Light-Responsive Pt(IV) Prodrugs with Controlled Photoactivation and Low Dark Toxicity

Light-induced release of cisplatin from Pt(IV) prodrugs represents a promising approach for precise control over the antiproliferative activity of Pt-based chemotherapeutic drugs. This method has the potential to overcome crucial drawbacks of conventional cisplatin therapy, such as high general toxicity toward healthy organs and tissues. Herein, we report two Pt(IV) prodrugs with BODIPY-based photoactive ligands Pt-1 and Pt-2, which were designed using carbamate and triazole linkers, respectively. Both prodrugs demonstrated the ability to release cisplatin under blue light irradiation without the requirement of an external reducing agent. Dicarboxylated Pt-2 prodrug turned out to be more stable in the dark and more sensitive to light than its monocarbamate Pt-1 counterpart; these observations were explained using DFT calculations. The investigation of the photoreduction mechanism of Pt-1 and Pt-2 prodrugs using DFT modeling and ΔG0 PET estimation suggests that the photoinduced electron transfer from the singlet excited state of the BODIPY axial ligand to the Pt(IV) center is the key step in the light-induced release of cisplatin from the complexes. Cytotoxicity studies demonstrated that both prodrugs were nontoxic in the dark and toxic to MCF-7 cells under low-dose irradiation with blue light, and the observed effect was solely due to the cisplatin release from the Pt(IV) prodrugs. Our research presents an elegant synthetic approach to light-activated Pt(IV) prodrugs and presents findings that may contribute to the future rational design of photoactivatable Pt(IV) prodrugs.

The role of biogenic amines in the modulation of monocytes in autoimmune neuroinflammation

Multiple sclerosis (MS) is inflammatory demyelinating and neurodegenerative disease of the central nervous system (CNS) with autoimmune mechanism of development. The study of the neuroimmune interactions is one of the most developing directions in the research of the pathogenesis of MS. The influence of biogenic amines on the pathogenesis of experimental autoimmune encephalomyelitis (EAE) and MS was shown by the modulation of subsets of T-helper cells and B-cells, which plays a crucial role in the autoimmunity of the CNS. However, along with T- and B-cells the critical involvement of mononuclear phagocytes such as dendritic cells, macrophages, and monocytes in the development of neuroinflammation also was shown. It was demonstrated that the activation of microglial cells (resident macrophages of the CNS) could initiate the neuroinflammation in the EAE, suggesting their role at an early stage of the disease. In contrast, monocytes, which migrate from the periphery into the CNS through the blood-brain barrier, mediate the effector phase of the disease and cause neurological disability in EAE. In addition, the clinical efficacy of the therapy with depletion of the monocytes in EAE was shown, suggesting their crucial role in the autoimmunity of the CNS. Biogenic amines, such as epinephrine, norepinephrine, dopamine, and serotonin are direct mediators of the neuroimmune interaction and may affect the pathogenesis of EAE and MS by modulating the immune cell activity and cytokine production. The anti-inflammatory effect of targeting the biogenic amines receptors on the pathogenesis of EAE and MS by suppression of Th17- and Th1-cells, which are critical for the CNS autoimmunity, was shown. However, the latest data showed the potential ability of biogenic amines to affect the functions of the mononuclear phagocytes and their involvement in the modulation of neuroinflammation. This article reviews the literature data on the role of monocytes in the pathogenesis of EAE and MS. The data on the effect of targeting of biogenic amine receptors on the function of monocytes are presented.

Th17-cells in depression: Implication in multiple sclerosis

Depression is one of the most common neuropsychological symptoms of multiple sclerosis. However, in addition to mood disorder, depression can also influence on multiple sclerosis course. The mechanism of this dependence is not fully understood. The recent studies suggest the possible common immune mechanisms in the pathogenesis of depression and multiple sclerosis. In particular, it was shown that along with biogenic amines disturbance, neuroinflammation also play an important role in the pathogenesis of depression. Significant attention is drawn to Th17-cells subsets, which are considered as critical players in the pathogenesis of inflammatory diseases of the central nervous system, including multiple sclerosis. This brief report reviews the literature data on the role of neuroinflammation in the reciprocal influence of multiple sclerosis and depression with focus on Th17-cells, which may underlie pathogenetic mechanisms of both this diseases.

Serotonergic drug repurposing in multiple sclerosis: A new possibility for disease-modifying therapy

Investigation of neuroimmune interactions is one of the most developing areas in the study of multiple sclerosis pathogenesis. Recent evidence suggests the possibility of modulating neuroinflammation by targeting biogenic amine receptors. It has been shown that selective serotonin reuptake inhibitor fluoxetine modulates innate and adaptive immune system cells' function and can reduce experimental autoimmune encephalomyelitis and multiple sclerosis severity. This brief report discusses the immune mechanisms underlying the multiple sclerosis pathogenesis and the influence of fluoxetine on them. The retrospective data on the impact of fluoxetine treatment on the course of multiple sclerosis are also presented. The results of this and other studies suggest that fluoxetine could be considered an additional therapy to the standard first-line disease-modifying treatment for relapsing–remitting multiple sclerosis.

