What is the Human Cell Atlas (HCA)?
It is an ambitious project by global Scientists to map every single cell in the human body
Cells are the basic building blocks of any living organism. Counting cells in a human body is synonymous with counting the stars in the night sky. According to recent estimates by the researchers, there are an estimated 37.2 trillion cells in a human body— the figure only included the human cells and not all the microbes that reside in our body. The estimate was drawn based on the volume and density of cells in gallbladders, knee joints, intestines, bone marrow, and many other tissues.
The human body is basically an amalgamation of collaborative cellular activity. While we have a basic understanding of the functionality of different organs in our body, much needs to be learned about what happens at the cellular level. To better understand the inner workings of these individual cells, an international collaborative venture has been undertaken by National Institutes of Health (NIH).
It is perhaps one of the biggest & most ambitious endeavors ever since the Human Genome project — another international collaboration under the guidance of the U.S Department of Energy and the National Institutes of Health (NIH). They set out to sequence all 3 billion chemical base pairs in the human genome which are the complete set of DNA in the human body.
Started out in 1990 with a 15-year timeline, thanks to the rapid technological advancements, it was completed in the Spring of 2003, marking one of the biggest breakthroughs of our times in the healthcare industry.
The current Human Cell Atlas (HCA) started out in 2016 with a team collaborative community of 90 world-leading scientists. Just like a normal Atlas maps geographical areas, the HCA would provide us with a richer understanding of the life’s fundamental building blocks — the project would mark each cell with a unique identifier, provide a three-dimensional map of how individual cells function to form tissues & how different bodily systems are connected via these cells and how changes in them affect our health.
The global effort has now expanded to involve 1500 scientists from 65 countries with support from organizations like Wellcome Trust and the European Union’s Horizons 2020 program. Various teams are mapping the cells from different areas of the human body. The United States' contribution to the project comes in the shape of the Human BioMolecular Atlas Program (HuBMAP).
The NIH will spend about $200 million on HuBMAP over 8 years, of which $54 million has been awarded to 120 researchers for the next 4 years. Three different teams have been assigned to study different aspects. The first group will study the cells in detail gathering detailed information on proteins, DNA modifications, lipids, RNA using latest techniques.
The second group will develop computer tools to present the data in a meaningful way, while the third group will be working on developing better technologies to study the cells. Completion of the first few maps of the HCA project are already underway.
A recent study from Newcastle University, published in the journal Nature, mapped 140,000 liver cells as they developed in human fetuses between the age of 7 to 17 weeks. Another research paper published by the University of Edinburgh mapped the cells involved in forming scar tissue in the liver. Data from both these papers will be used to develop the Atlas.
The development of a Human Cell Atlas is a truly revolutionary development that can fundamentally change our understanding of biology & medicine. The day is not far-off when we can see the “Google map” of the cellular details of our body.