Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Singapore scientists discover rejuvenation factors

17.08.2015

Findings will advance our understanding of how cellular metabolism changes during aging and during rejuvenation after egg fertilisation.

Scientists from A*STAR’s Genome Institute of Singapore (GIS) have discovered metabolic rejuvenation factors in eggs. This critical finding furthers our understanding of how cellular metabolism changes during aging, and during rejuvenation after egg fertilisation.


Mitochondria during cellular aging. Copyright: A*STAR

When a sperm fertilises an egg to create a baby, two adult cells combine to form a new embryo. A similar process of combining an egg’s cytoplasm with an adult cell nucleus led to the cloning of Dolly the sheep. However, the metabolic factors underlying this fascinating process had remained unclear.

A new study from GIS suggests that old mitochondria – the oxygen-consuming metabolic engines in cells – are roadblocks to cellular rejuvenation. By tuning up a gene called Tcl1, which is highly abundant in eggs, researchers were able to suppress old mitochondria to enhance a process known as somatic reprogramming, which turn adult cells into embryonic-like stem cells.

GIS researchers found that Tcl1 does its job by suppressing mitochondrial polynucleotide phosphorylase, thereby inhibiting mitochondrial growth and metabolism.

Findings from the study were published in the scientific journal Cell Reports.

Stem cell researchers had known that egg (or oocyte) cytoplasm contains some special unknown factors that can reprogramme adult cells into embryonic-like stem cells, either during egg-sperm fertilisation or during artificial cloning procedures like those that created Dolly the sheep. While the Nobel Prize winner Dr Shinya Yamanaka had invented a technology called induced pluripotent stem cell (iPSC) reprogramming to replace the ethically controversial oocyte-based reprogramming technique, oocyte-based reprogramming was still deemed superior in complete cellular reprogramming efficiency.

To address this shortfall, the GIS team led by Dr Khaw Swea-Ling, Dr Lim Bing and Dr Ng Shyh-Chang combined oocyte factors with the iPSC reprogramming system. Their bioinformatics-driven screening efforts[1] led to two genes: Tcl1 and its cousin Tcl1b1. After a deeper investigation, the team found that the Tcl1 genes were acting via the mitochondrial enzyme, PnPase.

“We were quite surprised, because nobody would have thought that the key to the oocyte’s reprogramming powers would be a mitochondrial enzyme. The stem cell field’s conventional wisdom suggests that it should have been some other signalling genes instead,” said corresponding author of the research, Dr Ng Shyh-Chang.

Tcl1 is a cytoplasmic protein that binds to the mitochondrial enzyme PnPase. By locking PnPase in the cytoplasm, Tcl1 prevents PnPase from entering mitochondria, thereby suppressing its ability to promote mitochondrial growth and metabolism. Thus, an increase in Tcl1 suppresses old mitochondria’s growth and metabolism in adult cells, to enhance the somatic reprogramming of adult cells into embryonic-like stem cells.

Cracking the mystery of reprogramming factors in oocytes is an important milestone. These new insights could boost efficacy of the alternative, non-oocyte-based iPSC techniques for stem cell banking, organ and tissue regeneration, as well as further our understanding of how cellular metabolism rejuvenates after egg-sperm fertilisation. This could help address both the aging and the fertility problems of modern societies.

GIS Executive Director Prof Ng Huck Hui said, “This is an exciting step forward in the study of cellular aging. Although accumulated defects in mitochondrial metabolism were known to cause cellular aging, no solutions were available. Shyh-Chang’s team has uncovered a molecular pathway to solve this problem”.

[1] While the researchers attempted to deconstruct the mechanisms of oocyte-based reprogramming, no human oocytes or embryos were used or destroyed in the process as the screening effort was bioinformatics database-driven.


Associated links
Original press release from A*STAR

A*STAR Research | ResearchSea
Further information:
http://www.researchsea.com

More articles from Life Sciences:

nachricht Ion treatments for cardiac arrhythmia — Non-invasive alternative to catheter-based surgery
20.01.2017 | GSI Helmholtzzentrum für Schwerionenforschung GmbH

nachricht Seeking structure with metagenome sequences
20.01.2017 | DOE/Joint Genome Institute

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Traffic jam in empty space

New success for Konstanz physicists in studying the quantum vacuum

An important step towards a completely new experimental access to quantum physics has been made at University of Konstanz. The team of scientists headed by...

Im Focus: How gut bacteria can make us ill

HZI researchers decipher infection mechanisms of Yersinia and immune responses of the host

Yersiniae cause severe intestinal infections. Studies using Yersinia pseudotuberculosis as a model organism aim to elucidate the infection mechanisms of these...

Im Focus: Interfacial Superconductivity: Magnetic and superconducting order revealed simultaneously

Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.

While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...

Im Focus: Studying fundamental particles in materials

Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales

Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...

Im Focus: Designing Architecture with Solar Building Envelopes

Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.

As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Sustainable Water use in Agriculture in Eastern Europe and Central Asia

19.01.2017 | Event News

12V, 48V, high-voltage – trends in E/E automotive architecture

10.01.2017 | Event News

2nd Conference on Non-Textual Information on 10 and 11 May 2017 in Hannover

09.01.2017 | Event News

 
Latest News

Helmholtz International Fellow Award for Sarah Amalia Teichmann

20.01.2017 | Awards Funding

An innovative high-performance material: biofibers made from green lacewing silk

20.01.2017 | Materials Sciences

Ion treatments for cardiac arrhythmia — Non-invasive alternative to catheter-based surgery

20.01.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>