Celecoxib attenuates depressive-like behavior associated with immunological liver injury in C57BL/6 mice through TNF-α and NF-κb dependent mechanisms

Cyclooxygenase-2 inhibitors alleviated depressive and anxious-like behaviors in mice exposed to lipopolysaccharide: Involvement of oxidative stress and neuroinflammation

Depression and anxiety disorders have their pathophysiologies linked to inflammation and oxidative stress. In this context, celecoxib (CLX) and etoricoxib (ETR) inhibit cyclooxygenase 2 (COX-2), an enzyme expressed by cells involved in the inflammatory process and found in the brain. Studies have been using CLX as a possible drug in the treatment of depression, although its mechanisms at the central nervous system level are not fully elucidated. In this study, the effects of CLX and ETR on behavioral, oxidative, and inflammatory changes induced by systemic exposure to Escherichia coli lipopolysaccharide (LPS) were evaluated in adult male swiss mice. For ten days, the animals received intraperitoneal injections of LPS at 0.5 mg/kg. From the sixth to the tenth day, one hour after LPS exposure, they were treated orally with CLX (15 mg/kg), ETR (10 mg/kg), or fluoxetine (FLU) (20 mg/kg). Twenty-four hours after the last oral administration, the animals underwent evaluation of locomotor activity (open field test), predictive tests for depressive-like behavior (forced swim and tail suspension tests), and anxiolytic-like effect (elevated plus maze and hole board tests). Subsequently, the hippocampus, prefrontal cortex and striatum were dissected for the measurement of oxidative and nitrosative parameters (malondialdehyde, nitrite, and glutathione) and quantification of pro-inflammatory cytokines (IL-1β and IL-6). LPS induced depressive and anxious-like behavior, and treatment with CLX or ETR was able to reverse most of the behavioral changes. It was evidenced that nitrosative stress and the degree of lipid peroxidation induced by LPS were reduced in different brain areas after treatment with the drugs, as well as the endogenous defense system against free radicals was strengthened. CLX and ETR also significantly reduced LPS-induced cytokine levels. These data are expected to expand information on the role of inflammation in depression and anxiety and provide insights into possible mechanisms of COX-2 inhibitors in psychiatric disorders with a neurobiological basis in inflammation and oxidative stress.

Effects of chronic unpredictable mild stress on gut microbiota and fecal amino acid and short-chain fatty acid pathways in mice

Depression is a serious disease that has a significant impact on social functioning. However, the exact causes of depression are still not fully understood. Therefore, it is necessary to explore new pathways leading to depression. In this study, we used 16 S rDNA to examine changes in gut microbiota and predict related pathways in depression-like mice. Additionally, we employed liquid chromatography-mass spectrometry (LC-MS) to identify changes in amino acids and gas chromatography-mass spectrometry (GC-MS) to identify changes in short-chain fatty acids (SCFAs) in fecal samples. We conducted Pearson/Spearman correlation analysis to investigate the associations between changes in amino acids/SCFAs and behavioral outcomes. The 16 S rDNA sequencing revealed significant alterations in gut microbiota at the phylum and genus levels in mice subjected to chronic unpredictable mild stress (CUMS). The relative abundances of Bacteroidetes, Proteobacteria, Bacteroides, and Alloprevotella were increased, while Firmicutes, Verrucomicrobia, Actinobacteria, Lactobacillus, Akkermansia, Lachnospirillum, and Enterobacter were decreased in the CUMS mice. We used PICRUSt software to annotate the kyoto encyclopedia of genes and genomes (KEGG) pathway function related to depression-like behavior in mice. Our analysis identified sixty functional pathways associated with the gut microbiota of mice exhibiting depression-like behavior. In the amino acid concentration analysis, we observed decreased levels of hydroxyproline and tryptophan, and increased levels of alanine in CUMS mice. In the SCFAs concentration assay, we found decreased levels of butyric acid and valeric acid, and increased levels of acetic acid in CUMS mice. Some of these changes were significantly correlated with depressive-like behaviors. Our study contributes to the understanding of the mechanism of the gut-brain axis in the occurrence and development of depression.

