Curcumin downregulates the inflammatory cytokines CXCL1 and -2 in breast cancer cells via NFkappaB

The dietary antioxidant Curcumin has been proposed for cancer chemoprevention since it induces apoptosis and inhibits the formation of breast cancer metastases. Curcumin acts through the inhibition of phosphorylation of the inhibitor of kappa B (IkappaB), which in turn reduces the nuclear translocation of nuclear factor kappa B (NFkappaB), an inflammation- and cell survival-related transcription factor. However, it is not clear whether the strong antimetastatic effect can exclusively be explained by inhibition of NFkappaB. Here, we addressed the effects of Curcumin (IC(50) = 17 muM) in MDA-MB-231 breast cancer cells using microarray gene expression analyses. Among the 62 genes whose expression was significantly altered, we found the two inflammatory cytokines CXCL1 and -2 (Groalpha and -beta) that were downregulated. Further validation of the microarray results by quantitative real-time reverse transcription-polymerase chain reaction, western blots and enzyme-linked immunosorbent assay revealed that Curcumin impairs transcription of CXCL1 and -2 >24 h and reduces the corresponding proteins. Using small interfering RNA techniques, we elucidated the underlying molecular mechanism revealing that reduction of CXCL1 and -2 messenger RNA levels is NFkappaB dependent and requires intact IkappaBalpha expression. Moreover, CXCL1 and -2 silencing leads to downregulation of several metastasis-promoting genes among which we found the cytokine receptor CXCR4. We therefore suggest that the decrease of CXCL1 and -2 mediated by Curcumin is involved in the inhibition of metastasis.

The Wnt signal transduction pathway in stem cells and cancer cells: influence on cellular invasion

The regulative network conducting adult stem cells in endogenous tissue repair is of prime interest for understanding organ regeneration as well as preventing degenerative and malignant diseases. One major signal transduction pathway which is involved in the control of these (patho)physiological processes is the Wnt pathway. Recent results obtained in our laboratories showed for the first time that canonical Wnt signaling is critically involved in the control of the migration/invasion behaviour of human mesenchymal stem cells (hMSC). In the first part of this review, we describe that the regenerative state is closely linked to the activation of the Wnt pathway. Central hallmarks of activated stem cells are recapitulated in a similar way also in cancer metastasis, where the acquisition of an invasive cancer stem cell phenotype is associated with the induction of Wnt-mediated epithelial to mesenchymal transition (EMT). In the second part, the influence of proinflammatory cytokines such as transforming growth factor (TGF-)beta1, interleukin (Il-)1beta, and tumor necrosis factor (TNF-)alpha is discussed with regard to the invasive characteristics of hMSC. In this context, special attention has been paid on the role of matrix metalloproteinases (MMPs), such as MMP-2, MMP-9 and membrane type 1 (MT1)-MMP, as well as on the tissue inhibitors of metalloproteinases TIMP-1 and TIMP-2. Putative cross-talks between different signal transduction pathways that may amplify the invasive capacity of this stem cell population are also discussed. Finally, the consequences towards future drug-mediated therapeutical modifications of Wnt signaling in stem cells and tumor cells are highlighted.

Identification of a novel 82 kDa proMMP-9 species associated with the surface of leukaemic cells: (auto-)catalytic activation and resistance to inhibition by TIMP-1

MMP-9 (matrix metalloproteinase 9) plays a critical role in tumour progression. Although the biochemical properties of the secreted form of proMMP-9 are well characterized, little is known about the function and activity of cell surface-associated proMMP-9. We purified a novel 82 kDa species of proMMP-9 from the plasma membrane of THP-1 leukaemic cells, which has substantial differences from the secreted 94 kDa proMMP-9. The 82 kDa form was not detected in the medium even upon stimulation with a phorbol ester. It is truncated by nine amino acid residues at its N-terminus, lacks O-linked oligosaccharides present in the 94 kDa proMMP-9, but retains N-linked carbohydrates. Incubation of 94 kDa proMMP-9 with MMP-3 generated the well-known 82 kDa active form, but the 82 kDa proMMP-9 was converted into an active species of 35 kDa, which was also produced by autocatalytic processing in the absence of activating enzymes. The activated 35 kDa MMP-9 efficiently degraded gelatins, native collagen type IV and fibronectin. The enzyme was less sensitive to TIMP-1 (tissue inhibitor of metalloproteinase 1) inhibition with IC50 values of 82 nM compared with 1 nM for the 82 kDa active MMP-9. The synthetic MMP inhibitor GM6001 blocked the activity of both enzymes, with similar IC50 values below 1 nM. The 82 kDa proMMP-9 is also produced in HL-60 and NB4 leukaemic cell lines as well as ex vivo leukaemic blast cells. It is, however, absent from neutrophils and mononuclear cells isolated from peripheral blood of healthy individuals. Thus, the 82 kDa proMMP-9 expressed on the surface of malignant cells may escape inhibition by natural TIMP-1, thereby facilitating cellular invasion in vivo.

