Association between BCL11A, HSB1L-MYB, and XmnI γG-158 (C/T) gene polymorphism and hemoglobin F level in Egyptian sickle cell disease patients.

Sickle cell disease (SCD) is a monogenic disease characterized by multisystem morbidity and highly variable clinical course. Inter-individual variability in hemoglobin F (HbF) levels is one of the main modifiers that account for the clinical heterogeneity in SCD. HbF levels are affected by, among other factors, single nucleotide polymorphisms (SNPs) at the BCL11A gene and the HBS1L-MYB intergenic region and Xmn1 gene. Our aim was to investigate HbF-enhancer haplotypes at these loci to obtain a first overview of the genetic situation of SCD patients in Egypt and its impact on the severity of the disease. The study included 100 SCD patients and 100 matched controls. Genotyping of BCL11A (rs1886868 C/T), HBS1L-MYB (rs9389268 A/G) and Xmn1 γG158 (rs7842144 C/T) SNPs showed no statistically significant difference between SCD patients and controls except for the hetero-mutant genotypes of BCL11A which was significantly higher in SCD patients compared with controls. Baseline HbF levels were significantly higher in those with co-inheritance of polymorphic genotypes of BCL11A + HSB1L-MYB and BCL11A + Xmn1. Steady-state HbF levels, used as an indicator of disease severity, were significantly higher in SCD-Sß patients having the polymorphic genotypes of HSB1L-MYB. Fold change of HbF in both patient groups did not differ between those harboring the wild and the polymorphic genotypes of the studied SNPs. In conclusion, BCL11A, HSB1L, and Xmn1 genetic polymorphisms had no positive impact on baseline HbF levels solely but had if coexisted. Discovery of the molecular mechanisms controlling HbF production could provide a more effective strategy for HbF induction.

Endothelial Dysfunction Linked to Ventricular Dysfunction in Children With Sickle Cell Disease, a 3D Speckle Tracking Study.

Background: Sickle Cell Disease (SCD) is not a hematologic disease that occurs in isolation; it results in multi-organ complications. There is growing evidence of vascular stiffness as its underlying cause. This study aimed to investigate the relationship between endothelial stiffness and LV dysfunction in SCD patients and to explore its pathophysiology, particularly regarding the depletion of vasodilators such as Nitric Oxide (NO). Methodology: 32 patients with established criteria for SCD and 40 healthy control subjects were selected for this case-control study. Comprehensive clinical assessment and assessment of endothelial function using Brachial Flow-mediated dilation (FMD) were performed, along with serum NO measurement, which was followed by diagnosis and echocardiographic assessment using 3D speckle tracking echocardiography (STE) and tissue Doppler imaging (TDI). Results: Collected SCD cases showed echocardiographic features of Systo-diastolic dysfunction with reduced FMD compared to controls, denoting endothelial dysfunction in those patients. LDH showed a marked elevation, while serum NO showed a significant reduction in cases compared with controls. We also noted a positive correlation between FMD on the one hand and measures of ventricular dysfunction and level of serum NO on the other hand, the latter proving that reduction of NO is responsible for reduced endothelial function. Conclusion: We present the first report to date to outline the role of vascular stiffness as measured by brachial FMD in the induction of left ventricular dysfunction in SCD. We recommend that more research be conducted regarding possible strategies to replenish serum NO stores to delay microvascular injury and, in turn, ventricular dysfunction in SCD.

Evaluation of prognostic variables in chronic lymphocytic leukemia and association with disease stage.

