Bariatric surgery-induced weight loss led to major subcutaneous adipose tissue collagen remodeling, characterized by increased collagen degradation and decreased cross-linking.
Cohort (n=132)
Does bariatric surgery-induced weight loss alter the histological, transcriptomic, and physical characteristics of subcutaneous adipose tissue extracellular matrix in morbidly obese patients?
Bariatric surgery-induced weight loss is associated with major collagen remodeling in subcutaneous adipose tissue, characterized by increased degradation and decreased cross-linking, reflecting adequate extracellular matrix adaptation.
CONTEXT: Extracellular matrix (ECM) in sc adipose tissue (scAT) undergoes pathological remodeling during obesity. However, its evolution during weight loss remains poorly explored. OBJECTIVE: The objective of the investigation was to study the histological, transcriptomic, and physical characteristics of scAT ECM remodeling during the first year of bariatric surgery (BS)-induced weight loss and their relationships with metabolic and bioclinical improvements. DESIGN, SETTING, PATIENTS, AND INTERVENTIONS: A total of 118 morbidly obese candidates for BS were recruited and followed up during 1 year after BS. MAIN OUTCOME MEASURES: scAT surgical biopsy and needle aspiration as well as scAT stiffness measurement were performed in three subgroups before and after BS. Fourteen nonobese, nondiabetic subjects served as controls. RESULTS: Significantly increased picrosirius-red-stained collagen accumulation in scAT after BS was observed along with fat mass loss, despite metabolic and inflammatory improvements and undetectable changes of scAT stiffness. Collagen accumulation positively associated with M2-macrophages (CD163(+) cells) before BS but negatively afterward. Expression levels of genes encoding ECM components (eg, COL3A1, COL6A1, COL6A2, ELN), cross-linking enzymes (eg, lysyl oxidase LOX, LOXL4, transglutaminase), metalloproteinases, and their inhibitors were modified 1 year after BS. LOX expression and protein were significantly decreased and associated with decreased fat mass as well as other cross-linking enzymes. Although total collagen I and VI staining decreased 1 year after BS, we found increased degraded collagen I and III in scAT, suggesting increased degradation. CONCLUSIONS: After BS-induced weight loss and related metabolic improvements, scAT displays major collagen remodeling with an increased picrosirius-red staining that relates to increased collagen degradation and importantly decreased cross-linking. These features are in agreement with adequate ECM adaptation during fat mass loss.
Liu et al. (Thu,) conducted a cohort in Morbid obesity (n=132). Bariatric surgery vs. Baseline (before surgery) and nonobese, nondiabetic controls was evaluated on Histological, transcriptomic, and physical characteristics of subcutaneous adipose tissue extracellular matrix remodeling. Bariatric surgery-induced weight loss led to major subcutaneous adipose tissue collagen remodeling, characterized by increased collagen degradation and decreased cross-linking.