Osteoarthritis (OA) is a common degenerative disease caused by multiple pathological mechanisms wherein subchondral bone malfunction plays a substantial role. Recently, subchondral (SC) injection of orthobiologics has been attracting growing interest albeit the mainstream delivery method of mesenchymal stem cells (MSCs) is through intra-articular (IA). This study investigates the effect of SC injection of human umbilical cord mesenchymal stem cells (UCMSCs) on OA and its possible therapeutic mechanism compared to IA injection.
Male Sprague-Dawley rats with anterior cruciate ligament transection (ACLT) received saline or UCMSC injections via SC or IA. Consecutive injections once a week for three weeks and withdrawal for another four weeks, followed by Radiographical scanning, histopathological, immunohistochemical, and terminal deoxynucleotidyl transferase (TdT)-mediated dUTP nick-end labelling (TUNEL) staining. Cell counting Kit-8 (CCK-8) assay, alkaline phosphatase (ALP), alizarin red staining (ARS), TUNEL, flow cytometry, quantitative real-time polymerase chain reaction (qRT-PCR) and Western blotting were employed in TNFα-induced MC3T3-E1 cells to illustrate the exact pathogenesis mechanism.
IA and SC UCMSC injections preserved cartilage, synovium, and subchondral bone parameters like trabecular bone volume fraction (BV/TV). SC injection uniquely improved Trabecular separation (Tb.Sp) and Trabecular number (Tb.N). SC and IA injections of UCMSCs demonstrated equivalent efficacy in promoting osteoblastic bone formation and attenuating aberrant angiogenesis of subchondral bone. In addition, we demonstrated that osteoblast apoptosis and Smad2-dependent TGF-beta (TGF-β) are crucial and interactive subchondral bone pathological features in OA. In vivo and vitro studies further revealed that UCMSCs inhibited excessive TGF-β/pSmad2 signaling to regulate aberrant vascularization, osteoblast apoptosis and differentiation imbalance, ultimately maintaining osteochondral homeostasis.
The efficacy of UCMSCs for treating OA rats via SC injection was equivalent to that of IA; and even superior to IA in terms of subchondral bone phenotype via regulating apoptosis and TGF-β/pSmad2 signaling in osteoblasts, suggesting SC injection of UCMSCs as a potential and promising cell therapy for OA treatment.
© 2025. The Author(s).

The human vascular system, comprising endothelial cells (ECs) and mural cells, covers a vast surface area in the body, providing a critical interface between blood and tissue environments. Functional differences exist across specific vascular beds, but their molecular determinants across tissues remain largely unknown. In this study, we integrated single-cell transcriptomics data from 19 human organs and tissues and defined 42 vascular cell states from approximately 67,000 cells (62 donors), including angiotypic transitional signatures along the arterial endothelial axis from large to small caliber vessels. We also characterized organotypic populations, including splenic littoral and blood-brain barrier ECs, thus clarifying the molecular profiles of these important cell states. Interrogating endothelial-mural cell molecular crosstalk revealed angiotypic and organotypic communication pathways related to Notch, Wnt, retinoic acid, prostaglandin and cell adhesion signaling. Transcription factor network analysis revealed differential regulation of downstream target genes in tissue-specific modules, such as those of FOXF1 across multiple lung vascular subpopulations. Additionally, we make mechanistic inferences of vascular drug targets within different vascular beds. This open-access resource enhances our understanding of angiodiversity and organotypic molecular signatures in human vascular cells, and has therapeutic implications for vascular diseases across tissues.
© 2024. The Author(s).

PIK3CA-related overgrowth spectrum (PROS) encompasses several rare conditions that lead to overgrowth of various body parts resulting from activating variants in PIK3CA. The absence of ideal cell models significantly impedes progress in PROS research. In this study, we focused on facial infiltrating lipomatosis (FIL) (A disorder within PROS) and aimed to establish and characterize an immortalized PROS cell line. Primary adipose-derived stem cells of FIL were immortal-ized through the transfection of simian virus 40 large T antigen (SV40LT). No significant mor-phological differences were observed in immortalized FIL-ADSCs (Im FIL-ADSCs). Im FIL-ADSCs expressed original mesenchymal surface markers, confirmed by flow cytometry. It harbored PIK3CA mutation and an increased level of PI3K/AKT activation, revealed by sanger sequencing and Western blot respectively. Karyotype analysis revealed a stable chromosome in Im FIL-ADSCs. Higher adipogenic potential and lower osteogenic differentiation properties were de-tected in Im FIL-ADSCs. The proliferative potential of Im FIL-ADSCs increased, whereas malig-nant transformation was not observed in the tumorigenesis assay. Moreover, RNA sequencing further elucidated the role of the transcription factor E2F1 in Im FIL-ADSCs. Drug screening unveiled that STAT3, HSP, EGFR, and NF-kB might be potential therapeutic targets for FIL. This study provided a valuable cellular resource for exploring the underlying pathogenic mechanisms and developing new targeted therapeutic options for PROS.
© 2024 Published by Elsevier B.V.

Pancreatic ductal adenocarcinoma (PDAC) still has a poor response to therapies, partly due to their cancer-associated fibroblasts (CAFs). Here, we investigate the synergistic impact of a combinatory approach between a known chemotherapy agent, such as gemcitabine (GEM), and gene-modified human mesenchymal stromal/stem cells (MSCs) secreting the pro-apoptotic soluble (s)TRAIL (sTRAIL MSCs) on both PDAC cells and CAFs. The combo significantly impacts on PDAC survival in 2D and 3D models. In orthotopic xenograft models, GEM and sTRAIL MSCs induce tumor architecture shredding with a reduction of CK7- and CK8/18-positive cancer cells and the abrogation of spleen metastases. A cytotoxic effect on primary human CAFs is also observed along with an alteration of their transcriptome and a reduction of the related desmoplasia. Collectively, we demonstrate a promising therapeutic profile of combining GEM and sTRAIL MSCs to target both tumoral and stromal compartments in PDAC.
Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.

Bone marrow aspirate concentrate (BMAC) and adipose-derived stromal vascular fraction (ADSVF) are the most marketed stem cell therapies to treat a variety of conditions in the general population and elite athletes. Both tissues have been used interchangeably clinically even though their detailed composition, heterogeneity, and mechanisms of action have neither been rigorously inventoried nor compared. This lack of information has prevented investigations into ideal dosages and has facilitated anecdata and misinformation. Here, we analyzed single-cell transcriptomes, proteomes, and flow cytometry profiles from paired clinical-grade BMAC and ADSVF. This comparative transcriptional atlas challenges the prevalent notion that there is one therapeutic cell type present in both tissues. We also provide data of surface markers that may enable isolation and investigation of cell (sub)populations. Furthermore, the proteome atlas highlights intertissue and interpatient heterogeneity of injected proteins with potentially regenerative or immunomodulatory capacities. An interactive webtool is available online.