Glycerophosphrylocholine (GPC) is a renal medullary compatible organic osmolyte that is derived from choline via phosphatidylcholine, which is catalyzed in part by phospholipase A2 (PLA2) and its degradation by GPC: choline phosphodiesterase (GPC: choline PDE). We found that caffeine elevated intracellular free calcium ([Ca2+]i) and GPC level in cultured MDCK cells, canine kidney epithelial cells, and propose a possible biochemical mechanism. When MDCK cells were incubated for 3 h with 1 to 10 mM caffeine, cellular GPC was elevated in a dose-dependent manner, and this occurred independently of the extracellular osmolality. Caffeine stimulated the rate of [14C]choline incorporation into [14C]GPC and PLA2 activity. Whereas, GPC: choline PDE activity was accompanied by less of increase. These enzyme changes demonstrate the increased net synthesis of MDCK GPC. In order to identify what triggers the PLA2 activation, [Ca2+]i was measured by using a fluorescence dye, Fura-2. Caffeine (10 mM) resulted in a typical transient increase in MDCK [Ca2+]i concentration, and this increase was greatly inhibited by pretreatment of MDCK cells with 10 mM ryanodine for 5 min. Ryanodine (10 mM) also inhibited the caffeine-induced stimulation of PLA2 activity. These findings provide the first evidence that caffeine in MDCK cells causes a ryanodine-inhibitable increase of [Ca2+]i and PLA2 activity, resulting in cellular GPC accumulation.
Animal ; Caffeine/pharmacology* ; Calcium/metabolism* ; Carbon Radioisotopes ; Cell Line ; Choline/metabolism ; Dogs ; Glycerylphosphorylcholine/metabolism* ; Kidney/cytology ; Phospholipases A/metabolism* ; Phospholipases A/drug effects ; Phospholipases A/antagonists & inhibitors ; Phosphoric Diester Hydrolases/metabolism ; Phosphoric Diester Hydrolases/drug effects ; Ryanodine/pharmacology* ; Ryanodine/metabolism

Androgen has been claimed for so long as a pivotal hormone in regulating male sexual function, acting both at the central and peripheral level. We believe that androgen is indeed the main synchronizer of sexual activity regulating libido and enzymes as nitric oxide synthase (NOS) and phosphodiesterase type 5 ( PDE5) , which are crucial for the erectile process. The main action of androgen is to timely adjust the erectile process as a function manifestation of sexual desire, therefore finalizing erection to sex.
Androgens ; pharmacology ; physiology ; Animals ; Male ; Nitric Oxide Synthase ; metabolism ; Penile Erection ; drug effects ; physiology ; Phosphoric Diester Hydrolases ; metabolism ; Rats

Autotaxin (ATX), a member of nucleotide pyrophosphatase/phosphodiesterase (NPP) family, is also named as phosphodiesterase Iα (PD-Iα) or NPP2. ATX is the unique member among the NPPs that can function as a lysophospholipase D (lysoPLD), converting lysophosphatidylcholine into lysophosphatidic acid (LPA). LPA acts on specific G-protein-coupled receptors to elicit a wide range of cellular response, including cell proliferation, cell migration and cell contraction, etc. As the major LPA-producing phospholipase, many ATX's features and functions are dependent on the production of LPA. ATX and LPA together form the ATX-LPA functional axis. The present review summarizes the current progress in function and biological activities of ATX-LPA axis.
Animals ; Cell Movement ; physiology ; Cell Proliferation ; Humans ; Lysophosphatidylcholines ; metabolism ; Lysophospholipids ; metabolism ; physiology ; Phospholipases ; metabolism ; Phosphoric Diester Hydrolases ; metabolism ; physiology ; Receptors, G-Protein-Coupled ; physiology

OBJECTIVETo compare the differences of expressions of adenylyl cyclase (AC) and phosphodiesterase (PDE) in ejaculated spermatozoa between healthy volunteers and the patients with asthenospermia.

METHODSEjaculated spermatozoa were collected from healthy volunteers and the patients with asthenospermia. Reverse transcription polymerase chain reaction (RT-PCR) was used to detect mRNA expression of AC and PDE subtypes in human spermatozoa. The concentrations of cAMP and cGMP in the samples were detected by enzyme-linked immunosorbent assay (ELISA).

