Altered DNA methylation and Dnmt expression in obese uterus may cause implantation failure.

Obesity is defined by increased adipose tissue volume and has become a major risk factor for reproduction. Recent studies have revealed a substantial link between obesity and epigenetics. The epigenome is dynamically regulated mainly by DNA methylation. DNA methylation, which is controlled by DNA methyltransferases (Dnmts), has been widely studied because it is essential for imprinting and regulation of gene expression. In our previous study, we showed that the levels of Dnmt1, Dnmt3a and global DNA methylation was dramatically altered in the testis and ovary of high-fat diet (HFD)-induced obese mice. However, the effect of HFD on Dnmts and global DNA methylation in mouse uterus has not yet been demonstrated. Therefore, in the present study, we aimed to evaluate the effect of HFD on the level of Dnmt1, Dnmt3a, Dnmt3b, Dnmt3l and global DNA methylation in uterus. Our results showed that HFD significantly altered the levels of Dnmts and global DNA methylation in the uterus. The total expression of Dnmt1, Dnmt3a and Dnmt3b was significantly upregulated, while level of Dnmt3l and global DNA methylation were dramatically decreased (p < 0.05). Furthermore, we observed that the expression of Dnmt3b and Dnmt3l was significantly increased in endometrium including gland and epithelium (p < 0.05). Although Dnmt3b was the only protein whose expression significantly increased, the level of global DNA methylation and Dnmt3l significantly decreased in stroma and myometrium (p < 0.05). In conclusion, our results show for the first time that obesity dramatically alters global DNA methylation and expression of Dnmts, and decreased DNA methylation and Dnmt expression may cause abnormal gene expression, especially in the endometrium.

Antioxidant supplementation may effect DNA methylation patterns, apoptosis, and ROS levels in developing mouse embryos.

This study was designed to address the question: does antioxidant-containing embryo culture media affect DNA methyltransferases, global DNA methylation, inner cell mass/trophoblast differentiation, intracellular reactive oxygen species (ROS) levels, and apoptosis? Mouse zygotes were cultured in embryo culture media containing MitoQ, N-acetyl-L-cysteine (NAC), acetyl-L-carnitine (ALC), α-lipoic acid (ALA), or the mixture of NAC + ALC + ALA (AO) until the blastocyst stage, whereas in vivo-developed blastocysts were used as control. Protein expression levels of Dnmt1, 3a, 3b, and 3l enzymes were analyzed by immunofluorescence and western blot, while global DNA methylation, apoptosis, and ROS levels were evaluated by immunofluorescence. NAC, ALC, and MitoQ significantly increased the levels of all Dnmts and global methylation. ALA significantly induced all Dnmts, whereas global methylation did not show any difference. NAC and mixture AO applications significantly induced Nanog levels, ALA and MitoQ increased Cdx2 levels, while the other groups were similar. ALA and MitoQ decreased while ALC increased the levels of intracellular ROS. This study illustrates that antioxidants, operating through distinct pathways, have varying impacts on DNA methylation levels and cell differentiation in mouse embryos. Further investigations are warranted to assess the implications of these alterations on the subsequent offspring.

The Role of Cannabinoid-1 Receptor Ligands in the Ovalbumin-Induced Mouse Model of Allergic Asthma: Is It Related to Transient Receptor Potential Vanilloid-1 Channels?

