BioQuakes

AP Biology class blog for discussing current research in Biology

Tag: Cells (Page 1 of 2)

How To Map A Cell

In order to understand diseases on a cellular level, scientists must learn as much as they can about cells. One of the ways this is done, is through Nanomechanics. Through nanomechanics, scientists can measure many aspects of the cell. They can find the thickness, softness, viscoelasticity, and incompressibility, or how capable the cell is of being compressed. Living cells, specifically eukaryotic cells, are made of a plasma membrane with solids inside of it. The solids can range from proteins, to DNA, to organelles, to much more. As these solids move within a liquid type of mixture, they are considered viscoelastic. Through the use of Atomic Force Microscopy or AFM, a cell’s viscoelasticity can be mapped. Moreover, nanomechanics is able to find the rate at which a molecule spins by using Young’s modulus.

201710 SingleCell

Even further in the cell, scientists can now determine how the lipid bilayer of a cell change. Through AFM, the physical properties of the cell’s lipid bilayer have been seen to change due to the concentration of cholesterol. Low cholesterol regions had a more elastic lipid bilayer, while regions with less cholesterol were less elastic. Additionally, it was observed that during ionization, the elasticity of the lipid bilayer decreases as well.

Cell membrane detailed diagram blank

As scientists reveal more about the cell, they connect what they have learned to diseases. When a cell changes, or organelles it is composed of change, it can be a sign of disease. By looking into cells through ways such as optics-based non-invasive Brillouin microscopy, scientists can study the mechanical properties of cells and the smaller components that compose them. From using this type of technology, scientists have also learned that living eukaryotic cells are one of the softest materials on the planet. AFM uses the forces placed on the cell by the microscope to determine the properties of the cell.

Human eye detail, from- Human eye close up (cropped)

One specific use of nanomechanical mapping on cells is in microsurgeries conducted on the eye. Many ocular diseases are due to a change in the mechanical properties of the eye. Some diseases can be caused by macular holes or macular puckers. Through microsurgeries, the damage to the eye may be fixed. Scientists conducted measurements on cells on a nanometer scale in order to understand what microsurgeries are necessary to be performed. Moreover, nanomechanics allows scientists to understand how the proteins of the eyes work, and how mutations and other tissue can affect the eye. If specific mutations of causes of diseases can be found on a cellular or subcellular level, it would aid in the development of drugs that would be used against the diseases.

How Do Guard Cells Attain Energy?

Ever since we were young, we understood that plants utilize photosynthesis for energy, releasing oxygen in the process. But, we did not learn which parts of the plant actually perform photosynthesis. This is highlighted by guard cells, the cell located in the upper epidermis that controls the concentration of Carbon Dioxide in the plant. So how do they contribute to photosynthesis?

Stomata & Guard Cells

The team of Dr. Boon Leong Lim at HKU wanted to observe the real-time production of ATP and NADPH in the mesophyll cell chloroplasts, which was done by using planta protein sensors in a model plant, Arabidopsis thaliana. This plant is specifically used due to its small genome, short life cycle, simple process to mutagenize, and easily identifiable genes. Shockingly, the Guard Cells Chloroplasts have not detected any ATP or NADPH production whatsoever. Looking for answers, the researchers decided to contact Dr. Diana Santelia, an expert in cell metabolism. Throughout a decade of research and collaboration, they finally have an answer.

Unlike mesophyll cells, photosynthesis in the Guard Cells is inadequately regulated. This is because synthesized sugars from the mesophyll cells are imported into the Guard cells, in which is used ATP production for the opening of the stomata. Additionally, Guard Cells chloroplasts take cytosolic ATP through nucleotide transporters on the chloroplast membrane for starch synthesis throughout the day. At night, though, Guard Cells degrade starch into sugars for the opening of the stomata. Mesophyll Cells, on the other hand, synthesize starch and export sucrose at dawn. Thus, the chloroplasts of Guard Cells ultimately serve as starch storage for the opening of the stomata. Their function is closely linked to that of MCs in order to effectively coordinate CO2 absorption through stomata and CO2 fixation in MCs. 

Although the Guard Cells seem redundant, their role in the overall process of photosynthesis is absolutely necessary. As seen in AP Bio, the stomata are essential for gas exchange for photosynthetic reactions. The stomata’s main role is to take in Carbon Dioxide and release Oxygen, both of which are necessities for the reaction to occur. 

Thank you so much for reading this blog, and let me know what you think in the comments below!

New research exposes and demonstrates how damaged cells survive the cell cycle

In recent news, the Center for Cancer Research have recently discovered a previously unknown phenomenon, which allows certain cells to continue through the cell cycle despite experiencing DNA damage. This also includes past natural safety checkpoints within the cell cycle that are designed to stop the problem from occurring. On January 13, 2021 researchers, in Science Advances, suggested that the timing of DNA damage was crucial for determining whether a faulty cell would survive the cycle.

When cells begin to divide and replicate as part of their natural cycle, they transition from their resting state to one called the G1 phase. In this phase, cells have several important checkpoint mechanisms to ensure that the cell is healthy enough to proceed onto the next stage of the cell cycle. If/when these mechanisms fail due to genetic mutations, cells can progress through the G1 phase unobstructed, which can ultimately lead to cancer.

