Effects of long-term adrenalectomy on apoptosis and neuroprotection in the rat hippocampus

Reduction in corticosterone by acute adrenalectomy (5 d) promotes apoptosis in dentate gyrus (DG) granular neurons, an effect concomitant with variations in the expression of the Bcl-2 gene family implicated in apoptotic regulation. However, no studies exist correlating the effect of long-term adrenalectomy (30 d) on the hippocampus in terms of extent of apoptosis and the levels of proteins related to an apoptotic cascade. After 5 d of adrenalectomy, we found an increase in apoptosis of the DG granular region, correlated with an increase in the processing of caspase-9. The magnitude of apoptosis 30 d after adrenalectomy was reduced in the DG granular layer compared with 5 d after adrenalectomy, in close relation to a reduction in the level of processed caspase-9. To understand how the increase in cell survival long after adrenalectomy occurs, we analyzed changes in the expression of genes and proteins related to apoptosis. Long-term adrenalectomy did not change hippocampal pro-apoptotic Bax or antiapoptotic Bcl-2 mRNA levels or protein content with respect to control. However, we found an increase in mRNA levels of the GD's Bcl-x gene, in parallel with the increase in anti-apoptotic BCL-XL protein levels. These results suggest the reduction in apoptosis observed after long-term adrenalectomy occurs through mechanisms that repress proapoptotic genes previously found to be increased at shorter times of adrenalectomy.     

Noninvasive proportional assist ventilation and pressure support ventilation during arm elevation in patients with chronic respiratory failure. A preliminary, physiologic study

BACKGROUND: It has been shown that upper limbs activity increases the respiratory workload in patients with chronic respiratory failure (CRF). The object of the present study was to investigate whether, in these patients: (i) noninvasive positive pressure ventilation (NPPV) could sustain the inspiratory muscles to meet the greater ventilatory demand during upper limbs activity with the arm elevation test (AE); (ii) proportional assist ventilation (PAV) might be superior to pressure support ventilation (PSV) during AE, because of its potential more adaptable response to sudden changes in the ventilatory pattern. METHODS: The study was performed in the pulmonary function laboratory of the Pulmonary Division in Verona General Hospital, Verona, Italy. We studied 8 male patients with CRF due to chronic obstructive pulmonary disease (COPD). Each patient received 2 treatment in random order with a crossover design: spontaneous breathing (SB), SB with AE, either PSV or PAV without and with AE, SB without and with AE, either PSV or PAV without and with AE. We measured: lung function tests, lung mechanics, ventilatory pattern and diaphragmatic effort (pressure time product, PTP(di)). RESULTS: (i) AE increases minute ventilation (+14%) and PTP(di) (+64%); (ii) ventilatory support, both with PSV and PAV unloads the diaphragm both at rest (PTP(di) -77% and -54%, respectively) and during arm elevation (PTP(di) -54% and -44%, respectively). CONCLUSIONS: PAV and PSV unloads the diaphragm in patients with CRF due to COPD both during SB and AE; PAV can be more efficient than PSV in assisting the diaphragm during AE in producing a greater level of minute ventilation for a similar rise in PTP(di) compared to PSV. Noninvasive ventilatory support should be considered in rehabilitation programs for training of upper limbs activity.     

Isolated bone marrow occurrence of classic Hodgkin's lymphoma in an HIV-negative patient

Classic Hodgkin's Lymphoma is a disease usually characterized by lymph nodal presentation. Rare cases with extra-nodal first clinical manifestation may occur, and primary bone marrow involvement may be part of them: isolated bone marrow forms have been recently described in the context of HIV infection. We herein report a case of isolated bone marrow Hodgkin's Lymphoma occurrence in a HIV-negative, elderly patient. The impacts of such unusual Hodgkin's Lymphoma manifestation on clinical practice as well as the related diagnostic and therapeutic implications are discussed.     

Dysmetabolic syndrome in a man with a novel mutation of the aromatase gene: effects of testosterone, alendronate, and estradiol treatment

