by Keyword: fibrosis
Duch, P, Diaz-Valdivia, N, Ikemori, R, Gabasa, M, Radisky, ES, Arshakyan, M, Gea-Sorli, S, Mateu-Bosch, A, Bragado, P, Carrasco, JL, Mori, H, Ramirez, J, Teixido, C, Reguart, N, Fillat, C, Radisky, DC, Alcaraz, J, (2022). Aberrant TIMP-1 overexpression in tumor-associated fibroblasts drives tumor progression through CD63 in lung adenocarcinoma Matrix Biology 111, 207-225
Tissue inhibitor of metalloproteinase-1 (TIMP-1) is an important regulator of extracellular matrix turnover that has been traditionally regarded as a potential tumor suppressor owing to its inhibitory effects of matrix metal-loproteinases. Intriguingly, this interpretation has been challenged by the consistent observation that increased expression of TIMP-1 is associated with poor prognosis in virtually all cancer types including lung cancer, supporting a tumor-promoting function. However, how TIMP-1 is dysregulated within the tumor micro-environment and how it drives tumor progression in lung cancer is poorly understood. We analyzed the expression of TIMP-1 and its cell surface receptor CD63 in two major lung cancer subtypes: lung adenocarci-noma (ADC) and squamous cell carcinoma (SCC), and defined the tumor-promoting effects of their interac-tion. We found that TIMP-1 is aberrantly overexpressed in tumor-associated fibroblasts (TAFs) in ADC compared to SCC. Mechanistically, TIMP-1 overexpression was mediated by the selective hyperactivity of the pro-fibrotic TGF-61/SMAD3 pathway in ADC-TAFs. Likewise, CD63 was upregulated in ADC compared to SCC cells. Genetic analyses revealed that TIMP-1 secreted by TGF-61-activated ADC-TAFs is both nec-essary and sufficient to enhance growth and invasion of ADC cancer cells in culture, and that tumor cell expression of CD63 was required for these effects. Consistently, in vivo analyses revealed that ADC cells co-injected with fibroblasts with reduced SMAD3 or TIMP-1 expression into immunocompromised mice attenu-ated tumor aggressiveness compared to tumors bearing parental fibroblasts. We also found that high TIMP1 and CD63 mRNA levels combined define a stronger prognostic biomarker than TIMP1 alone. Our results identify an excessive stromal TIMP-1 within the tumor microenvironment selectively in lung ADC, and implicate it in a novel tumor-promoting TAF-carcinoma crosstalk, thereby pointing to TIMP-1/CD63 interaction as a novel therapeutic target in lung cancer. (c) 2022 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/)
JTD Keywords: Angiogenesis, Cancer cells, Cancer-associated fibroblast, Cd63, Expression, Fibrosis, Hepatocellular-carcinoma, Metalloproteinases, Nintedanib, Prognostic-significance, Protein, Smad3, Squamous-cell carcinoma, Tgf-? 1, Tgf-β1, Timp-1, Tissue inhibitor, Tumor microenvironment
Blanco-Cabra, N, Movellan, J, Marradi, M, Gracia, R, Salvador, C, Dupin, D, Loinaz, I, Torrents, E, (2022). Neutralization of ionic interactions by dextran-based single-chain nanoparticles improves tobramycin diffusion into a mature biofilm Npj Biofilms And Microbiomes 8, 52
The extracellular matrix protects biofilm cells by reducing diffusion of antimicrobials. Tobramycin is an antibiotic used extensively to treat P. aeruginosa biofilms, but it is sequestered in the biofilm periphery by the extracellular negative charge matrix and loses its efficacy significantly. Dispersal of the biofilm extracellular matrix with enzymes such as DNase I is another promising therapy that enhances antibiotic diffusion into the biofilm. Here, we combine the charge neutralization of tobramycin provided by dextran-based single-chain polymer nanoparticles (SCPNs) together with DNase I to break the biofilm matrix. Our study demonstrates that the SCPNs improve the activity of tobramycin and DNase I by neutralizing the ionic interactions that keep this antibiotic in the biofilm periphery. Moreover, the detailed effects and interactions of nanoformulations with extracellular matrix components were revealed through time-lapse imaging of the P. aeruginosa biofilms by laser scanning confocal microscopy with specific labeling of the different biofilm components.
