Experimental Endpoints Research Articles

Abstract B051: Influence of MUC16 on the immune tumor microenvironment of PDAC

Abstract Pancreatic ductal adenocarcinoma (PDAC) is an aggressive disease. In most cases, PDAC initiation results from oncogenic KRAS mutations, that act in part by directly increasing levels of a glycoprotein called Mucin-16 (MUC16). MUC16 is virtually absent in the normal pancreas, expressed on tumor cells in >65% of PDAC and is a marker of poor prognosis. The cell autonomous roles of MUC16 involve signaling through the ErbB-1/2/3 axes, and eliciting downstream AKT and GSK-3β activation to promote cell proliferation and survival. PDAC has a very interesting “immune cold” tumor microenvironment (TME) that is devoid of anti-tumor T cells and is instead flush with pro-tumor myeloid cells like macrophages. However, the role of MUC16 in influencing immune cells, particularly macrophages has not been investigated. Methods: We use immunohistochemistry to check for macrophage populations in spontaneous and orthotopic models of PDAC, KPC (LSL-Kras G12D/+ ; LSL-Trp53 R172H/+ ; Pdx-1- Cre) and a derived KPC-MUC16 knockout (KPC-M16KO). Orthotopic implantation with KPC and KPC-M16- cells was done to assess survival. In vitro cytokine screening from M16+/- cells was done to understand cytokine players in MUC16-mediated immunosuppression. Clodronate liposomes (CL) and neutral control liposomes (NL) were used to deplete macrophages in orthotopically implanted KPC and KPC-M16- tumor-bearing mice, and flow cytometry was conducted to profile macrophages and T cells in the pancreas and spleens at the experimental endpoint. Results: We show that KPC-M16KO tumors have decreased M2-like macrophages, and a modest increase in M1-like macrophages, leading to a high M1/M2 ratio suggesting reduced immune suppressed cells in the KPC-M16KO models. KPC-M16KO tumor-bearing mice showed longer survival compared to the KPC group. In addition, we detect low levels of CCL2 and Serpin-E1 in cell lines and tumor tissues from KPC-M16KO models suggesting that they could serve as potential regulators of macrophage infiltration and M2-like polarization downstream of MUC16. Siglec-E (murine homolog of human Siglec-7/9) was also downregulated in KPC-M16KO tumors, suggesting MUC16-Siglec mediated immunosuppression as another mechanism. CL administration (versus NL) resulted in significant macrophage depletion in the spleens of mice with KPC and KPC-M16KO tumors, however, such depletion was not robust in the pancreas. Immune profiling studies showed a high M1/M2 ratio in the spleen and pancreas of mice treated with CL, suggesting a tumor cell-macrophage crosstalk, that could mediate M2-like macrophage states in a macrophage-rich TME. Mice treated with CL have smaller tumors, and KPC-M16KO+CL group had the smallest tumors, indicative that dual disruption of MUC16 and macrophages lowers tumor burden. Conclusions: These results suggest that MUC16 plays a crucial role in modulating the tumor immune microenvironment by increasing the accumulation of immunosuppressive macrophages in PDAC. Citation Format: Christabelle Rajesh, Satish Sagar, Prakash Radhakrishnan. Influence of MUC16 on the immune tumor microenvironment of PDAC [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Advances in Pancreatic Cancer Research; 2024 Sep 15-18; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2024;84(17 Suppl_2):Abstract nr B051.

Characterization of Effect of Enterovirus D68 in 129/Sv Mice Deficient in IFN-α/β and/or IFN-γ Receptors.