Human mesenchymal stem cells at the single-cell level: simultaneous seven-colour immunofluorescence

Extracellular, intracellular or surface proteins can be used as putative markers to characterize human mesenchymal stem cells (hMSC). However, these markers are also expressed by other cell types and primary cell pools reveal considerable heterogeneity. Therefore, the simultaneous detection of several markers on a single cell appears to be an attractive approach to identify hMSC. Here we demonstrate the specific distinction of human MSC from human osteoblasts via seven-colour fluorescence on the single cell level with simultaneous marker detection of CD44, CD105/endoglin, CD106/VCAM-1, collagen-IV, fibronectin, actin and DAPI nuclear staining. We performed spectral image acquisition using a Sagnac-type interferometer. Subsequent linear unmixing allowed for decomposition of each pixel in its spectral components. Our approach reveals a typical expression profile of the adherent singular cells, allowing the specific distinction between hMSC and osteoblasts on the single cell level.

The chemopreventive polyphenol Curcumin prevents hematogenous breast cancer metastases in immunodeficient mice

Dissemination of metastatic cells probably occurs long before diagnosis of the primary tumor. Metastasis during early phases of carcinogenesis in high risk patients is therefore a potential prevention target. The plant polyphenol Curcumin has been proposed for dietary prevention of cancer. We therefore examined its effects on the human breast cancer cell line MDA-MB-231 in vitroand in a mouse metastasis model. Curcumin strongly induces apoptosis in MDA-MB-231 cells in correlation with reduced activation of the survival pathway NFkappaB, as a consequence of diminished IotakappaB and p65 phosphorylation. Curcumin also reduces the expression of major matrix metalloproteinases (MMPs) due to reduced NFkappa B activity and transcriptional downregulation of AP-1. NFkappa B/p65 silencing is sufficient to downregulate c-jun and MMP expression. Reduced NFkappa B/AP-1 activity and MMP expression lead to diminished invasion through a reconstituted basement membrane and to a significantly lower number of lung metastases in immunodeficient mice after intercardiac injection of 231 cells (p=0.0035). 68% of Curcumin treated but only 17% of untreated animals showed no or very few lung metastases, most likely as a consequence of down-regulation of NFkappa B/AP-1 dependent MMP expression and direct apoptotic effects on circulating tumor cells but not on established metastases. Dietary chemoprevention of metastases appears therefore feasible.

Analysis of Tissue Distribution of TNF- , TNF- -Receptors, and the Activating TNF- -Converting Enzyme Suggests Activation of the TNF- System in the Aging Intervertebral Disc

We immunohistochemically analyzed the expression and localization of TNF-alpha, its receptors TNF-RI and -RII, and the TNF-alpha-activating enzyme TACE in human autopsy (n=63) and surgical (n=35) lumbar intervertebral disc samples. In parallel, the TNF-alpha-mRNA was quantified by reverse transcriptase-polymerase chain reaction (RT-PCR). All samples were morphometrically evaluated for the proportion of positively labeled cells in the different anatomical regions of the disc. We detected a significant and comparable expression of all four parameters beginning in young adult age (c. 18 years) and being most extensive in the nucleus pulposus. This level was slightly reduced in older age discs. The annulus fibrosus contained significantly less labeled cells. In accord, the number of TNF-alpha-transcripts was elevated in most cases with immunohistochemical TNF-alpha expression. We provide clear evidence that TNF-alpha is expressed in discs of increasing age, which correlates with histomorphological signs of disc degeneration. In consequence, TNF-alpha seems to be activated (by the converting enzyme TACE) and biologically active through its receptors in human lumbar disc tissue.

