The effect of the mitochondria-targeted antioxidant Mito-tempo during sperm ultra-rapid freezing.

During the freeze-thaw process, human spermatozoa are susceptible to oxidative stress, which may cause cryodamage and reduce sperm quality. As a novel mitochondria-targeted antioxidant, Mito-tempo has been used for sperm cryopreservation. However, it is currently unknown what role it will play in the process of sperm ultra-rapid freezing. The purpose of this study was to investigate whether Mito-tempo can improve sperm quality during ultra-rapid freezing. In this study, samples with the addition of Mito-tempo (0, 5, 10, 20, and 40 µM) to sperm freezing medium were selected to evaluate the changes in sperm quality, antioxidant capacity and ultrastructure after ultra-rapid freezing. After ultra-rapid freezing, the quality and antioxidant function of the spermatozoa were significantly reduced and the spermatozoa ultrastructure was destroyed. The addition of 10 µM Mito-tempo significantly increased post thaw sperm motility, viability, plasma membrane integrity and mitochondrial membrane potential (P < 0.05). Moreover, the DNA fragmentation index (DFI), ROS levels and MDA content were reduced, and the antioxidant enzyme (CAT and SOD) activities were enhanced in the 10 µM Mito-tempo group (P < 0.05). Moreover, Mito-tempo protected sperm ultrastructure from damage. In conclusion, Mito-tempo improved the quality and antioxidant function of sperm after ultra-rapid freezing while reducing freezing-induced ultrastructural damage.

Concordance of PGT for aneuploidies between blastocyst biopsies and spent blastocyst culture medium.

RESEARCH QUESTION: Non-invasive preimplantation genetic testing for aneuploidies (niPGT-A) avoids the possible detrimental impact of invasive PGT-A on embryo development and clinical outcomes. Does cell-free DNA (cfDNA) from spent blastocyst culture medium (BCM) reflect embryonic chromosome status better than trophectoderm (TE) biopsy? DESIGN: In this study, 35 donated embryos were used for research and the BCM, TE biopsy, inner cell mass (ICM) and residual blastocyst (RB) were individually picked up from these embryos. Whole genome amplification (WGA) was performed and amplified DNA was subject to next-generation sequencing. Chromosome status concordance was compared among the groups of samples. RESULTS: The WGA success rates were 97.0% (TE biopsy), 100% (ICM), 97.0% (RB) and 88.6% (BCM). Using ICM as the gold standard, the chromosomal ploidy concordance rates for BCM, TE biopsy and RB were 58.33% (14/24), 68.75% (22/32) and 78.57% (22/28); the diagnostic concordance rates were 83.33% (20/24), 87.50% (28/32) and 92.86% (26/28); and the sex concordance rates were 92.31% (24/26), 100% (32/32) and 100% (28/28), respectively. Considering RB the gold standard, the chromosome ploidy concordance rates for BCM and TE biopsy were 61.90% (13/21) and 81.48% (22/27); the diagnostic concordance rates were 71.43% (15/21) and 88.89% (24/27); and the sex concordance rates were 91.30% (21/23) and 100% (27/27), respectively. CONCLUSIONS: The results of niPGT-A of cfDNA of spent BCM are comparable to those of invasive PGT-A of TE biopsies. Modifications of embryo culture conditions and testing methods will help reduce maternal DNA contamination and improve the reliability of niPGT-A.

Effect of MnTBAP on sperm ultra-rapid freezing and its proteomics study.

MnTBAP is a new synthetic antioxidant that has been used for the cryopreservation of sperm. However, the exact mechanism of its cryoprotection at the molecular level is largely unknown. Therefore, in this study, normal human semen samples were selected and MnTBAP (0, 5, 10, 20, 40 µM) was added to sperm freezing medium to assess changes in kinetics parameters, apoptosis, reactive oxygen species (ROS), and DNA fragmentation index (DFI) after sperm ultra-rapid freezing. The tandem masstagging (TMT) proteomics technique was used to further investigate the changes in proteins after sperm ultra-rapid freezing. The kinetic parameters of sperm after ultra-rapid freezing and thawing were significantly reduced and apoptosis, ROS production and DFI were significantly increased. The addition of 40 µM MnTBAP improved the kinetic parameters, while it reduced apoptosis, ROS production, and DFI of sperm after ultra-rapid freezing and thawing (P < 0.05). Compared with the fresh semen, 1978 differential proteins were identified in the frozen-thawed sperm without MnTBAP and 1888 differential proteins were identified in the frozen-thawed sperm with MnTBAP (40 µM) added. The proteins affected during ultra-rapid freezing were mainly related to sperm metabolism, flagellar structure motility, apoptosis, intracellular signaling, capacitation and fertilization, while the addition of MnTBAP reduced the alterations of these proteins.

