The epididymis is a highly specialized organ essential for promoting the post-testicular functional maturation of spermatozoa, a process underpinning male fertility. This review examines the latest proteomics advances that have been used to unravel the complex molecular landscape of the epididymis, revealing the dynamic protein networks that shape sperm function beyond their genomic and transcriptomic blueprints. Here, we highlight how high-resolution mass spectrometry has helped to map the proteomic signatures of epididymal tissue, luminal extracellular vesicles (epididymosomes), and spermatozoa at different maturation stages, pinpointing key regulators of motility, capacitation, fertilization competence, and immune regulation. However, critical knowledge gaps remain, including deep protein characterization of the cytoplasmic droplet, epididymal fluid, and relatively underexplored anatomical tissue segments such as the corpus and cauda epididymis. We discuss how integrating global proteomic insights with complementary omics, single-cell proteomics, and advanced imaging is poised to reveal the spatial and temporal refinement of the sperm proteome, providing insights into how its disruption may contribute to idiopathic infertility. To promote data accessibility and accelerate discovery in epididymal biology, we introduce ShinyEpididymis (https://reproproteomics.shinyapps.io/ShinyEpididymis/), an interactive, web-based resource integrating publicly available proteomic datasets from spermatozoa, epididymosomes, and epididymal tissue. This platform enables researchers to rapidly query proteins of interest, explore spatial patterns of expression, and identify potential biomarkers or therapeutic targets. By consolidating current knowledge and defining future priorities, this review positions proteomics at the forefront of understanding epididymal biology, emphasising its clinical relevance and untapped potential for diagnosing and treating male infertility.

Sodium-glucose co-transporter 2 inhibitors (SGLT2i), when combined with metformin (COMBI), offer multi-organ protective effects in patients with type 2 diabetes (T2D), particularly those at high risk of cardiovascular or renal complications. However, the underlying molecular mechanisms remain poorly understood. We profiled 303 targeted serum metabolites in 1494 participants of the KORA study, including T2D patients treated with COMBI therapy, metformin monotherapy, or no glucose-lowering medication. Additionally, metabolomic profiling was quantified on seven tissues (plasma, liver, adrenal glands, adipose tissue, testis, lung, and cerebellum), and related hepatic transcripts were evaluated in 40 mice. Multivariable linear regression analyses, adjusted for age, sex, BMI, lifestyle, glycemic, and cardiovascular risk factors, were applied to human data; tissue-specific regression analyses were conducted for murine samples. Identified metabolites were further investigated using biochemical pathway analyses and literature review. COMBI therapy was associated with significant changes in metabolite profiles. In humans, 10 metabolites were significantly altered compared to metformin monotherapy. In mice, 82 altered metabolites were identified in plasma, 52 in liver, 30 in adrenal glands, 12 in adipose tissue, seven in testis, seven in lung, and six in cerebellum. COMBI therapy lowered threonine concentrations in both human serum and murine plasma but raised threonine, glycine, and urea cycle metabolites (citrulline, asymmetric dimethyl arginine (ADMA), and ornithine) in murine liver. This was accompanied by enhanced hepatic expression of Slc38a2, a threonine transporter gene. In humans, urea cycle metabolites correlated strongly with the fibrosis-4 index, a marker of liver fibrosis. Additionally, COMBI therapy elevated ketone body markers, such as hydroxybutyrylcarnitine, across murine liver, plasma, adrenal glands, adipose tissue, and testis. COMBI therapy modulates amino acid metabolism, the urea cycle, and ketone body production, suggesting potential mechanisms underlying its protective effects against liver fibrosis and male subfertility. These findings provide novel insights into the systemic metabolic actions of COMBI therapy and highlight its translational potential to improve clinical outcomes in T2D patients.

Residential wood combustion (RWC) contributes significantly to urban air pollution; however, the influence of atmospheric aging on adverse health effects of RWC emissions remains uncertain. We exposed C57BL/6J mice in parallel with different in vitro models of first-line of defense cells (macrophages: RAW264.7 and lung epithelial cells: A549) at the air-liquid interface to either fresh or aged RWC emissions generated from an oxidation flow reactor. Both in vivo and in vitro cellular and molecular outcomes show that photochemically aged emissions play a key role in triggering lung inflammation and the polarization of macrophages into an M2 phenotype, bridging the gap between epidemiology and toxicology on inflammatory lung responses. Furthermore, evidence of protumorigenic activity in lung epithelial cells is detected after exposure to both emissions, but more pronounced after exposure to aged RWC emissions. This study highlights the importance of considering atmospheric aging in the assessment of air-pollution-related health effects.

