Rationale: Mesenchymal stem cells (MSCs) possess potent immunomodulatory capability, but occasionally, clinical application of MSCs is hindered by compromised cell functionality and insufficient therapeutic efficacy. Methods: Here, well-established mouse models of dextran sulfate sodium (DSS)-induced colitis and streptozotocin (STZ)-induced type 1 diabetes (T1D) were used to evaluate therapeutic immunomodulatory effects of human umbilical cord-derived MSCs. MSCs were examined at the fifth (P5) and the fifteenth (P15) passages, and three-dimensional (3D) culture was conducted by Matrigel incorporation. A series of biochemical, histopathological and cellular assays were performed to investigate the MSC function and therapeutic performance, and immunoregulation was evaluated by in vitro co-culture with T cells and in vivo analyses of T-cell infiltration into target tissues. RNA sequencing (RNA-seq) analysis followed by immunofluorescence staining, gene expression analyses and chemical regulation were used to investigate the molecular targets. Results: MSCs lose therapeutic immunomodulatory effects after extensive expansion to P15 when cell senescence occurs. Intriguingly, 3D preconditioning of MSCs in Matrigel promotes diminished immunoregulatory capability despite extensive passages, which benefits function of P15-MSCs to modulate T-cell subsets in co-culture, suppress infiltration of pro-inflammatory T cells in the colon and pancreas tissues after infusion, ameliorate systemic inflammation, and alleviate colitis and T1D in mice. Mechanistically, 3D culture provokes transcriptomic reprogramming of MSCs toward a Yes-associated protein 1 (YAP1)-marked, Hippo signaling pathway-upregulated state with promoted release of the anti-inflammatory cytokine, transforming growth factor-beta1 (TGF-β1). Moreover, chemical regulation of YAP1 by clinically relevant drugs, verteporfin (VP) and prostaglandin E2 (PGE2), affects TGF-β1 expression and the immunomodulatory capability of MSCs during dimensional culture. Conclusions: Taken together, these findings unravel YAP1-based dimensional and chemical coordination of expanded MSC immunoregulation, which will shed light on precisely controlled translational application.
© The author(s).

Severe acute respiratory syndrome coronavirus 2 mRNA vaccination has reduced effectiveness in certain immunocompromised individuals. However, the cellular mechanisms underlying these defects, as well as the contribution of disease-induced cellular abnormalities, remain largely unexplored. In this study, we conducted a comprehensive serological and cellular analysis of patients with autoimmune systemic lupus erythematosus (SLE) who received the Wuhan-Hu-1 monovalent mRNA coronavirus disease 2019 vaccine. Our findings revealed that patients with SLE exhibited reduced avidity of anti-receptor-binding domain antibodies, leading to decreased neutralization potency and breadth. We also observed a sustained anti-spike response in IgD-CD27- 'double-negative (DN)' DN2/DN3 B cell populations persisting during memory responses and with greater representation in the SLE cohort. Additionally, patients with SLE displayed compromised anti-spike T cell immunity. Notably, low vaccine efficacy strongly correlated with higher values of a newly developed extrafollicular B and T cell score, supporting the importance of distinct B cell endotypes. Finally, we found that anti-BAFF blockade through belimumab treatment was associated with poor vaccine immunogenicity due to inhibition of naive B cell priming and an unexpected impact on circulating T follicular helper cells.
© 2024. The Author(s).

Chronic atrophic gastritis (CAG) is a chronic disease of the gastric mucosa characterized by a reduction or an absolute disappearance of the original gastric glands, possibly replaced by pseudopyloric fibrosis, intestinal metaplasia, or fibrosis. CAG develops progressively into intestinal epithelial metaplasia, dysplasia, and ultimately, gastric cancer. Epidemiological statistics have revealed a positive correlation between the incidence of CAG and age. Mesenchymal stem cells (MSCs) are a type of adult stem cells derived from mesoderm, with strong tissue repair capabilities. Therefore, the restoration of the gastric mucosa may serve as an efficacious strategy to ameliorate CAG and avert gastric cancer. However, the mechanisms by which MSCs inhibit the relentless progression of aging atrophic gastritis remain to be elucidated. This study endeavored to assess a novel approach utilizing MSCs to treat CAG and forestall carcinogenics.
In this study, we selected mice with atrophic gastritis from naturally aging mice and administered human umbilical cord-derived mesenchymal stem cells (hUMSCs) via tail vein injection to evaluate the therapeutic effects of hUMSCs on age-related chronic atrophic gastritis. Initially, we employed methods such as ELISA, immunohistochemical analysis, and TUNEL assays to detect changes in the mice post-hUMSC injection. Proteomic and bioinformatics analyses were conducted to identify differentially expressed proteins, focusing on NADH: ubiquinone oxidoreductase core subunit S8 (Ndufs8). Co-culturing hUMSCs with Ndufs8 knockout gastric mucosal epithelial cells (GMECs), we utilized flow cytometry, Western blotting, real-time quantitative PCR, and immunofluorescence to investigate the mechanisms of action of hUMSCs.
We observed that hUMSCs are capable of migrating to and repairing damaged gastric mucosa. Initially, hUMSCs significantly enhanced the secretion of gastric proteins PG-1 and G17, while concurrently reducing inflammatory cytokines. Furthermore, hUMSCs mitigated gastric fibrosis and apoptosis in mucosal cells. Proteomic and bioinformatic analyses revealed alterations in the protein network involved in mitochondrial autophagy, with Ndufs8 playing a pivotal role. Upon knocking out Ndufs8 in GMECs, we noted mitochondrial damage and reduced autophagy, leading to an aged phenotype in GMECs. Co-culturing Ndufs8-knockout GMECs with hUMSCs demonstrated that hUMSCs could ameliorate mitochondrial dysfunction and restore the cell cycle in GMECs.
© 2024. The Author(s).

Mesenchymal stem cells (MSCs) have been proposed to treat osteoarthritis (OA) for many years. However, clinical outcomes have been inconsistent due to biological variation between patients, differences in tissue source and preparation of the MSCs, and type of donor (e.g. allogenic versus autologous). Here, we test the hypothesis that inconsistent clinical outcomes are related to variations in the stemness and senescence of the injected autologous adipose-derived (AD) MSCs.
In the prospective randomized trial, 45 knee OA patients were divided into two groups: Group 1 (n = 22) patients treated with high tibial osteotomy (HTO) alone and Group 2 (n = 23) patients treated with HTO followed by intra-articular injection of autologous AD-MSCs (HTO + AD-MSCs). MRI and X-ray were performed pre-operation and 12 months post-operation. WOMAC and VAS score were collected four times, every 6 months over a 24-month follow-up. We observed the proliferation and stemness of AD-MSCs selected from the 5 patients showing the most improvement and from the 5 patients with the least improvement, and completed further in vitro experiments including beta-galactosidase activity, reactive oxygen species and bioinformatic analysis.
The results showed that patients treated with HTO + AD-MSCs had a significant reduction in knee OA severity as compared to patients treated with HTO alone. Moreover, we discovered that proliferation and colony forming efficiency of AD-MSCs selected from the 5 patients showing the most improvement performed significantly better than cells selected from the 5 patients with the least improvement. AD-MSCs from the patients with the most improvement also had lower amounts of senescent cells and intracellular reactive oxygen species.
Clinical outcomes of autologous AD-MSCs therapy in knee osteoarthritis are correlated with stem cell stemness and senescence. Our study highlights emerging opportunities and trends in precision medicine that could potentially improve autologous MSC-based therapies.
© 2024. The Author(s).

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.