Three-Dimensional Aggregate Culture Enhances the Therapeutic Efficacy of Human Umbilical Cord-Derived Mesenchymal Stem Cells in the Mouse Model of Metabolic Dysfunction-Associated Steatohepatitis.

Metabolic dysfunction-associated steatohepatitis (MASH) is a progressive liver disease lacking effective therapies. Mesenchymal stem cells (MSCs) show therapeutic potential; however, their efficacy is often limited. Aggregates of human umbilical cord-derived MSCs (hUC-MSCs) were generated using AggreWell™ 400 plates. The paracrine and mechanotransduction profiles of three-dimensional (3D)-MSCs were assessed by reverse transcription quantitative PCR and western blot. MASH was induced in C57BL/6J mice via a 32-week high-fat, high-fructose, and high-cholesterol (HFFC) diet, followed by tail vein injection of PBS, two-dimensional (2D)-MSCs, or 3D-MSCs. Therapeutic efficacy was evaluated via histological staining, immunohistochemistry, and serum biochemistry. RNA sequencing was performed to elucidate underlying molecular mechanisms. Under 3D culture conditions, hUC-MSCs formed relatively uniform aggregates with preserved MSC phenotypic characteristics after recovery. 3D aggregate culture enhanced the paracrine, anti-inflammatory, mechanosensitive phenotype, pro-survival, and matrix-remodeling properties of hUC-MSCs, evidenced by increased expression of hepatocyte growth factor, tumor necrosis factor-stimulated gene 6, cyclooxygenase-2, prostaglandin E synthase, B-cell lymphoma-2, and mechanotransduction-related genes, accompanied by elevated matrix metalloproteinase-2 (MMP2) and MMP9 expression in vitro. In vivo fluorescence imaging showed no significant difference in early hepatic retention between intravenously infused single-cell hUC-MSCs and 3D aggregates. In the MASH model, 3D-MSCs more effectively reduced lipid accumulation, collagen deposition, α-smooth muscle actin, hepatomegaly, and serum total cholesterol levels compared with 2D-MSCs. Moreover, 3D-MSCs enhanced the expression of anti-inflammatory interleukin-10, while suppressing inducible nitric oxide synthase. 3D-MSC therapy induced broader transcriptional remodeling than conventional MSCs, with enrichment in extracellular matrix organization, focal adhesion, and the phosphatidylinositol 3-kinase-protein kinase B signaling pathway. Consistently, western blot analysis showed that 3D-MSCs more effectively reduced hepatic p-PI3K and p-AKT levels, indicating stronger inhibition of PI3K/AKT pathway activation. 3D aggregate culture enhances the therapeutic efficacy of hUC-MSCs against MASH, supporting its translational potential for MSC-based liver therapy.