Genetic Polymorphism of rs13306146 Affects α2AAR Expression and Associated With Postpartum Depressive Symptoms in Chinese Women Who Received Cesarean Section

Effects of dexmedetomidine on depression-like behaviour in chronic restraint stress mice: Involvement of specific brain regions

It is crucial to develop novel antidepressants. Dexmedetomidine (DEX) can exert antidepressant effects, but its underlying mechanism remains unclear. We used chronic restraint stress (CRS) to induce depression-like behaviour in mice and administered low-dose DEX (2 μg/kg per day) during CRS modelling or one injection of high-dose DEX (20 μg/kg) after CRS. The results of the behavioural tests revealed that both methods ameliorated CRS-induced depression. The brain slices of the mice were subjected to immunohistochemical staining for c-fos and phosphorylated ERK (pERK). Results showed that the continuous low-dose DEX-treated group, but not the single high-dose DEX-treated group expressed less c-fos in the nucleus locus coeruleus (LC) with a mean optical density (MOD) of 0.06. Other brain regions, including the dentate gyrus (DG), pyriform cortex (Pir), anterior part of paraventricular thalamic nucleus (PVA), arcuate nucleus (Arc), and core or shell of accumbens nucleus (Acbc or Acbs), presented differences in c-fos expression. In contrast, the low-dose DEX-treated group exhibited three-fold greater pERK expression in the LC of the CRS mice, with a MOD of 0.15. Pir, cingulate cortex (Cg) and, anterior and posterior part of paraventricular thalamic nucleus (PVA and PVP) exhibited pERK expression differences due to distinct reagent treatments. These changes indicate that the responses of brain regions to different DEX administration methods and doses vary. This study confirmed the ability of DEX to ameliorate CRS-induced depression and identified candidate target brain regions, thus providing new information for the antidepressant mechanism of DEX.

Perioperative intravenous infusion of dexmedetomidine for alleviating postpartum depression after cesarean section: A meta-analysis and systematic review

The efficacy of perioperative dexmedetomidine (DEX) infusion as a precaution against postpartum depression (PPD) in women undergoing cesarean section has not been substantiated systematically. A literature search for RCTs on DEX against PPD was retrieved in the following databases from inception to January 3, 2024: PubMed, Embase, Web of Science, the Cochrane Library, CNKI, Wanfang, CBM, VIP, etc. A total of 13 RCTs with 1711 participants were included. Meta-analysis was performed by RevMan5.3 and Stata16 using a random-effects model. EPDS scores were significantly decreased in the DEX group within one week or over one week postpartum compared to the control group (SMD = -1.25, 95 %CI: -1.73 to -0.77; SMD = -1.08, 95 %CI: -1.43 to -0.73). The prevalence of PPD was significantly inferior to the control at both time points (RR = 0.36, 95 %CI: 0.24 to 0.54; RR = 0.39, 95 %CI: 0.26 to 0.57). Univariate meta-regression suggested that age influenced the heterogeneity of the EPDS scores (P = 0.039), and DEX infusion dose was a potential moderator (P = 0.074). The subgroup analysis results of PPD scores at both time points were consistent, showing that: ① Mothers younger than 30 years old had better sensitivity to DEX for treating PPD. ② The anti-PPD efficacy of continuous infusion of DEX by PCIA was superior to both single infusion and combined infusion. ③ DEX showed a better anti-PPD effect when the total infusion dose was ≤ 2 μg/kg. Moreover, DEX improved analgesia and sleep quality, provided appropriate sedation, and reduced the incidence of nausea, vomiting, and chills. The current evidence confirmed the prophylaxis and superiority of DEX for PPD. More high-quality, large-scale RCTs are required for verifying the reliability and formulating administration methods.

Genetic Markers Associated with Postpartum Depression: A Review

Postpartum depression (PPD) is a common illness in mothers after childbirth. PPD negatively affect the mother's quality of life and the bond with the infant, which can interfere with the infant's emotional, social, and cognitive development. PPD is caused by various biological and psychosocial factors. The aim of this review is to summarize the latest evidence of the associations between genetic polymorphisms and PPD. PubMed and Scopus were used as the literature search databases for this review. The keywords used were postpartum depression, postnatal depression, genetic, and polymorphism. Twenty-seven articles were reviewed after screening and applying the inclusion criteria. As results, the serotonin gene (5-HTTLPR) and oxytocin genes (OXTR) have the most significant associations with PPD among other genes. Further research on PPD biomarkers should be conducted to diagnose and treat PPD patients.

Effect of Dexmedetomidine on Postpartum Depression in Women With Prenatal Depression: A Randomized Clinical Trial

Importance

Postpartum depression (PPD) is emerging as a major public health problem worldwide. Although the particular period and context in which PPD occurs provides an opportunity for preventive interventions, there is still a lack of pharmacologic prevention strategies for PPD.

Objective

To assess the efficacy and safety of dexmedetomidine for prevention of PPD among women with prenatal depression undergoing cesarean delivery.

