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Archive for the ‘biotech/medical’ category: Page 2527

Sep 1, 2015

DNA-guided 3-D printing of human tissue is unveiled

Posted by in categories: 3D printing, biotech/medical, chemistry

A UCSF-led team has developed a technique to build tiny models of human tissues, called organoids, more precisely than ever before using a process that turns human cells into a biological equivalent of LEGO bricks. These mini-tissues in a dish can be used to study how particular structural features of tissue affect normal growth or go awry in cancer. They could be used for therapeutic drug screening and to help teach researchers how to grow whole human organs.

The new technique — called DNA Programmed Assembly of Cells (DPAC) and reported in the journal Nature Methods on August 31, 2015 — allows researchers to create arrays of thousands of custom-designed organoids, such as models of human mammary glands containing several hundred cells each, which can be built in a matter of hours.

There are few limits to the tissues this technology can mimic, said Zev Gartner, PhD, the paper’s senior author and an associate professor of pharmaceutical chemistry at UCSF. “We can take any cell type we want and program just where it goes. We can precisely control who’s talking to whom and who’s touching whom at the earliest stages. The cells then follow these initially programmed spatial cues to interact, move around, and develop into tissues over time.”

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Sep 1, 2015

New ‘Tissue Velcro’ could help repair damaged hearts

Posted by in categories: biotech/medical, engineering

Engineers at the University of Toronto just made assembling functional heart tissue as easy as fastening your shoes. The team has created a biocompatible scaffold that allows sheets of beating heart cells to snap together just like Velcro™.

“One of the main advantages is the ease of use,” says biomedical engineer Professor Milica Radisic, who led the project. “We can build larger tissue structures immediately before they are needed, and disassemble them just as easily. I don’t know of any other technique that gives this ability.”

Growing heart muscle cells in the lab is nothing new. The problem is that too often, these cells don’t resemble those found in the body. Real heart cells grow in an environment replete with protein scaffolds and support cells that help shape them into long, lean beating machines. In contrast, lab-grown cells often lack these supports, and tend to be amorphous and weak. Radisic and her team focus on engineering artificial environments that more closely imitate what cells see in the body, resulting in tougher, more robust cells.

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Aug 31, 2015

A Surprise Source of Life’s Code

Posted by in category: biotech/medical

Junk DNA can occasionally spit out useful genes. Randomly?


Emerging data suggests the seemingly impossible — that mysterious new genes arise from “junk” DNA.

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Aug 31, 2015

Scientists ‘delete’ HIV virus from human DNA for the first time

Posted by in category: biotech/medical

smile


A team at Temple University in Philadelphia used a combination of a DNA-snipping enzyme to eradicate the viral genome from the human cell.

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Aug 31, 2015

Hacking Aging

Posted by in categories: biotech/medical, life extension

What would you say if I told you that aging happens not because of accumulation of stresses, but rather because of the intrinsic properties of the gene network of the organism? I’m guessing you’d be like: surprised .

So, here’s the deal. My biohacker friends led by Peter Fedichev and Sergey Filonov in collaboration with my old friend and the longevity record holder Robert Shmookler Reis published a very cool paper. They proposed a way to quantitatively describe the two types of aging – negligible senescence and normal aging. We all know that some animals just don’t care about time passing by. Their mortality doesn’t increase with age. Such negligibly senescent species include the notorious naked mole rat and a bunch of other critters like certain turtles and clams to name a few. So the paper explains what it is exactly that makes these animals age so slowly – it’s the stability of their gene networks.

What does network stability mean then? Well, it’s actually pretty straightforward – if the DNA repair mechanisms are very efficient and the connectivity of the network is low enough, then this network is stable. So, normally aging species, such as ourselves, have unstable networks. This is a major bummer by all means. But! There is a way to overcome this problem, according to the proposed math model.

Continue reading “Hacking Aging” »

Aug 28, 2015

Editing humanity

Posted by in categories: biotech/medical, genetics

THE genome is written in an alphabet of just four letters. Being able to read, study and compare DNA sequences for humans, and thousands of other species, has become routine. A new technology promises to make it possible to edit genetic information quickly and cheaply. This could correct terrible genetic defects that blight lives. It also heralds the distant prospect of parents building their children to order.

The technology is known as CRISPR-Cas9, or just CRISPR. It involves a piece of RNA, a chemical messenger, designed to target a section of DNA; and an enzyme, called a nuclease, that can snip unwanted genes out and paste new ones in. Other ways of editing DNA exist, but CRISPR holds the promise of doing so with unprecedented simplicity, speed and precision.