Celecoxib abrogates concanavalin A-induced hepatitis in mice: Possible involvement of Nrf2/HO-1, JNK signaling pathways and COX-2 expression

Concanavalin A (ConA) is an established model for inducing autoimmune hepatitis (AIH) in mice, mimicking clinical features in human. The aimof the current study is to explore the possible protective effect of celecoxib, a cyclooxygenase-2 inhibitor,on immunological responses elicited in the ConA model of acute hepatitis. ConA (20 mg/kg) was administered intravenously to adult male mice for 6 h. Prior to ConA intoxication, mice in the treatedgroups received daily doses of celecoxib (30 and 60 mg/kg in CMC) for 7 days. Results revealed that administration of celecoxib 60 mg/kg for 7 days significantly protected the liver from ConA-induced liver damage revealed by significant decrease in ALT and AST serum levels. Celecoxib 30 and 60 mg/kg pretreatment enhanced oxidant/antioxidant hemostasis by significantreduction of MDA and NO content and increase hepatic GSH contents and SOD activity. In addition, celecoxib 30 and 60 mg/kg caused significant increase in hepatic nuclear factor erythroid 2-related factor 2 (Nrf2) and the stress protein heme oxygenase-1 (HO-1) levels. Moreover, celecoxib 30 and 60 mg/kg inhibited the release of proinflammatory markers including IL-1β and TNF-α along with significant decrease in p-JNK, AKT phosphorylation ratio and caspase-3 expression. Besides, Con A was correlated to high expression of cyclooxygenase COX-2 and this increasing was improved by administration of celecoxib. These changes were in good agreement with improvement in histological deterioration. The protective effect of celecoxib was also associated with significant reduction of autophagy biomarkers (Beclin-1 and LC3II). In conclusion, celecoxib showed antioxidant, anti-inflammatory, anti-apoptotic and anti-autophagy activity against Con A-induced immune-mediated hepatitis. These effects could be produced by modulation of Nrf2/HO-1, IL-1B /p-JNK/p-AKT, JNK/caspase-3, and Beclin-1/LC3II signaling pathways.

Unique brain endothelial profiles activated by social stress promote cell adhesion, prostaglandin E2 signaling, hypothalamic-pituitary-adrenal axis modulation, and anxiety

Chronic stress may precipitate psychiatric disorders including anxiety. We reported that Repeated Social Defeat (RSD) in mice increased accumulation of inflammatory monocytes within the brain vasculature, which corresponded with increased interleukin (IL)-1 Receptor 1-mediated activation of endothelia, and augmented anxiety-like behavior. One unknown, however, is the role of immune-activated endothelia in regulating the physiological and behavioral responses to social stress. Thus, we sought to determine the RNA profile of activated endothelia and delineate the pathways by which these endothelia communicate within the brain to influence key responses to social stress. First, endothelial-specific RiboTag mice were exposed to RSD and brain endothelial mRNA profiles from the whole brain and prefrontal cortex were determined using RNAseq. RSD increased expression of cell adhesion molecules (Icam1), inflammatory genes (Lrg1, Lcn2, Ackr1, Il1r1), and cyclooxygenase-2 (Ptgs2/COX-2). In studies with IL-1R1KO mice, there was clear dependence on IL-1R1 on endothelia-associated transcripts including Lrg1, Icam1, Lcn2. Moreover, prostaglandin (PG)E2 was increased in the brain after RSD and Ptgs2 was localized to endothelia, especially within the hypothalamus. Next, a selective COX-2 inhibitor, Celecoxib (CCB), was used with social stress. RSD increased PGE2 in the brain and this was abrogated by CCB. Moreover, CCB reduced RSD-induced Hypothalamic-Pituitary-Adrenal (HPA) axis activation with attenuation of hypothalamic paraventricular neuron activation, hypothalamic Crh expression, and corticosterone in circulation. Production, release, and accumulation of inflammatory monocytes after RSD was COX-2 independent. Nonetheless, CCB blocked anxiety-like behavior in response to RSD. Collectively, social stress stimulated specific endothelia RNA profiles associated with increased cell adhesion, IL-1 and prostaglandin signaling, HPA axis activation, and anxiety.