It was previously believed that cells with DNA damage could not pass through these safety checkpoints in the G1 phase and that the cells would either repair the DNA damage or die. However, scientists helped uncover evidence proving that cells with damaged DNA can actually progress past these critical checkpoints. A team of scientists studied individual cells for days at a time, using live cell time-lapse microscopy, single-cell tracking software, and fluorescent biosensors to detect the cell’s safety checkpoint mechanisms. They added a substance to induce DNA damage for cells of different ages in the cell cycle. Strikingly, the majority of cells seemed to ignore the DNA damage because they failed to trigger the checkpoint between G1 and the next phase, and proceeded into the next phase anyway.

Further investigation revealed that the timing of DNA damage during the cell cycle influenced the likelihood that damaged cells would slip past the checkpoints. The researchers found that the cell’s response to DNA damage is relatively slow compared to the speed of the cell cycle. This means if cells were already very close to the next phase of the cell cycle at the time DNA damage happened, they were more likely to continue into that phase. If the cells were still early in the G1 phase, they were more likely to revert back to a resting state. These observations are a form of inertia, where the cell will continue moving towards the next phase regardless of safety checkpoint signals.

It was also discovered that cells which were genetically identical were more likely to share the same cell cycle fate than non-identical cells. This suggests that factors specific to the cells themselves influence their fate during the cycle, rather than random chance. More studies are needed to understand how these findings apply to cancer. Testing is also extremely important in order to fully understand what the long-term consequences of the checkpoint failures are and find out if the cells that entered the next phase despite considerable DNA damage can become cancerous and eventually form a tumor, which, in my opinion and most likely the opinion of others, will be groundbreaking for cancer research.

Are You Happy With Your Current Cell Provider?

Stem cells are defined as a specific type of cell that is capable of evolving into many different types of cells throughout the human body. Although they may be one of the most promising medical and biological discoveries, not many people know enough about them. The term “stem cell” has actually been dated back to the 19th century, but it wasn’t until 1981 that the first embryonic cells were isolated. In the year 1981, scientists Martin Evans and Gail Martin conducted separate studies and they were able to derive pluripotent stem cells from the embryos of mice.

Why Are They Useful?

In 1959 Physician E. Donnall Thomas conducted the first human hematopoietic stem cell transplant. The transplant was actually conducted on twin sisters. One sister with end stage leukemia received total body irradiation in order to kill the cancer. Soon after, her twin sister donated bone marrow, resulting in the regression of her twin sister’s leukemia. Because of stem cells’ ability to repair, regenerate and develop into specific specialized cell types, they prove to be therapy for many diseases and disorders. People that benefit from stem cell therapy are people who suffer from:

  • Spinal cord injuries
  • Type 1 diabetes
  • Parkinson’s disease
  • Amyotrophic lateral sclerosis
  • Alzheimer’s disease
  • Heart disease
  • Stroke
  • Burns
  • Cancer
  • Osteoarthritis

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Types of Stem Cells and Their Therapies

There are three types of stem cells, each with their own respective therapies and uses. The first types are Adult Stem Cells (ASCs). ASCs are found in small numbers in tissues such as bone marrow or fat. Researchers used to think that ASCs could create only similar types of cells. New evidence shows that ASCs may be able to create various types of cells. This means that bone marrow stem cells, for example, could be able to create bone and heart muscle cells. The other kind of stem cells are Embryonic Stem Cells (ESCs). ESCs come from embryos that are three to five days old. These stem cells are pluripotent, which means they can divide into more stem cells or become any cell in the body. This means that ESCs can be used to regenerate and repair diseased tissue and organs. The third kind of stem cells are induced pluripotent stem cells (iPSCs). These kinds of stem cells are ones created in a laboratory and they are a mixture of adult stem cells and embryonic stem cells. Scientists altering genes in adult cells allows them to reprogram the cells into behaving like embryonic stem cells.

 

 

 

 

 

 

 

ITS ALIVE!!! Scientists bring their creation to life.

Cells are the basic units of life, but now scientists found a way to take matters into their own hands and actually create their own Frankenstein of cells. Scientists first created a single-celled organism with only 473 genes five years ago. Unlike the most recent cellular innovation, this simple cell grew and divided into cells of strange and unusual shapes and sizes. In an attempt to fix this, scientists identified 7 genes that when added to the cell, cause them to divide into perfectly uniform shapes. The J. Craig Venter Institute (JCVI), the National Institute of Standards and Technology(NIST), and the Massachusetts Institute of Technology(MIT) Center for Bits and Atoms all together can be accredited with this success.Cell division

How Was It Done?

The first cell with a synthetic genome was created in 2010 by the scientists at JCVI. Rather than building a cell from scratch, they started with cells from a simple bacteria called mycoplasma. The DNA already in those cells were destroyed and replaced with computer designed DNA. Thus lead to the first ever organism on Earth to have an entirely synthetic genome. It was named “JCVI-syn1.0”. Since then scientists have been working on stripping it down and reaching its minimum genetic components. Now scientists added 19 genes into this cell(including the 7 genes needed for proper cell division) and call it JCVI-syn3A. This cell variant also has fewer than 500 genes(a human cell has about 30,000). To find those 7 genes the JCVI synthetic biology group, led by John Glass and Lijie Sun, constructed multiple variants by adding and removing genes. NIST had to observe and measure the changes under a microscope. The difficulty here lay in observing the cells while they were alive, which made imaging them harder because of how small and fragile they were. Even the smallest of force could rupture them. Strychalski and MIT co-authors James Pelletier, Andreas Mershin and Neil Gershenfeld designed a microfluidic chemostat to remedy this. The article by NIST best describes this as a “sort of mini-aquarium where the cells could be kept fed and happy under a light microscope”. They discovered two known cell division genes, ftsZ and sepF, a hydrolase of unknown substrate, and four genes that encode membrane-associated proteins of unknown function, were all required together for cell division. As we learned in AP Bio, organelles like mitochondria and chloroplasts are also autonomous. That simply means that they are self replicating similar to this man-made cell.

