Distinct Levels of Sox9 Expression Mark Colon Epithelial Stem Cells that Form Colonoids in Culture

Sox9 is an high-mobility group box transcription factor that is expressed in the stem cell zone of the small intestine and colon. We have previously used a Sox9EGFP mouse model to demonstrate that discrete levels of Sox9 expression mark small intestine epithelial stem cells that form crypt/villus-like structures in a three-dimensional culture system (Formeister EJ, Sionas AL, Lorance DK, Barkley CL, Lee GH, Magness ST. Am J Physiol Gastrointest Liver Physiol 296: G1108–G1118, 2009; Gracz AD, Ramalingam S, Magness ST. Am J Physiol Gastrointest Liver Physiol 298: G590–G600, 2010). In the present study, we hypothesized that discrete levels of Sox9 expression would also mark colonic epithelial stem cells (CESCs). Using the Sox9EGFP mouse model, we show that lower levels of Sox9 mark cells in the transit-amplifying progenitor cell zone, while higher levels of Sox9 mark cells in the colonic crypt base. Furthermore, we demonstrate that variable SOX9 levels persist in cells of colonic adenomas from mice and humans. Cells expressing lower Sox9 levels demonstrate gene expression profiles consistent with more differentiated populations, and cells expressing higher Sox9 levels are consistent with less differentiated populations. When placed in culture, cells expressing the highest levels of Sox9 formed “colonoids,” which are defined as bodies of cultured colonic epithelial cells that possess multiple cryptlike structures and a pseudolumen. Cells expressing the highest levels of Sox9 also demonstrate multipotency and self-renewal in vitro, indicating functional stemness. These data suggest a dose-dependent role for Sox9 in normal CESCs and cells comprising colon tumors. Furthermore, distinct Sox9 levels represent a new biomarker to study CESC and progenitor biology in physiological and disease states

Therapeutically engineered induced neural stem cells are tumour-homing and inhibit progression of glioblastoma

Transdifferentiation (TD) is a recent advancement in somatic cell reprogramming. The direct conversion of TD eliminates the pluripotent intermediate state to create cells that are ideal for personalized cell therapy. Here we provide evidence that TD-derived induced neural stem cells (iNSCs) are an efficacious therapeutic strategy for brain cancer. We find that iNSCs genetically engineered with optical reporters and tumouricidal gene products retain the capacity to differentiate and induced apoptosis in co-cultured human glioblastoma cells. Time-lapse imaging shows that iNSCs are tumouritropic, homing rapidly to co-cultured glioblastoma cells and migrating extensively to distant tumour foci in the murine brain. Multimodality imaging reveals that iNSC delivery of the anticancer molecule TRAIL decreases the growth of established solid and diffuse patient-derived orthotopic glioblastoma xenografts 230- and 20-fold, respectively, while significantly prolonging the median mouse survival. These findings establish a strategy for creating autologous cell-based therapies to treat patients with aggressive forms of brain cancer

Identification of Phytoplankton Blooms under the Index of Inherent Optical Properties (IOP Index) in Optically Complex Waters