We present the fourth case of an adult man (29 yr old) affected by aromatase deficiency resulting from a novel homozygous inactivating mutation of the CYP19 (P450(arom)) gene. At first observation, continuing linear growth, eunuchoid body proportions, diffuse bone pain, and bilateral cryptorchidism were observed. The patient presented also a complex dysmetabolic syndrome characterized by insulin resistance, diabetes mellitus type 2, acanthosis nigricans, liver steatohepatitis, and signs of precocious atherogenesis. The analysis of the effects induced by the successive treatment with high doses of testosterone, alendronate, and estradiol allows further insight into the roles of androgens and estrogens on several metabolic functions. High doses of testosterone treatment resulted in a severe imbalance in the estradiol to testosterone ratio together with the occurrence of insulin resistance and diabetes mellitus type 2. Estrogen treatment resulted in an improvement of acanthosis nigricans, insulin resistance, and liver steatohepatitis, coupled with a better glycemic control and the disappearance of two carotid plaques. Furthermore, the study confirms previous data concerning the key role of estrogens on male bone maturation, at least in part, and regulation of gonadotropin secretion. The biopsy of the testis showed a pattern of total germ cell depletion that might be due to the concomitant presence of bilateral cryptorchidism. Thus, a possible role of estrogen in male reproductive function is suggested but without revealing a direct cause-effect relationship. Data from this case provide new insights into the role of estrogens in glucose, lipid, and liver metabolism in men. This new case of aromatase deficiency confirms previous data on bone maturation and mineralization, and it reveals a high risk for the precocious development of cardiovascular disease in young aromatase-deficient men.     

Paraoxonase polymorphisms PON1 192 and 55 and longevity in Italian centenarians and Irish nonagenarians. A pooled analysis

BACKGROUND: PON1, an arylesterase, associated with high density lipoprotein (HDL), protects low density lipoprotein (LDL) against oxidative modification. Common polymorphisms PON1 55 (L/M) and 192 (Q/R) in the PON1 gene associate with atherosclerosis and heart disease. Because long-lived people seem protected from premature vascular death, we conducted a pooled statistical analysis to assess any association between these polymorphisms and longevity in a large combined group of Italian centenarians and octo/nonagenarians from Northern Ireland (NI). MATERIALS AND METHODS: Separated DNA was available from 1479 subjects from Italy and Northern Ireland (NI). In Italy 308 centenarians (males 67, females 241, mean age 100.8, SD2.1 years) and 579 young controls (males 347, females 232, mean age 40.7, SD 12.7 years) were included in the study. In NI, 296 octo/nonagenarians (males 92, females 204, mean age 89.8, SD 5.7 years) and 296 young sex-matched subjects (mean age 13.0, SD 1.4 years) had available DNA. PON1 55 (L/M) and 192 (Q/R) polymorphisms were studied using a PCR-RFLP approach. RESULTS: There was a significant difference in PON1 192 genotypes in Italian centenarians compared to younger controls (X(2)= 6.8, df = 2 p= 0.03) and a similar but non significant trend between octo/nonagenarian and young subjects in NI (X(2) = 4.0, df=2, p=0.14). Using logistic regression analysis on the combined Italian and Irish datasets, there was a small survival advantage for centenarian and octo/nonagenarian subjects who were heterozygous for PON1 192 R allele, (OR 1.3, CI 1-1.6; p=0.04 with a stepwise increase for RR homozygous subjects (OR 1.7, CI 1.1-2.6; p = 0.02) compared to QQ subjects. Comparing R and Q alleles there was a survival advantage for octo/nonagenarian/centenarian subjects who carried the R allele (OR 1.3, CI 1.1-1.5; p = 0.007) but there was no sex-specific effect p =0.77) LL, LM and MM genotypes of PON 55 polymorphisms showed similar frequencies in Italy (39.9, 47.0, 13.1%) and Ireland (39.5, 48.6, 11.9%) with no age or sex-related differences. The PON1 192R/Q and PON55L/M loci were in strong linkage disequilibrium with a Lewontin's D' coefficient -0.928 (elderly) and -0.965 (young). There was a significant difference in haplotype frequency of these linked loci in older compared to younger subjects (Likelihood Ratio X(2) = 9.60, df = 3, p= 0.02). CONCLUSION: These data suggest a modest association between the 192R allele and longevity in two very elderly populations in two European countries. Being homozygous for 192 RR further enhances survival advantage but this effect was not found to be sex specific. This finding is of interest because the 192R allele has previously been associated with increased risk of coronary heart disease. On the other hand, the 192R allele shows higher enzymatic activity, using paraoxon as substrate, and we postulate that its role in the metabolism of potentially toxic chemicals or other metabolic pathways may be important in survival to very old age.     

