Mast cell accumulation in glioblastoma with a potential role for stem cell factor and chemokine CXCL12

Glioblastoma multiforme (GBM) is the most common and malignant form of glioma with high mortality and no cure. Many human cancers maintain a complex inflammatory program triggering rapid recruitment of inflammatory cells, including mast cells (MCs), to the tumor site. However, the potential contribution of MCs in glioma has not been addressed previously. Here we report for the first time that MCs infiltrate KRas+Akt-induced gliomas, using the RCAS/TV-a system, where KRas and Akt are transduced by RCAS into the brains of neonatal Gtv-a- or Ntv-a transgenic mice lacking Ink4a or Arf. The most abundant MC infiltration was observed in high-grade gliomas of Arf-/- mice. MC accumulation could be localized to the vicinity of glioma-associated vessels but also within the tumor mass. Importantly, proliferating MCs were detected, suggesting that the MC accumulation was caused by local expansion of the MC population. In line with these findings, strong expression of stem cell factor (SCF), i.e. the main MC growth factor, was detected, in particular around tumor blood vessels. Further, glioma cells expressed the MC chemotaxin CXCL12 and MCs expressed the corresponding receptor, i.e. CXCR4, suggesting that MCs could be attracted to the tumor through the CXCL12/CXCR4 axis. Supporting a role for MCs in glioma, strong MC infiltration was detected in human glioma, where GBMs contained significantly higher MC numbers than grade II tumors did. Moreover, human GBMs were positive for CXCL12 and the infiltrating MCs were positive for CXCR4. In conclusion, we provide the first evidence for a role for MCs in glioma.     

Secular trends in self reported sexual activity and satisfaction in Swedish 70 year olds: cross sectional survey of four populations, 1971-2001

Objective To study secular trends in self reported sexual behaviour among 70 year olds.Design Cross sectional survey.Settings Four samples representative of the general population in Gothenburg, Sweden.Participants 1506 adults (946 women, 560 men) examined in 1971-2, 1976-7, 1992-3, and 2000-1.Main outcome measures Sexual intercourse, attitudes to sexuality in later life, sexual dysfunctions, and marital satisfaction.Results From 1971 to 2000 the proportion of 70 year olds reporting sexual intercourse increased among all groups: married men from 52% to 68% (P=0.002), married women from 38% to 56% (P=0.001), unmarried men from 30% to 54% (P=0.016), and unmarried women from 0.8% to 12% (P<0.001). Men and women from later birth cohorts reported higher satisfaction with sexuality, fewer sexual dysfunctions, and more positive attitudes to sexuality in later life than those from earlier birth cohorts. A larger proportion of men (57% v 40%, P<0.001) and women (52% v 35%, P<0.001) reported very happy relationships in 2000-1 compared with those in 1971-2. Sexual debut before age 20 increased in both sexes: in men from 52% to 77% (P<0.001) and in women from 19% to 64% (P<0.001).Conclusion Self reported quantity and quality of sexual experiences among Swedish 70 year olds has improved over a 30 year period.     

The Role of Heparanase in Pulmonary Cell Recruitment in Response to an Allergic but Not Non-Allergic Stimulus

Heparanase is an endo-β-glucuronidase that specifically cleaves heparan sulfate proteoglycans in the extracellular matrix. Expression of this enzyme is increased in several pathological conditions including inflammation. We have investigated the role of heparanase in pulmonary inflammation in the context of allergic and non-allergic pulmonary cell recruitment using heparanase knockout (Hpa^-/-) mice as a model. Following local delivery of LPS or zymosan, no significant difference was found in the recruitment of neutrophils to the lung between Hpa^-/- and wild type (WT) control. Similarly neutrophil recruitment was not inhibited in WT mice treated with a heparanase inhibitor. However, in allergic inflammatory models, Hpa^-/- mice displayed a significantly reduced eosinophil (but not neutrophil) recruitment to the airways and this was also associated with a reduction in allergen-induced bronchial hyperresponsiveness, indicating that heparanase expression is associated with allergic reactions. This was further demonstrated by pharmacological treatment with a heparanase inhibitor in the WT allergic mice. Examination of lung specimens from patients with different severity of chronic obstructive pulmonary disease (COPD) found increased heparanase expression. Thus, it is established that heparanase contributes to allergen-induced eosinophil recruitment to the lung and could provide a novel therapeutic target for the development of anti-inflammatory drugs for the treatment of asthma and other allergic diseases.     

