Animals ; Cell Differentiation ; genetics ; physiology ; Humans ; MicroRNAs ; genetics ; Ossification, Heterotopic ; genetics ; Signal Transduction ; genetics ; physiology

OBJECTIVETo investigate the role of antiapoptotic Bcl-x(L) protein in megakaryocyte differentiation and maturation.

METHODSRNA interference was used to block the expression of Bcl-x(L) when K562 cells were induced to differentiate into megakaryocyte (CD61 + cells) by PDBu, and the expression of Bcl-x(L) was evaluated with flow cytometry and reverse transcription polymerase chain reaction (RT-PCR). The CD34 + cell fraction was positively isolated by using the MiniMACS system from normal bone marrow. Immunochemical staining and flow cytometry were used to detect the expression of Bcl-x(L) in the differentiation (CD41 + cells) of CD34 + cells induced by trombopoietin (TPO).

RESULTSAmong K562 cells induced by PDBu, the percentage of CD6L + cells rapidly increased in 24 hours and maintained at a high positive level in 72 hours. When exposured to si-Bcl-x(L), the percentage of CD6 1 + cells only slightly increased in 72 hours. The expression of Bcl-x(L) mRNA was significantly decreased after transfection compared with that of control group, and Bcl-x(L) protein expression decreased correspondingly. After the CD34 + bone marrow cells having been treated with TPO for 5 days to 20 days, the Bcl-x(L)-megakaryocytes increased as the culture time prolonged, and there was a strong expression of Bcl-x(L) in immature megakaryocyte and an obviously decreased expression in degenerating megakaryocytes maturation.

CONCLUSIONSIncreased expression of antiapoptotic Bcl-x(L) may be essential to mature megakaryocyte. The down-regulation of antiapoptotic Bcl-x(L) in mature megakaryocyte may be crucial to platelets formation.

Cell Differentiation ; Humans ; K562 Cells ; Megakaryocytes ; physiology ; RNA Interference ; bcl-X Protein ; biosynthesis ; genetics ; physiology

Animals ; Cell Differentiation ; physiology ; Cell Proliferation ; Hepatocytes ; transplantation ; Humans ; Transcription Factors ; genetics ; Transcription, Genetic

Self-renewal and multilineage differentiation of hematopoietic stem cell (HSC) are their functional characteristics. The regulation of HSC self-renewal is governed by a balance between positive regulatory signals promoting growth and negative regulatory signals resulting in apoptosis. Among the positive regulatory signals, HOXB4 activates distinct pathways that enhance self-renewal divisions of HSC without overriding the regulatory mechanisms that maintain normal steady-state hemopoiesis. The upregulation of HOXB4 gene expression can greatly promote the HSC self-renewal, but does not affect the HSC differentiation, the morphology and function of linage-specific cells and terminally-differentiated blood cells. Furthermore, HOXB4 can enhance the hematopoietic potential of embryonic stem cell (ESC), promoting the differentiation of ESC into hematopoietic cells. As a consequence, upregulation of HOXB4 expression and/or corresponding HOXB4 target genes can have enormous therapeutical potential for human HSC in the stem cell transplantation and gene therapy. In this review the regulatory role of HOXB4 in HSC self-renewal, "zero" effect of HOXB4 on differentiation specificity of HSC lines and terminal differentiation cells, and molecular mechanisms of regulating HSC self-renewal by HOXB4 are summarised.
Animals ; Apoptosis ; genetics ; Cell Differentiation ; genetics ; Cell Proliferation ; Hematopoietic Stem Cell Transplantation ; Hematopoietic Stem Cells ; cytology ; metabolism ; Homeodomain Proteins ; genetics ; physiology ; Humans ; Transcription Factors ; genetics ; physiology

The root is crucial for the physiological function of the tooth, and a healthy root allows an artificial crown to function as required clinically. Tooth crown development has been studied intensively during the last few decades, but root development remains not well understood. Here we review the root development processes, including cell fate determination, induction of odontoblast and cementoblast differentiation, interaction of root epithelium and mesenchyme, and other molecular mechanisms. This review summarizes our current understanding of the signaling cascades and mechanisms involved in root development. It also sets the stage for de novo tooth regeneration.
Cell Differentiation ; genetics ; Dental Cementum ; physiology ; Epithelium ; physiology ; Humans ; Mesoderm ; physiology ; Molecular Biology ; Odontoblasts ; physiology ; Odontogenesis ; genetics ; Signal Transduction ; genetics ; Tooth Root ; embryology ; growth & development

Bone marrow mesenchymal stem cells (MSCs) are defined as pluripotent cells which have high self-renewal capacity and multipotentiality for differentiation. Because of their characteristics of supporting hematopoietisis, multipotentiality for differentiation and their possible use for both cell and gene engineerings, MSCs will have important value in clinic use.
Animals ; Cell Differentiation ; genetics ; physiology ; Humans ; Mesenchymal Stem Cell Transplantation ; Mesenchymal Stromal Cells ; cytology ; metabolism ; physiology ; Models, Biological

Male meiosis is a complex process whereby spermatocytes undergo cell division to form haploid cells. This review focuses on the role of retinoic acid (RA) in meiosis, as well as several processes regulated by RA before cell entry into meiosis that are critical for proper meiotic entry and completion. Here, we discuss RA metabolism in the testis as well as the roles of stimulated by retinoic acid gene 8 (STRA8) and MEIOSIN, which are responsive to RA and are critical for meiosis. We assert that transcriptional regulation in the spermatogonia is critical for successful meiosis.
Animals ; Cell Differentiation/genetics* ; Humans ; Meiosis/drug effects* ; Spermatogenesis/physiology* ; Tretinoin/metabolism*

Heart is the first organ to function during mammalian embryogenesis. The differentiation of embryonic stem cells (ESCs) into cardiomyocyte is complex and dynamic, which involves 4 differentiation stages including ESCs, mesoderm, cardiac precursor, and terminal cardiomyocytes. Abnormal expression of certain genes can lead to congenital heart diseases during cardiomyocyte differentiation. Epigenetic regulation plays a crucial role on the switch of gene activation and deactivation during cardiomyocyte differentiation. Non-coding RNA, particularly microRNA and long non-coding RNA, may significantly influence gene expression. Exploring the regulatory roles of non-coding RNA in cardiomyocyte differentiation may contribute to the understanding of the functions of myocardial cells and mechanism of congenital heart diseases.
Animals ; Cell Differentiation ; genetics ; Embryo, Mammalian ; physiology ; Embryonic Stem Cells ; physiology ; Epigenesis, Genetic ; genetics ; Humans ; Myocytes, Cardiac ; physiology ; RNA, Long Noncoding ; genetics

Apoptosis ; Cell Cycle ; Cell Differentiation ; Cell Proliferation ; Humans ; Neoplastic Processes ; Proto-Oncogene Proteins c-jun ; genetics ; metabolism ; physiology

Self-renewal of hematopoietic stem cells is vital for the sustained daily production of blood cells. The Bmi-1 gene is a putative oncogene belonging to the Polycomb group family. Recent studies have shown that the Polycomb-group gene Bmi-1 is indispensable for regulation of self-renewal of normal and leukemic stem cells. The research progress on structure and function of Bmi-1 gene, and its role in self-renewal of hematopoietic stem cells was reviewed.
Cell Differentiation ; physiology ; Cell Division ; physiology ; Hematopoietic Stem Cells ; cytology ; physiology ; Humans ; Nuclear Proteins ; genetics ; physiology ; Polycomb Repressive Complex 1 ; Proto-Oncogene Proteins ; genetics ; physiology ; Repressor Proteins ; genetics ; physiology