PCSK9 involves in the high-fat diet-induced abnormal testicular function of male mice.

In brief: Impaired spermatogenesis resulting from disturbed cholesterol metabolism due to intake of high-fat diet (HFD) has been widely recognized, however, the role of preprotein invertase subtilin 9 (PCSK9), which is a negative regulator of cholesterol metabolism, has never been reported. This study aims to reveal the role of PCSK9 on spermatogenesis induced by HFD in mice. Abstract: Long-term consumption of a high-fat diet (HFD) is an important factor that leads to impaired spermatogenesis exhibiting poor sperm quantity and quality. However, the mechanism of this is yet to be elucidated. Disrupted cholesterol homeostasis is one of many crucial pathological factors which could contribute to impaired spermatogenesis. As a negative regulator of cholesterol metabolism, preprotein invertase subtilin 9 (PCSK9) mediates low density lipoprotein receptor (LDLR) degradation to the lysosome, thereby reducing the expression of LDLR on the cell membrane and increasing serum low-density lipoprotein cholesterol level, resulting in lipid metabolism disorders. Here, we aim to study whether PCSK9 is a pathological factor for impaired spermatogenesis induced by HFD and the underlying mechanism. To meet the purpose of our study, we utilized wild-type C57BL/6 male mice and PCSK9 knockout mice with same background as experimental subjects and alirocumab, a PCSK9 inhibitor, was used for treatment. Results indicated that HFD induced higher PCSK9 expression in serum, liver, and testes, and serum PCSK9 is negatively correlated with spermatogenesis, while both PCSK9 inhibitor treatment and PCSK9 knockout methodologies ameliorated impaired lipid metabolism and spermatogenesis in mice fed a HFD. This could be due to the overexpression of PCSK9 induced by HFD leading to dyslipidemia, resulting in testicular lipotoxicity, thus activating the Bcl-2-Bax-Caspase3 apoptosis signaling pathway in testes, particularly in Leydig cells. Our study demonstrates that PCSK9 is an important pathological factor in the dysfunction of spermatogenesis in mice induced by HFD. This finding could provide innovative ideas for the diagnosis and treatment of male infertility.

Relationship between Helicobacter pylori and Incident Hypertension as well as Blood Pressure: A Systematic Review and Meta-Analysis.

BACKGROUND: Helicobacter pylori (H. pylori) may be a risk factor for hypertension, but the reported studies have given conflicting results. This study aimed to explore the association between H. pylori infection and hypertension risk and blood pressure. METHOD: PubMed, Embase, Web of Science, CNKI, Weipu, and Wanfang databases were searched for articles published up to June 2, 2021. Dual-selection and data abstraction were conducted. Random-effect models were used to measure pooled estimates. All data were analyzed with Stata 14.0 SE (StataCorp, College Station, TX, USA). RESULTS: A total of 55 studies with 198,750 individuals were included in the meta-analysis. Among them, 33 studies reported the relationship between H. pylori infection and the risk of hypertension, and 25 studies reported the association of H. pylori infection with systolic blood pressure (SBP) and diastolic blood pressure (DBP). Three studies reported both of the above. Meta-analysis showed that H. pylori infection increased the risk of hypertension by 32% (odd ratio: 1.32, 95% CI: 1.15-1.52). Compared with non-H. pylori-infection individuals, the subjects with H. pylori infection had elevated levels of SBP (WMD: 1.86, 95% CI: 1.21-2.50) and DBP (WMD: 1.12, 95% CI: 0.81-1.43). CONCLUSION: This meta-analysis suggested that H. pylori infection increased the risk of hypertension. This may provide a new strategy for hypertension prevention. However, the association between H. pylori infection and hypertension needs to be confirmed in further prospective cohort studies.

Age-related promoter-switch regulates Runx1 expression in adult rat hearts.

