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.

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.

NLRP3 inflammasome activation in gestational diabetes mellitus placentas is associated with hydrogen sulfide synthetase deficiency.

The placenta may play a key role in the activation of inflammation and initiation of insulin resistance (IR) during gestational diabetes mellitus (GDM) pathogenesis. Interleukin (IL)-1ß and IL-18, regulated by NLR family pyrin domain containing-3 (NLRP3) inflammasome, are important inflammatory cytokines in the initiation of maternal IR during GDM. However, the mechanism responsible for the regulatory of NLRP3 inflammasome in placenta remains unknown. Hydrogen sulfide (H2S) exerts anti-inflammatory function partially via suppressing the activation of the NLPR3 inflammasome. The present study aimed to investigate the role of NLRP3 inflammasome, H2S synthetase cystathionine-γ-lyase (CSE) and cystathionine-ß-synthetase (CBS) in placenta in the pathogenesis of GDM. Clinical placenta samples were collected from pregnant women with GDM (n=16) and healthy pregnant women at term (n=16). Western blot analysis was performed to detect the protein expression levels of NLRP3, cleaved caspase-1, CBS and CSE in the placenta samples. Pearson's correlation analysis was performed to assess the correlation between NLRP3 inflammasome and H2S synthetase. Human placental cells were cultured and treated with different concentrations of NaHS (0, 10, 25 and 50 nmol/l) or L-cysteine (0, 0.25, 0.50 and 1.00 mmol/l). In addition, western blot analysis was performed to detect the protein expression levels of NLRP3 and cleaved caspase-1, while ELISA was performed to measure the production of IL-1ß and IL-18 in the culture media. The results demonstrated that the expression levels of NLRP3 and cleaved caspase-1 increased, while the expression levels of CBS and CSE decreased in the placenta samples. In addition, the expression levels of NLRP3 and cleaved caspase-1 were inversely correlated with the expression levels of CBS and CSE. Notably, NaHS and L-cysteine significantly suppressed the expression levels of NLRP3 and cleaved caspase-1, and the production of IL-1 and IL-18 in human placental cells. Taken together, the results of the present study suggest that H2S synthetase deficiency in placenta may contribute to excessive activation of NLRP3 inflammasome in GDM.

Hydrogen sulfide modulates high glucose-induced NLRP3 inflammasome activation in 3T3-L1 adipocytes.

Activation of the NACHT leucine rich repeat and pyd domains-containing 3 (NLRP3) inflammasome plays an important role in the initiation of inflammation in adipose tissue in diabetic patients. However, the mechanisms underlying this are not fully understood. Hydrogen sulfide (H2S) has been shown to have anti-inflammatory properties in various cell types. The present study aimed to investigate the effect of H2S on high glucose (HG)-induced NLRP3 inflammasome activation in adipocytes. Adipocytes were differentiated from 3T3-L1 cells and treated with low glucose (LG), HG, H2S donor sodium hydrosulfide (NaHS) or N-acetyl-tyrosyl-valyl- alanyl-aspartyl chloromethyl ketone, an inhibitor of the cysteine protease caspase-1. The expression levels of NLRP3, apoptosis-associated speck-like protein containing A CARD (ASC) and caspase-1, and the release of interleukin (IL)-1ß and IL-18 were measured. The results of the present study indicated that HG increased the expression levels of NLRP3, ASC and cleaved caspase-1, and the release of IL-1ß and IL-18 in adipocytes. Caspase-1 inhibition abolished HG-induced production of IL-1ß and IL-18 in adipocytes. Furthermore, NaHS inhibited the expression of NLRP3, ASC and cleaved caspase-1, and the production of IL-1ß and IL-18 in adipocytes treated with HG. In conclusion, HG may increase and exogenous H2S may inhibit HG-induced NLRP3 inflammasome activation in adipocytes.

Reduced cystathionine-γ-lyase (CSE) expression is involved in high glucose induced MMP14 expression in adipocytes and adipose tissues.

