BACKGROUND: Intestinal organoids have evolved as potential molecular tools that could be used to study host-microbiome interactions, nutrient uptake, and drug screening. Gut epithelial barrier functions play a crucial role in health and diseases, especially in autoimmune diseases, such as inflammatory bowel diseases (IBDs), because they disrupt the epithelial mucosa and impair barrier function. METHODS: In this study, we generated an in vitro IBD model based on dextran sodium sulfate (DSS) and intestinal organoids that could potentially be used to assess barrier integrity. Intestinal organoids were long-term cultivated and characterized with several specific markers, and the key functionality of paracellular permeability was determined using FITC-dextran 4 kDa. Intestinal organoids that had been treated with 2 lM DSS for 3 h were developed and the intestinal epithelial barrier function was sequentially evaluated. RESULTS: The results indicated that the paracellular permeability represented epithelial characteristics and their barrier function had declined when they were exposed to FITC-dextran 4 kDa after DSS treatment. In addition, we analyzed the endogenous mRNA expression of pro-inflammatory cytokines and their downstream effector genes. The results demonstrated that the inflammatory cytokines genes significantly increased in inflamed organoids compared to the control, leading to epithelial barrier damage and dysfunction. CONCLUSION The collective results showed that in vitro 3D organoids mimic in vivo tissue topology and functionality with minor limitations, and hence are helpful for testing disease models.

BACKGROUND: Intestinal organoids have evolved as potential molecular tools that could be used to study host-microbiome interactions, nutrient uptake, and drug screening. Gut epithelial barrier functions play a crucial role in health and diseases, especially in autoimmune diseases, such as inflammatory bowel diseases (IBDs), because they disrupt the epithelial mucosa and impair barrier function. METHODS: In this study, we generated an in vitro IBD model based on dextran sodium sulfate (DSS) and intestinal organoids that could potentially be used to assess barrier integrity. Intestinal organoids were long-term cultivated and characterized with several specific markers, and the key functionality of paracellular permeability was determined using FITC-dextran 4 kDa. Intestinal organoids that had been treated with 2 lM DSS for 3 h were developed and the intestinal epithelial barrier function was sequentially evaluated. RESULTS: The results indicated that the paracellular permeability represented epithelial characteristics and their barrier function had declined when they were exposed to FITC-dextran 4 kDa after DSS treatment. In addition, we analyzed the endogenous mRNA expression of pro-inflammatory cytokines and their downstream effector genes. The results demonstrated that the inflammatory cytokines genes significantly increased in inflamed organoids compared to the control, leading to epithelial barrier damage and dysfunction. CONCLUSION The collective results showed that in vitro 3D organoids mimic in vivo tissue topology and functionality with minor limitations, and hence are helpful for testing disease models.

Purpose: Papillary thyroid cancer (PTC) has a high incidence of BRAF V600E mutation. The purpose of this study was to evaluate the potential relationship between thyroiditis and BRAF V600E mutation status in patients with PTC. We investigated how a selective inhibitor of BRAF V600E PLX4032 affects the proliferation and inflammatory cytokine levels of thyroid cancer. Methods: Two thyroid cancer cell lines TPC1 and 8505C were treated with PLX4032, an analysis was done on cell growth, cell cycle, the degree of apoptosis, and levels of inflammatory cytokines. To identify the functional links of BRAF, we used the STRING database. Results: Docking results illustrated PLX4032 blocked the kinase activity by exclusively binding on the serine/threonine kinase domain. STRING results indicated BRAF is functionally linked to mitogen-activated protein kinase. Both cell lines showed a dose-dependent reduction in growth rate but had a different half maximal inhibitory concentration value for PLX4032. The reaction to PLX4032 was more sensitive in the 8505C cells than in the TPC1 cells. PLX4032 induced a G2/ M phase arrest in the TPC1 cells and G0/G1 in the 8505C cells. PLX4032 induced apoptosis only in the 8505C cells. With PLX4032, the TPC1 cells showed decreased levels of vascular endothelial growth factor, granulocyte-macrophage colonystimulating factor, chemokine (C-C motif) ligand 2/monocyte chemoattractant protein 1, whereas the 8505C cells showed significantly decreased levels of IL-8, serpin E1/plasminogen activator inhibitor-1, and matrix metalloproteinase (MMP)-3. Conclusion PLX4032 was cytotoxic in both TPC1 and 8505C cells and induced apoptosis. In the 8505C cells, inflammatory cytokines such as IL-8 and MMP-3 were down-regulated. These findings suggest the possibility that the BRAF V600E mutation needs to target inflammatory signaling pathways in the treatment of thyroid cancer.