JTD Keywords: Cystic-fibrosis sputum, Delivery, Extracellular dna, Infections, Pseudomonas-aeruginosa, Transport
Chulia-Peris, L, Carreres-Rey, C, Gabasa, M, Alcaraz, J, Carretero, J, Pereda, J, (2022). Matrix Metalloproteinases and Their Inhibitors in Pulmonary Fibrosis: EMMPRIN/CD147 Comes into Play International Journal Of Molecular Sciences 23, 6894
Pulmonary fibrosis (PF) is characterized by aberrant extracellular matrix (ECM) deposition, activation of fibroblasts to myofibroblasts and parenchymal disorganization, which have an impact on the biomechanical traits of the lung. In this context, the balance between matrix metalloproteinases (MMPs) and their tissue inhibitors of metalloproteinases (TIMPs) is lost. Interestingly, several MMPs are overexpressed during PF and exhibit a clear profibrotic role (MMP-2, -3, -8, -11, -12 and -28), but a few are antifibrotic (MMP-19), have both profibrotic and antifibrotic capacity (MMP7), or execute an unclear (MMP-1, -9, -10, -13, -14) or unknown function. TIMPs are also overexpressed in PF; hence, the modulation and function of MMPs and TIMP are more complex than expected. EMMPRIN/CD147 (also known as basigin) is a transmembrane glycoprotein from the immunoglobulin superfamily (IgSF) that was first described to induce MMP activity in fibroblasts. It also interacts with other molecules to execute non-related MMP aactions well-described in cancer progression, migration, and invasion. Emerging evidence strongly suggests that CD147 plays a key role in PF not only by MMP induction but also by stimulating fibroblast myofibroblast transition. In this review, we study the structure and function of MMPs, TIMPs and CD147 in PF and their complex crosstalk between them.
JTD Keywords: Basigin, Cd147, Cell-surface, Emmprin, Extracellular-matrix, Gelatinase-b, Gene-expression profiles, Growth-factor-beta, Immunoglobulin superfamily, Induced lung injury, Inducer emmprin, Mmps, Pulmonary fibrosis, Timps, Tissue inhibitor, Transforming growth-factor-beta-1
Júnior C, Narciso M, Marhuenda E, Almendros I, Farré R, Navajas D, Otero J, Gavara N, (2021). Baseline stiffness modulates the non-linear response to stretch of the extracellular matrix in pulmonary fibrosis International Journal Of Molecular Sciences 22,
Pulmonary fibrosis (PF) is a progressive disease that disrupts the mechanical homeostasis of the lung extracellular matrix (ECM). These effects are particularly relevant in the lung context, given the dynamic nature of cyclic stretch that the ECM is continuously subjected to during breathing. This work uses an in vivo model of pulmonary fibrosis to characterize the macro-and micromechanical properties of lung ECM subjected to stretch. To that aim, we have compared the micromechanical properties of fibrotic ECM in baseline and under stretch conditions, using a novel combination of Atomic Force Microscopy (AFM) and a stretchable membrane-based chip. At the macroscale, fibrotic ECM displayed strain-hardening, with a stiffness one order of magnitude higher than its healthy counterpart. Conversely, at the microscale, we found a switch in the stretch-induced mechanical behaviour of the lung ECM from strain-hardening at physiological ECM stiffnesses to strain-softening at fibrotic ECM stiffnesses. Similarly, we observed solidification of healthy ECM versus fluidization of fibrotic ECM in response to stretch. Our results suggest that the mechanical behaviour of fibrotic ECM under stretch involves a potential built-in mechanotransduction mechanism that may slow down the progression of PF by steering resident fibroblasts away from a pro-fibrotic profile. © 2021 by the authors. Licensee MDPI, Basel, Switzerland.
