Microbiome and Prostate Cancer: A Novel Target for Prevention and Treatment.

Growing evidence of the microbiome's role in human health and disease has emerged since the creation of the Human Microbiome Project. Recent studies suggest that alterations in microbiota composition (dysbiosis) may play an essential role in the occurrence, development, and prognosis of prostate cancer (PCa), which remains the second most frequent male malignancy worldwide. Current advances in biological technologies, such as high-throughput sequencing, transcriptomics, and metabolomics, have enabled research on the gut, urinary, and intra-prostate microbiome signature and the correlation with local and systemic inflammation, host immunity response, and PCa progression. Several microbial species and their metabolites facilitate PCa insurgence through genotoxin-mediated mutagenesis or by driving tumor-promoting inflammation and dysfunctional immunosurveillance. However, the impact of the microbiome on PCa development, progression, and response to treatment is complex and needs to be fully understood. This review addresses the current knowledge on the host-microbe interaction and the risk of PCa, providing novel insights into the intraprostatic, gut, and urinary microbiome mechanisms leading to PCa carcinogenesis and treatment response. In this paper, we provide a detailed overview of diet changes, gut microbiome, and emerging therapeutic approaches related to the microbiome and PCa. Further investigation on the prostate-related microbiome and large-scale clinical trials testing the efficacy of microbiota modulation approaches may improve patient outcomes while fulfilling the literature gap of microbial-immune-cancer-cell mechanistic interactions.

Tumor Antigenicity and a Pre-Existing Adaptive Immune Response in Advanced BRAF Mutant Colorectal Cancers.

The main hypothesis of this study is that gene expression profiles (GEPs) integrating both tumor antigenicity and a pre-existing adaptive immune response can be used to generate distinct immune-related signatures of BRAF mutant colorectal cancers (BRAF-CRCs) to identify actionable biomarkers predicting response to immunotherapy. GEPs of 89 immunotherapy-naïve BRAF-CRCs were generated using the Pan-Cancer IO 360 gene expression panel and the NanoString nCounter platform and were correlated with microsatellite instability (MSI) status and with CD8+ tumor-infiltrating lymphocyte (TIL) content. Hot/inflamed profiles were found in 52% of all cases, and high scores of Tumor Inflammation Signature were observed in 42% of the metastatic BRAF-CRCs. A subset of MSI tumors showed a cold profile. Antigen Processing Machinery (APM) signature was not differentially expressed in MSI tumors compared with MSS cases. By contrast, the APM signature was significantly upregulated in CD8+ BRAF-CRCs versus CD8- tumors. Our study demonstrates that a significant fraction of BRAF-CRCs may be a candidate for immunotherapy and that the simultaneous analysis of MSI status and CD8+ TIL content increases accuracy in identifying patients who can potentially benefit from immune checkpoint inhibitors. GEPs may be very useful in expanding the spectrum of patients with BRAF-CRCs who can benefit from immune checkpoint blockade.

BRCA Methylation Testing Identifies a Subset of Ovarian Carcinomas without Germline Variants That Can Benefit from PARP Inhibitor.

Homologous Recombination Deficiency (HRD) is a frequent feature of high-grade epithelial ovarian carcinoma (EOC), associated with sensitivity to PARP-inhibitors (PARPi). The best characterized causes of HRD in EOCs are germline or somatic mutations in BRCA1 and BRCA2 genes. Although promoter methylation is a well-known mechanism of gene transcriptional repression, few data have been published about BRCA gene methylation in EOCs. In this retrospective study, we quantitatively analyzed by pyrosequencing a selected series of 90 formalin-fixed (FFPE) primary EOCs without BRCA germline mutations. We identified 20/88 (22.7%) EOCs showing BRCA promoter methylation, including 17/88 (19.3%) in BRCA1 and 4/86 (4.6%) in BRCA2 promoters, one of which showing concomitant BRCA1 methylation. Mean methylation levels were 49.6% and 45.8% for BRCA1 and BRCA2, respectively, with methylation levels ≥50% in 10/20 methylated EOCs. Constitutive BRCA methylation was excluded by testing blood-derived DNA. In conclusion, pyrosequencing methylation analysis of BRCA genes is a robust, quantitative and sensitive assay applicable to FFPE samples. Remarkably, a considerable subset of germline BRCA-negative EOCs showed somatic methylation and, likely, HRD. A subpopulation of women with BRCA methylation, even without BRCA mutations, could potentially benefit from PARP-inhibitors; further clinical studies are needed to clarify the predictive role of somatic BRCA methylation of PARP-therapy response.

