Decreased T lymphocyte infiltration in bronchial biopsies of subjects with severe chronic obstructive pulmonary disease

BACKGROUND: Studies on the inflammatory process in the large airways of patients with mild/moderate COPD have shown a prevalent T lymphocyte and macrophage infiltration of the bronchial mucosa. However, bronchial inflammation in more severe disease has not been extensively studied. OBJECTIVE: The aim of the present study was to characterize the lymphocyte infiltration in the bronchial mucosa of subjects with severe, compared to mild, COPD, and to examine the relationship between airflow limitation and T lymphocyte numbers in the bronchial mucosa. METHODS: We examined bronchial biopsies obtained from nine smokers with severe airflow limitation, nine smokers with mild/moderate airflow limitation and 14 smokers with normal lung function. Immunohistochemical methods on cryostat sections were used to assess the number of CD3+, CD4+, CD8+ cells and the number of CD3+ cells coexpressing the chemokine receptor CCR5 (CCR5+CD3+) in the subepithelium. RESULTS: Subjects with severe COPD had lower numbers of CD3+, CD8+ and CCR5+CD3+ cells than mild/moderate COPD (P < 0.012, P < 0.02 and P < 0.02, respectively) and control smokers (P < 0.015, P < 0.005 and P < 0.015, respectively). In subjects with airflow limitation the number of CD3+ and CD8+ cells was inversely correlated with the degree of airway obstruction (r = 0.59, P < 0.015 and r = 0.52, P < 0.032, respectively). CONCLUSIONS: Bronchial inflammation in severe COPD is characterized by lower numbers of CD3+ and CD8+ cells and decreased numbers of CD3+ cells coexpressing the chemokine receptor CCR5. T lymphocyte infiltration is inversely correlated with the degree of airflow limitation.     

Increased MCP-1 and MIP-1beta in bronchoalveolar lavage fluid of chronic bronchitics.

CC-chemokines are chemotactic factors expressed in a wide range of cell types and tissues. The aim of this study was to evaluate the involvement of CC-chemokines in the airways inflammation of patients affected by chronic bronchitis. The study evaluated, with an immunoassay, the concentrations of monocyte chemotactic protein-1 (MCP-1), macrophage inflammatory protein-1alpha (MIP-1alpha) and macrophage inflammatory protein-1beta (MIP-1beta), in the bronchoalveolar lavage fluid (BALF) of 12 smokers affected by chronic bronchitis and 14 smoking, 15 nonsmoking and six exsmoking healthy subjects. MCP-1 was significantly increased in patients with chronic bronchitis ((mean+/-SD) 10.75+/-4.04 pg x mL(-1)) and in the smoker control group (12.39+/-5.87 pg x mL(-1)) compared with healthy exsmokers: (7.12+/-1.60 pg x mL(-1), p=0.035 and p=0.045, respectively) and nonsmokers (6.41+/-3.87 pg x mL(-1), p=0.003 and p=0.006, respectively). MIP-1alpha concentrations were undetectable. A significant difference was observed in MIP-1-beta levels in BALF of chronic bronchitics (8.11+/-5.97 pg x mL(-1)) compared to smoker (3.57+/-2.90 pg x mL(-1), p=0.018), exsmoker (3.43+/-0.68 pg x mL(-1), p=0.025) and nonsmoker (3.39+/-3.73 pg x mL(-1), p=0.008) control groups. A negative correlation was observed between MIP-1beta levels and forced expiratory volume in one second values (p=-0.64, p=0.035) in chronic bronchitics. An increase of monocyte chemotactic protein-1 is related to smoking habit and seems consistent with a lung inflammatory reaction. On the contrary, an increase in macrophage inflammatory protein-1beta levels is restricted to smokers developing chronic obstructive pulmonary disease. These data suggest a role of CC-chemokines in the pathogenesis of chronic bronchitis.     

Regeneration of perivascular adrenergic innervation in rat tibial nerve after nerve crush

Summary Adrenergic innervation of blood vessels in the rat tibial nerve during degeneration and regeneration was studied using the formaldehyde-induced fluorescence method. The left sciatic nerve was crushed with suture threads to produce a 4-mm length of crushed nerve. At 1, 3, 7, 14, 28, 56 and 84 days after nerve crush, degenerative and regenerative changes in the nerve were verified using light microscopy. At each time point, adrenergic innervation was examined in epi-perincurial whole mount and nerve cross-section preparations. One day after nerve crush, fluorescence of adrenergic nerve fibers in the endoneurium was absent. Fluorescent adrenergic nerve fibers reappeared in the endoneurium at day 56 and reached the control density by 84 days. In the epi-perineurium, adrenergic innervation of small and medium-size arterioles was absent at 3 days, in large arterioles at 7 days. At 56 days, all epi-perineurial arterioles were reinnervated by a faint, sparse adrenergic network, which reached the control density at 84 days. The results suggest that adrenergic innvervation in the rat peripheral nerve is lost during nerve degeneration, but recovers when the nerve has regenerated.     

