The D9N, N291S, and T495G Polymorphisms of the Lipoprotein Lipase Gene Are Not Associated with Cerebral Infarction.

BACKGROUND: Lipoprotein lipase (LPL) plays an important role in plasma lipoprotein metabolism and its polymorphisms are possibly implicated in the etiology of ischemic cerebrovascular disease (CVD). The aim of this work was to determine the association of the of D9N, N291S, and T495G polymorphisms of the LPL gene as a risk factor for the development of CVD. METHODS: A case-control study was conducted that included 100 patients with CVD and 120 healthy controls. All the subjects were genotyped for the D9N, N291S, and T495G polymorphisms of the LPL gene through polymerase chain reaction-restriction fragment length polymorphism, and the results were analyzed for their association with CVD. RESULTS: The D9N genotype was not significantly correlated with CVD; the odds ratio (OR) between the control subjects and CVD patients was .29 (95% confidence interval [CI], .03-2.66; P = .27). The N291S polymorphism was not significantly correlated with CVD either; the OR between the control subjects and CVD patients was 1.2 (95% CI, .07-19.46; P = .89). And the T495G mutation was not significantly correlated with CVD; the OR between the control subjects and the CVD patients was 1.21 (95% CI, .7-2.08; P = .48). CONCLUSIONS: In the present study, the D9N, N291S, and T495G polymorphisms of the LPL gene were not risk factors for the development of CVD.

Stress and trauma: BDNF control of dendritic-spine formation and regression.

Chronic restraint stress leads to increases in brain derived neurotrophic factor (BDNF) mRNA and protein in some regions of the brain, e.g. the basal lateral amygdala (BLA) but decreases in other regions such as the CA3 region of the hippocampus and dendritic spine density increases or decreases in line with these changes in BDNF. Given the powerful influence that BDNF has on dendritic spine growth, these observations suggest that the fundamental reason for the direction and extent of changes in dendritic spine density in a particular region of the brain under stress is due to the changes in BDNF there. The most likely cause of these changes is provided by the stress initiated release of steroids, which readily enter neurons and alter gene expression, for example that of BDNF. Of particular interest is how glucocorticoids and mineralocorticoids tend to have opposite effects on BDNF gene expression offering the possibility that differences in the distribution of their receptors and of their downstream effects might provide a basis for the differential transcription of the BDNF genes. Alternatively, differences in the extent of methylation and acetylation in the epigenetic control of BDNF transcription are possible in different parts of the brain following stress. Although present evidence points to changes in BDNF transcription being the major causal agent for the changes in spine density in different parts of the brain following stress, steroids have significant effects on downstream pathways from the TrkB receptor once it is acted upon by BDNF, including those that modulate the density of dendritic spines. Finally, although glucocorticoids play a canonical role in determining BDNF modulation of dendritic spines, recent studies have shown a role for corticotrophin releasing factor (CRF) in this regard. There is considerable improvement in the extent of changes in spine size and density in rodents with forebrain specific knockout of CRF receptor 1 (CRFR1) even when the glucocorticoid pathways are left intact. It seems then that CRF does have a role to play in determining BDNF control of dendritic spines.