Cerebrospinal fluid proteomics reveal potential protein targets of JiaWeiSiNiSan in preventing chronic psychological stress damage.

CONTEXT: Chinese herbal formula JiaWeiSiNiSan (JWSNS) has been widely used to prevent stress-induced neuropsychiatric ailments in clinics and proven to have therapeutic anti-stress effects on rats. However, the mechanism remains unclear. OBJECTIVE: Based on the proteomics of cerebrospinal fluid (CSF), this study explores the possible mechanism and target proteins of JiaWeiSiNiSan raising stress resilience and preventing stress damage. MATERIALS AND METHODS: A 6-week Chronic Unpredictable Mild Stress (CUMS) model was applied on adult Wistar male rats to observe the effects of JWSNS on improving mental stress resilience. Tandem Mass Tag (TMT) proteomics and bioinformatics analysis were used to screen and analyze differentially expressed proteins (DEPs) in CSF. Parallel Reaction Monitoring (PRM) was used to validate target DEPs. RESULTS: Significantly decreased sucrose preference, locomotion activity level and accuracy of T-maze, as well as increased immobility time, were observed in CUMS rats compared to CON rats while JWSNS improved above depression-like behaviours. The quantitative proteomics and bioinformatics analysis showed that JWSNS decreased the expression of Rps4x, HSP90AA1, Rps12, Uba1, Rsp14, Tuba1b in CUMS rats CSF (p < 0.05, FDR < 0.5). Immunofluorescence results showed that the number of BrdU/DCX positive cells (p < 0.01) and the relative number of neurons (p < 0.01) in the hippocampus dentate gyrus (DG) of the JSWNS group significantly increased, compared with the CUMS group. CONCLUSIONS: JWSNS could increase mental stress resilience and prevent stress damage by regulating proteins in CSF. This study provides a scientific basis for further study on Chinese formulas preventing mental illness.

[Preliminary study on cerebrospinal fluid proteomics of Erxian Decoction against neurogenesis impairment in late-onset depression].

This study aims to elucidate the underlying mechanism of Erxian Decoction(EXD) against neurogenesis impairment in late-onset depression(LOD) rats based on cerebrospinal fluid(CSF) proteomics. A total of 66 20-21-month-old male Wistar rats were randomized into naturally aged(AGED) group, LOD group, and EXD group. All rats received chronic unpredictable mild stress(CUMS) for 6 weeks for LOD modeling except for the AGED group. During the modeling, EXD group was given EXD(ig, twice a day at 4 g·kg~(-1)) and other groups received equivalent amount of normal saline(ig). After modeling, a series of behavioral tests, such as sucrose preference test(SPT), open-field test(OFT), forced swimming test(FST), and Morris water maze test(MWMT) were performed. Immunofluorescence method was used to detect the number of Ki-67/Nesti-positive cells and BrdU/DCX-positive cells in the hippocampal DG area of each group. High-concentration corticosterone(CORT) was combined with D-galactose(D-gal) to simulate the changes of LOD-related stress and aging and the proliferation and differentiation of primary neural stem cells of hippocampus in each group were observed. Data independent acquisition(DIA)-mass spectrometry(MS) was used to analyze the differential proteins in CSF among groups and bioinformatics analysis was performed to explore the biological functions of the proteins. Behavioral tests showed that sucrose consumption in SPT, total traveling distance in OFT, and times of crossing the platform in MWMT were all reduced(P<0.01) and the immobility time in FST was prolonged(P<0.01) in the LOD group compared with those in the AGED group, suggesting that LOD rats had developed depression symptoms such as anhedonia, decreased locomotor activity ability, and cognitive dysfunction. Behavioral abnormalities were alleviated(P<0.01, P<0.05) in the EXD group as compared with those in the LOD group. Immunofluorescence results demonstrated that Ki-67/Nesti-positive cells and BrdU/DCX-positive cells in the hippocampal DG area were fewer(P<0.05) in LOD group than in the AGED group, and the positive cells in the EXD group were more(P<0.05) than those in the LOD group. In vitro experiment showed that the proliferation and differentiation of primary hippocampal neural stem cells under the CORT+D-gal treatment were reduced(P<0.01). The proliferation rate of neural stem cells decreased(P<0.05) in CORT+D-gal+LOD-CSF group but increased(P<0.01) in CORT+D-gal+EXD-CSF group compared with that in the CORT+D-gal group. A total of 2 620 proteins were identified from rat CSF, with 135 differential proteins between the LOD group and AGED group and 176 between EXD group and LOD group. GDF11, NrCAM, NTRK2, and GhR were related to neurogenesis and 39 differential proteins were regulated by both LOD and EXD. EXD demonstrated obvious anti-LOD effect, as it improved the locomotor activity ability and cognitive function of LOD rats and protected the proliferation and differentiation of hippocampal neural stem cells. EXD exerts anti-LOD effect by regulating the proteins related to neurogenesis in CSF, such as GDF11, NrCAM, NTRK2, and GhR and maintaining hippocampal neurogenesis.

