Safe coordinated trafficking of heme and iron with copper maintain cell homeostasis: modules from the hemopexin system.

Studies with patients, animal models of human disease and hemopexin null mice have shown that the heme-binding protein hemopexin is vital for the protection of a variety of cell types and tissues against heme toxicity. The presence of hemopexin in all biological fluids examined to date indicates wide roles in abrogating heme toxicity in human tissues; and, thus, is clinically relevant. Heme-hemopexin endocytosis leads to coordinated trafficking of heme, iron and copper as heme traffics from endosomes to heme oxygenases (HOs) in the smooth endoplasmic reticulum and to the nucleus. This is safe redox-metal trafficking, without oxidative stress, as iron released from heme catabolism by HOs as well as copper taken up with heme-hemopexin move through the cell. To our knowledge, this coordinated metal trafficking has been described only for the hemopexin system and differs from the cell's response to non-protein bound heme, which can be toxic. We propose that defining how cells respond to heme-hemopexin endocytosis, a natural cytoprotective system, will aid our understanding of how cells adapt as they safely respond to increases in heme, Fe(II) and copper. This is relevant for many genetic hemolytic diseases and conditions, stroke and hemorrhage as well as neurodegeneration. Such analyses will help to define a pattern of events that can be utilized to characterize how dysfunctional redox and transition metal handling is linked to the development of pathology in disease states such as Alzheimer's disease when metal homeostasis is not restored; and potentially provide novel targets and approaches to improve therapies.

Sulphilimine cross-links in Goodpasture's disease.

The sulphilimine cross-link of the Goodpasture (GP) autoantigen is a novel molecular mechanism (structural constraint) for conferring immune privilege to a site which otherwise is susceptible to structural changes that induce an immunogenic and pathogenic conformation. Perturbation of the assembly or cleavage of the sulphilimine cross-links could be a key factor in the aetiology of Goodpasture's disease in susceptible individuals.

Role for copper in transient oxidation and nuclear translocation of MTF-1, but not of NF-kappa B, by the heme-hemopexin transport system.

Heme-hemopexin (2-10 microM) is used as a model for intravenous heme released in trauma, stroke, and ischemia-reperfusion. A transient increase in cellular protein oxidation occurs during receptor-mediated heme transport from hemopexin which is inhibited by the nonpermeable Cu(I) chelator, bathocuproinedisulfonate. Thus, participation of surface redox process involving Cu(I) generation are proposed to be linked to the induction of the protective proteins heme oxygenase-1 (HO-1) and metallothionein-1 (MT-1) by heme-hemopexin. The region (-153 to -42) in the proximal promoter of the mouse MT-1 gene responds to heme- and CoPP-hemopexin in transient transfection assays and contains metal-responsive elements for MTF-1 and an antioxidant-responsive element (ARE) overlapping a GC-rich E-box to which USF-1 and -2 bind. No decreases in DNA binding of the diamide-oxidation sensitive USF-1 and -2 occur upon exposure of cells to heme-hemopexin. MTF-1 and the ARE-binding proteins are relatively resistant to diamide oxidation and are induced approximately eight- and two-fold, respectively, by heme-hemopexin. BCDS prevents the nuclear translocation of MTF-1 by both heme- and CoPP-hemopexin complexes as well as MT-1 mRNA induction by CoPP-hemopexin. Thus, copper is needed for the surface oxidation events and yet the nuclear translocation of MTF-1 in response to hemopexin occurs via copper, probably Cu(I),-dependent signaling cascades from the hemopexin receptor rather than the oxidation per se.

FcRIII (CD16) expression on neutrophils from chronic myeloid leukemia. A flow cytometric study.