Effects of different sperm sources on clinical outcomes in intracytoplasmic sperm injection cycles.

The aim was to investigate the influences of different sperm sources on clinical outcome and neonatal outcome of patients with intracytoplasmic sperm injection. We retrospectively analysed patients who underwent intracytoplasmic sperm injection in our reproductive centre from 2011 to 2020. We screened data on assisted reproductive outcomes from four groups of sources: testicular sperm, epididymal sperm, ejaculated sperm and donor sperm for analysis and divided the non-ejaculated group from the ejaculated group to explore their impact on clinical outcomes and neonatal outcomes. A total of 2139 cycles were involved in this study. There were significant differences in fertilisation rate (77.0% vs. 73.6%, p < .001), cleavage rate (97.4% vs. 94.4%, p < .001) and high-quality embryo rate (52.8% vs. 49.9%, p < .001) between the ejaculated and non-ejaculated sperm groups. There were no significant differences amongst the four groups in biochemical pregnancy rate, clinical pregnancy rate, abortion rate, live birth rate, male-female ratio and single-twin ratio. Different sperm sources did not affect the length, weight or physical defects of newborns amongst the groups. Sperm source did not affect pregnancy and neonatal outcomes of intracytoplasmic sperm injection in general.

Perfluorooctane sulfonate affects mouse oocyte maturation in vitro by promoting oxidative stress and apoptosis induced bymitochondrial dysfunction.

Perfluorooctane sulphonate (PFOS), as a surfactant, is widely applied in the agricultural production activities and has become a potential menace to human health. The mechanism of its effect on the maturation of mammalian oocytes is unclear. This study explored the toxic effect of PFOS on mouse oocyte maturation in vitro. The results revealed that PFOS under a concentration of 600 µM could significantly reduce the polar body extrusion rate (PBE) of mouse oocytes and cause symmetrical cell division. Further experiments showed that PFOS resulted in the abnormal cytoskeleton of the oocytes, causing the abnormal spindles and misplaced chromosomes, as well as the impaired dynamics of actin. Moreover, PFOS exposure inhibited the process of oocyte meiosis, which reflected in the slower spindle migration and continuous activation of spindle assembly checkpoint (SAC), then ultimately increased the probability of aneuploidy. Most importantly, PFOS exposure reduced the quality of oocytes, specifically by disrupting the function of mitochondria, inducing cell oxidative stress, and triggering early apoptosis. Furthermore, the level of methylation of histones is additionally influenced. In summary, our findings showed that PFOS exposure interfered with the maturation of mouse oocytes through affecting cytoskeletal dynamics, meiotic progression, oocyte quality, and histone modifications.

Nickel sulfate exposure induces ovarian inflammation and fibrosis and decreases oocyte quality in mice.

Nickel is a heavy metal element extensively distributed in the environment and widely used in modern life. Divalent nickel is one of the most widespread forms of nickel and has been reported as toxic to various tissues. However, whether exposure to divalent nickel negatively affects ovarian homeostasis and oocyte quality remains unclear. In this study, we found that 3 weeks of nickel sulfate exposure affected body growth and decreased the weight and coefficient of the ovary, and increased atretic follicles exhibiting enhanced apoptosis in granulosa cells. Further studies have found that nickel sulfate triggered ovarian fibrosis and inflammation via transforming growth factor-ß1 and nuclear factor-κB pathways, and reduced oocyte development ability. In addition, nickel sulfate increased the level of reactive oxygen species, which induced DNA damage and early apoptosis. Moreover, it was found that nickel sulfate caused damage to the mitochondria showing aberrant morphology, distribution and membrane potential while decreased levels of histone methylation. To summarize, our results indicated that nickel sulfate exposure triggered ovarian fibrosis and inflammation and caused structural and functional disorders of mitochondria in oocytes, which consequently disturbed ovarian homeostasis and follicle development and decreased oocyte quality.

