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A prevalence of cigarette smoking can cause the accumulation of cadmium (Cd2+) in the lungs, kidneys, and blood. The effects of exposure can cause multiple chronic disease types to emerge in the affected organ systems. The only moderately effective therapeutic option is chelation therapy; the health risks associated with this therapy have caused much criticism. The disease types associated with Cd2+ toxicity have inflammatory components and greatly impact innate immunity. These factors are affected at the cellular level and cause pathways like apoptosis, pyroptosis, and necroptosis. A development in understanding these pathways stipulates that these three pathways act as one complex of pathways, known together as PANoptosis. The inflammatory mechanisms of PANoptosis are particularly interesting in Cd2+ toxicity due to its inflammatory effects. Proteins in the gasdermin family act to release inflammatory cytokines, like interleukin-1β, into the extracellular environment. Cytokines cause inflammatory disease pathologies like fibrosis and cancer. RAW 264.7 monocytes are key in the murine immune system and provide an excellent model to investigate Cd2+ toxicity. Exposure of 0–15 µM CdCl2 was sufficient to increase expression of cleaved gasdermin D (GSDMD) and gasdermin E (GSDME) in this cell type. Cd2+ also exhibits a dose–dependent cytotoxicity in this cell type. [ABSTRACT FROM AUTHOR]

In Europe and North America, the prevalence of pulmonary nontuberculous mycobacteria (NTM) is increasing. Most pulmonary NTM infections are caused by the Mycobacterium avium complex (MAC). Sadly, the treatment of pulmonary MAC is suboptimal with failure rates ranging from 37% to 58%. Therefore, there is a need to develop new therapeutics. Developing new immunotherapies and studying their interaction with standard or new drugs requires reliable assays. Four different assays including CFSE-based flow cytometry, in vitro protection assays, IFN-γ ELISPOT, and murine infection models were optimized using a reference strain of MAC (ATCC 700898) to help with the development of immunotherapies for MAC. Expansion of proliferating and IFN-γ producing human T cells is optimal after 7 days of stimulation with MAC at a multiplicity of infection (MOI) of 0.1, achieving a stimulation index of 26.5 ± 11.6 (mean ± SE). The in vitro protection assay for MAC works best by co-culturing T cells expanded for 7 days with MAC (MOI 1)-infected autologous macrophages. Aerosol MAC infection of mice allows measurement of the effects of the BCG vaccine and clarithromycin. IFN-γ ELISPOT assays with live MAC (MOI 3) stimulation of splenocytes from mice immunized with BCG help identify differences between unimmunized mice and mice immunized with BCG. In conclusion, multiple assays are available for use to identify MAC-specific effector T cells, which will help in the development of new therapeutics or vaccines against pulmonary MAC. [ABSTRACT FROM AUTHOR]

Adrenocortical carcinoma (ACC) and pheochromocytoma (PCC) are malignancies originating from distinct layers of the adrenal gland. ACCs arise from the adrenal cortex, are often detected at advanced stages and are associated with poor prognosis. PCCs are mostly benign, arise from the adrenal medulla and have a variable prognosis, with 10% of PCCs resulting in metastasis. Genetic background strongly influences metastasis of PCCs, and no reliable biomarkers that predict metastatic behavior exist to date. Current therapeutic strategies for both ACCs and PCCs are overall limited. Thus, novel preclinical models and drug screening approaches need to be established to aid in the identification of more promising drugs and treatment schemes. In this review, we summarize the currently available human and murine cell lines for both tumor entities. [ABSTRACT FROM AUTHOR]

Background/Aim: We and others have previously shown that cell fusion plays an important role in cancer metastasis. Color coding of cancer and stromal cells with spectrally-distinct fluorescent proteins is a powerful tool, as pioneered by our laboratory to detect cell fusion. We have previously reported color-coded cell fusion between cancer cells and stromal cells in metastatic sites by using color-coded EL4 murine lymphoma cells and host mice expressing spectrally-distinct fluorescent proteins. Cell fusion occurred between cancer cells or, between cancer cells and normal cells, such as macrophages, fibroblasts, and mesenchymal stem cells. In the present study, the aim was to morphologically classify the fusion-hybrid cells observed in the primary tumor and multiple metastases EL4 formed from cells expressing red fluorescent protein (RFP) in transgenic mice expressing green fluorescent protein (GFP), in a syngeneic model. Materials and Methods: RFP-expressing EL4 murine lymphoma cells were cultured in vitro. EL4-RFP cells were harvested and injected intraperitoneally into immunocompetent transgenic C57/BL6- GFP mice to establish a syngeneic model. Two weeks later, mice were sacrificed and each organ was harvested, cultured, and observed using confocal microscopy. Results: EL4 intraperitoneal tumors (primary) and metastases in the lung, liver, blood, and bone marrow were formed. All tumors were harvested and cultured. In all specimens, RFP-EL4 cells, GFPstromal cells, and fused yellow-fluorescent hybrid cells were observed. The fused hybrid cells showed various morphologies. Immune cell-like round-shaped yellow-fluorescent fused cells had a tendency to decrease with time in liver metastases and circulating blood. In contrast fibroblast-like spindle-shaped yellow-fluorescent fused cells increased in the intraperitoneal primary tumor, lung metastases, and bone marrow. Conclusion: Cell fusion between EL4-RFP cells and GFP stromal cells occurred in primary tumors and all metastatic sites. The morphology of the fused hybrid cells varied in the primary and metastatic sites. The present results suggest that fused cancer and stromal hybrid cells of varying morphology may play an important role in cancer progression. [ABSTRACT FROM AUTHOR]

Hepatic ischemia–reperfusion injury (IRI) is a major cause of postoperative hepatic dysfunction and liver failure involving cellular damage to previously ischemic tissues to which blood flow is restored. The reestablishment of blood flow is essential for salvaging ischemic tissues. The reperfusion itself, however, can paradoxically lead to further cellular damage, which involves a multi-factorial process resulting in extensive tissue damage, which can threaten the function and viability of the liver and other organ systems. The following review outlines multiple models for in-lab analysis of the various hepatic IRI mechanisms, including murine, porcine, cell lines, and machine perfusion models. [ABSTRACT FROM AUTHOR]

Adrenocortical carcinoma (ACC) and pheochromocytoma (PCC) are malignancies originating from distinct layers of the adrenal gland. ACCs arise from the adrenal cortex, are often detected at advanced stages and are associated with poor prognosis. PCCs are mostly benign, arise from the adrenal medulla and have a variable prognosis, with 10% of PCCs resulting in metastasis. Genetic background strongly influences metastasis of PCCs, and no reliable biomarkers that predict metastatic behavior exist to date. Current therapeutic strategies for both ACCs and PCCs are overall limited. Thus, novel preclinical models and drug screening approaches need to be established to aid in the identification of more promising drugs and treatment schemes. In this review, we summarize the currently available human and murine cell lines for both tumor entities.

Background and Aim: Although widely employed in traditional remedies globally, the safety and efficacy of Moringa oleifera remain inadequately documented through scientific research. This study evaluated the oral toxicity of M. oleifera leaf aqueous extract (MoAE) and its impact on gout-induced rats. Materials and Methods: 2000 mg/kg was given in a single dose during the acute oral toxicity test, while 100 mg/kg, 250 mg/kg, and 500 mg/kg were given daily for 28 days in the repeated dose toxicity test. 100 mg/kg, 250 mg/kg, and 500 mg/kg MoAE doses were administered during the assessment of its impact on gout caused by monosodium urate. In the hyperuricemia model induced by oxonic acid, serum uric acid levels were assessed and pain response was measured through acetic acid-induced writhing. Results: In acute oral and 28-day repeated dose tests, no indications of toxicity were detected, while MoAE alleviated ankle joint swelling and reduced serum uric acid concentrations in arthritic rats, causing a significant reduction in acetic acid-induced contortions. Conclusion: No acute oral toxicity or toxicity in 28-day repeated doses was found for MoAE, while it exhibited antiarthritic, antihyperuricemic, and pain-relieving effects in the murine model.