Polyguanine alleviated autoimmune hepatitis through regulation of macrophage receptor with collagenous structure and TLR4‐TRIF‐NF‐κB signalling

Autoimmune hepatitis (AIH) is a progressive and chronic inflammatory disease in the liver. MARCO is a surface receptor of macrophage involving in tissue inflammation and immune disorders. Moreover, polyguanine (PolyG) is considered to bind to macrophage receptor with collagenous structure (MARCO). However, the role of MARCO and PolyG in the development and treatment of AIH still remains unclear. Therefore, this study explores the expression of MARCO and therapeutic activity of PolyG in both S100‐induced AIH in mouse and Lipopolysaccharide (LPS)‐treated macrophage (RAW264.7 cells). Moreover, there were significant increases in inflammatory factors and MARCO, as well as decrease in I‐kappa‐B‐alpha (Ik‐B) in the liver of AIH mice and LPS‐induced cells. However, PolyG treatment significantly reversed the elevation of inflammatory cytokins, MARCO and reduction of Ik‐B. In addition, PolyG treatment could downregulate the expression of Toll‐like receptor 4 (TLR4) and TIR‐domain‐containing adaptor inducing interferon‐β (TRIF), decrease macrophage M1 polarization and increase macrophage M2 polarization. When hepatocytes were co‐cultured with different treatment of macrophages, similar expression profile of inflammatory cytokines was observed in hepatocytes. The research revealed that MARCO expression was elevated in AIH mice. PolyG treatment and inhibition of MARCO significantly reduced inflammatory cytokines expression in the liver as well as hepatocytes and macrophages. Therefore, MARCO could be a target for the treatment of AIH.

Nootkatone improves anxiety- and depression-like behavior by targeting hyperammonemia-induced oxidative stress in D-galactosamine model of liver injury

Acute or chronic liver injury is closely related to hyperammonemia, which will result in oxidative stress and damage to nerve cells, and these factors are vital to the development of anxiety and depression. In this study, the effect of Nootkatone (NKT) on the anxiety- and depression-like behavioral changes in mice induced by liver injury was investigated. Liver injury was induced by D-galactosamine (D-GalN; 350 mg/kg) three times a week for 4 weeks. NKT (5 mg/kg or 10 mg/kg) was given as co-treatment daily for 4 weeks. NKT (5 mg/kg) co-treatment remarkably ameliorates D-GalN-induced anxiety- and depression-like behaviors as evident from the results of sucrose preference test, forced swimming test, tail suspension test, and novelty suppressed feeding test. Results showed that NKT could induce an elevation in serum alanine transaminase and aspartate transaminase level, alleviate the oxidative stress induced by hyperammonemia through activating Keap1/Nrf2/HO-1 antioxidant pathways, decrease the expression of inducible nitric oxide synthase and NOX2 in hippocampus and prefrontal cortex, enhance the vitality of superoxide dismutase, catalase, and glutathione levels in serum, liver, and brain, and significantly reduce the generation of malondialdehyde. At the same time, NKT also reduces the level of ammonia in serum and brain and upgrades the activity of glutamine synthetase in the hippocampus and prefrontal cortex. Taken together, the present results suggested that NKT has a significant antidepressant effect through modulation of oxidative stress induced by D-GalN administration.

Stem cells from human exfoliated deciduous teeth ameliorate concanavalin A-induced autoimmune hepatitis by protecting hepatocytes from apoptosis

BACKGROUND

Autoimmune hepatitis is a serious autoimmune liver disease that threatens human health worldwide, which emphasizes the urgent need to identify novel treatments. Stem cells from human exfoliated deciduous teeth (SHED), which are easy to obtain in a non-invasive manner, show pronounced proliferative and immunomodulatory capacities.

AIM

To investigate the protective effects of SHED on concanavalin A (ConA)-induced hepatitis in mice, and to elucidate the associated regulatory mechanisms.

METHODS

We used a ConA-induced acute hepatitis mouse model and an in vitro co-culture system to study the protective effects of SHED on ConA-induced autoimmune hepatitis, as well as the associated underlying mechanisms.