The Role of D2-like Dopaminergic Receptor in Dopamine-mediated Modulation of Th17-cells in Multiple Sclerosis

BACKGROUND

Dopamine is one of the main mediators capable regulate the neuroimmune interaction and is involved in multiple sclerosis (MS) pathogenesis.

OBJECTIVE

The aim of this study was to clarify the role of dopamine and its receptors in modulation of Th17-cells in MS.

METHODS

34 relapsing-remitting MS patients and 23 healthy subjects were examined. To assess the effect of dopamine on Th17-cells, CD4+ T-cells were cultured in the presence of dopamine and antagonist or agonist of D₁- or D₂-like dopaminergic receptors and stimulated with anti-CD3/CD28- microbeads. The levels of cytokines in supernatants were assessed by ELISA.

RESULTS

Production of interleukin-17 (IL-17), interferon-γ (IFN-γ), granulocyte-colony stimulating factor (GM-CSF), and IL-21 by CD4+ T-cells as well as dopamine were comparable between the groups. Dopamine suppressed cytokine secretion by activated СD4+ T-cells in both groups. Blockade of D1-like dopaminergic receptor with a specific antagonist SCH23390 did not affect dopaminemediated cytokine suppression. In contrast, blockade of D₂-like dopaminergic receptor by sulpiride decreased dopamine's inhibitory effect on IL-17 secretion in both groups and GM-CSF and IL-21 production in MS patients. Blockade of D₁-like dopaminergic receptor directly inhibited IL-17, IFN- γ, GM-CSF in both groups and IL-21 production in healthy subjects, while blockade of D₂-like dopaminergic receptor had no effect on cytokine secretion. Finally, activation of D₂-like dopaminergic receptor with a specific agonist quinpirole decreased cytokine production in both groups.

CONCLUSION

These data suggest an inhibitory role of dopamine on Th17-cells in MS, which could be mediated by the activation of the D₂-like dopaminergic receptor.

Survey of diagnostic and treatment practices for multiple sclerosis in Russian Federation in comparison to European data

INTRODUCTION

The data of the survey of European (EU) neurologists on the methods of diagnosis and treatment of multiple sclerosis in Europe were compared with the data of the similar survey of neurologists of the Russian Federation (RF).

METHOD

Seventy-five neurologists specialized in MS from RF completed questionnaires on radiologically isolated syndrome (RIS), clinically isolated syndrome (CIS), relapsing-remitting (RRMS), secondary progressive (SPMS), and primary progressive (PPMS) multiple sclerosis.

RESULTS

In the case of RIS, only 46% of neurologists from the RF recommended CSF analysis for oligoclonal IgG and only 54.3% performed magnetic resonance imaging (MRI) of the spinal cord, which is significantly lower than in the EU (78% and 80%, respectively). In the case of CIS, significantly more neurologists from the Russian Federation would have tested for antibodies to disorders of the optical spectrum of neuromyelitis (57% in the EU and 94% in the RF). In case of typical RRMS, more neurologists from the RF preferred to start with the second line of disease-modifying therapy (DMT), a lower percentage would choose dimethyl fumarate as the first line DMT (9% in the RF and 25% in the EU). In case of escalating therapy, the majority of EU respondents (68%) indicated that one relapse would be sufficient (only 28% in RF), while in RF, 58% indicated that two relapses would be sufficient (22% in EU). Fewer neurologists from RF would use fingolimod, natalizumab or mitoxantrone for SPMS. 91% of neurologists in RF would like to prescribe ocrelizumab for PPMS.

CONCLUSION

MS specialists from RF are less active in monitoring RIS than MS specialists from EU. CIS is not indication to use any DMT in RF. MS specialists in RF are more conservative in changing DMT as escalation in cases with breakthrough RRMS. The products without indication to be used in SPMS are rarely prescribed in RF in comparison to EU. Most cases of PPMS in RF would be treated with ocrelizumab.

Dopaminergic Receptor Targeting in Multiple Sclerosis: Is There Therapeutic Potential?

Dopamine is a neurotransmitter that mediates neuropsychological functions of the central nervous system (CNS). Recent studies have shown the modulatory effect of dopamine on the cells of innate and adaptive immune systems, including Th17 cells, which play a critical role in inflammatory diseases of the CNS. This article reviews the literature data on the role of dopamine in the regulation of neuroinflammation in multiple sclerosis (MS). The influence of dopaminergic receptor targeting on experimental autoimmune encephalomyelitis (EAE) and MS pathogenesis, as well as the therapeutic potential of dopaminergic drugs as add-on pathogenetic therapy of MS, is discussed.

