5-Hydroxytryptophan plus SSRIs for interferon-induced depression: Synergistic mechanisms for normalizing synaptic serotonin

An integrated computational pipeline for designing high-affinity nanobodies with expanded genetic codes

Protein engineering and design principles employing the 20 standard amino acids have been extensively used to achieve stable protein scaffolds and deliver their specific activities. Although this confers some advantages, it often restricts the sequence, chemical space, and ultimately the functional diversity of proteins. Moreover, although site-specific incorporation of non-natural amino acids (nnAAs) has been proven to be a valuable strategy in protein engineering and therapeutics development, its utility in the affinity-maturation of nanobodies is not fully explored. Besides, current experimental methods do not routinely employ nnAAs due to their enormous library size and infinite combinations. To address this, we have developed an integrated computational pipeline employing structure-based protein design methodologies, molecular dynamics simulations and free energy calculations, for the binding affinity prediction of an nnAA-incorporated nanobody toward its target and selection of potent binders. We show that by incorporating halogenated tyrosines, the affinity of 9G8 nanobody can be improved toward epidermal growth factor receptor (EGFR), a crucial cancer target. Surface plasmon resonance (SPR) assays showed that the binding of several 3-chloro-l-tyrosine (3MY)-incorporated nanobodies were improved up to 6-fold into a picomolar range, and the computationally estimated binding affinities shared a Pearson's r of 0.87 with SPR results. The improved affinity was found to be due to enhanced van der Waals interactions of key 3MY-proximate nanobody residues with EGFR, and an overall increase in the nanobody's structural stability. In conclusion, we show that our method can facilitate screening large libraries and predict potent site-specific nnAA-incorporated nanobody binders against crucial disease-targets.

5-Hydroxytryptophan as adjuvant therapy in treatment of moderate to severe obsessive-compulsive disorder: a double-blind randomized trial with placebo control

On the basis of numerous previous studies, the serotonergic system plays a role in the pathogenesis of obsessive-compulsive disorder (OCD) and effective agents in this pathway, such as 5-hydroxytryptophan, can potentially contribute to treatment of patients with this disorder. Evaluating the efficacy of 5-hydroxytryptophan in treating OCD was the aim of the present randomized, double-blind, placebo-controlled 12-week trial. In a 12-week, randomized double-blind study, 60 patients with a Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition diagnosis of moderate to severe OCD and a Yale-Brown Obsessive Compulsive Scale (Y-BOCS) score of >21 were randomly assigned to receive either fluoxetine plus placebo or fluoxetine plus 5-hydroxytryptophan (100 mg twice daily). All patients, regardless of their treatment group, received fluoxetine at 20 mg/day for the initial 4 weeks of the study followed by 60 mg/day of fluoxetine for the rest of the trial course. Symptoms were assessed using the Y-BOCS at baseline and weeks 4, 8 and 12. General linear model repeated measure showed significant effects for time × treatment interaction on total Y-BOCS (F = 12.07, df = 2.29, P-value <0.001), obsession (F = 8.25, df = 1.91, P-value = 0.001) and compulsion subscale scores (F = 6.64, df = 2.01, P-value = 0.002). 5-Hydroxytryptophan augmentation therapy demonstrated higher partial and complete treatment response rate (P = 0.032 and P = 0.001, respectively) according to the Y-BOCS total scores. The results of this study confirm that 5-hydroxytryptophan may be effective as an augmentative agent in treatment of moderate-to-severe OCD.

Phenolic Melatonin-Related Compounds: Their Role as Chemical Protectors against Oxidative Stress

There is currently no doubt about the serious threat that oxidative stress (OS) poses to human health. Therefore, a crucial strategy to maintain a good health status is to identify molecules capable of offering protection against OS through chemical routes. Based on the known efficiency of the phenolic and melatonin (MLT) families of compounds as antioxidants, it is logical to assume that phenolic MLT-related compounds should be (at least) equally efficient. Unfortunately, they have been less investigated than phenols, MLT and its non-phenolic metabolites in this context. The evidence reviewed here strongly suggests that MLT phenolic derivatives can act as both primary and secondary antioxidants, exerting their protection through diverse chemical routes. They all seem to be better free radical scavengers than MLT and Trolox, while some of them also surpass ascorbic acid and resveratrol. However, there are still many aspects that deserve further investigations for this kind of compounds.

