News From Molecular & Cellular Proteomics

Main Category: Pregnancy / Obstetrics
Also Included In: Genetics;  Alzheimer's / Dementia;  Biology / Biochemistry
Article Date: 27 Aug 2007 - 4:00 PDT

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Articles selected from the August 2007 issue of Molecular & Cellular Proteomics (Vol. 6, No. 8):

* Designing better markers for pregnancy-associated pathological conditions
* Potential new therapy for the treatment of Alzheimer's disease and other neurodegenerative conditions
* First comprehensive study of proteins inside a single type of cell

Designing better markers for pregnancy-associated pathological conditions

Researchers report the most complete list so far of proteins present in the human amniotic fluid, the liquid that surrounds a fetus during pregnancy. The new information may be used to develop new or improved markers of pregnancy-associated pathological conditions, such as preterm delivery, intra-amniotic infection, and chromosomal anomalies in the fetus.

The amniotic fluid is initially formed from maternal plasma that later crosses fetal membranes from 10 to 20 weeks of gestation. By looking at the composition of the amniotic fluid in this gestational stage, scientists can provide valuable information about the health of the fetus and may indicate potential pathological conditions. Although many amniotic fluid proteins are known and are currently used to detect potential fetal anomalies, little is known about the functions of these proteins and how they interact with one another.

Eleftherios P. Diamandis and colleagues showed that the amniotic fluid contains at least 850 proteins, many of which have not been discovered before and that could be used as new markers for genetic defects or pathological conditions in the fetus. Current markers used for that purpose either do not detect defects in all affected fetuses -- leaving some mothers with a negative diagnosis while their baby actually has a defect -- or incorrectly diagnose some fetuses as having a defect when no such defect exists. Also, although they reveal defects, these markers cannot pinpoint the origin of the defect. The newly identified proteins could help design markers that are easier to detect and provide more details about potential defects.

Article: "Proteomic Analysis of Human Amniotic Fluid," by Chan-Kyung J. Cho, Shannon J. Shan, Elizabeth Winsor, and Eleftherios P. Diamandis

Potential new therapy for the treatment of Alzheimer's disease and other neurodegenerative conditions

Researchers have provided new information about how communication among neurons may be prevented from deteriorating in conditions such as Alzheimer's disease (AD). The new results may lead to new therapies for the treatment of not only AD but also motor neuron diseases and prion diseases.

Most current research efforts to find a treatment for AD and similar conditions focuses on what happens to the main part -- or body -- of a neuron, but recent studies have examined how neuronal communication is impaired in human diseases such as AD. When a neuron interacts with another neuron, it uses an extension called an axon that releases chemicals, which diffuse across a tiny gap between the neurons called a synapse and crosses the other neuron. Deterioration of synapses and axons can be delayed thanks to a protein created by a gene called the slow Wallerian degeneration (Wlds) gene. How this protein works is still a mystery, but it may lead to new therapies for the treatment of AD and other conditions.

Thomas H. Gillingwater and colleagues identified 16 proteins that are affected by the Wlds gene. Although details are still missing, Wlds probably prevents these proteins from deteriorating synapses and axons. The scientists found that some of the proteins had previously been shown to deteriorate synapses and axons, but, unexpectedly, eight proteins regulate the function of mitochondria -- cellular organelles that supply energy to cells. These results reveal for the first time that mitochondria are involved in the protection of neurons provided by the Wlds gene and suggest that targeting some of the proteins identified in this study may lead to novel therapies for the treatment of AD, motor neuron diseases, and prion diseases.

Article: "Differential proteomic analysis of synaptic proteins identifies potential cellular targets and protein mediators of synaptic neuroprotection conferred by the slow Wallerian degeneration (Wlds) gene," by Thomas M. Wishart, Janet M. Paterson, Duncan M. Short, Sara Meredith, Kevin A. Robertson, Calum Sutherland, Michael A. Cousin, Mayank B. Dutia, and Thomas H. Gillingwater

First comprehensive study of proteins inside a single type of cell

Scientists have provided the first large-scale study of proteins inside human cells called Jurkat T cells. The study could provide a better understanding of how proteins inside a specific type of cell work together and may pave the way for future detailed studies of how proteins work in other types of cells.

Past studies have been performed in model organisms such as yeast and different organelles from mice, but no comprehensive analysis of a single type of human cell has been carried out to date. David K. Han and colleagues report a survey of proteins present in Jurkat T cells, which are derived from human T-cell leukemia and is one of the popular types of cells used to study how proteins work inside cells in general.

The scientists identified over 6,400 proteins in a Jurkat T cell and localized them in various parts of the cell. This information will help to understand how proteins move and interact with one another inside the cell and how they perform various cellular functions. The study is also a proof-of-principle that a large-scale study of approximately half of the expressed proteins in a single human cell type is now possible, although more studies will be needed to investigate less abundant proteins and how proteins interact with one another.

Article: "Global survey of human T leukemic cells by integrating proteomic and transcriptomic profiling," by Linfeng Wu, Sun-Il Hwang, Karim Rezaul, Long J. Lu, Viveka Mayya, Mark Gerstein, Jimmy K. Eng, Deborah H. Lundgren, and David K. Han

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Article adapted by Medical News Today from original press release.
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The American Society for Biochemistry and Molecular Biology is a nonprofit scientific and educational organization with over 11,900 members in the United States and internationally. Most members teach and conduct research at colleges and universities. Others conduct research in various government laboratories, nonprofit research institutions and industry. The Society's student members attend undergraduate or graduate institutions.

Founded in 1906, the Society is based in Bethesda, Maryland, on the campus of the Federation of American Societies for Experimental Biology. The Society's purpose is to advance the science of biochemistry and molecular biology through publication of the Journal of Biological Chemistry, the Journal of Lipid Research, and Molecular and Cellular Proteomics, organization of scientific meetings, advocacy for funding of basic research and education, support of science education at all levels, and promoting the diversity of individuals entering the scientific work force.

For more information about ASBMB, see the Society's Web site at http://www.asbmb.org/.

Source: Pat Pages
American Society for Biochemistry and Molecular Biology