Broad-Spectrum Matrix Metalloproteinase Inhibition Curbs Inflammation and Liver Injury but Aggravates Experimental Liver Fibrosis in Mice

Background Liver fibrosis is characterized by excessive synthesis of extracellular matrix proteins, which prevails over their enzymatic degradation, primarily by matrix metalloproteinases (MMPs). The effect of pharmacological MMP inhibition on fibrogenesis, however, is largely unexplored. Inflammation is considered a prerequisite and important co-contributor to fibrosis and is, in part, mediated by tumor necrosis factor (TNF)-α-converting enzyme (TACE). We hypothesized that treatment with a broad-spectrum MMP and TACE-inhibitor (Marimastat) would ameliorate injury and inflammation, leading to decreased fibrogenesis during repeated hepatotoxin-induced liver injury.Methodology/Principal Findings Liver fibrosis was induced in mice by repeated carbon tetrachloride (CCl4) administration, during which the mice received either Marimastat or vehicle twice daily. A single dose of CCl4was administered to investigate acute liver injury in mice pretreated with Marimastat, mice deficient in Mmp9, or mice deficient in both TNF-α receptors. Liver injury was quantified by alanine aminotransferase (ALT) levels and confirmed by histology. Hepatic collagen was determined as hydroxyproline, and expression of fibrogenesis and fibrolysis-related transcripts was determined by quantitative reverse-transcription polymerase chain reaction. Marimastat-treated animals demonstrated significantly attenuated liver injury and inflammation but a 25% increase in collagen deposition. Transcripts related to fibrogenesis were significantly less upregulated compared to vehicle-treated animals, while MMP expression and activity analysis revealed efficient pharmacologic MMP-inhibition and decreased fibrolysis following Marimastat treatment. Marimastat pre-treatment significantly attenuated liver injury following acute CCl4-administration, whereas Mmp9 deficient animals demonstrated no protection. Mice deficient in both TNF-α receptors exhibited an 80% reduction of serum ALT, confirming the hepatoprotective effects of Marimastat via the TNF-signaling pathway.Conclusions/Significance Inhibition of MMP and TACE activity with Marimastat during chronic CCl4administration counterbalanced any beneficial anti-inflammatory effect, resulting in a positive balance of collagen deposition. Since effective inhibition of MMPs accelerates fibrosis progression, MMP inhibitors should be used with caution in patients with chronic liver diseases

Cleavage of the urokinase receptor (uPAR) on oral cancer cells : regulation by transforming growth factor - beta 1 (TGF-beta 1) and potential effects on migration and invasion

Background: Urokinase plasminogen activator (uPA) receptor (uPAR) is up-regulated at the invasive tumour front of human oral squamous cell carcinoma (OSCC), indicating a role for uPAR in tumour progression. We previously observed elevated expression of uPAR at the tumour-stroma interface in a mouse model for OSCC, which was associated with increased proteolytic activity. The tumour microenvironment regulated uPAR expression, as well as its glycosylation and cleavage. Both full-length- and cleaved uPAR (uPAR (II-III)) are involved in highly regulated processes such as cell signalling, proliferation, migration, stem cell mobilization and invasion. The aim of the current study was to analyse tumour associated factors and their effect on uPAR cleavage, and the potential implications for cell proliferation, migration and invasion. Methods: Mouse uPAR was stably overexpressed in the mouse OSCC cell line AT84. The ratio of full-length versus cleaved uPAR as analysed by Western blotting and its regulation was assessed by addition of different protease inhibitors and transforming growth factor - beta 1 (TGF-beta 1). The role of uPAR cleavage in cell proliferation and migration was analysed using real- time cell analysis and invasion was assessed using the myoma invasion model. Results: We found that when uPAR was overexpressed a proportion of the receptor was cleaved, thus the cells presented both full-length uPAR and uPAR (II-III). Cleavage was mainly performed by serine proteases and urokinase plasminogen activator (uPA) in particular. When the OSCC cells were stimulated with TGF-beta 1, the production of the uPA inhibitor PAI-1 was increased, resulting in a reduction of uPAR cleavage. By inhibiting cleavage of uPAR, cell migration was reduced, and by inhibiting uPA activity, invasion was reduced. We could also show that medium containing soluble uPAR (suPAR), and cleaved soluble uPAR (suPAR (II-III)), induced migration in OSCC cells with low endogenous levels of uPAR. Conclusions: These results show that soluble factors in the tumour microenvironment, such as TGF-beta 1, PAI-1 and uPA, can influence the ratio of full length and uPAR (II-III) and thereby potentially effect cell migration and invasion. Resolving how uPAR cleavage is controlled is therefore vital for understanding how OSCC progresses and potentially provides new targets for therapy.Peer reviewe