In the present study, we investigate the effect of reduced cystathionine-γ-lyase (CSE) expression in high glucose induced metalloproteinases14 (MMP14) expression in adipocytes and visceral adipose tissues. Diabetic mice were prepared by injections of STZ and the expression of CSE, MMP14 in visceral adipose tissues were determined. Adipocytes were differentiated from 3T3-L1 cells and treated with high glucose (HG), H2S slow-releasing compound GYY4137 or transfected with CSE siRNA. Then the expression of CSE, MMP14 were determined by western blotting. CSE knockout mice were generated by crossing CSE+/- heterozygous mice and given intraperitoneally (i.p.) injections of GYY4137, and then the expression of CSE and MMP14 in visceral adipose tissues were determined by quantitative real-time PCR and western blotting. The following results were obtained from the study. In adipose tissues of diabetic mice, the mRNA and protein expression of MMP14 increased while the mRNA and protein expression of CSE decreased. In 3T3-L1 adipocytes, both HG DMEM and CSE siRNA transfection increased the mRNA and protein of MMP14. The addition of GYY4137 inhibited HG-induced upregulation of MMP14 expression. In CSE knockout mice, the mRNA and protein expression of MMP14 in adipose tissues increased, which could be inhibited by i.p. injections of GYY4137. In conclusion, high glucose increased the expression of MMP14 in adipocytes and visceral adipose tissues through inhibiting the expression of CSE.

Hydrogen Sulfide Inhibits High Glucose-Induced sFlt-1 Production via Decreasing ADAM17 Expression in 3T3-L1 Adipocytes.

Hydrogen sulfide (H2S) has recently been identified as an endogenous gaseous signaling molecule. The aim of the present study was to investigate the effect of H2S on high glucose- (HG-) induced ADAM17 expression and sFlt-1 production in 3T3-L1 adipocytes. Firstly, we found that HG DMEM upregulated the expression of ADAM17 and production of sFlt-1 in 3T3-L1 adipocytes. Knocking down ADAM17 attenuated the effect of high glucose on sFlt-1 production in adipocytes. HG decreased the expression of CSE and 3-MST, as well as the endogenous H2S production. Furthermore, knocking down CSE and 3-MST significantly increased ADAM17 expression and sFlt-1 production. The addition of exogenous H2S through the administration of sodium hydrosulfide (NaHS) inhibited HG-induced upregulation of ADAM17 expression and sFlt-1 production. In conclusion, decreased expression of CSE and 3-MST and the subsequent decrease in H2S production contribute to high glucose-induced sFlt-1 production via activating ADAM17 in adipocytes. Exogenous H2S donor NaHS has a potential therapeutic value for diabetic vascular complications.

[Alisma versus Gliclazide in the Treatment of Primary Diabetes in Goto-Kakizaki Rats].

OBJECTIVE: To compare the roles of alisma and gliclazide in the treatment of diabetes in Goto-Kakizaki (GK) rats. METHODS: GK rats were randomly divided into alisma group, gliclazide group, and blank group, and Wistar rats were used as the normal group. After two weeks of treatment, body weight, food intake,fasting glucose, impaired glucose tolerance, and other indicators were measured. RESULTS: The body weight increased after the treatment in the normal group,blank group,and gliclazide group [(241.3 ± 7.0)g vs.(263.5 ± 11.1)g, (242.8 ± 7.1)g vs.(267.9 ± 16.8)g, (243.9 ± 12.2)g vs.(277.9 ± 9.8)g, P<0.05] but decreased in alisma group [(244.6 ± 9.2)g vs.(227.9 ± 13.7)g, P<0.05]. The food intake showed no significant change before and after administration among different groups(P>0.05). Fasting glucose was significantly lower in normal group than in control group,alisma group,and gliclazide group [(4.8 ± 0.2) mmol/L vs.(8.2 ± 1.4) mmol/L,(8.1 ± 0.6) mmol/L, (8.1 ± 0.9)mmol/L, P<0.05] one week after drug administration; it was not significantly different among blank group,alisma group,and gliclazide group before drug administration (P>0.05); however, it significantly decreased in alisma group and gliclazide group two weeks after administration [(6.9 ± 0.7) mmol/L vs.(8.1 ± 0.6) mmol/L; (5.8 ± 0.5) mmol/L vs.(8.1 ± 0.9) mmol/L, P<0.05]; compared with the blank group, the fasting glucose was significantly lower in the alisma group and gliclazide group,and it was also significantly different between these two groups [(6.9 ± 0.7) mmol/L vs.(8.8 ± 0.6) mmol/L,(5.8 ± 0.5)mmol/L vs.(8.8 ± 0.6)mmol/L, (6.9 ± 0.7) mmol/L vs.(5.8 ± 0.5)mmol/L, P<0.05]. Compared with the normal group,glucose tolerance was abnormal in blank group,alisma group,and gliclazide group;after two weeks of treatment,glucose tolerance was significantly improved in alisma group (P<0.05); compared with the pretreatment level and that in the blank group,the glucose tolerance in gliclazide group showed no significant difference (P> 0.05). CONCLUSIONS: Both alisma and gliclazide monotherapy is effective in lowering fasting blood glucose. As a single-target drug,gliclazide has stronger effecacy in lowering fasting glucose. However, alisma, as a mixture, can also control weight and improve glucose intolerance.