Stefano Soldano

Use of glucocorticoids and risk of infections.

Glucocorticoids (GC) exert many complex quantitative and qualitative immunosuppressive effects that induce cellular immunodeficiency and consequently might increase host susceptibility to various viral, bacterial, fungal, and parasitic infections. In chronic immune/inflammatory conditions cortisol is secreted at inadequate levels and GC therapy today is devoted in substituting this hormone in adequate doses (low) to compensate just for this; therefore, the correct timing of GC administration, such as given during the turning-on phase of TNF secretion (night), can be of major importance. Consequently, the use of the lowest possible GC dose, at the night time and even for the shortest possible time, should decrease dramatically the risk of infections.

Circadian rhythms: glucocorticoids and arthritis.

Abstract:  Circadian rhythms are driven by biological clocks and are endogenous in origin. Therefore, circadian changes in the metabolism or secretion of endogenous glucocorticoids are certainly responsible in part for the time‐dependent changes observed in the inflammatory response and arthritis. More recently, melatonin (MLT), another circadian hormone that is the secretory product of the pineal gland, has been found implicated in the time‐dependent inflammatory reaction with effects opposite those of cortisol. Interestingly, cortisol and MLT show an opposite response to the light. The light conditions in the early morning have a strong impact on the morning cortisol peak, whereas MLT is synthesized in a strictly nocturnal pattern. Recently, a diurnal rhythmicity in healthy humans between cellular (Th1 type) or humoral (Th2 type) immune responses has been found and related to immunomodulatory actions of cortisol and MLT. The interferon (IFN)‐γ/interleukin (IL)‐10 ratio peaked during the early morning and correlated negatively with plasma cortisol and positively with plasma MLT. Accordingly, the intensity of the arthritic pain varies consistently as a function of the hour of the day: pain is greater after waking up in the morning than in the afternoon or evening. The reduced cortisol and adrenal androgen secretion, observed during testing in rheumatoid arthritis (RA) patients not treated with glucocoticoids, should be clearly considered as a “relative adrenal insufficiency” in the presence of a sustained inflammatory process, and allows Th1 type cytokines to be produced in higher amounts during the late night. In conclusion, the right timing (early morning) for the glucocorticoid therapy in arthritis is fundamental and well justified by the circadian rhythms of the inflammatory mechanisms.

Raynaud’s Phenomenon and Plasma Endothelin: Correlations with Capillaroscopic Patterns in Systemic Sclerosis

Objective. We evaluated endothelin (ET)-1 plasma levels and some clinical measures in patients with primary Raynaud’s phenomenon (PRP), and in patients with systemic sclerosis (SSc) and secondary RP (SRP), in the latter according to their different nailfold videocapillaroscopy (NVC) patterns of microangiopathy (early, active, and late). Methods. Ninety-nine patients with SSc, 49 with PRP, and 45 control subjects were studied. NVC was performed in all patients to distinguish the pattern of microvascular damage, and the morphological alterations were scored by a semiquantitative rating scale. ET-1 plasma levels were evaluated in all individuals by ELISA. Results. ET-1 plasma levels were significantly higher (p = 0.001) in patients with both PRP and SRP, compared to controls. A significant positive correlation (p = 0.03) was found between ET-1 plasma levels and SRP duration, but not between ET-1 plasma levels and PRP duration. Significant correlations were observed in patients with SSc between ET-1 plasma levels and clinical measures (e.g., digital ulcers), as well as the score value of single NVC measures, such as the number of capillaries, “ramified” capillaries, and enlarged capillaries (p < 0.05). Finally, the highest ET-1 plasma levels were found in patients with SSc showing the late pattern of microangiopathy when compared to the early pattern (p = 0.03) and to controls (p = 0.003). Conclusion. Highest ET-1 plasma levels were detected in the more advanced stage of the SSc microangiopathy, namely the late NVC pattern, characterized by capillary loss and increased tissue fibrosis; this might support the involvement of ET-1 in the progression of the microvascular/fibrotic SSc damage.

