Context:
A recent serendipitous discovery in a study published in Nature found that chondrocytes, which produce cartilage, also produce and rely on haemoglobin for their survival, revealing that haemoglobin isn’t exclusive to red blood cells (RBCs). Chondrocytes are the cells that make cartilage, the connecting tissue between bones.
Relevance:
GS II: Science and Technology
Dimensions of the Article:
- Haemoglobin Bodies or ‘Hedy’
- Significance of Haemoglobin in Chondrocytes
Haemoglobin Bodies or ‘Hedy’
Discovery of Haemoglobin Bodies:
- In 2017, while researching growth plates (cartilaginous tissue at the ends of certain long bones), a pathologist in China stumbled upon spherical structures that strikingly resembled red blood cells (RBCs) and contained haemoglobin.
- These structures, referred to as ‘haemoglobin bodies’ or ‘Hedy,’ were discovered within chondrocytes in the cartilage.
Formation of Haemoglobin Bodies:
- Haemoglobin bodies seemed to form within chondrocytes through a process similar to phase separation, akin to the separation of oil from water.
Potential Implications for Joint Diseases:
- The discovery of functional haemoglobin in cartilage raises the possibility that it may have a role in certain joint diseases, as bone deformities can result from defects in chondrocytes.
Insights into Stem Cells:
- In 2018, research revealed a special group of stem cells in the growth plate, sparking excitement about the potential implications of this discovery for stem cells in the growth plate.
- One intriguing idea is that haemoglobin in the growth plate could influence the fate or development of these stem cells.
Stem Cells:
- Stem cells serve as the body’s fundamental building blocks, giving rise to other cells with specialized functions.
- Under specific conditions, whether in the body or a laboratory, stem cells divide to generate daughter cells.
Significance of Haemoglobin in Chondrocytes
Essential for Chondrocyte Survival:
- Haemoglobin plays a crucial role in ensuring the survival of chondrocytes, which are responsible for forming cartilage.
- In experiments conducted on mice, it was observed that the absence of haemoglobin in chondrocytes led to the death of these cells, resulting in embryonic lethality in the mice.
Coping with Low Oxygen Levels:
- Haemoglobin is vital for helping chondrocytes cope with low oxygen levels, a condition known as hypoxia.
- It achieves this by facilitating the transport of oxygen within the chondrocytes. Without haemoglobin, chondrocytes are subjected to hypoxic stress, which impairs their normal functioning.
Oxygen Reservoir and Release:
- Haemoglobin serves as an oxygen reservoir within chondrocytes, storing oxygen and releasing it when needed.
- Without haemoglobin, chondrocytes are unable to maintain adequate oxygen levels, leading to their demise.
-Source: The Hindu
