Functional characterization of TMEM86A and TMEM86B mutants by a novel lysoplasmalogenase assayKummer, Dorigatti, Dunzendorfer-Matt
et alJ Lipid Res (2025)
Abstract: Plasmalogens are an abundant class of glycerophospholipids with a characteristic 1-O-alk-1'-enyl double bond. While their synthesis has been extensively investigated, their degradation remains understudied. Plasmalogen deficiencies are associated with severe disorders in humans and interfering with their degradation would be a treatment option, but it remains out of reach due to limited knowledge. The plasmalogen double bond is degraded either directly by a plasmalogenase or by conversion to the 2' lyso forms by phospholipase and subsequent cleavage by lysoplasmalogenase (E.C. 3.3.2.2). Two lysoplasmalogenases are known so far, TMEM86A and TMEM86B. While TMEM86B has been expressed in bacteria, purified and shown to encode lysoplasmalogenase activity by a coupled optical assay, the closely related protein TMEM86A has not yet been purified, but its activity was shown indirectly by a lipidomics approach. Here, we present a novel assay for lysoplasmalogenase activity based on incubation with lysoplasmenylethanolamine or lysoplasmenylcholine, derivatization of the aldehyde product with dansylhydrazine and hydrazine quantification by reversed-phase HPLC with fluorescence detection. The method was sensitive enough to robustly detect lysoplasmalogenase activity in human embryonic kidney cells following transient expression of TMEM86A or TMEM86B and also suitable for the determination of lysoplasmalogenase activity in mouse tissues where highest activities were found in liver and duodenum. We introduced point mutations at positions proposed to be catalytically relevant and provided experimental evidence that all but one affected lysoplasmalogenase activity. Our novel assay allows direct and fast measurement of lysoplasmalogenase activity thereby providing a tool to advance research in the field of plasmalogen degradation.Copyright © 2025 The Authors. Published by Elsevier Inc. All rights reserved.
Spitz Spindle Cell/Reed Nevus With SQSTM1::NTRK2 Fusion and Atypical Features in an Older Male Patient: A Case Report and Review of LiteratureScarfò, Brunetto, Magliacane
et alJ Cutan Pathol (2025)
Abstract: Spitz lesions display a set of genetic alterations that differ from classical melanocytic lesions: examples include mutations in HRAS and fusions involving ALK, ROS1, MET, MAP3K8, BRAF, and the NTRK genes. We present a Spitz spindle cell/Reed nevus with atypical junctional features and an NTRK2 translocation in a patient of unusual age. The patient was a 61-year-old man with a pigmented brown flat 6 mm lesion growing on the skin over the left scapula. The lesion was composed of spindled and epithelioid melanocytes and was arranged in nests with some scattered focal pagetoid cells as well as intraepidermal nests at the center of the lesion and occasional mitotic figures. The melanocytes showed diffuse staining for pan-Trk antibodies. p16 staining was focally and weakly positive. The cells showed staining for HMB-45, MART-1, and tyrosinase, whereas they were negative for PRAME, ALK-1, and ROS-1 immunostaining. BAP-1 was preserved. Next-generation sequencing detected a SQSTM1::NTRK2 fusion and showed no alterations of ALK, ROS1, RET, NTRK1, and NTRK3 genes, as well as no pathogenic variants of BRAF. Fluorescent in situ hybridization showed NTRK2 translocation in all melanocytes evaluated. This case presents a Spitz nevus with a rare translocation in an older patient.© 2025 The Author(s). Journal of Cutaneous Pathology published by John Wiley & Sons Ltd.
AntiCD30-Conjugated Antibody Plus Standard BEAM as Conditioning Regimen for Autologous Hematopoietic Stem Cell Transplantation in Systemic Anaplastic Large Cell LymphomaKaloyannidis, Al-Charfli, George
et alHematol Rep (2025) 17 (1)
Abstract: Background/objectives: The outcome of refractory/relapsed systemic Anaplastic Large Cell Lymphoma (R/R-sALCL), especially for anaplastic lymphoma kinase-1 (ALK-1)-negative disease, remains dismal even after autologous hematopoietic stem cell transplantation (AHSCT). The intensification of both salvage and conditioning regimens, without increasing the toxicity, could improve the outcome of AHSCT in R/R-sALCL. Methods: Based on the successful experience of the incorporation of antiD20 monoclonal antibodies in the treatment of B-Cell Lymphomas, we designed a salvage and conditioning regimen incorporating the antiCD30-conjugated antibody (Brentuximab Vedotin, BV) to standard chemotherapy regimens, and we describe herein the clinical course of a patient with AKL-ve, R/R-sALCL, who received salvage regimen BV + DHAP, followed by AHSCT with preparative regimen consisted of BV plus standard BEAM. Results: The novel regimen was well tolerated, and no severe adverse effects were noticed. The engraftment was prompt and successful. The patient remained in complete metabolic remission for almost 12 months post-transplant. Conclusions: The proposed treatment approach, which combines antiCD30-conjugated antibody with standard salvage and conditioning regimens, demonstrated a completely acceptable toxicity with promising efficacy.
An activin receptor-like kinase 1-governed monocytic lineage shapes an immunosuppressive landscape in breast cancer metastasesSafaee Talkhoncheh, Sjölund, Bolivar
et alJ Clin Invest (2025) 135 (5)
Abstract: The biology centered around the TGF-β type I receptor activin receptor-like kinase (ALK) 1 (encoded by ACVRL1) has been almost exclusively based on its reported endothelial expression pattern since its first functional characterization more than 2 decades ago. Here, in efforts to better define the therapeutic context in which to use ALK1 inhibitors, we uncover a population of tumor-associated macrophages (TAMs) that, by virtue of their unanticipated Acvrl1 expression, are effector targets for adjuvant antiangiogenic immunotherapy in mouse models of metastatic breast cancer. The combinatorial benefit depended on ALK1-mediated modulation of the differentiation potential of bone marrow-derived granulocyte-macrophage progenitors, the release of CD14+ monocytes into circulation, and their eventual extravasation. Notably, ACVRL1+ TAMs coincided with an immunosuppressive phenotype and were overrepresented in human cancers progressing on therapy. Accordingly, breast cancer patients with a prominent ACVRL1hi TAM signature exhibited a significantly shorter survival. In conclusion, we shed light on an unexpected multimodal regulation of tumorigenic phenotypes by ALK1 and demonstrate its utility as a target for antiangiogenic immunotherapy.
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