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Insulin-producing cells could not mimic the physiological regulation of insulin secretion performed by pancreatic beta cells.

Shi Q, Luo S, Jia H, Feng L, Lu X, Zhou L, Cai J - Nanoscale Res Lett (2013)

Bottom Line: The morphological features were detected by atomic force microscopy (AFM) and laser confocal scanning microscopy.IPCs and normal human pancreatic beta cells were similar to each other under the observation in AFM with the porous structure features in the cytoplasm.Both number of membrane particle size and average roughness of normal human beta cells were higher than those of IPCs.

View Article: PubMed Central - HTML - PubMed

Affiliation: Institute for Nano-Chemistry, Department of Chemistry, Jinan University, Guangzhou 510632, China. tjycai@jnu.edu.cn.

ABSTRACT

Objective: The aim of this study was to compare the difference between insulin-producing cells (IPCs) and normal human pancreatic beta cells both in physiological function and morphological features in cellular level.

Methods: The levels of insulin secretion were measured by enzyme-linked immunosorbent assay. The insulin gene expression was determined by real-time quantitative polymerase chain reaction. The morphological features were detected by atomic force microscopy (AFM) and laser confocal scanning microscopy.

Results: IPCs and normal human pancreatic beta cells were similar to each other under the observation in AFM with the porous structure features in the cytoplasm. Both number of membrane particle size and average roughness of normal human beta cells were higher than those of IPCs.

Conclusions: Our results firstly revealed that the cellular ultrastructure of IPCs was closer to that of normal human pancreatic beta cells, but they still could not mimic the physiological regulation of insulin secretion performed by pancreatic beta cells.

No MeSH data available.


Morphological changes of IPCs, as detected by AFM. Treated with D-PBS (A1 to A4), high-glucose medium for 1 h (B1 to B4), high-glucose medium for 30 min (C1 to C4), low-glucose medium for 1 h (D1 to D4), low-glucose medium for 30 min (E1 to E4). A1, B1, C1, D1, and E1 show the morphology of the whole cell; A3, B3, C3, D3, and E3 show surface ultrastructures on corresponding cells in images A2, B2, C2, D2, and E2; A4, B4, C4, D4, and E4 show 3D structures of the cells.
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Figure 3: Morphological changes of IPCs, as detected by AFM. Treated with D-PBS (A1 to A4), high-glucose medium for 1 h (B1 to B4), high-glucose medium for 30 min (C1 to C4), low-glucose medium for 1 h (D1 to D4), low-glucose medium for 30 min (E1 to E4). A1, B1, C1, D1, and E1 show the morphology of the whole cell; A3, B3, C3, D3, and E3 show surface ultrastructures on corresponding cells in images A2, B2, C2, D2, and E2; A4, B4, C4, D4, and E4 show 3D structures of the cells.

Mentions: Figures 2 and 3 show a characteristic structure with many holes located in the cytoplasm in beta cells and IPCs. The porous structure was more obvious in the glucose-stimulated group. We measured the Ra in the analytical area. The statistical results showed that the Ra of the beta cells was bigger than that of the IPCs, regardless of whether glucose stimulation was provided (Table 4). We also measured the nanoparticle size of cells through AFM. The data indicate that the nanoparticle size of beta cells was bigger than that of IPCs, regardless of whether they were subject to glucose stimulation. Moreover, for normal human pancreatic beta cells, the Ra values were similar to each other when comparing 30-min stimulation with 1-h stimulation within the same glucose concentration (P < 0.05). However, in the IPCs group, Ra values were much lower when cells were stimulated for 30 min by low glucose concentrations, which was similar to the case observed in a non-glucose state (P > 0.05). Particle size trends resembled those of the Ra values. Meanwhile, due to the nanometer-scale resolution of AFM, we observed single-membrane proteins and revealed details of the cellular surface structure. Figures 2 (A3) and 3 (A3) showed that the membrane proteins of both beta cells and IPCs exhibited a homogeneous granular distribution. Figures 2 (B1 to B4, C1 to C4, D1 to D4, E1 to E4) and 3 (B1 to B4, C1 to C4, E1 to E4) evidenced that the cell surface architecture of the normal human pancreatic beta cells and IPCs had been changed and membrane proteins exhibited some extent of aggregation after glucose stimulation, except for IPCs stimulated for 30 min in low glucose concentrations (Figure 3 (D1 to D4)).


