Multiple Mouse Organs Research Articles

Biofluid GPNMB/osteoactivin as a potential biomarker of ageing: A cross-sectional study

BackgroundGlycoprotein non-metastatic melanoma B (GPNMB)/osteoactivin was first identified in the human melanoma cell lines. GPNMB plays a key role in the anti-inflammatory and antioxidative functions as well as osteoblast differentiation, cancer progression, and tissue regeneration. Recently, GPNMB was used as an anti-aging vaccine for mice. The present study aimed to investigate the potential of biofluid GPNMB as an aging biomarker in humans using serum and urine samples from an aging Chinese population. MethodsWe analyzed RNA-sequencing data (GSE132040) from 17 murine organs across different ages to assess the gene expression of potential ageing biomarkers. Spearman's correlation coefficients were used to evaluate the relationship between gene expression and age. Meanwhile, a cross-sectional population study was conducted, which included 473 participants (aged 25–91 years), a representative subset of participants from the Peng Zu Study on Healthy Ageing in China (Peng Zu Cohort). Biofluid GPNMB levels were measured by ELISA. The associations of serum and urine GPNMB levels with various clinical and anthropometrical indices were assessed using ANOVA, Kruskal-Wallis H test, and univariate and multivariate linear regression analyses. ResultsIn mice, the Gpnmb mRNA expression levels showed a significant positive association with age in multiple organs in mice (P < 0.05). In Peng Zu Cohort, biofluid (both serum and urine) GPNMB levels showed a positive correlation with age (P < 0.05). Univariate linear regression analysis revealed that serum GPNMB levels were negatively associated with skeletal muscle mass index (SMI, P < 0.05) and insulin-like growth factor 1 (IGF-1, P < 0.05), and urine GPNMB levels showed a negative association with total bile acids (TBA, P < 0.05). Multivariate linear regression analysis further indicated that serum GPNMB levels negatively correlated with the systemic immune-inflammation index (SII, P < 0.05), and the urine GPNMB levels maintained a negative association with TBA (P < 0.05), additionally, urine GPNMB levels in men were significantly lower than in women (P < 0.05). ConclusionsThe biofluid GPNMB was a strong clinical biomarker candidate for estimating biological aging.

Abstract 2336: A prototype for a machine-learning assisted image analysis tool for preclinical in vivo studies

Abstract The purpose of this study was to build a software tool to test the feasibility of machine-learning (ML) assisted analysis of in vivo 3D images in oncology research studies. Conventionally, in vivo image segmentations are performed by hand, and are a bottleneck for data analysis, taking time and introducing both inter and intra-user variability. Recently, advances in ML have shown promise in accelerating similar clinical image analysis tasks. Our objective was to work toward making this technology accessible to preclinical cancer researchers. 3D image data across multiple mouse models, organs, modalities, and imaging systems were used. ML segmentation models were trained with user-defined masks on images of mouse bladders (N=134), kidneys (N=131), livers (N=65), and lungs (N=26) from either ultrasound or micro-computed tomography (uCT) scanners. Models were developed using PyTorch/MONAI, hosted in an AWS cloud environment, and served to users via a custom extension for 3D Slicer (www.slicer.org). Performance was assessed as the difference between the human vs. ML organ volumes on a test set unseen by the models during training. Lastly, the functionality of on-the-fly segmentation improvement tools through iterative user feedback was assessed. Results demonstrated that generating segmentations with the prototype ML software took 2-6 seconds per image running on a modern GPU (NVIDIA RTX 3090), compared to 3-7 minutes if performed manually by an expert user (&amp;gt;30x improvement). The Dice scores between the ML generated and human segmentations ranged from 0.81 (liver ultrasound) to 0.84 (bladder ultrasound) but could be improved using ML-based on-the-fly mask improvement tools. Using data from this pilot study, we estimate that the threshold to achieve 90% accuracy on first-pass segmentations is between 200-300 training images, depending on the variance observed in the image data. In summary, the prototype software was able to decrease the manual analysis time across a variety of preclinical in vivo image modalities, which is broadly relevant to preclinical oncology research. The next steps for this project will be to extend the platform to additional orthotopic tumor models (e.g. pancreatic, liver, prostate, etc.) and deploy to the field to enable access to this toolset by preclinical imaging scientists across the world. Citation Format: Adam M. Aji, Thomas M. Kierski, Juan D. Rojas, Hannah Morilak, Olivia J. Kelada, Kathryn H. Gessner, Andrew S. Gdowski, Lucia Kim, William Y. Kim, Ryan C. Gessner, Tomek J. Czernuszewicz. A prototype for a machine-learning assisted image analysis tool for preclinical in vivo studies [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 2336.