Objectives: The aim of this study was to investigate the role of cannabinoid (CB1) receptors on airway inflammation and hypersensitivity in allergic asthma and the potential interactions with TRPV1 channels. Materials and Methods: BALB/c mice were sensitized and provoked with ovalbumin to create a model of allergic asthma. CB1 selective agonist arachidonoyl 2'-chloroethylamide (ACEA) was administered intraperitoneally at doses of 0.5, 3, and 5 mg/kg. Receptor antagonism studies were performed utilizing selective CB1 antagonists AM251 at a dose of 3 mg/kg. TRPV1 channel was selectively blocked by capsazepine at a dose of 2.5 mg/kg. Penh values were recorded in vivo by a whole-body plethysmograph under methacholine challenge. Inflammatory cell count was performed in bronchoalveolar lavage fluid (BALF). Serum levels of proinflammatory cytokines were measured by Enzyme-Linked ImmunoSorbent Assay (ELISA). Inflammation in the lung tissue was scored histopathologically. Statistical significance was determined using one-way analysis of variance or Kruskal-Wallis test and expressed as p<0.05. Results: In sensitized animals, provocation with inhaled ovalbumin increased Penh values, serum interleukin (IL)-4, IL-5, IL-13 levels, eosinophil, neutrophil, lymphocyte, macrophage counts in BALF, and inflammation in the lung tissue. ACEA applications did not significantly alter Penh values, BALF inflammatory cell levels, and histological changes related to inflammation in the lung tissue according to the disease group; however, only at a dose of 5 mg/kg, it reduced the levels of the inflammatory cytokine IL-4. AM251 decreased Penh values, eosinophil and neutrophil migration in BALF, and inflammation score of lung tissue compared with the disease group. Although BALF inflammatory cell levels and Penh values were higher in the AM251+ACEA group than in the AM251 group, the differences were insignificant. In the CPZ+ACEA group, Penh values were significantly higher, and serum IL-4 and IL-13 levels and BALF eosinophil counts were lower than that in the CPZ group. Conclusions: This study demonstrated an important role of the CB1 receptors in allergic asthma. CB1 antagonism reduced airway hyperresponsiveness and inflammation and showed immunomodulatory effects. The effect of the CB1 agonist ACEA on asthma does not appear to be related to TRPV1 channels.

Unveiling the impact of DNA methylation machinery: Dnmt1 and Dnmt3a in orchestrating oocyte development and cellular homeostasis.

DNA methylation can be considered the most prominent in controlling the gene expression responsible for the balance between cell proliferation and cell death. In this study, we aimed to analyze the distinct contributions of Dnmt1 and Dnmt3a enzymes in oocyte maturation, survival, autophagy, reactive oxygen species (ROS) production, and compensation capacity of Dnmt3b and Dnmt3l enzymes in mouse oocytes. Following confirming the suppression of Dnmt1or Dnmt3a through siRNA application, the assessment involved immunofluorescence staining for Dnmts, 5mC, p62, and ROS levels. Cell death rates showed a noticeable increase while oocyte maturation rates exhibited significant reduction. Global DNA methylation showed a decline, concomitant with elevated p62 and ROS levels upon Dnmt1 or Dnmt3a knockdown. Remarkably, silencing of Dnmt1 led to an upsurge in Dnmt3a expression, whereas Dnmt3a knockdown triggered an increase in Dnmt1 levels. Furthermore, Dnmt3l expression exhibited a notable decrease after silencing of either Dnmt1 or Dnmt3a, while Dnmt3b levels remained comparable between control and siRNA-treated groups. Collectively, this study underscores the pivotal roles of Dnmt1 and Dnmt3a in orchestrating various facets of oocyte development, encompassing maturation, survival, autophagy, and ROS production. These findings offer valuable insights into the intricate regulatory network governed by DNA methylation machinery within the context of oocyte physiology.

DNA methyltransferase (Dnmt) silencing causes increased Cdx2 and Nanog levels in surviving embryos.

Epigenetic mechanisms are one of the essential regulators of gene expression which do not involve altering the primary nucleotide sequence. DNA methylation is considered among the most prominent epigenetic mechanisms in controlling the functions of genes related to cell differentiation, cell cycle, cell survival, autophagy, and embryo development. DNA methyl transferases (Dnmts) control DNA methylation, the levels of which are differentially altered during embryonic development, and may determine cell differentiation fate as in the case of pluripotent inner cell mass (ICM) or trophectoderm (TE). In this study, we aimed to analyze the role of Dnmt1 and Dnmt3a enzymes in ICM (using the Nanog marker) and TE (using the Cdx2 marker) differentiation, autophagy (using p62 marker), reactive oxygen species (ROS) production, and apoptosis (using TUNEL) during mouse preimplantation embryo development. Following knockdown of Dnmt1 and Dnmt3a in zygotes, expression levels of Cdx2 in the trophectoderm and Nanog in the inner cell mass were measured, as well as p62 levels, reactive oxygen species (ROS) production, and apoptosis levels after 96 hours in embryo culture. We found that knockdown of Dnmt1 or Dnmt3a significantly induced Cdx2 and Nanog expression. Similarly, p62 expression, ROS levels and apoptosis significantly increased after silencing. This study shows that Dnmt genes are highly crucial for embryonic fate determination and survival. Further studies are required to reveal the specific targets of these methylation processes related to cell differentiation, survival, autophagy, and ROS production in mouse and human preimplantation embryos.

