Monitoring Blood Glucose in Mouse Offspring After Intracytoplasmic Sperm Injection

Summary

Here, we present a protocol to establish an intracytoplasmic sperm injection (ICSI)-embryo transfer (ET) mouse model, allowing us to observe age-related changes in glucose metabolism that may be attributed to ICSI, providing insights into its potential long-term impacts on human development.

Abstract

Human lifespan is considerably long, while mouse models can simulate the entire human lifespan in a relatively short period, with one year of mouse life roughly equivalent to 40 human years. Intracytoplasmic sperm injection (ICSI) is a commonly used assisted reproductive technology in clinical practice. However, given its relatively recent emergence about 30 years ago, the long-term effects of this technique on human development remain unclear. In this study, we established the ICSI combined with embryo transfer (ET) method using a mouse model. The results demonstrated that normal mouse sperm, after undergoing in vitro culture and subsequent ICSI, exhibited a fertilization rate of 89.57% and a two-cell rate of 87.38%. Following ET, the birth rate of offspring was approximately 42.50%. Furthermore, as the mice aged, fluctuations in glucose metabolism levels were observed, which may be associated with the application of the ICSI technique. These findings signify that the mouse ICSI-ET technique provides a valuable platform for evaluating the impact of sperm abnormalities on embryo development and their long-term effects on offspring health, particularly concerning glucose metabolism. This study provides important insights for further research on the potential effects of the ICSI technique on human development, emphasizing the necessity for in-depth investigation into the long-term implications of this technology.

Introduction

Fertility issues have emerged as a major focus of medical and sociological concern, especially in modern society where declining fertility rates and the increasing severity of infertility prevalence and severity have risen to prominence. Assisted Reproductive Technology (ART) provides a wide array of possibilities to tackle these challenges, with Intracytoplasmic Sperm Injection (ICSI) commonly utilized as a therapeutic intervention.

Since Palermo reported the first successful pregnancy achieved through Intracytoplasmic Sperm Injection (ICSI) in 1992, ICSI has become a pivotal technique in Assisted Reproductive Technol....

Protocol

The protocol of ICSI-ET described below follows the guidelines and has been approved by the Animal Ethical Review of the Shanghai Institute of Planned Parenthood research. Safety Procedures: Always wear appropriate personal protective equipment (PPE) when handling chemicals or biological materials. Use of Hoods: Perform all procedures involving volatile chemicals or aerosol generation within a certified fume hood or biosafety cabinet. Use female mice (6-8 weeks old B6D2F1 strain) for the superovulation procedure.

Discussion

This study integrated mouse intracytoplasmic sperm injection (ICSI) and embryo transfer (ET) techniques to comprehensively recapitulate human assisted reproductive technology (ART) and examine the impact of ICSI in conjunction with ET on offspring development. The application of the ICSI technique with normal mouse sperm yielded high fertilization (86.76%) and 2-cell rates (88.48%). Following ET, the birth rate of offspring mice was approximately 42.50%, indicating the robustness of the technical platform. The most notew.......

Materials

Name	Company	Catalog Number	Comments
1.25% avertin (2,2,2-tribromoethanol)	Nanjing Aibei	M2960	for anesthetization
Bacteriological Petri Dishes 35 x 10 mm style w/tight lid, crystal-grade virgin polystyrene, sterile	BD	353001
Bacteriological Petri Dishes 50 x 9 mm style w/tight lid, crystal-grade virgin polystyrene, sterile	BD	351006
Biosafety Cabinet	ESCO	class BSC	Aseptic operations, making culture dishes, aliquoting reagents, etc.
CO2 Incubator	Thermo	8000DH	Embryo culture
Dissection Microscope	Olympus	SZX16	Use in mouse embryo transfer
Fluorinert Fc-770	SIGMA	F3556	Fluorinert FC-770 is a thermally stable fully fluorinated liquid with high dielectric strength and resistivity, used as operating fluid
handheld glucometer	Roche	AccuChek performa	Blood glucose measurement
HTF	Merck	MR-070-D	The EmbryoMax Human Tubal Fluid (HTF) (1x), liquid designed for use with Mouse IVF is available in a 50 mL format and has been optimized and validated for Embryo Culture.
Hydraulic Microinjector	Eppendorf	CellTram 4r Oil, 5196000030	For sperm injection
Inverted Microscope	Nikon	TI2-U	Micromanipulation observation host
KSOM	Merck	MR-020P-D	(1x), Powder, w/o Phenol Red, 5 x 10 mL
M2	Merck	MR-015-D	EmbryoMax M2 Medium (1x), Liquid, with Phenol Red
Micromanipulator	NARISHIGE	NTX-N4	Micromanipulation arm
mineral oil	SIGMA	M8410	Mineral oil is suitable for use as a cover layer to control evaporation and cross-contamination in various molecular biology applications.
Needle Cutter	Nanjing Aibei	Sutter MF-800	Use for fabricating micromanipulation needles
Needle Puller	Nanjing Aibei	Sutter model p-100	Use for making micromanipulation needles
Piezo Drill Trip Mouce ICSI	Eppendorf	5195000.087	Application of ICSI injection needle.
Piezoelectric Micromanipulator (Membrane Breaker)	Eppendorf	Eppendorf PiezoXpert	Use of micro-pulses to break the zona pellucida and oolemma of the oocyte
Pneumatic Microinjector	Eppendorf	CellTram 4r Air, 5196000013	For fixing the oocyte
Ready-to-use Human Chorionic Gonadotropin (Hcg)	Nanjing Aibei	M2520	Sterilization reagent, intraperitoneal injection. 50 IU/mL
Ready-to-use Pregnant Mare's Serum Gonadotropin (PMSG)	Nanjing Aibei	M2620	Sterilization reagent, intraperitoneal injection. 50 IU/mL
Stereomicroscope	Olympus	SZX7	Oocyte retrieval and observation of embryo development