Macrophage elastase (MMP-12): a pro-inflammatory mediator?

As many metalloproteinases (MMPs), macrophage elastase (MMP-12) is able to degrade extracellular matrix components such as elastin and is involved in tissue remodeling processes. Studies using animal models of acute and chronic pulmonary inflammatory diseases, such as pulmonary fibrosis and chronic obstrutive pulmonary disease (COPD), have given evidences that MMP-12 is an important mediator of the pathogenesis of these diseases. However, as very few data regarding the direct involvement of MMP-12 in inflammatory process in the airways were available, we have instilled a recombinant form of human MMP-12 (rhMMP-12) in mouse airways. Hence, we have demonstrated that this instillation induced a severe inflammatory cell recruitment characterized by an early accumulation of neutrophils correlated with an increase in proinflammatory cytokines and in gelatinases and then by a relatively stable recruitment of macrophages in the lungs over a period of ten days. Another recent study suggests that resident alveolar macrophages and recruited neutrophils are not involved in the delayed macrophage recruitment. However, epithelial cells could be one of the main targets of rhMMP-12 in our model. We have also reported that a corticoid, dexamethasone, phosphodiesterase 4 inhibitor, rolipram and a non-selective MMP inhibitor, marimastat could reverse some of these inflammatory events. These data indicate that our rhMMP-12 model could mimic some of the inflammatory features observed in COPD patients and could be used for the pharmacological evaluation of new anti-inflammatory treatment. In this review, data demonstrating the involvement of MMP-12 in the pathogenesis of pulmonary fibrosis and COPD as well as our data showing a pro-inflammatory role for MMP-12 in mouse airways will be summarized.

Coating carbon nanotubes with a polystyrene-based polymer protects against pulmonary toxicity.

BACKGROUND: carbon nanotubes (CNT) can have adverse effects on health. Therefore, minimizing the risk associated with CNT exposure is of crucial importance. The aim of this work was to evaluate if coating multi-walled CNT (MWCNT) with polymers could modify their toxicity, thus representing a useful strategy to decrease adverse health effects of CNT. We used industrially-produced MWCNT uncoated (NT1) or coated (50/50 wt%) with acid-based (NT2) or polystyrene-based (NT3) polymer, and exposed murine macrophages (RAW 264.7 cell line) or Balb/c mice by intratracheal administration. Biological experiments were performed both in vitro and in vivo, examining time- and dose-dependent effects of CNT, in terms of cytotoxicity, expression of genes and proteins related to oxidative stress, inflammation and tissue remodeling, cell and lung tissue morphology (optical and transmission electron microscopy), and bronchoalveolar lavage fluid content analysis.RESULTS: extensive physico-chemical characterization of MWCNT was performed, and showed, although similar dimensions for the 3 MWCNT, a much smaller specific surface area for NT2 and NT3 as compared to NT1 (54.1, 34 and 227.54 m(2)/g respectively), along with different surface characteristics. MWCNT-induced cytotoxicity, oxidative stress, and inflammation were increased by acid-based and decreased by polystyrene-based polymer coating both in vitro in murine macrophages and in vivo in lung of mice monitored for 6 months.CONCLUSIONS: these results demonstrate that coating CNT with polymers, without affecting their intrinsic structure, may constitute a useful strategy for decreasing CNT toxicity, and may hold promise for improving occupational safety and that of general the user.

Evolution and pathology in Chagas disease: a review

Trypanosoma cruzi acute infections often go unperceived, but one third of chronically infected individuals die of Chagas disease, showing diverse manifestations affecting the heart, intestines, and nervous systems. A common denominator of pathology in Chagas disease is the minimal rejection unit, whereby parasite-free target host cells are destroyed by immune system mononuclear effectors cells infiltrates. Another key feature stemming from T. cruzi infection is the integration of kDNA minicircles into the vertebrate host genome; horizontal transfer of the parasite DNA can undergo vertical transmission to the progeny of mammals and birds. kDNA integration-induced mutations can enter multiple loci in diverse chromosomes, generating new genes, pseudo genes and knock-outs, and resulting in genomic shuffling and remodeling over time. As a result of the juxtaposition of kDNA insertions with host open reading frames, novel chimeric products may be generated. Germ line transmission of kDNA-mutations determined the appearance of lesions in birds that are indistinguishable from those seen in Chagas disease patients. The production of tissue lesions showing typical minimal rejection units in birds' refractory to T. cruzi infection is consistent with the hypothesis that autoimmunity, likely triggered by integration-induced phenotypic alterations, plays a major role in the pathogenesis of Chagas disease.

