease progression have led to the introduction of novel therapeutic approaches, such as the addition of venetoclax to hypomethylating agents and, more recently, triplet therapies and agents targeting specific mutations, including FLT3 and IDH1/2. In this review, we analyze the pre-clinical data supporting that high-risk MDS and AML-MRC share the same genetic abnormalities and represent a continuum, describe the recent changes in the classification of these neoplasms and summarize the advances in the management of patients with these neoplasms.

Angiogenesis is Differentially Modulated by Anthocyanin and Phenolic Acid Extracts from Wild Blueberry (V. angustifolium) Through PI3K Pathway.

Wild blueberries rank very high in anthocyanins (ACNs) and phenolic acids (PA) among other berries. Previous work from our group has documented their beneficial effects. In this study, human umbilical vein endothelial cells were used, and ACNs, PAs, and their combination (ACNs:PAs) at concentrations of 0.002, 8, 15, 60, and 120 µg/mL were tested for endothelial tube formation. Treatment with ACNs decreased, while treatment with PAs and ACNs:PAs increased overall endothelial cell tube formation compared to control. Endothelial cells exposed to ACNs downregulated gene expression of AKT1 and endothelial nitric oxide synthase (eNOS), while PAs upregulated AKT1 and vascular endothelial growth factor (VEGF) gene expression. Combination of ACNs:PAs decreased gene expression of AKT1 and eNOS, while protein levels of AKT1 increased. In summary, based on the type of wild blueberry extract, angiogenesis is differentially modulated and is concentration dependent. Further experiments will delineate the mechanism(s) of the differential action of the aforementioned extracts on angiogenesis.

Whole Red Raspberry (Rubus idaeus)-Enriched Diet Is Hepatoprotective in the Obese Zucker Rat, a Model of the Metabolic Syndrome.

Non-alcoholic fatty liver disease is a major risk factor of the metabolic syndrome (MetS). The effect of whole red raspberry (WRR) consumption on lipid metabolism was investigated in the obese Zucker rat (OZR), a model for the MetS. Male OZRs (n = 16) and their lean littermates (lean Zucker rat) (n = 16) at 8 weeks of age were placed on a control or an 8% WRR-enriched diet for 8 weeks. Plasma triglycerides (TGs), total cholesterol, high-density lipoprotein cholesterol (HDL-C), and non-HDL-C levels, and hepatic concentration of TG were measured. The expression of nine genes related to lipid metabolism was evaluated, both in liver and adipose tissue. A WRR-enriched diet reduced plasma cholesterol and HDL-C and increased plasma TG, while it decreased hepatic TG accumulation in the OZR. The OZR assigned to a WRR exhibited upregulation of microsomal triglyceride transfer protein (Mttp) and downregulation of fatty acid synthase (Fas) expression in the liver. Results showed a decrease in accumulation of liver TG and gene expression modulation of enzymes and transcription factors associated with lipid metabolism, suggesting a possible hepatoprotective role of a WRR-enriched diet.

Double the trouble: giant proteins with dual kinase activity in the heart.

Obscurin and its homolog, striated muscle preferentially expressed gene (SPEG), constitute a unique group of proteins abundantly expressed in striated muscles that contain two tandemly arranged MLCK-like kinases. The physiological significance of the dual kinase motifs is largely understudied; however, a collection of recent studies characterizing their binding interactions, putative targets, and disease-linked mutations have begun to shed light on their potential roles in muscle pathophysiology. Specifically, obscurin kinase 1 is proposed to regulate cardiomyocyte adhesion via phosphorylating N-cadherin, whereas SPEG kinases 1 and 2 regulate Ca2+ cycling by phosphorylating junctophilin-2 and the sarcoendoplasmic Ca2+ ATPase 2 (SERCA2). Herein, we review what is currently known regarding the potential substrates, physiological roles, and disease associations of obscurin and SPEG tandem kinase domains and provide future directions that have yet to be investigated.

Role of Berry Anthocyanins and Phenolic Acids on Cell Migration and Angiogenesis: An Updated Overview.

Cell migration is a critical process that is highly involved with normal and pathological conditions such as angiogenesis and wound healing. Important members of the RHO GTPase family are capable of controlling cytoskeleton conformation and altering motility characteristics of cells. There is a well-known relationship between small GTPases and the PI3K/AKT pathway. Endothelial cell migration can lead to angiogenesis, which is highly linked to wound healing processes. Phenolics, flavonoids, and anthocyanins are major groups of phytochemicals and are abundant in many natural products. Their antioxidant, antimicrobial, anti-inflammatory, antidiabetic, angiogenenic, neuroprotective, hepatoprotective, and cardioprotective properties have been extensively documented. This comprehensive review focuses on the in vitro and in vivo role of berry extracts and single anthocyanin and phenolic acid compounds on cell migration and angiogenesis. We aim to summarize the most recent published studies focusing on the experimental model, type of berry extract, source, dose/concentration and overall effect(s) of berry extracts, anthocyanins, and phenolic acids on the above processes.

