The FASEB Journal

Intervertebral disc degeneration is associated with loss of nucleus pulposus (NP) cell phenotype and extracellular matrix, both processes linked to changes in cytoskeletal contractility and cell shape. Here, we tested whether microenvironment-specific modulation of RhoA signaling can restore NP-like morphology and gene expression in NP cells cultured in 2D and in 3D alginate. In 2D monolayer culture, where cells are spread and mechanically activated, pharmacologic inhibition of RhoA with CT04 reduced RhoA activity, decreased actomyosin contractility gene expression, and shifted morphology toward a smaller, more circular phenotype. Bulk RNA sequencing showed that CT04 treatment increased expression of NP phenotypic and matrix-related genes including ACAN, GDF5, CHST3, and MUSTN1 while decreasing expression of catabolic and fibroblast-associated genes including ADAMTS1/9 and COL1, consistent with enrichment of extracellular matrix pathways. In contrast, RhoA activation with CN03 in 2D culture increased actin and phosphorylated myosin light chain intensity but produced limited phenotypic improvement. In 3D alginate, which minimizes integrin-mediated adhesion, baseline actomyosin markers were reduced relative to 2D culture. In alginate, RhoA activation with CN03 increased the amount of actin, phosphorylated myosin light chain, and actomyosin gene expression, yet also promoted a more compact, circular morphology and increased NP markers, including ACAN and KRT19 with repeated dosing. Across culture conditions, increased cell roundness was consistently associated with increased ACAN expression, indicating strong coupling between cytoskeletal state, morphology, and NP matrix programs. Together, these findings demonstrate that RhoA pathway perturbation can promote NP phenotypic gene expression in both 2D and 3D culture, but the direction of optimal modulation depends on the microenvironment, supporting RhoA signaling as a context-dependent therapeutic target for disc regeneration.

Human embryo implantation, occurring approximately one week after fertilization, remains poorly understood due to ethical and technical limitations of in vivo investigation. To overcome these barriers, and model this critical developmental event, encompassing peri- and early post-implantation stages, we used an in vitro embryo attachment model composed of donor-derived endometrial epithelial cells forming an open-faced endometrial layer (OFEL) and human stem cell-derived blastoids recapitulating human day 5 blastocysts in peri-implantation model. Following attachment, developmental progression was further investigated on laminin-coated substrates to capture early post-implantation dynamics. Despite its central role as the primary endocrine signal of early pregnancy, human chorionic gonadotropin (hCG) remains largely uncharacterized in this context. Here, we describe the transcriptomic profile of blastoid-endometrial co-cultures relative to OFEL alone, identifying CGA and CGB3/5/8 as among the most strongly upregulated genes following blastoid attachment to hormonally stimulated OFEL. Consistent with these findings, immunoassays and luteinizing hormone/choriogonadotropin receptor (LHCGR) activation assays of conditioned media confirmed the secretion of heterodimeric, biologically active hCG and its free subunits in co-cultures, but not in endometrial layers alone. Notably, the hyperglycosylated hCG heterodimer was the predominant isoform detected. Co-culture with the endometrial component significantly increased hCG secretion compared with blastoids cultured alone, an effect further enhanced by hormonal priming in the peri-implantation model. Collectively, these findings indicate that a hormonally primed endometrial environment not only promotes blastoid attachment but also amplifies embryonic hCG production and bioactivity, underscoring the importance of maternal endocrine cues in early embryo-endometrium communication. Furthermore, our peri- and early post-implantation models recapitulate key aspects of reciprocal endocrine signaling between embryonic and endometrial tissues, providing a tractable experimental framework to investigate embryo-endometrium crosstalk.

The human endometrium undergoes cyclic, hormone-driven remodeling that establishes a transient window of receptivity required for embryo implantation, placentation, and maintenance of pregnancy. Decidualization of endometrial stromal cells is a central component of this process and can be induced in vitro using cAMP alone or in combination with ovarian steroid hormones (EPC: estradiol, progesterone, and cAMP). Although cAMP activates the core decidual transcriptional program, whether hormone supplementation induces a more physiologically relevant response remains unclear, particularly in 3D endometrial organoid (Endo-organoid) models which have emerged as a new alternative methodology (NAM). Here, we compared morphological and transcriptomic responses of human endometrial stromal cell-derived Endo-organoids undergoing decidualization induced by cAMP or EPC stimulation. EPC-treated Endo-organoids exhibited enhanced structural remodeling and more advanced morphological transformation compared with cAMP-treated organoids. RNA-seq analysis revealed substantial overlap in canonical decidual gene expression between the two conditions, but EPC induced broader transcriptional and pathway-level changes, including enrichment of metabolic, stress-response, and differentiation-related processes. Together, these findings demonstrate that while cAMP activates the core decidual program, EPC elicits a broader and more physiologically relevant decidualization response in 3D human Endo-organoids, providing guidance for optimizing Endo-organoids to study endometrial receptivity, implantation, and early pregnancy success.

