stem cells

Question 1

why are they special

Answer 1

develope into many cell types

Question 2

internal repair system

Answer 2

dividing to replenish lost, defective, sick cells

Question 3

define stem cells

Answer 3

Unspecialized Cells, capable of renewal, even after long periods of inactivity

Question 4

adult stem cells environment

Answer 4

stem cell niche

Question 5

under specific physiologic or experimental conditions

Answer 5

induced to become tissue- or organ-specific cells with special functions

Question 6

to be a stem cell it must be a

Answer 6

clonogenic cell (ability of a single cell to grow into a colony of cells)

Question 7

clonogenic cell survival assay determines what

Answer 7

ability of acellto proliferate indefinitely, thereby retaining its reproductive ability to form a large colony or a clone. Thiscellis then said to beclonogenic

Question 8

to be a stem cell must be

Answer 8

1. clonogenuc
2. differentiation into atleast 1 differentiated cell type
   self renewing

Question 9

multipotency of adult stem cells

Answer 9

that adult mesenchymal stem cells (MSCs) can differentiate into different cell types

Question 10

stem cell classification

Answer 10

totipotent
pluripotent
multipotent
oligopotent
unipotent

Question 11

totipotent

Answer 11

embroonic stem cells - zygotes

Can give rise to all cell types, including both embryonic and extra-embryonic tissues (e.g., placenta).
The zygote (fertilized egg) is a classic example of a totipotent stem cell.

Question 12

pluripotent

Answer 12

embroyonic stem cells- iPSC
differentiate into cells from any of the three germ layers

Can differentiate into nearly all cell types but cannot form extra-embryonic tissues.
Examples include embryonic stem cells and induced pluripotent stem cells.
‘intra-embryonic structures’. Early in embryonic development, these stem cells separate to become the endoderm, mesoderm or ectoderm layers of the blastocyst.
The cells are no longer pluripotent and don’t transdifferentiate into cells of the other two lineages.

Question 13

multipotent

Answer 13

adult stem cells- mesynchymal and hemapooietic
differentiate into limited numver cell tyoes
Examples include hematopoietic stem cells (which can form various blood cells) and neural stem cells (which can become different types of neural cells).
round 15 days into embryonic development, the multipotent stem cells in each germline lineage begin to differentiate into more specialised lineages. They can still differentiate into multiple cell types. The options diverge at forks that occur at different times in natural development. Once the multipotent stem cells pass a certain fork, they belong to a more specialised lineage. They are still multipotent, but within the new lineage that will fork again later.

Question 14

oligopotent

Answer 14

adult stem cells- lymphoid and myeloid
Can differentiate into a few cell types, often within a specific tissue or organ.
Examples include lymphoid and myeloid stem cells in the blood.

Question 15

unipotent

Answer 15

adult stem cells- satilite and epidermal
single cell types
self-renewal capability.
An example is the muscle stem cell (satellite cell), which can only form muscle cells.
s have distinct properties and reside in a niche in a specific tissue. They carry markers that define the lineage from which they arose. They can still proliferate extensively. They can no longer differentiate into even two cell types (no multipotency). Also called committed progenitor cells, they proceed to generate a particular mature cell when the cues to differentiate are present in their niche. In skeletal muscle the progenitor cells are the satellite cells.

Question 16

progenitor cells

Answer 16

are descendants ofstem cellsthat then further differentiate to create specializedcelltypes.
They are more specialized than stem cells
There are many types ofprogenitor cellsthroughout the human body
Eachprogenitor cellis only capable of differentiating intocellsthat belong to the same tissue or organ

Question 17

adult blood stem cells- multipotent hematopoeietic stem cell

Answer 17

common lymphoid progenitor
myeloid progenitor

Question 18

common myeloid progenitor cells can differentiate into

Answer 18

megakaryocyte
erythrocyte
mastcell
myeloblast
- basophil
- neutrophil
-eosinophil
- monocyte- macrophage

Question 19

common lymphoid progenitor cell can differentiate into

Answer 19

Natural killer cell- large granular lymphocyte
small lymphocyte
- T lymphocyte
-B lymphocye- plasma cell

Question 20

phases of stem cells

Answer 20

stemness
potency
terminal differentiation
senscence

Question 21

stem cell can either

Answer 21

self renew
progenitor

Question 22

progenitor can become

Answer 22

immature precursor

Question 23

immature precursor becomes

Answer 23

differentiated

Question 24

telomere shortening during aginsg leads to

Answer 24

cellular senscence

Question 25

telomeres are found

Answer 25

ends of chromosomes\ repetitive nucleotide sequences at each end of a chromosome, which protects the end of the chromosome from deterioration or from fusion with neighboring chromosomes