Enterovirus D68 (EV-D68), a respiratory RNA virus in the family Picornaviridae, is implicated as a potential etiological agent for acute flaccid myelitis in preteen adolescents. The absence of a specific therapeutic intervention necessitates the development of an effective animal model for EV-D68. The AG129 mouse strain, characterized by the double knockout of IFN-α/β and IFN-γ receptors on the 129 genetic background, has been proposed as a suitable model for EV-D68. The goals of this study were to assess the effect of a nonmouse-adapted EV-D68 strain (US/MO/14-18947, NR-49129) in AG129 (IFN-α/β and IFN-γ receptors null), A129 (IFN-α/β receptor null), G129 (IFN-γ receptor null), and the 129 background strain (129S2/SvPasCrl) when infected intraperitoneally at 10 d of age. Both AG129 and A129 strains demonstrated similar clinical signs (paralysis, paresis, lethargy, dyspnea [characterized by prominent abdominal respiration], and morbidity requiring euthanasia) induced by EV-D68. While G129 and 129S2 strains also exhibited susceptibility to EV-D68, the severity of clinical signs was less than in AG129 and A129 strains, and many survived to the experimental endpoint. Histopathological and immunohistochemical data confirmed EV-D68 tropism for the skeletal muscle and spinal cord and suggest that the dyspnea observed in infected mice could be attributed, in part, to lesions in the diaphragmatic skeletal muscles. These findings contribute valuable insights into the pathogenesis of EV-D68 infection in this mouse model and provide investigators with key information on virus dose and mouse strain selection when using this mouse model to evaluate candidate EV-D68 therapeutics.

Enhanced atherosclerosis in apolipoprotein E knockout rabbits: role of apoB48-rich remnant lipoproteins.

Apolipoprotein E (apoE) acts as a binding molecule for both the low-density lipoprotein receptor and the lipoprotein receptor-related protein and this function is essential for facilitating the hepatocyte uptake of lipoproteins containing apoB. The absence of apoE leads to increased atherogenicity in both humans and mice, although the precise molecular mechanisms remain incompletely understood. This study aimed to investigate the susceptibility of apoE knockout (KO) rabbits, in comparison with wild-type (WT) rabbits, to diet-induced hyperlipidemia and atherosclerosis. ApoE KO rabbits and WT rabbits were fed a diet containing 0.3% cholesterol for 16 weeks. Plasma lipid levels, lipoproteins, and apolipoproteins were analyzed. Atherosclerosis was evaluated at the endpoint of experiments. In addition, we evaluated the oxidizability of those lipoproteins containing apoB to investigate the possible mechanisms of atherosclerosis. Male apoE KO rabbits showed significantly elevated levels of total cholesterol and triglycerides compared to WT rabbits, while female apoE KO rabbits displayed similar high total cholesterol levels, albeit with significantly higher triglycerides levels than WT controls. Notably, both male (2.1-fold increase) and female (1.6-fold increase) apoE KO rabbits exhibited a significantly augmented aortic lesion area compared to WT controls. Pathological examination showed that the increased intimal lesions in apoE KO rabbits were featured by heightened infiltration of macrophages (2.7-fold increase) and smooth muscle cells (2.5-fold increase). Furthermore, coronary atherosclerotic lesions were also increased by 1.3-fold in apoE KO rabbits. Lipoprotein analysis revealed that apoB48-rich beta-very-low-density lipoproteins were notably abundant in apoE KO rabbits, suggesting that these remnant lipoproteins of intestinal origin serve as the primary atherogenic lipoproteins. Moreover, apoB48-rich remnant lipoproteins isolated from apoE KO rabbits exhibited heightened susceptibility to copper-induced oxidation. The findings indicate that apoB48-rich remnant lipoproteins, resulting from apoE deficiency, possess greater atherogenic potential than apoB100-rich remnant lipoproteins, regardless of plasma TC levels.

Photoactivated Chromophore for Keratitis-Corneal Cross-linking (PACK-CXL)-A Scoping Review Based on Preclinical Studies.

Photoactivated chromophore for keratitis-corneal cross-linking (PACK-CXL) stabilizes the corneal stroma and eliminates microorganisms. Numerous PACK-CXL protocols, using different energy sources and chromophores, have been applied in preclinical studies, including live animal studies, with various experimental designs and endpoints. So far, a systematic mapping of the applied protocols and consistency across studies seems lacking but is essential to guide future research. The scoping review protocol was in line with the JBI Manual for Evidence Synthesis. Electronic databases were searched (Embase, MEDLINE, Scopus, Web of Science) to identify eligible records, followed by a two-step selection process (title and abstract screening, full text screening) for record inclusion. We extracted information on (1) different PACK-CXL protocol characteristics; (2) infectious pathogens tested; (3) study designs and experimental settings; and (4) endpoints used to determine antimicrobial and tissue stabilizing effects. The information was charted in frequency maps. The searches yielded 3654 unique records, 233 of which met the inclusion criteria. With 103 heterogeneous endpoints, the researchers investigated a wide range of PACK-CXL protocols. The tested microorganisms reflected pathogens commonly associated with infectious keratitis. Bacterial solutions and infectious keratitis rabbit models were the most widely used models to study the antimicrobial effects of PACK-CXL. If preclinical PACK-CXL studies are to guide future translational research, further cross-disciplinary efforts are needed to establish, promote, and facilitate acceptance of common endpoints relevant to PACK-CXL. Systematic mapping of PACK-CXL protocols in preclinical studies guides future translational research.