The role of 5-HT2B-receptors in fluoxetine-mediated modulation of Th17- and Th1-cells in multiple sclerosis

Fluoxetine is a selective serotonin reuptake inhibitor, which also has an immunomodulatory effect. We investigated the effects of fluoxetine and serotonin (5-HT) on the pro-inflammatory Th17- and Th1-cells in 30 patients with relapsing-remitting MS and 20 healthy subjects. Fluoxetine and 5-HT suppressed IL-17, IFN-γ and GM-CSF production by stimulated СD4⁺ T-cells in both groups. Blockade of 5-HT_2B-receptors decreased the inhibitory effect of fluoxetine on cytokine production in MS patients. Finally, 5-HT_2B-receptor activation inhibits IL-17, IFN-γ and GM-CSF production in both groups. These data suggest an anti-inflammatory role for fluoxetine in MS, which could be mediated by the activation of 5-HT_2B-receptors.

Serotoninergic system targeting in multiple sclerosis: the prospective for pathogenetic therapy

Serotonin (5-hydroxytryptamine) (5-HT) is a neurotransmitter, which mediates neuropsychological functions of the central nervous system (CNS). Recent studies have shown the modulatory effect of 5-HT on gut microbiota functions, which play an essential role in developing CNS inflammatory diseases. Finally, 5-HT is a direct mediator of neuroimmune interaction. The article reviews the literature data on the role of 5-HT in the regulation of neuroinflammation in multiple sclerosis (MS). The influence of 5-HT and selective serotonin reuptake inhibitors (SSRIs) on experimental autoimmune encephalomyelitis (EAE) and MS pathogenesis, as well as the therapeutic potential of serotoninergic drugs as a pathogenetic therapy of MS, are discussed.

The influence of glatiramer acetate on Th17-immune response in multiple sclerosis

Glatiramer acetate (GA) is approved for the treatment of multiple sclerosis (MS). However, the mechanism of action of GA in MS is still unclear. In particular, it is not known whether GA can modulate the pro-inflammatory Th17-type immune response in MS. We investigated the effects of original GA (Copaxone^®, Teva, Israel) and generic GA (Timexone^®, Biocad, Russia) on Th17- and Th1-type cytokine production in vitro in 25 patients with relapsing-remitting MS and 25 healthy subjects. Both original and generic GA at concentrations 50–200 μg/ml dose-dependently inhibited interleukin-17 and interferon-γ production by anti-CD3/anti-CD28-activated peripheral blood mononuclear cells from MS patients and healthy subjects. This effect of GA was reproduced using purified CD4⁺ T cells, suggesting that GA can directly modulate the functions of Th17 and Th1 cells. At high concentrations (100–200 μg/ml), GA also suppressed the production of Th17-differentiation cytokines (interleukin-1β and interleukin-6) by lipopolysaccharide (LPS)-activated dendritic cells (DCs). These GA/LPS-treated DCs induced lower interleukin-17 and interferon-γ production by autologous CD4⁺ T cells compared to LPS-treated DCs. These data suggest that GA can inhibit Th17-immune response and that this inhibitory effect is preferentially exercised by direct influence of GA on T cells. We also demonstrate a comparable ability of original and generic GA to modulate pro-inflammatory cytokine production.

Hyperhomocysteinemia and Endothelial Dysfunction in Multiple Sclerosis

Endothelial dysfunction is recognized as one of the leading factors in the pathogenesis of diseases of the central nervous system of various etiologies. Numerous studies have shown the role of hyperhomocysteinemia in the development of endothelial dysfunction and the prothrombogenic state. The most important condition in the development of multiple sclerosis (MS) is a dysregulation of the blood-brain barrier (BBB) and transendothelial leukocyte migration. It has been proven that homocysteine also contributes to the damage of neurons by the mechanism of excitotoxicity and the induction of the apoptosis of neurons. These processes can be one of the factors of neurodegenerative brain damage, which plays a leading role in the progression of MS. This review describes the pleiotropic effect of homocysteine on these processes and its role in MS pathogenesis.

Prevalence and Incidence of Multiple Sclerosis in Russian Federation: 30 Years of Studies

In the Russian Federation, multiple sclerosis prevalence rates vary from 10 to 80 cases per 100,000, depending on region and the nationality of the population. The main characteristics of multiple sclerosis epidemiology in the XX century in this big territory are: (1) steady increase in multiple sclerosis prevalence and incidence rates, maybe because of better diagnosis and treatment, but also changes in environmental/epigenetic risk profile and/or lifestyle factors; (2) increase of the female to male ratio, increase in multiple sclerosis incidence mainly in females; (3) appearance and increasing frequency of multiple sclerosis in ethnic groups, previously free of multiple sclerosis (Northern Tribes, Yakuts and others). The latest data show that in European Russia, the multiple sclerosis prevalence varies from 30 to 80 cases, in Siberia-from 20 to 70 cases, with steady increases, especially in women.

