[Restraint Stress-Induced Expression of Fos and Several Related Genes in the Hypothalamus of Hypertensive ISIAH Rats].

Stress can play a significant role in arterial hypertension and many other complications of cardiovascular diseases. Considerable attention is paid to the study of the molecular mechanisms involved in the body response to stressful influences, but there are still many blank spots in understanding the details. ISIAH rats model the stress-sensitive form of arterial hypertension. ISIAH rats are characterized by genetically determined enhanced activities of the hypothalamic-pituitary-adrenocortical and sympathetic-adrenomedullary systems, suggesting a functional state of increased stress reactivity. For the first time, the temporal expression patterns of Fos and several related genes were studied in the hypothalamus of adult male hypertensive ISIAH rats after a single exposure to restraint stress for 30, 60, or 120 min. Fos transcription was activated and peaked 1 h after the start of restraint stress. The time course of Fos activation coincided with that of blood pressure increase after stress. Activation of hypothalamic neurons also alters the transcription levels of several transcription factor genes (Jun, Nr4a3, Jdp2, and Ppargc1a), which are associated with the development of cardiovascular diseases. Because Fos induction is a marker of brain neuron activation, activation of hypothalamic neurons and an increase in blood pressure were concluded to accompany increased stress reactivity of the hypothalamic-pituitary-adrenocortical and sympathoadrenal systems in hypertensive ISIAH rats during short-term restraint.

The TF/Nrf2/GSTP1 pathway is involved in stress-induced hepatocellular injury through ferroptosis.

Stress triggers a comprehensive pathophysiological cascade in organisms. However, there is a substantial gap in the research regarding the effects of stress on liver function. This study aimed to investigate the impact of restraint stress on hepatocellular damage and elucidate the underlying molecular mechanisms. An effective mouse restraint stress model was successfully developed, and liver function analysis was performed using laser speckle imaging, metabolomics and serum testing. Alterations in hepatocyte morphology were assessed using haematoxylin and eosin staining and transmission electron microscopy. Oxidative stress in hepatocytes was assessed using lipid reactive oxygen species and malondialdehyde. The methylation status and expression of GSTP1 were analysed using DNA sequencing and, real-time PCR, and the expression levels of GPX4, TF and Nrf2 were evaluated using real-time quantitative PCR, western blotting, and immunohistochemical staining. A stress-induced model was established in vitro by using dexamethasone-treated AML-12 cells. To investigate the underlying mechanisms, GSTP1 overexpression, small interfering RNA, ferroptosis and Nrf2 inhibitors were used. GSTP1 methylation contributes to stress-induced hepatocellular damage and dysfunction. GSTP1 is involved in ferroptosis-mediated hepatocellular injury induced by restraint stress via the TF/Nrf2 pathway. These findings suggest that stress-induced hepatocellular injury is associated with ferroptosis, which is regulated by TF/Nrf2/GSTP1.

Neuro-stimulating effect of Citri Reticulata Pericarpium Viride essential oil through regulating Glu/NMDAR on olfactory bulb to improve anxiety-like behavior.

ETHNOPHARMACOLOGICAL RELEVANCE: Citri Reticulata Pericarpium Viride (also known Qing-Pi or QP) is a plant in the Rutaceae family, QP is a traditional Qi-regulating medicine in Chinese medicine that is compatible with other Chinese medicine components and has extensive clinical practice in treating anxiety and depression. Reports on the pharmacological effects of QP have demonstrated its neuroprotective effects and antioxidant capacities. Numerous pharmacological benefits of QP are attributed to its antioxidant abilities. Anxiety disorders are a broadly defined category of mental illnesses. Oxidative stress and an imbalance in the antioxidant defense system are typical pathological features of these disorders. AIM OF THE STUDY: The aim of this study was to evaluate the effects of QP essential oil on anxiety using animal models and investigate the underlying neurobiological mechanisms. MATERIALS AND METHODS: This study aimed to develop an animal model of anxiety using chronic restraint stress and investigate the effects of inhalation of Citri Reticulata Pericarpium Viride essential oil on anxiety-like behavior, olfactory function, and olfactory bulb neurogenesis in mice with anxiety. RESULTS: The results showed that long-term chronic restraint stimulation caused a decrease in olfactory function, significant anxiety-like behavior, and a notable reduction in the number of neurons in the olfactory bulb. However, inhalation of Citri Reticulata Pericarpium Viride essential oil reversed these effects, improving the olfactory function, neuro-stimulating effect, alleviating anxiety-like behavior, and regulating theta (4-12Hz) oscillation in the hippocampus DG area. These effects were associated with changes in the expression levels of glutamate receptor NMDAR and NeuN in olfactory bulb. CONCLUSIONS: The study revealed that mice with anxiety induced by chronic restraint stress exhibited significant olfactory dysfunction, providing strong evidence for the causal relationship between anxiety disorders and olfactory dysfunction. Moreover, QP essential oil has the potential to be developed as a therapeutic drug for anxiety disorders, in addition to its role as a complementary anxiolytic.