RESULTSCompared with healthy volunteers, expression of sAC mRNA and concentration of cAMP were significantly decreased in the patients with asthenospermia (P < 0.01) , while the expression of PDE4C mRNA was significantly increased at the same time (P <0.01). There were no marked differences in the expression of ACIII mRNA and concentration of cGMP between the two groups.

CONCLUSIONThe sAC down-regulation and PDE4C up-regulation are possible reasons for asthenospermia.

Adenylyl Cyclases ; biosynthesis ; Asthenozoospermia ; metabolism ; Cyclic AMP ; metabolism ; Humans ; Male ; Phosphoric Diester Hydrolases ; biosynthesis ; Reverse Transcriptase Polymerase Chain Reaction ; Spermatozoa ; metabolism

This study aimed to explore the positive inotropic effect of phosphodiesterase type 9 (PDE9) inhibitor PF-04449613 in ratsand its cellular and molecular mechanisms. The heart pressure-volume loop (P-V loop) analysis was used to detect the effects of PF-04449613 on rat left ventricular pressure-volume relationship, aortic pressures and peripheral vessel resistance in healthy rats. The Langendorff perfusion of isolated rat heart was used to explore the effects of PF-04449613 on heart contractility. The cardiomyocyte sarcoplasmic reticulum (SR) Ca
Animals ; Calcium/metabolism* ; Myocardial Contraction ; Myocytes, Cardiac/metabolism* ; Phosphodiesterase Inhibitors ; Phosphoric Diester Hydrolases ; Rats ; Ryanodine Receptor Calcium Release Channel ; Sarcoplasmic Reticulum

OBJECTIVETo study the effect of PC-1 gene knockdown on the biological action of prostate cancer cell line C4-2.

METHODSRecombinant plasmids of expressing short hairpin RNA targeting PC-1 mRNA were constructed using DNA recombinant technology and transfected into C4-2 cells via liposome. The positive cell clones were selected by G418. The expression of PC-1 gene was analyzed by RT-PCR and Western blotting technology. MTT and soft agar cloning formation were applied to observe the changes of the growth rate and independent anchor ability of C4-2 cells.

RESULTSPC-1 RNA interference severely affected the expression of PC-1 gene and reduced the growth and colony formation ability of C4-2 cells.

CONCLUSIONRNA interference-mediated PC-1 gene knockdown can decrease the growth and cloning formation ability of C4-2 cells.

Cell Line, Tumor ; Down-Regulation ; Gene Expression ; Humans ; Male ; Phosphoric Diester Hydrolases ; biosynthesis ; genetics ; Prostatic Neoplasms ; genetics ; metabolism ; pathology ; Pyrophosphatases ; biosynthesis ; genetics ; RNA Interference ; RNA, Messenger ; genetics ; Transfection

No abstract available.
Basophils/cytology/*metabolism ; Flow Cytometry ; HLA-DR Antigens/metabolism ; Humans ; Interleukin-3 Receptor alpha Subunit/metabolism ; Leukocyte Count ; Phosphoric Diester Hydrolases/metabolism ; Pyrophosphatases/metabolism ; Receptors, CCR3/metabolism ; Urticaria/*diagnosis/immunology/metabolism

Cementum is critical for anchoring the insertion of periodontal ligament fibers to the tooth root. Several aspects of cementogenesis remain unclear, including differences between acellular cementum and cellular cementum, and between cementum and bone. Biomineralization is regulated by the ratio of inorganic phosphate (Pi) to mineral inhibitor pyrophosphate (PPi), where local Pi and PPi concentrations are controlled by phosphatases including tissue-nonspecific alkaline phosphatase (TNAP) and ectonucleotide pyrophosphatase/phosphodiesterase 1 (NPP1). The focus of this study was to define the roles of these phosphatases in cementogenesis. TNAP was associated with earliest cementoblasts near forming acellular and cellular cementum. With loss of TNAP in the Alpl null mouse, acellular cementum was inhibited, while cellular cementum production increased, albeit as hypomineralized cementoid. In contrast, NPP1 was detected in cementoblasts after acellular cementum formation, and at low levels around cellular cementum. Loss of NPP1 in the Enpp1 null mouse increased acellular cementum, with little effect on cellular cementum. Developmental patterns were recapitulated in a mouse model for acellular cementum regeneration, with early TNAP expression and later NPP1 expression. In vitro, cementoblasts expressed Alpl gene/protein early, whereas Enpp1 gene/protein expression was significantly induced only under mineralization conditions. These patterns were confirmed in human teeth, including widespread TNAP, and NPP1 restricted to cementoblasts lining acellular cementum. These studies suggest that early TNAP expression creates a low PPi environment promoting acellular cementum initiation, while later NPP1 expression increases PPi, restricting acellular cementum apposition. Alterations in PPi have little effect on cellular cementum formation, though matrix mineralization is affected.
Alkaline Phosphatase ; metabolism ; Animals ; Cell Line, Transformed ; Dental Cementum ; cytology ; metabolism ; physiology ; Gene Expression Profiling ; Humans ; Mice ; Models, Animal ; Phosphoric Diester Hydrolases ; metabolism ; Pyrophosphatases ; metabolism ; Tooth Root ; metabolism ; physiology ; X-Ray Microtomography