Introduction: Podocyte injury is central to the pathogenesis of most glomerulonephritides (GN) and causes segmental glomerulosclerotic lesions that predict progression in IgA Nephropathy (IgAN). Recent advances in high-resolution microscopy and AI-assisted image analysis have enabled detailed quantification of podocyte foot process (FP) morphology. However, whether nanoscale podocyte morphometrics can predict disease progression or treatment response in GN has not been investigated. Aim: To evaluate whether nanoscale podocyte morphometric parameters predict clinical characteristics, disease progression, and treatment response in GN, with a focus on IgAN. Method: Podocyte morphometrics were analyzed in kidney biopsies from patients with GN using high-resolution microscopy and the deep learning-based tool Automatic Morphometric Analysis of Podocytes (AMAP). Four morphometric parameters were quantified: slit diaphragm length (SDL), FP area, FP circularity and FP perimeter. These parameters were correlated with clinical characteristics, conventional electron microscopy (EM) findings and longitudinal follow-up data. Results: The study included 37 patients with GN from Danderyd University Hospital (Stockholm, Sweden), with IgAN representing the largest diagnostic subgroup (n = 19). The median follow-up for the cohort was 3.0 years. SDL correlated significantly with urine albumin-to-creatinine ratio (uACR; p = 0.021), whereas conventional EM measurements did not (p = 0.22). Within the IgAN subgroup, lower SDL was associated with a steeper decline in eGFR, higher FP area with increased long-term proteinuria, and higher FP circularity with improvement in uACR during the first year. The association between lower SDL and eGFR decline remained as a trend in IgAN patients not treated with corticosteroids (p = 0.068) but was absent in the treatment group (p = 0.59). Conclusion: In this proof-of-concept study, nanoscale podocyte morphometrics demonstrated greater sensitivity than conventional EM in quantifying podocyte injury and predicting progression in IgAN. These findings suggest that high-resolution morphometrics may improve risk stratification in IgAN but require validation in larger, independent cohorts before clinical implementation.

Autophagy is a critical homeostatic mechanism in podocytes, maintaining cellular integrity under stress and proteostatic challenges. Dysregulation of autophagy has been implicated in different glomerular diseases such as diabetes and membranous glomerulonephropathy (MGN), yet the underlying molecular drivers remain incompletely understood. We identified microRNA-378a (miR-378a), previously found upregulated in MGN, as a functional enhancer of autophagic flux in human podocytes and tubular epithelial cells. While miR-378a did not directly alter transcription of canonical autophagy genes (ATG2A, ATG5, ATG7, ATG12), it increased autophagic flux through suppression of mTOR phosphorylation at Ser2448. Given that NPNT is a miR-378a target and a key glomerular basement membrane component, we investigated its role in autophagy regulation. NPNT knockdown reduced ATG2A, ATG7, and BCN1 expression, but paradoxically increased autophagic flux, independent of mTOR, accompanied by enhanced ERK1/2 phosphorylation. These findings reveal a dual-layered regulatory network in which miR-378a promotes autophagy via mTOR inhibition, whereas NPNT modulates autophagy probably through MAPK-dependent signaling. Our results highlight the complex interplay between miRs, extracellular matrix components, and intracellular signaling pathways in podocyte autophagy. Dysregulation of these pathways in kidney disease may reflect both adaptive and maladaptive responses, providing mechanistic insights and potential therapeutic targets to preserve glomerular filtration barrier integrity in immune-mediated kidney disease.