Kinin receptors in stimulated and characterized decidua tissue-derived cells

Bradykinin and its kinin B(2) receptor are autocrine and paracrine mediators in foetal membranes and decidua. As a first step we characterized the intracellular morphology of decidual cells. Cultured decidua tissue-derived cells immunolabel for vimentin fibrils, and are considered to be of mesenchymal origin. They show characteristics of macrophages and can be distinguished from endothelial cells and cells of the trophoblast lineage. These cellular features were determined by means of immunocytochemistry. Furthermore cultured decidua tissue-derived cells express kinin B(2) receptors and in this context we demonstrated its expression at mRNA level by in situ reverse transcriptase polymerase chain reaction. Following stimulation with bacterial lipopolysaccharide, we have observed a marginal upregulation of the expression of kinin B(1) receptors and carboxypeptidase M by quantitative RT-PCR. Equilibrium binding experiments with [(3)H]des-Arg(10)-kallidin, the kinin B(1) receptor agonist, did not result in detectable binding sites.

MMP-2, MT1-MMP, and TIMP-2 are essential for the invasive capacity of human mesenchymal stem cells: differential regulation by inflammatory cytokines

Human mesenchymal stem cells (hMSCs) represent promising tools in various clinical applications, including the regeneration of injured tissues by endogenous or transplanted hMSCs. The molecular mechanisms, however, that control hMSC mobilization and homing which require invasion through extracellular matrix (ECM) barriers are almost unknown. We have analyzed bone marrow-derivedhMSCs and detected strong expression and synthesis of matrix metalloproteinase 2 (MMP-2), membrane type 1 MMP (MT1-MMP), tissue inhibitor of metalloproteinase 1 (TIMP-1), and TIMP-2. The ability of hMSCs to traverse reconstituted human basement membranes was effectively blocked in the presence of synthetic MMP inhibitors. Detailed studies by RNA interference revealed that gene knock-down of MMP-2, MT1-MMP, or TIMP-2 substantially impaired hMSC invasion, whereas silencing of TIMP-1 enhanced cell migration, indicating opposing roles of both TIMPs in this process. Moreover, the inflammatory cytokines TGF-beta1, IL-1beta, and TNF-alpha up-regulated MMP-2, MT1-MMP, and/or MMP-9 production in these cells, resulting in a strong stimulation of chemotactic migration through ECM, whereas the chemokine SDF-1alpha exhibited minor effects on MMP/TIMP expression and cell invasion. Thus, induction of specific MMP activity in hMSCs by inflammatory cytokines promotes directed cell migration across reconstituted basement membranes in vitro providing a potential mechanism in hMSC recruitment and extravasation into injured tissues in vivo.

Significance of Elecsys S100 immunoassay for real-time assessment of traumatic brain damage in multiple trauma patients

BACKGROUND

The neuroprotein S100 released into the circulation has been suggested as a reliable marker for primary brain damage. However, safe identification of relevant traumatic brain injury (TBI) may possibly be hampered by S100 release from peripheral tissue. The objective of this study was to measure early S100 levels using the Elecsys S100 immunoassay for real-time assessment of severe TBI in multiple trauma.

METHODS

Consecutively admitted multiple trauma patients (injury severity score >or=16 points) were stratified according to the results of the initial cerebral computed tomography (CCT) examination. S100 serum levels were determined at admission and at 6, 12, 24, 48 and 72 h after trauma. Data were correlated to creatine phosphokinase (CK) and lactate dehydrogenase (LDH) serum levels. Using receiver operating characteristic (ROC) analysis, the discriminating power of S100 measurement was calculated for the detection of CCT+ findings.

RESULTS

Median S100 levels of CCT+ patients (n=9; 37 years) decreased from 3.30 microg/L at admission to 0.41 microg/L 72 h after trauma. They revealed no significant differences to CCT- patients (n=18; 44 years), but remained elevated compared to controls. Median CK and LDH levels correlated with the corresponding S100 levels during the first 24 h after trauma. ROC analysis displayed a maximum area under the curve of only 0.653 at 12 h after trauma. No significant difference was calculated for the differentiation between CCT+ and CCT- patients.

CONCLUSIONS

Measurements of S100 serum levels using the Elecsys S100 immunoassay are not reliable for the real-time detection of severe TBI in multiple trauma patients. Due to soft tissue trauma or bone fractures, S100 is mainly released from peripheral sources such as adipocytes or skeletal muscle cells.

