Optogenetics technology will restore blindness

Are optogenetics helpful to treat vision disorders in human?

Researchers at the University of Southern California (USC) used technology that is developed by using optogenetics to restore visual behavior in mice, which holds promise for treating human blindness. Optogenetics is new technology of using association of optics and genetics to control neuron activity.
The main purpose of my blog is to instruct audience about new scientific method optogenetics and explain the effectiveness of the method in biology as it has potential role in medicine, namely my area of study.
According to Ed Boyden, a professor at the MIT Media Lab, the research on mice by using the new study opens new frames to get visual information that might correct human sight in the future.
Some people suffer from damaging light-sensitive cells in the retina, which leads to a serious disease, retinius pigmentosa. Mostly the cause of eyesight diseases is genetic mutations, which leads to damaging of light sensitive cells of the retina called photoreceptors. There are two types of photopeceptors: rods and cones. The function of rods and cones is to convert light into electrical signals by bipolar cells of the retina. Optogenetics allows to repair destroyed cells of the retina.
The new technology involves addition genes that code proteins called channelrhodopsins, which are present  in the photoreceptors. Light-sensitive proteins are activated by channels which control the flow of ions (charged molecules) in order to stimulate the electrical activity of the cell.

Image 1

The researchers decided to set a target on bipolar cells called ON cells. In fact, ON cells are activated in light in order to express the channelrhodopsin gene including DNA sequence, whereas OFF bipolar cells are restricted in bright light.
Turning to the experimental part, the experiment was performed on the blind mice, which have some genetic mutations including the absence of photoreceptor cells and on sighted mice as a control. At the beginning of the experiment, some blind mice were injected by the virus containing the channelrhodopsin gene and others were not. The gene was accurately inserted to the ON bipolar cells. Then they are observed the ability of mice to see objects by letting them go through a maze in order to test their vision. During the experiment, normal (sighted) mice were able to easily navigate through the maze, whereas blind mice, untreated ones have some difficulties. At the first time treated mice and untreated ones had similar activity functions. However after two weeks the researchers found out unusual thing, blind (treated) mice were able to navigate the maze as well as the sighted mice.
Sheila Nirenberg, associate professor of physiology at Weill Medical College of Cornell University states that according to the study mice had some vision restored, as a result of successfully expressed gene activity in ON cells and there were no side effects.

Image 2

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The treatment is expected to be developed for medical purposes to human patients.
Nowadays many research groups are still working on  the usage of optogenetics method to treat sight disorders in people.
However it is believed that optogenetics, an unknown test for human could be used to restore human blindness  in the near future.

Reference

Anne Trafton, 2011. "MIT News Office" Last modified April 20, 2011.
http://newsoffice.mit.edu/2011/blindness-boyden-0420
http://transhumanismwr10206.weebly.com/optogenetic-therapy.html
http://transhumanismwr10206.weebly.com/optogenetic-therapy.html

Sense of smell "may predict longevity"

Human beings can recognize thousands of different smells. Actually, our sense of smell is very essential, because it helps to enjoy our life. Most importantly, without it we would not be able to get pleasure from our favorite food and flowers or other enjoyable smells from the environment. Recent studies from the University of Chicago suggested that measuring the sense of smell helps doctors to predict the health condition of a patient in five years. So the main focus of my blog is to discuss how the sense of smell "may predict lifespan" and explain some causes for that.

Image 1

Research 

Recently, researchers from the University of Chicago made a smell test among 3,000 adults aged between 57-85. The purpose of the test was to determine the ability of participants to specific odors. During this test, there were 5 samples of smells including peppermint, rose, orange, leather and fish. 

 After 5 years, the study showed that 430 of the original participants had died, it is 12.5% of the total number. According to the test, scientists from National Social Life, Health, and Aging Project (NSHAP) found out that  39% of old people who had the poorest sense of smell had passed away.

Despite taking several factors such as nutrition, lifestyle, bad habits, poverty into consideration, scientists claimed that adults, who have a poor sense of smell or losing the sense of smell, are most likely to be in a big danger and, even, pass away within 5 years.

Image 2. Adults who did well the test are most likely to life longer

  Loss of smell. Smell disorders. Depth causes.

In fact, smell loss is tightly connected with smell disorders in human olfactory system (Image 3). There are several types of smell disorders: 

Hyposmia - inability to detect specific smell.
Anosmia - inability to detect any smell.
Dysosmia - an alternation in the perception of smell.
Phantosmia - ability to perceive an odor that does not exist.
Presbyosmia - smell loss due to the process of aging.

For older people, the sense of smell, known as olfactory function, plays a key role in health. According to the above mentioned studies, there are some possible assumptions regarding main causes of death. Particularly, human olfactory ends are linked to parts of central nervous system which is responsible for smelling. Therefore, loss of smell can be a signal in decreasing body's inactivity. 
Moreover,  cellular degeneration of older people is weak due to aging process. As a result of this, organism starts to degrade and refuse normal activity of olfactory system. 
In addition, loss of smell can cause symptoms of neurogenerative diseases such as  Alzheimer's and Parkinson's diseases which are lead to an early death. 

