BUSCADOR RECOLECTA

Achilles tendon rupture is a frequent injury with an increasing incidence. After clinical surgical repair, aimed at suturing the tendon stumps back into their original position, the repaired Achilles tendon is often plastically deformed and mechanically less strong than the pre-injured tissue, with muscle fatty degeneration contributing to function loss. Despite clinical outcomes, pre-clinical research has mainly focused on tendon structural repair, with a lack of knowledge regarding injury progression from tendon to muscle and its consequences on muscle degenerative/regenerative processes and function. Here, we characterize the morphological changes in the tendon, the myotendinous junction and muscle belly in a mouse model of Achilles tendon complete rupture, finding cellular and fatty infiltration, fibrotic tissue accumulation, muscle stem cell decline and collagen fiber disorganization. We use novel imaging technologies to accurately relate structural alterations in tendon fibers to pathological changes, which further explain the loss of muscle mechanical function after tendon rupture. The treatment of tendon injuries remains a challenge for orthopedics. Thus, the main goal of this study is to bridge the gap between clinicians’ knowledge and research to address the underlying pathophysiology of ruptured Achilles tendon and its consequences in the gastrocnemius. Such studies are necessary if current practices in regenerative medicine for Achilles tendon ruptures are to be improved., Research support was provided by the Spanish Ministerio de Ciencia, Innovación y Universidades (Grant PID2020-113822RB-C21 & PID2020-113822RB-C22) and the Department of Industry and Innovation (Government of Aragon) through the research group Grant T24-20R (cofinanced by Feder). Part of the work was performed by the ICTS ‘‘NANBIOSIS’’ specifically by the Tissue & Scaffold Characterization Unit (U13) of the CIBER in Bioengineering, Biomaterials & Nanomedicine (CIBER-BBN at the University of Zaragoza). CIBER actions are financed by the Instituto de Salud Carlos III with assistance from the European Regional Development Fund. C.O.-d.-S. acknowledges funding project RTI2018-094494-B-C22 financed by MCIN/AEI /10.13039/501100011033 and FEDER Funds.

Multiplex immunofluorescence is a novel, high-content imaging technique that allows simultaneous in situ labeling of multiple tissue antigens. This technique is of growing relevance in the study of the tumor microenvironment, and the discovery of biomarkers of disease progression or response to immune-based therapies. Given the number of markers and the potential complexity of the spatial interactions involved, the analysis of these images requires the use of machine learning tools that rely for their training on the availability of large image datasets, extremely laborious to annotate. We present Synplex, a computer simulator of multiplexed immunofluorescence images from user-defined parameters: i. cell phenotypes, defined by the level of expression of markers and morphological parameters; ii. cellular neighborhoods based on the spatial association of cell phenotypes; and iii. interactions between cellular neighborhoods. We validate Synplex by generating synthetic tissues that accurately simulate real cancer cohorts with underlying differences in the composition of their tumor microenvironment and show proof-of-principle examples of how Synplex could be used for data augmentation when training machine learning models, and for the in silico selection of clinically relevant biomarkers. Synplex is publicly available at https://github.com/djimenezsanchez/Synplex., This work was supported by Ministerio de Ciencia, Innovacion y Universidades, Agencia Estatal de Investigacion (MCIU/AEI/10.13039/50110011033) and FEDER funds UE under Grant RTI2018-094494-B-C22, Grant RTC-2017-6218-1, Grant PDI2021-122409OB-C22 and Grant TED2021-131300B-I00.