A Novel Animal Model for Pulmonary Hypertension: Lung Endothelial-Specific Deletion of Egln1 in Mice.

Pulmonary arterial hypertension (PAH) is a devastating disease characterized by high blood pressure in the pulmonary arteries, which can potentially lead to heart failure over time. Previously, our lab found that endothelia-specific knockout of Egln1, encoding prolyl 4-hydroxylase-2 (PHD2), induced spontaneous pulmonary hypertension (PH). Recently, we elucidated that Tmem100 is a lung-specific endothelial gene using Tmem100-CreERT2 mice. We hypothesize that lung endothelial-specific deletion of Egln1 could lead to the development of PH without affecting Egln1 gene expression in other organs. Tmem100-CreERT2 mice were crossed with Egln1 flox/flox mice to generate Egln1 f/f ;Tmem100-CreERT2 (LiCKO) mice. Western blot and immunofluorescent staining were performed to verify the knockout efficacy of Egln1 in multiple organs of LiCKO mice. PH phenotypes, including hemodynamics, right heart size and function, pulmonary vascular remodeling, were evaluated by right heart catheterization and echocardiography measurements. Tamoxifen treatment induced Egln1 deletion in the lung endothelial cells (ECs) but not in other organs of adult LiCKO mice. LiCKO mice exhibited an increase in right ventricular systolic pressure (RVSP, ~35 mmHg) and right heart hypertrophy. Echocardiography measurements showed right heart hypertrophy, as well as cardiac and pulmonary arterial dysfunction. Pulmonary vascular remodeling, including increased pulmonary wall thickness and muscularization of distal pulmonary arterials, was enhanced in LiCKO mice compared to wild-type mice. Tmem100 promoter-mediated lung endothelial knockout of Egln1 in mice leads to development of spontaneous PH. LiCKO mice could serve as a novel mouse model for PH to study lung and other organ crosstalk.

Fetuin B in white adipose tissue induces inflammation and is associated with peripheral insulin resistance in mice and humans.

Fetuin B is a steatosis-responsive hepatokine that causes glucose intolerance in mice, but the underlying mechanisms remain incompletely described. This study aimed to elucidate the mechanisms of action of fetuin B by investigating its putative effects on white adipose tissue metabolism. First, fetuin B gene and protein expression was measured in multiple organs in mice and in cultured adipocytes. Next, the authors performed a hyperinsulinemic-euglycemic clamp in mice and in humans to examine the link between white adipose tissue fetuin B content and indices of insulin sensitivity. Finally, the effect of fetuin B on inflammation was investigated in cultured adipocytes by quantitative polymerase chain reaction and full RNA sequencing. This study demonstrated in adipocytes and mice that fetuin B was produced and secreted by the liver and taken up by adipocytes and adipose tissue. There was a strong negative correlation between white adipose tissue fetuin B content and peripheral insulin sensitivity in mice and in humans. RNA sequencing and polymerase chain reaction analysis revealed that fetuin B induced an inflammatory response in adipocytes. Fetuin B content in white adipose tissue strongly associated with peripheral insulin resistance in mice and humans. Furthermore, fetuin B induced a proinflammatory response in adipocytes, which might drive peripheral insulin resistance.

Multi-organ comparison and quantification parameters of [18F]THK-5317 uptake in preclinical mouse models of tau pathology