JTD Keywords: atomic force microscopy, extracellular matrix, fibrosis, mechanics, mechanosensing, strain, system, viscoelasticity, Atomic force microscopy, Extracellular matrix, Fibrosis, Lung fibrosis, Mechanosensing
Ortiz C, Schierwagen R, Schaefer L, Klein S, Trepat X, Trebicka J, (2021). Extracellular Matrix Remodeling in Chronic Liver Disease Current Tissue Microenvironment Reports 2, 1-12
Abstract Purpose of the Review This review aims to summarize the current knowledge of the extracellular matrix remodeling during hepatic fibrosis. We discuss the diverse interactions of the extracellular matrix with hepatic cells and the surrounding matrix in liver fibrosis, with the focus on the molecular pathways and the mechanisms that regulate extracellular matrix remodeling. Recent Findings The extracellular matrix not only provides structure and support for the cells, but also controls cell behavior by providing adhesion signals and by acting as a reservoir of growth factors and cytokines. Summary Hepatic fibrosis is characterized by an excessive accumulation of extracellular matrix. During fibrogenesis, the natural remodeling process of the extracellular matrix varies, resulting in the excessive accumulation of its components, mainly collagens. Signals released by the extracellular matrix induce the activation of hepatic stellate cells, which are the major source of extracellular matrix and most abundant myofibroblasts in the liver. Graphical abstract
JTD Keywords: collagen, extracellular matrix, hepatic stellate cell, liver fibrosis, metalloproteinases, Tgf-?1
Torp N, Israelsen M, Madsen B, Lutz P, Jansen C, Strassburg C, Mortensen C, Knudsen AW, Sorensen GL, Holmskov U, Schlosser A, Thiele M, Trebicka J, Krag A, (2021). Level of MFAP4 in ascites independently predicts 1-year transplant-free survival in patients with cirrhosis Jhep Rep 3,
Background & Aims: Prognostic models of cirrhosis underestimate disease severity for patients with cirrhosis and ascites. Microfibrillar-associated protein 4 (MFAP4) is an extracellular matrix protein linked to hepatic neoangiogenesis and fibrogenesis. We investigated ascites MFAP4 as a predictor of transplant-free survival in patients with cirrhosis and ascites. Methods: A dual-centre observational study of patients with cirrhosis and ascites recruited consecutively in relation to a paracentesis was carried out. Patients were followed up for 1 year, until death or liver transplantation (LTx). Ascites MFAP4 was tested with the model for end-stage liver disease (MELD-Na), CLIF Consortium Acute Decompensation (CLIF-C AD), and Child-Pugh score in Cox regression models. Results: Ninety-three patients requiring paracentesis were included. Median ascites MFAP4 was 29.7 U/L [22.3–41.3], and MELD-Na was 19 [16–23]. A low MELD-Na score (<20) was observed in 49 patients (53%). During follow-up, 20 patients died (22%), and 6 received LTx (6%). High ascites MFAP4 (>29.7 U/L) was associated with 1-year transplant-free survival (p = 0.002). In Cox regression, ascites MFAP4 and MELD-Na independently predicted 1-year transplant-free survival (hazard ratio [HR] = 0.97, p = 0.03, and HR = 1.08, p = 0.01, respectively). Ascites MFAP4 and CLIF-C AD also predicted survival independently (HR = 0.96, p = 0.02, and HR = 1.05, p = 0.03, respectively), whereas only ascites MFAP4 did, controlling for the Child-Pugh score (HR = 0.97, p = 0.03, and HR = 1.18, p = 0.16, respectively). For patients with MELD-Na <20, ascites MFAP4 but not ascites protein predicted 1-year transplant-free survival (HR 0.91, p = 0.02, and HR = 0.94, p = 0.17, respectively). Conclusions: Ascites MFAP4 predicts 1-year transplant-free survival in patients with cirrhosis and ascites. In patients with low MELD-Na scores, ascites MFAP4, but not total ascites protein, significantly predicted 1-year transplant-free survival. Lay summary: Patients with cirrhosis who have fluid in the abdomen, ascites, are at an increased risk of death and in need for liver transplantation. Our study identified patients with ascites and a poor prognosis by measuring microfibrillar associated protein 4 (MFAP4), a protein present in the abdominal fluid. Patients with low levels of the MFAP4 protein are at particularly increased risk of death or liver transplantation, suggesting that clinical care should be intensified in this group of patients. © 2021 The Authors
JTD Keywords: biomarker, clif-c ad, clif consortium acute decompensation, cps, child-pugh score, crp, c-reactive protein, ct, computed tomography, decompensated, ecm, extracellular matrix, fibrosis, fluid protein, gfr, glomerular filtration rate, hr, hazard ratio, inr, internationalised normal ratio, liver disease, liver-cirrhosis, ltx, liver transplantation, markers, meld-na, model for end-stage liver disease, mfap4, microfibrillar associated protein 4, mortality, nash, non-alcoholic steatohepatitis, natural-history, prognosis, risk-factors, sbp, spontaneous bacterial peritonitis, scores, stage, Biomarker, Decompensated, Egfr, estimated gfr, Fibrosis, Liver disease, Mortality, Prognosis, Spontaneous bacterial peritonitis
Dhillon P, Park J, Hurtado del Pozo C, Li L, Doke T, Huang S, Zhao J, Kang HM, Shrestra R, Balzer MS, Chatterjee S, Prado P, Han SY, Liu H, Sheng X, Dierickx P, Batmanov K, Romero JP, Prósper F, Li M, Pei L, Kim J, Montserrat N, Susztak K, (2021). The Nuclear Receptor ESRRA Protects from Kidney Disease by Coupling Metabolism and Differentiation Cell Metabolism 33,
© 2020 Elsevier Inc. Using single-cell RNA sequencing, Susztak and colleagues, show major changes in cell diversity in mouse models of kidney fibrosis. Proximal tubule (PT) cells are highly vulnerable to dysfunction in fibrosis and show altered differentiation. Nuclear receptors such as ESRRA maintain both PT cell metabolism and differentiation by directly regulating PT-cell-specific genes.