Chemogenetic inhibition of the lateral hypothalamus effectively reduces food intake in rats in a translational proof-of-concept study

Despite the therapeutic potential of chemogenetics, the method lacks comprehensive preclinical validation, hindering its progression to human clinical trials. We aimed to validate a robust but simple in vivo efficacy assay in rats which could support chemogenetic drug discovery by providing a quick, simple and reliable animal model. Key methodological parameters such as adeno-associated virus (AAV) serotype, actuator drug, dose, and application routes were investigated by measuring the food-intake-reducing effect of chemogenetic inhibition of the lateral hypothalamus (LH) by hM4D(Gi) designer receptor stimulation. Subcutaneous deschloroclozapine in rats transfected with AAV9 resulted in a substantial reduction of food-intake, comparable to the efficacy of exenatide. We estimated that the effect of deschloroclozapine lasts 1–3 h post-administration. AAV5, oral administration of deschloroclozapine, and clozapine-N-oxide were also effective but with slightly less potency. The strongest effect on food-intake occurred within the first 30 min after re-feeding, suggesting this as the optimal experimental endpoint. This study demonstrates that general chemogenetic silencing of the LH can be utilized as an optimal, fast and reliable in vivo experimental model for conducting preclinical proof-of-concept studies in order to validate the in vivo effectiveness of novel chemogenetic treatments. We also hypothesize based on our results that universal LH silencing with existing and human translatable genetic neuroengineering techniques might be a viable strategy to affect food intake and influence obesity.

The Influence of Emodin Succinyl Ethyl Ester on Non-alcoholic Steatohepatitis Induced by a Diet High in Fructose, Cholesterol, and Fat in Mice.

Nonalcoholic steatohepatitis (NASH) is a subtype of nonalcoholic fatty liver disease (NAFLD) characterized by hepatic steatosis and evidence of hepatocyte injury (ballooning) and inflammation, with or without liver fibrosis. In this study, after 12 weeks of induction, the mice were treated with emodin succinyl ethyl ester (ESEE) for four weeks at doses of 10/30/90 mg/kg/d. The blood analysis of experimental endpoints showed that ESEE exhibited significant therapeutic effects on the progression of disorders of glycolipid metabolism and the induced liver injury in the model animals. Histopathological diagnosis of the liver and total triglyceride measurements revealed that ESEE had a significant therapeutic effect on the histopathological features of nonalcoholic fatty liver disease/hepatitis, such as cellular steatosis and activation of intrahepatic inflammation. Additionally, ESEE was able to improve hepatocyte fat deposition, steatosis, and the course of intrahepatic inflammatory activity. Furthermore, it showed some inhibitory effect on liver fibrosis in the model animals. In summary, this study confirms the therapeutic effects of ESEE on the NAFLD/NASH model in C57BL/6J mice induced by a high-fat, high cholesterol, and fructose diet. These effects were observed through improvements in liver function, inhibition of fibrosis, and inflammatory responses. Changes in blood glucose levels, blood lipid metabolism, liver histopathological staining, liver fibrosis staining, and related pathological scores further supported the therapeutic effects of ESEE. Therefore, this study has important implications for the exploration of novel drugs for nonalcoholic fatty liver disease.

High-salt diet induces microbiome dysregulation, neuroinflammation and anxiety in the chronic period after mild repetitive closed head injury in adolescent mice.

