Effect of Human Umbilical Cord Mesenchymal Stem Cells on Ovarian Function in Lupus Mice

Research Article

J Stem Cell Res Transplant. 2022; 9(1): 1040.

Effect of Human Umbilical Cord Mesenchymal Stem Cells on Ovarian Function in Lupus Mice

Meng D¹*, Tang Y², Li H¹, Xie J¹ and Wei H¹*

¹Department of Rheumatology and Immunology, Affiliated Hospital to Yangzhou University, China

²Department of Rheumatology and Immunology, Affiliated Hospital of Jiangsu University, China

*Corresponding author: Hua Wei and Defang Meng, Department of Rheumatology and Immunology, Affiliated Hospital to Yangzhou University and Jiangsu University, China

Received: June 30, 2022; Accepted: July 22, 2022; Published: July 29, 2022

Abstract

Background: Systemic Lupus Erythematosus (SLE) is an autoimmune disease that occurs in women of childbearing age. Clinical treatment of SLE is associated with a high incidence of premature ovarian failure, which is attributed to cyclophosphamide gonadal toxicity; however, the role of immune abnormalities, if any, remains unclear.

Material and Methods: In this study, we used MRL/lpr mice to observe changes in ovarian structure and secretory function in SLE. Further, lupus and control mice were injected with human umbilical cord mesenchymal stem cells (HUC-MSCs) via the tail vein at weeks 12 and 16; serum was collected at week 20, and serum estradiol (E2), Follicle Stimulating Hormone (FSH), and ELISA determined Anti-Mullerian Hormone (AMH) levels. HE staining was used to observe the morphology of the ovary and count all levels of follicles. Hepatocyte Growth Factor (HGF) and Independent Games Festiva-1(IGF-1) expression in the ovarian tissue was observed by immunohistochemistry.

Results: Ovarian function in lupus mice was abnormal, as indicated by decreased serum E2 and AMH levels, and increased FSH level. HUC-MSCs transplantation could cause a significant up-regulation of serum E2 and AMH, down-regulation of FSH, improved follicular development, inhibition of follicular atresia, and enhanced ovarian reserve capacity. Immunohistochemically results showed that expression of IGF-1 and HGF increased after HUC-MSC transplantation.

Conclusion: HUC-MSC transplantation could promote IGF-1 and HGF expression in the ovarian tissue of SLE mice, which could be a mechanism by which HUC-MSCs improve ovarian function of lupus mice.

Keywords: Human umbilical cord mesenchymal stem cells; Systemic lupus erythematosus; Premature ovarian failure; MRL/lpr mice

Introduction

Systemic Lupus Erythematosus (SLE) is a systemic autoimmune disease that occurs in women of childbearing age. The incidence of Premature Ovarian Failure (POF), which seriously affects reproductive function and consequently mental health, is significantly higher in women with SLE than in healthy women. Therefore, protection of ovarian function in patients with SLE is of great clinical interest [1]. Gonadal toxicity of Cyclophosphamide (CTX) treatment is a common cause of POF in patients with SLE [2]; however, immune abnormalities could also be involved [3]. The involvement and role of abnormal immune function in POF remains unclear. Mesenchymal Stem Cells (MSCs) have shown significant safety and efficacy in the treatment of POF in animal models [4]. However, the use of MSCs to treat POF in lupus mice has not been reported. Human umbilical cord mesenchymal stem cells (HUC-MSCs) are capable of several functions including self-renewal, multi-directional differentiation, and immune regulation. They are also easy to obtain and are not associated with ethical concerns. HUC-MSCs have been used in the clinical treatment of several diseases, including refractory lupus nephritis [5]. The main aim of this study was to examine ovarian function, and the occurrence of POF in lupus mice, and subsequently determine the effects of HUC-MSCs transplantation on ovarian function in lupus mice. We also aimed to identify potential mechanisms underlying these effects, to provide a theoretical basis for the development of novel HUC-MSCs-based strategies for the treatment of POF in patients with SLE.

