Transfer learning of clinical outcomes from preclinical molecular data, principles and perspectives.

Accurate transfer learning of clinical outcomes from one cellular context to another, between cell types, developmental stages, omics modalities or species, is considered tremendously useful. When transferring a prediction task from a source domain to a target domain, what counts is the high quality of the predictions in the target domain, requiring states or processes common to both the source and the target that can be learned by the predictor reflected by shared denominators. These may form a compendium of knowledge that is learned in the source to enable predictions in the target, usually with few, if any, labeled target training samples to learn from. Transductive transfer learning refers to the learning of the predictor in the source domain, transferring its outcome label calculations to the target domain, considering the same task. Inductive transfer learning considers cases where the target predictor is performing a different yet related task as compared with the source predictor. Often, there is also a need to first map the variables in the input/feature spaces and/or the variables in the output/outcome spaces. We here discuss and juxtapose various recently published transfer learning approaches, specifically designed (or at least adaptable) to predict clinical (human in vivo) outcomes based on preclinical (mostly animal-based) molecular data, towards finding the right tool for a given task, and paving the way for a comprehensive and systematic comparison of the suitability and accuracy of transfer learning of clinical outcomes.

Dysbiosis and reduced small intestinal function are required to induce intestinal insufficiency in mice.

Extensive bowel resection can lead to short bowel syndrome and intestinal failure. Resection-induced dysbiosis may be related to the specific anatomic site of resection and influences the disease progression. Although patients with end-jejunostomy are at high risk for intestinal failure, preservation of the ileocecal valve and colon counteracts this risk. The present study investigated the role of the cecum in maintaining microbial homeostasis after different types of small bowel resection. Male C57BL6/J mice were anesthetized by intraperitoneal injection of ketamine-xylazine and received extended ileocecal resection (extended ICR), limited ileocecal resection (limited ICR), or mid-small bowel resection (SBR). Stool samples were collected before surgery and between postoperative days 2-7, for 16S rRNA gene sequencing. Only extended ICR, but neither limited ICR nor SBR, induced intestinal insufficiency. α-Diversity was reduced in both ICR variants but not after SBR. All resections resulted in an increase in Proteobacteria. Pathobionts, such as Clostridia, Shigella, and Enterococcus, increased after SBR while Muribaculaceae, Lactobacillus, and Lachnospiraceae decreased. Limited ICR resulted in an increase of members of the Clostridium sensu stricto group, Terrisporobacter and Enterococcus and a decrease of Muribaculaceae. The increase of Enterococcus was even more pronounced after extended ICR while Muribaculaceae and Akkermansia were dramatically reduced. Both ICR variants caused a decrease in steroid biosynthesis and glycosaminoglycan degradation-associated pathways, suggesting altered bile acid transformation and mucus utilization.NEW & NOTEWORTHY Resection-induced dysbiosis affects disease progression in patients with short bowel syndrome. Severe dysbiosis occurs after removal of the ileocecal valve, even in the absence of short bowel conditions, and is associated with the loss of Muribaculaceae and Akkermansia and an increase of Clostridium and Enterococcus. The preservation of the cecum should be considered in surgical therapy, and dysbiosis should be targeted based on its specific anatomical signature to improve postoperative bacterial colonization.

The 2-methylpropene degradation pathway in Mycobacteriaceae family strains.

Mycolicibacterium gadium IBE100 and Mycobacterium paragordonae IBE200 are aerobic, chemoorganoheterotrophic bacteria isolated from activated sludge from a wastewater treatment plant. They use 2-methylpropene (isobutene, 2-MP) as the sole source of carbon and energy. Here, we postulate a degradation pathway of 2-methylpropene derived from whole genome sequencing, differential expression analysis and peptide-mass fingerprinting. Key genes identified are coding for a 4-component soluble diiron monooxygenase with epoxidase activity, an epoxide hydrolase, and a 2-hydroxyisobutyryl-CoA mutase. In both strains, involved genes are arranged in clusters of 61.0 and 58.5 kbp, respectively, which also contain the genes coding for parts of the aerobic pathway of adenosylcobalamin synthesis. This vitamin is essential for the carbon rearrangement reaction catalysed by the mutase. These findings provide data for the identification of potential 2-methylpropene degraders.

Biomarkers of geroprotection and cardiovascular health: An overview of omics studies and established clinical biomarkers in the context of diet.

