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Subcellular glucose exposure biases the spatial distribution of insulin granules in single pancreatic beta cells.

Terao K, Gel M, Okonogi A, Fuke A, Okitsu T, Tada T, Suzuki T, Nagamatsu S, Washizu M, Kotera H - Sci Rep (2014)

Bottom Line: Using the device, we showed that subcellular glucose exposure triggers an intracellular [Ca(2+)] change in the β-cells.In addition, the imaging of a cell expressing GFP-tagged insulin showed that continuous subcellular exposure to glucose biased the spatial distribution of insulin granules toward the site where the glucose was delivered.Our approach illustrates an experimental technique that will be applicable to many biological experiments for imaging the response to subcellular chemical exposure and will also provide new insights about the development of polarity of β-cells.

View Article: PubMed Central - PubMed

Affiliation: Department of Intelligent Mechanical Systems Engineering, Kagawa University, Takamatsu 761-0396, Japan.

ABSTRACT
In living tissues, a cell is exposed to chemical substances delivered partially to its surface. Such a heterogeneous chemical environment potentially induces cell polarity. To evaluate this effect, we developed a microfluidic device that realizes spatially confined delivery of chemical substances at subcellular resolution. Our microfluidic device allows simple setup and stable operation for over 4 h to deliver chemicals partially to a single cell. Using the device, we showed that subcellular glucose exposure triggers an intracellular [Ca(2+)] change in the β-cells. In addition, the imaging of a cell expressing GFP-tagged insulin showed that continuous subcellular exposure to glucose biased the spatial distribution of insulin granules toward the site where the glucose was delivered. Our approach illustrates an experimental technique that will be applicable to many biological experiments for imaging the response to subcellular chemical exposure and will also provide new insights about the development of polarity of β-cells.

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Related in: MedlinePlus

Concept of subcellular chemical delivery.The two microchannels are separated by a thin vertical wall with a lateral micro-orifice smaller than the size of the target cell. The cells are applied to microchannel Ch2; one of them is trapped at the micro-orifice by the flow through it (1. cell trap) and is then allowed to spread on the substrate to seal the orifice (2. cell adhesion and spreading). The chemical substances are applied to the microchannel (Ch1) and delivered to a limited area of the cell surface (3. subcellular delivery). The cellular responses are observed by optical microscopy.
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f1: Concept of subcellular chemical delivery.The two microchannels are separated by a thin vertical wall with a lateral micro-orifice smaller than the size of the target cell. The cells are applied to microchannel Ch2; one of them is trapped at the micro-orifice by the flow through it (1. cell trap) and is then allowed to spread on the substrate to seal the orifice (2. cell adhesion and spreading). The chemical substances are applied to the microchannel (Ch1) and delivered to a limited area of the cell surface (3. subcellular delivery). The cellular responses are observed by optical microscopy.

Mentions: Subcellular chemical delivery is performed with two microchannels (Ch1 and Ch2) separated by a solid wall with a lateral micro-orifice smaller than a cell (Fig. 1). A cell in Ch2 is first trapped at the micro-orifice by the flow from Ch2 to Ch1, where the pressure in Ch2 is higher than that in Ch1. The trapped cell is allowed to adhere to the channel and to spread at the orifice and seal it. The chemical substances are introduced into Ch1 for partial delivery to the cell surface. The consequent responses are visualized by optical microscopy. This technique allows a subcellular chemical delivery with a constant concentration over time without diffusion of chemicals and disturbance of the boundary between the solution of Ch1 and Ch2, because the solid wall physically separates them.


Subcellular glucose exposure biases the spatial distribution of insulin granules in single pancreatic beta cells.

Terao K, Gel M, Okonogi A, Fuke A, Okitsu T, Tada T, Suzuki T, Nagamatsu S, Washizu M, Kotera H - Sci Rep (2014)

Concept of subcellular chemical delivery.The two microchannels are separated by a thin vertical wall with a lateral micro-orifice smaller than the size of the target cell. The cells are applied to microchannel Ch2; one of them is trapped at the micro-orifice by the flow through it (1. cell trap) and is then allowed to spread on the substrate to seal the orifice (2. cell adhesion and spreading). The chemical substances are applied to the microchannel (Ch1) and delivered to a limited area of the cell surface (3. subcellular delivery). The cellular responses are observed by optical microscopy.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3927211&req=5

f1: Concept of subcellular chemical delivery.The two microchannels are separated by a thin vertical wall with a lateral micro-orifice smaller than the size of the target cell. The cells are applied to microchannel Ch2; one of them is trapped at the micro-orifice by the flow through it (1. cell trap) and is then allowed to spread on the substrate to seal the orifice (2. cell adhesion and spreading). The chemical substances are applied to the microchannel (Ch1) and delivered to a limited area of the cell surface (3. subcellular delivery). The cellular responses are observed by optical microscopy.
Mentions: Subcellular chemical delivery is performed with two microchannels (Ch1 and Ch2) separated by a solid wall with a lateral micro-orifice smaller than a cell (Fig. 1). A cell in Ch2 is first trapped at the micro-orifice by the flow from Ch2 to Ch1, where the pressure in Ch2 is higher than that in Ch1. The trapped cell is allowed to adhere to the channel and to spread at the orifice and seal it. The chemical substances are introduced into Ch1 for partial delivery to the cell surface. The consequent responses are visualized by optical microscopy. This technique allows a subcellular chemical delivery with a constant concentration over time without diffusion of chemicals and disturbance of the boundary between the solution of Ch1 and Ch2, because the solid wall physically separates them.

Bottom Line: Using the device, we showed that subcellular glucose exposure triggers an intracellular [Ca(2+)] change in the β-cells.In addition, the imaging of a cell expressing GFP-tagged insulin showed that continuous subcellular exposure to glucose biased the spatial distribution of insulin granules toward the site where the glucose was delivered.Our approach illustrates an experimental technique that will be applicable to many biological experiments for imaging the response to subcellular chemical exposure and will also provide new insights about the development of polarity of β-cells.

View Article: PubMed Central - PubMed

Affiliation: Department of Intelligent Mechanical Systems Engineering, Kagawa University, Takamatsu 761-0396, Japan.

ABSTRACT
In living tissues, a cell is exposed to chemical substances delivered partially to its surface. Such a heterogeneous chemical environment potentially induces cell polarity. To evaluate this effect, we developed a microfluidic device that realizes spatially confined delivery of chemical substances at subcellular resolution. Our microfluidic device allows simple setup and stable operation for over 4 h to deliver chemicals partially to a single cell. Using the device, we showed that subcellular glucose exposure triggers an intracellular [Ca(2+)] change in the β-cells. In addition, the imaging of a cell expressing GFP-tagged insulin showed that continuous subcellular exposure to glucose biased the spatial distribution of insulin granules toward the site where the glucose was delivered. Our approach illustrates an experimental technique that will be applicable to many biological experiments for imaging the response to subcellular chemical exposure and will also provide new insights about the development of polarity of β-cells.

Show MeSH
Related in: MedlinePlus