Fenofibrate attenuates asthma features in an ovalbumin-induced mouse model via suppressing NF-κB binding activity.

BACKGROUND/AIM: Asthma is a chronic inflammatory disease of the airways with a high prevalence. Asthma has a complex pathophysiology and about 5-10% of patients are not fully responsive to the currently available treatments. The aim of this study is to investigate the involvement of NF-κB in the effects of fenofibrate on a mouse model of allergic asthma. MATERIALS AND METHODS: A total of 49 BALB/c mice were randomly distributed into 7 groups (n = 7). Allergic asthma model was created by administering i.p. injections of ovalbumin on days 0, 14 and 21, followed by provocation with inhaled ovalbumin on days 28, 29 and 30. Fenofibrate was orally given in 3 different doses; 1, 10 and 30 mg/kg through days 21-30 of the experiment. On day 31, pulmonary function test using whole body plethysmography was performed. The mice were sacrificed 24 h later. Blood samples were obtained, and serum of each sample was separated for IgE determination. Bronchoalveolar lavage fluid (BALF) and lung tissues were collected to measure IL-5 and IL-13 levels. Nuclear extracts of lung tissues were employed to assess nuclear factor kappa B (NF-κB) p65 binding activity. RESULTS: Enhanced Pause (Penh) values were significantly increased in ovalbumin-sensitized and challenged mice (p < 0.01). Administration of fenofibrate (10 and 30 mg/kg) resulted in improved pulmonary function as shown by significantly lower Penh values (p < 0.01). Interleukin (IL) - 5 and IL-13 levels in BALF and lung tissues and immunoglobulin E (IgE) levels in serum were significantly elevated in the allergic mice. IL-5 levels in the lung tissues of mice treated with 1 mg/kg fenofibrate (FEN1) group were significantly reduced (p < 0.01). BALF and lung tissue IL-5 and IL-13 levels in mice treated with 10 and 30 mg/kg fenofibrate, FEN10 and FEN30, respectively, were significantly diminished when compared to the ovalbumin-treated (OVA) group, whereas treatment with 1 mg/kg fenofibrate resulted in insignificant changes. IgE levels in the serum of FEN30 group mice have shown a prominent reduction (p < 0.01). NF-κB p65 binding activity was higher in mice sensitized and challenged with ovalbumin (p < 0.01). NF-κB p65 binding activity was significantly reduced in allergic mice treated with 30 mg/kg (p < 0.01) fenofibrate. CONCLUSIONS: In this study, we showed that administration of 10 and 30 mg/kg fenofibrate effectively attenuated airway hyperresponsiveness and inflammation in a mouse model of allergic asthma, possibly through inhibition of NF-κB binding activity.

Histone acetyltransferases and histone deacetyl transferases play crucial role during oogenesis and early embryo development.

Dynamic epigenetic regulation is critical for proper oogenesis and early embryo development. During oogenesis, fully grown germinal vesicle oocytes develop to mature Metaphase II oocytes which are ready for fertilization. Fertilized oocyte proliferates mitotically until blastocyst formation and the process is called early embryo development. Throughout oogenesis and early embryo development, spatio-temporal gene expression takes place, and this dynamic gene expression is controlled with the aid of epigenetics. Epigenetic means that gene expression can be altered without changing DNA itself. Epigenome is regulated through DNA methylation and histone modifications. While DNA methylation generally ends up with repression of gene expression, histone modifications can result in expression or repression depending on type of modification, type of histone protein and its specific residue. One of the modifications is histone acetylation which generally ends up with gene expression. Histone acetylation occurs through the addition of acetyl group onto amino terminal of the core histone proteins by histone acetyltransferases (HATs). Contrarily, histone deacetylation is associated with repression of gene expression, and it is catalyzed by histone deacetylases (HDACs). This review article focuses on what is known about alterations in the expression of HATs and HDACs and emphasizes importance of HATs and HDACs during oogenesis and early embryo development.