[EN] Phytoplankton blooms are sporadic events in time and are isolated in space. This complex phenomenon is produced by a variety of both natural and anthropogenic causes. Early detection of this phenomenon, as well as the classification of a water body under conditions of bloom or non-bloom, remains an unresolved problem. This research proposes the use of Inherent Optical Properties (IOPs) in optically complex waters to detect the bloom or non-bloom state of the phytoplankton community. An IOP index is calculated from the absorption coefficients of the colored dissolved organic matter (CDOM), the phytoplankton (phy) and the detritus (d), using the wavelength (lambda) 443 nm. The effectiveness of this index is tested in five bloom events in different places and with different characteristics from Mexican seas: 1. Dzilam (Caribbean Sea, Atlantic Ocean), a diatom bloom (Rhizosolenia hebetata); 2. Holbox (Caribbean Sea, Atlantic Ocean), a mixed bloom of dinoflagellates (Scrippsiella sp.) and diatoms (Chaetoceros sp.); 3. Campeche Bay in the Gulf of Mexico (Atlantic Ocean), a bloom of dinoflagellates (Karenia brevis); 4. Upper Gulf of California (UGC) (Pacific Ocean), a diatom bloom (Coscinodiscus and Pseudo-nitzschia) and 5. Todos Santos Bay, Ensenada (Pacific Ocean), a dinoflagellate bloom (Lingulodinium polyedrum). The diversity of sites show that the IOP index is a suitable method to determine the phytoplankton bloom conditions.CONACYT supported this research with a doctorate scholarship to Jesús A. Aguilar-Maldonado, with the announcement number 251025 in 2015. María-Teresa Sebastiá-Frasquet was a beneficiary of the BEST/2017/217 grant, supported by the Valencian Conselleria d Educació, Investigació, Cultura i Esport (Spain) during her stay at the Universidad Autónoma de Baja California (Mexico). Thanks are extended to the Strategic Action Program of the Gulf of Mexico Large Marine Ecosystem (GoM-LME), of the United Nations Industrial Development Organization (UNIDO).Aguilar-Maldonado, J.; Santamaría-Del-Ángel, E.; González-Silvera, A.; Cervantes-Rosas, OD.; López-Acuña, LM.; Gutiérrez-Magness, A.; Cerdeira, S.... (2018). Identification of Phytoplankton Blooms under the Index of Inherent Optical Properties (IOP Index) in Optically Complex Waters. Water. 10(2). https://doi.org/10.3390/w10020129S102Gower, J., King, S., Borstad, G., & Brown, L. (2005). Detection of intense plankton blooms using the 709 nm band of the MERIS imaging spectrometer. International Journal of Remote Sensing, 26(9), 2005-2012. doi:10.1080/01431160500075857Carstensen, J., & Conley, D. J. (2004). Frequency, composition, and causes of summer phytoplankton blooms in a shallow coastal ecosystem, the Kattegat. Limnology and Oceanography, 49(1), 191-201. doi:10.4319/lo.2004.49.1.0191Legendre, L. (1990). 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Estuaries and Coasts, 33(2), 428-439. doi:10.1007/s12237-009-9161-0Cui, T., Cao, W., Zhang, J., Hao, Y., Yu, Y., Zu, T., & Wang, D. (2013). Diurnal variability of ocean optical properties during a coastal algal bloom: implications for ocean colour remote sensing. International Journal of Remote Sensing, 34(23), 8301-8318. doi:10.1080/01431161.2013.833356Loisel, H., Vantrepotte, V., Norkvist, K., Mériaux, X., Kheireddine, M., Ras, J., … Moutin, T. (2011). Characterization of the bio-optical anomaly and diurnal variability of particulate matter, as seen from scattering and backscattering coefficients, in ultra-oligotrophic eddies of the Mediterranean Sea. Biogeosciences, 8(11), 3295-3317. doi:10.5194/bg-8-3295-2011Mercado, J. M., Ramírez, T., Cortés, D., Sebastián, M., Reul, A., & Bautista, B. (2006). Diurnal changes in the bio-optical properties of the phytoplankton in the Alborán Sea (Mediterranean Sea). 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(2015). Water quality assessment in the Mexican Caribbean: Impacts on the coastal ecosystem. Continental Shelf Research, 102, 62-72. doi:10.1016/j.csr.2015.04.015Merrell, W. J., & Morrison, J. M. (1981). On the circulation of the western Gulf of Mexico with observations from April 1978. Journal of Geophysical Research, 86(C5), 4181. doi:10.1029/jc086ic05p04181Carriquiry, J. D., & Sánchez, A. (1999). Sedimentation in the Colorado River delta and Upper Gulf of California after nearly a century of discharge loss. Marine Geology, 158(1-4), 125-145. doi:10.1016/s0025-3227(98)00189-3Brusca, R. C., Álvarez-Borrego, S., Hastings, P. A., & Findley, L. T. (2017). Colorado River flow and biological productivity in the Northern Gulf of California, Mexico. Earth-Science Reviews, 164, 1-30. doi:10.1016/j.earscirev.2016.10.012Daesslé, L. W., Orozco, A., Struck, U., Camacho-Ibar, V. F., van Geldern, R., Santamaría-del-Angel, E., & Barth, J. A. C. (2017). Sources and sinks of nutrients and organic carbon during the 2014 pulse flow of the Colorado River into Mexico. Ecological Engineering, 106, 799-808. doi:10.1016/j.ecoleng.2016.02.018Orozco-Durán, A., Daesslé, L. W., Camacho-Ibar, V. F., Ortiz-Campos, E., & Barth, J. A. C. (2015). Turnover and release of P-, N-, Si-nutrients in the Mexicali Valley (Mexico): Interactions between the lower Colorado River and adjacent ground- and surface water systems. Science of The Total