BACKGROUND: Runt-related transcription factor-1 (RUNX1), a key member of the core-binding factor family of transcription factors, has emerged as a novel therapeutic target for cardiovascular disease. There is an urgent need to fully understand the expression pattern of Runx1 in the heart and the mechanisms by which it is controlled under normal conditions and in response to disease. The expression of Runx1 is regulated at the transcriptional level by two promoters designated P1 and P2. Alternative usage of these two promoters creates differential mRNA transcripts diversified in distribution and translational potential. While the significance of P1/P2 promoter-switch in the transcriptional control of Runx1 has been highlighted in the embryogenic process, very little is known about the level of P1- and P2-specific transcripts in adult hearts, and the underlying mechanisms controlling the promoter-switch. METHODS: To amplify P1/P2 specific sequences in the heart, we used two different sense primers complementary to either P1 or P2 5'-regions to monitor the expression of P1/P2 transcripts. DNA methylation levels were assessed at the Runx1 promoter regions. Rats were grouped by age. RESULTS: The expression levels of both P1- and P2-derived Runx1 transcripts were decreased in older rats when compared with that in young adults, paralleled with an age-dependent decline in Runx1 protein level. Furthermore, older rats demonstrated a higher degree of DNA methylation at Runx1 promoter regions. Alternative promoter usage was observed in hearts with increased age, as reflected by altered P1:P2 mRNA ratio. CONCLUSION: Our data demonstrate that the expression of Runx1 in the heart is age-dependent and underscore the importance of gene methylation in the promoter-mediated transcriptional control of Runx1, thereby providing new insights to the role of epigenetic regulation in the heart.

Activation of SGLT3a in endometrial epithelial cells induces paracrine stromal cell decidualization.

Endometrial epithelial cells (EECs) and stromal cells (ESCs) have a close functional association. During the peri-implantation period, EECs with enhanced functional activities secrete a variety of paracrine factors to promote the decidualization of ESCs. However, little is known about the specific process by which EECs secrete paracrine factors to induce the decidualization of ESCs. Some evidence suggests that the activation of sodium-glucose cotransporter 3a (SGLT3a) induces the depolarization of ESCs to affect their function. Therefore, SGLT3a acts as a sensor molecule in certain cell types. In this study, the expression of SGLT3a was investigated in EECs to determine whether its levels increased during the peri-implantation period in female mice. The activation of SGLT3a in mouse EECs induced Na+ -dependent depolarization of the cell membrane and an influx of extracellular Ca2+ , which further promoted the expression and release of the paracrine factors prostaglandin E2 (PGE2) and F2-alpha (PGF2α) by upregulating the expression of cyclooxygenase-2. In turn, PGE2 and PGF2α induced the decidualization of ESCs. Importantly, we identified SGLT3a as a key molecule involved in the cross-talk between EECs and ESCs during the process of uterine decidualization.

Consistency and synchronization of AMPK-glycogen in endometrial epithelial cells are critical to the embryo implantation.

Uterine receptivity to the embryo is crucial for successful implantation. The establishment of uterine receptivity requires a large amount of energy, and abnormal energy regulation causes implantation failure. Glucose metabolism in the endometrium is tissue specific. Glucose is largely stored in the form of glycogen, which is the main energy source for the endometrium. AMP-activated protein kinase (AMPK), an important energy-sensing molecule, is a key player in the regulation of glucose metabolism and its regulation is also tissue specific. However, the mechanism of energy regulation in the endometrium for the establishment of uterine receptivity remains to be elucidated. In this study, we aimed to investigate the energy regulation mechanism of mouse uterine receptivity and its significance in embryo implantation. The results showed that the AMPK, p-AMPK, glycogen synthase 1, and glycogen phosphorylase M levels and the glycogen content in mouse endometrial epithelium varied in a periodic manner under regulation by the ovarian hormone. Specifically, progesterone significantly activated AMPK, promoted glycogenolysis, and upregulated glycogen phosphorylase M expression. AMPK regulated glycogen phosphorylase M expression and promoted glycogenolysis. AMPK was also found to be activated by changes in the energy or glycogen of the endometrial epithelial cells. The inhibition of AMPK activity or glycogenolysis altered the uterine receptivity markers during the window of implantation and ultimately interfered with implantation. In summary, consistency and synchronization of AMPK and glycogen metabolism constitute the core regulatory mechanism in mouse endometrial epithelial cells involved in the establishment of uterine receptivity.

[Progress in the role of endometrial glucose metabolism in embryo implantation].