The therapeutic potential of curculigoside in poststroke depression: a focus on hippocampal neurogenesis and mitochondrial function.

OBJECTIVES: To investigate the effects and mechanism of curculigoside against poststroke depression (PSD). METHODS: In vivo, a PSD rat model was created by combining bilateral common carotid artery occlusion and chronic unpredictable mild stress stimulations. After 4-week modeling and intragastrically administration of curculigoside, the effects of curculigoside on behavior, hippocampal neurogenesis, and hippocampal mitochondrial oxidative phosphorylation (OxPhos) were investigated. In vitro, PSD-like primary neural stem cells (NSCs) model was established by oxygen-glucose deprivation/recovery (OGD/R) combing high-corticosterone (CORT) concentration, followed by treatment with curculigoside. The investigation subsequently examined the impact of curculigoside on mitochondrial OxPhos, proliferation, and differentiation of NSCs under OGD/R + CORT conditions. KEY FINDINGS: In vivo, PSD rats showed significantly depressive behaviors, dysfunctional neurogenesis in hippocampus, as well as decreased hippocampus adenosine triphosphate (ATP) levels, reduced electron transport chain complexes activity, and downregulates mitochondrial transcription factor A (TFAM) and PPAR-gamma coactivator 1 alpha (PGC-1α) expression in hippocampus. In vitro, OGD/R +CORT significantly injured the proliferation and differentiation, as well as impaired the mitochondrial OxPhos in NSCs. Curculigoside treatment was effective in improving these abnormal changes. CONCLUSION: Curculigoside may repair hippocampal neurogenesis in PSD rats by enhancing hippocampal mitochondrial OxPhos, and has shown a great potential for anti-PSD.

Therapeutic potential of Erxian decoction and its special chemical markers in depression: a review of clinical and preclinical studies.

The increasing prevalence of depression is a major societal burden. The etiology of depression involves multiple mechanisms. Thus, the outcomes of the currently used treatment for depression are suboptimal. The anti-depression effects of traditional Chinese medicine (TCM) formulations have piqued the interest of the scientific community owing to their multi-ingredient, multi-target, and multi-link characteristics. According to the TCM theory, the functioning of the kidney is intricately linked to that of the brain. Clinical observations have indicated the therapeutic potential of the kidney-tonifying formula Erxian Decoction (EXD) in depression. This review aimed to comprehensively search various databases to summarize the anti-depression effects of EXD, explore the underlying material basis and mechanisms, and offer new suggestions and methods for the clinical treatment of depression. The clinical and preclinical studies published before 31 August 2023, were searched in PubMed, Google Scholar, China National Knowledge Infrastructure, and Wanfang Database. This review followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Clinical studies have demonstrated that EXD exhibits therapeutic properties in patients with menopausal depression, postpartum depression, and maintenance hemodialysis-associated depression. Meanwhile, preclinical studies have reported that EXD and its special chemical markers exert anti-depression effects by modulating monoamine neurotransmitter levels, inhibiting neuroinflammation, augmenting synaptic plasticity, exerting neuroprotective effects, regulating the hypothalamic-pituitary-adrenal axis, promoting neurogenesis, and altering cerebrospinal fluid composition. Thus, the anti-depression effects of EXD are mediated through multiple ingredients, targets, and links. However, further clinical and animal studies are needed to investigate the anti-depression effects of EXD and the underlying mechanisms and offer additional evidence and recommendations for its clinical application. Moreover, strategies must be developed to improve the quality control of EXD. This review provides an overview of EXD and guidance for future research direction.

Luteolin Enhances Choroid Plexus 5-MTHF Brain Transport to Promote Hippocampal Neurogenesis in LOD Rats.