Pachymic acid protects oocyte by improving the ovarian microenvironment in polycystic ovary syndrome mice†.

Women with polycystic ovary syndrome (PCOS) are characterized by endocrine disorders accompanied by a decline in oocyte quality. In this study, we generated a PCOS mice model by hypodermic injection of dehydroepiandrosterone, and metformin was used as a positive control drug to study the effect of pachymic acid (PA) on endocrine and oocyte quality in PCOS mice. Compared with the model group, the mice treated with PA showed the following changes (slower weight gain, improved abnormal metabolism; increased development potential of GV oocytes, reduced number of abnormal MII oocytes, and damaged embryos; lower expression of ovarian-related genes in ovarian tissue and pro-inflammatory cytokines in adipose tissue). All these aspects show similar effects on metformin. Most notably, PA is superior to metformin in improving inflammation of adipose tissue and mitochondrial abnormalities. It is suggested that PA has the similar effect with metformin, which can improve the endocrine environment and oocyte quality of PCOS mice. These findings suggest that PA has the similar effect with metformin, which can improve the endocrine environment and oocyte quality of PCOS mice.

Single-cell RNA sequencing reveals distinct gene expression patterns in glucose metabolism of human preimplantation embryos.

Precise regulation of glucose metabolism-related genes is essential for early embryonic development. Although previous research has yielded detailed information on the biochemical processes, little is yet known of the dynamic gene expression profiles in glucose metabolism of preimplantation embryos at a single-cell resolution. In the present study, we performed integrated analysis of single-cell RNA sequencing (scRNA-seq) data of human preimplantation embryos that had been cultured in sequential medium. Different cells in the same embryo have similar gene expression patterns in glucose metabolism. During the switch from the cleavage to morula stage, the expression of glycolysis-related genes, such as glucose transporter genes (solute carrier family 2 (facilitated glucose transporter), member 1 (SLC2A1) and solute carrier family 2 (facilitated glucose transporter), member 3 (SLC2A3) and genes encoding hexokinase, phosphofructokinase, pyruvate kinase and lactate dehydrogenase, is increased. The genes involved in the pentose phosphate pathway are highly expressed at the cleavage stage, generating the reducing power to balance oxidative stress derived from biosynthesis. Expression of the genes involved in the biosynthesis of glycerophospholipids is increased after the morula stage. Nevertheless, the expression of tricarboxylic acid-related genes remains relatively unchanged during the preimplantation stages. In conclusion, we discovered that the gene expression profiles are dynamic according to glucose utilisation in the embryos at different stages, which contributes to our understanding of regulatory mechanisms of glucose metabolism-related genes in human preimplantation embryos.

[Clinical and genetic features of 45,X maleness: A case report and review of the literature].

OBJECTIVE: To explore the relationship between the clinical and genetic features of a short-statured azoospermia male with the karyotype of 45,X. METHODS: Using GTG-banded chromosome analysis, we performed karyotyping for a 150 cm-high infertile male with azoospermia and investigated the presence and location of the genes on the Y chromosome by FISH and PCR. RESULTS: GTG-banded chromosome analysis showed the karyotype of the patient to be 45,X,add(14)(p11). The results of PCR manifested the deletion of AZFa, AZFb, AZFc, and AZFd in the SRY gene. FISH revealed the translocation of the short arm of the Y chromosome to that of chromosome 14 and deletion of most proportions of its long arm, with the disruption site close to the centromere region. The karyotype of the patient was 45,X,der(Y)t(Y;14)(q11;q11.2), 14.ish (SRY+, CEP Y+ , DYZ1－). CONCLUSIONS: The karyotype of the patient was unbalanced Y/14 translocation. The SRY gene is the key to maleness. The deletion of AZFa－ d induces spermatogenic disturbance, and the deletion of the q arm of the Y chromosome may be related with short stature.

Rab11-FIP2 promotes colorectal cancer migration and invasion by regulating PI3K/AKT/MMP7 signaling pathway.

