Gut Inflammation Induced by Finasteride Withdrawal: Therapeutic Effect of Allopregnanolone in Adult Male Rats

The interaction between finasteride and corticosterone levels: implications for depression-, and anxiety-like behavior and hippocampal synaptic plasticity in male rats

RATIONALE

Finasteride is FDA-approved for the treatment of hair loss and in older men for benign prostatic hyperplasia. However, some patients treated with finasteride reported suicidal ideation, depression, and anxiety. The neurobiological mechanisms underlying this are not clearly understood. Previously, we showed that short-term finasteride administration results in depression- and anxiety-like behaviour. Since finasteride treatment is long-term in the clinic, we examine the effects of chronic finasteride administration in the current study.

OBJECTIVE

This study aims to understand the behavioral, cellular, and molecular changes in male rats following 21 days of finasteride (3 mg, 10 mg, and 30 mg/Kg) administration.

METHODS

Depression-like behavior was evaluated using forced swim (FST), sucrose preference (SPT), and splash tests. Anxiety-like behavior was assessed using elevated plus maze (EPM), open field (OFT), light-dark (LDT), Vogel's conflict (VCT), and home cage emergence (HCET), and depression-related anxiety in novelty-suppressed feeding task (NSFT) tests. Hippocampal synaptic plasticity was assessed by field excitatory post-synaptic potentials (fEPSP) recordings in the Schaffer-collateral-CA1 synapses, and plasma corticosterone levels were estimated using ELISA.

RESULTS

Chronic finasteride administration induced depression-like and anxiety-like behavior in SPT and EPM, respectively, but not in the other paradigms. There was a modest decrease in long-term potentiation in the hippocampus. Interestingly, there was an increase in the plasma corticosterone levels with 6 days of finasteride administration, but not after 14 or 21 days of administration.

CONCLUSIONS

Chronic administration of finasteride did not induce a robust depression- and anxiety-like behavior and modestly affected synaptic plasticity. This could be potentially because of the adaptive response observed in the plasma corticosterone levels.

Analysis of the finasteride treatment and its withdrawal in the rat hypothalamus and hippocampus at whole-transcriptome level

PURPOSE

As reported in patients treated for androgenetic alopecia with finasteride (i.e., a blocker of the enzyme 5 alpha-reductase) and in an animal model, side effects affecting sexual, psychiatric, neurological, and physical domains, may occur during the treatment and persist with drug suspension. The etiopathogenesis of these side effects has been poorly explored. Therefore, we performed a genome-wide analysis of finasteride effects in the brain of adult male rat.

METHODS

Animals were treated (i.e., for 20 days) with finasteride (1mg/rat/day). 24 h after the last treatment and 1 month after drug suspension, RNA sequencing analysis was performed in hypothalamus and hippocampus. Data were analyzed by differential expression analysis and Gene-Set Enrichment Analyses (GSEA).

RESULTS

Data obtained after finasteride treatment showed that 186 genes (i.e., 171 up- and 15 downregulated) and 19 (i.e., 17 up- and 2 downregulated) were differentially expressed in the hypothalamus and hippocampus, respectively. Differential expression analysis at the drug withdrawal failed to identify dysregulated genes. Several gene-sets were enriched in these brain areas at both time points.

CONCLUSION

Some of the genes reported to be differentially expressed (i.e., TTR, DIO2, CLDN1, CLDN2, SLC4A5, KCNE2, CROT, HCRT, MARCKSL1, VGF, IRF2BPL) and GSEA, suggest a potential link with specific side effects previously observed in patients and in the animal model, such as depression, anxiety, disturbance in memory and attention, and sleep disturbance. These data may provide an important background for future experiments aimed at confirming the pathological role of these genes.

Exposure to Progestin 17-OHPC Induces Gastrointestinal Dysfunction through Claudin-1 Suppression in Female Mice with Increased Anxiety-Like Behaviors

INTRODUCTION

Progestin, commonly used in oral contraception and preventing preterm birth, elicits various off-target side effects on brain and gastrointestinal (GI) functions, yet the precise mechanisms remain elusive. This study aims to probe progestin's impact on GI function and anxiety-like behaviors in female mice.

METHODS

Colon stem cells were utilized to explore the mechanism underlying progestin 17-hydroxyprogesterone caproate (17-OHPC)-mediated suppression of claudin-1 (CLDN1), crucial for epithelial integrity. Chromatin immunoprecipitation and luciferase assays identified potential progestin-response elements on the CLDN1 promoter, with subsequent assessment of oxidative stress and pro-inflammatory cytokine release. Manipulation of vitamin D receptor (VDR) or estrogen receptor β (ERβ) expression elucidated their roles in 17-OHPC-mediated effects. Intestine-specific VDR deficient mice were generated to evaluate 17-OHPC's impact on GI dysfunction and anxiety-like behaviors in female mice. Additionally, gene expression was analyzed in various brain regions, including the amygdala, hypothalamus, and hippocampus.