Studies on the further activation of benzo[a]pyrene diol epoxides by rat liver microsomes and nuclei

The syn- and anti-diastereoisomers of trans-7,8-dihydroxy-9,10-oxy-7,8,9,10-tetrahydrobenzo[a]pyrene (BPDE) were further metabolized by rat liver microsomes obtained from 3-methylcholanthrene(MC)-pretreated rats and NADPH to reactive intermediates, presumably 1,7,8- and 3,7,8-trihydroxy-9,10-oxy-7,8,9,10-tetrahydrobenzo[a]pyrenes (triol-epoxides), that bound to macromolecules or decomposed to products consistent with pentahydroxy derivatives of benzo[a]pyrene (BP-pentols). Three major metabolites of syn-BPDE and four major metabolites of anti-BPDE were isolated by high performance liquid chromatography and characterized by spectroscopic techniques. When fluorescence spectroscopy was employed all metabolites exhibited very similar spectral properties and showed substantial shifts in excitation and emission maxima to longer wavelengths when measured under alkaline conditions, consistent with the presence of a phenolic hydroxyl group. Furthermore, the spectral properties of the metabolites from syn- and anti-BPDE were similar to those of 1-hydroxypyrene. Previous data from this laboratory together with the data presented in this study thus strongly suggest that further metabolism of BPDE involves hydroxylation at the 1- and 3-positions to yield the corresponding triol-epoxides and various BP-pentols. The pentols could also be formed by incubating tetrols derived from syn- and anti-BPDE with microsomes and NADPH. However, the rate of formation of pentols from the BP-tetrols was much slower than the rate of further metabolism of BPDE. Accordingly, the major route of BP-pentol formation is likely to be via the intermediate formation of triol-epoxides. Isolated liver nuclei from MC-pretreated rats were also found to catalyze the activation of anti-BPDE in presence of NADPH to reactive intermediates. This resulted in a substantial increase in binding to histone and non-histone proteins, with a concomitant decrease in binding to DNA. No qualitative change in the distribution of DNA-bound products of anti-BPDE could be demonstrated as a result of the further metabolism of anti-BPDE.     

Intracellular mapping of the distribution of metals derived from the antitumor metallocenes

The intracellular distribution of transition metals in V79 Chinese hamster lung cells treated with subtoxic doses of the organometallic anticancer complexes Cp₂MCl₂, where Cp is η ⁵ -cyclopentadienyl and M is Mo, Nb, Ti, or V, has been studied by synchrotron-based X-ray fluorescence (XRF). While significantly higher concentrations of Mo and Nb were found in treated cells compared with control cells, distinct differences in the cellular distribution of each metal were observed. Analysis of thin sections of cells was consistent with some localization of Mo in the nucleus. Studies with a noncytotoxic thiol derivative of molybdocene dichloride showed an uneven distribution of Mo in the cells. For comparison, the low levels of Ti and V in cells treated with the more toxic titanocene and vanadocene complexes, respectively, resulted in metal concentrations at the detection limit of XRF. The results agree with independent chemical studies that have concluded that the biological chemistry of each of the metallocene dihalides is unique.Electronic Supplementary Material Supplementary material is available for this article at .     

A role for serglycin proteoglycan in mast cell apoptosis induced by a secretory granule-mediated pathway

Mast cell secretory granules (secretory lysosomes) contain large amounts of fully active proteases bound to serglycin proteoglycan. Damage to the granule membrane will thus lead to the release of serglycin and serglycin-bound proteases into the cytosol, which potentially could lead to proteolytic activation of cytosolic pro-apoptotic compounds. We therefore hypothesized that mast cells are susceptible to apoptosis induced by permeabilization of the granule membrane and that this process is serglycin-dependent. Indeed, we show that wild-type mast cells are highly sensitive to apoptosis induced by granule permeabilization, whereas serglycin-deficient cells are largely resistant. The reduced sensitivity of serglycin(-/-) cells to apoptosis was accompanied by reduced granule damage, reduced release of proteases into the cytosol, and defective caspase-3 activation. Mechanistically, the apoptosis-promoting effect of serglycin involved serglycin-dependent proteases, as indicated by reduced sensitivity to apoptosis and reduced caspase-3 activation in cells lacking individual mast cell-specific proteases. Together, these findings implicate serglycin proteoglycan as a novel player in mast cell apoptosis.     

An approach to the differentiation of leucine and isoleucine residues in EI mass spectra of peptides

Residues of leucine and isoleucine cannot generally be distinguished in the electron impact (EI) generated mass spectra of N-acylated peptide esters. We have obtained the mass spectra of model peptide esters containing leucine or isoleucine in various positions and trifluoroacetyl perdeutero leucine as the N-terminal blocking group. The mass spectra of the peptide derivatives show a pair of peaks as a result of the elimination from the M⁺ ion of neutral fragment of perdeuterated isobutene (M⁺-64) from the leucine side chain of the N-terminal blocking group and isobutene or butene (M⁺-56) from leucine or isoleucine residues of the peptide. The ratios of the intensities of the peaks $\text{M}{}^{\mathrm{+}}\text{-56}\text{M}{}^{\mathrm{+}}\text{-64}$ show considerable variation with the position of leucine or isoleucine in the peptide chain and the length of the peptide, but for peptides which are identical except for the fact that one contains leucine and the other isoleucine in a given position the ratio is always smaller for the isoleucine containing peptide. The differences are sufficient to distinguish the isomeric residues if comparison spectra are available.