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Glycoaminoglycans (GAGs)

Unbranched polysaccharide chains with repeating disaccharide units, taking up space in ECM and attracting cations to provide turgor pressure.

Hyaluronan

GAG composed of non-sulfated repeats, resisting compressive forces in joints and acting as a space-filling molecule.

Proteoglycans

GAGs attached to core proteins, taking up space in ECM and providing turgor pressure.

Collagen

Rope-like fibrous protein forming helical structures, resisting stretching and compression to hold ECM together.

Elastin

Protein with random coils, providing structural integrity in tissues that stretch and relax frequently.

Fibronectin

Adhesive protein in ECM holding cells together and to other components.

Laminin

Multi-subunit protein forming basal lamina, acting as a filter and surrounding tissues in ECM.

Crystallins

Water-soluble proteins filling lens fibers in the eye for focusing light.

Photoreceptors

Neurons in the retina receiving light signals and transmitting them to the brain for visual perception.

Rhodopsin-transducin

Protein complex in photoreceptor cells activated by light, initiating a cascade of events for signal transmission.

Hepatocytes

Mature liver cells capable of regeneration, performing various functions like detoxification and protein production.

Liver regeneration

Process triggered by external signals, involving protease activation, growth factor binding, and cell cycle re-entry.

Endothelial cells

Cells lining blood vessels, forming a semi-permeable barrier with basal lamina and controlling molecule diffusion.

Pericytes

Cells associated with capillaries, regulating endothelial cell function through direct contact or paracrine signaling.

Capillaries

Help maintain homeostatic and hemostatic function within blood vessels, abundant at the blood-brain barrier, and clean up debris via phagocytosis.

Angiogenesis

The growth of new blood vessels, occurring after wound healing or tissue damage, involving the formation of capillary-like structures and signaling for blood supply.

Stem cells

Relatively undifferentiated cells capable of indefinite division and terminal differentiation, requiring a conducive environment for growth and connection to areas needing their products.

Keratinocytes

Cells in the epidermis filled with keratin, forming layers with different shapes and sizes as they move away from the basal layer.

Fibronectin

Multi-subunit protein with various binding sites in the extracellular matrix, forming disulfide bonds to hold subunits together.

Cell proliferation

Process occurring mainly in the basal layer of the epidermis, with different layers showing distinct characteristics and functions.

Gut stem cells

Stem cells located in the gut lining, hidden in crypts to avoid exposure to digestive juices, responsible for constant turnover and differentiation into various cell types.

Founder stem-cell population

Cells communicating to establish patterns in growing embryos, leading to the development of transit amplifying cells for tissue regeneration.

EphB/ephrinB

Proteins involved in signaling for cell segregation between crypts and villi in the gut lining, controlling cell division and differentiation.

EphB proteins

Proteins expressed by proliferative cells and Paneth cells in the gut, involved in repulsive cell-cell interactions to segregate cell classes.

ephrinB proteins

Proteins expressed by differentiated, nondividing cells covering the villi in the gut, involved in repulsive interactions with EphB proteins.

Paneth cells

Cells in the gut that, in a normal gut, remain confined to the bottoms of the crypts.

Megakaryocyte

Large cell in the bone marrow that produces platelets and has a highly polyploid nucleus.

Selectin

Transmembrane protein that mediates the slowing down of white blood cells during inflammation by binding to specific carbohydrates.

Integrins

Adhesive proteins that form a strong connection between cell surfaces, aiding in the migration of cells through endothelial cells.

Hemopoiesis

The process of blood cell production originating from a pluripotent stem cell.

Marrow stromal cells

Cells in the bone marrow that form connections with blood cell types during development and can differentiate into various cell types.

Colony-stimulating factors (CSFs)

Factors that stimulate the differentiation of stem cells into specific cell types based on signals from the bone marrow.

Satellite cells

Muscle stem cells that can fuse with existing muscle fibers to contribute to muscle growth and repair.

Muscle Cell Rupture

Muscles can rupture when contracting without resistance, leading to cell damage that requires repair or replacement.

MSC Migration

Mesenchymal stem cells (MSCs) can leave the bone marrow, travel through the bloodstream, and repair damaged muscle tissue.

Gene Modification Experiment

Used gene-modifying techniques to study MSC migration and repair by incorporating a reporter gene into a fertilized mouse egg.

Chondrocyte Differentiation

Cartilage cells differentiate into mature chondrocytes that secrete collagen type 2, distinguishing them from fibroblasts that secrete collagen type 1.

Adipocytes

Fat cells that store energy, provide insulation, and can be derived from fibroblast-like cell precursors.

Pref-1

Transmembrane protein involved in cell signaling, including alteration of gene expression during adipocyte differentiation.

Fibroblast-like Cell Precursor

Can be converted into mature fat cells through the accumulation of lipid droplets, with some reversibility indicated.

Leptin

Hormone produced by white fat cells that signals fullness to the brain, influencing weight regulation and fat accumulation.

Beta-Actin

Housekeeping gene used to assess gene expression changes related to fat metabolism in response to leptin injections.

Wound Healing Process

Involves hemostasis, inflammation, proliferation, and remodeling stages to repair damaged tissue.

Regeneration

The restoration or new growth of lost or injured organs or tissues without scarring, often involving multiple tissue types and functional restoration.

Blastema

Regenerating tissue characterized by rapid cell proliferation and de-differentiation, essential for tissue regrowth in organisms capable of regeneration.

Retinoblastoma Protein

Tumor suppressor gene that regulates cell proliferation by binding to gene regulatory proteins, deactivated by phosphorylation.

Retinoic Acid

Signaling molecule involved in tissue regeneration, such as in the growth and development of body parts in organisms like newts.

Regeneration in Newts

Newt arms can regenerate extra body parts like elbows and forearms when coated with retinoic acid, indicating the role of retinoic acid signals in regeneration.

Tissue Regeneration in MRL Mice

MRL mice show multiple tissue types, no scarring, and functional recovery after injuries, contrasting with control mice that exhibit scarring and slower tissue regrowth.

Basal Lamina in Regeneration

Basal lamina in MRL mice needs to be digested for damaged epithelium to regrow, allowing communication between cells and facilitating tissue regeneration.

Pref1 Gene in Regeneration

Pref1 gene expression is associated with stem cell proliferation and is higher in MRL mice, indicating its role in promoting cell growth during regeneration.

Proteases in Regeneration

MMPs in MRL mice tissue aid in ECM remodeling, providing space for cell growth and facilitating tissue regeneration.

Heart Regeneration in MRL Mice

MRL mice exhibit rapid heart regeneration with organized muscle fibers, while control mice show scar tissue formation and slower tissue repair after heart injuries.

Cardiomyocyte Regeneration

BrdU labeling confirms that regenerated cells in MRL mice hearts are cardiomyocytes, demonstrating successful regeneration of damaged heart tissue.

Functional Heart Regeneration

Echocardiograph shows that regenerated hearts in MRL mice are functional, with restored ventricular contraction and blood-pumping capabilities post-injury.

Collagen Remodeling in Heart Regeneration

MRL mice exhibit collagen production followed by remodeling, indicating a more effective wound repair process compared to control mice during heart regeneration.