» » » Simply put, we have no idea. Those claiming otherwise are either
» experts
» » or
» » » We can only guess.
» »
» » No. The guessing game is over since years. The REAL inventor of the
» » Replicel procedure found finally out that his initial guess has proven
» » be right.
»
» Who are you referring to? Jahoda? Nobody else has focused on DSC cells.
Of course Jahoda. He is the REAL inventor of the Replicel procedure. He knows what works and what not works (and why) due to a lot of hardcore research since decades – and he is still doing this today.
Anyway, almost 10 years ago, Dr. Jahoda analyzed McElwee’s (TrichoScience/Replicel) findings concerning whether or not these findings for hair growth/hair regeneration are relevant or not and published his analysis/thoughts in the journal NATURE:
http://www.nature.com/jid/journal/v121/n6/full/5602054a.html
Here once again the ESSENTIAL parts of Jahoda’s analysis/thoughts in 2003:
These new findings [McElwee’s findings]
have particular significance for those interested in hair follicle restoration by transplantation of cultured follicle dermal cells, since up to now, the attempts to translate animal work to a human context has focused on the creation of completely new follicular structures.
The fact that follicle dermal cells [or “dermal sheath cup cells”] can be recruited into existing follicles suggests the possibility of augmenting the size of existing follicles rather than creating new ones.
In androgenetic alopecia [AGA],
-
it raises the prospect of being able to convert small vellus follicles [or miniaturized follicles] into large terminal structures,
-
or perhaps more realistically of halting the reduction of follicle size during the terminal to vellus transition, by the judicious local addition of appropriate cells.
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In this paragraph (above), Jahoda summarized in his own words the idea of the Replicel procedure. Here he already excluded the idea of “creating new follices” with this procedure due to his own research findings. This suggests, that IF such a procedure should be successful, you need EXISTING hair follicles in your balding areas;
- either any circulating vellus hairs
- or miniaturized terminal hairs.
That means, these still existing hairs MUST still be able to recruit (additional) cells. If not, because these follicles are 1) already too damaged or 2) simply not able anymore to recruit (additional) dermal cells with such a procedure, as described by Jahoda above, simply CAN’T work anymore, of course. But that’s -like Jahoda says- not the whole story …
In the next cited paragraph, in 2003, Jahoda tried to analyze the BIG in this thread discussed question concerning whether or not these so called “dermal sheath cup cells” (DSCS) are a SPECIFIC cell compartment/cell niche of the dermal sheath (DS) as a whole, which surrounds the whole hair follicle in general…
Dr. Jahoda: “This brings up the question of whether there [in the dermal sheath] are also specific DS cell compartments.
If McElwee et al are correct,
the close phenotypic and functional relationship between the DSC cells and the DP segregates them from the rest of the DS.
But what is the evidence that this is a specialized DS cell compartment?
In work using microinjected dyes to investigate compartmentalization within rodent follicles, no clear evidence was found for a junctional link between the papilla and adjoining dermal sheath cells (Kam and Hodgins, 1992;Choudhry et al, 1997).
However,
in a recently published paper in which the location and density of gap junctions was investigated in human hair follicles using EM and antibody staining, clear evidence of gap junctions was found within separate DP and DP compartments (Iguchi et al, 2003).
Moreover,
a particularly strong line of expression of gap junction proteins was observed at the base of the follicle exactly at the junction between the DP and the DS cells.
Indeed,
the authors postulated that these may “form a sort of functional syncytium through the gap junctions by which they may play a pivotal role in controlling hair growth and its cycle”.
Nevertheless
there is evidence that, functionally, dermal sheath cells from above the DSC are not dissimilar to those in the bulb region.
For example,
Oliver (1967) showed that dermal sheath cells from the middle of the follicle were able to regenerate a DP within implanted follicle sections.
Moreover,
another group have shown that dermal sheath cells from the upper half of follicles can regenerate when transplanted ectopically into the kidney capsule (Matsuzaki et al, 1996).
Therefore,
there are circumstances in which other follicle DS cells can become papilla cells.
These discrepancies may be explained by proximity of the DSC cells to the germinative epithelial cells, insofar as these cells may be “primed” by contact with epidermal cells to be inductive.
Generally speaking,
it suggests that the nature and role of the cells is [always] influenced,
as in most progenitor populations, by location."
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In addition, Jahoda also tried to analyse the TYPE of cells located in this “specific” cell compartment/niche beneath the hair follicle bulb/dermal papilla and which role they may play for hair growth in general - but I do not explain this part in detail in this post/thread.
Anyway, Jahoda finally also published a highly simplified and speculative model diagram for the explanation of the KEY problem that he sees with this kind of “cell based procedure” what the Replicel claim to accomplish…
http://www.nature.com/jid/journal/v121/n6/fig_tab/5602054f1.html?url=/jid/journal/v121/n6/full/5602054a.html#figure-title
And here is IronMan’s simplified model diagram for HairSite readers…
Anyway, so far, at least here at HairSite, the answer to the BIG question whether or not Jahoda or IronMan are right or wrong with their “speculative model diagrams” is still not CEARLY answered – again, at least here at HairSite. In reality, the answer (by different experts in this field) already exists since years. So do you guys want to hear/read them?
If you just want the simple answer, whether or not the Replicel procedure is working or not for you as an AGA candidate, experts in this field KNOW it and say – NO. If you want to hear why exactly it doesn’t/can’t work – that’s another story for another post/thread…
As a matter of fact, Jahoda was (of course) right in 2003 - that’s the point. I assume Jahoda KNEW it already in 2003 and his paper/analysis was actually just a kind of “warning” and at the same time without trying to discourage researchers/scientists to proceed with their research work.
DO NOT QUOTE SUCH LONG POSTS!!
.
