Follicular fluid humanin concentration is related to ovarian reserve markers and clinical pregnancy after IVF-ICSI: a pilot study

[Gly14]-humanin exerts a protective effect against D-galactose-induced primary ovarian insufficiency in mice

RESEARCH QUESTION

Is there a protective effect of the humanin derivative [Gly14]-humanin (HNG) on a D-gal-induced mouse model of primary ovarian insufficiency (POI), and what is the underlying mechanism?

DESIGN

D-gal (200 mg/kg/day) was injected subcutaneously for 6 weeks to induce the mouse POI model. Mice treated with HNG were injected intraperitoneally with different concentrations for 6 weeks. Ovarian morphology, function, levels of sex hormones and states of oxidative stress in the ovary and body were evaluated.

RESULTS

Compared with the D-gal group, 10 mg/kg HNG improved the abnormal ovarian morphology and oestrous cycle (P = 0.0036), increased the number of ovarian follicles (P = 0.0016) and litters (P = 0.0127), and increased the levels of oestrogen (P = 0.0043) and AMH (P = 0.0147). Antioxidant indicators in the ovaries and serum of mice, including total antioxidant capacity (P = 0.0004 and P = 0.0032, respectively), catalase (P = 0.0173 and P = 0.0103, respectively) and glutathione (both P < 0.0001) were significantly increased. The oxidation indicator malondialdehyde decreased significantly (all P < 0.01). Apoptosis of ovarian granulosa cells was significantly reduced (P = 0.0140) as was the expression of senescence-related proteins p53, p21 and p16 (all P < 0.01). The level of autophagy in ovarian tissue of mice treated with high increased (significantly increased LC3 protein [P < 0.0001] and significantly reduced p62 protein [P = 0.0007]).

CONCLUSIONS

HNG inhibited D-gal-induced oxidative stress, apoptosis and ovarian damage, promoting ovarian autophagy. HNG may be a potential prophylactic agent against POI.

Neuroprotective Action of Humanin and Humanin Analogues: Research Findings and Perspectives

Humanin is a 24-mer peptide first reported in the early 2000s as a new neuroprotective/cytoprotective factor rescuing neuronal cells from death induced by various Alzheimer's disease-associated insults. Nowadays it is known that humanin belongs to the novel class of the so-called mitochondrial-derived peptides (which are encoded by mitochondrial DNA) and has been shown to exert beneficial cytoprotective effects in a series of in vitro and/or in vivo experimental models of human diseases, including not only neurodegenerative disorders but other human diseases as well (e.g., age-related macular degeneration, cardiovascular diseases, or diabetes mellitus). This review article is focused on the presentation of recent in vitro and in vivo research results associated with the neuroprotective action of humanin as well as of various, mainly synthetic, analogues of the peptide; moreover, the main mode(s)/mechanism(s) through which humanin and humanin analogues may exert in vitro and in vivo regarding neuroprotection have been reported. The prospects of humanin and humanin analogues to be further investigated in the frame of future research endeavors against neurodegenerative/neural diseases have also been briefly discussed.

The Impact of Follicular Fluid Oxidative Stress Levels on the Outcomes of Assisted Reproductive Therapy

Oocyte quality is a pivotal determinant of assisted reproductive outcomes. The quality of oocytes is intricately linked to their developmental microenvironment, particularly the levels of oxidative stress within the follicular fluid. Oxidative stress levels in follicular fluid may have a substantial influence on oocyte health, thereby impacting the outcomes of ART procedures. This review meticulously explores the intricate relationship between oxidative stress in follicular fluid and ART outcomes. Furthermore, it delves into strategies aimed at ameliorating the oxidative stress status of follicular fluid, with the overarching goal of enhancing the overall efficacy of ART. This research endeavors to establish a robust foundation and provide valuable guidance for clinical treatment approaches, particularly in the context of infertile women, including those of advanced maternal age.

The humanin analogue (HNG) alleviates intrauterine adhesions by inhibiting endometrial epithelial cells ferroptosis: a rat model-based study

STUDY QUESTION

Does a humanin analogue (HNG) have a therapeutic effect on intrauterine adhesions (IUAs) caused by uterine cavity surgery in a rat model?

