The FASEB Journal

Whole-body estrogen receptor (ER) knockout mice develop hepatic steatosis; however, liver-specific ER knockout (LERKO) mice fail to recapitulate this susceptibility and maintain normal hepatic mitochondrial function. However, estrogen-mediated protection against hepatic steatosis is lost in LERKO mice following ovariectomy (OVX). Here, we tested whether loss of hepatic ER blunts estrogen modulation of hepatic mitochondrial respiratory capacity and mitochondrial proteome following ovariectomy (OVX). Sham or ovariectomy (OVX) surgery was performed in middle-aged female mice (36-40 weeks), followed by AAV injection to generate Control (Con; GFP) or LERKO mice (Cre). All mice were placed on a high-fat diet (HFD) for 10 weeks following surgery. Half of the OVX mice received 17-beta estradiol (E2) replacement (OVX+E2) for the last 4 weeks of HFD. OVX mice had greater body mass and adiposity, which was reversed by E2 replacement in both Con and LERKO mice. While E2 replacement reduced steatosis in both Con and LERKO OVX mice, the LERKO OVX mice maintained greater hepatic triglyceride content. E2 replacement promoted greater basal and ADP-stimulated (State 3) mitochondrial respiration in Con OVX but not in LERKO OVX mice under palmitate-supported conditions. Changes in mitochondrial respiration could not be attributed to altered responses to changes in energy demand (GATP) or to alterations in mitochondrial H2O2 production. Conversely, maximal coupled branched-chain amino acid-supported respiration was universally suppressed by E2 replacement. Proteomics analysis revealed E2-mediated reductions in hepatic mitochondrial energy transduction, with relatively minimal differences between Con and LERKO mice. In conclusion, post-ovariectomy estrogen treatment reduces steatosis in the absence of hepatic ER; however, triglyceride levels remain higher, and mitochondrial respiratory deficits persist despite similar proteomic signatures, suggesting that ER signaling is required for optimal estrogen hepatic responsiveness.

Cancer and inflammation are associated with vascular diseases that affect endothelial cells (ECs) and alter gene expression. We aimed at understanding whether the site Y685 in the cytoplasmic domain of VE-cadherin triggers epigenetic programming in vivo. Using our knock-in mice carrying the Y685F VE-cadherin mutation, RNA sequencing from lung ECs identified 884 differentially expressed genes (DEG) involved in processes such as cell-cell adhesion, vascular development, and angiogenesis. The 30 DEGs include 22 down-regulated genes (genes encoding cell signalling enzymes, anion transport and lipid metabolism) and 8 up-regulated genes, including the endothelial-specific S1PR1. Analysis of the VEGF/VEGFR2 signaling pathway shows a significant decrease in the expression of pY1173VEGFR2 whereas VEGF remains constant, this was consistent with impaired migration, proliferation and protrusive properties of ECs in vitro. Co-immunoprecipitation experiments showed that c-Src and Y685F-VE-cadherin association which was enhanced in KI compared to WT, resulting in increased in Y685F-VE-cadherin phosphorylation at site Y731. As a consequence, its partner {beta}-catenin translocates to the nucleus. CHIPS assay showed that FOXF1 binds to the s1pr1 promoter, leading to increased expression of the S1PR1. In vivo, in the lung vasculature, this process was associated with increased vessel wall thickness and reduced fibrosis. Overall, our findings provide a novel transcriptomic profile triggered by Y685F-VE-cadherin ECs for potential insights into therapeutic targets to envisage normalisation of the tumor vasculature.

Acute tendon injuries are characterized by excessive matrix deposition that impedes regeneration and disrupts functional improvements. Inflammation is postulated to drive pathologic scar tissue formation, with nuclear factor kappa B (NF-{kappa}B) signaling emerging as a candidate pathway in this process. However, characterization of the spatial and temporal activation of canonical NF-{kappa}B signaling during tendon healing in vivo, including identification of the cell populations activating NF-{kappa}B, is currently unexplored. Therefore, we aimed to determine which cell populations activate canonical NF-{kappa}B signaling following flexor tendon repair with the goal of delineating cell-specific functions of NF-{kappa}B signaling during scar mediated tendon healing. Immunofluorescence revealed that both tendon cells and myofibroblasts exhibit prolonged activation of canonical NF-{kappa}B signaling into the remodeling phase of healing. Using cre-mediated knockout of the canonical NF-{kappa}B kinase (IKK{beta}), we discovered that suppression of canonical NF-{kappa}B signaling in Scleraxis-lineage cells increased myofibroblast content and scar tissue formation. Interestingly, Scleraxis-lineage specific knockout of IKK{beta} increased the incidence of apoptosis, suggesting that canonical NF-{kappa}B signaling may be mediating cell survival during tendon healing. These findings suggest indispensable roles for canonical NF-{kappa}B signaling during flexor tendon healing. One Sentence SummaryScleraxis-lineage specific knockdown of persistent canonical IKK{beta}/NF-{kappa}B drives scar formation and apoptotic signaling during flexor tendon healing.