Epidermal Growth factor (EGF) signaling is associated with (oncogenic) proliferation. Conversely, EGF-family ligands are able to trigger a differentiation program in cultured cells, an effect attributed to ligand affinity and EGFR phosphorylation. How EGF/EGFR driven proliferation-differentiation dynamics underlie tissue self-renewal has not been addressed. We show that culturing mouse small intestinal organoids (mSIOs) without EGF enhanced EGFR expression and base phosphorylation while maintaining a balanced development of proliferative crypts and differentiated villi. Addition of EGF or EREG triggers receptor endocytosis, reducing cell-surface and expression levels. While EGF promoted crypt proliferation, EREG promoted both proliferation and villus differentiation compared to untreated controls. Removal or re-introduction of EGF or EREG proved sufficient to induce development comparable to constant presence of ligands over 96h. Sub-saturating concentrations of EGF led to increased villus differentiation, resembling EREG treatments, suggesting that control over EGFR endocytic cycle ultimately regulates the balance of proliferation and differentiation in mSIOs SummaryExpression and signaling competency at the plasma membrane of EGFR drives crypt proliferation vs villus differentiation by medium ligand-composition, aiding mouse intestinal organoids self-renewal and regeneration.

The liver is widely considered to be one of the most conserved organs amongst vertebrates, with it being involved in blood detoxification, bile production and the metabolism of xenobiotic compounds. Liver organoids have previously been derived from several species and used as models of drug metabolism, toxicity, and fundamental tissue biology. To date, however, these models have not been developed from ruminant species, specifically cattle and sheep. Here we present the first report of the development and comprehensive characterisation of bovine and ovine liver organoids derived from primary liver tissue. When initially established, organoids from both species were comprised of KRT19- and KRT18-positive cholangiocytes. The capacity for organoids to differentiate into hepatocyte-enriched cultures was evaluated and it was noted that there was an increase in hepatocyte markers in bovine cultures. A comparative analysis of the liver tissue and organoids of both species revealed species-specific differences in gene expression, which were conserved within organoid cultures. Most notably, bovine liver tissue and organoids had enriched expression of genes associated with fatty acid uptake and storage whereas ovine samples had higher expression of genes associated with fatty acid conversion, highlighting fundamental differences between these two ruminant species. Differences in expression of cytochrome P450 family genes were identified alongside those associated with an inflammatory response specifically in bovine samples, whereas ovine samples had higher expression of genes associated with a protective immune response. Despite this, transcriptomic analysis of organoids from both species, cultured in both growth and differentiation media, revealed preserved expression of genes associated with key liver functions, including gluconeogenesis and xenobiotic metabolism. Transcripts associated with the flavin-containing monooxygenases (FMO) family were expressed in both organoid growth media and organoid development media (OGM and ODM respectively), and both species could metabolise triclabendazole into its primary metabolite triclabendazole sulfoxide, therefore validating the potential of the organoids to be applied as in vitro models of metabolism and/or toxicity. Overall, this study provides novel insights into differences in liver composition and function between ruminant species, as well as providing novel experimental models of the liver for both cattle and sheep.

Intervertebral disc (IVD) injury is a major cause of low-back pain and can lead to structural deficits and mechanical instability. When the IVD is compromised, neuromuscular compensation by paraspinal muscles, such as the multifidus (MF) and longissimus (ML), is critical for maintaining spine stability. However, it is unknown how IVD injury and its interaction with nociception affect neuromuscular control. This study assessed the effects of IVD injury and additional muscle-derived nociception on trunk motor control during locomotion in a rat model. IVD injury was induced via needle puncture at L4/L5. One week later, hypertonic saline was injected into the lumbar MF to induce nociception. Trunk and pelvic kinematics, bilateral EMG activity of MF and ML were recorded during treadmill locomotion at baseline, one week after IVD injury, and immediately following hypertonic saline injection. Trunk and pelvic kinematics and bilateral muscle activation patterns remained largely consistent across conditions. No significant changes were found in stride duration, pelvic, lumbar and spine angle changes, variability, or movement asymmetry. MF activation was bilaterally synchronized, whereas ML showed left-right alternating activation patterns. Following IVD injury, right MF mean activation and EMG variability increased significantly compared to baseline. When muscle-derived nociception was added in the unstable spine (IVD injury) condition, left MF minimum amplitude was significantly reduced, and instability-related increases in right MF mean activation and variability were attenuated, but not fully reversed. These findings suggest that IVD injury, alone or in combination with muscle-derived nociception, elicits localized neuromuscular adaptations without disrupting the global locomotor patterns.

