Iron metabolism markers and haptoglobin phenotypes in susceptibility to HSV-1 or/and HSV-2 lesion relapses.

Different haptoglobin (Hp) phenotypes play a role in several pathologic processes including infectious diseases. In order to evaluate the role of iron storage and metabolism in susceptibility to herpetic manifestations, we studied the frequency of the Hp phenotypes and iron metabolism in patients affected by H. Simplex virus 1 or 2 (HSV-1 or HSV-2), compared with controls. Hp phenotype and iron metabolism were determined in 100 patients with recurrent HSV-1 or HSV-2 manifestations during the relapses, and in 110 healthy subjects. The frequencies of the three Hp phenotypes in the patient group compared to the control group were 18% versus 14.5% p = NS for Hp 1.1, 25% versus 40% p = 0.03 for Hp 2.2 and 57% versus 45.5% p = NS for Hp 2.1. All iron metabolism parameters tested showed significant differences between patients and controls; haemoglobin (Hb), ferritin, and serum iron were lower, while transferrin was higher in the patients than in controls. Reductions in iron availability may be a risk factor for relapsing lesions of HSV-1 or HSV-2. Hp 2.2 phenotype may offer some protection against the recurrence of Herpes labialis or genitalis manifestations.

Infectious and inflammatory stimuli decrease endothelial nitric oxide synthase activity in vitro.

BACKGROUND: Perturbation of iron metabolism, especially the increase of serum ferritin levels, is often associated with both inflammation and hypertension. Changes in iron availability can affect an important regulator of vascular tone, the endothelial nitric oxide synthase (eNOS), activated by a heme-dependent dimerization. OBJECTIVE: To study the regulation of the anti-hypertensive eNOS in human endothelial cells, in correlation with iron metabolism alterations and stimuli triggering them in vivo, such as inflammation or infection. DESIGN: Cells were treated with stimuli mimicking infection or inflammation [lipopolysaccharide (LPS) and/or tumor necrosis factor alpha (TNFalpha)]. and iron shortage (succinylacetone and desferrioxamine). The effect on eNOS expression and activation was evaluated, as well as ferritin content. METHODS: eNOS protein expression was evaluated by separating the monomeric from the active dimeric form by low-temperature sodium dodecyl sulphate poly-acrylamide gel electrophoresis (SDS-PAGE), and mRNA was analyzed by semi-quantitative reverse transcriptase (RT)-polymerase chain reaction (PCR). As for LPS and TNFalpha, eNOS monomer decreased already after a 72-h treatment and further at 144 h, whereas the down-regulation of the dimer was slower, peaking at 144 h. Succinylacetone and desferrioxamine were effective only at 144 h. The mRNA levels were increasingly reduced after incubation, more markedly by LPS and TNFalpha together, whereas succinylacetone and desferrioxamine had no effect on transcription. We found that endothelial cells are not the source of increased ferritin production. CONCLUSIONS: The results of this study suggest a down-regulating effect of infectious and inflammatory stimuli on eNOS expression, both at the mRNA level and protein expression or stability and dimerization, enhanced by heme and iron shortage, and indicate eNOS as a possible link between infection and hypertension.

Role of iron metabolism and oxidative damage in postmenopausal bone loss.

It has been suggested that iron-deficient rats have lower bone mass than iron-replete animals, but a clear association between bone and iron repletion has not been demonstrated in humans. A growing body of evidences also suggests a relation between lipid oxidation and bone metabolism and between iron metabolism and LDL oxidation. Iron availability to cells also depends on haptoglobin (Hp) phenotypes. Hp has also important antioxidant properties according to its phenotype, hence we evaluate whether Hp phenotype could influence bone density, iron metabolism and lipid oxidation. This cross-sectional study enrolled 455 postmenopausal women affected by osteoporosis (260) or not (195). Bone mineral density, markers of bone and iron metabolism, levels of oxidized LDL (oxLDL) and Hp phenotype were measured in all the subjects. Hp 1.1 and 2.2 frequency was higher and Hp 2.1 was lower in the patients with fragility fractures (80) compared with the controls. We therefore evaluate different Hp phenotypes as risk or protective factors against fragility fracture: Hp 2.1 is a protective factor against fracture while 1.1 is an important and 2.2 a moderate risk factor for fragility fractures. Lower serum iron was associated with elevated transferrin in patients with Hp 1.1; moreover patients had relative iron deficiency compared with the controls and fractured patients had higher level of oxLDL. We found that both iron metabolism and oxLDL varies according to Hp phenotypes and are predictive of bone density. Our data indicate that Hp 2.1 is a protective factor for fragility fractures, depending on its role on iron metabolism and its antioxidant properties.

Anti-HIV effects of chloroquine: inhibition of viral particle glycosylation and synergism with protease inhibitors.

OBJECTIVE: We tested the effects of chloroquine (CQ) on glycosylation of HIV particles and in combination with protease inhibitors (PIs) on HIV replication and on P-glycoprotein (P-gp)/multidrug resistance protein-1 (MRP1). DESIGN: CD4 cell lines were infected with laboratory strains and peripheral blood mononuclear cells were infected with primary isolates for evaluation of the anti-HIV effects. Peripheral blood lymphocytes were evaluated for of P-gp and MRP1 functions. METHODS: HIV replication was assessed by enzyme-linked immunosorbent assay. HIV glycosylation was measured by metabolic labeling of viral particles with [H] glucosamine. Synergism was tested using isobolograms. P-gp and MRP1 functions were assayed using rhodamine 123 (Rh123) and carboxyfluorescein (CF) efflux assays, respectively. RESULTS: CQ alone inhibited HIV replication and glycosylation in a dose-dependent manner. In combination with indinavir (IDV), ritonavir, or saquinavir (SQV), CQ had a synergistic effect at concentrations found in plasma of subjects receiving malaria prophylaxis. CQ decreased the 50% effective concentration of IDV in primary isolates from Africa and restored the response to IDV or SQV in 3 PI-resistant isolates. CQ increased the block of Rh123 and CF efflux activity exerted by PIs. CONCLUSION: The inhibitory effects of CQ on HIV glycosylation are associated with synergistic effects in combination with PIs. The CQ/PI combination exerts combined inhibitory effects on P-gp and MRP1 function.