RGD-dependent binding of procathepsin X to integrin alphavbeta3 mediates cell-adhesive properties

Secreted lysosomal cysteine proteases (cathepsins) are involved in degradation and remodeling of the extracellular matrix, thus contributing to cell adhesion and migration. Among the eleven human lysosomal cysteine proteases, only procathepsin X contains an RGD motif located in a highly exposed region of the propeptide, which may allow binding of the proenzyme to RGD-recognizing integrins. Here, we have tested procathepsin X for cell-adhesive properties and found that it supports integrin alpha(v)beta(3)-dependent attachment and spreading of human umbilical vein endothelial cells. Using site-directed mutants of procathepsin X, we proved that this effect is mediated by the RGD sequence within the proregion of the protease. Endogenous procathepsin X is transported to the plasma membrane, accumulates in vesicles at lamellipodia of the human umbilical vein endothelial cell, and is partly associated with the cell surface, as shown by immunofluorescence. In addition, procathepsin X is partly co-localized with integrin beta(3), as detected by immunogold electron microscopy. A direct interaction between endogenous procathepsin X and alpha(v)beta(3) was demonstrated by co-immunoprecipitation. Moreover, surface plasmon resonance analysis revealed significant and RGD-dependent binding of procathepsin X to integrin alpha(v)beta(3). Our results provide for the first time evidence that the extracellular function of cathepsin X may include binding to integrins thereby modulating the attachment of migrating cells to ECM components.

C-terminal fusion of eGFP to the bradykinin B2 receptor strongly affects down-regulation but not receptor internalization or signaling

A functional comparison was made between the wild-type bradykinin B2 receptor (B2wt) and the chimera B2eGFP (enhanced green-fluorescent protein fused to the C-terminus of B2wt), both stably expressed in HEK 293 cells. There was almost no difference in terms of ligand-inducible receptor phosphorylation and internalization, signal transduction (accumulation of inositol phosphates) or expression and affinity. However, stimulation for up to 8 h with 10 microM bradykinin (BK) resulted in a strong decrease in surface receptors (by 60% within 5 h) in B2wt, but not in B2eGFP. When the expression levels of both constructs where comparably reduced using a weaker promoter, long-term stimulation resulted in a reduction in surface receptors for B2wt(low) to less than 20% within 1 h, whereas the chimera B2eGFP(low) still displayed 50% binding activity after 2 h. A 1-h incubation in the absence of BK resulted in a recovery of 60% of the binding in B2wt(low) after 1-h stimulation with BK, but of only 20% after 7-h stimulation. In contrast, B2eGFP(low) levels were restored to more than 70%, even after 7-h stimulation. These data indicate that although the fusion of eGFP to B2wt does not affect its ligand-induced internalization, it strongly reduces the down-regulation, most likely by promoting receptor recycling over degradation.

Identification of calpain cleavage sites in the G1 cyclin-dependent kinase inhibitor p19(INK4d)

Calpains are a large family of Ca2+-dependent cysteine proteases that are ubiquitously distributed across most cell types and vertebrate species. Calpains play a role in cell differentiation, apoptosis, cytoskeletal remodeling, signal transduction and the cell cycle. The cell cycle proteins cyclin D1 and p21(KIP1), for example, have been shown to be affected by calpains. However, the rules that govern calpain cleavage specificity are poorly understood. We report here studies on the pattern of mu-calpain proteolysis of the p19(INK4d) protein, a cyclin-dependent kinase 4/6 inhibitor that negatively regulates the mammalian cell cycle. Our data show new characteristics of calpain action: mu-calpain cleaves p19(INK4d) immediately after the first and second ankyrin repeats that are structurally less stable compared to the other repeats. This is in contrast to features observed so far in the specificity of calpains for their substrates. These results imply that calpain may be involved in the cell cycle by regulating the cell cycle regulatory protein turnover through CDK inhibitors and cyclins.

Serum S-100B protein levels during and after successful carotid artery stenting or carotid endarterectomy

PURPOSE

To characterize the course of S-100B serum levels, a reliable marker for cellular brain damage, in patients undergoing carotid artery stenting (CAS) or endarterectomy (CEA) for carotid artery stenosis compared to control groups undergoing hemithyroidectomy (HT) or coronary angiography (CA).