Plantar tissue adaptation during activity is thought to contribute to diabetic foot ulceration (DFU), yet most existing studies only measure compressive quasi-static properties. This pilot study developed an ultrasound-loadcell measurement tool, PlantarSense, and used an infrared thermometer to measure dynamic compressive and shear energy dissipation ratio (EDR) and temperature of plantar-tissue at the first metatarsal head (1stMTH) and calcaneus in people living with and without diabetes at baseline, post-walk, and post-recovery. People living with diabetes showed significantly greater post-walk temperature increases (11.0 % vs 6.9% in controls at calcaneus, p=0.03) and less complete thermal recovery than controls. Baseline compressive EDR at the 1stMTH was significantly higher in people living with diabetes (67.8% vs 56.0% in controls, p=0.04). EDR modulation was greater from shear loading (21.5%) than compression (5.4%) and post-walk induced reductions in EDR were present in all participants, but people living with diabetes showed a 20% lower recovery than controls. Impaired thermoregulation and tissue adaptation in people living with diabetes was demonstrated by plantar temperature and EDR differences in post-walk and post-recovery. Future work is needed to test more participants with a greater range of diabetes progression to quantify statistically significant plantar tissue differences to inform DFU risk management.

BackgroundCarnitine plays an obligatory role in energetics owing to its role in the translocation of long-chain fatty acids into the mitochondrion for oxidation. Here, we determined the metabolic and behavioral consequences of systemic carnitine deficiency (SCD) in mice. MethodsFemale C57BL/6J mice were randomized to receive normal drinking water (control, n = 8) or drinking water supplemented with mildronate 4g.L-1 (mildronate, n = 8) for 21 days. Body composition was assessed at baseline and post treatment. Metabolic and behavioral phenotyping was performed continuously over 72 hours following 14 days of control or mildronate treatment. Stable isotope were used to assess whole-body substrate oxidation. Carnitine subfractions were quantified in skeletal muscle and liver, as was mitochondrial respiratory function. Liver and muscle samples also underwent proteomic analysis. ResultsMildronate treatment depleted total carnitine in muscle and liver by [~]97% (P < 0.001) and [~]90% (P < 0.001), respectively. Carnitine depletion was accompanied by lower total energy expenditure (P = 0.01), attributable to lower voluntary wheel running (P = 0.01). Oxidation rates of palmitate (P < 0.01) but not octanoate were lower whereas rates of glucose oxidation were greater in carnitine depleted mice (P < 0.01). Mitochondrial respiratory capacity was unaltered by carnitine deficiency. Carnitine deficiency remodeled muscle and liver proteomes to support lipid oxidation and energy production. SummaryIn mice, carnitine deficiency is characterized by decreased long-chain fatty acid oxidation despite preserved mitochondrial respiratory capacity. Carnitine deficiency resulted in lower voluntary exercise and a concomitant reduction in energy expenditure.

This study aimed to determine the impact of inborn metabolic fitness and early life exercise training on whole body and brown adipose tissue (BAT) energetics. We carried out comprehensive metabolic phenotyping on 4-week old rats bred for high (high-capacity runner, HCR) and low (low-capacity runner, LCR) running capacity following randomization to voluntary wheel running (VWR) or control (CRTL) for 6-weeks. High-resolution respirometry and untargeted proteomics were then employed to determine the impact of inborn fitness and early life exercise on BAT function. When accounting for differences in body mass, early life exercise (VWR) resulted in greater basal and total energy expenditure, irrespective of strain (P < 0.0001 for both). Both leak and uncoupling protein 1 (UCP1) dependent respiratory capacities in isolated BAT mitochondria were greater in rats randomized to VWR compared to CTRL in both HCR (P < 0.01) and LCR (P < 0.05) strains. Similarly, mitochondrial sensitivity to the UCP1 inhibitor GDP was greater in both HCR (P < 0.01) and LCR (P < 0.05) rats randomized to VWR versus control. The BAT proteome differed in CTRL HCR and LCR rats, were there was enrichment in proteins related to branched chain oxidation and mitochondrial fatty acid oxidation in HCR rats. VWR remodeled the BAT proteome, where 151 proteins were differentially expressed in LCR BAT and 209 differentially expressed in LCR BAT following VWR. In both stains, there was an enrichment in proteins related to metabolism mitochondrial function in response to VWR. However, when comparing strains, 39 proteins were differentially expressed in BAT in HCR rats compared to LCR rats in response to VWR. These proteins were related to carboxylic acid and amino acid metabolism. Collectively, inborn fitness impacts body mass and composition, exercise behaviors, and the BAT proteome in early life. Early life exercise alters whole body and BAT energetics irrespective of inborn fitness, augmenting basal and total energy expenditure and BAT thermogenic capacity and function.

