Single-cell 3D genome structure reveals distinct human pluripotent states.

BACKGROUND: Pluripotent states of embryonic stem cells (ESCs) with distinct transcriptional profiles affect ESC differentiative capacity and therapeutic potential. Although single-cell RNA sequencing has revealed additional subpopulations and specific features of naive and primed human pluripotent stem cells (hPSCs), the underlying mechanisms that regulate their specific transcription and that control their pluripotent states remain elusive. RESULTS: By single-cell analysis of high-resolution, three-dimensional (3D) genomic structure, we herein demonstrate that remodeling of genomic structure is highly associated with the pluripotent states of human ESCs (hESCs). The naive pluripotent state is featured with specialized 3D genomic structures and clear chromatin compartmentalization that is distinct from the primed state. The naive pluripotent state is achieved by remodeling the active euchromatin compartment and reducing chromatin interactions at the nuclear center. This unique genomic organization is linked to enhanced chromatin accessibility on enhancers and elevated expression levels of naive pluripotent genes localized to this region. In contradistinction, the primed state exhibits intermingled genomic organization. Moreover, active euchromatin and primed pluripotent genes are distributed at the nuclear periphery, while repressive heterochromatin is densely concentrated at the nuclear center, reducing chromatin accessibility and the transcription of naive genes. CONCLUSIONS: Our data provide insights into the chromatin structure of ESCs in their naive and primed states, and we identify specific patterns of modifications in transcription and chromatin structure that might explain the genes that are differentially expressed between naive and primed hESCs. Thus, the inversion or relocation of heterochromatin to euchromatin via compartmentalization is related to the regulation of chromatin accessibility, thereby defining pluripotent states and cellular identity.

O-GlcNAcylation Regulates Centrosome Behavior and Cell Polarity to Reduce Pulmonary Fibrosis and Maintain the Epithelial Phenotype.

O-GlcNAcylation functions as a cellular nutrient and stress sensor and participates in almost all cellular processes. However, it remains unclear whether O-GlcNAcylation plays a role in the establishment and maintenance of cell polarity, because mice lacking O-GlcNAc transferase (OGT) are embryonically lethal. Here, a mild Ogt knockout mouse model is constructed and the important role of O-GlcNAcylation in establishing and maintaining cell polarity is demonstrated. Ogt knockout leads to severe pulmonary fibrosis and dramatically promotes epithelial-to-mesenchymal transition. Mechanistic studies reveal that OGT interacts with pericentriolar material 1 (PCM1) and centrosomal protein 131 (CEP131), components of centriolar satellites required for anchoring microtubules to the centrosome. These data further show that O-GlcNAcylation of PCM1 and CEP131 promotes their centrosomal localization through phase separation. Decrease in O-GlcNAcylation prevents PCM1 and CEP131 from localizing to the centrosome, instead dispersing these proteins throughout the cell and impairing the microtubule-centrosome interaction to disrupt centrosome positioning and cell polarity. These findings identify a previously unrecognized role for protein O-GlcNAcylation in establishing and maintaining cell polarity with important implications for the pathogenesis of pulmonary fibrosis.

Short telomeres impede germ cell specification by upregulating MAPK and TGFß signaling.

Functional telomeres protect chromosome ends and play important roles in stem cell maintenance and differentiation. Short telomeres negatively impact germ cell development and can contribute to age-associated infertility. Moreover, telomere syndrome resulting from mutations of telomerase or telomere-associated genes exhibits short telomeres and reduced fertility. It remains elusive whether and how telomere lengths affect germ cell specification. We report that functional telomere is required for the coordinated germ cell and somatic cell fate decisions. Using telomerase gene Terc deficient mice as a model, we show that short telomeres restrain germ cell specification of epiblast cells but promote differentiation towards somatic lineage. Short telomeres increase chromatin accessibility to elevate TGFß and MAPK/ERK signaling for somatic cell differentiation. Notably, elevated Fst expression in TGFß pathway represses the BMP4-pSmad signaling pathway, thus reducing germ cell formation. Re-elongation of telomeres by targeted knock-in of Terc restores normal chromatin accessibility to suppress TGFß and MAPK signaling, thereby facilitating germ cell formation. Taken together, our data reveal that functional telomeres are required for germ cell specification by repressing TGFß and MAPK signaling.

