Tuesday, January 31, 2012

Scientists Prove Plausibility of New Pathway to Life's Chemical Building Blocks

For decades, chemists considered a chemical pathway known as the formose reaction the only route for producing sugars essential for life to begin, but more recent research has called into question the plausibility of such thinking. Now a group from The Scripps Research Institute has proven an alternative pathway to those sugars called the glyoxylate scenario, which may push the field of pre-life chemistry past the formose reaction hurdle.
Science Daily, Jan. 31, 2012
Vasudeva Naidu Sagi, et al.
Exploratory Experiments on the Chemistry of the “Glyoxylate Scenario”: Formation of Ketosugars from Dihydroxyfumarate. 
Journal of the American Chemical Society, 2012; : 120113151919003 DOI:10.1021/ja211383c

Tuesday, January 24, 2012

Scientists Discover New Clue to Chemical Origins of Life

Organic chemists at the University of York have made a significant advance towards establishing the origin of the carbohydrates (sugars) that form the building blocks of life.  A team led by Dr Paul Clarke at York has re-created a process which could have occurred in the prebiotic world.  They have made the first step towards showing how simple sugars -- threose and erythrose -- developed.   All biological molecules have an ability to exist as left-handed forms or right-handed forms. All sugars in biology are made up of the right-handed form of molecules and yet all the amino acids that make up the peptides and proteins are made up of the left-handed form. The researchers found using simple left-handed amino acids to catalyse the formation of sugars resulted in the production of predominately right-handed form of sugars. It could explain how carbohydrates originated and why the right-handed form dominates in nature.
Science Daily, Jan. 24, 2012
Laurence Burroughs, et al.
Asymmetric organocatalytic formation of protected and unprotected tetroses under potentially prebiotic conditions. 
Organic & Biomolecular Chemistry, 2012; DOI: 10.1039/C1OB06798B

Friday, January 20, 2012

Epigenetic understanding of gene-environment interactions in psychiatric disorders: a new concept of clinical genetics

Epigenetics is a mechanism that regulates gene expression independently of the underlying DNA sequence, relying instead on the chemical modification of DNA and histone proteins. Although environmental and genetic factors were thought to be independently associated with disorders, several recent lines of evidence suggest that epigenetics bridges these two factors. Epigenetic gene regulation is essential for normal development, thus defects in epigenetics cause various rare congenital diseases. Because epigenetics is a reversible system that can be affected by various environmental factors, such as drugs, nutrition, and mental stress, the epigenetic disorders also include common diseases induced by environmental factors. In this review, we discuss the nature of epigenetic disorders, particularly psychiatric disorders, on the basis of recent findings: 1) susceptibility of the conditions to environmental factors, 2) treatment by taking advantage of their reversible nature, and 3) transgenerational inheritance of epigenetic changes, that is, acquired adaptive epigenetic changes that are passed on to offspring. These recently discovered aspects of epigenetics provide a new concept of clinical genetics.

Takeo Kubota, Kunio Miyake and Takae Hirasawa
Clin Epigenetics. 2012; 4(1): 1.
Published online 2012 January 20. doi: 10.1186/1868-7083-4-1

Thursday, January 12, 2012

Interneuron dysfunction in psychiatric disorders

Schizophrenia, autism and intellectual disabilities are best understood as spectrums of diseases that have broad sets of causes. However, it is becoming evident that these conditions also have overlapping phenotypes and genetics, which is suggestive of common deficits. In this context, the idea that the disruption of inhibitory circuits might be responsible for some of the clinical features of these disorders is gaining support. Recent studies in animal models demonstrate that the molecular basis of such disruption is linked to specific defects in the development and function of interneurons — the cells that are responsible for establishing inhibitory circuits in the brain. These insights are leading to a better understanding of the causes of schizophrenia, autism and intellectual disabilities, and may contribute to the development of more-effective therapeutic interventions.