Obesity and type II Diabetes Mellitus (T2DM) have substantial pathological effects on tendon homeostasis, including loss of collagen organization and increased risk of tendon rupture. Moreover, following rupture or acute injury, the healing process is impaired by T2DM. We have previously demonstrating that restoring normal metabolic function in a murine model of obesity/ T2DM is insufficient to blunt or reverse the progression of diabetic tendinopathy, indicating the need for identification of novel therapeutic approaches to both maintain tendon homeostasis, and to improve the healing process. RAGE, the Receptor for Advanced Glycation Endproducts has been implicated as a key driver of several diabetic pathologies. We have demonstrated that pharmacological antagonism of RAGE is sufficient to partially improve tendon healing in non-diabetic animals. Therefore, in the current study we tested the efficacy of blunted RAGE signaling, via treatment with a RAGE Antagonist Peptide (RAP), to improve tendon healing in the context of T2DM. While our study did not find a beneficial effect of short-term RAP treatment on the healing process of T2DM mice, we did identify several important challenges brought about by this model of diet-induced obesity and T2DM. Both high fat (HFD) and low fat diet (LFD) feeding shifted the temporal molecular profile of healing compared to standard laboratory chow fed mice. Moreover, RAP treatment resulted in a transient disruption in homeostasis in the contralateral control tendons of both HFD and LFD mice, and this was due to a potential interaction with the systemic response to tendon injury as this response was not observed in HFD and LFD fed mice that did not undergo tendon repair surgery. Collectively, these data highlight the complications associated with models of diet induced obesity, and the lean control diets that should be considered in future studies.

Barth Syndrome (BTHS) is a rare X-linked genetic disorder caused by mutations in tafazzin and characterized by loss of cardiolipin and severe cardiomyopathy. Mitochondrial superoxide/H2O2 production has been implicated in the cardiomyopathy observed in different BTHS models. There are at least 11 mitochondrial sites that produce superoxide/H2O2 at significant rates. Which of these sites generate oxidants at excessive rates in BTHS is unknown. Here, we measured the maximum capacity of superoxide/H2O2 production from each site in mitochondria isolated from heart and skeletal muscle of the tafazzin knockdown mice (tazkd) at 3, 7 and 12 months of age. Strikingly, the superoxide/H2O2 production capacities of these sites were overall indistinguishable between tazkd mice and their wildtype littermates across the time points analyzed. The only exception was site GQ in glycerol phosphate dehydrogenase, which was increased in the skeletal muscle of 7 months old tazkd mice. Mitochondrial superoxide/H2O2 production was also measured ex vivo during the oxidation of a complex mixture of substrates mimicking either heart or skeletal muscle cytosol and was found to be indistinguishable between wildtype and tazkd mice. However, we consistently measured decreased FAD-linked respiration in mitochondria isolated from tazkd mice. We conclude that the maximum capacity and ex vivo rates of superoxide/H2O2 production were not increased in mitochondria isolated from heart and skeletal muscle of tazkd mice, despite reduced oxidative capacity. Therefore, it seems unlikely that mitochondrial oxidants contribute to the development of cardiomyopathy in tazkd mice. These observations raise questions about the involvement of mitochondrial oxidants in BTHS pathology.

