Name: focal adhesions and cell mechanics
Uploaded: 2023-04-30T11:54:43.000Z
Duration: 1 min 13 s
Channel: JoVE

Le giunzioni cellula-matrice, come le aderenze focali, sono direttamente collegate a una rete di proteine contrattili come l'actina e la miosina.
Quando le forze meccaniche allontanano le giunzioni da una matrice extracellulare rigida, la cellula forma ulteriori aderenze focali per resistere alla tensione.
Una ECM più morbida genera meno resistenza, consentendo alla cellula di rispondere in base alla rigidità delle ECM nei diversi tessuti.
Tale meccanorilevamento dipende da proteine giunzionali come la talina e la fibronectina che cambiano la loro conformazione quando la giunzione viene allungata.
Quando i filamenti di actina vengono attirati dalla miosina, la talina si dispiega, esponendo i siti di legame della vinculina. La vinculina recluta ulteriori filamenti di actina per rafforzare la giunzione.
Sulla faccia della ECM, la tensione applicata su tutta la lunghezza della fibronectina durante l'assemblaggio della matrice di fibrille espone siti di legame nascosti per il collagene.
Il legame del collagene rafforza la giunzione consentendo alle cellule di rispondere alle forze meccaniche provenienti dai loro ambienti.

<ol>
	<li>Liu Z, Tan JL, Cohen DM, Yang MT, Sniadecki NJ, Ruiz SA, Nelson CM, Chen CS. La forza di trazione meccanica regola la dimensione delle giunzioni cellula-cellula. Atti dell'Accademia Nazionale delle Scienze. 1 giugno 2010; 107(22):9944-9.</li>
	<li>David G. Menter, Raymond N. DuBois, "Prostaglandine nell'adesione, migrazione e invasione delle cellule tumorali", International Journal of Cell Biology, vol. 2012, ID articolo 723419, 21 pagine, 2012. <a href="https://doi.org/10.1155/2012/723419">https://doi.org/10.1155/2012/723419</a></li>
	<li>Angulo-Urarte, A., van der Wal, T., & Huveneers, S. (2020). Giunzioni cellula-cella come sensori e trasduttori di forze meccaniche. Biochimica et Biophysica Acta (BBA)-Biomembranes, 1862(9), 183316.</li>
</ol>

risposta della matrice cellulare alle forze meccaniche

Cell-matrix's Response to Mechanical Forces

Nelle cellule animali, la matrice extracellulare consente alle cellule all'interno dei tessuti di resistere agli stress esterni e trasmette segnali dall'esterno della cellula all'interno. La matrice extracellulare è estesa e la sua composizione varia tra i diversi tipi di tessuti. Ad esempio, le fibre reticolari e la sostanza fondamentale costituiscono l’ECM nel tessuto connettivo lasso, mentre il collagene e i minerali ossei costituiscono l’ECM del tessuto osseo.

Le giunzioni di ancoraggio collegano meccanicamente una cellula alla matrice extracellulare o ad altre cellule. Un gruppo di giunzioni di ancoraggio forma complessi macromolecolari chiamati aderenze focali o FA. Gli FA regolano l'adesione cellulare e la meccanotrasduzione, che è la conversione di segnali meccanici in segnali chimici nella cellula. I FA si verificano comunemente sulle superfici laterali e basali delle cellule, fornendo connessioni forti e flessibili. Sono stati riconosciuti per la prima volta utilizzando un siero antitumorale nelle cellule renali di ratto trasformate dal virus del sarcoma di Rous. Tre proteine, talina, vinculina e tensina, e le loro isoforme, collegano le integrine al citoscheletro, rafforzando così la giunzione. I cambiamenti conformazionali dipendenti dalla tensione attivano talina e vinculina, suggerendo così il loro coinvolgimento nei segnali di meccanosensazione provenienti dal loro ambiente.

Adapted from section 4.2 Epithelial tissue- Anatomy and Physiology 2 e, Openstax

Risposta della matrice cellulare alle forze meccaniche

Nelle cellule animali, la matrice extracellulare consente alle cellule all'interno dei tessuti di resistere a stress esterni e trasmette segnali dall'esterno della cellula a ...

cell-matrix-s-response-to-mechanical-forces

Education

Didattica

JoVE Core

Cell Biology

Biologia cellulare

Unit 1

Unità 1

Cell-Matrix Interactions

Interazioni cellula-matrice

KEY TERMS AND CONCEPTS

TERMINI E CONCETTI CHIAVE

focal adhesions and cell mechanics

Focal adhesions help animal cells connect to the extracellular matrix and sense mechanical forces. The extracellular matrix, or ECM, sits outside cells and helps tissues withstand stress. It also sends signals from outside the cell to the inside.