Improved solubility and increased biological activity of NeoSol™RCL40, a novel Red Clover Isoflavone Aglycones extract preparation.

Red clover (Trifolium pratense L., Fabaceae; RCL), a perennial plant rich in isoflavones, is a natural alternative for menopausal symptoms, as well as antiaging and antioxidant. Isoflavone preparations usually contain aglycones and ß-glycosides. Aglycones, the active moieties, are absorbed slowly and unevenly due to reduced water solubility and biotransformation from ß-glycosides. NeoSol™RCL40 is a novel RCL isoflavone aglycones preparation based on active solubilization technologies. In the present study, NeoSol™RCL40 was shown to induce solubilization of isoflavones and to increase estrogenic and antioxidative effects in comparison to a standard RCL extract (RCLE). NeoSol™RCL40 was prepared from RCLE using as host molecules either 2-pyrrolidone, 1-ethenyl homopolymer (PVP), γ-cyclodextrin, or maltodextrin. Solubilisation assays, performed by means of HPLC-UV, showed that solubilization of isoflavone aglycones was highest with RCLE processed with PVP, which was therefore selected for functional assays. In comparison to RCLE, NeoSol™RCL40 containing the same amount of isoflavone aglycones displayed 3.4 times higher estrogenicity in MCF-7 cell, 1.9-2.0 higher antioxidant activity in the DPPH and in the FRAP assay, and was cytoprotective in PC12 cells. As a whole, results support the ability of NeoSol™RCL40 to promote isoflavones solubilization leading to increased biological activity. NeoSol™RCL40 is therefore an interesting novel preparation providing improved availability of active isoflavones aglycones.

Parkinson's disease patients have a complex phenotypic and functional Th1 bias: cross-sectional studies of CD4+ Th1/Th2/T17 and Treg in drug-naïve and drug-treated patients.

BACKGROUND: Parkinson's disease (PD) affects an estimated 7 to 10 million people worldwide, and only symptomatic treatments are presently available to relieve the consequences of brain dopaminergic neurons loss. Neuronal degeneration in PD is the consequence of neuroinflammation in turn influenced by peripheral adaptive immunity, with CD4+ T lymphocytes playing a key role. CD4+ T cells may however acquire proinflammatory phenotypes, such as T helper (Th) 1 and Th17, as well as anti-inflammatory phenotypes, such as Th2 and the T regulatory (Treg) one, and to what extent the different CD4+ T cell subsets are imbalanced and their functions dysregulated in PD remains largely an unresolved issue. METHODS: We performed two cross-sectional studies in antiparkinson drug-treated and drug-naïve PD patients, and in age- and sex-matched healthy subjects. In the first one, we examined circulating Th1, Th2, Th17, and in the second one circulating Treg. Number and frequency of CD4+ T cell subsets in peripheral blood were assessed by flow cytometry and their functions were studied in ex vivo assays. In both studies, complete clinical assessment, blood count and lineage-specific transcription factors mRNA levels in CD4+ T cells were independently assessed and thereafter compared for their consistency. RESULTS: PD patients have reduced circulating CD4+ T lymphocytes, due to reduced Th2, Th17, and Treg. Naïve CD4+ T cells from peripheral blood of PD patients preferentially differentiate towards the Th1 lineage. Production of interferon-γ and tumor necrosis factor-α by CD4+ T cells from PD patients is increased and maintained in the presence of homologous Treg. This Th1-biased immune signature occurs in both drug-naïve patients and in patients on dopaminergic drugs, suggesting that current antiparkinson drugs do not affect peripheral adaptive immunity. CONCLUSIONS: The complex phenotypic and functional profile of CD4+ T cell subsets in PD patients strengthen the evidence that peripheral adaptive immunity is involved in PD, and represents a target for the preclinical and clinical assessment of novel immunomodulating therapeutics.