High-fat diet induced obesity alters Dnmt1 and Dnmt3a levels and global DNA methylation in mouse ovary and testis.

Obesity impairs reproductive capacity, and the link between imprinting disorders and obesity has been discussed in many studies. Recent studies indicate that a high-fat diet may cause epigenetic changes in maternal and paternal genes, which may be transmitted to offspring and negatively affect their development. On this basis, our study aims to reveal the changes in DNA methylation and DNA methyltransferase enzymes in the ovaries and testes of C57BL/6 mice fed a high-fat diet and created a model of obesity, by comparing them with the control group. For this purpose, we demonstrated the presence and quantitative differences of DNA methyltransferase 1 and DNA methyltransferase 3a enzymes as well as global DNA methylation in ovaries and testis of C57BL/6 mice fed a high-fat diet by using immunohistochemistry and western blot methods. We found that a high-fat diet induces the levels of Dnmt1 and Dnmt3a proteins (p < 0.05). We observed increased global DNA methylation in testes but, interestingly, decreased global DNA methylation in ovaries. We think that our outcomes have significant value to demonstrate the effects of obesity on ovarian follicle development and testicular spermatogenesis and may bring a new perspective to obesity-induced infertility treatments. Additionally, to the best of our knowledge, this is the first study to document dynamic alteration of Dnmt1 and Dnmt3a as well as global DNA methylation patterns during follicle development in healthy mouse ovaries.

Young plasma transfer recovers decreased sperm counts and restores epigenetics in aged testis.

BACKGROUND AND AIM: Aging is one of the causes of male infertility, and abnormal global DNA methylation and imprinting defects have been characterized in testis during biological aging. One of the important emerging approaches aims to take advantage of the healing properties of young blood plasma to limit the progression of aging in various organs in the body. We aimed to show whether blood plasma transfer has an effect on DNA methylation and spermatogenetic cell development. In addition, we aimed to show whether the young plasma transfer to old mice has an effect on the rejuvenation of the old and whether the impaired DNA methylation and PCNA expression in old age can be restored. METHODS: Groups were (i) young control, (ii) young plasma transfer to aged, (iii) aged control, (iv) aged plasma transfer to young. We utilized IHC and WB in protein level of Dnmts. For the global DNA methylation level, we used 5-methylcytosine staining. We also analyzed PCNA protein expressions in all groups by IHC. RESULTS: We found that transfusion of young plasma into the old animal restored DNA methylation and PCNA expression as it did in the young animal. Most importantly, we observed an increase in spermatogonia and spermatid counts in older animals after young blood plasma transfer. CONCLUSIONS: Our findings show that young plasma transfer can restore epigenetic disorders that occur with aging and solve infertility problems by increasing the sperm count that decreases. It needs to be supported by different studies, especially human studies.

Hydroxychloroquine induces endothelium-dependent and endothelium-independent relaxation of rat aorta.

BACKGROUND: Hydroxychloroquine (HCQ) is an antimalarial that is widely used in the management of rheumatoid arthritis and other autoimmune diseases. In this study, we aimed to examine the vascular effects of HCQ on rat aorta (RA). METHODS: The RA rings were suspended in isolated organ baths and tension was recorded isometrically. HCQ-induced relaxations were tested in the presence of the nitric oxide synthase inhibitor, nitro-L-arginine methyl ester (L-NAME, 100 mM); the cyclooxygenase enzyme inhibitor, indomethacin (10 mM); the calcium (Ca2+) ion channel blocker, nilvadipine (10 µM); and the K+ ion channel inhibitors, tetraethylammonium (1 mM), glibenclamide (10 mM), 4-aminopyridine (1 mM), and barium chloride (30 mM). The effect of HCQ on Ca2+ channels was examined using Ca2+-free Krebs solution, and adding calcium chloride (CaCl2 , 10-5- 10-2 M) cumulatively to baths incubated with HCQ. RESULTS: Removing the endothelium resulted in less relaxation of RA rings compared to endothelium-intact rings (p < 0.05). The effect of endothelium was supported by using L-NAME where HCQ produced-vasorelaxation was decreased (p < 0.05). The contraction of vascular rings was inhibited to a significant degree following the addition of CaCl2 , PE, or KCl on HCQ-incubated RA rings (p < 0.05). The incubation of the RA rings with the Ca2+ channel blocker, the K+ channel blockers, and the COX inhibitor, indomethacin did not significantly affect vascular relaxation induced by HCQ. DISCUSSION: HCQ produced relaxation of RA rings. The relaxation mechanism differs according to the concentration of HCQ. At con-centrations of 10-6 and 10-5 M, the relaxation is endothelium-dependent and mediated by NO. We strongly suggest that Ca2+ channel inhibition is involved at concentrations of 10-5 and 10-4 M, as well as NO.

