Cellen, de meest elementaire levenseenheden die alle levende organismen vormen, hebben lang hun geheimen bewaard, maar nu heeft een internationaal team van de Universiteit van Sydney, ETH Zürich en de Universiteit van Basel enkele van hun geheimen blootgelegd door de ontwikkeling van een wereld -eerste techniek.

Wetenschappers weten dat cellen groeien, maar algemeen werd aangenomen dat ze lineair of exponentieel groeien voordat ze zich delen.

Nu, in een paper gepubliceerd in Nature Communications mede geleid door de natuurkundige Dr. David Martinez-Martin van de Universiteit van Sydney, met behulp van een nanotechnologietechniek genaamd "inertiële picobalans", hebben wetenschappers vastgesteld dat gist op het niveau van een enkele cel groeit in opeenvolgende intervallen of segmenten van lineaire groei (constante groeisnelheid) . Bij elk interval schakelen gistcellen over op snellere of langzamere groei - een "versnellingsachtige" neiging.

Het onderzoek werd uitgevoerd met saccharomyces cerevisiae, een eencellig gistorganisme dat essentieel is voor de productie van brood, bier, wijn en farmaceutica. De eiwitcoderende genen van veel soorten gist spiegelgenen in dierlijke cellen, waardoor het gedrag ervan de sleutel is tot het begrijpen van menselijke ziekten.

Met name het gedrag dat in gist wordt aangetroffen, verschilt aanzienlijk van dat van dierlijke cellen (inclusief mensen). It was not until 2017 that Dr. Martinez-Martin and colleagues, also using picobalance, first observed that the mass of living mammalian cells fluctuate intrinsically—they "yo-yo" in size.

"We have uncovered processes that challenge models in biology that have been central for decades," said Dr. Martinez-Martin. "The behaviors we have identified in cells from fungus and animal kingdoms provide strong evidence that cells have different strategies to regulate their mass and size, paving the way to better understand how they can accurately form and reform complex structures such as the eyes, brain and fingers in our bodies."

A recent mathematical model published in Journal of Biological Research—Thessaloniki by Dr. Martinez-Martin also offers fresh insight into the meaning of this once-secretive cellular flux.

"Another of our recent studies has found that while cell mass fluctuations have been detected in single mammalian cells, they can be perfectly viable in organisms comprised of many mammalian cells, including humans. Our modeling suggests that the body's cells don't all swell and decrease at the same time—instead they give and take from each other, maintaining an adequate distribution of the body's mass and volume.

"Mass fluctuations may be used by cells to regulate cellular functions such as metabolism, gene expression, proliferation and cell death, by means of altering the concentration and crowdedness of chemical cellular components."

The model also suggests that mass fluctuations allow cells to communicate, both by acting as biomechanical signals through volume fluctuations, and through the exchange of water and molecules.

"I believe this could be a fundamental mechanism which may help cells locate and communicate their position within an organism," Dr. Martinez-Martin said. "Therefore, it could be incredibly important, because it could allow cells to identify and serve their distinct role and purpose in the body."

"Researchers believe that a better understanding of how cells change their mass and size over time, as well as dysregulation of this process (when cells change their size atypically), could be the key to developing the next generation of diagnostics and treatments for a range of diseases, such as cancer, diabetes and cardiovascular disease."

About inertial picobalance:The technique used in the discovery

Dr. Martinez-Martin, who has been recently distinguished by the World Intellectual Property Organization as a young change maker, is the principal inventor of inertial picobalance, a new technology that measures the mass of single or multiple living cells in real-time, enhancing the understanding of cell physiology. The technology is currently being commercialized by the Swiss nanotech company, Nanosurf AG.

In a Nature paper published in 2017, using inertial picoblance, Dr. Martinez-Martin and his colleagues discovered that the mass of living mammalian cells fluctuates intrinsically by one to four percent over seconds, largely due to water entering and exiting cells.

Using this technique, they were also able to observe cells infected with the vaccinia virus (a virus from the poxvirus family). The infected cells showed different mass behavior over time than non-infected cells, potentially enabling a new way of detecting viral infections. + Verder verkennen

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