The Effect of Melatonin on OCT4 Expression and Granulosa Cell Growth in Female Mice.

Melatonin is mainly secreted by the pineal gland as a neurotransmitter. Moreover, melatonin is also produced by the ovary and plays important roles in female reproduction. However, it is unclear whether melatonin has any effect on the transition from the preantral follicle to the early antral follicle. Octamer-binding transcription factor 4 (OCT4) is important to granulosa cells development, which is regulated by gonadotropin. And these regulations are mediated by the GSK3ß/ß-catenin pathway via the activated PI3K/Akt signaling. The aim of the present study was to determine the effects and the possible mechanisms of melatonin on ovarian cells development. The results showed that melatonin inhibited granulosa cells development, which was accompanied by the downregulation of OCT4 expression. Meanwhile, melatonin also decreased the expression of p-GSK3ß (glycogen synthase kinase 3 beta), p-Akt, ß-catenin, and its translocation to the nucleus in granulosa cells. Moreover, melatonin attenuated the effects of FSH in vitro and eCG in vivo on these regulations. In conclusion, this study shows that melatonin inhibits ovarian cell development by downregulating the OCT4 expression level, which is possibly mediated by inhibiting the PI3K/Akt and GSK3ß/ß-catenin pathway. Melatonin attenuates the effects of gonadotropin on ovarian granulosa cells as a negative regulator.

Induction of meiosis by embryonic gonadal somatic cells differentiated from pluripotent stem cells.

BACKGROUND: Depletion of oocytes leads to ovarian aging-associated infertility, endocrine disruption and related diseases. Excitingly, unlimited oocytes can be generated by differentiation of primordial germ cell like cells (PGCLCs) from pluripotent stem cells. Nevertheless, development of oocytes and follicles from PGCLCs relies on developmentally matched gonadal somatic cells, only available from E12.5 embryos in mice. It is therefore imperative to achieve an in vitro source of E12.5 gonadal somatic cells. METHODS: We explored to identify small molecules, which can induce female embryonic stem cells (ESCs) into gonadal somatic cell like cells. RESULTS: Using RNA-sequencing, we identified signaling pathways highly upregulated in E12.5_gonadal somatic cells (E12.5_GSCs). Through searching for the activators of these pathways, we identified small-molecule compounds Vitamin C (Vc) and AM580 in combination (V580) for inducing differentiation of female embryonic stem cells (ESCs) into E12.5_GSC-like cells (E12.5_GSCLCs). After V580 treatment for 6 days and sorted by a surface marker CD63, the cell population yielded a transcriptome profile similar to that of E12.5_GSCs, which promoted meiosis progression and folliculogenesis of primordial germ cells. This approach will contribute to the study of germ cell and follicle development and oocyte production and have implications in potentially treating female infertility. CONCLUSION: ESCs can be induced into embryonic gonadal somatic cell like cells by small molecules.

Generation of developmentally competent oocytes and fertile mice from parthenogenetic embryonic stem cells.

Parthenogenetic embryos, created by activation and diploidization of oocytes, arrest at mid-gestation for defective paternal imprints, which impair placental development. Also, viable offspring has not been obtained without genetic manipulation from parthenogenetic embryonic stem cells (pESCs) derived from parthenogenetic embryos, presumably attributable to their aberrant imprinting. We show that an unlimited number of oocytes can be derived from pESCs and produce healthy offspring. Moreover, normal expression of imprinted genes is found in the germ cells and the mice. pESCs exhibited imprinting consistent with exclusively maternal lineage, and higher X-chromosome activation compared to female ESCs derived from the same mouse genetic background. pESCs differentiated into primordial germ cell-like cells (PGCLCs) and formed oocytes following in vivo transplantation into kidney capsule that produced fertile pups and reconstituted ovarian endocrine function. The transcriptome and methylation of imprinted and X-linked genes in pESC-PGCLCs closely resembled those of in vivo produced PGCs, consistent with efficient reprogramming of methylation and genomic imprinting. These results demonstrate that amplification of germ cells through parthenogenesis faithfully maintains maternal imprinting, offering a promising route for deriving functional oocytes and having potential in rebuilding ovarian endocrine function.

