Question

What factors affect affect development and differentiation of stem cells in tissue and organ development?

Answer 1

Stem cell developed in more specialized cell in the tissue and organ, in this process it undergoes a series of differentiation process. And a number of factor contribute to control how a new specific cell develop. These include cell shape (growth factor, cytokines), cell’s extracellular matrix, physical forces, mechanical forces, morphogenic factor and cell to cell contact.

Apart from this environmental factor also affect the cell differentiation.

1. Environmental factor- Any environment impact that can alter cell signaling, gene expression can alter cell differentiation. Like temperature influence the growth of cell in some organism. High temperature promote growth and low temperature reduce growth.
2. Drug and injury can differentiate the process as injury can affect gene expression and influence what type of cell need to be differentiated. Apart from this any infection can also affect this.

Internal factor of cell- Cell differentiate depending on which type of protein encoded in expressed gene. The different gene for different protein make a cell special to perform specific task. This different protein is key during cell division say- special protein gather at one end of cell and when cell divide, one daughter cell has more of this protein than another one and this cell become different type of cell because of the presence of different protein.

DNA transcription to mRNA occurs in such a way that produce certain protein at one end of the cell and specialized protein on other side. And cell division of this cell resulted in two different type of cell.

Cell signaling – It is the internal mechanism of the cell that influence the differentiation of pluri-potent cell. The requirement of kind of protein or cell in body is known to cell by cell-signaling. Cell continuously receive signals from surrounding and send signal regarding their activity. This signal effect cell differentiation.

Cell become sensitive to some chemical signal to which they have receptor on membrane. This receptor depends on the type of cell as what gene has expressed to them and this receptor activated and initiate differentiation. When a cell send a signal and this signal captured by the membrane of another surrounding cell trigger response in each cell this response cause to differentiate in specific way. For example- A Cell that is going to become part of epithelial cell emits chemical that trigger the receptor to nearby cell and all the cell in that region differentiate to become epithelial cell. As the epithelial tissue forms, further cell signaling trigger some other cell to differentiate into connective tissue.

Cell shape- Shape of cell plays key role in development. Change cell shape via binding of specific growth factor to receptor can switch cells between differentiation, apoptosis and discrete fate of growth.

Cell to cell contact- Cell to cell contact also plays key role as with stromal cell (connective tissue cell of organ) has shown to induce marked alteration in gene expression in stem cell and alter their proliferation. In the same way certain minimum density of cell required for adipogenic differentiation and smooth muscle differentiation from cortical stem cell.