Background: There is a lack of automated tools for the segmentation and quantification of neuromelanin (NM) and iron in the nigrosome-1 (N1). Existing tools evaluate the N1 sign, i.e., the presence or absence of the ‘swallow-tail’ in iron-sensitive MRI, or globally analyze the MRI signal in an area containing the N1, without providing a volumetric delineation. Purpose: Present an automated method to segment the N1 and quantify differences in N1's NM and iron content between Parkinson's disease (PD) patients and healthy controls (HCs). Study whether N1 degeneration is clinically related to PD and could be used as a biomarker of the disease. Study Type: Prospective. Subjects: Seventy-one PD (65.3 ± 10.3 years old, 34 female/37 male); 30 HC (62.7 ± 7.8 years old, 17 female/13 male). Field Strength/Sequence: 3 T Anatomical T1-weighted MPRAGE, NM-MRI T1-weighted gradient with magnetization transfer, susceptibility-weighted imaging (SWI). Assessment: N1 was automatically segmented in SWI images using a multi-image atlas, populated with healthy N1 structures manually annotated by a neurologist. Relative NM and iron content were quantified and their diagnostic performance assessed and compared with the substantia nigra pars compacta (SNc). The association between image parameters and clinically relevant variables was studied. Statistical Tests: Nonparametric tests were used (Mann-Whitney's U, chi-square, and Friedman tests) at P = 0.05. Results: N1's relative NM content decreased and relative iron content increased in PD patients compared with HCs (NM-CRHC = 22.55 ± 1.49; NM-CRPD = 19.79 ± 1.92; NM-nVolHC = 2.69 × 10-5 ± 1.02 × 10-5; NM-nVolPD = 1.18 × 10-5 ± 0.96 × 10−5; Iron-CRHC = 10.51 ± 2.64; Iron-CRPD = 19.35 ± 7.88; Iron-nVolHC = 0.72 × 10-5 ± 0.81 × 10-5; Iron-nVolPD = 2.82 × 10−5 ± 2.04 × 10−5). Binary logistic regression analyses combining N1 and SNc image parameters yielded a top AUC = 0.955. Significant correlation was found between most N1 parameters and both disease duration (ρNM-CR = -0.31; ρiron-CR = 0.43; ρiron-nVol = 0.46) and the motor status ρNM-nVol = -0.27; ρiron-CR = 0.33; ρiron-nVol = 0.28), suggesting NM reduction along with iron accumulation in N1 as the disease progresses. Data Conclusion: This method provides a fully automatic N1 segmentation, and the analyses performed reveal that N1 relative NM and iron quantification improves diagnostic performance and suggest a relative NM reduction along with a relative iron accumulation in N1 as the disease progresses. Evidence Level: 1. Technical Efficacy: Stage 1., The authors would like to thank all the subjects who participated in this study. This work was supported by Instituto de Salud Carlos III (ISCIII) and European Union NextGenerationEU/PRTR (grant number PMP22/00100) and by FEDER and the Spanish Ministry of Science and Innovation and Universities MCIN/AEI (10.13039/501100011033) (grant numbers PDI2021-122409OB-C22, RTI2018-094494-B-C22, and TED2021-131300B-I00 [C.O.S] and SAF2016-81016-R [M.A.P]). The funders had no role in study design, data collection, data analysis, data interpretation, or writing of the report. The corresponding author had full access to all the data and the final responsibility to submit for publication.