Introduction: Current small-animal PET instrumentation provides sufficient resolution, sensitivity, and quantitative accurate information on the radiotracer distribution within the whole body. However, most preclinical imaging studies focus on the disease-related organ of interest and do not use the total body information provided by small-animal PET. In this study, we investigated the distribution of [18F]THK-5317 (also referred to as (S)-[18F]THK-5117), a radiotracer initially developed to visualize tau deposits in the brain, in two transgenic mouse models of tau overexpression and littermate controls at different ages and of both sexes. We compared multiple quantitative parameters of radiotracer uptake in multiple organs of mice to investigate sex, age, or strain-related differences.Methods: After intravenous administration, 60-min dynamic PET scans were acquired, followed by venous blood sampling, organ harvesting, and metabolite analysis by radio-thin-layer chromatography.Results: Blood pharmacokinetics and metabolism of [18F]THK-5317 significantly differed between males and females across all strains. Sex-related differences in organ VTs were identified from two-way ANOVA analysis. Organ-to-blood concentration ratios correlated well with organ VTs in all investigated organs.Conclusion: Following our workflow, a straightforward multiple-organ analysis of [18F]THK-5317 uptake in mice was easily achievable. From the derived quantitative parameters, the organ-to-blood values correlate best with the calculated VTs. Given the active incorporation of 3R principles into preclinical quantitative imaging, we propose that this workflow might be suitable to select novel radiotracer candidates before more complex kinetic models, comprising invasive methods such as full arterial blood sampling, for radiotracer quantification are applied.

Endothelial progenitor cells systemic administration alleviates multi-organ senescence by down-regulating USP7/p300 pathway in chronic obstructive pulmonary disease

BackgroundChronic obstructive pulmonary disease (COPD) has impacted approximately 390 million people worldwide and the morbidity is increasing every year. However, due to the poor treatment efficacy of COPD, exploring novel treatment has become the hotpot of study on COPD. Endothelial progenitor cells (EPCs) aging is a possible molecular way for COPD development. We aimed to explore the effector whether intravenous administration of EPCs has therapeutic effects in COPD mice.MethodsCOPD mice model was induced by cigarette smoke exposure and EPCs were injected intravenously to investigate their effects on COPD mice. At day 127, heart, liver, spleen, lung and kidney tissues of mice were harvested. The histological effects of EPCs intervention on multiple organs of COPD mice were detected by morphology assay. Quantitative real-time PCR and Western blotting were used to detect the effect of EPCs intervention on the expression of multi-organ senescence-related indicators. And we explored the effect of EPCs systematically intervening on senescence-related USP7/p300 pathway.ResultsCompared with COPD group, senescence-associated β-galactosidase activity was decreased, protein and mRNA expression of p16 was down-regulated, while protein and mRNA expression of cyclin D1 and TERT were up-regulated of multiple organs, including lung, heart, liver, spleen and kidney in COPD mice after EPCs system intervention. But the morphological alterations of the tissues described above in COPD mice failed to be reversed. Mechanistically, EPCs systemic administration inhibited the expression of mRNA and protein of USP7 and p300 in multiple organs of COPD mice, exerting therapeutic effects.ConclusionsEPCs administration significantly inhibited the senescence of multiple organs in COPD mice via down-regulating USP7/p300 pathway, which presents a possibility of EPCs therapy for COPD.

Nicotinamide mononucleotide as a therapeutic agent to alleviate multi-organ failure in sepsis

BackgroundSepsis-caused multi-organ failure remains the major cause of morbidity and mortality in intensive care units with limited therapeutics. Nicotinamide mononucleotide (NMN), a precursor of nicotinamide adenine dinucleotide (NAD+), has been recently reported to be protective in sepsis; however, its therapeutic effects remain to be determined. This study sought to investigate the therapeutic effects of NMN in septic organ failure and its underlying mechanisms.MethodsSepsis was induced by feces-injection-in-peritoneum in mice. NMN was given after an hour of sepsis onset. Cultured neutrophils, macrophages and endothelial cells were incubated with various agents.ResultsWe demonstrate that administration of NMN elevated NAD+ levels and reduced serum lactate levels, oxidative stress, inflammation, and caspase-3 activity in multiple organs of septic mice, which correlated with the attenuation of heart dysfunction, pulmonary microvascular permeability, liver injury, and kidney dysfunction, leading to lower mortality. The therapeutic effects of NMN were associated with lower bacterial burden in blood, and less ROS production in septic mice. NMN improved bacterial phagocytosis and bactericidal activity of macrophages and neutrophils while reducing the lipopolysaccharides-induced inflammatory response of macrophages. In cultured endothelial cells, NMN mitigated mitochondrial dysfunction, inflammation, apoptosis, and barrier dysfunction induced by septic conditions, all of which were offset by SIRT3 inhibition.ConclusionNAD+ repletion with NMN prevents mitochondrial dysfunction and restrains bacterial dissemination while limiting inflammatory damage through SIRT3 signaling in sepsis. Thus, NMN may represent a therapeutic option for sepsis.

