The Desaturase Genes

[Luann]

I hope most of you know that the body can rearrange its composition of fatty acids, to a limited degree, starting with a PUFA and further removing hydrogens, or starting with a saturated acid and turning it into a MUFA. These are some studies on the desaturases' role in cancer cells, and how stopping the body's production of them can slow the growth of tumors in some cases.


Inhibition of Stearoyl-CoA Desaturase 1 Expression Induces CHOP-Dependent Cell Death in Human Cancer Cells
Inhibition of Stearoyl-CoA Desaturase 1 Expression Induces CHOP-Dependent Cell Death in Human Cancer Cells

Stearoyl CoA Desaturase (SCD) Facilitates Proliferation of Prostate Cancer Cells through Enhancement of Androgen Receptor Transactivation
Stearoyl CoA Desaturase (SCD) Facilitates Proliferation of Prostate Cancer Cells through Enhancement of Androgen Receptor Transactivation

Inhibition of fatty acid desaturation is detrimental to cancer cell survival in metabolically compromised environments
Inhibition of fatty acid desaturation is detrimental to cancer cell survival in metabolically compromised environments

Cancer Cell Dependence on Unsaturated Fatty Acids Implicates Stearoyl-CoA Desaturase as a Target for Cancer Therapy
Cancer Cell Dependence on Unsaturated Fatty Acids Implicates Stearoyl-CoA Desaturase as a Target for Cancer Therapy | Molecular Cancer Research

 

[Such_Saturation]

I think humans can't start from saturated fat

 

[Luann]

Stearoyl-CoA desaturase-1 - Wikipedia

 

[Such_Saturation]

my bad

 

[Orion]

Stearoyl-CoA desaturase-1 - Wikipedia

Yep just listened to an interview where RP stated humans can turn SFA to PUFA. I am assuming he means to omega-9(Mead acid).

 

[Luann]

Yeah the Mead acid is the only fat that can be made in the body from a fat with less than one double carbon bond.

 

[lvysaur]

Stearoyl CoA Desaturase (SCD) Facilitates Proliferation of Prostate Cancer Cells through Enhancement of Androgen Receptor Transactivation

I love me some political incorrectness

 

[Luann]

What do you mean Ivysaur, what is politically incorrect about 'Androgen receptor'?

 

[lvysaur]

Politically incorrect in the context of the Ray Peat-sphere, where the androgenic response is sometimes seen as infallible.

 

[Luann]

Ah! Cool

 

[Luann]

Okay, some info on why the good effects of restricting methionine and iron are due to lipid metabolism.

Methionine is turned into cysteine, which binds iron to sulfur to make something called ferredoxin. Ferredoxin is needed for the delta-6 desaturase to turn UFA into even less saturated fat, by adding double carbon bonds to the chain. Adding cysteine to a diet low in methionine will reverse the good effects. So cysteine can be reduced to starve the delta-6.

Iron is needed for ferredoxin. Eating less iron also affects the amount of ferredoxin and thus the action of delta-6 desaturase. It seems that the harmful protein methionine, and iron, are bad partly due to their support of the desaturase enzymes, which weaken cells by adding double bonds.

And iron also assists in lipid oxidation, so there's that.

 

[Such_Saturation]

Okay, some info on why the good effects of restricting methionine and iron are due to lipid metabolism.

Methionine is turned into cysteine, which binds iron to sulfur to make something called ferredoxin. Ferredoxin is needed for the delta-6 desaturase to turn UFA into even less saturated fat, by adding double carbon bonds to the chain. Adding cysteine to a diet low in methionine will reverse the good effects. So cysteine can be reduced to starve the delta-6.

Iron is needed for ferredoxin. Eating less iron also affects the amount of ferredoxin and thus the action of delta-6 desaturase. It seems that the harmful protein methionine, and iron, are bad partly due to their support of the desaturase enzymes, which weaken cells by adding double bonds.

And iron also assists in lipid oxidation, so there's that.

 

[Luann]

Yeah the Mead acid is the only fat that can be made in the body from a fat with less than one double carbon bond.

I was wrong! Sebaleic acid, a lipid in human sebum, is made from a monounsaturated acid which is first made from a saturated fat! Humans can synthesize PUFA, but fortunately we only do it in the case of sebaleic acid.

Sebaleic will comprise about a quarter of sebum's weight at the most, so I don't know how much it contributes to the PUFA inside a person, especially since it winds up on your skin rather than inside you.