RESULTS

SHED infusion could prevent aberrant histopathological liver architecture caused by ConA-induced infiltration of CD3⁺, CD4⁺, tumor necrosis-alpha⁺, and interferon-gamma⁺ inflammatory cells. Alanine aminotransferase and aspartate aminotransferase were significantly elevated in hepatitis mice. SHED infusion could therefore block ConA-induced alanine aminotransferase and aspartate aminotransferase elevations. Mechanistically, ConA upregulated tumor necrosis-alpha and interferon-gamma expression, which was activated by the nuclear factor-kappa B pathway to induce hepatocyte apoptosis, resulting in acute liver injury. SHED administration protected hepatocytes from ConA-induced apoptosis.

CONCLUSION

SHED alleviates ConA-induced acute liver injury via inhibition of hepatocyte apoptosis mediated by the nuclear factor-kappa B pathway. Our findings could provide a potential treatment strategy for hepatitis.

Brain TNF drives post-inflammation depression-like behavior and persistent pain in experimental arthritis

Patients with rheumatoid arthritis experience chronic pain, depression and fatigue, even when inflammation of the joints is well controlled. To study the relationship between arthritis, depression, and sustained pain when articular inflammation is no longer observed, we tested the hypothesis that brain TNF drives post-inflammation depression-like behavior and persistent pain in experimental arthritis. The murine model of antigen-induced arthritis (AIA) was used to evaluate the effects of knee inflammation on sustained pain and depression-like behavior. We measured joint pain using an automated dynamic plantar algesiometer and depression-like behavior with the tail suspension test. Cytokines were measured by Luminex assay and ELISA. TNF in the brain was blocked by intracerebroventricular injection of anti-TNF antibodies. Histological damage and elevated levels of cytokines were observed in the knee 24 h after antigen treatment, but not at 13 days. Reduced pain thresholds were seen 24 h and 13 days after treatment. Depression-like behavior was observed on day 13. Treatment with the antidepressant imipramine reduced both depression-like behavior and persistent pain. However, blocking joint pain with the analgesic dipyrone did not alter depression-like behavior. Elevated levels of TNF, CCL2, and CXCL-1 were observed in the hippocampus 24 h after treatment, with TNF remaining elevated at day 13. Intracerebroventricular infusion of an anti-TNF antibody blocked depression-like behavior and reduced persistent pain. We have demonstrated that depression-like behavior and pain is sustained in AIA mice after the resolution of inflammation. These changes are associated with elevated levels of TNF in the hippocampus and are dependent upon brain TNF. The findings reveal an important mechanistic link between the expression of chronic pain and depression in experimental arthritis. Furthermore, they suggest treating depression in rheumatoid arthritis may positively impact other debilitating features of this condition.

Involvement of NF-κB in the reversal of CYP3A down-regulation induced by sea buckthorn in BCG-induced rats

Previous studies reported that sea buckthorn (Hippophae rhamnoides L., Elaeagnaceae, HRP) exhibits hepatoprotective effects via its anti-inflammatory and antioxidant properties as well as its inhibitory effects on collagen synthesis. However, it is unclear whether this hepatoprotective effect is also achieved by regulating liver drug metabolism enzyme pathways. Herein, we examined the regulatory effect of HRP on cytochrome P450 3A (CYP3A) in rats with immune liver injury, and explored the molecular mechanism of its hepatoprotective effect. Rat models of immunological liver injury were induced by intravenous injections of Bacillus Calmette-Guerin (BCG; 125 mg kg-1; 2 wks). Specific protein levels were detected by ELISA or western blot, and CYP3A mRNA expression was detected by RT-PCR. High-performance liquid chromatography (HPLC) detected relative changes in CYP3A metabolic activity based on the rates of 1-hydroxylation of the probe drug midazolam (MDZ). BCG pretreatment (125 mg kg-1) significantly down-regulated liver CYP3A protein expression compared with the control, metabolic activity, and transcription levels while up-regulating liver NF-κB, IL-1β, TNF-α and iNOS. HRP intervention (ED50: 78 mg kg-1) moderately reversed NF-κB, inflammatory cytokines, and iNOS activation in a dose-dependent manner (P < 0.05), and suppressed CYP3A down-regulation (P < 0.05); thereby partially alleviating liver injury. During immune liver injury, HRP may reverse CYP3A down-regulation by inhibiting NF-κB signal transduction, and protect liver function, which involves regulation of enzymes transcriptionally, translationally and post-translationally. The discovery that NF-κB is a molecular target of HRP may initiate the development and optimization of a clinical therapeutic approach to mitigate hepatitis B and other immunity-related liver diseases.

