AdultStemCellsHomeostasisandRegenerativeMedicine分子与细胞课件

1、adult stem cells, homeostasis,and regenerative medicine分子与细胞1adult stem cells, homeostasis, and regenerative medicineadult stem cells, homeostasis,and regenerative medicine分子与细胞2what are adult stem cells? an adult stem cell is an undifferentiated (or partially-differentiated) cell found in tissues a

2、nd organs they can self-renew and differentiate to become most or all of the specialized cell types within their specific tissue lineage. adult stem cells maintain cell populations help you heal play a role in aging 尼龙板棒 pom板棒 环氧板 尼龙板 尼龙棒 ttp:/ 高压油管 金属软管 液压接头adult stem cells, homeostasis,and regener

3、ative medicine分子与细胞3homeostasis the ability to regulate internal conditions, usually by a system of feedback controlsstabilize health and functioning, regardless of the outside changing conditions. one piece of homeostasis is the constant or periodic generation of new cells to replace old, damaged,

4、and dying cells adult stem cells fulfill this role through the process of regeneration adult stem cells, homeostasis,and regenerative medicine分子与细胞4how regeneration works adult stem cells normally remain quiescent (non-dividing) for relatively long periods of time until they are activated by signals

5、 to maintain tissues when activated they divide through a process called asymmetric cell division through this process they are able to maintain their populations and differentiate into the desired cell types by the creation of a progenitor cell a progenitor cell, in contrast to stem cells, is alrea

6、dy far more specific: they are pushed to differentiate into their target cell.adult stem cells, homeostasis,and regenerative medicine分子与细胞5asymmetric cell divisionproliferates maintains pop. creates progenitor cellprogenitor cellstem cellstem celladult stem cells, homeostasis,and regenerative medici

7、ne分子与细胞6adult stem cells, homeostasis,and regenerative medicine分子与细胞7location of adult stem cells adult stem cells and progenitor cells reside through out your body these stem cells reside in a specific area of each tissue called the “stem cell niche” this niche is a particular microenvironment that

8、 fosters the growth of resident stem cells mutations in cells, signals they receive, and changes in the microenvironment can activate a stem celladult stem cells, homeostasis,and regenerative medicine分子与细胞8types of adult stem cellshematopoietic stem cells: blood and immune system mesenchymal stem ce

9、lls: bone, cartilage, fat, muscle, tendon/ligamentneural stem cells: neurons, glial cellsepithelial stem cells: skin, liningsadult stem cells, homeostasis,and regenerative medicine分子与细胞9hematopoietic stem cellsgive rise to all the blood cell types: myeloid (monocytes and macrophages, neutrophils, ba

10、sophils, eosinophils, erythrocytes, megakaryocytes/platelets, dendritic cells) lymphoid (t-cells, b-cells, nk-cells)found in the bone marrow from very early on in development, as well as in umbilical cord blood and placental tissueadult stem cells, homeostasis,and regenerative medicine分子与细胞10mesench

11、ymal stem cells these stem cells will differentiate into: cartilage cells (chondrocytes) muscle cells (myocytes) fat cells (adipocytes) tendons, ligaments, and connective tissue (epithelial cells including osteoblasts) these cells are located throughout the body bone marrow, fat, and cord blood are

12、easiest to isolatesmooth muscle cells (red) cirmadult stem cells, homeostasis,and regenerative medicine分子与细胞11neural stem cells they are located in: subventricular zone lining the lateral ventricles, where they give rise to newly-born neurons that migrate to the olfactory bulb via the rostral migrat

13、ory stream subgranular zone, part of the dentate gyrus of the hippocampus neural stem cells (also called neural precursor cells) give rise to neurons, oligodendrocytes, and astrocytestop: section of the hippocampus, blue dots are neural stem cellsleft: mature neuron (red) cirmadult stem cells, homeo

14、stasis,and regenerative medicine分子与细胞12epithelial stem cells give rise to epithelial cells which constitute 60 percent of the differentiated cells in the body. responsible for covering the internal (i.e. intestinal lining) and external surfaces (i.e. skin) of the body, including the lining of vessel

15、s, glands, and other cavities. epithelial stem cells are also found in the bulge region of the hair follicleretinal pigment epithelial cells cirmadult stem cells, homeostasis,and regenerative medicine分子与细胞13adult stem cell therapiesbone marrow transplantadult stem cells, homeostasis,and regenerative

16、 medicine分子与细胞14tissue specific organsin november 2008, scientists in spain carried out a trachea transplant for a woman whose windpipe had been damaged by tuberculosis. the doctors took adult stem cells and some other cells from the healthy right airway of the woman needing the trachea transplant,

17、grafted those cells onto the stripped-down donated (cadaver) trachea, and marinated the trachea in chemicals in a lab to coax the trachea into rebuilding itself.adult stem cells, homeostasis,and regenerative medicine分子与细胞15clinical trials clinical trials are conducted in phases. the trials at each p

18、hase have a different purpose and help scientists answer different questions:phase i trials: researchers test an experimental drug or treatment in a small group of people (20-80) for the first time to evaluate its safety, determine a safe dosage range, and identify side effects.phase ii trials: the

19、experimental study drug or treatment is given to a larger group of people (100-300) to see if it is effective and to further evaluate its safety.phase iii trials: the experimental study drug or treatment is given to large groups of people (1,000-3,000) to confirm its effectiveness, monitor side effe

20、cts, compare it to commonly used treatments, and collect information that will allow the experimental drug or treatment to be used safely.phase iv trials: post marketing studies delineate additional information including the drugs risks, benefits, and optimal use.adult stem cells, homeostasis,and re

21、generative medicine分子与细胞16risk vs. benefits of participating in a clinical trial riskthe patient must stop taking other treatments before the trialthere may be unpleasant, serious or even life-threatening side effects to experimental treatment.the experimental treatment may not be effective for the

22、participant, or given a placebothe protocol may require more of their time and attention than would a non-protocol treatment, including trips to the study site, more treatments, hospital stays or complex dosage requirements.benefit play an active role in their own health care.gain access to new research treatments before they are widely available. obtain expert medical care at leading health care facilities during the trial.help others by contributing to medical research.the patient may get better a