Role of prostacyclin versus peroxisome proliferator-activated receptor beta receptors in prostacyclin sensing by lung fibroblasts.

Prostacyclin and its mimetics are used therapeutically for the treatment of pulmonary hypertension. These drugs act via cell surface prostacyclin receptors (IP receptors); however, some of them can also activate the nuclear receptor peroxisome proliferator-activated receptor beta (PPARbeta). We examined the possibility that PPARbeta is a therapeutic target for the treatment of pulmonary hypertension. Using the newly approved (for pulmonary hypertension) prostacyclin mimetic treprostinil sodium, reporter gene assays for PPARbeta activation and measurement of lung fibroblast proliferation were analyzed. Treprostinil sodium was found to activate PPARbeta in reporter gene assays and to inhibit proliferation of human lung fibroblasts at concentrations consistent with an effect on PPARs but not on IP receptors. The effects of treprostinil sodium on human lung cell proliferation are mimicked by those of the highly selective PPARbeta ligand GW0742. There are no receptor antagonists for PPARbeta or for IP receptors, but by using lung fibroblasts cultured from mice lacking PPARbeta (PPARbeta-/-) or IP (IP-/-), we demonstrate that the antiproliferative effects of treprostinil sodium are mediated by PPARbeta and not IP in lung fibroblasts. These observations suggest that some of the local, longer-term benefits of treprostinil sodium on reducing the remodeling associated with pulmonary hypertension may be mediated by PPARbeta. This study is the first to identify PPARbeta as a potential therapeutic target for the treatment of pulmonary hypertension, which is important because orally active PPARbeta ligands have been developed for the treatment of dyslipidemia.

Epigenetic features of human mesenchymal stem cells determine their permissiveness for induction of relevant transcriptional changes by SYT-SSX1.

BACKGROUND: A characteristic SYT-SSX fusion gene resulting from the chromosomal translocation t(X;18)(p11;q11) is detectable in almost all synovial sarcomas, a malignant soft tissue tumor widely believed to originate from as yet unidentified pluripotent stem cells. The resulting fusion protein has no DNA binding motifs but possesses protein-protein interaction domains that are believed to mediate association with chromatin remodeling complexes. Despite recent advances in the identification of molecules that interact with SYT-SSX and with the corresponding wild type SYT and SSX proteins, the mechanisms whereby the SYT-SSX might contribute to neoplastic transformation remain unclear. Epigenetic deregulation has been suggested to be one possible mechanism. METHODOLOGY/PRINCIPAL FINDINGS: We addressed the effect of SYT/SSX expression on the transcriptome of four independent isolates of primary human bone marrow mesenchymal stem cells (hMSC). We observed transcriptional changes similar to the gene expression signature of synovial sarcoma, principally involving genes whose regulation is linked to epigenetic factors, including imprinted genes, genes with transcription start sites within a CpG island and chromatin related genes. Single population analysis revealed hMSC isolate-specific transcriptional changes involving genes that are important for biological functions of stem cells as well as genes that are considered to be molecular markers of synovial sarcoma including IGF2, EPHRINS, and BCL2. Methylation status analysis of sequences at the H19/IGF2 imprinted locus indicated that distinct epigenetic features characterize hMSC populations and condition the transcriptional effects of SYT-SSX expression. CONCLUSIONS/SIGNIFICANCE: Our observations suggest that epigenetic features may define the cellular microenvironment in which SYT-SSX displays its functional effects.

Cutting edge: IL-1α is a crucial danger signal triggering acute myocardial inflammation during myocardial infarction.

