Effect of prostaglandin analogs: Latanoprost, bimatoprost, and unoprostone on matrix metalloproteinases and their inhibitors in human trabecular meshwork endothelial cells.

Bimatoprost, latanoprost, and unoprostone are prostaglandin F2α analogs (PGAs) and are used to lower intraocular pressure. We investigated the free acid effects of these three prostaglandin analogs: bimatoprost, latanoprost, and unoprostone on human matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMP) in the trabecular meshwork (TM) cells. Immunoblot results show that all three PGAs generally increased MMPs-1,9 and TIMPs-4. Additionally, bimatoprost and latanoprost both increased MMP-3 and TIMP-2, while unoprostone had an indeterminate effect on both. Zymography results show that all three PGAs except unoprostone increased intermediate MMP-1 activity while bimatoprost and latanoprost increased MMP-9 activity. Together, these data suggest that the balance between MMPs and TIMPs correlate to the relative intraocular pressure lowering effectiveness observed in clinical studies of these PGAs.

Ocular Pharmacology.

Medications are a common treatment for glaucoma. Pharmacologic agents include sympathomimetics, beta-blockers, miotics (direct acting and cholinesterase inhibitors), carbonic anhydrase inhibitors, and prostaglandin agonists. Other agents include hyperosmotic agents and nonsteroidal anti-inflammatory drugs. Members of the ophthalmic health-care team, with heightened attention to patient safety, prescribe, administer, monitor side effects, and educate patients on glaucoma medications.

Synthesis and in vitro cytotoxicity of cross-conjugated prostaglandin A and J series and their hydroxy derivatives.

The synthesis of two cross-conjugated prostaglandin analogues of known neurotrophic activity and their new hydroxy derivatives was accomplished starting from the diastereoisomeric (+)-camphor protected 3-[(dimethoxyphosphoryl)methyl]-4,5-dihydroxycyclopent-2-enones. The cytotoxicity of these compounds was determined against HeLa, K562, HL-60 human cancer cell lines and normal human cells (HUVEC). We found that NEPP11 and its C7-hydroxy derivative demonstrated high anticancer activity against the HeLa and HL-60 human cancer cell lines at concentrations ranging from 1 to 2 µM. Moreover, the C7-hydroxy derivative of NEPP11 displayed high cytotoxic selectivity between cancer cell lines and normal human cells. On the other hand, the J-type prostaglandin analogue of NEPP11 and its C13-hydroxy derivatives were much less toxic or nontoxic against the cancer and normal cells at concentrations up to 1 mM.

Traceless stereoinduction for the enantiopure synthesis of substituted-2-cyclopentenones.

The pseudoenantiomeric 4-O-Boc- and 4-OPMP-cyclopent-2-enones, readily available from hydroxymethylenefurane on multigram scale, are demonstrated to be exceptional building blocks for the synthesis of enantiopure 4-alkyl-5-(1'-hydroxyalkyl) substituted 2-cyclopentenones and derivatives thereof. The 4-OR substituent acts as a traceless stereoinducing element, conferring not only 1,2- but also 1,4-stereocontrol with excellent selectivity. The methodology developed here was applied for the rapid synthesis of natural products and biologically active 2-cyclopentenones such as TEI-9826, guaianes, and pseudoguaianolides.

Inhibition of the proliferation of transformed epidermal cells in culture by various prostaglandins.

Cytotoxic action of various prostaglandins (PGs) was examined on the PAM 212 transformed mouse epidermal cell line, and delta 7-PGA1 was found most active. delta 7-PGA1 exerted a dose-dependent inhibition of PAM 212 cell growth over 0.1 microgram/ml (0.3 microM). At 1.6 microgram/ml (4.6 microM) growth was completely inhibited, and the number of viable cells decreased remarkably during culture. The concentration needed for 50% growth inhibition (IC50) value of delta 7-PGA1 on PAM 212 cell growth was calculated as 0.4 microgram/ml (1.1 microM). At this concentration, the DNA synthesis in 24- and 48-h cultured cells was decreased to a half of the level in the control cells, and microscopically, remaining cells showed degenerative changes with many vacuoles in their cytoplasm. Prostaglandin D2, a major PG in mast cells, also showed potent cytotoxic activity. However, this action was expressed as 9-deoxy-delta 9,12-13,14-dihydro-PGD2 (delta 12-PGJ2), which was converted from PGD2 in plasma, and had a 3-fold stronger growth inhibitory activity than PGD2; the IC50 values of PGD2 and delta 12-PGJ2 were 2 micrograms/ml (5.7 microM) and 0.75 microgram/ml (2.1 microM), respectively. Among other PGs tested, PGA2 showed a comparable growth inhibitory activity, and PGB2, PGE1, and PGE2 less but significant activity. Prostaglandin F2 alpha and PGI2 however, had no such effect on cell proliferation at 5 micrograms/ml (14.3 microM) concentration, suggesting that cyclopentenone structure is an essential moiety of PG derivatives for cell growth inhibition. This cytotoxic action of delta 7-PGA1 and delta 12-PGJ2 appears to be independent of cyclic-AMP, since these PGs were virtually inactive in raising intracellular cyclic-AMP levels in PAM 212 cells.