Standardized clinical procedures for antibiotic administration rely on pathogen identification and antibiotic susceptibility testing, often performed on single-colony bacterial isolates. For respiratory pathogens, this could be questionable, as chronic patients may be persistently colonized by multiple clones or lineages from the same bacterial pathogen species. Indeed, multiple strains of nontypeable Haemophilus influenzae, with different antibiotic susceptibility profiles, can be co-isolated from cystic fibrosis and chronic obstructive pulmonary disease sputum specimens. Despite this clinical evidence, we lack information about the dynamics of H. influenzae polyclonal infections, which limits the optimization of therapeutics. Here, we present the engineering and validation of a plasmid toolkit (pTBH, toolbox for Haemophilus), with standardized modules consisting of six reporter genes for fluorescent or bioluminescent labeling of H. influenzae. This plasmid set was independently introduced in a panel of genomically and phenotypically different H. influenzae strains, and two of them were used as a proof of principle to analyze mixed biofilm growth architecture and antibiotic efficacy, and to visualize the dynamics of alveolar epithelial co-infection. The mixed biofilms showed a bilayer architecture, and antibiotic efficacy correlated with the antibiotic susceptibility of the respective single-species strains. Furthermore, differential kinetics of bacterial intracellular location within subcellular acidic compartments were quantified upon co-infection of cultured airway epithelial cells. Overall, we present a panel of novel plasmid tools and quantitative image analysis methods with the potential to be used in a whole range of bacterial host species, assay types, and¿or conditions and generate meaningful information for clinically relevant settings., J.A.-L. is funded by a PhD studentship from Regional Navarra Government, Spain, reference 0011-1408-2020-000007. C.S.M. is funded by a Formación de Profesorado Universitario PhD studentship from the Spanish Ministry of Science and Innovation (MCINN), Spain, reference FPU20/06252. This work has been funded by grants from Ministerio de Ciencia, Innovación y Universidades, Agencia Estatal de Investigación (MCIU/AEI/10.13039/50110011033) and FEDER funds EU, RTI2018-094494-BC22, PDI2021-122409OB-C22 (C.O.S.), and RTI2018-096369-B-I00, PID2021-125947OB-I00 (J.G.); from SEPAR, 875/2019 (J.G.); from Gobierno de Navarra, PC150 and PC136 (J.G.) and PC151 and PC137 (C.O.S.). CIBER is an initiative from Instituto de Salud Carlos III, Madrid, Spain. Experimental design: B.R.A., I.S.B., M.L.D., A.T.A., C.O.S., J.G.; experimental work: B.R.A., I.S.B., J.A.L., B.E., M.L.D., C.O.M., A.F.C.; data analysis: B.R.A., I.S.B., M.L.D., M.A.; writing of the manuscript: J.G., C.O.S.; correction of the manuscript: all authors; funding¿ I.C.D., S.B., C.O.S., J.G.; Funding text 2: J.A.-L. is funded by a PhD studentship from Regional Navarra Govern, Spain, reference 0011-1408-2020-000007. C.S.M. is funded by a Formación de Profesorado Universitario PhD studentship from the Spanish Ministry of Science and Innovation (MCINN), Spain, reference FPU20/06252. This work has been funded by grants from Ministerio de Ciencia, Innovación y Universidades, Agencia Estatal de Investigación (MCIU/AEI/10.13039/50110011033) and FEDER funds EU, RTI2018-094494-BC22, PDI2021-122409OB-C22 (C.O.S.), and RTI2018-096369-B-I00, PID2021-125947OB-I00 (J.G.); from SEPAR, 875/2019 (J.G.); from Gobierno de Navarra, PC150 and PC136 (J.G.) and PC151 and PC137 (C.O.S.). CIBER is an initiative from Instituto de Salud Carlos III, Madrid, Spain.

Chronic obstructive pulmonary disease (COPD) patients undergo infectious exacerbations whose frequency identifies a clinically meaningful phenotype. Mouse models have been mostly used to separately study both COPD and the infectious processes, but a reliable model of the COPD frequent exacerbator phenotype is still lacking. Accordingly, we first established a model of single bacterial exacerbation by nontypeable Haemophilus influenzae (NTHi) infection on mice with emphysema-like lesions. We characterized this single exacerbation model combining both noninvasive in vivo imaging and ex vivo techniques, obtaining longitudinal information about bacterial load and the extent of the developing lesions and host responses. Bacterial load disappeared 48 hours post-infection (hpi). However, lung recovery, measured using tests of pulmonary function and the disappearance of lung inflammation as revealed by micro-computed X-ray tomography, was delayed until 3 weeks post-infection (wpi). Then, to emulate the frequent exacerbator phenotype, we performed two recurrent episodes of NTHi infection on the emphysematous murine lung. Consistent with the amplified infectious insult, bacterial load reduction was now observed 96 hpi, and lung function recovery and disappearance of lesions on anatomical lung images did not happen until 12 wpi. Finally, as a proof of principle of the use of the model, we showed that azithromycin successfully cleared the recurrent infection, confirming this macrolide utility to ameliorate infectious exacerbation. In conclusion, we present a mouse model of recurrent bacterial infection of the emphysematous lung, aimed to facilitate investigating the COPD frequent exacerbator phenotype by providing complementary, dynamic information of both infectious and inflammatory processes., This work was supported by the Departamento de
Universidad, Innovación y Transformación Digital,
Gobierno de Navarra [PC150-151-152]; Ministerio de
Ciencia, Innovación y Universidades (MICIU), Gobierno de
España [RTI2018-096369-B-I00]; MICIU, Gobierno de
España [RED2018-102469-T]; MICIU , Gobierno de España
[SAF2015-66520-R]; MICIU , Gobierno de España [RTI2018-
094494-B-C222]; Departamento de Salud, Gobierno de
Navarra [03/2016]; Sociedad Española de Neumología
y Cirugía Torácica [31/2015].