Bilirubin protects astrocytes from its own toxicity by inducing up-regulation and translocation of multidrug resistance-associated protein 1 (Mrp1)

Unconjugated bilirubin (UCB) causes encephalopathy in severely jaundiced neonates by damaging astrocytes and neurons. Astrocytes, which help defend the brain against cytotoxic insults, express the ATP-dependent transporter, multidrug resistance-associated protein 1 (Mrp1), which mediates export of organic anions, probably including UCB. We therefore studied whether exposure to UCB affects the expression and intracellular localization of Mrp1 in cultured mouse astroglial cells (>95% astrocytes). Mrp1 was localized and quantitated by confocal laser scanning microscopy and double immunofluorescence labeling by using specific antibodies against Mrp1 and the astrocyte marker glial fibrillary acidic protein, plus the Golgi marker wheat germ agglutinin (WGA). In unexposed astrocytes, Mrp1 colocalized with WGA in the Golgi apparatus. Exposure to UCB at a low unbound concentration (Bf) of 40 nM caused rapid redistribution of Mrp1 from the Golgi throughout the cytoplasm to the plasma membrane, with a peak 5-fold increase in Mrp1 immunofluorescence intensity from 30 to 120 min. Bf above aqueous saturation produced a similar but aborted response. Exposure to this higher Bf for 16 h markedly decreased Trypan blue exclusion and methylthiazoletetrazoilum activity and increased apoptosis 5-fold by terminal deoxynucleotidyltransferase-mediated dUTP nick end labeling assay. These toxic effects were modestly increased by inhibition of Mrp1 activity with 3-([3-(2-[7-chloro-2-quinolinyl]ethenyl)phenyl-(3-dimethylamino-3-oxopropyl)-thio-methyl]thio)propanoic acid (MK571). By contrast, Bf=40 nM caused injury only if Mrp1 activity was inhibited by MK571, which also blocked translocation of Mrp1. Our conclusion is that in astrocytes, UCB up-regulates expression of Mrp1 and promotes its trafficking from the Golgi to the plasma membrane, thus moderating cytotoxicity from UCB, presumably by limiting its intracellular accumulation.     

Gas1 is induced by VE-cadherin and vascular endothelial growth factor and inhibits endothelial cell apoptosis

The junctional membrane protein vascular endothelial (VE)-cadherin mediates contact inhibition of growth and inhibits apoptosis of endothelial cells. In this article we show that VE-cadherin induces expression of growth arrest-specific 1 (Gas1), an integral membrane protein up-regulated in nonproliferating cells. By comparing syngenic endothelial cell lines, we found that Gas1 mRNA was increased by 3-fold in VE-cadherin-positive cells in comparison to VE-cadherin-null cells. Ectopic expression of Gas1 in endothelial or 293 cells strongly reduced apoptosis without affecting cell growth. Addition of vascular endothelial growth factor (VEGF) also up-regulated Gas1 and this effect was augmented more so in confluent nonproliferating cells than in sparse cultures. VE-cadherin-blocking antibody partially inhibited VEGF-induced Gas1, suggesting that VE-cadherin clustering is required for an optimal response to this stimulus. Inhibition of phosphoinositole-3-OH kinase (PI3-kinase) pathway by Wortmannin prevented Gas1 synthesis and the antiapoptotic effect of VEGF, but, in cells ectopically expressing Gas1, Wortmannin was ineffective. Furthermore, inhibition of Gas1 expression by short interfering RNA (siRNA) both in vitro and in allantois organ cultures made endothelial cells refractory to the antiapoptotic effect of VEGF. Overall these data indicate that Gas1 induction by VE-cadherin and VEGF in endothelial cells requires activation of PI3-kinase. Gas1 expression positively correlates with inhibition of endothelial cell apoptosis and may contribute to the integrity of resting endothelium.     

Implication of inflammation-related cytokines in the natural history of liver cirrhosis.

BACKGROUND/AIMS: Increased serum concentrations of pro-inflammatory cytokines have been detected in patients with liver cirrhosis. However, their role in the natural history of cirrhosis and portal hypertension, in the absence of infection, and the prognostic significance of inflammation-related cytokines have not been reported. Our objective was the analysis of the prognostic value of inflammation-related cytokines in cirrhotic patients. PATIENTS AND METHODS: Serum concentrations of tumor necrosis factor (TNF-alpha) and its soluble receptors I and II and interleukin 6 (IL-6), as well as mean blood pressure, plasma renin activity, aldosterone, vasopressin and norepinephrine concentrations were determined in 72 cirrhotic patients (Child-Pugh score: A 50%, B 33.3%, C 16.7%), without any evidence of infection, and in 25 healthy controls. Patients were followed up for a median of 35.9 (range 6-60) months. RESULTS: Increased concentrations of soluble TNF receptors were detected in cirrhotic patients when compared with healthy controls. TNF receptors and IL-6 concentrations were both significantly more elevated in advanced phases of cirrhosis (Child-Pugh score C vs B and vs A). Sixteen patients died as a related consequence of liver cirrhosis. Multivariant analysis demonstrated that Child-Pugh score, mean blood pressure and serum levels of TNF receptor I were associated with mortality. CONCLUSIONS: In addition to the classic factors implicated in mortality (Child-Pugh score and hemodynamic parameters), alterations in inflammation-related components are of prognostic significance in cirrhotic patients.