Tag Archives: Medicine

Newly discovered hormone can possibly change the future of weight loss?

Obesity is a leading health problem in Canada and many other countries throughout the world, with it becoming one of the leading causes of death worldwide. However, what if someone who is clinically obese can decrease their body fat simply by taking a pill? Modern prescription drugs for weight loss do exist; however, they aren’t very effective and can have messy side effects! 

Obesity, Author: Tony Alter, Source: Flickr Commons

Well, recent scientific discoveries may have found the perfect candidate to serve as a replacement for the current prescription drugs available for treating clinical obesity. Irisin, a hormone produced by skeletal muscle cells during exercise is capable of burning fat tissue reserves when introduced into circulation. Irisin achieves this by converting white fat cells, which are the fat cells used to store fat in the human body, into brown fat cells, which are fat cells responsible for burning fat to produce heat. 

An article published in Nature showed that increased irisin levels in humans and mice causes more brown fat cell development, which lead to an increase in energy usage in the form of burning existing fat tissues. This increase in energy consumption occurred in a controlled environment, without any changes in the mice’s amount of physical movement or food intake, which can lead to induced weight loss in obese individuals (Bostrom et al.). 

Tension quickly rose due to researchers speculating if irisin actually exists in the human body, with studies criticizing the methodologies that Bostrom et al. used to detect irisin within humans. However, a recent article published in Cell Metabolism  by Bruce Spiegelman showed definitive proof that irisin does exist in the human body. Instead of using more traditional methodologies commonly used to detect hormones in the human body; Bruce Spiegelman and his colleagues used  a new method involving mass spectrometry to accurately detect and quantify the amount of irisin in participating human subjects (Spiegelman et al.).

Isn’t that great then? Shouldn’t pharmaceutical companies quickly adapt the hormone irisin and start producing a weight loss pill? However, I think the issue of time restricts any advancements in the pharmaceutical industry in actually producing such a pill. Since irisin has only been discovered in mice recently, and confirmation of irisin in humans was only published in August 2015. 

Diet Pills

Diet Pills, Author: joaneQEscobe, Source: Flicker Commons

As well, I would like to bring up a similar weight loss drug that was invented in 1933 that also showed the same promise as irisin. DNP, or 1,3 dinitrophenol was shown to increase metabolism rates by converting chemical energy into heat. Though the mechanisms that they occur aren’t identical, the end result of increased body metabolism and body temperature is observed for both DNP and irisin. DNP quickly became a wonder drug that took North America by storm; even now, DNP can be purchased online as a diet pill. However, tragic deaths have been associated with usage of DNP as a weight loss treatment, with terrible consequences of DNP overdosing including fatal hyperthermia (extreme body heat).

I feel that with something as promising as irisin being capable of helping obese individuals loose weight, the pharmaceuticals, FDA, and researchers have to take responsibility and caution in the future. Making sure that if irisin does become a prescription drug to treat morbid obesity, the tragedies associated with DNP will not occur again in the 21st century. 

Here’s a video on Scishow explaining current weight loss pills :

YouTube Preview Image

By: Yu Chieh (Brian) Cheng

Jelly-like Features of Disease-causing Proteins

I remember when I was a kid (or even now), one of my all time favourite snack is strawberry flavoured Jell-O (or jelly). Not to mention, making it was so easy and so much fun, as the strawberry aroma would fill the kitchen.

C. elegans worm used in the study. Source: Wiki Commons

C. elegans worm used in the study. Source: Wiki Commons

Scientists at the University of Cambridge, led by Peter St George-Hyslop used nematode worm C. elegans as a model for amyloid lateral sclerosis (ALS) and frontotemporal dementia to study the physical properties of FUS, an essential RNA-binding protein in the body. The behaviour and physical properties of FUS can be closely compared to that of jelly. All RNA-binding proteins have two common domains: one for binding RNA and the other where the protein appears to be unfolded. It is at this unfolded region that the FUS undergo a process of reversible ‘phase transition’, which closely resembles the formation of jelly.

