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.

Increased soluble endoglin levels in newly-diagnosed type 2 diabetic patients are associated with endothelial dysfunction.

Endothelial dysfunction (ED) contributes to the pathologic process underlying macrovascular complications, a common complication of type 2 diabetes mellitus (T2DM). Soluble endoglin (sEng) shed from the extracellular domain of the entire endoglin molecule blocks endothelial protection mediated by transforming growth factor-beta 1 (TGF-ß1). The reactive hyperemia index (RHI), which is determined by reactive hyperemia peripheral arterial tonometry (RH-PAT), is a new index with which to evaluate ED. This study determined the changes in serum sEng levels in newly-diagnosed (untreated) T2DM patients and the correlation with the RHI. The T2DM group included 34 newly-diagnosed T2DM patients, while the control group included 53 healthy adults. The clinical data from the two groups were evaluated retrospectively. The intima-media thickness (IMT) of the common carotid artery (CCA) and the ankle-brachial index (ABI) of both legs were used to assess structural vascular changes. The serum sEng level was determined using an ELISA kit. Endothelial function was assessed using RH-PAT and the RHI was computed. The serum sEng level in the T2DM group was significantly greater than the control group, although the RHI was significantly lower in the T2DM group (p < 0.05). The serum sEng level was negatively correlated with the RHI in T2DM patents (r = 0.354, p = 0.041). The serum sEng level, CCA-IMT, and ABI were not significantly correlated with T2DM (p > 0.05). In summary, among newly-diagnosed T2DM patients, the serum sEng levels were inversely correlated with the RHI, and an elevated sEng level may be associated with ED.

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.

The Association of Serum Irisin with Bone Mineral Density and Turnover Markers in New-Onset Type 2 Diabetic Patients.

Background: Irisin, an exercise-induced myokine and adipocytokine, has been reported to decrease in type 2 diabetic patients. Recently, several research studies indicated that circulating levels were correlated with bone mineral density (BMD). To evaluate bone metabolism, bone turnover markers (BTMs) should be included. However, with respect to newly diagnosed T2DM patients, the relevance of their irisin levels to their BTMs and BMD remains unclear. The investigation of serum irisin levels in patients who have been newly diagnosed with type 2 diabetes and illumination of the relationship between serum irisin levels and those two indices of BMD and BTMs mentioned above are the intention of this cross-sectional study. Methods: 66 new-onset type 2 diabetic patients (T2DM group), together with 82 control subjects (NGT group), were recruited in this study. Serum irisin concentrations and BTMs (including osteocalcin (OC), procollagen type 1 N-terminal propeptide (P1NP), and ß-C-terminal telopeptides of type I collagen (ß-CTX)) were determined by the enzyme-linked immunosorbent assay (ELISA). Glucose, lipid profile, and insulin were considered as measuring indicators as well. Dual-energy X-ray absorptiometry (DXA) was utilized to evaluate the indicator of BMD. Serum irisin, BTMs, and BMD were compared between diabetic patients and healthy individuals. Pearson and Spearman correlation analyses were applied as well to assess correlations between irisin and BTMs and BMD. Multiple stepwise regression analysis was conducted to identify the independent factors of irisin. ROC curve analyses were carried out for serum irisin prediction for osteoporosis/osteopenia (OP). Results: The serum levels of irisin, procollagen type 1, intact N-terminal propeptide (P1NP), and osteocalcin (OC) were evidently lower in T2DM subjects than in NGT subjects (10.90 ± 1.88 vs .11.69 ± 2.06 ng/mL, P < 0.05; 36.42(25.68,51.70) vs. 44.52(35.73,58.05)ng/ml, P < 0.05; 16.15(12.40,21.66) vs. 18.70(15.56, 23.22)ng/ml, P < 0.05). Among patients with T2DM, the circulating irisin level of those with OP was lower than that of normal BMD (9.98 ± 2.09 vs. 11.39 ± 1.57 ng/ml, P < 0.01); irisin had a negative correlation with ß-C-terminal telopeptides of type I collagen (ß-CTX) (r = -0.496, P < 0.001) and came back unrelated to Lumbar BMD; Lumbar BMD was negatively relevant to OC (r = -0.274, P < 0.05) and ß-CTX (r = -0.410, P < 0.01). Multiple linear regression analyses of stepwise models implied that TG, LDL-C, and ß-CTX were independently associated with serum irisin concentrations (P < 0.01 or P < 0.05). Conclusion: Serum irisin level was declined in patients with type 2 diabetes diagnosed in the near term and had a certain association with bone turnover markers. It is suggested to consider irisin as a potential biomarker of bone metabolic disorder in T2DM patients with the initial diagnosis.

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.