The slowdown, inhibition, or reversal of age-related decline (as a composite of disease, dysfunction, and, ultimately, death) by diet or natural compounds can be defined as dietary geroprotection. While there is no single reliable biomarker to judge the effects of dietary geroprotection, biomarker signatures based on omics (epigenetics, gene expression, microbiome composition) are promising candidates. Recently, omic biomarkers started to supplement established clinical ones such as lipid profiles and inflammatory cytokines. In this review, we focus on human data. We first summarize the current take on genetic biomarkers based on epidemiological studies. However, most of the remaining biomarkers that we describe, whether omics-based or clinical, are related to intervention studies. Then, because of their promising potential in the context of dietary geroprotection, we focus on the effects of berry-based interventions, which up to now have been mostly described employing clinical markers. We provide an aggregation and tabulation of all the recent systematic reviews and meta-analyses that we could find related to this topic. Finally, we present evidence for the importance of the "nutribiography," that is, the influence that an individual's history of diet and natural compound consumption can have on the effects of dietary geroprotection.Supplemental data for this article is available online at https://doi.org/10.1080/10408398.2021.1975638.

MAIT Cells Are Major Contributors to the Cytokine Response in Group A Streptococcal Toxic Shock Syndrome.

Streptococcal toxic shock syndrome (STSS) is a rapidly progressing, life-threatening, systemic reaction to invasive infection caused by group A streptococci (GAS). GAS superantigens are key mediators of STSS through their potent activation of T cells leading to a cytokine storm and consequently vascular leakage, shock, and multiorgan failure. Mucosal-associated invariant T (MAIT) cells recognize MR1-presented antigens derived from microbial riboflavin biosynthesis and mount protective innate-like immune responses against the microbes producing such metabolites. GAS lack de novo riboflavin synthesis, and the role of MAIT cells in STSS has therefore so far been overlooked. Here we have conducted a comprehensive analysis of human MAIT cell responses to GAS, aiming to understand the contribution of MAIT cells to the pathogenesis of STSS. We show that MAIT cells are strongly activated and represent the major T cell source of IFNγ and TNF in the early stages of response to GAS. MAIT cell activation is biphasic with a rapid TCR Vß2-specific, TNF-dominated response to superantigens and a later IL-12- and IL-18-dependent, IFNγ-dominated response to both bacterial cells and secreted factors. Depletion of MAIT cells from PBMC resulted in decreased total production of IFNγ, IL-1ß, IL-2, and TNFß. Peripheral blood MAIT cells in patients with STSS expressed elevated levels of the activation markers CD69, CD25, CD38, and HLA-DR during the acute compared with the convalescent phase. Our data demonstrate that MAIT cells are major contributors to the early cytokine response to GAS, and are therefore likely to contribute to the pathological cytokine storm underlying STSS.

Metagenomic Sequencing for the Diagnosis of Plasmodium spp. with Different Levels of Parasitemia in EDTA Blood of Malaria Patients-A Proof-of-Principle Assessment.

Molecular diagnostic approaches are increasingly included in the diagnostic workup and even in the primary diagnosis of malaria in non-endemic settings, where it is difficult to maintain skillful microscopic malaria detection due to the rarity of the disease. Pathogen-specific nucleic acid amplification, however, bears the risk of overlooking other pathogens associated with febrile illness in returnees from the tropics. Here, we assessed the discriminatory potential of metagenomic sequencing for the identification of different Plasmodium species with various parasitemia in EDTA blood of malaria patients. Overall, the proportion of Plasmodium spp.-specific sequence reads in the assessed samples showed a robust positive correlation with parasitemia (Spearman r = 0.7307, p = 0.0001) and a robust negative correlation with cycle threshold (Ct) values of genus-specific real-time PCR (Spearman r = -0.8626, p ≤ 0.0001). Depending on the applied bioinformatic algorithm, discrimination on species level was successful in 50% (11/22) to 63.6% (14/22) instances. Limiting factors for the discrimination on species level were very low parasitemia, species-depending lacking availability of reliable reference genomes, and mixed infections with high variance of the proportion of the infecting species. In summary, metagenomic sequencing as performed in this study is suitable for the detection of malaria in human blood samples, but the diagnostic detection limit for a reliable discrimination on species level remains higher than for competing diagnostic approaches like microscopy and PCR.

Nod2 deficiency functionally impairs adaptation to short bowel syndrome via alterations of the epithelial barrier function.