Background and Aim: Although widely employed in traditional remedies globally, the safety and efficacy of Moringa oleifera remain inadequately documented through scientific research. This study evaluated the oral toxicity of M. oleifera leaf aqueous extract (MoAE) and its impact on gout-induced rats. Materials and Methods: 2000 mg/kg was given in a single dose during the acute oral toxicity test, while 100 mg/kg, 250 mg/kg, and 500 mg/kg were given daily for 28 days in the repeated dose toxicity test. 100 mg/kg, 250 mg/kg, and 500 mg/kg MoAE doses were administered during the assessment of its impact on gout caused by monosodium urate. In the hyperuricemia model induced by oxonic acid, serum uric acid levels were assessed and pain response was measured through acetic acid-induced writhing. Results: In acute oral and 28-day repeated dose tests, no indications of toxicity were detected, while MoAE alleviated ankle joint swelling and reduced serum uric acid concentrations in arthritic rats, causing a significant reduction in acetic acid-induced contortions. Conclusion: No acute oral toxicity or toxicity in 28-day repeated doses was found for MoAE, while it exhibited antiarthritic, antihyperuricemic, and pain-relieving effects in the murine model. [ABSTRACT FROM AUTHOR]

Pro‐inflammatory fungal β‐d‐glucan (BDG) polysaccharides cause respiratory pathology. However, specific immunological effects of unique BDG structures on pulmonary inflammation are understudied. We characterized the effect of four unique fungal BDGs with unique branching patterns, solubility, and molecular weights in murine airways. Scleroglucan (1 → 3)(1 → 6)‐highly branched BDG, laminarin (1 → 3)(1 → 6)‐branched BDG, curdlan (1 → 3)‐linear BDG, and pustulan (1 → 6)‐linear BDG were assessed by nuclear magnetic resonance spectroscopy. Each BDG was tested by inhalation model with C3HeB/FeJ mice and compared to saline‐exposed control mice and unexposed sentinels (n = 3–19). Studies were performed ±heat‐inactivation (1 h autoclave) to increase BDG solubility. Outcomes included bronchoalveolar lavage (BAL) differential cell counts (macrophages, neutrophils, lymphocytes, eosinophils), cytokines, serum IgE, and IgG2a (multiplex and ELISA). Ex vivo primary cells removed from lungs and plated at monolayer were stimulated (BDG, lipopolysaccharide (LPS), anti‐CD3), and cytokines compared to unstimulated cells. Right lung histology was performed. Inhalation of BDGs with distinct branching patterns exhibited varying inflammatory potency and immunogenicity. Lichen‐derived (1 → 6)‐linear pustulan was the most pro‐inflammatory BDG, increasing inflammatory infiltrate (BAL), serum IgE and IgG2a, and cytokine production. Primed lung cells responded to secondary LPS stimulation with a T‐cell‐specific response to pustulan. Glucan source and solubility should be considered in exposure and toxicological studies. [ABSTRACT FROM AUTHOR]

Background: Ischemic post-conditioning (IPoC) has been shown to improve outcomes in limited pre-clinical models. As down-time is often unknown, this technique needs to be investigated over a range of scenarios. As this tool limits reperfusion injury, there may be limited benefit or even harm after short arrest and limited ischemia-reperfusion injury. Methods: Eighteen male Wistar rats underwent 7 min of asphyxial arrest. Animals randomized to IPoC received a 20 s pause followed by 20 s of compressions, repeated four times, initiated 40 s into cardiopulmonary resuscitation. If return of spontaneous circulation (ROSC) was achieved, epinephrine was titrated to mean arterial pressure (MAP) of 70 mmHg. Data were analyzed using t-test or Mann–Whitney test. Significance set at p ≤ 0.05. Results: The rate of ROSC was equivalent in both groups, 88%. There was no statistically significant difference in time to ROSC, epinephrine required post ROSC, carotid flow, or peak lactate at any timepoint. There was a significantly elevated MAP with IPoC, 90.7 mmHg (SD 13.9), as compared to standard CPR, 76.7 mmHg (8.5), 2 h after ROSC, p = 0.03. Conclusions: IPoC demonstrated no harm in a model of short arrest using a new arrest etiology for CPR based IPoC intervention in a rat model. [ABSTRACT FROM AUTHOR]

Intestinal manipulation (IM)–induced inflammation could contribute to postoperative ileus (POI) pathophysiology via the modulation of prostanoid pathways. To identify the prostanoids involved, we aimed to characterize the profile of prostanoids and their synthesis enzyme expression in a murine model of POI and to determine whether the altered prostanoids could contribute to POI. Four or 14 h after IM in mice, gastrointestinal (GI) motility and intestinal epithelial barrier (IEB) permeability were assessed in vivo and ex vivo in Ussing chambers. Using high sensitivity liquid chromatography-tandem mass spectrometry, we characterized the tissue profile of polyunsaturated fatty acid metabolites in our experimental model. Finally, we evaluated in vivo the effects of the prostanoids studied upon IM-induced gut dysfunctions. We first showed that 14 h after IM was significantly faster than jejunal transit at 4 h post-IM, although it remained significantly increased compared to the control. In contrast, we showed that IM-induced inflammation increase in jejunum permeability was similar after four and 14 h. We next showed that expression of prostacyclin synthase and hemopoietic prostaglandin-D synthase mRNA and their products were significantly reduced 14 h after IM as compared to controls. Furthermore, 15-deoxy-delta 12,14-Prostaglandin J2 reduced the IM-induced inflammation increase in IEB permeability but had no effect on GI motility. In contrast, PGI 2 increased IM-induced IEB permeability and motility dysfunctions. Arachidonic acid derivative contributes differentially to GI dysfunction in POI. The decrease of 15-deoxy-delta 12,14-Prostaglandin J2 levels induced by IM could contribute to impaired GI dysfunctions in POI and could be considered as putative therapeutic targets to restore barrier dysfunctions associated with POI. [ABSTRACT FROM AUTHOR]

There are technical challenges in imaging studies that can three‐dimensionally (3D) analyze a single fiber (SF) to observe the functionality of the entire muscle after stroke. This study proposes a 3D assessment technique that only segments the SF of the right stroke‐induced soleus muscle of a gerbil using synchrotron radiation x‐ray microcomputed tomography (SR‐μCT), which is capable of muscle structure analysis. Curvature damage in the SF of the left soleus muscle (impaired) progressed at 7‐day intervals after the stroke in the control; particularly on the 7 days (1 week) and 14 days (2 weeks), as observed through visualization analysis. At 2 weeks, the SF volume was significantly reduced in the control impaired group (p =.033), and was significantly less than that in the non‐impaired group (p =.009). We expect that animal post‐stroke studies will improve the basic field of rehabilitation therapy by diagnosing the degree of SF curvature. Research Highlights: Muscle evaluation after ischemic stroke using synchrotron radiation x‐ray microcomputed tomography (SR‐μCT).Curvature is measured by segmenting a single fiber (SF) in the muscle.Structural changes in the SF of impaired gerbils at 7‐day intervals were assessed. [ABSTRACT FROM AUTHOR]