Comparison of ALS-affected and normal nerve cell. Source: Sarah Scoles

Comparison of ALS-affected and normal nerve cell. Source: Sarah Scoles

One common characteristic of all neurodegenerative disease is the irreversible accumulation of misfolded or mutated proteins aggregates in the brain, which as a result causes damage to the brain and disrupts communication between brain cells.  FUS is one of many types of RNA-binding proteins that is essential to the brain. It is essential in the regulation of protein synthesis, with functions in the nucleus and cytoplasm of a cell. However, the accumulation of mutated FUS and other associated proteins is also the underlying cause of the neurodegenerative diseases such as ALS and frontotemporal  dementia. Until recently, the significance and how FUS proteins affects the development of these neurodegenerative disease has been unclear.

YouTube Preview Image

[Video courtesy of C.D. Net]

FUS starts out as soluble monomers (like the initial powered-form of jelly), and forms distinct localized accumulations. As it further condenses, a thick gel-like hydrogel structure is formed (like the formation of jelly after it cools in the fridge). This process can be reversible (like warming and cooling jelly repeatedly). Furthermore, during these transitions, RNA and proteins are continuously released from protein assemblies (like suspended fruits in the jelly as it is re-warmed and re-cooled).

The above processes are beneficial because it allows the cells to accumulate cellular machinery in a confined three-dimensional space (with no cell membrane required)  when needed to perform key tasks, but also disassemble when not needed. In addition, it is also faster and less-energy costly compared to the formation of a membrane-bound vesicle.

Although FUS is able to carry out vital cell processes by interchanging between different states, “this essential property also makes them vulnerable to forming more fixed structures if mutated, disrupting their normal function and causing disease” says Professor St George Hyslop. Mutation of FUS causes it to over-condense and become a thick fibrous gel, irreversibly trapping the essential RNA and proteins required for protein synthesis. It is the accumulation of misshaped FUS and other RNA-binding proteins that causes serious neurodegenerative diseases. However, further research and understanding of what are in these assemblies can bring us one step closer to curing ALS and other neurodegenerative diseases.

 

 

Image

Kidneys Grown in Petri Dishes Claimed to Be Functional When Transplanted in Animals

 

WEB_mouse-kidney-stem-cells

Source: Flickr Commons. Credit to: Alpha

This past decade has been an exciting time for regenerative science. Developmental biologists have been striving to discover new methods to grow organs such as hearts, brains, muscles, and even a hamburger patty from stem cells. As of only this September, kidneys grown in Petri dishes have been shown to be functional in animal studies!

Japanese researcher Dr. Shinya Yokote and his team have come across a scientific breakthrough within the stem cell research field in their recent early edition paper published on September 21st, 2015.

The early edition paper claims that transplant of lab-grown kidneys from stem cells are fully functional – in the sense that they can generate and excrete urine – in their animal studies with rats and pigs. Other groups in the past have generated half functioning kidneys that could generate urine when transplanted into animals, but not excrete it – a disorder known as hydronephrosis.

Dr. Yokote’s group managed to overcome hydronephrosis by inventing a new system within the rat’s body for the stem cell-generated kidneys to excrete their waste in to prevent hydronephrosis. They biologically engineered a persistent drainage tube to the kidney and connected it to a temporary bladder which was transplanted along with the kidney. This new system would empty its waste to the animal’s real bladder when it became full. The scientists named this system the “stepwise peristaltic ureter,” (SWPU) and believe that this could be the future of kidney transplantation.

kidney

A picture of the SWPU system that were used to transplant into rats. Source: Yokote, S., Matsunari, H., Iwai, S., Yamanaka, S., Uchikura, A., Fujimoto, E., Matsumoto, K., Nagashima, H., Kobayashi, E., Yokoo, T. (2015). Urine excretion strategy for stem cell-generated embryonic kidneys. PNAS Early Edition September 21, 2015. doi: 10.1073/pnas.1507803112

Although this discovery could impact millions with kidney failures in the future, readers should be warned that this is only an early access article. The researchers have not shown any empirical data to support their claims in their early access article. Those interested should keep a keen eye open for the full paper to be released!

By Justin Yoon