Neutralization of IL-1β and P-Selectin Inhibition Attenuate Organ Injury in Mice with Sickle Cell Disease

Advances in the clinical management of sickle cell disease (SCD) have significantly improved the life expectancy of patients. However, aging in SCD is worryingly associated with extensive end-organ damage, including nephropathy, hepatopathy, and pulmonary alterations. Continuous vaso-occlusive (VO) and inflammatory processes in the vasculature are most likely the principal cause of such lesions, and there is little evidence, to date, that long-term hydroxyurea therapy (the standard of care for SCD) reduces organ damage in SCD adults. Inhibition of P-selectin activity, using crizanlizumab, has shown some success for reducing VO crisis frequency in SCD. Furthermore, interleukin (IL)-1β blockade, in the form of canakinumab administration, was well tolerated in young patients with SCD and associated with inflammatory marker reduction. Exploring the hypothesis that a multi-target approach could potentiate the effects of biological agents such as crizanlizumab, we recently showed that acute neutralization of inflammasome-processed cytokines potentiated the effects of anti-P-selectin on tumor necrosis factor (TNF)-α-induced VO events in SCD mice. The aim of this study was to evaluate the effects of 6 weeks (wks) of anti-IL-1β and/or anti-P-selectin (CD62P) immunotherapy on inflammatory parameters and the organ histology of SCD mice. Transgenic Berkeley SCD mice (4-mo old) received ( i.p.) either anti-IL-1β monoclonal antibody (mAb) (01BSUR IgG2a; 7.5 mg/Kg; 2x/week), and/or anti-murine CD62P (RB40.34 IgG1; 30 µg/mouse; 3x/week), or an IgG1 mAb (30 µg/mouse; 3x/week) or saline (2x/week) for 6 wks (N=4-5 for each group). Prior dosing protocols determined the optimal mAb concentrations in SCD mice (data not shown). At two days after the last mAb administration, blood samples were analyzed by flow cytometry and serum stored for biomarker analysis (ELISA/colorimetric assays). Animals were then euthanized and organs were immediately collected and processed for staining with hematoxylin &amp; eosin or Masson's trichrome (for collagen fiber staining). Histological analysis of 4 sections from each organ was performed blindly and alterations were scored qualitatively on a scale of 0 (absent) to 3 (severe). P-selectin inhibition, but not IL-1β blockade, for 6 wks resulted in inhibition (55.4 ± 6.4% inhibition, P=0.002) of the formation of circulating neutrophil-platelet (CD45 +Ly6G +CD41 +) aggregates in SCD mice, compared to non-specific IgG1, as did the combination of both anti-P-selectin/ anti-IL-1β administration (44.4 ± 5.2% inhibition, P=0.016). In contrast, IL-1β blockade, but not P-selectin inhibition, significantly reduced the circulating levels of TNF-α, compared to the saline/IgG1 controls, after 6 wks (40.4 ± 8.9% decrease, P=0.03). No significant alterations in serum biochemical markers (aspartate/alanine aminotransferase, total/direct/indirect bilirubins) were observed following any of the immunotherapies (P&amp;gt;0.05). With regard to effects on organ histology (see Figure): In the liver, P-selectin inhibition reduced tissue injury, while anti- IL-1β therapy significantly reduced sinusoidal congestion, injury and fibrosis, compared to saline/IgG1-treated SCD mice. In the kidney, anti-P-selectin therapy reduced renal congestion, while anti-IL-1β therapy ameliorated fibrosis, compared to saline/IgG1-treated SCD mice. In contrast, in the lungs, anti-P-selectin therapy reduced lung congestion and cell infiltrate, and significantly reduced bronchiole injury, while IL-1β immunotherapy and P-selectin/IL-1β inhibition combination therapy abrogated bronchiole injury/ fibrosis. As such, single immunotherapies had significant effects on multiple organs in SCD mice; P-selectin inhibition abrogated pulmonary bronchiole injury and vascular congestion, possibly mediated by reduced heterocellular aggregate formation, while IL-1β neutralization protected against liver and kidney alterations, and improved lung fibrosis, in association with reduced inflammatory cytokine production. Combination treatments, however, especially in the kidney and liver, had more complex effects. We suggest that future preclinical and clinical studies should investigate the potential of anti-inflammatory/adhesion approaches (alone or in combination) for preventing damage to multiple organs, in addition to preventing VO events.