FcRIII (CD16) expression on neutrophils from 17 patients with chronic myeloid leukemia (CML) was studied by flow cytometry using monoclonal antibodies. A variable proportion of CD16-negative neutrophils were found both in CML patients in chronic phase (3 out of 8 patients) and in CML patients in hematological remission (3 out of 9 patients). Neutrophils with reduced FcRIII expression showed more defective chemiluminescence and phagocytosis than neutrophils with normal FcRIII expression. Circulating myeloid cells from three patients in chronic phase, showing a normal percentage of CD16-positive neutrophils, were isolated and fractionated by discontinuous Percoll gradients. This study showed that CD16 appears at the stage of metamyelocyte, that band cells and segmented neutrophils display an identical pattern of membrane FcRIII, and that the fluorescence intensity shown by metamyelocytes is different from that displayed by more mature cells. The association between low FcRIII expression and function abnormality could be suggestive of a defect in CML neutrophil maturation.

CD5+ B lymphocytes and T-cell subsets in a case of juvenile rheumatoid arthritis.

Recent research has demonstrated that CD5+ B lymphocytes have an important role in autoimmune and rheumatic diseases. In a case of juvenile rheumatoid arthritis (JRA), we observed the behavior of these cells and other subpopulations of T lymphocytes of peripheral blood before and after therapy with thymopentin (TP5). All the lymphocyte subpopulations returned to normal range, except the CD5+ B cells, where the percentage remained abnormally high (60%). These data suggest that CD5+ B cells can be a useful monitoring index and confirm their important role in the pathogenesis of juvenile rheumatoid arthritis.

Lymphocyte subsets in multiple sclerosis. A study with two-colour fluorescence analysis.

Multiple sclerosis (MS) is postulated to be an immunopathologically mediated disease. This concept is supported by the finding of abnormally distributed peripheral blood T-cell subsets and a decreased T-suppressor function. Thirty-seven MS patients have been selected according to the criteria for definite MS. Fluorescein- or phycoerythrin-conjugated monoclonal antibodies have been used to define different lymphocyte subsets: CD4+, CD5+, CD8+, CD19+, CD38+, CD45RA+, CD4+CD45RA+, CD19+CD5+, CD8+CD38+. In relapsing-remitting (RR)-MS patients a significantly decreased percentage of CD19+ cells and in progressive MS patients a significantly increased percentage of CD19+CD5+ cells have been found. During a relapse in RR-MS, a significantly decreased percentage of CD4+CD45RA+ cells and a significantly increased percentage of CD8+CD38+ cells have been observed. Moreover, in RR-MS patients a significantly increased percentage of CD38+ cells and significantly high IgM amounts have been found. The increased percentage of CD19+CD5+ and CD38+ cells (together with high IgM levels) and the reduced percentage of CD4+CD45RA+ lymphocytes could be related to an activation of both cellular and humoral immune response in acute MS.

Plasma exchange for polyradiculoneuropathy following kidney transplantation: a case report.

We describe a case of polyradiculoneuropathy (PRN) following living donor kidney transplantation, without clinical evidence of preexisting infection. In this study plasma exchange treatment resulted 6 days later in improvement in extremity weakness and paresthesias in the upper and lower extremities. Total neurological recovery was obtained 3 months after the onset of symptoms.

The use of extracorporeal photopheresis for allograft rejection in liver transplant recipients.