The associations between human concussions and subsequent sequelae of chronic neuropsychiatric and cardiovascular diseases such as hypertension have been reported; however, little is known about the underlying biological processes. We hypothesized that dietary changes, including a high-salt diet, disrupt the bidirectional gut-brain axis, resulting in worsening neuroinflammation and emergence of cardiovascular and behavioural phenotypes in the chronic period after repetitive closed head injury in adolescent mice. Adolescent mice were subjected to three daily closed head injuries, recovered for 12 weeks and then maintained on a high-salt diet or a normal diet for an additional 12 weeks. Experimental endpoints were haemodynamics, behaviour, microglial gene expression (bulk RNA sequencing), brain inflammation (brain tissue quantitative PCR) and microbiome diversity (16S RNA sequencing). High-salt diet did not affect systemic blood pressure or heart rate in sham or injured mice. High-salt diet increased anxiety-like behaviour in injured mice compared to sham mice fed with high-salt diet and injured mice fed with normal diet. Increased anxiety in injured mice that received a high-salt diet was associated with microgliosis and a proinflammatory microglial transcriptomic signature, including upregulation in interferon-gamma, interferon-beta and oxidative stress-related pathways. Accordingly, we found upregulation of tumour necrosis factor-alpha and interferon-gamma mRNA in the brain tissue of high salt diet-fed injured mice. High-salt diet had a larger effect on the gut microbiome composition than repetitive closed head injury. Increases in gut microbes in the families Lachnospiraceae, Erysipelotrichaceae and Clostridiaceae were positively correlated with anxiety-like behaviours. In contrast, Muribaculaceae, Acholeplasmataceae and Lactobacillaceae were negatively correlated with anxiety in injured mice that received a high-salt diet, a time-dependent effect. The findings suggest that high-salt diet, administered after a recovery period, may affect neurologic outcomes following mild repetitive head injury, including the development of anxiety. This effect was linked to microbiome dysregulation and an exacerbation of microglial inflammation, which may be physiological targets to prevent behavioural sequelae in the chronic period after mild repetitive head injury. The data suggest an important contribution of diet in determining long-term outcomes after mild repetitive head injury.

Mammalian target of rapamycin mediates expression and activity of ADAM 17 in diabetic kidney disease

Purpose: Previous data have illustrated a role for the matrix metalloprotease A Disintegrin And Metalloprotease 17 (ADAM17), known to cleave growth factors and cytokines, in renal cell injury in diabetes. The goal of this study was to identify upstream regulators of ADAM17 in the cascade of events contributing to extracellular matrix accumulation in diabetic nephropathy. Rationale: Diabetic kidney disease is a serious complication faced by type 1 and type 2 diabetic patients alike. Albuminuria and extracellular matrix accumulation are prominent features of the disease and this accumulation of extracellular matrix is a contributing factor to renal fibrosis and decline in renal function. The mechanisms involved in the pathogenesis of diabetic kidney disease have not been completely identified. Methodology: Age and weight-matched Sprague Dawley rats were obtained from Harlan Laboratories (Indianapolis, IN). Type 1 diabetes was induced through tail vein injection of streptozotocin. After rats were determined to be diabetic by blood glucose measurement, rapamycin treatments were administered intraperitoneally for two months. Both kidneys were removed and frozen in liquid nitrogen for microscopy and experimental analyses or formalin fixed for morphometric imaging at the experimental endpoint. Kidney cortex homogenates were used for western blot analyses and enzymatic activity assays. Findings: Using the mTOR complex 1 inhibitor rapamycin, it was determined that increased ADAM17 enzymatic activity and ADAM17 protein expression is dependent on mTORC1 in streptozotocin-induced type 1 diabetic rats. Inhibition of mTORC1 with rapamycin abrogated the increase in collagen IV α 2 protein expression observed in diabetic rat cortex. Additionally, this study is the first to provide evidence that mTOR complex 1 activates ADAM17 contributing to extracellular matrix accumulation in diabetic nephropathy. Studies are continuing looking at the molecular mechanisms involved in mTOR activation of ADAM17 resulting in downstream effects in cultured human proximal tubular epithelial cells. Research reported in this poster was supported by the University of the Incarnate Word Offce of Research and Graduate Studies. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Methyl-CpG binding domain protein 2 (Mbd2) drives breast cancer progression through the modulation of epithelial-to-mesenchymal transition