SUMMARY ANSWER

HNG supplementation attenuated the development of endometrial fibrosis and IUAs, improved fertility, and contributed to the regulation of endometrial fibrosis by inhibiting endometrial ferroptosis in rats with IUAs.

WHAT IS KNOWN ALREADY

IUAs, which are characterized by endometrial fibrosis, are a common cause of female infertility. Humanin (rattin in rats) is a mitochondrial-derived peptide that is widely expressed in multiple tissues. S14G-humanin (HNG) is an HNG that has been reported to have a protective effect against myocardial fibrosis.

STUDY DESIGN, SIZE, DURATION

Endometrial tissues from three patients with IUAs and three controls were tested for humanin expression. Two animal models were used to evaluate the modelling effect of IUAs and the preventive effect of HNG against IUAs. In the first model, 40 rats were equally randomized to control and Day 7, 14, and 21 groups to establish the IUA model. In the second model, 66 rats were equally randomized to the control, IUA, and IUA + humanin analogue (HNG) groups. Erastin was used to induce ferroptosis in the Ishikawa cell line.

PARTICIPANTS/MATERIALS, SETTING, METHODS

The endometrium was scraped with a surgical spatula, combined with lipopolysaccharide treatment, to establish the rat model of IUAs. Rats were intraperitoneally injected with 5 mg/kg/day HNG for 21 consecutive days beginning from the day of operation to evaluate the therapeutic effect on IUAs. Haematoxylin-eosin and Masson's trichrome staining were used to assess endometrial morphology and evaluate fibrosis. Ferroptosis-related markers, namely nuclear factor E2-related factor 2 (Nrf2), acyl-CoA synthetase long-chain family member 4 (ACSL4), haeme oxygenase-1 (HO-1), solute carrier family 7 member 11 (SLC7A11), glutathione peroxidase 4 (GPX4), and ferritin, were measured by immunohistochemistry and western blotting to determine whether ferroptosis was involved in the development of IUAs and to assess the attenuative effect of HNG on ferroptosis. Additionally, the female rats were mated with male rats with normal fertility to assess fertility.

MAIN RESULTS AND THE ROLE OF CHANCE

Humanin was widely expressed in endometrial cells, including epithelial and stromal cells, in both humans and rats. Humanin expression levels were downregulated in the endometria of patients and rats with IUAs relative to the endometria of controls. Endometrial thickness and the number of glands were significantly decreased on Day 7, 14, and 21 after endometrial scraping when compared with the controls (all P < 0.05), whereas the fibrotic area was significantly increased (P < 0.05). Among the tested ferroptosis markers, the expression levels of Nrf2, SLC7A11, and GPX4 were significantly downregulated and those of ACSL4, HO-1, and ferritin were significantly upregulated after endometrial scraping relative to their expression levels in controls (all P < 0.05). The mating rates in the control, IUA, and IUA + HNG groups were 100% (10/10), 40% (4/10), and 80% (8/10), respectively. The number of embryos in rats with IUAs (mean ± SD: 1.6 ± 2.1) was significantly less than the number in the controls (11.8 ± 1.5). HNG supplementation significantly attenuated this decrease in the number of implanted embryos (6.3 ± 4.5) (P < 0.01). Further results showed that HNG significantly attenuated the altered expression levels of proteins involved in ferroptosis in the endometria of rats with IUAs. Moreover, in vitro experiments showed that HNG significantly attenuated the erastin-induced decrease in the viability of the Ishikawa cell line and also attenuated the increase in reactive oxygen species production and the downregulation of GPX4.

LARGE SCALE DATA

None.

LIMITATIONS, REASONS FOR CAUTION

The findings of this study showed that HNG inhibited ferroptosis and reduced fibrosis in a rat model of IUAs. However, we could not establish a causal relationship between ferroptosis and the development of IUAs.

WIDER IMPLICATIONS OF THE FINDINGS

HNG may be effective at alleviating fibrosis during the development of IUAs, and the inhibition of ferroptosis is a promising new strategy for IUA therapy.

STUDY FUNDING/COMPETING INTEREST(S)

This study was supported by the National Natural Science Foundation of China (No. 82171647); the '1000 Talent Plan' of Yunnan Province (No. RLQN20200001); and the Basic Research Project of the Yunnan Province-Outstanding Youth Foundation (No. 202101AW070018). The authors declare no competing financial interests.

