A Method for Islet Transplantation to the Omentum in Mouse

Summary

A method for the omental transplantation of islets in a mouse is introduced. The isolated islets are mixed with hydrogel and the mixture is placed into the omental pouch of a diabetic mouse. Then, the blood glucose is monitored, and immuno-histochemical analysis is performed.

Abstract

Islet transplantation has been proposed to be a potential treatment for type 1 diabetes. Recent compelling evidence indicates that intravascular islet infusion is far from ideal and therefore, the omentum is re-emerging as a potentially valuable site for islet transplantation. This experiment requires the isolation of high quality islets and the implantation of the islets to the diabetic recipients. Transplantation to the omentum requires surgical steps that can be better demonstrated visually. Here, the detailed steps for this procedure are presented. Two methods of mixing the isolated islets with hydrogel before placing the mixture into the omental pouch of diabetic mice are described here. Different hydrogels are used for the different conditions. Blood glucose levels of diabetic mouse recipients of syngeneic islets in the omentum were monitored for up to 35 days. Some animals were sacrificed after 14 days to perform immuno-histochemical analysis. This pre-clinical transplantation approach can be used as preliminary data leading up to translation to clinical transplantation.

Introduction

According to the International Diabetes Federation (IDF), diabetes mellitus currently affects 382 million people, with a projected increase to 592 million people by 2035¹. In both allogeneic and xenogeneic islet transplantation, systemic immunosuppressive therapy is necessary. Without immunosuppression, immune rejection is a major cause of graft loss². There is also a significant problem of transplanted islet loss due to the instant blood mediated inflammatory reaction (IBMIR)^3,4. However, even in the absence of an immune response such as in syngeneic or auto-tra....

Protocol

All mice used in this study were obtained from the Medical Animal Center of Guangdong Province. The use of animals was approved by the Ethics Review Committee of Shenzhen Second People's Hospital, in accordance with the principles of animal welfare.

1. Islet Transplantation to the Omentum

NOTE: This protocol requires 2 persons to accomplish.

1. Assemble surgical materials which are listed in Table 1. Prepare aseptic field in surgical area with sterile materials such as drapes and disposables and maintain aseptic conditions throughout surgery. Sterilize all surgical instruments. Wear ....

Results

Post-digestive state of the pancreas is shown in Figure 1A. Purified islets are shown in Figure 1B. Dithizone staining and viability testing of the islets are shown in Figure 2. The main steps of the islet transplantation to the omentum are shown in Figure 3. The blood glucose levels of the recipients after omental transplantation are shown in Figure.......

Discussion

Islet transplantation to the liver via the portal vein is the most commonly used method of islet transplantation in humans, but there are still efficiency and safety concerns such as portal vein thrombosis and liver steatosis¹⁷. Recent studies show that the omentum may be a suitable alternative to the liver, but more research needs to be conducted prior to clinical translation^12,14,18,

Materials

List of materials used in this article

Name	Company	Catalog Number	Comments
Equipment
5 inch (12-13 cm) Scissors	RWD Life Science	S12030-11
Fine Forceps	RWD Life Science	F11010-13
Small wound clips	RWD Life Science	R33003-01
Acutenaculum	RWD Life Science	F31044-13
2 pair tissue forceps	RWD Life Science	F13023-10
4-0 Suture with needle	Chenghe, China	17094
200 μL Pipette and tips	Gilson	PN11
One Touch ultraeasy Basic blood glucose monitoring system	Johnson & Johnson	33391713
razor blade	Philips	HC1099/15
Material and animals
Pentobarbital Sodium	Sigmaaldrich.com	P3761	For anesthesia
Hydrogel	bdbiosciences.com	356234	Basement Membrane Matrix
Fibrin-Thrombin Hydrogel	Baxter.com	1501250	Components clot when mixed
70% Ethanol	Yingniu medical, Anhui, China	23170608
Iodophor	Lierkang medical technology, Shangdong, China	170521
Normal saline	Baxter.com	2B1324
Cephalosporin	Lukang medical, Shangdong, China	150303
Cefazolin	Baxter.com	2G3508
lubricant eye ointment	Major Pharmaceuticals	203964
streptozotocin	Sigmaaldrich.com	S0130
collagenase Type V	Sigmaaldrich.com	C9262
CMRL-1066 media	celltrans, Wenzhou, China	X018D1
histopaque	Sigmaaldrich.com	10771	density gradient
PE50 tubing	Braintreesci.com	PE50 100 FT	Polyethylene .023" x .038
Calcein AM	Sigmaaldrich.com	C1359
Propidium iodide	Sigmaaldrich.com	P4864
optimal cutting temperature compound (OCT)	Tissue-Tek; Miles, Naperville, IL	4583	embedding medium
insulin antibody	Cell Signaling Technology, Danvers, MA 01923	8138S
hematoxylin staining media	Cell Signaling Technology, Danvers, MA 01923	14166S
eosin staining media	Beyotime Biotech, China	C0109
DAPI	Thermo Fisher Scientific Inc.	D1306
C57Bl/6 Mice	Medical Animal Center of Guangdong Province	/
Fetal Bovine Serum	GE Healthcare Life Sciences	SH30084
T175 flasks	Falcon	353112
1.5 mL Snap-top tubes	Axygen	MCT-150-C