Down syndrome (DS) is the most prevalent form of intellectual disability (ID) globally, with an incidence rate of approximately 1 in 1000 births, affecting over 5 million individuals worldwide. DS is characterized by a genetic profile that predisposes individuals to a range of medical and cognitive conditions, including ID and obesity, which place considerable demands on healthcare systems and families alike. Mouse models carrying DS-related genetic mutations offer valuable tools for investigating the pathophysiological mechanisms underlying DS-associated behavioral and metabolic alterations. These models also allow for an evaluation of the impact of both intrinsic and extrinsic environmental factors, aiding in the development of biomarkers and personalized therapies for individuals with DS. In this article, we establish a detailed and comprehensive phenotyping pipeline designed to incorporate high-resolution assessments of cognitive, metabolic, and behavioral variables. Using advanced phenotyping techniques alongside standardized protocols in DS mouse models, this approach systematically captures the variability of DS-associated traits. Our phenotyping pipeline aims to cover the pathways leading to cognitive dysfunction and metabolic imbalances in DS, paving the way for targeted intervention strategies. © 2026 The Author(s). Current Protocols published by Wiley Periodicals LLC. Basic Protocol 1: Diet challenge (chow diet vs. high-fat diet) Basic Protocol 2: Fecal or saliva microbiota analysis Basic Protocol 3: Body composition assessment by quantitative nuclear magnetic resonance Basic Protocol 4: Indirect calorimetry Basic Protocol 5: Blood collection and processing Basic Protocol 6: Oral glucose tolerance test Basic Protocol 7: Long-term monitoring of social groups Alternate Protocol 1: Analysis of short-term dyadic interactions between unfamiliar mice of the same genotype Alternate Protocol 2: Analysis of short-term dyadic interactions of mice from the tested strain with an unfamiliar C57BL/6J mouse Basic Protocol 8: Intraperitoneal insulin sensitivity test Basic Protocol 9: Y-maze spontaneous alternation test Alternate Protocol 3: Y-maze spontaneous alternation test version 2 Basic Protocol 10: Marble-burying analysis Alternate Protocol 4: Marble-burying analysis version 2 Basic Protocol 11: Object location memory/novel object recognition Alternate Protocol 5: Novel object recognition in the Y-maze apparatus Basic Protocol 12: Nest-building test Basic Protocol 13: Sucrose preference analysis Basic Protocol 14: Histopathology © 2026 by John Wiley & Sons, Inc.

In recent decades, obesity and diabetes have reached pandemic levels, with obesity now recognised as a major health risk factor. Evidence shows that metabolic diseases are more pronounced in the offspring of malnourished parents, suggesting that predisposition can be inherited via epigenetic information in gametes. This has sparked growing interest in small regulatory RNAs in sperm as carriers of epigenetic inheritance. However, the functional annotation of dysregulated sperm microRNAs (miRNAs) in obesity and diabetes remains limited. This work addresses this gap by analysing publicly available datasets of diet-regulated sperm miRNAs and linking them to genes functionally associated with obesity and diabetes. We systematically identified diet-responsive sperm miRNAs and overlapped their predicted targets with genes associated with metabolic phenotypes, as catalogued by the International Mouse Phenotyping Consortium (IMPC). First, in a sequence-based approach, we uncovered 11,272 and 6528 potential target genes for miRNAs regulated by the acute and chronic HFD interventions, respectively. Second, by overlapping these predicted target genes of sperm miRNAs with our IMPC-derived list of 889 genes associated with obesity and diabetes, we identified 805 acute- and 546 chronic-HFD predicted response genes. This approach thus associates function with regulated miRNAs and revealed distinct miRNA-gene networks in acute versus chronic HFD models, including shared nodes in pathways related to insulin signalling, lipid metabolism, and β-cell function. To support further research, we provide the field with the ShinyFatSperm App (https://reproproteomics.shinyapps.io/ShinyFatSperm/), which facilitates the functional interpretation of diet-regulated sperm miRNAs and enables users to explore their roles in the intergenerational transmission of metabolic disease risk. Taken together, our findings reinforce the concept that paternal dietary exposures can influence offspring health through epididymal- and sperm-borne miRNAs, and related epigenetic mechanisms. This work provides a roadmap for hypothesis-driven investigation into the intergenerational inheritance of metabolic diseases and highlights the urgent need for translational strategies to interrupt this cycle.