The decidual immunome is dynamic, dramatically changing its composition across gestation. Early pregnancy is dominated by decidual NK cells, with a shift towards T cells later in pregnancy. However, the degree, timing, and subsetspecific nature of leukocyte traffic between the decidua and systemic circulation during gestation remains poorly understood. Herein, we employed intravascular staining in pregnant C57BL/6J mice and cynomolgus macaques (Macaca fascicularis) to examine leukocyte traffic into the decidual basalis during pregnancy. Timed-mated or virgin mice were tail-vein injected with labelled αCD45 antibodies 24 hours and 5 minutes before sacrifice. Pregnant cynomolgus macaques (GD155) were infused with labelled αCD45 at 2 hours or 5 mins before necropsy. Decidual cells were isolated and resulting suspensions analyzed by flow cytometry. We found that the proportion of intravascular (IVAs)-negative leukocytes (cells labeled by the 24h infusion of αCD45 or unlabeled) decreased across murine gestation while recent immigrants (24h label only) increased in mid- to late-gestation. In the cynomolgus model our data confirmed differential labeling of decidual leukocytes by the infused antibody, with the 5 min infused animal having a higher proportion of IVAs+ cells compared to the 2hr infused animal. Decidual tissue sections from both macaques showed the presence of intravascularly labeled cells, either in proximity to blood vessels (5min infused animal) or deeper into decidual stroma (2hr infused animal). These results demonstrate the value of serial intravascular staining as a sensitive tool for defining decidual leukocyte traffic during pregnancy. [ABSTRACT FROM AUTHOR]

ABSTRACT A Mycobacterium ulcerans human challenge model has the potential to fundamentally advance our understanding of early human immune responses to infection, while rapidly evaluating vaccines and other therapeutic interventions. Here, using a murine tail infection model, we tested a very well-characterized working cell bank of the proposed challenge isolate M. ulcerans JKD8049 in naïve and Mycobacterium bovis bacille Calmette–Guérin (BCG)-vaccinated BALB/c mice. All 10 naïve mice were successfully infected with 20 colony-forming units (CFU) of M. ulcerans [95% confidence interval (CI) 17–22 CFU] with a mean time to visible lesion of 86 days (95% CI 79–92 days). In the 10 vaccinated mice, there was a significant delay in the mean time to lesion compared to the naïve controls of 24 days (P = 0.0003), but all mice eventually developed ulcerative lesions. This study informs a future human infection model by demonstrating the successful application of the challenge agent in this in vivo model and highlights both the promise and the problems with trying to induce protective immunity against M. ulcerans.IMPORTANCEIn preparation for its proposed use in a controlled human infection model (CHIM), this study reports the successful infection of BALB/c mice using a carefully characterized, low-dose inoculum of Mycobacterium ulcerans JKD8049 (our proposed CHIM strain). We also demonstrate that Mycobacterium bovis bacille Calmette–Guérin delays the onset of disease but cannot alter the course of illness once a lesion becomes apparent. We also validate the findings of previous low-dose challenges that used less accurate methods to determine the inoculum, but our presented methodology is practical, accurate, and anticipated to be reproducible.

Preclinical models of large‐vessel occlusion (LVO) stroke play an important role in testing novel thrombolytic and neuroprotective agents, as well as assessing endovascular devices for endovascular thrombectomy. Depending on the modality used to model LVO stroke, different aspects of human stroke pathophysiology can be recapitulated. Thus, variables including size and region of the occlusion, composition of the clot, and degree of reperfusion can be controlled. We conducted a thorough literature review of all the preclinical models of stroke used currently. We searched for studies using the PubMed database and included original studies, reviews, systematic reviews, and meta‐analyses. In this review, we describe the considerations in choosing a preclinical model of LVO stroke. We provide an overview of available small‐ and large‐animal LVO stroke models that can be used in stroke research as well as the benefits and limitations of each. We then discuss the current outcome measures that can be evaluated through these models, in terms of both tissue damage and behavioral outcome. We also discuss the advantages and disadvantages of each animal model. Finally, based on this summary, we propose that mice represent the most versatile small‐animal LVO model and dogs are the most appropriate large‐animal LVO stroke model to translate candidate drugs and devices into clinical trials.

Abstract Pro‐inflammatory fungal β‐d‐glucan (BDG) polysaccharides cause respiratory pathology. However, specific immunological effects of unique BDG structures on pulmonary inflammation are understudied. We characterized the effect of four unique fungal BDGs with unique branching patterns, solubility, and molecular weights in murine airways. Scleroglucan (1 → 3)(1 → 6)‐highly branched BDG, laminarin (1 → 3)(1 → 6)‐branched BDG, curdlan (1 → 3)‐linear BDG, and pustulan (1 → 6)‐linear BDG were assessed by nuclear magnetic resonance spectroscopy. Each BDG was tested by inhalation model with C3HeB/FeJ mice and compared to saline‐exposed control mice and unexposed sentinels (n = 3–19). Studies were performed ±heat‐inactivation (1 h autoclave) to increase BDG solubility. Outcomes included bronchoalveolar lavage (BAL) differential cell counts (macrophages, neutrophils, lymphocytes, eosinophils), cytokines, serum IgE, and IgG2a (multiplex and ELISA). Ex vivo primary cells removed from lungs and plated at monolayer were stimulated (BDG, lipopolysaccharide (LPS), anti‐CD3), and cytokines compared to unstimulated cells. Right lung histology was performed. Inhalation of BDGs with distinct branching patterns exhibited varying inflammatory potency and immunogenicity. Lichen‐derived (1 → 6)‐linear pustulan was the most pro‐inflammatory BDG, increasing inflammatory infiltrate (BAL), serum IgE and IgG2a, and cytokine production. Primed lung cells responded to secondary LPS stimulation with a T‐cell‐specific response to pustulan. Glucan source and solubility should be considered in exposure and toxicological studies.

In Europe and North America, the prevalence of pulmonary nontuberculous mycobacteria (NTM) is increasing. Most pulmonary NTM infections are caused by the Mycobacterium avium complex (MAC). Sadly, the treatment of pulmonary MAC is suboptimal with failure rates ranging from 37% to 58%. Therefore, there is a need to develop new therapeutics. Developing new immunotherapies and studying their interaction with standard or new drugs requires reliable assays. Four different assays including CFSE-based flow cytometry, in vitro protection assays, IFN-γ ELISPOT, and murine infection models were optimized using a reference strain of MAC (ATCC 700898) to help with the development of immunotherapies for MAC. Expansion of proliferating and IFN-γ producing human T cells is optimal after 7 days of stimulation with MAC at a multiplicity of infection (MOI) of 0.1, achieving a stimulation index of 26.5 ± 11.6 (mean ± SE). The in vitro protection assay for MAC works best by co-culturing T cells expanded for 7 days with MAC (MOI 1)-infected autologous macrophages. Aerosol MAC infection of mice allows measurement of the effects of the BCG vaccine and clarithromycin. IFN-γ ELISPOT assays with live MAC (MOI 3) stimulation of splenocytes from mice immunized with BCG help identify differences between unimmunized mice and mice immunized with BCG. In conclusion, multiple assays are available for use to identify MAC-specific effector T cells, which will help in the development of new therapeutics or vaccines against pulmonary MAC.

A prevalence of cigarette smoking can cause the accumulation of cadmium (Cd2+) in the lungs, kidneys, and blood. The effects of exposure can cause multiple chronic disease types to emerge in the affected organ systems. The only moderately effective therapeutic option is chelation therapy; the health risks associated with this therapy have caused much criticism. The disease types associated with Cd2+ toxicity have inflammatory components and greatly impact innate immunity. These factors are affected at the cellular level and cause pathways like apoptosis, pyroptosis, and necroptosis. A development in understanding these pathways stipulates that these three pathways act as one complex of pathways, known together as PANoptosis. The inflammatory mechanisms of PANoptosis are particularly interesting in Cd2+ toxicity due to its inflammatory effects. Proteins in the gasdermin family act to release inflammatory cytokines, like interleukin-1β, into the extracellular environment. Cytokines cause inflammatory disease pathologies like fibrosis and cancer. RAW 264.7 monocytes are key in the murine immune system and provide an excellent model to investigate Cd2+ toxicity. Exposure of 0–15 µM CdCl2 was sufficient to increase expression of cleaved gasdermin D (GSDMD) and gasdermin E (GSDME) in this cell type. Cd2+ also exhibits a dose–dependent cytotoxicity in this cell type.