Palaeogenomics of Upper Palaeolithic to Neolithic European hunter-gatherers

Modern humans have populated Europe for more than 45,000 years1,2. Our knowledge of the genetic relatedness and structure of ancient hunter-gatherers is however limited, owing to the scarceness and poor molecular preservation of human remains from that period3. Here we analyse 356 ancient hunter-gatherer genomes, including new genomic data for 116 individuals from 14 countries in western and central Eurasia, spanning between 35,000 and 5,000 years ago. We identify a genetic ancestry profile in individuals associated with Upper Palaeolithic Gravettian assemblages from western Europe that is distinct from contemporaneous groups related to this archaeological culture in central and southern Europe4, but resembles that of preceding individuals associated with the Aurignacian culture. This ancestry profile survived during the Last Glacial Maximum (25,000 to 19,000 years ago) in human populations from southwestern Europe associated with the Solutrean culture, and with the following Magdalenian culture that re-expanded northeastward after the Last Glacial Maximum. Conversely, we reveal a genetic turnover in southern Europe suggesting a local replacement of human groups around the time of the Last Glacial Maximum, accompanied by a north-to-south dispersal of populations associated with the Epigravettian culture. From at least 14,000 years ago, an ancestry related to this culture spread from the south across the rest of Europe, largely replacing the Magdalenian-associated gene pool. After a period of limited admixture that spanned the beginning of the Mesolithic, we find genetic interactions between western and eastern European hunter-gatherers, who were also characterized by marked differences in phenotypically relevant variants

Desert-kites of the Hemma Plateau (Hassake, Syria)

Since 2001 , the remains of 11 individual desert kites have been discovered on the eastern border of the Hemma basaltic plateau (Hassake, Syria). The enclosure is polygonal or sub-rectangular. One of the guide walls generally runs along the border of the plateau, while the other goes down to the wadi. At Hemma, as in Jordan, desert kites are generally built on a slope, balanced on a natural crest with guide walls on one side, enclosure on the other. The dating of these structures is still discussed : in Southern Syria and Jordan, some have been assigned to the Neolithic, others to the Chalcolithic or the EBA, but later dates and uses cannot be excluded. Peripheral cells have been placed at the angles of the polygon, along its lower wall or at the far end of the enclosure. No definitive solution has been reached regarding the function of these buildings but they were probably intended to accommodate animals. Some 70 carved depictions of desert kites have been discovered. Their rocky support is often used as a natural landscape. The carvings belong to the same cultural phases as the buildings, but show a more diversified typology. Anthropomorphic and zoomorphic figures associated with them refer to hunting, divinities or uninterpretable scenes. Similar representations discovered in Jordan often show the same stylistic characteristics as those of the Hemma, which raises the question of their possible attribution to mobile populations.De nombreux sites archéologiques et d'art rupestre ont été découverts depuis dix ans en bordure orientale du plateau basaltique du Hemma (Hassake, Syrie) et le long des wadis qui l'entaillent. Les récoltes de surface montrent que la zone est occupée du 7e millénaire à la fin de l'époque parthe ; la période néo-assyrienne est la mieux représentée. Les vestiges archéologiques comportent des desert-kites, des cercles de pierre (non datés) et des habitats d'époque néo-assyrienne et achéménide. Quelque 2 500 roches gravées s'échelonnent entre le 5e/4e millénaire et le IIIe siècle de notre ère, avec deux concentrations principales sur les sites de Khishâm-2 et de Kefra. Depuis 2001, le travail de terrain est assuré par une mission syro-belge qui pratique des sondages, des prospections et des relevés de l 'art rupestre. L 'article est consacré aux desert-kites, illustrés par des structures construites et des gravures rupestres. Les vestiges de 11 desert-kites, ont été découverts sur une distance de 25 km. Celui de Khishâm-2, muni d'un enclos long de 140 m, est le plus grand et le mieux conservé. Ces constructions se présentent individuellement et non en chaînes, comme ce peut être le cas en Syrie méridionale et en Jordanie. Aucun nouvel élément de datation n 'est apparu jusqu 'ici. Les dates proposées ailleurs se répartissent généralement du Néolithique au Bronze ancien, sans que des constructions et des usages plus tardifs puissent être exclus. Les enclos polygonaux ou sub-rectangulaires sont généralement installés sur une pente, en équilibre sur une crête naturelle, murs d'accès d'un côté, enclos de l 'autre. Les cellules périphériques se trouvent aux angles du polygone, le long du mur le plus bas et le long du mur opposé à l 'entrée. Aucune solution définitive n 'a été atteinte en ce qui concerne l'utilisation de ces structures sans doute destinées à accueillir des animaux. Quelque 70 représentations rupestres de desert-kites ont été découvertes. Leur support rocheux est souvent utilisé comme un paysage naturel. Ces figures appartiennent aux mêmes phases culturelles que les constructions, mais leur typologie est plus diversifiée. Les figures anthropomorphes et surtout zoomorphes associées renvoient tantôt à la thématique de la chasse, tantôt à des divinités ou présentent des scènes non interprétables. Des représentations similaires découvertes en Jordanie présentent souvent les mêmes caractères stylistiques que celles du Hemma, ce qui soulève la question de leur attribution éventuelle à des populations mobiles.Van Berg P.-L., Vander Linden Marc, Lemaitre Serge, Cauwe Nicolas, Picalause Vincianne. Desert-kites of the Hemma Plateau (Hassake, Syria). In: Paléorient, 2004, vol. 30, n°1. pp. 89-99