ß2 -Adrenoceptors inhibit neutrophil extracellular traps in human polymorphonuclear leukocytes.

This study tests the hypothesis that in isolated human polymorphonuclear leukocytes (PMN) adrenergic ligands can affect neutrophil extracellular trap (NET) formation. We have previously shown that, in PMN, adrenaline (A), through the activation of adrenergic receptors (AR), reduces stimulus-dependent cell activation; we have, therefore, planned to investigate if AR are involved in NET production. PMN were obtained from venous blood of healthy subject. The ability of adrenergic ligands to affect reactive oxygen species (ROS) production, NET production, and cell migration was investigated in cells cultured under resting conditions or after activation with N-formyl-methionyl-leucyl-phenylalanine (fMLP), LPS, or IL-8. Stimuli-induced NET production measured as ROS, microscopic evaluation, and elastase production was reverted by A and this effect was blocked by the selective ß2 -AR antagonist ICI-118,551. The stimulus-induced ROS generation and migration was prevented by A and by isoprenaline (ISO), and these effects were counteracted only by ICI-118,551 and not by the other two selective ligands for the ß1 and ß3 -AR. Finally, the presence of the ß-ARs on PMN was confirmed, by means of microscopy and flow cytometry. The data of the present study suggest that adrenergic compounds, through the interaction of mainly ß2 -AR, are able to affect neutrophil functions. These data are suggestive of a possible therapeutic role of ß2 -AR ligands (in addition to their classical use), promoting the possible therapeutic relevance of adrenergic system in the modulation of innate immunity proposing their possible use as anti-inflammatory drugs.

Dataset of mRNA levels for dopaminergic receptors, adrenoceptors and tyrosine hydroxylase in lymphocytes from subjects with clinically isolated syndromes.

This data article presents a dataset of mRNA levels for dopaminergic receptors, adrenoceptors and for tyrosine hydoxylase, the rate-limiting enzyme in the synthesis of catecholamines, in peripheral blood mononuclear cells as well as in CD4+ T effector and regulatory cells from subjects with clinically isolated syndromes (CIS), which is a first episode of neurological disturbance(s) suggestive of multiple sclerosis. CIS subjects are divided into two groups according to their eventual progression, after 12 months from CIS, to clinically established multiple sclerosis. The data reported are related to the article entitled "Dopaminergic receptors and adrenoceptors in circulating lymphocytes as putative biomarkers for the early onset and progression of multiple sclerosis" (M. Cosentino, M. Zaffaroni, M. Legnaro, R. Bombelli, L. Schembri, D. Baroncini, A. Bianchi, R. Clerici, M. Guidotti, P. Banfi, G. Bono, F. Marino, 2016) [1].

Dopaminergic Receptors on CD4+ T Naive and Memory Lymphocytes Correlate with Motor Impairment in Patients with Parkinson's Disease.

Parkinson's disease (PD) is characterized by loss of dopaminergic neurons in substantia nigra pars compacta, α-synuclein (α-syn)-rich intraneuronal inclusions (Lewy bodies), and microglial activation. Emerging evidence suggests that CD4+ T lymphocytes contribute to neuroinflammation in PD. Since the mainstay of PD treatment is dopaminergic substitution therapy and dopamine is an established transmitter connecting nervous and immune systems, we examined CD4+ T naive and memory lymphocytes in PD patients and in healthy subjects (HS), with specific regard to dopaminergic receptor (DR) expression. In addition, the in vitro effects of α-syn were assessed on CD4+ T naive and memory cells. Results showed extensive association between DR expression in T lymphocytes and motor dysfunction, as assessed by UPDRS Part III score. In total and CD4+ T naive cells expression of D1-like DR decrease, while in T memory cells D2-like DR increase with increasing score. In vitro, α-syn increased CD4+ T memory cells, possibly to a different extent in PD patients and in HS, and affected DR expression with cell subset-specific patterns. The present results support the involvement of peripheral adaptive immunity in PD, and may contribute to develop novel immunotherapies for PD, as well as to better use of current dopaminergic antiparkinson drugs.