The synthesis and decomposition of glycogen adjust the blood glucose dynamically to maintain the energy supply required by the cells. As the only hormone that lowers blood sugar in the body, insulin can promote glycogen synthesis by activating the phosphatidylinositol 3-kinase (PI3K)/protein kinase B (Akt) signaling pathway and increasing glucose transporter translocation, and inhibit gluconeogenesis to lower blood glucose. In the endometrium, glycogen metabolism is active, but gluconeogenesis does not occur. The glycogen metabolism in the endometrium is controlled not only by the classical glucose regulating hormones, but also by the ovarian hormones. The functional activities related to implantation of the endometrium during the implantation window require glucose as energy source. A large amount of glucose is used to synthesize glycogen in the endometrium before implantation, which could meet the increased energy demand for embryo implantation. In diabetes, glycogen metabolism in the endometrium is impaired, which frequently leads to implantation failure and early abortion. This article reviews the glycogen metabolism in the endometrium and discusses its role in embryo implantation, which provide new ideas for embryo implantation research and infertility treatment.

Contribution of high-fat diet-induced PCSK9 upregulation to a mouse model of PCOS is mediated partly by SREBP2.

The incidence of polycystic ovary syndrome (PCOS) due to high-fat diet (HFD) consumption has been increasing significantly. However, the mechanism by which a HFD contributes to the pathogenesis of PCOS has not been elucidated. Proprotein convertase subtilisin/kexin type 9 (PCSK9) is a key protein that regulates cholesterol metabolism. Our previous study revealed abnormally high PCSK9 levels in serum from patients with PCOS and in serum and hepatic and ovarian tissues from PCOS model mice, suggesting that PCSK9 is involved in the pathogenesis of PCOS. However, the factor that induces high PCSK9 expression in PCOS remains unclear. In this study, Pcsk9 knockout mice were used to further explore the role of PCSK9 in PCOS. We also studied the effects of a HFD on the expression of PCSK9 and sterol regulatory element-binding protein 2 (SREBP2), a regulator of cholesterol homeostasis and a key transcription factor that regulates the expression of PCSK9, and the roles of these proteins in PCOS pathology. Our results indicated HFD may play an important role by inducing abnormally high PCSK9 expression via SREBP2 upregulation. We further investigated the effects of an effective SREBP inhibitor, fatostain, and found that it could reduce HFD-induced PCSK9 expression, ameliorate hyperlipidemia and improve follicular development in PCOS model mice. Our study thus further elucidates the important role of an HFD in the pathogenesis of PCOS and provides a new clue in the prevention and treatment of this disorder.

CBS gene polymorphism and promoter methylation-mediating effects on the efficacy of folate therapy in patients with hyperhomocysteinemia.

BACKGROUND: A decrease in cystathionine beta-synthase (CBS) enzyme activity could lead to hyperhomocysteinemia (HHcy). Studies have revealed that DNA methylation has a mediating effect on the development of diseases. The present study aimed to explore CBS promoter methylation-mediating effects on the efficacy of folate treatment for HHcy. METHODS: HHcy patients were treated with folate (5 mg/day) for 90 days and then divided into a failure group (Hcy ≥ 15 µmol/l) and a success group (Hcy < 15 µmol/l) according to post-treatment plasma Hcy levels. Genotyping of CBS gene (rs2851391 and rs706209) in patients (n = 638) was detected using a MassArray system (Sequenom, San Diego, CA, USA). The baseline DNA methylation levels of patients (n = 299) were detected using MethylTarget™ technology (Genesky Biotechnologies Inc., Shanghai, China). RESULTS: The CBS rs2851391 TC + CC genotype was related to a 57% reduction of failure risk in HHcy treatment compared to the TT genotype (95% confidence interval [CI] = 0.19-0.97). The CBS rs706209 CT + TT genotype had a 2.97-fold increased risk of failure to treatment compared to the CC genotype (95% CI = 1.52-5.80). After adjustment for confounding factors, the odds ratio (95% CI) for the risk of failure in HHcy treatment in total and male patients was 0.55 (0.32-0.93) and 0.34 (0.16-0.69), respectively, for patients with higher methylation levels (≥ methylation median). Additionally, baseline CBS promoter methylation mediated 33.39% of the effect of rs2851391 on the efficacy of folate treatment for HHcy (ACME [average causal mediation effects]: -0.05, 95% CI = -0.11 to 0.00, p = 0.046). CONCLUSIONS: The present study indicates that CBS gene polymorphism and promoter methylation could affect the efficacy of HHcy. There were potentially causal effects of genetic, epigenetic variations at the CBS rs2851391 locus on the efficacy of HHcy therapy with folate.