 

The ability to create synthetic cells could lead to potential cells that produce drugs, foods and even fuels. Others can detect disease and the drugs to treat it all while being inside your body. It’s amazing to think that humans are capable of creating synthetic life on a molecular level. One can only hope that this power is used for good in the future. Do you believe that what these scientists are doing is ethical or is “playing God” tampering with forces unknown? 

Quit Hogging All the Kidneys

Xenotransplantation is defined as the process of transplanting organs between members of different species. Saying it out loud it sounds like mad science but the it’s not as crazy you might think. Xenotransplantation has actually been a process that has been used for many years, even dating back to the 1960s. This journey began with apes and monkeys. Scientists believe that it would make the most amount of sense to use because they were essentially the most promising source of organs and tissue due to their being primates. However, this unraveled into a series of problems that were due to them being contaminated with viruses that are pathogenic to human beings. Baby monkeys were also researched but the idea was dismissed due to ethical reasons. This consequently led to the study of pig tissue.

We have actually been utilizing things from pigs that most people may not even be aware of. One example of this is pig insulin. It would replace the insulin that your body would usually make in order to get blood sugar into your cells. We obviously can’t take just any part of a pig and use it. We can, however, utilize a pig’s kidneys and transplant it into a human body. On September 25th, scientists and researchers  successfully transplanted a kidney from a genetically altered pig into a human patient and discovered that it functioned normally.

Little piggies

How Did It Work?

According to the an article by the New York Times, the pig needed to be genetically altered in order to be transplanted into the patient. What was altered? Essentially the kidney in the procedure was obtained by removing a pig gene that encodes a sugar molecule that elicits an aggressive human rejection response. Interestingly enough, the genetic difference between pig DNA and human DNA is 98 percent.

What Were The Risks?

While pigs and humans may share a lot of DNA, they are not a match right away. A non altered pig would cause many risks if any part of it were transplanted into the human body. A way it could pose an issue is through the viruses they may contain. Pig viruses may not cause disease in pigs, but they can in fact be pathogenic to humans. The human proteins that are expressed onto the transgenic pig cells can be receptors for viruses. An article on pig DNA from PMC explains that CD55 is a receptor for human Coxsackie B and ECHO viruses (these are relatives of poliovirus), and these cause a disease called myocarditis. The protein CD46 can act as as a receptor for the measles virus, so it is possible that morbilliviruses of animals could be preadapted in the same pigs used for xenotransplantation.

Another way that these transgenic pigs may heighten risk of virus is through viruses with lipid envelopes that are from host cell membranes would be less likely to inactivated by human compliment. What could have been a protective mechanism against infections from viruses derived from farm animals could be broken down in attempts to make xenografts for humans (The tissue or organ being transplanted from the other species).

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Diagram of a pig kidney

The future of xenotransplantation looks promising. While it may have worked, scientists are still doing studies and still trying to find out more about the viruses pigs may carry. While we can weed out the viruses we are aware of, we still can’t account for the ones we don’t know exist. There is a reason this topic is somewhat new and that is because of ethics. Apes and Monkeys could’ve actually been genetically altered the same way these pigs were, however it was deemed unethical. I personally agree that apes and monkeys shouldn’t be harvested, but that begs the question of whether harvesting organs from pigs is ethical. And with that I ask you what you ate for breakfast, lunch or dinner. Pigs and other animals are already being harvested for food and I believe that if there is a problem with xenotransplants, there would be a problem with the food industry. With that being said, if you’re ever in the market for a kidney, you have options.

Small But Mighty: Sea Otters And Their Leaky Mitochondria

Sea otters: they bob up and down in the water, hold hands when they are sleeping, poop together at social events, stay warm by their fur and leaky mitochondria… wait, what?

Let’s rewind.

Sea-otter-morro-bay 13

A Cute Sea Otter Floating On Its Back

Warm-blooded marine mammals have a thick layer of fat and oils, known as blubber, as their skin layer to insulate their body. In cold waters, blubber helps retain heat and maintain homeostasis.

But what if warm-blooded marine mammals lack blubber? Sea otters are a prime example (and the only example) of a marine mammal without a layer of blubber. Instead, they have a thick coat of dense hairs, 1000x denser than human hair–the thickest on earth. This enables sea otters to trap large amounts of air within their fur coat, acting as insulation. (This is the same reason why sea otters float: the air trapped in their fur coat makes them buoyant).

But with that said, can you stay warm in a fleece jacket? Possibly. What if you were wearing it while in the ocean? That might be somewhat difficult. Similarly, fur can’t solely protect these animals from losing too much heat. These mammals are still living in water, which transfers heat 23 times as efficiently as air. Since sea otters are the smallest aquatic mammals, they have a lot of surface area relative to their volume, making it even harder for these animals to maintain homeostasis.

