Jyotsna Dhawan, a scientist talks about her research on quiet proteins which could have implications for therapeutic treatment of age and disease related muscle degeneration.
“I have a friend who says that in science, what usually precedes a discovery is not ‘eureka’, but a ‘hmm that’s strange.’,” said Jyotsna Dhawan, a scientist at Centre for Cellular and Molecular Biology, a CSIR research establishment situated in Hyderabad. Some years back Dhawan and her team had a ‘hmm that’s strange’ moment while studying the role of a protein in mice. In their quest to demystify the ‘hmm’, they ended up making an important discovery that has brought science one step closer to therapy for age and disease related muscle degeneration.
“In a way, skeletal muscle is a wonderful tissue – so contractile and stretchy – but it’s also a very human tissue. It forms about 40% of our body mass and allows us to move, breathe, and even express emotions through the 72 muscles in our face,” started Dhawan, softly introducing me to her complex research. “But because it is used so often, it often needs replacement.” Luckily for us, we have a batch of reserve cells that our body kept aside exactly for this purpose. These are called muscle stem cells.
A crash-course in stem cells
The very first cell formed from the fusion of an egg cell and a sperm cell is called the zygote. The zygote grows and multiplies rapidly to form a hollow ball of cells called a blastocyst. From this early stage of the embryo, cells start becoming specialised or differentiated into different kinds of tissues. “What you end up with at birth is a fully functioning organism that has all these different tissues and around 200 cell types,” explained Dhawan. “Usually there’s no stopping once you set the ball of development rolling. It’s a linear process, one-way path… no returns.”
But what is fascinating is that not all cells differentiate. Take muscle development for example. “At birth, the whole muscle tissue includes thousands of muscle fibres but in between, there are also satellite cells or muscle stem cells.” Stem cells are kept aside in an undifferentiated state at some point late in embryonic development. “And it’s not a musical chairs scenario where these are the cells that failed to develop – there’s a specific programme that sets them aside and tells them they are not going to differentiate,” stressed Dhawan. These cells stay quiet until there is a need for replacement muscle cells due to wear-and-tear, injury, disease or ageing. During such times, these stem cells develop into muscle cells and cater to the demand.
Here’s a nice intro about cell differentiation and stem cells: