Enhanced glomerular Toll-like receptor 4 expression and signaling in patients with type 2 diabetic nephropathy and microalbuminuria.

Toll-like receptor 4 (TLR4), a component of the innate immune system, is recognized to promote tubulointerstitial inflammation in overt diabetic nephropathy (DN). However, there is no information on immune activation in resident renal cells at an early stage of human DN. In order to investigate this, we studied TLR4 gene and protein expression and TLR4 downward signaling in kidney biopsies of 12 patients with type 2 diabetes and microalbuminuria, and compared them with 11 patients with overt DN, 10 with minimal change disease (MCD), and control kidneys from 13 patients undergoing surgery for a small renal mass. Both in microalbuminuria and in overt DN, TLR4 mRNA and protein were overexpressed 4- to 10-fold in glomeruli and tubules compared with the control kidney and in MCD. In addition, NF-κB signaling was about fourfold higher in the glomeruli. TNF-α, IL6, CCR2, CCL5, and CCR5 mRNAs were markedly (about three- to fivefold) upregulated in microdissected glomeruli. While IL6, CCL2 and CCR5-mRNA, and CD68 were overexpressed in the tubulointerstitial compartment in clinical DN, they were not expressed in microalbuminuria. In a 6-year follow-up of microalbuminuric patients, glomerular TLR4 gene expression was associated with the subsequent loss of kidney function. Thus, innate immunity is activated in the glomeruli of patients with diabetic microalbuminuria. Enhanced TLR4 signaling may contribute to the progression occurring after the incipient, microalbuminuric form of nephropathy evolves to overt disease.

High ERp5/ADAM10 expression in lymph node microenvironment and impaired NKG2D ligands recognition in Hodgkin lymphomas.

Herein we describe that in classic Hodgkin lymphomas (cHL, n = 25) the lymph node (LN) stroma displayed in situ high levels of transcription and expression of the disulfide-isomerase ERp5 and of the disintegrin-metalloproteinase ADAM10, able to shed the ligands for NKG2D (NKG2D-L) from the cell membrane. These enzymes were detected both in LN mesenchymal stromal cells (MSCs) and in Reed-Sternberg (RS) cells; in addition, MIC-A and ULBP3 were present in culture supernatants of LN MSCs or RS cells. NKG2D-L-negative RS cells could not be killed by CD8(+)αßT or γδT cells; tumor cell killing was partially restored by treating RS cells with valproic acid, which enhanced NKG2D-L surface expression. Upon coculture with LN MSCs, CD8(+)αßT and γδT cells strongly reduced their cytolytic activity against NKG2D-L(+) targets; this seems to be the result of TGF-ß, present at the tumor site, produced in vitro by LN MSCs and able to down-regulate the expression of NKG2D on T lymphocytes. In addition, CD8(+)αßT and γδT cells from the lymph nodes of cHL patients, cocultured in vitro with LN MSCs, underwent TGF-ß-mediated down regulation of NKG2D. Thus, in cHL the tumor microenvironment is prone to inhibit the development of an efficient antitumor response.

Visceral leishmaniasis due to Leishmania infantum with renal involvement in HIV-infected patients.

BACKGROUND: We describe histological, clinical findings and outcomes of renal involvement during Leishmania infantum infection in four HIV-infected patients in South France and North Italy hospital settings. CASES PRESENTATION: Four HIV-infected Caucasian patients (age 24-49) performed renal biopsy during episodes of visceral leishmaniasis. They presented severe immunosuppression, frequent relapses of visceral leishmaniasis during a follow-up period of several years and partial or complete recovery of renal function after anti-parasitic treatment. Main clinical presentations were nephrotic or nephritic syndrome and/or acute renal failure secondary to membranoproliferative type III glomerulonephritis or acute interstitial nephritis. Clinical outcome was poor, probably as a consequence of insufficient immuno-virological control of the HIV infection. CONCLUSIONS: Our findings suggest that the main histological findings in case of renal involvement due to Leishmania infantum infection in HIV-infected patients are type III MPGN and acute interstitial nephritis, with a histological specificity similar to that observed in canine leishmaniasis. Poor immune status in HIV-infected patients, altering the capacity for parasite clearance, and prolonged course of chronic active VL in this population may lead to the development of specific renal lesions.

