Related Experiment Video
Updated: Nov 5, 2025
Measurement of Fatty Acid β-Oxidation in a Suspension of Freshly Isolated Mouse Hepatocytes
Published on: September 9, 2021
Blocking TLR4-NF-κB pathway protects mouse islets from the combinatorial impact of high fat and fetuin-A mediated
Alpana Mukhuty1, Chandrani Fouzder1, Rakesh Kundu1
1Cell Signaling Laboratory, Department of Zoology, Visva-Bharati University, Santiniketan, 731 235, India.
Abstract:
Lipid mediated pancreatic β-cell dysfunction during Type 2 diabetes is known to be regulated by activation of TLR4 (Toll Like Receptor 4) and NF-κB (Nuclear factor kappa B). Recently we have reported that MIN6 cells (mouse insulinoma cells) secrete fetuin-A on stimulation by palmitate that aggravates β-cell dysfunction, but the mechanism involved in-vivo has not been demonstrated and thus remained unclear. Here we attempted to dissect the role of palmitate and fetuin-A on insulin secretion using high fat diet (HFD) fed mice model. HFD islets showed curtailed insulin secretion after 20 weeks of treatment with activated TLR4-NF-κB pathway. Further treatment of islets with palmitate raised fetuin-A expression by ~2.8 folds and cut down insulin secretion by ~1.4 folds. However, blocking the activity of TLR4, fetuin-A and NF-κB using specific inhibitors or siRNAs not only restored insulin secretion by ~2 folds in standard diet fed mice islets and MIN6 cells but also evoke insulin secretory ability by ~2.3 folds in HFD islets. Altogether this study demonstrated that blocking TLR4, fetuin-A and NF-κB protect pancreatic β-cells from the negative effects of free fatty acid and fetuin-A and restore insulin secretion.
Insights
Blocking Toll Like Receptor 4 (TLR4), fetuin-A, and Nuclear Factor kappa B (NF-κB) protects pancreatic beta cells from free fatty acid damage. This intervention restores insulin secretion impaired by Type 2 diabetes.
Area of Science:
- Endocrinology
- Molecular Biology
- Metabolic Diseases
Background:
- Lipid-induced pancreatic beta-cell dysfunction in Type 2 diabetes involves Toll Like Receptor 4 (TLR4) and Nuclear Factor kappa B (NF-κB) activation.
- Previous studies showed palmitate-stimulated MIN6 cells secrete fetuin-A, worsening beta-cell dysfunction, but in-vivo mechanisms were unclear.
Purpose of the Study:
- To investigate the in-vivo roles of palmitate and fetuin-A in insulin secretion using a high-fat diet (HFD) mouse model.
- To determine if blocking TLR4, fetuin-A, and NF-κB can protect pancreatic beta cells.
Main Methods:
- Utilized a high-fat diet (HFD) mouse model over 20 weeks.
- Administered specific inhibitors or siRNAs to block TLR4, fetuin-A, and NF-κB pathways.
- Assessed insulin secretion in islets and MIN6 cells.
Main Results:
- HFD islets exhibited reduced insulin secretion linked to TLR4-NF-κB pathway activation.
- Palmitate treatment increased fetuin-A expression (~2.8-fold) and decreased insulin secretion (~1.4-fold) in islets.
- Blocking TLR4, fetuin-A, and NF-κB restored insulin secretion (~2-fold in standard diet, ~2.3-fold in HFD islets).
Conclusions:
- Blocking TLR4, fetuin-A, and NF-κB effectively protects pancreatic beta cells from detrimental free fatty acid and fetuin-A effects.
- This therapeutic strategy can restore insulin secretory function in the context of Type 2 diabetes.