BackgroundBile acids (BAs), which act in the liver-brain axis, are liver-derived signaling molecules found in the brain. However, how they modulate neurological function remains largely unknown. MethodsTo assess the role of BAs in the brain, we generated mice with absent 12-hydroxylase (Cyp8b1), a BA synthesis enzyme, and determined if brain BA levels were altered in these mice, and if and how this may modulate neuronal function. ResultsThe absence of CYP8B1 increased brain levels of the primary BA chenodeoxycholic acid (CDCA), and decreased ischemic stroke infarct area. Furthermore, CDCA administration reduced ischemic stroke lesion area in wild-type mice. Excitotoxicity due to elevated extra-cellular glutamate contributes to neuronal death in ischemic stroke. Neurons from Cyp8b1-/- mice showed reduced susceptibility to glutamate-induced toxicity, and exogenous CDCA reduced glutamate-induced toxicity in neurons from wild-type mice. These data suggest that CDCA-mediated decreases in excitotoxic neuronal death contributes to the reduced stroke lesion area in Cyp8b1-/- mice. Aberrant N-methyl-D-aspartate receptor (NMDAR) over-activation contributes to excitotoxicity. CDCA decreased NMDAR-mediated excitatory post-synaptic currents (EPSCs) in wild-type brain slices, by reducing over-activation of the NMDAR subunit GluN2B. In line with this, synaptic NMDAR activity was also decreased in Cyp8b1-/- brain slices. Expression level and synaptic distribution of GluN2B were unaltered in Cyp8b1-/- mice, suggesting that CDCA may directly antagonize GluN2B-containing NMDARs. ConclusionsOur data suggests that CDCA acts in the liver-brain axis and decreases the aberrant over-activation of neuronal GluN2B-containing NMDARs, contributing to neuroprotection.

There is limited understanding of how mechanical signals regulate tendon development. The nucleus has emerged as a major regulator of cellular mechanosensation, via the linker of nucleoskeleton and cytoskeleton (LINC) protein complex. Specific roles of LINC in tenogenesis have not been explored. In this study, we investigate how LINC regulates tendon development by disabling LINC-mediated mechanosensing via dominant negative (dn) expression of the Klarsicht, ANC-1, and Syne Homology (KASH) domain, which is necessary for LINC to function. We hypothesized that LINC regulates mechanotransduction in developing tendon, and that disabling LINC would impact tendon mechanical properties and structure in a mouse model of dnKASH. We used Achilles (AT) and tail (TT) tendons as representative energy-storing and limb-positioning tendons, respectively. Mechanical testing at postnatal day 10 showed that disabling the LINC complex via dnKASH significantly impacted tendon mechanical properties and cross-sectional area, and that effects differed between ATs and TTs. Collagen crimp distance was also impacted in dnKASH tendons, and was significantly decreased in ATs, and increased in TTs. Overall, we show that disruption to the LINC complex specifically impacts tendon mechanics and collagen crimp structure, with unique responses between an energy-storing and limb-positioning tendon. This suggests that nuclear mechanotransduction through LINC plays a role in regulating tendon formation during neonatal development.

Withdrawal StatementThe authors have withdrawn their manuscript owing to erroneous labeling in two figures that have recently come to light. Experiments aiming to confirm the data presented are underway. Therefore, the authors do not wish this work to be cited as reference for the project. If you have any questions, please contact the corresponding author.

Following anabolic stimuli (e.g. mechanical loading and/or amino acid provision) the mechanistic target of rapamycin complex 1 (mTORC1), a master regulator of protein synthesis, translocates toward the cell periphery. However, it is unknown if mTORC1 activity occurs prior to or following this translocation. We therefore aimed to determine the cellular location of mTORC1 activity in human skeletal muscle following anabolic stimuli. Fourteen young, healthy males either ingested a protein-carbohydrate beverage (0.25g/kg protein, 0.75g/kg carbohydrate) alone (n=7, 23{+/-}5yrs, 76.8{+/-}3.6kg, 13.6{+/-}3.8%BF, FED) or following a whole-body resistance exercise bout (n=7, 22{+/-}2yrs, 78.1{+/-}3.6kg, 12.2{+/-}4.9%BF, EXFED). Vastus lateralis muscle biopsies were obtained at rest (PRE) and 120 and 300min following anabolic stimuli. The spatial regulation of mTORC1 activity was assessed through immunofluorescent staining of p-RPS6Ser240/244, an mTORC1-specific phosphorylation event. p-RPS6Ser240/244 measured by immunofluorescent staining or immunoblot was positively correlated (r=0.76, p<0.001). Peripheral staining intensity of p-RPS6Ser240/244 increased above PRE in both FED and EXFED at 120min (~54% and ~138% respectively, p<0.05) but was greater in EXFED at both post-stimuli time points (p<0.05). The peripheral-central ratio of p-RPS6240/244 staining was displayed a similar pattern, suggesting mTORC1 activity occurs predominantly in the periphery of fibers. Moreover, p-RPS6Ser240/244 intensity within paxillin-positive regions, a marker of focal adhesion complexes, was elevated at 120min irrespective of stimulus (p=0.006) before returning to PRE at 300min. These data confirm that mTORC1 activity occurs in the region of human muscle fibers to which mTORC1 translocates following anabolic stimuli and identifies focal adhesion complexes as a potential site of mTORC1 activation in vivo.

