The cytokine network in the pathogenesis of major depressive disorder. Close to translation?

Longitudinal relationships of cytokines, depression and anhedonia in depressed adolescents

BACKGROUND

Depression has been associated with low-grade elevation of plasma cytokines (e.g. interleukin-6, IL-6; tumor necrosis factor alpha, TNFα) in both cross-sectional and longitudinal studies in adults. Preclinical and clinical studies also suggest that IL-6 and TNFα elevation are associated with anhedonia. However, few studies have examined longitudinal relationships between cytokines and depression/anhedonia in clinically depressed samples, particularly adolescents.

METHODS

Thirty-six adolescents with a depressive disorder receiving standard-of-care community treatment were assessed at a baseline and a follow-up timepoint. Self-report and clinical measures of depression and anhedonia, along with plasma IL-6 and TNFα levels, were obtained at both timepoints. Baseline cytokine measures were examined in association with baseline and follow-up clinical measures. On an exploratory basis, change in clinical measures over time was examined in relation to change in cytokine levels over time.

RESULTS

Higher baseline TNFα levels predicted higher follow-up depression severity after approximately four months (controlling for baseline depression). Higher baseline TNFα levels also associated positively with baseline anhedonia and predicted higher anhedonia at follow-up (controlling for baseline anhedonia). No association was found between change in clinical measures and change in cytokine levels over time.

CONCLUSIONS

Among adolescents receiving standard-of-care community treatment for depression, higher levels of TNFα predicted greater depressive symptoms at 4-month follow-up, suggesting this cytokine may be used to help identify patients in need of more intensive treatment. Elevated TNFα levels were also associated with concurrent and future anhedonia symptoms, suggesting a specific mechanism in which TNFα affects depression trajectories. Future studies should examine the relationships between cytokine levels and depression/anhedonia symptoms at multiple timepoints in larger cohorts of depressed adolescents.

Infections, inflammation, and risk of neuropsychiatric disorders: the neglected role of "co-infection"

Neuropsychiatric disorders (NPDs) have multiple etiological factors, mainly genetic background, environmental conditions and immunological factors. The host immune responses play a pivotal role in various physiological and pathophysiological process. In NPDs, inflammatory immune responses have shown to be involved in diseases severity and treatment outcome. Inflammatory cytokines and chemokines are involved in various neurobiological pathways, such as GABAergic signaling and neurotransmitter synthesis. Infectious agents are among the major amplifier of inflammatory reactions, hence, have an indirect role in the pathogenesis of NPDs. As such, some infections directly affect the central nervous system (CNS) and alter the genes that involved in neurobiological pathways and NPDs. Interestingly, the most of infectious agents that involved in NPDs (e.g., Toxoplasma gondii, cytomegalovirus and herpes simplex virus) is latent (asymptomatic) and co-or-multiple infection of them are common. Nonetheless, the role of co-or-multiple infection in the pathogenesis of NPDs has not deeply investigated. Evidences indicate that co-or-multiple infection synergically augment the level of inflammatory reactions and have more severe outcomes than single infection. Hence, it is plausible that co-or-multiple infections can increase the risk and/or pathogenesis of NPDs. Further understanding about the role of co-or-multiple infections can offer new insights about the etiology, treatment and prevention of NPDs. Likewise, therapy based on anti-infective and anti-inflammatory agents could be a promising therapeutic option as an adjuvant for treatment of NPDs.

Effectiveness and Tolerability of Korean Red Ginseng Augmentation in Major Depressive Disorder Patients with Difficult-to-treat in Routine Practice

Objective

: To test clinical effectiveness and tolerability of Korean Red Ginseng augmentation (RGA) in major depressive disorder (MDD) patients with difficult-to-treat.

Methods

Thirty six patients were enrolled in this 6 weeks, prospective, clinical trial. Rating scales were MontgomeryÅsberg Depression Rating Scale (MADRS), Patient Health Questionnaire-15, Clinical Global Impression-improvement (CGI-I), and Patient Satisfaction Score. The primary endpoint was a remission rate measured by MADRS score at the end of study (≤ 10). Clinical outcomes and tolerability were assessed at baseline, week 2, and week 6.

Results

Among 36 patients, 26 patients completed the study and 28 patients had post-baseline visit data. The remission rate by MADRS score was 39.3% (11/28) and 57.1% by CGI-I scores of 1 or 2 at the end of the study. The mean change of MADRS score was significantly decreased by 44.4% from baseline to the end of study. The most frequent adverse events were headache (7/28, 25.0%) during the study.

Conclusion

Our study indicates the putative effectiveness and tolerability of RGA for treating MDD with difficult-to-treat in clinical practice. However, adequately powered, randomized, controlled trials will be needed to confirm these results.