High-dose ascorbic acid potentiates immune modulation through STAT1 phosphorylation inhibition and negative regulation of PD-L1 in experimental sepsis.

Sepsis is a complex, multifactorial syndrome characterized by a dysregulated host response to infection, leading to severe organ dysfunction and high mortality rates among critically ill patients. Hypovitaminosis C and vitamin C deficiency are frequently observed in septic patients, prompting interest in the potential therapeutic role of ascorbic acid. Although intravenous administration of ascorbic acid has been investigated in multiple clinical trials for sepsis treatment, the specific immunomodulatory mechanisms underlying its effects remain elusive. This study aimed to investigate the protective effects of high-dose ascorbic acid on experimental sepsis. Results show that intravenous administration of high-dose ascorbic acid (250mg/kg) attenuated sepsis-induced organ dysfunctions in a cecal ligation and puncture (CLP)-induced septic mouse model. Ascorbic acid improved splenic cell apoptosis and increased the number of CD3+ T cells in septic mice induced by CLP. Furthermore, ascorbic acid downregulated PD-L1 expression in livers, reduced PD-1 expression in spleens, and inhibited the phosphorylation of STAT1 at Y701 in multiple organs of CLP-induced septic mice. The in vitro experiments also revealed that 800μM ascorbic acid suppressed STAT1 phosphorylation and inhibited lipopolysaccharide (LPS) and IFN-γ-induced PD-L1 expression in macrophages. These findings suggest that ascorbic acid prevents sepsis-associated organ dysfunction through the p-STAT1/PD-L1 signaling pathway. Our study provides new insights into the potential therapeutic use of ascorbic acid in sepsis.

Four-week repeated exposure to tire-derived 6-PPD quinone causes multiple organ injury in male BALB/c mice

N-(1,3-dimethylbutyl)-N′-phenyl-p-phenylenediamine quinone (6-PPDQ) is the ozonation product of tire antioxidant 6-PPD. 6-PPDQ can be detected in different environments, such as roadway runoff and dust. Although 6-PPDQ toxicity has been frequently assessed in aquatic organisms, the possible toxic effects of 6-PPDQ on mammals remain largely unclear. We here aimed to perform systematic assessment to evaluate 6-PPDQ toxicity on multiple organs in mice. Male BALB/c mice were intraperitoneally injected with 6-PPDQ for two exposure modes, single intraperitoneal injection and repeated intraperitoneal injection every four days for 28 days. Serum, liver, kidney, lung, spleen, testis, brain, and heart were collected for injury evaluation by organ index, histopathology analysis and biochemical parameters. In 0.4 and 4 mg/kg 6-PPDQ single injected mice, no significant changes in organ indexes and biochemical parameters were detected, and only moderate pathological changes were observed in organs of liver, kidney, lung, and brain. Very different from this, in 0.4 and 4 mg/kg 6-PPDQ repeated injected mice, we observed the obvious increase in organ indexes of liver, kidney, lung, testis, and brain, and the decrease in spleen index. Meanwhile, the significant pathological changes were formed in liver, kidney, lung, spleen, testis, and brain in 0.4 and 4 mg/kg 6-PPDQ repeated injected mice. Biochemical parameters of liver (alanine aminotransferase (ALT), aspartate aminotransferase (AST), and alkaline phosphatase (ALP)) and kidney (urea and creatinine) were all significantly upregulated by repeated injection with 0.4 and 4 mg/kg 6-PPDQ. After repeated exposure, most of 6-PPDQ was accumulated in liver and lung of mice. Therefore, our results suggested the risk of repeated exposure to 6-PPDQ in inducing toxicity on multiple organs in mice.

Translating from mouse to man to better understand immune-mediated inflammatory diseases

Lilja etal.1 explore single-cell transcriptomes across multiple organs of mice with collagen-induced arthritis. They apply network analysis to prioritize functional pathways that support or suppress inflammation and integrate findings with tissue transcriptomics in human immune-mediated inflammatory diseases.