A rare case of DIC in a patient with Wilson's disease: D-penicillamine.

D-penicillamine therapy is considered an effective and safe treatment for Wilson's disease. Except for one experimental study, there has been no report in the literature about the development of disseminated intravascular coagulation (DIC) with the use of the drug. A 24-year-old female patient with Wilson's disease, followed up with zinc and D-penicillamine treatment, was admitted to the emergency service because of oral mucosal bleeding and lethargy. Initial laboratory tests showed hemoglobin 7.1 g/dL (11.7-15.5), platelet 24×103 µL-1 (159-388), total bilirubin 18 mg/dL (0.3-1.2), direct bilirubin 9.8 mg/dL (0-0.2), INR >10 (0.8-1.2), aPTT 64.5 s (22.5-32), fibrinogen 23 mg/dL (180-350), and factor 8 26.4% (70-150). Melena, hematemesis, and hematochezia were not present, and no active bleeding focus was detected on endoscopic evaluation. Upon meeting the DIC criteria, the patient underwent plasma exchange four times for the treatment of acute-on-chronic liver failure. Haemocomplettan-P, cryoprecipitate replacements were made as a supportive treatment for DIC. As the clinical bleeding continued despite plasma exchanges and factor replacement treatment, D-penicillamine was switched to trientine (1250 mg/day). After this change, the mucosal bleeding stopped, and DIC parameters improved. We suggest that if hemorrhagic complications develop on D-penicillamine treatment, the possibility of DIC induced by D-penicillamine activating the fibrinolysis should also be considered.

DNMT enzymes differentially alter global DNA methylation in a stage-dependent manner during spermatogenesis.

DNA methylation plays important roles during spermatogenesis. This mechanism includes maintenance and de novo methylation which are catalysed by DNA methyltransferase enzymes. DNMT1 plays role in maintenance methylation, while DNMT3A, DNMT3B and DNMT3L are primarily responsible for de novo methylation. Both maintenance and de novo methylation processes appears during primordial germ cell development and spermatogenesis. However, the function(s) of the methylation and DNMTs during spermatogenesis still remain elusive. The aim of the study was to evaluate the relationship between DNMTs levels and global DNA methylation in total testis and during spermatogenesis. For this purpose, DNMTs were analysed using Western blot and immunohistochemistry techniques. We also analysed global DNA methylation level by 5mC staining. We found that DNMTs expression and global DNA methylation levels were significantly differed in total testes and spermatogenetic cells in a stage-dependent manner. DNMT3B and DNMT3L were more abundant in testes, while DNMT1 and DNMT3A were comparatively low. Interestingly, no DNMTs signal was seen in elongated spermatid whereas global DNA methylation was at the highest level. To understand the meaning of differential expressions of DNMTs in the testes, further molecular biological studies are required.

Embryo culture media differentially alter DNA methylating enzymes and global DNA methylation in embryos and oocytes.