So how do they do it? Researchers have already understood that sea otters have an extreme metabolism, how food gets converted to energy in cells, eating about twenty-five percent of their body mass in food every day. But the pieces were still not adding up, which prompted researcher T. Wright to investigate this question on a cellular level. He and his colleagues searched for the source of heat in otters’ muscles. Playing a pivotal role in the body’s metabolism, the skeletal muscle makes up 40 to 50 percent of the sea otters’ entire body mass. His study required the collection of tissue from 21 sea otters of different ages and then measured the muscle cells’ respiratory capacity compared to that of other animals. The sea otters’ oxygen flow rate would roughly indicate the measurement of the cells’ heat production.

Mitochondria pump protons across their cell membranes to store energy in the form of ATP, like we learned in AP Biology’s diffusion unit. From this study, T. Wright concluded that the protons are diffusing back through the membrane before being used for work, resulting in excess heat. Since some of the energy is lost as heat, sea otters need to eat more food to compensate for the lost energy. This “leak in energy” is what contributes to the sea otters’ speedy metabolism.

It’s unknown if sea otters develop leaky mitochondria by living in cold water or simply inherit it. Future research into the fascinating design of sea otters may potentially reveal intriguing insight into their evolution, behavior, and maybe someday, their cuteness.

 

 

Can Deodorant Cause Cancer?

Did you ever think you were harming your health while going through your morning routine? Applying deodorant is a daily practice of many people around the world. However, we often don’t realize what exactly we are applying to our bodies and what chemicals the products we are using are made up of. When was the last time you checked the label to see if there were any potentially harmful elements in something as basic as deodorant? Not often, I presume. But I think we all need to start!

The article from Penn Medicine explores the effects the deodorant can have. Deodorant’s contain chemicals which can be absorbed into the body from applying it onto the skin. The theory people have formed about deodorant is that the toxins from the deodorant will collect in the lymph nodes that will turn healthy cells into cancer cells, especially breast cancer as it located closest to the armpit where the deodorant is applied. The difference between a cancer cell and a healthy cell a cancerous cells is a mutation of its DNA (contains the genetic code for organisms). Nucleic acids are DNA. Nucleic acids consist of nucleotides that are made up of a five carbon sugar, a phosphate group and a nitrogenous base. The mutation of the DNA causes uncontrolled cellular proliferation which can occur due to mutations in genes that control cell death and regular cell growth. Healthy cells carry out their ‘normal’ specialized functions. However, the American Cancer Society has said that there is not enough scientific evidence to back the theory. Aluminum is a big ingredient in deodorant needed to prevent sweating. Our bodies ability to sweat is controlled by our nervous system. But how does deodorant really accomplish what it is supposed to? Essentially, the salts in the aluminum have to break down in order to prevent sweat on the pores. The National Center for Biotechnology information claimed that breast tissue does, indeed, have an increase of aluminum in them with daily use of deodorant.

 Harmful Effects of Aluminum on Kidney’s 

A extreme excess of aluminum in the body can result in bone diseases or dementia. Also, a excess of aluminum can also cause kidney issues with people with pre-existing kidney conditions since aluminum gets filtered out of the body through the kidney’s. For the most part, though, there is not enough aluminum in the sticks for it to do enough damage for people with healthy kidneys.

Other Harmful Chemicals Used In Deodorant

Parabens is another ingredient used in deodorant to prevent bacteria from growing on the deodorant, basically being used as a preservative. Parabens also get absorbed through the skin and function as estrogen. Why exactly are parabens bad for us? A excess of estrogen throughout a lifetime, however, can result in increase breast cancer or even a tumor. The positive is that it is in too little of an amount to really make a difference in our bodies.

Just to be safe, though, I think it is time to go buy some aluminum free deodorant- a quick, easy and convenient solution! Here are some great aluminum free deodorants and here are some natural deodorants to get started on using!

Ever Wonder What It Feels Like to Dance In A Cell? Well, You Might Be Able To Find Out.

The never-ending innovations of technology have hit us again, and this time its something very groundbreaking. Recently, the University of Cambridge had partnered up with a 3D image analysis company known as Lume VR Ltd to make a new software called vLume. What is vLume? It’s the future. This new cutting edge technology was developed for scientists to aid them in studying everything from individual proteins to entire cells. How? Well thanks to Lume VR Ltd, vLume allows super-resolution microscopy data to be envisioned and examined in virtual reality.

So you might be wondering, what in the world is super-resolution microscopy? This is basically the reason why we can see such small things in clear high resolution. Essentially, they are approaches to eliminate light diffraction– the slight bending of light which causes low resolution imaging.

 

Why is this such a big deal?

Numerous reasons! For starters, this breakthrough allows us to mingle with the 3D world of biology as if it were up close and in person. Before, we would try to interact with data through a 2D computer screen. Now, we can see a whole 3D view in virtual reality. This new revolutionary imaging software allows scientists to see, question and play around with 3D biological data, seeming like its real, but its in a virtual environment! This is so important because it allows us to find answers to questions we have about biology immensely quicker. This software allows us to make new discoveries in a blink of an eye. Even a PhD student, Anoushka Handa, said, “It’s incredible — it gives you an entirely different perspective on your work.” This is so cool, she took her own immune cell and was able to virtually stand inside her own cell!

This is so amazing, there has to be a catch?

No, there is no catch! Super-resolution microscopy analysis can be very time consuming, but with the vLume software, it was able to cut the wait times significantly which allows the tests to be quicker and ultimately making analysis quicker. All you will need is a VR!

What does this mean going forward?