Mtor inhibition by INK128 extends functions of the ovary reconstituted from germline stem cells in aging and premature aging mice.

Stem cell transplantation has been generally considered as promising therapeutics in preserving or recovering functions of lost, damaged, or aging tissues. Transplantation of primordial germ cells (PGCs) or oogonia stem cells (OSCs) can reconstitute ovarian functions that yet sustain for only short period of time, limiting potential application of stem cells in preservation of fertility and endocrine function. Here, we show that mTOR inhibition by INK128 extends the follicular and endocrine functions of the reconstituted ovaries in aging and premature aging mice following transplantation of PGCs/OSCs. Follicular development and endocrine functions of the reconstituted ovaries by transplanting PGCs into kidney capsule of the recipient mice were maintained by INK128 treatment for more than 12 weeks, in contrast to the controls for only about 4 weeks without receiving the mTOR inhibitors. Comparatively, rapamycin also can prolong the ovarian functions but for limited time. Furthermore, our data reveal that INK128 promotes mitochondrial function in addition to its known function in suppression of immune response and inflammation. Taken together, germline stem cell transplantation in combination with mTOR inhibition by INK128 improves and extends the reconstituted ovarian and endocrine functions in reproductive aging and premature aging mice.

Effect of thyroid dysfunction on NOS expression in the female rat.

Thyroid hormones (THs) are vital for normal reproductive function and dysregulation of TH impairs follicular development. Although the functions of THs on female reproduction are of great interest, the mechanisms still remain unclear. Many studies have shown that NO plays important roles in female reproduction. In the present study, we investigate the effects of TH dysregulation on nitric oxide synthase types (NOS) expression in rats. Propylthiouracil (PTU) and L-thyroxine were administered to rats to induce hypo- and hyperthyroidism, respectively. Ovarian histology was detected by immunohistochemistry (IHC) and protein or mRNA content was analyzed by Western blotting or RT-PCR, respectively. The results showed that NOS1, NOS2 and NOS3 expressions were detected in the oocyte, granulosa cell and theca cell in all follicular stages, which were up-regulated by eCG treatment. NOS1 protein content was increased in both PTU and L-thyroxine treatments. There were no significant differences in NOS2 levels between the treatment and the control group. However, NOS3 was only increased in the hyperthyroid group. These results were consistent with the IHC staining. The present study provides evidence that TH dysregulation alters NOSs profiles, which suggests that NOSs/nitric oxide (NO) is possibly involved in the regulation of female reproduction.

Functional Oocytes Derived from Granulosa Cells.

The generation of genomically stable and functional oocytes has great potential for preserving fertility and restoring ovarian function. It remains elusive whether functional oocytes can be generated from adult female somatic cells through reprogramming to germline-competent pluripotent stem cells (gPSCs) by chemical treatment alone. Here, we show that somatic granulosa cells isolated from adult mouse ovaries can be robustly induced to generate gPSCs by a purely chemical approach, with additional Rock inhibition and critical reprogramming facilitated by crotonic sodium or acid. These gPSCs acquired high germline competency and could consistently be directed to differentiate into primordial-germ-cell-like cells and form functional oocytes that produce fertile mice. Moreover, gPSCs promoted by crotonylation and the derived germ cells exhibited longer telomeres and high genomic stability like PGCs in vivo, providing additional evidence supporting the safety and effectiveness of chemical induction, which is particularly important for germ cells in genetic inheritance.

Qian lie an suppository (prostant) for chronic prostatitis: A systematic review and meta-analysis of randomized controlled trials.