Lay summary:The aim of this study is to highlight potential differences between embryos conceived naturally and those conceived via in vitro fertilisation (IVF). While the current scientific literature generally assumes that differences between these two modes of conception exist, many studies do not provide detailed phenotypic data, e.g. bodyweight, blood glucose and other observational metabolic health parameters. In addition, comparisons are often complicated by variations in choosing different strains of foster mothers to carry embryos. By addressing these limitations, our short summary and overview provide a well-defined comparison within a controlled experimental setup including a high-fat diet feeding period as metabolic challenge. We make the resulting data publicly available to offer a reference point for researchers using a specific mouse strain as fosters and to improve transparency regarding the specific differences in metabolic health observed between natural conception and IVF in this context.

ABCB5 is a member of the ATP-binding cassette transporter superfamily that is expressed as a full transporter (ABCB5FL) and half transporter (ABCB5β). The ABCB5FL transporter mediates low-level multidrug resistance in cancer and is normally expressed in the prostate and testis, while ABCB5β has been found to be a marker of melanoma and limbal stem cells and is expressed in pigmented cells. To explore ABCB5's role in normal physiology, we generated Abcb5-deficient C57BL/6J mice by the deletion of Abcb5 exon 2, knocking out both forms of ABCB5, which were completely phenotyped. The mice were fertile and demonstrated altered bioenergetics and fat metabolism, along with alterations in their blood composition, including anisocytosis and decreased white blood cells and platelet counts. This study uncovers further avenues of investigation into the role of Abcb5 in intermediary metabolism, particularly in relation to atherogenesis.

In the ventricular-subventricular zone (V-SVZ), both apical and basal NSCs undergo quiescence and proliferation. The epidermal growth factor receptor (EGFR) and interactions with the extracellular matrix are key regulators of adult NSC proliferation and quiescence, respectively. Here, we show that activation of EGFR significantly declines after the first postnatal weeks in apical NSCs. This decline is accompanied by a shift in serum responsive factor (SRF)-dependent transcription in apical NSCs. Specifically, growth-promoting genes targeted by SRF and ternary complex transcription factors are downregulated, whereas those targeted by SRF and myocardin-related transcription factors (MRTFs), including those involved in the extracellular matrix remodeling, are upregulated. Blocking of MRTFs, whose activity is regulated by the Rho/actin pathway and extracellular matrix interactions, restores EGFR activation and EGFR-dependent proliferation in adult apical NSCs. Thus, transcriptional programs regulated by extracellular cues differentially control EGFR activation and proliferation in neonatal and adult apical NSCs. ### Competing Interest Statement The authors have declared no competing interest.

OBJECTIVES:Endurance exercise reduces the risk of metabolic diseases by improving skeletal muscle metabolism, particularly in individuals with overweight and obesity. As biological sex impacts glucose and fatty acid handling in skeletal muscle, we hypothesized sex differences at the transcriptomic and proteomic level in the acute response to exercise and after an 8-week exercise intervention. METHODS:We analyzed skeletal muscle biopsies from 25 sedentary subjects (16f/9 m) with overweight and obesity using transcriptomics and proteomics at baseline, after acute exercise, and following an 8-week endurance training program. Regulation of sex-specific differences was studied in primary myotubes from the donors. RESULTS:At baseline, differentially methylated CpG-sites potentially explain up to 59% of transcriptomic and 67% of proteomic sex differences. Differences were dominated by higher abundance of fast-twitch fiber type proteins, and transcripts and proteins regulating glycogen degradation and glycolysis in males. Females showed higher abundance of proteins regulating fatty acid uptake and storage. Acute exercise induced stress-responsive transcripts and serum myoglobin predominantly in males. Both sexes adapted to 8-week endurance training by upregulating mitochondrial proteins involved in TCA cycle, oxidative phosphorylation, and β-oxidation. Training equalized fast-twitch fiber type protein levels, mainly by reducing them in males. In vivo sex differences in autosomal genes were poorly retained in myotubes but partially restored by sex hormone treatment. CONCLUSIONS:Our findings highlight sex-specific molecular signatures that reflect known differences in glucose and lipid metabolism between female and male skeletal muscle. After just 8 weeks of endurance training, these sex differences were attenuated, suggesting a convergence towards a shared beneficial adaptation at the molecular level.