The ECM is large and its makeup changes from one tissue to another. In loose connective tissue, reticular fibers and ground substance form the ECM. In bone tissue, collagen and bone minerals make up the ECM.

Anchoring junctions hold a cell to the extracellular matrix or to other cells. When many of these junctions cluster together, they form focal adhesions, or FAs. These structures support cell adhesion and mechanotransduction, which is the conversion of mechanical signals into chemical signals inside the cell.

Focal adhesions are often found on the lateral and basal surfaces of cells. This location gives cells strong but flexible connections. They were first recognized with an antitumor serum in Rous sarcoma virus-transformed rat kidney cells.

Several proteins connect integrins to the cytoskeleton and strengthen the junction. These proteins include talin, vinculin, and tensin, along with their isoforms. Tension can change the shape of talin and vinculin, which suggests that they help cells sense forces from their environment.

Focal Adhesions and Cell Mechanics

overview of cell-matrix interactions

ECM Proteins and Cell Signaling

The extracellular matrix, or ECM, is the material that helps hold cells together in a tissue. It also lets cells in that tissue communicate with one another. The ECM contains proteins such as fibronectin, collagen, and laminin. Collagen is the most abundant protein in this space. Collagen fibers are woven together with proteoglycans, which are protein molecules with carbohydrates attached. This mix gives the ECM its structure. It also supports cell migration and provides a scaffold for cell...

integrins

Integrins in Cell Adhesion

Integrins help animal and protozoan cells attach to the extracellular matrix, or ECM. These cells do not have cell walls, so the ECM helps maintain shape and provide structural stability. The ECM is a sticky network of carbohydrates and proteins found between adjacent cells. Some ECM proteins form a basement membrane, and other ECM parts adhere to it. Proteoglycans make up much of the ECM, while fibrous proteins such as collagen give it strength. Fibronectin connects proteoglycans and collagen...

activation of integrins

How Integrins Link Cells to Their Environment

Integrins help cells connect with their environment and send signals across the cell membrane. They can carry information from outside the cell to the inside, or from inside the cell to the outside. These two paths are called outside-in signaling and inside-out signaling. In outside-in signaling, molecules in the extracellular space bind to exposed ligand-binding sites on integrins. A ligand is a molecule that binds to a protein. This binding makes the inactive integrin change shape and become...

intracellular signaling affects focal adhesions

intracellular-signaling-affects-focal-adhesions

Integrins Trigger Focal Adhesion Signaling

Integrins trigger focal adhesion signaling at the cell membrane. These membrane receptors sit in the phospholipid bilayer with hydrophobic regions that match the membrane interior. They provide attachment sites for outside signals such as hormones and growth factors. When these effectors bind and become active, integrins can start response pathways inside the cell. Some integrin-driven pathways support cell growth and help cells survive. The signal begins at the membrane, but G-proteins and...

anchoring junctions

Cell Adhesion in Anchoring Junctions

Anchoring junctions are multiprotein complexes that help cells connect to other cells and to the extracellular matrix. They sit on the lateral and basal surfaces of cells. These junctions create strong, flexible links that help maintain tissue stability and integrity. Focal adhesions often form when cells interact with the extracellular matrix, or ECM, substrata. These contacts can start signal transduction through kinase cascades and other pathways. Together, these junctions help cells stay...

cell-matrix's response to mechanical forces

Focal adhesions help animal cells connect to the extracellular matrix and sense mechanical forces. The extracellular matrix, or ECM, sits outside cells and helps tissues withstand stress. It also sends signals from outside the cell to the inside. The ECM is large and its makeup changes from one tissue to another. In loose connective tissue, reticular fibers and ground substance form the ECM. In bone tissue, collagen and bone minerals make up the ECM. Anchoring junctions hold a cell to the...

key terms and concepts

Learn how focal adhesions connect animal cells to the extracellular matrix, support adhesion, and convert mechanical signals into chemical signals.

Focal Adhesions and Cell Mechanics | JoVE K12

cell biology

JoVE Core Cell Biology illustrates complex cellular processes in easy-to-understand yet comprehensive animated video lessons. This collection focuses on the essential components and functions of cells, including organelles and membranes, cellular transport, and cell energetics. It is complemented by scientist-in-action videos that demonstrate the application of cell biology in real-world research experiments.

Focal Adhesions and Cell Mechanics

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