Interaction of potato-derived RG-I with galectin-3 and gene regulation in human mesenchymal stem cells

Area of Science:

• Biomaterials Science
• Stem Cell Biology
• Regenerative Medicine

Background:

• Mesenchymal stem cells (MSCs) are crucial for bone regeneration.
• Poly-(l-lactide-co-ε-caprolactone) scaffolds functionalized with modified rhamnogalacturonan-I (RG-I) potato pectin can modulate inflammation and promote bone regeneration.
• This modulation is achieved by influencing the action of galectin-3.

Purpose of the Study:

• To determine the binding affinity of unmodified RG-I (PU) and its arabinose-deficient form (PA) to galectin-3.
• To investigate the transcriptomic effects of PA treatment on human MSCs (hMSCs).
• To analyze these effects in silico using pathway analysis in relation to galectin-3.

Main Methods:

• Binding affinity of RG-I (PU and PA) to galectin-3 was assessed using tryptophan fluorescence spectroscopy.
• Human MSCs (hMSCs) from elderly patients (>60 yrs) were analyzed via transcriptomic profiling.
• The effect of PA surface coating on gene expression was evaluated in silico using Ingenuity Pathway Analysis (IPA).

Main Results:

• RG-I binds to galectin-3 with a binding affinity of 8.66 × 10⁻⁶ M.
• The galactose sidechains of PA increased RG-I binding to galectin-3 approximately 10-fold compared to PU.
• Forty-two genes were differentially expressed in hMSCs on PA coating (FDR < 0.1), including LGALS3 (encoding galectin-3). IPA revealed enrichment for disorders/abnormalities, connective tissue/musculoskeletal disorders, and immunological/inflammatory diseases, identifying networks related to infectious diseases, immune/inflammatory response, and cell cycle control.

Conclusions:

• Modified potato pectin (PA) regulates a wide range of genes in hMSCs, including those involved in cellular, inflammatory, and immunological functions.
• PA's ability to modulate galectin-3 expression suggests its potential in promoting bone regeneration.
• Further investigation into PA's role in modulating inflammation for therapeutic applications is warranted.