Neuroprotective Role of Selenium Nanoparticles Against Behavioral, Neurobiochemical and Histological Alterations in Rats Subjected to Chronic Restraint Stress.

Chronic stress induces changes in the prefrontal cortex and hippocampus. Selenium nanoparticles (SeNPs) showed promising results in several neurological animal models. The implementation of SeNPs in chronic restraint stress (CRS) remains to be elucidated. This study was done to determine the possible protective effects of selenium nanoparticles on behavioral changes and brain oxidative stress markers in a rat model of CRS. 50 rats were divided into three groups; control group (n = 10), untreated CRS group (n = 10) and CRS-SeNPs treated group (n = 30). Restraint stress was performed 6 h./day for 21 days. Rats of CRS-SeNPs treated group received 1, 2.5 or 5 mg/kg SeNPs (10 rats each) by oral gavage for 21 days. Rats were subjected to behavioral assessments and then sacrificed for biochemical and histological analysis of the prefrontal cortex and hippocampus. Prefrontal cortical and hippocampal serotonin levels, oxidative stress markers including malondialdehyde (MDA), reduced glutathione (GSH) and glutathione peroxidase (GPx), tumor necrosis factor alpha (TNF-α) and caspase-3 were assessed. Accordingly, different doses of SeNPs showed variable effectiveness in ameliorating disease parameters, with 2.5 mg/kg dose of SeNPs showing the best improving results in all studied parameters. The present study exhibited the neuroprotective role of SeNPs in rats subjected to CRS and proposed their antioxidant, anti-inflammatory and anti-apoptotic effects as the possible mechanism for increased prefrontal cortical and hippocampal serotonin level, ameliorated anxiety-like and depressive-like behaviors and improved prefrontal cortical and hippocampal histological architecture.

LEPR/FOS/JUNB signaling pathway contributes to chronic restraint stress-induced tumor proliferation.

BACKGROUND & AIMS: Psychosocial stress has become an unavoidable part of life, which was reported to promote tumor development. Chronic stress significantly promotes the norepinephrine (NE) secretion and the expression of leptin receptor (LEPR), leading to tumor invasion, metastasis, and proliferation. However, the mechanism of chronic stress-induced tumor proliferation remains unclear. METHODS: To reveal the effect of chronic stress on tumor proliferation, subcutaneous tumor models combined with chronic restraint stress (CRS) were established. Combined with the transcript omics database of liver cancer patients, the target pathways were screened and further verified by in vitro experiments. RESULTS: The results showed that the CRS with subcutaneous tumor transplantation (CRS + tumor) group exhibited significantly larger tumor sizes than the subcutaneous tumor transplantation (tumor) group. Compared with the tumor group, CRS obviously increased the mRNA levels of LEPR, FOS, and JUNB of tumor tissues in the CRS + tumor group. Furthermore, the treatment with norepinephrine (NE) significantly elevated the survival rate of H22 cells and enhanced the expression of LEPR, FOS, and JUNB in vitro. Silencing LEPR significantly reduced the expression of FOS and JUNB, accompanied by a decrease in H22 cell viability. CONCLUSIONS: Our study demonstrated that CRS activates the LEPR-FOS-JUNB signaling pathway by NE, aggravating tumor development. These findings might provide a scientific foundation for investigating the underlying pathological mechanisms of tumors in response to chronic stress.

A chronic stress-induced microbiome perturbation, highly enriched in Ruminococcaceae_UCG-014, promotes colorectal cancer growth and metastasis.