METHODS

Forty-six consecutive patients scheduled for revascularization of internal carotid artery (ICA) stenosis were included in the study. Fourteen patients (11 men; median age 70 years, interquartile range [IQR] 63-74) were selected for treatment with CAS, while CEA was performed in 31 patients (24 men; median age 68 years, IQR 54-78) during the same time period. Fourteen consecutive patients (8 men; median age 60 years, IQR 48-70) undergoing CA for suspected coronary heart disease and 14 patients (10 women; median age 36 years, IQR 26-54) undergoing HT for a single thyroid nodule served as controls.

RESULTS

All procedures were completed successfully. During ICA clamping in CEA patients without postoperative neurological deficits, median S-100B serum levels transiently increased from 0.04 to 0.26 ng/mL (p<0.01) and returned to baseline levels after declamping. Median S-100B serum levels of CAS patients without neurological impairment remained at baseline values. No increase in S-100B levels occurred in either control group. Three CEA patients who suffered from neurological deficits (1 transient ischemic attack and 1 major stroke) showed sustained elevation of S-100B serum levels 6 hours after extubation.

CONCLUSION

In patients without neurological complications, CEA but not CAS was associated with a transient increase in the S-100B serum levels. Results indicate that the increase in S-100B does not originate from extracerebral sources, but rather appears to represent an impairment of the blood-brain barrier integrity or subtle brain cell damage probably due to hypoperfusion during clamping. Sustained elevation of S-100B serum levels corresponded to the development of postoperative neurological deficits.

Wnt signaling regulates the invasion capacity of human mesenchymal stem cells

Human mesenchymal stem cells (hMSCs) exhibit the potential to contribute to a wide variety of endogenous organ tissue repair. However, the signals governing hMSC mobilization out of the bone marrow, release into the bloodstream, and migration/invasion into the target tissue are largely unknown. Since canonical Wnt signaling regulates not only tumor but also various stem cell attributes, we hypothesized that this signal transduction pathway might also be involved in governing the transmigration of hMSCs through human extracellular matrix (ECM). Stimulation of hMSCs with recombinant Wnt3a or LiCl resulted in the accumulation of the transcriptional activator beta-catenin, its translocation into the nucleus, and the upregulation of typical Wnt target genes such as cyclin D1 and membrane-type matrix metalloproteinase-1 (MT1-MMP). Moreover, both stimuli significantly enhanced hMSC proliferation up to 40%. In addition, an increase of more than twofold in the ability of hMSCs to transmigrate through Transwell filters coated with human ECM was observed. In a reverse approach, Wnt signaling in hMSCs was inhibited by knocking down the expression of either beta-catenin or low-density lipoprotein receptor-related protein 5 using RNA interference technology. These inhibition strategies resulted in downregulation of the Wnt target genes cyclin D1 and MT1-MMP, in a reduced proliferation rate, and in a strikingly diminished invasion capacity (64% and 52%). Taken together, this study provides for the first time decisive evidence that canonical Wnt signaling is critically involved in the regulation of the proliferation, as well as of the migration/invasion capacity of hMSCs, representing essential stem cell features indispensable during tissue regeneration processes.

SERUM S-100B CONCENTRATION PROVIDES ADDITIONAL INFORMATION FOT THE INDICATION OF COMPUTED TOMOGRAPHY IN PATIENTS AFTER MINOR HEAD INJURY

Ninety percent of patients with minor head injury (MHI) who have cranial computed tomography (CCT) under the present clinical decision rules have normal scans. Serum concentrations of the astroglial protein S-100B were recently found to provide useful information, but these studies were too small to provide a statistically safe basis for changing the present rule. We have investigated whether S-100B concentrations in patients with MHI can provide additional information to improve indication of the need for an initial CCT scan. One thousand three hundred nine patients with MHI were enrolled in this prospective, multicenter study. All had a CCT scan to confirm diagnosis in accordance with the present clinical decision rules. S-100B was measured in serum samples obtained upon admission. Data were analyzed using contingency table and receiver operating characteristic curve and compared with those for healthy donors (n = 540) and with those for patients with moderate to severe head injury (n = 55). Of the 1309 patients studied, 93 exhibited trauma-relevant intracerebral lesions on the CCT scan (CCT+). With a cutoff limit of 0.10-microg/L S-100B (95th percentile of values in healthy volunteers), CCT+ patients were identified with a sensitivity level of 99% (95% confidence interval, 96% - 100%) and a specificity level of 30% (95% confidence interval, 29% - 31%). Adding the measurement of S-100B concentration to the clinical decision rules for a CCT scan in patients with MHI could allow a 30% reduction in scans. A prospective study of the clinical value of S-100B measurement in such patients is now under way.