JTD Keywords: chronic kidney disease, esrra, fatty-acid oxidation, fibrosis, kidney, organoids, ppara, proximal tubule cells, single-cell atac sequencing, Chronic kidney disease, Esrra, Fatty-acid oxidation, Fibrosis, Kidney, Organoids, Ppara, Proximal tubule cells, Single-cell atac sequencing, Single-cell rna sequencing
Del Mar Cendra, Maria, Torrents, Eduard, (2020). Differential adaptability between reference strains and clinical isolates of Pseudomonas aeruginosa into the lung epithelium intracellular lifestyle Virulence 11, (1), 862-876
Intracellular invasion is an advantageous mechanism used by pathogens to evade host defense and antimicrobial therapy. In patients, the intracellular microbial lifestyle can lead to infection persistence and recurrence, thus worsening outcomes. Lung infections caused by Pseudomonas aeruginosa, especially in cystic fibrosis (CF) patients, are often aggravated by intracellular invasion and persistence of the pathogen. Proliferation of the infectious species relies on a continuous deoxyribonucleotide (dNTP) supply, for which the ribonucleotide reductase enzyme (RNR) is the unique provider. The large genome plasticity of P. aeruginosa and its ability to rapidly adapt to different environments are challenges for studying the pathophysiology associated with this type of infection.
Using different reference strains and clinical isolates of P. aeruginosa independently combined with alveolar (A549) and bronchial (16HBE14o- and CF-CFBE41o-) epithelial cells, we analyzed host–pathogen interactions and intracellular bacterial persistence with the aim of determining a cell type-directed infection promoted by the P. aeruginosa strains. The oscillations in cellular toxicity and oxygen consumption promoted by the intracellular persistence of the strains were also analyzed among the different infectious lung models. Significantly, we identified class II RNR as the enzyme that supplies dNTPs to intracellular P. aeruginosa. This discovery could contribute to the development of RNR-targeted strategies against the chronicity occurring in this type of lung infection.
Overall our study demonstrates that the choice of bacterial strain is critical to properly study the type of infectious process with relevant translational outcomes.