Cyclic diguanylate (c-di-GMP) is a ubiquitous second messenger present in a wide variety of bacteria, which is responsible for cell differentiation, biofilm formation, pathogenic factor generation, and so on. The level of c-di-GMP in bacteria is regulated by two opposing active domains, diguanylate cyclase (DGC) and phosphodiesterase (PDE), which are present in the same bifunctional protein, and in charge of the synthesis and the degradation of c-di-GMP, respectively. The target of c-di-GMP in the bacterial cell consists of PilZ domain and GEMM riboswitch, the only riboswitch that involved in signal transduction. This article gives an overview of c-di-GMP, focusing on its metabolic pathway, regulatory mechanism, biological function of c-di-GMP, and the synthesis of c-di-GMP analogues and their biological activity.
Bacteria ; metabolism ; Cyclic GMP ; analogs & derivatives ; biosynthesis ; metabolism ; Escherichia coli Proteins ; chemistry ; metabolism ; Phosphoric Diester Hydrolases ; chemistry ; metabolism ; Phosphorus-Oxygen Lyases ; chemistry ; metabolism ; Riboswitch ; Second Messenger Systems ; Signal Transduction

BACKGROUNDEctonucleotide pyrophosphatase/phosphodiesterase (ENPP)-1 is a membrane-bound protein that catalyzes the hydrolysis of extracellular nucleoside triphosphates to monophosphate and extracellular inorganic pyrophosphate (ePPi). Mechanical stimulation regulates ENPP-1 expression. This study sought to investigate the changes in ENPP-1 expression after stimulation using cyclic mechanical tension (CMT).

METHODSRat end-plate chondrocytes were cultured and subjected to CMT (at 3%, 6%, and 9% elongation) for 20, 40, and 60 minutes to observe changes in the expression of ENPP-1. To investigate the pathway, end-plate chondrocytes were exposed to 10 ng/ml of transforming growth factor beta 1 (TGF-β1), TGF-β1 siRNA, or a specific extracellular signalregulated kinase (ERK)1/2 inhibitor, U0126, in addition to CMT. Changes in ENPP-1 expression were measured by reverse transcription PCR (RT-PCR) and Western blotting.

RESULTSWe observed the largest increase in ENPP-1 expression following 3% elongation CMT stimulation. ENPP-1 expression was also increased when end-plate chondrocytes were exposed to 10 ng/ml of TGF-β1, but decreased after TGF-β knockdown with siRNA. ERK1/2 phosphorylation was activated after 3% elongation for 40 minutes, and the stimulatory effect of TGF-β1 on ENPP-1 mRNA and protein expression was inhibited by the suppression of the ERK1/2 pathway using U0126.

CONCLUSIONCMT increases the expression of ENPP-1 in end-plate chondrocytes in a manner likely dependent on TGF-β induction by the ERK1/2 signaling pathway.

Animals ; Blotting, Western ; Cells, Cultured ; Chondrocytes ; metabolism ; Phosphoric Diester Hydrolases ; genetics ; metabolism ; Pyrophosphatases ; genetics ; metabolism ; RNA, Small Interfering ; Rats ; Rats, Sprague-Dawley ; Reverse Transcriptase Polymerase Chain Reaction ; Signal Transduction ; Stress, Mechanical ; Transforming Growth Factor beta1 ; genetics ; metabolism