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Aug 27, 2015

Telomere dysfunction induces metabolic and mitochondrial compromise. Nature

Posted by in categories: biotech/medical, life extension

Dr DePinho released a paper in 2012, this builds on previous papers and his theory of the “telomere-p53-PGC axis”. This is a big reason along with the work of Dr Michael Fossel I believe telomerase therapy is probably the best chance of radical life extension in the near future. This is one of a number of papers that implicate dysfunctional telomeres in a cascade that causes mitochondrial dysfunction and various other aging consequences.

ABSTRACT Telomere dysfunction activates p53-mediated cellular growth arrest, senescence and apoptosis to drive progressive atrophy and functional decline in high-turnover tissues. The broader adverse impact of telomere dysfunction across many tissues including more quiescent systems prompted transcriptomic network analyses to identify common mechanisms operative in haematopoietic stem cells, heart and liver. These unbiased studies revealed profound repression of peroxisome proliferator-activated receptor gamma, coactivator 1 alpha and beta (PGC-1α and PGC-1β, also known as Ppargc1a and Ppargc1b, respectively) and the downstream network in mice null for either telomerase reverse transcriptase (Tert) or telomerase RNA component (Terc) genes. Consistent with PGCs as master regulators of mitochondrial physiology and metabolism, telomere dysfunction is associated with impaired mitochondrial biogenesis and function, decreased gluconeogenesis, cardiomyopathy, and increased reactive oxygen species. In the setting of telomere dysfunction, enforced Tert or PGC-1α expression or germline deletion of p53 (also known as Trp53) substantially restores PGC network expression, mitochondrial respiration, cardiac function and gluconeogenesis. We demonstrate that telomere dysfunction activates p53 which in turn binds and represses PGC-1α and PGC-1β promoters, thereby forging a direct link between telomere and mitochondrial biology. We propose that this telomere-p53-PGC axis contributes to organ and metabolic failure and to diminishing organismal fitness in the setting of telomere dysfunction.

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Aug 27, 2015

Discovery of new code makes reprogramming of cancer cells possible

Posted by in category: biotech/medical

Cancer researchers dream of the day they can force tumor cells to morph back to the normal cells they once were. Now, researchers on Mayo Clinic’s Florida campus have discovered a way to potentially reprogram cancer cells back to normalcy.

The finding, published in Nature Cell Biology, represents “an unexpected new biology that provides the code, the software for turning off cancer,” says the study’s senior investigator, Panos Anastasiadis, Ph.D., chair of the Department of Cancer Biology on Mayo Clinic’s Florida campus.

That code was unraveled by the discovery that adhesion proteins — the glue that keeps cells together — interact with the microprocessor, a key player in the production of molecules called microRNAs (miRNAs). The miRNAs orchestrate whole cellular programs by simultaneously regulating expression of a group of genes. The investigators found that when normal cells come in contact with each other, a specific subset of miRNAs suppresses genes that promote cell growth. However, when adhesion is disrupted in cancer cells, these miRNAs are misregulated and cells grow out of control. The investigators showed, in laboratory experiments, that restoring the normal miRNA levels in cancer cells can reverse that aberrant cell growth.

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Aug 27, 2015

Anti-cancer vaccine uses patient’s own cancer cells to trigger immune responses

Posted by in categories: biotech/medical, genetics

Cancerous melanoma cells, shown with their cell bodies (green) and nuclei (blue), are nestled in tiny hollow lumens (tubes) within the cryogel (red) structure. (credits: Thomas Ferrante, Sidi A. Bencherif / Wyss Institute at Harvard University)

A new biologically inspired “injectable cryogel whole-cell cancer vaccine” combines patient-specific harvested cancer cells and immune-stimulating chemicals or biological molecules to help the body attack cancer. It has been developed by scientists at Harvard’s Wyss Institute and Dana-Farber Cancer Institute.

This new approach is simpler and more economical than other cancer cell transplantation therapies, which harvest tumor cells and then genetically engineer them to trigger immune responses once they are transplanted back into the patient’s body, the researchers say.

Continue reading “Anti-cancer vaccine uses patient’s own cancer cells to trigger immune responses” »

Aug 27, 2015

PGC-1α Modulates Telomere Function and DNA Damage in Protecting against Aging-Related Chronic Diseases

Posted by in categories: biotech/medical, life extension

An interesting paper that uses ALA to shore up telomerase activity, loss of telomeres inhibition of P53 expression and mitochondrial dysfunction in one go. They use ALA (alpha lipoic acid) to induce PGC-1α in this case though PGC1-alpha seems to be a potential target for intervention as I understand that ALA is difficult to deliver to cells. In this case this involves the vascular system and atherosclerosis.

http://www.cell.com/cell-reports/abstract/S2211-1247(15)00825-6

Short telomeres and Mitochondrial dysfunction are increasingly implicated as being closely linked as this 2012 Dephino paper demonstrates in the aging heart:

Continue reading “PGC-1α Modulates Telomere Function and DNA Damage in Protecting against Aging-Related Chronic Diseases” »