Modulation of autocrine TNF-alpha-stimulated matrix metalloproteinase 9 (MMP-9) expression by mitogen-activated protein kinases in THP-1 monocytic cells

Matrix metalloproteinase 9 (MMP-9) is implicated in various physiological processes by its ability to degrade the extracellular matrix (ECM) and process multiple regulatory proteins. Normally, MMP-9 expression is tightly controlled in cells. Sustained or enhanced MMP-9 secretion, however, has been demonstrated to contribute to the pathophysiology of numerous diseases, including arthritis and tumor progression, rendering this enzyme a major target for clinical interventions. Here we show that constitutive MMP-9 secretion was abrogated in THP-1 monocytic leukemia cells by addition of neutralizing antibodies against tumor necrosis factor alpha (TNF-alpha) or TNF receptor type 1 (TNF-R1), as well as by inhibition of TNF-alpha converting enzyme (TACE). This indicates that MMP-9 production in these cells is maintained by autocrine stimulation, with TNF-alpha acting via TNF-R1. To investigate the intracellular signaling routes involved in MMP-9 gene transcription, cells were treated with different inhibitors of major mitogen-activated protein kinase (MAPK) pathways. Interruption of the extracellular signal-regulated kinase pathway 1/2 (ERK1/2) using PD98059 significantly downregulated constitutive MMP-9 release. In contrast, blockage of p38 kinase activity by addition of SB203580 or SB202190, as well as inhibition of c-Jun N-terminal kinase (JNK) using L-JNK-I1, clearly augmented MMP-9 expression and secretion by an upregulation of ERK1/2 phosphorylation. Moreover, exogenously added TNF-alpha augmented MMP-9 synthesis and secretion in THP-1 cells via enhancement of ERK1/2 activity. Taken together, our results indicate that ERK1/2 activity plays a pivotal role in TNF-alpha-induced MMP-9 production and demonstrate its negative modulation by p38 and JNK activity. These findings suggest ERK1/2 rather than p38 and JNK as a reasonable target to specifically block MMP-9 expression using MAPK inhibitors in therapeutic applications.

Rapid measurement of S-100B serum protein levels by Elecsys S100 immunoassay in patients undergoing carotid artery stenting or endarterectomy

OBJECTIVES

This study was designed to apply the rapid Elecsys S100 immunoassay for real-time measurement of S100 protein serum levels indicating acute brain damage in patients undergoing carotid artery stenting (CAS) or endarterectomy (CEA).

DESIGN AND METHODS

Data of 14 CAS patients were compared to those of 43 CEA and 14 control patients undergoing coronary angiography (CA). S100 serum levels were measured by the full-automatic Elecsys S100 immunoassay and compared to those obtained by the well-established LIA-mat S100 system.

RESULTS

In contrast to CAS and CA patients, median S100 serum levels of CEA patients significantly increased to 0.24 ng/mL before declamping, but subsequently returned to baseline. Three CEA patients with neurological deficits showed sustained elevated S100 levels 6 h after extubation. Absolute S100 values were not significantly different between the two methods. Bland-Altman plot analyses displayed a good agreement, mostly indicating slightly smaller values applying the Elecsys S100 system.

CONCLUSIONS

The Elecsys S100 system appears to be suitable for rapid real-time detection of neurological deficits in patients undergoing CAS and CEA. Persistent elevations of Elecsys S100 levels during CEA were associated with prolonged neurological disorders, whereas transient increases seem to represent impaired blood-brain barrier integrity without neurological deficits.