Dopaminergic receptors and adrenoceptors in circulating lymphocytes as putative biomarkers for the early onset and progression of multiple sclerosis.

Clinically isolated syndrome (CIS) is a first, usually recovering, episode of neurological disturbance(s) suggestive of multiple sclerosis (MS). CIS subjects might benefit from early disease-modifying drugs, provided that those at high risk of developing MS can be identified. Gene expression for dopaminergic receptors (DR) and adrenoceptors (AR) is dysregulated in lymphocytes of MS patients and is affected by treatment with interferon (IFN)-ß. In particular, lymphocyte DR D5 mRNA might be a marker of IFN-ß response in MS patients. No information exists so far in CIS subjects. We investigated DR and AR gene expression in peripheral blood mononuclear cells (PBMC) and in CD4+ T effector (Teff) and regulatory (Treg) cells from CIS subjects, and assessed their relationship with MS progression after 12months. Expression of several DR and AR are upregulated in PBMC, Teff and Treg from CIS subjects. DR D3 and α2A-AR mRNA in PBMC, and DR D5 mRNA in Treg correlate with the risk of MS at 12months. Results show the involvement of dopaminergic and adrenergic pathways in CIS as well as in MS pathogenesis, supporting the evaluation of dopaminergic and adrenergic agents in MS.

Adrenergic modulation of migration, CD11b and CD18 expression, ROS and interleukin-8 production by human polymorphonuclear leukocytes.

OBJECTIVES: Adrenergic modulation of immunity has been extensively characterized, however, few information exist regarding polymorphonuclear leukocytes (PMN), despite their key role in immunity and inflammation. We investigated the effect of adrenergic agents on human PMN migration, CD11b and CD18 expression, reactive oxygen species (ROS) and interleukin (IL)-8 production, and on adrenoceptor (AR) expression. METHODS: Migration was measured by the Boyden chamber assay, CD11b/CD18 expression was assessed by flow cytometry, intracellular ROS were detected by spectrofluorimetry, and IL-8 was quantitated by standard ELISA assay. AR mRNA levels were measured by real-time PCR and PMN morphology was studied by scanning electron microscopy. RESULTS: Adrenaline(A), noradrenaline and the ß-AR agonist isoprenaline reduced N-formyl-Met-Leu-Phe (fMLP)-induced migration, CD11b/CD18 expression, and ROS production, without affecting IL-8. The effect of A on CD11b was antagonized by yohimbine and propranolol, and increased by prazosin. The effect on ROS production was completely abolished by propranolol. PMN expressed α(1A)-, α(1B)-, α(1D)-, α(2A)-, α(2C)-, ß(1)-, ß(2)-, and ß(3)-AR mRNA. A prevented fMLP-induced morphological changes of PMN. CONCLUSIONS: Adrenergic agents reduced PMN responses mainly through ß-AR, although α-AR may contribute at least to CD11b expression. AR-operated pathways in PMN should be investigated in disease conditions and in the response to therapeutic agents.

Increased expression of dopamine receptors in synovial fibroblasts from patients with rheumatoid arthritis: inhibitory effects of dopamine on interleukin-8 and interleukin-6.

