Aerobic exercise reverses the NF-κB/NLRP3 inflammasome/5-HT pathway by upregulating irisin to alleviate post-stroke depression

Physical exercise regulates microglia in health and disease

There is a well-established link between physical activity and brain health. As such, the effectiveness of physical exercise as a therapeutic strategy has been explored in a variety of neurological contexts. To determine the extent to which physical exercise could be most beneficial under different circumstances, studies are needed to uncover the underlying mechanisms behind the benefits of physical activity. Interest has grown in understanding how physical activity can regulate microglia, the resident immune cells of the central nervous system. Microglia are key mediators of neuroinflammatory processes and play a role in maintaining brain homeostasis in healthy and pathological settings. Here, we explore the evidence suggesting that physical activity has the potential to regulate microglia activity in various animal models. We emphasize key areas where future research could contribute to uncovering the therapeutic benefits of engaging in physical exercise.

Unveiling the potential of estrogen: Exploring its role in neuropsychiatric disorders and exercise intervention

Neuropsychiatric disorders shorten human life spans through multiple ways and become major threats to human health. Exercise can regulate the estrogen signaling, which may be involved in depression, Alzheimer's disease (AD) and Parkinson's disease (PD), and other neuropsychiatric disorders as well in their sex differences. In nervous system, estrogen is an important regulator of cell development, synaptic development, and brain connectivity. Therefore, this review aimed to investigate the potential of estrogen system in the exercise intervention of neuropsychiatric disorders to better understand the exercise in neuropsychiatric disorders and its sex specific. Exercise can exert a protective effect in neuropsychiatric disorders through regulating the expression of estrogen and estrogen receptors, which are involved in neuroprotection, neurodevelopment, and neuronal glucose homeostasis. These processes are mediated by the downstream factors of estrogen signaling, including N-myc downstream regulatory gene 2 (Ndrg2), serotonin (5-HT), delta like canonical Notch ligand 1 (DLL1), NOD-like receptor thermal protein domain associated protein 3 (NLRP3), etc. In addition, exercise can act on the estrogen response element (ERE) fragment in the genes of estrogenic downstream factors like β-amyloid precursor protein cleavase 1 (BACE1). However, there are few studies on the relationship between exercise, the estrogen signaling pathway, and neuropsychiatric disorders. Hence, we review how the estrogen signaling mediates the mechanism of exercise intervention in neuropsychiatric disorders. We aim to provide a theoretical perspective for neuropsychiatric disorders affecting female health and provide theoretical support for the design of exercise prescriptions.

Effect of Shenqi Jieyu formula on inflammatory response pathway in hippocampus of postpartum depression rats

Aim

To investigate whether SJF functions in similar manner as the key substance in the inflammatory process, soluble epoxide hydrolase (sEH) inhibitor, to inhibit the arachidonic acid metabolic pathway and nuclear factor kappa-B(NF-κB) signal path in the hippocampi of postpartum depression rats.

Methods

The rats were subcutaneous injected estradiol benzoate and progesterone to build PPD rat model. SJF, paroxetine hydrochloride and sEH inhibitor (AUDA) were used to treat PPD rats for 3 weeks. Then the morphological changes of hippocampi and various proteins were observed after that behavioral test were conducted in all 36 SD rats in six group: SJF, paroxetine, AUDA, PPD, sham and normal group.

Results

Weight, results of sucrose preference, upright times, total and center squares crossing decreased significantly (P < 0.01), whereas immobility time increased (P < 0.01). Results above were reversed in animals that in the SJF, paroxetine and AUDA groups. Hippocampal neurons in PPD rats partially degenerated with narrowed nuclei, increased autophagy and mitochondria bound to lysosomes were visible while the autophagy of hippocampal neurons in the paroxetine and AUDA group decreased, with a small amount of lysosomes. sEH, COX-2, 5-LOX, TNF-α, IL-1, IL-6, NF-κB p65, and Cor increased in hippocampi of PPD rats while EETs and 5-HT decreased. Protein expressions of Ibal, GFAP, p-IκBα, p65, and p-p65(S536)increased in PPD animals. Those changes were reversed by SJF, paroxetine and AUDA. Gene expressions of TNF-α, IL-1β, IL-6, 5-LOX, COX-2 and p65 increased in PPD rats and the changes of expression in these genes were reversed by paroxetine and AUDA. SJF reversed the gene expression changes of COX-2, TNF-α, and IL-1β.

Conclusion

SJF may have an analogous effect as sEH inhibitor to relieve depressive symptoms by suppressing inflammatory signaling pathways in hippocampi of PPD rats, which involves AA metabolic pathway and NF-κB signal pathway.