The effects of culture media on DNA methylation process, which is one of the epigenetic mechanisms, have not been clearly elucidated although it is known that in vitro culture conditions alter epigenetic mechanisms. This study was designed to address the question: does embryo culture media approach, sequential or single step, differentially affect DNA methylating enzymes and global DNA methylation. Mouse zygotes were cultured either in single step or sequential culture media until the blastocyst stage and in vivo developed blastocyst were utilized as control. Similarly, GV stage oocytes were in vitro matured either in single step or first step of sequential culture media. In vivo matured MII oocytes were used as control. The expression levels and cellular localization of Dnmt1 and 3a enzymes were analyzed by immunofluorescence and western blot analysis while global DNA methylation was evaluated by immunofluorescence. We found that signal intensities of Dnmt1 and Dnmt3a enzymes were significantly low in embryos or oocytes cultured in sequential media compared to single step media and control, which were comparable amongst themself. Similarly, global DNA methylation level in single step media and control groups was comparable but both was higher than the sequential media. This study demonstrated that composition of culture media may differentially affect DNA methylation levels in mouse embryos and oocytes. Since abnormal DNA methylation may cause aberrant oocyte or embryo development, we think that further studies are needed to test human embryos and oocyte, and to explain molecular mechanisms.

Knockdown of Dnmt1 and Dnmt3a gene expression disrupts preimplantation embryo development through global DNA methylation.

PURPOSE: DNA methylation is one of the epigenetic mechanisms that plays critical roles in preimplantation embryo development executed by DNA methyltransferase (Dnmt) enzymes. Dnmt1, responsible for the maintenance of methylation, and Dnmt3a, for de novo methylation, are gradually erased from the zygote in succeeding stages and then reestablished in the blastocyst. This study was designed to address the vital role of Dnmt1 and Dnmt3a enzymes by silencing their gene expressions in embryonic development in mice. METHODS: Groups were (i) control, (ii) Dnmt1-siRNA, (iii) Dnmt3a-siRNA, and (iv) non-targeted (NT) siRNA. Knockdown of Dnmt genes using siRNAs was confirmed by measuring the targeted proteins using Western blot and immunofluorescence. Following knockdown of Dnmt1 and Dnmt3a in zygotes, the developmental competence and global DNA methylation levels were analyzed after 96 h in embryo cultures. RESULTS: A significant number of embryos arrested at the 2-cell stage or had undergone degeneration in the Dnmt1 and Dnmt3a knocked-down groups. By 3D observations in super-resolution microscopy, we noted that Dnmt1 was exclusively found in juxtanuclear cytoplasm, while the Dnmt3a signal was preferentially localized in the nucleus, both in trophoblasts (TBs) and embryoblasts (EBs). Interestingly, the global DNA methylation level decreased in the Dnmt1 knockdown group, while it increased in the Dnmt3a knockdown group. CONCLUSION: Precisely aligned expression of Dnmt genes is highly essential for the fate of an embryo in the early developmental period. Our data indicates that further analysis is mandatory to designate the specific targets of these methylation/demethylation processes in mouse and human preimplantation embryos.

Decreased expression of TERT and telomeric proteins as human ovaries age may cause telomere shortening.

OBJECTIVE: Telomeres are repetitive sequences localized at the ends of eukaryotic chromosomes comprising noncoding DNA and telomere-binding proteins. TRF1 and TRF2 both bind to the double-stranded telomeric DNA to regulate its length throughout the lifespan of eukaryotic cells. POT1 interacts with single-stranded telomeric DNA and contributes to protecting genomic integrity. Previous studies have shown that telomeres gradually shorten as ovaries age, coinciding with fertility loss. However, the molecular background of telomere shortening with ovarian aging is not fully understood. METHODS: The present study aimed to determine the spatial and temporal expression levels of the TERT, TRF1, TRF2, and POT1 proteins in different groups of human ovaries: fetal (n = 11), early postnatal (n = 10), premenopausal (n = 12), and postmenopausal (n = 14). Also, the relative telomere signal intensity of each group was measured using the Q-FISH method. RESULTS: We found that the telomere signal intensities decreased evenly and significantly from fetal to postmenopausal groups (P < 0.05). The TERT, TRF1, TRF2, and POT1 proteins were localized in the cytoplasmic and nuclear regions of the oocytes, granulosa and stromal cells. Furthermore, the expression levels of these proteins reduced significantly from fetal to postmenopausal groups (P < 0.05). CONCLUSION: These findings suggest that decreased TERT and telomere-binding protein expression may underlie the telomere shortening of ovaries with age, which may be associated with female fertility loss. Further investigations are required to elicit the molecular mechanisms regulating the gradual decrease in the expression of TERT and telomere-binding proteins in human oocytes and granulosa cells during ovarian aging.