BACKGROUND: Chronic prostatitis (CP) is an inflammation of the prostate gland that seriously affects the quality of life of patients. The existing evidence of antibiotics and α-blockers for the treatment of CP is limited. OBJECTIVES: This review evaluated the effectiveness and safety of Qian Lie An Suppository (Prostant) in treating CP. METHODS: Randomized controlled trials comparing Prostant (alone or plus the control) with placebo, conventional drugs, or nonpharmaceutical therapies for CP were included in this article through searching from 6 databases. Data were analyzed using RevMan 5.3 software. Meta-analysis was performed when the clinical or statistical heterogeneity was found acceptable among trials. Estimate effects were present with risk ratio (RR) or mean difference and their 95% confidence interval (CI) for dichotomies or continuous variables. Quality of the evidence for each primary outcome was assessed using GRADE criteria. RESULTS: Totally 21 trials involving 3359 participants were included. There were 2 included trials had unclear risk of bias, and the remaining trials had high risk of bias. Meta-analyses showed the number of cured patients in the Prostant group was 2 times more than that of the placebo (RR 2.05, 95%CI 1.10 to 3.81) or antibiotics (RR 1.95, 95%CI 1.18 to 3.23) groups. Similar results were found when Prostant in combination with antibiotics or hyperthermia compared with the antibiotics (RR 1.78, 95% CI 1.10-2.89) or hyperthermia (RR 1.72, 95% CI 1.23-2.40) alone. However, there was no difference in the number of cured patients between Prostant and α-blockers or hyperthermia therapy. No severe adverse event was reported in all included trials. The main adverse events in Prostant group were reported (in 8 included trials) as diarrhea and anal discomfort. CONCLUSIONS: Low-quality evidence showed that the Prostant may have add-on effect for patients with CP on increasing the number of cured patients, relieving pain, and improving the quality of life. There is not sufficient evidence to determine the effectiveness and safety of Prostant for the treatment of CP compared with placebo, antibiotics, α-blockers or the hyperthermia therapy.

Role of OCT4 in the Regulation of FSH-Induced Granulosa Cells Growth in Female Mice.

As a member of the POU (Pit-Oct-Unc) transcription factor family, OCT4 (Octamer-binding transcription factor 4) is associated with the cellular proliferative. However, the roles of OCT4 in regulating the transition from preantral follicle to early antral follicle are still remains unclear. To evaluate the effect of OCT4 on cellular development in ovary, mice were injected with eCG in vivo or granulosa cells were co-cultured with FSH in vitro. The results showed that eCG up-regulated ovarian OCT4 expression. Meanwhile, OCT4 expression in granulosa cells was also up-regulated by FSH, and knockdown of OCT4 by siRNA significantly decreased FSH-induced cellular viability. Moreover, gonadotropin increased p-GSK3ß (Glycogen synthase kinase 3-beta) level, ß-catenin expression and its translocation to nuclear in ovarian cells. In addition, the inhibition of GSK3ß activity by CT99021 significantly increased the expression of ß-catenin and OCT4 in granulosa cells. And knockdown ß-catenin by siRNA dramatically abolished FSH-induced OCT4 expression and cellular development. Furthermore, FSH-induced the phosphorylation of GSK3ß, expression of ß-catenin and OCT4, and translocation of ß-catenin were mediated by the PI3K/Akt pathway. Taken together, the present study demonstrates that FSH regulated OCT4 expression via GSK3ß/ß-catenin pathway, which was mediated by the PI3K/Akt pathway. And these regulations are involved in ovarian cell development.

Effects of Thyroid Dysfunction on Reproductive Hormones in Female Rats.