Bridging the gap: Integrating exercise mimicry into chronic disease management through suppressing chronic inflammation

BACKGROUND

Chronic inflammation is a common hallmark of many chronic diseases. Although exercise holds paramount importance in preventing and managing chronic diseases, adherence to exercise programs can be challenging for some patients. Consequently, there is a pressing need to explore alternative strategies to emulate the anti-inflammatory effects of exercise for chronic diseases.

AIM OF REVIEW

This review explores the emerging role of green tea bioactive components as potential mitigators of chronic inflammation, offering insights into their capacity to mimic the beneficial effects of exercise. We propose that bioactive components in green tea are promising agents for suppressing chronic inflammation, suggesting their unique capability to replicate the health benefits of exercise.

KEY SCIENTIFIC CONCEPTS OF REVIEW

This review focuses on several key concepts, including chronic inflammation and its role in chronic diseases, the anti-inflammatory effects of regular exercise, and bioactive components in green tea responsible for its health benefits. It elaborates on scientific evidence supporting the anti-inflammatory properties of green tea bioactive components, such as epigallocatechin gallate (EGCG), and theorizes how these bioactive components might replicate the effects of exercise at a molecular level. Through a comprehensive analysis of current research, this review proposes a novel perspective on the application of green tea as a potential intervention strategy to suppress chronic inflammation, thereby extending the benefits akin to those achieved through exercise.

Paroxetine Effect on Nerve Growth Factor, Human Neurotrophin-4, Brain-Derived Neurotrophic Factor Levels in Post-stroke Depression

The aim of this study is to explore paroxetine's effect on nerve growth factor (NGF), human neurotrophin-4 (NT-4), and brain-derived neurotrophic factor (BDNF) levels in post-stroke depression. Ninety-two post-stroke depression patients from April 2021 to April 2023 in our hospital were selected and numbered 1 to 92 after enrollment. Forty-six patients with odd number and 46 patients with even number were, respectively, included in the control and observation group. In addition to basic treatment, control group was treated with flupentixol melitracen tablets orally, and observation group received paroxetine hydrochloride orally. The levels of NGF, NT-4, BDNF, 5-hydroxytryptamine (5-HT), homocysteine (Hcy), noradrenaline (NE), Hamilton Depression Scale (HAMD) changes of National Institute of Health Stroke Scale (NIHSS). NGF, NT-4, and BDNF levels were compared between groups at T0, T1, and T2 levels were higher, and the levels at T2 were higher than those at T1, and observation group levels were higher (P < 0.05); NGF, NT-4, and BDNF levels were compared among groups, time, and interaction. 5-HT, Hcy, and NE levels at T0 were compared between groups; 5-HT and NE levels at T1 and T2 were higher than those at T0, the levels at T2 were higher than those at T1, and observation group levels were higher (P < 0.05); Hcy level at T1 and T2 was lower, its level at T2 was lower than those at T1, and observation group levels were lower (P < 0.05); 5-HT, Hcy, and NE levels were compared among groups, time, and interaction (P < 0.05). HAMD and NIHSS at T0 were compared; T1 and T2 were lower than T0, T2 was lower than T1, and observation group was lower (P < 0.05); HAMD and NIHSS were compared among groups, time, and interaction (P < 0.05). For post-stroke depression, paroxetine treatment can effectively improve NGF, NT-4, BDNF, 5-HT, Hcy, and NE levels and effectively reduce the degree of neurological damage and depression, which has high clinical application value.

Possible role of exercise therapy on depression: Effector neurotransmitters as key players

About 280 million people suffer from depression as the most common neurological disorder and the most common cause of death worldwide. Exercise with serotonin released in the brain by the 5-HT3-IGF-1 mechanism can lead to antidepressant effects. Swimming exercise has antidepressant effects by increasing the sensitivity of serotonin 5-HT2 receptors and postsynaptic 5-HT1A receptors, increasing 5-HT and 5HIAA levels, increasing TPH and serotonin, and decreasing inflammatory levels of IFN-γ and TNF-α. Anaerobic and aerobic exercises increase beta-endorphin, enkephalin, and dynorphin and have antidepressant effects. Exercise by increasing dopamine, D1R, and D2R leads to the expression of BDNF and activation of TrkB and has antidepressant behavior. Exercise leads to a significant increase in GABAAR (γ2 and α2 subunits) and reduces neurodegenerative disorders caused by GABA imbalance through anti-inflammatory pathways. By increasing glutamate and PGC1α and reducing glutamatergic neurotoxicity, exercise enhances neurogenesis and synaptogenesis and prevents neurodegeneration and the onset of depression. Irisin release during exercise shows an important role in depression by increasing dopamine, BDNF, NGF, and IGF-1 and decreasing inflammatory mediators such as IL-6 and IL-1β. In addition, exercise-induced orexin and NPY can increase hippocampal neurogenesis and relieve depression. After exercise, the tryptophan to large neutral amino acids (TRP/LNAA) ratio and the tryptophan to branched-chain amino acids (BCAA) ratio increase, which may have antidepressant effects. The expression of M5 receptor and nAChR α7 increases after exercise and significantly increases dopamine and acetylcholine and ameliorates depression. It appears that during exercise, muscarinic receptors can reduce depression through dopamine in the absence of acetylcholine. Therefore, exercise can be used to reduce depression by affecting neurotransmitters, neuromodulators, cytokines, and/or neurotrophins.