Glabridin attenuates airway inflammation and hyperresponsiveness in a mice model of ovalbumin-induced asthma.

Asthma is an inflammatory disease of the airways of the lungs, which is characterized by airflow obstruction and bronchospasms. Glabridin is a major flavonoid, especially found in root of Glycyrrhiza glabra, and has several pharmacological activities, including antioxidant and anti-inflammatory effects. The anti-asthmatic effect and possible mechanism of glabridin, however, have not been revealed so far. The aim of this study is to investigate the effects and possible mechanisms of glabridin against ovalbumin (OVA)-induced airway hyperresponsiveness (AHR) and inflammation in mice. In male BALB/c mice, asthma was induced by intraperitoneal (i.p) injection of OVA mixed with 2 mg aluminium hydroxide on days 0, 14 and boosted with OVA aerosol challenge on days 21, 22, and 23. Mice were either treated with dexamethasone (i.p, 1 mg/kg) or glabridin (10, 20, and 30 mg/kg) from days 18-23. Pulmonary function parameters such as peak inspiratory flow, peak expiratory flow, tidal volume, expiratory volume, the frequency of breathing, enhanced pause values were evaluated by using whole-body plethysmography. Measurements were performed at baseline and following methacholine (50 mg/mL) challenges. In addition, white blood cells (WBC) count, total protein, and IgE levels were measured in bronchial alveolar lavage fluid (BALF), lung, and serum, respectively. Glabridin (20 or 30 mg/kg) significantly attenuated (p < 0.05) OVA-induced alteration in respiratory parameters. Elevated counts of total WBC, differential WBC (neutrophils, lymphocytes, monocytes, and eosinophils) in BALF and the total protein in lungs and BALF were significantly decreased (p < 0.05) by glabridin (20 or 30 mg/kg). It also significantly attenuated the increased serum IgE levels (p < 0.05). As glabridin reduces the level of serum IgE, the total protein and the count of WBC and improves respiratory function, it may be a novel therapeutic agent in asthma.

The loss of global DNA methylation due to decreased DNMT expression in the postnatal mouse ovaries may associate with infertility emerging during ovarian aging.

Ovarian aging is one of the main causes of female infertility, and its molecular background is still largely unknown. As DNA methylation regulates many oogenesis/folliculogenesis-related genes, the expression levels and cellular localizations of DNA methyltransferases (DNMTs) playing key roles in this process is important in the ovaries from early to aged terms. In the present study, we aimed to evaluate the spatial and temporal expression of the Dnmt1, Dnmt3a, Dnmt3b, and Dnmt3l genes as well as global DNA methylation levels in the mouse ovaries during aging. For this purpose, the following groups were created: young (1- and 2-week old; n = 3 from each week), prepubertal (3- and 4-week-old; n = 3 from each week), pubertal (5- and 6-week-old; n = 3 from each week), postpubertal (16- and 18-week-old; n = 3 from each week), and aged (52-, 60- and 72-week-old; n = 3 from each week). We found here that Dnmt1, Dnmt3a, and Dnmt3l genes' expression at mRNA and protein levels as well as global DNA methylation profiles were gradually and significantly decreased in the postnatal ovaries from young to aged groups (P < 0.05). In contrast, there was a remarkable increase of Dnmt3b expression in the pubertal, postpubertal and aged groups (P < 0.05). Our findings suggest that the significantly altered DNMT expression and global DNA methylation levels during ovarian aging may contribute to female infertility development at the later terms of lifespan. Also, new researches are required to determine the molecular biological mechanism(s) that how altered DNMT expression and decreased DNA methylation lead to ovarian aging.

The altered expression of telomerase components and telomere-linked proteins may associate with ovarian aging in mouse.