Phenolic and anthocyanin fractions from wild blueberries (V. angustifolium) differentially modulate endothelial cell migration partially through RHOA and RAC1.

The present study investigates the effect of anthocyanin (ACN), phenolic acid (PA) fractions, and their combination (ACNs:PAs) from wild blueberry powder (Vaccinum angustifolium) on the speed of endothelial cell migration, gene expression, and protein levels of RAC1 and RHOA associated with acute exposure to different concentrations of ACNs and PAs. Time-lapse videos were analyzed and endothelial cell speed was calculated. Treatment with ACNs at 60 µg/mL inhibited endothelial cell migration rate ( P ≤ 0.05) while treatment with PAs at 0.002 µg/mL ( P ≤ 0.0001), 60 µg/mL ( P ≤ 0.0001), and 120 µg/mL ( P ≤ 0.01) significantly increased endothelial cell migration rate compared with control. Moreover, exposure of HUVECs to ACNs:PAs at 8:8 µg/mL ( P ≤ 0.05) and 60:60 µg/mL increased ( P ≤ 0.001) endothelial cell migration. Gene expression of RAC1 and RHOA significantly increased 2 hours after exposure with all treatments. No effect of the above fractions was observed on the protein levels of RAC1 and RHOA. Findings suggest that endothelial cell migration is differentially modulated based on the type of blueberry extract (ACN or PA fraction) and is concentration-dependent. Future studies should determine the mechanism of the differential action of the above fractions on endothelial cell migration.

Wild blueberry consumption attenuates local inflammation in the perivascular adipose tissue of obese Zucker rats.

Perivascular adipose tissue (PVAT) has been shown to play important roles in regulating vascular tone and linking local and systemic vascular inflammation. We examined the impact of PVAT on phenylephrine-mediated vasoconstriction in the aorta of obese Zucker rats (OZR) and their lean littermates (LZR) by comparing aortic rings with or without PVAT. Subsequently we placed OZR and LZR on a control (C) or an 8% wild blueberry (WB) diet and evaluated the effect of WB consumption on such response. PVAT-released adipokine concentrations were also measured as a function of WB diet. Maximal constrictor force (Fmax) in aortic rings without PVAT was significantly lower in OZR-C compared with LZR-C (0.41 ± 0.05 and 0.71 ± 0.06 g, respectively). Following WB diet, Fmax significantly increased in OZR (0.54 ± 0.06 g). In aortas with intact PVAT, Fmax was significantly lower in all groups (0.31 ± 0.06 OZR-C, 0.30 ± 0.05 OZR-WB, 0.29 ± 0.03 LZR-C, and 0.30 ± 0.04 g LZR-WB), but no difference was observed between treatments. PVAT concentrations of monocyte chemoactractant protein 1 (MCP-1), tumor necrosis factor alpha, and adiponectin were significantly higher in OZR compared with LZR (+102%, +108%, and +45%, respectively). Following WB diet, PVAT concentrations of interleukin-8 were significantly lower in both OZR (-37%) and LZR (-30%), while adiponectin concentrations significantly increased in both OZR (+11%) and LZR (+16%). MCP-1 concentrations significantly decreased (-31%) in the PVAT of OZR with the WB diet. WB consumption appears to attenuate local inflammation in PVAT, which may impact systemic vascular inflammation and endothelial function.

Biological activity of the e domain of the IGF-1Ec as addressed by synthetic peptides.

Insulin-like growth factor-1 (IGF-1) is a multipotent growth factor involved in the growth, development and regulation of homeostasis in a tissue-specific manner. Alternative splicing, multiple transcription initiation sites and different polyadelynation signals give rise to diverse mRNA isoforms, such as IGF-1Ea, IGF-1Eb and IGF-1Ec transcripts. There is increasing interest in the expression of the IGF-1 isoforms and their potential distinct biological role. IGF-1Ec results from alternative splicing of exons 4-5-6 and its expression is upregulated in various conditions and pathologies. Recent studies have shown that IGF-1Ec is preferentially increased after injury in skeletal muscle during post-infarctal myocardium remodelling and in cancer tissues and cell lines. A synthetic analogue corresponding to the last 24 aa of the E domain of the IGF-1Ec isoform has been used to elucidate its potential biological role. The aim of the present review is to describe and discuss the putative bioactivity of the E domain of the IGF-1Ec isoform.