Quinolinic Acid Responses during Interferon-α-Induced Depressive Symptomatology in Patients with Chronic Hepatitis C Infection - A Novel Aspect for Depression and Inflammatory Hypothesis

BACKGROUND

The aim of this exploratory study is to gain for the first time a more comprehensive picture of the impact of changes of quinolinic acid concentrations on depressive symptomatology during and after IFN-α therapy.

METHODS

The quinolinic acid concentrations of 35 HCV patients are examined in a prospective survey over the entire period of IFN-α treatment as well as three months later at six different times (baseline, one, three, six and nine months after the beginning of IFN-α treatment, and after the end of treatment).

RESULTS

During IFN-α treatment Hamilton Depression Rating Scale scores rise significantly. At the same time there is greater activity of indoleamine 2,3-dioxygenase, with a resulting increase in plasma kynurenine concentrations. Compared to baseline values quinolinic acid concentrations increase significantly during therapy, reflecting an increased neurotoxic challenge. In addition, patients with higher scores in the Hamilton Depression Rating Scale at six and nine months after starting therapy show significantly higher levels of quinolinic acid concentration.

CONCLUSIONS

The increase of quinolinic acid during IFN-α therapy might contribute to depressive symptomatology through the neurotoxic challenge caused by quinolinic acid. Subsequently, our exploratory study results support the inflammatory hypothesis of depression. The awareness of relevant risk factors of IFN-α treatment-induced depression is essential to develop preventative treatment strategies.

Prevention of interferon-alpha-associated depression with antidepressant medications in patients with hepatitis C virus: a systematic review and meta-analysis

OBJECTIVE

To conduct a systematic review and meta-analysis evaluating the efficacy and safety of antidepressant medications for the prevention of interferon-alpha (INF-α)-associated depression in patients with chronic hepatitis C virus (HCV).

DATA SOURCES

Medline, Cochrane Central and PsycInfo from inception to September 2012, without limitations using terms describing hepatitis C and the individual drug names.

STUDY SELECTION

We reviewed 132 citations for inclusion using the following criteria: randomised controlled trials in patients with chronic HCV initiating INF-α comparing prophylactic use of an antidepressant vs. placebo and reporting at least one outcome of interest [depression, completion of antiviral therapy, sustained virologic response (SVR), and serious adverse events and bleeding].

DATA EXTRACTION

Trial characteristics, assessment of risk of bias and data needed for analyses were extracted by two independent investigators using a standard extraction form. Disagreements were reviewed by a third investigator.

RESULTS

A DerSimonian and Laird random-effects model was used for analysis. Heterogeneity and publication bias were evaluated where applicable. Of the seven included trials, the risk of bias was low in four and unclear in the remaining three. All trials evaluated selective serotonin reuptake inhibitors (SSRIs). Prophylactic use of a SSRI significantly reduced the risk of depression by 41% compared with placebo [RR, relative risk 0.59 (0.37-0.93)]. The impact of SSRIs on completion of antiviral therapy, SVR and serious adverse events was not found to be significant.

CONCLUSIONS

SSRIs prevent depression in patients with HCV treated with INF-α therapy. The impact of SSRIs on completion of antiviral therapy or on the development of adverse events is less clear.

Bioanalysis for biocatalysis: multiplexed capillary electrophoresis-mass spectrometry assay for aminotransferase substrate discovery and specificity profiling

In this work, we introduce an entirely automated enzyme assay based on capillary electrophoresis coupled to electrospray ionization mass spectrometry termed MINISEP-MS for multiple interfluent nanoinjections-incubation-separation-enzyme profiling using mass spectrometry. MINISEP-MS requires only nanoliters of reagent solutions and uses the separation capillary as a microreactor, allowing multiple substrates to be assayed simultaneously. The method can be used to rapidly profile the substrate specificity of any enzyme and to measure steady-state kinetics in an automated fashion. We used the MINISEP-MS assay to profile the substrate specificity of three aminotransferases (E. coli aspartate aminotransferase, E. coli branched-chain amino acid aminotransferase, and Bacillus sp. YM-1 D-amino acid aminotransferase) for 33 potential amino acid substrates and to measure steady-state kinetics. Using MINISEP-MS, we were able to recapitulate the known substrate specificities and to discover new amino acid substrates for these industrially relevant enzymes. Additionally, we were able to measure the apparent K(M) and k(cat) parameters for amino acid donor substrates of these aminotransferases. Because of its many advantages, the MINISEP-MS assay has the potential of becoming a useful tool for researchers aiming to identify or create novel enzymes for specific biocatalytic applications.

