Transcriptomic profiling of LAMA5-deficient human stem cell–derived chondrogenesis reveals a human-specific ECM–WNT signaling axis
This study investigates the transcriptional consequences of Laminin-a5 (LAMA5) loss in human urine-derived stem cells (USCs) to understand the molecular etiology of idiopathic short stature. The experiment consists of two components:  1. Differentiation Profiling: CRISPR/Cas9-mediated LAMA5 knockout (KO) USCs and wild-type (WT) controls were profiled in three conditions: undifferentiated state, osteogenic differentiation, and chondrogenic differentiation. This analysis aims to interpret how cell-matrix interactions regulate lineage-specific transcriptional programs and spheroid architecture. 2. Pharmacological Rescue: To assess the functional role of canonical WNT signaling in LAMA5-mediated regulation, LAMA5 knockout USCs were undergoing chondrogenic differentiation were treated with the WNT agonist Lithium Chloride (LiCl) or left untreated.  Data analysis identifies a LAMA5-dependent gene regulatory network enriched for limb morphogenesis factors (including WNT7A, PITX1, and FLI1) and demonstrates partial restoration of this network upon ß-catenin stabilization via LiCl.  Study Design / Samples Total Samples: 24 Organism: Homo sapiens Cell Type: Urine-derived stem cells (USCs) Detailed Sample List:  Condition 1 (Genotype x Lineage): Comparison of WT vs. LAMA5 KO across three differentiation stages (n=18). 3x Wild-type (WT) - Undifferentiated 3x Wild-type (WT) - Osteogenic 3x Wild-type (WT) - Chondrogenic 3x LAMA5 KO - Undifferentiated 3x LAMA5 KO - Osteogenic 3x LAMA5 KO - Chondrogenic   Condition 2 (Rescue Treatment): Effect of LiCl treatment on LAMA5 KO cells (n=6). 3x LAMA5 KO (Clone 2) - Untreated (Control) 3x LAMA5 KO (Clone 2) - Treated with LiCl