ODP478 Effects of peripheral iodothyronine deiodinases on thyroid hormone economy: Insights from the overexpressing mice

Abstract Background In peripheral tissues, triiodothyronine (T3) production and consequent thyroid hormone actions are mainly regulated by iodothyronine deiodinases (DIOs) classified into 3 types: D1, D2, and D3. Although thyroid hormone economy in the DIO-deficient mice and patients carrying genetic variants of DIOs was well clarified, a condition of DIOs upregulation was not enough elucidated. We aimed to investigate effects of peripheral DIOs on thyroid hormone economy and consequent thyroid hormone action using novel DIO-overexpressing mice that were not yet generated. Methods We cloned coding sequences of human DIOs with FLAG-tag and HiBiT-tag sequences into a pcDNA3.1 vector. To obtain full-length proteins, we modified these vectors by cloning selenocysteine insertion sequence of each DIO (SECIS vectors). Western blot analyses and HiBiT lytic assay using HEK293T cells revealed that SECIS vectors expressed full-length proteins with substantial activity. Subsequently, in vivo transfections of pLIVE-based SECIS vectors into male C57BL/6J mice were performed by hydrodynamic gene delivery to generate mice overexpressing DIOs (D1, D2, and D3 mice). Results First, we verified that DIOs were successfully overexpressed in the livers using HiBiT lytic assay as well as RT-PCR. Analyses of multiple organs of D3 mice assured that full-length protein was not significantly expressed in the heart, the kidney, and the skeletal muscle. RT-PCR analyses also suggested that the pituitary glands and the thyroid glands were not transfected. We evaluated thyroid hormone economy of DIO-overexpressing mice compared to Empty mice transfected with pLIVE-Empty vector. D1 mice did not have changes in serum thyroid hormone levels, whereas D2 mice had higher serum fT3 levels. Clearer changes were found in D3 mice. They had hypothyroidism with higher serum rT3 levels. Correspondingly, in their livers, rT3 concentration was higher and T3-responsive genes were downregulated. We elucidated by adding the cohort with levothyroxine (LT4) administration because DIO-overexpressing mice had liver T4 insufficiency probably due to consumption by DIOs. Comparisons between the DIO-overexpressing mice with and without LT4 administration revealed that D2 mice presented upregulation of T3-responsive genes by LT4 administration distinct from Empty mice. Conclusions We generated DIO-overexpressing mice that expressed human DIOs predominantly in the liver. They provided physiological evidence to integrate the phenotypes of the knockout mice and specific clinical situations. D2 mice seemed to recruit T3 into the circulation as well as in the liver. D3 mice had an overt phenotype characterized by consumptive hypothyroidism. In addition, D3 mice are expected to be a novel hypothyroidism model that does not involve disruption of thyroidal hormone secretion. DIO-overexpressing mice can be generated by single injections of plasmid vectors of interest and can contribute to progress in the field of thyroid hormone economy and action. Presentation: No date and time listed

NUAK1 promotes organ fibrosis via YAP and TGF-β/SMAD signaling.

Fibrosis is a central pathway that drives progression of multiple chronic diseases, yet few safe and effective clinical antifibrotic therapies exist. In most fibrotic disorders, transforming growth factor-β (TGF-β)-driven scarring is an important pathologic feature and a key contributor to disease progression. Yes-associated protein (YAP) and transcriptional coactivator with PDZ-binding motif (TAZ) are two closely related transcription cofactors that are important for coordinating fibrogenesis after organ injury, but how they are activated in response to tissue injury has, so far, remained unclear. Here, we describe NUAK family kinase 1 (NUAK1) as a TGF-β-inducible profibrotic kinase that is up-regulated in multiple fibrotic organs in mice and humans. Mechanistically, we show that TGF-β induces a rapid increase in NUAK1 in fibroblasts. NUAK1, in turn, can promote profibrotic YAP and TGF-β/SMAD signaling, ultimately leading to organ scarring. Moreover, activated YAP and TAZ can induce further NUAK1 expression, creating a profibrotic positive feedback loop that enables persistent fibrosis. Using mouse models of kidney, lung, and liver fibrosis, we demonstrate that this fibrogenic signaling loop can be interrupted via fibroblast-specific loss of NUAK1 expression, leading to marked attenuation of fibrosis. Pharmacologic NUAK1 inhibition also reduced scarring, either when initiated immediately after injury or when initiated after fibrosis was already established. Together, our data suggest that NUAK1 plays a critical, previously unrecognized role in fibrogenesis and represents an attractive target for strategies that aim to slow fibrotic disease progression.

