Weekly Updates | April 1 | #6
Update #1 | Pig-To-Human Kidney Transplant
Doctors in the US have successfully transplanted a gene-edited pig kidney into a living person. This groundbreaking procedure could potentially address the shortage of organs available for transplantation. The patient, Richard "Rick" Slayman, is recovering well, and doctors expect the pig kidney to function for at least two years. This experiment is the latest development in xenotransplantation, which aims to use animal organs in human patients. However, further studies involving more patients in different medical centers are necessary for this procedure to become more widely available.
Key points:
Doctors in the US have transplanted a gene-edited pig kidney into a living person for the first time.
The patient, Richard "Rick" Slayman, is recovering well from the surgery and is expected to be discharged soon.
The pig kidney was provided by a company called eGenesis and was genetically edited to remove harmful pig genes and add certain human genes to improve compatibility.
This procedure is part of the ongoing efforts in xenotransplantation to use animal organs to address the shortage of organs available for transplantation.
While this is a significant step forward, more studies involving more patients in different medical centers are needed for this procedure to become more commonly available.
Highlights:
This is the first time a genetically modified pig kidney has been transplanted into a living person.
Previous experiments involved temporarily transplanting pig kidneys into brain-dead donors.
The patient, Richard Slayman, had a kidney transplant in 2018 but had to go back on dialysis when it showed signs of failure.
If the pig kidney fails, Slayman could go back on dialysis.
More than 100,000 people in the US are on the waiting list for a transplant, with most of them being kidney patients.
The Food and Drug Administration gave special permission for Slayman's transplant under "compassionate use" rules.
Reference:
Update #2 | A Non-Destructive Method of Monitoring Gene Expression
Researchers at MIT have developed a new method that combines Raman spectroscopy with machine learning to track changes in gene expression in live cells over time. This noninvasive imaging technique has the potential for applications in cancer research, developmental biology, and diagnostics.
Key points:
The new method uses Raman spectroscopy to study cellular differentiation and changes in gene expression without harming cells.
It combines the advantages of single-cell RNA sequencing and Raman spectroscopy to understand gene expression profiles at the single-cell level over time.
The researchers trained a computational model to translate Raman signals into RNA expression states to track gene expression changes.
The method was successfully tested on mouse fibroblast cells as they differentiated into other cell types.
The researchers plan to use this technique to study aging cells, cancerous cells, and other types of cell populations that change over time.
Highlights:
Raman spectroscopy is a noninvasive imaging technique that reveals the chemical composition of tissues or cells.
RNA sequencing provides detailed information about gene expression but is destructive to cells, making it difficult to study ongoing changes.
The combination of Raman spectroscopy and machine learning allows researchers to track gene expression changes in live cells without harming them.
This technique has the potential for applications in cancer research, developmental biology, and diagnostics.
Reference:
Redefining Cell Biology: Nondestructive Genetic Insights With Raman Spectroscopy (scitechdaily.com)
Prediction of single-cell RNA expression profiles in live cells by Raman microscopy with Raman2RNA” by Koseki J. Kobayashi-Kirschvink, Charles S. Comiter, Shreya Gaddam, Taylor Joren, Emanuelle I. Grody, Johain R. Ounadjela, Ke Zhang, Baoliang Ge, Jeon Woong Kang, Ramnik J. Xavier, Peter T. C. So, Tommaso Biancalani, Jian Shu and Aviv Regev, 10 January 2024, Nature Biotechnology. DOI: 10.1038/s41587-023-02082-2
Update #3 | DNA, RNA and TNA
Researchers at the University of Cologne have developed a new type of nucleic acid called threofuranosyl nucleic acid (TNA), which has enhanced stability and therapeutic potential. TNA has applications in drug delivery and diagnostics and could be used for targeted drug delivery and the recognition of viral proteins or biomarkers.
Key points
The creation of threofuranosyl nucleic acid (TNA) offers enhanced stability and therapeutic potential.
TNA has applications in drug delivery and diagnostics.
TNA is more stable than DNA and RNA.
TNA has an additional base pair, allowing for alternative binding options to target molecules in cells.
TNAs could be used for targeted drug delivery and the recognition of viral proteins or biomarkers.
Highlights
Researchers at the University of Cologne have developed threofuranosyl nucleic acid (TNA), a new type of nucleic acid with enhanced stability and therapeutic potential.
TNA has applications in drug delivery and diagnostics, as it is more stable than DNA and RNA.
TNA has an additional base pair, allowing for alternative binding options to target molecules in cells.
TNAs could be used for targeted drug delivery and the recognition of viral proteins or biomarkers.