The keratin cytoskeleton and associated desmosomes contribute to the mechanical stability of epithelial tissues, but their organization in bladder umbrella cells and their responses to bladder filling are poorly understood. Using super-resolution confocal microscopy, along with 3D image reconstruction and platinum replica electron microscopy, we observed that the apical keratin network of umbrella cells was organized as a dense tile-like mesh comprised of tesserae bordered on their edges by cortical actin filaments, filled with woven keratin filaments, and crosslinked by plectin. A band of keratin was also observed at the cell periphery that was linked to the junction-associated actin ring by plectin. During bladder filling, the junction-localized desmosomal necklace expanded, and a subjacent girded layer was formed that linked the keratin network to desmosomes, including those at the umbrella cell-intermediate cell interface. Disruption of plectin led to focal keratin network dissolution, loss of the junction-associated band of keratin, perturbation of tight junction continuity, and loss of cell-cell cohesion. Our studies reveal a novel tile-like organization of the umbrella cell keratin cytoskeleton that is dependent on plectin, that reorganizes in response to bladder filling, and that likely serves to maintain umbrella cell continuity in the face of mechanical distension.

RationalePhosphorylation-dephosphorylation are processes involved in the adhesion of endothelial cells (ECs) to maintain vascular integrity in adults. VE-cadherin is a target for Src-mediated Y685 phosphorylation, identified in highly vascularized human glioblastoma where it is involved in the abnormal feature of tumor blood vessels. ObjectiveWe aimed at understanding the molecular mechanisms through which Y685F-VE-cadherin triggers S1PR1 gene expression and stabilizes lung vessels in adult mice. Methods and ResultsWe compared lung ECs from a knock-in (KI) mouse carrying a point mutation in VE-cadherin (Tyr 685 to Phe) to Wild type. Analysis of EC parameters showed a difference in the migratory rate was between ECs from KI (22.45% {+/-} 5.207) and WT (13.24% {+/-} 5.17) (p-value=0.034). The direct adhesion of ECs from KI mice to fibronectin was significantly higher (37.625 {+/-} 9.23) than that of the WT (26.8 {+/-} 3.258, p-value=0.012). In the fibrin bead assay, ECs from KI showed a weaker angiogenic response. The transcriptome of mutated ECs showed that 884 genes were dysregulated of which 766 genes were downregulated and 118 genes were upregulated. The Gene Ontology Enrichment showed that most of the genes were related to cell-cell adhesion and angiogenesis. Focusing on angiogenic genes, we found that Sphingosine-1-phosphate-receptor was a gene upregulated in mutated ECs which was confirmed by RT-PCR and westernblotting. Mechanistically, chromatin immunoprecipitation assay (CHIPS) demonstrated that FOXF1 directly bound to the S1pr1 promoter 7 fold greater than WT. As a consequence, VE-cadherin at the membrane was higher in the mutant vs WT (100 {+/-} 6.52 for WT vs 189.7 {+/-} 21.06 for KI (p-value 0.0001). Finally, lung morphometric analysis showed less vessels and vascular remodeling with no fibrosis in mutated mice. ConclusionsThese data extend our knowledge on pY-VE-cadherin mediated pathological angiogenesis and provide new therapeutic opportunities to vascular normalization through pharmacological inhibition of the Y685-VE-cadherin phosphorylation.

