Stem Cells and Regenerative Medicine - Vocabulary Flashcards

A vocabulary-focused set of flashcards covering core stem cell biology concepts, major cell types, regulatory mechanisms, techniques, and regenerative medicine applications derived from the lecture notes.

Stem cells

Primitive, undifferentiated cells with the ability to self-renew and differentiate into multiple cell types, serving as a repair system during development, maintenance, and regeneration.

Self-renewal

The ability of stem cells to divide and produce identical copies while maintaining stem cell identity.

Potency

The potential of a stem cell to differentiate into different cell types, depending on its category.

Totipotent

Can form all cell types, including extraembryonic tissues (e.g., placenta); example: zygote.

Pluripotent

Can form all cell types from the three germ layers but not extraembryonic tissues; example: embryonic stem cells (ESCs).

Multipotent

Can form multiple, but limited, cell types within a lineage; example: hematopoietic stem cells (HSCs).

Unipotent

Can form only one specific cell type, but may retain self-renewal capacity.

Embryonic Stem Cells (ESCs)

Pluripotent stem cells derived from the inner cell mass of the blastocyst, capable of unlimited self-renewal in vitro.

Inner cell mass (ICM)

Cell mass inside the blastocyst that gives rise to ESCs.

Blastocyst

Early-stage embryo (about 4–5 days after fertilization) from which ESCs can be derived.

Induced Pluripotent Stem Cells (iPSCs)

Somatic cells genetically reprogrammed to a pluripotent state, similar to ESCs.

Yamanaka factors

The four transcription factors (Oct4, Sox2, Klf4, c-Myc) used to reprogram somatic cells to iPSCs.

Oct4

Core transcription factor that maintains pluripotency and represses differentiation.

Sox2

Transcription factor that works with Oct4 to regulate stem cell genes and maintain pluripotency.

Nanog

Transcription factor essential for maintaining the undifferentiated state of pluripotent cells.

Klf4

Reprogramming factor that modulates proliferation and contributes to reprogramming efficiency.

c-Myc

Reprogramming factor that promotes cell cycle progression; its exclusion can reduce tumor risk.

LIF/STAT3

Signaling axis that helps maintain pluripotency in mouse ESCs.

FGF2

Growth factor that supports pluripotency and self-renewal in human ESCs.

Activin/Nodal

Signaling pathway that reinforces pluripotency in human ESCs.

BMP

Signaling molecule that cooperates with LIF to support certain ESC self-renewal contexts.

Stem cell niche

Specialized microenvironment regulating self-renewal, quiescence, and differentiation.

Niche components

Supporting cells, extracellular matrix (ECM), soluble factors, and intrinsic/extrinsic signals that govern stem cell fate.

Feeder layers

Supportive cell layers (e.g., mouse embryonic fibroblasts) used to maintain pluripotent stem cells.

Teratoma formation

In vivo test for pluripotency where undifferentiated pluripotent cells form a teratoma containing multiple tissue types.

Directed differentiation

Protocol-based induction of stem cells to differentiate into specific lineages by stage-specific signals.

Ethics: 14-day rule

Regulatory guideline restricting culture of human embryos beyond 14 days in research.

iPSCs advantages

Eliminate embryo destruction and enable patient-specific disease modeling and therapies.

Hematopoietic Stem Cells (HSCs)

Multipotent stem cells that differentiate into all blood cell lineages; source: bone marrow, blood, cord blood.

Mesenchymal Stem Cells (MSCs)

Multipotent stromal cells with immunomodulatory properties; sources include bone marrow and adipose tissue.

Neural Stem Cells (NSCs)

Stem cells in neural niches that generate neurons, astrocytes, and oligodendrocytes.

Epithelial stem cells

Stem cells in skin, cornea, and intestine involved in renewal and repair.

Muscle satellite cells

Adult stem cells that repair and regenerate skeletal muscle.

Intestinal stem cells

Stem cells in intestinal crypts responsible for renewing the intestinal lining.

CD34

Surface marker used to identify and isolate hematopoietic stem cells by FACS.

FACS

Fluorescence-Activated Cell Sorting; high-speed cell sorting based on fluorescent markers.

MACS

Magnetic-Activated Cell Sorting; magnetic beads used to enrich target cells.

2D vs 3D cultures

2D: flat culture; 3D: scaffolds/organoids that better mimic tissue architecture and interactions.

Organoids

Self-organizing 3D cell cultures that recapitulate key features of real organs.

Organoid biobanks

Repositories of organoids from diverse individuals for research and drug screening.

CRISPR/Cas9

Gene-editing tool used to modify stem cells for disease modeling and therapy.

Direct reprogramming (transdifferentiation)

Converting one somatic cell type directly into another without a pluripotent intermediate.

In vivo reprogramming

Inducing reprogramming/regeneration within the living organism rather than in culture.

Synthetic biology in stem cells

Engineering stem cells with genetic circuits to control behavior and safety.

Omics

Comprehensive molecular profiling areas: genomics, transcriptomics, proteomics, epigenomics, metabolomics.

scRNA-seq

Single-cell RNA sequencing to analyze gene expression in individual cells and reveal heterogeneity.

Organoid vascularization

Incorporating blood vessels into organoids to improve growth and function.

Personalized regenerative medicine

Tailoring therapies using patient-specific iPSCs and gene editing for individual needs.

Stem cell tourism

Movement to obtain unproven, often unsafe stem cell therapies abroad.

Cancer stem cells (CSCs)

Subpopulation of tumor cells with self-renewal and tumor-initiating capacity driving relapse.

CSC hypothesis

Only CSCs, not bulk tumor cells, sustain tumor growth and recurrence.

Aging and stem cells

Aging impairs stem cell function (e.g., HSC skewing, NSC decline), reducing regenerative capacity.

Organoids in disease models

Organoids used to model diseases, test drugs, and study development in a controlled setting.