OBJECTIVE: Observations in both animal models of arthritis and patients with rheumatoid arthritis (RA) suggest a role for dopamine and its receptors in RA. Because synovial fibroblasts (SFs) contribute to inflammation and joint destruction in RA, the aim of this study was to investigate dopaminergic pathways in SFs obtained from patients with RA and, for comparison, in SFs from patients with osteoarthritis (OA) undergoing knee joint replacement surgery. METHODS: The expression of all dopamine receptors (D1 -D5 ) and dopamine transporter was assessed by immunofluorescence and immunohistochemical staining. The levels of dopamine receptor and tyrosine hydroxylase messenger RNA were measured by real-time polymerase chain reaction. The intracellular content of dopamine, its precursor, and its main metabolites was assayed by high-performance liquid chromatography. The influence of dopamine on proinflammatory interleukin-6 (IL-6) and IL-8, matrix metalloproteinase 3, and tissue inhibitor of metalloproteinases 1 (TIMP-1) and TIMP-2 was studied in SFs. RESULTS: SFs possess an intrinsic dopaminergic system, including dopamine receptors, dopamine transporter, and tyrosine hydroxylase, and contain dopamine, its precursor, and its main metabolites. SFs from patients with RA, in comparison with those from patients with OA, showed increased expression of dopamine receptors D1 and D5 , and exogenous dopamine strongly inhibited the production of IL-8 in patients with RA. CONCLUSION: SFs from patients with RA and patients with OA show a dopaminergic phenotype. The expression of D1-like dopamine receptors was higher in RASFs, and this increased expression may lead to antiinflammatory effects, as demonstrated by the expression of IL-8. Studies in animal models and patients with RA are needed to assess the therapeutic potential of endogenous, local production of dopamine in synoviocytes.

The essential oil of bergamot stimulates reactive oxygen species production in human polymorphonuclear leukocytes.

Bergamot (Citrus aurantium L. subsp. bergamia) essential oil (BEO) is used in folk medicine as an antiseptic and anthelminthic and to facilitate wound healing. Evidence indicates that BEO has substantial antimicrobial activity; however its effects on immunity have never been examined. We studied the effects of BEO on reactive oxygen species (ROS) production in human polymorphonuclear leukocytes (PMN) and the role of Ca(2+) in the functional responses evoked by BEO in these cells. Results show that BEO increased intracellular ROS production in human PMN, an effect that required the contribution of extracellular (and, to a lesser extent, of intracellular) Ca(2+) . Bergamot essential oil also significantly increased ROS production induced by the chemotactic peptide N-formyl-Met-Leu-Phe and reduced the response to the protein kinase C activator phorbol myristate acetate. In conclusion, this is the first report showing the ability of BEO to increase ROS production in human PMN. This effect could both contribute to the activity of BEO in infections and in tissue healing as well as underlie an intrinsic proinflammatory potential. The relevance of these findings for the clinical uses of BEO needs careful consideration.

Dopaminergic modulation of CD4+CD25(high) regulatory T lymphocytes in multiple sclerosis patients during interferon-ß therapy.

OBJECTIVE: We investigated dopaminergic inhibition of CD4+CD25(high) regulatory T lymphocytes (Treg) in relapsing-remitting multiple sclerosis (MS) patients treated with interferon (IFN)-ß. METHODS: MS patients were prospectively studied at baseline and during 1 year of IFN-ß, and compared with healthy controls (HCs). Treg were separated by immunomagnetic sorting and the effect of dopamine (DA) on Treg was assessed in coculture experiments with homologous effector T lymphocytes (Teff). Tyrosine hydroxylase (TH), dopaminergic receptors (DR) D3 and D5, and forkhead box protein P3 (FoxP3) mRNA were assessed by real-time PCR. Circulating CD4+ T cell subsets were assessed by flow cytometry. RESULTS: In coculture experiments, Treg inhibition of Teff proliferation was reduced by DA in HCs and completely abolished in MS patients at baseline. However, in patients after 12 months of IFN-ß, Teff proliferation was impaired and DA had no more effect on Treg. In comparison to cells from HCs, Treg from MS patients at baseline had increased mRNA for DR D5 and TH (but not for DR D3). During treatment with IFN-ß, both DR D5 and TH mRNA decreased down to values lower than those of cells from HCs. In comparison to HCs, MS patients had a higher frequency of circulating Treg, both at baseline and after IFN-ß, while FoxP3 mRNA levels in Treg were similar in patients and HCs and did not show major changes during IFN-ß. CONCLUSIONS: Dopaminergic inhibition of Treg in MS patients is suppressed during IFN-ß treatment. Treg play a key role in the suppression of autoimmunity, thus the effect may have a therapeutic repercussion.

