Expression of steroidogenic enzymes in human sebaceous glands.

[Armando Jose]

http://www.ncbi.nlm.nih.gov/pubmed/24938708
J Endocrinol. 2014 Jun 17. pii: JOE-14-0323. [Epub ahead of print]
[h=1]Expression of steroidogenic enzymes in human sebaceous glands.[/h]Inoue T1, Miki Y2, Kakuo S3, Hachiya A4, Kitahara T5, Aiba S6, Zouboulis CC7, Sasano H8.
[h=3]Author information[/h]

[h=3]Abstract[/h]Androgens are well known to influence sebum synthesis and secretion. Various factors related to androgen biosynthesis are expressed in human sebaceous glands. In our present study, immunohistochemical analysis of 43 human skin specimens demonstrated that various androgen producing- and metabolizing-enzymes were functionally localized in sebocytes accumulating lipid droplets and that the exclusive expression of 17β-HSD2 in sebaceous glands was negatively correlated with that of PPARγ , which also significantly changed in an age dependent manner. We also demonstrated that the changes of 17β-HSD2 expression in human immortalized sebocytes (SZ95) influenced on the expressions of sebogenesis-related factors. In addition, the overexpression of 17β-HSD2 in SZ95 significantly increased the androstendione production and markedly decreased the amounts of testosterone and dihydrotestosterone when dehydroepiandrosterone was externally added. On the other hand, the phosphorylation of mammalian target of rapamycin, which is well known to induce the sebum secretion and the onset and/or aggravation of acne, was increased by the addition of testosterone with the presence of IGF-1 in hamster sebocytes. These results all indicated that local androgen biosynthesis and metabolism in human sebaceous glands could play a pivotal role in sebum synthesis and secretion.


PMID: 24938708

 

[IDW2BB]

http://www.ncbi.nlm.nih.gov/pubmed/24938708
J Endocrinol. 2014 Jun 17. pii: JOE-14-0323. [Epub ahead of print]
[h=1]Expression of steroidogenic enzymes in human sebaceous glands.[/h]Inoue T1, Miki Y2, Kakuo S3, Hachiya A4, Kitahara T5, Aiba S6, Zouboulis CC7, Sasano H8.
[h=3]Author information[/h]

[h=3]Abstract[/h]Androgens are well known to influence sebum synthesis and secretion. Various factors related to androgen biosynthesis are expressed in human sebaceous glands. In our present study, immunohistochemical analysis of 43 human skin specimens demonstrated that various androgen producing- and metabolizing-enzymes were functionally localized in sebocytes accumulating lipid droplets and that the exclusive expression of 17β-HSD2 in sebaceous glands was negatively correlated with that of PPARγ , which also significantly changed in an age dependent manner. We also demonstrated that the changes of 17β-HSD2 expression in human immortalized sebocytes (SZ95) influenced on the expressions of sebogenesis-related factors. In addition, the overexpression of 17β-HSD2 in SZ95 significantly increased the androstendione production and markedly decreased the amounts of testosterone and dihydrotestosterone when dehydroepiandrosterone was externally added. On the other hand, the phosphorylation of mammalian target of rapamycin, which is well known to induce the sebum secretion and the onset and/or aggravation of acne, was increased by the addition of testosterone with the presence of IGF-1 in hamster sebocytes. These results all indicated that local androgen biosynthesis and metabolism in human sebaceous glands could play a pivotal role in sebum synthesis and secretion.


PMID: 24938708

Congratulations on some more confirmation for your theory! Because it is age dependent, I wonder the androgen level produced? No doubt that androgens are present.
Good find!

 

[Armando Jose]

Thank you IDW2BB for your support, this is a recent study,
There is some others, like this
http://journal.scconline.org/pdf/cc1969/cc020n09/p00565-p00575.pdf

Cosmetic Chemists, 20, 565-575 (Aug. 19, 1969)
The Etiology of Acne. I. Composition of Sebum Before and After Puberty

Reading the work we can think that prepubertals subjects have sebum even in the forehead and cheeks, a contravention of the current theory?

 

[Python]

Thank you IDW2BB for your support, this is a recent study,
There is some others, like this
http://journal.scconline.org/pdf/cc1969/cc020n09/p00565-p00575.pdf

Cosmetic Chemists, 20, 565-575 (Aug. 19, 1969)
The Etiology of Acne. I. Composition of Sebum Before and After Puberty

Reading the work we can think that prepubertals subjects have sebum even in the forehead and cheeks, a contravention of the current theory?

Im no expert, but I'm pretty sure 1969 doesn't qualify as recent

 

[Armando Jose]

the study is not recent, but the important question would be, is legit?
Because studies of Hamilton are even more ancient but they are many times cited in recent works

 

[Chelaxing]

Armando, since you are a sebum expert, are you aware of any way that we can reduce sebum production in the scalp? Regardless of wether it helps with hair loss or not.

 

[Armando Jose]

In order to reduce sebum production is needed to decrease the number of sebocytes,
different drugs can do as CB, retinoids,etc, but I think what is more advisable to maintain quality of the sebum in good condition, that is not oxidized and is removed at the same rate as production. There are people who for whatever reason produce a lot of hair fat but they have not balding problems, one need only think in Rastafarians. The problems come when the sebum flow stops.

 

[Chelaxing]

So you're saying that the sebum produced in people with male pattern baldness is different than the sebum produced in people with no male pattern baldness?

I'm asking because I noticed a huge increase in sebum production at the same time my hair loss kicked in. The sebum became really thick and not easy to remove. Not only did my scalp became very oily, but also my forehead, ears, and shoulders became oily as well. Much more oily that before I started losing hair.
It also seems that the more hair I lose, the more oily my scalp becomes.

 

[Armando Jose]

Yes, yourself said that the sebum became really thick and not easy to remove.
Sebum change with the time, physical (as you noticed), chemical (changing its composition) and biochemical....

My advise is the use of a product, if it is natural better, that facilite the removal,...., pure jojoba oil as a lotion during the night is a good chance

 

[Python]

What does it mean for me if I don't really see much sebum. I have very severe hairloss and I should be having lots of sebum rigth? But I check and I actually don't have a sweaty oily scalp.

 

[Armando Jose]

@phyton
I think that when the hair is lost years ago, the sebaceous gland is autoself regulated, and it make the appropriate sebum, normaly is less quantity than when you had hair.

 

[IDW2BB]

Interested in your thoughts on this free full text:






http://dev.biologists.org/content/141/13/2559.long

Abstract

The epidermis is an integral part of our largest organ, the skin, and protects us against the hostile environment. It is a highly dynamic tissue that, during normal steady-state conditions, undergoes constant turnover. Multiple stem cell populations residing in autonomously maintained compartments facilitate this task. In this Review, we discuss stem cell behaviour during normal tissue homeostasis, regeneration and disease within the pilosebaceous unit, an integral structure of the epidermis that is responsible for hair growth and lubrication of the epithelium. We provide an up-to-date view of the pilosebaceous unit, encompassing the heterogeneity and plasticity of multiple discrete stem cell populations that are strongly influenced by external cues to maintain their identity and function.

 

[Armando Jose]

Thank you very much IDW2BB for the study.
Cited ". Recent lineage-tracing data using Lrig1, whichmarks basal cells in both the JZ and the sebaceous gland, strongly
support the contention that basal cells within the sebaceous gland
form an autonomous source for cellular replenishment and that the
sebaceous gland is maintained independently of all other
compartments"

When the hair is lost for ever, the sebaceous gland is present in skin, due at the autonomous source of cellular replenishment.