The actin polymerization machinery, comprising the ARP2/3 complex and its activators, the WASP family proteins, has been implicated in regulating a broad spectrum of nuclear processes, such as transcriptional regulation and nuclear organization. Here, using clustered protocadherin (cPcdh) and {beta}-globin genes as model systems, we showed that WAVE2, a member of the WASP family, regulates chromatin organization by maintaining heterochromatin dynamics. Specifically, by CRISPR DNA-fragment editing, in conjunction with integrated analyses of ChIP-seq, MeDIP-seq, ATAC-seq, 4C-seq, and RNA-seq, we showed that deposition of H3K9me3, a key heterochromatin mark, is significantly decreased at the cPcdh locus upon WAVE2 deletion, concurrent with aberrant accumulation of CTCF/cohesin complex at promoter regions and spatial reorganization of chromatin architecture around nucleolus. In addition, REST/NRSF exerts a similar heterochromatindependent effect on the cPcdh locus. Finally, genetic and genomic data showed that WAVE2 regulates {beta}-globin gene expression by maintaining heterochromatin status. Together our data suggested that WAVE2 and REST/NRSF regulate clustered gene expression in a heterochromatin-dependent manner.

Intervertebral disc degeneration (IVDD) compromises disc structures and mechanics, yet systematic evaluations of the mechanical responses and their relationship to morphological changes in preclinical models remain limited. This systematic review and meta-analysis synthesized mechanical and morphological alterations following experimental disc injury in in vivo animal models. Searches of MEDLINE, EMBASE and Web of Science databases were conducted in accordance with PRISMA guidelines. Study quality and risk of bias were assessed using modified CAMARADES and SYRCLE tools. Twenty-eight studies were included. Pooled analyses showed significant reductions in stiffness, Youngs modulus, and disc height, and significant increases in range of motion and degeneration grade, indicating both mechanical and structural deterioration. Youngs modulus appeared to be the most sensitive marker of functional degeneration. By contrast, creep and other viscoelastic responses showed non-significant changes. High heterogeneity was evident across studies, reflecting variability in injury models, species, timepoints, and testing methods. Evidence of publication bias was detected in several domains, and moderate methodological quality was noted with overall insufficient blinding and lack of sample size calculations. In vivo animal models of IVDD demonstrate robust and consistent mechanical and morphological degeneration after injury. Youngs modulus is a sensitive mechanical indicator, supporting its use in future preclinical research. Standardization of outcome definitions, methodology, and reporting is essential to improve comparability and enhance translation of preclinical findings to clinical research.

ObjectiveTo evaluate the real-world effectiveness of Intact Fish Skin Graft (IFSG) compared with standard of care (SOC) in the treatment of Stage 3-4 pressure ulcers, using clinically meaningful outcomes including wound healing rate and percent area reduction (PAR). Materials and MethodsA retrospective matched cohort study was conducted using deidentified electronic health record (EHR) data from the U.S. Wound Registry. Patients with Stage 3-4 pressure ulcers treated with IFSG (n=40) were compared to a matched SOC control group (n=40). 1:1 covariate matching was performed to reduce confounding across key patient and wound characteristics, including age, mobility status, comorbidities (e.g., diabetes, peripheral artery disease), and wound features (age, size, location, and depth). Outcomes included healed status, healed or improved rate, and percent area reduction (PAR). ResultsThe study population represented a high-risk, real-world cohort (n=40 per group), with only 37.5% ambulatory patients and a high prevalence of multiple concurrent wounds. IFSG treatment demonstrated superior clinical outcomes compared to SOC: O_LIHealed or improved: 67.5% (IFSG) vs 55.0% (SOC) (p=0.0379) C_LIO_LIHealed: 45.5% (IFSG) vs 33.3% (SOC) C_LIO_LIPercent area reduction (PAR): 49% (IFSG) vs 34% (SOC) (p=0.0028) C_LI These findings indicate statistically significant improvements in percent area reduction and in the proportion of wounds that were healed or improved with IFSG. The proportion achieving complete healing was numerically higher with IFSG than with SOC, but this difference did not reach statistical significance. ConclusionIn this real-world matched cohort analysis, Intact Fish Skin Graft demonstrated superior effectiveness compared to standard of care in the management of Stage 3-4 pressure ulcers, with improvements in healing-related outcomes and percent area reduction. These results support the use of IFSG as an effective advanced therapy for hard-to-heal pressure ulcers.