Inhibition of growth in oral squamous carcinoma cells by cyclopentenone prostaglandins: comparison with chemotherapeutic agents.

Four cyclopentenone prostaglandins (CPPGs) and PGE2 caused significant dose-dependent inhibition in growth of human oral squamous carcinoma cells (SCC-15). The rank order of their potency was PGJ2>PGA1>16, 16-dimethyl PGA1>PGA2>PGE2. In a follow-up experiment it was found that the mean per cent inhibition in cell growth by PGJ2 and delta12-PGJ2 at 10(-5) M was 61.22 and 63.81, while that of 5-fluorouracil and methotrexate was 36.67 and 38.86, respectively. delta12-PGJ2 and PGJ2 induced significant dose-dependent inhibition in nuclear DNA synthesis (i.e. cell proliferation). Combining vitamin E succinate with lower concentrations of CPPGs enhanced significantly their inhibitory effect on nuclear DNA synthesis of cancer cells.

O-Monoacyltartaric acid catalyzed enantioselective conjugate addition of a boronic acid to dienones: application to the synthesis of optically active cyclopentenones.

Enantioselective conjugate addition of styrylboronic acid to dienones was effectively catalyzed by an O-monoacyltartaric acid to afford monostyrylated products with good enantioselectivity. The RCM of the monostyrylated products using the Hoveyda-Grubbs II catalyst afforded optically active cyclopentenones, including a synthetic intermediate of the antitumor agent TEI-9826. The study shows that a diene additive such as 1,6-heptadiene or diallyl ether was essential for the RCM.

Interaction between aldosterone and renomedullary prostaglandins. Competitive action between aspirin and spironolactone.

Aldosterone injected i.m. decreased the release of renomedullary PGEs and the index (urinary Na/K ratio) in conscious normotensive intact and adrenalectomized rats. Coadministration of spironolactone increased the release of PGEs as well as the index (urinary Na/K ratio). The effect of spironolactone was partly inhibited by aspirin injected in a ratio 5:1 (aspirin:spironolactone), and effect which could be reversed by the infusion of a synthetic prostaglandin (PGA2) in a subhypotensive dose.

Effects of prostaglandins and their methylated analogues upon human adenylate cyclase in the upper gastrointestinal tract.

The effects of prostaglandin E2, prostaglandin A2 and their methylated analogues upon the adenylate cyclase in human gastric mucosa were studied. PG E2 and 16,16-dimethyl-PG E2 stimulated the enzyme activity to a greater degree than PG A2 and 16,16-dimethyl-PG A2. 16,16-dimethyl-PG E2 was less potent in activating the enzyme system than its parent compound. The results suggest that the more pronounced antisecretory activity of 16,16-dimethyl-PG E2 is due to its greater resistance against enzymatic degradation.

Enantioselective synthesis of 12-amino alkylidenecyclopentenone prostaglandins.

An enantioselective synthesis of new 12-amino alkylidenecyclopentenone prostaglandins is reported. The key step of the synthesis involved a [3.3] sigmatropic rearrangement of an asymmetric allylic cyanate to elaborate an asymmetric 5-amino-1,6-diene which was further transformed into cyclopentenone by successive ring-closing metathesis reaction catalyzed by the Grubbs reagent and one-pot oxidation. A palladium-catalyzed cross-coupling reaction on a 5-iodo-1,5-diene allowed the synthesis of prostanoids with variable Rw side chains. These new compounds exhibit high cytotoxic activities.

Polycyclic aromatic hydrocarbon quinones and glutathione thioethers as substrates and inhibitors of the human placental NADP-linked 15-hydroxyprostaglandin dehydrogenase.

The human placental NADP-linked 15-hydroxyprostaglandin dehydrogenase catalyzes oxidoreduction at the 9- and 15-positions of many prostaglandins, but its catalytic efficiency (i.e. kcat/Km) for these reactions is low (Jarabak, J., Luncsford, A., and Berkowitz, D. (1983) Prostaglandins 26, 849-868). In the present study, we demonstrate that both K-region and non-K-region o-quinones of polycyclic aromatic hydrocarbons are excellent substrates for this enzyme. These compounds are reduced with kcat/Km values ranging from 3 to 20 X 10(6) S-1 M-1. The glutathione thioethers of menadione and toluquinone are reduced with similar catalytic efficiencies. Furthermore, these substances and certain other glutathione thioethers are potent inhibitors of prostaglandin B1 oxidation ([I50] = 7 X 10(-8) to 5 X 10(-6) M); while several glutathione thioethers also inhibit polycyclic aromatic hydrocarbon quinone reduction ([I50] = 1.7-6.5 microM). These findings raise the possibility that the potential toxicity of quinones of polycyclic aromatic hyrocarbons and other xenobiotic substances may be altered in the placenta by an oxidoreductase for which prostaglandins are relatively poor substrates. They also suggest that the presence in placental tissue of certain glutathione thioethers could influence the reduction of these quinones and other xenobiotic substances by this enzyme.

Involvement of prostaglandin-induced proteins in the inhibition of herpes simplex virus replication.