Environment, 512-513, 185-193. doi:10.1016/j.scitotenv.2015.01.016Aguilar-Maldonado, J. A., Santamaría-del-Ángel, E., & Sebastiá-Frasquet, M. T. (2017). Reflectances of SPOT multispectral images associated with the turbidity of the Upper Gulf of California. Revista de Teledetección, (50), 1. doi:10.4995/raet.2017.7795Cepeda-Morales, J. (2017). Response of primary producers to the hydrographic variability in the southern region of the California Current System. Ciencias Marinas, 40(2), 123-135. doi:10.7773/cm.v43i2.2752Delgadillo-Hinojosa, F., Camacho-Ibar, V., Huerta-Díaz, M. A., Torres-Delgado, V., Pérez-Brunius, P., Lares, L., … Castro, R. (2015). Seasonal behavior of dissolved cadmium and Cd/PO4 ratio in Todos Santos Bay: A retention site of upwelled waters in the Baja California peninsula, Mexico. Marine Chemistry, 168, 37-48. doi:10.1016/j.marchem.2014.10.010Durazo, R. (2005). Oceanographic conditions west of the Baja California coast, 2002?2003: A weak El Niño and subarctic water enhancement. Ciencias Marinas, 31(3), 537-552. doi:10.7773/cm.v31i3.43Linacre, L., Durazo, R., Hernández-Ayón, J. M., Delgadillo-Hinojosa, F., Cervantes-Díaz, G., Lara-Lara, J. R., … Bazán-Guzmán, C. (2010). Temporal variability of the physical and chemical water characteristics at a coastal monitoring observatory: Station ENSENADA. Continental Shelf Research, 30(16), 1730-1742. doi:10.1016/j.csr.2010.07.011Espinosa-Carreón, T. L., Gaxiola-Castro, G., Durazo, R., De la Cruz-Orozco, M. E., Norzagaray-Campos, M., & Solana-Arellano, E. (2015). Influence of anomalous subarctic water intrusion on phytoplankton production off Baja California. Continental Shelf Research, 92, 108-121. doi:10.1016/j.csr.2014.10.003Gutierrez-Mejia, E., Lares, M. L., Huerta-Diaz, M. A., & Delgadillo-Hinojosa, F. (2016). Cadmium and phosphate variability during algal blooms of the dinoflagellate Lingulodinium polyedrum in Todos Santos Bay, Baja California, Mexico. Science of The Total Environment, 541, 865-876. doi:10.1016/j.scitotenv.2015.09.081Santamaría-del-Ángel, E., Millán-Núñez, R., González-Silvera, A., Callejas-Jiménez, M., Cajal-Medrano, R., & Galindo-Bect, M. S. (2010). The response of shrimp fisheries to climate variability off Baja California, México. ICES Journal of Marine Science, 68(4), 766-772. doi:10.1093/icesjms/fsq186Hirata, T., Aiken, J., Hardman-Mountford, N., Smyth, T. J., & Barlow, R. G. (2008). An absorption model to determine phytoplankton size classes from satellite ocean colour. Remote Sensing of Environment, 112(6), 3153-3159. doi:10.1016/j.rse.2008.03.011Aiken, J., Hardman-Mountford, N. J., Barlow, R., Fishwick, J., Hirata, T., & Smyth, T. (2007). Functional links between bioenergetics and bio-optical traits of phytoplankton taxonomic groups: an overarching hypothesis with applications for ocean colour remote sensing. Journal of Plankton Research, 30(2), 165-181. doi:10.1093/plankt/fbm098Stuart, V., Sathyendranath, S., Platt, T., Maass, H., & Irwin, B. D. (1998). Pigments and species composition of natural phytoplankton populations: effect on the absorption spectra. Journal of Plankton Research, 20(2), 187-217. doi:10.1093/plankt/20.2.187Lohrenz, S. E. (2003). Phytoplankton spectral absorption as influenced by community size structure and pigment composition. Journal of Plankton Research, 25(1), 35-61. doi:10.1093/plankt/25.1.35Wu, J., Hong, H., Shang, S., Dai, M., & Lee, Z. (2007). Variation of phytoplankton absorption coefficients in the northern South China Sea during spring and autumn. Biogeosciences Discussions, 4(3), 1555-1584. doi:10.5194/bgd-4-1555-2007Millán-Núñez, E., & Millán-Núñez, R. (2010). Specific absorption coefficient and phytoplankton community structure in the southern region of the California Current during January 2002. Journal of Oceanography, 66(5), 719-730. doi:10.1007/s10872-010-0059-zHaywood, A. J., Steidinger, K. A., Truby, E. W., Bergquist, P. R., Bergquist, P. L., Adamson, J., & Mackenzie, L. (2004). COMPARATIVE MORPHOLOGY AND MOLECULAR PHYLOGENETIC ANALYSIS OF THREE NEW SPECIES OF THE GENUS KARENIA (DINOPHYCEAE) FROM NEW ZEALAND1. Journal of Phycology, 40(1), 165-179. doi:10.1111/j.0022-3646.2004.02-149.xQuijano-Scheggia, S. (2016). The inhibitory effect of a non-yessotoxin-producing dinoflagellate, Lingulodinium polyedrum (Stein) Dodge, towards Vibrio vulnificus and Staphylococcus aureus. Revista de Biología Tropical, 64(2), 805. doi:10.15517/rbt.v64i2.19320Holm-Hansen, O., & Riemann, B. (1978). Chlorophyll a Determination: Improvements in Methodology. Oikos, 30(3), 438. doi:10.2307/3543338Aguilar-Trujillo, A. C., Okolodkov, Y. B., Herrera-Silveira, J. A., Merino-Virgilio, F. del C., & Galicia-García, C. (2017). Taxocoenosis of epibenthic dinoflagellates in the coastal waters of the northern Yucatan Peninsula before and after the harmful algal bloom event in 2011–2012. Marine Pollution Bulletin, 119(1), 396-406. doi:10.1016/j.marpolbul.2017.02.074Ulloa, M. J., Álvarez-Torres, P., Horak-Romo, K. P., & Ortega-Izaguirre, R. (2017). Harmful algal blooms and eutrophication along the mexican coast of the Gulf of Mexico large marine ecosystem. 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Restriction of intestinal stem cell expansion and the regenerative response by YAP