Chronic wounds, such as diabetic and ischemic ulcers, involve impaired perfusion and delayed healing. TOP-N53 is a novel bifunctional molecule combining nitric oxide (NO) release with phosphodiesterase-5 (PDE5) inhibition to enhance local NO-cGMP signalling, resulting in vasodilation and angiogenesis. This first-in-human, randomized, double-blind, vehicle-controlled Phase I trial assessed the safety, tolerability, pharmacokinetics (PK), and pharmacodynamics (PD) of single subcutaneous TOP-N53 doses in 29 healthy male volunteers. Each participant received injections of TOP-N53 and vehicle in the same forearm, but either at the proximal or at the distal site in an intra-individually blinded manner. Safety assessments included local and systemic parameters. PK and PD responses were evaluated by analysis of TOPN53 and its bioactivation metabolite TOP-52 in plasma, and by Laser Speckle Contrast Imaging (LSCI), a non-invasive method to measure skin perfusion, respectively. TOP-N53 was safe and well tolerated, with no serious adverse events or local or systemic adverse reactions. Plasma concentrations remained below the quantification limit and LSCI showed sustained dose-dependent increases in local skin perfusion at doses of 4.84 ug and 9.075 ug TOP-N53 SC for up to 24 h post injection when compared to vehicle. These findings support the favourable safety and tolerability profile of TOP-N53 associated with locally improved skin perfusion, encouraging its further clinical development as a topical treatment for chronic wounds with microvascular dysfunction.

Abstract Objective: The objective of this study was to compare hospital length of stay and other clinical outcomes between intact fish skin graft (IFSG; Graftguide, Kerecis, Arlington, VA) and synthetic/biosynthetic dermal substitutes (SSS; Integra Dermal Regeneration Template and NovoSorb Biodegradable Temporizing Matrix) in propensity score matched burn patients using the American Burn Association Burn Care Quality Platform. Methods: This retrospective cohort study identified adult patients treated with a single dermal substitute product during hospitalization for acute burn injury. Patients receiving IFSG (n = 93) were matched 1:4 to patients receiving SSS (n = 372) using nearest neighbor propensity score matching on the logit scale. Matching covariates included total body surface area burned (TBSA), patient age, sex), burn severity classification, inhalation injury, and trauma diagnosis. The primary outcome was hospital length of stay (LOS), analyzed using a gamma generalized linear mixed model (GLMM). Secondary outcomes included the incidences of sepsis, graft loss, venous thromboembolism (VTE), and hospital acquired pressure injury (HAPI). A prespecified sensitivity analysis was performed using a broader mixed product cohort. Results: A total of 93 IFSG treated patients from 17 burn centers admitted between the years 2019 and 2025 were matched 1:4 to 372 SSS treated patients from 44 centers. Unadjusted mean LOS was 24.1 days (median 20, IQR 11 to 32) in the IFSG treated group and 36.7 days (median 31, IQR 17 to 52) in the SSS treated group representing a 12.6 day reduction. GLMM-adjusted estimated marginal mean LOS was 24.2 days (95% CI, 20.0 to 29.4) for IFSG versus 33.5 days (95% CI, 30.0 to 37.6) for SSS (ratio 0.723; p = 0.00245), representing a 9.3 day reduction. Sepsis (1.1% vs 4.6%), graft loss (3.2% vs 8.3%), VTE (2.2% vs 2.7%), and HAPI (2.2% vs 3.8%) were all numerically lower in the IFSG treated arm; although GLMM-adjusted odds ratios were not statistically significant for any individual complication. The mixed cohort sensitivity analysis (n = 229 IFSG vs 458 SSS across 67 centers) confirmed the primary finding with GLMM adjusted LOS ratio 0.716 (p = 0.0001). Conclusions: In this propensity score matched analysis of the ABA registry, IFSG was associated with a statistically significant and clinically meaningful reduction in hospital length of stay compared with synthetic/biosynthetic dermal substitutes, in requiring dermal substitution and autografting, with all complication rates, sepsis, graft loss, VTE, and HAPI, numerically lower in the IFSG-treated arm. The shorter hospitalization was not achieved at the expense of safety. These findings support IFSG as a viable alternative to synthetic dermal substitutes in burns requiring dermal substitution and autografting. Prospective studies are warranted particularly in larger burns requiring staged reconstruction.