Purpose: Mounting evidence indicates that psychological stress adversely affects cancer progression including tumor growth and metastasis. The aim of this study was to investigate the role of chronic stress-induced microbiome perturbation in colorectal cancer (CRC) progression. Methods: Chronic restraint stress (CRS) was used to establish the chronic stress mouse model, behavioral tests were used for the CRS model evaluation. Subcutaneous xenograft model and lung metastasis model were established to investigate the growth and metastasis of CRC promoted by CRS exposure. 16S rRNA gene sequencing and liquid chromatograph-mass spectrometer (LC-MS) were applied to observe the effects of CRS exposure on the alteration of the gut microbiome and microbial metabolites. Bioinformatics analysis and correlation analyses were applied to analyse the changes in the frequency of body mass, tumor volume, inflammatory factors, neuroendocrine hormones and metabolites of the gut microbiota. Results: In this study, we identifed that CRS exposure model was appropriately constructed by achieving expected increases in disease activity index and enhanced depressive-like behaviors. CRS exposure can promote growth and metastasis of CRC. Besides, the data indicated that CRS exposure not only increased the neuro- and immune-inflammation, but also weakened the gut mucosal immunological function. The 16s rRNA gene sequencing data showed that CRS exposure increased the abundance of g_Ruminococcaceae_UCG_014. Furthermore, the LC-MS data indicated that with only 2 exceptions of carpaine and DG (15:0/20:4(5Z,8Z,11Z,14Z)/0:0), the majority of these 24 metabolites were less abundant in CRS-exposed mice. Bioinformatics analysis and correlation analyses indicated that only Ruminoscoccaceae-UCG-014 was significantly associated with inflammation (IL-6), neurotransmission (5-HT), and microbial metabolism (PS). Conclusion: CRS exposure altered diversity, composition and metabolites of the gut microbiome, with Ruminococcaceae_UCG-014 perturbation consistently correlated to inflammatory responses, suggesting a particular role of this bacterial genus in CRC growth and metastasis.

Neurophysiological analysis of disadvantageous social inequity: Exploring emotional behavior changes and c-Fos expression in a male rat model.

Humans and other animals exhibit aversive behavioral and emotional responses to unequal reward distributions compared with their conspecifics. Despite the significance of this phenomenon, experimental animal models designed to investigate social inequity aversion and delve into the underlying neurophysiological mechanisms are limited. In this study, we developed a rat model to determine the effects of socially equal or unequal reward and stress on emotional changes in male rats. During the training session, the rats were trained to escape when a sound cue was presented, and they were assigned to one of the following groups: all escaping rats [advantageous equity (AE)], freely moving rats alongside a restrained rat [advantageous inequity (AI)], all restrained rats [disadvantageous equity (DE)], and a rat restrained in the presence of freely moving companions [disadvantageous inequity (DI)]. During the test session, rats in the advantageous group (AE and AI) escaped after the cue sound (expected reward acquisition), whereas rats in the disadvantageous group (DE and DI) could not escape despite the cue being presented (expected reward deprivation). Emotional alteration induced by exposure to restraint stress under various social interaction circumstances was examined using an open field test. Notably, the DI group displayed reduced exploration of the center zone during the open field tests compared with the other groups, indicating heightened anxiety-like behaviors in response to reward inequity. Immunohistochemical analysis revealed increased c-Fos expression in the medial prefrontal and orbitofrontal cortices, coupled with reduced c-Fos expression in the striatum and nucleus accumbens under DI conditions, in contrast to the other experimental conditions. These findings provide compelling evidence that rats are particularly sensitive to reward inequity, shedding light on the neurophysiological basis for distinct cognitive processes that manifest when individuals are exposed to social equity and inequity situations.

Effects of Interleukin-19 overexpression in the medial prefrontal cortex on anxiety-related behaviors, BDNF expression and p38/JNK/ERK pathways.

Anxiety is a prevalent mental illness known for its high incidence, comorbidity, and tendency to recur, posing significant societal and individual burdens. Studies have highlighted Interleukin-19 (IL-19) as having potential relevance in neuropsychiatric disorders. Our previous research revealed that IL-19 overexpression in colonies exacerbated anxiety-related behaviors induced by dextran sodium sulfate/stress. However, the precise role and molecular mechanisms of IL-19 in anxiety regulation remain uncertain. In this study, we initiated an acute restraint stress (ARS)-induced anxious mouse model and identified heightened expression of IL-19 and IL-20Rα in the medial prefrontal cortex (mPFC) of ARS mice. Notably, IL-19 and IL-20Rα were predominantly present in the excitatory pyramidal neurons of the mPFC under both basal and ARS conditions. Utilizing the adeno-associated virus (AAV) strategy, we demonstrated that IL-19 overexpression in the mPFC induced anxiety-related behaviors and elevated stress susceptibility. Additionally, we observed decreased protein levels of brain-derived neurotrophic factor (BDNF) and postsynaptic density protein 95 (PSD95) in the mPFC of IL-19 overexpression mice, accompanied by reduced phosphorylation of in the p38, JNK, and Erk signaling pathways. These findings emphasize the role of IL-19 in modulating anxiety-related behaviors within the mPFC and suggest its potential as a pathological gene and therapeutic target for anxiety.