Matrix metalloproteinases in cancer: comparison of known and novel aspects of their inhibition as a therapeutic approach

Matrix dissolution is a crucial step during tumor progression that converts a premalignant cell to an overtly malignant one. Main players in this step are the various matrix metalloproteinases (MMPs), which differ in substrate specificity and tissue distribution, and thereby also differ in presence and function during various stages of initial and systemic tumor spread. Accordingly, the inhibition of MMP synthesis and/or activity represents novel potential therapeutic strategies for the treatment of cancer patients. Considerable work has already been carried out on synthetic inhibitors of MMP activity, but with little or even adverse effects in recent clinical studies. The reasons may be inappropriate patient populations in too advanced tumor stages, or inappropriate enzymes as targets for inhibition. Upregulation of endogenous tissue inhibitors of MMP (TIMPs) also provided ambiguous results, since TIMPs possess biologic functions in addition to MMP inhibition, for example, TIMP-2 is a main player in the MMP-2 activation cascade. This may explain, at least in part, the adverse effects of TIMP application/upregulation. Other strategies have been sought in order to overcome these problems. These include the downregulation of MMP transcription by cytokines. However, the effects of cytokines (other than MMP inhibition) may also limit the use of this approach. Finally, empiric evidence for control and modulation of MMP transcription and/or activation by several naturally occurring substances, such as flavonoids, green tea polyphenols and curcumin, represent novel options for the control of MMP activity even in early tumor stages. Additionally, these substances have little or no toxic side effects and good bioavailability, and therefore their continuing analysis provides intriguing insight into tumor pathophysiology and possibly new therapeutic options.

Measurement of S-100B for risk classification of victims sustaining minor head injury--first pilot study in Brazil

BACKGROUND

Release of the neuronal protein S-100B into the circulation has been suggested as a specific indication of neuronal damage. The hypothesis that S-100B is a useful and cost-effective screening tool for the management of minor head injuries was tested.

METHODS

Fifty consecutive patients sustaining isolated minor head injury were prospectively evaluated in the emergency room of a Brazilian hospital by routine cranial computed tomography scan. Venous blood samples (processed to serum) were assayed for S-100B using a newly developed immunoassay test kit. Twenty-one normal healthy individuals served as negative controls. Data are presented as median and 25 to 75 percentiles.

RESULTS

Patients reached the emergency room an average of 45 minutes (range: 30-62 minutes) after minor head injury. Six of 50 patients (12%) showed relevant posttraumatic lesions in the initial cranial computed tomography scan and were counted as positive. The median systemic concentration of S-100B in those patients was 0.75 microg/L (range: 0.66-6.5 microg/L), which was significantly different (U-test, P < .05) from the median concentration of 0.26 microg/L (range: 0.12-0.65 microg/L), of patients without posttraumatic lesions as counted by the cranial computed tomography. A sensitivity of 100%, a specificity of 20%, a positive predictive value of 15%, and a negative predictive value of 100% was calculated for the detection of patients suffering from intracranial lesions.

CONCLUSIONS

Protein S-100B had a very high sensitivity and negative predictive value and could have an important role in ruling out the need for cranial computed tomography scan after minor head injury. This appears to be of substantial clinical relevance, particularly in countries where trauma incidence is high and medical resources are limited, such as in Brazil.

An enzyme-linked immunosorbent assay for human cathepsin X, a potential new inflammatory marker

The human lysosomal cysteine-type carboxypeptidase cathepsin X is mainly present in monocytes and macrophages and may be released into the circulation due to constitutive and/or regulated secretion by (activated) immune cells. To define its potential diagnostic value as an inflammatory marker, we have developed a highly sensitive and specific sandwich-type immunoassay (ELISA) for cathepsin X permitting both intra- and extracellular detection and quantification. The dynamic range of the cathepsin X ELISA was determined to be 100 (detection limit) to 8000 pg/ml. Reproducibility of both within and between runs yielded coefficients of variation (CVs) of 2.7-3.5% and 6.3-7.3%, respectively. Cross-reactivity with other members (cathepsin B, L) of the thiol-dependent cathepsin family was not observed. The ELISA was used to quantify cathepsin X in leukocytes as well as in plasma of healthy volunteers and patients with multiple trauma. During the first 72 h after trauma, plasma levels of cathepsin X increased significantly, particularly in patients who died during the posttraumatic period. In comparison to the well-known inflammation marker neutrophil elastase, cathepsin X levels predicted survival with a higher significance in the later posttraumatic phase. In conclusion, this report provides the first evidence of cathepsin X immunoreactivity not only in cell lysates but also in plasma samples. We suggest that the newly developed highly reproducible ELISA will be of great value for further evaluation of this protease as a diagnostic and/or prognostic marker in inflammatory diseases.