Immunohistochemistry (IHC) is widely used to assess protein expression in corneal tissue, yet staining outcomes are strongly influenced by tissue preparation methods and regional differences within the cornea. This study aimed to systematically compare three preparation techniques including paraffin (wax) embedding, wax embedding with antigen retrieval (wax AR), and cryosectioning for IHC analysis in embryonic day 18 chicken corneal tissue. Markers representing key biological functions were evaluated, including progenitor activity (PAX6, P40), tissue architecture (actin), and immune surveillance (TAP1, CD68), across central and limbal regions. Cryosectioning consistently produced the most specific staining for nuclear and antigen-sensitive markers. PAX6 and P40 exhibited strong, nuclear-localized expression in the corneal epithelium only under cryo conditions, whereas wax-based methods resulted in reduced specificity and irregular signal distribution. TAP1-positive immune cells were detectable in the limbal stroma exclusively in cryosections, highlighting improved antigen preservation. In contrast, actin staining, was best preserved with wax AR, and provided superior structural clarity and expected expression patterns across corneal layers. CD68 showed minimal or inconsistent staining in corneal tissue across all methods despite positive control validation. These findings demonstrate that optimal IHC outcomes in corneal tissue are marker-dependent and influenced by preparation methods and regional tissue context. Cryosectioning is recommended for detecting nuclear and immune-related antigens, while wax AR is preferable for preserving tissue architecture. This study provides a practical framework for improving reproducibility and interpretation of corneal immunostaining in avian models.

BackgroundIdiopathic pulmonary fibrosis (IPF) is a progressive and fatal lung disease characterized by aberrantly activated, apoptosis-resistant profibrotic lung (myo)fibroblasts. Prior research has demonstrated that lung fibroblasts from patients with IPF exhibit resistance to DNA damage, suggesting that this behavior contributes to their persistent survival and continuous proliferation. We propose that elevated levels of the DNA damage repair protein RAD51 regulate myofibroblast activation and apoptosis and provide a potential therapeutic target to impede fibrosis progression. MethodsHuman lung fibroblasts were transfected with siRNA against RAD51 or treated with RAD51-specific inhibitor B02 and markers of fibrosis, DNA damage, apoptosis, metabolic reprogramming, and mitochondrial dynamics were assessed. The preclinical efficacy of B02 was evaluated in human precision cut lung slices (PCLS) and in a mouse model of pulmonary fibrosis. FindingsRAD51 expression was significantly upregulated in the lungs and lung fibroblasts of IPF patients. Knockdown or inhibition of RAD51 in fibroblasts reduced profibrotic marker expression, suppressed mTORC1 signaling and mitochondrial function, and increased apoptosis susceptibility. Pharmacological inhibition of RAD51 shifted the profibrotic phenotype towards a fibrosis-resolving state in human and mouse PCLS, and in a bleomycin-induced mouse model of lung fibrosis. InterpretationThe inhibition of RAD51 exerts therapeutic benefits in lung fibrosis by promoting apoptosis. Our findings identify that inhibiting RAD51 with B02 in fibroblasts impairs DNA repair and induces metabolic reprogramming, making it a potential therapeutic target. Research in contextO_ST_ABSEvidence before this studyC_ST_ABSPulmonary fibrosis (PF) is characterized by excessive fibroblast activation and subsequent deposition of extracellular matrix (ECM) proteins, which ultimately disrupt normal lung architecture. A significant contributing factor to the pathogenesis of pulmonary fibrosis is the presence of fibroblasts that are resistant to apoptosis, preventing normal wound healing. Recent studies highlight the DNA repair protein RAD51 as effective in protecting fibroblasts from death induced by chemotherapy and ionizing radiation. These finding suggested that RAD51 could have a role in fibroblast activation and apoptosis resistance in pulmonary fibrosis. Added value of this studyWe demonstrated that RAD51 is important for maintaining apoptosis-resistant fibrotic fibroblasts and their metabolic abnormalities. Our findings indicated that TGF{beta}-mediated upregulation of RAD51 reduces DNA damage, activates multiple pathways related to fibroblast activation and proliferation, and induces metabolic reprogramming, ultimately regulating apoptosis. Mechanistically, RAD51 inhibition enhanced p53 acetylation at lysine 120 and upregulated the expression proapoptotic proteins PUMA/BAK in mitochondria, promoting apoptosis. Pharmacological inhibition of RAD51 using the specific inhibitor B02 during the fibrotic phase of experimental lung disease effectively ameliorated pulmonary fibrosis. Implications of all the available evidenceOur findings establish that RAD51 plays an important role in the survival of apoptosis-resistant fibrotic fibroblasts. We propose that reducing RAD51 expression leads to the metabolic reprogramming of activated fibroblasts, resulting in decreased mitochondrial respiration, reduced ATP levels, and diminished glycolysis or glutaminolysis. These observations suggest that targeting energy metabolism through RAD51 inhibition could be a viable strategy to enhance apoptosis, thereby creating a therapeutically targetable pathway in fibrotic cells. These findings highlight the potential of RAD51 as a therapeutic target for the treatment of IPF.