Hepatic ischemia–reperfusion injury (IRI) is a major cause of postoperative hepatic dysfunction and liver failure involving cellular damage to previously ischemic tissues to which blood flow is restored. The reestablishment of blood flow is essential for salvaging ischemic tissues. The reperfusion itself, however, can paradoxically lead to further cellular damage, which involves a multi-factorial process resulting in extensive tissue damage, which can threaten the function and viability of the liver and other organ systems. The following review outlines multiple models for in-lab analysis of the various hepatic IRI mechanisms, including murine, porcine, cell lines, and machine perfusion models.

Failure of healing after rotator cuff repair (RCR) is common. The purpose of the current study was to evaluate the effect of systemic estrogen or testosterone supplementation on tendon healing after RCR. Seventy‐two adult male mice were utilized for all experiments. The supraspinatus tendon was transected and repaired with 6‐0 Prolene suture on the left shoulder of 51 animals. Mice were segregated into three groups postoperative: (1) vehicle group (VG; n = 18), (2) estrogen group (EST; n = 17), and (3) testosterone group (TST; n = 16). An unrepaired control group (unrepaired, n = 21) did not have surgery. Utilizing these animals, histological analysis, activity testing, biomechanical testing and RNA sequencing (RNA‐seq) was performed. At 8 weeks post‐RCR, TST, and EST supplementation improved the overall histologic structure of the repaired enthesis site. No differences in ultimate failure loads or stiffness were detected between VG, EST, and TST groups after biomechanical testing. RCR caused a reduction in wheel activity compared to unrepaired controls and supplementation with TST restored wheel activity. RNA‐seq analysis indicated that estrogen and testosterone regulated different pathways associated with enthesis healing, including a suppression of inflammatory signaling. Supplementation with sex hormones improved the structure of the repaired tendon enthesis and significantly regulated expression of diverse pathways regulating multiple biological processes. Testosterone administration following RCR restored wheel activity without having a detrimental impact on biomechanical strength. Future human studies of sex hormone supplementation after RCR are warranted as supplementation in an animal model may improve tendon enthesis healing. [ABSTRACT FROM AUTHOR]

We previously reported that human keratinocytes express protease-activated receptor (PAR)-2 and play an important role in activated protein C (APC)-induced cutaneous wound healing. This study investigated the involvement of PAR-2 in the production of gelatinolytic matrix metalloproteinases (MMP)-2 and -9 by APC during cutaneous wound healing. Full-thickness excisional wounds were made on the dorsum of male C57BL/6 mice. Wounds were treated with APC on days 1, 2, and 3 post-wounding. Cultured neonatal foreskin keratinocytes were treated with APC with or without intact PAR-2 signalling to examine the effects on MMP-2 and MMP-9 production. Murine dermal fibroblasts from PAR-2 knock-out (KO) mice were also assessed. MMP-2 and -9 were measured via gelatin zymography, fluorometric assay, and immunohistochemistry. APC accelerated wound healing in WT mice, but had a negligible effect in PAR-2 KO mice. APC-stimulated murine cutaneous wound healing was associated with the differential and temporal production of MMP-2 and MMP-9, with the latter peaking on day 1 and the former on day 6. Inhibition of PAR-2 in human keratinocytes reduced APC-induced MMP-2 activity by 25~50%, but had little effect on MMP-9. Similarly, APC-induced MMP-2 activation was reduced by 40% in cultured dermal fibroblasts derived from PAR-2 KO mice. This study shows for the first time that PAR-2 is essential for APC-induced MMP-2 production. Considering the important role of MMP-2 in wound healing, this work helps explain the underlying mechanisms of action of APC to promote wound healing through PAR-2. [ABSTRACT FROM AUTHOR]

Megakaryocytes (MKs), the largest and rarest cells of the hematopoietic system, differentiate by increasing their size, DNA and cytoplasmic contents during maturation in order to release high numbers of blood platelets into the circulation. The gold-standard to study these complex cells is the isolation of primary MKs from the native bone marrow (BM). This is typically achieved by using fluorescence- or magnetic-activated cell sorting. However, both methods are timeconsuming and require a trained experimenter who is able to operate highly priced special equipment. Here, we demonstrate a simple and rapid alternative method to enrich mature MKs (=16 N) from murine adult BM by size exclusion. The purity of the MK fraction reached 70-80% after isolation (100- to 250-fold enrichment). Reanalysis of isolated MKs by confocal microscopy revealed the expected expression of lineage-defining MK- and platelet-specific surface receptors, including CD42a/b/d and CD41/CD61. In addition, we detected a clear enrichment of MKspecific proteins/transcripts like ß1-tubulin, ß3-integrin, GPVI and GPIba, whereas the neutrophil marker Ly6G was only detectable in the BM sample. Taken together, we demonstrate that the protocol proposed in this Technical Report is a compatible addition to established isolation methods. [ABSTRACT FROM AUTHOR]

ABSTRACTAlthough smallpox has been eradicated, other orthopoxviruses continue to be a public health concern as exemplified by the ongoing Mpox (formerly monkeypox) global outbreak. While medical countermeasures (MCMs) previously approved by the Food and Drug Administration for the treatment of smallpox have been adopted for Mpox, previously described vulnerabilities coupled with the questionable benefit of at least one of the therapeutics during the 2022 Mpox outbreak reinforce the need for identifying and developing other MCMs against orthopoxviruses. Here, we screened a panel of Merck proprietary small molecules and identified a novel nucleoside inhibitor with potent broad-spectrum antiviral activity against multiple orthopoxviruses. Efficacy testing of a 7-day dosing regimen of the orally administered nucleoside in a murine model of severe orthopoxvirus infection yielded a dose-dependent increase in survival. Treated animals had greatly reduced lesions in the lung and nasal cavity, particularly in the 10 µg/mL dosing group. Viral levels were also markedly lower in the UMM-766-treated animals. This work demonstrates that this nucleoside analog has anti-orthopoxvirus efficacy and can protect against severe disease in a murine orthopox model.IMPORTANCEThe recent monkeypox virus pandemic demonstrates that members of the orthopoxvirus, which also includes variola virus, which causes smallpox, remain a public health issue. While currently FDA-approved treatment options exist, risks that resistant strains of orthopoxviruses may arise are a great concern. Thus, continued exploration of anti-poxvirus treatments is warranted. Here, we developed a template for a high-throughput screening assay to identify anti-poxvirus small-molecule drugs. By screening available drug libraries, we identified a compound that inhibited orthopoxvirus replication in cell culture. We then showed that this drug can protect animals against severe disease. Our findings here support the use of existing drug libraries to identify orthopoxvirus-targeting drugs that may serve as human-safe products to thwart future outbreaks.

Objective. Scleroderma, or systemic sclerosis (SSc), is a chronic autoimmune connective disease with an unknown etiology and poorly understood pathogenesis. The striking array of autoimmune, vascular, and fibrotic changes that develop in almost all patients makes SSc unique among connective tissue diseases. Although no animal model developed for SSc to date fully represents all features of human disease, some animal models that demonstrate features of SSc may help to better understand the pathogenesis of the disease and to develop new therapeutic options. In this review, we aimed to evaluate skin fibrosis and lung involvement in a bleomycin (BLM)-induced mouse model and to evaluate the differences between studies. Methods. A systematic literature review (PRISMA guideline) on PubMed and EMBASE (until May 2023, without limits) was performed. A primary literature search was conducted using the PubMed and EMBASE databases for all articles published from 1990 to May 2023. Review articles, human studies, and non-dermatological studies were excluded. Of the 38 non-duplicated studies, 20 articles were included. Results. Among inducible animal models, the BLM-induced SSc is still the most widely used. In recent years, the measurement of tissue thickness between the epidermal-dermal junction and the dermal-adipose tissue junction (dermal layer) has become more widely accepted. Conclusions. In animal studies, it is important to simultaneously evaluate lung tissues in addition to skin fibrosis induced in mice by subcutaneous BLM application, following the 3R (replacement, reduction, and refinement) principle to avoid cruelty to animals.