PD-1/PD-L1 inhibitor ameliorates silica-induced pulmonary fibrosis by maintaining systemic immune homeostasis

Pulmonary fibrosis induced by silica particles is defined as silicosis, which is an incurable disease. The pathogenesis of silicosis is not completely clear, but it’s certain that immune system dysfunction is closely related to it. Immune checkpoint inhibitors (ICIs) are emerging immunotherapeutic agents that mainly target adaptive immune cells, and there is abundant evidence that ICIs are of great value in cancer treatment. However, whether these attractive agents can be implemented in silicosis treatment is unclear. In this study, we explored the efficacy of small molecule inhibitors targeted PD-1/PD-L1 and CTLA-4 on silica-induced pulmonary fibrosis in mice. ICIs were injected intraperitoneally into mice that received silica instillation twice a week. The mice were sacrificed 7 and 28 days after the injection. The lungs, spleen, hilar lymph nodes, thymus, and peripheral blood of mice were collected and subjected to histological examination, flow cytometry analysis, and mRNA and protein quantification. Our results demonstrated that silica exposure caused damage to multiple immune organs in mice, leading to an imbalance in systemic immune homeostasis. Specifically, proportions and subtypes of T and B cells were significantly altered, and the expressions of PD-1, PD-L1 and CTLA-4 were abnormal on these cells. Both PD-1/PD-L1 and CTLA-4 inhibitor administration modulated silica-induced immune system disruption, however, only PD-1/PD-L1 signaling inhibition showed significant amelioration of silicosis. Our findings confirmed for the first time the potential value of ICIs for the treatment of silica-induced pulmonary fibrosis, and this may provide new ideas for the treatment of other fibrosis-related diseases.

Ceruloplasmin Deficiency Impaired Brain Iron Metabolism and Behavior in Mice.

Iron accumulation is an important cause of various brain diseases. As a ferroxidase, ceruloplasmin (Cp) plays a key role in iron homeostasis and its abnormal activity leads to iron accumulation. However, the detailed biological function of Cp in brain iron homeostasis needs to be investigated. In this study, Cp knockout mice were prepared and the changes in iron content and protein expression related to iron metabolism were detected. The results showed that iron accumulation occurred in multiple tissues and organs of Cp knockout mice, but there was no obvious change in brain tissues. However, Cp deficiency affected the expression of many iron metabolism-related proteins in midbrain, such as DMT1+IRE, heavy chain ferritin (H-ferritin) and light chain ferritin (L-ferritin). Cp deficiency also impaired the behavioral ability of mice, including weakened exercise ability and reduced motor coordination. In vitro cell experiment indicated that the sensitivity of Cp knockout neuron and astrocyte to hypoxia was higher than that of wild type, which means Cp deficiency leads to the damage of cell self-protection. All these results confirm that Cp exerts a protective effect on the brain by regulating iron metabolism.

Adult spiny mice (Acomys) exhibit endogenous cardiac recovery in response to myocardial infarction

Complex tissue regeneration is extremely rare among adult mammals. An exception, however, is the superior tissue healing of multiple organs in spiny mice (Acomys). While Acomys species exhibit the remarkable ability to heal complex tissue with minimal scarring, little is known about their cardiac structure and response to cardiac injury. In this study, we first examined baseline Acomys cardiac anatomy and function in comparison with commonly used inbred and outbred laboratory Mus strains (C57BL6 and CFW). While our results demonstrated comparable cardiac anatomy and function between Acomys and Mus, Acomys exhibited a higher percentage of cardiomyocytes displaying distinct characteristics. In response to myocardial infarction, all animals experienced a comparable level of initial cardiac damage. However, Acomys demonstrated superior ischemic tolerance and cytoprotection in response to injury as evidenced by cardiac functional stabilization, higher survival rate, and smaller scar size 50 days after injury compared to the inbred and outbred mouse strains. This phenomenon correlated with enhanced endothelial cell proliferation, increased angiogenesis, and medium vessel maturation in the peri-infarct and infarct regions. Overall, these findings demonstrate augmented myocardial preservation in spiny mice post-MI and establish Acomys as a new adult mammalian model for cardiac research.