With this new technology, who knows what’s next. For now, this software will allow us to further understand the world of biology and it might help develop treatments for diseases that we do not have treatments for now. But, in terms of technology, who knows what’s possible. The thought of being able to stand in a cell seemed like fantasy, but it turns out that it is a reality now. We must be cautious, technology seems like it does good, but there can be some harm involved.

My take:

In my non-expert opinion, I think this is a very good sign. This technology is a positive, we can understand more about our world which is very resourceful. I also have emitted my excitement over the course of this article. This is groundbreaking and new which is something I always love to see. The only problem is that people might become reckless with their inventions now. This can be related to our class because we can have a greater understanding of cells and their structure and their functions along with the key organic compounds. Although this tech is used for good, there will be some that’s bad which may be problematic in the future. All in all, this innovation will help us understand ourselves a lot more and it will ultimately be positive in the long run. -Ghohesion

Can your diet’s effect on gut bacteria play a role in reducing Alzheimer’s risk?

Could following a certain type of diet affect the gut microbiome in ways that decrease the risk of Alzheimer’s disease? According to researchers at Wake Forest School of Medicine, that is a possibility.

In a small study, researchers were able to identify several distinct gut microbiome signatures in study participants with mild cognitive impairment (MCI), but not in the other participants with normal cognition. Researchers found that these bacterial signatures correlated with higher levels of markers of Alzheimer’s disease in the cerebrospinal fluid of the participants with MCI. Additionally, through cross-group dietary intervention, the study also revealed that a modified Mediterranean-ketogenic diet resulted in changes in the gut microbiome and its metabolites that correlated with reduced levels of Alzheimer’s markers in the members of both study groups.

“The relationship of the gut microbiome and diet to neurodegenerative diseases has recently received considerable attention, and this study suggests that Alzheimer’s disease is associated with specific changes in gut bacteria and that a type of ketogenic Mediterranean diet can affect the microbiome in ways that could impact the development of dementia,” said Hariom Yadav, Ph.D., assistant professor of molecular medicine at Wake Forest School of Medicine.

The randomized, double-blind, single-site study involved 17 older adults, 11 diagnosed with MCI and six with normal cognition. These participants were randomly assigned to follow either the low-carbohydrate modified Mediterranean-ketogenic diet or a low-fat, higher carbohydrate diet for six weeks then, after a six week “washout” period, to switch to the other diet. Gut microbiome, fecal short chain fatty acids, and markers of Alzheimer’s in the cerebrospinal fluid were measured before and after each dieting period.

The limitations of the study included the subject’s group size, which also accountns for the lack of diversity in terms of gender, ethnicity, and age.

“Our findings provide important information that future interventional and clinical studies can be based on,” Yadav said. “Determining the specific role these gut microbiome signatures have in the progression of Alzheimer’s disease could lead to novel nutritional and therapeutic approaches that would be effective against the disease.”

Each human contains trillions of organisms that influence our metabolism, immune function, weight, and even cognitive health. It is so fascinating to examine the role of gut microbiomes in the progression of Alzheimer’s disease. I believe diets can be very controversial, and I find it interesting to see researchers in this study show how the Mediterranean-ketogenic diet may be effective against Alzheimer’s. However, I am so intrigued to see where these findings may take us with approaches that may be effective against Alzheimer’s, whether they be nutritional or therapeutic approaches.

Nobel Prize awarded to Researchers for Key Discoveries in Cellular Respiration

Recent findings about the change in oxygen levels in cells show new important factors about oxygen that translate to one’s well-being. William G. Kaelin Jr., Sir Peter J. Ratcliffe and Gregg L. Semenza discovered how cells can “sense and adapt to changing oxygen availability,” and are now being awarded the Nobel Prize in Physiology or Medicine. Oxygen is a crucial aspect to how a cell’s functionality. Mitochondria in cells use oxygen to aid in converting food into ATP (energy), a process known as cellular respiration.

A representation of the reaction of cell respiration.

 

Gregg Semenza wanted to further look into the rise of levels of the hormone erythroprotein (EPO), a response to low levels of oxygen, or hypoxia. He found that “oxygen sensing mechanisms were present in virtually all tissues, not only in the kidney cells where EPO is normally produced.” While Semenza analyzing cultured liver cells, Semenza found a protein complex that was unknown to science. He named unidentified DNA segment the “hypoxia-inducible factor (HIF).”

Over the course of 24 years, Semanza continued to explore aspects of HIF and found two different DNA-binding proteins, now named “HIF-1a and ARNT.” Researchers worked with Semanza in finding out which parts of the HIF assist in cellular respiration. While Semenza and Ratcliffe were researching regulation of EPO, Kaelin Jr. was researching von-Hippel-Lindau’s disease (VHL). Kaelin Jr.’s research showed that VHL gene “encodes a protein that prevents the onset of cancer,” and that cancer cells lacking a functional VHL gene have “abnormally high levels of hypoxia-related genes.” But when the VHL gene was reintroduced into cancer cells, “normal levels were restored.” Eventually, Kaelin Jr. and his team found that VHL needs HIF-1a for degradation at normal oxygen levels.

Kaelin Jr. and Ratcliffe both published articles that center around protein modification called prolyl hydroxylation which “allows VHL to recognize and bind to HIF-1α degradation with the help of oxygen-sensitive enzymes.” The papers also wrote that the gene activating function of HIF-1α “was regulated by oxygen-dependent hydroxylation.” The researchers now had a much clearer idea of the effects of how oxygen is sensed within cells.

