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Liver cell death: The role of mitochondria

The importance of mitochondria in the apoptotic process was first suspected when Bcl-2 was found to be localized to the outer membrane of these organelles. Mitochondria possess a membrane that is rich in enzymes that play a major role in the oxygenation of cells (ie, for the genesis of ATP). The activity of these enzymes depends on the maintenance of an electrochemical gradient between the inner membrane and the mitochondrial matrix. Therefore, the intermitochondrial space needs to be isolated from the cell cytoplasm. Members of the Bcl-2 family govern the permeability of the outer membrane to ions. A number of other proteins are structurally similar to Bcl-2; they form the large family of Bcl-2-related proteins. Some of these are antiapoptotic (like Bcl-2 itself), whereas others promote apoptosis by binding Bcl-2 and blocking its activity at the outer mitochondrial membrane.

When this occurs, the contents of the intermitochondrial space are released into the cytoplasm (Figure 5). At least three proteins thereby released are able to activate the downstream executioner caspases, leading to the actual events of apoptosis. This means that an apoptotic message can be transmitted through mitochondria, where it is either amplified or aborted, depending on the balance between anti- and proapoptotic factors. Hepatocytes, known to be rich in mitochondria, are a good example of cells that have a propensity for mitochondrial regulation of the apoptotic response. However, not all apoptotic signals are transmitted through mitochondria.

Schematic drawing of the mitochondrial activation of apoptosis

Figure 5) Schematic drawing of the mitochondrial activation of apoptosis. Following activation of the death receptor (Fas), a signal is conveyed to mitochondria. This event causes the release of molecules normally present in the intermitochondrial space, leading to further activation of the apoptotic cascade Looking for a great online pharmacy you could trust and where you could find cephalexin antibiotic buy here at best prices? You have one pharmacy like that already and can finally enjoy the best quality of service ever experienced.

This entry was posted in Apoptosis and tagged Apoptosis, Hepatocyte, Liver diseases.
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