Design, Setting, and Participants

This randomized clinical trial enrolled 338 women who screened positive for prenatal depression at 2 hospitals in Hunan, China from March 28, 2022, to April 16, 2023. Women with an Edinburgh Postnatal Depression Scale score of more than 9 who were 18 years of age or older and were scheduled for elective cesarean delivery were eligible.

Interventions

Eligible participants were randomly assigned in a 1:1 ratio to either the dexmedetomidine group or the control group via centrally computer-generated group randomization. Dexmedetomidine, 0.5 μg/kg and 0.9% saline were intravenously infused for 10 minutes after delivery in the dexmedetomidine and control groups, respectively. After infusion, sufentanil or dexmedetomidine plus sufentanil was administered via patient-controlled intravenous analgesia for 48 hours in the control group and dexmedetomidine group, respectively.

Main Outcomes and Measures

The primary outcome was positive PPD screening results at 7 and 42 days post partum, defined as a postpartum Edinburgh Postnatal Depression Scale score of more than 9. Analysis was on an intention-to-treat basis.

Results

All 338 participants were female, with a mean (SD) age of 31.5 (4.1) years. Positive PPD screening incidence at 7 and 42 days post partum in the dexmedetomidine group vs the control group was significantly decreased (day 7, 21 of 167 [12.6%] vs 53 of 165 [32.1%]; risk ratio, 0.39 [95% CI, 0.25-0.62]; P < .001; day 42, 19 of 167 [11.4%] vs 50 of 165 [30.3%]; risk ratio, 0.38 [95% CI, 0.23-0.61]; P < .001). The dexmedetomidine group showed no significant difference in adverse events vs the control group (46 of 169 [27.2%] vs 33 of 169 [19.5%]; P = .10), but the incidence of hypotension increased (31 of 169 [18.3%] vs 16 of 169 [9.5%]; risk ratio, 2.15 [95% CI, 1.13-4.10]; P = .02).

Conclusions and Relevance

Dexmedetomidine administration in the early postpartum period significantly reduced the incidence of a positive PPD screening and maintained a favorable safety profile.

Trial Registration

Chinese Clinical Trial Registry Identifier: ChiCTR2200057213.

Dexmedetomidine in the Treatment of Depression: An Up-to-date Narrative Review

Depressive disorders (DD) are common, and their prevalence is expected to rise over the next decade. Depressive disorders are linked to significant morbidity and mortality. The clinical conundrum of depressive disorders lies in the heterogeneity of their phenomenology and etiology. Further, the currently available antidepressants have several limitations, including a delayed onset of action, limited efficacy, and an unfavorable side effect profile. In this review, Dexmedetomidine (DEX), a highly selective and potent α2-adrenergic receptor (α2-AR) agonist, is proposed as a potentially novel antidepressant with multiple mechanisms of action targeting various depression pathophysiological processes. These mechanisms include modulation of the noradrenergic system, regulation of neuroinflammation and oxidative stress, influence on the Brain-Derived Neurotrophic Factor (BDNF) levels, and modulation of neurotransmitter systems, such as glutamate. The review begins with an introduction before moving on to a discussion of DEX's pharmacological features. The pathophysiological and phenomenological targets of DD are also explored, along with the review of the existing preclinical and clinical evidence for DEX's putative anti-depressant effects. Finally, the review ends by presenting the pertinent conclusions and future directions.

The Role of miRNAs in Dexmedetomidine's Neuroprotective Effects against Brain Disorders

There are limited neuroprotective strategies for various central nervous system conditions in which fast and sustained management is essential. Neuroprotection-based therapeutics have become an intensively researched topic in the neuroscience field, with multiple novel promising agents, from natural products to mesenchymal stem cells, homing peptides, and nanoparticles-mediated agents, all aiming to significantly provide neuroprotection in experimental and clinical studies. Dexmedetomidine (DEX), an α2 agonist commonly used as an anesthetic adjuvant for sedation and as an opioid-sparing medication, stands out in this context due to its well-established neuroprotective effects. Emerging evidence from preclinical and clinical studies suggested that DEX could be used to protect against cerebral ischemia, traumatic brain injury (TBI), spinal cord injury, neurodegenerative diseases, and postoperative cognitive disorders. MicroRNAs (miRNAs) regulate gene expression at a post-transcriptional level, inhibiting the translation of mRNA into functional proteins. In vivo and in vitro studies deciphered brain-related miRNAs and dysregulated miRNA profiles after several brain disorders, including TBI, ischemic stroke, Alzheimer's disease, and multiple sclerosis, providing emerging new perspectives in neuroprotective therapy by modulating these miRNAs. Experimental studies revealed that some of the neuroprotective effects of DEX are mediated by various miRNAs, counteracting multiple mechanisms in several disease models, such as lipopolysaccharides induced neuroinflammation, β-amyloid induced dysfunction, brain ischemic-reperfusion injury, and anesthesia-induced neurotoxicity models. This review aims to outline the neuroprotective mechanisms of DEX in brain disorders by modulating miRNAs. We address the neuroprotective effects of DEX by targeting miRNAs in modulating ischemic brain injury, ameliorating the neurotoxicity of anesthetics, reducing postoperative cognitive dysfunction, and improving the effects of neurodegenerative diseases.