Accumulation of advanced glycation end products in follicles is associated with poor oocyte developmental competence.

Advanced glycation end products (AGEs) affect the follicular microenvironment. The close relationship between AGEs, proinflammatory cytokine production and activation of the unfolded protein response (UPR), which involves activating transcription factor 4 (ATF4), is crucial for regulation of various cellular functions. We examined whether accumulation of AGEs in follicles was associated with proinflammatory cytokine production and activation of the UPR in granulosa cells and decreased oocyte developmental competence. Concentrations of AGEs, soluble receptor for AGE (sRAGE), interleukin (IL)-6 and IL-8 in follicular fluid (FF) were examined by ELISAs in 50 follicles. mRNA expression of ATF4, IL-6 and IL-8 in cumulus cells (CCs) were examined by quantitative RT-PCR in 77 samples. Cultured human granulosa-lutein cells (GLCs) were treated with AGE-bovine serum albumin (BSA) alone or following transfection of ATF4-targeting small interfering RNA. The AGE concentration and the AGE/sRAGE ratio in FF were significantly higher in follicles containing oocytes that developed into poor-morphology embryos (group I) than those with good-morphology embryos (group II). When compared with sibling follicles from the same patients, the AGE/sRAGE and concentrations of IL-6 and IL-8 in FF, as well as ATF4, IL-6 and IL-8 mRNA expression in CCs, were significantly higher in group I follicles than group II. AGE treatment increased mRNA expression of ATF4, IL-6 and IL-8 in cultured GLCs. Knockdown of ATF4 abrogated the stimulatory effects of AGE on mRNA expression and protein secretion of IL-6 and IL-8. Our findings support the idea that accumulation of AGEs in follicles reduces oocyte competence by triggering inflammation via activation of ATF4 in the follicular microenvironment.

Role of oxidative stress in follicular fluid on embryos of patients undergoing assisted reproductive technology treatment.

AIM: Oxidative stress (OS) is defined as an imbalance between oxidants and antioxidants in favor of the oxidants, and the disruption of redox signaling leads to molecular damages. This study was conducted to clarify the effect of OS in individual follicular fluid (FF) on oocyte fertilization and embryonic division. METHODS: A total of 124 patients who underwent assisted reproductive technology treatment in our hospital underwent intracytoplasmic sperm injection and 211 FF were collected. The ova were fertilized, and embryos were individually cultured until cleavage stage or blastocyst stage and classified according to the Veeck classification system or Gardner classification system. RESULTS: The follicular fluid corresponding to the ovum was analyzed by measuring the OS marker, the reactive oxygen metabolites (d-ROM test), and the antioxidant marker (biological antioxidant potential marker [BAP] test), and the relation between these markers and clinical parameters was analyzed. The value of d-ROM was correlated with the proper fertilization status and formation of good quality cleavage embryo, whereas the elevated value of BAP was observed in better embryonic development group. Oxidative stress index, defined as d-ROM/BAP × 100 clearly indicated that lower oxidative stress index was associated with better fertilization status and embryo development. CONCLUSION: Our results clearly indicate that the balance between OS and antioxidant capacity in FF at the time of oocyte retrieval is possibly important in the processes of fertilization and embryo division; thus, we propose that oxidative status and balance in FF might be used as novel biomarkers in assisted reproductive technology.

Activation of Nrf2/Keap1 pathway by oral Dimethylfumarate administration alleviates oxidative stress and age-associated infertility might be delayed in the mouse ovary.

BACKGROUND: Age-associated infertility is a problem worldwide, and management of oxidative stress is known to be essential. Nuclear factor-E2-related factor 2 (Nrf2)/Kelch-like ECH-associated protein 1 (Keap1)-antioxidant response element (ARE) signaling pathway works as an essential defense mechanism against oxidative stress, and an oral drug Dimethylfumarate (DMF) is known to activate the pathway. METHODS: We tested the hypothesis that oral DMF could alleviate oxidative stress in the ovary, resulting in salvation of age-associated infertility in a mouse model of reproductive age, and we examined the effects of DMF administration. 20 mg/kg DMF was administrated to female mice from 32 to 48 weeks, and Nrf2 levels, antioxidant levels, ovarian reserve, DNA damage, and oxidative stress were examined. RESULTS: DMF administration resulted in elevated mRNA and protein levels of Nrf2, antioxidants, and telomere, and serum levels of Nrf2 and anti-mullerian hormone were also elevated. Results of TUNEL assay and Immunohistochemistry of mice ovarian tissues showed that DNA damage and oxidative stress were decreased by DMF administration, and significantly more oocytes were collected along with preservation of 60% more primordial follicles. CONCLUSIONS: Our data suggest that DMF administration activates the Nrf2/Keap1 pathway, elevate levels of antioxidants, and decrease DNA damage and oxidative stress, resulting in improved ovarian reserve in the mouse ovary.