Additional common loci associated with stroke and obesity identified using pleiotropic analytical approach.

Stroke is a complex disease with multiple etiologies. Numerous studies suggest an established association between obesity and stroke, which may partly arise from the shared genetic components between the two phenotypes. Despite genome-wide association studies (GWASs) have identified some loci associated with stroke and obesity individually, the estimated genetic variability explained by these loci is limited (especially for stroke) and the pleiotropic loci between them are largely unknown. In this study, we jointly applied the pleiotropy-informed conditional false discovery rate (cFDR) method and the genetic analysis incorporating pleiotropy and annotation (GPA) method on summary statistics of two large GWASs to detect the genetic overlap between stroke (n = 446,696) and obesity (n = 681,275). Stratified Q-Q and fold-enrichment plots showed strong pleiotropic enrichment between the two phenotypes. With cFDR < 0.05 and fdr.GPA < 0.2, we identified 24 (16 novel) stroke-associated SNPs and 12 (10 novel) of them to be potentially pleiotropic SNPs for both phenotypes. The corresponding genes were enriched in trait-associated gene ontology (GO) terms "brain development" and "negative regulation of transport". In conclusion, our study demonstrated the feasibility and effectivity of the two pleiotropic methods which successfully improved the genetic discovery by incorporating related GWAS datasets and validated the genetic intercommunity between stroke and obesity. The identification of pleiotropic loci may provide us any new insights into potential genetic and etiology mechanism between them for the further studies.

The correlation between body mass index and prostatic-related parameters in men 40 years or older in Zhengzhou.

PURPOSE: To understand the relationship between body mass index (BMI), age, prostate volume (PV), prostate-specific antigen (PSA), International Prostate Symptom Score (IPSS) and quality of life (QoL) in Zhengzhou. MATERIALS AND METHODS: In the cross-sectional study, men living in Zhengzhou were invited to participate in this study. Men who were 40 years or older were subjected to the IPSS and related examination. A total of 1360 participants were included. Body mass index < 18.5 kg/m2 was determined as underweight, 18.5-24.99 kg/m2 normal, 25-29.99 kg/m2 overweight, and ≥30 kg/m2 obese. RESULTS: The mean BMI was 24.92 ± 3.37 kg/m2. The mean PSA was 1.06 ± 0.85 ng/mL. The mean PV was 20.10 ± 9.96 mL. The mean age was 62.72 ± 11.03 years. The mean IPSS was 5.87 ± 3.48 scores. The mean QoL was 2.33 ± 1.28 scores. PSA showed a significant tendency to decrease with increasing BMI (r = -0.061, p = 0.018, ptrend = 0.037). The same with age (r = -0.109, p < .001; ptrend = .045). But the result suggested that both IPSS and QoL were positively correlated with BMI (r = 0.120, p < .001, ptrend < .001; r = 0.083, p = .001, ptrend = .021, respectively). PV increased with increasing BMI (r = 0.110, p < .001, ptrend = 0.045 ). CONCLUSIONS: Age, PSA decreased with increasing BMI. But larger PV, IPSS, and QoL were associated with higher BMI.

Superior CO2 uptake on nitrogen doped carbonaceous adsorbents from commercial phenolic resin.

In this study, N-doped porous carbons were produced with commercial phenolic resin as the raw material, urea as the nitrogen source and KOH as the activation agent. Different from conventional carbonization-nitriding-activation three-step method, a facile two-step process was explored to produce N-incorporated porous carbons. The as-obtained adsorbents hold superior CO2 uptake, i.e. 5.01 and 7.47 mmol/g at 25 °C and 0 °C under 1 bar, respectively. The synergistic effects of N species on the surface and narrow micropores of the adsorbents decide their CO2 uptake under 25 °C and atmospheric pressure. These phenolic resin-derived adsorbents also possess many extremely promising CO2 adsorption features like good recyclability, quick adsorption kinetics, modest heat of adsorption, great selectivity of CO2 over N2 and outstanding dynamic adsorption capacity. Cheap precursor, easy preparation strategy and excellent CO2 adsorption properties make these phenolic resin-derived N-doped carbonaceous adsorbents highly promising in CO2 capture.

