Quantitative Characterization of Macrophage, Lymphocyte, and Neutrophil Subtypes Within the Foreign Body Granuloma of Human Mesh Explants by 5-Marker Multiplex Fluorescence Microscopy

A LTB4/CD11b self-amplifying loop drives pyogranuloma formation in chronic granulomatous disease

Sterile pyogranulomas and heightened cytokine production are hyperinflammatory hallmarks of Chronic Granulomatous Disease (CGD). Using peritoneal cells of zymosan-treated CGD (gp91phox-/-) versus wild-type (WT) mice, an ex vivo system of pyogranuloma formation was developed to determine factors involved in and consequences of recruitment of neutrophils and monocyte-derived macrophages (MoMacs). Whereas WT cells failed to aggregate, CGD cells formed aggregates containing neutrophils initially, and MoMacs recruited secondarily. LTB4 was key, as antagonizing BLT1 blocked neutrophil aggregation, but acted only indirectly on MoMac recruitment. LTB4 upregulated CD11b expression on CGD neutrophils, and the absence/blockade of CD11b inhibited LTB4 production and cell aggregation. Neutrophil-dependent MoMac recruitment was independent of MoMac Nox2 status, BLT1, CCR1, CCR2, CCR5, CXCR2, and CXCR6. As proof of concept, CD11b-deficient CGD mice developed disrupted pyogranulomas with poorly organized neutrophils and diminished recruitment of MoMacs. Importantly, the disruption of cell aggregation and pyogranuloma formation markedly reduced proinflammatory cytokine production.

Coronary Microvascular Dysfunction in Acute Cholestasis-Induced Liver Injury

BACKGROUND

Previous studies have shown cardiac abnormalities in acute liver injury, suggesting a potential role in the associated high mortality.

METHODS

We designed an experimental study exploring the short-term effects of acute cholestasis-induced liver injury on cardiac function and structure in a rodent bile duct ligation (BDL) model to elucidate the potential interplay. Thirty-seven male Sprague-Dawley rats were subjected to BDL surgery (n = 28) or served as sham-operated (n = 9) controls. Transthoracic echocardiography, Doppler evaluation of the left anterior descending coronary artery, and myocardial contrast echocardiography were performed at rest and during adenosine and dobutamine stress 5 days after BDL. Immunohistochemical staining of myocardial tissue samples for hypoxia and inflammation as well as serum analysis were performed.

RESULTS

BDL animals exhibited acute liver injury with elevated transaminases, bilirubin, and total circulating bile acids (TBA) 5 days after BDL (TBA control: 0.81 ± 2.54 µmol/L vs. BDL: 127.52 ± 57.03 µmol/L; p < 0.001). Concurrently, cardiac function was significantly impaired, characterized by reduced cardiac output (CO) and global longitudinal strain (GLS) in the echocardiography at rest and under pharmacological stress (CO rest control: 120.6 ± 24.3 mL/min vs. BDL 102.5 ± 16.6 mL/min, p = 0.041; GLS rest control: -24.05 ± 3.8% vs. BDL: -18.5 ± 5.1%, p = 0.01). Myocardial perfusion analysis revealed a reduced myocardial blood flow at rest and a decreased coronary flow velocity reserve (CFVR) under dobutamine stress in the BDL animals (CFVR control: 2.1 ± 0.6 vs. BDL: 1.7 ± 0.5 p = 0.047). Immunofluorescence staining indicated myocardial hypoxia and increased neutrophil infiltration.

CONCLUSIONS

In summary, acute cholestasis-induced liver injury can lead to impaired cardiac function mediated by coronary microvascular dysfunction, suggesting that major adverse cardiac events may contribute to the mortality of acute liver failure. This may be due to endothelial dysfunction and direct bile acid signaling.

Electrokinetic properties of healthy and β-thalassemia erythrocyte membranes under in vitro exposure to static magnetic field

