Cilostazol blocks pregnancy in naturally cycling swine: An animal model

SWATH proteomics analysis of placental tissue with intrahepatic cholestasis of pregnancy

INTRODUCTION

Intrahepatic cholestasis of pregnancy (ICP) usually occurs in the second and third trimesters. The disease's etiology and diagnostic criteria are currently unknown. Based on a sequence window to obtain all theoretical fragment ions (SWATH) proteomic approach, this study sought to identify potential proteins in placental tissue that may be involved in the pathogenesis of ICP and adverse fetal pregnancy outcomes.

METHODS

The postpartum placental tissue of pregnant women with ICP were chosen as the case group (ICP group) (subdivided into mild ICP group (MICP group) and severe ICP group (SICP group)), and healthy pregnant women were chosen as the control group (CTR). The hematoxylin-eosin (HE) staining was used to observe the histologic changes of placenta. The SWATH analysis combined with liquid chromatography-tandem mass spectrometry (LC-MS) was used to screen the differentially expressed proteins (DEPs) in ICP and CTR groups, and bioinformatics analysis was used to find out the biological process of these differential proteins.

RESULTS

Proteomic studies showed there were 126 DEPs from pregnant women with ICP and healthy pregnant women. Most of the identified proteins were functionally related to humoral immune response, cell response to lipopolysaccharide, antioxidant activity and heme metabolism. A subsequent examination of placentas from patients with mild and severe ICP revealed 48 proteins that were differentially expressed. Through death domain receptors and fibrinogen complexes, these DEPs primarily regulate extrinsic apoptotic signaling pathways, blood coagulation, and fibrin clot formation. The differential expressions of HBD, HPX, PDE3A, and PRG4 were down-regulated by Western blot analysis, which was consistent with proteomics.

DISCUSSION

This preliminary study helps us to understand the changes in the placental proteome of ICP patients, and provides new insights into the pathophysiology of ICP.

Major histocompatibility complex class II genetic diversity and the genetic influence on gut microbiota in Guizhou minipigs

Major histocompatibility complex (MHC) is an important complex that presents antigen to T cells. The second exon of swine MHC (SLA) class II genes has antigen binding sites that bind with extracellular antigen. Populations with high MHC gene diversity result in low gut microbiota, and individuals with MHC gene heterozygote have lower gut microbiota diversity than that of homozygote. The pig is an animal with organs physiologically and anatomically similar to humans than any other mammal, and the pig is also suitably developed as a laboratory animal to establish the animal models of human disease. However, the relationship between SLA genetic diversity and the gut microbes of the pig is ambiguous. We studied the characterization of SLA class II genes and calculated the genetic diversity, and then we selected experimental animal groups divided by different SLA genotypes to investigate the gut microbiota composition by sequencing V3 to V4 hypervariable regions of bacterial 16 s rRNA from fecal samples. Our results showed that Guizhou minipigs had a low SLA genetic diversity, which may be due to the small founder population. The Guizhou minipig population deviated from neutral selection and balancing selection, which shows that Guizhou minipigs experience a strong artificial selection in recent years. We observed that the sex differences influenced gut microbiota much more deeply than that of genetics. Our results also showed that the individual with heterozygote of genes at the SLA class II region had much higher abundant gut microbiota than that of the homozygote.

Cyclic nucleotide phosphodiesterase inhibitors: possible therapeutic drugs for female fertility regulation

Cyclic nucleotide phosphodiesterases (PDEs) are group of enzymes responsible for the hydrolysis of cyclic adenosine 3', 5' monophosphate (cAMP) and cyclic guanosine 3', 5' monophosphate (cGMP) levels in wide variety of cell types. These PDEs are detected in encircling granulosa cells or in oocyte with in follicular microenvironment and responsible for the decrease of cAMP and cGMP levels in mammalian oocytes. A transient decrease of cAMP level initiates downstream pathways to cause spontaneous meiotic resumption from diplotene arrest and induces oocyte maturation. The nonspecific PDE inhibitors (caffeine, pentoxifylline, theophylline, IBMX etc.) as well as specific PDE inhibitors (cilostamide, milrinone, org 9935, cilostazol etc.) have been used to elevate cAMP level and inhibit meiotic resumption from diplotene arrest and oocyte maturation, ovulation, fertilization and pregnancy rates both in vivo as well as under in vitro culture conditions. The PDEs inhibitors are used as powerful experimental tools to demonstrate cyclic nucleotide mediated changes in ovarian functions and thereby fertility. Indeed, non-hormonal nature and reversible effects of nonspecific as well as specific PDE inhibitors hold promise for the development of novel therapeutic drugs for female fertility regulation.