The decidual immunome is dynamic, dramatically changing its composition across gestation. Early pregnancy is dominated by decidual NK cells, with a shift towards T cells later in pregnancy. However, the degree, timing, and subset-specific nature of leukocyte traffic between the decidua and systemic circulation during gestation remains poorly understood. Herein, we employed intravascular staining in pregnant C57BL/6J mice and cynomolgus macaques (Macaca fascicularis) to examine leukocyte traffic into the decidual basalis during pregnancy. Timed-mated or virgin mice were tail-vein injected with labelled αCD45 antibodies 24 hours and 5 minutes before sacrifice. Pregnant cynomolgus macaques (GD155) were infused with labelled αCD45 at 2 hours or 5 mins before necropsy. Decidual cells were isolated and resulting suspensions analyzed by flow cytometry. We found that the proportion of intravascular (IVAs)-negative leukocytes (cells labeled by the 24h infusion of αCD45 or unlabeled) decreased across murine gestation while recent immigrants (24h label only) increased in mid- to late-gestation. In the cynomolgus model our data confirmed differential labeling of decidual leukocytes by the infused antibody, with the 5 min infused animal having a higher proportion of IVAs+ cells compared to the 2hr infused animal. Decidual tissue sections from both macaques showed the presence of intravascularly labeled cells, either in proximity to blood vessels (5min infused animal) or deeper into decidual stroma (2hr infused animal). These results demonstrate the value of serial intravascular staining as a sensitive tool for defining decidual leukocyte traffic during pregnancy.

Sudden cardiac death (SCD) from ventricular tachycardia/fibrillation (VT/VF) is a leading cause of death, but current therapies are limited. Despite extensive research on drugs targeting sarcolemmal ion channels, none have proven sufficiently effective for preventing SCD. Sarcoplasmic ryanodine receptor 2 (RyR2) Ca2+ release channels, the downstream effectors of sarcolemmal ion channels, are underexplored in this context. Recent evidence implicates reactive oxygen species (ROS)-mediated oxidation and hyperactivity of RyR2s in the pathophysiology of SCD. We tested the hypothesis that RyR2 inhibition of failing arrhythmogenic hearts reduces sarcoplasmic Ca2+ leak and repolarization lability, mitigates VT/VF/SCD and improves contractile function. We used a guinea pig model that replicates key clinical aspects of human nonischemic HF, such as a prolonged QT interval, a high prevalence of spontaneous arrhythmic SCD, and profound Ca2+ leak via a hyperactive RyR2. HF animals were randomized to receive dantrolene (DS) or placebo in early or chronic HF. We assessed the incidence of VT/VF and SCD (primary outcome), ECG heart rate and QT variability, echocardiographic left ventricular (LV) structure and function, immunohistochemical LV fibrosis, and sarcoplasmic RyR2 oxidation. DS treatment prevented VT/VF and SCD by decreasing dispersion of repolarization and ventricular arrhythmias. Compared to placebo, DS lowered resting heart rate, preserved chronotropic competency during transient β-adrenergic challenge, and improved heart rate variability and cardiac function. Inhibition of RyR2 hyperactivity with dantrolene mitigates the vicious cycle of sarcoplasmic Ca2+ leak-induced increases in diastolic Ca2+ and ROS-mediated RyR2 oxidation, thereby reducing repolarization lability and protecting against VT/VF/SCD. Moreover, the consequent increase in sarcoplasmic Ca2+ load improves contractile function. These potentially life-saving effects of RyR2 inhibition warrant further investigation, such as clinical studies of repurposing dantrolene as a potential new therapy for heart failure and/or SCD.

ABSTRACTHuman aging is characterized by gut microbiome alteration and differential loss of gut commensal species associated with the onset of frailty. The administration of cultured commensal strains to replenish lost taxa could potentially promote healthy aging. To investigate the interaction of whole microbiomes and administered strains, we transplanted gut microbiota from a frail or healthy elderly subject into germ-free mice. We supplemented the frail-donor recipient group with a defined consortium of taxa (the “S7”) that we identified by analyzing healthy aging subjects in our previous studies and whose abundance correlated with health-promoting dietary intervention. Inoculation with a frail or a healthy donor microbiome resulted in differential microbiota compositions in murine recipients 5 weeks post-transplantation. Fecal acetate levels were significantly higher in healthy donor recipient mice than in frail donor recipient mice after 4 weeks. However, the frailty-related phenotype was not replicated in recipient mice with single-dose microbiota transplantation from a healthy and a frail donor. Five S7 species colonized successfully in germ-free mice, with a relatively high abundance of Barnesiella intestinihominis and Eubacterium rectale. The engraftment of five S7 species in germ-free mice increased fecal acetate levels and reduced colon permeability and plasma TNF-ɑ concentration. Supplementation with the S7 in frail-microbiota recipient mice did not increase alpha-diversity but significantly increased the abundance of Barnesiella intestinihominis. S7 supplementation showed the potential for improving spatial reference memory in frail-microbiota recipient mice. Collectively, these data highlight the challenge of elderly microbiota engraftment in the germ-free mouse model but show promise for modulating the gut microbiome of frail elderly subjects by administering an artificial gut microbe consortium associated with healthy aging.

Megakaryocytes (MKs), the largest and rarest cells of the hematopoietic system, differentiate by increasing their size, DNA and cytoplasmic contents during maturation in order to release high numbers of blood platelets into the circulation. The gold-standard to study these complex cells is the isolation of primary MKs from the native bone marrow (BM). This is typically achieved by using fluorescence- or magnetic-activated cell sorting. However, both methods are time-consuming and require a trained experimenter who is able to operate highly priced special equipment. Here, we demonstrate a simple and rapid alternative method to enrich mature MKs (≥16 N) from murine adult BM by size exclusion. The purity of the MK fraction reached 70–80% after isolation (100- to 250-fold enrichment). Reanalysis of isolated MKs by confocal microscopy revealed the expected expression of lineage-defining MK- and platelet-specific surface receptors, including CD42a/b/d and CD41/CD61. In addition, we detected a clear enrichment of MK-specific proteins/transcripts like $${\rm{\beta }}$$1-tubulin, $${\rm{\beta }}$$3-integrin, GPVI and GPIb$${\rm{\alpha }}$$, whereas the neutrophil marker Ly6G was only detectable in the BM sample. Taken together, we demonstrate that the protocol proposed in this Technical Report is a compatible addition to established isolation methods.

Background: Immune checkpoint inhibitor (ICI) therapy is first-line treatment for many advanced non-small cell lung cancer (aNSCLC) patients. Predicting response could help guide selection of intensified or alternative anti-cancer regimens. We hypothesized that radiomics and laboratory variables predictive of ICI response in a murine model would also predict response in aNSCLC patients. Methods: Fifteen mice with lung carcinoma tumors implanted in bilateral flanks received ICI. Pre-ICI laboratory and computed tomography (CT) data were evaluated for association with systemic ICI response. Baseline clinical and CT data for 117 aNSCLC patients treated with nivolumab were correlated with overall survival (OS). Models for predicting treatment response were created and subjected to internal cross-validation, with the human model further tested on 42 aNSCLC patients who received pembrolizumab. Results: Models incorporating baseline NLR and identical radiomics (surface-tomass ratio, average Gray, and 2D kurtosis) predicted ICI response in mice and OS in humans with AUCs of 0.91 and 0.75, respectively. The human model successfully sorted pembrolizumab patients by longer vs. shorter predicted OS (median 35 months vs. 6 months, p=0.026 by log-rank). Discussion: This study advances precision oncology by non-invasively classifying aNSCLC patients according to ICI response using pre-treatment data only. Interestingly, identical radiomics features and NLR correlated with outcomes in the preclinical study and with ICI response in 2 independent patient cohorts, suggesting translatability of the findings. Future directions include using a radiogenomic approach to optimize modeling of ICI response. [ABSTRACT FROM AUTHOR]