Folates, provided by food, are commonly used antidepressant synergists in late-onset depression (LOD). However, increased intake of folic acid in the elderly population might lead to the accumulation of unmetabolized folic acid in the systemic circulation, leading to enhanced deterioration of the central nervous system function. In addition, folates cannot access the brain directly because of the blood-brain barrier. Choroid plexus (CP) 5-methyltetrahydrofolate (5-MTHF) brain transport plays a critical role in regulating the cerebrospinal fluid (CSF) 5-MTHF content. Luteolin is a natural flavonoid that has antidepressant effects and is involved in the anti-folate resistance pathway. It remains unclear whether the antidepressant effects of luteolin are associated with the CP 5-MTHF brain transport. In this study, 20-21-month-old Wistar rats were exposed to the chronic unpredictable mild stress (CUMS) protocol for 6 consecutive weeks to explore the long-term effects of luteolin on behavior, 5-MTHF levels, hippocampal neurogenesis, and folate brain transport of the CP. In vitro primary hippocampal neural stem cells (NSCs) cultured in media containing 10% CSF from each group of rats and choroid plexus epithelial cells (CPECs) cultured in media containing 20 µM luteolin were treated with 100 µM corticosterone and 40 mg/ml D-galactose. We found that aged rats exposed to CUMS showed a significantly reduced sucrose preference, decreased locomotion activity in the open field test and accuracy of the Morris water maze test, increased immobility time in the forced swimming test, accelerated dysfunctional neurogenesis and neuronal loss in the dentate gyrus of LOD rats, as well as decreased CSF and hippocampus 5-MTHF levels, and zona occludens protein 1 (ZO-1), proton-coupled folate transporter (PCFT), and reduced folate carrier (RFC) protein levels. In vitro assays showed media containing 10% aged CSF or LOD+ Luteolin-CSF significantly increased the viability of CORT + D-gal-injured NSCs and alleviated dysfunctional neurogenesis and neuronal loss compared with the CORT + D-gal medium. However, media containing 10% LOD-CSF had no such effect. In the meantime, induction of CORT + D-gal significantly decreased the ZO-1, PCFT, RFC, and folate receptor alpha (FR-α) protein levels and transepithelial electrical resistance in rat CPECs. As expected, luteolin treatment was effective in improving these abnormal changes. These findings suggested that luteolin could ameliorate CUMS-induced LOD-like behaviors by enhancing the folate brain transport.

Exploration of the mechanism by which icariin modulates hippocampal neurogenesis in a rat model of depression.

Icariin (ICA) has a significant capacity to protect against depression and hippocampal injury, but it cannot effectively cross the blood-brain barrier and accumulate in the brain. Therefore, the mechanism by which ICA protects against hippocampal injury in depression remains unclear. In this study, we performed proteomics analysis of cerebrospinal fluid to investigate the mechanism by which ICA prevents dysfunctional hippocampal neurogenesis in depression. A rat model of depression was established through exposure to chronic unpredictable mild stress for 6 weeks, after which 120 mg/kg ICA was administered subcutaneously every day. The results showed that ICA alleviated depressive symptoms, learning and memory dysfunction, dysfunctional neurogenesis, and neuronal loss in the dentate gyrus of rats with depression. Neural stem cells from rat embryonic hippocampi were cultured in media containing 20% cerebrospinal fluid from each group of rats and then treated with 100 µM corticosterone. The addition of cerebrospinal fluid from rats treated with ICA largely prevented the corticosterone-mediated inhibition of neuronal proliferation and differentiation. Fifty-two differentially expressed proteins regulated by chronic unpredictable mild stress and ICA were identified through proteomics analysis of cerebrospinal fluid. These proteins were mainly involved in the ribosome, PI3K-Akt signaling, and interleukin-17 signaling pathways. Parallel reaction monitoring mass spectrometry showed that Rps4x, Rps12, Rps14, Rps19, Hsp90b1, and Hsp90aa1 were up-regulated by chronic unpredictable mild stress and down-regulated by ICA. In contrast, HtrA1 was down-regulated by chronic unpredictable mild stress and up-regulated by ICA. These findings suggest that ICA can prevent depression and dysfunctional hippocampal neurogenesis through regulating the expression of certain proteins found in the cerebrospinal fluid. The study was approved by the Experimental Animal Ethics Committee of Guangzhou University of Chinese Medicine of China in March 2017.

Dynamic changes of behaviors, dentate gyrus neurogenesis and hippocampal miR-124 expression in rats with depression induced by chronic unpredictable mild stress.