Antidepressant-like effect of ethanol extract from Zuojin Pill, containing two herbal drugs of Rhizoma Coptidis and Fructus Evodiae, is explained by modulating the monoaminergic neurotransmitter system in mice

ETHNOPHARMACOLOGICAL RELEVANCE

Zuojin Pill (ZJP), a traditional Chinese medicinal decoction, contains two herbal drugs: Coptis chinensis Franch. and Evodia rutaecarpa (Juss.) Benth. in the ratio of 6:1 (w/w). Previous pharmacological studies have shown that two herbs in ZJP have the antagonistic effects on catecholamine secretion in bovine adrenal medullary cells. Furthermore, the alkaloids from the two herbs in ZJP may provide a protective effect for depression in individuals with a low expressing 5-HTT allele by increasing receptor concentration in serotonergic neurons. However, antidepressant effect has not been reported before and has not been fully clarified.

AIM OF THE STUDY

The present study aimed to investigate the antidepressant potential of ethanol extract from ZJP and its monoaminergic mechanism in mice.

MATERIALS AND METHODS

Seven alkaloids were determined from the ethanol extract of ZJP using High Performance Liquid Chromatography (HPLC) with the gradient mobile phase. The ethanol extract from ZJP was used to evaluate the antidepressant potential in mice. Mouse models of depression including the tail suspension test (TST) and the forced swim test (FST) were used to evaluate the effects of the ethanol extract from ZJP. A possible mechanism was explored in the tests of antagonism of reserpine-induced ptosis and hypothermia, and 5-HTP induced head twitch response in mice. The contents of monoamine neurotransmitters including norepinephrine (NE), serotonin (5-hydroxytryptamine or 5-HT) in hippocampus of mice and NE, 5-HT, dopamine (DA) in striatum of mice were determined by HPLC system with Electrochemical Detector (ECD).

RESULTS

The results showed that intragastric administration of the ethanol extract from ZJP (5, 10, 20mg/kg) or fluoxetine (7.5mg/kg) significantly reduced the duration of immobility in TST and FST. However, the effect was not dose-dependent. Ethanol extract from ZJP (5, 10, 20mg/kg) also increased the accumulative number of the 5-HTP-induced head twitch response in mice. The mice were treated with the ethanol extract from ZJP (5, 10, 20mg/kg) or fluoxetine (7.5mg/kg), which could antagonize reserpine-induced ptosis and hypothermia, moreover, both of them could elevate the contents of NE, 5-HT in hippocampus as well as NE, 5-HT, DA in striatum significantly.

CONCLUSION

These results indicate that the ethanol extract from ZJP produced antidepressant-like effect and the possible mechanism, at least in part, is via the central monoaminergic neurotransmitter system and 5-HT plays a major role.

[Interferon α therapy in patients with chronic hepatitis C infection: biopsychosocial consequences]

BACKGROUND

Interferon α (IFN-alpha) is widely used in the treatment of viral infections, including hepatitis C. Unfortunately depression is a common side effect of IFN-alpha therapy. The presence of depressive symptoms is important because they have an adverse effect on the course of the illness and reduce the quality of life and the treatment adherence. The current prospective study examines the effects of IFN-alpha on the development of depressive disorders, on cognitive functioning and on quality of life.

METHOD

A total of 25 patients with chronic hepatitis C infection were investigated. All patients were treated in the Department of Gastroenterology and Hepatology, University of Medicine of Graz, Austria. Psychometric observer rating and self-rating scales were administered 1 month and 3 months after the beginning of the antiviral treatment to evaluate depressive symptoms [Beck Depression Inventory (BDI); Hamilton Depression Scale]. The data on life satisfaction before therapy and health-related quality of life were obtained from the Fragebogen zur Lebenszufriedenheit (FLZ) and the SF-36 (Health Status Questionnaire). Cognitive function was based on the SKT (Syndrom Kurztest). All patients completed the Social Support Questionnaire (SSS), a multidimensional self-report measure of social support.