Background & AimsMetabolic disorders such as dyslipidemia, metabolic dysfunction-associated steatotic liver disease (MASLD), and diabetes are promoted by chronic pro-inflammatory and pro-oxidative states. Paraoxonase 1 (PON1), a liver-derived HDL-associated enzyme, plays an important antioxidant role by hydrolyzing oxidized lipids and protecting against oxidative stress- induced damage. Genetic variation in PON1, particularly in promoter and coding regions, modulates enzyme expression and activity, thereby influencing susceptibility to metabolic and cardiovascular diseases. This study investigated the genetic determinants of serum paraoxonase (PONase) activity and their relationship with dysmetabolic phenotypes. MethodsA genome-wide association study was conducted in 922 Portuguese individuals from the PREVADIAB2 cohort. Genetic variants and haplotypes related to PONase activity were analyzed, and associations with dysglycemia and liver fibrosis were evaluated in individuals aged over 55 years. ResultsWe identified two key PON1 variants as determinants of PONase activity: rs2057681 (in strong linkage disequilibrium with the non-synonymous Q192R variant) and rs854572 (located in the promoter region). Analysis of rs854572-rs2057681 haplotypes revealed that specific combinations differentially modulate PONase activity and confer risk or protection for dysglycemia and liver fibrosis, depending on the rs2057681 genotype context. Notably, although PONase activity was strongly associated with PON1 variants, it did not directly correlate with dysmetabolic phenotypes, suggesting that genetic context and haplotype structure, rather than enzyme activity alone, shape disease susceptibility. ConclusionsThese findings highlight the complex genetic architecture of PON1 and its role in metabolic disease risk, supporting the use of PON1 genetic information to uncover predisposition to dysmetabolic conditions. Our results provide insights into the interplay between PON1 genetics, enzyme function, and dysmetabolism, with implications for risk stratification in metabolic liver disease. Lay SummaryPON1 is a liver-derived gene that encodes an enzyme involved in protection against oxidative stress, a key contributor to metabolic liver disease and diabetes. In this study, we found that specific combinations of PON1 genetic variants are associated with abnormalities in blood glucose regulation and with markers of liver fibrosis. These associations were dependent on genetic configuration rather than enzyme activity alone, suggesting that PON1 genetic information may help identify individuals at higher risk of metabolic liver disease.

The Ube2J1 enzyme that mediates the ubiquitination and proteasomal degradation of misfolded proteins at the ER is phosphorylated at serine S184. Following anisomycin treatment of HEK293T cells, we observed an inverse relationship between phosphorylation and dephosphorylation at this site. This suggested a dynamic interchange between the two forms, and we show that S184 is a target for protein phosphatase 2A. The S184-phosphorylated protein is known to exhibit increased sensitivity to proteasomal degradation, and we found that mutation at K186R increased the ratio of S184-phosphorylated to S184-dephosphorylated protein. Although the K186R mutant retained some sensitivity to proteasomal inhibition, our results show that Ube2J1 steady state expression can be exercised at multiple levels, and can involve dynamic phosphorylation and dephosphorylation at S184.