The Ratio of cf-mtDNA vs. cf-nDNA in the Follicular Fluid of Women Undergoing IVF Is Positively Correlated with Age

Age-related mitochondrial markers may facilitate the prognosis of artificial reproductive technology outcomes. In this report, we present our study concerning the ratio of cf-mtDNA/cf-nDNA, namely the amount of cell-free mitochondrial DNA relative to cell-free nuclear DNA, in the follicular fluid (FF) of women undergoing IVF, aiming to generate a molecular fingerprint of oocyte quality. The values of this ratio were measured and compared among three groups of women (101 in total): (A) 31 women with polycystic ovary syndrome (PCOS), (B) 34 women younger than 36 years, and (C) 36 women older than 35 years of age. Real-time quantitative PCR (qPCR) was performed to quantify the ratio by using nuclear- and mitochondrial-specific primers and analyzed for potential correlation with age and pregnancy rate. Our analysis showed that the level of FF-cf-mtDNA was lower in the group of advanced-age women than in the groups of PCOS and non-PCOS women. Moreover, a significant positive correlation between FF-cf-mtDNA and the number of mature (MII) oocytes was observed. Collectively, the data show that the relative ratio of cf- mtDNA to cf-nDNA content in human FF can be an effective predictor for assessing the corresponding oocyte's age-related performance in IVF.

Age-related Changes in Humanin Expression in the Ovarian Tissue of Rat

OBJECTIVE

This study examined humanin expression in rat ovarian tissue, its cellular localization, and its correlation with rat age under physiological conditions.

METHODS

A total of 40 Sprague-Dawley rats of various ages (2, 12, 30, and 60 days old and 1 year old) were grouped by age. Immunofluorescence and immunohistochemical techniques were used to observe humanin expression and cellular location in the ovarian tissues of rats from each age group. In addition, Western blotting and Real-time quantitative reverse transcription PCR (qRT-PCR) techniques were used to measure humanin expression level in the ovarian tissues of rats from each age group.

RESULTS

The immunofluorescence and immunohistochemical results confirmed that humanin was expressed in rat ovarian tissues. In addition, cellular localization analysis showed that humanin was expressed in the cytoplasm of oocytes, interstitial cells, granulosa cells and theca cells in all levels of follicles after the primary follicles, and in the corpus luteum. The qRT-PCR results revealed that the level of humanin expression in the ovarian tissues of 12-day-old rats was non-significantly higher than that in the ovarian tissues of 2-day-old rats (P>0.05), whereas the levels of humanin expression in the ovarian tissues of 30-day-old, 60-day-old, and 1-year-old rats were significantly lower than that in the ovarian tissues of 2-day-old rats (P<0.05). The Western blotting results demonstrated that the levels of humanin protein expression in the ovarian tissues of 60-day-old and 1-year-old rats were significantly lower than those of 2-day-old rats (P<0.01), whereas there was no significant difference in the level of humanin protein expression between the ovarian tissues of 12-day-old and 30-day-old rats.

CONCLUSION

This study confirmed that humanin is expressed in the cytoplasm of various cells in rat ovarian tissues. Moreover, the level of humanin expression was highest in the ovarian tissues of 12-day-old rats, and it subsequently decreased with age. The changes in the expression of humanin in the ovary of rats at different ages will lay the foundation for the role of humanin in ovarian aging. The effect of humanin on ovarian function is worthy of further study in the future.

The effect of individual oocyte matched follicular fluid oxidant, antioxidant status, and pro- and anti-inflammatory cytokines on IVF outcomes of patients with diminished ovarian reserve