The efficacy of non-assisted reproductive technology treatment might be limited in infertile patients with advanced endometriosis in their 30s.

AIM: To determine the efficacious treatment for infertile couples, we assessed the impact of infertility factors including endometriosis on assisted reproductive technology (ART) and non-ART treatment, and the effect of age in infertility treatment outcomes was also investigated. METHODS: The medical records of 1864 females, infertile patients from January 2000 to December 2015 at our hospital, were retrospectively reviewed under the approval of the Institutional Review Board. We extracted 10 representative factors and calculated the cumulative live birth rate (CLBR) in these patients. Multivariate analysis of ART and non-ART treatment was performed to assess the impact of infertility factors, and the age-related decline in cumulative live birth rate was calculated by creating eight age-stratified subgroups. RESULTS: In total, 21.9% and 49.4% of the patients conceived after being treated with non-ART and ART, respectively. Multivariate analysis revealed that age > 35, advanced endometriosis defined by the revised American Society for Reproductive Medicine classification system stages III to IV, and the past history or current presence of uterine fibroid had significantly negative impact on the outcome of non-ART. Age stratification revealed that advanced endometriosis adversely affected the outcome of non-ART, especially for patients in their 30s. Assisted reproductive technology treatment for patients with advanced endometriosis was shown to be efficacious because the negative impact had been diminished. CONCLUSION: Considering that non-ART treatment had limited role in patients with advanced endometriosis, prompt initiation of ART in these patients aged as young as 30 years can be recommended to achieve conception.

Activation of Nrf2 might reduce oxidative stress in human granulosa cells.

Nuclear factor-E2-related factor 2 (Nrf2)/Kelch-like ECH-associated protein 1 (Keap1)-antioxidant response element (ARE) signaling pathway is one of the most important defense mechanisms against oxidative stress (OS). It is well documented that equilibration status of OS plays fundamental roles in human reproductive medicine, and the physiological role of Nrf2 in ovarian granulosa cells (GCs) has not been determined yet. Herein we aimed to study the function of Nrf2 in GCs. Human ovarian tissues were subjected to immunohistochemistry to localize Nrf2 and Keap1 and we detected the expression of Nrf2 and Keap1 in the human GCs. Human luteinized GCs were isolated and cultured, and hydrogen peroxide (H2O2) or Dimethylfumarates (DMF), an activator of Nrf2, were added to GCs to analyze the relationship between Nrf2 and antioxidants by quantitative RT-PCR. The mRNA levels of Nrf2, catalase, superoxide dismutase 1 (SOD1), and 8-Oxoguanine DNA glycosylase (OGG1) were elevated by H2O2, and DMF treatment showed similar but pronounced effects through activation of Nrf2. To determine the relationship of Nrf2 and the generation of antioxidants, siRNAs were used and quantitative RT-PCR were conducted. Decreased expression of Nrf2 resulted in a decreased level of these antioxidant mRNA. Intracellular levels of ROS were investigated by fluorescence of 8-hydroxy-2'-deoxyguanosine and fluorescent dye, 2',7'-dichlorodihydrofluorescein diacetate after H2O2 and/or DMF treatment, and DMF treatment quenched intracellular ROS generation by H2O2. These results show that activation of Nrf2 might lead to alleviate OS in human GCs, and this could provide novel insight to conquer the age-related fertility decline that is mainly attributed to the accumulation of aberrant OS.

Secretory patterns of catecholamines in Indo-Pacific bottlenose dolphins.

Catecholamines (CAs), namely adrenaline (A), noradrenaline (NA), and dopamine (DA), are secreted by the sympathoadrenal system and participate in a diverse array of functions, e.g., heat production, cardiovascular regulation, stress response and so on. However, little is known regarding peripheral CA fluctuations in cetaceans; nevertheless aquatic animals like them have needed to modify their physiological response especially for thermoregulation in water and oxygen economy during diving. To understand CA dynamism in cetaceans, diurnal changes in serum A, NA, and DA concentrations were measured during the winter and summer solstices in four Indo-Pacific bottlenose dolphins (Tursiops aduncus). The average serum NA concentration was much higher than the average A and DA concentrations, and all concentrations were higher than those reported in other cetacean species. No distinct diurnal fluctuations were observed in CA concentrations in either solstice, suggesting inhibition of the decrease in CA concentrations during nocturnal periods by the unique sleep pattern of dolphins. All the serum CA concentrations were negatively correlated with water temperature as body temperatures were, indicating that the sympathoadrenal system might be more active during winter than in summer season, suggesting a role of CA in thermoregulation.