The Expression Pattern of Cypher in the Multiple Organs of Mice

Cypher, which is named ZASP/LDB3, one of the members of PDZ-LIM family, was well known to express in cardiac and skeletal muscles which played a functional role in muscles. It has shown that global deletion of Cypher in mice leads to lethality due to dysfunction of the skeletal muscles. Recently, the MGD database has been shown that conditional deletion of Cypher or gene mutations leads to human disease, the etiology and mechanism of which remained unknown. Therefore, it might be very important that we systemically investigated the expression of Cypher in organs or tissues from developmental stages through adulthood at first. We explored the expression pattern of Cypher by [Formula: see text]-gal staining of Cypher LacZ knockin mice combing with chemical staining, immunostaining and in situ hybridization, suggesting that Cypher might play a functional role in those organs. Further investigation will be done by cooperation with other groups by using the conditional deletion of Cypher or the point mutation of genes in the organs, which studied Cypher expression according to the MGD database.

Thresholds of Endoglin Expression in Endothelial Cells Explains Vascular Etiology in Hereditary Hemorrhagic Telangiectasia Type 1.

Hereditary Hemorrhagic Telangiectasia type 1 (HHT1) is an autosomal dominant inherited disease characterized by arteriovenous malformations and hemorrhage. HHT1 is caused by mutations in ENDOGLIN, which encodes an ancillary receptor for Transforming Growth Factor-β/Bone Morphogenetic Protein-9 expressed in all vascular endothelial cells. Haploinsufficiency is widely accepted as the underlying mechanism for HHT1. However, it remains intriguing that only some, but not all, vascular beds are affected, as these causal gene mutations are present in vasculature throughout the body. Here, we have examined the endoglin expression levels in the blood vessels of multiple organs in mice and in humans. We found a positive correlation between low basal levels of endoglin and the general prevalence of clinical manifestations in selected organs. Endoglin was found to be particularly low in the skin, the earliest site of vascular lesions in HHT1, and even undetectable in the arteries and capillaries of heterozygous endoglin mice. Endoglin levels did not appear to be associated with organ-specific vascular functions. Instead, our data revealed a critical endoglin threshold compatible with the haploinsufficiency model, below which endothelial cells independent of their tissue of origin exhibited abnormal responses to Vascular Endothelial Growth Factor. Our results support the development of drugs promoting endoglin expression as potentially protective.

Circular RNA circ_Cabin1 promotes DNA damage in multiple mouse organs via inhibition of non-homologous end-joining repair upon PM2.5 exposure.

Fine particulate matter (PM2.5) has been shown to induce DNA damage. Circular RNAs (circRNAs) have been implicated in various disease processes related to environmental chemical exposure. However, the role of circRNAs in the regulation of DNA damage response (DDR) after PM2.5 exposure remains unclear. In this study, male ICR mice were exposed to PM2.5 at a daily mean concentration of 382.18μg/m3 for 3months in an enriched-ambient PM2.5 exposure system in Shijiazhuang, China, and PM2.5 collected form Shijiazhuang was applied to RAW264.7 cells at 100µg/mL for 48h. The results indicated that exposure to PM2.5 induced histopathological changes and DNA damage in the lung, kidney and spleen of male ICR mice, and led to decreased cell viability, increased LDH activity and DNA damage in RAW264.7 cells. Furthermore, circ_Cabin1 expression was significantly upregulated in multiple mouse organs as well as in RAW264.7 cells upon exposure to PM2.5. PM2.5 exposure also resulted in impairment of non-homologous end joining (NHEJ) repair via the downregulation of Lig4 or Dclre1c expression in vivo and in vitro. Importantly, circ_Cabin1 promoted PM2.5-induced DNA damage via inhibiting of NHEJ repair. Moreover, the expression of circ_Cabin1 and Lig4 or Dclre1c was strongly correlated in multiple mouse organs, as well as in the blood. In summary, our study provides a new perspective on circRNAs in the regulation of DDR after environmental chemical exposure.

Crosstalk between γδ T cells and the microbiota.

The role of the microbiota in the development and function of γδ T cells-a T cell subset characterized by a T cell receptor composed of one γ-chain and one δ-chain-has been investigated in multiple organs in mice and humans. Interactions between the microbiota and γδ T cells affect both tissue homeostasis and disease pathologies. Notably, microbiota-induced interleukin-17 (IL-17)-producing-γδ T cells can mediate a range of immunological processes, from metabolic disorders to neuroinflammation via the gut-brain axis. However, the bidirectional interactions between γδ T cells and the microbiota have not been fully determined. In this Perspective, we dissect the roles of microbiota in modulating γδ T cell development and function, and evaluate the evidence for γδ T cell selection of commensal communities. We also discuss the potential implications of these cells in health and disease and the major open questions and research avenues in the field.