The expression levels of aftiphilin (AFTPH) are significantly lower in inflamed colonic tissues from patients with ulcerative colitis (UC) and mice with experimental colitis. During colonic inflammation, the selective permeability of the colonic epithelium is compromised largely due to dysregulation of proteins associated with either the tight junction (TJ) complex and actin-myosin contraction rings. Here, we hypothesized that inflammation-associated reduction in AFTPH levels might cause an increase in the selective permeability of the colonic epithelium. In this study, we measured the transepithelial electric resistance (TEER), sodium (Na+) ion flux and dextran permeability in polarized colonic epithelial cells after manipulation of AFTPH. Silencing of AFTPH reduced TEER, increased Na+ ion flow and dextran permeability. Examination of mRNA and protein levels of multiple TJ proteins and Na+ ion transporters suggested that AFTPH deficiency did not significantly change expression of most of these transmembrane proteins. While the gross structure of the TJs in AFTPH gene-silenced cells appeared normal, elevated levels of junctional Occludin were observed. Most notably we observed that AFTPH co-localized with myosin light chain kinase (MLCK) and attenuated cellular MLCK activity as observed by phospho-myosin light chain 2 (pMLC2) western blots. Importantly, inhibition of MLCK activity reversed the reduction of TEER in AFTPH-deficient monolayers. Lastly, examination on transmission electron microcopy on microvilli and immunofluorescent microscopy on actin filament arrangement showed that AFTPH deficiency also affected filament arrangement in colonic epithelial cells. Taken together, these results suggest that AFTPH regulates intestinal epithelial permeability and actin polymerization in colonic epithelium through interfering MLCK/MLC interactions.

Desminopathy the most common intermediate filament disease in humans. Desmin is an essential part of the filamentous network that aligns myofibrils, anchors nuclei and mitochondria, and connects the z-discs and the sarcolemma. We created a rat model with a mutation in R349P DES, analog to the most frequent R350P DES missense mutation in humans. To examine the effects of a chronic, physiological exercise stimulus on desminopathic muscle, we subjected R349P DES rats and their wildtype (WT) and heterozygous littermates to a treadmill running regime. We saw significantly lower running capacity in DES rats that worsened over the course of the study. We found indicators of increased autophagic and proteasome activity with running in DES compared to WT. Stable isotope labeling and LC-MS analysis displayed distinct adaptations of the proteomes of WT and DES animals at baseline as well as with exercise: While key proteins of glycolysis, mitochondria and thick filaments increased their synthetic activity with running in WT, these proteins were higher at baseline in DES and did not change with running. The results suggest an impairment in adaption to chronic exercise in DES muscle and a subsequent exacerbation in the functional and histopathological phenotype.

Tendons are composed of a heterogeneous cell environment, with Scleraxis-lineage (ScxLin) cells being the predominant population. Although ScxLin cells are required for maintenance of tendon homeostasis, their functions during tendon healing are unknown. To this end, we first characterized the spatiotemporal dynamics of ScxLin cells during tendon healing, and identified that the overall ScxLin pool continuously expands up to early remodeling healing phase. To better define the function of ScxLin cells during the late proliferative phase of healing, we inducibly depleted ScxLin cells from day 14-18 post-surgery using the Scx-Cre; Rosa-DTR mouse model, with local administration of diphtheria toxin inducing apoptosis of ScxLin cells in the healing tendon. At D28 post-surgery, ScxLin cell depleted tendons (DTR) had substantial impairments in structure and function, relative to WT, demonstrating the importance of ScxLin cells during tendon healing. Next, bulk RNAseq was utilized to identify the underlying mechanisms that were impaired with depletion and revealed that ScxLin depletion induced molecular and morphological stagnation of the healing process at D28. However, this stagnation was transient, such that by D56 tendon mechanics in DTR were not significantly different than wildtype repairs. Collectively, these data offer fundamental knowledge on the dynamics and roles of ScxLin cells during tendon healing.

Epithelial cells lining the lumen of organs have an apical-basal polarity, and mechanical cell contacts are located in the lateral and basal regions. During early pregnancy in rodents, the luminal space of the uterus is closed, and opposing epithelial cells attach to each other at apical-apical surfaces. Here, we show that cells are mechanically coupled at the apical cell-cell contacts. The apical plasma membrane was intricately intertwined between opposing cells. Extracellular matrix and tight junction molecules were localized at apical contacts. Claudin inhibition resulted in impaired luminal closure, suggesting a functional requirement of claudins for the establishment of transapical coupling. The present results demonstrate a mechanical cell-cell interaction that occurs between apical-apical surfaces in addition to lateral and basal cell junctions. One Sentence SummariesTransapical coupling of epithelial cells mediated by extracellular matrix and tight junction molecules

