SOX7-enforced expression promotes the expansion of adult blood progenitors and blocks B-cell development

Sox17 and Other SoxF-Family Proteins Play Key Roles in the Hematopoiesis of Mouse Embryos

During mouse development, hematopoietic cells first form in the extraembryonic tissue yolk sac. Hematopoietic stem cells (HSCs), which retain their ability to differentiate into hematopoietic cells for a long time, form intra-aortic hematopoietic cell clusters (IAHCs) in the dorsal aorta at midgestation. These IAHCs emerge from the hemogenic endothelium, which is the common progenitor of hematopoietic cells and endothelial cells. HSCs expand in the fetal liver, and finally migrate to the bone marrow (BM) during the peripartum period. IAHCs are absent in the dorsal aorta in mice deficient in transcription factors such as Runx-1, GATA2, and c-Myb that are essential for definitive hematopoiesis. In this review, we focus on the transcription factor Sry-related high mobility group (HMG)-box (Sox) F family of proteins that is known to regulate hematopoiesis in the hemogenic endothelium and IAHCs. The SoxF family is composed of Sox7, Sox17, and Sox18, and they all have the HMG box, which has a DNA-binding ability, and a transcriptional activation domain. Here, we describe the functional and phenotypic properties of SoxF family members, with a particular emphasis on Sox17, which is the most involved in hematopoiesis in the fetal stages considering that enhanced expression of Sox17 in hemogenic endothelial cells and IAHCs leads to the production and maintenance of HSCs. We also discuss SoxF-inducing signaling pathways.

Runx1+ vascular smooth muscle cells are essential for hematopoietic stem and progenitor cell development in vivo

Hematopoietic stem cells (HSCs) produce all essential cellular components of the blood. Stromal cell lines supporting HSCs follow a vascular smooth muscle cell (vSMC) differentiation pathway, suggesting that some hematopoiesis-supporting cells originate from vSMC precursors. These pericyte-like precursors were recently identified in the aorta-gonad-mesonephros (AGM) region; however, their role in the hematopoietic development in vivo remains unknown. Here, we identify a subpopulation of NG2+Runx1+ perivascular cells that display a sclerotome-derived vSMC transcriptomic profile. We show that deleting Runx1 in NG2+ cells impairs the hematopoietic development in vivo and causes transcriptional changes in pericytes/vSMCs, endothelial cells and hematopoietic cells in the murine AGM. Importantly, this deletion leads also to a significant reduction of HSC reconstitution potential in the bone marrow in vivo. This defect is developmental, as NG2+Runx1+ cells were not detected in the adult bone marrow, demonstrating the existence of a specialised pericyte population in the HSC-generating niche, unique to the embryo.

SOX7 methylation is an independent prognostic factor in myelodysplastic syndromes

OBJECTIVE

SOX7 downregulation caused by its promoter methylation was associated with poor survival in several types of human solid tumors. However, the pattern of SOX7 methylation and its clinical significance are less studied in hematological malignancies. Herein, we evaluated the methylation pattern of SOX7 in myelodysplastic syndrome (MDS) and determined its clinical implication in patients with MDS.

METHODS

SOX7 methylation was determined by real-time quantitative methylation-specific PCR (RQ-MSP) in 99 MDS patients. Bisulfite sequencing PCR was applied to confirm the results of RQ-MSP.

RESULTS

SOX7 methylation was detected in 55.6% of 99 patients but not in healthy donors. No correlation was found between SOX7 methylation and clinical parameters including patient age, gender, white blood cell count, hemoglobin, and platelet count. However, patients with SOX7 methylation harbored more U2AF1 mutation than patients without SOX7 methylation (P = 0.015). Kaplan-Meier curves indicated that the patients with SOX7 methylation presented reduced overall survival (OS) (P =  0.034). Furthermore, subgroup analysis indicated that SOX7 methylation was associated with poor OS in male patients (P = 0.034) and in patients older than 60 years (P = 0.019). According to the multivariate analysis, SOX7 methylation remained as an independent prognosis factor in MDS patients both as dichotomous (HR = 2.14, P =  0.041) and as continuous (HR = 1.55, P =  0.042) variable. Importantly, SOX7 methylation was significantly increased during progression from MDS to secondary acute myeloid leukemia (sAML).

CONCLUSIONS

Our findings demonstrated that SOX7 methylation conferred adverse prognosis in MDS patients and was associated with leukemia progression.