Nucleotide-binding oligomerization domain-containing protein 2 (NOD2) gene mutations are a risk factor for Crohn's disease and also associated with worse outcome in short bowel syndrome (SBS) patients independent of the underlying disease. The aim of this study was to analyze the effect of Nod2 deficiency on barrier function and stool microbiome after extensive ileocecal resection in mice. Male C57BL6/J wild-type (WT) and Nod2-knockout (KO) mice underwent 40% ileocecal resection. Sham control mice received simple transection of the ileum. Clinical outcome was monitored daily. Barrier function was measured with Ussing chambers using FITC-4-kDa-Dextran flux, transmucosal electrical resistance, and dilution potentials. Immunofluorescence of claudin-2 was studied. Composition of the stool microbiome was assessed by 16S rRNA gene sequencing. Resected Nod2-KO mice had impaired clinical outcome compared with resected WT mice. This was accompanied by increased stool water contents and increased plasma aldosterone. Histomorphological adaptation was independent of Nod2. Barrier function studies revealed impaired sodium to chloride permeability and altered claudin-2 localization in the absence of Nod2. Resection induced decreases of bacterial diversity and a shift of bacteriodetes-to-firmicutes ratios. Ileum and cecum resection-induced increase in proteobacteria was absent in Nod2-deficient mice. Verrucomicrobia were temporarily increased in Nod2-KO mice. Nod2 deficiency functionally impairs adaptation to short bowel syndrome via a lesser increase of epithelial sodium pore permeability, altered epithelial barrier function, and the microbiome.NEW & NOTEWORTHYNOD2 gene mutations are associated with the development of severe short bowel syndrome and intestinal failure. The influence of Nod2 mutations on intestinal adaptation in experimental short bowel syndrome has not been studied yet. Here, we provide data that Nod2 deficiency worsens clinical outcome and functional adaptation under SBS conditions in mice, indicating that NOD2 is required for successful adaptation after ileocecal resection.

Members of a new subgroup of Streptococcus anginosus harbor virulence related genes previously observed in Streptococcus pyogenes.

Conventionally categorized as commensals, the Streptococci of the species S. anginosus are facultative human pathogens that are difficult to diagnose and often overlooked. Furthermore, detailed investigation and diagnosis of S. anginosus infections is hampered by unexplored taxonomy and widely elusive molecular pathogenesis. To explore their pathogenic potential, S. anginosus isolates collected from patients of two geographical locations (Vellore, India and Leipzig, Germany) were subjected to multi-locus sequence analysis (MLSA). This analysis revealed the potential presence of a new distinct clade of the species S. anginosus, tentatively termed here as genomosubspecies vellorensis. A complementary PCR-based screening for S. pyogenes virulence factor as well as antibiotic resistance genes revealed not only the presence of superantigen- and extracellular DNase coding genes identical to corresponding genes of S. pyogenes, but also of erythromycin and tetracycline resistance genes in the genomes of the analyzed S. anginosus isolates, thus posing a matter of significant health concern. Identification of new pathogenic S. anginosus strains capable of causing difficult to treat infections may pose additional challenges to the diagnosis and treatment of Streptococcus based infections.

Computational identification of natural senotherapeutic compounds that mimic dasatinib based on gene expression data.

The major risk factor for chronic disease is chronological age, and age-related chronic diseases account for the majority of deaths worldwide. Targeting senescent cells that accumulate in disease-related tissues presents a strategy to reduce disease burden and to increase healthspan. The senolytic combination of the tyrosine-kinase inhibitor dasatinib and the flavonol quercetin is frequently used in clinical trials aiming to eliminate senescent cells. Here, our goal was to computationally identify natural senotherapeutic repurposing candidates that may substitute dasatinib based on their similarity in gene expression effects. The natural senolytic piperlongumine (a compound found in long pepper), and the natural senomorphics parthenolide, phloretin and curcumin (found in various edible plants) were identified as potential substitutes of dasatinib. The gene expression changes underlying the repositioning highlight apoptosis-related genes and pathways. The four compounds, and in particular the top-runner piperlongumine, may be combined with quercetin to obtain natural formulas emulating the dasatinib + quercetin formula.

The Gut Microbiome of an Indigenous Agropastoralist Population in a Remote Area of Colombia with High Rates of Gastrointestinal Infections and Dysbiosis.