Lysine triggers apoptosis through a NADPH oxidase-dependent mechanism in human renal tubular cells.

Progressive chronic kidney disease (CKD) is common in lysinuric protein intolerance (LPI), a primary inherited aminoaciduria characterized by massive Lysine excretion in urine. However, by which mechanisms Lysine may cause kidney damage to tubule cells is still not understood. This study determined whether Lysine overloading of human proximal tubular cells (HK-2) in culture enhances apoptotic cell loss and its associated mechanisms. Overloading HK-2 with Lysine levels reproducing those observed in urine of patients affected by LPI (10 mM) increased apoptosis (+30%; p < 0.01 vs.C), as well as Bax and Apaf-1 expressions (+30-50% p < 0.05), while downregulated Bcl-2 (-40% p < 0.05). Apoptosis induced by high Lysine was no longer observed after addition of caspase-9 and caspase-3 inhibitors while caspase-8 inhibitor had no protective effect. High Lysine induced elevations in ROS generation and NADPH oxidase subunits mRNAs (p22 (phox) +106 ± 23%, p67 (phox) +108 ± 22% and gp91 (phox) +75 ± 4% p < 0.05-0.01). In addition, the NADPH oxidase inhibitor DPI prevented both ROS production and apoptosis. Treating HK-2 with antioxidants, such as Cysteine and its analog, N-acetyl-L-cysteine (NAC), rescued the HK-2 from apoptosis induced by Lysine. In summary, our data show that high Lysine in vitro increases the permissiveness of proximal tubule kidney cells to apoptosis by triggering a pathway involving NADPH oxidase signaling. This event may represent a key cellular effect in the increasing the susceptibility of human tubular cells to apoptosis when the tubules cope with a high Lysine load. This effect is instrumental to renal damage and disease progression in patients with LPI.

1,25-dihydroxyvitamin D3 downregulates aromatase expression and inflammatory cytokines in human macrophages.

OBJECTIVES: Vitamin D deficiency seems to be involved in the development and severity of autoimmune/inflammatory diseases such as rheumatoid arthritis (RA). To evaluate the influence of calcitriol (1,25-dihydroxyvitamin D3, 1,25(OH)2D3) on aromatase expression in cultures of human macrophages, as a new target for vitamin D cell modulation and pro-inflammatory cytokine production. METHODS: Cultures of human monocytic THP-1 cells were activated to macrophages and treated for 24 hours with 1,25(OH)2D3 (10-8M), 17ß-estradiol (E2, 10-8M) both alone and in combination, in order to evaluate the effects on the intracrine estrogen metabolism. Untreated human macrophages were used as controls (basal). P450-aromatase synthesis was evaluated by immunocytochemistry (ICC) and western blot analysis (WB). The expression of P450-aromatase gene (CYP19A1) was investigated by real-time PCR (RT-PCR). Macrophage pro-inflammatory cytokines IL1-ß, IL-6 and TNF-α were evaluated by ELISA and WB. RESULTS: In E2 untreated condition, 1,25(OH)2D3 reduced P450-aromatase synthesis and CYP19A1 gene expression in cultured cells. Moreover, pro-inflammatory cytokine production (IL1-ß, IL-6 and TNF-α) was significantly reduced by 1,25(OH)2D3 treatment (p<0.001 vs. basal for all cytokines). However, 1,25(OH)2D3 was found to significantly downregulate the E2-mediated increase in P450-aromatase synthesis and gene expression (p<0.001 for both vs. E2-treated macrophages), as well as the production of all pro-inflammatory cytokines (p<0.001 vs. E2-treated cells). CONCLUSIONS: Our data suggest that 1,25(OH)2D3 may downregulate the pro-inflammatory cytokine production in human activated macrophages by significantly decreasing the aromatase activity, especially in presence of an estrogenic milieu such as in the RA synovial tissue.

Apoptosis and myostatin mRNA are upregulated in the skeletal muscle of patients with chronic kidney disease.

