Ameliorative effect of SIRT1 in postpartum depression mediated by upregulation of the glucocorticoid receptor

SIRT1: potential target in glucocorticoid-resistant diseases

Glucocorticoid resistance is a challenging problem in clinical practice. Increasing glucocorticoid sensitivity and reducing resistance are important in the management of certain diseases. In steroid-resistant airway inflammatory diseases, glucocorticoid receptor (GR) expression is reduced, and impaired GR nuclear translocation is closely related to glucocorticoid resistance. Histone deacetylase SIRT1 regulates steroid hormone receptor activity and interacts with the androgen receptor and GR. In some glucocorticoid-resistant diseases, SIRT1 expression is reduced. Here, we review recent advances in the role of SIRT1 in regulating glucocorticoid signaling. First, we describe the structure, tissue expression, and subcellular localization of SIRT1. We also discuss the molecular mechanisms by which SIRT1 regulates glucocorticoid activity and its association with GR, as well as the mechanisms and roles of SIRT1 in several common glucocorticoid-resistant diseases. SIRT1 may serve as a potential therapeutic target, providing an opportunity for the treatment of glucocorticoid-resistant diseases.

Gut microbiome-gut brain axis-depression: interconnection

OBJECTIVES

The relationship between the gut microbiome and mental health, particularly depression, has gained significant attention. This review explores the connection between microbial metabolites, dysbiosis, and depression. The gut microbiome, comprising diverse microorganisms, maintains physiological balance and influences health through the gut-brain axis, a communication pathway between the gut and the central nervous system.

METHODS

Dysbiosis, an imbalance in the gut microbiome, disrupts this axis and worsens depressive symptoms. Factors like diet, antibiotics, and lifestyle can cause this imbalance, leading to changes in microbial composition, metabolism, and immune responses. This imbalance can induce inflammation, disrupt neurotransmitter regulation, and affect hormonal and epigenetic processes, all linked to depression.

RESULTS

Microbial metabolites, such as short-chain fatty acids and neurotransmitters, are key to gut-brain communication, influencing immune regulation and mood. The altered production of these metabolites is associated with depression. While progress has been made in understanding the gut-brain axis, more research is needed to clarify causative relationships and develop new treatments. The emerging field of psychobiotics and microbiome-targeted therapies shows promise for innovative depression treatments by harnessing the gut microbiome's potential.

CONCLUSIONS

Epigenetic mechanisms, including DNA methylation and histone modifications, are crucial in how the gut microbiota impacts mental health. Understanding these mechanisms offers new prospects for preventing and treating depression through the gut-brain axis.

Hormone Regulation of Corticotropin-Releasing Factor Receptor 1 in the Female Mouse Brain

INTRODUCTION

Corticotropin-releasing factor receptor 1 (CRFR1) is a key regulator of neuroendocrine and behavioral stress responses. Previous studies have demonstrated that CRFR1 in certain hypothalamic and preoptic brain areas is modified by chronic stress and during the postpartum period in female mice, although the potential hormonal contributors to these changes are unknown.

METHODS

This study focused on determining the contributions of hormones associated with stress and the maternal period (glucocorticoids, prolactin, estradiol/progesterone) on CRFR1 levels using a CRFR1-GFP reporter mouse line and immunohistochemistry.

RESULTS

Administration of dexamethasone, an agonist of the glucocorticoid receptor, elevated CRFR1 in the anteroventral periventricular nucleus (AVPV/PeN) and paraventricular hypothalamus (PVN) with no changes found in the medial preoptic area (MPOA) or arcuate nucleus. Treatment with prolactin for 5 days elevated CRFR1 levels in the MPOA with no changes in other regions. Finally, we utilized the hormone-simulated pseudopregnancy (HSP) paradigm to mimic changes in estradiol and progesterone across pregnancy and the early postpartum period. Female mice receiving HSP treatment, as well as mice receiving HSP treatment that then underwent 5 days of estrogen withdrawal (EW), showed alterations in CRFR1 relative to control groups that mirrored changes previously reported in postpartum mice. Specifically, CRFR1 levels increased in the AVPV/PeN and decreased in the MPOA and PVN, with no changes found in the arcuate nucleus. HSP- and EW-treated mice also showed decreases in tyrosine hydroxylase-expressing neurons in the AVPV/PeN.

DISCUSSION/CONCLUSION

Overall, these hormone-induced changes in stress-regulating CRFR1 neurons may impact behavioral and neuroendocrine stress responses.

Resveratrol: A Multifaceted Guardian against Anxiety and Stress Disorders-An Overview of Experimental Evidence

The medicinal properties of resveratrol have garnered increasing attention from researchers. Extensive data have been accumulated on its use in treating cardiovascular diseases, immune system disorders, cancer, neurological diseases, and behavioral disorders. The protective mechanisms of resveratrol, particularly in anxiety-related stress disorders, have been well documented. However, less attention has been given to the side effects of resveratrol. This review explores not only the mechanisms underlying the anxiolytic effects of resveratrol but also the mechanisms that may lead to increased anxiety following resveratrol treatment. Understanding these mechanisms is crucial for enhancing the efficacy of resveratrol in managing anxiety disorders associated with stress and PTSD.