JTD Keywords: Pseudomonas aeruginosa, Intracellular persistence, Lung, Epithelial cells, Clinical isolates, Host-pathogen interactions, Intracellular lifestyle, Chronic infections, Cystic fibrosis, Ribonucleotide reductase
Schierwagen, R., Uschner, F. E., Ortiz, C., Torres, S., Brol, M. J., Tyc, O., Gu, W., Grimm, C., Zeuzem, S., Plamper, A., Pfeifer, P., Zimmer, S., Welsch, C., Schaefer, L., Rheinwalt, K. P., Clària, J., Arroyo, V., Trebicka, J., Klein, S., (2020). The role of macrophage-inducible C-type lectin in different stages of chronic liver disease Frontiers in Immunology 11, 1352
The macrophage-inducible C-type lectin (mincle) is part of the innate immune system and acts as a pattern recognition receptor for pathogen-associated molecular patterns (PAMPS) and damage-associated molecular patterns (DAMPs). Ligand binding induces mincle activation which consequently interacts with the signaling adapter Fc receptor, SYK, and NF-kappa-B. There is also evidence that mincle expressed on macrophages promotes intestinal barrier integrity. However, little is known about the role of mincle in hepatic fibrosis, especially in more advanced disease stages. Mincle expression was measured in human liver samples from cirrhotic patients and donors collected at liver transplantation and in patients undergoing bariatric surgery. Human results were confirmed in rodent models of cirrhosis and acute-on-chronic liver failure (ACLF). In these models, the role of mincle was investigated in liver samples as well as in peripheral blood monocytes (PBMC), tissues from the kidney, spleen, small intestine, and heart. Additionally, mincle activation was stimulated in experimental non-alcoholic steatohepatitis (NASH) by treatment with mincle agonist trehalose-6,6-dibehenate (TDB). In human NASH, mincle is upregulated with increased collagen production. In ApoE deficient mice fed high-fat western diet (NASH model), mincle activation significantly increases hepatic collagen production. In human cirrhosis, mincle expression is also significantly upregulated. Furthermore, mincle expression is associated with the stage of chronic liver disease. This could be confirmed in rat models of cirrhosis and ACLF. ACLF was induced by LPS injection in cirrhotic rats. While mincle expression and downstream signaling via FC receptor gamma, SYK, and NF-kappa-B are upregulated in the liver, they are downregulated in PBMCs of these rats. Although mincle expressed on macrophages might be beneficial for intestinal barrier integrity, it seems to contribute to inflammation and fibrosis once the intestinal barrier becomes leaky in advanced stages of chronic liver disease.
JTD Keywords: ACLF, Bacterial translocation, Fibrosis, Inflammation, NASH
Cremonese, C., Schierwagen, R., Uschner, F. E., Torres, S., Tyc, O., Ortiz, C., Schulz, M., Queck, A., Kristiansen, G., Bader, M., Sauerbruch, T., Weiskirchen, R., Walther, T., Trebicka, J., Klein, S., (2020). Short-term western diet aggravates non-alcoholic fatty liver disease (NAFLD) with portal hypertension in TGR(mREN2)27 rats International Journal of Molecular Sciences 21, (9), 3308
Non-alcoholic fatty liver disease (NAFLD) is gaining in importance and is linked to obesity. Especially, the development of fibrosis and portal hypertension in NAFLD patients requires treatment. Transgenic TGR(mREN2)27 rats overexpressing mouse renin spontaneously develop NAFLD with portal hypertension but without obesity. This study investigated the additional role of obesity in this model on the development of portal hypertension and fibrosis. Obesity was induced in twelve-week old TGR(mREN2)27 rats after receiving Western diet (WD) for two or four weeks. Liver fibrosis was assessed using standard techniques. Hepatic expression of transforming growth factor-β1 (TGF-β1), collagen type Iα1, α-smooth muscle actin, and the macrophage markers Emr1, as well as the chemoattractant Ccl2, interleukin-1β (IL1β) and tumor necrosis factor-α (TNFα) were analyzed. Assessment of portal and systemic hemodynamics was performed using the colored microsphere technique. As expected, WD induced obesity and liver fibrosis as confirmed by Sirius Red and Oil Red O staining. The expression of the monocyte-macrophage markers, Emr1, Ccl2, IL1β and TNFα were increased during feeding of WD, indicating infiltration of macrophages into the liver, even though this increase was statistically not significant for the EGF module-containing mucin-like receptor (Emr1) mRNA expression levels. Of note, portal pressure increased with the duration of WD compared to animals that received a normal chow. Besides obesity, WD feeding increased systemic vascular resistance reflecting systemic endothelial and splanchnic vascular dysfunction. We conclude that transgenic TGR(mREN2)27 rats are a suitable model to investigate NAFLD development with liver fibrosis and portal hypertension. Tendency towards elevated expression of Emr1 is associated with macrophage activity point to a significant role of macrophages in NAFLD pathogenesis, probably due to a shift of the renin–angiotensin system towards a higher activation of the classical pathway. The hepatic injury induced by WD in TGR(mREN2)27 rats is suitable to evaluate different stages of fibrosis and portal hypertension in NAFLD with obesity.