Methyl-CpG-binding domain protein 2 (Mbd2), a reader of DNA methylation, has been implicated in different types of malignancies, including breast cancer. However, the exact role of Mbd2 in various stages of breast cancer growth and progression in vivo has not been determined. To test whether Mbd2 plays a causal role in mammary tumor growth and metastasis, we performed genetic knockout (KO) of Mbd2 in MMTV-PyMT transgenic mice and compared mammary tumor progression kinetics between the wild-type (PyMT-Mbd2+/+) and KO (PyMT-Mbd2−/−) groups. Our results demonstrated that deletion of Mbd2 in PyMT mice impedes primary tumor growth and lung metastasis at the experimental endpoint (postnatal week 20). Transcriptomic and proteomic analyses of primary tumors revealed that Mbd2 deletion abrogates the expression of several key determinants involved in epithelial-to-mesenchymal transition, such as neural cadherin (N-cadherin) and osteopontin. Importantly, loss of the Mbd2 gene impairs the activation of the PI3K/AKT pathway, which is required for PyMT-mediated oncogenic transformation, growth, and survival of breast tumor cells. Taken together, the results of this study provide a rationale for further development of epigenetic therapies targeting Mbd2 to inhibit the progression of breast cancer.

Abstract 55: CD70-specific CAR-T cell therapy for the treatment of glioblastoma

Abstract Despite the remarkable success of chimeric antigen receptor (CAR)-T cell treatment for patients with hematologic malignancies, this method has yet failed to confer meaningful survival benefits to patients suffering from glioblastoma (GB), the most lethal type of brain tumor. This highlights the need to develop novel CAR-T cell approaches for this disease. CD70 is a member of the tumor necrosis factor receptor (TNFR) superfamily. Although absent on normal brain tissue, it is ectopically expressed in a substantial fraction of GB patients, indicating its suitability as a CAR-T cell therapy candidate. In this study, we generated CD70-targeting CAR-T cells and tested their cytotoxicity in vitro and in vivo. First, we detected CD70 in a panel of primary GB cell lines and to investigate its role, it was overexpressed in human and murine GB cells. In a syngeneic glioma model, C57BL/6J mice injected with CD70-overexpressing GL261 cells developed significantly larger tumors compared to the control counterparts. Additionally, RNA-sequencing revealed that CD70-overexpression in the same cells led to higher expression levels of immunosuppressive marker CD200 and lower levels of tumor inhibition genes Prkg2 and Sh3bgrl2, suggesting a tumor-promoting role in GB. For our immunotherapeutic intervention, we designed CD70-targeting CAR-T cell constructs featuring different co-stimulatory domains (CD27, CD28 or 4-1BB) and successfully transduced primary T-Cells from healthy donors. In an in vitro co-culture, all CAR-T cells recognized and eliminated primary cancer cells in a target-dependent and donor-independent manner, while secreting high levels of Granzyme B. The killing capacity of these cells was further highlighted in a 3D system in which in vitro-generated cortical organoids were treated with CAR-T cells after being infiltrated by CD70-expressing or control cells. Immunofluorescence (IF) staining and enzyme-linked immunosorbent assay (ELISA) revealed increased levels of Granzyme B and IFN-γ in all treated organoids previously infiltrated by CD70+ tumor cells. Importantly, generated CAR-T cells showed high specificity and efficiency in killing CD70+ tumors in vivo in the brains of immunodeficient mice. Namely, 80% of NSG mice orthotopically implanted with CD70+ GB cells and subsequently treated by CARs but not mock-transduced T-Cells showed complete tumor remission by the end of the experimental endpoint, determined by bioluminescence imaging (BLI). IF analysis of these brains showed high levels of apoptotic marker cleaved caspase-3, enhanced effector cell presence and significantly lower tumor cell occupancy compared to control-treated animals. In conclusion, we provide evidence in favor of utilization of CAR-T cells against CD70-expressing gliomas. Based on these findings, a phase-I clinical trial to assess the safety and efficacy of autologous CD70-specific CAR-T cells for relapsed CD70+ GB is being planned. Citation Format: Alexandros Kourtesakis, Hiu Nam Hannah Chow, Dennis Alexander Agardy, Eileen Bailey, Sandra Horschitz, Ammar Jabali, Rainer Will, Denise Reibold, Sonja Pusch, Christoph Schifflers, Manuel Fischer, Ling Hai, Dirk C. Hoffmann, Yu-Chan Chih, Robin Wagener, Leon Kaulen, Philipp Koch, Michael Breckwoldt, Michael Schmitt, Wolfgang Wick, Tim Sauer, Tobias Kessler. CD70-specific CAR-T cell therapy for the treatment of glioblastoma [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 55.

Double-branched stent graft and four-stage deployment in total arch repair: safety and feasibility evaluation in porcine models.

