The recent tendency to delay pregnancy has increased the incidence of age-related infertility, as female reproductive competence decreases with aging. Along with aging, a lowered capacity of antioxidant defense causes a loss of normal function in the ovaries and uterus due to oxidative damage. Therefore, advancements have been made in assisted reproduction to resolve infertility caused by reproductive aging and oxidative stress, following an emphasis on their use. The application of mesenchymal stem cells (MSCs) with intensive antioxidative properties has been extensively validated as a regenerative therapy, and proceeding from original cell therapy, the therapeutic effects of stem cell conditioned medium (CM) containing paracrine factors secreted during cell culture have been reported to be as effective as that of direct treatment of source cells. In this review, we summarized the current understanding of female reproductive aging and oxidative stress and present MSC-CM, which could be developed as a promising antioxidant intervention for assisted reproductive technology.

Several studies have examined exosomes derived from porcine follicular fluid (FF), but few have reported their application in controlled experiments. The main concern in the field of embryology may be that controlled conditions, such as using a defined medium intermittently, cause poor results in mammalian oocyte maturation and embryo development. The first reason is the absence of the FF, which copes with the majority of the processes emerging in oocytes and embryos. Therefore, we added exosomes derived from porcine FF to the maturation medium of porcine oocytes. For morphological assessment, cumulus cell expansion and subsequent embryonic development were evaluated. Moreover, several stainings, such as glutathione (GSH) and reactive oxygen species (ROS), fatty acid, ATP, and mitochondrial activity, as well as evaluations of gene expression and protein analysis, were used for the functional verification of exosomes. When the oocytes were treated with exosomes, the lipid metabolism and cell survival of the oocytes were fully recovered, as well as morphological evaluations compared to the porcine FF-excluded defined medium. Therefore, controlled experiments may produce reliable data if the exosomes are treated with the desired amounts, and we suggest applying FF-derived exosomes to promote experimental data when performing controlled experiments in embryology.

Oxidative stress is a major cause of damage to the quantity and quality of embryos produced in vitro. Antioxidants are usually supplemented to protect embryos from the suboptimal in vitro culture (IVC) environment. Amniotic membrane-derived mesenchymal stem cells (AMSC) have emerged as a promising regenerative therapy, and their paracrine factors with anti-oxidative effects are present in AMSC conditioned medium (CM). We examined the anti-oxidative potential of human AMSC-CM treatment during IVC on mouse preimplantation embryo development and antioxidant gene expression in the forkhead box O (FoxO) pathway. AMSC-CM (10%) was optimal for overall preimplantation embryo developmental processes and upregulated the expression of FoxOs and their downstream antioxidants in blastocysts (BL). Subsequently, compared to adipose-derived mesenchymal stem cell (ASC)-CM, AMSC-CM enhanced antioxidant gene expression and intracellular GSH levels in the BL. Total antioxidant capacity and SOD activity were greater in AMSC-CM than in ASC-CM. Furthermore, SOD and catalase were more active in culture medium supplemented with AMSC-CM than in ASC-CM. Lastly, the anti-apoptotic effect of AMSC-CM was observed with the regulation of apoptosis-related genes and mitochondrial membrane potential in BL. In conclusion, the present study established AMSC-CM treatment at an optimal concentration as a novel antioxidant intervention for assisted reproduction.

This study aimed to investigate the effect of a treadmill exercise on hematological and serum biochemical parameters and the expression of immune-related cytokine genes in leukocytes. For the experiment, six healthy adult dogs were divided into exercise and control groups. The exercise group performed an endurance exercise three times a week for four weeks. Blood samples were collected before exercise, two weeks after exercise, and post-exercise, and hematological and serum biochemical analysis and cytokine gene analysis were conducted. In the exercise group, white blood cell count (WBC), aspartate aminotransferase, serum alkaline phosphatase, and glucose levels were significantly decreased, but there was no change in the control group. The mRNA expression of TNF-α, IFN-γ, IL-1β, and IL-4 was significantly decreased in the exercise group compared to the control group. There was no difference in IL-6, IL-8, and IL-10 mRNA expression between groups. The results in the current study demonstrate that short-term moderate-intensity endurance exercise alters WBC levels and mRNA cytokine expression in leukocytes and may have a meaningful effect on immune health in dogs.

Oxidative stress is a crucial factor accelerating the age-related functional deterioration of reproductive organs and fertility. Recently, human amniotic-membrane-derived mesenchymal stem cells (AMSCs) have emerged as a promising source with notable potential to reduce oxidative damage and support tissue regeneration. This study investigates the impact of the intravenous administration of human amniotic membrane-derived mesenchymal stem cell conditioned medium (AMSC-CM) on oxidative stress and reproductive competence in aged female mice. Antioxidative effects of human AMSC-CM were found in the reproductive organs of aged mice at both the RNA and protein levels. Human AMSC-CM positively regulated age-dependent changes in reproductive hormones, comparable to those observed in younger mice. RNA sequencing analysis revealed alterations in ovarian and uterine gene expression in aged mice showing that AMSC-CM treatment promotes the expression of genes essential for anti-aging, energy metabolism, and female reproductive processes. These findings highlight the potential of human AMSC-CM as a therapeutic strategy with anti-aging and antioxidative effects against age-related female infertility.

Background/Objectives: Oxidative stress is a major cause of impaired oocyte quality and early embryo development, a challenge that still needs to be addressed in assisted reproduction. Mesenchymal stem cell secretomes have been investigated as cell-free therapeutics with antioxidant activity and relevant anti-apoptotic effects. This study aimed to evaluate the effects of human amniotic membrane-derived mesenchymal stem cell-conditioned saline (AMSC-CS) as an injectable formulation on oxidative stress–related markers in ovarian tissue and preimplantation developmental outcomes. Methods: AMSC-CS was administered intravenously to female mice in a dose-dependent manner. Safety assessments were conducted to evaluate systemic and target organ toxicity within the dosage range. In vitro fertilization (IVF) outcomes and oxidative status in ovaries, oocytes, and embryos were evaluated following treatment with low, medium, and high doses of AMSC-CS (1, 3, and 5 μL/g). Results: As an injectable formulation, the safety assessments did not reveal systemic or target organ toxicity of AMSC-CS within the dosage range. Medium-to-high doses of AMSC-CS improved the expression of folliculogenesis-related genes and decreased oxidative stress and apoptosis signaling in ovarian tissue. At the high dose, AMSC-CS promoted preimplantation embryo development to the blastocyst and hatched blastocyst stages, along with improved blastocyst quality and reduced oxidative stress in oocytes and blastocysts. Conclusions: These findings suggest that AMSC-CS at medium-to-high doses, as an injectable formulation with antioxidant activity, may be a promising adjunct for assisted reproductive technologies.