Progesterone-induced miR-152 interferes with embryonic implantation by downregulating GLUT3 in endometrial epithelium.

To investigate the role of progesterone-induced micro-RNA (miR)-152 in early embryonic development and implantation by regulating GLUT3 in endometrial epithelium, qRT-PCR was used to detect the expression of miR-152, GLUT1, and GLUT3 in the endometrial epithelial cells of female mice. GLUT1 and GLUT3 proteins were detected by immunohistochemical staining in the mouse endometrial epithelium. Bioinformatics prediction associated with a luciferase assay was performed to determine whether GLUT1 and GLUT3 are target genes of miR-152. Specific miR-152 mimics or inhibitors were transfected into the endometrial epithelial cells to, respectively, overexpress or downregulate miR-152. Next, the glucose concentration of uterine fluid was measured by conducting high-performance liquid chromatography in vivo, and the glucose uptake of the endometrial epithelial cells was observed using a fluorometric assay in vitro. Early embryonic development and implantation were also observed after the miR-152 mimics or inhibitors had been transfected. Embryo transfer was observed after the miR-152 mimic transfection. miR-152 was found to directly target and thereby downregulate GLUT3 expression. The expressions of both miR-152 and GLUT3 in the mouse endometrial epithelium had spatiotemporal characteristics on days 1-4 of pregnancy. miR-152 affected the glucose concentration of uterine fluid and the glucose uptake of endometrial epithelial cells. The transfection of specific miR-152 mimics led to impaired embryonic development and implantation. To conclude, in endometrial epithelial cells, progesterone-induced miR-152 downregulates GLUT3 at the posttranscriptional level to maintain a proper glucose concentration in the uterine fluid, which is necessary for early embryonic development and implantation.

Prevalence and heritability of benign prostatic hyperplasia and LUTS in men aged 40 years or older in Zhengzhou rural areas.

BACKGROUND: Benign prostate hyperplasia (BPH) is the most common disease among aging males, but no reports have addressed the prevalence of BPH in Zhengzhou. Therefore, we aimed to understand the prevalence of BPH in men aged 40 years or older in Zhengzhou's rural areas through a cross-sectional study and analyzed the correlation with epidemiologic factors and the heritability of the disease. MATERIALS AND METHODS: A multistage sampling method was used to randomly select male respondents in Zhengzhou's rural areas. Men who were 40 years of age or older and their first-degree relatives were subjected to the International Prostate Symptom Score (IPSS) and related examinations. Heritability was calculated according to the prevalence of the first-degree relatives in the case and control groups. RESULTS: The prevalence of BPH was 10.04%. Its prevalence increased with age, from 2.17% in men aged 40-44 years to 31.11% in men aged 80 years or older. The average volume of the prostate was 17.16 ± 7.96 mL, and the average IPSS was 5.89 ± 5.91. The analysis of the correlation between the associated risk factors and BPH revealed that prostatitis and a history of prostatic hyperplasia were significant factors. Obesity, smoking, drinking, diabetes, and hypertension were not correlated with BPH. Of the 94 first-degree relatives of the cases, 53 had BPH (56.38%); of the 106 first-degree relatives of the controls, five had BPH (4.72%). Heritability appeared to account for 40.48% of BPH cases. The heritability of incomplete emptying, frequency, intermittency, urgency, weak stream, straining, and nocturia was 43.28, 71.37, 9.67, 5.67, 2.70, 53.36, and 19.12%, respectively. CONCLUSION: The total prevalence of BPH in men aged 40 years or older in Zhengzhou's rural areas was 10.04%, and the heritability of prostatic hyperplasia was 40.48%.

Association between the BHMT gene rs3733890 polymorphism and the efficacy of oral folate therapy in patients with hyperhomocysteinemia.