Antioxidant and cytoprotective properties of infusions from leaves and inflorescences of Achillea collina Becker ex Rchb.

Plants are the main source of molecules with antioxidant and radical scavenging properties that aid the natural defence systems of cells and may be involved in the preservation of human health, particularly preventing all the physiopathological conditions where oxidative damage is a hallmark. Achillea collina Becker ex Rchb. is a medicinal plant of the Achillea millefolium aggregate (yarrow) traditionally used, particularly in mountain areas, as an infusion or alcohol extract for its digestive, antiinflammatory, analgesic, antipyretic and wound healing properties. The aim of this study was to investigate the antioxidant capacity and cytoprotective activity against oxidative stress of infusions obtained from the leaves and inflorescences of Achillea collina Becker ex Rchb., assessed by chemical (free radical scavenging activity by DPPH and Folin Ciocalteu assay) and biological assays (in vitro model of cytotoxicity and lipid peroxidation in PC12 cells line). Infusions of leaves had the highest antioxidant properties and cytoprotective activity. The antioxidant capacity was significantly correlated with the total phenolic content but not with the cytoprotective profile. Achillea collina Becker ex Rchb. has good antioxidant and cytoprotective properties, suggesting further investigations on its chemical composition and potential health value, particularly for traditionally prepared infusions of leaves.

Therapy with interferon-beta modulates endogenous catecholamines in lymphocytes of patients with multiple sclerosis.

OBJECTIVE: To investigate the endogenous dopaminergic/adrenergic system of lymphocytes in multiple sclerosis (MS) patients during treatment with interferon (IFN)-beta. METHODS: Patients with relapsing-remitting MS undergoing IFN-beta treatment were prospectively studied during the first year of treatment. Circulating lymphocytes were obtained at baseline and after 1, 3, 6 and 12 months of treatment and assayed for catecholamine (CA) production and mRNA expression of tyrosine hydroxylase (TH, the rate-limiting enzyme in the synthesis of CA), beta(2)-adrenoceptors (AR) and D2, D3 and D5 dopaminergic receptors (DR). RESULTS: In cells from patients treated with IFN-beta for 12 months the production of CA hugely increased and was less sensitive to IFN-gamma-induced inhibition. Expression of mRNA for TH, beta(2)-AR and DRD5 was already enhanced after 1 month and further increased up to 6-12 months of treatment. On the contrary, DRD2 mRNA progressively decreased and DRD3 mRNA did not significantly change over the whole study period. CONCLUSIONS: In MS patients IFN-beta treatment enhances the ability of lymphocytes to produce CA, and induces extensive modifications of both beta(2)-AR and DR-operated pathways. The clinical relevance of these effects deserves consideration.

Immunomodulatory properties of Achyrocline satureioides (Lam.) D.C. infusion: a study on human leukocytes.

