The impact of two mild stressors on the nerve growth factor (NGF) immunoreactivity in the amygdala in aged rats compared to adult ones

Obsessive-compulsive disorder and growth factors: A comparative review

The goal of this article is to clarify the role of various growth factors in the establishment and progression of obsessive-compulsive disorder (OCD). OCD is a chronic mental disorder with recurrent intrusive thoughts and/or repetitive compulsive behaviors that increase during stressful periods. Growth and neurotrophic factors may be contributing factors in the pathophysiology of OCD. Many of them are synthesized and released within the central nervous system and act as trophic agents in neurons; some of them are involved in brain growth, development, neurogenesis, myelination and plasticity, while others take part in the protection of the nervous system following brain injuries. This paper attempts to identify all articles investigating the relationship between OCD and neurotrophic and growth factors, in both animal and human studies, with a focus on adult brain studies. Based on the PubMed and Scopus and Science Direct search tools, the available articles and studies are reviewed. Out of 230 records in total, the ones related to our review topic were taken into account to further understand the pathophysiological mechanism(s) of OCD, providing methods to improve its symptoms via the modification of neurotrophins and growth factor imbalances.

Epigenetic Regulation of the Promotor Region of Vascular Endothelial Growth Factor-A and Nerve Growth Factor in Opioid-Maintained Patients

AIMS

The nerve growth factor (NGF) and the vascular endothelial growth factor-A (VEGF-A) may be of importance for psychiatric diseases including substance use disorders. The aim of the study was to identify differences in the regulation of both neuropeptides via the DNA-methylation status of the promotor regions of NGF and VEGF-A in different forms of maintenance therapy for opioid dependence and the related stress regulation via the hypothalamic-pituitary-adrenal axis.

METHODS

We compared methylation levels of opioid-dependent patients receiving treatment with diamorphine (n = 28) or levomethadone (n = 54) and similar levels in a healthy control group (n = 72).

RESULTS

There was a significantly higher methylation of VEGF-A in opioid-maintained patients with levomethadone compared to that in the control group (estimated marginal means [EMM] [SE]): 0.036 [0.003] vs. 0.020 [0.003]; p < 0.001). We performed a cluster analysis for NGF, splitting up the results in 4 clusters. We found significant changes in methylation rates of the opioid-maintained patients compared to the controls in cluster I ([EMM] [SE]: 0.064 [0.005] vs. 0.084 [0.006]; p = 0.03), cluster II ([EMM] [SE]: 0.133 [0.013] vs. 0.187 [0.014]; p < 0.001) and cluster III ([EMM] [SE]: 0.190 [0.014] vs. 0.128 [0.016]; p < 0.001).

CONCLUSIONS

The results are of importance, as they indicate that long-term changes in stress regulation regulated by neurotrophines are a crucial part of the symptomatology of opioid dependence, thus influencing drug consumption and the different forms of opioid-maintenance therapies.