Thyroid hormones (THs) play a critical role in the development of ovarian cells. Although the effects of THs on female reproduction are of great interest, the mechanism remains unclear. We investigated the effects of TH dysregulation on reproductive hormones in rats. Propylthiouracil (PTU) and L-thyroxine were administered to rats to induce hypo- and hyperthyroidism, respectively, and the reproductive hormone profiles were analyzed by radioimmunoassay (RIA). Ovarian histology was evaluated with hematoxylin and eosin (H&E) staining, and gene protein level or mRNA content was analyzed by western blotting or reverse transcription polymerase chain reaction (RT-PCR). The serum levels of gonadotropin releasing hormone (GnRH) and follicle stimulating hormone (FSH) in both rat models were significantly decreased on day 21, although there were no significant changes at earlier time points. There were no significant differences in luteinizing hormone (LH) or progesterone (P4) levels between the treatment and the control groups. Both PTU and L-thyroxine treatments downregulated estradiol (E2) concentrations; however, the serum testosterone (T) level was increased only in hypothyroid rats at day 21. In addition, the expression levels of FSH receptor, cholesterol side-chain cleavage enzyme (P450scc), and steroidogenic acute regulatory protein (StAR) were decreased in both rat models. Moreover, the onset of puberty was significantly delayed in the hypothyroid group. These results provide evidence that TH dysregulation alters reproductive hormone profiles, and that the initiation of the estrous cycle is postponed in hypothyroidism.

Regulation by 3,5,3'-tri-iodothyronine and FSH of cytochrome P450 family 19 (CYP19) expression in mouse granulosa cells.

Cytochrome P450 family 19 (CYP19) plays an important role in follicular development, which is regulated by FSH. Although 3,5,3'-tri-iodothyronine (T3) combines with FSH to induce preantral follicle growth and granulosa cell development, the mechanism involved remains unclear. The aim of the present study was to determine the cellular and molecular mechanisms by which thyroid hormone (TH) and FSH regulate CYP19 expression and sterol biosynthesis during preantral follicle growth. Mice were injected subcutaneously (s.c.) with eCG (Equine chorionic gonadotropin). The results showed that eCG increased CYP19 expression in ovarian cells. CYP19 expression in granulosa cells was increased after FSH treatment, and this response was enhanced by T3. Knockdown of CYP19 significantly decreased granulosa cell viability and hormone-stimulated proliferation. In addition, CYP19 knockdown also blocked T3- and FSH-induced oestradiol (E2) synthesis in granulosa cells. Furthermore, activation of the phosphatidylinositol 3-kinase (PI3K)/Akt pathway was required for T3 and FSH regulation of CYP19 expression. In conclusion, the results of the present study indicate that CYP19 is important for T3- and FSH-induced granulosa cell development in the early stages. CYP19 could be a downstream effector of the PI3K/Akt pathway in regulating TH and FSH during follicular development and sterol biosynthesis. The findings suggest that CYP19 is a novel mediator of T3- and FSH-induced follicular development.

cGMP/PKG-I Pathway-Mediated GLUT1/4 Regulation by NO in Female Rat Granulosa Cells.

Nitric oxide (NO) is a multifunctional gaseous molecule that plays important roles in mammalian reproductive functions, including follicular growth and development. Although our previous study showed that NO mediated 3,5,3'-triiodothyronine and follicle-stimulating hormone-induced granulosa cell development via upregulation of glucose transporter protein (GLUT)1 and GLUT4 in granulosa cells, little is known about the precise mechanisms regulating ovarian development via glucose. The objective of the present study was to determine the cellular and molecular mechanism by which NO regulates GLUT expression and glucose uptake in granulosa cells. Our results indicated that NO increased GLUT1/GLUT4 expression and translocation in cells, as well as glucose uptake. These changes were accompanied by upregulation of cyclic guanosine monophosphate (cGMP) level and cGMP-dependent protein kinase (PKG)-I protein content. The results of small interfering RNA (siRNA) analysis showed that knockdown of PKG-I significantly attenuated gene expression, translocation, and glucose uptake. Moreover, the PKG-I inhibitor also blocked the above processes. Furthermore, NO induced cyclic adenosine monophosphate response element binding factor (CREB) phosphorylation, and CREB siRNA attenuated NO-induced GLUT expression, translocation, and glucose uptake in granulosa cells. These findings suggest that NO increases cellular glucose uptake via GLUT upregulation and translocation, which are mediated through the activation of the cGMP/PKG pathway. Meanwhile, the activated CREB is also involved in the regulation. These findings indicate that NO has an important influence on the glucose uptake of granulosa cells.