Shen Yuan extract exerts a hypnotic effect via the tryptophan/5-hydroxytryptamine/melatonin pathway in mice.

ETHNOPHARMACOLOGICAL RELEVANCE: Sleep plays a critical role in several physiologic processes, and sleep disorders increase the risk of depression, dementia, stroke, cancer, and other diseases. Stress is one of the main causes of sleep disorders. Ginseng Radix et Rhizoma and Polygalae Radix have been reported to have effects of calming the mind and intensifying intelligence in Chinese Pharmacopoeia. Traditional Chinese medicine prescriptions composed of Ginseng Radix et Rhizoma and Polygalae Radix (Shen Yuan, SY) are commonly used to treat insomnia, depression, and other psychiatric disorders in clinical practice. Unfortunately, the underlying mechanisms of the SY extract's effect on sleep are still unknown. AIM OF THE STUDY: This study aimed to investigate the hypnotic effect of the SY extract in normal mice and mice with chronic restraint stress (CRS)-induced sleep disorders and elucidate the underlying mechanisms. MATERIALS AND METHODS: The SY extract (0.5 and 1.0 g/kg) was intragastrically administered to normal mice for 1, 14, and 28 days and to CRS-treated mice for 28 days. The open field test (OFT) and pentobarbital sodium-induced sleep test (PST) were used to evaluate the hypnotic effect of the SY extract. Liquid chromatography-tandem mass spectrometry and enzyme-linked immunosorbent assay were utilized to detect the levels of neurotransmitters and hormones. Molecular changes at the mRNA and protein levels were determined using real-time quantitative polymerase chain reaction and Western blot analysis to identify the mechanisms by which SY improves sleep disorders. RESULTS: The SY extract decreased sleep latency and increased sleep duration in normal mice. Similarly, the sleep duration of mice subjected to CRS was increased by administering SY. The SY extract increased the levels of tryptophan (Trp) and 5-hydroxytryptamine (5-HT) and the expression of tryptophan hydroxylase 2 (TPH2) in the cortex of normal mice. The SY extract increased the Trp level, transcription and expression of estrogen receptor beta and TPH2 in the cortex in mice with sleep disorders by decreasing the serum corticosterone level, which promoted the synthesis of 5-HT. Additionally, the SY extract enhanced the expression of arylalkylamine N-acetyltransferase, which increased the melatonin level and upregulated the expressions of melatonin receptor-2 (MT2) and Cryptochrome 1 (Cry1) in the hypothalamus of mice with sleep disorders. CONCLUSIONS: The SY extract exerted a hypnotic effect via the Trp/5-HT/melatonin pathway, which augmented the synthesis of 5-HT and melatonin and further increased the expressions of MT2 and Cry1.

Synergistic effects of citicoline and silymarin nanomicelles in restraint stress-exposed mice.

This study evaluated the effects of citicoline and silymarin nanomicelles (SMnm) in repeated restraint stress (RRS). METHOD: Mice were exposed to RRS for four consecutive days, 2 hrs. daily. On day 5 of the study, SMnm (25 and 50 mg/kg, i.p.) and citicoline (25 and 75 mg/kg), and a combination of them (25 mg/kg, i.p.) were initiated. On day 18, anxiety-like behavior, behavioral despair, and exploratory behavior were evaluated. The prefrontal cortex (PFC) and the hippocampus were dissected measuring brain-derived neurotrophic factor (BDNF), cAMP response element-binding protein (CREB), and tumor necrosis factor-alpha (TNF-α) through Western Blot and ELISA, respectively. RESULTS: In RR-exposed mice, anxiety-like behavior in the elevated plus maze (EPM) was enhanced by reductions in open arm time (OAT%) P < 0.001, and open arm entry (OAE%) P < 0.001. In the forced swimming test (FST), the immobility increased P < 0.001 while the swimming and climbing reduced P < 0.001. In the open field test (OFT), general motor activity was raised P < 0.05. Further, body weights reduced P < 0.001, and tissue BDNF and pCREB expressions decreased P < 0.001 while TNF-α increased P < 0.001. Conversely, SMnm, citicoline and their combination could reduce anxiety-like behavior P < 0.001. The combination group reduced the depressive-like behaviors P < 0.001. Moreover, body weights were restored P < 0.001. Besides, BDNF and pCREB expressions increased while TNF-α reduced, P < 0.001. CONCLUSION: The combination synergistically improved emotion-like behaviors, alleviating the inflammation and upregulating the hippocampal BDNF-mediated CREB signaling pathway.