Role of Inflammatory Mechanisms in Major Depressive Disorder: From Etiology to Potential Pharmacological Targets

The involvement of central and peripheral inflammation in the pathogenesis and prognosis of major depressive disorder (MDD) has been demonstrated. The increase of pro-inflammatory cytokines (interleukin (IL)-1β, IL-6, IL-18, and TNF-α) in individuals with depression may elicit neuroinflammatory processes and peripheral inflammation, mechanisms that, in turn, can contribute to gut microbiota dysbiosis. Together, neuroinflammation and gut dysbiosis induce alterations in tryptophan metabolism, culminating in decreased serotonin synthesis, impairments in neuroplasticity-related mechanisms, and glutamate-mediated excitotoxicity. This review aims to highlight the inflammatory mechanisms (neuroinflammation, peripheral inflammation, and gut dysbiosis) involved in the pathophysiology of MDD and to explore novel anti-inflammatory therapeutic approaches for this psychiatric disturbance. Several lines of evidence have indicated that in addition to antidepressants, physical exercise, probiotics, and nutraceuticals (agmatine, ascorbic acid, and vitamin D) possess anti-inflammatory effects that may contribute to their antidepressant properties. Further studies are necessary to explore the therapeutic benefits of these alternative therapies for MDD.

Aerobic Exercise Improves Depressive-like Behavior in CUMS-Induced Rats via the SIRT3/ROS/NLRP3 Signaling Pathway

OBJECTIVE

This study aimed to investigate the effect of exercise on depressive-like behavior induced by chronic unpredictable mild stress (CUMS) in rats and to explore the role of the SIRT3/ROS/NLRP3 signaling pathway in this process.

METHODS

Twenty-nine male 8-week-old Sprague Dawley rats were divided into a control group (CON) (nine rats) and a model group (twenty rats). Thirteen chronic stress stimuli were randomly applied once or twice per day for 35 days to induce depression in the model group rats. After the model was established, the model group rats were randomly divided into the CUMS group (CUMS) and the aerobic exercise + CUMS group (EX + CUMS). The EX + CUMS group received 8 weeks of aerobic exercise intervention for 6 days per week. Behavioral assessments were performed using the sucrose preference test and forced swimming test. The expression of SIRT3, NLRP3, IL-1β, and IL-18 in the hippocampus was detected using RT-PCR. The ROS level in the hippocampus was detected using immunofluorescence. The protein levels of SIRT3 and NLRP3 in the hippocampus were detected using western blotting. The protein levels of IL-1β and IL-18 in the hippocampus were measured using ELISA.

RESULTS

After 5 weeks of chronic stress stimuli, the hippocampal function of rats in the CUMS model group was impaired, and their sucrose preference was reduced, while their forced swimming time was prolonged. The expression of SIRT3 decreased, ROS increased, and the expression of NLRP3 and the levels of IL-1β and IL-18 increased. Aerobic exercise increased the sucrose preference of rats, shortened their immobility time, increased the expression of SIRT3, and reduced the levels of ROS, NLRP3, IL-1β, and IL-18.

CONCLUSION

Exercise can improve the depressive behavior of CUMS model rats, and its mechanism may be related to the upregulation of SIRT3 in the hippocampus, which plays an anti-inflammatory role.

A new perspective on hippocampal synaptic plasticity and post-stroke depression

Post-stroke depression, a common complication after stroke, severely affects the recovery and quality of life of patients with stroke. Owing to its complex mechanisms, post-stroke depression treatment remains highly challenging. Hippocampal synaptic plasticity is one of the key factors leading to post-stroke depression; however, the precise molecular mechanisms remain unclear. Numerous studies have found that neurotrophic factors, protein kinases and neurotransmitters influence depressive behaviour by modulating hippocampal synaptic plasticity. This review further elaborates on the role of hippocampal synaptic plasticity in post-stroke depression by summarizing recent research and analysing possible molecular mechanisms. Evidence for the correlation between hippocampal mechanisms and post-stroke depression helps to better understand the pathological process of post-stroke depression and improve its treatment.