Depressive-like behaviors are induced by chronic liver injury in male and female mice

Depression is a highly prevalent mental disease and increasingly become a global public health problem. Recent studies have shown that the dysfunction of liver was associated with depression. However, the previous studies have not been fully explained the relationship between depression and liver injury. The present study was aimed to investigate whether chronic liver injury could induce depressive-like behavior. Chronic liver injury was induced by intraperitoneal injection of carbon (CCl₄), D-galactosamine (D-GalN) and thioacetamide (TAA), respectively. And the results showed that the serum activities of ALT in CCl₄, D-GalN and TAA groups were significantly increased in both male and female mice compared with the control group, while the activities of AST increased only in CCl₄ group. Meanwhile, H&E staining showed that CCl₄, D-GalN and TAA induced hepatocytes injury in both male and female mice. Moreover, the sucrose preference was significantly decreased and the immobility time in forced swimming test and tail suspension test were significantly prolonged in CCl₄ and D-GalN group compared with control group. Our findings demonstrated that chronic liver injury induced by CCl₄ and D-GalN could induce depressive-like behaviors in mice.

Coadministration of lithium and celecoxib reverses manic-like behavior and decreases oxidative stress in a dopaminergic model of mania induced in rats

The present study intends to investigate the effect of lithium (Li) and celecoxib (Cel) coadministration on the behavioral status and oxidative stress parameters in a rat model of mania induced by dextroamphetamine (d-AMPH). Male Wistar rats were treated with d-AMPH or saline (Sal) for 14 days; on the 8th day of treatment, rats received lithium (Li), celecoxib (Cel), Li plus Cel, or water until day 14. Levels of oxidative stress parameters were evaluated in the serum, frontal cortex, and hippocampus. d-AMPH administration induced hyperlocomotion in rats, which was significantly reversed by Li and Cel coadministration. In addition, d-AMPH administration induced damage to proteins and lipids in the frontal cortex and hippocampus of rats. All these impairments were reversed by treatment with Li and/or Cel, in a way dependent on cerebral area and biochemical analysis. Li and Cel coadministration reversed the d-AMPH-induced decrease in catalase activity in cerebral structures. The activity of glutathione peroxidase was decreased in the frontal cortex of animals receiving d-AMPH, and treatment with Li, Cel, or a combination thereof reversed this alteration in this structure. Overall, data indicate hyperlocomotion and alteration in oxidative stress biomarkers in the cerebral structures of rats receiving d-AMPH. Li and Cel coadministration can mitigate these modifications, comprising a potential novel approach for BD therapy.

Putative neuroprotective pharmacotherapies to target the staged progression of mental illness

AIM

Neuropsychiatric disorders including depression, bipolar and schizophrenia frequently exhibit a neuroprogressive course from prodrome to chronicity. There are a range of agents exhibiting capacity to attenuate biological mechanisms associated with neuroprogression. This review will update the evidence for putative neuroprotective agents including clinical efficacy, mechanisms of action and limitations in current assessment tools, and identify novel agents with neuroprotective potential.

METHOD

Data for this review were sourced from online databases PUBMED, Embase and Web of Science. Only data published since 2012 were included in this review, no data were excluded based on language or publication origin.

RESULTS

Each of the agents reviewed inhibit one or multiple pathways of neuroprogression including: inflammatory gene expression and cytokine release, oxidative and nitrosative stress, mitochondrial dysfunction, neurotrophin dysregulation and apoptotic signalling. Some demonstrate clinical efficacy in preventing neural damage or loss, relapse or cognitive/functional decline. Agents include: the psychotropic medications lithium, second generation antipsychotics and antidepressants; other pharmacological agents such as minocycline, aspirin, cyclooxygenase-2 inhibitors, statins, ketamine and alpha-2-delta ligands; and others such as erythropoietin, oestrogen, leptin, N-acetylcysteine, curcumin, melatonin and ebselen.