Apoptosis and myostatin are major mediators of muscle atrophy and might therefore be involved in the wasting of uremia. To examine whether they are expressed in the skeletal muscle of patients with chronic kidney disease (CKD), we measured muscle apoptosis and myostatin mRNA and their related intracellular signal pathways in rectus abdominis biopsies obtained from 22 consecutive patients with stage 5 CKD scheduled for peritoneal dialysis. Apoptotic loss of myonuclei, determined by anti-single-stranded DNA antibody and terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling assays, was significantly increased three to fivefold, respectively. Additionally, myostatin and interleukin (IL)-6 gene expressions were significantly upregulated, whereas insulin-like growth factor-I mRNA was significantly lower than in controls. Phosphorylated JNK (c-Jun amino-terminal kinase) and its downstream effector, phospho-c-Jun, were significantly upregulated, whereas phospho-Akt was markedly downregulated. Multivariate analysis models showed that phospho-Akt and IL-6 contributed individually and significantly to the prediction of apoptosis and myostatin gene expression, respectively. Thus, our study found activation of multiple pathways that promote muscle atrophy in the skeletal muscle of patients with CKD. These pathways appear to be associated with different intracellular signals, and are likely differently regulated in patients with CKD.

Identification and quantification of selected inflammatory genes modulated by leflunomide and prednisone treatment in early rheumatoid arthritis patients.

OBJECTIVES: The present study evaluates the effects of combined leflunomide (LEF) and low dose of prednisone therapy, on selected inflammatory gene expression in peripheral blood mononuclear cells (PBMCs) of early rheumatoid arthritis (ERA) patients by gene microarray analysis and quantitative real time-polymerase chain reaction (qRT-PCR). METHODS: Ten ERA patients (mean age 53 ± 10 years) were assigned as untreated (group 1) or pre-treated (group 2) with prednisone (5 mg/day for 3 months) after informed consent and ethics committee approval. Five sex- and age-matched healthy subjects were used as controls (CNT). RNA was extracted by PBMCs, amplified, labelled and hybridised on inflammation DualChip microarray. The expression ratio of 282 inflammatory genes between CNT and ERA patients, before (T0) and after 12 weeks (T1) of combined therapy was detected. qRT-PCR was performed on 7 selected inflammatory RA-related genes (STAT4, MAPK9, HIF1A, MIF, STAT6, NFKB1, TNFRSF1B). RESULTS: At T0, microarray analysis showed 34 altered genes in both ERA groups when compared to CNT (vs. CNT). Seven RA-related genes, investigated in further details, were found up-regulated in group 1 and down-regulated or unchanged in group 2 vs. CNT. At T1, combined therapy induced the down-regulation of these genes in both groups vs. CNT as also confirmed by qRT-PCR performed on selected genes. CONCLUSIONS: Untreated ERA patients seem characterised by up-regulation of specific genes involved both in the resistance/inhibition to apoptosis and in the stimulation of pro-inflammatory cytokine production by immune inflammatory cells. Combined LEF and low dose of prednisone therapy seems to play synergistic effects on down-regulation of these genes.

Androgen-mediated apoptosis of kidney tubule cells: role of c-Jun amino terminal kinase.

The incidence and the rate of progression of chronic kidney diseases (CKD) are for most diseases greater in men than in age-matched women. We have previously shown that testosterone (T) promotes the apoptosis of proximal tubule kidney cells. To better understand the downstream signaling process associated with T-induced apoptosis, we examined the involvement of c-Jun amino terminal kinase (JNK) in a human proximal tubule cell line (HK-2) exposed to T: JNK and its downstream effector c-Jun were rapidly phosphorylated. By blocking androgen receptor, JNK phosphorylation was reduced and 17beta-Estradiol treatment had no effect on it. Similarly, pre-treatment with the JNK inhibitor SP600125 prevented the T-induced apoptosis, the phosphorylation of c-Jun and the upregulation of the Fas/FADD pathway. These data show that the JNK/c-Jun pathway is directly regulated by androgens in vitro and highlight a potential mechanism explaining the reported gender differences in the progression of renal diseases.