Insulin-producing cells could not mimic the physiological regulation of insulin secretion performed by pancreatic beta cells.

Shi Q, Luo S, Jia H, Feng L, Lu X, Zhou L, Cai J - Nanoscale Res Lett (2013)

Morphological changes of IPCs, as detected by AFM. Treated with D-PBS (A1 to A4), high-glucose medium for 1 h (B1 to B4), high-glucose medium for 30 min (C1 to C4), low-glucose medium for 1 h (D1 to D4), low-glucose medium for 30 min (E1 to E4). A1, B1, C1, D1, and E1 show the morphology of the whole cell; A3, B3, C3, D3, and E3 show surface ultrastructures on corresponding cells in images A2, B2, C2, D2, and E2; A4, B4, C4, D4, and E4 show 3D structures of the cells.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3585706&req=5

Figure 3: Morphological changes of IPCs, as detected by AFM. Treated with D-PBS (A1 to A4), high-glucose medium for 1 h (B1 to B4), high-glucose medium for 30 min (C1 to C4), low-glucose medium for 1 h (D1 to D4), low-glucose medium for 30 min (E1 to E4). A1, B1, C1, D1, and E1 show the morphology of the whole cell; A3, B3, C3, D3, and E3 show surface ultrastructures on corresponding cells in images A2, B2, C2, D2, and E2; A4, B4, C4, D4, and E4 show 3D structures of the cells.
Mentions: Figures 2 and 3 show a characteristic structure with many holes located in the cytoplasm in beta cells and IPCs. The porous structure was more obvious in the glucose-stimulated group. We measured the Ra in the analytical area. The statistical results showed that the Ra of the beta cells was bigger than that of the IPCs, regardless of whether glucose stimulation was provided (Table 4). We also measured the nanoparticle size of cells through AFM. The data indicate that the nanoparticle size of beta cells was bigger than that of IPCs, regardless of whether they were subject to glucose stimulation. Moreover, for normal human pancreatic beta cells, the Ra values were similar to each other when comparing 30-min stimulation with 1-h stimulation within the same glucose concentration (P < 0.05). However, in the IPCs group, Ra values were much lower when cells were stimulated for 30 min by low glucose concentrations, which was similar to the case observed in a non-glucose state (P > 0.05). Particle size trends resembled those of the Ra values. Meanwhile, due to the nanometer-scale resolution of AFM, we observed single-membrane proteins and revealed details of the cellular surface structure. Figures 2 (A3) and 3 (A3) showed that the membrane proteins of both beta cells and IPCs exhibited a homogeneous granular distribution. Figures 2 (B1 to B4, C1 to C4, D1 to D4, E1 to E4) and 3 (B1 to B4, C1 to C4, E1 to E4) evidenced that the cell surface architecture of the normal human pancreatic beta cells and IPCs had been changed and membrane proteins exhibited some extent of aggregation after glucose stimulation, except for IPCs stimulated for 30 min in low glucose concentrations (Figure 3 (D1 to D4)).

Bottom Line: The morphological features were detected by atomic force microscopy (AFM) and laser confocal scanning microscopy.IPCs and normal human pancreatic beta cells were similar to each other under the observation in AFM with the porous structure features in the cytoplasm.Both number of membrane particle size and average roughness of normal human beta cells were higher than those of IPCs.

View Article: PubMed Central - HTML - PubMed

Affiliation: Institute for Nano-Chemistry, Department of Chemistry, Jinan University, Guangzhou 510632, China. tjycai@jnu.edu.cn.

ABSTRACT

Objective: The aim of this study was to compare the difference between insulin-producing cells (IPCs) and normal human pancreatic beta cells both in physiological function and morphological features in cellular level.

Methods: The levels of insulin secretion were measured by enzyme-linked immunosorbent assay. The insulin gene expression was determined by real-time quantitative polymerase chain reaction. The morphological features were detected by atomic force microscopy (AFM) and laser confocal scanning microscopy.

Results: IPCs and normal human pancreatic beta cells were similar to each other under the observation in AFM with the porous structure features in the cytoplasm. Both number of membrane particle size and average roughness of normal human beta cells were higher than those of IPCs.

Conclusions: Our results firstly revealed that the cellular ultrastructure of IPCs was closer to that of normal human pancreatic beta cells, but they still could not mimic the physiological regulation of insulin secretion performed by pancreatic beta cells.

No MeSH data available.