Introduction: Invasive aspergillosis (IA) is the most prevalent infectious complication in patients with chronic granulomatous disease (CGD). Yet, understanding of fungal pathogenesis in the CGD host remains limited, particularly with regards to A. nidulans infection. Methods: We have used a murine model of X-linked CGD to investigate how the pathogenesis of IA varies between A. fumigatus and A. nidulans, comparing infection in both X-linked CGD (gp91-/-) mice and their parent C57BL/6 (WT) mice. A 14-colour flow cytometry panel was used to assess the cell dynamics over the course of infection, with parallel assessment of pulmonary cytokine production and lung histology. Results: We observed a lack of association between pulmonary pathology and infection outcome in gp91-/- mice, with no significant mortality in A. nidulans infected mice. An overwhelming and persistent neutrophil recruitment and IL-1 release in gp91-/- mice following both A. fumigatus and A. nidulans infection was observed, with divergent macrophage, dendritic cell and eosinophil responses and distinct cytokine profiles between the two infections. Conclusion: We have provided an in-depth characterisation of the immune response to pulmonary aspergillosis in an X-linked CGD murine model. This provides the first description of distinct pulmonary inflammatory environments in A. fumigatus and A. nidulans infection in X-linked CGD and identifies several new avenues for further research. [ABSTRACT FROM AUTHOR]

There is increased concern that the quality, generalizability and reproducibility of biomedical research can be influenced by the sex of animals used. We studied the differences between male and female mice in response to invasive pulmonary mucormycosis including susceptibility to infection, host immune reaction and responses to antifungal therapy. We used diabetic ketoacidotic (DKA) or neutropenic mice infected with either Rhizopus delemar or Mucor circinelloides. The only difference detected was that when DKA mice were infected with M. circinelloides, female mice were more resistant to infection than male mice (median survival time of 5 vs. 2 days for female and male mice, respectively). However, a 100% lethality was detected among infected animals of both sexes. Treatment with either liposomal amphotericin B (L-AMB) or posaconazole (POSA) protected mice from infection and eliminated the difference seen between infected but untreated female and male mice. Treatment with L-AMB consistently outperformed POSA in prolonging survival and reducing tissue fungal burden of DKA and neutropenic mice infected with R. delemar or M. circinelloides, in both mouse sexes. While little difference was detected in cytokine levels among both sexes, mucormycosis infection in the DKA mouse model induced more inflammatory cytokines/chemokines involved in neutrophil (CXCL1) and macrophage (CXCL2) recruitment vs. uninfected mice. As expected, this inflammatory response was reduced in the neutropenic mouse model. Our studies show that there are few differences between female and male DKA or neutropenic mice infected with mucormycosis with no effect on the outcome of treatment or host immune response.

Age-related macular degeneration (AMD) is a leading cause of irreversible vision loss and dysfunction in the retinal pigment epithelium (RPE) with age is known to contribute to disease development. The aim of this study was to investigate how the C57BL/6J mouse RPE changes with age. RPE structure was found to change with age and eccentricity, with cell size increasing, nuclei lost, and tight junctions altered in the peripheral retina. Phagocytosis of photoreceptor outer segments (POS) by the RPE was investigated using gene expression analysis and histology. RNA-Seq transcriptomic gene profiling of the RPE showed a downregulation of genes involved in phagosome processing and histological analysis showed a decline in phagosome-lysosome association in the aged tissue. In addition, failures in the autophagy pathway that modulates intracellular waste degradation were observed in the aged RPE tissue. These findings highlight that RPE cell loss and slowing of POS processing contribute to RPE dysfunction with age and may predispose the aging eye to AMD development. [ABSTRACT FROM AUTHOR]

Muscle fatigue is the diminution of force required for a particular action over time. Fatigue may be particularly pronounced in aging muscles, including those used for swallowing actions. Because risk for swallowing impairment (dysphagia) increases with aging, the contribution of muscle fatigue to age-related dysphagia is an emerging area of interest. The use of animal models, such as mice and rats (murine models) allows experimental paradigms for studying the relationship between muscle fatigue and swallowing function with a high degree of biological precision that is not possible in human studies. The goal of this article is to review basic experimental approaches to the study of murine tongue muscle fatigue related to dysphagia. Traditionally, murine muscle fatigue has been studied in limb muscles through direct muscle stimulation and behavioral exercise paradigms. As such, physiological and bioenergetic markers of muscle fatigue that have been validated in limb muscles may be applicable in studies of cranial muscle fatigue with appropriate modifications to account for differences in muscle architecture, innervation ratio, and skeletal support. Murine exercise paradigms may be used to elicit acute fatigue in tongue muscles, thereby enabling study of putative muscular adaptations. Using these approaches, hypotheses can be developed and tested in mice and rats to allow for future focused studies in human subjects geared toward developing and optimizing treatments for age-related dysphagia. [ABSTRACT FROM AUTHOR]

Therapeutic IgG mAbs have shown presence of three variations of their heavy chain C-termini, including the unprocessed C-terminal lysine, the processed C-terminal lysine, and C-terminal amidation. These variants are also present in endogenous human IgGs, although the level of unprocessed C-terminal lysine is very low. Here we report a new heavy-chain C-terminal variant, i.e., the des-GK truncation, which exists in both recombinant and endogenous human IgG4. The des-GK truncation was found in negligible amount in IgG1, IgG2 and IgG3 subclasses. Observation of a significant level of heavy-chain C-terminal des-GK truncation in endogenous human IgG4 suggests that low level of this variant present in therapeutic IgG4 is unlikely to be a safety concern. [ABSTRACT FROM AUTHOR]

Murine sepsis models play a crucial role in preclinical research, providing an essential platform for mimicking and understanding the complexity of sepsis pathogenesis. These models allow researchers to accurately reproduce critical aspects of the immune response and microbial interactions in a controlled environment. The use of endotoxins or the cecal ligation and puncture (CLP) method in murine models provides a systematic approach to studying the immune response, enabling the investigation of both the early and late phases of sepsis. The advantages of these models include reproducibility, control over experimental variables, and the ability to manipulate genetics to assess the specific role of genes. However, in selecting murine models for sepsis studies, careful consideration of ethical aspects, minimizing animal suffering, and maximizing scientific validity is crucial. In the context of future research, emerging technologies such as advanced imaging and personalized models represent promising directions to improve relevance and deepen our understanding of sepsis pathology at the molecular and functional levels. [ABSTRACT FROM AUTHOR]

Normalizing RT-qPCR miRNA datasets that encompass numerous preimplantation embryo stages requires the identification of miRNAs that may be used as stable reference genes. A need has also arisen for the normalization of the accompanying conditioned culture media as extracellular miRNAs may serve as biomarkers of embryo developmental competence. Here, we evaluate the stability of six commonly used miRNA normalization candidates, as well as small nuclear U6, using five different means of evaluation (BestKeeper, NormFinder, geNorm, the comparative Delta Ct method and RefFinder comprehensive analysis) to assess their stability throughout murine preimplantation embryo development from the oocyte to the late blastocyst stages, both in whole embryos and the associated conditioned culture media. In descending order of effectiveness, miR-16, miR-191 and miR-106 were identified as the most stable individual reference miRNAs for developing whole CD1 murine preimplantation embryos, while miR-16, miR-106 and miR-103 were ideal for the conditioned culture media. Notably, the widely used U6 reference was among the least appropriate for normalizing both whole embryo and conditioned media miRNA datasets. Incorporating multiple reference miRNAs into the normalization basis via a geometric mean was deemed beneficial, and combinations of each set of stable miRNAs are further recommended, pending validation on a per experiment basis. [ABSTRACT FROM AUTHOR]

