Proceedings of the National Academy of Sciences of the United States of America
Rather than being a passive, haphazard process of wear and tear, lifespan can be modulated actively by components of the insulin/insulin-like growth factor I (IGFI) pathway in laboratory animals. Complete or partial loss-of-function mutations in genes encoding components of the insulin/IGFI pathway result in extension of life span in yeasts, worms, flies, and mice. This remarkable conservation throughout evolution suggests that altered signaling in this pathway may also influence human lifespan.
A cholesteryl ester transfer protein (CETP) genotype (V/V homozygosity for I405V, NCBI dbSNP rs5882) has been associated with preservation of cognitive function in old age, in addition to its associations with exceptional longevity and cardiovascular disease. We tested the hypotheses that this polymorphism was associated with either level of cognitive function or lifetime cognitive change in 525 participants who took part in the Scottish Mental Survey of 1932. Participants took the same well-validated mental ability test at ages 11 and 79.
The Journals of Gerontology. Series A, Biological Sciences and Medical Sciences
Mutations causing decreased somatotrophic signaling are known to increase insulin sensitivity and extend life span in mammals. Caloric restriction and every other day (EOD) dietary regimens are associated with similar improvements to insulin signaling and longevity in normal mice; however, these interventions fail to increase insulin sensitivity or life span in growth hormone receptor knockout (GHRKO) mice.
Site-directed mutagenesis of the telomerase RNA from Tetrahymena thermophila was used previously to demonstrate the templating function of a sequence within this RNA; this sequence specifies the sequence of telomeric DNA in vivo. The possible functional importance of a phylogenetically conserved nucleotide outside the telomerase RNA template region was investigated by a similar experimental approach.
European Archives of Psychiatry and Clinical Neuroscience
Two siblings with the R269G mutation in the presenilin-1 gene causing early-onset Alzheimer's disease are presented, only the second family with this mutation to be reported. Behavioural and psychiatric symptoms were prominent in both cases, as well as cognitive decline. Other reports of presenilin-1 gene mutations associated with behavioural and psychiatric symptoms are reviewed.
American Journal of Medical Genetics. Part B, Neuropsychiatric Genetics: The Official Publication of the International Society of Psychiatric Genetics
Protocadherin X and Protocadherin Y (PCDHX and PCDHY) are cell-surface adhesion molecules expressed predominantly in the brain. The PCDHX/Y gene-pair was generated by an X-Y translocation approximately 3 million years ago (MYA) that gave rise to the Homo sapiens-specific region of Xq21.3 and Yp11.2 homology. Genes within this region are expected to code for sexually dimorphic human characteristics, including, for example, cerebral asymmetry a dimension of variation that has been suggested is relevant to psychosis.
Mutations in the dysferlin gene (DYSF) on chromosome 2p13 cause distinct phenotypes of muscular dystrophy: limb-girdle muscular dystrophy type 2B (LGMD2B), Miyoshi myopathy (MM), and distal anterior compartment myopathy, which are known by the term 'dysferlinopathy'. We performed mutation analyses of DYSF in 14 Italian patients from 10 unrelated families with a deficiency of dysferlin protein below 20% of the value in normal controls by immunoblotting analysis. We identified 11 different mutations, including eight missense and three deletion mutations.
Journal of Neural Transmission (Vienna, Austria: 1996)
NMDA receptors and especially the NR2B receptor subtype play a crucial role during chronic ethanol consumption and alcohol withdrawal. Therefore, the NR2B receptor subtype expression in peripheral blood cells of 32 male patients suffering from alcohol dependency were assessed through quantitative RT-PCR and to explore regulating epigenetic mechanisms, a methylation analysis was conducted using bisulfite sequencing of a fragment of the NR2B promoter region.
Adenosine-to-inosine (A-to-I) RNA editing is a neurodevelopmentally regulated epigenetic modification shown to modulate complex behavior in animals. Little is known about human A-to-I editing, but it is thought to constitute one of many molecular mechanisms connecting environmental stimuli and behavioral outputs. Thus, comprehensive exploration of A-to-I RNA editing in human brains may shed light on gene-environment interactions underlying complex behavior in health and disease.
INTRODUCTION: Dysfunctional serotonin signaling has been linked to the pathogenesis of autism, obsessive compulsive disorder, mood disorders and schizophrenia. While the hypo-activity of serotonin signaling is involved in the pathogenesis of depression, anxiety and obsessive compulsive disorder; LSD, an agonist of serotonin type 2 receptor (5-HTR2A) induces psychosis. Therefore, anxiety and depressive disorders are treated by SSRIs which inhibit serotonin transporter (5-HTT) while psychotic disorders are controlled by drugs that block serotonin and/or dopamine receptors.