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Background: Fluorescence molecular imaging, a potent and non-invasive technique, has become indispensable in medicine for visualizing molecular processes. In surgical oncology, it aids treatment by allowing visualization of tumor cells during fluorescence-guided surgery (FGS). Targeting the urokinase plasminogen activator receptor (uPAR), overexpressed during tissue remodeling and inflammation, holds promise for advancing FGS by specifically highlighting tumors. This study explores the extended use of Nanobody-based (Nb) anti-uPAR tracers, evaluating their receptor binding, ability to visualize and demarcate colorectal (CRC) and gastric cancer (GC), and detect localized (PC) and metastatic (PC-M) pancreatic carcinoma., Methods: First, the receptor structure interactions of Nb15, which binds specifically to the human homologue of uPAR, were characterized in vitro to deepen our understanding of these interactions. Subsequently, Nbs 15 and 13-where Nb13 targets the murine uPAR homologue-were labeled with the s775z fluorescent dye and validated in a randomized study in mice (n = 4 per group) using orthotopic human CRC, GC, and PC models, as well as a mouse PC-M model., Results: Nb15, which binds to the D1 domain of uPAR and competes with urokinase's binding fragment, showed rapid and specific tumor accumulation. It exhibited higher tumor-to-background ratios in CRC (3.35 ± 0.75) and PC (3.41 ± 0.46), and effectively differentiated tumors in GC (mean fluorescence intensity: 0.084 ± 0.017), as compared to control Nbs. Nb13 successfully identified primary tumors and liver metastases in PC-M models., Conclusion: The tested fluorescently-labeled anti-uPAR Nbs show significant preclinical and clinical potential for improving surgical precision and patient outcomes, with Nb15 demonstrating promise for real-time surgical guidance., Competing Interests: Competing interests I hereby declare, that with the exception of Mr. Lukasz Mateusiak and Prof. Sophie Hernot, none of the authors have conflicts of interest or financial disclosures. The aforementioned authors specifically acknowledge that they hold a patent for Anti-urokinase plasminogen activator receptor immunoglobulin single variable domains, under EP22199885.9., (Copyright © 2024 Elsevier Ltd, BASO ~ The Association for Cancer Surgery, and the European Society of Surgical Oncology. All rights reserved.)

Nephrotic syndrome is a common clinical presentation of glomerulopathy. A glomerulopathy as a paraneoplastic manifestation caused by underlying malignancy is rare. In patients with a solid tumor, membranous nephropathy is the most frequent paraneoplastic glomerulopathy. We present a case of recurrent paraneoplastic nephrotic syndrome caused by minimal change disease in a patient with Lynch syndrome. Over the years, a decrease in creatinine clearance and nephrotic-range proteinuria repeatedly functioned as a warning signal for underlying malignancies; consecutively, a colon adenocarcinoma, renal cell carcinoma and gastric adenocarcinoma were diagnosed. After treatment of the malignancies the nephrotic syndrome resolved without immunosuppressive therapy. Our patient also developed a primary lung carcinoma thrice, which did not cause an exacerbation of the minimal change disease. To further elucidate the mechanism behind the development of this phenomenon, we performed immunohistochemical analysis for vascular endothelial growth factor (VEGF) on the different tumor specimens. We found a high VEGF expression in the gastro-intestinal tumors, whereas the VEGF expression in the lung tumors was low, suggesting an association between VEGF expression and the development of paraneoplastic minimal change disease. This case report not only underlines the importance of considering a malignancy as a cause for (recurrent) nephrotic syndrome, especially in patients with an increased risk of developing malignancies like Lynch syndrome patients, but also suggests a role for VEGF in the pathogenesis of paraneoplastic minimal change disease., Competing Interests: Declarations. Informed consent: The patient approved of the publication of this case report by providing oral consent. This consent has been documented in his patient file. Competing interests: The authors declare no competing interests., (© 2024. The Author(s), under exclusive licence to Springer Nature B.V.)