BACKGROUND: Originally introduced for cutaneous T-cell lymphomas and autoimmune diseases, extracorporeal photopheresis (ECP) has been proven effective to reverse allograft rejection. The aim of the present work was to show the results of a single-center experience with ECP for the treatment of biopsy-proven rejection in selected liver transplant (LT) recipients. PATIENTS AND METHODS: A retrospective review of five LT patients (M:F=4:1; median age 51 years) undergoing ECP for biopsy-proven allograft rejection between January 1996 and December 2003. In this period 476 LT were performed on 441 patients. RESULTS: The indications for LT were three cases of HCV-related cirrhosis, complicated by hepatocellular carcinoma in two; one HBV-HDV-alcoholic cirrhosis; and one fulminant HBV hepatitis. All patients received calcineurin-inhibitor (CNI)-based immunosuppression with induction using anti-IL2R monoclonal antibodies. Indications for ECP were: ductopenic rejection in one patient with HCV recurrence; steroid-resistant acute rejection in two; acute rejection in a major ABO-mismatched liver graft; and one acute rejection in a patient with a proven allergy to steroids. The median interval from LT to inception of ECP was 43 days. The median number of ECP sessions per patient was 20. During the course of ECP, two patients tested positive for CMV antigenemia, associated in one case with bacterial pneumonia. All patients tolerated ECP and there were no procedure-related complications. At a median follow-up of 7.9 months after start of ECP, neither rejection relapses nor HCV/HBV recurrences have been observed. Three patients are off ECP with complete reversal and low-dose immunosuppression. Two patients are still receiving ECP with full-dose immunosuppression: one has achieved normal liver function but ECP is indicated due to a major ABO-incompatible liver graft, while the other patient's liver functions have not yet returned to baseline values.

Use of antisecretory drugs for gastroprotection during antiblastic chemotherapy.

Both prednisone and cytostatic drugs have an ulcerogenic effect on digestive mucosa. The protective action of the antisecretory drugs pirenzepine and ranitidine are compared against gastroduodenal lesions induced by antiblastic therapy. Twenty patients affected with lymphoproliferative disorders were endoscopically examined: none of them suffered from gastric or duodenal peptic ulcers or erosions. Ten out of the 20 patients received pirenzepine 100 mg/die/p.o. and the other 10 received ranitidine 300 mg/die/p.o. The study was performed according to a double-blind, randomized sequence. The antisecretory medication was administered together with antitumoral therapy for periods of 3-6 months. Four patients died of haematological complications before the course of treatment was completed. A further endoscopic examination was performed at the end of treatment: no patient showed evidence of gastric or duodenal peptic ulcers or erosions. Among the pirenzepine-treated cases, 1 out of the 7 evaluable patients showed a histological worsening of a pre-existing gastritis, while a slight duodenitis was observed in 1 out of the 9 ranitidine-treated patients. The comparable effectiveness of the two drugs is probably related to their antisecretory action, but cytoprotective mechanisms cannot be excluded.

Modifications in the concentrations of circulating myoglobin after treatment with low doses of adriamycin.

The modifications in the concentration of circulating myoglobin have been studied by means of a radioimmunoassay in 15 cancer patients undergoing polychemotherapy including adriamycin. In 8 patients significant increases in myoglobin levels were found after injection of low doses of the drug (25-50 mg/m2). Moreover, a disturbance of the normal biorhythm of the protein was evident in 12 patients. Creatine kinase-MB was evaluated by means of a radioimmunoassay, but there was no relation between an increase in the isoenzyme and an increase in myoglobin. No ECG modifications were detected. These data indicate that the measurement of myoglobin may offer an indication of myocardial or skeletal muscle damage caused by adriamycin.

[The role of flow cytometry in the study of physiopathology of neutrophilic granulocytes]. / Il ruolo della citometria a flusso nello studio della fisiopatologia dei granulociti neutrofili.

Flow cytometry represents an interesting methodological approach to human neutrophil function assessment and to the study of neutrophil biology. Several aspects of neutrophil activation can be evaluated by means of such technology: phagocytosis, respiratory burst, surface markers, modifications in intracellular pH, actin polymerization, membrane potential, aggregation. Neutrophil flow cytometric evaluation is suitable for whole blood evaluation and has been shown to be very specific and sensitive. In particular, whole blood methods have been developed in order to investigate phagocytosis, hydrogen peroxide production, and surface markers expression (integrins, receptors for the Fc fragment of IgG, selectins, etc.). Other aspects of neutrophil activation have to be investigated by using purified neutrophils.

In vitro effects of an immunoglobulin preparation for intravenous use (IVIG) on T-cells activation.

