StemCellsandDiabetesHowardHughesMedicalInstitute干细胞与糖尿病霍华德休斯医学研究所课件

StemCellsandDiabetesHowardHughesMedicalInstitute干细胞与糖尿病霍华德休斯医学研究所Stem Cells and DiabetesThe PresentThe Present StemCellsandDiabetesHowardHughesMedicalInstitute干细胞与糖尿病霍华德休斯医学研究所BackgroundnDiabetes affects more people and causes more deaths each year than breast cancer and AIDS combined.nThe American Diabetes Association estimates that 16 million people, 5.9% of the U.S. population, currently has some type of diabetes.StemCellsandDiabetesHowardHughesMedicalInstitute干细胞与糖尿病霍华德休斯医学研究所What is diabetes?ngroup of diseasesnabnormally high levels of glucose in the bloodnpossible complications include blindness, stroke, kidney failure, heart disease, poor circulation, and amputationStemCellsandDiabetesHowardHughesMedicalInstitute干细胞与糖尿病霍华德休斯医学研究所Type 1 Diabetesnjuvenile-onsetntypically affects children and young adultsnimmune system attacks and destroys beta cells ( cells) in the islets of Langerhans of the pancreas that normally produce insulinnglucose does not enter the cells and therefore accumulates in the bloodStemCellsandDiabetesHowardHughesMedicalInstitute干细胞与糖尿病霍华德休斯医学研究所Type 2 Diabetesnadult-onset diabetesntypically affects older, sedentary, and overweight individuals with a family history of diabetesnbody cannot use insulin effectivelyndue to insulin resistance, glucose accumulates in the bloodStemCellsandDiabetesHowardHughesMedicalInstitute干细胞与糖尿病霍华德休斯医学研究所Role of Pancreas in DiabetesStemCellsandDiabetesHowardHughesMedicalInstitute干细胞与糖尿病霍华德休斯医学研究所What is insulin?npeptide hormone nsynthesized within the cells of the islets of Langerhans located in the pancreasnaffects metabolism and other body functionsncauses cells in the liver, muscle, and fat tissue to take up glucose from the bloodstreamStemCellsandDiabetesHowardHughesMedicalInstitute干细胞与糖尿病霍华德休斯医学研究所Role of Pancreas in DiabetesStemCellsandDiabetesHowardHughesMedicalInstitute干细胞与糖尿病霍华德休斯医学研究所Question:In type I diabetics, is it possible to get cells to produce insulin?ntwo possible sources of cells existing cells adult stem cellsStemCellsandDiabetesHowardHughesMedicalInstitute干细胞与糖尿病霍华德休斯医学研究所What are adult stem cells?They are:nundifferentiated cells that occur in differentiated tissue nable to make identical copies of themselves nable to yield specialized cell types of the tissue from which they originatedndo not replicate indefinitely in cultureStemCellsandDiabetesHowardHughesMedicalInstitute干细胞与糖尿病霍华德休斯医学研究所Researchers are Investigating:nIs it possible to activate the differentiation of adult stem cells present in the pancreas in order to produce needed insulin in type I diabetics?nWhat advantage/disadvantage would this have over organ/islet transplantation or insulin injection?StemCellsandDiabetesHowardHughesMedicalInstitute干细胞与糖尿病霍华德休斯医学研究所Researchers Would Need to Know:nAre there adult stem cells present in the pancreas that differentiate into beta cells?nAre adult pancreatic beta cells formed by self-duplication, stem cell differentiation, or a combination of the two processes?StemCellsandDiabetesHowardHughesMedicalInstitute干细胞与糖尿病霍华德休斯医学研究所Mouse-Model StudyA pulse-chase experiment performed by Professor Douglas Melton and his team provides important information about how beta cells are replaced. StemCellsandDiabetesHowardHughesMedicalInstitute干细胞与糖尿病霍华德休斯医学研究所Keep in mind that cells are replaced by:nAdult stem cellsnMitotic division of existing cellsnCombination of the two