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Updated: May 28, 2026
Visualization and Quantification of Mesenchymal Cell Adipogenic Differentiation Potential with a Lineage Specific Marker
Published on: March 31, 2018
Brucella abortus Infection Promotes Mesenchymal Stem Cell Differentiation Toward Adipogenesis, Enhancing the
Rosa Nicole Freiberger1, Cynthia Alicia Marcela López1, María Belén Palma2,3
1Consejo Nacional de Investigaciones Científicas y Tecnológicas (CONICET), Laboratorio de Inmunopatología Viral, Instituto de Investigaciones Biomédicas en Retrovirus y Sida (INBIRS), Universidad de Buenos Aires (UBA), Buenos Aires 1121, Argentina.
Brucella abortus infection promotes mesenchymal stem cell differentiation into inflammatory adipocytes, potentially causing osteoarticular injury. This process involves bacterial DNA signaling through TLR9, independent of the type IV secretion system.
Area of Science:
- Immunology
- Cell Biology
- Microbiology
Background:
- Osteoarticular injury is a common complication of brucellosis.
- Mesenchymal stem cells (MSCs) differentiate into osteoblasts or adipocytes, a balance critical for bone health.
- Aberrant adipogenesis can lead to bone loss.
Purpose of the Study:
- To investigate the effect of Brucella abortus infection on MSC differentiation.
- To elucidate the mechanisms by which B. abortus influences adipogenesis and osteogenesis.
- To determine the role of bacterial components and host signaling pathways in these processes.
Main Methods:
- Infection of MSCs with Brucella abortus.
- Analysis of osteoblast and adipocyte differentiation markers.
- Assessment of lipolysis, lipogenesis, lipid droplet dynamics, and mitochondrial interactions.
- Evaluation of cytokine secretion (IL-6) and adipokine ratios (leptin/adiponectin).
- Experiments using purified Brucella DNA and TLR9 inhibition.
Main Results:
- B. abortus infection did not impair osteoblast differentiation but increased RANKL expression, promoting bone resorption.
- Infection significantly altered adipocyte differentiation, increasing lipolysis, cholesterol, and glycerol release, leading to larger lipid droplets.
- B. abortus induced an inflammatory adipocyte phenotype with increased IL-6 and leptin/adiponectin ratio.
- The adipogenic effect was mediated by bacterial DNA via TLR9 signaling, independent of the type IV secretion system.
Conclusions:
- Brucella abortus promotes MSC differentiation towards an inflammatory adipocyte phenotype through TLR9-mediated DNA detection.
- This shift in MSC differentiation may contribute to osteoarticular injury and bone resorption associated with brucellosis.
- Targeting TLR9 signaling could be a potential therapeutic strategy.