Genome-wide monocytic mRNA expression in polytrauma patients for identification of clinical outcome

Immune activation in multiple trauma is closely linked to the development of multiple organ dysfunction and failure, and consequently, has a profound influence on patient outcome. Although peripheral blood monocytes play a critical role in this immune response, the biological significance of changes in genome-wide expression immediately after traumatic injury have not been explored previously. Thirteen patients presenting with multiple blunt trauma were studied. Peripheral blood monocytes were obtained within 90 min and at 6, 12, 24, 48, and 72 h after trauma. Apparent genome-wide expression was determined with Affymetrix U133A microarrays. Supervised analysis identified 698 probe sets that were differentially expressed in the 13 trauma subjects (P < 0.001) over the 72-h study period. An additional 763 probe sets were differentially expressed in patients who died (n = 3) compared with those who survived (n = 10). The ability of these probe sets to function as a classifier of survival was significantly demonstrated with six prediction models. Using pathway analysis, a network of proinflammatory genes and intracellular signaling pathways leading to c-JUN activation were consistently overexpressed in patients who died. Genome-wide mRNA expression patterns in circulating peripheral blood monocytes from multiple-injured patients can discriminate clinical outcome. The pattern of gene expression in patients who died suggests that in these individuals, there is a reprioritization of gene expression consistent with an early activation of selected genes involved in the initiation and propagation of a proinflammatory response.

μ-Calpain binds to lipid bilayers via the exposed hydrophobic surface of its Ca2+-activated conformation

Mu- and m-calpain are cysteine proteases requiring micro- and millimolar Ca2+ concentrations for their activation in vitro. Among other mechanisms, interaction of calpains with membrane phospholipids has been proposed to facilitate their activation by nanomolar [Ca2+] in living cells. Here the interaction of non-autolysing, C115A active-site mutated heterodimeric human mu-calpain with phospholipid bilayers was studied in vitro using protein-to-lipid fluorescence resonance energy transfer and surface plasmon resonance. Binding to liposomes was Ca2+-dependent, but not selective for specific phospholipid head groups. [Ca2+]0.5 for association with lipid bilayers was not lower than that required for the exposure of hydrophobic surface (detected by TNS fluorescence) or for enzyme activity in the absence of lipids. Deletion of domain V reduced the lipid affinity of the isolated small subunit (600-fold) and of the heterodimer (10- to 15-fold), thus confirming the proposed role of domain V for membrane binding. Unexpectedly, mutations in the acidic loop of the 'C2-like' domain III, a putative Ca2+ and phospholipid-binding site, did not affect lipid affinity. Taken together, these results support the hypothesis that in vitro membrane binding of mu-calpain is due to the exposed hydrophobic surface of the active conformation and does not reduce the Ca2+ requirement for activation.

Bilateral lavage with diluted surfactant improves lung function after unilateral lung contusion in pigs*

OBJECTIVE

This study evaluates the effects of bronchoalveolar lavage with diluted surfactant on unilateral lung contusion-induced lung dysfunction.

DESIGN

Randomized prospective animal study.

SETTING

An animal laboratory.

SUBJECTS

Twenty adult pigs, weighing 25-35 kg.

INTERVENTIONS

Animals were randomly assigned to controls and surfactant treatment. Bilateral lavage with surfactant treatment began 30 mins after unilateral lung contusion. Then 25 mg/kg of body weight diluted Curosurf (5 mg/mL) was applied in a volume of 5 mL/kg of body weight. Observation time was 8 hrs postinjury.

MEASUREMENTS AND MAIN RESULTS

The Pao2/Fio2 ratio fell from 500 to 250 and then recovered gradually in controls and surfactant-treated pigs. After another 4 hrs, the Pao2/Fio2 ratio deteriorated again in controls, but not in surfactant-treated animals. Total compliance fell by 50% after injury but was completely restored by surfactant treatment. Lung contusion increased the median number of neutrophils in bronchoalveolar lavage fluid from 2% to 30% of total cells and peaked >60% at 480 mins in the contused lungs of control pigs. Surfactant-treated pigs had 40% neutrophils at 480 mins without reaching significant difference to controls. The leukocyte neutral proteinase inhibitor increased to 500 ng/mL at 30 mins postinjury in the contused lungs and increased to 2000 ng/mL after surfactant treatment.

CONCLUSIONS

Bilateral bronchoalveolar lavage with diluted surfactant can effectively improve lung function after experimental unilateral lung contusion in pigs.