Oocyte matched follicular fluid oxidant, antioxidant status, and pro- and anti-inflammatory cytokine levels were assessed to reveal a possible effect of local-intrafollicular levels of these markers on the individual oocyte with its quality, ability to achieve fertilization, further embryo development, and pregnancy. A cross-sectional study of infertile women with diminished ovarian reserve undergoing antagonist protocol in vitro fertilization (IVF); in the form of ICSI, and fresh single embryo transfer were included. When follicular fluid was collected, each ovarian follicle was aspirated independently, and each follicular fluid was collected into a separate test tube to match it with a single cumulus-oocyte complex obtained from the same follicle. Oocyte matched follicular fluid samples and blood specimens were taken from the participants. Relationships of total antioxidant status, total oxidant status, oxidative stress index, total thiol, interleukin (IL)-6, IL-8, and IL-10 levels of each follicle with oocyte grade, grade of transferred embryos, and pregnancy rate of a given follicle were assessed. A total of 23 infertile women with diminished ovarian reserve and 79 individual follicles of these women were assessed. Serum total oxidant status level of metaphase II (MII) group was significantly lower than non-MII group (P < .001). Follicular fluid IL-6 level of MII group was significantly lower than non-MII group (P = .005). Follicular fluid IL-8 value was significantly low with positive pregnancy results (P < .001). Serum oxidative stress status and follicular fluid pro-inflammatory cytokines were associated with IVF outcomes. This unique study might guide IVF practice with the aim of developing and establishing more effective therapeutic strategies and choosing embryos with more potential for success.

An evidence of Humanin-like peptide and Humanin mediated cryosurvival of spermatozoa in buffalo bulls

Buffalo spermatozoa are vulnerable to cryo-injuries due to inherent deficiency of endogenous antioxidants, high polyunsaturated fatty acids (PUFA) content in plasma membrane and low cholesterol/phospholipid (C/P) ratio. Humanin is a potent cytoprotective agent that protects the cells against oxidative stress and apoptosis. The present study was designed to establish the presence of Humanin in buffalo and effect of Humanin supplementation on freezability of buffalo spermatozoa. Indirect immunofluorescence test revealed presence of Humanin in ejaculated and epididymal spermatozoa, and, elongated spermatids and interstitial space in the testicular tissue section. Humanin levels in seminal plasma were significantly and positively correlated with sperm concentration and individual progressive motility (IPM) in good (n = 22; IPM >70%) and poor (n = 10; IPM <50%) quality ejaculates. For supplementation studies, a total of 24 ejaculates (IPM ≥70%) were collected and each ejaculate was then divided into four aliquots. First aliquot was diluted with egg yolk-tris-glycerol (EYTG) extender without Humanin and served as control group (Group I). Rest three aliquots were diluted with extender containing 2 (Group II), 5 (Group III) and 10 μM Humanin (Group IV), respectively. Semen was cryopreserved using standard protocol and evaluated at pre-freeze for lipid peroxidation (LPO) and post-thaw stages for spermatozoa kinematics, LPO, mitochondrial membrane potential (MMP), capacitation, apoptotic status and DNA integrity. The treatment group that showed best results (5 μM) was compared with control group for in vitro fertility assessment by homologous zona binding assay. The LPO levels were lower (p < 0.05) in 5 and 10 μM Humanin supplemented group. The MMP and DNA integrity were higher (p < 0.05) in 5 μM group than other groups. F-pattern was higher (p < 0.05) and B-pattern was lower (p < 0.05) in 5 and 10 μM Humanin supplemented groups. Lower apoptotic and higher viable spermatozoa (p < 0.05) were observed in 5 μM Humanin group. The mean number of spermatozoa bound to zona pellucida was higher (p < 0.05) in 5 μM Humanin treated group than the control group. The study established the presence of Humanin in buffalo spermatozoa and seminal plasma for very first time and concluded that Humanin supplementation at 5 μM concentration improves the freezability and in vitro fertility of buffalo spermatozoa.

The role of humanin in the regulation of reproduction

Humanin, a mitochondria-derived peptide, has been found to exert variously protective function in many tissues, especially in the nervous tissues. However, relatively limited studies have focused on the role of humanin in the regulation of reproduction. Current observations indicate that humanin plays an important role in regulating the response of the cell to oxidative stress and apoptosis in ovaries and testes via the modulation of several signaling pathways, especially when the body is in an abnormal state. Even so, the detailed mechanism of humanin function needs to be explored urgently. In this passage, we demonstrate how humanin exerts its protective role in female and male reproduction and raise several questions that need further investigations. Given humanin's new frontier for the design of novel therapeutic approaches for male infertility, male contraception, female infertility, and glucose metabolism in polycystic ovary syndrome, it is worthy of further study on its protective effects and clinical applications in reproductive function.

