Haemoglobin’s Surprising Role in Chondrocytes
An extra-erythrocyte role of haemoglobin body in chondrocyte hypoxia adaption
Haemoglobin, commonly known for carrying oxygen in red blood cells, has been discovered to play a significant role in chondrocytes, which are cells in cartilage. Chondrocytes produce large amounts of haemoglobin to create specialized structures called “haemoglobin bodies” (Hedy) within their cytoplasm. These bodies are unique as they don’t have membranes and are formed through a process called phase separation. Haemoglobin production in chondrocytes is influenced by low oxygen levels (hypoxia) and is regulated by a protein called KLF1, rather than the HIF1/2α pathway. Deleting haemoglobin in chondrocytes results in the loss of Hedy, severe hypoxia, increased glycolysis, and cell death in cartilage tissue’s central region. This study reveals a previously unknown function of haemoglobin in chondrocytes, offering insights into how these cells survive in low-oxygen environments through Hedy.
Zhang, F., Zhang, B., Wang, Y. et al. An extra-erythrocyte role of haemoglobin body in chondrocyte hypoxia adaption. Nature (2023). https://doi.org/10.1038/s41586-023-06611-6