RESULTS

Exposure to 17-OHPC suppressed CLDN1 expression via epigenetic modifications and VDR dissociation from the CLDN1 promoter. Furthermore, 17-OHPC intensified oxidative stress and pro-inflammatory cytokine release. VDR knockdown partly mimicked, while overexpression of either VDR or ERβ partly restored 17-OHPC-mediated effects. Intestinal VDR deficiency partly mirrored 17-OHPC-induced GI dysfunction, with minimal impact on 17-OHPC-mediated anxiety-like behaviors.

CONCLUSIONS

17-OHPC suppresses CLDN1 expression through VDR, contributing to GI dysfunction in female mice, distinct from 17-OHPC-induced anxiety-like behaviors. This study reveals a new mechanism and potential negative impact of progestin exposure on the GI tract, alongside inducing anxiety-like behaviors in female mice.

Post-Finasteride Syndrome And Post-Ssri Sexual Dysfunction: Two Clinical Conditions Apparently Distant, But Very Close

Post-finasteride syndrome and post-SSRI sexual dysfunction, are two poorly explored clinical conditions in which men treated for androgenetic alopecia with finasteride or for depression with SSRI antidepressants show persistent side effects despite drug suspension (e.g., sexual dysfunction, psychological complaints, sleep disorders). Because of some similarities in the symptoms, common pathological mechanisms are proposed here. Indeed, as discussed, clinical studies and preclinical data obtained so far suggest an important role for brain modulators (i.e., neuroactive steroids), neurotransmitters (i.e., serotonin, and cathecolamines), and gut microbiota in the context of the gut-brain axis. In particular, the observed interconnections of these signals in these two clinical conditions may suggest similar etiopathogenetic mechanisms, such as the involvement of the enzyme converting norepinephrine into epinephrine (i.e., phenylethanolamine N-methyltransferase). However, despite the current efforts, more work is still needed to advance the understanding of these clinical conditions in terms of diagnostic markers and therapeutic strategies.

Short-term effects of etifoxine on human gut microbiome in healthy men

BACKGROUND

Neurosteroids have recently gained in interest as a treatment strategy for affective disorders. Etifoxine is known for its dual mode of action, one of which is to stimulate endogenous neurosteroid synthesis. The gut microbiome has been studied in affective disorders, but it has not been investigated in the context of human etifoxine or neurosteroid interventions.

METHODS

We performed a crossover study with 36 healthy male volunteers who received etifoxine versus alprazolam and placebo in a balanced Williams design. Participants were randomized into six sequences and went through three 5-day treatments followed by wash-out phases of 9 days. Bacterial compositions in stool samples were determined by high-throughput 16S rRNA amplicon sequencing.

RESULTS

Gut microbiome analyses revealed no relevant effects between treatments with respect to alpha and beta diversity. Differential abundance analyses yielded etifoxine treatment as the only effect related to changes in microbial features with reductions of Faecalibacterium duncaniae, Roseburia hominis and Lactobacillus rogosae (i.e., Bacteroides galacturonicus).

CONCLUSION

Here we report on the first human investigation of the gut microbiome with short-term etifoxine intervention. Differences in diversity and compositional structure of the microbiome were more likely due to between- subject effects rather than medication. However, five-day treatment with etifoxine reduced the abundance of a few bacterial species. These species are currently seen as beneficial components of a healthy intestinal microbiome. This reduction in abundances may be related to elevated endogenous neurosteroids.

Neurosteroid influence on affective tone

Affective disorders such as depression and anxiety are among the most prevalent psychiatric illnesses and causes of disability worldwide. The recent FDA-approval of a novel antidepressant treatment, ZULRESSO® (Brexanolone), a synthetic neurosteroid has fueled interest into the role of neurosteroids in the pathophysiology of depression as well as the mechanisms mediating the antidepressant effects of these compounds. The majority of studies examining the impact of neurosteroids on affective states have relied on the administration of exogenous neurosteroids; however, neurosteroids can also be synthesized endogenously from cholesterol or steroid hormone precursors. Despite the well-established influence of exogenous neurosteroids on affective states, we still lack an understanding of the role of endogenous neurosteroids in modulating affective tone. This review aims to summarize the current literature supporting the influence of neurosteroids on affective states in clinical and preclinical studies, as well as recent evidence suggesting that endogenous neurosteroids may set a baseline affective tone.