HLA donor-specific antibodies (DSAs) binding to vascular endothelial cells of the allograft trigger inflammation, vessel injury, and antibody-mediated rejection (AMR). Accumulation of intragraft-recipient macrophages is a histological characteristic of AMR, which portends worse outcome. HLA class I (HLA I) DSAs enhance monocyte recruitment by activating endothelial cells and engaging FcγRs, but the DSA-activated donor endothelial influence on macrophage differentiation is unknown. In this study, we explored the consequence of DSA-activated endothelium on infiltrating monocyte differentiation. Here we show that cardiac allografts from murine recipients treated with MHC I DSA upregulated genes related to monocyte transmigration and Fc receptor stimulation. Human monocytes co-cultured with HLA I IgG-stimulated primary human endothelium promoted monocyte differentiation into CD68+ CD206+ CD163+ macrophages (M(HLA I IgG)), whereas HLA I F(ab')2 stimulated endothelium solely induced higher CD206 (M(HLA I F(ab')2 )). Both macrophage subtypes exhibited significant changes in discrete cytokines/chemokines and unique gene expression profiles. Cross-comparison of gene transcripts between murine DSA-treated cardiac allografts and human co-cultured macrophages identified overlapping genes. These findings uncover the role of HLA I DSA-activated endothelium in monocyte differentiation, and point to a novel, remodeling phenotype of infiltrating macrophages that may contribute to vascular injury.

There are limited treatment options for immunosuppressed patients with lethal invasive fungal infections due to Fusarium and Scedosporium Manogepix (MGX; APX001A) is a novel antifungal that targets the conserved Gwt1 enzyme required for localization of glycosylphosphatidylinositol-anchored mannoproteins in fungi. We evaluated the in vitro activity of MGX and the efficacy of the prodrug fosmanogepix (APX001) in immunosuppressed murine models of hematogenously disseminated fusariosis and pulmonary scedosporiosis. The MGX minimum effective concentration (MEC) for Scedosporium isolates was 0.03 μg/ml and ranged from 0.015 to 0.03 μg/ml for Fusarium isolates. In the scedosporiosis model, treatment of mice with 78 mg/kg and 104 mg/kg of body weight fosmanogepix, along with 1-aminobenzotriazole (ABT) to enhance the serum half-life of MGX, significantly increased median survival time versus placebo from 7 days to 13 and 11 days, respectively. Furthermore, administration of 104 mg/kg fosmanogepix resulted in an ∼2-log10 reduction in lung, kidney, or brain conidial equivalents/gram tissue (CE). Similarly, in the fusariosis model, 78 mg/kg and 104 mg/kg fosmanogepix plus ABT enhanced median survival time from 7 days to 12 and 10 days, respectively. A 2- to 3-log10 reduction in kidney and brain CE was observed. In both models, reduction in tissue fungal burden was corroborated with histopathological data, with target organs showing reduced or no abscesses in fosmanogepix-treated mice. Survival and tissue clearance were comparable to a clinically relevant high dose of liposomal amphotericin B (10 to 15 mg/kg). Our data support the continued development of fosmanogepix as a first-in-class treatment for infections caused by these rare molds.

AimsAs has been shown in larger animal models, knee immobilization can lead to arthrofibrotic phenotypes. Our study included 168 C57BL/6J female mice, with 24 serving as controls, and 144 undergoing a knee procedure to induce a contracture without osteoarthritis (OA).MethodsExperimental knees were immobilized for either four weeks (72 mice) or eight weeks (72 mice), followed by a remobilization period of zero weeks (24 mice), two weeks (24 mice), or four weeks (24 mice) after suture removal. Half of the experimental knees also received an intra-articular injury. Biomechanical data were collected to measure passive extension angle (PEA). Histological data measuring area and thickness of posterior and anterior knee capsules were collected from knee sections.ResultsExperimental knees immobilized for four weeks demonstrated mean PEAs of 141°, 72°, and 79° after zero, two, and four weeks of remobilization (n = 6 per group), respectively. Experimental knees demonstrated reduced PEAs after two weeks (p < 0.001) and four weeks (p < 0.0001) of remobilization compared to controls. Following eight weeks of immobilization, experimental knees exhibited mean PEAs of 82°, 73°, and 72° after zero, two, and four weeks of remobilization, respectively. Histological analysis demonstrated no cartilage degeneration. Similar trends in biomechanical and histological properties were observed when intra-articular violation was introduced.ConclusionThis study established a novel mouse model of robust knee contracture without evidence of OA. This was appreciated consistently after eight weeks of immobilization and was irrespective of length of remobilization. As such, this arthrofibrotic model provides opportunities to investigate molecular pathways and therapeutic strategies.Cite this article: Bone Joint Res 2023;12(1):58–71.

Galactomannan (GM) detection in biological samples has been shown to predict therapeutic response by azoles and polyenes. In a murine invasive pulmonary aspergillosis model, fosmanogepix or posaconazole treatment resulted in an ∼6- to 7-log reduction in conidial equivalents (CE)/g lung tissue after 96 h versus placebo. Changes in GM levels in BAL fluid and serum mirrored reductions in lung CE, with significant decreases seen after 96 h or 72 h for fosmanogepix or posaconazole, respectively (P < 0.02).

Purpose The cardiovascular (CV) system plays a vital role in thermoregulation because of its influence on heat transfer via forced convection and conduction by changes in blood distribution, blood velocity, and proximity of vessels to surrounding tissues. To fully understand the cardiovascular system’s role in thermoregulation, blood distribution (influenced by cardiac output, vessel size, blood flow, and pressure) must be quantified, ideally across sex and age. Additionally, wall shear stress is quantified because it is an important metric in cardiovascular disease localization and progression. By investigating the effect of thermal conditions on wall shear stress at a healthy baseline, researchers can begin to study the confluence of thermal condition with pathology or exercise. The purpose of this study is to determine the influence of sex and age on the CV response to temperature. In this work, the effect of core body temperature on hemodynamics of the murine arterial and venous systems has been studied non-invasively, at multiple locations across age and sex. Methods Male and female, adult and aged, mice (n = 20) were anesthetized and underwent MRI at 7 T. Data were acquired from four co-localized vessel pairs (the neck [carotid/jugular], torso [suprarenal and infrarenal aorta/inferior vena cava (IVC)], periphery [femoral artery/vein]) at core temperatures of 35, 36, 37, and 38 °C. Sixteen CINE, ECG-gated, phase contrast frames with one-directional velocity encoding (through plane) were acquired perpendicular to each vessel. Each frame was analyzed to quantify blood velocity and volumetric flow using a semi-automated in-house MATLAB script. Wall shear stress (WSS) was calculated using the Hagen-Poiseulle formula. A multivariable regression for WSS in the femoral artery was fitted with temperature, sex, age, body weight, and heart rate as variables. Results Blood velocity and volumetric flow were quantified in eight vessels at four core body temperatures. Flow in the infrarenal IVC linearly increased with temperature for all groups (p = .002; adjusted means of slopes: male vs. female, 0.37 and 0.28 cm/(s × °C); adult vs. aged, 0.22 and 0.43 cm/(s × °C)). Comparing average volumetric flow response to temperature, groups differed for the suprarenal aorta (adult adult males) and WSS at peak-systole (e.g., aged males