Inflammatory bowel disease (IBD) is a chronic relapsing inflammation of the intestinal tract with currently not well-understood pathogenesis. In addition to the involvement of immune cells, increasing studies show an important role for fibroblasts in the pathogenesis of IBD. Previous work showed that glycolysis is the preferred energy source for fibroblasts in fibrotic diseases. 6-phosphofructo-2-kinase/fructose-2, 6-bisphosphatase 3 (PFKFB3) is a key kinase supporting glycolysis. Increased expression of PFKFB3 in several cancers and inflammatory diseases has been previously reported, but the metabolic status of fibroblasts and the role of PFKFB3 in patients with IBD are currently unknown. Therefore, in this study, we evaluated the role of glycolysis and PFKFB3 expression in IBD. Single-sample gene set enrichment analysis (ssGSEA) revealed that glycolysis was significantly higher in IBD intestinal samples, compared to healthy controls, which was confirmed in the validation cohorts of IBD patients. Single-cell sequencing data indicated that PFKFB3 expression was higher in IBD-derived stromal cells. In vitro , PFKFB3 expression in IBD-derived fibroblasts was increased after the stimulation with pro-inflammatory cytokines. Using seahorse real-time cell metabolic analysis, inflamed fibroblasts were shown to have a higher extracellular acidification rate and a lower oxygen consumption rate, which could be reversed by inhibition of JAK/STAT pathway. Furthermore, increased expression of pro-inflammatory cytokines and chemokines in fibroblasts could be reverted by PFK15, a specific inhibitor of PFKFB3. In vivo experiments showed that PFK15 reduced the severity of dextran sulfate sodium (DSS)- and Tcell transfer induced colitis, which was accompanied by a reduction in immune cell infiltration in the intestines. These findings suggest that increased stromal PFKFB3 expression contributes to inflammation and the pathological function of fibroblasts in IBD. Inhibition of PFKFB3 suppressed their inflammatory characteristics., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Zhou, Plug, Patente, de Jonge-Muller, Elmagd, van der Meulen-de Jong, Everts, Barnhoorn and Hawinkels.)

Introduction: The complement system, an essential part of the innate immune system, is involved in various autoimmune diseases. Activation of the complement system by autoantibodies results in immune activation and tissue damage. At the moment little is known about the role of the complement system in autoimmune liver disease, including primary biliary cholangitis (PBC), primary sclerosing cholangitis (PSC) and autoimmune hepatitis (AIH). Since inhibition of the complement system is currently being tested in several autoimmune diseases as a therapeutic option, its role in autoimmune liver disease requires further clarification., Methods: A review of the literature was performed on studies investigating complement activation in PBC, PSC and AIH. Since data on AIH were lacking immunohistochemical staining for IgG, C1q, C3d, C4d and C5b9 was performed on liver tissue of nine AIH patients, two healthy controls and one positive control (acute liver failure caused by paracetamol intoxication)., Results: Immunohistochemical analysis in AIH revealed increased production of C3 and C4 by hepatocytes. Despite a strong staining for IgG in the immune infiltrate in AIH, C3d, C4d and C5b9 deposition was only present in one AIH patient and the deposition was restricted to the interface between portal tracts and liver parenchyma. No deposition was found in all other AIH patients or healthy controls. Literature review showed raised plasma C3 and C4 levels in AIH, PBC and PSC patients compared to healthy controls. For PBC and PSC no complement depositions at the bile ducts were reported., Conclusion and Discussion: Although complement is involved in various autoimmune diseases, the role of complement in autoimmune liver disease seems limited. Therefore it is unlikely that complement inhibition will become a novel treatment option for these diseases., (Copyright © 2020 The Authors. Published by Elsevier B.V. All rights reserved.)