Uncovering the effect and mechanism of Jiawei Xiaoyao Wan in treating breast cancer complicated with depression based on network pharmacology and experimental analysis.

BACKGROUND: Depression is a clinically common co-morbidity in breast cancer cases that brings negative outcomes on quality of life and potentially survival. Jiawei Xiaoyao Wan (JXW) is widely used in treating breast cancer and depressive disorder, but its potential pharmacological mechanisms remain elusive. PURPOSE: We aimed to explore the dual therapeutic effects and mechanisms of JXW acting on breast cancer complicated with depression (BCCD) by network pharmacology and in vivo experimental verification. METHODS: The chemical constituents of JXW were characterized using liquid chromatography-quadrupole time-of-flight tandem mass spectrometry (LC-Q-TOF/MS). The targets related to constituents of JXW were predicted by the TCMSP and Swiss Target Prediction databases, and targets of breast cancer and depression were screened by the GeneCards and OMIM databases. Gene Ontology annotation and KEGG enrichment analysis were performed with the DAVID database. Ultimately, a BCCD mouse model induced by chronic restraint stress (CRS) was used to explore therapeutic effects and mechanisms of JXW against BCCD. The efficacy of JXW in the treatment of BCCD was evaluated based on behavioral tests, tumor volume and weight, and pathological examination. Additionally, the underlying mechanisms were explored by measuring the levels of neurotransmitter and inflammatory factors, as well as detecting the expression of genes or proteins associated with candidate targets and the Janus kinase/signal transducer and activator of transcription (JAK/STAT) signaling pathway through RT-PCR, western blotting, and immunohistochemistry. RESULTS: Totals of 108 components were identified in JXW using LC-Q-TOF/MS. By network pharmacology analysis, 714 compound targets of JXW, 2114 breast cancer targets, 1122 depression targets, and 98 overlapping proteins were obtained. PPI network and KEGG analysis implied that TP53, ESR1, VEGFA, AKT1, IL6, TNF, EGFR and the JAK/STAT pathway might be the potential targets of JXW in treating BCCD. In vivo experiments indicated that JXW significantly ameliorated depressive symptoms and tumor progression in BCCD mice. Further mechanistic studies showed that JXW could reduce the levels of inflammatory factors, increase 5-HT level, and regulate mRNA expression levels of TP53, VEGFA, AKT1, IL6, TNF, and EGFR targets. Moreover, the expression levels of proteins related to the JAK2/STAT3 signaling pathway in BCCD mice were effectively regulated by JXW. CONCLUSION: JXW exerts dual therapeutic effects in a BCCD mouse via multiple targets. The underlying mechanisms might be associated with regulating the levels of neurotransmitter and inflammatory factors; more importantly, the JAK2/STAT3 pathway plays a significant role in this process.

Glycyrrhizic acid treatment ameliorates anxiety-like behaviour via GLT1 and Per1/2-dependent pathways.

ETHNOPHARMACOLOGICAL RELEVANCE: As a traditional Chinese medicinal herb, Glycyrrhiza. URALENSIS: Fisch. (licorice root, chinese name: Gancao) has a variety of medicinal values and is widely used clinically. Its main active ingredient, glycyrrhizic acid (GA), is believed to have a neuroprotective effect. However, the underlying biological mechanisms of GA on stress-induced anxiety disorders are still unclear. AIM OF THE STUDY: To investigate the anti-anxiety effect of GA and its underlying mechanism. METHODS: We selected the anxiety model induced by repeated chronic restraint stress (CRS) for 2 h on each of 7 consecutive days. GA (4, 20, 100 mg/kg) was injected intraperitoneally once daily for 1 week. The potential GA receptors were identified using whole-cell patches and computer-assisted docking of molecules. High-throughput RNA sequencing, adeno-associated virus-mediated gene regulation, Western blotting, and RT-qPCR were used to assess the underlying molecular pathways. RESULTS: GA alleviate depression-like and anxiety-like behaviors in CRS mice. GA decreased synaptic transmission by facilitating glutamate reuptaking in mPFC. Meanwhile, long-term GA treatment increased the expression of clock genes Per1 and Per2. Suppressing both Per1 and Per2 abolished the anxiolytic effects of GA treatment. CONCLUSION: Our study suggests that GA may be developed for the treatment of stress-induced anxiety disorders, and its mechanism is related to GLT1 and Per1/2-dependent pathways. This presents a novel approach to discovering potent therapeutic drugs.

Chronic restraint stress promotes oral squamous cell carcinoma development by inhibiting ALDH3A1 via stress response hormone.