Emerging Neurological and Psychobiological Aspects of COVID-19 Infection

The SARS-CoV-2 virus, first reported in December 2019 in China, is the causative agent of the current COVID-19 pandemic that, at the time of writing (1 November 2020) has infected almost 43 million people and caused the death of more than 1 million people. The spectrum of clinical manifestations observed during COVID-19 infection varies from asymptomatic to critical life-threatening clinical conditions. Emerging evidence shows that COVID-19 affects far more organs than just the respiratory system, including the heart, kidneys, blood vessels, liver, as well as the central nervous system (CNS) and the peripheral nervous system (PNS). It is also becoming clear that the neurological and psychological disturbances that occur during the acute phase of the infection may persist well beyond the recovery. The aim of this review is to propel further this emerging and relevant field of research related to the pathophysiology of neurological manifestation of COVID-19 infection (Neuro-COVID). We will summarize the PNS and CNS symptoms experienced by people with COVID-19 both during infection and in the recovery phase. Diagnostic and pharmacological findings in this field of study are strongly warranted to address the neurological and psychological symptoms of COVID-19.

Therapeutic effect of TRC105 and decitabine combination in AML xenografts

Acute myeloid leukemia (AML) is an aggressive hematologic malignancy, often characterized by poor prognosis following standard induction therapy. The hypomethylating agent decitabine (DAC) is an alternative treatment for elderly and relapsed/refractory AML patients, yet responses following DAC monotherapy are still modest. The transforming growth factor-β (TGF-β) receptor CD105 (endoglin) is expressed in various hematopoietic malignancies, and high CD105 expression correlates with poor prognosis in AML patients. Using a xenograft model, we have recently demonstrated that targeting CD105⁺ AML blasts with the TRC105 monoclonal antibody inhibits leukemia progression. Here we investigated whether administration of TRC105 along with DAC could represent a novel therapeutic option for relapsed/refractory AML. Our data show that the DAC/TRC105 combination results in a more durable anti-leukemic effect in AML xenografts compared to DAC monotherapy. Moreover, the DAC/TRC105 combination enhanced reactive oxygen species (ROS) activity, which correlated with reduced leukemia burden. RNA-sequencing studies suggest that TRC105 may alter TGF-β activity in AML blasts. Taken together, these findings provide rationale for the clinical evaluation of TRC105 in combination with DAC in AML patients.

Effects of Combined Admistration of Imatinib and Sorafenib in a Murine Model of Liver Fibrosis

Liver fibrosis is defined as excessive extracellular matrix deposition in the hepatic parenchyma as a consequence of complex interactions among matrix-producing hepatic stellate cells (HSCs) and liver-resident and infiltrating cells. In addition to the liver, the process of fibrosis may represent end-stage disease of several diseases including kidneys, lungs, spleens, heart, muscles and at certain extent, the central nervous system and the peripheral nerves. To date, antifibrotic treatment of fibrosis represents an unconquered area for drug development. The aim of the present study was to test the efficacy of a new drug combination for the treatment of hepatic fibrosis in order to provide a proof-of-concept for the use of therapeutic agents in clinical practice. For this purpose, we have studied the effects of the PDGF inhibitor imatinib and the angiogenesis inhibitor sorafenib, administered alone or in combination, in reducing the progression of the fibrogenetic process in a pre-clinical model of liver damage induced in mice by repeated administration of Concanavalin A (ConA), resembling long-tern autoimmune hepatitis. Our results suggest that treatments with imatinib and sorafenib can modulate potently and, in a superimposable fashion, the fibrinogenic process when administered alone. However, and in agreement with the computational data presently generated, they only exert partial overlapping antifibrotic effects in modulating the main pathways involved in the process of liver fibrosis, without significant additive or synergist effects, when administered in combination.

Novel Acetylcholinesterase Inhibitors Based on Uracil Moiety for Possible Treatment of Alzheimer Disease

In this study, novel derivatives based on 6-methyluracil and condensed uracil were synthesized, namely, 2,4-quinazoline-2,4-dione with ω-(ortho-nitrilebenzylethylamino) alkyl chains at the N atoms of the pyrimidine ring. In this series of synthesized compounds, the polymethylene chains were varied from having tetra- to hexamethylene chains, and secondary NH, tertiary ethylamino, and quaternary ammonium groups were introduced into the chains. The molecular modeling of the compounds indicated that they could function as dual binding site acetylcholinesterase inhibitors, binding to both the peripheral anionic site and active site. The data from in vitro experiments show that the most active compounds exhibit affinity toward acetylcholinesterase within a nanomolar range, with selectivity for acetylcholinesterase over butyrylcholinesterase reaching four orders of magnitude. In vivo biological assays demonstrated the potency of these compounds in the treatment of memory impairment using an animal model of Alzheimer disease.