Cyclopentenone prostaglandin (PG), delta7-PGA1 was found to induce several polypeptides in human embryonic fibroblast (HEF) cells which were noticed to be dose-related and appeared after 1 h of treatment with a peak at around 5 h and gradual disappearance after 12 h. PG-induced proteins were almost identical in terms of molecular weights with those induced by heat-shock at 42 degrees C. Regarding the mechanism of inhibition of herpes simplex virus (HSV) replication by PG in cell culture, dot blot hybridization has revealed that the level of immediate early (IE) mRNA of the virus was reduced after PG treatment with time dependence. And this delayed inhibitory effect of delta7-PGA1 on HSV was shown to be associated with the production and accumulation of the induced polypeptides.

Effects of prostaglandin A1 on renal handling of salt and water in congestive heart failure.

Prostaglandin A1 (PGA1) was infused at the rate of 1/microgram/kg/min in 10 patients with decompensated heart failure under conditions of water loading (5 patients) or water deprivation (5 patients). During water loading, PGA1 increased urinary excretion of sodium, potassium, chloride, calcium, and magnesium, as well as free-water clearance. During water deprivation, it increased free-water reabsorption. Gomerular filtration rate was increased slightly by PGA1 only when it was given with an infusion of hypertonic mannitol during water deprivation. This selective action of PGA1, which increased the excretion but not the reabsorption of free water, suggests its use to correct certain hypo-osmolar conditions. The site of action of PGA1 on the kidney seems to be in the tubules and mainly in the proximal tubules. These findings might be important in the understanding of the role of renal prostaglandins.

Effect of prostaglandin on ion transport across isolated colonic mucosa.

The effect of prostaglandins (PG) on colonic ion transport was investigated in in vitro experiments in the rat. Both PGE1 and PGA1 increased short-circuit current (Isc), potential difference, and mucosal cyclic AMP levels, but PGE1 was more potent than PGA1. 10(-4) M PGE1 inhibited active sodium transport across short-circuited colonic mucosa (6.1-1.3 microEq/hr/cm2). This effect, coupled with an increase in Isc, is consistent with prostaglandin stimulation of active anion secretion and with the recent suggestions that prostaglandins may be important intermediaries in the process by which several laxatives alter large-intestinal fluid and electrolyte movement.

Endocrine mechanisms in the pathogenesis of essential hypertension. II. Interference of prostaglandins with the blood pressure elevating and lowering systems.

Beside exerting an impressive variety of physiological and pharmacological actions on different systems of the organism, prostaglandins (PGs) may also be main factors in the pathogenesis of essential hypertension. Their role in this process is mostly explained by their multivalent interference with the tissue hormones which regulate the vascular tone and the water-sodium balance. In this paper a discussion regarding the results of a widespread research and the growing literature dealing with this interference is made on the basis of a personal point of view. The present paper is a continuation of a previous one on this topic.

Suppressive effects of various antitumor prostaglandin derivatives on the activity levels of DNA polymerases in human cultured tumor cells.

Some PG derivatives have been shown to be inhibitory for tumor cell growth. To elucidate the underlying mechanism(s) for this, we examined various DNA polymerase activities in PG-treated cultured cells. Human KBIII cells were exposed for one day to each of PGJ2, delta 7-PGA1 and delta 12-PGJ2 at a concentration of 5 micrograms/ml. The cells were harvested and homogenized, and the cell-free extracts were analyzed by phosphocellulose column chromatography for separation, identification, and quantification of each of the DNA polymerases. The results obtained were as follows: The activity of DNA polymerase alpha, which is responsible for DNA replication, has remained almost unchanged by any of the PG derivatives tested (77-87%), whereas the activity of DNA polymerase beta (repair enzyme) was found to dramatically decrease to 13 to 20% of that of the nontreated control cells by treatment with any of these PG derivatives. The results indicate that (a) these PG derivatives inhibit, either directly or indirectly, the synthesis of DNA polymerase beta in the KBIII cell, and (b) DNA polymerase beta may also participate in DNA replication other than DNA repair.

The effects of prostaglandins F2 alpha and E2 on the motility of the cat colon in vitro.

Controversy exists with respect to the motor effects of prostaglandins (PG) in the colon. We studied the actions of the prostaglandins F2 alpha and E2 on the spontaneous and stimulated contractions of the circular muscle of the cat colon in vitro. Both prostaglandins enhanced contractile activity. PG F2 alpha was more effective than PG E2, the ED50 were 4.2 X 10(-9) M and 2 X 10(-7) M, respectively. The prostaglandin antagonist 8 ethoxycarbonyl-5-methyl-10,11-dihydroxy-PG A1-ethyl-ester (HR 546) in a concentration of 10(-7) M shifted the ED50 of PG F2 alpha to the right by 1 log unit and unmasked motor stimulatory actions of low PG F2 alpha concentrations (10(-11) and 10(-10) M). The latter effect was atropine sensitive. In conclusion, PG F2 alpha and PG E2 stimulate contractions of the circular colon muscle at concentrations naturally occurring in the gut. It is conceivable that they play a role in the control of colonic motility, particularly in diseases like ulcerative colitis and Crohn's disease.