The aim of the present study was to investigate different biological prognostic markers to identify high-risk patients with chronic lymphocytic leukemia (CLL) with a higher tumor burden, in order to ensure appropriate management. A total of 81 Egyptian patients with CLL were enrolled in the present study, with 75 healthy subjects serving as the control group. The expression of CD49d, CD38 and ZAP-70 in CLL cells was assessed using flow cytometry. The fluorescence in situ hybridization technique was employed to evaluate TP53 (del17p), ataxia-telangiectasia (del11q) and 13q14 (del13q14) genes and the presence of trisomy 12. The serological markers ß2 microglobulin (B2M) and sCD23 were measured by ELISA. The CD49d gene was highly expressed in 25.9% and cytogenetic aberrations were observed in 66.6% of all recruited CLL patients. The patients were categorized according to the Binet staging system and a significant increase in the expression of sCD23, CD49d and ZAP-70 was detected in group C (P=0.008, 0.034 and 0.017, respectively) when compared to groups A and B. CD49d+ patients exhibited significantly higher expression of CD38 (P=0.002) and trisomy 12 (P=0.015) and lower expression of del13q14 (P=0.001). Patients who were CD49d+ with B2M>3.5 µg/ml exhibited higher total leukocyte count (P=0.048), higher absolute lymphocyte count (P=0.036), higher expression of CD38 (P=0.002) and trisomy 12 (P=0.034) and lower expression of del13q14 (P=0.002). Therefore, sCD23, CD49d and ZAP-70 may be considered as an optimal prognostic marker combination to be evaluated in the early stages of CLL and throughout disease management. Integrating both serological markers and CD49d expression by flow cytometry may add to the prognostic value of each marker alone and help identify high-risk patients with a higher tumor burden.

ITGA4 gene methylation status in chronic lymphocytic leukemia.

BACKGROUND: We aimed to investigate ITGA4 gene expression pattern and to explore its methylation heterogeneity in chronic lymphocytic leukemia (CLL). PATIENTS & METHODS: Eighty one CLL patients and 75 healthy subjects were enrolled and prognostic evaluation of patients was assessed. ITGA4 q-realtime PCR was performed using Applied Biosystems, TaqMan gene expression assay. ITGA4 gene-specific CpG methylation was investigated in real time using pyrosequencing technology. RESULTS: ITGA4 was differentially expressed in CLL patients. The CpG sites-1, 2 and 3 showed significantly higher mean levels than healthy controls (p = <0.001, 0.007 and 0.009). Significant association between CpG site-1 and CLL has been detected using age-adjusted logistic regression (p < 0.001). CONCLUSION: Hypermethylation at ITGA4 gene CpG sites (1,2,3) is a characteristic feature in CLL.

The impact of growth factors on human induced pluripotent stem cells differentiation into cardiomyocytes.

Human induced pluripotent stem cells (hiPSCs) act as a promising therapeutic alternative for cardiovascular diseases. They yield a large number of functional cardiomyocytes (CMs) from autologous cell sources without ethical or immunological problems. However, significant limitations still remain in terms of line-to-line variability in CM yield and reproducibility. AIM: To efficiently enhance NP0040 hiPSCs differentiation into CMs. MAIN METHODS: Following a standard cardiac differentiation protocol using small molecules targeting the canonical Wnt signaling, growth factors (BMP4 and FGF2) and ascorbic acid were added further in order to increase the cardiac differentiation efficiency. All cultures were conducted in serum-free, feeder-free monolayer system followed by lactate purification. KEY FINDINGS: Using NP0040 hiPSCs, the CM yield resulting from modulation of the Wnt signaling pathway alone was inefficient compared to previous studies while the addition of BMP4, FGF2 and ascorbic acid resulted in enhanced cardiac differentiation outcome. The later resulted in a high yield (up to 92%) of cardiac troponin-T (cTnT) + CMs contracting spontaneously as organized sheets in 15 independent experiments. They were validated structurally and functionally using immunofluorescent staining for sarcomeric α-actinin, cTnT, MLC2v and Connexin 43. Reverse-transcriptase PCR revealed cardiac transcription factors and cardiac-specific genes expression. CMs were electrically connected to one another. Recorded action potential (AP) showed waves of relatively mature ventricular-like phenotype. SIGNIFICANCE: We demonstrated that hiPSC lines respond differently to a standard cardiac differentiation protocol and that a well-orchestrated interplay between Wnt, BMP4, FGF/MEK and Ascorbic acid MEK/ERK1/2 signaling pathways is beneficial in enhancing the differentiation outcome.