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Published on: June 10, 2013
Enoxacin Elevates MicroRNA Levels in Rat Frontal Cortex and Prevents Learned Helplessness
Neil R Smalheiser1, Hui Zhang1, Yogesh Dwivedi2
1Department of Psychiatry, Psychiatric Institute, University of Illinois at Chicago , Chicago, IL , USA.
Abstract:
Major depressive disorder (MDD) is a major public health concern. Despite tremendous advancement, the pathogenic mechanisms associated with MDD are still unclear. Moreover, a significant number of MDD subjects do not respond to the currently available medication. MicroRNAs (miRNAs) are a class of small non-coding RNAs that control gene expression by modulating translation, mRNA degradation or stability of mRNA targets. The role of miRNAs in disease pathophysiology is emerging rapidly. Recently, we reported that miRNA expression is down-regulated in frontal cortex of depressed suicide subjects, and that rats exposed to repeated inescapable shock show differential miRNA changes depending on whether they exhibited normal adaptive responses or learned helpless (LH) behavior. Enoxacin, a fluoroquinolone used clinically as an anti-bacterial compound, enhances the production of miRNAs in vitro and in peripheral tissues in vivo, but has not yet been tested as an experimental tool to study the relation of miRNA expression to neural functions or behavior. Treatment of rats with 10 or 25 mg/kg enoxacin for 1 week increased the expression of miRNAs in frontal cortex and decreased the proportion of rats exhibiting LH behavior following inescapable shock. Further studies are warranted to learn whether enoxacin may ameliorate depressive behavior in other rodent paradigms and in human clinical situations, and if so whether its mechanism is due to upregulation of miRNAs.
Insights
Enoxacin, an antibacterial drug, may help treat depression by increasing microRNA (miRNA) expression in the brain. This study shows enoxacin reduced learned helplessness in rats, suggesting potential therapeutic benefits for major depressive disorder (MDD).
Area of Science:
- Neuroscience
- Molecular Biology
- Pharmacology
Background:
- Major depressive disorder (MDD) is a significant public health issue with unclear pathogenic mechanisms and limited treatment efficacy.
- MicroRNAs (miRNAs) are key regulators of gene expression, and their dysregulation is increasingly implicated in disease pathophysiology.
- Previous research indicated down-regulated miRNA expression in the frontal cortex of depressed individuals and altered miRNA profiles in learned helplessness (LH) rat models.
Purpose of the Study:
- To investigate the potential of enoxacin, an antibacterial compound known to enhance miRNA production, as a tool to study miRNA's role in neural function and behavior.
- To determine if enoxacin administration affects miRNA expression in the rat frontal cortex and influences the development of learned helplessness behavior.
Main Methods:
- Rats were treated with enoxacin (10 or 25 mg/kg) for one week.
- Following treatment, rats were exposed to inescapable shock to assess learned helplessness behavior.
- miRNA expression levels in the frontal cortex were analyzed.
Main Results:
- Enoxacin treatment led to increased miRNA expression in the frontal cortex of rats.
- Enoxacin administration decreased the incidence of learned helplessness behavior in rats subjected to inescapable shock.
- These findings suggest a correlation between enoxacin-induced miRNA upregulation and behavioral adaptation.
Conclusions:
- Enoxacin shows promise as an experimental tool for modulating miRNA expression in the brain.
- The drug's ability to upregulate miRNAs and reduce depressive-like behavior in rats warrants further investigation.
- Future research should explore enoxacin's therapeutic potential for MDD in other animal models and human clinical trials, focusing on its miRNA-mediated mechanisms.
