The Future of Hair: 3D-Bioprinting

The idea of combining hair follicles and 3D printing sounds like the start of a science fiction movie. The craziness of science fiction movies is well known. This experiment held by Rensselaer Polytechnic Institute showed an abundance of advantages to their remarkable innovation. By using 3D- bioprinting it offers to build upon the current knowledge obtained from skin grafting. 

Now, we are at the point where skin grafts can't fully mimic human skin without the production of hair. In order to understand why scientists are doing this, it's important to highlight the benefits of hair follicles. Hair follicles are most known for their supportive role. They provide benefits such as hair growth, thermoregulation, and protection with a much needed thank you to our stem cells that aid the skin to heal. 

It's already hard to believe that 3d-bioprinting can be successfully done at a cellular level. The printers can effectively produce skin tissue with working blood cells, which is amazing. It’s almost impossible to comprehend. However, we are still at the start of this sci-fi movie. Scientists are consistently working in order to achieve an even bigger goal. Not only are they working on skin grafts with hair follicles that strangely mimic our skin, they also would like to explore the unknown treatments, hair rejuvenation, tropical drug testing, and dermatological testing that can further expand our current knowledge of the skin.

 This sounds great, but we are nowhere near achieving these goals. it does make sense; the skin is the largest organ of the human body, providing an extra layer of complexity.  The main issue currently is the 3D printed hair follicle lifespan only lasting up to three weeks. Therefore, research on expanding the lifespan of hair follicles is necessary and a top priority. The main objective is to allow the hair shaft and soon enough hair follicles to mature. Once accomplished, it could be safe to say life is a true sci-fi movie. Moreover, it’s wonderful to envision the plethora of innovations that this technology could open the door for. 

Links: 

https://www.sciencedaily.com/releases/2023/11/231115113440.htm

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8283073/

https://www.youtube.com/watch?v=f7Y_gf6DD5E

 Genes to Increase Hair Growth

https://www.sciencedaily.com/releases/2010/04/100415085317.htm

Hair loss is very common in men once they past the age of 18 years old. Hair is important for temperature regulation, protection and social interactions. Hair are formed in hair follicles which are specialized organs for exactly that purpose. Hair loss is something common in men with many different causes. Hair goes through a growth phase where it can last for a couple months. Another phase is the rest phase, where it old hair is ejected and lost from the body. A recent study by Leif Carlsson's research team identifies the transciption factor Lhx2 gene as regulator of hair formation. If the Lhx2 gene was turned off the hair follicle was found not to be able to produce hair and activating it has been shown to activate the growth phase of the hair. If we are able to regulate this gene we can extend the length of the growth  (anagen) phase for quicker hairgrowth. I don't believe it would be possible because the function of the Lhx2 is only expressed periodically and we can't really skip the rest phase and just have the growth phase over and over.

Blonde Genes,Do You Want Them?

Even people that are related and look exactly alike possess a very vast range of genetic variations in their DNA, genes that are responsible for how their body will develop, or responds to outer stimuli. Some of these different variants are known as single nucleotide polymorphisms (SNPs). The chemical units that make up DNA are represented by the letters A,T,C, and G. Although most people may carry a C at a specific place in their DNA, some might have a T instead. There have been millions of SNPs discovered in people's DNA. Some of them may be linked to increasing the chances of getting a certain disease. However, others may affect height or a person's appearance.

Previous research has linked a specific SNP with blonde hair in European people. Now Kingsley's group has provided proof that the SNP that induced blonde hair lies within a piece of DNA that is known as an enhancer. Enhancers are pieces of stretched DNA that behave somewhat like light switches, which allows the gene to turn on under certain conditions. They are located far far away from genes, It is like a light switch in England controlling a bulb in California. Although there is quite some distance, they still have the ability to control the gene's activity.

Kingsley's team genetically modified mice to carry the blonde enhancer. As expected, mice carrying that DNA change began to develop light-colored fur coats compared to the mice with another type of that enhancer. This new enhancer has the ability to control the action of a gene that was already known for affecting hair color. This can ultimately lead to less pigment production in the hair follicles, which will lead to lighter hair. This cannot affect eye or skin color.