Ensuring the quality and reproducibility of biological resources is essential for advancing biomedical research and upholding animal welfare standards. The European Mouse Mutant Archive (EMMA), part of the INFRAFRONTIER research infrastructure, plays a key role in this effort by cryopreserving scientifically validated mutant mouse and rat strains and making them accessible to the global scientific community. To further enhance its processes and promote transparency, INFRAFRONTIER/EMMA has developed a set of ten Quality Principles specifically tailored to the unique requirements of cryopreserved rodent mutant strains. These principles guide EMMA’s workflows by providing a structured yet flexible quality framework across its distributed nodes. They encompass both general standards—such as adherence to the 3Rs (Replace, Reduce, Refine), staff competence, and continuous improvement—and more specific areas including scientific evaluation, data curation, and intellectual property rights. Each principle is presented with contextual background, defined requirements, practical recommendations, and key references. This initiative aims to strengthen the reliability, ethical integrity, and reproducibility of preclinical research resources.

Early-life programming is a major determinant of lifelong metabolic health, yet current preventive strategies focus almost exclusively on maternal factors. Emerging experimental and preclinical data reveal that a father's diet before conception, particularly high-fat intake, also shapes offspring physiology. Here, we synthesize the latest evidence on how such diets remodel the sperm epigenome during two discrete windows of vulnerability: (i) testicular spermatogenesis, via DNA methylation and histone modifications, and (ii) post-testicular epididymal maturation, where small non-coding RNAs are selectively gained. We examine how these epigenetic signals influence pregnancy, placental development, and ultimately, metabolic trajectories in progeny. To extend published work, we sourced publicly available diet-induced sperm epigenome datasets and provide new potential connections of these changes to genes governing placental development, vascularization and size using the International Mouse Phenotyping Consortium data. Moreover, we further interrogate these overlaps with intricate in-silico analyses to examine their potential consequences. To foster meaningful interactions with these findings, we have developed a web application for ease (ShinySpermPlacenta). Collectively, these findings support a biparental model of preconception care and position the sperm epigenome as a promising tractable biomarker platform for personalized paternal nutrition counselling aimed at improving fertility and reducing intergenerational metabolic disease risk.

Mutations in the gene encoding Tectonic β-propeller repeat-containing repeat protein 2 (TECPR2) cause hereditary sensory and autonomic neuropathy subtype 9 (HSAN9) which is a fatal neurodevelopmental and neurodegenerative disorder involving the sensory and peripheral nervous system. TECPR2 is ubiquitously expressed and linked to trafficking and sorting within the cell, however, its functional role remains poorly defined. Moreover, molecular insights into pathogenic mechanisms underlying HSAN9 are lacking. Here, we report a novel mouse model which harbors a HSAN9-associated nonsense mutation that causes loss of TECPR2 expression. Mice show altered gait, highly region-specific axonal dystrophy, and extensive local gliosis. The affected medulla area prominently features swollen axons filled with amorphous protein aggregates, glycogen granules, single and double membrane vesicles as well as aberrant organelles including ER and mitochondria whose proteome is distinctly altered. Despite the locally restricted pathology the neuronal demise is detectable in the cerebrospinal fluid and responded to by damage-associated microglia. However, their capacity to clear neuronal debris seems attenuated. Overall, neuronal and microglia phenotypes point to a dysfunctional endolysosomal system when TECPR2 is missing. This was confirmed in TECPR2 knockout cells and linked to TECPR2’s interaction with the homotypic fusion and protein sorting (HOPS)–tethering complex. Collectively, we uncovered a role of TECPR2 in endolysosome maintenance which seems relevant for healthy neurons in a particular brain region.