The "in vitro" effect of different concentrations of polyclonal human immunoglobulins for intravenous use (IVIG) on cultured T-lymphocyte response to phytohemagglutinin (PHA) was evaluated. Four dilutions of IVIG corresponding with the "in vitro" doses currently employed in therapy have been tested by the effect on PHA stimulated cultures. The dilution of IVIG corresponding with a low therapeutical dose gives a higher statistically significant stimulating effect. The results obtained in our work agree with previous studies performed on activated B-cells. We can suppose the immunoglobulins may control the T-lymphocyte activation either by a direct link with a specific Fc-receptor expressed on the surface of activated T-cell or by affecting the cytokines release from monocyte cells.

Mycobacterial infection in HIV+ patients detected with a new immunological method (TB test).

Antibody response to antigen A60 (a mycobacterial antigen) was evaluated in ELISA in 18 HIV+ subjects with clinical and cultural evidences of mycobacterial infections, in 10 HIV+ subjects without Mycobacterial infections and in 22 healthy donors. We found higher levels of specific IgG in the HIV+ patients with Mycobacterial infections (mean 179.2 +/- 83 U) compared to the values of the donors (mean 92.5 +/- 35.5 U: p < 0.01). This test may be useful in the diagnosis of tuberculosis, but it needs clinical validation.

IgE modification of the specific antidermatophagoides during the first year of specific immunotherapy (SIT).

Six subjects (4 female, 2 male), aged from 16 to 25 years, presented with allergic rhinitis to Dermatophagoides mites and received SIT by the sub-cutaneous route with delayed-release alpha fraction Bayropharm at the standard doses. Diagnosis was based on clinical history, skin tests and measurement of specific IgE at 0, 3, 9, and 12 months, by the fluoro-enzymatic technique (FAST). For comparison, in a reference group (n = 20) the IgE varied between 0.32 and 0.11 IU/ml for D1 and 0.31 to 0.09 IU/ml for D2. The eight patients had specific IgE titres of D1 = 0.96, D2 = 0.99. For these authors, the FAST technique used for the measurement of specific IgE, although less sensitive than the RIA technique of RAST, gives a good evaluation of SIT.

The mechanisms of nadroparin-mediated inhibition of proliferation of two human lung cancer cell lines.

OBJECTIVES: Clinical data suggest that heparin treatment improves survival of lung cancer patients, but the mechanisms involved are not fully understood. We investigated whether low molecular weight heparin nadroparin, directly affects lung cancer cell population growth in conventionally cultured cell lines. MATERIALS AND METHODS: A549 and CALU1 cells' viability was assessed by MTT and trypan blue exclusion assays. Cell proliferation was assessed using 5-bromo-2-deoxyuridine incorporation. Apoptosis and cell-cycle distribution were analysed by flow cytometry; cyclin B1, Cdk1, p-Cdk1 Cdc25C, p-Cdc25C and p21 expressions were analysed by western blotting. mRNA levels were analysed by real time RT-PCR. RESULTS: Nadroparin inhibited cell proliferation by 30% in both cell lines; it affected the cell cycle in A549, but not in CALU-1 cells, inducing arrest in the G(2) /M phase. Nadroparin in A549 culture inhibited cyclin B1, Cdk1, Cdc25C and p-Cdc25C, while levels of p-Cdk1 were elevated; p21 expression was not altered. Dalteparin caused a similar reduction in A549 cell population growth; however, it did not alter cyclin B1 expression as expected, based on previous reports. Fondaparinux caused minimal inhibition of A549 cell population growth and no effect on either cell cycle or cyclin B1 expression. CONCLUSIONS: Nadroparin inhibited proliferation of A549 cells by inducing G(2) /M phase cell-cycle arrest that was dependent on the Cdc25C pathway, whereas CALU-1 cell proliferation was halted by as yet not elucidated modes.

Glucose tolerance is negatively associated with circulating progenitor cell levels.