Potential therapeutic effects of Chinese herbal medicine in postpartum depression: Mechanisms and future directions

ETHNOPHARMACOLOGICAL RELEVANCE

Postpartum depression (PPD) is a common psychiatric disorder in women after childbirth. Per data from epidemiologic studies, PPD affects about 5%-26.32% of postpartum mothers worldwide. Biological factors underlying this condition are multiple and complex and have received extensive inquiries for the roles they play in PPD. Chinese herbal medicine (CHM), which is widely used as a complementary and alternative therapy for neurological disorders, possesses multi-component, multi-target, multi-access, and low side effect therapeutic characteristics. CHM has already shown efficacy in the treatment of PPD, and a lot more research exploring the mechanisms of its potential therapeutic effects is being conducted.

AIM OF THE REVIEW

This review provides an in-depth and comprehensive overview of the underlying mechanisms of PPD, as well as samples the progress made in researching the potential role of CHM in treating the disorder.

MATERIALS AND METHODS

Literature was searched comprehensively in scholarly electronic databases, including PubMed, Web of Science, Scopus, CNKI and WanFang DATA, using the search terms "postpartum depression", "genetic", "hormone", "immune", "neuroinflammation", "inflammation", "neurotransmitter", "neurogenesis", "brain-gut axis", "traditional Chinese medicine", "Chinese herbal medicine", "herb", and an assorted combination of these terms.

RESULTS

PPD is closely associated with genetics, as well as with the hormones, immune inflammatory, and neurotransmitter systems, neurogenesis, and gut microbes, and these biological factors often interact and work together to cause PPD. For example, inflammatory factors could suppress the production of the neurotransmitter serotonin by inducing the regulation of tryptophan-kynurenine in the direction of neurotoxicity. Many CHM constituents improve anxiety- and depression-like behaviors by interfering with the above-mentioned mechanisms and have shown decent efficacy clinically against PPD. For example, Shen-Qi-Jie-Yu-Fang invigorates the neuroendocrine system by boosting the hormone levels of hypothalamic pituitary adrenal (HPA) and hypothalamic pituitary gonadal (HPG) axes, regulating the imbalance of Treg/T-helper cells (Th) 17 and Th1/Th2, and modulating neurotransmitter system to play antidepressant roles. The Shenguiren Mixture interferes with the extracellular signal-regulated kinase (ERK) pathway to enhance the number, morphology and apoptosis of neurons in the hippocampus of PPD rats. Other herbal extracts and active ingredients of CHM, such as Paeoniflorin, hypericin, timosaponin B-III and more, also manage depression by remedying the neuroendocrine system and reducing neuroinflammation.

CONCLUSIONS

The pathogenesis of PPD is complex and diverse, with the main pathogenesis not clear. Still, CHM constituents, like Shen-Qi-Jie-Yu-Fang, the Shenguiren Mixture, Paeoniflorin, hypericin and other Chinese Medicinal Formulae, active monomers and Crude extracts, treats PPD through multifaceted interventions. Therefore, developing more CHM components for the treatment of PPD is an essential step forward.

Emerging roles of SIRT1 activator, SRT2104, in disease treatment

Silent information regulator 1 (SIRT1) is a NAD+-dependent class III deacetylase that plays important roles in the pathogenesis of numerous diseases, positioning it as a prime candidate for therapeutic intervention. Among its modulators, SRT2104 emerges as the most specific small molecule activator of SIRT1, currently advancing into the clinical translation phase. The primary objective of this review is to evaluate the emerging roles of SRT2104, and to explore its potential as a therapeutic agent in various diseases. In the present review, we systematically summarized the findings from an extensive array of literature sources including the progress of its application in disease treatment and its potential molecular mechanisms by reviewing the literature published in databases such as PubMed, Web of Science, and the World Health Organization International Clinical Trials Registry Platform. We focuses on the strides made in employing SRT2104 for disease treatment, elucidating its potential molecular underpinnings based on preclinical and clinical research data. The findings reveal that SRT2104, as a potent SIRT1 activator, holds considerable therapeutic potential, particularly in modulating metabolic and longevity-related pathways. This review establishes SRT2104 as a leading SIRT1 activator with significant therapeutic promise.