Sex hormones modulate the effects of Leflunomide on cytokine production by cultures of differentiated monocyte/macrophages and synovial macrophages from rheumatoid arthritis patients.

Immune response is greater in females than in males and lymphocytes/monocytes from female subjects (or tested in vitro with estrogens) show higher immune/inflammatory reactivity. In order to test in vitro the interactions between 17beta-estradiol (E2--10(-9) M), testosterone (T--10(-8) M) and the antiproliferative/immune suppressive drug Leflunomide metabolite A77 1726 (LEF-M--30 microM) employed in rheumatoid arthritis (RA), their combined effects were evaluated on inflammatory cytokine (CK) expression/production in cultures of differentiated macrophages (M) (from activated THP-1 monocytes) and primary cultures of RA synovial macrophages (SM). TNFalpha, IL-6 and TGFbeta were detected by immunocytochemistry (ICC), Western blot analysis (WB) and reverse transcriptase-polymerase chain reaction (RT-PCR). The ICC, WB and RT-PCR showed a significant down-regulation induced by LEF-M on CK expression by cultured M when compared to untreated cells (IL-6 p < 0.01, TNFalpha p < 0.001, TGFbeta p < 0.01). At ICC analysis E2 increased CK expression, whereas T decreased the expression, confirmed by WB and RT-PCR (range between p < 0.05 and p < 0.001). LEF-M treatment significantly downregulated the CK expression in E2/T treated M: the effect was more significant in LEF-M plus T-treated cells versus controls (range between p < 0.01 and p < 0.001). Concerning the RA SM, the results were replicated (range between p < 0.05 and p < 0.001). E2 seems to contrast, but T seems to synergize the LEF-M activity. Results might support a stronger therapeutical efficacy, at least for LEF, in male RA patients, as already reported by clinical evidences.

Role of estrogens in inflammatory response: expression of estrogen receptors in peritoneal fluid macrophages from endometriosis.

Estrogens are involved in the immune response, and macrophages express estrogen receptors (ER). Moreover, macrophages are the predominant cell type in the peritoneal fluid from endometriosis patients. On this basis, the aim of our study was to evaluate the expression of ER on peritoneal macrophages from endometriosis patients and to compare these results with what is already known about ER and macrophages in RA. After macrophage extraction from peritoneal fluids we performed the immunohistochemical localization of ERalpha and ERbeta and then the image analysis. We found that both ERs were significantly overexpressed in macrophages of women with endometriosis compared with controls. These results suggest that estrogens, through their functional receptors, might modulate the immune response at least on macrophages. Therefore, estrogens seem to play an important role in the immune response, independently from the pathology.

Estrogens and autoimmune diseases.

Sex hormones are implicated in the immune response, with estrogens as enhancers at least of the humoral immunity and androgens and progesterone (and glucocorticoids) as natural immune-suppressors . Several physiological, pathological, and therapeutic conditions may change the serum estrogen milieu and/or peripheral conversion rate, including the menstrual cycle, pregnancy, postpartum period, menopause, being elderly, chronic stress, altered circadian rhythms, inflammatory cytokines, and use of corticosteroids, oral contraceptives, and steroid hormonal replacements, inducing altered androgen/estrogen ratios and related effects. In particular, cortisol and melatonin circadian rhythms are altered, at least in rheumatoid arthritis (RA), and partially involve sex hormone circadian synthesis and levels as well. Abnormal regulation of aromatase activity (i.e., increased activity) by inflammatory cytokine production (i.e., TNF-alpha, IL-1, and IL-6) may partially explain the abnormalities of peripheral estrogen synthesis in RA (i.e., increased availability of 17-beta estradiol and possible metabolites in synovial fluids) and in systemic lupus erythematosus, as well as the altered serum sex-hormone levels and ratio (i.e., decreased androgens and DHEAS). In the synovial fluids of RA patients, the increased estrogen concentration is observed in both sexes and is more specifically characterized by the hydroxylated forms, in particular 16alpha-hydroxyestrone, which is a mitogenic and cell proliferative endogenous hormone. Local effects of sex hormones in autoimmune rheumatic diseases seems to consist mainly in modulation of cell proliferation and cytokine production (i.e., TNF-alpha, Il-1, IL-12). In this respect, it is interesting that male patients with RA seem to profit more from anti-TNFalpha strategies than do female patients.

