Inflammation and Depression: the Neuroimmune Connection

Mood, Anxiety, and Cognitive Alterations in Cancer Patients

BACKGROUND AND OBJECTIVE

To analyze the cytokine profile in cerebrospinal fluid (CSF), as well as mood, anxiety, and cognition profiles in patients with CC.

METHODS

One hundred and nine individuals were evaluated, 37 controls, 18 CWC, and 54 CC patients. Assessments included BDI, HADS, Digit Span, FAS-verbal, Animals/WMS-R, Matrix Reasoning and Vocabulary (WASI), and QLQ-C30.

RESULTS

The CC group exhibited 62.96% depression and probable anxiety/depression, with 75.92% showing attention deficits. The CC and CWC groups demonstrated significant cognitive impairment on the WASI-Vocabulary test (CWC: 13.4 ± 2.2; CC: 15.9 ± 1.1) compared to the control group (Ct: 22.8 ± 1.6; p = 0.0002). In the QLQ-C30 scores, the CC group reported a greater perceived loss of quality of life and health deterioration (score of 17.5 ± 2.6) and lower scores on the Functional Scale (49.8 ± 4.5). The CC group had 18.52% illiteracy, 18.52% incomplete higher education, and 22.22% complete elementary education. The CC group also had lower weight (Ct: 67.8 ± 1.4; CWC: 61.7 ± 3.1; CC: 59.6 ± 1.7; p = 0.0023) and BMI (CC: 21.5 [18.3; 24.8]; Ct: 24.9 [23; 25.8]; p = 0.0021) compared to controls. Cytokines detected in the CSF were MCP-1, VEGF, IL-8, IP-10, and MIP-1β. Higher concentrations of MCP-1 were found in cancer patients (CSC: 571.2 ± 105.8; CC: 399.5 ± 65.9; Ct: 1477 ± 0.1; p < 0.0001), along with lower levels of MIP-1β (CC: 4345 [3060; 7353]) and VEGF (CC: 48.3 ± 2.0; CWC: 49.8 ± 3.8; Ct: 64.8 ± 3.2; p < 0.0001).

CONCLUSIONS

The level of mental impairment (mood, anxiety, and cognitive deficits) correlated with cancer-associated and cachexia-associated inflammation, weight loss, low BMI, elevated C-reactive protein (CRP), leukocytosis, lymphopenia, anemia, hypoalbuminemia, and low scores on the QLQ-C30 questionnaire (Global Health Status, Functional Scale, Symptom Scale). The CC group exhibited a higher prevalence of depression/anxiety, a stronger correlation between depression and inflammation, and greater cognitive impairment in attention, reasoning, and language, alongside lower average educational attainment. The low concentration of certain cytokines in the CSF combined with elevated systemic CRP in cancer and cachexia, associated with mental disorders, presents a paradox that requires further investigation. Higher concentrations of the cytokine MCP-1 in cancer patient groups indicated a positive correlation with the preservation of language abilities in these patients.

The triterpenoid ursolic acid ameliorates stress in Caenorhabditis elegans by affecting the depression-associated genes skn-1 and prdx2

INTRODUCTION

Depression is one of the leading causes of death worldwide. Lower antioxidant concentrations and increased oxidative stress levels contribute to the development of depression. Effective and tolerable medications are urgently needed. Nrf2 and PRDX2 are promising targets in the treatment of oxidative stress and, therefore, promising for the development of novel antidepressants. Ursolic acid (UA), a natural triterpenoid found in various plants is known to exert neuroprotective and antioxidant effects. Skn-1 (which corresponds to human Nrf2) and prdx2 deficient mutants of the nematode Caenorhabditis elegans are suitable models to study the effect of UA on these targets. Additionally, stress assays are used to mimic stress or depressed state.

METHODS

We examined the antioxidant activity of UA in Caenorhabditis elegans wildtype and skn-1- and prdx2-deficient strains by H2DCF-DA and juglone assays as well as osmotic and heat stress assays. Additionally, we analyzed the binding of UA to human PRDX2 and Skn-1 proteins by molecular docking and microscale thermophoresis.

RESULTS

UA exerted strong antioxidant activities. Additionally, induction of stress resistance towards osmotic and heat stress was observed. qRT-PCR revealed that UA upregulated the gene expression of skn-1 and prdx2. Molecular docking studies supported these findings.

CONCLUSION

Our findings implicate that the strong antioxidant activity of UA may exert anti-depressive effects by its interaction with the Skn-1 transcription factor, which is part of a detoxification network, and the antioxidant PRDX2 protein, which protects the organism from the detrimental effects of radical oxygen species.

IGF-1 Alleviates Mitochondrial Apoptosis through the GSK3β/NF-κB/NLRP3 Signaling Pathway in LPS-Treated PC-12 Cells

Inflammation contributes to mitochondrial dysfunction and neuronal apoptosis. The aim of this study was to determine whether insulin-like growth factor-1 (IGF-1) alleviates mitochondrial apoptosis in lipopolysaccharide (LPS)-treated PC-12 cells, and to further explore the mechanism involved. Prepared PC-12 cells were treated with IGF-1, Mdivi-1 (DRP1 blocker), LY294002 (PI3K blocker), betulinic acid (NF-κB activator) or their combinations. Mitochondrial membrane potential and ATP generation were then measured to assess mitochondrial function. The rate of apoptosis was determined using flow cytometry. The expression of several apoptosis proteins (i.e. Bax, cleaved caspase-9 and cleaved caspase-3) and signaling proteins (i.e. p-GSK3β, NF-κB and NLRP3) was measured using western blotting. Compared with the control cells, the LPS-treated cells showed evidence of mitochondrial dysfunction, increased apoptosis and upregulation of apoptosis proteins, which were significantly alleviated by Mdivi-1. These findings indicate that neuronal apoptosis was activated partly through the mitochondrial pathway. IGF-1 treatment inhibited mitochondrial apoptosis in a dose-dependent manner in the LPS-treated cells. The reagent also increased the expression of p-GSK3β and decreased the expression of NF-κB and NLRP3. Both LY294002 and betulinic acid reversed the protective effect of IGF-1. In addition, LY294002 affected the expression of the three signaling proteins, while betulinic acid only affected the expression of NF-κB and NLRP3. These findings indicated a GSK3β/NF-κB/NLRP3 signaling pathway was existed and was involved in the protective mechanism of IGF-1. In conclusion, IGF-1 alleviated mitochondrial apoptosis through GSK3β/NF-κB/NLRP3 signaling pathway in LPS-treated PC-12 cells.

