Extramedullary hematopoiesis (EMH) is a rare cause of adrenal mass. We present a 44-year-old woman who has thalassaemia intermedia, referred to Endocrinology clinic for huge adrenal mass. Along with a paraspinal lesion discovered in this patient, the leading diagnosis was EMH. The patient was treated with hypertransfusion and hydroxyurea, which led to a reduction in the size of the right adrenal mass and paraspinal mass. This case highlights the challenges in managing this rare condition. Although EMH is a rare cause of adrenal mass, the diagnosis must be considered in any patient with a history of a congenital hemolytic disorder, to avoid unnecessary surgical procedures.
Hematopoiesis, Extramedullary

Current dogma suggests that hematopoietic stem cells (HSC) reside in the top of the hematopoietic hierarchy, which can provide all kinds of mature blood cells constantly through self-renewal and multilineage differentiation potential. HSC has been regarded as the main cell population that maintains the stable hematopoiesis and several differentiation and development patterns of HSC have been summarized based on transplantation results. However, in deed the transplantation experiment is based on an extremely situation of stress which could not really reflect the function of HSC in normal homeostatic condition. Recent studies show that hematopoietic progenitor cells (HPC) play the most important role in hematopoiesis based on different experimental strategies. This article focuses on the controversial subject of the function of HSC and HPC under homostasis.
Cell Differentiation ; Hematopoiesis ; Hematopoietic Stem Cells

Hematopoietic stem cells (HSCs) reside at the top of the hierarchy and have the ability to differentiate to variety of hematopoietic progenitor cells (HPCs) or mature hematopoietic cells in each system. At present, the procress of HSC and HPC differentiating to the complete hematopoietic system under physiological and stressed conditions is poorly understood. In vivo lineage tracing is a powerful technique that can mark the individual cells and identify the differentiation pathways of their daughter cells, it takes as a strong technical system to research HSC. Traditional lineage tracing studies mainly rely on imaging techniques with fluorescent dyes and nucleic acid analogs. Recently, newly cell tracing technologies have been invented, and the combination of clonal tracing and DNAsequencing technologies have provided a new perspective on cell state, cell fate, and lineage commitment at the single cell level. In this review, these new tracing methods were introduce and discuss, and their advantages over traditional methods in the study of hematopoiesis were summarized briefly.
Cell Differentiation ; Hematopoiesis ; Hematopoietic Stem Cells

Transient myeloproliferative disorder (TMD), which may mimic acute leukemia, occurs in neonates with Down syndrome along with hepatic fibrosis. TMD is recognized shortly after birth or in the neonatal period and is characterized by leukocytosis and thrombocytopenia, which resolve spontaneously in four to six weeks. And hepatic fibrosis is characterized by diffuse intralobular sinusoidal fibrosis, extramedullary hematopoiesis and hemochromatosis. A newborn male infant with Down syndrome, atrial septal defect and ventricular septal defect is reported. He showed abnormal myelopoiesis accompanying characteristic hepatic sinusoidal fibrosis. Knowing the cellular mechanism of hepatic fibrosis and its modulation by growth factors, a pathogenetic link between transient myeloproliferative disorder and the development of liver fibrosis in Down syndrome neonates, association of this triad no longer appears to be accidental.
Down Syndrome* ; Fibrosis* ; Heart Septal Defects, Atrial ; Heart Septal Defects, Ventricular ; Hematopoiesis, Extramedullary ; Hemochromatosis* ; Humans ; Infant ; Infant, Newborn ; Intercellular Signaling Peptides and Proteins ; Leukemia ; Leukocytosis ; Liver Cirrhosis ; Male ; Myelopoiesis ; Myeloproliferative Disorders* ; Parturition ; Thrombocytopenia

Cell reprogramming is a progress in which the memory of a mature cell is erased and then the cell develops novel phenotype and function; ultimately, the fate of the cell changes. Cell reprogramming usually occurs at genes expression levels that no genomic DNA sequence change will be involved. By changing the programs of the genetic expressions of cells in terms of space and time, cell reprogramming alters the differentiation of cells and thus produces the required cells. Further research on cells reprogramming will elucidate the mechanisms that govern the cell development, and thus provides more information of the sources of seed cells used for regeneration medicine. More cells differentiated from many terminally differentiated cells will be obtained, which is extremely important for the understanding of molecular differentiation and for the development of cell replacement therapy. This article summarizes the classification, influencing factors, approaches and latest advances of cells reprogramming.
Animals ; Cell Dedifferentiation ; genetics ; Cell Differentiation ; genetics ; Cellular Reprogramming ; Gene Expression ; Humans ; Nuclear Transfer Techniques