ObjectiveHydrogen sulfide (H2S) is a proangiogenic gas produced primarily by the transsulfuration enzyme cystathionine-gamma-lyase (CGL). CGL-dependant H2S production is required for neovasculariation in models of peripheral arterial disease. However, the benefits of increasing endogenous CGL and its mechanism of action have yet to be elucidated. Methods10 weeks old male whole-body CGL overexpressing mice (CGLTg) and wild type littermates (C57BL/6J) were subjected to the hindlimb ischemia model. Functional recovery was assessed through treadmill exercise endurance testing, while ischemic leg perfusion recovery was measured by laser Doppler perfusion imaging and tissue immunohistochemistry. To examine angiogenic potential, aortic ring sprouting assay and post-natal mouse retinal vasculature development studies were performed. Lastly, comparative metabolomics, NAD+/NADH analysis, and quantitative real-time PCR were performed on WT and CGLTg gastrocnemius muscles. ResultsThe restoration of blood flow upon femoral ligation occurred more rapidly in CGLTg mice. CGLTg mice were able to run further and for longer compared to WT mice. In ischemic gastrocnemius, capillary density was increased in mice overexpressing CGL. Endothelial cell sprouting was increased in aorta isolated from CGLTg mice, especially when cultured in VEGF-only media. Metabolomics analysis demonstrated an increased presence of niacinamide, a precursor of nicotinamide adenine dinucleotide (NAD+/ NADH) in the muscle of CGLTg mice. Finally, CGL overexpression and NMN supplementation improved endothelial cell migration in vitro. ConclusionsTaken together, our results demonstrate that CGL overexpression improves the neovascularization of skeletal muscle upon hindlimb ischemia. These effects are mediated by changes in the NAD pathway, which improves endothelial cell migration.

Exercise is generally beneficial for health but strenuous exercise can have detrimental effects on the gastrointestinal tract. The combination of ischemia and heat shock during exercise is a crucial contributor to intestinal epithelial damage. Growing evidence points towards an important regulatory role of gut microbes in intestinal homeostasis. Here, we characterize and compare the effects of moderate and vigorous exercise training on intestinal epithelial damage, stress response, inflammatory response, and gut microbiota alterations in mice and investigate the mechanisms underlying exercise-induced intestinal injury. Exercise training for six weeks caused heat stress in the intestine, resulting in the disruption of the intestinal epithelial barrier and local inflammation. This was characterized by increased colonic HSP-70 and HSF-1 protein expression, increased epithelial permeability, decreased colonic expression of tight junction proteins ZO-1 and occludin and intestinal morphological changes. Daily moderate exercise training caused hereby more severe injury than vigorous training on alternating days. Furthermore, exercise training altered the gut microbiota profile. The abundance of Lactobacillaceae was reduced, potentially contributing to the deteriorated intestinal status, while the abundance of short-chain fatty acid-producing Lachnospiraceae was increased, especially following vigorous training. This increase in short-chain fatty acid-producing bacteria following vigorous training possibly counteracted the impairment of the intestinal barrier function. In summary, exercise disrupts the intestinal barrier function, with vigorous exercise training with intermittent rest days being less damaging than daily moderate exercise training.

Seminolipids are testis-specific ether glycolipids that are important for spermatogenesis. The fatty alcohol (ether-linked alkyl moiety) in ether lipids is generated from an acyl-CoA by fatty acyl-CoA reductase (FAR). To date, the diversity of the alkyl and acyl moieties in seminolipids, the specific stage of spermatogenesis during which seminolipids are produced, and the FAR isozyme (FAR1 or FAR2) involved in the synthesis of the alkyl moieties have remained largely unclear. Here, we demonstrated that Far1 is expressed in the mouse testis via quantitative RT-PCR analysis, whereas Far2 was barely detectable. In situ hybridization and quantitative RT-PCR analysis of spermatogenic cells separated via FACS revealed that Far1 is expressed in spermatogonia, spermatocytes, and spermatids. We generated Far1 knockout (KO) mice and found that male Far1 KO mice were infertile. In these mice, sperms were absent in the epididymides and the testes were small, with multinucleated cells and vacuoles in the seminiferous tubules. LC-MS/MS analysis showed that the vast majority of seminolipids (> 90%) in wild-type mouse testes contained C16:0 in both the alkyl and the acyl moieties. Seminolipids were present in all subclasses of spermatogenic cells in wild-type mice, but they were absent in Far1 KO mice. Instead, the production of non-ether, diacyl-type sulfogalactosyl lipids (sulfogalactosyl diacylglycerols) was induced in Far1 KO mice. In conclusion, the alkyl and acyl moieties of seminolipids in the testis are low in diversity, and Far1 is essential for seminolipid synthesis and spermatogenesis.