The primary objective of this research was to evaluate the safety and feasibility of an innovative double-branched stent graft system employing four-stage deployment technology for aortic arch repair in porcine models. The double-branched stent graft system consisted of a proximal polyester artificial blood vessel, the main and double-branched stent grafts and a delivery system. We utilized 12 healthy pigs as experimental animals (6 per group). Postimplantation, samples were collected at 90 and 180 days after the operations. Preoperative and postoperative imaging and intraoperative arterial blood gas analyses were performed. After the pigs were euthanized, the implanted product, surrounding tissue and major organs were collected for pathological analysis. The technical success rate of the stent graft implants was 100% (12/12). All animals survived to the experimental end point. Perioperative assessments showed intact stent grafts, and imaging features at the end of the follow-up period revealed neither endoleak nor device migration. No major adverse cardiovascular events were observed during the postoperative follow-up period. Pathological examinations confirmed the satisfactory biocompatibility of the stent graft. This innovative double-branched stent graft system with four-stage deployment technology was affirmed as a safe and feasible option for aortic arch repair in accordance with our preclinical evaluation with porcine models.

Gut metabolic changes during pregnancy reveal the importance of gastrointestinal region in sample collection.

Studies of gastrointestinal physiology and the gut microbiome often consider the influence of intestinal region on experimental endpoints. However, this same consideration is not often applied to the gut metabolome. Understanding the contribution of gut regionality may be critically important to the rapidly changing metabolic environments, such as during pregnancy. We sought to characterize the difference in the gut metabolome in pregnant mice stratified by region-comparing the small intestine, cecum, and feces. Pre-pregnancy feces were collected to understand the influence of pregnancy on the fecal metabolome. Feces were collected from CD-1 female mice before breeding. On gestation day (GD) 18, gut contents were collected from the small intestine, cecum, and descending colon. Metabolites were analyzed with LC-MS/MS using the Biocrates MetaboINDICATOR™ MxP® Quant 500 kit. Of the 104 small molecule metabolites meeting analysis criteria, we found that 84 (81%) were differentially abundant based on gut region. The most significant regional comparison observed was between the cecum and small intestines, with 52 (50%) differentially abundant metabolites. Pregnancy itself altered 41 (39.4%) fecal small molecule metabolites. The regional variation observed in the gut metabolome are likely due to the microbial and physiological differences between the different parts of the intestines. Additionally, pregnancy impacts the fecal metabolome, which may be due to evolving needs of both the dam and fetus.

Combined Effect of Maternal Separation and Early-Life Immune Activation on Brain and Behaviour of Rat Offspring.

Adversity during early life, a critical period for brain development, increases vulnerability and can have a lasting impact on the brain and behaviour of a child. However, the long-term effects of cumulative early-life stressors on brain and behaviour are not well known. We studied a 2-hit rat model of early-life adversity using maternal separation (MS) and immune activation (lipopolysaccharide (LPS)). Rat pups underwent MS for 15 (control) or 180 (MS) minutes per day from postnatal day (P)2-14 and were administered saline or LPS (intraperitoneal) on P3. Open-field (OFT) and object-place recognition tests were performed on rat offspring at P33-35 and P42-50, respectively. The pre-frontal cortex (PFC) and hippocampus were removed at the experimental endpoint (P52-55) for mRNA expression. MS induced anxiety-like behaviour in OFT in male and reduced locomotor activity in both male and female offspring. LPS induced a subtle decline in memory in the object-place recognition test in male offspring. MS increased glial fibrillary acidic protein (GFAP) and brain-derived neurotrophic factor expression in PFC and ionised calcium-binding adapter molecule-1 expression in male hippocampus. MS and LPS resulted in distinct behavioural phenotypes in a sex-specific manner. The combination of MS and LPS had a synergistic effect on the anxiety-like behaviour, locomotor activity, and GFAP mRNA expression outcomes.

An Algebraic Blueprint for Predicting Turnover Numbers and Endpoints in Photocatalysis.

The front cover artwork is provided by the Institute of Analytical and Bioanalytical Chemistry and the Institute of Inorganic ChemistryI at Ulm University within the Collaborative Research Center TRR 234 CataLight. The image shows an algebraic approach to generically calculate and predict the turnover number (TON) and the endpoint of photocatalytic hydrogen gas evolution experiments. Read the full text of the Research Article at 10.1002/cphc.202300767.