Introduction: The current understanding of the biological impacts of a static magnetic field (SMF) is restricted to the direct interactions of the magnetic field with biological membranes. The electrokinetic (zeta) potential is an electrochemical property of erythrocyte surfaces which was negatively charged in physiological media after SMF exposure (0.1‒2.0 T). Methods: The novel data about electrokinetic parameters of the erythrocytes is determined by microelectrophoresis after SMF-exposure in norm and heterozygous β-thalassemia. The methods of light scattering, lipid peroxidation, fluorescence microscopy are used. Results: The electrokinetic potential of erythrocytes in norm is increased after SMF intensities due to enhanced negatively exposed charges on the outer surface of the membrane accompanied by an increase in light scattering where changes in cell morphology are observed. Conversely, a decrease in the zeta potential of β-thalassemia erythrocytes upon SMF-treatment was determined because of the reduction in the surface electrical charge of the membranes, where a significant decrease in light scattering at 1.5 T and 2.0 T was recorded. Exposure to SMF (0.5-2.0 T) was associated with an increase in the malondialdehyde content in erythrocytes. Biophysical studies regarding the influence of SMF on the electrostatic free energy of cells shows an increase in negative values in healthy erythrocytes, which corresponds to the implementation of a spontaneous process. This is also the process in β-thalassemia cells after SMF exposure with lower negative values of free electrostatic energy than erythrocytes in norm. Discussion: The effect of static magnetic field (SMF 0.1-2.0 T) on the electrokinetic and morphological characteristics of erythrocytes in norm and β-thalassemia is determined and correlated with the increase/reduction in surface charge and shrinkage/swelling of the cells, respectively. Lipid peroxidation of healthy and β-thalassemia erythrocytes caused an enhancement of lipid peroxidation because of the higher concentrations of TBARS products in cellular suspension. SMF (0.1‒2.0 T) altered the spontaneous chemical processes with negative values of electrostatic free energy of erythrocytes in norm and β-thalassemia accompanied by a lower FITC-Concanavalin A binding affinity to membrane receptors (SMF 2.0 T). The electrokinetic properties of human erythrocytes in norm and β-thalassemia upon SMF treatment and their interrelationship with the structural-functional state of the membrane were reported. The presented work would have future fundamental applications in biomedicine.

Transversalis fascia suture reinforcement may facilitate the performance of electrospun P(LLA-CL) nanoscale fibrinogen mesh in inguinal hernia repair: a prospective single-center cohort study

The aim of this study was to evaluate a new electrospun P(LLA-CL) nanoscale fibrinogen mesh performance in real-world clinical practice. A prospective, single-center evaluation of Lichtenstein inguinal hernia repair using electrospun P(LLA-CL) nanoscale fibrinogen mesh in elderly patients with comorbid diseases was conducted between 2020 and 2022. A suture reinforcement of transversalis fascia was applied before mesh implantation. Hernia recurrence, pain score and overall complication rate were measured. A total of 52 inguinal hernias in 48 patients were included. The age of patients ranged from 33 to 95 years, with a median of 78 years. Comorbid conditions included cardiopulmonary disease, organ dysfunction, anticoagulant use, diabetes and smoking. By optimizing the physical condition perioperatively, all patients finished treatment successfully. Four cases recurred secondary to direct hernias or combined hernias and were diagnosed in the first 24 case cohort during follow-up. With surgical procedural modification involving strengthening the posterior inguinal floor by reef-up suturing of the transversalis fascia and the inferior edge of mesh slit to accommodate the spermatic cord, no further recurrence was diagnosed. Postoperative pain was mild and the pain score decreased three months after surgery compared to 1 week after surgery (p = 0.0099). No severe complications occurred, while seroma occurred in six cases. Electrospun P(LLA-CL) nanoscale fibrinogen mesh is safe and effective in repairing inguinal hernias in elderly patients with comorbid disease. A strengthening of the transversalis fascia by suturing may enhance the performance of this mesh.

A Deep-Learning-Computed Cancer Score for the Identification of Human Hepatocellular Carcinoma Area Based on a Six-Colour Multiplex Immunofluorescence Panel

Liver cancer is one of the most frequently diagnosed and fatal cancers worldwide, with hepatocellular carcinoma (HCC) being the most common primary liver cancer. Hundreds of studies involving thousands of patients have now been analysed across different cancer types, including HCC, regarding the effects of immune infiltrates on the prognosis of cancer patients. However, for these analyses, an unambiguous delineation of the cancer area is paramount, which is difficult due to the strong heterogeneity and considerable inter-operator variability induced by qualitative visual assessment and manual assignment. Nowadays, however, multiplex analyses allow the simultaneous evaluation of multiple protein markers, which, in conjunction with recent machine learning approaches, may offer great potential for the objective, enhanced identification of cancer areas with further in situ analysis of prognostic immune parameters. In this study, we, therefore, used an exemplary five-marker multiplex immunofluorescence panel of commonly studied markers for prognosis (CD3 T, CD4 T helper, CD8 cytotoxic T, FoxP3 regulatory T, and PD-L1) and DAPI to assess which analytical approach is best suited to combine morphological and immunohistochemical data into a cancer score to identify the cancer area that best matches an independent pathologist’s assignment. For each cell, a total of 68 individual cell features were determined, which were used as input for 4 different approaches for computing a cancer score: a correlation-based selection of individual cell features, a MANOVA-based selection of features, a multilayer perceptron, and a convolutional neural network (a U-net). Accuracy was used to evaluate performance. With a mean accuracy of 75%, the U-net was best capable of identifying the cancer area. Although individual cell features showed a strong heterogeneity between patients, the spatial representations obtained with the computed cancer scores delineate HCC well from non-cancer liver tissues. Future analyses with larger sample sizes will help to improve the model and enable direct, in-depth investigations of prognostic parameters, ultimately enabling precision medicine.