Ring Opening of Donor–Acceptor Cyclopropanes with N-Nucleo­philes

Ring opening of donor–acceptor cyclopropanes with various N-nucleophiles provides a simple approach to 1,3-functionalized compounds that are useful building blocks in organic synthesis, especially in assembling various N-heterocycles, including natural products. In this review, ring-opening reactions of donor–acceptor cyclopropanes with amines, amides, hydrazines, N-heterocycles, nitriles, and the azide ion are summarized.

1 Introduction

2 Ring Opening with Amines

3 Ring Opening with Amines Accompanied by Secondary Processes Involving the N-Center

3.1 Reactions of Cyclopropane-1,1-diesters with Primary and Secondary Amines

3.1.1 Synthesis of γ-Lactams

3.1.2 Synthesis of Pyrroloisoxazolidines and -pyrazolidines

3.1.3 Synthesis of Piperidines

3.1.4 Synthesis of Azetidine and Quinoline Derivatives

3.2 Reactions of Ketocyclopropanes with Primary Amines: Synthesis of Pyrrole Derivatives

3.3 Reactions of Сyclopropane-1,1-dicarbonitriles with Primary Amines: Synthesis of Pyrrole Derivatives

4 Ring Opening with Tertiary Aliphatic Amines

5 Ring Opening with Amides

6 Ring Opening with Hydrazines

7 Ring Opening with N-Heteroaromatic Compounds

7.1 Ring Opening with Pyridines

7.2 Ring Opening with Indoles

7.3 Ring Opening with Di- and Triazoles

7.4 Ring Opening with Pyrimidines

8 Ring Opening with Nitriles (Ritter Reaction)

9 Ring Opening with the Azide Ion

10 Summary

The role of dopamine in modulation of Th-17 immune response in multiple sclerosis

Neuromediators may modulate neuroinflammation, particularly in multiple sclerosis (MS). We investigated the effects of dopamine (DA) on the pro-inflammatory Th17-branch of immunity in 43 patients with relapsing-remitting MS and 20 healthy subjects. Serum DA was lower in MS relapse, whereas percentages of blood CD4(+)CD26(+)CD161(+)CD196(+) Th17-cells and production of interleukin-17 (IL-17) and interferon-gamma by anti-CD3/anti-CD28-stimulated peripheral blood mononuclear cells (PBMC) were higher in MS relapse than in remission or healthy subjects. DA suppressed IL-17 production by PBMC from MS patients and healthy subjects. The suppressive effect of DA was abolished in the presence of an antagonist of D2-like receptors (sulpiride). These data suggest an anti-inflammatory role for DA in MS.

The Role of Biogenic Amines in the Regulation of Interaction between the Immune and Nervous Systems in Multiple Sclerosis

OBJECTIVE

Multiple sclerosis (MS) is a demyelinating, presumably autoimmune disease of the central nervous system. Biogenic amines may participate in MS pathogenesis modulating immune cell activity and cytokine production.

METHODS

Forty-three patients with relapsing-remitting MS were examined. Serotonin (SE), norepinephrine (NE) and epinephrine (EPI) concentrations in sera were measured by ELISA. The functional activity of Th17 and Th1 cells was assessed by the ability of peripheral blood mononuclear cells (PBMCs) to produce interferon-gamma (IFN-γ) and interleukin-17 (IL-17) and cell proliferation upon stimulation with microbeads coated with anti-CD3 and anti-CD28 antibodies. To evaluate the effect of biogenic amines on Th17 and Th1 cells, PBMCs were cultured in the presence of SE and NE. Statistical analysis was performed using Prism 6 software.

RESULTS

Concentrations of SE and EPI in sera were not different between the groups. Concentrations of NE in sera from MS patients were lower than those in the healthy control group. The production of IL-17 and IFN-γ in MS patients in relapse was higher than that in patients in remission or in the control group. SE at a concentration of 10-4M suppressed IL-17 production. NE at a concentration of 10-4M suppressed both IL-17 and IFN-γ production.

CONCLUSIONS

These data suggest an anti-inflammatory role for biogenic amines in MS.

Matrix isolation of intermediates on the activated silica surface: mechanisms and efficiencies of photochemical reactions of peroxy radicals

The technique of matrix isolation on the activated silica surface for the study of mechanisms and determination of efficiencies of photochemical reactions of alkylperoxy radicals has been used. The direct experimental evidence for photochemical dissociation of peroxy radicals via two parallel pathways by the rupture of O-O and C-O bonds under light of wavelength 313 nm has been obtained. It has been found that activated silica surface is not "inert" support in studies of transformations of surface-grafted peroxy radicals.