Thread by @NewHarvestOrg

We will be tweeting live again about today's session @CellAgOS!

Learn more how Prof. Masatoshi Suzuki's of @UWMadison applies #iPSCs for #culturedmeat production - starting in 30min at caos.community/live.

Today's tweets come to you from: @tobiasmess

#CAOS2020

Masa is a GFI grantee and is presenting the work of his GFI grant project: Engineered skeletal muscle from human induced pluripotent stem cells!

Muscle progenitors cells can not only be derived from the skeletal muscle but also from re-programmed somatic cells - or: iPSCs!

His talk will cover a quick dive into the background of muscle stem cell and iPSC biology, the derivation of myogenic progenitor cells from human iPSCs and his finally his GFI project: Cell-based meat production using plant-based tissue scaffolds.

There are a few types of stems cells in skeletal muscle: Satellite cells, Mesoangioblasts, pericytes and mesenchymal stem cells. While being multi-potent, they do have one important limitation: they lose their proliferation capacity quite quickly.

This is where induced pluripotent stem cells (iPSCs) are coming in place. They can divide limitlessly and differentiate into various cell types including cardiomyocytes, hepatocytes, neutrons but also: Skeletal muscle cells (wooho)!

Traditionally, human iPSCs have been used for disease modelling: Overexpression of myogenic transcription factors will help differentiate them towards muscle cells; and making them a nice model for diseases such as Duchenne Muscular Dystrophy (DMD).

You can also achieve myogenic differentiation of human iPSCs completely transgene-free by only using small molecules - no genetic modification needed!

Second part of his talk: A sphere-based culture enables the generation of myogenic progenitors directly from human iPSCs in an expansion medium (Stemline + EGF + FGF-2) and a 2-week terminal differentiation medium (DMEM +2% B27 supplement).

When terminally differentiation, those cells express MyoD, MyoG, MYH and other canonical muscle markers. Eventually, they even fuse and form nice myotubes, baby!

From 2D patterning to 3D muscle tissue tissue formation: Micro-patterning on PDMS slides increases the fusion index, average myotube diameter and striation as it helps the forming myocytes to align during maturation. These iPSC-derived myotubes even contract spontaneously!

However, 2D muscles are not very useful, are they? So let's check out the model of 3D bioartificial muscle organoids (BAM): Growing between two opposing velcro anchors, these muscle bundles can be assessed by measuring their contractile force or mechanical loading.

Now let's talk cell-based meat though! How do we apply this iPSC-derived 3D muscle model to make a tasty edible product?

The sphere-based culture protocol from HUMAN iPSCs can be applied to BOVINE muscle stem cells! These satellite cells (which usually only grow attached to a surface) now suddenly grow in suspension!

Decellularized tissues (by perfusion and detachment of cells from their surrounding extracellular matrix) can serve as a scaffold for these bovine muscle stem cells: For example spinach (not only tasty but will also make you strong! yeah)

Using these decellularized leaves, also hIPCs were able to differentiate into MHC-expressing myotubes!
What an exciting and grand prospect!

That's it for today!

Thanks for tuning in and join us for the next #CAOS session next Tuesday with Dr. Yuki Hanyu (@shojinmeat).

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