Peripheral Blood Perfusion Correlates with Microvascular Abnormalities in Systemic Sclerosis: A Laser-Doppler and Nailfold Videocapillaroscopy Study

Objective. To investigate possible correlations between fingertip blood perfusion (FBP) status, assessed by laser Doppler flowmetry (LDF), and morphological microvascular abnormalities, detected by nailfold videocapillaroscopy (NVC), in patients with systemic sclerosis (SSc). The effects on FBP of intravenous (IV) treatment with the prostacyclin analog iloprost were also investigated. Methods. Thirty-four consecutive patients with SSc and 16 healthy subjects were evaluated. LDF was performed by analyzing blood perfusion at the fingertips in both hands. Patients with SSc were distributed into the appropriate NVC pattern of microangiopathy (early, active, and late). Iloprost was administered to inpatients with SSc by 24-hour IV infusion for 7 consecutive days (4 μg/h). Results. FBP was significantly lower in patients with SSc (p < 0.05) compared to controls. Heating of the LDF probe at 36°C induced a significant increase of FBP in all subjects (p < 0.001), but the slope of variation was significantly lower in patients with SSc compared to controls (p < 0.05). Patients with SSc showing the late NVC pattern of microangiopathy had significantly lower FBP than patients with the active and early NVC patterns (p < 0.05). A negative correlation was observed between FBP and NVC rating of the microvascular damage (p < 0.05). After iloprost treatment, a significant increase of FBP was observed in patients with SSc (p < 0.05). Conclusion. Patients with SSc show a decreased FBP partially reversible by local skin heating. The FBP correlated negatively with the extent of nailfold microvascular damage, and IV iloprost treatment increased the FBP.

CTLA4-Ig interacts with cultured synovial macrophages from rheumatoid arthritis patients and downregulates cytokine production

IntroductionCo-stimulatory signal B7(CD80/CD86):CD28 is needed in order to activate T cells in immune response. Cytotoxic T lymphocyte-associated antigen-4-immunoglobulin (CTLA4-Ig) binding to the B7 molecules on antigen-presenting cells downregulates this activation and represents a recent biological treatment in rheumatoid arthritis (RA). Objectives of the study were to investigate the presence of the B7.2 (CD86) molecule and its masking by CTLA4-Ig on cultures of both RA synovial macrophages (RA SM), and of macrophages differentiated from THP-1 cells (M). In addition, the anti-inflammatory effects of CTLA4-Ig on co-cultures of RA SM and M with activated T cells were tested.MethodsAll macrophages were co-cultured for 24 hours with activated T cells, without or with CTLA4-Ig (10, 100, 500 μg/ml for 1 hour, 3 hours and overnight, respectively). Immunofluorescence (IF) staining for B7.2, and an analysis of inflammatory cytokine expression (interleukin (IL) -6, tumor necrosis factor (TNF) α, IL-1β, transforming growth factor (TGF) β) by immunocytochemistry (ICC), western blot (WB) and reverse transcriptase-polymerase chain reaction (RT-PCR) were performed.ResultsMacrophages showed intense B7.2 expression. CTLA4-Ig/B7.2 masking was evident for all macrophages, even after only 1 hour of cell culture (range from 10 to 100 μg/ml). ICC of co-cultures showed a dose-dependent decrease in inflammatory cytokines (P < 0.001 for IL-6, TNFα, IL-1β and TGFβ). Data were confirmed by WB and RT-PCR analysis.ConclusionsOptimal concentrations of CTLA4-Ig for the CTLA4-Ig/B7.2 masking on activated macrophages were identified and were found to induce significant downregulation in the cell production of IL-6, TNFα, IL1-β and TGFβ. In conclusion, macrophages would appear to be a sensitive target for CTLA4-Ig treatment in RA.

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.

Abstract:  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 ERα and ERβ 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.

Role of MT1-MMP in the osteogenic differentiation.