CONCLUSIONS

Signals of evidence of clinical neuroprotection are evident for a number of candidate agents. Adjunctive use of multiple agents may present a viable avenue to clinical realization of neuroprotection. Definitive prospective studies of neuroprotection with multimodal assessment tools are required.

Preventive Effect of Alkaloids from Lotus plumule on Acute Liver Injury in Mice

Lotus plumule is a traditional Chinese food that can be used as a beverage. In this study, three kinds of Lotus plumules from different regions of China were selected to observe the preventive effects of extracted alkaloids on CCl₄-induced liver injuries. Animal experiments revealed that alkaloids extracted from Lotus plumules decreased the serum AST (aspartate aminotransferase), ALT (alanine aminotransferase), and TBIL (total bilirubin) levels, enhanced SOD (superoxide dismutase) activity, and reduced MDA (malondialdehyde) level in the liver tissues of mice with liver injury. H&E observation confirmed that alkaloids from Lotus plumules could alleviate CCl₄-induced injuries of liver tissues and inhibit the inflammatory effect on hepatocytes. Further qPCR experiments also demonstrated that alkaloids from Lotus plumules upregulated the expression of IκB-α (inhibitor of NF-κB alpha), Cu/Zn-SOD (copper/zinc superoxide dismutase), Mn-SOD (manganese superoxide dismutase), and CAT (catalase) mRNA and downregulated TNF-α (tumor necrosis factor alpha) and NF-κB (nuclear factor kappa B) expression in the liver tissues of mice with liver injury. All three kinds of alkaloids from Lotus plumules could prevent CCl₄-induced liver injuries by regulating the levels of oxidative stress and inflammation in mice, and the therapeutic effect was comparable to that of silymarin, the medicine commonly used in the treatment of liver diseases. In summary, alkaloids from Lotus plumules contain bioactive substances with hepatic protective efficacy and possess potential application value in the field of functional food.

JSH-23 prevents depressive-like behaviors in mice subjected to chronic mild stress: Effects on inflammation and antioxidant defense in the hippocampus

Nuclear factor-kappa B (NF-κB), which is reported to play an important role in the pathogenesis of depression, also has a central role in the genesis and progression of inflammation. Here, we have targeted the nuclear translocation of NF-κB using 4-methyl-N1-(3-phenyl-propyl)-benzene-1,2-diamine (JSH-23) to elucidate its role in depression. We investigated the antidepressant-like effects of JSH-23 in the chronic mild stress (CMS) mouse model, which is a valid, reasonably reliable, and useful model of depression. The antidepressant-like effects of JSH-23 were evaluated using the sucrose preference test (SPT) and the forced swimming test (FST). We also assessed inflammatory markers [interleukin (IL)-6 and tumor necrosis factor-α (TNF-α)] and components of antioxidant defense [superoxide dismutase (SOD) and nuclear factor erythroid-2-related factor 2 (Nrf 2)] in the hippocampus. Fluoxetine, a classical antidepressant, was used in this study as a positive control. Administration of JSH-23 significantly prevented the decreased sucrose preference in the SPT and prevented the increased immobility time in the FST caused by CMS, but had no effect on locomotor activity. Expression of NF-κB p65 protein in the hippocampus was decreased, and elevated levels of IL-6 and TNF-α were reduced, after JSH-23 administration. In addition to its anti-inflammatory effect, JSH-23 treatment increased the expression of SOD and Nrf 2 in the hippocampus, suggesting that it strengthens antioxidant defense. The current study demonstrated that inhibiting the NF-κB signaling cascade using JSH-23 prevented depressive-like behaviors by decreasing inflammation and improving antioxidant defense in the hippocampus. We concluded that NF-κB activation plays an important role in the pathophysiology of depression and that targeting NF-κB signaling may provide a novel and effective therapy for depression. Additional preclinical studies and clinical trials are, however, needed to further elucidate the effects of this therapeutic strategy.