A remarkable feature of regenerative processes is their ability to halt proliferation once an organ’s structure has been restored. The Wnt signaling pathway is the major driving force for homeostatic self-renewal and regeneration in the mammalian intestine. The mechanisms that counterbalance Wnt-driven proliferation are poorly understood. We demonstrate here that YAP, a protein known for its powerful growth-inducing and oncogenic properties1-2, has an unexpected growth-suppressive function restricting Wnt signals during intestinal regeneration. Transgenic expression of YAP reduces Wnt target gene expression and results in the rapid loss of intestinal crypts. In addition, loss of YAP results in Wnt hypersensitivity during regeneration, leading to hyperplasia, expansion of intestinal stem cells (ISCs) and niche cells, and formation of ectopic crypts and microadenomas. We find that cytoplasmic YAP restricts elevated Wnt signaling independently of the APC/Axin/GSK3β complex partly by limiting the activity of Dishevelled (DVL). DVL signals in the nucleus of ISCs and its forced expression leads to enhanced Wnt signaling in crypts. YAP dampens Wnt signals by restricting DVL nuclear translocation during regenerative growth. Finally, we provide evidence that YAP is silenced in a subset of highly aggressive and undifferentiated human colorectal carcinomas (CRC) and its expression can restrict the growth of CRC xenografts. Collectively, our work describes a novel mechanistic paradigm for how proliferative signals are counterbalanced in regenerating tissues. Additionally, our findings have important implications for the targeting of YAP in human malignancies