Reperfusion after ischemia causes additional cellular damage, known as reperfusion injury, for which there is still no effective remedy. Poloxamer (P)188, a tri-block copolymer-based cell membrane stabilizer (CCMS), has been shown to provide protection against hypoxia/reoxygenation (HR) injury in various models by reducing membrane leakage and apoptosis and improving mitochondrial function. Interestingly, substituting one of its hydrophilic poly-ethylene oxide (PEO) blocks with a (t)ert-butyl terminus added to the hydrophobic poly-propylene oxide (PPO) block yields a di-block compound (PEO-PPOt) that interacts better with the cell membrane lipid bi-layer and exhibits greater cellular protection than the gold standard tri-block P188 (PEO75-PPO30-PEO75). For this study, we custom-made three different new di-blocks (PEO113-PPO10t, PEO226-PPO18t and PEO113-PPO20t) to systemically examine the effects of the length of each polymer block on cellular protection in comparison to P188. Cellular protection was assessed by cell viability, lactate dehydrogenase release, and uptake of FM1-43 in mouse artery endothelial cells (ECs) following HR injury. We found that di-block CCMS were able to provide the same or better EC protection than P188. Our study provides the first direct evidence that custom-made di-block CCMS can be superior to P188 in improving EC membrane protection, raising their potential in treating cardiac reperfusion injury. [ABSTRACT FROM AUTHOR]

5-Fluorouracil (5-FU) is an antineoplastic drug. Although 5-FU is effective in targeting cancer cells, it also affects healthy cells, which can lead to clear haematological toxicity. The present study aimed to determine whether the haematological toxicity of 5-FU varies over a 24-hour period. Female rats were synchronised to a 12/12 light-dark (L/D) cycle. Rats were injected with 300 mg/kg 5-FU at six different circadian stages (1, 5, 9, 13, 17, 21 Zeitgebers (ZT)). The maximum rhythmic alteration was observed when 5-FU was administered at 5-ZT, while the minimum was observed at 21-ZT. These results suggest that the haematological toxicity of 5-FU is maximal when administered in the middle of the light-rest phase, while the haematological tolerance is optimal when 5-FU is administered at the end of the dark phase in rats, which corresponds to the end of the daytime activity phase in human patients. [ABSTRACT FROM AUTHOR]

Studies on vitamin D supplementation have been performed in experimental and clinical investigations considering gestational diabetes and/or vitamin D deficiency in pregnancy. However, the results are controversial and few present the effects and mechanisms of this micronutrient on pregestational diabetes. The objective of this study was to evaluate the effect of vitamin D on the pregnancy of rats with pre-existing diabetes and their fetuses. Pregestational diabetes was induced in Sprague–Dawley rats at birth. The adult diabetic and nondiabetic rats were orally administered with vitamin D (cholecalciferol) throughout the pregnancy. The diabetes status was monitored during pregnancy by an oral glucose tolerance test (OGTT). At the end of the pregnancy, pancreas and blood samples were collected for morphological analyses and lipid peroxidation measurements, respectively. The influence of vitamin D treatment on reproductive outcomes, fetal growth, and development were compared to those of untreated diabetic and nondiabetic pregnant rats. P < 0.05 was considered a significant statistical limit. The diabetic rats given vitamin D had a greater number of insulin-positive cells, contributing to reduced blood glucose levels and thiobarbituric acid reactive substance concentrations (TBARS—an indicator of membrane lipid peroxidation), and increased reduced thiol group levels, contributing to suitable intrauterine conditions for better fetal development, which was confirmed by higher fetal viability rates. Thus, this study shows the effects and mechanisms of vitamin D supplementation on pre-existing diabetes in pregnant rats, confirming its beneficial effects on maternal redox status and glycemic control, and the decline of adverse maternal–fetal repercussions. [ABSTRACT FROM AUTHOR]

To evaluate a potentially valuable tool to study cancer progression and metastasis, we characterized a novel murine model composed of a parental oncogene-transformed embryonic fibroblast line and five cell lines isolated from progressively advanced tumors. Lines derived from distant metastases displayed significantly greater rates of motility, invasiveness, and extracellular acidification than lines derived from a primary tumor or local metastases. A comprehensive proteomic analysis of these cells showed numerous oncogenes to be upregulated and tumor suppressors to be downregulated in the advanced lines, and provided novel targets for future examination. The first cell line capable of extravasation displayed particularly high proteomic variation, which could provide insight into its epithelial to mesenchymal transition. The proteomic variation was less than that of an established human breast cancer model, indicating that the observed differences are more likely contributive to tumorigenesis. In total, we validated a novel cell model for the study of tumorigenesis, while providing a robust proteomic data set to guide future research.

We previously reported that human keratinocytes express protease-activated receptor (PAR)-2 and play an important role in activated protein C (APC)-induced cutaneous wound healing. This study investigated the involvement of PAR-2 in the production of gelatinolytic matrix metalloproteinases (MMP)-2 and -9 by APC during cutaneous wound healing. Full-thickness excisional wounds were made on the dorsum of male C57BL/6 mice. Wounds were treated with APC on days 1, 2, and 3 post-wounding. Cultured neonatal foreskin keratinocytes were treated with APC with or without intact PAR-2 signalling to examine the effects on MMP-2 and MMP-9 production. Murine dermal fibroblasts from PAR-2 knock-out (KO) mice were also assessed. MMP-2 and -9 were measured via gelatin zymography, fluorometric assay, and immunohistochemistry. APC accelerated wound healing in WT mice, but had a negligible effect in PAR-2 KO mice. APC-stimulated murine cutaneous wound healing was associated with the differential and temporal production of MMP-2 and MMP-9, with the latter peaking on day 1 and the former on day 6. Inhibition of PAR-2 in human keratinocytes reduced APC-induced MMP-2 activity by 25~50%, but had little effect on MMP-9. Similarly, APC-induced MMP-2 activation was reduced by 40% in cultured dermal fibroblasts derived from PAR-2 KO mice. This study shows for the first time that PAR-2 is essential for APC-induced MMP-2 production. Considering the important role of MMP-2 in wound healing, this work helps explain the underlying mechanisms of action of APC to promote wound healing through PAR-2.

Heart failure continues to be a common and deadly sequela of myocardial infarction (MI). Despite strong evidence suggesting the importance of myocardial mechanics in cardiac remodelling, many MI studies still rely on two-dimensional analyses to estimate global left ventricular (LV) function. Here, we integrated four-dimensional ultrasound with three-dimensional strain mapping to longitudinally characterize LV mechanics within and around infarcts in order to study the post-MI remodelling process. To induce infarcts with varying severities, we separated 15 mice into three equal-sized groups: (i) sham, (ii) 30 min ischaemia-reperfusion, and (iii) permanent ligation of the left coronary artery. Four-dimensional ultrasound from a high-frequency small animal system was used to monitor changes in LV geometry, function and strain over 28 days. We reconstructed three-dimensional myocardial strain maps and showed that strain profiles at the infarct border followed a sigmoidal behaviour. We also identified that mice with mild remodelling had significantly higher strains in the infarcted myocardium than those with severe injury. Finally, we developed a new approach to non-invasively estimate infarct size from strain maps, which correlated well with histological results. Taken together, the presented work provides a thorough approach to quantify regional strain, an important component when assessing post-MI remodelling.

Heart failure continues to be a common and deadly sequela of myocardial infarction (MI). Despite strong evidence suggesting the importance of myocardial mechanics in cardiac remodelling, many MI studies still rely on two-dimensional analyses to estimate global left ventricular (LV) function. Here, we integrated four-dimensional ultrasound with three-dimensional strain mapping to longitudinally characterize LV mechanics within and around infarcts in order to study the post-MI remodelling process. To induce infarcts with varying severities, we separated 15 mice into three equal-sized groups: (i) sham, (ii) 30 min ischaemia-reperfusion, and (iii) permanent ligation of the left coronary artery. Four-dimensional ultrasound from a high-frequency small animal system was used to monitor changes in LV geometry, function and strain over 28 days. We reconstructed three-dimensional myocardial strain maps and showed that strain profiles at the infarct border followed a sigmoidal behaviour. We also identified that mice with mild remodelling had significantly higher strains in the infarcted myocardium than those with severe injury. Finally, we developed a new approach to non-invasively estimate infarct size from strain maps, which correlated well with histological results. Taken together, the presented work provides a thorough approach to quantify regional strain, an important component when assessing post-MI remodelling.