Rab11-family interacting proteins (Rab11-FIPs) belong to an evolutionarily conserved protein family and act as effector molecules for the Rab11 family of small GTPases. Recent evidence suggests that Rab11-FIPs have important roles in tumor progression and metastasis. However, the contribution of Rab11-FIPs to colorectal carcinoma (CRC) remains elusive. Our study focuses on elucidating the role of Rab11-FIP2 in the migration and invasion of colorectal cancer cells. We firstly found upregulation of Rab11-FIP2 in CRC tissues compared with peritumor tissues by oncomine data-mining analysis, western blot analysis and immunohistochemistry (IHC) analysis, respectively. Then, we demonstrated that knockdown of Rab11-FIP2 via siRNAs transfection resulted in a decrease in migration and invasion of CRC cells, while overexpression of Rab11-FIP2 via lentiviral infection increased migration and invasion of CRC cells. In addition, we verified that Rab11-FIP2 promoted migration and invasion of CRC cells through upregulating MMP7 expression. Finally, using several kinase inhibitors, our results showed that Rab11-FIP2 regulated MMP7 expression through activating PI3K/Akt signaling. Our data suggested a potential role of Rab11-FIP2 in tumor progression and provided novel insights into the mechanism of how Rab11-FIP2 positively regulated cell migration and invasion in CRC cells.

Feeder-free and xeno-free culture of human pluripotent stem cells using UCBS matrix.

The ideal medium for human pluripotent stem cells (hPSCs) culture should be feeder-free, xeno-free, and completely defined. The present study aims to establish a new feeder-free and xeno-free system for culturing hPSCs. The system consists of the matrix, which was prepared from human umbilical cord blood serum (UCBS) and used to coat the culture plates, and the xeno-free medium, which was conventional serum-free hES medium supplemented with high concentrations of bFGF and Fibronectin. Compared with matrigel and mouse embryonic fibroblasts (MEFs), the UCBS matrix was proved to be equally suitable for the growth of hPSCs. After a series of experiments with different media and cytokins, the UCBS matrix was found worked the best with the basic medium (BM) supplemented with 20 ng/mL bFGF, 10 ug/mL fibronectin and Y-27632 for culture of hES cells. The hPSCs maintained normal karyotype, high proliferation rate and self-renewal ability after continuous culture more than 10 passages in this feeder-free and xeno-free system. Furthermore, a new human embryonic stem (hES) cell line was derived from discarded day 3 embryos in this newly developed culture system. In conclusion, this feeder-free and xeno-free system could not only be used to the culture hPSCs, but could also be used to derive new hES cell lines.

Associations of FUT2 and FUT3 gene polymorphisms with Crohn's disease in Chinese patients.

BACKGROUND AND AIM: FUT2 and FUT3 genes are responsible for the formation of histo-blood group antigens, which act as binding sites for some intestinal microbes. Several studies suggested that FUT2 gene might affect the intestinal microbiota composition and modulate innate immune responses. However, the effect of FUT2 polymorphisms on Crohn's disease (CD) is uncertain. Our study aimed to analyze associations of CD with FUT2 and FUT3 polymorphisms in Chinese population. METHODS: A total of 273 CD patients and 479 controls were recruited. The genotypes of FUT2 (rs281377, rs1047781, and rs601338) and FUT3 (rs28362459, rs3745635, and rs3894326) were detected by SNaPshot analysis. RESULTS: Compared with controls, homozygote TT of FUT2 (rs1047781) was significantly increased in CD patients (TT vs others; P = 0.002, odds ratio [OR] = 1.767, 95% confidence interval [CI] = 1.235-2.528). The haplotype TT formed with FUT2 (rs281377) and (rs1047781) was more prevalent in CD patients than in controls (48.9% vs 43.5%, P = 0.046). Mutant T allele and homozygote TT of FUT2 (rs1047781) were increased in colonic CD patients compared with controls (P < 0.001, OR = 1.843, 95% CI = 1.353-2.512; P < 0.001, OR = 2.607, 95% CI = 1.622-4.191, respectively). Although allele and genotypic distributions of FUT3 were not statistically different between CD patients and controls, mutant allele and genotype of FUT3 (rs28362459) and (rs3745635) were significantly discrepant in three subgroups of CD patients according to lesion locations (all P < 0.05). CONCLUSIONS: Our study strongly implicates the polymorphic locus of FUT2 (rs1047781) in CD susceptibility in Chinese population. Mutations of FUT3 (rs28362459) and (rs3745635) might influence the lesion locations in CD patients.

Aristolochic acid I exposure triggers ovarian dysfunction by activating NLRP3 inflammasome and affecting mitochondrial homeostasis.