These groundbreaking finds give the science world more information about how oxygen levels are regulated in cells in physiological processes. Sensing oxygen levels is important for muscles during physical exercise, as well as the generation of blood cells and strength of one’s immune system.

Stem Cells and CRISPR

Many cells can reproduce but there are a few types of cells that are not able to reproduce. One of these types are nerve cells, the cells that cary messages from your brain to your body.  There are many ways nerve cells can be destroyed or damaged, by trauma or drug use.  Millions of people are effected by losing nerve cells and for so long no one could think of a way to recreate them; until the discovery of stem cells.

After fertilization, and when the newly formed zygote is growing, it is made up of a sack of cells.  Some of these cells are stem cells which develop according to their environment. Because of the behavior of stem cells, scientists theorized that if they placed stem cells in the brain or spinal chord, two areas that have an abundance of neurons, the stem cells would turn into a neuron because of the environment it was in.  But, when they tried introducing stem cells into the body, the immune system treated them as an foreign body, as it should. Our immune system has to treat anything that does not come from our body as an enemy or we could get extremely sick.  However, the downside is organ transplants, blood transfusions, etc. are dangerous because they could cause a serious immune rejection.

Someone experiencing a spleen transplant rejection

Cells have a surface protein that displays molecular signals to identify if it is self or foreign.  Removing the protein causes NK (natural killer) cells to target the cell as foreign. Scientist haven’t been able to figure out how to make a foreign cell not seem foreign until Lewis Lanier, chair of UCSF’s Department of Microbiology and Immunology, and his team found a surface protein that, when added to the cell, did not cause any immune response.  The idea would be to use CRISPR/cas9 to edit the DNA of the stem cells, and in doing so would remove the code for the current surface protein and add the code for the new surface protein.

After the scientists had edited the stem cells, to have the correct signal protein, they released them into a mouse and observed that there was no immune rejection. Truly amazing. Maybe brain damage could be helped by this science one day. Tell me your thoughts on Stem Cells in the comments!

For more information, please go check out the primary source of this article.

 

 

Do humans have night vision?

Can humans see in the dark?

If you said yes, you are correct! When I saw the title of Emily Underwood’s article, “How humans- and other mammals- might have gotten their night vision“, it immediately intrigued me. Sight is an amazing gift that we all take for granted. Our eyes are incredible organs, and scientists are now discovering how they work when we see in the dark naturally. That is pretty cool!

Underwood’s article describes a study that gives insight into how our eyes work in the dark. According to her, “On a moonless night, the light that reaches Earth is a trillion–fold less than on a sunny day. Yet most mammals still see well enough to get around just fine—even without the special light-boosting membranes in the eyes of cats and other nocturnal animals.

In broad daylight, mammalian retinas respond to photons, which activate rods, which then send an electrical signal to the brain through a ganglion cell. It was thought that this retinal circuit was the same when the sun went down, but a new study by Greg Field and his colleagues at Duke University proves that the retinal cells adapt when there is no light to create what we know was natural night vision. How?

To understand this new study, we first need to know about direction-selective ganglion cells.

Direction-selective ganglion cells (DSGCs) specialize in motion detection. Depending on the movement of an object, different cells get excited. For example, some DSGCs fire when an object moves up and down and other DSGCs fire when an object moves from left to right. These ganglion cells play an important role in telling the brain where an object is moving towards. By doing this, the brain can make a decision as to how your body should act.

However, in the dark DSGCs behave very differently. Field’s experiments aimed to see how the DSGCs adapt when there is no light. His team examined slices of mouse retinas on glass plates embedded with electrode arrays. In an oxygenated solution, the mouse retinas could still “see” while the arrays recorded the electrical activity of the neurons. They ran the experiment twice: once under a normal “office light” setting, and once by dimming the lights to a moonlight setting. Looking at the results, Field found that three of the four directional DSGCs did not have a response to motion when they dimmed the lights. The only cells that were responding were the ones that usually respond to the motion “up” in daylight. In fact, these cells compensated for the other DSGCs, and were now responding to motions like “down” and “sideways”.

Why were the “up” DSGCs were acting differently? To answer this question, Field genetically engineered mice without intracellular gap junctions to run the experiment again. Gap junctions have previously been associated with night vision, and the results in Field’s experiment confirmed their relationship. The mice lacking gap junctions were not able to adapt to the dark. This shows that gap junctions are critical in boosting motion detection in the “up” cells when there is limited light.

It is still not known why specifically the “up” cells contribute to natural night vision, what do you think?

Field’s findings will be helpful to artificial vision efforts. DSGCs make up 4% of ganglion cells in humans, a small amount compared to 20% in mice. Yet a large part of retinal prosthetics relies on electrically stimulated ganglion cells. Studies like this can fine-tune the technologies that will be able to help visually impaired people, which is why I love reading about them. These experiments are crucial in progressing the future of medicine and the treatment of all kinds of health issues.

Design Your Own Organelle!

What?

All eukaryotic cells consist of compartmentalized organelles, each with a specific function. We’ve all heard of mitochondria, chloroplast, and lysosomes, but, what if we could design a new organelle?! That’s exactly what scientists are working on right now – modifying or hijacking existing organelles to fit new specific functions.

Why?

Scientists currently have the technology to alter the DNA of cells to manufacture proteins they couldn’t “naturally” make. However, this technique has a few flaws. The proteins produced or their intermediates could damage the cell and chemicals in the cell could damage the proteins. If we could compartmentalize the production of these new proteins, this problem would be avoided. So, we look to organelles!

