Arrector Pili muscle degeneration

[waynakyo]

Maybe was posted/discussed before:

http://onlinelibrary.wiley.com/doi/10.1111/bjd.12921/abstract

[h=4][FONT=Verdana, Arial, Tahoma, Calibri, Geneva, sans-serif]Background[/FONT][/h][FONT=Verdana, Arial, Tahoma, Calibri, Geneva, sans-serif]Androgenic alopecia (Androgenetic Alopecia) is the most common hair loss condition in men and women. Hair loss is caused by follicle miniaturization, which is largely irreversible beyond a certain degree of follicular regression. In contrast, hair loss in telogen effluvium (Telogen Effluvium) is readily reversible. The arrector pili muscle (APM) connects the follicle to the surrounding skin.[/FONT]


[h=4][FONT=Verdana, Arial, Tahoma, Calibri, Geneva, sans-serif]Objectives[/FONT][/h][FONT=Verdana, Arial, Tahoma, Calibri, Geneva, sans-serif]To compare histopathological features of the APM in Androgenetic Alopecia and Telogen Effluvium.[/FONT]


[h=4][FONT=Verdana, Arial, Tahoma, Calibri, Geneva, sans-serif]Methods[/FONT][/h][FONT=Verdana, Arial, Tahoma, Calibri, Geneva, sans-serif]Archival blocks of 4-mm scalp punch biopsies from eight patients with Androgenetic Alopecia and five with Telogen Effluvium were obtained. New 4-mm biopsies from five normal cases were used as controls. Serial 7-μm sections were stained with a modified Masson's trichrome stain. ‘Reconstruct’ software was used to construct and evaluate three-dimensional images of the follicle and APM.[/FONT]


[h=4][FONT=Verdana, Arial, Tahoma, Calibri, Geneva, sans-serif]Results[/FONT][/h][FONT=Verdana, Arial, Tahoma, Calibri, Geneva, sans-serif]The APM degenerated and was replaced by adipose tissue in all Androgenetic Alopecia specimens. Remnants of the APM remained attached to the hair follicle. There was no fat in the normal skin specimens. Fat was seen in two of five Telogen Effluvium specimens but could be attributed to these patients also showing evidence of Androgenetic Alopecia. Quantitative analysis showed that muscle volume decreased and fat volume increased significantly (P < 0·05) in Androgenetic Alopecia compared with controls.[/FONT]


[h=4][FONT=Verdana, Arial, Tahoma, Calibri, Geneva, sans-serif]Conclusions[/FONT][/h][FONT=Verdana, Arial, Tahoma, Calibri, Geneva, sans-serif]APM degeneration and replacement with fat in Androgenetic Alopecia has not previously been described. The underlying mechanism remains to be determined. However, we speculate that this phenomenon might be related to depletion of stem or progenitor cells from the follicle mesenchyme, explaining why Androgenetic Alopecia is treatment resistant.[/FONT]

 

[Armando Jose]

Thank you a lot Waynakyo for the link
It is a very interesting issue,
The key, APM aids to sebum flow, if it is deteriorated, can cause problems with sebum and can start the multifactorial events of common baldness

[h=3]Abstract[/h][h=4]BACKGROUND:[/h]New models of the structural relationship between the arrector pili (AP) muscle and the sebaceous gland (SG) have been proposed recently.
[h=4]OBJECTIVES:[/h]The purpose of the present study was to establish the actual morphological relationship between components of the follicular unit (FU) including the hair follicles, AP muscle and SG using 3D reconstruction of serially sectioned specimens so as to expand previous explanations of the secretory mechanism of the SG and to suggest other possible mechanisms based on newly proposed model.
[h=4]METHODS:[/h]Scalp skin specimens were processed using routine histological procedures, with serially sectioned tissue slides being stained with Masson's trichrome. 'Reconstruct' software was used to align, assemble and reconstruct the sections, with observations of the 3D-reconstructed FU [including hair follicles (HFs), AP muscle and SG].
[h=4]RESULTS:[/h]Fifty FUs were reconstructed. The AP muscle was curved and concave as it supported the basal portion of the sebaceous lobules in the perifolliculum. Sebaceous lobules were located between the AP muscle and HFs (angular area) and some sebaceous lobules located in the opposite (counter-angular) area.
[h=4]CONCLUSIONS:[/h]We propose that the concave part of the AP muscle pushes up the basal portion of the sebaceous lobule between the HFs and APmuscle during AP muscle contraction and hair erection. In addition, the sebaceous lobule located at the counter-angular position is squeezed by the HF during AP muscle relaxation and hair repositioning. Combined with the previous mechanism of SG secretion, this newly established mechanism based on the 3D structure of the FU will improve our understanding of AP muscle function and SG secretion.


http://www.ncbi.nlm.nih.gov/pubmed/17596168

A study of the secretion mechanism of the sebaceous gland using three-dimensional reconstruction to examine the morphological relationship between the sebaceous gland and the arrector pili muscle in the follicular unit.

 

[waynakyo]

Wondering if FUEs transplanted from the donor come with their own APM, since the bald area ones have already degenerated...

 

[Armando Jose]

probably trasplant FUE has its erector muscle inside.