Aristolochic acids are widely distributed in the plants of Aristolochiaceae family and Asarum species. Aristolochic acid I (AAI) is the most frequent compound of aristolochic acids, which can accumulate in the soil, and then contaminates crops and water and enters the human body. Research has shown that AAI affects the reproductive system. However, the mechanism of AAI's effects on the ovaries at the tissue level still needs to be clarified. In this research, we found AAI exposure reduced the body and ovarian growth in mice, decreased the ovarian coefficient, prevented follicular development, and increased atretic follicles. Further experiments showed that AAI upregulated nuclear factor-κB and tumor necrosis factor-α expression, activated the NOD-like receptor protein 3 inflammasome, and led to ovarian inflammation and fibrosis. AAI also affected mitochondrial complex function and the balance between mitochondrial fusion and division. Metabolomic results also showed ovarian inflammation and mitochondrial dysfunction due to AAI exposure. These disruptions reduced the oocyte developmental potential by forming abnormal microtubule organizing centers and expressing abnormal BubR1 to destroy spindle assembly. In summary, AAI exposure triggers ovarian inflammation and fibrosis, affecting the oocyte developmental potential.

Triptolide exposure induces oxidative stress and decreases oocyte quality in mouse.

Triptolide is a major active ingredient isolated from the traditional Chinese medicine Tripterygium wilfordii, which has anti-inflammatory, anti-cancer, and immunomodulatory effects. However, in clinical studies, triptolide has toxic side effects on the heart, kidney, liver and reproductive organs. With respect to female reproductive toxicity, damaging effects of triptolide on the ovary have been reported, but it has remained unknown whether oocytes are affected by triptolide. Therefore, this study established a concentration gradient of triptolide exposure in mice using 0 (control), 30, 60, and 90 µg triptolide/kg body weight/day administered by gavage. Triptolide administration for 28 d reduced body weight and ovarian weight and affected the developmental potential of oocytes. The triptolide-treated group exhibited meiotic failure of oocytes due to impaired spindle assembly, chromosome alignment, and tubulin stability. Triptolide was also found to induce mitochondrial dysfunction, autophagy and early apoptosis, iron homeostasis, and abnormal histone modifications. These adverse effects could be associated with oxidative stress induced by triptolide. In conclusion, our findings suggest detrimental effects of triptolide on mouse oocytes and, thus, on female reproduction.

Chloroacetonitrile exposure induces endoplasmic reticulum stress and affects spindle assembly in mouse oocytes.

Chloroacetonitrile (CAN) is a halogenated acetonitrile often produced while disinfecting drinking water. Previous studies have shown that maternal exposure to CAN interferes with fetal development; however, the adverse effects on maternal oocytes remain unknown. In this study, in vitro exposure of mouse oocytes to CAN reduced maturation significantly. Transcriptomics analysis showed that CAN altered the expression of multiple oocyte genes, especially those associated with the protein folding process. CAN exposure induced reactive oxygen species production, accompanied by endoplasmic reticulum (ER) stress and increased glucose regulated protein 78, C/EBP homologous protein and activating transcription factor 6 expression. Moreover, our results indicated that spindle morphology was impaired after CAN exposure. CAN disrupted polo-like kinase 1, pericentrin and p-Aurora A distribution, which may be an origin inducer that disrupts spindle assemble. Furthermore, exposure to CAN in vivo impaired follicular development. Taken together, our findings indicate that CAN exposure induces ER stress and affects spindle assembly in mouse oocytes.

Effect of culture medium volume and embryo density on early mouse embryonic development: tracking the development of the individual embryo.