Removal of vasopressin cells from the paraventricular nucleus of the hypothalamus enhances lipopolysaccharide-induced sickness behaviour in mice

Vasopressin (AVP) cells in the paraventricular nucleus of the hypothalamus (PVN) are activated during sickness and project to multiple nuclei responsible for the anxiety, social and motivated behaviours affected during sickness, suggesting that these cells may play a role in sickness behaviours, typically expressed as reduced mobility, increased anxiety, anhedonia and social withdrawal. In the present study, we selectively ablated AVP neurones in the PVN of male and female mice (Mus musculus) and induced sickness behaviour via injection of bacterial lipopolysaccharide (LPS). We found that PVN AVP ablation increased the effects of LPS, specifically by further decreasing sucrose preference in males and females and decreasing the social preference of males, monitored within 24 hours of LPS injection. These results suggest that PVN AVP contributes to the change in motivated behaviours during sickness and may help promote recovery from infection..

Skin and Psychosomatics - Psychodermatology today

Modern psychodermatology relies on the bio-psycho-social disease model in psychosomatics, according to which biological, psychological and social factors (on various levels, from molecules to the biosphere) play a major role in the disease pathogenesis through complex, non-linear interactions over the entire disease course. It is nowadays experimentally proven that "emotions get into the skin". Recent research shows close anatomical, physiological and functional connections between skin and nervous system, already known to be ontogenetically related. These connections are reflected in many skin diseases where psychological and somatic etiological factors are closely intertwined. A holistic approach by the physician should do justice to this interdependence; biological, psychological and social factors should be adequately taken into account when taking anamnesis, making a diagnosis and choosing a therapy. The "visibility" of the skin organ bestows dermatology a special position among the various other clinical subjects, and renders a holistic, psychosomatic approach to the patient that is particularly important. The life course belongs also to modern psychodermatological approaches. Based on the modern psychodermatology concept, other corresponding sub-areas such as psychogastroenterology, psychocardiology etc. have emerged. After the theoretical part of this article, some selected skin diseases are discussed in more detail from the psychosomatic point of view.

Plasma levels of Interleukin 18 but not amyloid-β or Tau are elevated in female depressive patients

BACKGROUND

Depression is associated with inflammation and Alzheimer's disease (AD). However, detailed molecular mechanisms linking mood, neuroinflammation and AD remain unclear. Although changes in peripheral inflammatory factors such as Interleukin 18 (IL18), and AD-associated amyloid-β (Aβ) peptides have been linked to depression, a solid relationship between these factors in depressive disorder has yet to be established. This study aims to further determine whether plasma IL18, Aβ40, Aβ42, and the AD-associated tangle component Tau, as well as IL18 single nucleotide polymorphisms (SNPs) may be biomarkers for depression.

METHODS

We measured plasma IL18, Aβ40, Aβ42, and Tau in 64 depressive patients and 75 healthy controls, and characterized genotypes of three IL18 SNPs (rs187238, rs1946518 and rs1946519) in these subjects. Comparisons between depressive patients and controls were carried out in males, in females or in combination. Regression analyses were conducted to examine the correlation between these parameters.

RESULTS

We found that none of the plasma levels of IL18, Aβ40, Aβ42, and Tau, the ratio of Aβ42/Aβ40, and the genotypes of IL18 SNPs were significantly different between combined depressive patients and combined healthy controls, or between male depressive patients and male controls. However, IL18 levels were less in females than in males in healthy people and were significantly increased in female depressive patients compared to female controls. Moreover, IL18 and standardized IL18 were correlated with standardized Aβ42/Aβ40 ratio and standardized Tau in depressive patients.

CONCLUSIONS

Plasma IL18 may be a potential biomarker for depression in women.

The cytokine IL-17A as a marker of treatment resistance in major depressive disorder?

Major depression is a complex disease and-among others, inflammation appears to play an important role in its pathophysiology. In this study, we investigated a broad range of cytokines in depressed patients. Plasma levels of interleukin (IL)-12/ IL-23p40, IL-15, IL-16, IL-17A, IL-1α, IL-7, tumor necrosis factorβ and vascular endothelial growth factor were compared in 48 patients suffering from major depression before, after one and after six weeks of antidepressive treatment in relation to therapy response. Interestingly, the level of IL-17A turned out to rise significantly in the non-responder group compared to responder during antidepressive treatment. IL-17A is a pro-inflammatory cytokine that initiates the production of other cytokines, thereby inducing and mediating immune response. It is also involved in allergic and autoimmune-related diseases. The database investigating the role of IL-17A in major depressive disorder has grown within the last few years comparing levels of this cytokine in depressed patients versus healthy subjects. However, little is known about the expression of IL-17A during the course of antidepressive treatment. In summary, our study provides valuable evidence that this cytokine might serve as a marker of therapy resistance to antidepressants.