RESULTS

Three months after the initial IFN-alpha administration in the whole sample significant impairments in health-related quality of life were found in the health-related domains "physical functioning", "role physical", "role emotional", "social functioning" and "vitality". The whole sample showed cognitive impairments. No changes in social support were recorded. Three months after the first INF-alpha administration, 48% (n=12) of the sample suffered from moderate clinical depression. In comparison to patients without pathological affective findings, patients with INF-alpha-induced clinical depression showed decreased life satisfaction before the initial antiviral therapy. Impairments in health-related quality of life (SF-36) were found in the sample with clinical depression in the health-related domains "general health", "social functioning", "role emotional", "vitality" and "mental health".

CONCLUSION

Hepatitis C is associated with an increased prevalence of psychiatric disorders, particularly depression. INF-alpha patients having low levels of life satisfaction in the domains "self-concept" (skills, appearance, self-confidence, vitality …), "employment" and "physical health and constitution" seem to face a major risk of depression.

SwissSidechain: a molecular and structural database of non-natural sidechains

Amino acids form the building blocks of all proteins. Naturally occurring amino acids are restricted to a few tens of sidechains, even when considering post-translational modifications and rare amino acids such as selenocysteine and pyrrolysine. However, the potential chemical diversity of amino acid sidechains is nearly infinite. Exploiting this diversity by using non-natural sidechains to expand the building blocks of proteins and peptides has recently found widespread applications in biochemistry, protein engineering and drug design. Despite these applications, there is currently no unified online bioinformatics resource for non-natural sidechains. With the SwissSidechain database (http://www.swisssidechain.ch), we offer a central and curated platform about non-natural sidechains for researchers in biochemistry, medicinal chemistry, protein engineering and molecular modeling. SwissSidechain provides biophysical, structural and molecular data for hundreds of commercially available non-natural amino acid sidechains, both in l- and d-configurations. The database can be easily browsed by sidechain names, families or physico-chemical properties. We also provide plugins to seamlessly insert non-natural sidechains into peptides and proteins using molecular visualization software, as well as topologies and parameters compatible with molecular mechanics software.

Symptomatic treatment of interferon-α-induced depression in hepatitis C: a systematic review

Despite its efficacy in treating hepatitis C, interferon-α (IFN-α) can cause depression. The purpose of this systematic review is to summarize and discuss the available and effective therapies in treating IFN-α-induced depression. Using PubMed, The Cochrane Library, Scopus, Embase, Ovid of Medline, PsycINFO, and ISI Web of Knowledge, we selected 64 articles concerning IFN-α-induced depression treatment in hepatitis C patients. Selective serotonin reuptake inhibitors can be considered the first choice for the treatment of IFN-α-induced depression, as demonstrated in open-label studies, case reports, and a randomized, double-blind, placebo-controlled trial. Also 5-hydroxytryptophan and tryptophan have been suggested to be effective as monotherapy or as augmentation of selective serotonin reuptake inhibitors. Clinical cases that show positive effects of tricyclic antidepressants, however, do not provide sufficient evidence for the use of these drugs. Two cohort studies have reported the effectiveness of amisulpride, but not of levosulpiride. Mirtazapine has been suggested to be a better choice of treatment in cases where insomnia or anorexia develop. Milnacipram can be useful in cases of concomitant medications, for the unlikely occurrence of drug-drug interactions. Psychostimulants represent an empirical treatment without controlled data to support their use. Two case reports have shown the favorable use of bupropion, particularly if sexual dysfunction or cravings for illicit drugs are present. A single case report suggests electroconvulsive therapy to be a possible choice when antidepressants are ineffective or poorly tolerated. The main limitation of our review is that the quality of the findings varied across the reviewed studies. Our observations may help clinicians with managing IFN-α-induced depression.

Three cases of successful tryptophan add-on or monotherapy of hepatitis C and IFNalpha-associated mood disorders

BACKGROUND

Interferon-alpha (IFN(alpha))-associated mood disorder is a major complication of treatment for chronic hepatitis C.

METHOD

The authors report on three patients infected with chronic hepatitis C showing severe depressive symptoms during or after IFN(alpha) treatment. Because patients had lowered tryptophan blood levels and did not response to antidepressants, they received tryptophan up to a dosage of 1,000 mg/day as mono- or add-on treatment.