Myocardial infarction (MI) induces a sterile inflammatory response that contributes to adverse cardiac remodeling. The initiating mechanisms of this response remain incompletely defined. We found that necrotic cardiomyocytes released a heat-labile proinflammatory signal activating MAPKs and NF-κB in cardiac fibroblasts, with secondary production of cytokines. This response was abolished in Myd88(-/-) fibroblasts but was unaffected in nlrp3-deficient fibroblasts. Despite MyD88 dependency, the response was TLR independent, as explored in TLR reporter cells, pointing to a contribution of the IL-1 pathway. Indeed, necrotic cardiomyocytes released IL-1α, but not IL-1β, and the immune activation of cardiac fibroblasts was abrogated by an IL-1R antagonist and an IL-1α-blocking Ab. Moreover, immune responses triggered by necrotic Il1a(-/-) cardiomyocytes were markedly reduced. In vivo, mice exposed to MI released IL-1α in the plasma, and postischemic inflammation was attenuated in Il1a(-/-) mice. Thus, our findings identify IL-1α as a crucial early danger signal triggering post-MI inflammation.

Characterization and clinical evaluation of CD10+ stroma cells in the breast cancer microenvironment.

PURPOSE: There is growing evidence that interaction between stromal and tumor cells is pivotal in breast cancer progression and response to therapy. Based on earlier research suggesting that during breast cancer progression, striking changes occur in CD10(+) stromal cells, we aimed to better characterize this cell population and its clinical relevance. EXPERIMENTAL DESIGN: We developed a CD10(+) stroma gene expression signature (using HG U133 Plus 2.0) on the basis of the comparison of CD10 cells isolated from tumoral (n = 28) and normal (n = 3) breast tissue. We further characterized the CD10(+) cells by coculture experiments of representative breast cancer cell lines with the different CD10(+) stromal cell types (fibroblasts, myoepithelial, and mesenchymal stem cells). We then evaluated its clinical relevance in terms of in situ to invasive progression, invasive breast cancer prognosis, and prediction of efficacy of chemotherapy using publicly available data sets. RESULTS: This 12-gene CD10(+) stroma signature includes, among others, genes involved in matrix remodeling (MMP11, MMP13, and COL10A1) and genes related to osteoblast differentiation (periostin). The coculture experiments showed that all 3 CD10(+) cell types contribute to the CD10(+) stroma signature, although mesenchymal stem cells have the highest CD10(+) stroma signature score. Of interest, this signature showed an important role in differentiating in situ from invasive breast cancer, in prognosis of the HER2(+) subpopulation of breast cancer only, and potentially in nonresponse to chemotherapy for those patients. CONCLUSIONS: Our results highlight the importance of CD10(+) cells in breast cancer prognosis and efficacy of chemotherapy, particularly within the HER2(+) breast cancer disease.

Intracoronary injection of bone marrow-derived mononuclear cells early or late after acute myocardial infarction: effects on global left ventricular function.

BACKGROUND: Intracoronary administration of autologous bone marrow-derived mononuclear cells (BM-MNC) may improve remodeling of the left ventricle (LV) after acute myocardial infarction. The optimal time point of administration of BM-MNC is still uncertain and has rarely been addressed prospectively in randomized clinical trials. METHODS AND RESULTS: In a multicenter study, we randomized 200 patients with large, successfully reperfused ST-segment elevation myocardial infarction in a 1:1:1 pattern into an open-labeled control and 2 BM-MNC treatment groups. In the BM-MNC groups, cells were administered either early (ie, 5 to 7 days) or late (ie, 3 to 4 weeks) after acute myocardial infarction. Cardiac magnetic resonance imaging was performed at baseline and after 4 months. The primary end point was the change from baseline to 4 months in global LV ejection fraction between the 2 treatment groups and the control group. The absolute change in LV ejection fraction from baseline to 4 months was -0.4±8.8% (mean±SD; P=0.74 versus baseline) in the control group, 1.8±8.4% (P=0.12 versus baseline) in the early group, and 0.8±7.6% (P=0.45 versus baseline) in the late group. The treatment effect of BM-MNC as estimated by ANCOVA was 1.25 (95% confidence interval, -1.83 to 4.32; P=0.42) for the early therapy group and 0.55 (95% confidence interval, -2.61 to 3.71; P=0.73) for the late therapy group. CONCLUSIONS: Among patients with ST-segment elevation myocardial infarction and LV dysfunction after successful reperfusion, intracoronary infusion of BM-MNC at either 5 to 7 days or 3 to 4 weeks after acute myocardial infarction did not improve LV function at 4-month follow-up. CLINICAL TRIAL REGISTRATION: URL: http://www.clinicaltrials.gov. Unique identifier: NCT00355186.