Metalloproteinase MT1-MMP is induced and Pro-MMP-2 up modulated early in rat preosteoblasts (ROB) set to differentiate. We here show that the induction of MMPs, accompanied by activation of Pro-MMP-2, occurs by 6 h of adhesion on endogenous extracellular matrix (ECM), Fibronectin (FN) and Collagen type I (CI). These events do not occur after adhesion on Collagen III (CIII), Vitronectin (VN) or BSA. Within the first hour on inducing substrata or plastic, FAK is unchanged and ERK(1,2), is activated, but this activation is not sufficient for MT1-MMP induction. The function of p38 MAPK and PTKs is not required for the induction by substrata of MMPs. Six hours after plating preosteoblasts on MMP-inducing substrata, complexes of beta1 integrin with MT1-MMP are formed, that contain integrin dimers specifically engaged by the substratum, alpha4 and alpha5 chains for cells plated on FN, and alpha2 chain for cells plated on CI and ECM. Induction of MT1-MMP and its expression during osteogenesis pleiotropically regulate alkaline phosphatase (AP) expression. During differentiation, variant clones derived from preosteoblasts and MMPs-over-expressing osteoblasts show high MT1-MMP level associated with high AP level both persisting in time, while inhibition of MMPs is accompanied by inhibition of AP. Up or down modulation of AP, transcriptionally or by inhibition of the enzyme activity, has no effect on level or timing of expression of MT1-MMP and Pro-MMP-2. The persistence in expression of MT1-MMP during differentiation, and the associated persistence in expression of AP, as well as their inhibition, both impair the formation of nodules and mineral deposition. A transient pattern of expression of MT1-MMP is required for the establishment of nodules, and MT1-MMP decrease is permissive for nodule mineralization. The expression of AP is required for nodule formation and its level modulates the mineralization. MT1-MMP has multiple functions and is implicated in multiple steps of the differentiation process, acting to regulate homeostasis of the osteogenic differentiation.

Effects of estrogens on extracellular matrix synthesis in cultures of human normal and scleroderma skin fibroblasts

To investigate the effects of 17beta‐estradiol (E2) on extracellular matrix (ECM) protein synthesis (collagen type I, fibronectin, and laminin) using cultures of normal and scleroderma (SSc) skin fibroblasts. Primary fibroblasts cultures, obtained from skin biopsies of six female voluntary subjects and three female SSc patients, were treated for 24 h with E2 (10−10M) alone or in combination with tamoxifene (TAM, 10−7M) as an estrogen receptor (ER) antagonist. ECM protein synthesis was analyzed by immunocytochemistry and Western blotting. E2 induced a significant increase of fibronectin, collagen type I, and laminin synthesis both in normal (P < 0.01, P < 0.05, P < 0.01, respectively) and SSc fibroblasts (P < 0.001, P < 0.05, P < 0.001, respectively) when compared to untreated fibroblasts. TAM induced a significant decrease of ECM protein synthesis when compared to E2‐treated TAM‐untreated fibroblasts. This study seems to support important modulatory effects of E2 in the fibrotic progression of the SSc process via ER interactions.

Endothelin and sex hormones modulate the fibronectin synthesis by cultured human skin scleroderma fibroblasts

Objective: To evaluate the influence of endothelin-1 (ET-1) and sex hormones on cell proliferation and extracellular matrix (ECM) synthesis (ie, fibronectin, laminin) by cultured normal and scleroderma (SSc) human skin fibroblasts (FBs). Methods: Primary cultures of FBs were treated with ET-1 and sex hormones (17β-oestradiol or testosterone) for 24 h. Cell growth was analysed by methiltetrazolium salt test, ECM synthesis was evaluated by immunocytochemistry and western blot, both at 24 h. Results: In normal FBs, ET-1 and 17β-oestradiol, as well as their combination, increased cell growth (p<0.001, p<0.001, p<0.01 vs untreated cells (control), respectively) and fibronectin synthesis (p<0.05, p<0.05, p<0.01 vs control, respectively). By contrast, testosterone either alone or in combination with ET-1 did not influence cell proliferation, but decreased fibronectin synthesis (p<0.05, testosterone vs control). In SSc FBs, ET-1 and 17β-oestradiol alone or their combination induced an increased fibronectin synthesis (p<0.05, p<0.05, p<0.01 vs control, respectively). Unexpectedly, testosterone induced an increase of fibronectin synthesis (p<0.05 vs control). Conclusions: ET-1 and 17β-oestradiol seem to exert a profibrotic effect in normal and SSc culture FBs and might suggest their synergistic effect in the pathogenesis of the fibrotic process in SSc.