An Algebraic Blueprint for Predicting Turnover Numbers and Endpoints in Photocatalysis.

Photocatalysis is a contemporary research field given that the world's fossil energy resources including coal, mineral oil and natural gas are finite. The vast variety of photocatalytic systems demands for standardized protocols facilitating an objective comparison. While there are commonly accepted performance indicators such as the turnover number (TON) that are usually reported, to date there is no unified concept for the determination of TONs and the endpoint of the reaction during continuous measurements. Herein, we propose an algebraic approach using defined parameters and boundary conditions based on partial-least squares regression for generically calculating and predicting the turnover number and the endpoint of a photocatalytic experiment. Furthermore, the impact of the analysis period was evaluated with respect to the fidelity of the obtained TON, and the influence of the data point density along critical segments of the obtained fitting function is demonstrated.

P2X7-Mediated Antigen-Independent Activation of CD8+ T Cells Promotes Salt-Sensitive Hypertension.

CD8+ T cells (CD8Ts) have been implicated in hypertension. However, the specific mechanisms are not fully understood. In this study, we explore the contribution of the P2X7 (purinergic receptor P2X7) receptor to CD8T activation and subsequent promotion of sodium retention in the kidney. We used mouse models of hypertension. Wild type were used as genetic controls, OT1 and Rag2/OT1 mice were utilized to determine antigen dependency, and P2X7-knockout mice were studied to define the role of P2X7 in activating CD8Ts and promoting hypertension. Blood pressure was monitored continuously and kidneys were obtained at different experimental end points. Freshly isolated CD8Ts from mice for activation assays and ATP stimulation. CD8T activation-induced promotion of sodium retention was explored in cocultures of CD8Ts and mouse DCTs. We found that OT1 and Rag2/OT1 mice, which are nonresponsive to common antigens, still developed hypertension and CD8T-activation in response to deoxycorticosterone acetate/salt treatment, similar to wild-type mice. Further studies identified the P2X7 receptor on CD8Ts as a possible mediator of this antigen-independent activation of CD8Ts in hypertension. Knockout of the P2X7 receptor prevented calcium influx and cytokine production in CD8Ts. This finding was associated with reduced CD8T-DCT stimulation, reversal of excessive salt retention in DCTs, and attenuated development of salt-sensitive hypertension. Our findings suggest a novel mechanism by which CD8Ts are activated in hypertension to exacerbate salt retention and infer that the P2X7 receptor on CD8Ts may represent a new therapeutic target to attenuate T-cell-mediated immunopathology in hypertension.

OMIP-100: A flow cytometry panel to investigate human neutrophil subsets.

This 14-color, 13-antibody optimized multicolor immunofluorescence panel (OMIP) was designed for deep profiling of neutrophil subsets in various types of human samples to contextualize neutrophil plasticity in a range of healthy and diseased states. Markers present in the OMIP allow the profiling of neutrophil subsets associated with ontogeny, migration, phagocytosis capacity, granule release, and immune modulation. For panel design, we ensured that the commonly available fluorophores FITC/AF488, PE, and APC were assigned to the intracellular subset marker Olfactomedin 4, the maturity and activation marker CD10, and whole blood subset marker CD177, respectively. These markers can be easily replaced without affecting the core identification of neutrophils, enabling antibodies to new neutrophil antigens of interest or for fluorescent substrates to assess different neutrophil functions to be easily explored. Panel optimization was performed on whole blood and purified neutrophils. We demonstrate applications on clinical samples (whole blood and saliva) and experimental endpoints (purified neutrophils stimulated through an in vitro transmigration assay). We hope that providing a uniform platform to analyze neutrophil plasticity in various sample types will facilitate the future understanding of neutrophil subsets in health and disease.