BACKGROUND: Chronic restraint stress (CRS) has iteratively been reported to be possibly implicated in the development of numerous cancer types. However, its role in oral squamous cell carcinoma (OSCC) has not been well elucidated. Here we intended to evaluate the role and mechanism. METHODS: The effects of CRS were investigated in xenograft models of OSCC by using transcriptome sequencing, LC-MS, ELISA and RT-PCR. Moreover, the role of CRS and ALDH3A1 on OSCC cells was researched by using Trans-well, flow cytometry, western blotting, immunofluorescence, ATP activity and OCR assay. Furthermore, immunohistochemical staining was employed to observe the cell proliferation and invasion of OSCC in xenotransplantation models. RESULTS: CRS promoted the progression of OSCC in xenograft models, stimulated the secretion of norepinephrine and the expression of ADRB2, but decreased the expression of ALDH3A1. Moreover, CRS changed energy metabolism and increased mitochondrial metabolism markers. However, ALDH3A1 overexpression suppressed proliferation, EMT and mitochondrial metabolism of OSCC cells. CONCLUSION: Inhibition of ALDH3A1 expression plays a pivotal role in CRS promoting tumorigenic potential of OSCC cells, and the regulatory of ALDH3A1 on mitochondrial metabolism may be involved in this process.

Preventive effects of melatonin on periodontal tissue destruction due to psychological stress in rats with experimentally induced periodontitis.

OBJECTIVE AND BACKGROUND: Psychological stress is a potential modifiable environmental risk factor causally related to the exacerbation of periodontitis and other chronic inflammatory diseases. This animal study aimed to investigate comprehensively the preventive efficacy of systemic melatonin administration on the possible effects of restraint stress on the periodontal structures of rats with periodontitis. METHODS: Forty-eight male Sprague Dawley rats were randomly divided into six groups: control, restraint stress (S), S-melatonin (S-Mel), experimental periodontitis (Ep), S-Ep, and S-Ep-Mel. Periodontitis was induced by placing a 3.0 silk suture in a sub-paramarginal position around the cervix of the right and left lower first molars of the rats and keeping the suture in place for 5 weeks. Restraint stress was applied simultaneously by ligation. Melatonin and carriers were administered to the control, S, Ep, and S-Ep groups intraperitoneally (10 mg/body weight/day, 14 days) starting on day 21 following ligation and subjection to restraint stress. An open field test was performed on all groups on day 35 of the study. Periodontal bone loss was measured via histological sections. Histomorphometric and immunohistochemical (RANKL and OPG) evaluations were performed on right mandibular tissue samples and biochemical (TOS (total oxidant status), TAS (total antioxidant status), OSI (oxidative stress index), IL-1ß, IL-10, and IL-1ß/IL-10) evaluations were performed on left mandibular tissue samples. RESULTS: Melatonin significantly limited serum corticosterone elevation related to restraint stress (p < .05). Restraint stress aggravated alveolar bone loss in rats with periodontitis, while systemic melatonin administration significantly reduced stress-related periodontal bone loss. According to the biochemical analyses, melatonin significantly lowered IL-1ß/IL-10, OSI (TOS/TAS), and RANKL/OPG rates, which were significantly elevated in the S-Ep group. CONCLUSION: Melatonin can significantly prevent the limited destructive effects of stress on periodontal tissues by suppressing RANKL-related osteoclastogenesis and oxidative stress.

Metabolomics reveals that chronic restraint stress alleviates carbon tetrachloride-induced hepatic fibrosis through the INSR/PI3K/AKT/AMPK pathway.

Hepatic fibrosis (HF) could be developed into liver cirrhosis or even hepatocellular carcinoma. Stress has an important role in the occurrence and development of various considerable diseases. However, the effect of a certain degree stress on HF is still controversial. In our study, stress was simulated with regular chronic restraint stress (CRS) and HF model was induced with CCl4 in mice. We found that CRS was able to attenuate CCl4-induced liver injury and fibrosis in mice. Surprisingly, behavioral analysis showed that the mice in the HF group exhibited depression-like behavior. Further, the metabolomic analysis revealed that 119 metabolites and 20 metabolic pathways were altered in mice liver, especially the betaine metabolism pathway. Combined with the results of Ingenuity Pathway Analysis (IPA), the key proteins INSR, PI3K, AKT, and p-AMPK were identified and verified, and the results showed that CRS could upregulate the protein levels and mRNA expression of INSR, PI3K, AKT, and p-AMPK in liver tissues of HF mice. It suggested that CRS alleviated CCl4-induced liver fibrosis in mice through upregulation of the INSR/PI3K/AKT/AMPK pathway. Proper stress might be a potential therapeutic strategy for the treatment of chronic liver disease, which provided new insights into the treatment of HF. KEY MESSAGES: Chronic restraint stress mitigated CCl4-induced liver injury and hepatic fibrosis. CCl4-induced liver fibrosis could cause depression-like behavior. Chronic restraint stress altered metabolomic profiles in hepatic fibrosis mice, especially the betaine metabolism pathway. Chronic restraint stress increased betaine levels in liver tissue. Chronic restraint stress regulated the INSR/PI3K/AKT/AMPK signaling pathway in hepatic fibrosis mice.