© The Author(s) 2021., Multiple myeloma (MM) progression and myeloma-associated bone disease (MBD) are highly dependent on bone marrow mesenchymal stromal cells (MSCs). MM-MSCs exhibit abnormal transcriptomes, suggesting the involvement of epigenetic mechanisms governing their tumor-promoting functions and prolonged osteoblast suppression. Here, we identify widespread DNA methylation alterations of bone marrow-isolated MSCs from distinct MM stages, particularly in Homeobox genes involved in osteogenic differentiation that associate with their aberrant expression. Moreover, these DNA methylation changes are recapitulated in vitro by exposing MSCs from healthy individuals to MM cells. Pharmacological targeting of DNMTs and G9a with dual inhibitor CM-272 reverts the expression of hypermethylated osteogenic regulators and promotes osteoblast differentiation of myeloma MSCs. Most importantly, CM-272 treatment prevents tumor-associated bone loss and reduces tumor burden in a murine myeloma model. Our results demonstrate that epigenetic aberrancies mediate the impairment of bone formation in MM, and its targeting by CM-272 is able to reverse MBD., We thank CERCA Program/Generalitat de Catalunya and the Josep Carreras Foundation for institutional support. E.B. was funded by the Spanish Ministry of Science and Innovation (grant numbers SAF2014-55942-R and SAF2017-88086-R), co-funded by FEDER funds/European Regional Development Fund (ERDF)—a way to build Europe, and a Senior Research Award from the Multiple Myeloma Research Foundation (MMRF). C.O.-d.-S. was funded by the Spanish Ministry of Science, Innovation and Universities, under grant RTI2018-094494-B-C22 (MCIU/AEI/FEDER, UE). M.G. received financial support from the Spanish FIS-ISCIII (PI15/02156 and PI19/01384) and FEDER. A.G.G is funded by a postdoctoral contract of the Asociación Española Contra el Cáncer (AECC). F.P. was funded by grants from Instituto de Salud Carlos III (ISCIII), PI17/00701 and PI19/01352, TRASCAN (EPICA and Immunocell), Fundació La Marató de TV3, the Accelerator award CRUK/AIRC/AECC joint funder-partnership, CIBERONC (CB16/12/00489) and co-financed with FEDER funds and Fundación Ramón Areces (PREMAMM).

Genomic diversity of nontypeable H. influenzae strains confers phenotypic heterogeneity. Multiple strains of H. influenzae can be simultaneously isolated from clinical specimens, but we lack detailed information about polyclonal infection dynamics by this pathogen. A long-term barrier to our understanding of this host-pathogen interplay is the lack of genetic tools for strain engineering and differential labeling. Here, we present a novel plasmid toolkit named pTBH (toolbox for Haemophilus), with standardized modules for fluorescent or bioluminescent labeling, adapted to H. influenzae requirements but designed to be versatile so it can be utilized in other bacterial species. We present detailed experimental and quantitative image analysis methods, together with proof-of-principle examples, and show the ample possibilities of 3D microscopy, combined with quantitative image analysis, to model H. influenzae polyclonal infection lifestyles and unravel the co-habitation and co-infection dynamics of this respiratory pathogen., J.A.-L. is funded by a PhD studentship from Regional Navarra Govern, Spain, reference 0011-1408-2020-000007. C.S.M. is funded by a Formación de Profesorado Universitario PhD studentship from the Spanish Ministry of Science and Innovation (MCINN), Spain, reference FPU20/06252. This work has been funded by grants from Ministerio de Ciencia, Innovación y Universidades, Agencia Estatal de Investigación (MCIU/AEI/10.13039/50110011033) and FEDER funds EU, RTI2018-094494-B-C22, PDI2021-122409OB-C22 (C.O.S.), and RTI2018-096369-B-I00, PID2021-125947OB-I00 (J.G.); from SEPAR, 875/2019 (J.G.); from Gobierno de Navarra, PC150 and PC136 (J.G.) and PC151 and PC137 (C.O.S.). CIBER is an initiative from Instituto de Salud Carlos III, Madrid, Spain., Peer reviewed