PURPOSE: To determine the optimal volume or density of embryos for the well-of-the-well (WOW) system in order to track the development of individual embryos and to determine whether the WOW system can reverse the negative impact of culturing embryos singly. METHODS: (1) Mouse embryos (groups of nine at the 2-cell stage) were cultured in 6.25 µl, 12.50 µl, 25.00 µl and 50.00 µl of droplets of culture medium under paraffin oil; (2) Groups of three, six, nine and twelve embryos at the 2-cell stage were cultured in 50 µl of droplet of culture medium under paraffin oil; (3) Groups of nine embryos at the 2-cell stage were cultured in 50 µl of droplet under paraffin oil with or without nine micro-wells made on the bottom of the Petri dish into each of which were placed one of the nine embryos (WOW system). Also single 2-cell stage embryos was cultured individually in 5.5 µl of droplet of culture medium under paraffin oil with or without a single micro-well made on the bottom of the Petri dish (WOW system for single culture). At the end of culture, the percentages of blastocyst development, hatching and hatched blastocysts were compared in each group. The blastocysts were fixed for differential staining. RESULTS: The blastocyst development was significantly higher (P < 0.05) when nine embryos were cultured in 50 µl of droplet of culture medium compared with other volumes. The blastocyst development was significantly reduced (P < 0.05) in single embryo culture compared to group embryo culture with or without the WOW system. The blastocyst development was not improved when single embryo cultured individually in a micro-well was compared to single embryo cultured individually without micro-well. The total cell numbers of blastocysts were significantly higher in group embryo culture than single embryo culture regardless of whether the WOW system was used. In addition, the total cell numbers of blastocysts were significantly higher (P < 0.05) in single embryo culture with the WOW system than without. CONCLUSIONS: Group embryo culture is superior to single embryo culture for blastocyst development. The WOW system with 50 µl of droplet of culture medium can be used to track the individual development of embryo cultured in groups while preserving good embryonic development. The reduced embryonic development with single embryo culture cannot be ameliorated by the WOW system.

[Correlations of genetic polymorphisms of tumor necrosis factor-related apoptosis-inducing ligand gene and its plasma phenotype with ulcerative colitis].

OBJECTIVE: To explore the correlations of genetic polymorphisms in tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) gene and the plasma levels of soluble TRAIL (sTRAIL) with ulcerative colitis (UC). METHODS: From May 2004 to April 2011, a total of 393 UC patients were recruited from Second and First Affiliated Hospitals of Wenzhou Medical College and Second Renmin Hospital of Wenzhou City. During the same period, a total of 1292 healthy controls were recruited from Physical Examination Center at Second Affiliated Hospital of Wenzhou Medical College. After PCR amplification, the genetic polymorphisms in TRAIL (G1525A, G1588A, C1595T) genes were examined by direct sequencing, and the haplotype analysis were also performed in all study subjects. Furthermore, the plasma levels of sTRAIL were determined by enzyme-linked immunosorbent assay (ELISA). RESULTS: The frequencies of variant genotypes in TRAIL (G1525A, G1588A, C1595T) genes were significantly lower in the UC patients than those in the controls (all P < 0.01). Both of variant allele frequencies in TRAIL G1525A and G1588A were significantly decreased in UC patients (40.08% (315/786) vs 54.95% (1420/2584), 49.49% (389/786) vs 55.53% (1435/2584), both P < 0.01). However, the variant allele frequency in TRAIL C1595T gene was not significantly lower in the UC patients (P = 0.133). According to disease severity, the UC patients were divided into mild, intermediate and severe groups. The frequencies of variant allele (T) and genotype (CT + TT) in TRAIL C1595T gene were also significantly higher in the patients with severe UC than those in others (63.50% (127/200) vs 49.15% (288/586), 77.00% (77/100) vs 61.43% (180/293), both P < 0.01). In haplotype analysis, the frequency of GAT haplotype was significantly higher in the UC patients than that in the controls. However, the frequency of AAT haplotype was significantly lower in the UC patients (both P < 0.01). Furthermore, the plasma levels of sTRAIL were significantly higher in the UC patients than those in the controls ((1.05 ± 0.48) vs (0.96 ± 0.90) ng/L, P < 0.01). CONCLUSION: The genetic polymorphisms of TRAIL (G1525A, G1588A, C1595T) and the plasma levels of sTRAIL are correlated with UC in Chinese patients.

Melatonin enhances spermatogonia activity through promoting KIAA1429-mediated m6A deposition to activate the PI3K/AKT signaling.