Humanin Alleviates Insulin Resistance in Polycystic Ovary Syndrome: A Human and Rat Model-Based Study

Polycystic ovary syndrome (PCOS), the most common endocrine disorder in women of reproductive age, is characterized by hyperandrogenism and insulin resistance (IR); however, the pathogenesis of local ovarian IR in PCOS remains largely unclear. Humanin, a mitochondria-derived peptide, has been reported to be associated with IR. Our previous study confirmed that humanin is expressed in multiple cell types in the ovary and is present in follicular fluid. However, it remains unknown whether humanin participates in the pathogenesis of local ovarian IR or whether humanin supplementation can improve IR in PCOS patients. In this study, we compared humanin concentrations in follicular fluid from PCOS patients with and without IR. We further investigated the effect of humanin analogue (HNG) supplementation on IR in a rat model of dehydroepiandrosterone-induced PCOS. Humanin concentrations in the follicular fluid were found to be significantly lower in PCOS patients with IR than in those without IR. HNG supplementation attenuated both the increases in the levels of fasting plasma glucose and fasting insulin in rats with PCOS and the decreases in phosphorylation of IRS1, PI3K, AKT, and GLUT4 proteins in the granulosa cells of these rats. Combined supplementation with HNG and insulin significantly improved glucose consumption in normal and humanin-siRNA-transfected COV434 cells. In conclusion, downregulated humanin in the ovaries may be involved in the pathogenesis of IR in PCOS, and exogenous supplementation with HNG improved local ovarian IR through modulation of the IRS1/PI3K/Akt signaling pathway in a rat model. This finding supports the potential future use of HNG as a therapeutic drug for PCOS.

Humanin regulates oxidative stress in the ovaries of polycystic ovary syndrome patients via the Keap1/Nrf2 pathway

Polycystic ovary syndrome (PCOS) is the most common endocrinological pathology among women of reproductive age, whereas the pathogenesis is still not fully understood. Systemic and ovarian oxidative stress (OS) imbalance is a pivotal feature of PCOS. Humanin, a mitochondria-derived peptide, has been reported to function as an antioxidant in cardiomyocytes, pancreatic beta cells and other cells, but how this function is regulated remains unclear. In this study, we investigated whether humanin expression differs in the granulosa cells (GCs) of PCOS patients versus controls, and whether humanin alleviates OS in PCOS ovaries. Sixteen PCOS patients and 28 age- and BMI-matched controls undergoing IVF were recruited, and their serum, follicular fluid and GCs were collected for humanin analysis. Dehydroepiandrosterone-induced rat PCOS models, and vitamin K3-induced OS COV434 cell lines were applied to investigate the mechanism. Humanin expression was significantly down-regulated in the ovaries of PCOS patients relative to those of non-PCOS patients. Exogenous humanin supplementation significantly attenuated body weight gain, ovarian morphological abnormalities, endocrinological disorders and ovarian and systemic OS in PCOS rat models. Our study further demonstrated that this attenuation effect was involved in the modulation of the Kelch-like ECH-associated protein 1 (Keap1)/nuclear factor-erythroid 2-related factor 2 (Nrf2) signalling pathway. In summary, this study reported for the first time that decreased expression of humanin in the GCs was associated with oxidative imbalance in PCOS. Humanin alleviates OS in ovarian GCs of PCOS patients via modulation of the Keap1/Nrf2 signalling pathway.

Paternal Subclinical Hypothyroidism Affects the Clinical Outcomes of In Vitro Fertilization/Intracytoplasmic Sperm Injection