Image 3. Human Olfactory system: 1. Olfactory bulb 2. Mitral cells 3. Bone 4. Nasal Epithelium 5. Glomerulus 6. Olfactory receptor cells

Lead scientist of the research, Jayant Pinto, mentioned that these findings could be a non-expensive clinical test for most patients. In fact, this easy medical test could be one of the helpful methods identifying the presence of health disorders in human. However, despite some mentioned scientific assumptions, such as how the loss of smell affects the lifespan, still remains unclear. Therefore, this study needs more research to clarify the reasons for that. It is believed that such finding will be used in medicine in order to achieve precise scientific results, of course,  if scientists improve this study in the near future.

References: 

"NHS Choices", last modified October 2, 2014,  http://www.nhs.uk/news/2014/10October/Pages/Does-losing-your-sense-of-smell-predict-death-risk.aspx

NIH Senior Health, last modified October 2, 2014, http://nihseniorhealth.gov/problemswithsmell/aboutproblemswithsmell/01.html

http://i.dailymail.co.uk/i/pix/2014/10/01/1412182041220_wps_11_image001_png.jpg

http://i.huffpost.com/gen/2126324/thumbs/o-SMELLING-AND-DEATH-facebook.jpg

http://www.youtube.com/watch?v=ZAUcpmrGN7Y

http://www.techtimes.com/articles/16954/20141001/how-good-is-your-nose-apparently-it-can-predict-your-life-span.htm

Blog 1: Genomic DNA isolation

What is the genetic material of living things?  How to easily isolate DNA from human cells? What is the importance of being able to extract DNA?

If you are interested in these questions, welcome to my blog!

 My name is Ayaulym Chamoieva, and I am a SST (School of Science and Technology) student at Nazarbayev Univesity. As I am a Biology major student, I am interested in biological sciences.  Particularly, this blog will focus on DNA extraction and describe how to isolate DNA from human cheek cells.

Life depends on the ability of living cells to compactly store and translate genetic materials. These materials have the stable storage within every cell in its genes, which are the elements containing information about the characteristics of living species.

According to the Alberts. B., Bray.D., Hopkins.K., Lewis.L.. Essential Cell Biology. 2010, Deoxyribonucleic acid (DNA) is a carrier of genetic information present in all living things. It is required for all cells to perform vital functions. DNA is located in the nucleus of the cell. It is estimated that the human body contains approximately 50 trillion cells; all of the cells contain the same DNA.

The most interesting factor is DNA is responsible for everything that makes a human individual. For instance, it determines a person’s hair, eye color, facial form, height, blood type and etc.  Genetic information is inherited; it passes from one generation to another. In fact, every person has own blueprint which is a joining of half of the mother’s DNA and another half of the father’s.

 At the molecular level, DNA has a double helix structure, it looks like a spiral ladder made by two strands that consisted of linear sequence of nucleotides(Adenine, Cytosine, Timin, Guanine and Uracil) – monomers of DNA molecule.

Image 1

Turning to the isolation of DNA, there are several types of DNA extraction procedures, such as from hair, onion cells, kiwi cells, cheek cells and etc. The most commonly used procedure is DNA isolation from human cheek cells, which is clearly shown on Image 2. This is easy and convenient procedure to do in the laboratory. Firstly, gently chew the inside of your cheeks for 30 seconds. This will remove dead cheek cells. Then swish the 3 ml of water and expel obtained sample into 15 ml tube. Then add 2 ml of lysis buffer to the tube and accurately invert it several times. It helps to DNA release by destroying nuclei membranes of the cells.  After this, add 50mL of proteinase K to the sample by using micro pipette and invert a few times. The role of proteinase is to catalyse the breakdown of unwanted proteins which are present in the solution.  It is important to mix it vigorously to avoid breaking down DNA fragments.  Test tube should be placed in water bath at 50^oC for 20 minutes. Addition of 10 drops of salt solution (NaCl) helps to improve precipitation by giving ionic strenght. Then by adding 10ml of cold 95% ethanol solution to your tube DNA will precipitate out and store forming white precipitate layer. The sample should not be disturbed for about 5 minutes; otherwise DNA does not aggregate in the tube. 

Image 2

Amazingly, we are able to see DNA from simple test tube. The reason is that length of DNA from one human cell (from 46 chromosomes) is about 2 meters long; however weigh is only 2 nanometres.

During the experiment on DNA purification, it can be concluded that isolation of DNA plays essential role in biology. The importance of DNA extraction is detection of viruses and bacteria, diagnose dangerous human diseases and prevent genetic disorders.  In addition, nowadays DNA extraction is commonly used in the area of genetic engineering. Especially, it can help to increase productivity of new biological discoveries and develop the sphere of medicine. 

References:

Bruce Alberts, Dennis Bray, Karen Hopkins, Julia Lewis. Essential Cell Biology. (New York: Garland Science, 2010)

http://akashictimes.co.uk/wp-content/uploads/2014/05/dna.jpg

http://www.bio-rad.com/webroot/web/images/lse/products/dna_analysis_kits/product_overlay_content/global/gib_flowchart.jpg