#23 New Hearts, eDNA Revealing Reefs and Stressed Mitochondria...
New miniature - plastic hearts helping research, locating fish without looking and the stressed mitochondria...
šNew Miniature Hearts
New hearts could help speed disease curesā¦
One of the fundamental issues in cardiac disease research is that there is no safe way to get a close up view of the heart in an āactiveā condition. All alternatives that are currently used, whether cadaver hearts hooked up to a machine or lab grown heart tissues, have their flaws. They cannot accurately replicate the forces at work on the real muscle. A multidisciplinary team of engineers, biologists and geneticists have built a miniature replica of a heart chamber by using a combination of nanoengineered parts and human heart tissue. What makes this breakthrough so important is the fact that that replica model doesnāt rely on springs or an external power source, it beats itself using the live heart tissue grown from stem cells. This could give the scientific community a more accurate view of how the organ and associated diseases work.
Nicknamed the miniPUMP (Aka. the cardiac miniaturized precision-enabled Unidirectional Microfluidic Pump) the technology could be a key starting point in the building of other lab based organs such as lungs and kidneys. Boston University College of Engineering professor said that "We can study disease progression in a way that hasn't been possible before," she went on to say that "We chose to work on heart tissue because of its particularly complicated mechanics, but we showed that, when you take nanotechnology and marry it with tissue engineering, there's potential for replicating this for multiple organs."
The heart is susceptible to a lot of issues. When properly functioning the top two, and bottom two chambers are all responsible for keeping blood flowing around the body, diseases can alter this integral functioning. Arteries could narrow or block, valves can leak or malfunction, the heart muscle can thin or thicken as well as a variety of other issues. The miniPUMP isnāt much bigger than a postage stamp and built to act like a human ventricle. The custom made heart is created on a thin piece of 3D printed plastic with acrylic valves, controlling the flow of liquid (water rather than blood in this caseā¦).
These mini hearts are created using induced pluripotent stem cells. Researchers take a cell from an adult and reprogram it into an embryonic like stem cell. This is then transformed into the heart cell and so makes the cardiomyocyte (cells responsible for generating contractile force in the intact heart).
"With this system, if I take cells from you, I can see how the drug would react in you, because these are your cells,". "This system replicates better some of the function of the heart, but at the same time, gives us the flexibility of having different humans that it replicates. It's a more predictive model to see what would happen in humansāwithout actually getting into humans." said Christos Michas, post doctoral researcher.
This new technology could be key in assessing a new heart disease drugās chances of success long before clinical trials. Adverse side effects, especially those specific to the individual, could be identified at a much earlier stage.
š§¬eDNA Revealing Inhabitants
eDNA used to reveal secret coral reef inhabitantsā¦
eDNA is defined as nuclear or mitochondrial DNA that is released from an organism into the environment. Through sampling of seawater an international research team has been able to identify species and families to see where reef fish naturally occur.
Tropical reefs are famously colourful, diverse and rich in species with researchers estimating that coral reefs are a habitat to as many as 8,000 species of fish worldwide. However, as with many habitats and ecosystems across the world, global warming and human activities are causing coral reefs to decline at an alarming rate meaning that the number as well as distribution of fish species has not been accurately measured.
One of the main reasons for this is due to the difficulty of detection. Not only are many similar in appearance but also behaviour. Normally visual observations or catches are the main way in which biodiversity research is undertaken. However, a new method is making its way into ecology. eDNA sampling utilises the genetic material left behind in the environment by the organism. This approach allows researchers to take samples at a location, isolate the DNA and compare the sequences with reference DNA (sequences that come from reliably identified specimens) and so in turn reference that with DNA found at other sites, across the world.
This method is already showing results with the research team finding a 16% higher diversity of reef fishes than through conventional survey methods such as those previously mentioned. This new approach has discovered more species swimming in the open water (pelagic) as well as reef bound species.
Whilst eDNA is clearly key for the future of marine life sampling, not all species can be sampled using this approach. Wrasses or blennies are two groups where the reference databases are only partial. Due to these gaps a considerable part of the eDNA found in the water samples is not assigned. Therefore there is still a use for visual observations and catch recordings.
šReporting Stress
How mitochondria report stressā¦
Researchers have long suggested a link between the dysfunction of mitochondria and the age related illness such as Alzheimerās disease. Professor Lucas Jae said how many illnesses cannot be cured, partly because we donāt yet understand fundamental mechanisms.
Whilst mitochondria have their own genome, they are incapable of responding independently to stress. Often dysfunction in this important organelle is a result of various forms of stress. Stress can come from the cell or organelle, however not being able to directly respond to stress, the disturbance must be āreportedā to the rest of the cell.
Two years ago, Jaeās team researched mitochondrial stress and how the organelle actually reported to the cell. The signalling pathway that consisted of proteins OMA1, HRI and DELE1 were found to complete this function. This still left the team with a number of questions such as "How does the DELE1 signal travel from the mitochondrion into the cytoplasm of the cell? And how can DELE1, as an individual protein, detect the many different types of stress?"
After years of researchers the team has found answersā¦ DELE1 is continuously imported into the mitochondria and processed by the proteases present. DELE1 is then quickly degraded. Resultantly there are molecules constantly passing through both the outer and inner membranes of mitochondria to be imported. Mitochondrial stress causes this importing process to fail.
Depending on the source of the disturbance, the new DELE1 molecules are either cut by OMA1 or remain un-cleaved outside the organelles meaning that either way they are āstoppedā on their way into the mitochondria. The portion of the DELE1 protein that holds the signalling effect is unmasked in the cytosol. "All the different types of stress lead to one of the sub-steps involved in the importing and processing of DELE1 coming to a halt," summarizes Jae. This is how mitochondrial stress is detected.
The researchers now want to discover how the decision is made as to whether the cell enters a repair phase due to a stress response or whether it goes into programmed cell death.
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š¦Marine
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š¼ Conservation
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š· Weekly Camera Roll
Click on the text below to keep readingā¦
Reference List
Content may be adapted and edited for style and length.
šNew Miniature Hearts
Michas, C., Karakan, M., Nautiyal, P., Seidman, J., Seidman, C., Agarwal, A., Ekinci, K., Eyckmans, J., White, A. and Chen, C., 2022. Engineering a living cardiac pump on a chip using high-precision fabrication. Science Advances, 8(16).
š§¬eDNA Revealing Inhabitants
Mathon, L., Marques, V., Mouillot, D., Albouy, C., Andrello, M., Baletaud, F., Borrero-PƩrez, G., Dejean, T., Edgar, G., Grondin, J., Guerin, P., HocdƩ, R., Juhel, J., Kadarusman, Maire, E., Mariani, G., McLean, M., Polanco F., A., Pouyaud, L., Stuart-Smith, R., Sugeha, H., Valentini, A., Vigliola, L., Vimono, I., Pellissier, L. and Manel, S., 2022. Cross-ocean patterns and processes in fish biodiversity on coral reefs through the lens of eDNA metabarcoding. Proceedings of the Royal Society B: Biological Sciences, 289(1973).
šReporting Stress
Fessler, E., Krumwiede, L. and Jae, L., 2022. DELE1 tracks perturbed protein import and processing in human mitochondria. Nature Communications, 13(1).
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