Reference:
Unlocking TNA: Researchers Develop Artificial Building Blocks of Life (scitechdaily.com)
Expanding the Horizon of the Xeno Nucleic Acid Space: Threose Nucleic Acids with Increased Information Storage” by Hannah Depmeier and Stephanie Kath-Schorr, 5 March 2024, Journal of the American Chemical Society. DOI: 10.1021/jacs.3c14626
Update #4 | New Insights Into The Evolution of Nervous System
New research explores the evolution of nervous systems across different species by comparing the sizes of genes in different organisms. The study reveals that many genes found in brain cells and synapses, which are implicated in neurological disorders, are among the largest in the animal kingdom. The research suggests that the growth and diversification of genes may have played a role in the development of complex nervous systems in multicellular animals.
Key points:
Genes found in brain cells and synapses are among the largest in the animal kingdom and are often associated with neurological disorders when mutated or misregulated.
The study compares gene sizes in different species that originated from a common ancestor and reveals a distinct class of large genes that existed before the diversification of animals.
Similar giant genes have been found in both humans and cephalopods, suggesting a general role for gene size in the development of complex nervous systems.
The research suggests that gene growth and diversification may have provided the flexibility needed for complex nervous systems to evolve.
Highlights:
Giant genes found in brain cells and synapses have evolved separately in humans and cephalopods, indicating a general role for gene size in the development of complex nervous systems.
The study suggests that gene growth and diversification may have contributed to the evolutionary development of complexity in the animal kingdom.
Understanding the genomic underpinnings of nervous system complexity can provide insights into the origins of complexity and the genetic basis of neurological diseases.
Reference:
Matthew J. McCoy et al, Parallel gene size and isoform expansion of ancient neuronal genes, Current Biology (2024). DOI: 10.1016/j.cub.2024.02.021. www.cell.com/current-biology/a … 0960-9822(24)00163-5
Update #5 | Memory Formation In Brain Requires DNA Damage And Repair
A study in mice has found that long-term memories are formed through a process of breaking and repairing DNA in brain cells. The study showed that when a memory is formed, some brain cells experience electrical activity that causes breaks in their DNA. This triggers an inflammatory response, which repairs the DNA and helps to solidify the memory. The researchers believe that this DNA damage-and-repair cycle could be faulty in people with neurodegenerative diseases such as Alzheimer's, leading to a buildup of errors in a neuron's DNA.
Key points:
Long-term memories are formed when DNA in brain cells is broken and then repaired.
The DNA damage and repair process helps to solidify the memory.
If the DNA repair process is faulty, it could contribute to neurodegenerative diseases such as Alzheimer's.
Highlights:
The study provides insight into the risky nature of memory formation, as DNA breaks are usually associated with diseases like cancer.
The inflammatory response triggered by the DNA damage suggests that memories could be encoded in the repair process.
Deleting the gene responsible for triggering the inflammatory response in mice resulted in impaired long-term memory recall.
Reference:
Update #6 | Break And Replicate - A Model For RNA Replication
Researchers have developed a model that suggests how ancient RNA molecules may have gained the ability to self-cut, a crucial step in the replication process essential for life. The model simulates basic RNA molecules without enzymatic activity, allowing random bond breakage to occur. The researchers observed that breakage led to more copies of the polymer, favoring molecules capable of self-cleavage and replication. In a second model, the researchers demonstrated how RNA molecules could evolve into complex ecosystems with functional properties. The findings shed light on the natural emergence and selection of ribozymes with enzymatic activity, providing insights into early life evolution.
Key points:
Scientists have developed a model to explain how ancient RNA molecules gained the ability to self-cut, an essential step in replication.
The model simulates basic RNA molecules without enzymatic activity and allows random bond breakage, mimicking real-world chemical processes.
Breakage leads to more copies of the polymer, favoring molecules capable of self-cleavage and replication.
In a second model, the researchers showed how RNA molecules could evolve into complex ecosystems with functional properties.
The findings offer insights into the natural emergence and selection of ribozymes with enzymatic activity, providing a better understanding of early life evolution.
Highlights:
RNA, similar to DNA, possesses the ability to store genetic information and is believed to have played a central role in early life.
The challenge lies in understanding how ancient RNA molecules acquired the ability to self-cut, a crucial step in replication.
The researchers propose a model that demonstrates how ancient RNA molecules could have gained functionality through random bond breakage.
These findings shed light on the natural emergence and selection of ribozymes with enzymatic activity, addressing a crucial aspect of early life evolution.
Reference:
Model suggests how ancient RNA may have gained self-cutting ability essential for life (phys.org)
Alexei V. Tkachenko et al, Emergence of catalytic function in prebiotic information-coding polymers, eLife (2024). DOI: 10.7554/eLife.91397.2