Islet Core

Perifusion

The Islet Core provides consultative advice and state-of-the-art equipment and services for the isolation and study of pancreatic islet structure and function in support of diabetes-related research.

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How We Serve Your Research Needs

• Pancreas
• Embryonic rudiments (E10.5 — birth)
• Islet isolation
 

Embryonic tissue dissection

embryonic-dissections

At chosen embryonic stages, the pancreas can be isolated from developing mice or rats. Early stages can also be put in culture embedded in a collagen.

Tissue harvesting and islet isolation

islet-isolation

We offer pancreas dissections and islet isolation from both rats and mice.

• β- α-cell mass
• Proliferation
• Apoptosis

β-cell mass

5 sections spread throughout the pancreas;

• Fluorescent Immunohistochemistry staining for insulin
• Imaging
• Morphometry

beta-cell-mass-calculation

Immunostaining

In addition to insulin and glucagon, a number of antibodies for pancreatic markers are available through the Core.

islets-staining
Immunostaining for insulin (blue), glucagon(red) and amylase (green) on a paraffin embedded pancreatic section.

 

beta-cell-mass-multiple-images
Immunostaining for insulin (red) for five randomly selected sections at different depths within the pancreas.

Software assisted nuclei counting

• Proliferation (Ki67) 
• Apoptosis (TUNEL) staining

In vivo imaging of fluorescent reporters in anesthetized mice

• Imaging during the course of a glucose tolerance test 
• Image processing for analysis 
• Islet tracking over the course of the glucose challenge

 

fluorescent-reporter-live-tracing
A. Schematic representation of the sfGFP-CPep reporter mouse model. B. The pancreas is externalized through laparotomy on an anesthetized mouse, and placed a heated slide for imaging throughout an IPGTT. C. Glucose measurements during the course of the glucose challenge. D. Fluorescence pancreas imaging from a CPep-sfGFP mouse (Top: fluorescence, Bottom: Intensities are presented in pseudo-colors from dark blue to yellow). E. Quantification of individual response of the islets over the course of the glucose challenge (Left: normal scale, and Right: Log scale showing fold changes independently of islet size).

 

fluorescent-reporter-quanditifcation

AI-based image analysis

Using Aivia (Microscopy and Imaging Core), we can automate morphometric assessments (β- α-cell mass, proliferation and apoptosis) as well as fluorescent islet tracking and signal quantification after neural network training.

AI-based-morphometry

 

• Static GSIS
• Perifusion
• Respirometry

Static Glucose-stimulated insulin secretion

In culture with transwell inserts

GSIS
GSIS plates
Culture plate (left) with transwell inserts (close-up on the right)

Perifusion

Up to 12 chambers can be used in parallel to measure islet secretions using the custom program of your choice.

The perifusion chambers and reagents are temperature-controlled. The reagents can be gazed with CO2.

perifusion
Top left: Immunostaining for β- (blue) and α-cells(red). Top right: Secretion profile for islets after a perifusion assay. Bottom left: Dissecting microscope. Bottom right: Perifusion apparatus.

Respirometry (BaroFuse)

Respirometry and perifusion can run concomitantly on up to 6 samples at the same time.

respirometry-barofuse
The BaroFuse instrument

barofuse
Simultaneous parallel measurements of mitochondrial respiration and insulin secretion in mouse islets. Representative measurement of oxygen consumption (top) and insulin release (bottom) from islets studied on the BaroFuse multichannel respirometry/perifusion system following infusion of glucose, nimodipine, and potassium cyanide. Top graph is the mean oxygen consumption (±SD) of two independent channels (75 islets each from islets isolated from the same mouse). Bottom graph is insulin secretion collected from the same islets from each independent well (blue, red).

Transfection

Islets can be transfected in vitro, or in vivo after I.P. delivery

islets-transfections
Transduction of pancreatic islets via AAV8 - Immunostaining of pancreas sections of C57BL/6 mice after A. Transfection of islets in vitro, and B. 2 weeks after I.P. delivery of 1.10^12 particles of β-cell specific AAV8-mIP (mouse insulin promoter)-eGFP vector.

Islet dissociation and pseudo-islets

• Islet dissociation
• MACS separation of the β-cells 
• Transfection of single cells 
• Pseudoislet generation

pseudoislets
Generation of human pseudoislets following high efficiency viral transduction. A. Brightfield (top), live cell confocal images (middle) and confocal images (bottom) of intact human islet and human pseudoislet transduced for 2 hrs with adenoviral particles expressing eGFP under control of the PDX1 promoter for #-cell specific expression. B. Insulin secretion measured after static incubation in low (LG; 2 mM) and high glucose (HG; 20 mM), from transduced intact human islets or human pseudoislets from the same donors. C. Immunostaining for insulin, glucagon, and somatostatin of fixed and cryoembedded human pseudoislet sections.

 

• Islet isolation
• Secretion assays
• Morphometry
• Experimental design

• sfGFP-CPep imaging
• Embryonic rudiments cultures
• Grafts and Imaging in the anterior chamber of the eye

Key Personnel

Scott Soleimanpour, MD
Core Director 
ssol@umich.edu

Corentin Cras Meneur, PhD
Core Technical Director 
corentin@umich.edu

Emily Walker, PhD
Research Assistant Professor
Department of Internal Medicine
emwal@umich.edu

Contact Us

islet-core@umich.edu