Utilizations Embryonic_stem_cell

1 utilizations

1.1 potential clinical use
1.2 human embryonic stem cells models of genetic disorders
1.3 repair of dna damage

utilizations
potential clinical use

according 2002 article in pnas, human embryonic stem cells have potential differentiate various cell types, and, thus, may useful source of cells transplantation or tissue engineering.

embryoid bodies 24 hours after formation.

current research focuses on differentiating es variety of cell types eventual use cell replacement therapies (crts). of cell types have or being developed include cardiomyocytes (cm), neurons, hepatocytes, bone marrow cells, islet cells , endothelial cells. however, derivation of such cell types ess not without obstacles , hence current research focused on overcoming these barriers. example, studies underway differentiate es in tissue specific cms , eradicate immature properties distinguish them adult cms.

besides in future becoming important alternative organ transplants, es being used in field of toxicology , cellular screens uncover new chemical entities (nces) can developed small molecule drugs. studies have shown cardiomyocytes derived es validated in vitro models test drug responses , predict toxicity profiles. es derived cardiomyocytes have been shown respond pharmacological stimuli , hence can used assess cardiotoxicity torsades de pointes.

es-derived hepatocytes useful models used in preclinical stages of drug discovery. however, development of hepatocytes es has proven challenging , hinders ability test drug metabolism. therefore, current research focusing on establishing functional es-derived hepatocytes stable phase , ii enzyme activity.

researchers have differentiated es dopamine-producing cells hope these neurons used in treatment of parkinson’s disease. recently, development of esc after somatic cell nuclear transfer (scnt) of olfactory ensheathing cells (oec s) healthy oocyte has been recommended neuro-degenerative diseases. ess have been differentiated natural killer (nk) cells , bone tissue. studies involving es underway provide alternative treatment diabetes. example, d’amour et al. able differentiate es insulin producing cells , researchers @ harvard university able produce large quantities of pancreatic beta cells es.

human embryonic stem cells models of genetic disorders

several new studies have started address issue. has been done either genetically manipulating cells, or more deriving diseased cell lines identified prenatal genetic diagnosis (pgd). approach may prove invaluable @ studying disorders such fragile-x syndrome, cystic fibrosis, , other genetic maladies have no reliable model system.

yury verlinsky, russian-american medical researcher specialized in embryo , cellular genetics (genetic cytology), developed prenatal diagnosis testing methods determine genetic , chromosomal disorders month , half earlier standard amniocentesis. techniques used many pregnant women , prospective parents, couples history of genetic abnormalities or woman on age of 35, when risk of genetically related disorders higher. in addition, allowing parents select embryo without genetic disorders, have potential of saving lives of siblings had similar disorders , diseases using cells disease free offspring.

scientists have discovered new technique deriving human embryonic stem cell (esc). normal esc lines different sources of embryonic material including morula , whole blastocysts have been established. these findings allows researchers construct esc lines embryos acquire different genetic abnormalities; therefore, allowing recognition of mechanisms in molecular level possibly blocked impede disease progression. esc lines originating embryos genetic , chromosomal abnormalities provide data necessary understand pathways of genetic defects.

a donor patient acquires 1 defective gene copy , 1 normal, , 1 of these 2 copies used reproduction. selecting egg cell derived embryonic stem cells have 2 normal copies, researchers can find variety of treatments various diseases. test theory dr. mclaughlin , several of colleagues looked @ whether parthenogenetic embryonic stem cells can used in mouse model has thalassemia intermedia. disease described inherited blood disorder in there lack of hemoglobin leading anemia. mouse model used, had 1 defective gene copy. embryonic stem cells unfertilized egg of diseased mice gathered , stem cells contained healthy hemoglobin genes identified. healthy embryonic stem cell lines converted cells transplanted carrier mice. after 5 weeks, test results transplant illustrated these carrier mice had normal blood cell count , hemoglobin levels.

repair of dna damage

differentiated somatic cells , es cells use different strategies dealing dna damage. instance, human foreskin fibroblasts, 1 type of somatic cell, use non-homologous end joining (nhej), error prone dna repair process, primary pathway repairing double-strand breaks (dsbs) during cell cycle stages. because of error-prone nature, nhej tends produce mutations in cell’s clonal descendants.

es cells use different strategy deal dsbs. because es cells give rise of cell types of organism including cells of germ line, mutations arising in es cells due faulty dna repair more serious problem in differentiated somatic cells. consequently, robust mechanisms needed in es cells repair dna damages accurately, , if repair fails, remove cells un-repaired dna damages. thus, mouse es cells predominantly use high fidelity homologous recombinational repair (hrr) repair dsbs. type of repair depends on interaction of 2 sister chromosomes formed during s phase , present during g2 phase of cell cycle. hrr can accurately repair dsbs in 1 sister chromosome using intact information other sister chromosome. cells in g1 phase of cell cycle (i.e. after metaphase/cell division prior next round of replication) have 1 copy of each chromosome (i.e. sister chromosomes aren’t present). mouse es cells lack g1 checkpoint , not undergo cell cycle arrest upon acquiring dna damage. rather undergo programmed cell death (apoptosis) in response dna damage. apoptosis can used fail-safe strategy remove cells un-repaired dna damages in order avoid mutation , progression cancer. consistent strategy, mouse es stem cells have mutation frequency 100-fold lower of isogenic mouse somatic cells.