Anti-TNF and sex hormones.

Whenever serum estrogen concentrations are normal in rheumatoid arthritis (RA) patients, lower androgen concentrations (i.e., testosterone, androstenedione, and dehydroepiandrosterone sulfate [DHEAS]) are detected in the serum as well as in the synovial fluid of male and female RA patients. The presence in the RA synovial fluid of a significant altered sex hormone balance resulting in lower immunosuppressive androgens and higher immuno-enhancing estrogens, might determine a favorable condition for the development of the immunomediated RA synovitis. The inflammatory cytokines (i.e., TNF-alpha), particularly increased in RA synovitis, are able to markedly stimulate the aromatase activity in peripheral tissues and, therefore, induce the peripheral metabolism from androgens to estrogens. The effects of TNF blockers (and generally of anticytokine agents) on peripheral sex hormone levels seem exerted in a faster way at the level of the RA synovial tissue (before any influence on serum levels) where they seem to block the conversion from androgens (anti-inflammatory) to estrogens (proinflammatory) induced by aromatase. Therefore, the beneficial effects of restoring synovial androgens might be clinically more evident in male RA patients (as recently observed in ANTARES study) since they suffer more for the lack of androgens (anti-inflammatory) on account of the action of TNF-alpha on peripheral hormonal conversion. However, therapy (3 months) with anti-TNF did not change serum levels of typical sex hormones in patients with RA, although baseline values were largely different from controls. In patients with at least long-standing RA, this indicates that alterations of serum sex hormones and altered activity of respective converting enzymes are imprinted for a long-lasting period over at least 12 weeks.

Effects of macitentan and its active metabolite on cultured human systemic sclerosis and control skin fibroblasts.

OBJECTIVE: To investigate the effects of the endothelin 1 (ET-1) receptor antagonists (ETRA) macitentan, its active metabolite ACT-132577, and bosentan on myofibroblast activation and extracellular matrix production induced by ET-1 in cultured systemic sclerosis (SSc) and control skin fibroblasts. METHODS: Fibroblasts were obtained from skin biopsies of 6 patients with SSc and 5 healthy subjects. Some cultured cells were untreated or treated with macitentan, ACT-132577, or bosentan alone (10 µM). Other cultured cells were treated with ET-1 alone (100 nM) or with ETRA, and after 1 h, also with ET-1. After 48 h of treatment, myofibroblast activation was investigated to evaluate the α-smooth muscle actin (α-SMA) expression by immunofluorescence; type I collagen (COL-1) and fibronectin (FN) were investigated by immunocytochemistry, Western blotting, and quantitative real-time PCR (qRT-PCR). Statistical analysis was performed by the nonparametric Mann-Whitney U test. RESULTS: In cultured SSc skin fibroblasts, only the treatment with macitentan significantly reduced the basal level of α-SMA expression (p = 0.03 vs untreated cells). Macitentan also significantly reduced the basal level of COL-1 synthesis, similarly to bosentan (p < 0.05 vs untreated cells). Macitentan or ACT-132577 antagonized the ability of ET-1 to further induce α-SMA expression (p = 0.03), COL-1, and FN synthesis (p = 0.03, p = 0.005); bosentan showed similar effects. These results obtained by immunofluorescence and immunocytochemistry were confirmed by Western blotting and qRT-PCR. The downregulatory effects exerted by ETRA were observed also in cultured human control skin fibroblasts. CONCLUSION: Macitentan and ACT-132577 seem to downregulate in vitro the profibrotic myofibroblast phenotype induced by ET-1 in cultured human SSc skin fibroblasts.

Sex hormones and rheumatoid arthritis.