RESULTS

Tryptophan, used as augmentation or monotherapeutic treatment, led to a significant improvement of depressive symptoms in all three patients.

CONCLUSION

A tryptophan deficit seems to be involved in the pathophysiology of persistent mood changes during and after IFN(alpha) treatment.

Risk management of nutritional supplements in chronic illness: the implications for the care of cancer and depression

The use of complementary medicines in patients suffering from chronic illnesses such as cancer and depression is widely documented. Current studies suggest that the prevalence of the use of complementary medicines in patients with cancer ranges from 7% to 80%. In patients suffering from severe depression the use of complementary medicines may be >40%. The aim of the present review is to systematically explore the main dimensions that clinicians have to consider when advising patients suffering from these conditions. The Medline and Cochrane databases were searched for evidence relating to the benefits and risks of supplements in the treatment of cancer and depression, including the potential interactions with pharmaco- and radiotherapy. Supplements predominantly used by patients with cancer include vitamins A, C and E, β-carotene and ubiquinone 10. Supplements predominantly used by patients with depression include S-adenosylmethionine, l-tryptophan and 5-hydroxytryptophan and inositol. Supplements potentially used by both groups include n-3 fatty acids, Se and folic acid. Four dimensions are identified and discussed: effectiveness; safety; communication; medico-legal aspects. These dimensions have to be addressed in an illness- and case-specific context. This task can be complex given the emerging clinical evidence, patients' own preferences and expectations and current prescribing guidelines.

Sympathetic nervous system and neurotransmitters: their possible role in neuroimmunomodulation of multiple sclerosis and some other autoimmune diseases

Multiple sclerosis is still a disease without a cure. Although intensive research efforts have led to the development of drugs that modify the activity of the disease, most of them have various side effects and are expensive. At the same time it is becoming apparent that some remedies usually used to treat somatic and psychic disorders also have immunomodulating properties, and may help manage multiple sclerosis and other autoimmune diseases. We describe here the role of the sympathetic nervous system in the neuro-immune interaction in multiple sclerosis and other immune diseases with increased cellular immunity as well as neurochemical disturbances that take place in these disorders.

Interferon-induced depressive illness in hep C patients responds to SSRI antidepressant treatments

This paper examines the role of selective serotonin reuptake inhibitors (SSRIs) in the treatment of hepatitis-C virus (HCV) patients who have developed interferon-alpha induced depression. A 2-year data analysis of HCV psychiatric liaison clinic has been undertaken. The diagnosis, treatment, and progress of those patients who were treated with interferon-alpha (INF-alpha) are reported. 53 of the 78 patients enrolled at the HCV Clinic and treated with INF-alpha were referred for psychiatric consultation. Six patients developed major depressive illness following INF therapy. They were all treated with SSRIs and they made full recovery. This is a significant observation and is concordant with other studies. Its biochemical ramifications are presented. It is concluded that INF-induced depression is fully reversible. A hypothesis is proposed that SSRIs modulate the neuro-protective neurotoxic ratio by possibly inhibiting the indole-2,3-dioxygenase induction of the kynurenine pathway.

Serotonin a la carte: supplementation with the serotonin precursor 5-hydroxytryptophan

This paper reviews the preclinical and clinical evidence regarding the use of the dietary supplement 5-hydroxytryptophan (5-HTP) for the treatment of depression. In the absence of supplementation with exogenous 5-HTP, the amount of endogenous 5-HTP available for serotonin synthesis depends on the availability of tryptophan and on the activity of various enzymes, especially tryptophan hydroxylase, indoleamine 2,3-dioxygenase, and tryptophan 2,3-dioxygenase (TDO). Factors affecting each of these are reviewed. The amount of 5-HTP reaching the central nervous system (CNS) is affected by the extent to which 5-HTP is converted to serotonin in the periphery. This conversion is controlled by the enzyme amino acid decarboxylase, which, in the periphery, can be blocked by peripheral decarboxylase inhibitors (PDIs) such as carbidopa. Preclinical and clinical evidence for the efficacy of 5-HTP for depression is reviewed, with emphasis on double-blind, placebo-controlled (DB-PC) trials. Safety issues with 5-HTP are also reviewed, with emphasis on eosinophilia myalgia syndrome (EMS) and serotonin syndrome.