An Indigenous agropastoralist population called the Wiwa from the Sierra Nevada de Santa Marta, in North-East Colombia, shows high rates of gastrointestinal infections. Chronic gut inflammatory processes and dysbiosis could be a reason, suggesting an influence or predisposing potential of the gut microbiome composition. The latter was analyzed by 16S rRNA gene amplicon next generation sequencing from stool samples. Results of the Wiwa population microbiomes were associated with available epidemiological and morphometric data and compared to control samples from a local urban population. Indeed, locational-, age-, and gender-specific differences in the Firmicutes/Bacteriodetes ratio, core microbiome, and overall genera-level microbiome composition were shown. Alpha- and ß-diversity separated the urban site from the Indigenous locations. Urban microbiomes were dominated by Bacteriodetes, whereas Indigenous samples revealed a four times higher abundance of Proteobacteria. Even differences among the two Indigenous villages were noted. PICRUSt analysis identified several enriched location-specific bacterial pathways. Moreover, on a general comparative scale and with a high predictive accuracy, we found Sutterella associated with the abundance of enterohemorrhagic Escherichia coli (EHEC), Faecalibacteria associated with enteropathogenic Escherichia coli (EPEC) and helminth species Hymenolepsis nana and Enterobius vermicularis. Parabacteroides, Prevotella, and Butyrivibrio are enriched in cases of salmonellosis, EPEC, and helminth infections. Presence of Dialister was associated with gastrointestinal symptoms, whereas Clostridia were exclusively found in children under the age of 5 years. Odoribacter and Parabacteroides were exclusively identified in the microbiomes of the urban population of Valledupar. In summary, dysbiotic alterations in the gut microbiome in the Indigenous population with frequent episodes of self-reported gastrointestinal infections were confirmed with epidemiological and pathogen-specific associations. Our data provide strong hints of microbiome alterations associated with the clinical conditions of the Indigenous population.

Microbial Communities in Biocrusts Are Recruited From the Neighboring Sand at Coastal Dunes Along the Baltic Sea.

Biological soil crusts occur worldwide as pioneer communities stabilizing the soil surface. In coastal primary sand dunes, vascular plants cannot sustain due to scarce nutrients and the low-water-holding capacity of the sand sediment. Thus, besides planted dune grass, biocrusts are the only vegetation there. Although biocrusts can reach high coverage rates in coastal sand dunes, studies about their biodiversity are rare. Here, we present a comprehensive overview of the biodiversity of microorganisms in such biocrusts and the neighboring sand from sampling sites along the Baltic Sea coast. The biodiversity of Bacteria, Cyanobacteria, Fungi, and other microbial Eukaryota were assessed using high-throughput sequencing (HTS) with a mixture of universal and group-specific primers. The results showed that the biocrusts recruit their microorganisms mainly from the neighboring sand rather than supporting a universal biocrust microbiome. Although in biocrusts the taxa richness was lower than in sand, five times more co-occurrences were identified using network analysis. This study showed that by comparing neighboring bare surface substrates with biocrusts holds the potential to better understand biocrust development. In addition, the target sequencing approach helps outline potential biotic interactions between different microorganisms groups and identify key players during biocrust development.

Gene co-expression analyses of health(span) across multiple species.

Health(span)-related gene clusters/modules were recently identified based on knowledge about the cross-species genetic basis of health, to interpret transcriptomic datasets describing health-related interventions. However, the cross-species comparison of health-related observations reveals a lot of heterogeneity, not least due to widely varying health(span) definitions and study designs, posing a challenge for the exploration of conserved healthspan modules and, specifically, their transfer across species. To improve the identification and exploration of conserved/transferable healthspan modules, here we apply an established workflow based on gene co-expression network analyses employing GEO/ArrayExpress data for human and animal models, and perform a comprehensive meta-study of the resulting modules related to health(span), yielding a small set of literature backed health(span) candidate genes. For each experiment, WGCNA (weighted gene correlation network analysis) was used to infer modules of genes which correlate in their expression with a 'health phenotype score' and to determine the most-connected (hub) genes (and their interactions) for each such module. After mapping these hub genes to their human orthologs, 12 health(span) genes were identified in at least two species (ACTN3, ANK1, MRPL18, MYL1, PAXIP1, PPP1CA, SCN3B, SDCBP, SKIV2L, TUBG1, TYROBP, WIPF1), for which enrichment analysis by g:profiler found an association with actin filament-based movement and associated organelles, as well as muscular structures. We conclude that a meta-study of hub genes from co-expression network analyses for the complex phenotype health(span), across multiple species, can yield molecular-mechanistic insights and can direct experimentalists to further investigate the contribution of individual genes and their interactions to health(span).

Distinct cavemoviruses interact synergistically with sweet potato chlorotic stunt virus (genus Crinivirus) in cultivated sweet potato.