 

[hellouser]

A few things:

1) Is the amount of contact between APM and the follicle relative to the size of the follicle? As in, less contact = thinner hair growth

2) Does the APM reconnect somehow through any of the treatments (finasteride, minoxidil, dkk1 inhibitors, cox inhibitors, pgd2 inhibitors, pge2 agonist, interleukin 6 inhibitors)?

3)
a) Does the APM reconnect after a hair transplant?
b ) What makes the APM reconnect after a hair transplant?

4) What is the APM's function for the hair follicle?

 

[Future_HT_Doc]

Hmm, interesting. It doesn't look like the studies evaluated the size of the follicle/pilosebacous unit compared to the amount of contact it has with the APM. It sounds like the muscle degenerating and being replaced by fat may be a downstream product of the entire Androgenetic Alopecia process (according to the article). It is possible that a preventive treatment could halt this process, but I'm not certain any of the listed treatments regenerate mesenchymal tissue. I'm not sure how much it would really "reconnect" after a hair transplant. It would be interesting to see biopsies evaluating the sate of the APM in transplanted follicles.

 

[hellouser]

Hmm, interesting. It doesn't look like the studies evaluated the size of the follicle/pilosebacous unit compared to the amount of contact it has with the APM. It sounds like the muscle degenerating and being replaced by fat may be a downstream product of the entire Androgenetic Alopecia process (according to the article). It is possible that a preventive treatment could halt this process, but I'm not certain any of the listed treatments regenerate mesenchymal tissue. I'm not sure how much it would really "reconnect" after a hair transplant. It would be interesting to see biopsies evaluating the sate of the APM in transplanted follicles.

There's this:

The APM is considered one of the most important appendageal structures in hair transplant studies. Sato et al. studied single follicular unit transplants in androgenic alopecia (Androgenetic Alopecia) patients. They demonstrated that restoration of the APM and adjacent nervous system induces the regeneration of the neurofollicular and neuromuscular junctions in the follicle bulge. [8],[48]

Source:
http://www.ijtrichology.com/article...=6;issue=3;spage=88;epage=94;aulast=Torkamani

That article is actually fairly new, it was presented by Dr. Rodney Sinclair at the 2014 World Hair Congress in South Korea. It explains a LOT about the APM's function, but doesn't really come to the conclusion that it somehow plays vital role in hair growth... my guess is that the disconnect happens due to the shrinkage of the follicle rather than the APM causing hair loss. We know there are a lot of things going on with Androgenetic Alopecia; over expression of DKK1, DHT, PGD2, IL-6 and under expression of PGE2. I think, all those things factor in to the choking away of the follicle and the disconnect of the APM from the follicle is just a result of that.

Also on the topic is this

We report successful establishment of mouse single follicular transplantation model and autonomous restoration of transplanted hair follicle piloerection in mouse skin. Transplanted hair follicles were responsive to the neurotransmitter acetylcholine and formed proper connections with surrounding host tissues such as APM and nerve fibers, which in turn connect with not only the hair follicle bulge region but also the APM. These results demonstrate that the piloerection ability of transplanted hair follicles can be estimated quantitatively. This study makes a substantial contribution towards the development of transplantation therapy that will facilitate future functional regeneration therapy for skin and skin appendages.

Source:
http://www.ncbi.nlm.nih.gov/pubmed/22380609

 

[Armando Jose]

Thank you Hellouser for the study, very interesting.....
Poblet at al studies are very convincing.

A question: Which are the secondary follicles?
"Initially, multiple compound follicular unitscomprising a primary follicle and several secondary follicles are found acrossthe scalp. In the early stages of hairloss, patients usually complain of hair thinning and a decrease in their ponytail volume, but there is little visible baldness. Miniaturization occurs firstin the secondary follicles. "

 

[I.D WALKER]

Can we extrapolate from this study that we have an actual "working therapy" that positively addresses the APM disconnection question?

 

[hellouser]

Can we extrapolate from this study that we have an actual "working therapy" that positively addresses the APM disconnection question?

Well... since theres many links to the Androgenetic Alopecia being based on inflammation and the recent arthritis discovery for Alopecia Areata... arthritis CAN damage muscles, which the APM is. So... there's that.

- - - Updated - - -

Thank you Hellouser for the study, very interesting.....
Poblet at al studies are very convincing.

A question: Which are the secondary follicles?
"Initially, multiple compound follicular unitscomprising a primary follicle and several secondary follicles are found acrossthe scalp. In the early stages of hairloss, patients usually complain of hair thinning and a decrease in their ponytail volume, but there is little visible baldness. Miniaturization occurs firstin the secondary follicles. "

I didn't understand that myself... what is a primary and secondary follicle?

 

[I.D WALKER]

I appreciate the direction your ideas are moving.

 

[Björn]

Even though I not really believe in them, I start to think back at these scalp exercises suggested by, for example, Tom Hagerty. Maybe these might be good for exercising the APMs to avoid or decrease the mentioned degeneracy. What do you think?

 

[hellouser]

Sorry for the layman's question, but could the stimulation of the APM aid?



http://www.bienetrespa.com/skin-care-101/arrector-pili-muscles/

How? If the follicle is miniaturized, then what is it going to connect to?