Spleen contributes to chronic restraint stress-induced lung injury through splenic CD11b+ cells.

Chronic stress can induce lung injury. The spleen, as the largest peripheral immune organ, plays a crucial role in various lung diseases. Our previous study found that the spleen underwent significant changes during chronic restraint stress (CRS). However, the exact role of the spleen in CRS-induced lung injury remains unclear. In this study, we found that CRS could increase lung index. CRS could lead to alterations of the lungs such as destruction of alveolar wall, thickening of alveolar septa, dilation of pulmonary capillaries, and increased inflammatory cell infiltration. CRS increases the concentration of malondialdehyde (MDA), decreases the level of surfactant protein A (SP-A), and elevates the levels of pro-inflammatory factors (TNF-α, IL-6, and IL-1ß) in the lungs. Additionally, CRS could increase the proportions and numbers of CD11b+Ly6ChiLy6G- monocytes in the lung, while cannot alter proportions and numbers of CD3-NK1.1+ NK cells, CD3+CD4+ T cells, CD3+CD8+ T cells, and CD11b+Ly6G+ neutrophils. Moreover, the levels of inflammatory markers in lung tissues were positively correlated with the proportion of CD11b+Ly6ChiLy6G- monocytes. Interestingly, splenectomy inhibited CRS-induced lung injury and attenuated the alteration in the proportion of CD11b+Ly6ChiLy6G- monocytes in the lungs induced by CRS. Moreover, splenic CD11b+ cells, rather than splenic CD11b- cells, transfused into splenectomized mice, and subsequently exposed to CRS, can cause lung injury. These results suggest that CRS could induce lung injury and CD11b+Ly6ChiLy6G- monocytes aggregation in the lung. The spleen could contribute to CRS-induced lung injury. Furthermore, splenic CD11b+ cells might play an important role in CRS-induced lung injury.

Protection of p-Coumaric acid against chronic stress-induced neurobehavioral deficits in mice via activating the PKA-CREB-BDNF pathway.

There is a body of evidence to suggest that chronic stress modulates neurochemical homeostasis, alters neuronal structure, inhibits neurogenesis and contributes to development of mental disorders. Chronic stress-associated mental disorders present common symptoms of cognitive impairment and depression with complex disease mechanisms. P-coumaric acid (p-CA), a natural phenolic compound, is widely distributed in vegetables, cereals and fruits. p-CA exhibits a wide range of health-related effects, including anti-oxidative-stress, anti-mutagenesis, anti-inflammation and anti-cancer activities. The current study aims to evaluate the therapeutic potential of p-CA against stress-associated mental disorders. We assessed the effect of p-CA on cognitive deficits and depression-like behavior in mice exposed to chronic restraint stress (CRS); we used network pharmacology, biochemical and molecular biological approaches to elucidate the underlying molecular mechanisms. CRS exposure caused memory impairments and depression-like behavior in mice; p-CA administration attenuated these CRS-induced memory deficits and depression-like behavior. Network pharmacology analysis demonstrated that p-CA was possibly involved in multiple targets and a variety of signaling pathways. Among them, the protein kinase A (PKA) - cAMP-response element binding protein (CREB) - brain derived neurotrophic factor (BDNF) signaling pathway was predominant and further characterized. The levels of PKA, phosphorylated CREB (pCREB) and BDNF were significantly lowered in the hippocampus of CRS mice, suggesting disruption of the PKA-CREB-BDNF signaling pathway; p-CA treatment restored the signaling pathway. Furthermore, CRS upregulated expression of proinflammatory cytokines in hippocampus, while p-CA reversed the CRS-induced effects. Our findings suggest that p-CA will offer therapeutic benefit to patients with stress-associated mental disorders.

Adolescent restraint stress enhances adult nicotine reinforcement in male and female rats.