Two serologically unrelated sweet potato viruses causing symptoms of vein clearing in the indicator plant Ipomoea setosa were isolated and their genomes have been sequenced. They are associated with symptomless infections in sweet potato but distinct vein-clearing symptoms and higher virus titres were observed when these viruses co-infected with sweet potato chlorotic stunt virus (SPCSV), a virus that is distributed worldwide and is a mediator of severe virus diseases in this crop. Molecular characterization and phylogenetic analysis revealed an overall nucleotide identity of 47.6 % and an arrangement of the movement protein and coat protein domains characteristic of members of the genus Cavemovirus, in the family Caulimoviridae. We detected both cavemoviruses in cultivated sweet potato from East Africa, Central America and the Caribbean islands, but not in samples from South America. One of the viruses characterized showed a similar genome organization as, and formed a phylogenetic sublineage with, tobacco vein clearing virus (TVCV), giving further support to the previously suggested separation of TVCV, and related viral sequences, into a new caulimovirid genus. Given their geographical distribution and previous reports of similar but yet unidentified viruses, sweet potato cavemoviruses may co-occur with SPCSV more often than previously thought and they could therefore contribute to the extensive yield losses and cultivar decline caused by mixed viral infections in sweet potato.

Diversity of Microorganisms in Biocrusts Surrounding Highly Saline Potash Tailing Piles in Germany.

Potash tailing piles located in Germany represent extremely hypersaline locations that negatively affect neighbouring environments and limit the development of higher vegetation. However, biocrusts, as cryptogamic covers, inhabit some of these areas and provide essential ecological functions, but, nevertheless, they remain poorly described. Here, we applied high-throughput sequencing (HTS) and targeted four groups of microorganisms: bacteria, cyanobacteria, fungi and other eukaryotes. The sequencing of the 16S rRNA gene revealed the dominance of Proteobacteria, Cyanobacteria and Actinobacteria. Additionally, we applied yanobacteria-specific primers for a detailed assessment of the cyanobacterial community, which was dominated by members of the filamentous orders Synechococcales and Oscillatoriales. Furthermore, the majority of reads in the studied biocrusts obtained by sequencing of the 18S rRNA gene belonged to eukaryotic microalgae. In addition, sequencing of the internal rDNA transcribed spacer region (ITS) showed the dominance of Ascomycota within the fungal community. Overall, these molecular data provided the first detailed overview of microorganisms associated with biocrusts inhabiting highly saline potash tailing piles and showed the dissimilarities in microbial diversity among the samples.

Microbial Diversity in Subarctic Biocrusts from West Iceland following an Elevation Gradient.

Biological soil crusts (biocrusts) are essential communities of organisms in the Icelandic soil ecosystem, as they prevent erosion and cryoturbation and provide nutrients to vascular plants. However, biocrust microbial composition in Iceland remains understudied. To address this gap in knowledge, we applied high-throughput sequencing to study microbial community composition in biocrusts collected along an elevation gradient (11-157 m a.s.l.) stretching away perpendicular to the marine coast. Four groups of organisms were targeted: bacteria and cyanobacteria (16S rRNA gene), fungi (transcribed spacer region), and other eukaryotes (18S rRNA gene). The amplicon sequencing of the 16S rRNA gene revealed the dominance of Proteobacteria, Bacteroidetes, and Actinobacteria. Within the cyanobacteria, filamentous forms from the orders Synechococcales and Oscillatoriales prevailed. Furthermore, fungi in the biocrusts were dominated by Ascomycota, while the majority of reads obtained from sequencing of the 18S rRNA gene belonged to Archaeplastida. In addition, microbial photoautotrophs isolated from the biocrusts were assigned to the cyanobacterial genera Phormidesmis, Microcoleus, Wilmottia, and Oscillatoria and to two microalgal phyla Chlorophyta and Charophyta. In general, the taxonomic diversity of microorganisms in the biocrusts increased following the elevation gradient and community composition differed among the sites, suggesting that microclimatic and soil parameters might shape biocrust microbiota.

Transcriptomic changes arising during light-induced sporulation in Physarum polycephalum.

