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Showing posts with label Living cells. Show all posts
Showing posts with label Living cells. Show all posts

Monday, 4 December 2017

Saturated fatty acids can damage cells


Excess saturated fats, such as those released from lard, are toxic to cells and cause a wide variety of lipid-related diseases, while unsaturated fats, such as those from fish and olive oil, can be protective. Researchers developed a new microscopy technique that allows for the direct tracking of fatty acids after they've been absorbed into living cells. The technique involves replacing hydrogen atoms on fatty acids with their isotope, deuterium, without changing their physicochemical properties and behavior like traditional strategies do.

By making the switch, all molecules made from fatty acids can be observed inside living cells by an advanced imaging technique called stimulated Raman scattering (SRS) microscopy.
What the researchers found using this technique could have significant impact on both the understanding and treatment of obesity, diabetes and cardiovascular disease.

The cellular process of building the cell membrane from saturated fatty acids results in patches of hardened membrane in which molecules are "frozen." Under healthy conditions, this membrane should be flexible and the molecules fluidic. The stiff, straight, long chains of saturated fatty acids rigidify the lipid molecules cause them to separate from the rest of the cell's membrane.

Under their microscope, the team observed that those lipid molecules then accumulate in tightly-packed clusters, that don't move much-a state called "solid-like." As more saturated fatty acids enter the cell, those clusters grow in size, creating increasing inelasticity of the membrane and gradually damaging the entire cell.

Lipid molecules made from unsaturated fatty acids bear a kink in their chains, which makes it impossible for these lipid molecules to align closely with each other as saturated ones do. They continue to move around freely rather than forming stationary clusters. In their movement, these molecules can jostle and slide in between the tightly-packed saturated fatty acid chains.
Adding unsaturated fatty acids could 'melt' the membrane clusters frozen by saturated fatty acids, the behavior of saturated fatty acids once they've entered cells contributes to major and often deadly diseases.
            haleplushearty.blogspot.com

Friday, 27 October 2017

DNA and RNA editing could heal many diseases


Scientists have discovered two gene editing techniques to fix mutations that cause diseases like cystic fibrosis and Duchenne muscular dystrophy. Both diseases, and about half all human genetic disorders, are caused by mutations in single letters in the human genome, in which an 'A' appears where there should be a 'B.'

The newly-developed gene editing systems can target the smallest units of human DNA or RNA to undo the mutation that causes cystic fibrosis. One system edits DNA in the genome itself, while the other targets RNA, which transports genetic messages for making proteins. The editing systems work in living cells, and if researchers can find ways to deliver them to human patients safely and effectively, they could be used to reverse the mutations that cause genetic diseases.

DNA and RNA contain four base components: adenine, thymine, guanine and cytosine. Cystic fibrosis is caused by an inherited genetic mutation that leads to abnormal mucus production in the lungs and digestive system. The thicker-than-normal mucus builds up in and blocks airways. It can be managed with breathing machines, inhalers and medications, but some affected by it will eventually need lung transplants. There is no cure for cystic fibrosis and it can be fatal.
Cystic fibrosis could be prevented or corrected if only there were a 'G' in the genome where the disease's victims have an 'A.' The new gene editing technologies could rewrite the part of the genome or its messenger that spells cystic fibrosis. The gene editing system is technically called the Adenine Base Editor, or ABE.

The ‘A’ in ABE is for ‘adenine,’ one of four chemical bases that are the smallest elements of our genomes. Adenine is always paired with thymine, and guanine is always paired with cytosine. ABE targets the ‘A,’ adenine, and rearranges its atoms to turn it into guanine. So, where there is an incorrect AT set of base pairs in the genome, ABE can reset it to a GC.

These genetic editors give scientists the remarkable ability to rewrite any mutated base pair in the genome. The gene editors are developments on the CRISPR technology which allows scientists to efficiently target and edit the genome.

RNA editing avoids interfering with the genome itself. Because RNA plays a communication role in humans, rather than being the fundamental genetic information itself, changes to it might be more flexible, and reversible.
However, RNA degrades over time, so the impermanence of changes to its component parts (called nucleoside bases) could be disadvantageous too.
          haleplushearty.blogspot.com