Predictors of cognitive impairment in treatment-resistant depression

BACKGROUND

Cognitive impairment is a well-recognized symptom of major depressive disorder; however, contributing factors are not fully characterized. The present study examined the neurocognitive profiles and predictors of cognitive impairment in patients with treatment-resistant depression (TRD).

METHODS

Moderate to severely depressed TRD patients were compared to matched healthy volunteers (HV) in verbal learning and recall and executive functions. Based on cognitive scores, cluster analysis was performed to identify subsets within the TRD sample. Predictors of cognitive impairment were also investigated.

RESULTS

TRD patients showed worse performance in tests assessing verbal memory, executive attentional shifting, and inhibitory control. The cluster analysis revealed two groups: a cognitively impaired (CI) group that showed a generalized deficit across cognitive domains, and a relatively cognitively intact group that performed better than CI in all domains except attentional shifting. A logistic binomial regression of the two groups revealed three significant contributing risk factors for CI: 1) older age, 2) lower premorbid IQ, and 3) benzodiazepine use. Cognitive impairment and benzodiazepine use were associated with worse functioning.

CONCLUSIONS

Significant cognitive impairment is present in TRD and is associated with worse functioning. Age, lower premorbid IQ, and benzodiazepine use increased the likelihood of generalized cognitive impairment in TRD patients. The detrimental effect of benzodiazepine on cognitive impairment is independent of anxiety symptoms. Further research is needed to characterize the timeline of cognitive impairment in depression.

Effects of Pyrrole-Imidazole Polyamides Targeting Human TGF-β1 on the Malignant Phenotypes of Liver Cancer Cells

Synthetic pyrrole-imidazole (PI) polyamides bind to the minor groove of double-helical DNA with high affinity and specificity, and inhibit the transcription of corresponding genes. In liver cancer, transforming growth factor (TGF)-β expression is correlated with tumor grade, and high-grade liver cancer tissues express epithelial-mesenchymal transition markers. TGF-β1 was reported to be involved in cancer development by transforming precancer cells to cancer stem cells (CSCs). This study aimed to evaluate the effects of TGF-β1-targeting PI polyamide on the growth of liver cancer cells and CSCs and their TGF-β1 expression. We analyzed TGF-β1 expression level after the administration of GB1101, a PI polyamide that targets human TGF-β1 promoter, and examined its effects on cell proliferation, invasiveness, and TGF-β1 mRNA expression level. GB1101 treatment dose-dependently decreased TGF-β1 mRNA levels in HepG2 and HLF cells, and inhibited HepG2 colony formation associated with downregulation of TGF-β1 mRNA. Although GB1101 did not substantially inhibit the proliferation of HepG2 cells compared to untreated control cells, GB1101 significantly suppressed the invasion of HLF cells, which displayed high expression of CD44, a marker for CSCs. Furthermore, GB1101 significantly inhibited HLF cell sphere formation by inhibiting TGF-β1 expression, in addition to suppressing the proliferation of HLE and HLF cells. Taken together, GB1101 reduced TGF-β1 expression in liver cancer cells and suppressed cell invasion; therefore, GB1101 is a novel candidate drug for the treatment of liver cancer.

Inflammation-Associated Synaptic Alterations as Shared Threads in Depression and Multiple Sclerosis

In the past years, several theories have been advanced to explain the pathogenesis of Major Depressive Disorder (MDD), a neuropsychiatric disease that causes disability in general population. Several theories have been proposed to define the MDD pathophysiology such as the classic "monoamine-theory" or the "glutamate hypothesis." All these theories have been recently integrated by evidence highlighting inflammation as a pivotal player in developing depressive symptoms. Proinflammatory cytokines have been indeed claimed to contribute to stress-induced mood disturbances and to major depression, indicating a widespread role of classical mediators of inflammation in emotional control. Moreover, during systemic inflammatory diseases, peripherally released cytokines circulate in the blood, reach the brain and cause anxiety, anhedonia, social withdrawal, fatigue, and sleep disturbances. Accordingly, chronic inflammatory disorders, such as the inflammatory autoimmune disease multiple sclerosis (MS), have been associated to higher risk of MDD, in comparison with overall population. Importantly, in both MS patients and in its experimental mouse model, Experimental Autoimmune Encephalomyelitis (EAE), the notion that depressive symptoms are reactive epiphenomenon to the MS pathology has been recently challenged by the evidence of their early manifestation, even before the onset of the disease. Furthermore, in association to such mood disturbance, inflammatory-dependent synaptic dysfunctions in several areas of MS/EAE brain have been observed independently of brain lesions and demyelination. This evidence suggests that a fine interplay between the immune and nervous systems can have a huge impact on several neurological functions, including depressive symptoms, in different pathological conditions. The aim of the present review is to shed light on common traits between MDD and MS, by looking at inflammatory-dependent synaptic alterations associated with depression in both diseases.