BACKGROUND: Physarum polycephalum is a free-living amoebozoan protist displaying a complex life cycle, including alternation between single- and multinucleate stages through sporulation, a simple form of cell differentiation. Sporulation in Physarum can be experimentally induced by several external factors, and Physarum displays many biochemical features typical for metazoan cells, including metazoan-type signaling pathways, which makes this organism a model to study cell cycle, cell differentiation and cellular reprogramming. RESULTS: In order to identify the genes associated to the light-induced sporulation in Physarum, especially those related to signal transduction, we isolated RNA before and after photoinduction from sporulation- competent cells, and used these RNAs to synthesize cDNAs, which were then analyzed using the 454 sequencing technology. We obtained 16,669 cDNAs that were annotated at every computational level. 13,169 transcripts included hit count data, from which 2,772 displayed significant differential expression (upregulated: 1,623; downregulated: 1,149). Transcripts with valid annotations and significant differential expression were later integrated into putative networks using interaction information from orthologs. CONCLUSIONS: Gene ontology analysis suggested that most significantly downregulated genes are linked to DNA repair, cell division, inhibition of cell migration, and calcium release, while highly upregulated genes were involved in cell death, cell polarization, maintenance of integrity, and differentiation. In addition, cell death- associated transcripts were overrepresented between the upregulated transcripts. These changes are associated to a network of actin-binding proteins encoded by genes that are differentially regulated before and after light induction.

Single-cell analyses of aging, inflammation and senescence.

Single-cell gene expression (transcriptomics) data are becoming robust and abundant, and are increasingly used to track organisms along their life-course. This allows investigation into how aging affects cellular transcriptomes, and how changes in transcriptomes may underlie aging, including chronic inflammation (inflammaging), immunosenescence and cellular senescence. We compiled and tabulated aging-related single-cell datasets published to date, collected and discussed relevant findings, and inspected some of these datasets ourselves. We specifically note insights that cannot (or not easily) be based on bulk data. For example, in some datasets, the fraction of cells expressing p16 (CDKN2A), one of the most prominent markers of cellular senescence, was reported to increase, in addition to its upregulated mean expression over all cells. Moreover, we found evidence for inflammatory processes in most datasets, some of these driven by specific cells of the immune system. Further, single-cell data are specifically useful to investigate whether transcriptional heterogeneity (also called noise or variability) increases with age, and many (but not all) studies in our review report an increase in such heterogeneity. Finally, we demonstrate some stability of marker gene expression patterns across closely similar studies and suggest that single-cell experiments may hold the key to provide detailed insights whenever interventions (countering aging, inflammation, senescence, disease, etc.) are affecting cells depending on cell type.

Complete Genome Sequence of the Plant Pathogen Ralstonia solanacearum Strain CIAT-078, Isolated in Colombia, Obtained Using Oxford Nanopore Technology.

Moko is one of the main diseases affecting banana and plantain in Colombia. Here, we report the genome sequence of the causal agent, the bacterium Ralstonia solanacearum (Smith) strain CIAT-078, collected in 2004 from affected plantains in central-west Colombia. The assembled genome was obtained using Oxford Nanopore Technology.

Nanopore-Based Complete Genome Sequence of a Sri Lankan Cassava Mosaic Virus (Geminivirus) Strain from Thailand.

Sri Lankan cassava mosaic virus is an emerging pathogen in Southeast Asia. Here, we report the complete genome of a Thai isolate obtained using Nanopore technology. The isolate was collected in 2019 from the northeastern province of Surin, soon after disease eradication was reported in the country.

Suppression of the TGF-ß pathway by a macrolide antibiotic decreases fibrotic responses by ocular fibroblasts in vitro.

To elucidate and to inhibit post-surgical fibrotic processes after trabeculectomy in glaucoma therapy, we measured gene expression in a fibrotic cell culture model, based on transforming growth factor TGF-ß induction in primary human tenon fibroblasts (hTFs), and used Connectivity Map (CMap) data for drug repositioning. We found that specific molecular mechanisms behind fibrosis are the upregulation of actins, the downregulation of CD34, and the upregulation of inflammatory cytokines such as IL6, IL11 and BMP6. The macrolide antibiotic Josamycin (JM) reverses these molecular mechanisms according to data from the CMap, and we thus tested JM as an inhibitor of fibrosis. JM was first tested for its toxic effects on hTFs, where it showed no influence on cell viability, but inhibited hTF proliferation in a concentration-dependent manner. We then demonstrated that JM suppresses the synthesis of extracellular matrix (ECM) components. In hTFs stimulated with TGF-ß1, JM specifically inhibited α-smooth muslce actin expression, suggesting that it inhibits the transformation of fibroblasts into fibrotic myofibroblasts. In addition, a decrease of components of the ECM such as fibronectin, which is involved in in vivo scarring, was observed. We conclude that JM may be a promising candidate for the treatment of fibrosis after glaucoma filtration surgery or drainage device implantation in vivo.