Sex hormones are implicated in the immune response, with estrogens as enhancers at least of the humoral immunity and androgens and progesterone as natural immune-suppressors. In male rheumatoid arthritis (RA) patients, androgen replacement seems to ameliorate the disease and supports their involvement in the pathophysiology of the disease. The combination of androgens with cyclosporin A or methotrexate has been found to potentiate the apoptosis of monocytic inflammatory cells as well as to reduce the cell growth at least in vitro. Considerable interest has been devoted in the last years as to whether the use of oral contraceptive pills (OCs) may have a protective effect on the risk of RA. The results of many controlled studies have been found contradictory. At the present time, no consensus has been achieved regarding OCs administration and its relationship to the prevention or development of RA. In addition, an association of estrogen receptor gene polymorphism with age at onset of RA has been observed and might further explain inter-individual clinical and therapeutical-response variations. Local increased estrogen concentrations and decreased androgen levels have been observed in RA synovial fluids and seem to play a more important role in the immune/inflammatory local response.

Synovial fluid estrogens in rheumatoid arthritis.

Experimental and clinical evidence suggest that immune reactivity is modulated by gender. Immune reactivity is greater in females than in males and lymphocytes and monocytes from female subjects shows higher antigen presenting activity and mitogenic responses. Steroid hormones can be converted along defined pathways to downstream hormones in the periphery. The conversion of dehydroepiandrosterone (DHEA) in target macrophages leads to an increase of downstream effector hormones (including estrogens), which may be an important factor for local immunomodulation at least in RA synovitis. The presence in the RA synovial fluids (SF) of an altered sex hormone balance resulting in lower immunosuppressive androgens and higher immunoenhancing estrogens, might determine a favorable condition for the development of the immuno-mediated RA synovitis and synovial hyperplasia. The increased estrogen concentration observed in RA SF of both sexes are characterized by the hydroxylated forms, in particular 16alpha-hydroxyestrone, that is a mitogenic and proliferative endogenous hormone. In contrast to 16alpha-hydroxylated estrogens, the 2-hydroxylated forms inhibit growth promoting effects of E2 and were found low in RA SF. Therefore, dose-related conversion to pro- or anti-inflammatory downstream metabolites of estrogens might support the dual role of estrogens (pro or anti-inflammatory) for example during estrogen replacement therapy, depending on local concentration (i.e. SF in RA) of 16alpha-hydroxyestrone or 2-hydroxyestrogens.

Inverse correlation between p16INK4A expression and NF-kappaB activation in melanoma progression.

Expression of p16INK4A, the product of the melanoma susceptibility gene CDKN2A, has been shown to decrease in correlation with tumor progression. P16INK4A is a key regulator of cell-cycle function, and likely interacts with a variety of targets alongside cyclin-dependent kinases (CDKs). One such target is nuclear factor KB (NF-kappaB), a pleiotropic transcription factor that plays a crucial role in apoptosis, oncogenesis and cell cycle control. NF-kappaB p65 has been shown to be activated in melanoma cell lines but few studies decribe its expression in the tissue. In the present study we focused on synchronous expression of p16INK4A and NF-kappaB p65 and their functional activation in melanoma cell lines and biopsy tissue. Activation of NF-kappaB p65, as observed by electrophoretic mobility shift assay in cell lines, was correlated with expression and cellular localization of the active and inactive forms of its inhibitor, IkappaB-alpha. In melanocytic lesions, p16INK4A and NF-kappaB p65 expression were inversely correlated with levels of the nuclear component of NF-kappaB p65 increasing from nevi to primary melanomas and metastases.

Expression and localization of mutant p16 proteins in melanocytic lesions from familial melanoma patients.

Little is known about the correlation between the loss of p16 expression and tumor progression in familial melanoma; no systematic study has been conducted on p16 expression in melanocytic tumors from patients carrying germline CDKN2A mutations. We analyzed 98 early primary lesions from familial patients, previously tested for germline CDKN2A status, by quantitative immunohistochemistry using 3 p16 antibodies. We found that p16 expression was inversely correlated with tumor progression and was significantly lower in melanomas, including in situ lesions, than in nevi. Of other features analyzed, tumor thickness showed the most significant correlation with p16 levels. Lesions from mutation-negative patients displayed combined nuclear and cytoplasmic staining. However, some mutation-positive lesions (ie, G101W, 113insR, M53I, R24P, and 33ins24), including benign nevi, showed nuclear mislocalization, confirming previous studies suggesting that subcellular distribution indicates functional impairment of p16.