Patients with the mesenchymal subtype colorectal cancer (CRC) have a poor prognosis, in particular patients with stroma-rich tumors and aberrant SMAD4 expression. We hypothesized that interactions between SMAD4-deficient CRC cells and cancer-associated fibroblasts provide a biological explanation. In transwell invasion assays, fibroblasts increased the invasive capacity of SMAD4-deficient HT29 CRC cells, but not isogenic SMAD4-proficient HT29 cells. A TGF-β/BMP-specific array showed BMP2 upregulation by fibroblasts upon stimulation with conditioned medium from SMAD4-deficient CRC cells, while also stimulating their invasion. In a mouse model for experimental liver metastasis, the co-injection of fibroblasts increased metastasis formation of SMAD4-deficient CRC cells (p = 0.02) but not that of SMAD4-proficient CRC cells. Significantly less metastases were seen in mice co-injected with BMP2 knocked-down fibroblasts. Fibroblast BMP2 expression seemed to be regulated by TRAIL, a factor overexpressed in SMAD4-deficient CRC cells. In a cohort of 146 stage III CRC patients, we showed that patients with a combination of high stromal BMP2 expression and the loss of tumor SMAD4 expression had a significantly poorer overall survival (HR 2.88, p = 0.04). Our results suggest the existence of a reciprocal loop in which TRAIL from SMAD4-deficient CRC cells induces BMP2 in fibroblasts, which enhances CRC invasiveness and metastasis.

Chronic liver injury leads to the accumulation of myofibroblasts resulting in increased collagen deposition and hepatic fibrogenesis. Treatments specifically targeting fibrogenesis are not yet available. Mesenchymal stromal cells (MSCs) are fibroblast-like stromal (stem) cells, which stimulate tissue regeneration and modulate immune responses. In the present study we assessed whether liver fibrosis and cirrhosis can be reversed by treatment with MSCs or fibroblasts concomitant to partial hepatectomy (pHx)-induced liver regeneration. After carbon tetrachloride-induced fibrosis and cirrhosis, mice underwent a pHx and received either systemically or locally MSCs in one of the two remaining fibrotic/cirrhotic liver lobes. Eight days after treatment, liver fibrogenesis was evaluated by Sirius-red staining for collagen deposition. A significant reduction of collagen content in the locally treated lobes of the regenerated fibrotic and cirrhotic livers was observed in mice that received high dose MSCs. In the non-MSC-treated counterpart liver lobes no changes in collagen deposition were observed. Local fibroblast administration or intravenous administration of MSCs did not ameliorate fibrosis. To conclude, local administration of MSCs after pHx, in contrast to fibroblasts, results in a dose-dependent on-site reduction of collagen deposition in mouse models for liver fibrosis and cirrhosis., (© 2019 The Authors. Journal of Cellular and Molecular Medicine published by John Wiley & Sons Ltd and Foundation for Cellular and Molecular Medicine.)

Chronic liver damage leads to the onset of fibrogenesis. Rodent models for liver fibrosis have been widely used, but are less suitable for screening purposes. Therefore the aim of our study was to design a novel model for liver fibrosis in zebrafish embryos, suitable for high throughput screening. Furthermore, we evaluated the efficacy of mesenchymal stromal cells (MSCs) to inhibit the fibrotic process and thereby the applicability of this model to evaluate therapeutic responses. Zebrafish embryos were exposed to TAA or CCL4 and mRNA levels of fibrosis-related genes (Collagen-1α1, Hand-2, and Acta-2) and tissue damage-related genes (TGF-β and SDF-1a, SDF-1b) were determined, while Sirius-red staining was used to estimate collagen deposition. Three days after start of TAA exposure, MSCs were injected after which the fibrotic response was determined. In contrast to CCL4, TAA resulted in an upregulation of the fibrosis-related genes, increased extracellular matrix deposition and decreased liver sizes suggesting the onset of fibrosis. The applicability of this model to evaluate therapeutic responses was shown by local treatment with MSCs which resulted in decreased expression of the fibrosis-related RNA markers. In conclusion, TAA induces liver fibrosis in zebrafish embryos, thereby providing a promising model for future mechanistic and therapeutic studies.

[This corrects the article DOI: 10.1371/journal.pone.0022620.].