Restriction of intestinal stem cell expansion and the regenerative response by YAP

A remarkable feature of regenerative processes is their ability to halt proliferation once an organ’s structure has been restored. The Wnt signaling pathway is the major driving force for homeostatic self-renewal and regeneration in the mammalian intestine. The mechanisms that counterbalance Wnt-driven proliferation are poorly understood. We demonstrate here that YAP, a protein known for its powerful growth-inducing and oncogenic properties1-2, has an unexpected growth-suppressive function restricting Wnt signals during intestinal regeneration. Transgenic expression of YAP reduces Wnt target gene expression and results in the rapid loss of intestinal crypts. In addition, loss of YAP results in Wnt hypersensitivity during regeneration, leading to hyperplasia, expansion of intestinal stem cells (ISCs) and niche cells, and formation of ectopic crypts and microadenomas. We find that cytoplasmic YAP restricts elevated Wnt signaling independently of the APC/Axin/GSK3β complex partly by limiting the activity of Dishevelled (DVL). DVL signals in the nucleus of ISCs and its forced expression leads to enhanced Wnt signaling in crypts. YAP dampens Wnt signals by restricting DVL nuclear translocation during regenerative growth. Finally, we provide evidence that YAP is silenced in a subset of highly aggressive and undifferentiated human colorectal carcinomas (CRC) and its expression can restrict the growth of CRC xenografts. Collectively, our work describes a novel mechanistic paradigm for how proliferative signals are counterbalanced in regenerating tissues. Additionally, our findings have important implications for the targeting of YAP in human malignancies

Distinct Populations of Hepatic Stellate Cells in the Mouse Liver Have Different Capacities for Retinoid and Lipid Storage

Hepatic stellate cell (HSC) lipid droplets are specialized organelles for the storage of retinoid, accounting for 50–60% of all retinoid present in the body. When HSCs activate, retinyl ester levels progressively decrease and the lipid droplets are lost. The objective of this study was to determine if the HSC population in a healthy, uninjured liver demonstrates heterogeneity in its capacity for retinoid and lipid storage in lipid droplets. To this end, we utilized two methods of HSC isolation, which leverage distinct properties of these cells, including their vitamin A content and collagen expression. HSCs were isolated either from wild type (WT) mice in the C57BL/6 genetic background by flotation in a Nycodenz density gradient, followed by fluorescence activated cell sorting (FACS) based on vitamin A autofluorescence, or from collagen-green fluorescent protein (GFP) mice by FACS based on GFP expression from a GFP transgene driven by the collagen I promoter. We show that GFP-HSCs have: (i) increased expression of typical markers of HSC activation; (ii) decreased retinyl ester levels, accompanied by reduced expression of the enzyme needed for hepatic retinyl ester synthesis (LRAT); (iii) decreased triglyceride levels; (iv) increased expression of genes associated with lipid catabolism; and (v) an increase in expression of the retinoid-catabolizing cytochrome, CYP2S1. Conclusion: Our observations suggest that the HSC population in a healthy, uninjured liver is heterogeneous. One subset of the total HSC population, which expresses early markers of HSC activation, may be “primed” and ready for rapid response to acute liver injury

Matrix Metalloproteinase Gene Delivery for Liver Fibrosis

The resolution of advanced liver fibrosis has been recently recognized to be possible, if the causative stimuli are successfully removed. However, whether complete resolution from cirrhosis, the end stage of liver fibrosis, can be achieved is still questionable. Delivery of interstitial collagenases, such as matrix metalloproteinase (MMP)-1, in the liver could be an attractive strategy to treat advanced hepatic fibrosis from the view point that the imbalance between too few interstitial collagenases and too many of their inhibitors is the main obstacle to the resolution from fibrosis. Remodeling of hepatic extracellular matrix by delivered interstitial collagenases also facilitates the disappearance of activated hepatic stellate cells, the main matrix-producing cells in the liver, and promotes the proliferation of hepatocytes. This review will focus on the impact of the gene delivery of MMPs for the treatment of advanced liver fibrosis while discussing other current therapeutic strategies for liver fibrosis, and on the need for the development of a safe and effective delivery system of MMPs

