DNA

A DNA Voltmeter To Measure A Cell’s Electric Life

A DNA Voltmeter To Measure A Cell's Electric Life

From our heart’s beating to the neural networks in our brain, many biological processes rely on cells, which use electricity to send signals. Chicago Researchers have now built a DNA-based tool – a voltmeter – that can measure this electricity. So how did they do it? Can this be used in bio-electronics?

Crux of the Matter

What Is The Tool Used?
A DNA voltmeter called Voltair, that can measure the membrane potential i.e voltage differences between the inside and the outside of sub-cellular structures called organelles, which are found in the cells of organisms.

  • A Voltmeter, that measures the electric potential difference between two points in an electric circuit. Source: GI

Integral Organelles

  • The nuclei, which store genetic information.
  • Mitochondria, which produces chemical energy.
  • Ribosomes, which assemble proteins.
  • Lysosomes, which break down excess or worn-out cell parts.

Dye Used As A Sensor
Yamuna Krishnan from the University of Chicago, Illinois and her colleagues developed a sensor comprised of 2 DNA strands, which links to molecules of fluorescent dye. This dye responds to voltage fluctuations by changing its brightness. Then the DNA can bind to specific proteins on a cell’s surface, allowing the sensor to enter the cell.

How Can This Help?
When a membrane breaks, voltage is expected to be null, while when a membrane is repaired, voltage varies. Voltair can detect and report such fluctuation in real-time. The sensor could help reveal how organelles use electricity to regulate their function and its further role in biocompatible electronics.

  • The working of Voltair depicted by researchers, Source: Nature

What Are Bio-compatible Electronics?
They refer to various electrical components that are biocompatible, i.e. not toxic to living cells. Thus, as opposed to traditional electronic devices, bioelectronic devices can be implanted without any protective encasing. They are organic in form and can be safely inserted into the human body consequently.

List Some Uses

  • Pacemakers, used to treat arrhythmias i.e problems with the rhythm of our heartbeat.
  • Brain implants, that can treat depression and epilepsy, a disorder that causes seizures.

  • A regular artificial cardiac pacemaker, Source: Wikipedia

Curiopedia
  • The phrase “powerhouse of the cell” used to describe the function of mitochondria was coined by biologist Philip Siekevitz in the article “Powerhouse of the Cell” published in 1957. Over the years, this phrase is used as an example of impractical information taught in public schools by netizens.
  • The first digital voltmeter was invented and produced by Andrew Kay of Non-Linear Systems (and later founder of Kaypro) in 1954.
  • Chromosome 1 is the designation for the largest human chromosome. Chromosome 1 spans about 249 million nucleotide base pairs, which are the basic units of information for DNA. It would be 85 mm long if straightened.
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DNA Hack May Allow Reversal Of Aging Effects

HDAC1 may prevent aging

Should you stop worrying about aging after MIT researchers have found enzyme HDAC1 having a potential to prevent the DNA from damaging, which results in Alzheimer’s and cognitive disorder in old age?

Crux of the Matter

Research
An enzyme called HDAC1 is responsible for preventing DNA damage to genes involved in memory and other cognitive functions. As per research, enzymes diminish in conditions of Alzheimer’s and aging. Previous studies focus on the involvement of HDAC1 in repairing DNA but this new study focuses on what happens to DNA in the absence of HDAC1.

A study was conducted on mice to understand the role of Enzyme HDAC1. Neurologists engineered mice without HDAC1 enzyme and compare results with healthy mice. The study confirms that in the absence of HDAC1, specific DNA damages build up in mice as the mice age.

What Can It Mean?
Researchers found that HDAC1 loss led to a specific type of DNA damage called 8-oxo-guanine lesions. An enzyme called OGG1 repairs the damage to DNA. HDAC1 is responsible to activate the OGG1 enzyme in the body. Based on the results, researchers showed that they can reverse this damage and improve cognitive function with a drug that activates HDAC1.

This study really positions HDAC1 as a potential new drug target for age-related phenotypes, as well as neurodegeneration-associated pathology and phenotypes.

Li-Huei Tsai, Director, Picower Institute for Learning and Memory, MIT

This study will be a major breakthrough in the treatment of Alzheimer’s and people suffering from cognitive problems in old age. Researchers tested an old dementia drug called exifone, which activates HDAC1 on mice. The result was beneficial as it reduced DNA damage in the brain, improving cognitive functions like memory. But exifone is harmful to the patient’s liver.