Question 26

downside of telomere shortening

Answer 26

limits stem cell function, regeneration, and organ maintenance during ageing

Question 27

telomere shortening during aging and disease associated with

Answer 27

inreasing risk of cancer

Question 28

stem cell types

Answer 28

Embryonic Stem Cells Adult Stem Cells (mesenchymal stem cells, haemopoietic stem cells, myeloid stem cells, satellite stem cells, epidermal stem cells) Induced Pluripotent Stem Cells (iPSCs)

Question 29

name 5 differences between adult and embroyonic stem cell

Answer 29

adult mutipotent, oligopotent and unipotent - rare population derived from adult tissues differentiate into ;limmited types of progenitors and terminally differentiated cells autologous cells mount low immune responce embroyonic - pluripotent - derived from inner cell mass of blastocyst - differentiate into cells of three germ layers - devlopment - mount an immune response

Question 30

embroyonic stem cells

Answer 30

Can proliferate/renew indefinitely Pluripotent Due to their ability to maintain their telomeres intact This is in contrast to normal cells where telomeres shorten during successive cell divisions Ethical issues

Question 31

bone marrow stem cells- 2 main types

Answer 31

Hematopoietic stem cells (differentiate into white & red blood cells, and platelets) 2) Mesenchymal stem cells: can differentiate into osteoblasts, osteoclasts, adipocytes and chondrocytes a population of non-hematopoietic cells described in the bone marrow, adipose tissue, liver, amniotic fluid, embryonic placenta, umbilical cord blood, and other tissues

Question 32

BM MSC differentiate into

Answer 32

bone marrow mesynchymal cells - adipocyetes chondrocytes osteoblasts myocytes keratinocytes

Question 33

HSC found in

Answer 33

haemopoietic stem cells - endosteal region and near blood vessels in bone marrow

Question 34

different populations in bone marrow stem cells

Answer 34

Long-term hematopoietic stem cells Short-term hematopoietic stem cells Multi-potent progenitor cells

Question 35

bone marrow stem cells where. and what can they treat

Answer 35

between bone marrow itself and blood transplant- blood diseases- leukemia

Question 36

MSC- where found, role

Answer 36

all tissues homeostasis and rrepair during disease regenerative medicine

Question 37

why use MSC

Answer 37

Easily culture in vivo High proliferation rates Can become many cell types: e.g. Osteoblasts, Chondrocytes, Adipocytes, Hepatocytes, Neurons and glial cells

Question 38

MSC can differentiate into specialised cells of

Answer 38

skeletal tissue - adipocyte chondrocyte osteocyte

Question 39

stem cell niche or environment play role in

Answer 39

maintaining stem cells or preventing tumorigenesis by providing primarily inhibitory signals for both proliferation and differentiation

Question 40

loss of niche leads to

Answer 40

loss of stem cells indicating reliance of stem cells on niche signalling

Question 41

cancer stem cells may arise from

Answer 41

intrinsic mutation leading to self sufficiant cell prolifferation involve deregulation or alteration of niche by dominant proliferation promotind signals molecular machinery used by normal stem cells for homing to or mobilizing from the niche may be "hijacked" by cancer stem cells for invasion and metastasis

Question 42

stem cell niche defiition

Answer 42

the in vivo microenvironment where stem cells both reside and receive stimuli that determine their fate Therefore, the niche should not be considered simply a physical location for stem cells, rather as the place where extrinsic signals interact and integrate to influence stem cell behavior

Question 43

similarity of normal stem cells in adult somatic tissue and cancer stem cels

Answer 43

self renewal and slow cycling Mutations in stem/progenitor cells most likely undergo uncontrolled proliferation (i.e. lead to malignancy)

Question 44

difference between normal stem cells and cancer stem cells

Answer 44

degree of dependence of stem cell niche cancer cells modulate their extracellular environment

Question 45

why do bone barrow transplants fail

Answer 45

- presence of immune regulatory T cells While regulatory T-cells play a protective role in preventing GVHD, their presence in high numbers or in a dysfunctional state can lead to transplant failures due to inadequate immune reconstitution, inhibition of antitumor responses, and impaired HSC engraftment. Balancing Treg activity post-transplant is critical for promoting successful outcomes and preventing complications. Therefore, understanding the dynamics of Tregs and their functional state in the context of bone marrow transplantation is essential for optimizing treatment protocols and improving patient outcomes.