The return of increased blood pressure after discontinuation of antihypertensive treatment is associated with an impaired post-ischemic skin blood flow response.

OBJECTIVE: To assess the post-ischemic skin blood flow response after withdrawal of antihypertensive therapy in hypertensive patients with normal blood pressure during treatment. DESIGN AND METHODS: Twenty hypertensive patients (group A) with a normal clinic blood pressure (<140/ 90 mmHg) receiving antihypertensive treatment (any monotherapy; one pill per day for at least 6 months) had their treatment discontinued. Before medication withdrawal and 2, 4, 12 and 24 weeks thereafter, the following measurements were made: clinic blood pressure, home blood pressure (three times per week, morning and evening) and skin blood flow response to a 5 min forearm arterial occlusion (using laser Doppler flowmetry). The patients were asked to perform an ambulatory blood pressure recording at any time if home blood pressure was > or =160/95 mmHg on two consecutive days, and treatment was initiated again, after determination of the skin hyperemic response, if daytime ambulatory blood pressure was > or =140/90 mmHg. The same studies were performed in 20 additional hypertensive individuals in whom antihypertensive treatment was not withdrawn (group B). The allocation of patients to groups A and B was random. RESULTS: The data fom 18 patients in group A who adhered strictly to the procedure were available for analysis. Seven of them had to start treatment again within the first 4 weeks of follow-up; four additional patients started treatment again during the next 8 weeks (group A1). The seven other patients remained untreated (group A2). The skin hyperemic response decreased significantly in patients in group A1 and returned to baseline values at the end of the study, when there were again receiving antihypertensive treatment. In patients in group A2 a significant attenuation of the hyperemic response was also observed. This impaired response was present even at the end of the 6 month follow-up, at which time the patients were still untreated but exhibited a significantly greater blood pressure than before drug discontinuation. The hyperemic response of patients who did not stop treatment (group B) did not change during the course of the study. CONCLUSIONS: Our findings show a decrease in the postischemic skin blood flow response after withdrawal of antihypertensive treatment in hypertensive patients. This impaired response may be due to the development of endothelial dysfunction, vascular remodeling, or both, and might contribute to the return of blood pressure to hypertensive values after withdrawal of antihypertensive therapy.

Functionalized nanostructures with application in regenerative medicine

In the last decade, both regenerative medicine and nanotechnology have been broadly developed leading important advances in biomedical research as well as in clinical practice. The manipulation on the molecular level and the use of several functionalized nanoscaled materials has application in various fields of regenerative medicine including tissue engineering, cell therapy, diagnosis and drug and gene delivery. The themes covered in this review include nanoparticle systems for tracking transplanted stem cells, self-assembling peptides, nanoparticles for gene delivery into stem cells and biomimetic scaffolds useful for 2D and 3D tissue cell cultures, transplantation and clinical application.

A nutritional intervention study with hydrolyzed collagen in pre-pubertal Spanish children: influence on bone modeling biomarkers

Aim: The aim of the study was to investigate the influence of dietary intake of commercial hydrolyzed collagen (Gelatine Royal ®) on bone remodeling in pre-pubertal children. Methods: A randomized double-blind study was carried out in 60 children (9.42 ± 1.31 years) divided into three groups according to the amount of partially hydrolyzed collagen taken daily for 4 months: placebo (G-I, n = 18), collagen (G-II, n = 20) and collagen + calcium (G-III, n = 22) groups. Analyses of the following biochemical markers were carried out: total and bone alkaline phosphatase (tALP and bALP), osteocalcin, tartrate-resistant acid phosphatase (TRAP), type I collagen carboxy terminal telopeptide, lipids, calcium, 25-hydroxyvitamin D, insulin-like growth factor 1 (IGF-1), thyroid-stimulating hormone, free thyroxin and intact parathormone. Results: There was a significantly greater increase in serum IGF-1 in G-III than in G II (p < 0.01) or G-I (p < 0.05) during the study period, and a significantly greater increase in plasma tALP in G-III than in G-I (p < 0.05). Serum bALP behavior significantly (p < 0.05) differed between G-II (increase) and G-I (decrease). Plasma TRAP behavior significantly differed between G-II and G-I (p < 0.01) and between G-III and G-II (p < 0.05). Conclusion: Daily dietary intake of hydrolyzed collagen seems to have a potential role in enhancing bone remodeling at key stages of growth and development.