AIMS/HYPOTHESIS: Circulating progenitor cells participate in cardiovascular homeostasis. Depletion of the pool of endothelial progenitor cells (EPCs) is associated with increased cardiovascular risk. Furthermore, EPCs are reduced in the presence of classical risk factors for atherosclerotic disease, including diabetes mellitus. This study was designed to evaluate progenitor cell levels in volunteers with different degrees of glucose tolerance. METHODS: Cardiovascular parameters and the levels of circulating CD34(+) and CD34(+) kinase insert domain receptor (KDR)(+) cells were determined in 219 middle-aged individuals with no pre-diagnosed alterations in carbohydrate metabolism. Glucose tolerance was determined by fasting and 2 h post-challenge glucose levels, with IFG and IGT considered as pre-diabetic states. RESULTS: CD34(+) and CD34(+)KDR(+) cells were significantly reduced in individuals who were found to have diabetes mellitus, and were negatively correlated with both fasting and post-challenge glucose in the whole population. While only CD34(+) cells, but not CD34(+)KDR(+) cells, were significantly reduced in pre-diabetic individuals, post-challenge glucose was an independent determinant of the levels of both CD34(+) and CD34(+)KDR(+) cells. CONCLUSIONS/INTERPRETATION: Glucose tolerance was negatively associated with progenitor cell levels in middle-aged healthy individuals. Depletion of endothelial progenitors with increasing fasting and post-meal glucose may be one cause of the high incidence of cardiovascular damage in individuals with pre-diabetes.

Cellular protection mechanisms against extracellular heme. heme-hemopexin, but not free heme, activates the N-terminal c-jun kinase.

Hemopexin protects cells lacking hemopexin receptors by tightly binding heme abrogating its deleterious effects and preventing nonspecific heme uptake, whereas cells with hemopexin receptors undergo a series of cellular events upon encountering heme-hemopexin. The biochemical responses to heme-hemopexin depend on its extracellular concentration and range from stimulation of cell growth at low levels to cell survival at otherwise toxic levels of heme. High (2-10 microM) but not low (0.01-1 microM) concentrations of heme-hemopexin increase, albeit transiently, the protein carbonyl content of mouse hepatoma (Hepa) cells. This is due to events associated with heme transport since cobalt-protoporphyrin IX-hemopexin, which binds to the receptor and activates signaling pathways without tetrapyrrole transport, does not increase carbonyl content. The N-terminal c-Jun kinase (JNK) is rapidly activated by 2-10 microM heme-hemopexin, yet the increased intracellular heme levels are neither toxic nor apoptotic. After 24 h exposure to 10 microM heme-hemopexin, Hepa cells become refractory to the growth stimulation seen with 0.1-0.75 microM heme-hemopexin but HO-1 remains responsive to induction by heme-hemopexin. Since free heme does not induce JNK, the signaling events, like phosphorylation of c-Jun via activation of JNK as well as the nuclear translocation of NFkappaB, G2/M arrest, and increased expression of p53 and of the cell cycle inhibitor p21(WAF1/CIP1/SDI1) generated by heme-hemopexin appear to be of paramount importance in cellular protection by heme-hemopexin.

Immune cell imbalance in major depressive and panic disorders.

We investigated subsets of peripheral immunologic cells in 12 drug-free patients affected by major depression according to DSM-III-R criteria, and who had recent evidence of somatic diseases. They were compared with 10 drug-free depressives, with 10 patients with panic disorder, and with 12 healthy volunteers, all without somatic disease. The immune subsets were measured by flow cytometry. The results showed that both groups of depressives had the same abnormalities in immune cells compared with the healthy volunteers or the panic disorder patients; in particular they presented a lower number of CD3+, CD8+ and HLA-DR+. The patients with panic attacks did not differ from healthy controls, except for CD4+ cells which were significantly lowered, even in comparison with the depressive groups. These data, although preliminary and in a small sample, suggest that some immune parameters may be influenced by the presence of a major psychiatric disorder.