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Background and Aims Glycoprotein VI (GPVI) is a platelet collagen/fibrin(ogen) receptor and an emerging pharmacological target for the treatment of thrombotic and thrombo-inflammatory diseases, notably ischaemic stroke. A first anti-human GPVI (hGPVI) antibody Fab-fragment (ACT017/glenzocimab, K D: 4.1 nM) recently passed a clinical phase 1b/2a study in patients with acute ischaemic stroke and was found to be well tolerated, safe, and potentially beneficial. In this study, a novel humanized anti-GPVI antibody Fab-fragment (EMA601; K D: 0.195 nM) was developed that inhibits hGPVI function with very high potency in vitro and in vivo. Methods Fab-fragments of the mouse anti-hGPVI IgG Emf6.1 were tested for functional GPVI inhibition in human platelets and in hGPVI expressing (hGP6tg/tg) mouse platelets. The in vivo effect of Emf6.1Fab was assessed in a tail bleeding assay, an arterial thrombosis model and the transient middle cerebral artery occlusion (tMCAO) model of ischaemic stroke. Using complementary-determining region grafting, a humanized version of Emf6.1Fab (EMA601) was generated. Emf6.1Fab/EMA601 interaction with hGPVI was mapped in array format and kinetics and quantified by bio-layer interferometry. Results Emf6.1Fab (K D: 0.427 nM) blocked GPVI function in human and hGP6tg/tg mouse platelets in multiple assays in vitro at concentrations ≥5 µg/mL. Emf6.1Fab (4 mg/kg)-treated hGP6tg/tg mice showed potent hGPVI inhibition ex vivo and were profoundly protected from arterial thrombosis as well as from cerebral infarct growth after tMCAO, whereas tail-bleeding times remained unaffected. Emf6.1Fab binds to a so far undescribed membrane proximal epitope in GPVI. The humanized variant EMA601 displayed further increased affinity for hGPVI (K D: 0.195 nM) and fully inhibited the receptor at 0.5 µg/mL, corresponding to a >50-fold potency compared with ACT017. Conclusions EMA601 is a conceptually novel and promising anti-platelet agent to efficiently prevent or treat arterial thrombosis and thrombo-inflammatory pathologies in humans at risk. [ABSTRACT FROM AUTHOR]

Bronchopulmonary dysplasia (BPD) is a chronic lung disease commonly seen in preterm infants, and is triggered by infection, mechanical ventilation, and oxygen toxicity. Among other problems, lifelong limitations in lung function and impaired psychomotor development may result. Despite major advances in understanding the disease pathologies, successful interventions are still limited to only a few drug therapies with a restricted therapeutic benefit, and which sometimes have significant side effects. As a more promising therapeutic option, mesenchymal stem cells (MSCs) have been in focus for several years due to their anti-inflammatory effects and their secretion of growth and development promoting factors. Preclinical studies provide evidence in that MSCs have the potential to contribute to the repair of lung injuries. This review provides an overview of MSCs, and other stem/progenitor cells present in the lung, their identifying characteristics, and their differentiation potential, including cytokine/growth factor involvement. Furthermore, animal studies and clinical trials using stem cells or their secretome are reviewed. To bring MSC-based therapeutic options further to clinical use, standardized protocols are needed, and upcoming side effects must be critically evaluated. To fill these gaps of knowledge, the MSCs' behavior and the effects of their secretome have to be examined in more (pre-) clinical studies, from which only few have been designed to date. [ABSTRACT FROM AUTHOR]

Background: Deficient mismatch repair (MMR) leading to microsatellite instability (MSI) in tumors is thought to be present in over 15% of colorectal cancer (CRC) cases. Testing CRC for MSI has traditionally been recommended following the fulfillment of clinical criteria. However, the performance of clinical criteria, especially the family history, as a selection tool for MSI screening in CRC is questionable., Methods: We retrospectively investigated the incidence of high degree MSI (MSI-H) tumors in an unselected population of CRC patients and compared its prevalence between individuals with and without family history of cancers within the spectrum of MSI-H tumors as defined in the revised Bethesda criteria., Results: The study population included 274 patients, 70 with positive and 204 without family history of MSI-H tumors with complete data including findings from MSI analysis. The overall incidence of MSI-H CRC was 18.98%. There was no statistically significant difference in the incidence of MSI-H CRC amongst both groups. The sensitivity and specificity of family history with regard to the presence of an MSI-H tumor in this collective was 36.5% and 77.5%, respectively., Conclusions: A relevant number of cases with high MSI-H CRC may be missed secondary to screening based on clinical criteria like family history alone. Thus, systematic screening independent of clinical characteristics, especially family history of cancer should be recommended in all cases with CRC., Competing Interests: Conflicts of Interest: All authors have completed the ICMJE uniform disclosure form (available at https://tgh.amegroups.com/article/view/10.21037/tgh-23-71/coif). The authors have no conflicts of interest to declare., (2024 Translational Gastroenterology and Hepatology. All rights reserved.)