Oral folate is currently the most common treatment for hyperhomocysteinemia (HHcy), which seriously threatens human health, but its efficacy is unsatisfactory. Betaine-homocysteine methyltransferase (BHMT) is a key enzyme that regulates Hcy metabolism. We investigated the association between the BHMT rs3733890 and the efficacy of oral folate therapy for HHcy in the Chinese Han population and analysed the effects of gene-environmental interactions on the efficacy. Blood samples were collected from 1071 eligible patients at baseline, and these individuals received subsequent folate treatment for 90 days. A total of 638 patients included in the final analysis were grouped into the treatment success group or the treatment failure group based on posttreatment Hcy levels. Hcy concentrations were measured by fluorescence polarization immunoassay. Time-of-flight mass spectrometry (MassArray system) was used to assess the genotype of BHMT rs3733890. Stratified analyses based on additive models and generalized multifactor dimensionality reduction were used to explore gene-environmental interactions. The genotype distribution presented distinct differences in the two groups. The mutant genotype and allele had significantly increased risk of treatment failure (p < 0.05). Furthermore, synergistic effects of the BHMT rs3733890 polymorphism with environmental risk factors (smoking, drinking, past history) on the efficacy of therapy were also found. However, future, large well-designed studies, as well as mechanistic studies, are still needed to validate our findings.

Association between BHMT and CBS gene promoter methylation with the efficacy of folic acid therapy in patients with hyperhomocysteinemia.

Both betaine homocysteine methyltransferase (BHMT) and cystathionine ß-synthase (CBS) are major enzymes in the metabolism of plasma homocysteine (Hcy). Abnormal methylation levels of BHMT and CBS are positively associated with Hcy levels. The present study is performed to explore the association between the methylation levels in the promoter regions of the BHMT and CBS genes and the efficacy of folic acid therapy in patient with hyperhomocysteinemia (HHcy). A prospective cohort study recruiting HHcy (Hcy ≥ 15 µmol/L) patients was performed. The subjects were treated with oral folic acid (5 mg/d) for 90 days, and the patients were divided into the success group (Hcy < 15 µmol/L) and the failure group (Hcy ≥ 15 µmol/L) according to their Hcy levels after treatment. In the logistic regression model with adjusted covariates, the patients with lower total methylation levels in the BHMT and CBS promoter regions exhibited 1.627-fold and 1.671-fold increased risk of treatment failure compared with higher methylation individuals, respectively. Similarly, subjects who had lower methylation levels (

Prediction model for the efficacy of folic acid therapy on hyperhomocysteinaemia based on genetic risk score methods.

No risk assessment tools for the efficacy of folic acid treatment for hyperhomocysteinaemia (HHcy) have been developed. We aimed to use two common genetic risk score (GRS) methods to construct prediction models for the efficacy of folic acid therapy on HHcy, and the best gene-environment prediction model was screened out. A prospective cohort study enrolling 638 HHcy patients was performed. We used a logistic regression model to estimate the associations of two GRS methods with the efficacy. Performances were compared using area under the receiver operating characteristic curve (AUC). The simple count genetic risk score (SC-GRS) and weighted genetic risk score (wGRS) were found to be independently associated with the efficacy of folic acid treatment for HHcy. Using the SC-GRS, per risk allele increased with a 1·46-fold increased failure risk (P < 0·001) after adjustment for traditional risk factors, including age, sex, BMI, smoking, alcohol consumption, history of diabetes, history of hypertension, history of hyperlipidaemia, history of stroke and history of CHD. When used the wGRS, the association was strengthened (OR = 2·08, P < 0·001). Addition of the SC-GRS and wGRS to the traditional risk model significantly improved the predictive ability by AUC (0·859). A precise gene-environment predictive model with good performance was developed for predicting the treatment failure rate of folic acid therapy for HHcy.

Genetic and epigenetic regulation of BHMT is associated with folate therapy efficacy in hyperhomocysteinaemia.