High-fat Western diet alters crystalline silica-induced airway epithelium ion transport but not airway smooth muscle reactivity

ObjectivesSilicosis is an irreversible occupational lung disease resulting from crystalline silica inhalation. Previously, we discovered that Western diet (HFWD)-consumption increases susceptibility to silica-induced pulmonary inflammation and fibrosis. This study investigated the potential of HFWD to alter silica-induced effects on airway epithelial ion transport and smooth muscle reactivity.MethodsSix-week-old male F344 rats were fed a HFWD or standard rat chow (STD) and exposed to silica (Min-U-Sil 5®, 15 mg/m3, 6 h/day, 5 days/week, for 39 d) or filtered air. Experimental endpoints were measured at 0, 4, and 8 weeks post-exposure. Transepithelial potential difference (Vt), short-circuit current (ISC) and transepithelial resistance (Rt) were measured in tracheal segments and ion transport inhibitors [amiloride, Na+ channel blocker; NPPB; Clˉ channel blocker; ouabain, Na+, K+-pump blocker] identified changes in ion transport pathways. Changes in airway smooth muscle reactivity to methacholine (MCh) were investigated in the isolated perfused trachea preparation.ResultsSilica reduced basal ISC at 4 weeks and HFWD reduced the ISC response to amiloride at 0 week compared to air control. HFWD + silica exposure induced changes in ion transport 0 and 4 weeks after treatment compared to silica or HFWD treatments alone. No effects on airway smooth muscle reactivity to MCh were observed.

Establishing a Mouse Genotyping Core Facility Based on Automation, High-resolution Melting Analysis, and Purpose-developed MATLAB Applications for Sample Tracking, Data Analysis, and Report Generation

An in-house genotyping facility should aim to be more cost-effective than outsourced service and more reliable than genotyping performed by short-term employees or students of individual research groups. Reliable genotyping allows efficient and economical management of mice colonies and promotes accurate and reproducible research results. Here we provide a detailed description of our approach to establishing a genotyping core facility, relying on automated PCR assembly and high-resolution melting (HRM) analysis (first derivative). The workflow we devised was tightly managed by purpose-designed applications developed using MATLAB App Designer that allowed straightforward work planning, ensured sample tracking throughout the process, and provided a platform for reliable data analysis and generation of genotyping reports. We successfully transitioned PCR product analysis of more than 250 different target genes from standard gel electrophoresis to the more advanced HRM analysis. About 23% of the target genes required a redesign of primers to adapt to our protocol. The process was highly universal, and only 2% of the target genes required deviation from the standard PCR method to a more restricted protocol that reduces the amplification of nonspecific products. We currently run more than 1,000 PCR reactions weekly, of samples taken at weaning or experimental endpoint, and assemble a large variety of target genes in every PCR plate. We also showed that genotyping of blastocytes instead of embryos can serve as quality control of cryopreservation. Thus, our genotyping protocol promotes the 3Rs (Replacement, Reduction, and Refinement) principles. Our refined genotyping process facilitates cost-effective colony management, replaces tissue types as well as traditional methods with advanced ones, and provides reliable results in a timely manner. MATLAB codes and related data are available in supplementary materials and online.

Huang Lian Jie Du decoction attenuated colitis via suppressing the macrophage Csf1r/Src pathway and modulating gut microbiota.

Ulcerative colitis, a subtype of chronic inflammatory bowel disease (IBD), is characterized by relapsing colonic inflammation and ulcers. The traditional Chinese herbal formulation Huang Lian Jie Du (HLJD) decoction is used clinically to treat diarrhea and colitis. However, the mechanisms associated with the effects of treatment remain unclear. This study aims to elucidate the molecular mechanistic effects of HLJD formulation on colitis. Chronic colitis in mice was induced by adding 1% dextran sulfate sodium (DSS) to their drinking water continuously for 8 weeks, and HLJD decoction at the doses of 2 and 4 g/kg was administered orally to mice daily from the second week until experimental endpoint. Stool consistency scores, blood stool scores, and body weights were recorded weekly. Disease activity index (DAI) was determined before necropsy, where colon tissues were collected for biochemical analyses. In addition, the fecal microbiome of treated mice was characterized using 16S rRNA amplicon sequencing. HLJD decoction at doses of 2 and 4 g/kg relieved DSS-induced chronic colitis in mice by suppressing inflammation through compromised macrophage activity in colonic tissues associated with the colony-stimulating factor 1 receptor (Csf1r)/Src pathway. Furthermore, the HLJD formula could modify the gut microbiota profile by decreasing the abundance of Bacteroides, Odoribacter, Clostridium_sensu_stricto_1, and Parasutterella. In addition, close correlations between DAI, colon length, spleen weight, and gut microbiota were identified. Our findings revealed that the HLJD formula attenuated DSS-induced chronic colitis by reducing inflammation via Csf1r/Src-mediated macrophage infiltration, as well as modulating the gut microbiota profile.