Telomeres are repetitive DNA sequences localized at the ends of eukaryotic chromosomes, and shorten during ovarian aging. The molecular background of telomere shortening during ovarian aging is not fully understood. As the telomerase components (TERT and Terc) and telomere-associated proteins (TRF1, TRF2, and POT1a) play key roles in the elongation and maintenance of telomeres, we aimed to determine their spatial and temporal expression and cellular localization in the mouse ovaries at the different ages of postnatal life. For this purpose, five groups were generated based on the ovarian histological changes in the postnatal mouse ovaries as follows: young (1- and 2-week-old; n = 3 from each week), prepubertal (3- and 4-week-old; n = 3 from each week), pubertal (5- and 6-week-old; n = 3 from each week), postpubertal (16- and 18-week-old; n = 3 from each week) and aged (52-, 60- and 72-week-old, n = 3 from each week). We found significant changes for the Tert, Terc, Trf1, Trf2, and Pot1a genes expression in the postnatal ovary groups from young to aged (P < 0.05) as well as in the follicles from primordial to antral stages and their oocytes and granulosa cells. Also, we have detected gradually decreasing telomere length from young to aged groups (P < 0.001). In conclusion, the altered Tert, Terc, Trf2, and Pot1a genes expression compatible with telomere shortening may be associated with ovarian aging.

PFA is superior to glyoxal in preserving oocyte, embryo, and stem cell proteins evidenced by super-resolution microscopical surveys of epitopes.

PURPOSE: Chemical fixation is a critical step to retaining cellular targets as naturally as possible. Recent developments in microscopy allow sophisticated detection and measuring techniques with which spatio-temporal molecular alterations are conceivable. In this study, we compare two members of aldehyde fixatives [i.e., glyoxal (Gly) and paraformaldehyde (PFA)] to determine whether Gly, a less toxic dialdehyde fixative that is considered to retain immunoreactivity could provide a successful and consistent cell fixation in favor of PFA in various cell preparations and types. METHODS: We document the fixation competence of Gly and PFA side-by-side (with or without Triton X-100 permeabilization) in live- and fixed-cell preparations in mouse oocytes, embryos, and human somatic cells (human umbilical cord-derived mesenchymal stromal cells) using protein quantification by Western blot assay and super-resolution microscopy. RESULTS: Although Gly seemed to act faster than PFA, catastrophic consequences were found not acceptable, especially in oocytes and embryos. Due to cell lysate and immunocytochemistry surveys, it was obvious that PFA is superior to Gly in retaining cellular proteins in situ with little/no background staining. In many samples, PFA revealed more reliable and consistent results regarding the protein quantity and cellular localization corresponding to previously defined patterns in the literature. CONCLUSION: Although the use of Gly is beneficial as indicated by previous reports, we concluded that it does not meet the requirement for proper fixation, at least for the tested cell types and proteins. However, PFA alone with no addition of TX displayed a significant cytoplasmic loss by generating membrane blebs during fixation.

The effect of GnRH antagonist cetrorelix on Wnt signaling members in pubertal and adult mouse ovaries.

Wide application of gonadotropin-releasing hormone (GnRH) agonists and antagonists for clinical purposes determines their effects on ovarian signaling pathways. Our study aimed to determine the localization, expression levels of Wnt signaling members in the pubertal and adult mouse ovary and the impact of GnRH antagonist cetrorelix on these signaling members. 0.5 mg/kg of cetrorelix was injected to 3-and 6-week-old mice for 2 weeks. At the end of injection, ovaries from 5 (5Ce)- to 8-week (8Ce)-old mice were embedded in paraffin for immunohistochemistry and homogenized for western blot to compare with control (5C-8C) and sham groups (5S-8S). WNT2 and WNT4 showed higher expression in thecal and stromal cells in adult mouse ovaries and only WNT4 expression was affected by cetrorelix. FZD1 was localized mainly in oocytes of pubertal ovaries and granulosa cells and oocytes of adult ovaries. FZD1 was reduced by cetrorelix in pubertal ovaries. FZD4 was abundantly localized in thecal and stromal cells of all groups and protein level was not affected by cetrorelix. LRP-6 was expressed mainly in oocytes and stromal cells of pubertal, oocytes of adult ovaries and its expression was reduced by cetrorelix in adult ovaries. CTNNB1 intensity in granulosa cells was the lowest in pubertal and the highest in adult ovaries and its expression was decreased by cetrorelix in adult ovaries. Cetrorelix affected the expression of specific members of the Wnt signaling depending on the developmental stage of mice, pointing out its possible interaction with gonadotropins during pubertal and adult stages.