Curiopedia
  • James Dewey Watson KBE is an American molecular biologist, geneticist and zoologist. Watson was awarded the 1962 Nobel Prize in Physiology or Medicine “for discoveries concerning the molecular structure of nucleic acids and its significance for information transfer in living material”.
  • Johannes Friedrich Miescher was a Swiss physician and biologist. DNA was first isolated by Miescher in 1869. The significance of the discovery was first published in 1871.
  • Aloysius Alzheimer was a German psychiatrist and neuropathologist. Alzheimer is credited with identifying the first published case of “presenile dementia”, which Emil Kraepelin (psychiatrist and colleague of Alzheimer) would later identify as Alzheimer’s disease.
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The return of Retrovirus buried in human DNA

retrovirus

A team of scientists at the University of Oxford has discovered that a protein called Hemo, made by a fetus and the placenta, is produced from viral DNA that entered our ancestors’ genomes 100 million years ago. This protein that courses through the veins of pregnant women, may reawaken retrovirus that contributes to diseases like multiple sclerosis, diabetes, and schizophrenia.

Crux of the Matter

There is a Retro Version of a Virus too?
A retrovirus (RV) invades a host cell and inserts its genes into that cell’s DNA. These viral genes co-opt the cell’s machinery, using it to make new viruses that escape to infect more cells. If a retrovirus happens to infect an egg or sperm, its DNA can potentially be passed to the next generation and the generation after that. They can force cells to make copies of their DNA, which are inserted back in the cell’s own genome.

What do the Virologists Know About it?
Aris Katzourakis, a virologist at the University of Oxford, and his colleagues recently published a commentary in the journal Trends in Microbiology in which they explored the possibility of viral genes affecting our health in a variety of unexpected ways. In January, Dr. Katzourakis was a co-author on a study showing that one retrovirus common in mammals also is present in fish like cod and tuna.

A team of French researchers engineered healthy human cells to make a viral protein found in many tumors and watched the cells grow in a petri dish. They changed shape, as cancer cells do, becoming long and skinny. And they also started to move across the dish.

Can These Ancient Genomes be Used for a Good Cause?
Researchers have added that some of the RVs become endogenous retroviruses that provide an innate immune response, which is the body’s first line of defense against pathogens. They can fight off infections including viruses and bacteria. A genome-editing technique was used to remove an ERV sequence that was found close to an immunity gene. The team will next investigate whether endogenous retroviruses play a similar role in the immune systems of other animals

Curiopedia

DNA or deoxyribonucleic acid is a long molecule that contains our unique genetic code. Like a recipe book, it holds the instructions for making all the proteins in our bodies. DNA contains four basic building blocks or ‘bases’: adenine (A), cytosine (C), guanine (G) and thymine (T). The order, or sequence, of these bases form the instructions in the genome. Being a two-stranded molecule, it has a unique ‘double helix’ shape, like a twisted ladder. The human genome is made of 3.2 billion bases of DNA but other organisms have different genome sizes. It was first discovered by Francis Crick and James Watson with the help of Rosalind Franklin and Maurice Wilkins. More Info

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Damaged DNA Repair Formula discovered by researchers at IIT-H

One of the premier institutes of India, IIT Hyderabad in partnership with IIT Guwahati, has claimed that its researchers have unravelled working of a protein that repairs damaged DNA. The team has discovered the mechanism by which these repair proteins assemble when DNA is under threat. The researchers studied the action of one specific protein, called alkB homolog 3 (ALKBH3) and stumbled upon this positive result.

Crux of the Matter
  • With the increasing awareness about the impact of DNA damage, efforts were being made globally to understand how these repair proteins work.
  • The results of the study conducted by IIT-H researchers in collaboration with Arun Goyal, Professor at the Department of Biosciences and Bioengineering, IIT-Guwahati, was recently published in Nucleic Acid Research, a peer-reviewed journal.
  • According to the reports, any damage to DNA is caused by the sudden appearance of a harmless mole to catastrophic diseases like cancer.
  • The finding is an output of both an academic exercise and therapeutic interventions.
  • One of the co-authors of the paper, Anindya Roy believes that the knowledge gained from these studies can be beneficial from a cancer edradication perspective.
Curiopedia

DNA or Deoxyribonucleic acid is a molecule composed of two chains that coil around each other to form a double helix carrying genetic instructions for the development, functioning, growth and reproduction of all known organisms and many viruses. Friedrich Miescher discovered DNA in 1869, although scientists did not understand DNA was the genetic material in cells until 1943. Prior to that time, it was widely believed that proteins stored genetic information.Every human being shares 99% of their DNA with every other human. More Info

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