教案615mct讨论课细生pbl3

1、Stem Cell Tissue RenewalTissue Renewal -the inspiration of Blood they are fragments of cytoplasm which are derived from the megakaryocytes of the bone marrow, and then enter the circulation. *The main function of platelets is to contribute to hemostasis: the process of stopping bleeding at the site

2、of interrupted endothelium. They gather at the site and unless the interruption is physically too large, they plug the hole. 5.Example Hematopoietic stem cells (HSCs) 5.Example Hematopoietic stem cells (HSCs) 5.Example (1) Megakaryocytes are derived from hematopoietic stem cell precursor cells in th

3、e bone marrow. They are produced primarily by the liver, kidney, spleen, and bone marrow. These multipotent stem cells live in the marrow sinusoids and are capable of producing all types of blood cells depending on the signals they receive. (2) The primary signal for megakaryocyte production is thro

4、mbopoietin血小板生成素 or TPO. TPO is sufficient but not absolutely necessary for inducing differentiation of progenitor cells in the bone marrow towards a final megakaryocyte phenotype. Other molecular signals for megakaryocyte differentiation include GM-CSF, IL-3, IL- 6, IL-11, chemokines (SDF-1, FGF-4)

5、. and erythropoietin. (3)The megakaryocyte develops through the following lineage: CFU-Megmegakaryoblastpromegakaryocytemegakaryocyte. Ps:CFU-Me: pluripotential hemopoietic stem cell or hemocytoblast Hematopoietic stem cells (HSCs) *So HSCs need continuously differentiation and replication to produc

6、e terminally differentiated cells and self clonal cells. *This phenomenon is also seen happening in other tissues of human body, though through a little different pathways! Clinical Correlation Since hematopoietic stem cells can differentiate into blood cells that belongs to the systemic circulation

7、, they are an ideal target cell for gene therapy, which is why most gene therapy projects list hematopoeitic stem cells as the main study. Now, the hematopoeitic stem cell has become the stem cell people understand and use the most. Radiotherapy and chemotherapy are the two major clinical treatments

8、 for malignant hematologic diseases. By the 80s bone marrow transplant has become a main measure to support hematopoietic cure which rebuilds and repairs the damaged hematopoietic system and immune system. 2021-7-27 Besides hematopoietic function, many researches have suggested that hematopoietic st

9、em cells have a stunningly amazing ability of cross mesoderm differentiation. Whats more, they also attack tumor cells. The most possible explanation to this phenomenon would be because the newly transplanted allogeneic hematopoietic stem cells started up another immune system inside the patient that caus