Androgens and estrogens modulate the immune and inflammatory responses in rheumatoid arthritis.

Generally, androgens exert suppressive effects on both humoral and cellular immune responses and seem to represent natural anti-inflammatory hormones; in contrast, estrogens exert immunoenhancing activities, at least on humoral immune response. Low levels of gonadal androgens (testosterone/dihydrotestosterone) and adrenal androgens (dehydroepiandrosterone and its sulfate), as well as lower androgen/estrogen ratios, have been detected in body fluids (that is, blood, synovial fluid, smears, salivary) of both male and female rheumatoid arthritis patients, supporting the possibility of a pathogenic role for the decreased levels of the immune-suppressive androgens. Several physiological, pathological, and therapeutic conditions may change the sex hormone milieu and/or peripheral conversion, including the menstrual cycle, pregnancy, the postpartum period, menopause, chronic stress, and inflammatory cytokines, as well as use of corticosteroids, oral contraceptives, and steroid hormonal replacements, inducing altered androgen/estrogen ratios and related effects. Therefore, sex hormone balance is still a crucial factor in the regulation of immune and inflammatory responses, and the therapeutical modulation of this balance should represent part of advanced biological treatments for rheumatoid arthritis and other autoimmune rheumatic diseases.

Modulation of cell growth and apoptosis by sex hormones in cultured monocytic THP-1 cells.

Several authors have reported the regulation of apoptotic phenomena by sex hormones in different cell lines, including T lymphocytes and mononuclear cells. Since androgens can modulate the programmed cell death in responsive cell lines, we decided to investigate the induction of apoptosis in THP-1 cells following their differentiation into macrophage-like cells and exposure to sex hormones. In addition, we decided to evaluate the proto-oncogene Bax and Fas (CD 95) and cleaved PARP (poly-adp-ribose-polymerase) expression in the same cultured cells. The results showed for the first time the dose-/time-dependent regulation of the apoptotic event in human monocytic THP-1 cells treated with different concentrations of androgens. No significant changes were observed for estrogen-treated and unstimulated control cells. In particular, the cells, after stimulation with androgens but not with estrogens, were found to be positive for the proto-oncogene Bax, Fas, and for cleaved subunits of PARP expression as demonstrated with different assays including immunocytochemical assay and Western blot analysis. In conclusion, these results support the possibility of sex hormone modulation of apoptosis in macrophage-like cells, with interesting therapeutic perspectives in rheumatoid arthritis.

Antiproliferative-antiinflammatory effects of methotrexate and sex hormones on cultured differentiating myeloid monocytic cells (THP-1).

Methotrexate (MTX) is believed to exert both antiproliferative and antiinflammatory effects in a dose-related manner in a majority of rheumatoid arthritis (RA) patients along with an abrupt flare of the disease after drug discontinuation. To investigate the antiproliferative and antiinflammatory actions of MTX and the combined action of sex hormones, we evaluated these effects in differentiated monocytic myeloid cells (THP-1) prestimulated with testosterone (T) or 17-beta estradiol (E2). The effects of MTX and T combined treatment (T/MTX) on THP-1 cells showed a significant inhibition of cell proliferation when compared with E2/MTX- treated cells or controls: 53% at 72 h versus E2-treated cells; 58% at 96 h versus E2-treated cells; and 41% versus controls, respectively. Bax and Fas CD95 expression was found increased in T-treated cells: 14% T at 48 h vs. E(2)-treated cells and controls; 45% T at 72 h versus E2-treated cells and controls; 97% at 96 h versus E2-treated cells and 37% versus controls for Bax: 33%, 41%, and 42% T versus E2-treated cells for Fas. Moreover, a significant decrease of IL-12 levels in T/MTX treated cells was found at any time when compared to E2-treated cells. In summary, the association of testosterone and MTX compared to MTX alone suggests possible synergistic actions. Therefore, the enhancing antiinflammatory effects exerted by androgens might represent a further explanation for the reduced frequency of inflammatory diseases in male subjects.