IntroductionPregnancy-related disorders such as preeclampsia are associated with syncytiotrophoblast (STB) stress and monocyte dysregulation. It remains unclear whether this stress derives from prolonged placental hypoxia or a hypoxia-reperfusion-type injury. Thus, this study investigated how these two models of STB stress impact trophoblast-monocyte interactions. MethodCobalt chloride chemically induced hypoxia in BeWo b30 cells. A transwell coculture system was used to examine trophoblast-monocyte signaling. qPCR quantified gene expression changes following coculture. Monocyte phagocytosis of E. Coli or adhesion to placental cells was determined via flow cytometry. Monocyte migration to placental signals was quantified using a cell counter. ResultsCobalt chloride induced a hypoxic state in BeWo b30s. Reperfusion restored the expression of indirect hypoxia genes and ER stress genes. Coculturing THP-1 monocytes with normoxic, hypoxic, and hypoxic-reperfused BeWo b30s promoted b30 survival but not wound-healing capacity. Compared to hypoxic-reperfused BeWos, hypoxic cells increased monocyte adhesion and inflammatory gene expression, decreased monocyte phagocytosis, and did not change monocyte migration. Finally, placental signaling in early-onset PE decreased monocyte chemotaxis, but monocyte precondition more strongly influenced migration compared to placental state. DiscussionOverall, hypoxic placental signals most effectively recapitulate monocyte functional behavior observed in preeclampsia. Further research is needed to understand spatial and temporal changes in monocyte-trophoblast interactions and pregnancy outcomes. Monocyte chemotaxis to primary placental signals varied by gestational age, maternal diagnosis, and monocyte condition, implying monocytes could be used as functional biomarkers to predict their behavior at the maternal-fetal interface as well as the onset of disease. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=79 SRC="FIGDIR/small/558721v1_ufig1.gif" ALT="Figure 1"> View larger version (24K): org.highwire.dtl.DTLVardef@15dae34org.highwire.dtl.DTLVardef@157dec7org.highwire.dtl.DTLVardef@1e2db81org.highwire.dtl.DTLVardef@b90ab6_HPS_FORMAT_FIGEXP M_FIG C_FIG

PurposePneumoconiosis is characterized by pulmonary fibrosis. The activation of fibroblasts play an important role in the pathological development of pulmonary fibrosis. Chest CT, as a conventional examination to diagnose pulmonary fibrosis of pneumoconiosis, cannot evaluate the fibrosis activity. The application value of 18F-FAPI in pneumoconiosis is unclear. This study aimed to clarify the feasibility of 18F-FAPI PET/CT in non-invasively monitoring the activity evolution of pulmonary fibrosis in pneumoconiosis and the anti-fibrotic treatment. Materials and MethodsA preliminary clinical study was conducted on 6 pneumoconiosis patients and 4 healthy control individuals, correlation analysis was performed between the 18F-FAPI uptake in pulmonary fibrosis areas and the pulmonary diffusing function. Sprague-Dawley rat experiments were performed on three groups concluding pneumoconiosis model, pirfenidone-treated, and normal control groups. 18F-FAPI and 18F-FDG PET/CT, histopathologic, and hematological analysis were assessed monthly from modeling until 6 months. Results18F-FAPI uptake in fibrotic areas was found in the pneumoconiosis patients, and negatively correlated with the diffusing function (r = -0.929, P = 0.022). In the pneumoconiosis model, 18F-FAPI activity preceded one month earlier than relative collagen content (%) in Masson trichrome staining and the level of connective tissue growth factor in plasma, an indicator reflecting the fibroblast activation. The uptake of 18F-FAPI, rather than 18F-FDG, significantly decreased in the pirfenidone-treated group compared to the pneumoconiosis group (P < 0.05). Conclusion18F-FAPI PET/CT imaging holds promise for the early identification of pulmonary fibrosis activity and monitoring its evolution in pneumoconiosis, offering a precise clinical opportunity for targeted anti-fibrotic treatment.