Materials and Methods

Experimental animals and HUC-MSC transplantation protocol

We used 30 SPF female MRL/lpr mice (6 weeks old; Shanghai Lingchang Biotechnology Co., Ltd., license number: SCXK [Shanghai] 2013-0018) and 6 SPF female C57BL/6 mice (6 weeks old; Experimental Animal Center of Jiangsu University, license number: SCXK (Jiangsu) 2013-0011). All experimental mice were raised in the SPF-class breeding area of the Animal Experiment Center of Jiangsu University until they were 20 weeks old. The Animal Experiment Ethics Committee of Jiangsu University approved all animal experiments. The MRL/lpr mice were randomly divided into the MSC1 (n = 6), MSC2 (n = 6), PBS1 (n = 6), PBS2 (n = 6), and model control (n = 6) groups; C57BL/6 mice (n = 6) were used as normal controls. The MSC1 group was injected with passage 3 (P3) HUC-MSCs (1×107 cells/mL, 0.1 mL/10g body weight) via the tail We used 30 SPF female MRL/lpr mice (6 weeks old; Shanghai Lingchang Biotechnology Co., Ltd., license number: SCXK [Shanghai] 2013-0018) and 6 SPF female C57BL/6 mice (6 weeks old; Experimental Animal Center of Jiangsu University, license number: SCXK (Jiangsu) 2013-0011). All experimental mice were raised in the SPF-class breeding area of the Animal Experiment Center of Jiangsu University until they were 20 weeks old. The Animal Experiment Ethics Committee of Jiangsu University approved all animal experiments. The MRL/lpr mice were randomly divided into the MSC1 (n = 6), MSC2 (n = 6), PBS1 (n = 6), PBS2 (n = 6), and model control (n = 6) groups; C57BL/6 mice (n = 6) were used as normal controls. The MSC1 group was injected with passage 3 (P3) HUC-MSCs (1×10M7 cells/mL, 0.1 mL/10g body weight) via the tail We used 30 SPF female MRL/lpr mice (6 weeks old; Shanghai Lingchang Biotechnology Co., Ltd., license number: SCXK [Shanghai] 2013-0018) and 6 SPF female C57BL/6 mice (6 weeks old; Experimental Animal Center of Jiangsu University, license number: SCXK (Jiangsu) 2013-0011). All experimental mice were raised in the SPF-class breeding area of the Animal Experiment Center of Jiangsu University until they were 20 weeks old. The Animal Experiment Ethics Committee of Jiangsu University approved all animal experiments. The MRL/lpr mice were randomly divided into the MSC1 (n = 6), MSC2 (n = 6), PBS1 (n = 6), PBS2 (n = 6), and model control (n = 6) groups; C57BL/6 mice (n = 6) were used as normal controls. The MSC1 group was injected with passage 3 (P3) HUC-MSCs (1×107 cells/mL, 0.1 mL/10g body weight) via the tail

Detection of serum hormone levels by elisa

The concentration of serum FSH, E2, and AMH was determined using an ELISA kit (Nanjing Jiancheng Institute of Bioengineering Co., Ltd.) according to the manufacturers’ instructions.

Ovarian histomorphology and follicular count

After the mice were sacrificed, the ovarian tissues were separated, fixed in formaldehyde fixative, embedded in paraffin, and stained with HE. The ovarian structure was observed under a microscope, and the number of follicles at various stages noted. Follicular grading criteria were: primordial follicles: oocytes enclosed by a single layer of flat granular cells; primary follicles: oocytes enclosed by one or more layers of cubic granular cells with zona pellucida between the two; secondary follicles: appearance of follicular cavities, some forming cumulus, and two layers of follicular membrane; atresia follicle: collapsed follicular wall, absent or unclear structure of the egg cell, and shrunken zona pellucida.

Immunohistochemical staining of ovarian tissue

After the mice were sacrificed, the ovarian tissues were separated. Fresh ovarian tissues were embedded in OCT and cut into 5-μmthick sections for HGF and IGF-1 immunohistochemically staining. Immunohistochemistry was performed by SP method, according to manufacturers’ instructions.

Statistical analysis

SPSS 20.0 statistical software was used for analysis. The data in accordance with normal distribution were expressed as mean ± standard deviation (x ± s). T-test was used for comparison between the two groups, one-way ANOVA was used for comparison among groups, and Dunnett’s T3 test was used for paired comparison. P < 0.05 was considered statistically significant.

Results

Changes in ovarian function in lupus mice

We evaluated ovarian function in the mice by measuring the serum levels of E2, FSH, and AMH in each experimental group. Serum E2 levels (296.75 ± 61.42 vs. 117.73 ± 25.87, P < 0.01) and AMH levels (308.41 ± 48.64 vs. 116.75 ± 31.10, P < 0.001) were significantly lower, and FSH levels (191.21 ± 76.80 vs. 742.80 ± 100.63, P < 0.001) were significantly higher in the MRL/lpr lupus group than in the C57BL/6 group.

We used HE staining to observe ovarian structural changes, and found that the follicles of the normal group of mice grew actively and were clearly visible. The follicles in the model group were significantly fewer, disorderly in arrangement, and with different shapes. The number of follicles in the treatment group was higher than that in the model group, and the level was clear, which was second to the shape of the control group. The number of primordial follicles (7.00 ± 1.83 vs. 2.50 ± 1.29, P < 0.01), primary follicles (10.25 ± 1.89 vs. 5.50 ± 1.29, P < 0.01), and secondary follicles (6.50 ± 2.08 vs. 2.00 ± 0.82, P < 0.01) were significantly lower, and the number of atresia follicles (1.00 ± 0.82 vs. 2.75 ± 0.96, P < 0.05) significantly higher, in the MRL/ lpr lupus mice than in the C57BL/6 mice.

Effect of HUC-Mscs transplantation on the ovarian function of lupus mice

The differences in serum E2, FSH, and AMH levels between the PBS1, MSC1, PBS2, and MSC2 groups were statistically significant (Table 1). Serum E2 (P < 0.001) and AMH (P < 0.05) levels were significantly higher, and serum FSH level (P < 0.001) significantly lower, in the MSC1 group than in the PBS1 group. Serum E2 (P < 0.001) and AMH (P < 0.01) levels were significantly higher, and serum FSH level (P <0.001) significantly lower in the MSC2 group than in PBS2 group. There was no significant difference in serum E2 and FSH levels between the MSC1 and MSC2 groups (P > 0.05). The serum AMH level in the MSC2 group was significantly higher than that in the MSC1 group (P < 0.05).

Citation: Meng D, Tang Y, Li H, Xie J and Wei H. Effect of Human Umbilical Cord Mesenchymal Stem Cells on Ovarian Function in Lupus Mice. J Stem Cell Res Transplant. 2022; 9(1): 1040.