Melatonin is a key neuroendocrine hormone that promotes spermatogenesis and sperm motility, but the underlying mechanisms remains poorly understood. In this study, we aimed to investigate the possible roles of m6A (N6--methyl-adenosine) in mediating melatonin-regulated spermatogonia activity alterations. In this study, mouse-derived GC-1 spermatogonia (spg) cell line was used as the in vitro cellular model. The viability, proliferation rates and apoptosis of spermatogonia were detected via CCK-8, Edu staining and flow cytometry respectively. Total m6A level was quantitated by dot blot, while mRNA and proteins contents in spermatogonia were measured by qRT-PCR and western blot respectively. Differentially expressed mRNAs were characterized by deep RNA sequencing method. Results showed that melatonin significantly promoted viability and proliferation rate while inhibited apoptosis in the GC-1 spg cells. The total m6A levels in GC-1 spg cells were also greatly increased by melatonin treatment, accompanied by remarkable expressional elevation of the m6A writer KIAA1429. Moreover, the regulation of GC-1 spg cell viability, proliferation and apoptosis by melatonin were greatly abrogated by KIAA1429 silencing but effectively strengthened by KIAA1429 overexpression. In addition, KIAA1429 overexpression regulates multiple biological process and signaling pathways in spermatogonia such as the PI3K/AKT signaling. The PI3K inhibitor LY294002 effectively mitigated the regulation of spermatogonia activity by KIAA1429 overexpression under melatonin treatment. Taken together, melatonin promotes spermatogonia activity via enhancing KIAA1429 expression and m6A RNA methylation to activate the downstream PI3K/AKT signaling pathway.

Association of Dietary Intake and Biomarker of α-Linolenic Acid With Incident Colorectal Cancer: A Dose-Response Meta-Analysis of Prospective Cohort Studies.

Background and Objective: There is keen interest in better understanding the impacts of alpha-linolenic acid (ALA), a plant-derived n-3 fatty acid, in ameliorating the development of cancer; however, results of several prospective cohorts present an inconsistent association between ALA intake and the incident colorectal cancer (CRC). We aimed to investigate the summary association of dietary intake and biomarkers of ALA with CRC risk based on the prospective cohorts. Methods: Pertinent prospective cohorts were identified in Cochrane Library, PubMed, and EMBASE from inception to February 2022. Study-specific risk ratios (RRs) with 95% confidence intervals (CIs) for comparing the top with the bottom quartiles of ALA levels were combined using a random-effects model. Nonlinear dose-response relationships of ALA levels in diet and blood with CRC risk were assessed using the restricted cubic spline models, respectively. Results: Over the duration of follow-up with a median of 9.3 years ranging from 1 to 28 years, 12,239 CRC cases occurred among 861,725 participants from 15 cohorts (11 studies on diet and 5 studies on biomarkers including 4 on blood and 1 on adipose tissue). The summary RR was 1.03 (95% CI: 0.97, 1.10; I2: 0.00%) for dietary intake and 0.83 (95% CI: 0.69, 0.99; I2: 0.00%) for biomarker. Each 0.1% increase in the levels of ALA in blood was associated with a 10% reduction in risk of CRC (summary RR: 0.90, 95% CI: 0.80, 0.99; I2: 38.60%), whereas no significant dose-response association was found between dietary intake of ALA and the incident CRC (p for non-linearity = 0.18; p for linearity = 0.24). Conclusions: Blood levels of ALA were inversely and linearly associated with the risk of CRC, which suggested that increased intake of ALA to improve circulating levels was beneficial for CRC prevention.

Captan exposure disrupts ovarian homeostasis and affects oocytes quality via mitochondrial dysfunction induced apoptosis.

Captan is a non-systematic fungicide widely used in agricultural production, and its residues have been found in the environment and daily diet. Previous studies confirmed that captan exerts several toxic effects on tissues, but its effect on the mammalian female reproductive system is unclear. In current study, we reported that captan affected mouse ovarian homeostasis and disrupted female hormone receptor expression, leading to impaired follicular development. Ovarian follicles from the captan exposure group showed an increased level of inflammation, endoplasmic reticulum stress and apoptosis. In addition, captan exposure disrupted oocyte development. Transcriptomic analysis indicated that captan changed multiple genes expression in oocytes, including autophagy and apoptosis. Further molecular testing showed that captan induced oxidative stress and mitochondrial dysfunction, as indicated by the increased level of reactive oxygen species, disrupted mitochondrial structure and distribution, and depolarized membrane potential. Furthermore, captan triggered DNA damage, autophagy and early apoptosis, as shown by the enhanced levels of γ-H2AX, LC3, and Annexin-V and increased expression of related genes. Taken together, these results indicated that captan exposure impairs ovarian homeostasis and subsequently affects oocyte development.