The emergence of new genes on the young therian X.

Recent studies have revealed that our sex chromosomes differentiated relatively recently from ancestral autosomes in the common ancestor of placental and marsupial mammals (therians). Here, we show that the therian X started to accumulate new retroduplicate genes with overall sex-biased expression upon therian sex chromosome differentiation. This process reached its peak within the first approximately 90 million years of sex chromosome evolution and then leveled off. Taken together, our observations suggest that the major sex-related functional remodeling of the X was completed relatively soon after the origination of therian sex chromosomes.

Estudi històric i patològic del Mas Vell: rehabilitació del Mas Vell i transformació en centre d’esports d’aventura

L’objectiu que es va marcar abans de començar el projecte, era el de realitzar la rehabilitació del Mas Vell convertint-lo en un centre d’esports d’aventura. Per fer això creiem convenient que abans calia realitzar un estudi de les principals patologies que l’afectaven i de pas, datar la seva construcció i estudiar l’evolució i modificacions que ha patit al llarg dels anys. Per realitzar l’estudi patològic es crearien unes fitxes, localitzant, descrivint, explicant la causa de cada patologia en concret i donant la solució més adequada per reparar cada una d’elles. La rehabilitació del mas es faria pensant amb l’ús immediat que se li donarà, que serà un centre d’esports d’aventura. Les premisses que volíem seguir eren: no augmentar la volumetria que la masia tenia en el moment del seu abandonament, conservar l’aspecte rústic de l’edifici, tant en les parts que es conserven com en les que reconstruïm. Es pensava mantenir l’estructura de fusta de coberta i forjat que es trobés en bon estat. A la zona que estava en ruïnes es pensava construir les parets aterrades amb els mateixos materials originaris

Projecte de rehabilitació del Mas Sitjar de Salt

El motiu principal que ens ha portat a la realització d’aquest treball ha sigut el nostreinterès en el camp de la rehabilitació. També ha influït en aquesta decisió la possibilitat d’accedir a documentació gràfica i històrica, ja que es tracta d’un edifici històric patrimoni del municipi de Salt. Com a coneixedors de l’estat actual de l’edifici s’ha decidit que l’objecte principal del projecte estigui basat en la consolidació estructural, considerant que no hi ha un ús definit, decidim que l’ús serà el que ve definit al CTE com a categoria C (zones d’accés al públic), que és el més desfavorable en quant a sobrecàrregues d’ús. Llavors, la finalitat del projecte és dur a terme la rehabilitació de l’edifici perquè és pugui adaptar a qualsevol ús que se li vulgui donar. Per tant, cal deixar clar que no és objecte redissenyar o redistribuir l’edifici per donar-li un ús concret

Overexpression of SMARCE1 is associated with CD8+ T-cell infiltration in early stage ovarian cancer.

T-lymphocyte infiltration in ovarian tumors has been linked to a favorable prognosis, hence, exploring the mechanism of T-cell recruitment in the tumor is warranted. We employed a differential expression analysis to identify genes over-expressed in early stage ovarian cancer samples that contained CD8 infiltrating T-lymphocytes. Among other genes, we discovered that TTF1, a regulator of ribosomal RNA gene expression, and SMARCE1, a factor associated with chromatin remodeling were overexpressed in first stage CD8+ ovarian tumors. TTF1 and SMARCE1 mRNA levels showed a strong correlation with the number of intra-tumoral CD8+ cells in ovarian tumors. Interestingly, forced overexpression of SMARCE1 in SKOV3 ovarian cancer cells resulted in secretion of IL8, MIP1b and RANTES chemokines in the supernatant and triggered chemotaxis of CD8+ lymphocytes in a cell culture assay. The potency of SMARCE1-mediated chemotaxis appeared comparable to that caused by the transfection of the CXCL9 gene, coding for a chemokine known to attract T-cells. Our analysis pinpoints TTF1 and SMARCE1 as genes potentially involved in cancer immunology. Since both TTF1 and SMARCE1 are involved in chromatin remodeling, our results imply an epigenetic regulatory mechanism for T-cell recruitment that invites deciphering.