Background: Maternal subclinical hypothyroidism (SCH) is a risk factor for adverse pregnancy outcomes. However, it is still unclear whether SCH affects male fertility. The aim of this study was to determine the association between paternal SCH and clinical outcomes after in vitro fertilization/intracytoplasmic sperm injection (IVF/ICSI). Methods: This retrospective study included 2511 couples with paternal euthyroidism (n = 2282) or SCH (n = 229) who visited our clinic for infertility treatment between April 1, 2017, and September 30, 2019. The primary outcomes were the fertilization rate and clinical pregnancy rate; the secondary outcomes were the good-quality embryo rate, blastocyst formation rate, implantation rate, and early miscarriage rate. These outcomes were compared between the euthyroid and the SCH groups after adjusting for various potential confounders. Results: The mean paternal ages in the euthyroid and SCH groups were 34.5 and 36.0 years, respectively (p = 0.002). Semen parameters and sperm DNA fragmentation index were similar between the two groups (all p > 0.05). The adjusted fertilization (0.69 vs. 0.71, p = 0.30), good-quality embryo (0.49 vs. 0.52, p = 0.31), blastocyst formation (0.51 vs. 0.53, p = 0.57), and early miscarriage (0.11 vs. 0.10, p = 0.81) rates were also similar between the two groups. There was a significantly decreased adjusted clinical pregnancy rate [confidence interval, CI] and implantation rate [CI] in the paternal SCH group compared with the euthyroid group (0.32 [0.26-0.40] vs. 0.42 [0.40-0.45], p = 0.009 for the clinical pregnancy rate; 0.24 [0.19-0.29] vs. 0.29 [0.27-0.31], p = 0.037 for the implantation rate). Stratified analysis indicated that these differences were only significant in men aged ≥35 years (p = 0.009 and 0.022, respectively) and not in men <35 years (p = 0.39 and 0.45, respectively). Conclusions: Paternal SCH was associated with worse clinical outcomes after IVF/ICSI, whereas this detrimental impact was only present in males ≥35 years old. Prospective studies and basic research are warranted to confirm these results and to clarify the mechanisms underlying these associations, respectively.

Ovarian Aging: Role of Pituitary-Ovarian Axis Hormones and ncRNAs in Regulating Ovarian Mitochondrial Activity

The number of mitochondria in the oocyte along with their functions (e.g., energy production, scavenger activity) decline with age progression. Such multifaceted functions support several processes during oocyte maturation, ranging from energy supply to synthesis of the steroid hormones. Hence, it is hardly surprising that their impairment has been reported in both physiological and premature ovarian aging, wherein they are crucial players in the apoptotic processes that arise in aged ovaries. In any form, ovarian aging implies the progressive damage of the mitochondrial structure and activities as regards to ovarian germ and somatic cells. The imbalance in the circulating hormones and peptides (e.g., gonadotropins, estrogens, AMH, activins, and inhibins), active along the pituitary-ovarian axis, represents the biochemical sign of ovarian aging. Despite the progress accomplished in determining the key role of the mitochondria in preserving ovarian follicular number and health, their modulation by the hormonal signalling pathways involved in ovarian aging has been poorly and randomly explored. Yet characterizing this mechanism is pivotal to molecularly define the implication of mitochondrial dysfunction in physiological and premature ovarian aging, respectively. However, it is fairly difficult considering that the pathways associated with ovarian aging might affect mitochondria directly or by altering the activity, stability and localization of proteins controlling mitochondrial dynamics and functions, either unbalancing other cellular mediators, released by the mitochondria, such as non-coding RNAs (ncRNAs). We will focus on the mitochondrial ncRNAs (i.e., mitomiRs and mtlncRNAs), that retranslocate from the mitochondria to the nucleus, as active players in aging and describe their role in the nuclear-mitochondrial crosstalk and its modulation by the pituitary-ovarian hormone dependent pathways. In this review, we will illustrate mitochondria as targets of the signaling pathways dependent on hormones and peptides active along the pituitary/ovarian axis and as transducers, with a particular focus on the molecules retrieved in the mitochondria, mainly ncRNAs. Given their regulatory function in cellular activities we propose them as potential diagnostic markers and/or therapeutic targets.

Cell-free mitochondrial DNA increases granulosa cell apoptosis and reduces aged oocyte blastocyst development in the mouse

Cell-free mitochondrial DNA (cf-mtDNA) released into the extracellular environment can cause cellular inflammatory responses and damage. Here, we investigated the effects of cf-mtDNA on mouse ovarian granulosa cell function and on the developmental competence of oocytes matured in vitro. Granulosa cells in the cf-mtDNA treatment group had a lower ATP content (P < 0.05), a higher apoptotic cell percentage (P < 0.01), and higher mRNA and protein levels of apoptosis-related factors than the control group (P < 0.01). TLR9, NF-кB p65 and MAPK p38 expression levels in granulosa cells were significantly increased in the cf-mtDNA treatment group (P < 0.05). The blastocyst formation rate of aged mice oocytes matured in vitro decreased significantly (P < 0.05) when cf-mtDNA was added to the media, compared with the control. However, the oocytes from young mice were not affected. Our results suggest that cf-mtDNA may impair granulosa cell function and induce granulosa cell apoptosis, subsequently decreasing blastocyst development in aged oocytes. This role of cf-mtDNA may be associated with the binding to TLR9 and the activation of NF-кB p65 and MAPK p38 signaling pathways.