Genetics of resistance to photobacteriosis in gilthead sea bream (Sparus aurata) using 2b-RAD sequencing

Background

Photobacteriosis is an infectious disease developed by a Gram-negative bacterium Photobacterium damselae subsp. piscicida (Phdp), which may cause high mortalities (90–100%) in sea bream. Selection and breeding for resistance against infectious diseases is a highly valuable tool to help prevent or diminish disease outbreaks, and currently available advanced selection methods with the application of genomic information could improve the response to selection. An experimental group of sea bream juveniles was derived from a Ferme Marine de Douhet (FMD, Oléron Island, France) selected line using ~ 109 parents (~ 25 females and 84 males). This group of 1187 individuals represented 177 full-sib families with 1–49 sibs per family, which were challenged with virulent Phdp for a duration of 18 days, and mortalities were recorded within this duration. Tissue samples were collected from the parents and the recorded offspring for DNA extraction, library preparation using 2b-RAD and genotyping by sequencing. Genotypic data was used to develop a linkage map, genome wide association analysis and for the estimation of breeding values.

Results

The analysis of genetic variation for resistance against Phdp revealed moderate genomic heritability with estimates of ~ 0.32. A genome-wide association analysis revealed a quantitative trait locus (QTL) including 11 SNPs at linkage group 17 presenting significant association to the trait with p-value crossing genome-wide Bonferroni corrected threshold P ≤ 2.22e-06. The proportion total genetic variance explained by the single top most significant SNP was ranging from 13.28–16.14% depending on the method used to compute the variance. The accuracies of predicting breeding values obtained using genomic vs. pedigree information displayed 19–24% increase when using genomic information.

Conclusion

The current study demonstrates that SNPs-based genotyping of a sea bream population with 2b-RAD approach is effective at capturing the genetic variation for resistance against Phdp. Prediction accuracies obtained using genomic information were significantly higher than the accuracies obtained using pedigree information which highlights the importance and potential of genomic selection in commercial breeding programs.

Electronic supplementary material

The online version of this article (10.1186/s12863-018-0631-x) contains supplementary material, which is available to authorized users.

Identification, molecular characterization and analysis of the expression pattern of SoxF subgroup genes the Yellow River carp, Cyprinus carpio

Sox7, Sox17 and Sox18 are the members of the Sry-related high-mobility group box family (SoxF) of transcription factors. SoxF factors regulate endothelial cell fate as well as development and differentiation of blood cells and lymphatic vessels. There is very less information about the functions of these genes in fish. We obtained the full-length cDNA sequence of SoxF genes including Sox7, Sox17 and Sox18 in Cyprinus carpio, where Sox7 and Sox18 had two copies. The construction of a phylogenetic tree showed that these genes were homologous to the genes in other species. Chromosome synteny analysis indicated that the gene order of Sox7 and Sox18 was highly conserved in fish. However, immense change in genomic sequences around Sox17 had taken place. Numerous putative transcription factor binding sites were identified in the 5_ flanking regions of SoxF genes which may be involved in the regulation of the nervous system, vascular epidermal differentiation and embryonic development. The expression levels of SoxF genes were highest in gastrula, and was abundantly expressed in the adult brain.We investigated the expression levels of SoxF genes in five specific parts of the brain. The expression levels of Sox7 and Sox18 were highest in the mesencephalon, while the expression level of Sox17 was highest in the epencephalon. In carp, the expression patterns of SoxF genes indicated a potential function of these genes in neurogenesis and in vascular development. These results provide new information for further studies on the potential functions of SoxF genes in carp.

Novel molecular signatures in mononuclear cell populations from patients with systemic lupus erythematosus

To gain novel insights into the immunopathogenesis of systemic lupus erythematosus we have analyzed gene expression data from isolated CD4⁺ T cells, CD8⁺ T cells, CD19⁺ B cells, and CD56⁺ NK-cell enriched peripheral blood cell fractions from patients and healthy donors. As predicted, type I interferon-inducible gene transcripts are overexpressed in all populations. Transcripts preferentially expressed in SLE CD4⁺ and CD8⁺ T cells include those associated with Tregulatory and Th17 effector cell programs, respectively, but in each case additional transcripts predicted to limit differentiation of those effector cells are detected. Evidence for involvement of the Wnt/β-catenin pathway was observed in both B and T cell fractions, and novel transcripts were identified in each cell population. These data point to disrupted T effector cell differentiation and the Wnt/β-catenin pathway as contributors to immune dysfunction in SLE while further supporting a central role for the type I interferon pathway in lupus.