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Science Square (Issue 111)
May 1, 2016

Artificial Skin That Can Sprout Hair and Grow Glands

Takagi R. et al. Bioengineering a 3D integumentary organ system from iPS cells using an in vivo transplantation model. Science Advances, April 2016.

Skin is the human body’s largest organ, weighing 3.6 kg and having a total area of 2 m2.  It acts as a waterproof shield against extreme temperatures, harmful chemicals, and infectious agents. Once skin is damaged beyond the ability of the body’s self-repair mechanisms, re-generation of patient-specific skin cells in lab conditions could be an essential tool used for successful skin grafts. Although there have been many methods developed to generate skin cells in lab conditions, none of these approaches gave rise to functional skin cells, complete with hair follicles and exocrine glands. In a recent study, scientists demonstrated the first lab-grown skin that contains hair follicles and sweat glands, making this skin akin to biological skin. Using a special cocktail of chemicals, scientists were able to first convert gum cells from mice into undifferentiated stem cells, then they directed these stem cells into mouse skin cells. Next, they grafted the artificial skin cells onto genetically modified hairless mice. The grafted skin cells ended up maturing into skin cells capable of growing hair, excreting oil, and connecting with the nerve and muscle cells of the test animals. Although these experiments were conducted only on mice, it still represents a leap of sophistication in the development of artificial skin. In the future, researchers hope that this technique will have applications for patients with serious burns, scars, or alopecia, and it could potentially be an alternative to animal testing for chemical products.

More Friends, Less Pain

Johnson KVA & Robin IM. Pain tolerance predicts human social network size. Scientific Reports, April 2016.

According to a recent study, people with large groups of friends have higher pain thresholds. In this study, scientists focused on the chemical endorphin, a major regulator of the brain’s pain and pleasure circuitry. Although these two senses seem like opposites, both are fundamentally reward behaviors, since we search for things that give us pleasure and avoid painful stimuli. Endorphins not only make us feel good, but also act as a pain reliever – one that is even stronger than morphine. Endorphins have also been shown to build and maintain social bonds.  Scientists hypothesized that if endorphins help social bonding, people with more friends would have a higher endorphin count – and thus, a higher pain threshold. The research team recruited 101 adults, aged between 18 and 34, and asked them to fill out a social network questionnaire, which asked how many people they contacted on a weekly or monthly basis. Next, researchers tested the participants’ pain tolerances through the wall sit test, in which participants had to squat against a wall with their knees at a 90 degree angle and to hold the pose as long as possible.  Interestingly, those with larger social networks showed significantly higher thresholds to pain. This study is one of many studies that linked social behavior and physical fitness. There has been a lot of evidence that suggests having an active social life and a bigger circle of friends can prevent depression, contribute to successful aging, and promote longevity. Our social lives are as critical to our overall health as our diets and exercise habits.

Three Potentially Habitable Planets Discovered

Gillon M et al. Temperate Earth-sized planets transiting a nearby ultracool dwarf star. Nature, May 2016.

The search for life on Earth-like planets beyond our solar system has been very active, thanks to new high-precision instruments and advanced analysis techniques. Scientists have discovered hundreds of terrestrial worlds over the past few years, including some that are the right distance from their host stars to contain liquid water. Astronomers have been investigating these habitable planets, and one research group, using the Transiting Planets and Planetesimals Small Telescope (TRAPPIST) at the La Silla Observatory in Chile’s Atacama Desert, recently discovered three Earth-like planets orbiting an ultracool dwarf star just 40 light-years from Earth. The planetary system is named TRAPPIST-1 and the three planets are designated TRAPPIST-1b, c, and d. These three planets orbit very close to the star, at 1-3% of the distance that Earth lies from the sun. A year on them passes in only 1.5-4.5 Earth days. They have sizes and temperatures similar to those of Venus and Earth, and are the most promising candidates found so far in the search for life outside our solar system. Scientists are already excited about further studying these planets in greater detail. They plan to use the Hubble space telescope to investigate whether the planets have their own atmospheres or not. If they do, analysis of the presence and proportions of water, carbon dioxide, and ozone in their atmospheres will shed light on the real possibility of “life” on these planets.