Predictive value of the sperm DNA fragmentation index for low or failed IVF fertilization in men with mild-to-moderate asthenozoospermia

INTRODUCTION

It has been observed that there is an increased incidence of total fertilization failure (TFF) and a low fertilization rate (LFR, <25 %) during conventional in vitro fertilization (IVF) treatments involving men with poor sperm motility. These men also exhibit a high sperm DNA fragmentation index (DFI), which has adverse effects on various IVF outcomes. However, the relationship between a high DFI and an increased TFF or LFR during IVF cycles has not been elucidated. Here, we aimed to investigate the association between the sperm DFI and TFF or LFR in IVF cycles involving men with mild-to-moderate asthenozoospermia and normozoospermia.

MATERIALS AND METHODS

This retrospective study included 116 men diagnosed as mild-to-moderate asthenozoospermia, and 407 men with normozoospermia. The sperm DFI was assessed using the sperm chromatin dispersion (SCD) test.

RESULTS

Men in the asthenozoospermia group had a significantly higher incidence of cycles with a TFF or LFR (9.5 % vs 2.7 %, P = 0.01), and these were associated significantly with an increased DFI (P < 0.01). After adjustment for confounding factors, a TFF or LFR was to correlate significantly with the DFI (odds ratio: 1.188; 95 % confidence interval, 1.035-1.363; P = 0.014). Area under the receiver operating characteristic curve was 0.772. No similar relationships between the DFI and IVF outcomes were observed in the normozoospermia group.

CONCLUSIONS

For men with mild-to-moderate asthenozoospermia, a high sperm DFI is associated with a decreased fertilization rate and an increased risk of a TFF or LFR. Additional prospectively-designed studies are warranted to confirm our results.

Subclinical Hypothyroidism Is Associated with Lower Ovarian Reserve in Women Aged 35 Years or Older

Background: Overt thyroid diseases have been identified as risk factors for female infertility. However, it remains largely unclear whether subclinical hypothyroidism (SCH), a very common thyroid disorder, is associated with female infertility. This study aimed to investigate the potential association between SCH and the ovarian reserve in women seeking infertility treatment. Methods: This retrospective study included 2568 women with normal thyroid function (n = 2279) or SCH (n = 289) who visited our clinic for infertility treatment. Ovarian reserve markers, including follicle-stimulating hormone (FSH) concentrations on days 2-4, the antral follicle count (AFC), and anti-Müllerian hormone (AMH) concentration, were compared between euthyroid women and those with SCH. Multiple linear and Poisson regression analyses were used to estimate the associations of SCH with ovarian reserve markers. These analyses were repeated separately in women aged <35 (n = 1349) and ≥35 years (n = 1219). Results: In the total study population, women with SCH had significantly lower AMH concentrations (median: 2.05 vs. 2.51 ng/mL, p = 0.015) and AFCs (median: 10.0 vs. 11.0, p = 0.013), compared with euthyroid women. In linear and Poisson regression analyses, SCH was significantly associated with a higher basal FSH concentration (mean difference = 1.13 mIU/mL [95% confidence interval (CI) 0.97 to 1.29 mIU/mL], p < 0.001), lower AMH concentration (mean difference = -0.27 ng/mL [CI -0.43 to -0.12 ng/mL], p = 0.001), and lower AFC (mean difference = -0.7 [CI -1.3 to -0.2], p = 0.005). In women aged ≥35 years, SCH was significantly associated with FSH (mean difference = 1.74 mIU/mL, p < 0.001) and AMH concentrations (mean difference = -0.40 mg/mL, p < 0.001) and AFC (mean difference = -0.8, p < 0.001). In women <35 years old, SCH was significantly associated with a higher FSH concentration (mean difference = 0.30 mIU/mL, p < 0.001), but not with AMH or AFC concentrations (p = 0.84 and 0.06, respectively). Thyroperoxidase antibody (TPOAb) positivity was not associated with measures of ovarian reserve. Conclusions: The data suggest that SCH is associated with decreased ovarian reserve during later reproductive age. TPOAb positivity was not associated with ovarian reserve. Future research is necessary to investigate the underlying molecular mechanisms regulating the diminished ovarian reserve in women with SCH and to evaluate whether levothyroxine supplementation may improve the ovarian function of women with SCH.