BACKGROUND AND OBJECTIVES: Hyperhomocysteinaemia (HHcy) is an independent risk factors for several disorders, including cardiovascular disease. The understanding of the relationship among genetic, epigenetic and the efficacy of folate therapy for HHcy remain unclear. This study aim to investigate whether betaine-homocysteine methyltransferase (BHMT) single-nucleotide polymorphisms (SNPs) and DNA methylation are related to the efficacy of folate therapy for HHcy and whether BHMT DNA methylation mediates the SNP-folate therapy efficacy association. METHODS AND STUDY DESIGN: A total of 638 patients with HHcy were involved in this prospective cohort study. Logistic and linear regression was used to explore associations among SNPs, DNA methylation, and folate therapy efficacy. Finally, mediation analysis was performed to investigate whether DNA methylation of BHMT mediates the association between SNPs and folate therapy efficacy. RESULTS: BHMT rs3733890 was significantly associated with folate therapy efficacy (p<0.05). BHMT and BHMT_1 DNA methylation level was significantly associated with folate therapy efficacy (p=0.017 and p=0.028). DNA methylation of BHMT and BHMT_1 mediated 34.84% and 33.06% of the effect of rs3733890 on folate therapy efficacy, respectively. CONCLUSIONS: There has a consistent interrelationship among BHMT genetic variants, methylation levels of BHMT, and folate therapy efficacy. BHMT and BHMT_1 DNA methylation proportionally mediated the effects of rs3733890 SNPs on the efficacy of folate therapy for HHcy.

Immunoglobulin-like domain 4-mediated ligand-independent dimerization triggers VEGFR-2 activation in HUVECs and VEGFR2-positive breast cancer cells.

PURPOSE: The extracellular region (EC) of the vascular endothelial growth factor (VEGF) receptor-2 (VEGFR-2) contains seven immunoglobulin-like (Ig-like) domains that are required for specific ligand binding and receptor dimerization. Studies of domain 4-7 deletions and substitutions provided insights into the interaction between receptors in the absence of VEGF. In this study, we investigated the effect of domain 4 in ligand-independent VEGFR-2 dimerization and activation in human vascular endothelial cells and human breast cancer cells. METHODS: To confirm the role of domain 4 in ligand-independent receptor dimerization and activation, two VEGFR-2 fragments with and without domain 4, KFP1 and KFP2, were generated by recombinant DNA technology. We measured the affinity of KFP1 and KFP2 with VEGFR-2, and the roles of KFP1 and FKP2 in dimerization and phosphorylation of VEGFR-2. We also evaluated the effect of KFP1 and FKP2 on cell proliferation and migration in HUVECs and in human breast cancer cells. RESULTS: We showed that KFP1 did not affect the interaction of VEGFR-2 and VEGF but bound VEGFR-2 in the absence of VEGF. Furthermore, cross-linking and cross-linking immunoblotting demonstrated that KFP1 could form a complex with VEGFR-2, which resulted in VEGFR-2 dimerization in the absence of VEGF. Importantly, we found that the KDR fragment with domain 4 induced phosphorylation of VEGFR-2, as well as phosphorylation of downstream receptor kinases in HUVECs and VEGFR-2-positive breast cancer cells. Consistent with these results, this ligand-independent activation of VEGFR-2 also promoted downstream signaling and cell proliferation and migration. CONCLUSIONS: The domain 4 of VEGFR-2 plays an important role in the interaction between VEGFR receptors in the absence of VEGF.

[Progress of non-genomic action of estrogen and its impact on female reproduction].

Estrogen is one of the steroid hormones. Besides the genomic action mediated by its intracellular receptor on target cells, there is now increasing body of evidence indicating that estrogen also has non-genomic action. For the non-genomic action, estrogen binds to its receptor on cell membrane, subsequently rapidly activates various intracellular signaling pathways, such as PLC/Ca(2+), ERK/MAPK, cAMP-PKA, PI3K-AKT-NOS, and finally induces biological effects. The non-genomic effects of estrogen on physiologic and pathologic processes have been found in many tissues within the reproductive, nervous and cardiovascular systems and bone etc. In reproductive system, it has been demonstrated that estrogen plays important roles in follicle development, fertilization and embryo implantation, and it is involved in the genesis and development of genital tract tumors and breast cancer. In this review, we focus on the general characteristics of non-genomic action of estrogen, its main nonnuclear signaling pathways and physiological and pathological significance, especially its influences in female reproductive functions.