Role of CYP51 in the Regulation of T3 and FSH-Induced Steroidogenesis in Female Mice.

Cytochrome P450 lanosterol 14α-demethylase (CYP51) is a key enzyme in sterol and steroid biosynthesis that is involved in folliculogenesis and oocyte maturation, which is regulated by follicle-stimulating hormone (FSH), as a key reproductive hormone during follicular development. Thyroid hormone (TH) is also important for normal reproductive function. Although 3,5,3'-triiodothyronine (T3) enhances FSH-induced preantral follicle growth, whether and how TH combines with FSH to regulate CYP51 expression during the preantral to early antral transition stage is unclear. The objective of this study was to determine the cellular and molecular mechanisms by which T3 and FSH regulate CYP51 expression and steroid biosynthesis during preantral follicle growth. Our results indicated that CYP51 expression was upregulated in granulosa cells by FSH, and this response was enhanced by T3. Moreover, knockdown CYP51 decreased cell viability. Meanwhile, gene knockdown also blocked T3 and FSH-induced estradiol (E2) and progesterone (P4) synthesis. These changes were accompanied by upregulation of phospho-GATA-4 content. Results of small interfering RNA analysis showed that knockdown of GATA-4 significantly diminished CYP51 gene expression as well as E2/P4 levels. Furthermore, thyroid hormone receptor ß was necessary to the activation of phosphatidylinositol 3-kinase (PI3K)/protein kinase B (Akt), which was required for the regulation of CYP51 expression; activated GATA-4 was also involved these processes. Our data demonstrate that T3 and FSH cotreatment potentiates cellular development and steroid biosynthesis via CYP51 upregulation, which is mediated through the activation of the PI3K/Akt pathway. Meanwhile, activated GATA-4 is also involved in this regulatory system. These findings suggest that CYP51 is a mediator of T3 and FSH-induced follicular development.

Nitric Oxide-Mediated Regulation of GLUT by T3 and Follicle-Stimulating Hormone in Rat Granulosa Cells.

Thyroid hormones are important for normal reproductive function. Although 3,5,3'-triiodothyronine (T3) enhances follicle-stimulating hormone (FSH)-induced preantral follicle growth and granulosa cells development in vitro, little is known about the molecular mechanisms regulating ovarian development via glucose. In this study, we investigated whether and how T3 combines with FSH to regulate glucose transporter protein (GLUT) expression and glucose uptake in granulosa cells. In this study, we present evidence that T3 and FSH cotreatment significantly increased GLUT-1/GLUT-4 expression, and translocation in cells, as well as glucose uptake. These changes were accompanied by upregulation of nitric oxide (NO) synthase (NOS)3 expression, total NOS and NOS3 activity, and NO content in granulosa cells. Furthermore, we found that activation of the mammalian target of rapamycin (mTOR) and phosphoinositide 3-kinase (PI3K)/Akt pathway is required for the regulation of GLUT expression, translocation, and glucose uptake by hormones. We also found that l-arginine upregulated GLUT-1/GLUT-4 expression and translocation, which were related to increased glucose uptake; however, these responses were significantly blocked by N(G)-nitro-l-arginine methylester. In addition, inhibiting NO production attenuated T3- and FSH-induced GLUT expression, translocation, and glucose uptake in granulosa cells. Our data demonstrate that T3 and FSH cotreatment potentiates cellular glucose uptake via GLUT upregulation and translocation, which are mediated through the activation of the mTOR/PI3K/Akt pathway. Meanwhile, NOS3/NO are also involved in this regulatory system. These findings suggest that GLUT is a mediator of T3- and FSH-induced follicular development.

Effects of dietary soybean isoflavones (SI) on reproduction in the young breeder rooster.