How?

Stuart Warriner, a chemical biologist at the University of Leeds, and his colleagues believe peroxisomes are the key. Current techniques allow scientists to manipulate these organelles. Their experiments show that they could deliver certain proteins into the peroxisomes of most cells. These selective proteins are ones that are not usually made; therefore, we say that humans have “hijacked” the cell.

https://commons.wikimedia.org/wiki/File:OSC_Microbio_03_04_Peroxisome.jpg

What’s Next?

Scientists are hopeful that future research could lead to the ability to use peroxisomes to manufacture compounds by importing specific proteins into them. Currently, when an organelle is modified, every organelle of that type must be modified. Future research could ensure that modified and conventional organelles could coexist in the same cell. In addition, Warriner and his team are working on the modification of peroxisomes in yeast to produce desirable compounds. Despite these studies, Warriner believes that this technique of hijacking organelles will not be implemented in humans for decades, if not never, because it wouldn’t be particularly useful. To learn more, check out their findings!

Who Cares?

We have the ability to alter DNA and cells! That is amazing! Although peroxisome altercation may not prove to be essential to humans, it is still an impressive exploratory feat and a step toward greater modification in microscopic organisms. What do you think similar cell modification research should be focused on?

Our Intestines Cure Cancer??

There are over one hundred trillion organisms- most are bacteria- living in our intestine today. These are referred to as the gut microbiota.

While trillions of bacteria sounds scary, they can actually be very helpful. Research has been done worldwide and the discovery has been that gut microbes actually can kill cancer cells all over the body. (Not just in the intestines) But how? Gut microbes and cancer actually cross paths. Gut microbes can manipulate the immune system and can either increase inflammation or lower it as needed. This means the bacteria can actually work with cancer treatments, boost T-cells, and control other factors that help cancer grow such as fungi, or viruses.

However, this is not all. While some cells help against cancer growth, others do the opposite. It varies cancer to cancer, and all have different results. As said by microbiologist and immunologist Patrick Schloss “What we really need is to have a much better understanding of which species, which type of bug, is doing what and try to change the balance.” So more research is still being done to decide how to control the microbiota, but a possible theory is that because it’s in the intestine it is related to our metabolisms and so what we eat controls the bacterium- this can also then effect the colon, thus effecting more cancer: colon cancer.

 

Stem Cells…Key to Youth and Controversy

Have you ever wondered what it would be like to be young forever? With the help of stem cells, this is possible. Stem cells can regenerate skin tissues and can also be used to treat diseases. However, something as enticing as living forever has its controversies. There are two types of stem cells: embryonic (ES) and adult (iPS); the embryonic stem cells are the controversial type.

Embryonic Stem Cell

Embryonic Stem Cell

The only way to effectively use the embryonic stem cell is to kill a four to six day old embryo. Some people view this act as killing a baby, which sparks ethical arguments about whether or not to utilize embryonic stem cells. To avoid this controversy, scientists have been trying to use stem cells from iPS cells instead of ES cells, but they questioned the power of iPS cells compared to the ES ones.

Because genes may differ in the iPS cells from the its source, the ES cells, there is a possibility that these two cells do not have the same capability. One scientist notes that the source of iPS and ES cells differ, which can lead to differences in gene activity. The ES cells are derived from embryos, which are not completely identical to iPS adult cells.  However, recent scientific research shows that these two types of stem cells have more equal capabilities than scientists’ initially thought.

Scientists conducted an experiment to compare the genetic makeup between the ES and iPS cell. They manipulated the male type of each cell, which eventually allowed the ES cell to transform into the iPS cell. They concluded that the iPS cells genetically matched the ES cells’ parents, and that the iPS cells had more similarities with the ES cells than iPS cells had to each other.

Even though these two experimental cells genetically matched, the two cells were not identical. The experiment showed 49 genes that differed between the two stem cells. Because of this difference, scientists needed to see if this affected the functional capability of the cells. The researchers conducted another experiment that analyzed 2 of the 49 genes. One helps take in glucose, while the other helps break it down. Even though these two genes were more active in the ES cell than the iPS cell, they were equally efficient at their respective jobs. The scientists concluded that these two specific cells were functionally equivalent.

The many experiments that have been conducted on the topic of stem cells contribute to the increase in research for more ways to utilize stem cells, without the ethical controversy. Scientists are starting to employ different technological devices, such as 3-D printers to help develop and build stem cells. This ability to fabricate cells using technology overcomes previous obstacles of limited stem cell resources.

– Source Article

– More fun facts about stem cells here

Do Viruses Make Us Smarter?

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Sanofi Pasteur

A study conducted at the Lund University shows that “inherited viruses” that are millions of years old play an important role in building up the complex networks that characterize the human brain.” It is well known that retroviruses are make up about five percent of our DNA. Research under Johan Jakobsson indicate that retroviruses may play a critical role in the basic functions of the brain, “in the regulation of which genes are to be expressed, and when.”

Studies of neural stem cells show that these cells use a particular molecular mechanism to control the activation processes of the retroviruses. Findings have shown to have increasingly gained control in our cellular machinery. Because tumors are unable to form in nerve cells, different from other teachers, viruses are activated specifically in the brain. The results open up potential for new research paths concerning brain diseases linked to genetic factors.