Adolescent stress is a risk factor for the initiation of nicotine use, but whether adolescent stress can enhance nicotine reinforcement when it is initiated later in adulthood is unknown, and it is unclear whether males and females are equally impacted. Therefore, this study assessed physiological responses (body weight and blood serum corticosterone - CORT) to restraint stress (RS) during adolescence (P28-55) or during adulthood (P70-96) in male and female Sprague-Dawley rats. When all subjects reached adulthood (P69 or 110; 2 weeks after termination of stress exposure), they were tested on sucrose preference and intravenous single-dose nicotine (0.03 mg/kg/infusion) self-administration. It was found that all rats displayed a significant CORT response to RS. Importantly, stress during adolescence, but not during adulthood, enhanced subsequent acquisition of nicotine intake tested in adulthood. Although this effect was observed in both sexes, only males displayed reduced body weight gain and adult sucrose preference. Moreover, regardless of stress exposure, females were more stimulated by nicotine, consumed more nicotine overall, and displayed enhanced nicotine seeking. These results suggest that adolescence is a period of heightened sensitivity to the enhancing effect of repeated stress on the susceptibility to develop nicotine dependence later in life in both sexes.

Gallic acid ameliorates behavioral dysfunction, oxidative damage, and neuronal loss in the prefrontal cortex and hippocampus in stressed rats.

Gallic acid (GA) is known to be a natural phenolic compound with antioxidant and neuroprotective effects. This study aims to investigate the impact of GA against restraint stress-induced oxidative damage, anxiety-like behavior, neuronal loss, and spatial learning and memory impairment in male Wistar rats. The animals were divided into four groups (n = 8) and subjected to restraint stress for 4 h per day for 14 consecutive days or left undisturbed (control without inducing stress). In the treatment group, the animals were treated with 2 mL normal saline plus 100 mg/kg GA per day for 14 consecutive days (STR + GA group). The animals received the drug or normal saline by gavage 2 h before inducing restraint stress. ELISA assay measured oxidative stress factors. Elevated-plus maze and Morris water maze tests assessed anxiety-like behavior and spatial learning and memory, respectively. Also, neuronal density was determined using Nissl staining. Restraint stress significantly increased MDA and reduced the activities of GPX and SOD in the stressed rats, which were reserved by treatment with 100 mg/kg GA. Restraint stress markedly enhanced the anxiety-like behavior and spatial learning and memory impairment that were reserved by GA. In addition, treatment with GA reduced the neuronal loss in the stressed rats in the hippocampus and prefrontal cortex (PFC) regions. Taken together, our findings suggest that GA has the potential to be used as a good candidate to attenuate neurobehavioral disorders as well as neuronal loss in the hippocampus and PFC induced by restraint stress via reducing oxidative damage.

PACAP Controls Endocrine and Behavioral Stress Responses via Separate Brain Circuits.

Background: The neuropeptide PACAP (pituitary adenylate cyclase-activating polypeptide) is a master regulator of central and peripheral stress responses, yet it is not clear how PACAP projections throughout the brain execute endocrine and behavioral stress responses. Methods: We used AAV (adeno-associated virus) neuronal tracing, an acute restraint stress (ARS) paradigm, and intersectional genetics, in C57BL/6 mice, to identify PACAP-containing circuits controlling stress-induced behavior and endocrine activation. Results: PACAP deletion from forebrain excitatory neurons, including a projection directly from medial prefrontal cortex to hypothalamus, impairs c-fos activation and corticotropin-releasing hormone (CRH) messenger RNA elevation in the paraventricular nucleus after 2 hours of restraint, without affecting ARS-induced hypophagia, or c-fos elevation in nonhypothalamic brain. Elimination of PACAP within projections from lateral parabrachial nucleus to extended amygdala, on the other hand, attenuates ARS-induced hypophagia, along with extended amygdala fos induction, without affecting ARS-induced CRH messenger RNA elevation in the paraventricular nucleus. PACAP projections to extended amygdala terminate at protein kinase C delta type (PKCδ) neurons in both the central amygdala and the oval bed nucleus of the stria terminalis. Silencing of PKCδ neurons in the central amygdala, but not in the oval bed nucleus of the stria terminalis, attenuates ARS-induced hypophagia. Experiments were carried out in mice of both sexes with n ≥ 3 per group. Conclusions: A frontocortical descending PACAP projection controls paraventricular nucleus CRH messenger RNA production to maintain hypothalamic-pituitary-adrenal axis activation and regulate the endocrine response to stress. An ascending PACAPergic projection from the external lateral parabrachial nucleus to PKCδ neurons in the central amygdala regulates behavioral responses to stress. Defining two separate limbs of the acute stress response provides broader insight into the specific brain circuitry engaged by the psychogenic stress response.