In a new project, Harvard University researchers investigated an experimental method on mice that might be able to reverse the aging process.

Harvard Medical School (HMS) scientists have investigated the cause of aging and identified a possible way to reverse it. In experiments on mice, they showed that problems in epigenetics trigger the signs of aging and that a reboot can reverse them and perhaps extend life.

Our genome contains a complete map of the DNA found in every cell in our body. This is not the whole picture but an additional layer of information called the epigenome, which controls which genes are turned on and off in different cell types. It’s as if all the cells in our body work based on an operating manual, the genome, but the epigenome is like a list of contents that directs different cells to different chapters, which are genes. After all, lung cells need very further instructions from heart cells.

Reverse aging process

Environmental and lifestyle factors such as diet, exercise, and even childhood experiences can alter epigenetic expression. Epigenetic changes have been linked to the rate of biological aging, but whether they represent signs of aging or are themselves a symptom was not yet clear. Researchers in this project conducted experiments on mice to find out the answer. Using a system called ‘Induced Changes in the Epigenome’ (ICE), they sped up the natural process of DNA damage and repair in mice to see if this accelerated the signs of aging.

In mammalian cells, chromosomes undergo a million DNA breaks per minute, and epigenetic factors rapidly coordinate the repairs before returning to their original sites. The research group engineered mice that underwent DNA breakage at a rate three times faster than usual.

Over time, researchers discovered that epigenetic factors become increasingly disturbed and do not return home after repairing DNA breaks. This leads to epigenome scrambling. At six months, the mice showed physical signs of aging and appeared in significantly worse health than age-matched unedited mice.

Researchers say that this research has confirmed the role of the epigenome in aging. The next step was to test whether something could be done about the problem. Researchers tested a gene therapy combination of three genes named “Oct4”, “Sox2,” and “Klf4”. These genes are active in stem cells, and the researchers found in their previous study that they could be used to restore vision to mice with age-related glaucoma.

New experiments on reverse aging

In this case, the ICE mice experienced a dramatic reduction in biomarkers of aging. Their epigenome was ripped apart, restoring their tissues and organs to a youthful state. David Sinclair, the project’s lead researcher, said: “It’s like restarting a broken computer, and it sets off an epigenetic program that directs the cells to restore the epigenetic information they had when they were young.” This is a permanent reset.

Read more : How humans lose their body hairs 

Researchers believe that this discovery is enormous. Many diseases caused by this natural process can be treated more effectively by tackling aging. Sinclair wrote in a tweet: “If the result is correct, it means that cancer, diabetes, and Alzheimer’s may have the same underlying cause.” In this way, the cause can be reversed to treat age-related diseases.

Although there is still much research to be done before such lofty goals can be realized, research is being done. A preprint paper, which has not yet been reviewed, applied the same gene therapy combination to aged mice, which are the equivalent of 77 years in humans. These mice lived 9% longer than untreated mice.

Via : New atlas

In their new research, a group of American scientists has investigated the reasons for body hair loss in mammals such as humans.

Body hair is a defining characteristic of mammals, but several mammals, such as whales, nudibranchs, and humans, have significantly less hair. Why we have significantly less hair than other mammals has long remained a mystery.

To find the genetic basis of hair loss, scientists at the University of Utah (UofU) and the University of Pittsburgh identified coding and non-coding sequences that evolve at different rates in hairless mammals compared to hairy mammals.

Humans body hair is about genetic

They found that humans seem to have the gene for a complete body hair covering. This research identifies several genes and genomic regions critical for hair growth. Also, this research shows that nature has used the same tactic at least nine times in different mammals. Ancestors of rhinos, nudibranchs, dolphins, and other hairless mammals used to swim and submerge to turn off a set of genes needed to lose hair and fur.

“We have taken a creative approach to use biodiversity to learn about our genetics,” said Dr. Nathan Clark, a human geneticist at the University of Utah who has conducted much of this research. This helps us identify regions of our genome that contribute to an important trait.

How humans lose their body hair

Scientists used an evolutionary rate-based method called RERconverge to perform a genome scan of 62 mammal species using 19,149 genes and 343,598 non-coding regions.

The analysis showed that many hairless mammals have mutations in many of the same genes. These genes encode keratin and extra elements that build the hair shaft and facilitate growth.

Also, this research showed that the genome’s regulatory regions seem equally important. Rather than encoding the structures that produce hair, these regions indirectly affect hair production. They control the amount of hair produced and when and where special genes are activated.

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Amanda Kowalczyk, one of the researchers of this project, said: There are many genes that we don’t know much about. We believe these genes can play a role in hair growth and maintenance.

As animals are under evolutionary pressure to lose hair, the genes that code for hair become less important, Clark said. This is why they increase the rate of genetic variation allowed by natural selection. Some genetic changes may lead to hair loss, and others may be collateral damage after hair growth stops.

He added: “When a screen identified known hair genes, it showed that this method was efficient.” Also, this research shows that the genes identified on the screen, which are not well defined, can be equally important for having hair. It is a way to determine the global genetic mechanisms that underlie different traits.

Scientists have discovered a way to create eye tissue using stem cells and 3D printing, which may lead to breakthroughs in the treatment of a wide range of degenerative eye diseases.

Scientists at the National Institute of Vision (NEI) have 3D printed a group of cells that can form the outer blood barrier of the retina. The outer retinal blood barrier is an eye tissue that supports the photoreceptor cells.

Creating eye tissue using stem cells

The method presented by this research group theoretically provides an unlimited source of patient-derived tissue to study retinal degenerative diseases such as macular degeneration (AMD) and use them to better understand how to treat these diseases.

Dr. Kapil Bharti, director of the stem cell and eye research at the National Institute of Vision, said: We know that macular degeneration begins in the outer blood barrier of the retina. Despite this, the mechanisms of initiation and progression of macular degeneration are still poorly understood due to the lack of physiologically relevant human models.

Nearly 20 million Americans suffer from some form of age-related macular degeneration. It is the leading cause of vision loss in Americans age 60 and older and the leading cause of irreversible blindness and vision loss worldwide.

Marc Ferrer, director of the 3D Tissue Bioprinting Laboratory at the National Institute of Vision, said: Our joint efforts have led to the presentation of retinal tissue models that are highly relevant to degenerative eye diseases. Such tissue models have many potential applications in therapeutic development.

Read more : Scientists discovered a new way for imaging blood flow 

Bharti and colleagues combined three types of immature choroidal cells into a hydrogel. These three types of cells are pericytes and endothelial cells, which are the main components of capillaries, and fibroblasts, which form the structure of tissues. They then printed the gel onto a biodegradable framework, and within days, the cells began to mature and transform into a dense capillary network.

On day 9, the scientists’ cultured retinal pigment epithelial cells on the other side of the biodegradable framework. Just one month later, the tissue reached full maturity. During subsequent experiments, the scientists found that the printed tissue resembled the outer blood barrier and retina of the real eye.

“By printing the cells, we facilitate the exchange of cellular signals that are essential for the normal anatomy of the blood-outer retinal barrier,” Bharti explained.

Via : NIH