The Surprising Discovery: Haemoglobin in Cartilage Cells

Haemoglobin has long been known as a vital component of red blood cells, responsible for carrying oxygen throughout our body. However, a recent study published in Nature has shed light on a new and unexpected role for haemoglobin. Chinese scientists have discovered that chondrocytes, the cells responsible for cartilage production, also produce and rely on haemoglobin for their survival.

‘Haemoglobin bodies’ in Cartilage Cells

Dr. Feng Zhang, a pathologist at the Fourth Military Medical University in China, stumbled upon this intriguing phenomenon while studying bone development. During his research on growth plates, the cartilaginous tissue at the ends of long bones, he noticed spherical structures resembling red blood cells. These structures, which he called haemoglobin bodies or ‘Hedy’, were found to contain haemoglobin.

In collaboration with Dr. Quiang Sun from the Beijing Institute of Biotechnology, advanced microscopy techniques were used to investigate the haemoglobin bodies further. Similar to oil separating into globules in water, the chondrocytes in cartilage exhibited phase separation, resulting in the formation of large haemoglobin blobs without a membrane.

The Importance of Haemoglobin in Cartilage Cells

The scientists sought to determine the functionality of these haemoglobin bodies. To do so, they conducted experiments using genetically modified mice that lacked the gene responsible for haemoglobin production. These mice showed a severe deficiency in haemoglobin and died as embryos. Additionally, when the gene was specifically removed in the cartilage tissue, the chondrocytes experienced cell death. This indicated that haemoglobin is essential for the survival of chondrocytes.

In red blood cells, haemoglobin carries and delivers oxygen to various parts of the body. The researchers hypothesized that haemoglobin in chondrocytes might also function in oxygen transport. They found that chondrocytes lacking haemoglobin exhibited signs of low oxygen or hypoxic stress. This led them to believe that the haemoglobin in chondrocytes likely stored oxygen and supplied it to the cells when needed.

Haemoglobin’s Role in Joint Diseases and Beyond

This groundbreaking discovery bridges the fields of haematology and skeletal biology, revealing their interconnectedness. It opens up new possibilities for understanding the mechanisms underlying joint diseases and bone deformities. Defects in chondrocytes can lead to various bone deformities, and this study suggests that abnormalities in chondrocyte haemoglobin may contribute to increased cell death in certain conditions.

The findings also raise interesting questions about the role of haemoglobin in other regions of cartilage, such as the ribs or spine. Further research is needed to determine if haemoglobin plays a similar role in these areas.

Fun Fact: Haemoglobin in Unexpected Places

The discovery that chondrocytes produce functional haemoglobin highlights the complexity of the human body. It showcases how even well-established scientific understanding can be challenged and expanded by new discoveries.

Conclusion

The serendipitous discovery of haemoglobin in cartilage cells has unveiled an unexpected function of this important molecule. Chondrocytes, the cells responsible for producing cartilage, rely on haemoglobin for survival. This finding not only offers insights into the mechanisms of joint diseases but also emphasizes the interconnectedness of different biological processes within our bodies. Through ongoing research, scientists hope to uncover further roles and effects of haemoglobin in various tissues and cells.

Mutiple Choice Questions

1. What is the main function of haemoglobin in red blood cells (RBCs)?
a) It makes blood red
b) It carries oxygen
c) It makes RBCs survive
d) It connects tissue between bones

Explanation: Haemoglobin in red blood cells carries oxygen to different parts of the body to ensure proper functioning.

2. Which type of cells other than red blood cells produce haemoglobin according to the study?
a) Nerve cells
b) Liver cells
c) Chondrocytes
d) Skin cells

Explanation: The study reveals that chondrocytes, which make cartilage, also produce haemoglobin.

3. What are the spherical blob-like structures containing haemoglobin called?
a) Erythrocytes
b) Haemoglobin bodies
c) Globules
d) Chondrocytes

Explanation: The scientists refer to the spherical blob-like structures containing haemoglobin as haemoglobin bodies or Hedy.

4. What happens to chondrocytes when the gene that makes haemoglobin is removed?
a) They become healthier
b) They start multiplying
c) They die
d) They grow larger

Explanation: When the gene that makes haemoglobin is removed, the chondrocytes start dying.

5. What did the experiments reveal about the role of haemoglobin in chondrocytes?
a) Haemoglobin carries oxygen in chondrocytes
b) Haemoglobin protects chondrocytes from stress
c) Haemoglobin helps in cell division
d) Haemoglobin regulates cell growth

Explanation: The experiments indicate that haemoglobin in chondrocytes carries oxygen and helps in overcoming low-oxygen conditions.

6. What did the researchers observe about the behavior of haemoglobin-free chondrocytes in a low-oxygen environment?
a) They release more oxygen
b) They adapt to the conditions
c) They become healthier
d) They die

Explanation: Haemoglobin-free chondrocytes started dying in a low-oxygen, or hypoxic, environment, confirming the importance of haemoglobin in their survival.

7. Where else in the body, apart from cartilage, was haemoglobin found according to the study?
a) Nerve cells
b) Muscle cells
c) RBCs
d) Ribs and spine

Explanation: The study found haemoglobin in cartilage outside of the growth plate, such as in the ribs and spine.

8. What did Gerard Karsenty, a professor studying skeletal biology, mention about the discovery?
a) It connects haematology and skeletal biology
b) It explains the mechanism of joint diseases
c) It changes the stem cells’ fate in the growth plate
d) It reveals more about cell death in joint diseases

Explanation: Gerard Karsenty states that the discovery breaks down barriers between haematology and skeletal biology, showing their connection.

9. How does the discovery of functional haemoglobin in cartilage contribute to understanding joint diseases?
a) It explains the cause of joint diseases
b) It reveals the role of chondrocytes in joint diseases
c) It helps interpret the mechanisms underlying joint diseases
d) It leads to the prevention of joint diseases

Explanation: The discovery of functional haemoglobin in cartilage opens up possibilities for understanding and interpreting the mechanisms of joint diseases.

10. Who made the discovery of functional haemoglobin in chondrocytes?
a) Noriaki Ono
b) Gerard Karsenty
c) Feng Zhang
d) Rohini Subrahmanyam

Explanation: The discovery of functional haemoglobin in chondrocytes was made by Dr. Zhang in collaboration with Quiang Sun.

Brief Summary | UPSC – IAS

Scientists have discovered that chondrocytes, the cells responsible for making cartilage, produce not only haemoglobin but also depend on it for survival. The team used advanced microscopy techniques and genetically modified mice to investigate the role of haemoglobin within chondrocytes, finding that it stores oxygen and releases it as necessary, maintaining normal cell function. Interestingly, the study also found haemoglobin in cartilage outside of the growth plate, such as in the ribs and spine. While the study opens up new possibilities for understanding joint diseases and the role of haemoglobin in the body, further research is needed to uncover the full scope of its functions.