I believe this is a great opportunity for those people who have an issue with their hair color. If they do not want their kids to have that hair color, this can be a way out for them.

Scientists Pinpoint Molecule That Controls Stem Cell Plasticity by Boosting Gene Expression

A team of researchers from the Rockefeller University has identified a protein, Sox9, which can control stem cell plasticity by boosting gene expression in the hair follicles. Sox9 makes the genes needed by stems cell to become active and later recruit other proteins to give the genes a boost. Also, a less common, yet more powerful version, the super-enhancer was identified by scientists. Super-enhancers contain a large number of transcription factors, histones, DNA packaging proteins, and epigenetic marks. Scientists found 377 super-enhancers in the hair follicle stem cells and many of them were bound by five transcription factors, usually to Sox9.

During the research, scientists took an epicenter from the super-enhancer and linked it to a gene, which would glow green when transcription factors were present. They found that in living mice, all of the hair follicle stem cells glowed green, but did not when the cells were removed from the follicle and placed in culture. Also, scientists found that some of the stem cells glowed green during a wound-repair when culture. The scientists concluded that Sox9 was the only transcription factor expressed in culture and living tissue and it is needed to prevent the death of the stem cells.

The study shows how stem cells response to different environments (culture or repairing wounds) as it maintains plasticity. Researchers studying Sox9 can use it to further the study of male pattern baldness. It could also aid in hair growth methods people who are balding. 

Original link: http://www.newswise.com/articles/scientists-pinpoint-molecule-that-controls-stem-cell-plasticity-by-boosting-gene-expression2
Related Link: http://link.springer.com/referenceworkentry/10.1007%2F978-3-642-16483-5_5492

Is Gray/white hair genetic?

                The cause of white hair is not always genetics. However the two main reasons of gray hair is because of age and genetics. Genes control the exhaustion of the pigment potential of each hair follicle. Each different hair follicle has its own different rates. In certain people, this rate occurs much quicker. 

Human hair grows in stages in which a part of a hair is either growing or resting at a certain hair. Hair follicles contain pigments called melanin. The hair becomes colorless when the body stops producing pigments. This results in white hair, whereas gray hair is produced from a result of pigment dilution.

The two pigments that give hair its color are eumelanin and pheomelanin. Each human has a bit of pheomelanin in their hair, which is hair color orange and yellow. It is found that two gene pairs control human hair color. Several gene pairs control the light versus dark hair in effect. The children born with some hair colors that darkens with growth, which is caused by genes being turned off and on during early puberty. The two genes responsible for gray hair is Bcl2 and Bcl-w.

Link 1: http://www.nytimes.com/2009/03/10/health/10well.html?_r=0

Related link: http://www.womansday.com/style-beauty/beauty-tips-products/why-does-hair-turn-gray-118871

Using Human Cells to Produce Hair Follicle-Generating Stem Cells

     Are you suffering from hair loss because of old age, or other genetic circumstances? You may soon have a solution to your problem, with the help of research work being done at the Perelman School of Medicine at the University of Pennsylvania. Researchers here have been working hard to determine a method to convert adult cells from the body into epithelial stem cells, which would aid in the generation of hair follicles.

                                   Arrows showing hair shafts formed from epithelial stem cells.

 

      By using human skin cells called dermal fibroblasts, and adding three genes, the scientists successfully converted those cells into induced pluripotent stem cells (iPSCs). These researchers have been observing mice with the stem cells implanted into them. They have observed that the mice did, in fact, regenerate skin and hair follicles similar to human hair follicles. However, there are two types of cells, epithelial and dermal papillae cells that are lost when hair is lost. This research pushes forward the production of epithelial cells, but no one has determined how to produce new dermal papillae cells yet.

Article: http://www.sciencedaily.com/releases/2014/01/140128094141.htm

Related Site: http://www.the-scientist.com/?articles.view/articleNo/37149/title/A-Hair-Raising-Solution-/