Hematopoietic stem cells (HSC) maintain homeostatic hematopoiesis via their multi-lineage differentiation and self-renewal potentials. HSC can be enriched and purified by flow cytometry relying on their cell surface markers and functional characteristics, however, these methods can not meet the need for deep analysis of HSC biological property and function because of the poor purity. Recent studies have successfully purified and tracked HSC using specifically expressed genes, which can enhance the purification efficiency of HSC, thus provide a better tool for the in-vivo study of HSC. This review summarizes the new techniques and discusses their advantages and disadvantages.
Cell Differentiation ; Flow Cytometry ; Gene Expression ; Hematopoiesis ; Hematopoietic Stem Cells

Mitochondria are double-membrane organelles existing only in eukaryotic cells. Mitochondria perform various important functions，such as producing energy，regulating signal transduction，and contributing to stress response. Recent studies have highlighted an important role of mitochondria in the determination of hematopoietic stem cells （HSC） fate. Limited biogenesis or timely clearance of mitochondria is an important way against oxidative stress，which favors the quiescence of HSC. Accumulation of mitochondria may lead to proliferation of HSC，even the aging of HSC. Mitochondrial signaling regulates Ca concentration，which is essential for HSC differentiation. This review summarizes the current findings of the mitochondrial roles in HSC quiescence，self-renewal，lineage differentiation and aging.
Cell Differentiation ; Hematopoiesis ; Hematopoietic Stem Cells ; Mitochondria ; Oxidative Stress

Abstract　　The physiological hematopoiesis depends on the programmed expression of a series of gene regulated by mechanisms at various levels. Currently, the epigenetic regulation has been considered as the most important mechanism during hematopoietic differentiation, resulting in a specific epigenomic landscape in the hematopoietic stem/progenitor cells. We try to concisely review the epigenetic mechanisms, including the genomic methylation, the histone modifications and the expression profiles of noncoding RNA, illustrating briefly the differentiation from the hematopoietic stem/progenitor cells to to the erythroid, myeloid and lymphoid cells.
Cell Differentiation ; Epigenesis, Genetic ; Epigenomics ; Hematopoiesis ; Hematopoietic Stem Cells

The success of yielding induced pluripotent stem (iPS) cells from human somatic cells demonstrates the important role of reprogramming in the formation of stem/progenitor cells and initiates the exploration of the origin of leukemia stem cells. In our previous work, we have found two types of leukemia, bona fide leukemia and non-bona fide leukemia. Different leukemias originate from different leukemia stem/progenitor cells which are critical to the genesis and evolution of leukemia. Bona fide leukemia and non-bona fide leukemia originate from leukemia stem cells and progenitor cells, respectively. Recent research suggests that different types of leukemia are influenced by the reprogramming state of their origin cells.
Cell Differentiation ; Cellular Reprogramming ; Humans ; Induced Pluripotent Stem Cells ; Leukemia ; genetics ; Neoplastic Stem Cells ; Stem Cells

The somatic epigenome can be reprogrammed to a pluripotent state by a combination of transcription factors. Altering cell fate involves transcription factors cooperation, epigenetic reconfiguration, such as DNA methylation and histone modification, posttranscriptional regulation by microRNAs, and so on. Nevertheless, such reprogramming is inefficient. Evidence suggests that during the early stage of reprogramming, the process is stochastic, but by the late stage, it is deterministic. In addition to conventional reprogramming methods, dozens of small molecules have been identified that can functionally replace reprogramming factors and significantly improve induced pluripotent stem cell (iPSC) reprogramming. Indeed, iPS cells have been created recently using chemical compounds only. iPSCs are thought to display subtle genetic and epigenetic variability; this variability is not random, but occurs at hotspots across the genome. Here we discuss the progress and current perspectives in the field. Research into the reprogramming process today will pave the way for great advances in regenerative medicine in the future.
Animals ; Cell Differentiation ; Cellular Reprogramming ; MicroRNAs ; genetics ; Models, Biological ; Pluripotent Stem Cells ; cytology ; metabolism ; Stochastic Processes