Mitochondrial Transfer from Mouse Adipose-Derived Mesenchymal Stem Cells into Aged Mouse Oocytes

Summary

Here, we describe the isolation of mitochondria from mouse adipose-derived mesenchymal stem cells, and then transfer the mitochondria into aged mouse oocytes to improve the quality of the oocytes.

Abstract

Due to the decline in the quantity and quality of oocytes related to age, the fertility of women over 35 years of age has declined sharply. The molecular mechanisms that maintain oocyte quality remain unclear, thus it is difficult to increase the birth rate of women over 35 years old at present. Oocytes contain more mitochondria than any type of cell in the body, and any mitochondrial dysfunction can lead to reduced oocyte quality. In the 1990s, oocyte cytoplasmic transfer resulted in great success in human reproduction but was accompanied by ethical controversies. Autologous mitochondrial transplantation is expected to be a useful technique to increase the quality of oocytes that have decreased due to age. In the present study, we used adipose-derived stem cells from aged mice as a mitochondria donor to increase the quality of oocytes of aged mice. Further development of autologous mitochondrial transfer technology will provide a new and effective treatment for infertility in aged women.

Introduction

One of the important factors that affects female fertility is oocyte aging; decline in oocyte quality is the main cause of infertility in aged women. However, the main cause of oocyte aging and the molecular mechanism that regulates oocyte quality are still unclear. Previous studies have indicated that both the number and quality of mitochondria are involved in the quality control of oocytes and embryonic development^1,2,3. The decrease in the quantity and quality of mitochondria is closely related to aging³.

Many attempts ha....

Protocol

All the animal experiments described were approved by the Animal Research Ethics Committee of the Third Affiliated Hospital, Soochow University. All operations follow appropriate animal care and use agency and national guidelines. See the Table of Materials for details of all materials, instruments, and reagents used in this protocol.

1. Isolation and characterization of aged mouse adipose-derived mesenchymal stem cells (ADSCs)

1. Sacrifice the aged mice (10-month-old, an average of three) by cervical dislocation under pentobarbital sodium anesthesia and soak them in 75% alcohol for 5 min before ad....

Results

In this protocol, we isolated and characterized ADSCs from mouse fat (Figure 1). To obtain isolated mitochondria, the cell membrane must be disrupted using a glass homogenizer. (Figure 2A). It is important to obtain a uniform mitochondrial fraction without large clumps so that the microinjection tube is not blocked. First, 200 µL, and then 10 µL, pipette tips must be used to resuspend the homogenates gently; finally, a 29 G needle must be used to slowly aspirate.......

Discussion

Oocytes contain more mitochondria than any type of cell in the body, with ~1-5 × 10⁵ mtDNA copy numbers. Mitochondria are essential for oocyte maturation, fertilization, and embryonic development, thus, any mitochondrial dysfunction can lead to decreased oocyte quality. Decreased mitochondrial quantity and quality are closely related to physiological aging. In this protocol, a simple method for isolating mitochondria from the ADSCs of aged mice and transfer to aged mouse oocytes was introduced to attempt .......

Materials

List of materials used in this article

Name	Company	Catalog Number	Comments
0.05% trypsin/EDTA	Gibco	25300054	Cell Culture
4% paraformaldehyde	beyotime	P0099	immunofluorescence
40 μm cell strainer	Corning	352340	ADSC isolation
adipogenic induction	Cyagen	HUXXC-90031	Multidirectional differentiation
Alizarin red staining solution	Sigma	A5533	Multidirectional differentiation
Antibody against CD29	BD Biosciences	558741	flow analysis
Antibody against CD34	BD Biosciences	560942	flow analysis
Antibody against CD90	BD Biosciences	553016	flow analysis
Antibody against HLA-DR	BD Biosciences	555560	flow analysis
β-actin	Abcam	ab-8226	Mitochondrial function test
BSA	Sigma	V900933	immunofluorescence
CCCP	Solarbio	C6700	mitochondria JC-1 flow analysis
ChamQ Universal SYBR qPCR Master Mix	Vazyme	Q711	qPCR
collagenase type I	Sigma	SCR103	ADSC isolation
DAPI	Invitrogen	D1306	immunofluorescence
DMEM-F12	Gibco	11320033	Cell Culture
DMSO	Sigma	276855	mitochondria JC-1 flow analysis
EGTA	Sigma	324626	Mitochondria isolation
FBS	Gibco	10100147	Cell Culture
Flow cytometry	BD Biosciences	FACSCanto™ II	Characteristics of ADSCs
fluorescence microscope	leica	DM2500	immunofluorescence
gelatin	Sigma	48722	Multidirectional differentiation
glass homogenization tube	Sangon	F519062	Mitochondria isolation
hCG	Aibei	M2520	Ovarian superstimulation
hyaluronidase	Sigma	H1115000	Ovarian superstimulation
Inverted microscope	Olympus	IMT-2	Microinjection
Isolated Mitochondria Staining Kit	Sigma	CS0760	mitochondria JC-1 flow analysis
JC-1	Sigma	T4069	Mitochondrial function test
KCl	Sigma	P5405	Mitochondria transfer
KH2PO4	Sigma	P5655	Mitochondria transfer
LaminB	Abcam	ab-16048	Mitochondrial function test
M16 Medium	Sigma	M7292	embryo cell culture
M2 Medium	Sigma	M7167	embryo cell culture
mannitol	Sigma	M9546	Mitochondria transfer
Microinjector	Olympus+ eppendorf	IX73	Mitochondria transfer
MitoTracker red	Invitrogen	M22425	Mitochondria staining
MOPS	Sigma	M1442	Mitochondria isolation
neurofilament mediator polypeptide (NFM)	Santa Cruz Biotechnology	sc-16143	Multidirectional differentiation
neurogenic induction	Gibco	A1647801	Multidirectional differentiation
Neuron-specific enolase (NSE)	Santa Cruz Biotechnology	sc-292097	Multidirectional differentiation
Oil Red O	Sangon	E607319	Adipogenic differentiation
oil red O solution	Sigma	O1516	Multidirectional differentiation
osteogenic induction	Cyagen	HUXXC-90021	Multidirectional differentiation
PBS (phosphate buffered saline)	Hyclone	SH30256.LS	Cell Culture
penicillin and streptomycin	Hyclone	SV30010	Cell Culture
PMSG	Aibei	M2620	Ovarian superstimulation
protease Inhibitor cocktail	Sigma	P8340	Mitochondria isolation
sucrose	Sigma	V900116	Mitochondria isolation
Tris	Sigma	648314	Mitochondria isolation
Tris-HCl	Sigma	108319	Mitochondria transfer
Triton X-100	beyotime	P0096	immunofluorescence
VDAC	Abcam	ab-14734	Mitochondrial function test