Cell-free mitochondrial DNA in human follicular fluid: a promising bio-marker of blastocyst developmental potential in women undergoing assisted reproductive technology

BACKGROUND

Cell-free mitochondrial DNA (cf-mtDNA) in body fluids has attracted much attention for the purpose of monitoring disease because of the clinical advantages. This study investigated whether the cf-mtDNA content in human follicular fluid samples was associated with oocyte and embryo developmental competence.

METHODS

We collected 225 individual follicular fluid samples from 92 patients undergoing conventional in vitro fertilization (n = 53) or intracytoplasmic sperm injection (n = 39). cf-mtDNA and cell-free nuclear DNA (cf-nDNA) were measured using real-time quantitative PCR for the ND1 and β-globin genes. Multivariate logistic regression and linear regression were used to analyze data.

RESULTS

The relative cf-mtDNA content (cf-ND1/cf-β-globin ratio) in follicular fluid was significantly lower in the group showing blastocyst development than in the non-blastocyst group (P = 0.030). Additionally, the relative cf-mtDNA content was significantly and positively correlated with the age of the female patient (P = 0.009), while the relative cf-mtDNA content for older women (≥38 years old) with anti-Müllerian hormone (AMH) ≤1.1 ng/ml was significantly higher than in those with AMH > 1.1 ng/ml (P <0.05). The cf-nDNA content was significantly positively correlated with the antral follicle count (P = 0.012), and significantly negatively correlated with both the number of days of stimulation and the total dose of gonadotropin administration (P = 0.039 and P = 0.015, respectively). Neither cf-mtDNA nor cf-nDNA levels in follicular fluid were associated with oocyte maturation, fertilization, or Day 3 embryo morphological scoring.

CONCLUSIONS

The relative cf-mtDNA content in human follicular fluid was negatively correlated with blastulation and positively correlated with the patient age, indicating that it is a promising bio-marker to evaluate oocyte developmental competence.

Humanin levels in human seminal plasma and spermatozoa are related to sperm quality

BACKGROUND

Humanin has reportedly been expressed in testis and spermatozoa, but no study has yet reported its presence in human seminal plasma (SP).

OBJECTIVE

The aim of this study was to investigate the presence of humanin in human SP and to determine the correlation between humanin levels in SP/spermatozoa and sperm quality.

MATERIALS AND METHODS

Semen samples for SP/sperm humanin level measurement were collected from 164 patients who attended our andrology clinic for fertility evaluation. The localization of humanin in spermatozoa was evaluated using an immunofluorescence method, and SP/sperm humanin levels were measured with ELISA. Correlations between SP/sperm humanin levels and sperm parameters were analyzed.

RESULTS

Humanin was expressed in the midpiece of the spermatozoa. Humanin concentrations in the SP ranged from 24.4 to 285.1 pg/mL, with a median of 89.7 pg/mL. The SP humanin concentrations in patients with normospermia were significantly higher than those in patients with oligospermia (p < 0.001), asthenospermia (p = 0.002), and oligoasthenospermia (p < 0.001). Spearman analysis showed a positive and significant correlation between SP humanin concentration and sperm concentration (r = 0.75, p < 0.001), and progressive sperm motility (r = 0.29, p < 0.001). Sperm humanin level was significantly and positively associated with progressive sperm motility (r = 0.70, p < 0.001). In addition, a significantly higher level of humanin was found in swim-up spermatozoa than in non-swim-up spermatozoa (p = 0.03).

CONCLUSIONS

Seminal plasma and sperm humanin levels were significantly and positively correlated with sperm quality, especially sperm motility. Further studies of the origin of SP humanin and its role in spermatogenesis should be conducted.