The depression-like behavior phenotype, neurogenesis in the dentate gyrus and miR-124 expression in the hippocampus are the focus of current research on the pathogenesis of depression and antidepressant therapy. The present study aimed to clarify the dynamic changes of depression-like behavior, dentate gyrus neurogenesis and hippocampal miR-124 expression during depression induced by chronic stress to reveal pathological features at different stages of depression and to further provide insight into depression treatment. Chronic unpredictable mild stress depression models were established by exposing Sprague-Dawley rats to various mild stressors, including white noise, thermal swimming, stroboscopic illumination, soiled cages, pairing with three other stressed animals, cold swimming, tail pinch, restraint and water and food deprivation. Chronic unpredictable mild stress model rats underwent dynamic observation from 1 to 8 weeks and were compared with a control group (normal feeding without any stressors). To observe changes in the depression-like behavior phenotype during chronic unpredictable mild stress-induced depression, a sucrose preference test was used to evaluate the degree of anhedonia. An open-field test was used to evaluate locomotor activity and anxiety status. Compared with the control group, chronic unpredictable mild stress rats lost weight but did not have a depression-like behavioral phenotype at 1-4 weeks. Chronic unpredictable mild stress rats presented decreased sucrose preference and locomotor activity at 5-8 weeks. In addition, chronic unpredictable mild stress rats did not have significant anxiety-like behavior during 1-8 weeks of modeling. To observe neurogenesis dysfunctions and changes in neuronal number in the dentate gyrus during chronic unpredictable mild stress-induced depression, markers (DCX and DCX/BrdU) of neural proliferation and differentiation and the neuronal marker NeuN were assessed by immunofluorescence. Compared with the control group, neurogenesis and the neuronal number in the dentate gyrus did not change from 2 to 6 weeks; however, neural proliferation and differentiation in the dentate gyrus decreased, and the number of neurons decreased until the eighth week in the chronic unpredictable mild stress group. Real-time quantitative reverse transcription polymerase chain reaction assays and fluorescence in situ hybridization were used to measure the expression of hippocampal miR-124 during chronic unpredictable mild stress-induced depression. The results showed that the expression of hippocampal miR-124 was unchanged during the first 4 weeks but increased from 5 to 6 weeks and decreased from 7 to 8 weeks compared with the control group. These findings indicate that during chronic unpredictable mild stress-induced depression, the behavioral phenotype, miR-124 expression in the hippocampus, neurogenesis in the dentate gyrus and neuronal numbers showed dynamic changes, which suggested that various pathological changes occur at different stages of depression. All experimental procedures and protocols were approved by the Experimental Animal Ethics Committee of Guangzhou University of Chinese Medicine of China in March 2015.

Icariin induces irisin/FNDC5 expression in C2C12 cells via the AMPK pathway.

Backgroud Icariin, a major bioactive pharmaceutical component of the Chinese herbal medicine Epimedii Herba, has demonstrated lipid-lowering and anti-obesity effects. Irisin/ fibronectin type III domain-containing 5 (FNDC5) protects against obesity by inducing browning in white adipose tissue. Objectives This study investigated the effects of icariin on irisin/FNDC5 expression in C2C12 myotubes. Method Cultured murine C2C12 myocytes were used to study the effects of icariin on irisin/FNDC5 expressions by Western-blot, qPCR, Elisa and Immunofluorescence. We also investigated FNDC5 expression in icariin-treated intact mice. Results Icariin increased irisin/FNDC5 protein levels. mRNA levels of irisin/FNDC5 were also increased in C2C12 myocytes after treatment with icariin. Icariin increased peroxisome proliferator-activated receptor gamma co-activator 1alpha (PGC-1α) protein and mRNA levels. Additionally, icariin exposure resulted in phosphorylation of AMP-activated protein kinase (AMPK) in a dose-dependent manner. The regulatory effect of icariin on FNDC5 protein expression was blocked by the AMPK antagonist compound C or silencing of AMPK, suggesting that icariin increased FNDC5 protein expression via the AMPK pathway. In vivo, icariin decreased body weight gain in C57BL/6 mice and increased FNDC5, PGC-1α, and p-AMPK expression levels in skeletal muscle. Conclusions Taken together, our results indicated that icariin induces irisin/FNDC5 expression via the AMPK pathway, indicating that icariin may be promising as an anti-obesity drug.

Browning of Abdominal Aorta Perivascular Adipose Tissue Inhibits Adipose Tissue Inflammation.

BACKGROUND: Perivascular adipose tissue (PVAT) can regulate vascular homeostasis by secreting various adipokines. This study investigated the effects of PVAT browning on its endocrine function. METHODS: In the first section of our study, male Sprague-Dawley rats were randomly divided into cold exposure (8°C) and 24°C acclimation groups. After cold exposure for 7 days, interscapular brown adipose tissue (iBAT), subcutaneous white adipose tissue, thoracic aortic PVAT, and abdominal aortic PVAT (aPVAT) were harvested for histological and brown marker gene expression analysis. In the second part, male rats were fed a high fat diet (HFD) for 10 weeks. In the 11th week, the rats were treated with or without cold exposure. After 14-day cold exposure, aPVAT was collected for histological, gene, and protein expression analysis. RESULTS: Cold exposure had a browning effect on aPVAT by increasing UCP-1 and PGC-1α expression levels. After HFD feeding for 10 weeks, 14-day cold exposure was still able to induce aPVAT browning. Compared with thermoneutrality acclimation rats, TNF-α, IL-6, and p-p65 expression levels were significantly lower in aPVAT from HFD-fed rats with cold exposure. In contrast, p-AMPK expression levels were increased in aPVAT from HFD-fed rats with cold exposure. CONCLUSIONS: Our study demonstrated that browning of aPVAT in HFD-fed rats lowered the pro-inflammatory adipokine expression levels and activated AMPK.