Increased synaptic depression in the Ts65Dn mouse, a model for mental retardation in Down syndrome

Long-term potentiation (LTP) and depression (LTD) were investigated in hippocampus of a genetic model of Down syndrome, the segmental trisomy (Ts65Dn) mouse. Field excitatory postsynaptic potentials were recorded from hippocampal slices and LTP and LTD evoked sequentially. LTP decreased whereas LTD increased significantly in Ts65Dn compared with control hippocampus.     

Correlation between serum retinol and alpha-tocopherol levels in centenarians

Recent evidence indicates that longevity may be achieved when efficient defence mechanisms against oxidative stress, infections, neoplasia, and cardiovascular events are preserved. Centenarians represent an example of "successful aging," and the aim of this study was to evaluate serum levels of vitamins A and E, which represent two important nonenzymatic antioxidant defence systems, and their correlation in 16 healthy centenarians and two groups of control subjects. Centenarians showed normal values of retinol (450.9 +/- 240.3 ng/mL) and alpha-tocopherol (9220.2 +/- 3410.9 ng/mL). Moreover, a significant direct correlation between the two vitamins was observed in centenarians (Rho = 0.715, p = 0.0056), such as in younger control subjects (Rho = 0.618, p = 0.0168), but not in older control subjects. We assume that the preservation of normal values and the correlation between vitamin A and E concentrations protects centenarians against oxidative stress and contributes to their extreme longevity.     

Studies on inhibition of human platelet function by sodium nitroprusside. Kinetic evaluation of the effect on aggregation and cyclic nucleotide content

In this study, we explored the ability of sodium nitroprusside to inhibit the aggregation of human platelets in platelet-rich plasma (PRP) and whole blood and its effects on intracellular levels of guanosine 3',5'-cyclic monophosphate (cGMP) and adenosine 3',5'-cyclic monophosphate (cAMP). The experiments investigated dose-dependent effects of nitroprusside starting from concentrations in the range of circulating levels achievable in vivo during drug administration in humans. Furthermore, we investigated the time-course of both antiaggregating action and the influence on cyclic nucleotide synthesis. Results showed that sodium nitroprusside inhibited the aggregation induced by adenosine 5-diphosphate (ADP) and collagen starting from concentration as low as 2 micromol/l. The IC(50) value for ADP-induced aggregation in PRP was 18.7+/-2.4 micromol/l. The inhibition of platelet aggregation showed a time-dependent behaviour and was not reversible within 90 min. The accumulation of intraplatelet cGMP in the presence of sodium nitroprusside exhibited a comparable time-course characterized by an early increase, a steady state and a late further increase. The time-course of cAMP synthesis was very similar to that of cGMP. Our data evidenced a long-lasting inhibition of platelet responses by sodium nitroprusside and excluded a desensitization of platelet guanylyl cyclase after 3-h exposure to nitric oxide (NO). Furthermore, they indicated a role of cAMP accumulation in the antiaggregating effects of nitroso donor: the simultaneous increase of intracellular content of cAMP and cGMP can synergize in the reduction of the platelet responses.     

RB18A, whose gene is localized on chromosome 17q12-q21.1, regulates in vivo p53 transactivating activity

Among the different cellular factors that regulated p53 functions, we previously identified (P. Drane et al., Oncogene, 15: 3013-3024, 1997) RB18A, a new gene whose encoded Mr 205,000 protein interacted in vitro, through its COOH-terminal domain, with p53. Therefore, we analyzed the in vivo role of RB18A by measuring its effect on the transactivating activity of p53 on physiological promoters. We herein demonstrated that RB18A, which interacted also in vivo with p53, activated Bax promoter and inhibited p21Waf1 or IGF-BP3 promoters. In addition, fluorescence in situ hybridization mapping led to localizing the RB18A gene on chromosome 17q12-q21.1, loci associated with human cancers. This is the first demonstration that in vivo RB18A, in a protein-protein interaction, regulates p53 transactivating activity.