JTD Keywords: ADGRE1, EMR1, F4/80, Immunity, Liver fibrosis, Macrophage, NAFLD, Portal hypertension, TGR(mREN2)27, Western diet
Brol, M. J., Rösch, F., Schierwagen, R., Magdaleno, F., Uschner, F. E., Manekeller, S., Queck, A., Schwarzkopf, K., Odenthal, M., Drebber, U., Thiele, M., Lingohr, P., Plamper, A., Kristiansen, G., Lotersztajn, S., Krag, A., Klein, S., Rheinwalt, K. P., Trebicka, J., Galaxy, Consortium, (2019). Combination of CCL4 with alcoholic and metabolic injuries mimics human liver fibrosis American Journal of Physiology - Gastrointestinal and Liver Physiology 317, (2), G182-G194
Metabolic and alcoholic liver injuries result in nonalcoholic (NAFLD) or alcoholic (ALD) fatty liver disease, respectively. In particular, presence of fibrosis in NAFLD and ALD requires treatment, but development of drugs is hampered by the lack of suitable models with significant fibrosis. The carbon tetrachloride (CCl4) liver fibrosis model does not reflect human NAFLD or ALD, but CCl4 may serve as a fibrosis accelerator in addition to another injury. Ethanol in drinking water (16%) or Western diet (WD) were administered for 7 wk in mice either alone or in combination with CCl4 intoxications. Extent of fibrosis, steatosis, and inflammation was assessed by histology, transcription, and biochemistry. Furthermore, transcription of fibrosis, proliferation, and inflammation-related genes was studied on human liver samples with fibrosis resulting from hepatitis C virus infection (n = 7), NAFLD (n = 8), or ALD (n = 7). WD or ethanol alone induced only mild steatosis and inflammation. Combination of CCl4 and WD induced the most severe steatosis together with significant liver fibrosis and moderate inflammation. Combination of CCl4 and ethanol induced the strongest inflammation, with significant liver fibrosis and moderate steatosis. The relationship pattern between fibrosis, proliferation, and inflammation of human ALD was mostly similar in mice treated with CCl4 and ethanol. The combination of CCl4 intoxication with WD validates previous data suggesting it as an appropriate model for human nonalcoholic steatohepatitis. Especially, CCl4 plus ethanol for 7 wk induces ALD in mice, providing a model suitable for further basic research and drug testing.
NEW & NOTEWORTHY Alcoholic fatty liver disease with significant fibrosis is generated within 7 wk using carbon tetrachloride as a fibrosis accelerator and administering gradually ethanol (up to 16%) in mice. The similarity in the pattern of steatosis, inflammation, and fibrosis involved in alcoholic fatty liver disease to those of the human condition renders this mouse model suitable as a preclinical model for drug development.
JTD Keywords: ASH, Liver fibrosis, NAFLD, NASH
Beiert, T., Tiyerili, V., Knappe, V., Effelsberg, V., Linhart, M., Stöckigt, F., Klein, S., Schierwagen, R., Trebicka, J., Nickenig, G., Schrickel, J. W., Andrié, R. P., (2017). Relaxin reduces susceptibility to post-infarct atrial fibrillation in mice due to anti-fibrotic and anti-inflammatory properties Biochemical and Biophysical Research Communications , 490, (3), 643-649
Relaxin-2 (RLX) is a peptide hormone that exerts beneficial anti-fibrotic and anti-inflammatory effects in diverse models of cardiovascular disease. The goal of this study was to determine the effects of RLX treatment on the susceptibility to atrial fibrillation (AF) after myocardial infarction (MI).
Mice with cryoinfarction of the left anterior ventricular wall were treated for two weeks with either RLX (75 μg/kg/d) or vehicle (sodium acetate) delivered via subcutaneously implanted osmotic minipumps.
RLX treatment significantly attenuated the increase in AF-inducibility following cryoinfarction and reduced the mean duration of AF episodes. Furthermore, epicardial mapping of both atria revealed an increase in conduction velocity. In addition to an attenuation of atrial hypertrophy, chronic application of RLX reduced atrial fibrosis, which was linked to a significant reduction in atrial mRNA expression of connective tissue growth factor. Transcript levels of the pro-inflammatory cytokines interleukin-6 and interleukin-1β were reduced in RLX treated mice, but macrophage infiltration into atrial myocardium was similar in the vehicle and RLX treated groups.