AIM OF THE STUDY: Achyrocline satureioides (Lam.) D.C. is a South American native medicinal herb known by the popular name of "Marcela". Its infusion is widely utilized for the treatment of several digestive ailments, as an anti-inflammatory preparation, as a sedative and anti-atherosclerotic. Circumstantial evidence suggests that extracts of Achyrocline satureioides may have immunomodulatory properties. The present study was therefore devised to investigate the in vitro effects Achyrocline satureioides infusion on human peripheral blood mononuclear cells (PBMCs) and polymorphonuclear leukocytes (PMNs). MATERIALS AND METHODS: Experiments were performed on cells isolated from venous blood obtained from healthy donors. PBMC proliferation and cytokine production were assessed by standard ELISA methods. Reactive oxygen species (ROS) production by PMNs was evaluated by spectrofluorimetry. RESULTS: In PBMCs, Achyrocline satureioides infusion in the 0.06-0.24microg/ml quercetin equivalent (QE) concentration range concentration-dependently reduced PHA-induced proliferation and production of interferon (IFN)-gamma and interleukin (IL)-4. Lower concentrations of the infusion (0.006-0.03microg/ml QE), which were ineffective on cell proliferation, significantly increased the production of both IFN-gamma and IL-4 and decreased the ratio IFN-gamma/IL-4. In PMNs, Achyrocline satureioides infusion slightly increased the spontaneous generation of ROS only at concentrations > or =0.06microg/ml QE. On the contrary, in the 0.0012-0.03microg/ml QE concentration range the infusion profoundly inhibited fMLP-induced ROS generation as well as spontaneous and fMLP-induced IL-8 production. CONCLUSIONS: The present results provide evidence that Achyrocline satureioides infusion may exert several immunomodulatory effects, in line with its traditional use as an anti-inflammatory agent in many disease conditions. Further studies are warranted to better characterize such effects and to assess their therapeutic relevance.

Estrogenic activity of 7-hydroxymatairesinol potassium acetate (HMR/lignan) from Norway spruce (Picea abies) knots and of its active metabolite enterolactone in MCF-7 cells.

Lignans are plant polyphenols which may possess anticancer, antioxidant, antimicrobial, anti-inflammatory and immunomodulatory activities. In particular, the lignan 7-hydroxymatairesinol (HMR/lignan, HMR) is a novel precursor of the mammalian lignan enterolactone (EL). In the present study, we investigated the estrogenicity of HMR and of EL in comparison to estradiol (E2), by measuring their effects on growth and apoptotic markers in the human estrogen-sensitive cell line MCF-7. HMR, EL and E2 concentration-dependently increased the percentage of MCF-7 cells in the S phase of the cell cycle, with the following relative potencies: E2 congruent with EL>>HMR, and efficacies: E2>HMR>>EL. Treatment of MCF-7 cells with either HMR, EL or E2 also increased the Bcl-2/Bax mRNA ratio. The effects of HMR and EL were reduced in the presence of the estrogen receptor (ER) antagonist tamoxifene. We conclude that both HMR and its metabolite EL are endowed with estrogenic activity, which is likely to be exerted through the contribution of ER-dependent pathways and to target the same intracellular mechanisms acted upon by E2. The estrogenicity of HMR and EL is however milder than that of E2, as indicated by the lower potencies and efficacies of both lignans. The present results support the notion that dietary supplementation with HMR may result in a mild estrogenic activity, both directly and by providing a suitable source for endogenous EL.

Human CD4+CD25+ regulatory T cells selectively express tyrosine hydroxylase and contain endogenous catecholamines subserving an autocrine/paracrine inhibitory functional loop.

CD4+CD25+ regulatory T lymphocytes (Tregs) are specialized T cells playing a key role in the control of immune homeostasis. Here, we show that human Tregs constitutively express tyrosine hydroxylase (TH, EC 1.14.16.2), the rate-limiting enzyme in the synthesis of catecholamines, and contain substantial amounts of dopamine, norepinephrine, and epinephrine, which are released upon treatment with reserpine. Catecholamine release results in reduced production of interleukin-10 and transforming growth factor-beta by Tregs, and in down-regulation of Treg-dependent inhibition of effector T-lymphocyte (Teff) proliferation, which occurs without affecting the production of tumor necrosis factor-alpha or interferon-gamma. Tregs and Teffs express on the cell membrane both D1-like and D2-like dopaminergic receptors to a similar extent (12%-29% of the cells). Catecholamine-dependent down-regulation of Tregs is, however, selectively reversed by pharmacological blockade of dopaminergic D1-like receptors, which in Tregs only (and not in Teffs) are also expressed at the level of mRNA and are functionally coupled to intracellular production of cAMP. These findings indicate that in human Tregs endogenous catecholamines subserve an autocrine/paracrine loop involving dopaminergic pathways and resulting in down-regulation of Treg function.