NADPH oxidase and reactive oxygen species contribute to alcohol-induced microglial activation and neurodegeneration

<p>Abstract</p> <p>Background</p> <p>Activation of microglia causes the production of proinflammatory factors and upregulation of NADPH oxidase (NOX) that form reactive oxygen species (ROS) that lead to neurodegeneration. Previously, we reported that 10 daily doses of ethanol treatment induced innate immune genes in brain. In the present study, we investigate the effects of chronic ethanol on activation of NOX and release of ROS, and their contribution to ethanol neurotoxicity.</p> <p>Methods</p> <p>Male C57BL/6 and NF-κB enhanced GFP mice were treated intragastrically with water or ethanol (5 g/kg, i.g., 25% ethanol w/v) daily for 10 days. The effects of chronic ethanol on cell death markers (activated caspase-3 and Fluoro-Jade B), microglial morphology, NOX, ROS and NF-κB were examined using real-time PCR, immunohistochemistry and hydroethidine histochemistry. Also, Fluoro-Jade B staining and NOX gp91^phoximmunohistochemistry were performed in the orbitofrontal cortex (OFC) of human postmortem alcoholic brain and human moderate drinking control brain.</p> <p>Results</p> <p>Ethanol treatment of C57BL/6 mice showed increased markers of neuronal death: activated caspase-3 and Fluoro-Jade B positive staining with Neu-N (a neuronal marker) labeling in cortex and dentate gyrus. The OFC of human post-mortem alcoholic brain also showed significantly more Fluoro-Jade B positive cells colocalized with Neu-N, a neuronal marker, compared to the OFC of human moderate drinking control brain, suggesting increased neuronal death in the OFC of human alcoholic brain. Iba1 and GFAP immunohistochemistry showed activated morphology of microglia and astrocytes in ethanol-treated mouse brain. Ethanol treatment increased NF-κB transcription and increased NOX gp91^phoxat 24 hr after the last ethanol treatment that remained elevated at 1 week. The OFC of human postmortem alcoholic brain also had significant increases in the number of gp91^phox+ immunoreactive (IR) cells that are colocalized with neuronal, microglial and astrocyte markers. In mouse brain ethanol increased gp91^phoxexpression coincided with increased production of O₂^-and O₂^-- derived oxidants. Diphenyleneiodonium (DPI), a NOX inhibitor, reduced markers of neurodegeneration, ROS and microglial activation.</p> <p>Conclusions</p> <p>Ethanol activation of microglia and astrocytes, induction of NOX and production of ROS contribute to chronic ethanol-induced neurotoxicity. NOX-ROS and NF-κB signaling pathways play important roles in chronic ethanol-induced neuroinflammation and neurodegeneration.</p

Notch signaling modulates proliferation and differentiation of intestinal crypt base columnar stem cells

Notch signaling is known to regulate the proliferation and differentiation of intestinal stem and progenitor cells; however, direct cellular targets and specific functions of Notch signals had not been identified. We show here in mice that Notch directly targets the crypt base columnar (CBC) cell to maintain stem cell activity. Notch inhibition induced rapid CBC cell loss, with reduced proliferation, apoptotic cell death and reduced efficiency of organoid initiation. Furthermore, expression of the CBC stem cell-specific marker Olfm4 was directly dependent on Notch signaling, with transcription activated through RBP-Jκ binding sites in the promoter. Notch inhibition also led to precocious differentiation of epithelial progenitors into secretory cell types, including large numbers of cells that expressed both Paneth and goblet cell markers. Analysis of Notch function in Atoh1-deficient intestine demonstrated that the cellular changes were dependent on Atoh1, whereas Notch regulation of Olfm4 gene expression was Atoh1 independent. Our findings suggest that Notch targets distinct progenitor cell populations to maintain adult intestinal stem cells and to regulate cell fate choice to control epithelial cell homeostasis

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