Treatment with RLX in mice after MI reduces susceptibility to AF due to anti-inflammatory and anti-fibrotic properties. Because to these favorable actions, RLX may become a new therapeutic option in the treatment of AF, even when complicating MI.
JTD Keywords: Atrial fibrillation, Atrial fibrosis, Myocardial infarction, Relaxin-2
Melo, E., Cárdenes, N., Garreta, E., Luque, T., Rojas, M., Navajas, D., Farré, R., (2014). Inhomogeneity of local stiffness in the extracellular matrix scaffold of fibrotic mouse lungs Journal of the Mechanical Behavior of Biomedical Materials , 37, 186-195
Lung disease models are useful to study how cell engraftment, proliferation and differentiation are modulated in lung bioengineering. The aim of this work was to characterize the local stiffness of decellularized lungs in aged and fibrotic mice. Mice (2- and 24-month old; 14 of each) with lung fibrosis (N=20) and healthy controls (N=8) were euthanized after 11 days of intratracheal bleomycin (fibrosis) or saline (controls) infusion. The lungs were excised, decellularized by a conventional detergent-based (sodium-dodecyl sulfate) procedure and slices of the acellular lungs were prepared to measure the local stiffness by means of atomic force microscopy. The local stiffness of the different sites in acellular fibrotic lungs was very inhomogeneous within the lung and increased according to the degree of the structural fibrotic lesion. Local stiffness of the acellular lungs did not show statistically significant differences caused by age. The group of mice most affected by fibrosis exhibited local stiffness that were ~2-fold higher than in the control mice: from 27.2Â±1.64 to 64.8Â±7.1. kPa in the alveolar septa, from 56.6Â±4.6 to 99.9Â±11.7. kPa in the visceral pleura, from 41.1Â±8.0 to 105.2Â±13.6. kPa in the tunica adventitia, and from 79.3Â±7.2 to 146.6Â±28.8. kPa in the tunica intima. Since acellular lungs from mice with bleomycin-induced fibrosis present considerable micromechanical inhomogeneity, this model can be a useful tool to better investigate how different degrees of extracellular matrix lesion modulate cell fate in the process of organ bioengineering from decellularized lungs.
JTD Keywords: Ageing, Atomic force microscopy, Decellularization, Lung fibrosis, Tissue engineering, Atomic force microscopy, Biological organs, Peptides, Sodium dodecyl sulfate, Sodium sulfate, Tissue engineering, Ageing, Decellularization, Extracellular matrices, Healthy controls, Inhomogeneities, Lung fibrosis, Micro-mechanical, Statistically significant difference, Mammals, bleomycin, adventitia, animal experiment, animal model, article, atomic force microscopy, bleomycin-induced pulmonary fibrosis, cell fate, controlled study, extracellular matrix, female, intima, lung alveolus, lung fibrosis, lung mechanics, mechanical probe, microenvironment, mouse, nonhuman, pleura, priority journal, rigidity, tissue engineering
Sjoberg, B. M., Torrents, E., (2011). Shift in ribonucleotide reductase gene expression in pseudomonas aeruginosa during infection Infection and Immunity , 79, (7), 2663-2669
The roles of different ribonucleotide reductases (RNRs) in bacterial pathogenesis have not been studied systematically. In this work we analyzed the importance of the different Pseudomonas aeruginosa RNRs in pathogenesis using the Drosophila melanogaster host-pathogen interaction model. P. aeruginosa codes for three different RNRs with different environmental requirements. Class II and III RNR chromosomal mutants exhibited reduced virulence in this model. Translational reporter fusions of RNR gene nrdA, nrdJ, or nrdD to the green fluorescent protein were constructed to measure the expression of each class during the infection process. Analysis of the P. aeruginosa infection by flow cytometry revealed increased expression of nrdJ and nrdD and decreased nrdA expression during the infection process. Expression of each RNR class fits with the pathogenicities of the chromosomal deletion mutants. An extended understanding of the pathogenicity and physiology of P. aeruginosa will be important for the development of novel drugs against infections in cystic fibrosis patients.
JTD Keywords: Broad-host-range, Anaerobic growth, Drosophila-melanogaster, Bacterial biofilms, Escherichia-coli, Cystic-fibrosis, Model host, Virulence, Promoter, Vectors