Exercise is a potent skeletal muscle stimulus and one of the most effective strategies to prevent muscle loss and type 2 diabetes. Biological sex-based differences are reported for aerobic capacity, muscle mass, and exercise performance. We aimed to provide a yet missing comprehensive picture of molecular differences between female and male skeletal muscle at baseline, after acute exercise and training. Further we investigated which differences were conserved in vitro. We characterized muscle biopsies from 25 (16f/9m) subjects in a multi-omics approach employing epigenomics, transcriptomics and proteomics at baseline, after acute exercise and 8 weeks of supervised endurance training. Donor matched myoblasts and myotubes were analyzed in vitro. We found differential CpG-site methylation in 16.012 genes, 1.366 differentially expressed genes and 120 proteins at baseline. Differential transcripts were associated with translational regulation, histone methylation, glucose homeostasis and insulin signaling. Type-2 fast-twitch fiber-type proteins were elevated in males, along with proteins regulating glycolysis. Y-linked transcript expression was conserved in vitro, but only a few differences in expression of autosomal genes, e.g. elevated LDHB in females. Acute exercise upregulated oxidative stress-responsive transcripts predominantly in males. After 8-week-training, both sexes had upregulated mitochondrial proteins involved in substrate oxidation and ATP production, while glycolytic fiber marker MYH1 and MYH3 were only reduced in males. Thus, sex specific differences exist in resting skeletal muscle and in exercise adaptation on epigenomic, transcriptomic and proteomic level. The few conserved differences in vitro hint towards hormonal or yet undefined mechanisms. Training might mitigate initially differential responses to exercise. The question remains whether there are sex specific differences within individual fiber-types or whether it is just a matter of composition. Disclosure S.I. Dreher: None. T. Goj: None. C. von Toerne: None. M. Hoene: None. M. Irmler: None. M. Ouni: None. M. Jähnert: None. J. Beckers: None. A. Peter: None. A.L. Birkenfeld: None. A. Schürmann: None. S.M. Hauck: None. C. Weigert: None.

Biological sex has a strong impact on skeletal muscle metabolism and performance. By a comprehensive investigation of epigenetic, transcriptomic and proteomic differences between female and male skeletal muscle of untrained subjects we provide a molecular basis for the sexual dimorphism of glucose and lipid metabolism. The sex-specific multi-OMICs profiles indicate higher degree of glucose turnover and higher abundance of fast-twitch fibers in males and high degree of lipid handling in females. Eight-week endurance training equalized initial differences toward an endurance-trained proteomic profile in both sexes. The untrained muscle of females was more resistant to an acute exercise challenge since stress-responsive transcripts were predominantly upregulated in males. In myotubes from the same donors, transcriptomic differences were hardly conserved, but could be partially restored by treatment with sex hormones. In conclusion, after only 8 weeks training mitigates deeply rooted sex-specific molecular profiles in skeletal muscle toward a common metabolically beneficial response. ### Competing Interest Statement The authors have declared no competing interest.

Context Exercise training is known to improve glucose tolerance and reverse insulin resistance in people with obesity. However, some individuals fail to improve or even decline in their clinical traits following exercise intervention.Objective This study focused on gene expression and DNA methylation signatures in skeletal muscle of low (LRE) and high responders (RES) to 8 weeks of supervised endurance training.Methods We performed skeletal muscle gene expression and DNA methylation analyses in LRE and RES before and after exercise intervention. Additionally, we applied the least absolute shrinkage and selection operator (LASSO) approach to identify predictive marker genes of exercise outcome.Results We show that the two groups differ markedly already before the intervention. RES were characterized by lower expression of genes involved in DNA replication and repair, and higher expression of extracellular matrix (ECM) components. The LASSO approach identified several novel candidates (eg, ZCWPW2, FOXRED1, STK40) that have not been previously described in the context of obesity and exercise response. Following the intervention, LRE reacted with expression changes of genes related to inflammation and apoptosis, RES with genes related to mitochondrial function. LRE exhibited significantly higher expression of ECM components compared to RES, suggesting improper remodeling and potential negative effects on insulin sensitivity. Between 45% and 70% of differences in gene expression could be linked to differences in DNA methylation.Conclusion Together, our data offer an insight into molecular mechanisms underlying differences in response to exercise and provide potential novel markers for the success of intervention.