Soybean isoflavones (SIs) are phytoestrogens that competitive with estrogens in body. Although SIs play an important role in reproduction, their role in testicular development in roosters is unknown. This study was conducted to investigate the effect of SIs on testicular development and serum reproductive hormone profiles in young breeder roosters (70-133days old). Gene expression of steroidogenic acute regulatory protein (StAR), cholesterol side-chain cleavage enzyme (P450scc), and 3ß-hydroxysteroid dehydrogenase (3ß-HSD), which are related to testosterone synthesis, in rooster testis were also evaluated after treatment with different SI doses. Although SIs had no significant effect on body weight, 5mg/kg SIs significantly increased the testis index and serum levels of reproductive hormones (gonadotropin releasing hormone, follicle- stimulating hormone, luteinizing hormone, and testosterone).To further investigate whether SIs regulate hormone synthesis via StAR, p450scc, 3ß-HSD, real time-PCR was performed to measure the mRNA levels of the corresponding genes. The results showed that 5mg/kg of SIs significantly increased StAR mRNA levels. However, there were no significant effects on p450scc or 3ß-HSD mRNA levels. Moreover, the spermatogonial development and the number of germ cell layers were increased by treatment with 5mg/kg of SIs. These results suggest that SIs promote testicular growth by increasing reproductive hormone secretion, which is closely related to StAR expression, to positively regulate reproduction in young roosters.

Regulation of glucose transport by thyroid hormone in rat ovary.

Thyroid hormone (TH) plays an important role in regulating ovarian development. However, the mechanism involved remains unclear. Evidence suggests that glucose is essential for ovarian development, and its uptake is mediated by several glucose transporter proteins (Glut). We have investigated the effects of TH on Glut in rat ovary. Immature rats were treated with 6-propyl-2-thiouracil or L-thyroxine to induce hypothyroidism (hypo) or hyperthyroidism (hyper), respectively. Ovarian weights significantly decreased in both treated groups compared with the control group, although the body weights were not markedly altered. Glut1 expression significantly decreased without further changes being detected in the other Glut isforms in the hypo group and was accompanied by minimal change in mRNA content. The expression of Glut1 decreased in the hyper group. In contrast, L-thyroxine significantly increased Glut4 mRNA level and protein content but had little effect on Glut2 and Glut3 expression. Serum glucose concentrations in the hyper group were dramatically reduced compared with those in the control group. However, the serum glucose levels in the hypo group were not significantly changed. In addition, equine chorionic gonadotropin (eCG) increased ovarian weights in both the hypo and hyper groups compared with those in the rats without eCG injection. Glut2-4 protein content was significantly increased by eCG in hyper rats. Only the Glut4 mRNA content was significantly increased by eCG in the hyper group. Although the mRNA levels were not significantly changed by eCG in the hypo group, the protein level of Glut4 was markedly up-regulated. Serum glucose levels were not significantly altered by eCG in the two groups. Thus, dysfunction of the thyroid gland changes Glut expression in rat ovary and ovarian growth, both of which are also regulated by gonadotropin.

Polyethylene glycosylation prolongs the stability of recombinant human paraoxonase-1.

Paraoxonase-1 (PON1) is a native enzyme that is synthesized in the liver and is capable of hydrolyzing organophosphates (OPs). It is regarded as part of a promising approach for the pretreatment and therapy of OP poisoning. Previous experiments with purified rabbit serum PON1 have established that it can protect rats against many OP exposures. In the current paper, we described a preparation of active recombinant human PON1 (rHuPON1) by engineering an Escherichia coli expression system. Recombinant HuPON1 was purified by Ni-NTA affinity chromatography followed by DEAE sepharose fast-flow chromatography. After purification, rHuPON1 was chemically modified with polyethyleneglycol (PEG)-20K. Recombinant HuPON1 exhibited a mean residence time (MRT) of 8.9h, which was threefold shorter than that of native HuPON1 in rats. However, rHuPON1 chemically modified with PEG-20K displayed an MRT of 19.5h, suggesting that PEG modification can prolong the circulatory stability of rHuPON1. PEG-rHuPON1 had a catalytic efficiency sufficient in protecting rats against OP poisoning, as measured by acetylcholinesterase activity in tissues and signs after poisoning.