A Proof-of-Concept Preclinical Study Using a Novel Thermal Insulation Device in a Porcine Kidney Auto-Transplantation Model

Ischemia-reperfusion injury remains a fundamental problem during organ transplantation logistics. One key technical factor is the rapid allograft rewarming during the time of vascular reconstruction in the recipient. In this pilot study, a new thermal insulation bag (TIB) for organ transplantation was used. Insulation capacity, tissue compatibility, and usability were tested initially ex vivo on porcine kidneys (n = 24) followed by the first in vivo usage. Fourteen female German landrace pigs underwent kidney auto-transplantation after 24 h cold storage (4 °C). During the implantation process the kidney was either insulated with the new TIB, or it was not thermo-protected at all, which represents the clinical standard. In this proof-of-concept study, the usability (knife-to-skin-time) and the general thermal capacity (30 min warm storage at 38 °C ex vivo p < 0.001) was shown. The clinical outcome showed significant differences in the determination of CRP and pi-GST levels. Syndecan-1 Antibody staining showed clear significant higher counts in the control group (p < 0.01) indicating epithelial damage. However, the effect on renal outcomes in not severely pre-damaged kidneys does not appear to be conclusively significant. A close follow-up study is warranted, especially in the context of marginal organs or in cases where anastomosis-times are prolonged due to surgical complexity (e.g., multiple vessels and complex reconstructions).

The extended effect of adsorbed damage-associated molecular patterns and Toll-like receptor 2 signaling on macrophage-material interactions

Implanted biomaterials elicit an immune-mediated foreign body reaction (FBR) that results in the fibrous encapsulation of the implant and can critically impact the performance of some implants. Consequently, understanding the molecular mechanisms that underpin cell-materials interactions that initiate biomaterial-induced inflammation and fibrosis is critical to improving the performance of biomaterial implants negatively impacted by the FBR. Damage-associated molecular patterns (DAMPs) are endogenous mediators of inflammation that are released upon tissue injury and induce sterile inflammation via Toll-like receptors (TLRs). However, the prevalence of DAMPs within the adsorbed protein layer on material surfaces and their role mediating cell-material interactions is unclear. Previously, our group demonstrated that molecules in fibroblast lysates adsorbed to various biomaterials and induced a potent TLR2-dependent inflammatory response in macrophages at 24 h. In this study, we examined the extended response of RAW-Blue reporter macrophages on lysate or serum-adsorbed Teflon™ AF surfaces to understand the potential role of adsorbed DAMPs in macrophage-material interactions at later time points. Lysate-conditioned surfaces maintained increased nuclear factor kappa B (NF-κB) and activator protein 1 (AP-1) transcription factor activity and increased expression Regulated upon Activation, Normal T Cell Expressed and Presumably Secreted (RANTES/CCL5) at 72 h and 120 h, compared to FBS-conditioned surfaces. In contrast, monocyte chemoattractant protein 1 (MCP-1/CCL2) was only elevated at 72 h in lysate conditions. Transforming growth factor beta 1 (TGF-β1) secretion was significantly increased on lysate-conditioned surfaces, while conditioned media from macrophages on lysate-conditioned surfaces induced alpha smooth muscle actin (αSMA) expression in 3T3 fibroblasts. TLR2 neutralizing antibody treatment significantly decreased NF-κB/AP-1 activity and attenuated TGF-β1 expression at both time points, and MCP-1 and RANTES at 72 h. Finally, multinucleated cells were observed on lysate-conditioned surfaces at 72 h, indicating adsorbed DAMPs induced a fusion permissive environment for adherent macrophages. This study demonstrates that adsorbed DAMPs continue to influence macrophage-material responses beyond the initial 24-h period and maintain a pro-inflammatory and fibrotic response that models aspects of the early FBR. Furthermore, the transient inhibition of TLR2 continued to exert an effect at these later time points, suggesting TLR2 may be a target for therapeutic interventions in FBR.