Cilostamide and rolipram prevent spontaneous meiotic resumption from diplotene arrest in rat oocytes cultured in vitro

The involvement of specific phosphodiesterases (PDEs) in the modulation of cAMP and thereby spontaneous meiotic resumption remains poorly understood. This work aims to evaluate the effects of cilostamide and rolipram (PDE 3A and PDE 4D inhibitors) on spontaneous meiotic resumption from diplotene arrest in rat oocytes cultured in vitro. For this purpose, diplotene-arrested cumulus oocyte complexes (COCs) were collected from rat ovary. The COCs and denuded oocytes were exposed to various concentrations of cilostamide (0.0, 2.5, 5.0 and 10 μM) and rolipram (0, 10, 50 and 100 μM) for various times (0, 3, 5, 7, 14, 16, 18, 20, 22 and 24 h). Cilostamide inhibited spontaneous meiotic resumption in a concentration- and time-dependent manner in COCs and denuded oocytes. Although rolipram showed inhibition of spontaneous meiotic resumption up to some extent, cilostamide was more potent to prevent spontaneous meiotic resumption in both COCs and denuded oocytes. Cilostamide significantly reduced PDE 3A expression, increased cAMP level and prevented spontaneous meiotic resumption in COCs and denuded oocytes. Although rolipram inhibited PDE 4D expression in cumulus cells, increased cAMP level but was not sufficient to prevent spontaneous meiotic resumption. We conclude that both drugs prevent spontaneous resumption from diplotene-arrest through PDE 3A/PDE 4D-cAMP mediated pathway. However, as compare to rolipram, cilostamide was more potent in preventing spontaneous resumption from diplotene-arrest in rat oocytes cultured in vitro. Thus, cilostamide could be used as a potential candidate for the development of female contraceptive drug in future.

A rapid and efficient method for the collection of highly developmental murine immature oocytes using cilostazol, a phosphodiesterase 3A inhibitor

AIMS

The present study aims to define maturation, yield, health, and ease of collection of murine immature oocytes recovered using the conventional method or from mice treated with cilostazol.

MAIN METHODS

The conventional method included the superovulation of mice and the recovery of germinal vesicle (GV) or metaphase (MI) oocytes from preovulatory follicles. The cilostazol method included the oral treatment of superovulated mice with 7.5 mg cilostazol once or twice to result in the ovulation of MI or GV oocytes, respectively.

KEY FINDINGS

The cilostazol method resulted in >95% of GV or MI oocytes with a diameter range of 60-90 μm or 50.1-70 μm in comparison to <60.0% of GV or MI oocytes resulting from the conventional method, respectively (P < 0.0001). The cilostazol method resulted in GV oocytes having higher levels of co-occurrence of peripheral cortical granules (CG) and chromatin configuration of surrounded nucleolus and MI oocytes having higher levels of co-occurrence of normally organized spindles/chromosomes and peripheral CG with free domains than did the conventional method (P < 0.001). The cilostazol method was more time and labor efficient and resulted in higher oocyte yields of normal morphology than did the conventional method (P < 0.01).

SIGNIFICANCE

The presented method provides not only oocytes with uniform size and synchronized developmental maturation but also a technique of oocyte collection that is efficient and resourceful. It is possible that not all immature oocytes resulting from the conventional method are from preovulatory follicles nor have been developed adequately and consequently ovulated as opposed to the presented method.

Therapeutic targeting of 3',5'-cyclic nucleotide phosphodiesterases: inhibition and beyond

Phosphodiesterases (PDEs), enzymes that degrade 3',5'-cyclic nucleotides, are being pursued as therapeutic targets for several diseases, including those affecting the nervous system, the cardiovascular system, fertility, immunity, cancer and metabolism. Clinical development programmes have focused exclusively on catalytic inhibition, which continues to be a strong focus of ongoing drug discovery efforts. However, emerging evidence supports novel strategies to therapeutically target PDE function, including enhancing catalytic activity, normalizing altered compartmentalization and modulating post-translational modifications, as well as the potential use of PDEs as disease biomarkers. Importantly, a more refined appreciation of the intramolecular mechanisms regulating PDE function and trafficking is emerging, making these pioneering drug discovery efforts tractable.

Role of Cyclic Nucleotide Phosphodiesterases During Meiotic Resumption From Diplotene Arrest in Mammalian Oocytes

Cyclic nucleotide phosphodiesterases (PDEs) are group of enzymes that hydrolyze cyclic nucleotides in wide variety of cell types including encircling granulosa cells as well as associated oocytes. One group of PDEs are located in encircling granulosa cells and another group get expressed in the oocyte, while few other PDEs are expressed in both compartments. The PDE1A, PDE4D, PDE5A, PDE8A, and PDE8B are granulosa cell specific PDEs that hydrolyze adenosine 3',5'-cyclic monophosphate (cAMP) as well as guanosine 3',5'-cyclic monophosphate (cGMP) with different affinities. PDE3A, PDE8A as well as PDE9A are expressed in oocyte and specifically responsible for the cyclic nucleotide hydrolysis in the oocyte itself. Few other PDEs such as PDE7B, PDE10A, and PDE11A are either detected in granulosa cells or oocytes. Activation of these PDEs either in encircling granulosa cells or in oocyte directly or indirectly reduces intraoocyte cAMP level. Reduction of intraoocyte cAMP level modulates phosphorylation status of cyclin-dependent kinase 1 (Cdk1) and triggers cyclin B1 degradation that destabilizes maturation promoting factor (MPF) and/or increases Cdk1 activity. The destabilized MPF and/or increased Cdk1 activity leads to resumption of meiosis, which initiates the achievement of meiotic competency in preovulatory follicles of several mammalian species. Use of specific PDEs inhibitors block cyclic nucleotides hydrolysis that results in increase of intraoocyte cyclic nucleotides level, which leads to maintenance of meiotic arrest at diplotene stage in vivo as well as in vitro. Thus, cyclic nucleotide PDEs play important role in the achievement of meiotic competency by reducing intraoocyte cyclic nucleotides level in mammalian oocytes. J. Cell. Biochem. 118: 446-452, 2017. © 2016 Wiley Periodicals, Inc.