March is Mitochondria Month for Melanoma and Hair—A Trifecta

A photograph of a box of Good & Plenty Candy

Without energy, metabolism collapses; aerobic metabolism in eukaryotes requires mitochondria. In medical school, in ancient days, our study rooms displayed large charts explaining the Krebs mitochondrial tricarboxylic acid cycle, like religious icons to be venerated . I was  imprinted with the importance of those “good & plenty”- appearing  mitochondrial organelles, and this month I am reminded of them by a trio of publications.

 

First was the triparental egg conceived in Great Britain (sorry for the pun) as treatment for a maternal mitochondrial  genetic defect. Sperm are really important, half the world might say, but so packed with DNA and motile mechanisms that, alas, there is no room for mitochondria. Thus, maternal mitochondria have overtaken the world. The popular press went gaga over this triparental fertilized ova.

 

The second mitochondrial event was the publication in JID by Kloepper and coworkers on the role of  mouse mitochondria transcription factor A (TFAM) in Keratin 14 positive cells in hair development. Absense of TFAM   was associated  with decreased hair density and altered  hair morphogenesis, although epidermal development was intact.

 

Finally, the trifecta (March JID pages 657 for the commentary and 807 for the article by Chang and colleagues): levels of mitchondrial malic enzyme 2 (“Me Too”, to its selfie friends), during the progression from nevi to melanoma. Such new findings may lead to new drugs aimed at ME2 and — ultimately — melanoma.

 

Salute a mitochondria daily in March.

Eyelash Physiology and Extensions

A photograph of a pair of false eyelashes with long lashes

I must  confess I do not read the Journal of the Royal Society Interface regularly, but luckily, the ECONOMIST devoted two thirds of a page to describing how eyelashes work. Eyelashes were last discussed in this blog on Oct 29, 2013, showing a dogged  persistence and perseveration about this skin appendage, which is often relegated solely  to the cosmetic domain.

The basic finding in the study is that the average length of the eye lashes is about one  third of the eye’s width in the 22 animal species studied. Seeing a constant mathematical relationship set the boffins to deriving mathematical and physical models to explain the basis for it.  Most believe that dust, and other physical matter gets stuck on the cilia, but there is a new  and deeper interpretation from these new studies. Eyelashes control the flow of air to and around the cornea so that the water in the corneal  film does not evaporate excessively. The ever-imaginative  authors built wind tunnels to test these functions and to derive differential equations to describe their results.  Question for those of us who don’t do advanced math: if eyelashes are longer and wider owing to drugs, or if  eyelash extenders  are applied, will this alter the physiological water balance between the tear film and the cornea? (When you charge eyelash extensions to your research grant funds, please have an excellent justification.

 

Amador, GJ Eyelids divert airflow to protect the eye  J Royal Soc Interface  DOI 10.1098/rsif.2014.1294   published 26 February 2015.