The migration of cancer cells is highly regulated by the biomechanical properties of their local microenvironment. Using 3D scaffolds of simple composition, several aspects of cancer cell mechanosensing (signal transduction, EMC remodeling, traction forces) have been separately analyzed in the context of cell migration. However, a combined study of these factors in 3D scaffolds that more closely resemble the complex microenvironment of the cancer ECM is still missing. Here, we present a comprehensive, quantitative analysis of the role of cell-ECM interactions in cancer cell migration within a highly physiological environment consisting of mixed Matrigel-collagen hydrogel scaffolds of increasing complexity that mimic the tumor microenvironment at the leading edge of cancer invasion. We quantitatively show that the presence of Matrigel increases hydrogel stiffness, which promotes ß1 integrin expression and metalloproteinase activity in H1299 lung cancer cells. Then, we show that ECM remodeling activity causes matrix alignment and compaction that favors higher tractions exerted by the cells. However, these traction forces do not linearly translate into increased motility due to a biphasic role of cell adhesions in cell migration: at low concentration Matrigel promotes migration-effective tractions exerted through a high number of small sized focal adhesions. However, at high Matrigel concentration, traction forces are exerted through fewer, but larger focal adhesions that favor attachment yielding lower cell motility.

Achilles tendon rupture is a frequent injury with an increasing incidence. After clinical surgical repair, aimed at suturing the tendon stumps back into their original position, the repaired Achilles tendon is often plastically deformed and mechanically less strong than the pre-injured tissue, with muscle fatty degeneration contributing to function loss. Despite clinical outcomes, pre-clinical research has mainly focused on tendon structural repair, with a lack of knowledge regarding injury progression from tendon to muscle and its consequences on muscle degenerative/regenerative processes and function. Here, we characterize the morphological changes in the tendon, the myotendinous junction and muscle belly in a mouse model of Achilles tendon complete rupture, finding cellular and fatty infiltration, fibrotic tissue accumulation, muscle stem cell decline and collagen fiber disorganization. We use novel imaging technologies to accurately relate structural alterations in tendon fibers to pathological changes, which further explain the loss of muscle mechanical function after tendon rupture. The treatment of tendon injuries remains a challenge for orthopedics. Thus, the main goal of this study is to bridge the gap between clinicians'' knowledge and research to address the underlying pathophysiology of ruptured Achilles tendon and its consequences in the gastrocnemius. Such studies are necessary if current practices in regenerative medicine for Achilles tendon ruptures are to be improved.

Multiple myeloma (MM) progression and myeloma-associated bone disease (MBD) are highly dependent on bone marrow mesenchymal stromal cells (MSCs). MM-MSCs exhibit abnormal transcriptomes, suggesting the involvement of epigenetic mechanisms governing their tumor-promoting functions and prolonged osteoblast suppression. Here, we identify widespread DNA methylation alterations of bone marrow-isolated MSCs from distinct MM stages, particularly in Homeobox genes involved in osteogenic differentiation that associate with their aberrant expression. Moreover, these DNA methylation changes are recapitulated in vitro by exposing MSCs from healthy individuals to MM cells. Pharmacological targeting of DNMTs and G9a with dual inhibitor CM-272 reverts the expression of hypermethylated osteogenic regulators and promotes osteoblast differentiation of myeloma MSCs. Most importantly, CM-272 treatment prevents tumor-associated bone loss and reduces tumor burden in a murine myeloma model. Our results demonstrate that epigenetic aberrancies mediate the impairment of bone formation in MM, and its targeting by CM-272 is able to reverse MBD.