Background Chronic obstructive pulmonary disease (COPD) has the highest increased risk due to household air pollution arising from biomass fuel burning. However, knowledge on COPD patho-mechanisms is mainly limited to tobacco smoke exposure. In this study, a repeated direct wood smoke (WS) exposure was performed using normal- (bro-ALI) and chronic bronchitis-like bronchial (bro-ALI-CB), and alveolar (alv-ALI) lung mucosa models at air–liquid interface (ALI) to assess broad toxicological end points. Methods The bro-ALI and bro-ALI-CB models were developed using human primary bronchial epithelial cells and the alv-ALI model was developed using a representative type-II pneumocyte cell line. The lung models were exposed to WS (10 min/exposure; 5-exposures over 3-days; n = 6–7 independent experiments). Sham exposed samples served as control. WS composition was analyzed following passive sampling. Cytotoxicity, total cellular reactive oxygen species (ROS) and stress responsive NFkB were assessed by flow cytometry. WS exposure induced changes in gene expression were evaluated by RNA-seq (p ≤ 0.01) followed by pathway enrichment analysis. Secreted levels of proinflammatory cytokines were assessed in the basal media. Non-parametric statistical analysis was performed. Results 147 unique compounds were annotated in WS of which 42 compounds have inhalation toxicity (9 very high). WS exposure resulted in significantly increased ROS in bro-ALI (11.2%) and bro-ALI-CB (25.7%) along with correspondingly increased NFkB levels (bro-ALI: 35.6%; bro-ALI-CB: 18.1%). A total of 1262 (817-up and 445-down), 329 (141-up and 188-down), and 102 (33-up and 69-down) genes were differentially regulated in the WS-exposed bro-ALI, bro-ALI-CB, and alv-ALI models respectively. The enriched pathways included the terms acute phase response, mitochondrial dysfunction, inflammation, oxidative stress, NFkB, ROS, xenobiotic metabolism of AHR, and chronic respiratory disorder. The enrichment of the ‘cilium’ related genes was predominant in the WS-exposed bro-ALI (180-up and 7-down). The pathways primary ciliary dyskinesia, ciliopathy, and ciliary movement were enriched in both WS-exposed bro-ALI and bro-ALI-CB. Interleukin-6 and tumor necrosis factor-α were reduced (p < 0.05) in WS-exposed bro-ALI and bro-ALI-CB. Conclusion Findings of this study indicate differential response to WS-exposure in different lung regions and in chronic bronchitis, a condition commonly associated with COPD. Further, the data suggests ciliopathy as a candidate pathway in relation to WS-exposure.

Childhood obesity and type 2 diabetes are two emerging health issues worldwide. To analyze their underlying causes and develop prevention strategies, mouse models are urgently needed. We present novel insights into the polygenic TALLYHO/JngJ mouse model for diabetes. By precisely analyzing our original phenotypic data, we discovered that body weight at weaning age is the main predictor of the adult phenotype in TALLYHO/JngJ mice. The higher the weaning weight of male mice, the more likely they are to develop diabetes later in life. In contrast, a low weaning weight protected against the development of the diabetic phenotype in adults. In females, we found that high weaning body weights led to a constant higher body weight throughout life. We also showed that specifically the suckling period, rather than the in utero period, is crucial for the development of the metabolic phenotype in later life. We observed an earlier onset of diabetes when the mice had higher body weights at weaning, aligning with metabolic histories observed in humans. Therefore, we recommend TALLYHO/JngJ mice as a model to investigate childhood obesity and to develop prevention strategies.Highlights

BACKGROUND:Fibroblast-to-myofibroblast conversion is a major driver of tissue remodelling in organ fibrosis. Distinct lineages of fibroblasts support homeostatic tissue niche functions, yet their specific activation states and phenotypic trajectories during injury and repair have remained unclear. METHODS:We combined spatial transcriptomics, multiplexed immunostainings, longitudinal single-cell RNA-sequencing and genetic lineage tracing to study fibroblast fates during mouse lung regeneration. Our findings were validated in idiopathic pulmonary fibrosis patient tissues in situ as well as in cell differentiation and invasion assays using patient lung fibroblasts. Cell differentiation and invasion assays established a function of SFRP1 in regulating human lung fibroblast invasion in response to transforming growth factor (TGF)β1. MEASUREMENTS AND MAIN RESULTS:We discovered a transitional fibroblast state characterised by high Sfrp1 expression, derived from both Tcf21-Cre lineage positive and negative cells. Sfrp1 + cells appeared early after injury in peribronchiolar, adventitial and alveolar locations and preceded the emergence of myofibroblasts. We identified lineage-specific paracrine signals and inferred converging transcriptional trajectories towards Sfrp1 + transitional fibroblasts and Cthrc1 + myofibroblasts. TGFβ1 downregulated SFRP1 in noninvasive transitional cells and induced their switch to an invasive CTHRC1+ myofibroblast identity. Finally, using loss-of-function studies we showed that SFRP1 modulates TGFβ1-induced fibroblast invasion and RHOA pathway activity. CONCLUSIONS:Our study reveals the convergence of spatially and transcriptionally distinct fibroblast lineages into transcriptionally uniform myofibroblasts and identifies SFRP1 as a modulator of TGFβ1-driven fibroblast phenotypes in fibrogenesis. These findings are relevant in the context of therapeutic interventions that aim at limiting or reversing fibroblast foci formation.