“I believe that this can lead to new, exciting studies on the diseases of the brain. Currently, when we look for genetic factors linked to various diseases, we usually look for the genes we are familiar with, which make up a mere two per cent of the genome. Now we are opening up the possibility of looking at a much larger part of the genetic material which was previously considered unimportant. The image of the brain becomes more complex, but the area in which to search for errors linked to diseases with a genetic component, such as neurodegenerative diseases, psychiatric illness and brain tumors, also increases”.

Original Article: http://www.biologynews.net/archives/2015/01/12/do_viruses_make_us_smarter.html

For More Info:

http://www.sciencedaily.com/releases/2015/01/150112093129.htm

Human skin cells reprogrammed directly into brain cells

Brain

 

Original article: http://www.sciencedaily.com/releases/2014/10/141022123021.htm

Some key words:

Neurodegenerative diseases: Disease such as Alzheimer’s, Parkinson’s and Huntington’s disease that undergo a neurodegenerative process, specific neurons are targeted for degeneration.

Spiny brain cell: The desired end brain cell in this study, and a brain cell affected by Huntington’s disease

 

In a study by the researchers at Washington University School of Medicine in Saint Louis, they demonstrate a way for human skin cells to be specifically converted to a type of brain cell. This study can help in the rehabilitation of people with Huntington’s disease by turning skin cells in to brain cells that are lost through this neurodegenerative disease. This is all accomplished without passing through the stem cell phase preventing other cell types forming.

This research involved adult skin cells that Yoo, the senior author, and his colleagues reprogrammed by using two microRNAs: miR-9, and miR-124. These micro RNAs open up the otherwise tightly packaged and inactive sections of the gene critical to the formation of brain cells. While the micro RNAs open up genes used for the creation and functionality of neurons, transcription factors taken from a part of the brain where medium spiny neurons are common directs the newly formed brain cells to a specific subunit of brain cells. The researchers then observed that the newly formed brain cells behave and function in a similar way to the native medium spiny neurons in mice, allowing this study to proceed in to further stages of experimentation, and hopefully result in a treatment practical for human use.

This study is very critical in the advancement of the treatment for neurodegenerative disease such as Huntington’s disease. Using different transcription factors from parts of the brain, alternate types of brain cells can be created to replace cells lost from neurodegenerative effects. This form of treatment will also prevent rejection of the transplant because the skin cells can be taken from the patient’s own body. This is a breakthrough in our pursuit of cures for these lethal neurodegenerative diseases.

Coral Reef Bleaching Puts Fish’s Ability to “Just Keep Swimming” in Danger

Coral reefs are vital sources of life for many sea creatures. The diversity of the underwater ecosystems surrounding coral reefs are, unfortunately, being put in danger because of coral bleaching. According to the National Ocean Service, coral bleaching is due in part by a process that is the result of damaged chloroplasts in coral cells which produce “toxic, highly reactive oxygen molecules during photosynthesis.” The main cause of this issue, is temperature; the coral respond to the drastic changes in temperature, whether they be hot or cold, by releasing the symbiotic algae that dwell in their tissues, which result in the coral taking on a white, “bleached” color.

Found on Flickr, Licensed under Creative Commons Licensing

Coral bleaching has both negative internal and external effects. Internally, the coral’s ecosystems are placed at risk because they “rely on live coral for food, shelter, or recruitment habitat.” This is a major issue, as we have the potential to lose certain, diverse, species that live off of and around coral reefs, which, in turn, could negatively influence the food chain. The external effect is that there will not be tourism revenue brought in from people who scuba dive to the coral reefs affected by bleaching. This is due to the fact that they will no longer be aesthetically appealing. Thus, leading to a negative economic state in tourism hot spots.

Unfortunately, the temperature of the Earth is out of human control, so there is little we can do to prevent coral bleaching, but we can use the rapidity of the bleaching as a marker to gauge the temperature of the world.

HeLa Cells Sequenced!

Photo By: University of Arkansas
Wellcome Trust

The immortal cell, also known as HeLa cells, have been used by scientists for years for various medical research. But, until today the genome of HeLa cells was never known. Jonathan Landry and Paul Pyl, from the European Molecular Biology Laboratory in Heidelberg, performed the study to sequence Henrietta Lacks‘ genome, and what they found was quite remarkable. They found striking differences between her cells and the cells of a normal human being. The genome had abnormalities in both chromosome number and structure. They also found that countless regions of the chromosomes in each cell were arranged in the wrong order and had extra or fewer copies of genes, all telltale signs of chromosome shattering. Chromosome shattering has recently been found to be linked to 2-3% of cancers. Seeing as how Henrietta Lacks’ cells were taken from a cervical tumor, this is not a surprising find. However, because her genome had never been sequenced this was all new to Landry and Pyl. They said, “The results provide the first detailed sequence of a HeLa genome. It demonstrates how genetically complex HeLa is compared to normal human tissue. Yet, possibly because of this complexity, no one had systematically sequenced the genome, until now.” Another scientist, Lars Steinmetz, who led the project, added, “Our study underscores the importance of accounting for the abnormal characteristics of HeLa cells in experimental design and analysis, and has the potential to refine the use of HeLa cells as a model of human biology.” Although this study is nowhere near groundbreaking, it still helps to highlight the importance of the extensive differences that cell lines can have from their human references.

For more information on this study and HeLa cells in general, you can go to:http://www.science20.com/news_articles/genome_hela_cell_line_sequenced-106181

 

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