The role of polyunsaturated fatty acids in the neurobiology of major depressive disorder and suicide risk

Long-chain polyunsaturated fatty acids (LC-PUFAs) are obtained from diet or derived from essential shorter-chain fatty acids, and are crucial for brain development and functioning. Fundamentally, LC-PUFAs' neurobiological effects derive from their physicochemical characteristics, including length and double bond configuration, which differentiate LC-PUFA species and give rise to functional differences between n(omega)-3 and n-6 LC-PUFAs. LC-PUFA imbalances are implicated in psychiatric disorders, including major depression and suicide risk. Dietary intake and genetic variants in enzymes involved in biosynthesis of LC-PUFAs from shorter chain fatty acids influence LC-PUFA status. Domains impacted by LC-PUFAs include 1) cell signaling, 2) inflammation, and 3) bioenergetics. 1) As major constituents of lipid bilayers, LC-PUFAs are determinants of cell membrane properties of viscosity and order, affecting lipid rafts, which play a role in regulation of membrane-bound proteins involved in cell-cell signaling, including monoaminergic receptors and transporters. 2) The n-3:n-6 LC-PUFA balance profoundly influences inflammation. Generally, metabolic products of n-6 LC-PUFAs (eicosanoids) are pro-inflammatory, while those of n-3 LC-PUFAs (docosanoids) participate in the resolution of inflammation. Additionally, n-3 LC-PUFAs suppress microglial activation and the ensuing proinflammatory cascade. 3) N-3 LC-PUFAs in the inner mitochondrial membrane affect oxidative stress, suppressing production of and scavenging reactive oxygen species (ROS), with neuroprotective benefits. Until now, this wealth of knowledge about LC-PUFA biomechanisms has not been adequately tapped to develop translational studies of LC-PUFA clinical effects in humans. Future studies integrating neurobiological mechanisms with clinical outcomes may suggest ways to identify depressed individuals most likely to respond to n-3 LC-PUFA supplementation, and mechanistic research may generate new treatment strategies.

Study on the Mechanism for SIRT1 during the Process of Exercise Improving Depression

The mechanism behind the onset of depression has been the focus of current research in the neuroscience field. Silent information regulator 1 (SIRT1) is a key player in regulating energy metabolism, and it can regulate depression by mediating the inflammatory response (e.g., nuclear factor-kappa B (NF-κB), tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β)), gene expression in the nucleus accumben (NAc) and CA1 region of the hippocampus (e.g., nescient helix-loop-helix2 (NHLH2), monoamine oxidase (MAO-A), and 5-Hydroxyindole-3-acetic acid (5-HIAA)), and neuronal regeneration in the CA3 region of the hippocampus. Exercise is an important means to improve energy metabolism and depression, but it remains to be established how SIRT1 acts during exercise and improves depression. By induction and analysis, SIRT1 can be activated by exercise and then improve the function of the hypothalamic-pituitary-adrenal (HPA) axis by upregulating brain-derived neurotrophic factors (BDNF), inhibit the inflammatory response (suppression of the NF-κB and TNF-α/indoleamine 2,3-dioxygenase (IDO)/5-Hydroxytryptamine (5-HT) pathways), and promote neurogenesis (activation of the insulin-like growth factor1 (IGF-1) and growth-associated protein-43 (GAP-43) pathways, etc.), thereby improving depression. The present review gives a summary and an outlook based on this finding and makes an analysis, which will provide a new rationale and insight for the mechanism by which exercise improves depression.

Exploration for biomarkers of postpartum depression based on metabolomics: A systematic review

BACKGROUND

Postpartum depression (PPD) is the most frequent psychiatric complication during the postnatal period and its mechanisms are not fully understood. Metabolomics, can quantitatively measure metabolites in a high-throughput method, and thus uncover the underlying pathophysiology of disease.

OBJECTIVES

In this study, we reviewed metabolomics studies conducted on PPD, aiming to understand the changes of metabolites in PPD patients and analyze the potential application of metabolomics in PPD prediction and diagnosis.

METHODS

Relevant articles were searched in PubMed, Google scholar, and Web of Science databases from January 2011 to July 2022. The metabolites involved were systematically examined and compared. MetaboAnalyst online software was applied to analyze metabolic pathways.

RESULTS

A total of 14 papers were included in this study. There were several highly reported metabolites, such as kynurenine, kynurenic acid, and eicosapentaenoic acid. Dysregulation of metabolic pathways involved amino acids metabolism, fatty acids metabolism, and steroids metabolism.

LIMITATIONS

The included studies are relatively inadequate, and further work is needed.

CONCLUSIONS

This study summarized significant metabolic alterations that provided clues for the prediction, diagnosis, and pathogenesis of PPD.

Animal models of postpartum depression revisited

Postpartum depression (PPD) is a heterogeneous mood disorder and the most frequent psychiatric complication of the postnatal period. Given its potential long-lasting repercussions on the well-being of the mother and the infants, it should be a priority in public health. In spite of efforts devoted to clinical investigation and preclinical studies, the underlying neurobiological mechanisms of this disorder remain unknown in detail. Much of the progress in the area has been made from animal models, especially rodent models. The aim of this mini-review is to update the current rodent models in PPD research and their main contributions to the field. Animal models are critical tools to advance understanding of the pathophysiological basis of this disorder and to help the development of new therapeutic strategies. Here, we group PPD models into 2 main categories (Models based on hormone manipulations, Models based on stress exposure), each of which includes different paradigms that reflect risk factors or physiological conditions associated with this disease. Finally, we provide an overview of emerging models that provide new perspectives on the study of possible pathophysiological factors related to PPD, to contribute to tackling potential therapeutic targets.